Text

Responds to Request for Scram Data for 1989-90.Scram Data Encl
	ML20134Q044
Person / Time
Issue date:	04/26/1991
From:	Ingram F; NRC OFFICE OF GOVERNMENTAL & PUBLIC AFFAIRS (GPA)
To:	Trickett D; Public Citizen's Critical Mass Energy Project
Shared Package
ML20134Q043	List: ML20134Q041; ML20134Q044;
References
	NUDOCS 9612020090
	Download: ML20134Q044 (150)
	v • d • e

'o g UNITED $TATES

[ g NUCLEAR REGULATORY COMMISSION l 5 E WASHINGTON, D. C. 20555 !

\***** April 26, 1991 Nr. David Trickett !

Public Citizen i 215 Pennsylvania Avenue, S. E.

Washington, D.C. 20003

Dear Dave:

Enclosed are the scram data for 1989 and 1990 which you requested. The data ;

are based on the following definition of a scram: "A reactor scram is any l automatic or manual actuation of the reactor protection system which results in control rod motion while the reactor core of the unit is either critical or subcritical".

The data are divided into two parts. The first part is a listing by unit docket number (the first three digits in the "LER Number" column) of the ,

reactor scrams experienced in 1989 and 1990, including the event date, the l licensee event report number, the type of scram and whether the scram occurred !

while the unit was either critical or subcritical.

The second part is by unit docket number and gives an event abstract for each !

of the scrams as captured by the Sequence Coding and Search System (SCSS). This system does not include data on the Ft. St. Vrain nuclear power plant and no i data are included for the five subcritical automatic scrams experienced there I in 1989 just prior to its permanent shutdown. Information on these scrams my l be obtained from the referenced licensee event reports. !

As you know, the individual safety significance of these scram events varies greatly and is determined on a case-by-case basis using more information that l 1s contained in the SCSS abstract. In particular, scrams with the reactor subcritical have little safety significance.

Sincerely, j T

h% l. e Frank L. Ingram Assistant to the Director Public Affairs l

Enclosure:

As stated 9612O20090 910426 PDR ORG NOPZ

1989 AND 1990 REAC !M :{ RAM DATA FOR PUBLIC CITIZEN ,

Mote: Sequence Coding and Search System does not f contain LER data on Fort St. Vrain )

i Plant Name Event Date LER Number Scram Tvoe Critical YANKEE-ROWE O1/11/89 02989002 AUTOMATIC SUBCRmCAL 1 1

YANKEE-ROWE 04S6/89 02989005 MANUAL CRmCAL YANKEE-ROWE 04/23/89 02989007 AUTOMATIC CRmCAL YANKEE-ROWE 08/29/89 02989013 AUTOMATIC CRmCAL ,

< YANKEE-ROWE 12/05/90 02990011 AUTOMATIC CRmCAL l BIG ROCK POINT 08/22/89 15589008 AUTOMATIC CRmCAL SAN ONOFRE 1 05N3/89 20689017 AUTOMATIC SUBCRmCAL SAN ONOFRE 1 07/24/89 20689019 MANUAL CRmCAL SAN ONOFRE 1 08M3/89 20689021 AUTOMATIC CRmCAL SAN ONOFRE 1 09/18/89 20689023 MANUAL CRmCAL SAN ONOFRE 1 04/30/90 20690007 AUTOMATIC CRmCAL SAN ONOFRE 1 05/15/90 20690011 MANUAL CRmCAL HADDAM NECK 09/03/90 21390018 MANUAL CRmCAL HADDAM NECK 09/20/90 21390020 MANUAL CRmCAL OYSTER CREEK M/22/89 2198901J MANUAL CRmCAL OYSTER CREEK 05/18/89 21989013 AUTOMATIC CRmCAL OYSTER CREEK 06/25/89 219C016 AUTOMATIC CPITICAL OYSTER CREEK 07/11/89 21989017 AUTOMATIC CRmCAL l 4

OYSTER CREEK 09/22/89 21989021 AUTOMATIC CRmCAL

, OYSTER CREEK 02/20/90 21990004 MANUAL CRmCAL OYSTER CREEK 04/21/90 21990005 MANUAL CRmCAL OYSTER CREEK 06/25/90 21990008 AUTOMATIC CRmCAL NINE MILE PT.1 08/06/90 22090017 MANUAL CRmCAL l NINE MILE Fr. I 12/29/90 22090019 AUTOMATIC CRmCAL l NINE MILE PT.1 08/19/90 22090020 MANUAL CRmCAL l

NINE MILE Fr. I 11/17/90 22090026 AUTOMATIC CRmCAL DRESDEN 2 03/N/89 23789012 AUTOMATIC CRmCAL i

DRESDEN 2 07/12/89 23789019 AUTOMATIC CRmCAL DRESDEN 2 0145/90 23790001 AUTOMATIC CRmCAL DRESDEN 2 01/16/90 23790002 AUTOMATIC CRmCAL DRESDEN 2 08/02/90 23790006 MANUAL CRmCAL DRESDEN 2 11/23/90 23790015 AUTOMATIC SUBCRITICAL GINNA 06Ml/89 24489004 AUTOMATIC CRmCAL GINNA 03/23/90 24490003 AUTOMATIC SUBCRmCAL GINNA 05/10/90 24490007 AUTOMATIC CRmCAL GINNA 06/09/90 24490010 AUTOMATIC CRmCAL GINNA 09/26/90 24490012 AUTOMATIC CRmCAL GINNA 12/11/90 24490013 AUTOMATIC CRmCAL 1 GINNA 12/12/90 24490016 AUTOMATIC CRITICAL GINNA 12/20/90 24490018 AUTOMATIC CRmCAL GINNA 12/21/90 24490019 AUTOMATIC CRmCAL MILLSTONE 1 04/07/89 24589005 AUTOMATIC CRmCAL 2 MILLSTONE 1 06/02/89 24589015 AUTOMATIC CRITICAL MILLS'IDNE 1 10/19/89 24589021 AUTOMATIC CRmCAL

MILLSTONE 1 09/14/90 24590015 AUTOMATIC CRITICAL INDIAN POINT 2 02/28/89 24789002 AUTOMATIC CRmCAL INDIAN POINT 2 12/13/89 24789013 AUTOMATIC CRmCAL DRESDEN 3 03/25/89 24989001 AUTOMATIC CRmCAL DRESDEN 3 03/30/89 24989002 AUTOMATIC CRITICAL DRESDEN 3 04/15/89 24959006 AUTOMATIC CRmCAL DRESDEN 3 03/10/90 24990005 AUTOMATIC CRmCAL TURKEY POINT 3 02/10/89 25089004 ALTOMATIC CRITICAL TURKEY POINT 4 12/23/89 25089020 AUTOMATIC CRmCAL TURKEY POINT 3 06/09/90 25090011 AUTOMATIC CRmCAL TURKEY POINT 3 06/15/90 25090013 AUTOMATIC CRmCAL TURKEY POINT 4 05 S 5/89 25189003 AUTOMATIC SUBCRmCAL TURKEY POINT 4 09/15/89 25189011 MANUAL CRmCAL TURKEY POINT 4 04/09/90 25190003 AUTOMATIC CRmCAL TURKEY POINT 4 05/26/90 25190004 MANUAL CRITICAL TURKEY POINT 4 08/12/90 25190008 AUTOMATIC CRITICAL QUAD CITIES 1 04/12/89 25489003 MANUAL CRmCAL QUAD CmES 1 04/17/89 25489004 MANUAL CRmCAL QUAD CITIES 1 06/29/89 25489010 AUTOMATIC CRITICAL Page1

Plant Name Event Date LER Number Scram Tvoe Critical QUAD CmES 1 03/10/90 25490004 AUTOMATIC CRITICAL PALISADES 02/28/89 25589004 AUTOMATIC SUBCRmCAL PALISADES 08M/89 25589020 AUTOMATIC CRmCAL PALISADES 11/21/89 25589025 f.UTOMATIC SUSCRmCAL

, PALISADES OlS9/90 25590001 MANUAL CRITICAL

^

PALISADES 02/28/90 25590002 AUTOMATIC CRITICAL ROBINSON 2 02/27/89 26189004 AUTOMATIC CRmCAL ROBINSON 2 03/22/89 26189005 AUTOMATIC CRmCAL ROBINSON 2 03/30/89 26189006 AUTOMATIC CRITICAL ROBINSON 2 01/17/90 26190002 AUTOMATIC CRmCAL ROBINSON 2 05/17/90 26190007 AUTOMATIC CRITICAL MONTICELLO 06/19/89 26389009 AUTOMATIC CRmCAL MONTICELLO 11/15/89 26389038 AUTOMATIC CRmCAL 4 MONTICELLO 10/29/90 26390017 AUTOMATIC CRmCAL QUAD CITIES 2 04/06/89 26589001 AUTOMATIC CRmCAL QUAD CmES 2 10/12/89 26589005 AUTOMATIC CRITICAL QUAD CITIES 2 10/15/90 26590010 AUTOMATIC CRITICAL QUAD CmES 2 10/27/90 26590011 AUTOMATIC CRmCAL

FORT ST. VRAIN 03/22/89 26789004 AUTOMATIC SUBCRmCAL FORT ST. VRAIN 03/23/89 26789004 AUTOMATIC SUBCRmCAL FORT ST. VRAIN 03/23/89 267890N AUTOMATIC SUBCRITICAL FORT ST. VRAIN 03/23/89 26789004 AUTOMATIC SUBCRmCAL FORT ST. VRAIN 03/23/89 26789004 AUTOMATIC SUBCRmCAL !

, OCONEE1 01/02/89 26989001 AUTOMATIC CRmCAL l OCONEE1 01/03/89 26989002 MANUAL CRmCAL OCONEE1 08/10/89 26989013 AUTOMATIC CRmCAL OCONEE1 04/26/90 26990006 ALTTOMATIC SUBCRmCAL OCONEE1 08/28/90 26990013 AUTOMATIC CRmCAL

~.

OCONEE2 02/03/89 27089002 AUTOMATIC CRmCAL OCONEE2 02/05/89 27089003 AUTOMATIC CRmCAL OCONEE2 04/03/89 27089004 AUTOMATIC CRmCAL 4

VERMONT YANKEE 03/21/90 27190004 AUTOMATIC CRmCAL

! VERMONT YANKEE 0641/90 27190009 AUTOMATIC CRmCAL

! VERMONT YANKEE 11/r WO 27190015 AUTOMATIC CRmCAL l SALEMI 02 S 6/89 27289007 AUTOMATIC CRITICAL l l SALEMI 02/18/89 27289012 AUTOMATIC CRmCAL 1

SALEMI 06/19/89 27289027 AUTOMATIC CRITICAL SALEMI N/03/90 27290010 AUTOMATIC SUBCRmCAL SALEMI 04/09/90 27290012 AUTOMATIC CRmCAL i SALEMI 08/17/90 27290029 AUTOMATIC CRITICAL SALEMI 09/10/90 27290030 AUTOMATIC CRmCAL DIABLO CANYON 1 10 S 6/89 27589009 AUTOMATIC CRmCAL DIABLO CANYON 1 02/20/90 27590002 MANUAL CRmCAL DIABLO CANYON 1 06/14/90 27590005 AUTOMATIC CRITICAL DIABLO CANYON 1 12 S 5/90 27590014 AUTOMATIC CRmCAL DIABLO CANYON 1 12/24/90 27590017 AUTOMATIC CRmCAL i PEACll BOTTOM 2 05/19/89 27789012 AUTOMATIC CRmCAL !

PEACH BOTTOM 2 07/21/89 27789015 AUTOMATIC CRmCAL !

PEACH BOTTOM 2 10/05/89 27789023 AUTOMATIC CRITICAL PEACH BOTTOM 2 12/20/89 27789033 AUTOMATIC CRmCAL l PEACH BOTTOM 3 01/28/90 27890002 MANUAL CRITICAL PEACH BOTTOM 3 03 S 6/90 27890003 AUTOMATIC CRmCAL PEACH BOTTOM 3 07/27/90 27890008 MANUAL CRmCAL SURRYI 07S9/89 28089026 AUTOMATIC CRITICAL SURRYl 12/21/89 28089M4 MANUAL CRmCAL SURRYl 05/22/90 280900M AUTOMATIC CRITICAL SURRY 2 05/22/90 280900M MANUAL CRITICAL SURRY1 MANUAL 07/01/90 28090006 CRITICAL SURRY2 09/16/89 28189007 MANUAL SUBCRmCAL SURRY2 09/18/89 28189009 AUTOMATIC CRmCAL SURRY2 09/19/89 28189010 AUTOMATIC CRmCAL SURRY2 05/31/90 28190003 MANUAL CRITICAL SURRY2 08/27/90 281900N MANUAL CRITICAL PRAIRIEISLAND 1 07/21/89 28289010 AUTOMATIC CRmCAL PRAIRIE ISLAND 1 11/21/90 28290017 AUTOMATIC CRmCAL FORT CALHOUN 09/24/89 28589019 MANUAL CRITICAL

FORT CALHOUN 11/19/90 28590026 MANUAL CRITICAL INDIAN POINT 3 02 S /89 28689004 AUTOMATIC SUBCRmCAL Page 2

1

. . i Plant Name Event Date LER Number Scram Tvoe Critical i INDIAN POINT 3 10/19/89 28689015 MANUAL CRITICAL l' INDIAN POINT 3 12/27/90 28690003 MANUAL CRmCAL INDIAN POINT 3 06/29/90 286900N AUTOMATIC CRmCAL OCOMEE3 03 S 6/89 28789002 AUTOMATIC CRMCAL OCONEE 3 08/18/89 28789004 AUTOMATIC CRmCAL OCONEE3 01/19/90 28790001 AUTOMATIC CRmCAL l OCONEE3 03/07/90 28790002 AUTOMATIC CRmCAL l OCONEE3 11/13/90 28790003 MANUAL CRmCAL 1 TIIREE MILEISL 1 11/29/89 28989003 AUTOMATIC CRmCAL l THREE MILE ISL 1 03/N/90 28990004 AUTOMATIC CRmCAL '

PILGRIM 03/04/89 29389011 AUTOMATIC CRmCAL I PILGRIM 05/03/89 29389015 AUTOMATIC CRmCAL l PILGRIM 07/18/89 29389023 MANUAL CRmCAL !

PILGRIM 08/30/89 29389026 AUTOMATIC CRmCAL '

l PILGRIM 12/08/89 29389038 AUTOMATIC CRmCAL PILGRIM 05/13/90 29390008 AUTOMATIC CRITICAL l PILGRIM 09/02/90 29390013 MANUAL CRmCAL ]

ZION 1 01/27/89 29589002 AUTOMATIC CRmCAL ;

ZION 1 01/27/90 295900N AUTOMATIC CRmCAL I ZION 1 08/13/90 29590017 AUTOMATIC CRmCAL f COOPER STATION 01/25/89 29889001 AUTOMATIC CRmCAL l COOPER STATION 09/28/89 29889025 AUTOMATIC CRmCAL l COOPER STATION 11/25/89 29889026 AUTOMATIC CRmCAL COOPER STATION 10/17/90 29890011 AUTOMATIC CRITICAL l POINT BEACH 2 03/29/89 30189002 AUTOMATIC CRITICAL POINT BEACH 2 08/20/89 30189004 AUTOMATIC CRmCAL CRYSTAL RIVER 3 06/14/89 30289020 AUTOMATIC SUBCRmCAL ,

CRYSTAL RIVER 3 06/16/89 30289023 AUTOMATIC CRmCAL i ZION 2 01/31/89 30489003 MANUAL SUBCRmCAL l ZION 2 01/18/90 3N90001 MANUAL CRITICAL l ZION 2 09 S 7/90 3N90010 AUTOMATIC CRmCAL ZION 2 09/22/90 3N900ll AUTOMATIC CRmCAL ZION 2 11/11/90 3N90013 AUTOMATIC CRmCAL KEWAUNEE 12/27/89 30589016 AUTOM ATIC CRmCAL l PRAIRIEISLAND 2 05/26/89 3%89002 AUTO h iIC CRmCAL PRAIRIE ISLAND 2 12/21/89 306890N AUTOMA'nC CRmCAL PRAIRIEISLAND 2 12/26/89 306890N AUTOMATIC CRmCAL PRAIRIEISLAND 2 03 S 8/90 30690001 AUTOMATIC CRITICAL PRAIRIEISLAND 2 03/09/90 30690002 AUTOMATIC CRmCAL PRAIRIEISLAND 2 03/16/90 30690003 AUTOMATIC CRmCAL PRAIRIEISLAND 2 10/07/90 30690009 AU. JMATIC CRmCAL PRAIRIEISLAND 2 12/29/90 30690012 AUTOMATIC CRmCAL MAINE YANKEE 01/10/89 30989001 AUTOMATIC CRmCAL MAINE YANKEE N/05/89 30989003 AUTOMATIC CRmCAL SALEM 2 02/05/89 31189003 AUTOMATIC CRmCAL SAlIM 2 03/12/89 31189005 AUTOMATIC CRmCAL SALEM 2 03/29/89 31189006 AUTOMATIC SUBCRmCAL SALEM 2 N/II/89 31189008 AUTOMATIC CRmCAL SALEM 2 06/10/89 31189013 MANUAL CRmCAL SALEM 2 06/28/90 31190029 AUTOMATIC CRmCAL SALEM 2 09/N/90 31190036 AUTOMATIC CRITICAL RANCHO SECO 02/01/89 31289001 MANUAL SUBCRmCAL RANCllO SECO 03/28/89 31289004 AUTOMATIC CRmCAL ARKANSAS 1 01/20/89 31389002 AUTOMATIC CRmCAL ARKANSAS 1 05/01/89 31389018 AUTOMATIC CRITICAL ARKANSAS 1 11/10/89 31389037 AUTOMATIC CRmCAL ARKANSAS 1 11/14/89 31389038 AUTOMATIC CRmCAL ARKANSAS 1 12/28/89 31389N8 AUTOMATIC CRmCAL ARKANSAS 1 12/18/90 31390022 AUTOMATIC SUBCRmCAL COOK 1 01/16/89 31589001 AUTOMATIC CRmCAL COOK 1 03/18/89 31589003 AUTOMATIC .CRmCAL COOK 2 08/14/89 31689014 AUTOMATIC CRmCAL COOK 2 06/11/90 316900N AUTOMATIC CRmCAL COOK 2 12/12/90 31690012 AUTOMATIC CRmCAL COOK 2 12/15/90 31690013 AUTOMATIC CRITICAL HATCHI 06/10/90 32190012 MANUAL CRITICAL llATCII 1 06/20/90 32190013 AUTOMATIC CRmCAL HATCll1 10 S 6/90 32190020 AUTOMATIC CRmCAL Page 3

1 Phndim Event Date LER Number Spram Tyne Critical j HATC11 10/15/90 32190021 MANUAL CRITICAL I DIABLO CANYON 2 04/16/89 32389005 AUTOMATIC CRmCAL l DIABLO CANYON 2 07/16/89 32389007 MANUAL CRmCAL I l

DIABLO CANYON 2 08/28/89 32389008 MANUAL CRITICAL DIABLO CANYON 2 10/27/89 32389010 MANUAL CRmCAL 4 BRUNSWICK 2 06/17/89 32489009 MANUAL CRmCAL l BRUNSWICK 2 03/13/90 324900N MANUAL CRmCAL l BRUNSWICK 2 08/16/90 32490008 AUTOMATIC CRmCAL BRUNSWICK 2 08/19/90 32490009 AUTOMATIC CRmCAL BRUNSWICK 2 08/30/90 32490012 AUTOMATIC CRmCAL I BRUNSWICK 2 09/27/90 32490015 AUTOMATIC CRITICAL BRUNSWICK 2 10/12/90 32490016 AUTOMATIC CRmCAL BRUNSWICK 1 02/11/89 32589002 AUTOMATIC SUBCRITICAL BRUNSWICK 1 02/11/89 32589002 AUTOMATIC SUBCRJTICAL l BRUNSWICK 1 09/27/90 32590017 AUTOMATIC CRITIC AL i SEQUOYAH1 02/10/89 32789005 AUTOMATIC CRmCAL l SEQUOYAH1 12/10/89 32789035 AUTOMATIC CRIT JAL SEQUOYAH1 06/02/90 32790012 AUTOMATIC CRITICAL SEQUOYAHI 09/14/90 32790021 AUTOMATIC CRmCAL SEQUOYAHI 09/19/90 32790022 AUTOMATIC CRmCAL SEQUOYAH 2 04/15/89 32889005 AUTOMATIC CRITICAL SEQUOYAH 2 04/16/89 32889005 AUTOMATIC CRITICAL j SEQUOYAH 2 04/19/89 32889005 AUTOMATIC CRmCAL ,

SEQUOYAH 2 07/10/89 32889008 AUTOMATIC CRmCAL SEQUOYAH 2 04/10/90 32890008 AUTOMATIC CRmCAL i SEQUOYAH 2 11/23/90 32890017 AUTOMATIC CRITICAL DUANE ARNOLD 01/18/89 33189001 MANUAL CRmCAL DUANE ARNOLD 02/02/89 33189003 AUTOMATIC CRmCAL DUANE ARNOLD 0345/89 33189008 AUTOMATIC CRmCAL l 1

DUANE ARNOLD 06/12/89 33189009 AUTOMATIC CRITICAL DUANE ARNOLD 08/26/89 33189011 AUTOMATIC CRmCAL I DUANE ARNOLD 03/29/90 33190002 MANUAL CRITICAL DUANE ARNOLD 04/01/90 33190004 AUTOMATIC CRITICAL DUANE ARNOLD 09/10/90 33190014 AUTOMATIC CRmCAL DUANE ARNOLD 09/13/90 33190015 MANUAL CRITICAL DUANE ARNOLD 09/18/90 33190016 AUTOMATIC CRmCAL DUANE ARNOLD 10/19/90 33190019 AUTOMATIC CRmCAL FITZPATRICK 11/05/89 33389020 AUTOMATIC CRmCAL FIT 2 PATRICK 11/12/89 33389023 AUTOMATIC CRITICAL FITZPATRICK 01/19/90 33390001 AUTOMATIC CRmCAL )

FITZPATRICK 03/19/90 33390009 AUTOMATIC CRITICAL FITZPATRICK 10/19/90 33390023 MANUAL CRmCAL FITZPATRICK 12/12/90 33390026 AUTOMATIC CRITICAL FITZPATRICK 12/15/90 33390027 AUTOMATIC CRITICAL BEAVER VALLEY I 01/17/89 33489001 AUTOMATIC CRmCAL j BEAVER VALLEY I 02/13/89 33489002 AUTOMATIC CRITICAL BEAVER VALLEY l 05/18/89 33489007 AUTOMATIC CRmCAL a

BEAVER VALLEY I 09/01/89 33489008 AUTOMATIC SUBCRmCAL BEAVER VALLEY l 12/27/89 33489018 AUTOMATIC CRmCAL BEAVER VALLEY I 03/30/90 33490007 AUTOMATIC CRITICAL ST. LUCIE 1 07/17/89 33589003 AUTOMATIC CRmCAL ST. LUCIE 1 09/13/89 33589005 AUTOMATIC CRmCAL ST. LUCIE 1 05/24/90 33590007 MANUAL CRITICAL MILLSTONE 2 05 08/90 33690006 MANUAL CRmCAL MILLSTONE 2 08/27/90 33690012 AUTOMATIC CRITICAL NORTH ANNA 1 02/25/89 33889005 AUTOMATIC CRmCAL NORTH ANNA 1 07/19/89 33889014 AUTOMATIC CRITICAL NORTH ANNA 1 12/05/89 33889017 AUTOMATIC CRmCAL NORTH ANNA 1 01/23/90 33890001 AUTOMATIC CRITICAL NORTH ANNA 2 11/02/90 33990010 AUTOMATIC CRmCAL FERMI 2 02/26/89 34189006 AUTOMATIC CRmCAL FERMI 2 03/07/89 34189007 MANUAL CRmCAL FERM12 12/18/89 34189036 AUTOMATIC CRmCAL FERMI 2 12/23/89 34189038 MANUAL CRITICAL FERMI 2 04/10/90 34190003 AUTOMATIC CRITICAL FERMI 2 10/06/90 34190011 AUTOMATIC CRITICAL TROJAN 0809/89 34489017 AUTOMATIC CRITICAL

'IROJAN 08/09/90 34490034 AUTOMATIC CRmCAL Page 4 I 1

j

I

?lant Name Event Date LE R Number . Scram Tvoc >

JAVIS-BESSE 01/18/89 34619003 AUTOMATIC l

~ DAVIS-BESSE 05/30/89 34689005 AUTOMARC CRmCAL !

DAVIS-BESSE 01/26/90 34690002 AUTOMATIC CRITICAL 1 DAVIS-DESSE 12/13/90 34690016- AUTOMAVC CRmCAL !

FARLEYl 11/12/89 34889006 AUTOMATIC CRmCAL '

FARLEYI 07/20/90 34890005 MANUAL CRmCAL 1 l

i LIMERICK 2 11/10/89 35389013 AUTOMATIC CRmCAL 4

LIMERICK 2 07/15/90 35390012 AUTOMATIC CRmCAL ,

LIMERICK 2 09/10/90 35390015 AUTOMATIC CRmCAL HOPE CREEK 08/30/89 35489017 AUTOMATIC CRmCAL !

HOPE CREEK 12/30/89' 35489025 AUTOMATIC CRmCAL HOPE CREEK - - 01/06/90 35490001 AUTOMATIC CRmCAL 4 HOPE CREEK 03/19/90 35490003 AUTOMATIC CRITICAL HOPE CREEK 1IS4/90 35490024 AUTOMATIC CRmCAL HOPE CREEK 11/17/90 35490028 AUTOMATIC CRmCAL l SAN ONOFRE 2 0249/89 36189004 AUTOMATIC SUBCRmCAL ;

SAN ONOFRE 2 - 09/02/89 36189019 MANUAL CRmCAL SAN ONOFRE 2 1246/90 36190016 AUTOMATIC CRmCAL '

SAN ONOFRE 3 01/06/89 36289001 AUFOMATIC CRmCAL <

SAN ONOFRE 3 04/07/89 36289006 AUTOMATIC CRmCAL !

I SAN ONOFRE 3 02/23/90 36290002 AUTOMATIC CRmCAL PARLEY 2 - 05/22/89 36489007 AUTOMATIC CRmCAL FARLEY 2 05/27/89 36489008 AUTOMATIC CRmCAL FARLEY 2 09/20/89 36489010 MANUAL CRmCAL PARLEY 2 10/18/89 36489012 AUTOMATIC CRmCAL FARLEY 2 10/19/89 36489013 AUTOMATIC CRmCAL FARLEY 2 11/18/89 36489015 AUTOMATIC CRmCAL ,

FARLEY 2 05/12/90 36490001 AUTOMATIC CRmCAL 1 HATCH 2 09/03/89 36689005 AUTOMATIC CRITICAL HATCH 2 01/12/90 36690001 AUTOMATIC CRmCAL HATCH 2 03/28/90 36690003 AUTOMATIC CRmCAL ARKANSAS 2 04/18/89 36889006 AUTOMATIC CRmCAL ARKANSAS 2 12/31/89 36889024 AUTOMATIC CRmCAL ARKANSAS 2 03/04/90 36890005 MANUAL CRmCAL ARKANSAS 2 03/05/90 36890006 MANUAL SUBCRmCAL ARKANSAS 2 06/26/90 36890014 AUTOMATIC CRmCAL ARKANSAS 2 08/21/90 36890019 AUTOMATIC CRITICAL ARKANSAS 2 09/28/90 36890020 MANUAL CRmCAL MCGUIRE 1 03 S 7/89 36989004 MANUAL CRmCAL MCGUIRE I 08/26/89 36989022 AUTOMATIC CRmCAL MCGUIRE 1 01 S 8/90 36990001 AUTOMATIC CRmCAL MCGUIRE 1 10/13/90 36990027 AUTOMATIC CRmCAL MCGUIRE 1 11/17/90 36990032 AUTOMATIC CRmCAL MCGUIRE 2 03S3/89 37089001 AUTOMATIC CRmCAL MCGUIRE 2 03/14/89 37089002 AUTOMATIC CRmCAL MCGUIRE 2 04 S 6/89 37089003 AUTOMATIC CRmCAL MCGUIRE 2 12/27/90 37090008 MANUAL CRmCAL LASALLE1 03 S 2/89 37389009 AUTOMATIC CRITICAL LASALLE1 03/28/90 37390006 AUTOMATIC CRmCAL LASALLE1 06/26/90 37390010 AUTOMATIC CRmCAL LASALLE 2 08/26/89 37489011 MANUAL SUBCRmCAL LASALLE 2 08/26/89 37489011 AUTOMATIC CRmCAL LASALLE 2 02 S 6/90 37490001 AUTOMATIC CRmCAL LASALLE 2 09/12/90 37490010 AUTOMATIC CRmCAL WATERFORD 3 07/15/89 38289013 MANUAL CRmCAL WATERFORD 3 08/19/89 38289017 AUTOMATIC CRmCAL WATERFORD 3 12/23/89 38289024 MANUAL CRITICAL WATERFORD 3 03/22/90 38290002 AUTOMATIC CRITICAL WATERFORD 3 03/29/90 38290003 AUTOMATIC CRITICAL WATERFORD 3 08/25/90 38290012 AUTOMATIC CRmCAL SUSQUEHANNA1 01/04/89 38789001 AUTOMATIC CRmCAL SUSQUEHANNA1 01/12/89 38789002 AUTOMATIC CRmCAL SUSQUEHANNA1 02/07/89 38789005 MANUAL CRmCAL SUSQUEHANNA1 12/24/89 38789027 AU'OMATIC CRmCAL SUSQUEHANNA 2 02/27/89 38889003 MANUAL CRmCAL SUSQUEHANNA 2 02 S 6/90 38890002 AUTOMATIC CRmCAL SUSQUEHANNA 2 05/28/90 38890005 AUTOMATIC CRITICAL ST.LUCIE 2 06/26/89 38989005 AUTOMATIC CRmCAL Pese 5

)

Plant Name Event Date LER Number Scram Tvoe Critical ST.LUCIE 2 09/23/89 38989007 MANUAL CRITICAL ST. LUCIE 2 01/14/90 38990001 AUTOMATIC CRmCAL SUMMER 04/01/89 39589006 AUTOMATIC CRmCAL SUMMER 05/28/89 39589011 MANUAL CRITICAL SUMMER 07/11/89 39589012 AUTOMATIC CRmCAL SUMMER 08/25/89 39589015 MANUAL CRmCAL SUMMER 12S2/89 39589020 AUTOMATIC CRmCAL WASH. NUCLEAR 2 01/30/89 39789002 AUTOMATIC CRITICAL WASH. NUCLEAR 2 06/29/89 39789028 AUTOMATIC CRITICAL WASIL NUCLEAR 2 0806/89 39789031 AUTOMATIC CRITICAL WASH. NUCLEAR 2 08/17/89 39789035 AUTOMATIC CRITICAL WASH. NUCLEAR 2 09/25/90 39790021 MANUAL CRmCAL WASH. NUCLEAR 2 12S7/90 39790031 AUTOMATIC CRmCAL SIIEARON HARRIS 01/16/89 40089001 AITTOMATIC CRmCAL SHEARON HARRIS 02S6/89 40089003 AUTOMATIC CRmCAL SHEARON HARRIS 02/07/89 40089004 AUTOMATIC CRmCAL SHEARONIIARRIS 02/22/89 40089005 AUTOMATIC CRmCAL SHEARON llARRIS 03/14/89 40089006 AUTOMATIC CRmCAL SHEARON' HARRIS 10 S 9/89 40089017 AUTOMATIC CRmCAL SHEARON IIARRIS 12S7/89 40089018 MANUAL SUBCRmCAL NINE MILE Pr. 2 N/22/89 41089009 AUTOMATIC CRITICAL NINE MILE PT. 2 04/13/89 41089014 AUTOMATIC CRmCAL NINE MILE Fr.2 09 S 8/89 41089024 AUTOMATIC CRITICAL NINE MILE Fr.2 10/13/89 41089035 AUTOMATIC CRITICAL NINE MILE PT.2 10/18/89 41089036 AUTOMATIC CRmCAL NINE MILE Fr.2 12/01/89 41089M 0 AUTOMATIC CRITICAL i NINE MILE PT. 2 05/14/90 41090009 MANUAL CRmCAL NINE MILE Fr.2 09/05/90 41090013 AUTOMATIC CRITICAL BEAVER VALLEY 2 02/12/89 41289003 AUTOMATIC CRITICAL BEAVER VALLEY 2 05/27/89 41289018 AUTOMATIC SUBCRmCAL BEAVER VALLEY 2 07/02/90 41290008 AUTOMATIC CRmCAL CATAWBA 1 03/05/89 41389008 AUTOMATIC CRITICAL CATAWBA 1 06/26/89 41389017 MANUAL CRITICAL CATAWBA 1 08/24/89 41389022 MANUAL CRmCAL l CATAWBA 2 01/12/89 41489001 AUTOMATIC CRITICAL l CATAWBA 2 01/21/89 41489002 MANUAL CRITICAL i CATAWBA 2 02/21/89 41489003 AUTOMATIC CRITICAL CATAWBA 2 10 S 7/90 41490013 AUTOVATIC CRmCAL GRAND GUU 05/05/89 41689006 AUTOMTIC CRmCAL GRAND GUU 07/22/89 41689010 AIJiOMATIC CRmCAL GRAND GUU 08/14/80 41689012 AUTOMATIC CRmCAL GRAND GUU 11S7/89 41689016 AUTOMATIC CRITICAL GRAND GUU 12/30/89 41689019 MANUAL CRmCAL GRAND GUU 07/24/90 41690011 AUTOMATIC CRmCAL GRAND GUG 09/16/90 41690017 AUTOMATIC CRITICAL GRAND GUU 11/24/90 41690026 MANUAL CRITICAL GRAND GUU 12/10/90 41690028 AUTOMATIC CRITICAL GRAND GUG 12/18/90 41690029 AUTOMATIC CRmCAL MILLSTONE 3 05S6/89 42389008 MANUAL CRITICAL MILLSTONE 3 05/11/89 42389009 AUTOMATIC CRmCAL MILLSTONE 3 01/18/90 42390005 MANUAL CRmCAL MILLSTONE 3 03/09/90 42390009 AUTOMATIC CRmCAL MILLSTONE 3 03/30/90 42390011 MANUAL CRmCAL MILLSTONE 3 04/16/90 42390013 MANUAL CRITICAL MILLSTONE 3 05/10/90 42390014 MANUAL CRITICAL MILLSTONE 3 06/06/90 42390019 AUTOMATIC CRmCAL MILLSTONE 3 12/31/90 42390030 MANUAL CRmCAL VOGTLE1 02/10/89 42489005 MANUAL CRITICAL VOGTLE 1 05/09/89 42489012 AUTOMATIC CRITICAL VOGTLE1 0708/89 42489016 MANUAL CRmCAL VOGTLE1 08/03/89 42489016 MANUAL CRmCAL VOGTLE 1 10 S 2/89 42489018 AUTOMATIC CRmCAL VOGTLE1 01/24/90 42490001 AUTOMATIC CRmCAL VOGTLE1 04/25/90 42490011 MANUAL CRmCAL VOGTLE1 07/23/90 42490016 MANUAL CRmCAL VOGTLE 1 12/18/90 42490023 MANUAL CRITICAL VOGTLE 2 05/02/89 42589019 AUTOMATIC CRmCAL VOGTLE 2 05/12/89 42589020 AUTOMATIC CRmCAL Page 6

V

~

! Plant Yame Event Date I El Number Scram Tyne VOOT22- AUTOMATIC AL

~

4 05/22/89 42519021 i VOOTLE 2 07/26/89 42589024 AUTOMA'11C CRmCAL VOOTIE 2 10/11/89- 42589027 AWOMATIC CRmCAL

VOOTLE 2 1IS5/89 42589029 MANUAL CRmCAL

- VOOTLE 2 12S2/89 42589031 AUTOMATIC CRmCAL VOGTLE 2 03/20/90 42590002 AUTOMATIC CRITICAL VOGTLE 2 05 S 6/90 42590007 AUTOMATIC CRmCAL'- -

. VOGTLE 2 06/28/90 42590008 MANUAL CRmCAL VOGTLE 2 - 06/30/90 42590009 MANUAL CRmCAL PERRY OlS7/90 44090001 AUTOMARC CRmCAL ,

SEABROOK 06/22/89 44389008 MANUAL CRmCAL !

SEABROOK 06/20/90 44390015 AUTOMATIC CRmCAL SEABROOK 07 S 5/90 44390018 AUTOMATIC CRmCAL SEABROOK 08/22/90 44390022 AUTOMATIC CRmCAL '

SEABROOK 1199/90 44390025 AUTOMATIC CRmCAL i

' COMANCHE PEAK 1 03/05/90 -44590002 AUTOMARC SUBCRmCAL ;

COMANCHE PEAK 1 04/21/90 44590009 AUTOMATIC CRmCAL !

COMANCHE PEAK 1 05 S 9/90 44590013 AUTOMATIC CRmCAL COMANCHE PEAK 1 05/27/90 44590017 MANUAL CRITICAL COMANCHEPEAK1 08 S 8/90 44590023 AUTOMATIC CRmCAL COMANCHE PEAK 1 08/25/90 44590025 AUTOMATIC CRmCAL -

COMANCHE PEAK 1 09S 7/90 44590027 MANUAL CRmCAL :

COMANCHE PEAK 1. 09/08/90 44590028 AUTOMATIC CRmCAL .:

COMANCHE PEAK 1 09/10/90 44590029 AUTOMATIC CRmCAL +

COMANCHE PEAK 1 09/15/90 44590030 MANUAL CRmCAL BYRON 1 01 S 1/89 45489002 MANUAL CRmCAL BYRON 1 03SI/90 45490002 AUTOMATIC CRmCAL 1 CRmCAL BYRON 1 05 S 3/90 45490006 AUTOMATIC BYRON 1 08/19/90 45490011 AUTOMATIC CRmCAL l BYRON 1 12/03/90 45490014 AUTOMATIC CRmCAL '

BYRON 2 01/18/90 45590001 AUTOMATIC CRmCAL BYRON 2 12/20/90 45590010 MANUAL CRITICAL BRAIDWOOD 1 03/06/89 45689004 AUTOMATIC CRmCAL BRAIDWOOD 1 07/18/89 45689006 AUTOMATIC CRmCAL l BRAIDWOOD 2 07/18/89 45689006 AUTOMATIC CRmCAL l BRAIDWOOD 1 ' 01/12/90 45690001 AUTOMATIC CRmCAL

BRAIDWOOD 1 06/08/90. 45690008 AUTOMATIC CRITICAL BRAIDWOOD 1 - 09/29/90 45690018 - AUTOMATIC CRmCAL l

' BRAIDWOOD 1 12SI/90 45690021 AUTOMATIC CRmCAL l BRAIDWOOD 1. 12SO/90 45690023 AUTOMATIC CRmCAL i BRAIDWOOD 2 05/11/89 45789002 AUTOMATIC CRmCAL ,

. BRAIDWOOD 2 09 S 7/89 45789004 AUTOMA'11C CRmCAL l BRAIDWOOD 2 06/09/90 45790010 AUTOMATIC CRmCAL

' RIVER BEND 02/20/89 45889007 AUTOMATIC CRmCAL RIVER BEND 02/25/89 45889008 AUTOMATIC CRmCAL RIVER BEND 09/30/89 45889035 AUTOMATIC CRmCAL RIVER BEND 12 S 1/89 45889042 AUTOMATIC CRmCAL RIVER BEND 03/15/90 45890008- AUTOMATIC CRmCAL RIVER BEND 04/07/90 45890014 AUTOMATIC CRmCAL RIVER BEND 12/12/90 45890047 AUTOMATIC CRmCAL CLINTON 1 05/26/89 46189022 MANUAL CRmCAL CLINTON 1 06 S 1/89 46189022 MANUAL CRmCAL CLINTON 1 06/28/89 46189028 AUTOMATIC CRmCAL CLINTON 1 07/14/89 46189029 MANUAL CRmCAL CLINTON 1 07/31/89 46189032 MANUAL CRmCAL CLINTON 1 05/17/90 46190012 MANUAL CRmCAL CLINTON 1 07 S 9/90 46190013 AUTOMATIC CRmCAL WOLFCREEK 01/23/89 48289002 AUTOMATIC CRmCAL WOLFCREEK 02S2/89. 48289004 AUTOMATIC CRmCAL WOLF CREEK 02S6/90 48290001 AUTOMATIC CRITICAL WOLF CREEK . 05/14/90 48290011 AUTOMATIC CRmCAL WOLFCREEK 05/17/90 48290012 AUTOMATIC CRmCAL WOLF CREEK 05/19/90 48290013 AUTOMATIC CRmCAL CALLAWAY ' 05/29/89 48389006 AUTOMATIC CRmCAL CALLAWAY - 06/23/89 48389008 MANUAL CRmCAL CALLAWAY - 05SI/90 48390005 AUTOMATIC CRmCAL 1 CALLAWAY 06/11/90 48390007 AUTOMATIC CRmCAL !

CALLAWAY 06/12/90 48390007 MANUAL SUBCRmCAL l

- Pase 7

Plant Nan

Event Date i RR Number Scram Tyne CALLAWAY 11/24/90 48390016 AUTOMATIC AL CALLAWAY 12/30/90 48390017 AUTOMATIC CRmCAL

SOUTH TEXAS 1 -0183/89 49889001 AtJIDMATIC CRmCAL s 3 . SOWH TEXAS 1 01/20/89 49889005 AUTOMATIC CRmCAL L SOtJTH TEXAS 1 07/04/89 49889015 AUTOMATIC CRmCAL SOUTH TEXAS 1 03/29/90 49890005 AUTOMATIC CRmCAL ,

MANUAL CRmCAL 4 SOUTH TEXAS 1 07/30/90 49890006 2 SOUTH TEXAS 1 06/20/90 49890014 AUTOMATIC CRmCAL I' SOIJTHTEXAS 1 06/28/90 49890015 AUTOMATIC CRmCAL SOUTH TEXAS 1 07/02/90 49890016 AUTOMATIC CRmCAL ,

I SOUTH TEXAS 1 07/16/90 49890020 AUTOMATIC CRmCAL SOUTH TEXAS 1 09/29/90 49890023 MANUAL CRmCAL SOUTHTEXAS 1 11/24/90 49890025 AUTOMATIC CRmCAL SOUTH TEXAS 2 04 S 5/89 49989009 AUTOMATIC CRmCAL

- SOUTH TEXAS 2 04/15/89 49989013 AUTOMATIC CRmCAL SOUTHTEXAS 2 0642/89 49989016 AUTOMATIC CRmCAL SOUTA TEXAS 2 07/13/89 49989017 AUTOMATIC CRmCAL SOUTH TPXAS 2 08/23/89 49989019 AUTOMATIC CRmCAL

< SOUTH TEXAS 2 08/29/89 49989020 MANUAL CRmCAL ,

SOUTHTEXAS 2 09 S 5/89 49989021 AUTOMATIC CRmCAL

SOUTH TEXAS 2 09/19/89 49989022 AUTOMATIC CRmCAL SOUTH TEXAS 2 09/22/89 49989023 AUTOMATIC CRmCAL SOtJTHTEXAS 2 10/13/89 49989026 AUTOMATIC CRmCAL i

i. SOUTH TEXAS 2 02 S 2/90 49990002 AUTOMATIC CRmCAL SOUTH TEXAS 2 03/26/90 49990004 AUTOMA11C CRmCAL i SOUTH TEXAS 2 04/14/90 49990005 AUTOMATIC CRmCAL l

SOUTH TEXAS 2 09/17/90 49990013 AUTOMATIC CRmCAL :

PALO VERDE 1 0345/89 52889004 AUTOMATIC CRmCAL 4 PALO VERDE 1 08/14/90 52890006 AUTOMATIC CRmCAL l PALO VERDE 2 02/16/89 52989003 AUTOMATIC CRmCAL i PALO VERDE 2 07/12/89 52989009 AIJTOMATIC CRmCAL 1 PALO VERDE 2 10/31/89 52989010 AUTOMATIC CRmCAL i PALO VERDE 2 02/23/90 52990001 MANUAL CRmCAL

< PALO VERDE 3 03 S 3/89 53089001 AUTOMATIC CRmCAL

! PALO VERDE 3 04/14/90 - 53090004 AUTOMATIC CRmCAL >

j PALO VERDE 3 10/20/90 53090007 AUTOMATIC CRmCAL 4

j Records pissed: 5M 4

4 9

4 i

1 I

I i

i Pese 8

THIS SESSION IS READY T3 BEGIN.

D '1

had LER GROUP SPU8LIC1 IS K0W " ACTIVE" WITH 237 LERs i

U" THE 237 KETS IN THE CURRENT ACTIVE GROUP WILL SE SORTED Ed CURRENT OPTIONS FOR LIST COMMAND g4 N0 DOCK NOCOMM NOMAT bd j NOWATCH NOREF

>q NODEC t, ABSTRACT NOTPD U NOFLOW Ii YOU HAVE REQUESTED LISTING 237 RECORDS, ARE YOU SURET

>q f' 1

88 FORM 1 LER SCSS DATA 04-1 0****************************************************************8-91 ****

>e DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT OATE 029 1989 002 0 8902170016 213101 01/11/89 g, ***************************************************wa***************

ABSTRACT

- POWER LEVEL - 000%. ON 1/11/89, AT 1937 HOURS, WITH THE PLANT IN MODE 3, WHILE CONDUCTING CONTROL ROD OROP TIME MEASUREMENTS FOLLOWING A Lq REFUELING OUTAGE, THE REACTOR PROTECTION SYSTEM AUTOMATICALLY ACTUATED. AT THE TIME OF THE

VENT THE NO. 1 VITAL SUS INVERTER WAS

- OUT OF SERVICE FOR MAINTENANCE, WITH THE VITAL SUS INVERTER POWER SUPPLY IN BVPASS. IN THIS CONFIGURATION POWER TO THE VITAL gel 5 WAS SUPPLIED FROM EMERGENCY MCC-5. THE REACTOR WAS SUSCRITICAL AND THE 8

GROUP A CONTROL RODS WERE AT 82 INCHES, BEING WITHORAWN TO 90 INCHES.

THE ROOT CAUSE OF THIS EVENT IS ATTRISUTED TO A VOLTAGE FLUCTUATION

, ON THE VITAL BUS WHICH INDUCED A FALSE HIGH STARTUP RATE SCRAM SIGNAL, OPENING THE SCRAM SREAKERS, BK-1 AND 8K-2. THE UNPLANNEO OPENING OP

' BK-1 AND 2 CONSTITUTES AN ACTUATION OF THE RPS. THE VOLTAGE FLUCTUATION OCCURRED WHEN THE NO. 1 BOILER FEED PUMP WAS STARTED.

-- NORMALLV, THE VITAL SUS INVERTER WOUL3 HAVE PREVENTED THE VOLTAGE FLUCTUATION ON THE EMERGENCY MCC-5 FROM AFFECTING THE RPS. THE OPERATORS TOOK ACTION TO PRECLUDE THE STARTING OF HEAVY LOA 05 WHILE

, THE VITAL SUS INVERTER WAS IN BYPASS. TO PREVENT A RECURRENCE OF THIS EVENT CONDITIONAL PRECAUTIONS WILL SE ADDED TO THE APPROPRI ATE PL ANT

OPERATING PROCEDURES. THIS IS THE FIRST OCCURRENCE OF THIS NATURE.

NO FURTHER CORRECTIVE ACTIONS ARE DEEMED NECESSART. THE RPS FUNCTIONED AS DESIGNED.

,9 FORM 2 LER SCSS DATA 04-18-91 0********************************************************************

I DOCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE p+ 029 1939 005 0 8905160098 213945 04106/89 I

u A85 TRACT I

, POWER LEVEL - 1001. 04 416/*9 AT 1123 wouoS WTTu Tw= m swT av inn

otsame w+LL :s l*4131 a f tu TO CETERMINE IF HUMAN FACTORS INSINEERIN3 IS APDPOPRIATE. THIS IS THE SECONC EVENT OF THIS NATURE. A PREVIOUS P1 REACTOR SCRAM DUE TO INADVERTENT MISPOSITIONING OF THE NRW TRIP SWITCH WAS REPORTED AS LER 86-13. THERE WAS NO ADVERSE EFFECT ON THE HEALTH gq A%D SAFETY OP THE PUBLIC AS A RESULT OF THIS EVENT.

' \t i

b"4 FORM 5 LER SCSS DATA r

04-18-91

.i

' 0*.a.**.*******..**.*****..***...*****.****.**.************. ..*....*

t-g 00CKEY YEAR LER NUMSER REVISION OCS NUM8ER NSIC EVENT DATE

! 029 1990 011 0 9101090143 221095 12/05/90 i

j A85 TRACT be ,

POWER LEVEL - 100%. ON 12/5/90, AT 0702 HOURS, WITH THE PLANT IN MODE 1 AT 100% POWER, FOLLOWING PERFORMANCE OF VALVING TO SUPPORT REPAIR OF i gg A CONTROL AIR LEAK, AN AUTOMATIC REACTOR SCRAM OCCURRED. CLOSURE OF 1

~ A CONTROL AIR ISOLATION VALVE (CA-V-1239) RESULTED IN AN UNANTICIPATED U" LOSS OF AIR TO THE HFATER ORAIN TANK HIGH LEVEL DUMP VALVE CAUSING IT Yo OPEN. THIS RESULTED IN SEQUENTIAL AUTOMATIC TRIPPING OF THE b4 HEATER DRAIN PUMP DN LOW HEATER DRAIM TANK LEVEL AND THE 80!LER FEED PUMPS (BFPS) ON LOW SUCTION Pk?SSURE. THE LOSS OF FEEDWATER FLOW FROM THE 8 FPS RESULTED IN A LOW LEVEL CONDITION IN THE STEAM GENERATORS yg WHICH INITIATED THE AUTOMATIC REACTOR SCRAM. THE ROOT CAUSE OF THIS EVENT HAS SEEN ATTRIBUTED TO PERSONNEL ERROR. AN INCOMPLETE NOTATION 88 ON 4 PLANT ORAWING AND THE VALVE IDENTIFICATION TAG CONTRIBUTED TO THE ERROR. AS CORRECTIVE ACTIONS THE DRAWING AND VALVE TAG HAVE BEEN CORRECTED AND A WALK 00WN OF THE CONTROL AIR SYSTEM DRAWINGS IS IN D1 PROGRESS. ALL PLANT SYSTEMS FUNCTIONED 45 DESIGNED DURING THE EVENT.

THERE WAS NO ADVERSE EFFECT ON THE HEALTH OR SAFETY OF THE PUBLIC AS g, A RESULT OF THIS EVENT.

4 l he FORM 6 LER SCSS DATA 0......................................,.............................

04-18-91 te DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 155 1989 008 0 8909270133 215298 08/22/89 A85 TRACT I

POWER LEVEL - 074%. ON 8/22/89 THE UNIT WAS OPERATING AT APPROXIMATELY 74% POWER FOLLOWING START-UP FROM THE REFUELING OUTAGE A WEEK 3 EARLIER.- AT 0635 HOURS, OPERATORS NOTICED A SLOW REACTOR PRESSURE INCREASE AND A3 JUSTED THE INITIAL PRESSURE REGULATOR TO RESTORE

' PRESSURE TO N0aMAL. 47 0645 HOURS, REACTOR PRESSURE INCREASED RAPIDLY CAUSING A REACTOR TRIP 04 HIGH NEUTRON FLUX. ALL CONTROL RODS INSERTE0 AND PLANT COOLING WAS MAINTAINED WITH THE MAIN CONDENSER. NO 8

i ENGINEERED SAFETY SYSTEMS OTHER THAN THE REACTOR PROTECTION SYSTEM WERE ACTUATED DURING THE EVENT. CAUSE OF THE TRIP WAS A RAPID CLOSURE OF THE TURSINE ADMISSION VALVES OUE TO GROSS LEAKAGE IN THE TURSINE

, INITIAL PRESSURE REGULATOR SELLOWS ASSEMBLY. AFTER REPAIR OF THE BELLOWS ASSEMSLV AND SUCCESSFUL TESTING, THE PLANT WAS RESTARTED ON

=

8/22/89 AT 2211 hours0.0256 days 0.614 hours 0.00366 weeks 8.412855e-4 months .

! ,i 1 s

l FORM 7 LER SCSS DATA 04-18-91 C..**.***..****.****..*..**...*..**...*...**.*..**.**.**************.

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT OATE 206 1959 017 0 8906090317 214248 05/03/S9

ABSTRACT g, POWER LEVEL - 000T. AT 0401 ON 5/3/89, WITH U NI T 1 IN MODE 3, WHILE

, PERFORMING CONTROL ROD DROP TESTING FOR THE FIDST TIME USINr. A wfW

^ '

. ==

vaultt 10N STSYiH (R's) ACTUATION. THE ACTU4 TION OCCURRE3 WHILE P1 CONTROL EANK II WAS BEING WITHCRAWN. INVESTIG4710H HAS DETERMINED TH47 THE ROOT CAUSE OF THE IR HIGH SUR ACTUATION WAS NOISE SPIKES GENERATED BY SEVERAL SOURCES A550CIATED WITH ROD CONTROL BANK II. THE g4 PCEDOMINANT CAUSE OF THE NOISE FROM TH5SE SOUICES IS BELIEVED TO BE q; DISSIPATION OF STORED ENERGY WHICH RESULTS FROM THE COLLAPSE OF MAGNETIC FIELDS WHEN DC POWERED COILS ARE DE-ENERGIIEO. THE 2 f4 PREDOMINATE SOURCES WERE: 1) THE PULSE-TO-4NALOG (P-4) DC STEPPER

\ g, MOTOR AND, 2) THC ROD POSITION DEVIATION ALARM RELAYS. OTHER SOURCES b1 0F NOISE INCLUDED: 1) THE CONTROL ROD ORIVE MECHANISM (CRDM) CONTROL CIRCUIT CAM ACTUATED SWITCHES AND CONTACTOR COILS, AND 2) THE ROD

. 80TTOM SIGNAL RELAYS. TROUBLESHOOTING ESTABLISHED A DIRECT CAUSE AND

,4 EFFECT RELATIONSHIP BETWEEN OPERATION OF EACH OF THESE COMPONENTS AND bd THE N0!$E SPIKES OBSERVED ON THE IR CHANNELS. FOR CORRECTIVE ACTION, i CIRCUIT MODIFICATIONS CONSISTING OF NOISE SUPPRESSION DEVICES (I.E.,

RESISTOR-CAPACITOR FILTERS AND DIODES) HAVE BEEN INSTALLED.

be 1 FORM 8 LER SCSS DATA he I

0************************************************************04-18-91 ********

be 4 DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 206 1939 019 0 8903310024 215104

>4 '

....................................**..................... 07/24/89 ........

A85 TRACT De POWER LEVEL - 076%. ON 7/24/39, AT 1216 WHILE AT 76% POWER, UNIT 1 WAS MANUALLY TRIPPED DUE TO 4 LOSS OF FEEDWATER FLOW TO STEAM GENERATOR (SG) "A" AND RESULTANT LOW LEVEL ALARM AT 1215. OPERATOR $ AUTHORIZED D4 MAINTENANCE TECHNICIANS TO PERFORM TESTING OF THE SG "A" HIGH LEVEL

' ALARM AND STEAM FLOW / FEED FLOW MISMATCH REACTOR TRIP ALARM. CURING b, THE HIGH LEVEL ALARM PORTION OF THE TEST, THE SG "A" HIGH LEVEL ALARM g

ANNUNCIATED AS ANTICIPATED. THE HIGH LEVEL ALARM WAS PROMPTLY FOLLOWED BY THE SG "A" STEAM / FEED MISMATCH ALARM, WHICH WAS NOT ANTICIPATED AT bs THIS POINT IN THE TEST SEQUENCE. 4FTER OBSERVING THAI SG "A" LEVELS WERE RAPIDLY DECRESSING AND THE SG "A" MAIN FEEDW4TER FLOW CONTROL ge VALVE (FCV) HAD TRIPPED CLOSED OPERATORS UNSUCCESSFULLY ATTEMPTED TO OPEN THE FCV AND, IN ACCORDANCE WITH PROCEDURE 5, MANUALLY TRIPPED THE

, ,, REACTOR. SG "A" M4Y HAVE ORIED OUT FOR A BRIEF PERIOD SHORTLY AFTER THE REACTOR HAD BEEN TRIPPED UNTIL THE AUXILIARY FEEDWATER SYSTEM ACTU4TED AT 1217. ALL REQUIRED SYSTEMS FUNCTIONED NORMALLY. THE 8

EFFECTS OF A RECENT DESIGN CHANGE ON THE TCv CIRCUITRY WERE NOT RECOGN!!ED TO RESULT IN A LOSS OF FEE 0 WATER FLOW AND WERE, THEREFORE,

p. NOT TRANSFERRED INTO STATION PROCEDURES OR OPERATOR TRAINING. THE ROOT CAUSE IS ATTRIBUTED TO WEAKNESSES IN SCE'S PROCESSES FOR ENSURING

' THAT DESIGN CHANGE INFORMATION IS ADEQU4TELY INCORPORATED INTO PROCEDURES.

1 e

FORM 9 LER SCSS DATA 04-19-91

, 0********************************************************************

DOCKET YEAR LER DUMBER REVISION DCS NUMSER NSIC EVENT DATE 206 1989 021 1 9003200230 217402 08/03/89 4

ABSTRACT POWER LEVEL - 0912. AT 1800 ON 8/3/59, WITH UNIT 1 AT 91% POWER, A REACTOR TRIP OCCURRED OUE TO ACTUATION OF THE REACTOR PROTECTION SYSTEM (R PS) ON LOW REACTOR COOLANT SYSTEM (RCS) FLOW IN ONE LOOP.

i

' ALL SYSTEMS REPONDED NORMALLY 70 THE TRIP AND THE OPERATORS (UTILITY,

,- LICENSED) STABILIZED THE PLANT IN MODE 3. THE RPS OPERATED IN ACCORDANCE WITH DESIGN, WITH NO MALFUNCTIONS NOTED. THE BRIEF LOW RCS l

FLOW SIGNAL OCCURRED IN LOOP "C" AND WAS CAUSED BY A LOSS OF 4 INSULATION RESISTANCE OF THE FLOW TRANSMITTER CABLE. THE LOSS OF INSULATION R E SI ST ANC E R E SUL T

D S R n= T I=s-v e ne r e a tno c-o s a * * *

a.-

l

. mm

. . . . . s s . .. c i;2: or tac

' r> Liv AUTOMATIC CONTROL SYSTEM. THE MANUAL TRIP WAS INITIATED, AS REQUIRED 3V PROCEDURE, TO PREVENT A POSSIELE pe CHALLENGE TO THE MAIN STEAM LINE SAFETY VALVES ON NUNSER 1 STEAM LINE.

FULL CLOSURE OF THE WALVE OCCURRED WHEN INSTRUMENTATION AND CONTROL PER$0:2EL PERFORMING THE CONTROL SYSTEM FUNCTIONAL TEST MISSED 4 g4. q ; PROCEDURE STEP. THE MISSED STEP REQUIRES THE INSERTION AND REMOVAL OF b4 A TEST PLUG INTO A TEST JACK TERMINAL TO 6 LOCK 4 TRIP SIGNAL PRIOR TO 4

OPERATING THE CONTROL SWITCH, THE VALVE WOULO NOT HAVE CLOSED. AFTER

! sg THE PLANT TRIP, ALL PLANT SYSTEMS FUNCTIONED AS DESIGNED. THE ROOT i

pq ' CAUSE OF THE EVENT HAS SEEN ATTRIEUTED TO PER$0NNEL ERROR IN THAT THE 3

TECHNICIAN PERFORMING THE PROCEDURE MISSED A STEP. CORRECTIVE ACTIONS i

(4 q : INCLUDED COUNSELING THE TECHNICIANS ON THE IMPORTANCE OF FOLLOWING PROCEDURE STEPS AS WRITTEN, AND UNDERSTANDING THE EXPECTED RESULTS OF EACH STEP PRIOR TO ITS* PERFORMANCE. ALL SPECIAL SURVEILLANCE i DG ,. PROCEDURES OF THIS TYPE WILL BE REVIEWED FOR HUMAN FACTORS CONSIDERATIONS AN3 REVISED AS NECESSARY TO IMPROVE USABILITY.

gg 1 i,

FORM 3 LER SCS$ DATA D"

0******e*****************************************************04-18-91 **e*****

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

>= 029 1989 007 e..

0 8906050266 214083 04/23/89

....................................................e***e***een.

Di ABSTRACT b4 POWER LEVEL - 100%. ON 4/23/89, AT 1830 HOURS, OURING NORMAL STEADY STATE OPERATION, (MODE 1, AT 100% POWER) THE CONTROL ROOM OPERATOR p4 OBSERVED THAT GROUP C CONTROL RODS COULO NOT BE MOVED. THE OPERATING CREW DETERMINED THAT THE CONTROL RODS' CAM MOTOR WAS INOPERA8LE. AN ELECTRICIAN WAS CALLED IN. THE ELECTRICIAN PERFORMING TROUBLESHOOTING g, REQUESTED THE CONTROL ROOM OPERATOR WITHDRAW THE GROUP ONE STEP FOR

TROU8LESH00 TING PURPOSES. THE CAM MOTOR AND CONTROL RODS APPEARED TO E' OPERATE PROPERLY WHILE 8EING PULLEC ONE STEP. ALMOST IMMEDIATELY THE CONTROL ROOM RECEIVED INDICATION OF OROPPED RODS. WITHIN 5 TO 10 SECONDS AFTER THE RODS DROPPED AN AUTOMATIC SCRAM OCCURRED AS A RESULT te OF LOW MAIN COOLANT PRES $URE. AN UNUSUAL EVENT WAS DECLARED AT 1910 HOURS AND TERMINATED AT 1915 HOURS. MRC NOTIFICATION WAS MADE AT 1938

HOURS. A THOROUGH INVESTIGATION WAS CONOUCTED TO DETERMINE THE CAUSE 0F THE DROPPED R005. THE CAUSE OF THE INOPERABLE CAM MOTOR WAS I

ATTRIBUTED TO A SROKEN COMPRESSION CONNECTOR FOUN3 ON THE MOTOR'S BRAKE $0LEN010 CIRCUIT. THE CONNECTOR WAS REPLACED IN KIND. NO A8 NORMALITIES WERE FOUND OURING THE INSPECTION OR TESTING OF THE

,, CONTROL RODS

CIRCUITS AND COMPONENTS. CONTROL ROD EXERCISING WAS PERFORMED WITHOUT ANY ABNORMAL INDICATIONS. A ROOT CAUSE FOR THIS 4

' EVENT COULD NOT BE POSITIVELY DETEPMINEO.

1 e FORM 4 LER SCSS DATA 04-18-91 0********************e****e******e*******e*e***e****+e***************

, DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 029 1989 013 0 8910030514 215338 08/29/89 eeeeeeeeeeeee****ee.............. *** eeeeeeeeeee ****ee.******esee.

ABSTRACT POWEC LEVEL - 001%. ON 8/29/89, AT 173S HOURS, FOLLOWING A MAINTENANCE CUTAGE, WHILE IN MODE 2 AT APPR0xIMATELY 1% PCWER WITH MAIN COOLANT

, SYSTEM PRESSURE AT 2000 PSIG, A REACTOR SCRAM RESULTED WHEN THE TRAIN 5 N04 RETURN bALVE (NRW) TRIP SWITCH WAS INADVERTENTLY PLACED IN THE TRIP POSITION. PLANT RESPONSE FOLLOWING RECEIPT OF THE TRIP SIGNAL

, WAS NORMAL. THE ROOT CAUSE OF THIS EVENT IS ATTRIBUTED TO PERSONNEL ERROR. A CONTRIBUTING CAUSE WAS A PROCEOURAL DEFICIENCY. THE CONTROL i

200M OPERATOR INADVERTENTLY TURNED THE TRAIN 8 NRV TRIP SWITCH TO THE 4

g, TRIP POSITION WHTLE PERFORMING PROCEDURE STEPS THAT WERE NOT REQUIRED

, FOR THE PLANT OPERATING CONDITIONS. THE 8RCCEDU*E MAS esFw RcVvssn

. ==

resus eu e *c u . 43 LJMK:LilVt ACTION, THE CASLE WAS REPLACED AN3 THE RCS LOOP "C" P 't FL0d INSTRUMENT WAS VERIFIED TO 9E OPERATING PROPERLY.

THE REMAINING TWO RCS LJ0P FLOW INSTRU9ENTATICN CABLES WERE TESTED AND WEKE FOUND TO SE SATISFACTORY. THE RCS LOOP FLOW INSTRUMENTATION

>q CABLIEG AND THE REMAINING CASLING HAVING THE SAME INSULATION, WHICH REMAIN IN SERVICE IN IMPORTANT-TO-SAFETY APPLICATIONS, ARE NOT bd REQUIRED TO BE ENVIRONMENTALLY QUALIFIED (EQ). THE REMAINING CABLES e

HAVING SIMILAR INSULATION WILL SE PERIODICALLY TESTED FOR INSULATION DEGRATION. A SAMPLE OF THESE CABLES WILL SE REMOVED FROM SERVICE P1 OURING THE NEXT REFUELING OUTAGE AND REPLACED.

1 FORM 10 LER SCSS DATA h3 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 206 1959 023 0 8910300220 215692 kg ********************... **.***............................. 09/18/89 ........

A85 TRACT POWER LEVEL - 0912. *T 1921 ON 9/18/89, WITH UNIT 1 IN MODE 1 AT 91%

POWER, 4 CONTROL L: ; (CRS) FROM SHUT 00WN BANK 2 OROPPED INTO THE b1 CORE. APPROX. 23 SEC. L ATER, THE REMAINING 12 SHUTDOWN 8ANK CRS (4 FROM SHUYDOWN SANK 2 AND 8 FROM SHUT 00dN BANK 1) OROPPED INTO THE be CORE. OPERATIONS PERSONNEL RESPONDED SV MANUALLV TRIPPING REACTOR, VERIFTING THAT ALL SYSTEMS Resp 0NDED NORMALLY TO THE TRIP, AND 88 COMPLETING REQUIREMENTS OF THE REACTOR TRIP RESPONSE PROCEDURE. AT 194 2, THE PLANT WAS STABILIZED IN MODE 3 (HOT STANOST) AND THE REACTOR TRIP RESPONSE PROCEDURE WAS EXITED. INVESTIGATION INTO THE CAUSE OF Pe THE DROPPED CRS REVEALED THAT: 1) SHUTDOWN SANK 2 CONTACTOR COIL 2M51 FAILED, RESULTING IN THE DE-ENERGIIATION OF 4 MOVEA8LE GRIPPER COILS

,, AND SUBSEQUENT DROP OF INITIAL 4 CPS AND 2) AS THE FAULT FROM 2MS1

' PROGRESSED, CURRENT PASSING THROUGH THE (*) 125 VOC FUSE TO BOTH D' SHUTOOWN SANK 1 AND 2 CONTACTOR COILS INCREASED TO THE POINT AT WHICH THE FUSE BLEW, DE-ENERGIZING MOVEASLE GRIPPER COILS FOR THE REMAINING 12 CRS AND CAUSING THE CRS TO OROP INTO THE CORE. THE FAILED CONTACTOR

e. COIL AND FUSE WERE REPLACED WITH IN-KINO PARTS. INSULATION RESISTANCE OF ALL SHUTOOWN BANK AND CONTROL BANK CONTACTOR COILS WAS

' CHECKED AND DETERMINED TO BE SATISFACTORY. A THERM 0 GRAPHIC INSPECTION WAS PERFORMED AND NO ANOMALOUS CON 01TIONS WERE IDENTIFIE0. THE ROOT CAUSE OF TME CONTACTOR COIL 2MS1 FAILURE IS UNKNOWN.

e 1

, FORM 11 LER SCSS DATA 04-1E-91 0********************************************************************

' DOCKET YEAR LER NUMSER REVISION DCS NUMSER NSIC EVENT DATE 206 1990 007 1 9011020028 219807 04/30/90 7

A8STRACT

, POWER LEVEL - 091%. AT 2202 ON 4/30/90, WITH UNIT 1 AT 91% POWER, A REACTOR TRIP OCCURRED DUE T3 ACTUATION OF THE REACTOR PROTECTION

' SYSTEM (RPS) ON A SPURICUS LOW REACTOR COOLANT SYSTEM (RCS) FLOW

$1GNAL IN LOOP 5. ALL SYSTEMS RESPONDED NORMALLY TO THE TRIP AND THE OPERATORS STABILIIED THE PLANT IN MODE 3. THE RPS OPERATED IN ACCORDANCE WITH OESIGN WITH NO MALFUNCTIONS NOTE 0; THEREFORE THERE WAS NO SAFETY SIGNIFICANCE TO THIS EVENT. THE ROOT CAUSE OF THIL EVENT

,3 IS SELIEVED TO 8E THE EXISTENCE 05 VOIDS IN THE LOOP B RCS FLOW TRANSMITTER COIL INSULATION, WHICH CAUSED A GROUND IN THE COIL. IT

' HAS SEEN DETERMINED THAT THE WOIDS WERE DUE TO AN ISOLATED

, MANUFACTURING OEFECT. SCE SELIEVES THAT THE GROUND IN THE FLOW TRANSMITTER COIL CAUSED THE INSTRUMENT LOOP TO SE SENSITIVE TO THE e

PRESENCE OF MAGNETIC FIELDS ADJACENT T3 THE INSTRUMENT LOOP CABLES.

, THE OCCURRENCE OF A MAGNETIC FIELD, WHICH COULO SE CAUSED SY THE

. NORMAL OPERATION OF PLANT EQUIPMENT, NEAR TME SLOW Te AwSMTTTse ticMen

ows...,=

eo saast 44 1AucEJ LURRENT IN THE FL3W INSTRUMENTATION CIRCUIT SUFFICIENT TO ACTUATE TME LOW FLOW TRIP $!GNAL, THERE3T Pt CAUSING THE RESCTOR TRIP. CORRECTIVE ACTIONS INCLUDED REPLACEMENT OF THE DEFECTIVE TRANSMITTER AND VERIFTING THAT ALL RCS LOOP FLOu D4 INSTRUMENTS WERE GPERATING PROPERLY.

y

$ D4 FORM 12 LER SCSS DATA 04-18-91 0.................e......................................... ........

pq DOCKET YEAR LER NUMSER REVISION OCS NUMSER NSIC EVENT DATE 206 1990 011 0 9006200030 218499

,, ... .............................................................. 0 05#15/9 A85 TRACT b4 POWER LEVEL - 092%. ON 5/15/90, AT 0243 WITH UNIT 1 AT 91.5% POWER, THE REACTOR WAS MANUALLY TEIPPED OUE TO 4 LOW AND DECREASING LEVEL IN s' b1 STEAM GENERATOR (SG) "C" RESULTING FROM A LOSS OF FEEDWATER FLOW. THE LOSS OF FEE 0 WATER FLOW OCCURRED DURING MAINTENANCE ON AN AUX.

" FEE 0 WATER (AFW) PUMP WHILE DE-TERMINATING A VALVE CONTROL CIRCUIT WHICH RESULTED IN AN INADVERTENT SHORT CIRCUIT TO GROUND. SHORT

, b4 CIRCUIT INITIATED AUTOMATIC TRANSFER OF A VITAL GUS AND A MOMENTARY POWER INTERRUPTION TO THE SG "C" HIGH LEVEL ACTUATION WHICH, IN TURN, i

INITIATED CLOSURE OF SG "C" MAIN FCV. HIGH LEVEL ACTUATION CIRCUITRY

yg RESET WHEN IT WAS RE-ENERGIIED AT THE COMPLETION OF THE TRANSFSR.

CONTROL ROOM OPERATOR THEN RESET THE FCW CONTROLS IN ORDER TO GAIN I8 MANUAL CONTROL OF THE FCV IN ACCORDANCE WITH P R OC E D UR E S. HOWEVER, THE CONTROL OPERATOR WAS UNABLE TO R!-ESTABLISH FEEDWATER FLOW BEFORE SG i

"C" REACHED THE LEVEL AT WHICH PROCEDURES REQUIRE THE REACTOR TO BE D1 TRIPPEO. CLOSURE OF FCV RESULTED FRON 4 RELAY /SISTABLE RACE WHICH 4

OCCURRED WHEN SG "C" HIGH LEVEL PCW CLOSURE CIRCUITRY WAS

,, RE-ENERGIZED. THE POTENTIAL FOR THIS INTERACTION WAS NOT PREVIOUSLY

RECOGNIZE 0. CORRECTIVE ACTIONS INCLUDE: 1) TEMPORARILY DISABLING THE n' SG HIGH LEVEL CLOSURE OF THE FCV AND 2) TESTING OF THE VITAL BUSES WHICH ARE SUSCEPT18LE TO BRIEF POWER INTERRUPTIONS REVEALED NO OTHER UNACCEPTABLE INTERACTIONS.

t9 1 FORM 13 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE

213 1990 018 0 9010090212 219663 09/03/90

.................. ....... ...ee *e. ..... e.ee... **.e.......*.**.*

I =

A85 TRACT POWER LEVEL - 080%. OM 9/3/90, AT 0457 HOURS, WITH THE PLANT IN MODE 1 l AT 80% POWER, THE MAIN FEE 0 WATER REGULATING VALVE FOR THE No. 1 STEAM GENERATOR FAILED OPEN. IMMEDIATE OPERATOR ACTION CONSISTED OF

' MANUALLY TRIPPING THE PLANT, CLOSING THE MAIN STEAM TRIP VALVE AND ISOLATING FEE 0 WATER TO THE NO. 1 STEAM GENERATOR. THIS EVENT ALSO

, RESULTED IN AUTOMATIC ACTUATION OF THE AUXILIARY FEEDWATER SYSTEM.

SUBSEQUENT DISASSEMBLY AND INSPECTION OF THE VALVE REVEALED THAT THE PLUG HAD SEPARATED FROM THE VALVE STEM. IT WAS ALSO NOTED THAT FRAGMENTS OF THE VALVE STEM WERE CARRIED DOWNSTREAM IN THE FEEDWATER SYSTEM. AN ENGINEERING EVALUATION DE14RMINED THAT THE LOOSE P ARTS

, WERE NOT A CONCERN FOR ONE OPERATING CYCLE. THE ROOT CAUSE WAS IMPROPER PART F48RICATION AT THE FACTORT. CORRECTIVE ACTION CONSISTED OF MODIFTING THE STEM-PLUG ASSEMSLIES ON ALL FOUR FEE 0 WATER REGULATING VALVES WITH A WELDED JOINT WHERE THE PLUG ATTACHES TO THE STEM. THIS l

EVENT 15 REPORTA8LE UNDER 10CFP50.73(4)(2)(IV) SINCE IT RESULTED IN

, MANUAL ACTUATION OF THE REACTOR PROTECTION SYSTEM AND AUTOMATIC ACTUATION OF AN ENGINEERED SAFETY FEATURE.

1 I

, FORM 14 LER SCSS DATA ns-ta.ot 4

n --r ,,g-r,-- , , , , , ,-,, w a - - - , - - . - ,- ,n._ ,,.- , ,,, n- -w , ,,..,w, - , , ~_ - , - , n ,- , , ,,. , ,

mia ee,a Jia U 7013200384 213209 07/20/90 D4 ABSTRACT pq F0WEQ LEVEL - 050%. ON SEPTEM9ER 20, 1990, AT 0715 HOUR S, WITH THE g PLANT IN MODE 1 AT 50 PERCENT POWER THE "B" CONDENSATE PUMP WAS SHUT DOWN FOR TROUBLESHOOTING. THE "A" CONDENSATE PUMP WAS UNABLE TO UN PROVIDE SUFFICIENT PRES $URE TO THE SUCTION OF THE MAIN FEED PUMP 4

REQUIRING CONTROL ROOM OPERATORS TO MANUALLY TRIP THE PLANT. THE ROOT P1 CAUSES OF THE EVENT CONSISTED OF THE DEGRADATION OF THE RUBSER FLEXIBLE COUPLINGS IN THE CONDENSATE PUMP SUCTION PIPING TO THE POINT g4 THAT FLOW WAS RESTRICTED AND PERSONNEL ERROR SINC E THE PUMP WAS SHUT DOWN AT A HIGHER POWER LEVEL THAN THAT REQUIRED BY PROCc0URE.

bN CORRECTIVE ACTION INCLUDE 0 REPLACING THE FLEXIBLE RUBSER COUPLINGS WITH STAINLESS STEEL COUPLINGS AND RE-EMPHASIZING THE IMPORTANCE OF PROCEDURAL COMPLIANCE TO ALL OPEPATORS. THIS EVENT IS REPORTABLE gg UNDER 10CFR50.73(A)(2)(IV) SINCE IT RESULTED IN MANUAL ACTUATION OF an? REACTOR PROTECTION SYSTEM.

De FORM 15 LER SCSS DATA 04-18-91 kw 0********************************************************************

00CKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE y, 219 1959 011 0 8906010306 214086 04/22/89

- 88 ASSTRACT POWER LEVEL - 0021. ON 4/22/89 47 1850 HOURS, THE MECH ANIC AL VACUUM D-e PUMP WAS PLACE 3 INTO SERVICE IN ORDER TO MAINTAIN CONDENSER VACUUM DURING A PLANNED SHUTDOWN EVOLUTION. THE EQUIPMENT OPERATOR WHO

,, PLACE 0 THE VACUUM PUMP INTO SERVICE FAILE0 TO PROPERLY ALIGN THE SEAL y WATER MAKEUP SUPPLY. AT 1935 HOURS A GR ADUAL DECRE ASE IN THE MAIN CONDENSER VACUUM WAS NOTED. THE RATE OF DECREASE IN CONDENSER VACUUM Di PEEVENTED ANY SIGNIFICANT ATTEMPTS TO CORRECT THE PROBLEM $0 THE GROUP SHIFT SUPERVISOR DIRECTED THE OPERATOR $ TO MANUALLY SCRAM THE REACTOR

. AT 1945 HOURS. THE CAUSE OF THIS OCCURRENCE IS ATTRIBUTED TO OPERATOR ERROR. THE OPERATOR FAILED TO ESTABLISH A COMPLETE VALVE

,, LINEUP TO THE SEAL WATER MAKEUP SUPPLY IN ACCORDANCE WITH THE OPERATING PROCEDURE. STARTING THE MECHANICAL VACUUM PUMP IS A SIMPLE EVOLUTION BUT INFREQUENTLY PERFORMED ST INDIVIDUAL OPERATORS.

8 OPERATOR $ ARE NOT REQUIRED TO HAVE A PROCEDURE IN HAND WHEN PERFORMING A SIMPLE OR ROUTINE EVOLUTION. THIS CONTRIBUTED TO THE OVERSIGHT BY THE OPERATOR. WITHOUT SEAL WATER MAKEUP THE MECHANICAL VACUUM PUMP OPERATED PROPERLY UNTIL THE SEAL WATER TANK EMPTIED WHICH THEN CAUSED

' A SIGNIFICANT AIR LEAK TO THE MAIN CONDENSERS. THIS CAUSED THE DECREASE IN CONDENSER VACUUN WHICH RESULTED IN THE REACTOR SCRAM. THE SAFETY SIGNIFICANCE OF THIS EVENT IS MINIMAL SECAUSE THE REACTOR WAS

' AT LOW POWER (APPROXIMATELY 21) WHEN THE EVENT OCCURRED.

1 FORM 16 LER SCSS DATA 04-18-91 0********************************************************************

00CKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 219 1989 015 0 8906290*10 214440 05/18/89

,, A85 TRACT POWER LEVEL - 100%. ON 5/15/89 AT 1103 PRS THE REACTOR AUTOMATICALLY SHUT DOWN DUE TO A TRIP OF THE MAIN TUR81NE GENERATOR. AN INSTRUMENT I

,, TECHNICIAN HAD SEEN ASSIGNED THE TASK OF CALIBRATING THE PLANT MEGAVAR RECORDER. ME DISCUSSED THE ACTIVITY WITH SHIFT MANAGEMENT BUT CID f NOT MENTION THAT INPUT LEADS TO THE RECORDER WCULO SE DISCONNECTED.

g. THE TECHNICIAN STARTED THE EVOLUTION 1 1/2 HRS LATER WITHOUT INFORMING

, CONTROL ROOM. A HI/ LOW VAR ALARM WAS RECEIVED. OPEDATORS DID NOT

. . . _ . _ .._m ..- __. - - - _. . .. . .

' ' suassac enas nc was AtluALLY INCREa$1NG MEGAVARS SECAUSE Hs WAS NOT OBSERVING BUS VOLTAGES, WHICH WERE INCREASING. A GENERATOR i P1 OVEREXC1TATION CONDITION RESULTED WHICH TRIPPED THE MAIN GENERATOR, CAUSED A REACTOR SCRAM, AND RESULTED IN A FAST START OF SOTH DIESEL

.yq GENERATOR $. THE OPERAT025 PROCEDED TO C00LOOWN THE PLANT WITH THE i

ISOLATION CONDEN5ERS UNTIL THE SHUT 00WN COOLING SYSTEM WAS PLACEO INTO i

SERVICE AT 1525 HR$. THE PL ANT REACHED COLO 5HUTDOWN CONDITIONS AT

! b"4 APPROM. 1700 HRS. TH! ROGT CAUSE OF THIS EVENT WAS PERSONNEL ERROR ST l i SOTH OPERATIONS AND MAINTENANCE PERSONNEL. TO PREVENT A RECURRENCE l P1 'i 0F A SIMILAR EVENT, ADMINISTRATIVE CONTROLS HAVE BEEN IMPLEMENTED AND

, [ INCREASE 0 EMPHASIS HAS BEEN PLACEO 04 COMMUNICATIONS BETWEEN THE WORK -

-- 4 3 GROUP ANO THE CONTROL ROOM.

54 'g. FORM 17 LER SCSS DATA. 04-4 0**********************************************************eme**18-91 *****

. gg 00CKET TEAR LER NUMBER REVISION OCS MUMBER NSIC EVENT DATE 219 1989 016 0 8907310154 214866 06/25/89 l bd ********************************************************************

! g. 455ftACT

) b4 ~ POWER LEVEL - 0973. 04 JUNE 25, 1999 AT 0008 HOURS, THE MAIN GENERATOR l TRIPPE0 OUE TO A PHASE DIFFERENTIAL CONDITION CAUSED BY A FAULT IN j yg 9 ONE OF THE MAIN OUTPUT TRANSFORMERS. WHEN THE GENERATOR TRIPPE0 A-TURBINE TRIP SIGNAL WAS GENERATED WHICH RESULTED IN AN ANTICIPATORY Il REACTOR SCRAM. THE PLANT WAS COOLED DOWN WITH THE MAIN CONDENSERS AND THE SHUT 00WN COOLING SYSTEM AND REACHED A COLO SHUYDOWN CONDITION AT 1100 HOURS. THE CAUSE OF THIS EVENT WAS EQUIPMENT FAILURE. ERAMINATION D1 0F THE TRANSFORMER DETERMINE 0 THAT AN INTERNAL WINDING HAD FAILED

THEREST C40$ING THE PHASE DIFFERENTIAL CONDITION WHICH CAUSED THE g, GENERATOR TRIP. THIS TRANSIENT WAS WITHIN THE DESIGN BASIS OF THE

, - PLANT AND HAD NO SAFETT SIGNIFICANCE. PREPARATIONS HAVE BEEN MADE TO I

+

b' REMOVE THE FAILED TRANSFORMER AND INSTALL A $ PARE. UNTIL THE SPARE 15 INSTALLED THE PLANT WILL BE OPERATED AT HALF LOAD. NO OTHER CORRECTIVE ACTION WAS DETERMINED NECESSARY.

g at. 1

,, FORM 18 LER SCSS DATA 04-18-91 0*ene *e *******e ************eme*****..e************e.******e*******

DOCKET TEAR LER NUMBER REVISION OCS NUM8ER N5IC EVENT DATE D

219 1987 017 1 9005260545 217417 07/11/89 t ******e ***************** **************** ***** *****eae**********

Ie ABSTRACT POWER LEVEL - 0001. ON 7/11/89 AT 0055 HOURS, THE MAIN GENERATOR TRIPPED OUE TO A PHASE DIFFERENTIAL CONDITION CAUSED BY A FAULT IN THE OPERATING MAIM OUTPUT TRANSFORMER (THE OTHER MAIN TRANSFORMER FAILEO

,{'* . ON A/25#89). WHEN THE GENERATOR TRIPPE0, A TURSINE TRIP SIGNAL WAS GENERATED WHICH RESULTED IN AN ANTICIPATORY REACTOR SCRAM. THE PLANT

.. WAS C00 LEO DOWN UTILIZING THE MAIN CONDENSER AND THE SHUTOOWN COOLING SYSTEM ANO REACHE0 THE COLO SHUTOOWN CONDITION AT 0950 HOURS. THE CAU5E OF THIS EVENT WAS EQUIPMENT FAILURE. EXAMINATION OF THE

TRAN5FORMER DETER 4INEO THAT AN INTERNAL WINDING MAO FAILEO, CAUSING THE PHASE DIFFERENTIAL CONDITION WHICH CAUSE0 THE GENERATOR TRIP. THE PL ANY RESPONDED A5 OE51GNEO AND OPERATOR ACTION WAS PROMPT AND "

APPROPRIATE. THIS TRANSIENT Was WITHIN THE DESIGN BASIS OF THE PLANT AND HAO'NO SAFETY SIGNIFICANCE. THE ENTIRE ELECTRICAL SYSTEM M45 EVALUATED FOR ADVERSE EFFECTS OUE TO THE FAULT, AND AN EVALUATION WAS

'CONPLETED TO DETERMIME IF A GENERIC PR05LEM EXISTED SETWEEN THE TWO I I ,3- FAILES TRANSFORMERS AND THE OTHER POWER TRANSFORMERS AT THE STATION.

A5 A RESULT, IT WAS DETERMINED TH8 FAILURE WAS CONFINED TO THE TWO

-t MAIN OUTPUT TRANSFORMERS ANO DIO NOT INVOLVE ANT OTHER TRANSFORMERS.

gj, THE PLANT WAS RETURNED TO POWER OPERATION ON 7/19/99 USING THE SPARE ,

1 TRANSFORMER.145fALLED OUs,To Tue p o s v im.t e a t. in s t as vue a*w-- -"-

i [

t

,y ~, - . . - . , . - ,, v-.-,, ,- --,m- .,,.m , , , . , , - , - , ,m ,,_,,,s_ ,, , , _ . , - , . . .-.m_ _o, ,m,.- s., em. ,,.m . .,,m.,- ,_, ,.. , , ,, -

~

FORM 19 LER SCSS DATA 04-18-9 P-g Deeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeen....eeeeeeeeeeeee***1 DOCKET TEAR LER NUMBER REVISION DCS NUMBER QSIC EVENT DATE kW 219 1989 021 1 9001220235 216442 09/22/89 h4 ABSTRACT

, POWER LEVEL - 000%. OM SEPTEMBER 22, 1989, AT APPROXIMATELY 1418 g-q HOURS, MECHANICAL YEST EQUIPMENT WAS INADVERTENTLY LEFT CONNECTED TO ONE OF THE REACTOR PRESSURE VESSEL (RPV) WATER LEVEL INSTRUMENTS AFTER "4 p' TESTING WAS COMPLETE. WHILE BEING PLACED BACK IN SERVICE, THE REFERENCE LEG OF THE INSTRUMENT WA$ VENTED TO THE TEST EQUIPMENT DW CAU5ING A FALSE HIGH RPV WATER LEVEL SIGNAL TO BE GENERATED IN ALL

[i FIVE LEVEL INSTRUMENTS ATTACHED TO THAT COMMON REFERENCE LEG. THE FALSE HIGH RPV WATER LEVEL CAUSED A TRIP OF THE TUR8INE GENERATOR gg WHICH RESULTED IN A REACTOR SCRAM. THE TECHNICIAN PERFORMING THE

j VALVE MANIPULATION RECOGNIZED THE PROBLEM AND CLOSED THE ROOT VALVE.

h4 THE CAUSE OF THIS EVENT WAS PERSONNEL ERROR SINCE THE TEST EQUIPMENT WAS NOT REMOVED AS REQUIRED BY THE SURVEILLANCE PROCEDURE. THIS EVENT bg

HAD MINIMAL SAFETY SIGNIFICANCE BECAUSE THE REACTOR PROTECTION SYSTEM IS DESIGNED TO PROTECT THE REACTOR FROM ANY TURSINE TRIP CON 0! TION, AND THE EXCESS FLOW CHECK VALVES IN THE INSTRUMENT LINE WOULD HAVE y, PR*!: !"O ANY $1GNIFICANT LOSS OF COOLANT. ALL ENGINEERED SAFETV

EATURES b3ULO HAVE FUNCTIONED NORMALLY DUE TO REDUNDANT RPV LEVEL

' INSTRUMENTAtt0N. ALL INSTRUMENTS INVOLVED IN THIS EVENT WERE

, CALIBRATION CHECKED TO ENSURE NO PROBLEMS HAD RESULTED FROM THE MOMENTARY DEPRESSURIZATION. THE TECHNICIANS INVOLVED IN THIS EVENT 39 WERE COUN5ELED.

1 g

FORM 20 LER SCSS DATA 04-18-91 I

g, 0********e*****************e***ee********e****o*e****e***************

h* 00CKET VEAR LER NUMBER REVISION DCS NUMSER N5IC EVENT DATE 219 1990 004 0 9003290123 217466 02/20/90 ee*eme ****ee******eeeee*e eee**ee**************eee**eeeeee*********

A85 TRACT E'

q' POWER LEVEL - 000I. ON 2/20/90, WHILE PERFORMING A SURVEILLANCE ON A REACTOR VESSEL INSTRUMENT, AN INSTRUMENT & CONTROLS (IEC) TECHNICIAN B

KEYED A HAND-MELD RADIO NEAR THE ANALOG TRIP UNITS FOR THE ALTERNATE

g. ROD INJECTION (ARI) SYSTEM CAUSING THE SYSTEM TO ACTUATE DUE TD RADIO

, , FREQUENCY INTERFERENCE (RFI). CONTROL ROOM OPERATORS NOTED THAT AIR OPERATED VALVES SUPPLIED FROM THE SCRAM AIR SYSTEM WERE REPOSITIONING i,

AND THAT CONTROL RODS WERE ORIFTING INTO THE CORE. THE OPERATORS INITIATED A MANUAL REACTOR SCRAM AS REQUIRED BY PROCEDURE DUE TO THE DRIFYING CONTROL R005. THE CAUSE OF THIS OCCURRENCE HAS SEEN 4

t ATTRIBUTED TO PERSONNEL ERROR BY THE TECHNICIAN PERFORMING THE SURVEILLANCE PROCEDURE. THE ACCE55 DOOR 70 THE AREA WHERE THE ARI

, SYSTEM COMPONENTS ARE LOCATED IS WELL MARKED WITH REFERENCE TO THE RESTRICTION ON THE USE OF RADIOS IN THE AREA. THIS EVENT IS DETERMINED To HAVE MINIMAL SAFETY SIGNIFICANCE SECAUSE A MANUAL SCRAM WAS INITIATED ST THE OPERATOR 5 WITHIN 5 SECONDS OF ROD MOVEMENT.

{ .. CHEMISTRY SAMPLES INDICATE THAT NO FUEL DAMAGE RESULTED FROM THIS EVENT. THE USE OF RADIOS SY ISC TECHNICIANS MUST NOW BE APPROVED BY THE TECHNICIAN'S SUPERVISOR. APPROPRIATE SITE PERSONNEL WILL RECEIVE

, TRAINING ON THIS EVENT AND AN INVESTIGATION WILL BE CONOUCTED INTO MINIMIZING THE ARI SYSTEM'S SEN5ITIVITY TO RFI.

1 FORM 21 LER SCSS DATA 04-18-91

. De*eeeeeeeeeeeeeeeee..........e***ee**emee***e.***ee*********eeeeeeen

, DOCKEY YEAR LER NUMBER REVISIOd 'C5 NUMBER NSIC EVENT DATE 219 1990 005 0 21052901 4 ?tasia nAsstrom

-. . m. . , . ._ ,- _ _ , - . --

POWEQ LEVEL - 100%. ON APRIL 21, 1990 AT 0955 HOUR $, P0uER WAS LOST TO Pg UNIT SU0 STATION (C55) 182 Ud!N A P0 DER SUPPLY CACLE SHORTED TO GROUND

5EVERAL SAFETY RELATED COMPONENTS WERE AFFECTED GY THE LOSS g4 (F 005EO, FAD ORYLELL U210ENTIFIED LEAK CATE INCREASED TO GREATER THAN 5 GPM DUE TO LOS$ OF POWER TO THE ORTWELL EQUIPMENT ORAIN TANK PUMP CONTROL CIRCUIT. THE PL ANT W A5 5HUTOOWN OUE TO LOSS-OF-POWER To b4 REQUIRED ELECTRICAL' BUSSES, AND ON APRIL 22ND AT 1005 HOURS, THE si REACTOR REACHED ChiS SHUTDOWN. U55 182 WAS !$0 LATED FROM THE FAILED P1 SUPPLY CABLE AND REENERGIIt0 FROM USS 1A2 VIA THE CR055 CONNECT BREAKER. DURING THE COOLDOWN, THE A ISOLATION CONDENSER WAS DECLARED d I INOPERABLE OUE TO THE INASILITY TO ELECTRICALLY CTCLE A OC ISCLATION VALVE BECAUSE OF THERMAL 8INDING. THIS THERMAL SINDING PROBLEM WILL WW SE CORRECTED BT MODIFICATIONS SCHEDULED FOR THE NEXT REFUELING OUTAGE.

ji THE CAUSE OF THE CASLE FAILURE 15 $USPECTED TO BE A DEFECT IN THE INSULATION OF THE C48LE. A NEW SUPPLY CABLE WAS INSTALLED AND THE U55 gg WAS REPOWERED FROM IT'S NORMAL SOURCE. A REPRESENTATIVE SAMPLE OF

, OTHER CABLES SUPPLYING SAFETY RELATED COMPONENTS WERE TESTED, AND NO GENERIC CONCERN 5 WERE FOUND.

l-

>W FORM 22 LER 3C55 DATA 04-18-91 0********************************************************************

y, ! DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT 0 ATE 219 1990 008 0 9008010237 219003 06/25#90 It ABSTRACT p-g POWER LEVEL - 000%. ON JUNE 25, 1990, AT APPROXIMATELY 6:18 AM, A REACTOR SCRAM OCCURRED ON LOW CONDEN5ER VACUUM. THE SCRAM OCCURRED

,, OURING INITIATION OF SACKWASHING OF THE "A" NORTH MAIN CONDENSER. THE

, SCRAM WAS CAUSE0 SY THE FAILURE OF THE SACKWASH OUTLET VALVE TO OPEN, CAU5ING A LOSS OF CIRCULATING WATER TO THE "A" CONDEN5ER. THE bt SACKWASH OUTLET VALVE FAILED TO OPEN DUE TO A BREAKER TRIP OF THE MOTOR OPERATOR. THE PLANT WAS STASILIIED IN A HOT STAND 8Y CONDITION re AND SUBSEQUENTLY TAKEN TO COLD SHU100dN. THE MOTOR OPERATOR, THE BREAKER AND THE VALVE WERE ALL INSPECTED AND TESTED SATISFACTORILY.

' THE AUXILIARY CONTACTS ON THE MOTOR CLOSE COIL WERE REPLACED AND AUXILIARY CONTACTS ON THE MOTOR OPEN COIL WERE REALIGNED. THE REMAINING 20 CIRCULATING WATER VALVES MANIPULATED DURING BACKb'5HING

' EVOLUTIONS WERE TESTED AND WERIFIED TO BE OPERATING PROPERLV.

1 p .

FORM 23 LER SC55 OATA 04-18-91 0********************************************************************

00CKET TEAR LER NUMBER REVISION DC5 NUMBER N5IC EVENT DATE 220 1990 017 0 9009130070 219453 08/06/90

, A857RACT POWER LEVEL - 019%. 04 AUGUST 6, 1990, WITH THE REACTOR MODE SWITCH IN THE RUN POSITION, REACTOR POWER AT 19 PERCENT, NINE MILE POINT UNIT 1 (NMP1) EXPERIENCE 0 TUR8INE BEARING WISRATION PROBLEMS WHEN STARTING UP THE TURSINE-GENERATOR. THE TURBINE WAS MANUALLY TRIPPE0, CONDENSER VACUUM WAS BROKEN, AND A MANUAL REACTOR SCRAM WAS INSERTED.

CONSEQUENTLT, A HIGH PRESSURE COOLANT INJECTION (MODE OF FEEDWATER CONTROL) SIGNAL WAS RECEIVED OUE TO LOW REACTOR WATER LEVEL (53 INCHES) AND A MAIN STEAM ISOLATION VALVE ISOLATION OCCURRED ON DECREA5ING CONDENSER VACUUM (7 INCHE5 MERCURY HG). THE IMMEDIATE CAUSE

, OF THIS EVENT WA5 THE FAILURE OF TUR8INE SEARING e5 DUE TO A SLANK FOUND INSTALLED IN THE SEARING OIL SUPPLT LINE. AN INCIDENT INVESTIGATION DETERMINED THAT THE CAUSE OF THE EVENT WAS INADEQUATE g

REVIEW 08 4 POLICY CHANGE AND PERSONNEL ERROR. IMMEDIATE r0RRECTIVE

, ACTIONS INCLUDED REPAIR OF THE BEARING, INSPECTION OF Twr ntwee

. . . . . . . . 6 . 6 w .. . .soteauN4LLT, A 4EVIEW Of TsE NMPC TURBINE MAINTENANCE LOG WA5 PERFORMED TO IDENTIFT ANT OTHER POTENTIAL j P1 WEAKNESSES.

1

l FORM 24 LER SC55 DATA DN 0***..*****.a.**..*.***.***..*.e..*.....**.....*.**.*.**.a.**04-18-91 ..**.***

DOCKET TEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 1 ;. 220 1990 019 0 9101290395 220836 12/29/90 pq ********************************************************************

i A8STRACT

5 POWER LEVEL - 010%. 04 12/29/90, AT 1719 HOURS, NINE MILE POINT UNIT 1

! b4 (NMP1) EPMERIENCED A FULL REACTOR SCRAM WHEN A TRIP SIGNAL WAS RECEIVED ON REACTOR PROTECTION SYSTEM (RP5) CHANNEL 11 DUE TO A SPIKE 37 ON INTERME0! ATE RANGE MONITOR (IRM) 12. AT THE TIME OF THE EVENT THE go MODE SWITCH WAS IN THE "STARTUP" POSITION, REACTOR POWER WA5 AT j ., APPROXIMATELY 10% AND A RPS TRIP HAD 8EEN INSERTED ON CHANNEL 12 DUE i

U" TO THE FAILURE OF A MAIN STEAM I5CLATION VALVE (MSIV) TO MEET ITS SURVEILLANCE TEST REQUIREMENTS. WHEN THE SCRAM CCCURRED THE UNIT WAS bw CONDUCTING A FORCED SHUTDOWN OUE TO THE M5IV FAILURE AND INCREASED DRYWELL LEAKAGE. THE CAUSE OF THE EVENT WAS A SPIKE ON IRM 12 (RPS CHANNEL 11) COINCIDENT WITH A HALF-TRIP INSERTE0 ON RPS CHANNEL 12 00E y TO THE MSIV FAILURE. THE CORRECTIVE ACTION FOR THE IRM SPIKE 15 THE CONTINUATION OF THE NEUTRON MONITORING TROU8LE5H00 TING AND UPGRADE EFFORTS.

De g p-e FORM 25 LER SC55 OATA 0************************************************************04-18-91 ********

,, DOCKET VEAR LER NUMBER REVISION CCS NUMBER NSIC EVENT DATE

, , 220 1990 020 0 9010020046 219605 08/19/90 De A85 TRACT te POWER LEVEL - 021%. 04 AUGUST 19, 1990, WITH THE REACTOR MODE SWITCH IN THE RUN POSITION, REACTOR POWER AT APPROXIMATELY 21.5 PERCENT, NINE

MILE POINT UNIT 1 (NMP1) EXPERIENCEO TURSINE VISR& TION PROBLEMS WHEN 5, CONDUCTING POWER ASCENSION PROCEDURE N1-PAT-12-1, " MAIN TURBINE-GENERATOR ROTOR SYSTEM TORSIONAL SCREENING TEST". THE TUR8INE B

WA5 MANUALLY TRIPPED, SUBSEQUENTLY A MANUAL REACTOR SCRAM WAS INSERTED PRIOR TO 8REAKING VACUU4 TO PRECLUDE AN AUTOMATIC REACTOR

, . SCRAM ON LOW CONDENSER VACUUM. CONSEQUENTLY, A HIGH PRESSURE COOLANT INJECTION (HPCI) (MODE OF FEEDWATER CONTROL) SIGNAL WAS RECEIVED DUE

' TO LOW REACTOR WATER LEVEL (53 INCHES) AND A MAIN STEAM ISOLATION VALVE ISOLATION CCCURRED 04 DECRE451NG CONDEN5ER VACUUM (T INCHES MERCURY HG). A ROOT CAUSE INVESTIGATION DETERMINED THAT THE MOST I

LIKELT CAUSE OP THE LOW PRESSURE (L.P.) TUR8INE ROTOR VISRATION WAS THAT 4 SLOW ACCELERATION RATE THROUGH AN L.P. TURBINE CRITIC AL SPEED g RANGE LEO TO THE L.P. TURBINE ROTOR DEVELOPING AN INTER 5TAGE PACKING

, RUB AND BOWED ROTOR. IMMEDIATE CORRECTIVE ACTION WA5 TO TERMINATE N1-PAT-12-1. ADDITIONALLT, REVISION TO THE TURBINE TOR 5 ION AL TEST 15 f'

SEING PUR5UED ST ENGINEERING AND GENERAL CLECTRIC TO ADDRESS THE TECHNICAL *ROBL EMS ENCDUNTERED DURING THE INITIAL RUN.

i 1

, FORM 26 LER SC55 DATA 04-18-91 0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE I 220 1990 026

, 0 9012250132 220572 11/17190 g; ABSTRACT

. P0WER LEVEL - 0961. ON NOVEMBER 17, 1990, AT 2109 WITH REACTOR DnW8R

. m

. . . - - . . . ..........+.s :Lebe.us.til 1:LIcF VALVE (ERV) INIT14 TION CUE TO M414 STEAM ISOLATION VALVE (MSIV) ISOLATION. THE MSIV P e ISOLATION OCCURRED AS A RESULT 0* 4N INCORRECT FUSE BEING REMOVED DU2I:G A SURVEILL4NCE TEST OF A MAIN STEAM LIEE RADIATION MONIT02 gq THE PL437 KAS SAFELY SHUTDOWN AND NO ADVERSE $4FETT CONSEQUENCES RESULTED. THE PRIMART CAUSE OF THIS EVENT WAS DETERMINED TO BE PERSONNEL ERROR, SPECIFICALLY POOR WORK PRACTICES. IMMEDIATE b4 CORRECTIVE ACTIONS INCLUDE 0 PLACING THE PLANT IN A SAFE SHUTDOWN

, i.

CONDITION AND RESETTING THE REACTOR SCRAM. SUBSEQUENT CORRECTIVE

! pq ACTIONS INCLUDED COUNSELING AND DISCIPLINE OF OPERATIONS PERSONNEL INVOLVED IN THE TEST PERFORMANCE.

i go 'l FORM 27 LER SCSS DATA

>4 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE be 237 1989 012 0 8904060431 213498

- - - - 03/04/89 ********

i D4 A85 TRACT Do POWER LEVEL - 0922. ON 3/4/89 WITH UNIT 2 IN THE RUN MODE AT 92X RATED CORE THERMAL POWER, THE REACTOR SCRAMMED ON LOW REACTOR WATER LEVEL FOLLOWING THE TRIP OF SOTH OPERATING REACTOR FEEDWATER PUMPS (RFPS).

D4 AT THE TIME, OPERATIONS DEPT. PERSONNEL WERE GROUND CHECKING ON THE 12SV DC BATTERT STSTEM. THE CAUSE OF THE EVENT HAS SEEN DETERMINED TO BE PERSONNEL ERROR. THE HIGH VOLTAGE OPERATOR (HWO) PERFORMING THE D'

GROUND CHECK OPENED THE WRONG BREAKER WHICH RESULTED IN THE TRIP OF THE RFPS. THE GROUND DETECTION PROCEDURE STATES THAT THE BRE4KER 15 Re ONLY TO BE OPENED WITH PERMISSION OF THE OPERATING ENGINEER. THE HVO DID NOT HAVE THE PROCEDURE IN HAND AT THE TIME OF THE EVENT. THE

g. LABELING OF THE BREAKER ALSO CONTRIBUTED TO THE EVENT. THE PLANT

' RESPONDED AS DESIGNED DURING THE EVENT, THEREFORE THE EVENT WAS DEEMED

&' TO BE OF MINIMAL SAFETT $1GNIFICENCE. A DISCUSSION WAS HELD WITH THE HVO AND ALL OTHER SHIFT PERSONNEL TO EMPHASIZE ATTENTION TO DETAIL, COMMUNICATIONS AND PROCEDUR AL 80HERENCE. THE CRITICAL SREAKERS HAVE

t. SEEN RELA 8ELLED So THET WILL STAND OUT FROM THE REMAINING BREAKERS.

THE GROUNO DETECTION PROCEDURES ARE BEING REVIEWED AND WILL SE REVISE 0

AS REQUIRED TO ASSURE THAT CRITICAL 8REAKERS ARE CLEARLY IDENTIFIED AND THE CONSEQUENCES OF THEIR OPERATION UNDERSTOOD. THESE PROCEDURES WILL 8E POSTED AT THE APPROPRIATE DC SWITCHGEAR LOCATIONS WHEN THE REVISIONS ARE APPROVED.

1 FORM 29 LER SCSS DAT4 04-18-91

'* 0********************************************************************

DOCKET TEAR LER NUMBER REVISION OCS MUMBER NSIC EVENT DATE 237 1999 019 0 8908160015 214977 07/12/S9

, 485 TRACT POWER LEVEL - 0632. ON 7/12/89 AT 1049 HOURS WITH UNIT 2 OPERATING AT 632 POWER WHILE PERFORMING ORESDEN TECHNICAL STAFF SURVEILLANCE (OTS) 500-2, FUNCTIONAL TESTING OF REACTOR PROTECTION SYSTEM (RPS) MOTOR GENERATOR (MG) SET AND RPS RESERVE POWER SUPPLT, CHANNEL 'A' HALF PRIMARY CONTAINMENT GROUP I ISOL4 TION AND HALF SCRAM SIGNALS COULD NOT SE RESET PROMPTLY OUE TO DIFFICULTIES ENCOUNTERED IN RESETTING THE

.i 'A' MAIN STEAM LINE (MSL) LOCRITHMIC PRIMARY CONTAINMENT GROUP I ISOL4 TION AND REACTOR SCRAM. THE CAUSE OF THE MSL AREA HIGH

' TEMPERATURE TRIP WAS ATTRIBUTED TO SETPOINT DRIFT. THE ROOT CAUSE OF YHE MSL LRM RESET DIFFICULTIES (WHICH OCCURRED CURING TRANSFER OF POWER SUPPLIES IN ACCORDANCE WITH DTS 500-2) IS UNDER INVESTIGATION.

. AS CORRECTIVE ACTION, THE "A" MSL LRM W45 REPLACED, IN ADDITION TO ALL

,; 0F THE CHANNEL "5" MSL TUNNEL AREA TEMPERATURE SWITCHES. THE SAFETT

, SIGNIFIC4NCE 05 THIS EVENT WAS MINIMAL SINCE THE PRIMART CONTAINMENT

. =

.m. . w . . t a a w. cow aus uttuk4c0 AN3 PROCEE0fD dITH A CONTROLLED SCRAM RECOVEPYo A PREVIOUS EVENV INVOLVING A SCRAM OURING THE pq PERFORMANCE OF DTS 500-2 WAS REPORTED SV LEQ 80-02/0502400 1

kW FORM 29 LER SC55 DATA W4 0.*......*.* ****.* .*.e.*..* ***.*** **...*..**.**********. 04-18-91 DOCKET TEAR LER NUMBER REVISION OC$ NUMBER NSIC EVENT DATE

, ;; 237 1990 001 0 9002090035 216710 01/05/9 pq ...**..*...*****...*..*....**.*.***..****..*.*.***..* ..*...**.... 0*

. ABSTRACT I4 POWER LEVEL - 0991. AT 2241 HOURS ON 1/5/90, WITH UNIT 2 OPERATING AT 99.3% POWER, A PRIMARY CONTAINMENT GROUP I ISOLATION AND SUSSEQUENT be ,

REACTOR SCRAM OCCURRED WHILE AN INSTRUMENT MECHANIC (IM) WA5 PERFORMING ORE 50EN INSTRUMENT SURVEILLANCE (015) 250-1, MAIN STEAM i

kO LINE HIGH FLOW ISOLATION SWITCH CALIBRATION. THE ROOT C AUSE OF THE UNPLANNED GROUP I I$0LATION HAS SEEN ATTRIBUTED TO A PROCEDURAL D4 OEFICIENCY WITHIN DIS 250-1 SUCH THAT INADEQUATE CONTROLS WERE PROVIDED TO PREVENT A POTENTIAL PRESSURE TRANSIENT LARGE ENOUGH TO q, CAUSE A TRIP ON INSTRUMENTS IN 60TH TRIP CHANNEL 5, LOCATED ON A COMMON bg INSTRUMENT SENSING LINE HEADER. CORRECTIVE ACTION INCLUDED A SPECIAL TEST OF THE TRIPPED HIGH FLOW SWITCH AND ISOLATION MANIFOLO, POSSISLE g, g, H ARDW ARE CHANGES TO ASSIST THE IM IN PERFORMING THE SURVEILLANCE, AND A STUDY TO INVESTIGATE FEASIBILITV 0F REPLACING THE PRESENT SWITCHES pe WITH AN ANALOG TRIP. THE $4FETV SIGNIFICANCE OF THIS EVENT 15 MINIMAL g SINCE THE HIGH FLOW SWITCHES RESPONDED AS DESIGNED AND TRIPPED IN RESPONSE TO PRES 5URE TRANSIENT INDUCED TO THE COMMON HEADER, THU$

g3 INITIATING THE AUTOMATIC GROUP I ISOLATION AND REACTOR SCRAM. A t

i. PREVIOUS EVENT WAS REPORTED SY LER 87-016/050249.

1 I FORM 30 3, LER SC55 OATA 04-18-9 he - 0*.* ***...*..*..*.......*..*......****..*..... ...*...*..* ....*...*1 DOCKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE i g. 237 1990 002 0 9002230211 216898 01/16/90 I' ASSTRACT POWER LEVEL - 100%. AT APPROXIMATELY 1724 HOUR $ ON 1/16/90, AN

AUTOMATIC UNIT 2 REACTOR SCRAM ON A LOW REACTOR WATER LEVEL (TECH SPEC

\ SETPOINT OF EIGHT INCHES 480VE INSTRUMENT 0) SIGNAL OCCURRED. THE 20

, -CONDENSATE / CONDENSATE BOOSTER PUMP FAILED DUE TO AN INTERNAL MOTOR FAULT APPROXIMATELY 13 SECON05 PRIOR TO THE SCRAM, PRECIPITATING f*

, AUTOMATIC TRIP OF THE RUNNING REACTOR FEED PUMP 5 ON LOW SUCTION PRES 5URE AND THUS RESULTING IN REDUCTION OF REACTOR WATER LEVEL TO THE LOW LEVEL SCRAM SETPOINT. ADDITIONALLT, RESERVE AUXILIARY TRANSFORMER

, , (TR) 22 TRIPPE0 OURING AUTOMATIC TRANSFER OF HOUSE LCA05, RESULTING IN INTERRUPTION OF NORMAL AC AUXILIARY POWER UNTIL THE EMERGENCY

, DIESEL GENERATORS AUTOMATICALLY LOADED. COLD $4UT00WN CON 0!TIONS WERE

, ACHIEVED ST 0210 HOURS ON 1/17/90. COMPREHENSIV! ROOT C AUSE INVESTIGATIONS WERE IMMEDIATELY INITIATED FOR ALu COMPONENT PERFORMANCE PR08LEMS, AND CORRECTIVE ACTIONS IMPLEMENTED. THE SAFETT

, SIGNIFIC ANCE OF THIS TRANSIENT WAS MITIGATED BY THE FACT THAT REACTOR WATER LEVEL WAS MAINTAINED WELL ABOVE THE AUTOMATIC EMERGENCY CORE COOLING SYSTEM INITIATION SETPOINT AT ALI TIMES, AND MULTIPLE SYSTEMS g WERE AVAILABLE FOR REACTOR PRES $URE CONTP74 INCU!DIMG TSOLATION CONDEN5ER, MIGH PRES 5URE COOLANT INJECTION, AND MAIN STEAM RELIEF WALVES. A PREVIOUS EVENT INVOLVING A UNIT 3 LOSS OF 0FFSITE POWER IS

't g REPORTED SY LER 59-1/050249 t

g FORM 31 LER SC55 OATA 04-18-91 0.*...*..........**........................ ...............*.........

, --- -~ _ . _ -- , , . - . -- .. -

pw A8STRACT POUER LEVEL - 037%. ON AUGUST 2, 1990, OURING NORMAL PouER OPEJ ATION IN THE RUM MODE, THE 2-203-3A MAIN STEAM TAGGET ROCK SAFETY-RELIEF

.q' VALVE (TRSRV) ACOUSTIC MONITOR ALARME3, INDICATING THAT THE VALVE HAD b4 SPURIOU$LY CPENED AND WA$ RELIEVING REACTOR PRE 550RE TO THE

$UPPRESSION CHAMBER. THE REACTOR WAS SUBSEQUENTLY MANUALLY SCRAMMEO

FROM 87% POWER AT 0116 HOURS. ALL CONTAINMENT COOLING SERVICE WATER pq AND LOW PRES 5URE COOLANT INJECTION PUMPS WERE MANUALLY STARTED FOR MAXIMUN SUPPRESSION CHAM 8ER COOLING. THE MAXIMUM AVERAGE C00LOOWN O RATE WHEN AVERAGED OVER A ONE HOUR PERIOD RCACHED 129.3 DEGREES F/HR, AND MAXIMUM BULK SUPPRESSION CHAMBER TEMPERATURE WAS 122 OEGREES F.

DW THE OPENING OF THE TR5RV WAS APPARENTLY CAUSED BT STEAM CUTS ON THE l FIRST STAGE PILOT VALVE DISC. ANALYSES WERE PERFORMED TO VERIFY THAT THE COOLDOWN RATE AND THE BULK SUPPRESSION CHAMBER TEMPERATURE g3 ATTAINED OURING THIS EVENT WERE WITHIN DESIGN LIMITS. A j: SATISFACTORILY LEAK TESTE0, REBUILT TR$RV WAS INSTALLE0. THE U" TECHNICAL STAFF WILL MONITOR THE TRSRV TAIL PIPE TEMPERATURES TO VERIFY PROPER PILOT VALVE OPERATION. IN ADDITION, ANY TRSRW PILOT

.g. VALVE OF GREATER THAN EIGHT MONTHS SERVICt WILL BE REPLACEO 00 RING be ' FUTURE SHORT UNIT OUTAGES WITH PRIMART CONTAINMENT ORYWELL ACCES$1BILITY. THE TR5Rv5 ARE ROUTINELY REPLACE 0 AT EACH REFUEL g, z. OUTAGE. A PREVIOUS TR$RV FAILURE EVENT WAS REPORTED BY LER 50-237/76-34.

1 k' ' i.

FORM 32 LER SCS5 DATA 31 0************************************************************04-18-91 ********

DOCKET YEAR LER NUMBER REVISION OC5 NUM8ER N5IC EVENT DATE 3, 237 1990 015 0 9101020273 221096 11/23/90 g ********************************************************************

b4 ABSTRACT POWER LEVEL - 000t. At 1017 HOURS ON 11/23/90, AN AUTOMATIC REACTOR

t. SCRAM OCCURRED OUE TO A SPURIOUS HIGH CORE FLUX SIGNAL FROM INTERMEDIATE RANGE MONITORS (IRM) 13 AND 15. CURING THE PERFORMANCE

OF ORESDEN INSTRUMENT SURVEILLANCE (015) 1500-5, LOW PRE 55URE COOLANT INJECTION LOGIC (LPCI) TEST LOGIC RELAY 2-1530-115 AY GENERATED AN ABNORMALLY LARGE VOLTAGE SPIKE ON THE 125 VOLT DC POWER SYSTEM.

8 THROUGH ELECTROMAGNETIC INDUCTION THIS VOLTAGE SPIKE WAS TRANSFERRED

, TO THE 24/48 VOLT OC POWER SYSTEM. THE 24/48 VOLT OC SYSTEM PROVIDES POWER TO THE CONTROL LOGIC FOR ALL EIGHT IRM CHANNELS. THE SPIKE CAUSED THE IRM CHANNELS TO EXCEED THE HIGH CORE FLUX SCRAM SETPOINT

'* THUS CAUSING A REACTOR SCRAM. CORRECTIVE ACTIONS INCLUDED REPLACEMENT OF THE SUSPECT RELAY AND THE INITIATION OF FURTHER INVESTIGATIr4.

THE SAFETY SIGNIFICANCE OF THIS EVENT 15 MINIMAL SINCE UNIT 2 WAS s

ALREADY SHUT 00WN FOR A REFUELING OUTAGE WHEN THE EVtNT OCCURRED.

1

, FORM 33 LER SCSS DATA 04-18-91 0********************************************************************

' DOCKET YEAR LER NUM8ER REVISION DCS MUM 8ER NSIC EVENT DATE

, 244 1989 004 0 8907170091 214600 06/01/89

,, AB5 TRACT POWER LEVEL - 053X. ON JUNE 1, 1989 At 1332 EOST, WITH THE REACTOR AT APPROXIMATELY 53% POWER, A TURSINE TRIP WITH SUBSEQUENT REACTOR TRIP g- OCCURRED OUE TO A ATWS MITIGATION SYSTEM ACTUATION CIRCUITRY (AMSAC)

ACTUATION. THE CONTROL ROOM OPERATOR $ VERIFIED THE REACTOR AND TURBINE TRIPS AND PERFORMED THE ACTIONS OF E-0 (REACTOR TRIP OR SAFETY

! g INJECTION) AND E5-0.1 (REACTOR TRIP RESPONSE). THE PLANT WAS

, $TABILIZED IN THE HOT SHUTOOWN CONDITION.

THE INTERMEDIATE CAuts op

o.rwon.e.ve us:u to bcNtRetE *ROCECURE CMANGES CONCERNING THE 4HSAC MODIFICATION. AFTER THE CAUSE OF THE EVENT WAS IDENTIFIED, THE P1 PROCFOURE W45 C.4NGED BASED ON FORPALLY 4PPROVED INFORMATION TO PREVENT RECCURENCE.

b4

FORM 34 LER SCSS DATA kW 0************************************************************04-18-91 ********

i ,s DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC

EVENT DATE p1 244 1990 003 0 9004270283 217995 03/23/9

- - - - 0*

] ABSTRACT POWER LEVEL - 000%. ON MARCH 23, 1990 AT 1804 EST WITH THE REACTOR 1 DN g: SU8 CRITICAL DURING A PLANNED SHUTDOWN FOR THE ANNUAL REFUELING AND MAINTENANCE OUT4GE, A REACTOR TRIP OCCURRED FROM SOURCE RANGE (SR) HI i

ga FLUR. THE TWO REACTOR TRIP BREAKERS OPENED AS REQUIREO AND ALL 9: SHUTDOWN AND CONTROL RODS THAT WERE WITHORAWN INSE4TED AS DESIGNED.

U" ~THE REACTOR TRIP WAS DUE TO SR CHANNEL N-31 INDICATING HIGHER THAN NORMAL COUNT RATE WHEN IT RE-ENERGIZED DURING THE CONTROLLEO SHUTDOWN.

bg THE UNDERLTING CAUSE OF THE HIGHER TH4N NORMAL COUNT RATE WAS 4 LOW INTERNAL RESISTANCE ON THE SOURCE RANGE DETECTOR. IMMEDIATE CORRECTIVE ACTION W45 TO STABILIIE THE PLANT IN HOT SHUTDOWN.

gg SUBSEQUENT ACTION WAS TO CHANGE OUT THE F4ULTY SOURCE RANGE DETECTOR.

1 84 FORM 35

g. LER SCSS DATA 04-1 0****************************************************************5-91 ****

R1 DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 244 1990 007 0 9006220036 218502 05110/90 I

,, ABSTRACT be POWER LEVEL - 098X. ON M4V 10, 1990, AT 0219 EDST, WITH THE REACTOR AT APPRONIMAIELY 88% FULL POWER, A REACTOR TRIP OCCURRED FROM "A" STEAM Re , GENERATOR (StG) LOW LEVEL COINCIDENT WITH "A" S/G FEED FLOW / STEAM FLOW MISM4TCH. THE TWO REACTOR TRIP BRE AKERS OPENED AS REQUIRED AND ALL

SHUTDOWN AND CONTROL kODS IN5ERTED AS DESIGNE0. THE REACTOR TRIP WAS DUE TO A MALFUNCTIONING "A" S/G M4IN FEEDWATER REGULATING VALVE CONTRUL SYSTEM. THE UNDERLTIMG CAUSE OF THE M4LFUNCTIONING "A" S/G l M4!N FEE 0 WATER REGULATING VALVE CONTROL SYSTEM WAS ATTRIBUTED TO THE SHORTING OF TWO HIGH GAIN AC AMPLIFIER TRANSISTORS IN THE FLOW l ,, CONTROLLER, DUE TO THE TRANS!$ TOR CANS TOUCHING EACH OTHER. IMMEDIATE

CORRECTIVE ACTION WAS TO ST481LIIE THE PLANT IN HOT SHUTDOWN.

i

'* SUBSEQUENT ACTION WAS TO PHYSICALLY SEP4 RATE THE TWO TRANSISTOR CANS 30 THAT THET COULD NOT TOUCH EACH OTHER.

I t

FORM 36 LER SCS$ DATA 04-18-91

, 0********************************************************************

,' DOCKET TE4R LER NUMBER REVISTUN DCS NUM8ER NSIC EVENT DATE 244 1990 010 0 9007170232 218836 06/09/90 i .***.*.a..*.e.**....**..****...*..*.a......**.**.......*...........*

i ABSTRACT POWER LEVEL - 097%. ON 6/9/90, AT 0411 EDST WITH THE REACTOR AT

, APPROMIMATELY 971 FULL POWER, A REACTOR TRIP OCCURRED FROM "A" STEAM GENERATOR (S/G) LOW LEVEL COINCIDENT WITH "A" $IG STEAM FLOW # FEED FLOW MISMATCH. THE TWO REACTOR TRIP SWE AKERS OPENED AS REQUIRED AND ALL i SHUTDOWN AND CONTROL RODS INSERTED AS DESIGNE0. THE REACTOR TRIP W45 OUE TO A MALFUNCTIONING "A" $/G MAIN F!EDWATER REGULATING VALVE t CONTROL SYSTEM. THE UNDERLYING CAUSE OF THE MALFUNCTIONING "A" StG g F E E DW AT E R REGULATING VALVE CONTROL SYSTEN WAS A FAULTT FEE 0 WATER FLOW CONTROLLER. TME REASON FOR THY pauti It U4n=Y88*T4*a *' 'a '*"*

, . ==

as n - ar**=.

1 PM FORM 37 LER 3 CSS DATO 06-18-91 ,

g4 0********************************************************************

.g DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 244 1990 012 0 9011060419 219814 09/26/90 kW ********************************************************************

i si eq ABSTRACT POWER LEVEL - 097%. ON SEPTEMBER 26, 1990, AT 1100 EDST WITH THE e

r REACTOR AT APPROXIMATELY 97% FULL POWER, A REACTOR TRIP OCCURRED FROM AN OPENING OF THE "A" REACTOR TRIP SREAKER, FOLLOWED IN APPRONIMATELT b8 SEVEN (7) SECONOS SY A LOW PRES $URIZER PRES 5URE REACTOR TRIP SIGNAL AND THE OPENING OF THE "B" REACTOR TRIP BREAKER. THE "A" REACTOR TRIP BREAKER OPENING WAS CAUSED BY THE INADVERTENT DROPPING OF A FLASHLIGHT

[g ON TWO OF THREE TURBINE AUTOSTOP TRIP RELAYS. THE LOW PRE 55URIZER PRES $URE REACTOR TRIP WAS CAUSED SY THE REACTOR COOLANT SYSTEM

" COOLDOWN OUE TO THE REACTOR SEING TRIPPED WITH THE TURBINE STILL 04 THE LINE. IMMEDIATE C3RRECTIVE ACTION WAS TO STABILIZE THE PLANT IN HOT SHUT 00WN. CORRECTIVE ACTION TO PREVENT RECURRENCE WILL BE BASED b4 UPON THE RECOMMENDATIONS OF A HUMAN PERFORMANCE ENHANCEMENT SYSTEM (HPES) EVALUATION OF THE OROPPE0 FLASHLIGHT EVENT. CORRECTIVE ACTION y, , FOR SUBSEQUENT HARDWARE MALFUNCTIONS WILL ALSO BE TAKEN.

1 E8 FORM 38 LER SCSS DATA 04-18-91 0********************************************************************

Rt DOCKET YEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 244 1990 013 0 9101140089 220643 12#11/90 g, ********************************************************************

ABSTRACT be POWER LEVEL - 097I. ON DECEMBER 11, 1990 AT 1517 EST WITH THE REACTOR 47 APPROXIMATELY 97X FULL POWER, A TURRINE TRIP WITH $U8 SEQUENT te . REACTOR TRIP OCCURRED DuE TO A INADVERTENT ATWS MITIGATION SYSTEM ACTUATION CIRCUITRY (AMSAC) ACTUATION. THE CONTROL ROOM OPERATORS

VERIFIED THE REACTOR AND TURBINE TRIPS AND PERFORMED THE APPROPRIATE ACTIONS OF E-0 (REACTOR TRIP OR SAFETY INJECTION) AND ES-0.1 (REACTOR TRIP RESPONSE). THE PLANT WAS SUBSEQUENTLY STABILIZED IN THE HOT 8 SHUTOOWN CONDITION. THE INTERMEDIATE CAUSE OF THE AMSAC ACTUATED TURBINE TRIP WAS DETERMINED TO BE DUE TO A LOW VOLTAGE POTENTIAL OF A i , LOGIC OUTPUT FROM THE AMSAC LOGIC CIRCUITRT. THE UNDERLYING CAU$E WAS DETERMINED TO BE A VENDOR CIRCUIT DESIGN DEFICIENCY. CORRECTIVE ACTION TAKEN WAS TO INSTALL THE JUMPER OMITTED IN THE CIRCUIT DESIGN.

i FORM 39 LER SCSS DATA 04-18-91 '

0********************************************************************

, DOCKET YEAR LER NUMBER REVI5!ON DCS NUM8ER NSIC EVENT CATE 244 1990 016 0 9101160176 220646 12/12/90

> A85 TRACT POWER LEVEL - 0031. ON DECEMBER 12, 1990 AT 2322 EST WITH THE REACTOR AT APPROXIMATELY 3% FULL POWER, A REACTOR TRIP OCCURRED FROM ONE (1)

CUT OF TWO (2) INTERMEDIATE RANGE NUCLEAR INSTRUMENT HIGH FLUX TRIP.

THE TWO REACTOR TRIP BREAKERS OPENED AS REQUIRED AND ALL SHUTDONN AND CONTROL R005 IN5ERTED AS DESIGNED. THE REACTOR TRIP WAS DUE TO ONE (1) OUT OF TWO (2) INTERMEDIATE RANGE NUCLEAR INSTRUMENT SYSTEM HIGH FLUX TRIP 81STA8LE SECOMING DE-EMERGIZED DURING THE TRANSFER OF SUS 14 t POWER FROM ITS NORMAL SUPPLY TO THE "A" EMERGENCY DIESEL GENERATOR.

, IMMEDIATELY, CORRECTIVE ACTION WAS TO STABILIZE THE PLANT IN HOT SHUTOOWN pee EMERGENCY OPERATINP. D90rE9H3Et. Tuc H=aew wtwa emoe- ar

. ~

, ., o.s....a. -ci.+*2 wall sc 14LtN 11 IDENTIFY THE OPTIMAL l HETH000 LOGY *DR TRANSFERRING ELECTRICAL DOWER SUPPLIES.

P1 1 1

b4 FORM 40 LER SCSS DATA y 0************************************************************04-18-91 ********

bW DOCEET TEAR LER NUMBER QEVISION DCS NUMBER NSIC EVENT DATE 244 1990 018 0 9101290229 220862 12/20/90 i ,g *******************a...*............................................

P1 ~

A85 TRACT kN 'g POWER LEVEL - 0221. ON DECEMBER 20, 1990 AT 1321 EST, WITH THE REACTOR 47 APPROXIMATELY 22% FULL POWER, A TURSINE RUNBACE OCCURRED DUE TO A DW .g DROPPE0 CONTROL ROD. THE CONTROL ROOM OPERATORS PERFORMED THE APPROPRIATE ACTIONS OF ABNORMAL PROCEDURES AP-TUR8.2 (AUTOMATIC TURBINE RUNBACK) AND AP-RCC.2 (RCC/RPI M4LFUNCTION) TO ST481LIZE THE gg PLANT. THE CONTROL ROOM OPERATORS MANUALLY TRIPPED THE TURBINE TO

.qg PREVENT REVERSE POWER TO THE GENERATOR. SUESEQUENTLY THE REACTOR WAS TAREN U" SUSCRITICAL TO ACCOMMODATE ANTICIPATED CORRECTIVE MAINTENANCE ACTIVITTES. THE MAIN STEAM ISOL4 TION VALVES WERE THEN CLOSED TO LIMIT g ': A PLANT C00LDOWN. THE UNDERLYING CAUSE OF THE EVENT WAS ATTRIBUTED kg '

TO DEGRADED POWER BRIDGE THYRISTOR SUPPRESSION FILTER CAPACITORS IN THE CIRCUIT SUPPLYING POWER TO THE STATIONARY, POVABLE AND LIFT COILS p, q; 0F THE AFFECTE3 CONTROL ROD. CORRECTIVE ACTION WAS TO REPLACE THE DEGRADED CAPACITORS IN THE POWER CASINET SUPPLYING POWER TO THE AFFECTED ROD.

94 y FORM 61 LER SCSS DATA fe ..

0************************************************************04-18-91 ********

,, DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

, 244 1990 019 0 9101290215 220963 12/21/90 ke A85 TRACT

3. POWER LEVEL - 016%. ON DECEMBER 21, 1990 AT 1237 EST, WITH THE REACTOR AT APPROXIMATELY 16% FULL POWER, A REACTOR TRIP OCCURRED DUE To LO L0

LEVEL (< OR = 17%) IN THE "A" STEAM GENERATOR. THE CONTROL ROOM OPERATORS IMMEDIATELY PERFORME0 THE APPROPRIATE ACTIONS OF E-0 t

(REACTOR TRIP OR SAFETY INJECTION) AND ES-0.1 (REACTOR TRIP RESPONSE).

80TH MAIN STEAM ISOLATION VALVES WERE SUSSEQUENTLY CLOSED 10 LIMIT AN RCS C00LOOWN AND THE PLANT WAS STABILIZED IN HOT SHUTDOWN. THE

, INTERMEDIATE CAUSE OF THE EVENT WAS THE "A" MAIN FEEDW4TER PUMP

TRIPPING DUE TO FEED PUMP SEAL WATER LOW DIFFERENTI AL PRES $URE C AUSED

' BY A CONDENSATE LOW HEADER PRESSURE TRANSIENT. THE UNDERLYING CAUSE 0F THE EVENT WAS 4 DEFICIENCY IN THE OPERATING PHILOSOPHY FOR THE PROPER NUMBER OF CONDENSATE PUMPS RUNNING DURIN, LOW POWER CONDITIONS.

s CORRECTIVE ACTION WILL BE TO CHANGE THE APPROPRIATE PROCEDURES INVOLVED, TO BE CONSISTENT WITH THE NEW OPERATING PHILOSOPHY.

4 0 4

FORM 42 LER SCSS DATA 04-18-91 0...........***** ..............****...... * ..................**....

,' DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 245 1989 005 0 8905150298 213949 04/07/89 A857RACT POWER LEVEL - 0$0%. CN 4/7/89 AT 1238 MOURS, WHILE THE UNIT WAS AT 80%

' R E a CT OR POWER (530F ANO 1030 PSIG), AS PART OF THE SHUTDOWN FOR A q

SCHEDCLED REFUELING CUTAGE, A REACTOR SCRAM OCCURRED ON TURBINE STOP t VALVE CLOSURE. AS A RESULT OF THE SCR4M A GROUP II ISOLATION OCCURRED g; AND THE STAND 8Y GAS TREATMENT SYSTEM (SH), WHICH IS AN ENGINEERED

, SAFEGUARDS SYSTEM, INITIATED. THE Tue5INE STOP VALVE CLOSurr SIcgat.

, . ==

....a ....a.

sans UJraue ra2 A f c LEVEL WAS LOST AND STEAM ENTERED THE ORAIN PIPING. THIS TRANSIENT CAUSED VIORATION OF THE ASSOCIATED P1 ,

PIPING WHICH CAUSED THE FALSE MOISTURE SEPARATOR HIGH LEVEL SWITCH (LS) ACTUATION. ALL SYSTEMS FUNCTIONED AS REQUIRED AND NO SAFETY b4 g CCNSEQUEKCES RESULTED FRCM THIS EVENT.

Dd FORM 43 LER SCSS DATA pq

.g 0************************************************************04-18-91 ********

DOCKET TEAR LER HUMBER REVISION DCS NUMBER NSIC EVENT DATE 245 1989 015 0 8907100037 214501 b4 'N ************************************************************06/02/89 ********

ABSTRACT b4 g POWER LEVEL - 001E. ON 6/2/89 AT 1037 HOURS OURING REACTOR STARTUP, A REACTOR SCRAM OCCURRED OUE TO MAIN CONDENSER LOW VACUUM. AT THE TIME pq OF THE EVENT, REACTOR CONDITIONS WERE $80 PSIG AND 480F AT q7 ' '

APPROXIMATELY ONE (1) PERCENT POWER. THE CAUSE OF THE EVENT WAS LACK U" 0F ATTENTION TO DETAIL ON THE PART OF THE REACTOR OPERATOR. THE PLANT RESPONDED AS DESIGNED AND ALL APPLICABLE POST-SCRAM PROCECURES WERE

.{r CORRECTLT FOLLOWED. THERE WERE NO CONSEQUENCES.

I g4 q. FORM 44 LER ICS? OATA 0*****************************-******************************04-18-91 ********

81 DOCKET YEAR LER NUMBER REVISION OCS MUMBER NSIC EVENT DATE

,, 245 1989 021 0 3911220182 215816 10/1

- - - - e********************************************************1/89 ***

R4 A85 TRACT j- ,, .,

POWER LEVEL - 070I. ON 10/19/89 AT 1515 HOURS WITH THE PLANT AT 70X g POWER (530F AND 1000 PSIG) A FULL REACTOR SCRAM OCCURRED AS A RESULT b8 OF A MAIN TURBINE TRIP (TURBINE STOP VALVES GREATER THAN 10% CLOSURE).

THE MAIN TURSINE TRIP WAS THE RESULT OF A HIGH REACTOR WATER LEVEL TUR81NE TRIP SIGNAL (+48"). THE HIGH REACTOR WATER CONDITION WAS THE 44 ,i RESULT OF "A" FEE 0 WATER REGULATTNG VALVE SECOMING STUCK IN THE OPEN POSITION WHICH OCCURRED WHILE hcTURNING "8" FEE 0 WATER REGULATING VALVE

"' TO SERVICE. OURING THE LEVEL DECREASE WHICH FOLLOWED THE SCRAM,

, STAN06T GAS TREATMENT SYSTEM INITIATED AS EIPECTED. ALL SYSTEMS FUNCTIONED AS EXPECTED. NO SAFETY CONSEQUENCES RESULTED FROM THIS e EVENT.

1 v.

FORM 45 LER SCSS DATA 04-18-91 0********************************************************************

00CKET VEAR LER NUMBER REVISION DCS MUMSER NSIC EVEMT DATE 245 1990 015 0 9010230202 219695 09/14/90

, A85 TRACT

,- POWER LEVEL - 1001. 04 9/14/90, WITH THE PLANT AT 1001 POWER (530F AND 1030 PSIG), 4 FULL REACTOR SCRAM OCCURRED ON LOW REACTOR WATER LEVEL

(*8 INCHES) AFTER THE FEE 0 WATER REGULATING VALVES SEGAN TO CLOSE. THE

, FEE 0 WATER REGULATING VALVES WERE RESPONDING TO A HIGH INDICATED REACTOR WATER LEVEL SIGNAL FROM THE 'A' CHANNEL OF THE FEE 0 WATER CONTROL SYSTEM, WHICH WAS CONTROLLING FEEDWATER FLOW. AT THE TIME OF

,, THE SCRAM, A TECHNICIAN WAS PERFORMING A CALI8 RATION ON A PRESSURE SWITCH WHICH SENSES PRESSURE FROM AN INSTRUMENT LINE COMMON TO THE REFERENCE LEG OF THE 'A' FEE 0 WATER CONTROL SYSTEM. ALL SAFETY SYSTEMS

' FUNCTIONED AS REQUIRED AND NO SAFETY CONSEQUENCES RESULTED FROM THIS g

EVENT.

9 1 I FORM 46 LER SCSS DATA "A-9*-o'

. . . ..., .. u s*J412ddiU 213542 02 eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee/22/30 eeeeee

>a A85 TRACT g4 PorER LEVEL - 100%. C3 FE82U4RY 25, 1999, WHILE THE PLANY WAS af FULL 9, POWER, A REACTOR TRIP OCCURRED ON AN OVERPOWER DELTA T SIGNAL.

>9 IMMEDIATELY PRIOR TO THE TRIP, AN INSTRUMENT AIR LINE FOR THE CONTROL 0F THE HEATER DRAIN TANK OISCHARGE CONTROL VALVES PARTED AT A SOLDERED CONNECTION. THE RESULTANT LOSS OF INSTRUMENT AIR CAUSED THE pq DISCHARGE VALVES TO GO 10 THE FULL OPEN POSITION. A HEATER OR41N TANK LOW LEVEL SIGNAL TRIPPED THE HEATER OR4IN TANK PUMP $. A THIRO G CONDENSATE PUM*, WHICH WOULO HAVE NORMALLY STARTED UNDER THESE CIRCUMSTANCES, HAD ITS AUTO-START CONTROLS QUT OF SERVICE DUE TO A DO ROUTINE SURVEILL4NCE TEST. PUMP LOSS WAS OBSERVED IN 1HE CONTROL ROOM, AND PLANT OPERATORS REDUCED TURSINE LOAD AND INSERTED ROD $ WHILE gg SIMULTANEOU$LV PLACING THE THIRD CONDENSATE PUMP IN SERVICE MANUALLY.

APPROEIMATELY THREE MINUTES INTO THE EVENT THE REACTOR TRIPPE0. WITH THE LOAD 8EING REDUCED AND RODS INSERTED, THE DELTA FLUX IN THE CORE b" INCREASED FROM - 4% TO GREATER THAN - 20%. SECAUSE OF THE DELY4 FLUX PENALTY, THE REACTOR TRIPPED WHEN THE LOOP DELTA T EXCEEDED THE b4 LOWERED TRIP SETPOINT DURING THE TRANSIENT. ALL RODS INSERTED ON THE RE4CTOR TRIP SIGNAL, AND ALL SAFETY SYSTEMS FUNCTIONED AS DESIGNED.

1 F03M 47 LER SCSS DATA 88 O****************************************e........... ......*04-18-91 00CKEY TEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE 247 1989 013 0 9001250351 216483 12/13189 p3 .............................eee..................... .............e

,, AB5 TRACT I POWER LEVEL - 100%. ON 12/13189, WHILE THE PLANT WAS AT 100% POWER, A I9 MOMENTARY DECRE45E IN MAIN TURSINE GOVERNOR OIL PRESSURE, BROUGHT ABOUT ST OPERATOR ACTION, ACTUATED THE "TUR81NE TRIPPE0" LOGIC (TUR8INE STILL RESET) WHICH IN TURN GENERATED A REACTOR TRIP SIGNAL.

Ea THE SUSSEQUENT REACTOR TRIP GENERATED A TUR8INE TRIP SIGNAL CAUSING A TUR8INE AND GENERATOR TRIP. FOLLOWING THE TRIP ANO DATA REVIEW, IT

WAS DETERMINED THAT REACTOR COOLANT SYSTEM LETDOWN ISCLATION DID NOT OCCUR, AND THAT LOOP 23 PRESSURIIER SPRAY FLOW WAS UNEXP?!TE0LY I RE00CEO TO AN INSUFFICIENT AMOUNT CUE TO AN INCORRECT Bn IS VALVE POSITION, CAUSING LOWER 1H4N EXPFCTED TEMPERATURES IN THi 550CIATED SPRAY (INE.

, 1 FORM 48- LER SCS5 DATA 04- 18-91 8

0**e*********ee**e.*ee.............. **eeeeeeeeeeeeeeeee mene .....

DOCKET TEAR LER NUMBER REVISION OCS NUMBER N5IC EVENT DATE o 249 1989 001 1 8907250110 214841 03/25/89

....eeeeeeeeeeeeeeeee...............................................

s 485 TRACT POWER LEVEL - 089%. AT APPROX. 0133 HOUR 5 ON 3/25/89, A FAULT OCCURRED WITHIN 345 KV SWITCHTARD POWER CIRCUIT SREAKER (PCB) *-15. LOC 4L 8REAKER SACKUP LOGIC CIRCUITRY THEN AUTOMATICALLY ISOLATED PCS 8-15; YHIS DE-ENERGIIED UNIT 3 RESERVE AUX. TRANSFORMER (TR) 32, CAUSING A LOSS OF OFFSITE POWER (LOOP) TO UNIT 3. THE AUTOMATIC TRANSFER OF 4 KV BUS 32 FROM TR 32 Yo UNIT 3 AUIILIART TR 31 010 NOT OCCUR QUICKLY ENOUGH TO PREVENT UNDERVOLTAGE TRIPS OF THE 38 REACTOR FEED PUMP (RFP)

AND THE 35 REACTOR RECIRCULATION PUMP. WHEN THE STAN05Y 3C RFP t STARTED, REACTOR WATER LEVEL ROSE TO THE MAIN TUR8INE AND RFP TRIP SETPOINT AND A RE ACTOR 3 CRAM ON TUR8INE STOP VALVE CLOSURE RESULTED.

THE MAIN STEAM ISOL4 TION VALYF5 (MSIVS) WERE MANUALLY CLOSED TO g CONSERVE REACTOR INVENTORY AND THE ISOLATION CONDEN5ER WAS USED FOR

, REACTOR PRESSURE CONTROL.

MILOLY CONTAMINATED CONDENSATE WAS

. m

%. ..s. . . . 6..

L c e t L' L Jh e e'11N A I I ON TU THE 49EA SURROUNDING THE ISOLATION CONDENSER WENT. COLD SHUTD0d4 CONDITIONS UERE ACHIEVED EY P1 2230 HOURS ON 3/25/89. CORRECTIVE ACTIorts INCLUDED INSPECTION, TESTING AND REPAIR OF VA210US 8REAKERS AND LOGIC CIRCUITS AtD'SURVE15/CLEAMUP b4 0F THE AREAS AFFECTED SY THE ISOLATION C0:2E%5ER VENT. SIMILAR g;'

EVENT: 237/85-034.

1 DM i ; FORM 49 LER SCSS DATA rq 04-18-91 Oseee*********ee**********eae *******e*********************** ********

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE g4 ,, 249 1989 002 0 8905050348 2 03/30/89

- - - - ee************************************13805 ******************

D4 485 TRACT POWER LEVEL - 070%. ON 3/20/89 AT 1253 HOURS WITH UNIT 3 0FERATING AT be 704 RATED CORE THERMAL POWER, A REACTOR SCRAM OCCURRED WHILE THE TECHNICAL STAFF WAS PERFORMING DRESDEN TECHNICAL SURVEILLANCE (DTS)

U" 500-2, FUNCTIONAL TESTING OF '.P5 MG SET AND RPS RESERVE POWER SUPPLY.

THE CAUSE OF THE SCRAM WAS CUE TO A SPURIOUS TRIP 0F ELECTRICAL bg PROTECTION ASSEMBLY (EPA) BREAKER 3A-1 ON R* ACTOR PROTECTION SYSTEM (RPS) 8US 8 WITH A CONCURRENT LOCK-UP CONDITION OF THE 3A MAIN STEAM LINE (MSL) RADIATION MONITOR. THE RPS BUS 8 TRIP OCCURRED AT THE SAME g,.; TIME ATTEMPTS TO RESET THE HALF $ CRAM ON RP5 CHANNEL A WERE TAKING PLACE.

THE NUCLEAR STATION OPERATOR (NS0) WAS UNA8LE TO RESET THE RPS I'l CHANNEL A HALF ICRAh DUE TO THE LOCK-UP CONDITION ON THE 34 MSL RADIATION MONITOR. THE LOCK-UP CONDITION HAS THE POTENTIAL OF 31 OCCURRING UPON RE-ENERGIZING THE MONITOR FOLLOWING A MOMENTARY (LESS THAN APPRORIMATELV ONE SECOND) POWER INTERRUPTION. OURING THE LOCK-UP CONDITION THE RADIATION MONITOR REMAINS IN A TRIPPED CONDITION. THE g, CONDITION IS CORRECTED BY DE-ENERGIZING THE MONITOR FOR APPROXIMATELY I TEN SECONDS AFTER WHICH TIME THE MONITOR 15 RE-ENERGIIED. A SECOND AND k'

' THIRD REACTOR SCRAM OCCURRED AT 1338 HOURS AND 1742 HOURS RESPECTIVELY. THE SECOND SCRAM WAS CAUSED ST OPERATIONS DEPARTMENT PERSONNEL TRANSFERRING CVER POWER SUPPLIES TO RPS SUS A IN AN ATTEMPT te TO CLEAR THE RADIATION MONITOR LOCK-UP CONDITION.

1 FORM 50 LER SCSS LATA 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 249 1959 006 0 8905220193 213883 04/15/89

,, e*ee **eene **ee... eeeeeeeeeee**eeeeeeeeeeeeee****eeeeeeeee**ee**** ..

485 TRACT POWER LEVEL - 092%. OM 4/15/89 AT 0320 HOURS WITH UNIT 3 OPERATING AT 92% RATED CORE THERMAL POWER, A REACTOR SCRAM OCCURRED OURING 8

SURVEILLANCE TESTING OF THE MAIN TUR8INE STOP VALVES (T5V5). THE CAU5E OF THE SCRAM WAS DETERMINED TO BE COMPONENT FAILURE. HIGH CONTACT RESISTANCE ON A NORMALLY OPEN CONTACT PREVENTED ITS REQUIRED CLO5URE DURING TESTING OF THE s2 TSV. THIS FAILURE RESULTED IN THE

REMAINING THREE TSV5 STARTING TO CLOSE WHEN 82 TSV STARTED TO CLOSE.

ALSO OURING THIS EVENT THE MAIN GENERATOR OUTPUT CIRCUIT OREAKERS FAILE0 TO OPEN ON REVERSE POWER. THUS THE MAIN TUR8INE WAS MANUALLY a

TRIPPE0 AT 0323 HOUR $. THE RDOT CAUSE OF THIS FAILURE WAS ALSO ATTRIBUTED TO COMPONENT FAILURE. UPON INSPECTION OF THE MAIN

. GENERATOR SECONDARY REVERSE POWER RELAT, DIRT WAS FOUND BETWEEN THE BEARING AND CONTACT PIVOT ARM ON THE RELAY DIRECTIONAL UNIT PREVENTING PROPER OPERATION. 45 CORRECTIVE ACTIONS, TWO TSV CONTROL RELAYS WERE g REPLACEO. THE MAIN GENERATOR SECONDART REVERSE POWER RELAY WAS CLEANED AND VERIFIED TO OPERATE PROPERLY. TO HELP PREVENT FUTURE 9

FAILURES OF REVERSE POWER RELAY WAS CLEANED AND VERIFIED TO OPERATE

( ;' PROPERLT. TO HELP PREVENT FUTURE FAILURES OF REVERSE POWER RELAYS THE CALIsRATION PROCEDURE WILL SE REVISED TO SPECIsItatty annosts

p$ FOR4 51 lee SCSS DATA 0************************************************************04-18-91 ********

b" DSCKET VEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE gg 249 1990 005 0 9004180282 217792 03/10/9 DM

- - - .***.e.*.e.*.***.**...**.e.**..**...**.***....**.**....**.**.*.0 *

, g A85 TRACT pq POWER LEVEL - 094%. AT APPROXIMATELY 2030 HOURS ON 3/10/90, AN AUTOMATIC UNIT 3 SCRAM ON AN AVERAGE POWER RANGE MONITOR (APRM) HIGH LO ,' '

FLUM SIGNAL OCCURRED. THE AIR LINE TO THE PILOT SOLENOID FOR OUTSOARD MAIN STEAM ISOL ATION VALVE (MSIV) 3-203-24 HAD FAILEO PRIOR TO THE be ai SCRAM CAUSING CLOSURE OF THE MSIV AND A RESULTING REACTOR VESSEL PRESSURE TRANSIENT WHICH LED TO THE SCRAM ON APRM HIGH FLUX. THE RESULTING MAIN STEAM LINE FLOW INCREASE AND CORRESPONDING LOW REACTOR gg WATER LEVEL CONDITION RESULTED IN GROUP I, II AND III PRIMARY CONTAINMENT ISCLATIONS VIA MAIN STEAM LINE HIGH FLOW (G R E A TE R THAN b" 120% OF RATED STEAM FLOW) SWITCH AND +8 INCH REACTOR WATER LOW LEVEL SWITCH ACTUATIONS. CORRECTIVE ACTION INCLUDED SAFEY SIGNIFICANCE OF bg THIS TRANSIENT WAS MITIGATED SY THE FACT THAT REACTOR WATER WAS MAINTAINED WELL ABOVE THE AUTOMATIC EMERGENCY CORE COOLING SYSTEM (ECCS) INITIATION SETPOINT AT %LL TIMES AND MULTIPLE SYSTEMS WERE y, AVAILASLE FOR REACTOR PRESSURE CONTROL INCLUDING ISOLATION CONDENSER, HIGH PRES $URE COGL ANT INJECTION (HPCI) AND MAIN STEAM RELIEF VALVES.

I4 ALTHOUGH PREVIOUS FAILURES OF INBOARD MSIV PNEUMATIC LINES AT THE MANIFOLD BLOCK HAVE OCCURRED, THIS IS SELIEVED TO BE THE FIRST FAILURE OF AN OUT80ARD AIR LINE FITTING CONNECTION.

ps 1

,, FORM 52 LER SCSS DATA 04-1 0*****************************************************************8-91 ***

k' 00CKET TEAR LER NUMSER REVISION DCS NUMSER NSIC EVENT DATE 250 1959 004 0 8903230293 213325 02/10/89 te ABSTRACT

POWER LEVEL - 000%. ON FEBRUARY 10, 1989, AT 1151, WITH UNIT 3 REACTOR CRITICAL AT 0% POWER (APPROXIMATELT 1 E-6 AMPS IN THE INTERMEDIATE RANGE) A REACTOR TRIP OCCURRED. WHILE PERFORMING PROCEDURE OP 14004.1 l

A BISTABLE WAS PLACED IN TEST CAUSING THE REACTOR PROTECTION SYSTEM (EIIS:JC) 10 SEE PCWER LEVEL GREATER THAE 10%, ENABLING THE P-7

,, REACTOR TRIPS. P-7 IS A TRIP PERMISSIVE, ENABLED WHENEVER EITHER REACTOR POv#.R OR TURBINE POWER IS GREATER THAN 10%. THIS, COINCIDENT

, WITH THE TORBINE TRIP SIGNAL FROM THE UNLATCHED TURSINE, CAUSED THE 8

REACTOR TR7P. THE CAUSE OF THE TRIP WAS A DEFECTIVE PROCEDURE IN THAT THE STEP WHICH RESULTED IN THE TRIP WAS NOT IDENTIFIED AS HAVING THE POTENTIAL TO CAUSE A TRIP. A CONTRIBUTING CAUSE WAS INADEQUATE CONTROL OF PROCEDURE REPLACEMENTS WHICH ALLOWED TWO APPLICABLE

, PROCEDURES 10 BE IN EFFECT AT THE SAME TIME. AN EVENT RESPONSE TEAM

,, WAS FORMED TO DETERMINE ROOT C AUSE(S) AND CORRECTIVE ACTIONS. THE OLD PROCEDURE WAS REVISED TO CORRECT THE ERRORS AND WAS COMPLETED TO SATISFT THE SURVEILLANCE REQUIREMENT. THE NEW PROCEDURES ARE GEING

, FIRST-USE VERIFIED, AND WORK CONTROLS WILL SE DEVELOPED TO ENSURE OLD PROCEDURES ARE CANCELLED IN A TIMELY MANNER.

1 FORM 53 LER SCSS DATA 04-18-91 0********************************************************************

gi DOCKET TEAR LER NUMBER REVISION DCS NUMSER MSIC EVENT DATE 250 1989 020 1 9006120016 218400 12/23/89

A85 TRACT w

s,3Avs.

. . . . . . . - . . 6,2 89c auJotN LOSS OF STEAM FLOW FROM THE 44 STEAM GENERATOR C30 SED AN INCREASE IN PRESSURE IN THAT STEAM P* GENERATOR. THE PRESSURE INCREASE CAUSFO THE STEAM GENERATOR LEVEL To "5HRINK" TO THE Luu-LO3 LEVEL SETPOINT OF 15%. THE AUX. FEE 0UATER SYSTEM RESPONDED AS CESIGNEO. CO2R05I0N ACRD55 TERHIKAL BOARD g-' CONTACTS SUPPLYING WITAL 125 VDC POWER TO ONE OF TWO 4A MSIV OPENING 50LENOIO v4LVES CAUSED A FUSE To BLOW. UPON DE-ENERGIIATION, THE b4 OPENING SOLENOID FAILED TO THE VENT POSITION. THIS ALLOWED AIR TO

. : 8LEED FWOM THE 80TTOM OF THE MSIV PISTON. THE MSIV DISC OROPPE0 DOWN pq INTO THE STEAM FLOW, RESULTING RAPID CLOSURE OF THE MSIV. THE ACCELERATED CORROSION RATE Wat .'d TO STRAY DC LEAKAGE CURRENTS. UPON i

E4 INSPECTION OF THE TERMINAL 80 dos SUDPLTING VITAL 125 VDC POWER TO THE OPENING AND CLO5ING SOLENUID VALVE 5 FOR THE 34, 38 AND 3C MSIV5, b4 CORROSION WAS IDENTIFIED ON ONE OF THE TWO TERMINAL BOAAus FOR EACH THE 38 AND 3C MSIVS. THE 38 AND 3C MSIVS WERE DECLARED INOPERASLE AND UNIT 3 ENTERED TECH SPEC (TS) 3.0.1 47 2300 ON 12/24/89 T"I TWO gg TERMINAL E0AR05 WERE REPLACED, THE 38 AND 3C MSIVS WERE DECL-4E0 i OPER4BLE, AND UNIT 3 EXITED T5 3.0.1 AT 0455 ON 12/25/89.

1 aus FORM 54 LER SC55 DATA kg 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION DC5 NUM8ER N5IC EVENT DATE y, , 250 1990 011 1 9008310218 219385 06

- - - - /09/90 ******

pa 485 TRACT POWER LEVEL - 0263. ON JUNE 9, 1990, AT 0648 EDT, WITH UNIT 3 IN MDOE D1 1 (POWER OPERATION) AT 26 PERCENT POWER AND UNIT 4 IN MODE 1 AT 100 PERCENT POWER, UNIT 3 EXPERIENCED 4 HI-HI STEAM GENERATOR WATER LEVEL

' TUR8INE TRIP AND SUSSEQUENT REACTOR TRIP. ALL SAFETY SYSTEMS I

PERFORMED 45 DESIGNED. 4FTER THE TRIP, THE OPERATOR 5 STASILIIED THE ka UNIT IN MODE 3 (HOT STANDBY) ST USING APPLICABLE PROCEDURES. THE CAUSE OF THIS EVENT WAS A MALFUNCTION OF THE 3C FEECWATER REGULATOR MAND / AUTO STATION OPEN PUSH 5UTTON SWITCH FOR VALVE CONTROLLER g, FC-3-498F. THE SWITCH IS 4 MOMENTARY ACTION SWITCH DESIGNED TO SPRING BACK TO THE "N0 CONTACT" POSITION UPON RELEASE. THE SWITCH WAS FOUNO

SPRUNG 84CK TO TH! "NO CONTACT" POSITION, BUT THE SWITCH CONTACTS WERE STILL CLOSED. THIS RESULTED IN A FULL OPEN DEMAND SIGNAL CAU5ING THE 3C FEEDW4TER REGULATING VALVE TO FULLY OPEM. THE FAILED 3C I

FEEDWATER REGULATING VALVE MAND / AUTO STATION AND THE HAND / AUTO STATION FOR THE 38 FEE 0 WATER REGULATING VALVE WERE REPLACED WITH HAND / AUTO

,, STATIONS HAVING NEW STTLE SWITCHES. THE MAND / AUTO STATION FOR THE 3A FEEDWATER REGULATING VALVE MAD SEEN REPLACED IN JUNE, 1989. ON JUNE 9, 1990, at 0716 EDT, THE NRC WAS NOTIFIED OF THIS EVENT IN ACCORDANCE WITH 10 CFR 50.72(8)(2)(II).

1

' i FORM 55 LER SCSS DATA 04-18-91

, 0********************************************************************

, DOCKET YEAR LER NUMBER REVISION 005 NUMBER NSIC EVENT DATE 250 1990 013 0 9007230140 218896 06/15/90 6

4557RACT POWER LEVEL - 0103. ON JUNE 15, 1990, AT 1203 EDT, WITH UNIT 3 IN MODE

,! 1 (POWER OPERATION) AT 10 PERCENT POWER AND UNIT 4 IN MODE 1 AT 100 PERCENT POWER, UNIT 3 EXPERIENCED A RE4CTOR TRIP WHEN THE OPERATOR I

RAISED POWER A80VE 10 PERCENT WITH THE TUR8INE IN A TRIPPED CONDITION.

,, REACTOR POWER ABOVE 10 PERCENT AUTOMATICALLY RE5ETS THE P-10 REACTOR TRIP PERNISSIVE (REACTOR POWER GREATER THAN 10 PERCENT) WHICH IN t CONJUNCTION WITH & TURSINE TRIP PROVIDES 4 REACTOR TRIO. THE UNIT WAS g- STABILIIED IN MODE 3 (>0T STANDST) IN ACCORDANCE WITH APPROVED PLANT

, PROCEDURES. THIS EVENT Was CAUSED ST COGNITIVE PERSONNEL ERROR IN

- . . - . . . -- .. . . -- . .. . ~ - -

.-s. . . . . = > ..ei a:2rces to <taLiga inIn SET POINTS. THIS EVENT WILL p1 BE REVIEWED WITH ALL APPLICA?LE OPERATIONS PERSONNEL TO INCREASE AWARENESS OF THE POTENTIAL FOR UNDESIRASLE RESULTS DUE TO A FAltURE 70 i

MENTALLY REVIEU THE CONSEQUENCES OF ACTIONS BEING PERFORME0. IN h4 ADDITION, THE RECE55ITY OF ADEQUATE COMMUNICATIOMS BETWEEN THE l} DIFFERENT OPERATOR $ AND THE PLANT SUPERVISOR NUCLEAR IS ALSO BEING STRESSED DURING THE OPERATOR REVIEW SINCE INADEQUATE COMMUNICATIONS

. WW WAS DETERMINED TO H4VE SEEN A SIGNIFICANT CONTRIBUTING CAUSE OF THIS l g; EVENT. ON JUNE 15, 1990, AT 1253 EDT, THE NRC WAS NOTIFIED OF THIS

, eq ' EVENT IN ACCORDANCE WITH 10 CFR 50.72(B)(2)(11).

4 1 fM FORM 56 LER SCS$ DATA 04-18-91 1 0........................................................... ........

l D4 ,i DOCKET TEAR LER NUMBER REVISION DCS NUMEER NSIC EVENT DATE l }g, 251 1989 003 1 8910240294 215631 05/05/89

+

A85 TRACT U"

POWEtt LEVEL - 0002. ON 5/5/89, AT 0152, WITH UNIT 4 IN HOT STAND 8Y, AND DURING ROD OROP TESTING, AN RPS ACTU4 TION OCCURRED WHILE bg PERFORMING PROCEDURE 4-SMI-071.4. THE REACTOR TRIPPED WHEN IRC PERSONNEL (NON-LICENSED UTILITY PERSONNEL) PLACED SISTABLE 85-4-446-1 4

p, IN THE TEST POSITION IN A ACCORDANCE WITH PROC EDURE 4-SMI-071.4 THIS 3 , SIMULATED A REACTOR POWER GREATER THAN 103, EN48 LING THE LOW POWER j PERMfSSIVE'S REACTOR TRIPS. AN INVESTIGATION DETERMINED THAT REACTOR ,

I4 Tate LOGIC WAS COMPLETED SY A TUR8INE TRIP SIGNAL GENERATED BY INDICATION OF CLOSED TURBINE STOP VALVES. ALTHOUGH THE TUR81NE STOP

y, VALVES (T5d) WERE PHYSICALLY VERIFIED TO BE IN OPEN POSITION, THE RPS INDICATED THEY WERE CLOSED DUE TO PRESENCE OF LIFTED LEAD $ IN THE TSV5 g, POSITION SENSING CIRCUITRY. THE EVENT RESPONSE TEAM HAS IDENTIFIE0 o

I THE PHYSICAL ROOT CAUSE A5 THE PRESENCE OF LIFTED LE405 IN THE TSV'S.

k' POSITION SENSING CIRCUITRY DUE TO INADEQUATE ACMINISTRATIVE CONTROL $.

l A CONTRIBUTING FACTOR WAS DETERMINED TO OE THAT THE SEQUENCE OF

! EVENTS GENERAL ALARM

SUMMARY

010 NOT IDENTIFY THE T$YS IN THE " ALARM i te CONDITION." THE SUBJECT LEADS WERE LANDED. A NEW ADMINISTRATIVE SITE I

PROCEDURE WAS DEVELOPED TO IMPROVE CONTROL OF PROCESS SHEETS AND INSTALLATION LISTS. THE GENERAL ALARM $UMMARY SOFTWARE M45 SEEN i MODIFIED TO PREVENT LOS$ OF ALAEM STATUS.

1 o

FORM 57 LER SC55 DATA 04-18-91 l , 0....................................................................

DOCKET TEAR LER NUM8ER REVISION DCS NUM8ER N5IC EVENT DATE 251 1980 011 0 8910190123 215534 09/15/89 I 1

485 TRACT POWER LEVEL - 100X. AT 0426, ON 9/15/89, WITH UNIT 4 OPERATING AT 100X

, POWER, A MANUAL REACTOR TRIP WAS INITIATED. A HIGH PRES 5URE (HP)

TUR8INE STOP VALVE AUTO STOP OIL LINE WELD LEAK IDENTIFIED AT 0045 LED TO CLOSURE OF THE STOP VALVE. WHEN THE CONTROL ROD $ F4ILED TO INSERT IN AUTOMATIC OR MANUAL IN RESPONSE TO THE SUDDEN TUR8INE POWER

' DECREASE, AS CALLED FOR SY A T-AVEIT-REF MISMATCH $1GNAL, A MANUAL RE4CTOR TRIP W45 INIT!aTED. A FAILURE OF THE 4C STEAM GENERATOR FEE 0 WATER CONTROL VALVE TO CLOSE DURING A SUBSEQU!NT FEEDWATER

, ISOLATION ($ LOW CLO5URE) SIGNAL RESULTED IN OVERFEED OF THE STEAM GENERATOR AND "5HRINE" 0F THE REACTOR COOLANT SYSTEM INVENTORY. 4 M ANUAL S AFETY INJECTION SIGN 4L WAS INITIATED'8Y PROCEDURE SECAUSE

! I '

. PRES $URIZER LEVEL OROPPED BELOW 123. THE AUTO STOP OIL LINE WELD FAILURE WAS DUE TO AN INADEQUACT IN THE REFUELING PREVENTIVE e MAINTENANCE PROGRAM. THE AUTOMATIC RCD CONTROL SPEED SIGN AL OUTPUT I $UMMATOR WAS OUT OF CALIBRATION. THE FEE 0 WATER CONTROL VALVE F4ILURE TO CLOSE IS DUE TO AN INADEQUATE PROCEDURE USED 00RINr, A estsgv

.- , , - - , ,r, - . , _-s. . - _ , . , , _ - , , . - - _ , , - . - - - . , , . , , , - - - _ , - - - , - - - . . , . , , ,,, -c,-- , , , , , . - , , .,y . _ . , ,r. . , ~ ~ - ---- , - , _ .- _ - ,A

swsatseave acasug3 nav: occN/WILL SE PERFORMED.

1 P9 FO*M SS LER SCSS DATA

,4 0********************************************************.***04-18-91 **.*****

DOCKET TEAR LER NUNSER REVISION DCS NUMBER NSIC EVENT DATE 251 1990 003 0 9005160071 218153 kW

.................................................................. 0 04/09/9 U

pq A85 TRACT POWER LEVEL - 100%. 04 4/9/90 AT 1814 EDT, WITH UNIT 4 IN MODE 1 4 q, (POWER OPERATION) AT 1001 POWER, A REACTOR PROTECTION SYSTEM ACTUATION OCCURRED DUE TO A FAILURE OF A REACTOR COOLANT PUMP (RCP) kW ,g, UNDERFREQUENCY RELAY POWER SUPPLY CAPACITOR. THE REACTOR TRIP OCCURRED BECAUSE ONE OF THREE REACTOR COOLANT PUMP POWER SUPPLY OREAKERS OPENED WITH THE REACTOR AT GREATER THAN 45% POWER. THE gg FAULTV UNDERFREQUENCY RELAY WAS REPLACED AND UNIT 4 WAS RETURNED TO

.;, SERVICE. THE RCP POWER SUPPLY UNDERFREQUENCY RELAYS ON BOTH UNIT 3 U" ANO UNIT 4 HAVE BEEN REPLACED WITH NEW MODELS. A REVIEW OF THE FAILURE MODES OF THE REPLACEMENT RELAYS WILL BE PERFORMED AND PLANNED l, MAINTENANCE WILL BE DEVELOPED AS APPROPRIATE. ON 4/9/90, AT 1914 EDT, be A 4 HOUR REPORT OF THE EVENT WAS MADE TO THE NRC IN ACCORDANCE WITH 10 CFR 50.72.

De 1 l=

FORM 59 LER SCSS DATA R'8 ,

0********************************************************** *04-18-91 ********

DOCKET VEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 81 251 1990 004 0 9006190055 218504 05/Z6/90 f, ....................................................................

f' g AB5 TRACT POWER LEVEL - 0013. ON MAY 26, 1990, AT 0556 EDT, DURING START-UP OF k' 80TH UNITS, WITH UNIT 3 IN MODE 3 (HOT STAND 81) AND UNIT 4 IN MODE 2 (START-UP) AT APPROEIMATELY ONE (1) PERCENT POWER, A LICENSING TRAINEE ge UNDER THE DIRECTION OF THE UNIT 4 REACTOR OPERATOR MANUALLY TRIPPED THE UNIT 4 REACTOR. THIS OCCURRED DURING THE RESTORATION PHASE OF THE I* TURBINE VALVE YEST ON UNIT 4. THE UNIT 4 REACTOR WAS MANUALLY TRIPPED IN AN ERR 0NEOUS RESPONSE TO STEP 7.2.59 0F PROCEDURE 4-05P-089

" MAIN TURSINE VALVES OPERABILITY TEST." SUS $EQUENT TO THE TRIP, THE D

OPERATORS VERIFIED THE UNIT TO 8E IN A STABLE CONDITION BY USING

' APPLICASLE EMERGENCY OPERATING PROCEDURES. THIS EVENT WAS CAUSED ST COGNITIVE PERSONNEL ERROR ON THE PART OF PLANT LICENSE 0 OPERATOR 5. TO PRECLUDE RECURRENCE OF THIS EVENT, PROCEDURES 3-05P-089 AND 4-35P-089 '

'* HAVE BEEN REVISED TO CLARIFY THE INTENT OF STEP 7.2.59 IN ADDITION, THIS EVENT IS BEING REVIEWED WITH APPLICABLE OPERATIONS PERSONNEL.

04 MAY 26, 1990, AT 0634 EDT, THE NRC WAS NOTIFIED OF THIS ! VENT IN e

,9 ACCORDANCE WITH 10 CFR 50.72(8)(2)(II) 8

,9 FORM 60 LER SC55 DATA 04-18-91 0....................................................................

I DOCKET TEAR LER NUMBER REVISION OCS NUMBER N5IC EVENT DATE g -

251 1990 005 0 9009250140 219487 08/12/90

yy A85 TRACT POWER LEVEL - 100%. AT 1625, 04 AUGUST 12, 1990, WITH UNIT 4 IN MODE 1 AT 100 PERCENT POWER, THE 48 CONDENSATE PUMP MOTOR AUTOMATICALLY I

p' TRIPPE0 ON OVERCURRENT. THE 4A CONDENSATE PUMP AUTOMATIC ALLY STARTED 45 DESIGNED. THE 44 STEAM GENERATOR FEEDWATER PUMP TRIPPED t UNEEPECTEDLT AND INITIATED A TUR5INE RUNSACK. THE TURSINE RUNSACK AND g; THE REDUCED FEEDWATER FLOW CAUSED THE STE44 GENERATOR LEVELS TO DECRE ASE. OPERATOR ACTIONS WERE TSEEN IN AN ATT*Mpf 79 octToes cess.

. .m a vv a s .v u. e assanalat aud21Ne TRI*. THE UNIT Was STABILIZE 0 IN MODE 3 (NOT STANO3V) USING EXISTING SITE PROCEDURES. THE 49 CON 3ENSATE DUMP p,

MOTOR TRIP WAS CAUSED SV 4 PHASE-TO-PHASE SHORT. FPL POSTULATES THAT A WEAK SPOT IN THE INSULATION WAS CREATED WHEN THE MOTOR WAS RECCUND h4 IN 1980.

THE CEAK SPOT DEGRADED TO THE POINT THAT MOISTURE COULD g:

PENETRATE THE INSULATION. THE MOISTURE PROVIDED AN ELECTRICAL SHORT ACROSS THE COILS. THE UNEXPECTED 44 STEAM GENERATOR FEEDWATER PUMP b4 (SGFP) TRIP WAS CAUSED BV AN INCORRECT SETPOINT ON AN AGASTAT TIME g, DELAY BREAKER TRIP RELAY. THE 4A AND 48 SGFP BREAAER TRIP RELAYS HAVE pq 1

8EEN RECALIBRATED. THE CONDENSATE PUMP IS 8EING REPAIRED.

Id FORM 61 LER SCSS DATA 04-18-91 0........................................................... ........

D4 ,g DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 254 1989 003 0 8905160294 21 g3 e.*ee ................e.......................... 3950 04/12/89 c'

ABSTRACT U"

POWER LEVEL - 0642. ON 4/12/89, QUAD CITIES UNIT ONE WAS IN THE RUN be MODE AT APPROXIMATELY 74% OF RATED CORE THERMAL POWER. AT 1136 HOURS, A MANUAL REACTOR SCRAM WAS INITIATED DUE TO MAIN TURBINE BVPASS VALVES OPENING. ONE SVPASS VALVE HAD OSCILLATED OPEN DURING THE NIGHT y, SEFORE, BUT AT 1126 HOURS, ALL NINE SVP455 VALVES HAD OPENED IN SEQUENCE. NRC NOTIFICATION WAS COMPLETED AT 1210 HOURS To COMPLY WITH 81 10CFR50.72(8)(2)(II). AN INVESTIGATION REVEALED THAT THE CAUSE FOR THIS EVENT WAS COMPONENT FAILURE. A CIRCUIT BOARD WITHIN THE COM81NED pq MAXIMUM FLOW LIMIT CIRCUIT HAD A DECREASING OUTPUT. THE BOARD LIMITS THE OPENING OF CONTROL VALVES, AND AS A RESULT OF THE DECREASING OUTPUT, CAUSED THE CONT 10L VALVES 70 CLOSE. THE SYPASS VALVES WERE

"' OPENING AS DESIGNED TO CONTROL REACTOR PRESSURE. THE CIRCUIT 804RO I

WAS REPLACED. THIS REPORT IS PROVIDED TO SATISFY 10 CPR 50.73(A)(7)(IV).

Ee 1

3. . FORM 62 LER SCSS DATA 0*.** *********.*********************************************04-18-91 ********

DOCKET YEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE 254 1989 004 0 8905240440 213953 04/17/89 a

485 TRACT 4

,, POWER LEVEL - 0102. ON APRIL 17, 1989, QUAD CITIES UNIT ONE WAS IN THE RUN MODE AT 10 PERCENT OF RATED CORE THERMAL POWER FOLLOWING A

' MAINTENANCE OUTAGE. AT 0330 HOURS, THE REACTOR WAS MANUALLY SCRAMMED DUE TO THE 1-203-30 ELECTROMATIC RELIEF VALVE SEING STUCK OPEN. THIS OCCURRED WHILE THE OPERATING DEPARTMENT WAS PERFORMING ROUTINE RELIEF t VALVE TESTING. AT 0331 HOURS, AN UNUSUAL EVENT WAS INITIATED. NRC NOTIFICATION WAS COMPLETED AT 0347 HOURS TO COMPLY WITH 10 CFR

, 50.72(4)(1)(I). 47 0753 HOURS, THE UNIT WAS IN COLD SHUYDOWN, AND THE

', UNUSUAL EVENT WAS TERMINATED. AN INVESTIGATION REVEALED THAT THE CAUSE FOR THIS EVENT WAS COMPONENT FAILURE. THE PILOT VALVE SHOWED SIGNS OF STE AM LEAK AGE AND THE DR AIN ORIFICE IN THE DISC RETAINER OF g THE MAIN VALVE WAS PLUGGED. THE ELECTROMATIC RELIEF VALVE AND THE PILOT VALVE WERE REPLACED. THE ELECTROMATIC RELIEF VALVES ARE TESTED EVERT SII MONTHS OR AFTER MAINTENANCE. THIS REPORT IS PROVIDED TO

, SATISFY 10 CFR 50.73(A)(2)(II) AND 10 CFR 50.73(A)(2)(IV).

FORM 63 LER SCSS DATA 04-1 I.

0***************************.+.****.**** .*. *** *************** 8-91..**

i DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE g- 254 1989 010 1 5909120444 215207 06/20/89

Lcv;L Uv.4 UN e/ li/ t s,

,v.c4 QUA3 CITIc5 UNIT ONE W45 IN THE RUN MODE AT 94% OF RATED CORE THERMAL POWER. AT 2239 HOURS, 4 REACTOR P4 S C R /.M OCCURRED DU2 TO TUR51NE STOP VALVE CLOSURE. THE STOP VALVE CLOSURE WAS THE RESULT OF A TUR8INE TRIP. ALL SAFETY FEATURE g4 ACTUATIONS OCCURRED AS DESIGNED. EMERGENCY NOTIFICATION SYSTEM (ENS)

NOTIFICATION W45 COMPLETED AT 2330 HOURS ON 6/29/89, TO COMPLY WITH b4 THE REQUIREMENTS OF 10 CFR 50.72(S)(2)(II). AN INVESTIG4 TION REVEALED THE CAUSE FOR THIS EVENT WAS 4 LOOSE CONNECTION ON THE 1-5600-PS-1058 CONDENSER LOW VACUUM PRESSURE SWITCH INDICATING LAMP. WHEN THE LENS t1 COVER FOR THE LAMP WAS PUT ON, THE LOOSE WIRE INDUCED A VOLTAGE IN THE K2018 RELAY AND ENERGIZED THE MASTER TRIP BUS. THIS RESULTED IN A g4 TURSINE TRIP.

59 FORM 64 LER SCSS DATA 0...........................................................04-18-91 ...,....

D4 00CKET YEAR LER NUMBER REVISION 005 NUMBER NSIC EVENT DATE 254 1990 004 0 9004180239 217734 03/10/90 ABSTRACT DQ POWER LEVEL - 095% ON MARCH 10, 1990, QU4D CITIES UNIT ONE W45 IN THE RUN MODE AT APPROXIM4TELY 98 PERCENT OF RATED CORE THERMAL POWER. AT g 0114 HOURS, a REACTOR SCRAM OCCURRED DUE TO A TURBINE-GENERATOR (TG)

LOAD MISMATCH. THE TURBINE-GENERATOR LO AO MISMATCH WAS THE RESULT OF A GENERATOR TRIP. ALL $4FETY FEATURE ACTUATION $ OCCURRED AS DESIGNED.

EMERGENCY NOTIFICATION SYSTEM (ENS) PHONE NOTIFICATION WAS COMPLETED AT 0209 HOURS ON MARCH 10, 1990, TO COMPLY WITH THE REQUIREMENTS OF 10 Pe CFR 50.72(8)(2)(11). AN INVESTIG4 TION R!vEALEO THE CAUSE FOR THIS EVENT WAS 4 FAILURE OF THE MEGATIVE SEQUENCE TIME OVERCURRENT REL AY.

,, WHEN 4 FAULT OCCURRED ON LINE 0402, THE RELAY ACTUATED RESULTING IN A

, GENERATOR TRIP. THE FAULT WAS MOST LIKELY 4 RESULT OF A LIGHTNING STRIKE. THE RELAY WAS REPAIRED. THIS REPORT IS SEING SUBMITTED IN l'

ACCORDANCE hITH 10 CFR 50.73 (4)(2)(IV).

1 te FORM 65 LER SCSS DATA 04-18-91

0**************************************.*.****...****** .*..*.*******

00CKEY YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 255 1989 004 0 8900000000 214312 02/28/99 i ..**.................**.............................................

485 TRACT POWER LEVEL - 000%. ON 2/29/89, AT 2135, WITH THE PL4NT IN THE HOT

' STAND 8Y CONDITION (PRIMARY COOLANT SYSTEM 47 532F AND 2060 PSIA) A REACTOR TRIP OCCURRED. THE INADVERTENT TRIP OCCURRED DURING THE PERFORMANCE OF TECH SPECS SURVEILLANCE PROCEDURE R0-21, " CONTROL ROD

' DRIVE SYSTEM INTERLOCKS". AS A RESULT OF THE EVENT, ALL CONTROL RODS (A47R00) WERE RESTARTED. ALL OTHER EQUIPMENT PERFORMED PROPERLY. AT

, THE TIME OF THE EVENT, PLANT OPERATORS WERE PREPARING TO VERIFY THAT A

, REACTOR PROTECTION SYSTEM HIGH RATE OF POWER CHANGE WOULO RESULT IN PROHIBITING CONTROL R00 WITHDRAWAL. DURING THIS PORTION OF THE TEST, ONE OF THE FOUR REACTOR PROTECTION SYSTEM C H ANN EL S IS BYPASSED AND OPERATORS $1MULATE A HIGH RATE OF POWER CHANGE SIGNAL ON THE WIDE RANGE INSTRUMENT ASSOCIATED WITH THE PDEVIOUSLY SYPASSED CHANNEL. A REACTOR TRIP WAS INITISTED WHEN OPERATORS NOT UTILIZING THE

,, APPROPRIATE WIDE RANGE INSTRUMENTATION CHANNEL CAUSED TWO ACTIVE REACTOR PROTECTION SYSTEM CHANNELS To RECOGNIZE THE SIMULATED SIGNAL.

' 4 CONTROL ROD W45 INSERTED AS DESIGNED. THIS EVENT HAS BEEN

, ATTRIBUTED TO 20-21 NOT PROVIDING SUFSICIENT GUID4NCE TO ASSIST OPERATORS IN DETERMINING THE CORRECT RELATIONSHIP SETWEEN ASSOCIATED 1

WIDE RANGE NUCLEAR INSTRUMENTATION AND REACTOR PROYECTION SYSTEM g+ CHANNELS.

.-...--...=*==*=5++=*********************=*******************

DOCKET TE AR LER N UC: E R REVISION DCS NUM3ER NSIC EVENT DATE

. Pq 255 1989 023 0 8909120376 21520S 09/04/89 eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeene h A85 TRACT POWER LEVEL - 0501. ON 8/4, at 1945, A REACTOR TRIP FROM 80% POWER b4 OCCURRED DUE TO A SLOWN FUSE (J8;FU) IN A FLOW INDICATING CONTROLLER j i, (SJJFIC) THAT CAUSED THE FEEDWATER REGULATING VALWE (5J;LCV) FOR THE 8 pq STEAM GENERATOR TO CLOSE, THERE8T DECREASING FEEDWATER FLOW TO THE STEAM GENERATOR AND RESULTING IN A REACTOR TRIP ON LOW STEAM GENERATOR LEVEL. THE PLANT RESPON5E TO THE TRIP WAS CONSIDERED NORMAL WITH N0 f"3 5AFETY SIGNIFICANT DEVIATIONS OR ANOMALIES OBSERVED. ON 8/5/S9 AT 5

0300, AN UNANTICIPATED START OF AUXILIARY FEE 0 WATER PUMP P-88 (8A;P) be i3 i

OCCURRED WHILE THE PLANT WAS IN THE HOT SHUTDOWN CONDITION. THE SPURIOUS SIGNAL WAS CAUSED ST A FAILURE ST THE OPERATORS TO RESET THE gg AF45 SIGNAL FOLLOWING THE REACTOR TRIP. CORRECTIVE ACTIONS TD BE TAKEN IN RESPONSE TO THESE INCIDENTS INCLUDE A REVIEW OF THE FUSE CONTROL b" PROGRAM AND A REV!5104 TO POST TRIP OPERATING PROCEDURES THAT WILL ADD INSTRUCTIONS TO THE OPERATORS FOR RESETTING ALARMS AND ACTIVATED ACTUATION SIGNALS.

>= 1 y, FORM 67 LER SC55 DATA 0************************************************************04-18-91 88 DOCKET TEAR LER NUMEER REV!510N DCS MUM 8ER MSIC EVENT DATE

, 255 1989 025 0 8912280118 216257 11/21/89 W1 A55 TRACT

,, POWER LEVEL - 000%. ON 11/21/89 AT 0225 POWER OPERATED RELIEF WAlvE I (PORV), PRV-10428 (A85RW) INSTANTANE0USLT OPENED FOLLOWING THE MANUAL OPENING OF ITS ASSOCIATED MOTOR OPERATED SLOCK VALVE (MOV), MD-10242 ke (A8;ISV). BOTH MOV AND PORV, ANO THE REDUNDANT VALVES MO-10434 AND PRV-10438, HAD RECENTLY BEEN REPLACEO DURING ONGOING MAINTENANCE y, OUTAGE. THE MOV WAS OPENED WITH THE REACTOR SU8 CRITICAL AND THE PRIMART COOLANT SYSTEM (PCS) AT 2154 PSIA TO PERMIT ASME SECTION XI

' LEAK TESTING OF THE WELDS MADE DURING VALVE INSTALLATION. APPROX. 24 SECS FOLLDWING THE OPENING OF THE PO R V, THE REACTOR AUTOMATICALLY I

TRIPPED 00E TO THE RECEIPT OF ALL 4 THERMAL MARGIN LOW PRESSURE (TMLP)

SIGNALS. APPROX. 3 MINS LATER A SAFETV INJECTION ACTUATION SIGNAL (SIAS) WAS RECEIVED WHEN PCS PRESSURE DROPPED TO THE SAFETY INJECTION

, SYSTEM ACTUATION PRESSURE OF 1605 PSIA. ALL SAFETT INJECTION EQUIPMENT THEN STARTED OR OTHERWISE PERFORMED ITS DESIGN FUNCTION.

BOTH DIESEL GENERATORS STARTED 04 LOW BUS VOLTAGE, SUT NO EQUIPMENT WAS AUTOMATICALLY LOADED ONTO THE DIES!L GENERATOR 5. WITH THE PCS AT 1565 P5IA THE PORY CLOSED AND THE MOV FULLY CLOSED. AN UNUSUAL EVENT

, WAS DECLARED DUE TO THE PORY OPENING AT 0256. THE PORV AND THE MOV WHICH OPENED WERE REMOVED FROM THE PLANT AND INSPECTED AND TESTED.

, THE VALVE OPERATING CHARACTERISTICS WERE DETERMINED, AND THE PLANT

, OPER ATOR5 TR AINED AND OPERATING PROCEDURES MODIFIED TO REFLECT THOSE CHARACTERISTICS.

1 FORM 68 LER SC55 DATA 04-18-91 0********************************************************************

, DOCKET TEAR LER MUMBER REVISION OCS MUMSER N5IC EVENT DATE 255 1990 001 0 9002230093 216882 01/09/90 A85 TRACT e

POWER LEVEL - 035%. 04 1/9/90 AT 0514 WITH POWER AT A STEA0V STATE OF g, 35 PERCENT, THE REACTOR WAS MANUALLY TRIPPED FOLLOWING THE LOSS CF ALL MAIN FEEDWATER FLOW. MAI4 FEEDWATER WAS L95T AT nSt> wwwM *a= ween 4

-% v - w , -,ws- -

--w-, ,, , , - , y

....4 ...ai. .u, neraag. In: PLA41 RE3PONSE TO THE TRIP WAS CONSICE RED f40RMAL WITH NO SAKETT SIGNIFICANT CEVIATIONS OR ANOMALIES yi OBSERVED. THE ROOT CAULE OF THE EVENT HAS NOT Y!T BEEN CONCLUSIVELV DETERMINED. TROUBLE 5H00 TING IS ONGOING. A SU7PLEMENTAL LICENSEC l

g, EVEET REP 02T WILL BE SU8MITTED PENDING THE RESULTS OF THE g: INVESTIGATION.

1 km

. ,,' FORM 69 LER SCSS DATA pq 0*** .*************************************** .......... **e.04-18-91........

DOCKET VEAR LER NUMBER REVISION DCS NUMBER N5IC EVENT DATE 255 1990 002 0 9004180204 217777 02/2S/90 L4 I he p' 485 TRACT POWER LEVEL - 0803. AY 1526 HOURS ON FEBRUARY 28, 1990, PALISADES be EXPERIENCED AN UNANTtCIPATED TRIP OF THE "B" MAIN FEE 0 WATER PUMP

, (MFP). DURING RECot?RY e40M THE PUMP TRIP, A REACTOR TRIP WAS bu INITI ATED S~/ AN AUT0kaf1C ACTUATION OF THE REACTOR PROTECTION SYSTEM (RP5). PRIOR TO THE FEEDWATER PUMP TRIP THE REACTOR HAD BEEN g, OPERATING AT 80 PERCENT POWER, WITH BOTH FEEDWATER PUMP 5 OPERATING AND

>= THE PRIMARY COOLANT SYSTEM (PCS) AT 556 OEGREES F AND 2060 PSIA.

WHEN THE REACTOR TRIP OCCURRES, THE PLANT WAS OPERATING AT 55 PERCENT p, REACTOR POWER. THE INITATING EVENT FOR THE REACTOR TRIP WAS C00LDOWN OF THE PCS OURING RECOVERY FROM LOSS OF A MAIN FEE 0 WATER PUMP. THE D8 REACTOR TRIP WAS NOT CAUSED ST PERSONNEL ERROR. HOWEVER, OPERATOR ACTIONS WHICH COULD HAVE BEEN TAKEN TO CONTROL THE EFFECTS OF THE COOLDOWN TRANSIENT AND PREVENT THE REACTOR TRIP WERE IMPAIRED BY A D1 MOMENTARY LOSS OF AUDISLE ANNUNCIATOR SYSTEM AND A MALFUNCTION OF THE AUTOMATIC START FEATURE FOR CHARGING PUMP "C". THE CAUSE OF THE MFP

TRIP REMAINS INDETERMINATE. INVESTIGATION OF THE FEE 0 WATER PUMP TRIP

' REMAIN 5 IN PROGRESS. TEMPOR ARY MONITORS HAVE BEEN INSTALLED 04 THE to gp MFPS IN ORDER TO PROVIDE ADDITIONAL INFORMATION SHOULO THERE BE ANY FURTHER MFP A840RMALITIES OR TRIPS. LICENSED OPERATORS WILL RECEIVE TRAINING ON THE CIRCUM 5TANCES SURROUNDING THE REACTOR TRIP.

re i 1 FORM 70 LER SC55 DATA 04-18-91 I*

.; 0********************************************************************

DOCKET VEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE o 261 1989 004 1 8906120260 214256 02/27/89

, e.....e.............................................................

ABSTRACT l , POWER LEVEL - 0303. ON 2/27/89, AT 1617 HOUR $, UNIT 2 RECEIVED A

~'*

SAFETT INJ!CTION SIGNAL AND, SUSQUENTLY, AN AUTOMATIC REACTOR TRIP l

FROM 30X POWER WHEN THE TURBINE EXPERIENCED MOMENTARY LOSS OF LOAD.

,i AT THE TIME, MAINTENANCE PERSONNEL WERE INVESTIGATING A POWER SUPPLY TROUSLE ALARM IN THE TURBINE CONTROL SYSTEM WHEN A TECHNICIAN

, INADVERTENTLY CAUSED A 5HORT CIRCUIT, CAU5ING THE GOVERNOR VALVES TO

, CLOSE. THE STEAM DUMP SYSTEM RESPONDED. WHEN THE ELECTRICAL SHORT WAS CORRECTED, THE GOVERNOR VALVES REOPENED, RESULTING IN HIGH STEAM FLOW, BUT THE STEAM-DUMP VALVES HAD NOT MODULATED CLOSED AND A SAFETY

,, INJECTION SIGNAL WA$ INITIATED 04 HIGH STEAM FLOW WITH LOW STEAM LINE PRES 5URE/ LOW AVERAGE REACTOR COOLANT TEMPERATURE. THE TECHNICIAN WHO CAUSED THE SHORT FOUND THAT THE MULTIMETER BEING USED WRONGLY

, CONFIGURED TO MEASURE AMPERAGE VERSUS VOLTAGE. THIS HAD APPARENTLT l CREATED THE SHORT IN THE TUR8INE DC POWER SUPPLY. THE LICENSEE DECLARED AN UNUSUAL EVENT AT 1618 HOURS, THEN TERMINATED THE EVENT AT

g. 1651 HOURS, AND UNIT 2 WAS RETURNED TO POWER OPERATIONS ON 2/2S/89.

THE CAUSE OF THE EVENT HAS SEEN ATTRIBUTED TO INATTENTIVENESS SY THE e

MAINTENANCE TECHNICIAN TO THE CONFIGURATION OF THE MULTIMETER. PLANT g SAFETY WA5 MAINTAINED THROUGHOUT THE EVENT. THE PROBLEM OF IMPROPER

, STEAM DUMP MODULATION WAS THE RESULT OF THE SatunATTng na tur ("reu m , . -- . - , .

-_.- - -,, . . - .- . .. _ . - . ~ . , ,

FORN 71 LYR SCSS DATA p3 Le***********************************************************04-18-91 ********

DOCKET TEAR LER NUMSER REVISION- DCS HUMBER NSIC EVENT DATE h4 261 1989 005 0 8904260179 213719 03/22/

,: ******************************************************************89 **

kW A85 TRACT POWER LEVEL - 100%. ON MARCH 22, 1989, WITH UNIT NO. 2 OPERATING AT eq ONE HUNDRED PERCENT (X) POWER, A REACTOR TRIP OCCURRED OUE TO THE INADVERTENT CLOSURE OF A MAIN STEAM ISOLATION VALVE (MSIV), WHICH ISOLATED FLOW FROM "A" $ TEAM GENERATOR. ALL PLANT SYSTEMS PERFORMED A5 DESIGNED THROUGHOUT THE EVENT, AND THE PLANT WAS STABILIIED USING b8 EMERGENCY OPERATING PROCEDURES. THE NRC OPERATIONS CENTER WAS 4; '

NOTIFIED OF THE EVENT IN ACCOR3ANCE WITH 10CFR50.72 At 0256 HOURS VIA THE E45. THE EVENT IS ATTRI8UTED TO PERSONNEL ERROR 04 THE PART OF t

Do THE LICENSED CONTROL OPERATOR WHO MANIPULATED THE INCORRECT SWITCH DURING THE. PERFORMANCE OF A SURVEILLANCE TEST. THE CONTROL OPERATOR l

' U" HAS SEEN DI5CIPLINE0 FOR INATTENTION TO DETAIL. ADDITIONALLY, THE HUMAN FACTORS ASPECTS ASSOCIATED WITH THE EVENT ARE 8EING REVIEWEO.

,. THIS LER IS SUSMITTED PURSUANT TO 10CFR50.73(4)(2)(IV).

y, gi FORM 72 LER SC55 DATA 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION OCS MUM 8ER M5IC EVENT DATE

, 261 1989 006 0 8905100285 213808 03/30/89 D -s g, 485 TRACT g, POWER LEVEL - 100%. ON MARCH 30, 1999, At 0320 HOURS, THE UNIT

ERPERIENCED A REACTOR TRIP FROM 100% POWER. THE REACTOR TRIP SIGNAL WAS INITIATED ET A TUR8INE TRIP, WHICH RESULTED FROM THE LOSS OF SOTH b'

THE MAIN AND BACKUP +15 WOLT TUR5INE ELECTRO-HTORAULIC (E*H) CONTROL POWER SUPPLIES. LOSS OF SOTH THE MAIN AND 8ACKUP POWER SUPPLIES te INITIATES AN AUTOMATIC TURSINE TRIP, WHICH IN TURN WILL INITIATE A REACTOR TRIP WHEN THE UNIT 15 ABOVE 10% POWER. AT 0400 HOURS, THE

LICENSEE MADE NOTIFICATION TO THE NRC OF THE REACTOR TRIP PURSUANT TO 10CFR50.79(8)(2)(II) VIA THE EMERGENCY NOTIFICATION SYSTEM.

e 5USSEQUENT INVESTIGATION AND TROUSLE5H00 TING ICENTIFIED SLOWN FUSES IN BOTH THE MAIN AND SACEUP POWER SUPPLIES AND FIVE DEFECTIVE OR SUSPECT POWER SUPPLT REGULATING TRANSISTOR $. THE POWER SUPPLY FUSES AND

,, TRANSISTORS WERE REPLACEO. ALSO, ADJUSTMENTS WERE MADE TO OVERVOLTAGE PROTECTIVE CIRCUITRY SETTING 5. SUBSEQUENT POST- MAINTENANCE TESTING

' SHOWED ALL EQUIPMENT TO BE OPERATING PROPERLY. THIS LICENSEE EVENT REPORT 15 SU6MITTED PURSUANT TO THE REQUIREMENT OF 10CFR50.73(A)(2)(IV).

1

, FORM ~73 LER SCSS DATA 04-18-91 0********************************************************************

! ' DOCKET TEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE 261 1990 002 0 9002220126 216584 01/17/90 485 TRACT

, POWER LEVEL - 100I. 04 JANUARY 17, 1990, AT 2026 HOURS, A REACTOR PROYECTION SYSTEM (RPS) ACTUATION OCCURRED WITH THE UNIT AT 100%

POWER. TME REACTOR TRIP GCCURRED OURING PERFORMANCE OF A ROUTINE

, OPERATIONS SURVEILLANCE TEST ON THE POWER RANGE NUCLE AR INSTRUMENT ATION CHANNELS. THE OPERATOR PERFORMING THIS TEST HAD INADVERTENTLY PLACEO THE BI5TA5LES FOR TWO INDEPENOENT CMANNELS OF THE g; OVERTEMPERATURE DIFFERENTIAL TEMPERATURE (OT DELTA T3 REACTOR TRIP FEATURE INTO THE TRIPPE0 POSITION, C098L* TING TwF

F MIT *

a 'neTe **

. . . . . . . . . . r o.... or to= et>I PaulkCURE. THE OPERATOR HAS SEEN pq COUN5ELED REGARDING PROCEDURE SCHERENCE AND 4TTENTION TO DETAIL. IN ADDITION, THE MANAGER - OPERATICNS HAS COMMUNICATED TO OPERATION $

PERSONNEL THE IMPORTANCE OF PROMPTLY IDECTIFYING AND CORRECTING b4 SITUATIO%S EHICH MIGHT LATER RESULT IN 4 PER5CNNEL ERROR OR INJURT.

q AL50, A REVIEW WILL BE PERFORMED TO ESTABLISH AND DOCUMENT THE ASPECTS 0F HUMAN FACTORS, PROCEDURE FORMAT, AND WORE PRACTICES WHICH M4Y HAVE WW CONTRIBUTED TO THE OCCURRENCE OF THIS EVENT. THE NRC WAS NOTIFIE0 0F e gi THIS EVENT PUR$UANT TO 10CFR50.72(8)(2)(II) A1 2105 HOURS VIA THE r3 EMERGENCY NOTIFICATION SYSTEM. THIS LICENSEE EVENT REPORT IS SU8MITTED PUR5UANT TO 10CFR50.73( A)(2)(IV).

1 g4 i' FORM 74 LER SCSS DATA h4 .; 0************************************************************04-18-91 ********

00CEET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE be 261 1990 007 0 9006250332 218697 05#17/9

, *******************************************************************0*

U" A85 TRACT

+

POWER LEVEL - 100%. ON MAY 17, 1990, AT 0606 HOUR $. AN AUTOMATIC bM REACTOR TRIP WAS RECEIVED FROM A STEAM FLOW-FEEDW4TER FLOW MISMATCH COINCIDENT WITH A LOW LEVEL IN STEAM GENERATOR (5G) "8". THE CAUSE OF I g, THE EVENT WAS AN EQUIPMENT FAILURE IN THAT THE SG "B" FEEDWATER REGULATING VALVE (FRV) MALFUNCTIONED IN A MANNER WHICH IMPECED FLOW TO SG "8". DISASSEMBLY AND INSPECTION REVEALED THAT A SPRING PIN HAD I'

$HE ARED WHICH ALLOWED THE VALVE PLUG TO UNTHREAD FROM THE VALVE STEM.

A POS$18LE CONT 5:ISUTING FACTOR WAS A PROCEDURAL DEFICIENCY IN THAT p1 THE VENDOR RECCMMENDEO STEM-TO-PLUG TORQUE REQUIREMENT W45 NOT PROVIDE 0 WITF4N THE FRV CORRECTIVE MAINTENANCE PROCEDURE. THE STEM

,, AND Pl%5 WF2E TORQUED TO THE REQUIRED VALUE AND A NEW STEM AND LONGER SPRING PIM WERE INSTALLED. THE FRVS FOR SGS "A" ANO "C" WERE ALSO DISA5SEMBLED AND INSPECTED, WITH PRECAUTIONARY REPLACEMENT OF BOTH b9 SPRING PINS, AND REPLACEMENT OF THE VALVE STEM FOR THE $G "C" FRV. A PROCEDURE REVISION HAS BEEN MADE TO INCORPORATE THE RECOMMENDED TOROUE

. -VALUE. THIS EVENT WAS REPORTED VIA THE EMERGENCY NOTIFICATION SYSTEM AT 0717 HOUas PURSUANT TO 10CFR50.72 (8)(2)(II). THIS LICENSEE EVENT

, REPORT IS SUBMITTED PUR$UANT TO 10CFR50.73 (A)(2)(IV).

I FORM 75 LER SCSS DATA 04-18-91 0********************************************************************

g. DOCKET TEAR LER NUMBER REVISION DC$ NUMBER NSIC EVENT DATE 263 1989 009 0 8907260021 214810 06/19/89 I +

ABSTRACT I POWER LEVEL - 0592. 00 RING THE SHUTDOWN OF A REACTOR FEED PUMP (RFP), i THE DISCHARGE CHECE VALVE, FW 67-2, FAILED TO SEAT. THIS PROVIDED A

, RECIRCULATION PATH FOR THE 0*ERATING RFP AND CAUSED REACTOR WATER LEVEL TO DECREASE TO THE SCRAM SET POINT. REACTOR WATER LEVEL WAS RESTORED WITH THE OPERATING RFP AND NORM 4L PROCEDURES WERE USED TO

' RECOVER FROM THE SCRAM. EXCESSIVE COMPONENT WEAR WHICH WOULO ALLOW

. THE TOP OF THE VALVE DISC TO WEDGE UNDER THE LIP OF THE SEATING

+

SURFACE IS PRESUMED TO BE THE FAILURE MODE. IF EXCESSIVE CLEARANCES MAD SEEN RECOGNIIED DURING A 1987 INSPECTION OF FW 67-2, REPAIRS COULD

, HAVE PREVENTED THIS EVENT. THE ROOT CAUSE OF THIS EVENT WAS INADEOUATE ACCEPTANCE CRITERIA FOR WALVE INSPECTION. CHECE VALVE

' PARTS WERE REPLACEO OR dESUILT. OTHER SIMILAR VALVES WERE TESTED.

,. THE RFP Shui 00WN PROCEDURE W AS CMANGED TO INCLUDE CLOSING THE RFP OISCHARGE VALV! TO HELP ASSURE NO SACK FLOW THROUGH THE PUMP. FUTURE =

t ACTIONS INCLUDE DEVELOPING ACCEPTANCE CRITERIA FOR CHECE VALVE g INSPECTIONS, MINIMIZING OPERATION AT CRITICAL SYSTEM FLOW RATES, AND

. INVESTIG4 TING 4 CHECK VALVE MODIPICATION.

. . . ==

.. .. Leu st>> UAIA 04-19-91 0********e *e....... .......e*e..eeeeeeeeeeeeeeeee ......ee.. ........

P1 DOCKET TEAR LER HUMBER REVISION OCS NUMBER NSIC EVENT DATE 263 1959 038 0 8912200016 216160 kW ************************************************************11/15/89 ********

U ABSTRACT bd POWER LEVEL - 1001. A REACTOR SCRAM OCCURRED FROM 1003 POWER. CHANNEL l i "A" 0F THE REACTOR PRESSURE SYSTEM WAS TRIPPED FOR ROUTINE pq $URVEILLANCE. A SPURIOUS, MOMENTARY HIGH REACTOR PRESSURE SIGNAL TRIPPED CHANNEL "B" 0F THE REACTOR PROTECTION SYSTEM. ALL TESTING g4 i3 VERIFIED THE CALIBRATION AND OPERASILITY OF THE PRES 5URE SWITCH.

COMPUTER EVENT LOG 5 INDICATED A MOMENTARY TRIP SIGNAL WITH

' CHARACTERISTICS RESEM8 LING A SUM 8 TO THE SWITCH. ALTHOUGH NO h4 g, INDIVIDUAL COULD SE LOCATED WHO WAS AWARE OF HAVING BUMPED THE SWITCH, THIS REMAINS THE PROBABLE CAUSE OF THIS EVENT. THE SWITCH WAS bg REPLACED IN KIND. SENCH TESTING OF THE REMOVED SWITCH VERIFIED PROPER OPERATION. THIS EVENT WILL SE ADDED TO GENERAL EMPLOTEE TRAINING TO

' U" RAISE AWARENESS OF THE CONSEQUENCES OF BUMPING PLANT INSTRUMENT 5.

TECHNICAL $PECIFICATION CHANGES WILL SE PURSUED TO REDUCE THE TOTAL

' bg TIME HALF SCRAM 5 ARE REQUIRED DURING MAINTENANCE AND TESTING. THE CLARITY AND VISIBILITY OF Po$TED WARNINGS TO PLANT PERSONNEL IN THE AREA 0F THESE $ WITCHES WILL BE IMPROVED. '

I

>t ;

FORM 77 LER SCS$ DATA R4 0*********************************************************e**04-18-91 ********

)

DOCKET VEAR LER NUMBER REVISION DC5 NUMBER NSIC EVENT DATE D1 263 1990 017 0 9012050132 220120 10/29/90 f' ,

ABSTRACT POWER LEVEL - 1003. A REACTOR SCRAM OCCURRED FROM 100% POWER DUE TO A ke SPURIOUS RE ACTOR HIGH PRES $URE SIGN AL WHICH ACTIVATED 80TH CHANNELS OF THE REACTOR PROTECTION SYSTEM HIGH PRES 5URE SCRAM LOGIC. SUBSEQUENT

! te INVESTIGATION REVEALED THAT WORKERS HAD SEEN MOVING SCAFFOLDING IN THE IMMEDIATE AREA 0F THE A SAFEGUARDS SENSING LINE WHICH IS COMMON TO

THE ACTIVATED SWITCHE5. FOLLOW-UP TESTING DEMONSTRATED THAT A REL AT IVELY SMALL EXTERNAL IMPACT ON THE SENSING LINE AT THE WORK I

LOCATION CREATES A HTORAULIC SHOCK IN THE SENSING LINE SUFFICIENT TO TRIP THE PRES $URE SWITCHES. THE CAUSE OF THIS EVENT WA$ FAILURE TO RECOGNIZE AND IDENTIFT THE SEN5ITIVITY OF THE SENSING LINE TO SUMPING.

, ,. WORK IN THE AREA OF BOTH A AND 8 SENSING LINES WAS RESTRICTED ST PLACING $IGN$ CN THE SENSING LINE AND INSTALLING PHYSICAL BARRIERS.

'* SCAFFOLDING AND OTHER EQUIPMENT WAS REMOVED FROM THE SENSING LINE AREAS PRIOR TO STARTUP. PAINTING IN THE AREAS WAS POSTPONED UNTIL THE NERT SCHEDULED REFUELING OUTAGE AND PAINTING AND SCAFFOLDING t PROCEDURES WERE REVISED TO IDENTIFY SENSITIVE INSTRUMENT LINES.

1 e

FORM F8 LER SC55 DATA 04-18-91 One**** ****************************************************=*******e DOCKET TEAR LER NUMBER REVISION OCS MUMSER N5IC EVENT DATE 265 1989 001 0 8905150206 213953 04/06/89 i eeeeeeeeeeeee*... *e.. ** ..........***** ........e*****ee ***ee ...

,; A85 TRACT POWER LEVEL - 0501. ON APRIL 6, 1989, QUAD CITIES UNIT TWO WAS IN THE I

RUN MODE AT 80 PERCENT OF RATED CORE THERMAL POWER. AT 0332 hours0.00384 days 0.0922 hours 5.489418e-4 weeks 1.26326e-4 months , A

, REACTOR SCRAM OCCURRED DUE TO A TUR8INE STOP VALVE CLOSURE. THIS OCCURREO WHILE THE OPERATING DEPARTMENT WAS PERFORMING WEEKLY t

TUR8INE/ GENERATOR TESTING. NRC NOTIFICATION WAS COMPLETED AT 0404 g- HOUR $ TO COMPLY WITH 10 CFR 50.72. AN INVESTIGATION REVEALED THAT THE CAUSE FOR THIS EVENT WAS COMPONENT FAILURE.. THE PILOT snt sworn was we

suessNutu 10 $g0w IHE PILOT 50LEN01C VALVE ENERGIZED. THUS, kHEN THE i

S MASTER TRIP SOLEN 010 WAS TESTED, a TUR31NE TRIP OCCURRED. THE 31 FAILED 50LEN31D WAS PEBUILT AND THE C0!L AND LIMIT SWITCH WERE REPLACEO. THE PILOT SOLENOIDS ARE TESTED WEERLT. THIS REPORT IS gq PRCVIDED TO SATISFT 10 CFR 50.73(A)(2)(IV).

h4 FORM 79 LER SCSS DATA e p 0*************************************************e *********04-18-91 e1 DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 265 1989 005 0 8911150265 215835 10/12/89 i

4 ;; ******e*****************************e **=***************************

ABSTRACT r b4 -' POWER LEVEL - 0553. ON 10/12/99, QUAD CITIES UNIT 2 WAS IN THE RUN MODE AT 55% OF RATED CORE THERMAL POWER. AT 0140 HOURS, A REACTOR go (RCT) SCRAM (JC) OCCURRED OUE TO TUR8INE (TRB) STOP VALVE ($HV)

- CLOSURE. THIS OCCURRED WHEN THE STATION'S ELECTRICAL MAINTENANCE he DEPARTMENT WAS REMOVING A LIMIT SWITCH (ZIS) FROM THE NUMSER TWO MAIN

, STOP VALVE (SHV)(MSV). NRC NOTIFICATION WAS COMPLETED AT 0227 HOURS y TO COMPLY WITH 10CFR50.72(8)(2)(II). AN INVESTIGATION REVEALED THAT be THE CAUSE FOR THIS EVENT WAS PERSONNEL ERROR. THE WORK ANALYST, WHILE DEVELOPING THE ELECTRICAL WORK PACKAGES, OVERLOOKED THE REMOVAL OF y, q, TWO CONNECTIONS (C04) ON THE MSV LIMIT SWITCH. THIS CAUSED THE NUMBER 1, 3, AND 4 TURBINE MAIN STOP VALVES TO CLOSE AND SUBSEQUENTLY THE REACTOR SCRAM. THE MAINTENANCE WORKERS WERE IMMEDIATELY COUNSELED.

E' g, FURTHER CORRECTIVE ACTIONS WILL INVOLVE TRAINING, A PROCEDURE REVISION, ISSUANCE OF AN OPERATING MEMO, AND A TRAINING LESSON PLAN Pe REVI510N. THIS REPORT IS PROVIDED TO SATISFY 10CFR50.73(A)(2)(IV).

p 1 FORM 80 LER SCSS DATA 04-18-91 i

,, ae.** ****e *****e *******.. ****e ********ee..........ee.***********

n' DOCKET TEAR LER NUMSER REVISION DCS NUM5ER NSIC EVENT DATE 265 1990 010 0 9011260172 220019 10/15190

g. 3, .***een ***** e**eeeeeeeeeee**ene*** ..e*******eeeee***eneee*e ee***

A85 TRACT

, POWER LEVEL - 1003. 04 10/15#90, OUAD CITIES UNIT 2 WAS IN THE RUN MODE AT 100 PERCENT OF RATED CORE THERMAL POWER. AT 1210 HOURS, A I

REACTOR SCRAM OCCURRED DUE TO TURSINE STOP VALVE CLO5URE. THE TURBINE

,;. STOP VALVE CLOSURE WAS A RESULT OF A TURSINE TRIP CAUSED BY MOISTURE

,, SEPARATOR HIGH LEVEL. ALL SAFETY FEATURE ACTUATIONS OCCURREO AS DESIGNED. EMERGENCY NOTIFICATION SYSTEM (EN5) NOTIFICATION WAS COMPLETED AT 1530 HOURS ON 10/15#90, 70 COMPLY WITH THE REQUIREMENTS I 0F 10CFR50.72(S)(2)(III. AN INVESTIGATION REVEALED THE CAUSE OF THIS EVENT WA5 DUE TO A PARTIALLY 8 LOCKED ORAIN LINE ON THE 2C MOISTURE SEPARATOR LEVEL SWITCH. SECAUSE WATER WAS NOT ORAINING PROPERLY FROM THE LEVEL SWITCH CHAMBER, THE LEVEL IN THE CHAMBER INCREASED TO THE

, HIGH LEVEL 5ETPOINT. THIS RESULTED IN A TURBINE TRIP.

, 1 FORM 81 LER SCSS DATA 04-18-91 0*****e*****e****************e****+**********************************

DOCKET TEAR LER NUM8ER REVISION DCS NUMSER N5IC EVENT DATE 265 1990 011 0 9012060175 221047 10/27/90

, .............. e*........e*****ee.******** *eaeeeee**e..**eeeeee****

A85 TRACT

, POWER LEVEL - 000%. 04 10/27/90 AT 1559 HOURS, UNIT TWO REACTOR SCRAMMED FROM INTERMEDIATE RANGE MONITORS (IRM) 13 AND 16 HIGH-HIGH e

SIGNALS. THE STATION WAS IN THE PROCESS OF RETURNING TO NORMAL g OPERATION FOLLOWING THE DISCONTINUATION OF A TURSINE TOR 5IONAL TEST.

, WHILE REDUCING REACTOR PRE 55URE TO RETURN THE TU89fM8

....e r as ,2wsc aus-c42:0 d:LGd :U) 05IG, THE N5O 3EGAN WITH3RAWING CONTROL R035 TO INCREASE REACTOR PRESSURE. THE 900 WITHDRAWALS P4 RESULTED IN A SHORT PERIOD AN3 THE IRM SCRAM. THE PRIM ART CAUSE OF TFE EVENT WAS PER50%NEL ERROR. CONTRISUTING CAUSES WERE INEFFECTIVE g4 COMMUNICATIONS AND MANAGEMENT OVERSIGHT, INSUFFICIENT TRAINING, AND 4

THE ON-SITE REVIEW PROCESS. CORRECTIVE ACTIONS COMPLETED INCLUDED:

AN IN-DEPTH DISCUSSION OF THE EVENT, ADDITIONAL MANAGEMENT OVERSIGHT, b4 REMEDIAL TRAINING, AND AN INDEPENDENT IN-DEPTH INVESTIGATION OF THE i

3; EVENT. FURTHER CORRECTIVE ACTIONS WILL INCLUDE: TRAINING ON THIS t1 EVENT DURING LICENSE REQUALIFICATION, PROCEDURE ENHANCEMENT, PERSONNEL COUNSELING, ASSESSMENT OF REACTIVITY MANAGEMENT TRAINING, Ld 'i: COMMUNICATIONS ENHANCEMENT, PROCEDURALIZED T*tRN-0VER CHECKLISTS, AND A COMMITTEE TO ADDRESS PROCEDURE ADHERENCE. THIS REPORT IS BEING SU8MITTED IN ACCORDANCE WITH 10CFR 50.73(A)(2)(IV).

D4 is 1 D0 FORM 82 LER SCS$ DATA 04-18-91 0********************************************************.....*......

D' DOCKET TEAR LER NUM8ER REVISIOM OCS NUMBER NSIC EVENT DATE 269 1989 001 0 8902070173 212926 01/02/89 e....... ***................................................ee......

>N A85 TRACT p, e POWER LEVEL - 100%. ON JANUARY 2, 1989, AT 1523 HOURS, UNIT 1 EXPERIENCED A REACTOR TRIP FROM 100% FULL POWER. INVESTIGATION p4 REVEALED THAT THE CAUSE OF THE TRIP WAS PERSONNEL ERROR DUE TO THE TRIPPING OF TWO REACTOR PROTECTIVE SYSTEM (RPS) CHANNELS DURING THE PERFORMANCE OF A RPS CALIBRATION PROCEDURE. A CONTRIBUTING CAUSE TO p4 THE EVENT WAS PROCEDURAL INCOMPLETENESS. AT THE TIME OF THE TRIP, SEVERAL INTEGRATED CONTROL SYSTEM (ICS) STATIONS, INCLUDING THE

,, FEEDWATER MASTERS, WERE IN MANUAL CONTROL. THIS CONDITION CONTRI8UTED TO AN OVERFEED SITUATION IN THE STEAM GENERATORS CAUSING A TRIP OF THE MAIN FEE 0 WATER PUMPS. HOWEVER, NO OVERC00 LING CONDITION WAS A' EXPERIENCE 0 FROM THIS OVERFEED OUE TO THE HIGH DECAT HEAT LOAD. THE IMMEDIATE CORRECTIVE ACTION WAS 10 STABILIZE THE UNIT AT HOT SHUTDOWN te CONDITIONS. OTHER SIGNIFICANT CORRECTIVE ACTIONS INCLUDED: THE REPLACEMENT OF FAILED COMPONENTS IN THE ICS 8TU LIMIT AND EMERGENCY FEEDWATER CIRCUITRT, THE COUNSELING OF CONTROL ROOM OPERATORS INVOLVED IN THE INCIDENT AND THE COUNSELING AND ADMINISTERING OF DISCIPLINART ACTIONS TO IEE TECHNICIANS INVOLVED IN THE INCIDENT.

e 1

, FORM 83 LER SCSS DATA 04-18-91 0 ..............****......... * ** ..**.....*......*** ..............

DOCKET TEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE

' 269 1989 002 0 8902140434 212987 01/03/99 t

A85 TRACT

, POWER LEVEL - 026%. ON 1/3/S9 WITH UNIT 1 AT 26% POWER DURING POWER ESCALATION AFTER A PREVIOUS TRIP A FIRE OCCURRE3 IN 174 SWITCHGEAR.

THE SWITCHGEAR FIRE RESULTED IN THE TRIPPING OF 2 REACTOR COOLANT PUMPS (RCP) FED FROM THE ITA SWITCHGEAR. AN UMU5UAL EVENT WAS DECLARED. THE REACTOR WAS MANUALLT TRIPPED AND THE 2 REMAINING RCP5 WERE SECURED IN PREPARATION FOR USING WATER TO EXTINGUISH THE SWITCHGEAR FIRE. C00LDOWN RATES SPECISIED ST TECH SPECS WERE VIOLATED

, A5 A RESULT OF OVERFEEDING THE SGS WHILE MITIGATING A RCS PRESSURE INCREASE. AFTER THE FIRE WAS DISTINGUI5HED THE RCS WAS NOT OPERATED WITHIN THE THERMAL 5HOCE OPERATING REGION (TSOR). THE ROOT CAUSE OF

, THE SWITCHGEAR FIRE WAS EQUIPMENT FAILURE OF UNKNOWN CAUSE. THE ROOT CAUSE OF THE VESSEL OVERCOOLING WA$ PERSONNEL ERROR. THE ROOT CAUSE t OF THE RCS NOT BEING OPERATED IN THE TSOR REGION FOR THE REQUIRED TIME g PERIOD IS MANAGEMENT DEFICIENCY. THE 403T CAUSE OF THE T5 VIOLATION

. FOR EXCEEDING THE TEMPER ATURE DI5FERENTIAL EFTWErw THE ***ttnoT'**

. . . , . , v. o . e t a . .. , ont asuk utul)N AND WHEM IT W A5 NECE 55 ART TO 90

50. IN 4001TIONo AN ANALT515 0F THE PRE 55URIZER SPRAT N0ZZLES STEAM Pt GENERATOR ANO THE REACTOR VESSEL WAS PER*0R920.

1 FORM 84 LER 5C55 DATA

4 0************************************************************04-18-91 ********

00CKET VEAR LER NUMBER REVISION OCS NUMBER N51C EVENT DATE

. . 269 1989 013 0 8909150357 215241 08/10/89 pq *********************.******************************.***************

ABSTRACT POWER LEVEL - 040%. ON 8/10/89, AT 1541 HOURS, UNIT 1 TRIPPE0 DUE To AN INADVERTENTLY INDUCED REACTOR PROTECTIVE SYSTEM (RPS) ACTUATION.

>$ AT THE TIME OF THE TRIP, UNIT 1 WAS AT 40% FULL POWER DUE TO A PREVIOUS POWER REDUCTION TO ADD OIL TO THE 142 REACTOR COOLANT PUMP Qq MOTOR. OURING THIS REDUCED POWER OPERATION WITH THREE PUMPS, THE STEADT STATE QUADRANT POWER TILT LIMIT WAS EXCEEDED IN ONE CORE QUADRANT. AS REQUIRED BY TECH SPEC 5, ACTIONS WERE INITIATED TO 80TH h"

REQUCE YME QUADRANT POWER TILT WITHIN LIMITS AND TO REDUCE THE b4 OVERPOWER TRIP SETPOINTS BASED ON FLUX AND FLUX / FLOW / IMBALANCE. WHILE PERFORMING THE PROCEDURE TO LOWER THE OVERPOWER TRIP SETPOINTS, AN INSTRUMENTATION AND ELECTRICAL TECHNICIAN INCORRECTLY POSITIONED A p, .

FLOW TEST CIRCU~T SELECTOR SWITCH. SINCE ANOTHER RPS CHANNEL WAS TRIPPED PER PRGCEDURE, A REACTOR TRIP WAS INITIATED WHEN THE CHANNEL I' WAS RETURNED TO SERVICE WITH THE INCORRECTLY POSITIONED SWITCH. THE ROOT CAUSE OF THIS EVENT IS CLASSIFIED A5 INAPPROPRIATE ACTION, FAILURE TO FOLLOW PROCEDURE. THE IMMEDI ATE CORRECTIVE ACTION WAS TG D1 STABILIZE THE UNIT AT HOT SHUT 00WN CONDITIONS.

1 FORM 85 LER SC55 DATA 04-19-91 0**** ***.*****************..**.********....***....**.**.************

Ae DOCKET YEAR LER NUMSER REVISION DC5 NUMBER N5IC EVENT DATE 269 1990 006 0 9005300009 218385 04/26/90 ae ********************************************************************

4857RACT POWER LEVEL - 000%. ON 4/26/90, UNIT 1 W AS SUSC RITIC AL AND PREP ARING FOR A REFUELING OUTAGE WITH ALL CONTROL R005 IN EXCEPT OROUP 1 WA5 50%

b WITHDRAWN. AT 1932 HOURS, WHEN A SECOND REACTOR COOLANT PUMP (RCP)

WAS SECURED AN UNANTICIPATED REACTOR PROTECTIVE SYSTEM (RPS) TRIP e CCCURRED. THIS WAS THE FIRST SHUT 00WN FOLLOWING IMPLEMENTATION OF A TECH SPEC REVISION WHICH REQUIRES A REACTOR TRIP IF ONLY TWO RCPS ARE I* RUNNING WITH A R E A CT OR POWER LEVEL ASOVE 0.0% FULL POWER. OEFICIENT COMMUNICATIONS AND INCORRECT ASSUMPTIONS BETWEEN THE RESPONSISLE GROUPS ALLOWED KEY TECHNICAL A' 'ECTS TH AT AFFECT PLANT OPERATION TO G0 t THROUGH THE REVIEW PROCESS * . *TED. THE ROOT CAUSE OF THIS EVENT W AS M AN AGEMENT DE FICIF- ;JATE REVIEW OP REVISED T5.

, CORRECTIVE ACTION WIr .FQ St '.HANGE TO THE T5 TO MOVE THE RP5 SETPOINT.

1 e

' FORM SA L(- J' .fA 04-18-91 i

0*******e . , <. ve... *****,** 3*********....*e..*...***********

DOCKET 4

'*"is=

1 < . , ,a 4 OC5 NUMSER N5IC EVENT DATE 269 i+ '

9010050174 219653 05/23/90

e****... ..< u*'.

a. ;***-, , ..*****.e.*********..******.*.*

, A85 TRACT POWER LEVEL t%" - % J, AT 14:27:26 HOURS, WHILE OPERATING AT-t 100% POWER, The w M*caf304 TRIPPED DUE TO HIGH REACTOR COOLANT g SYSTEM (RCS) PRES $Uki. TNE UNIT WAS OPERATING AT A STEADY STATE PRIOR

, TO THE TRIP. ALL FOUR REACTOR PROTECT!vE SYSTEM (RP5) CHANNEL $

. . ==

l

... v.u a ..> anvu,ne martLi 40 p]T SHUTCOWN. THE "B" C9P TRIP Was CAUSED 8T % "NOT OPEN" SIGNAL FROM THE PU*P's DISCHARGE VALVE 1 C- 5 4.

p1 PREVENTIVE MAINTENANCE HAD SEEN COMPLETED ON THE VALVE LESS THAN FIVE MINUTES PRIOR TO RECEIVING THE "NOT OPEN" SIGNAL. THE REASON FOR THE b4 "NOT OPEN" SIGNAL COULO NOT SE DETERMINED, THEREFORE, THE R001 CAUSE

0F THIS EVENT IS CLASSIFIED A5 " UNKNOWN". ADDITIONALLT, AT THE TIME 0F THE "8" C8P TRIP, THE "A" CSP WAS IN STAND 87 AND ALIGNED FOR b4 AUTOMATIC START. THE "A" CSP FAILED TO START DUE TO FAULTT BEARING .i i ,;

' OIL PRESSURE INSTRUMENTATION. THEREFORE, A CONTRIBUTING CAUSE OF THIS l pq TRIP 15 " EQUIPMENT FAILURE / MALFUNCTION" DUE TO THE MALFUNCTION OF THE SEARING OIL PRESSURE INSTRUMENTATION WHICH PREVENTED THE STANDBY C8P g :j FROM STARTING.

I be p '. FORM 87 LER SC55 OATA 04-18-91 l 0..............e...................e........................ ........

gg 00CEET VEAR LER NUMSER REVISION 0C5 NUNBER N5IC EVENT DATE

p 270 1989 002 0 8903170287 213293 02/03/89

...e.e...ee.................ee....ee.....ee. ...........ee.....e....

I be

: ; ABSTRACT DN ~ POWER LEVEL - 1003. 04 FEBRUART 3, 1989 AT 1545 HOURS WHILE OPERATING ,

AT 1002 REACTOR POWER, THE UNIT 2 MAIN TURSINE (MT) TRIPPED RESULTING y, IN AN ANTICIPATORY REACTOR TRIP. THE MT TRIP WA5 INITIATED 8V A LOSS OF 125 VDC POWER TO THE ELECTRO HTORAULIC CONTROL (EHC) SYSTEM. THE 8' LOSS OF DC POWER OCCURRED DUE TO THE INCORRECT WIRING OF A CIRCUIT DURING IMPLEMENTATION OF A NUCLEAR STATION MODIFICATION (N5M). THIS COM8INED WITH A PRE-SMISTING GROUND ON A CONOUCTOR SUPPLVING POWER 31 FRON THE EHC TO THE "2A2" MOISTURE SEPARATOR REHEATER HIGH WATER LEVEL SWITCH, CAUSED A LOSS OF 125 VDC POWER TO THE EHC. THE IMMEDIATE 4

,, CORRECTIVE ACTION WA5 TO STABILIIE THE UNIT AT HOT SHUT 00WN.

I SUPPLEMENTAL CORRECTIVE ACTIONS INCLUDED DETERMINING THE CAUSE OF THE i' TRIP, CORRECTING THE WIRING PROBLEM AND REPAIRING THE OEGRADED ke CONDUCTOR. THE ROOT CAUSES OF THIS TRIP WERE: A MANAGEMENT DEFICIENCY OF NOT PROPERLY IMPLEMENTING THE INDEPENDENT VERIFICATION PROGRAM AND g, OF ASSIGNING AN UNQUALIFIED PERSON TO PERFORM A TASK! AND AN EQUIPMENT FAILURE.

Le FORM 88 L:4 SC55 DATA 04-18-91 a 0**************************=*****************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

,, 270 1989 003 0 8903170289 213294 02/05/89

-............................e...........e...........................

i A85 TRACT POWER LEVEL - 1003. 04 FEBRUARY 5, 1959, AT 0023 HOURS WHILE OPERATING e AT 100X FULL POWER, THE UNIT 2 MAIN TURBINE (MT) TRIPPED RESULTING IN I AN ANTICIPATORY REACTOR TRIP. THE MT TRIPPED IMMEDIATELY FOLLOWING I

_ , THE PERFORMANCE OF STEP 2.2 0F PROCEDURE PT/218/290/05 (SECONDARY

. SYSTEMS PROTECTION TEST), WHICH PLACED THE MASTER TRIP 50LEMOID TEST LEVER IN THE TRIP *A" POSITION. A WORE REQUEST WAS WRITTEN TO INVESTIGATE THE MASTER TRIP 50LE40ZO TEST SWITCH. HOWEVER, INVESTIGATION INTO THE INCIDENT DID NOT ID!NTIFT THE CAUSE OF THE MT

TRIP. THE IMMEDIATE CORRECTIVE ACTION WA5 TO STASILIIE THE UNIT AT HOT SMUTDOWN. .THE SUPPLEMENTAL CORRECTIVE ACTIONS INCLUDE 0 TROUSLE5H00 TING THE ELECTRO HTORAULIC CONTROL SYSTEM AND REPLACING THE NASTER TRIP SDLENOID TEST SWITCH A5 A PRECAUTIONARY MEASURE. THE ROOT CAUSE OF THE UNIT TRIP COULD NOT SE DETERMINED BECAUSE THE I

i

,7' SCENARIO WA5 NOT REPEATABLE. THEREFORE, THIS INCIDENT IS CLASSIFIED 45 UNaNOWN.

' , 1

' FORM 89 LER SC55 OATA AA-19-81

. - _ - - - , _ , - - - - - - .-c m- - - _ _ - , , - - - _ - _ . _ _ _ _ _ , ,- _ - -- --

... ,,.- 4.- u 54J5150112 215054 34t03#39 l

1 P1 AS$ TRACT g4 PO%ER LEVEL - 100%. ON A8RIL 3, 1989, AT 1007 HOURS, OCONEE UNIT 2 g; TRIPPED FROM 1002 FULL POWER. PLANT R*SPONSE TO THE TRIP WAS NORMAL, bd WITH NO RADIOLOGICAL RELEASES 04 ENGINEERED SAFEGUARDS ACTUATION 5.

THE TRIP RESULTED FROM A FALLING OBJECT STRIKING THE CONDENSATE

, e f 8005TER PUMP (CSP) EMERGENCY LOW SUCTION PRES 5URE PRESSURE SWITCH.

>q THE IMPACT SHIFTED THE INSTRUMENT SETPOINT RESULTING IN 4 TRIP OF CSPS 1

FOLLOWED BV MAIN FEEDWATER PUMP TRIP AND ANTICIPATORY REACTOR TRIP.

' g4 q, EMERGENCY FEEDWATER ACTUATED AND M AINT AINED DEC AV HE AT REMOV AL. THE ROOT CAUSE IS MANAGEMENT OEFICIENCT, POOR HOUSEKEEPING.

1 QI FORM 90 LER SC55 DATA pg 0************************************************************04-18-91 ********

' q ,' 00CEET YEAR LER NUM8ER REVISION 0C5 NUMBER NSIC EVENT DATE 271 1990 004 0 9004260223 217752 03121/90 U"

l be A85 TRACT POWER LEVEL - 025I. 04 03/21/90 AT 2243 WITH REACTOR AT APPROXIMATELY g 4 .g 25I POWER, WHILE 8 RINGING THE TUR8INE (EII5*TA) UP TO SPEED IN 3 PREPARATION FOR PLACING GENERATOR IN SERVICE, A SCRAM OCCURRED DUE TO j

I' EXCEEDING THE REACTOR HIGH PRESSURE SET POINT. THE SCRAM WAS FOLLOWED

"' 8v PRIMART CONTAINMENT ISOLATION SYSTEM (PCIS, EII5*JE) GROUP I ISOLATION AT 2250. THE SCRAM AND THE ISOLATION WERE THE RESULT OF A R1 FAILURE OF THE PRE 55URE CONTROL SYSTEM (EII5*JI) TO CONTROL REACTOR 3, PRESSURE. SASED ON RESULTS OF FOLLOWUP TESTING, THE ROOT CAUSE

, g, APPE&R5 TO BE A LACK OF RESPONSE OF THE #1 TURSINE CONTROL VALVE AT i

i LOW HYORAULIC OIL PRESSURE. THE ROOT CAUSE OF THE GROUP I ISOLATION

('

P WAS THE FAILURE OF THE 81 8TPA55 VALVE TO G0 COMPLETELY CLOSED. THE IMMEDIATE CORRECTIVE ACTIONS WERE TO INCREASE THE DIFFERENTIAL PRESSURE ACROS5 THE CONTROL VALVE ACTUATOR AND LU6RICATE THE LINKAGE se FOR ALL THE BYPASS VALVES. UPON INITIATING THESE IMMEDIATE CORRECTIVE i

ACTIONS THE TURRINE-GENERATOR WAS SUCCESSFULLY BROUGHT SACK ON LINE.

, t*

, FORM 91 LER SC55 DATA 04-18-91

0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS MUMSER NSIC EVENT DATE

,; 271 1990 009 0 9007030031 218701 06/01/90 4

485 TRACT POWER LEVEL - 100E. CN 06#01/90, AT 1353 HOUPS, WITH THE REACTOR AT

> ' .100E POWER, A CONTRACT ELECTRICIAN WOREING ON A NORMALIEMERGENCY LIGHTING PANEL ALLOWE0 A GROUND WIRE TO COME IN CONTACT WITH A LIVE

, . , OUS. THE RESULTING SHORT CIRCUIT CAUSED THE VITAL AC MOTOR GENERATOR

, SET (EII5*EF) TO LOSE THE FIELD EXCITATION AND SU65ECUENTLY A LOSS OF GENERATOR OUTPUT. ON THE LOSS OF GENERATOR OUTPUT, THE VITAL AC SUS TRANSFERRED TO ITS ALTERNATE SOURCE. THIS CAUSED A PRESSURE TRAN5IENT

, IN THE REACTOR COOLANT SYSTEM DUE TO THE TRANSFER FRON THE ELECTRIC PRESSURE REGULATOR TO TME MECHANICAL PRESSURE REGULATOR, RESULTING IN A REACTOR SCRAN. ON 06/03/90, at 0103 HOUR $, THE REACTOR MODE SWITCH

,- WAS RETURNED TO THE RUM POSITION AND THE IN GENERATOR PHASED TO THE GRIO. THE ROOT CAUSE OF THIS EVENT WAS PERSONNEL ERROR QUE TO A LACE OF MENTAL ATTENTION. CORRECTIVE ACTIONS WILL INCLUDE ELECTRICAL g '. CONTRACTOR RETRAINING AND INCREASED EMPHASIS SAFETT AND ATTENTION TO OETAIL. AN EVALUATION WILL BE PERFORMED 04 THE VITAL AC MG SET TO t DETERMINE IF COLLAP5E OF THE GENERATOR FIELD A5 A RESULT OF THE FAULT

'(', .WAS THE APPROPRIATE EQUIPMENT RESP 045E. A PLANT OPERATIONAL REVIEW

, $US-COMMIT TEE WILL EV ALU ATE THE NEE 0 SOR A FORwAL GUTnesTur cowcowtec

._ _ _ _ . -_ . . _ . - . __ _ . _ , , _ _ _ . . . _ _ _ ~ - , _ _ , _ . --

.... . . . . ...na.

1 D1 FORM 92 LER SCS$ DATA 54 0************************************************************04-18-91 ********

p DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 271 1990 015 0 9012100223 220S87 11/04/9 bd

- - - - 0*

li pq 485 TRACT POWER LEVEL - 094%. ON 11/4/90 AT 0120 HOURS, WITH REACTOR POWER AT g; 94%, WHILE PERFORMING WEEKLT TESTING OF THE TURBINE EMERGENCY GOVERNOR (JC*), A REACTOR SCRAM OCCURRED AS A RESULT OF A TUR8INE CONTROL be q; VALVE FAST CLOSURE SIGNAL. THE TUR8INE CONTROL VALVE FAST CLOSURE SIGNAL WAS GENERATED BY 1HE ACCELERATION RELAY AFTER OPERATORS REMOVED A TRIP LOCKOUT FROM THE EMERGENCY TRIP VALVE. THIS OPERATOR ACTION p3 WAS TAKEN BASED ON EMERGENCY TRIP VALVE POSITION INFORMATION LATER

..i

IDENTIFIED AS ERR 0NEOUS DUE TO A MISSING SET SCREW QN A COLLAR IN THE U" TUR8INE FRONT STANDARD LINEAGE. SINCE THE COLLAR W45 NOT ATTACHED TO THE LINEAGE, A SPRING WAS NOT ASLE TO ACT UPON THE LINKAGE AND THE bg EMERGENCY TRIP VALVE LIMIT SWITCH DID NOT CHANGE STATE 4$ THE VALVE MOVED. THE PLANT WAS STASILIZED WITHOUT INCIDENT FOLLOWING THE TRANSIENT AND THE TUR8INE (TA*) WAS PLACED 04 THE TURNING GEAR AT 0241 pg ,g; HOURS. THE TURBINE VENDOR (GE) ASSISTED PLANT PERSONNEL IN REPAIRING AND TESTING THE MALFUNCTIONING LINKAGE PRIOR TO RESTORING THE TUR91NE 88 CONTROL SYSTEM (TG*) TO SERVICE. THE REACTOR WAS RETURNED TO CRITICAL ON 11/4/90 AT 2222 HOURS. A PROCEDURE IS 8EING REVISED TO PROVIDE ADDITIONAL OPERATOR ACTIONS TO BE TAKEN IF LIGHT INDICATIONS R1 ARE ABNORMAL. TUR8INE OUTAGE MAINTENANCE IS BEING EXP4NDED TO INCLUDE i

AN INSPECTION OF SIMILAR LOCKING COLLARS AND POSITION INDICATING.

b, I FORM 93 LER SCS$ DATA 04-1 ha 0****************************************************************8-91 ****

DOCKET YEAR LER NUMSER REVISION DCS NUM8ER NSIC EVENT DATE e4 272 1989 007 0 E903140553 213242 02/06/89 E'

, ABSTRACT POWER LEVEL - 1001. ON 2/6/89 AT 1055 HOURS, DURING ROUTINE POWER I OPERATION, THE UNIT EXPERIENCED 4 REACTOR TRIP 04 NO. 14 STE4M GENERATOR ($/G) LOW LEVEL CONCURRENT WITH STEAM FLOW / FEED FLOW

,, MISM4TCH. AT THE TIME OF THE EVENT, NO. 14 S/G STEA9 PRES $URE CHANNEL I FUNCTIONAL SURVEILLANCE WAS IN PROGRESS. THE ROOT CAUSE OF THIS

' EVENT HAS SEEN ATTRIBUTED TO PERSONNEL ERROR. POST TRIP DATA INDICATES THAT THE NUCLEAR CONTROL OPERATOR (NCO) DID NOT SELECT THE CORRECT CHANNEL DURING PERFORMANCE OF IEC PROCEDURE 1PD-2.6.060, e

" CHANNEL FUNCTIONAL TEST - 1PT-544 814 STEAM GENERATOR STEAM PRES $URE PROTECTION CHANNEL I". PRESSURE COMPENSATION FOR DETERMINING STEAM

, FLOW IS ELIMINATED WHEN THE CH4NNEL TEST SWITCH !$ PLACED IN THE TEST POSITION AS PER PROCEDURE. THIS CAUSES STEAM FLOW INDICATION TO OROP RADICALLY CAUSING A SIGNAL TO INITIATE CLOSURE OF THE 148F19 FEE 0 WATER CONTROL VALVE THEREST DECREASING FEED FLOW. WITH THE WRONG CHANNEL

, APPARENTLY CHOSEN AS THE CONTROLLING CHANNEL, THE 148F19 VALVE m" SAN CLOSING. ONCE $1G LEVEL DROPPED TO 25% THE REACTOR TRIP OCCUE. 0 SINCE THE SIGNAL FOR 'STE AM FLOW / FEED FLOW MI SPA TC H WAS PROCEDURALLY

, PREVIOUSLT ACTUATED. THIS EVENT HAS SEEN REVIEWED 8T OPERATIONS MANAGEMENT. APPROPRI4TE CORRICTIVE DISCIPLINARY ACTION HAS SEEN TAKEN. THIS EVENT WILL SE REf!EWED ST THE NUCLEAR TRAINING CENTER FOR 3

, INCORPORATION INTO APPLICABLE TRAINING PROGRAMS.

t

, FORM 96 LER SCSS DAT4 04-18-91

, 0********************************************************************

P1 A8STRACT POWER LEVEL - 0002. ON 2/18189, A REACTOR TRIP OCCUR 2ED. AT THE TIME h4 C7 THE EVENT, REACTOR PCWER AT AT 10(-9) AMPS (CCITICAL). THE TRIP i qg SIGNAL WAS THE RESULT OF A TURBINE TRIP WITH POWER ABOVE PERMISSIVE P-7 (10% POWER). WORK IN PROGRESS INCLUDED FUNCTIONAL TESTING OF THE h4 TURSINE IMPULSE CHAM 8ER PRES $URE TRANSMITTER. THE ROOT C AUSE OF THIS gg EVENT HAS BEEN ATTRIBUTED TO PERSONNEL ERROR. AN IRC TECHNICIAN pq PERFORMING THE TRANSMITTER FUNCTIONAL TEST DIO NOT COMPLT WITH THE PROCEDURE REQUIREMENTS. CONTRART TO THE REQUIREMENTS OF THE PROCEDURE, g THE TECHNICIAN DID NOT NOTIFT SU8ERVISION WHEN THE STATUS PANEL INDICATIONS WERE NOT CORRECT AND CONTINUED PERFORMING THE PROCEDURE.

DW THE TECHNICIAN WAS NOT AWARE THAT THE CONTINUANCE OF THE PROCEDURE gi '

WOULD RESULT IN A TRIP. WHEN THE BI-STABLES ARE TRIPPED, AS A RESULT 0F FUNCTIONAL TESTING, A SIGNAL INDICATING REACTOR POWER 480VE P-7 IS bG GENERATED. IF THE TURSINE IS NOT LATCHED, As WAS THE CASE IN THIS

. EVENT, A REACTOR TRIP WILL OCCUR. MAINTENANCE DEPT. MANAGEMENT HAS

' kN COMPLETED A REVIEW OF THIS EVENT AND HAS COMPLETED APPROPRIATE CORRECTIVE DISCIPLINART ACTION WITH THE IND;WIDUAL($) INVOLVED. THIS b4

.i. EVENT WILL BE REVIEWED WITH MAINTENANCE DEPT. PERSONNEL STRESSING THE NEED FOR PROCEDURAL COMPLIANCE. IEC PROCEDURES ASSOCIATED WITH THE TUR8INE IMPULSE PRES $URE TRANSMITTER CHANNELS HAVE BEEN MODIFIED.

>d -lI I FORN 95 LER SCSS DATA B8 0************************************************************04-18-91 00CKET VEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE p1 272 1989 027 0 8907210308 214844 06#19/89 ASSTRACT POWER LEVEL - 0452. ON 6/19189 AT 2100 HOURS, A REACTOR TRIP DN NO. 13 k'

STEAM GENERATOR (S/G) " LOW-LOW LEVEL" OCCURRED. THE NO. 13 MAIN STEAMLINE ISOLATION VALVE, 13MS167, HAD CLOSED. PRIOR TO THE EVENT, t4 REACTOR POWER WAS BEING INCREASED 3% PER HOUR. AT THE TIME OF THE EVENT, A POST MAINTENANCE SURVEILLANCE FOR THE 12MS18 MAIN STEAMLINE

STPASS STOP VALVE WAS IN PROGRESS. THE ROOT CAUSE OP THIS EVENT HAS BEEN ATTRISUTED TO INADEQUATE DESIGN OF THE CONTINUITT CHECK CIRCUITRT FOR THE MS167 VALVES. SURVEILLANCE TESTING OF VALVE 12M518 WAS IN I PROGRESS PRIOR TO THE EVENT. WHEN THE SOLIO STATE PROTECTION SYSTEM (SSPS) TRAIN "A" OUTPUT INTERFACE CASINET SWITCH Was TURNED TO

, " OPERATE OUTPUT", THE 13M5167 VALVE CLOSED FOLLOWED BT THE TRIP. THE "0PERATE OUTPUT" FUNCTION CAUSES CLOSURE OF THE MS18 VALVE WHILE

CHECKING CONTINUITT OF THE M5167 VALVE CLOSURE CIRCUIT. THIS DESIGN CAN CAUSE INADVERTENT CLOSURE OF THE M5167 VALVES AS OCCURRED DURING THIS EVENT AND A SIMILAR UNIT 2 EVENT ON 4f11/89 (REF. LER

' 311/89-005-00). A DESIGN CHANGE HAS 8EEN IMPLEMENTED WHICH CORRECTS THE CIRCUIT DESIGN CONCERN ST ADOING A CONTACT WHICH PREVENTS THE

, 74-34 RELAT FROM RESETTING DURING THE TESTING OF THE M518 VALVES.

THIS CONTACT DOES NOT PREVENT THE MS167 VALVES FROM FUNCTIONING IN THE

' EVENT OF A VALID MAIN STEAM ISOLATION SIGNAL.

1 i FORM 96 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE 272 1990 010 0 9005070358 218116 04/03/90 t

I A85 TRACT t POWER LEVEL - 0001. CN 4/3/90 AT 1558 HOURS, DURING REACTOR STARTUP g' OPERATIONS, A REACTOR TRIP SIGNAL WAS INITIATED OUE 10 LOW-LOW LEVEL

. IN NO. 12 STEAM GENERATOR (SIG). AT TM* TT== "" 7"* t' c*"- '"'

etwsuhN:L datua. THE NUCLEAR CONTROL CoERATOR (NCO) 010 NOT ENSURE D9 OPTIMUM INITIAL CONDITIONS PRIOR TO SWAPPING FROM NO. 11 5/G TO NO. 12 5/G FOR MAINTAINING RCS TEMPERATURE. $U35E3UENTLT, HO. 12 5/G LEVEL CONTINUED TO DECREASE, CFTER THE TRANSFER, OUE TO IN2DEQUATE AFU FLOW g4 WITH THE TRIP SETPOInf EVENTUALLY BEING REACHED. CONTRIBUTING TO THIS p EVENT WAS INADEQUATE COMMAND AND CONTROL ST THE NUCLEAR SHIFT kW SUPERVISOR (NSS) CURING THE TRAN5IENT. THIS EVENT WAS REVIEWED WITH

$USSEQUENT OPERATING SHIFT 5 PRIOR TO THEIR ASSUMING THE WATCH.

i; LESSONS LEARNED FROM THIS EVENT WAS STRESSED. THIS EVENT HAS BEEN P1 REVIEWED BY OPERATIONS DEPARTMENT MANAGEMENT AND PERSONNEL INVOLVED HAVE SEEN HELD ACCOUNTABLE. THIS EVENT WILL BE REVIEWED ST THE PSE8G g4 NUCLEAR TRAINING CENTER FOR INCORPORATION INTO APPLICABLE TRAINING PROGRAMS.

1 he FORM 97 LER SC55 DATA bc 0************************************************************04-18-91 DOCKET TEAR LER NUMBER REVISION OC5 NUMBER N51C EVENT OATE 272 1990 012 0 9005110218 218159 D4

............................ ..................................... 0 04/09/9

b4 4851RACT POWER LEVEL - 090%. ON 4/9/90 AT 1433 Hot!RS, 00 RING NORMAL POWER y ; OPERATIONS, A REACTOR TRIP ON NO. 12 5 TEAM GENERATOR ($/G) LOW-LOW LEVEL OCCURRED. PRIOR TO THE TRIP, AT 1430 HOURS, AFTER NOTING THAT I' NO. 12 STEAM GENERATOR FEEDWATER PUMP (SGFP) WAS IDLING, A TURBINE RUMBACK WAS INITIATED AT 200%/ MIN THEN WAS REDUCE 0 TO 15%/ MIN ONCE STEAM FLOW AND FEED FLOW WERE MATCHED. UPON REACHING 60% POWER, THE D1 RUN8ACK STOPPEO. HOWEVER, NO. 12 5/G LEVEL CONTINUED TO DECREASE. A SECOND RUN8ACK TO 50% POWER (AT 8%/ MIN) WAS INITIATED, HOWhWER, PRIOR

,, 10 ITS COMPLETION, THE LOW-LOW LEVEL TRIP SETPOINT (16%) WAS REACHEO.

g THE UNIT W45 STABILIIED IN MODE 3. THE ROOT CAUSE OF THIS EVENT IS i

' EQUIPMENT FAILURE. FLOW FROM THE No. 12 SGFP HAD CEASED UPON FAILURE D'

0F THE GOVERNOR VALVE CONTROL LINKAGE. THE PILOT R00 THAT DIVERTS OIL FLOW TO POSITION THE servo MOTOR PISTON HAD OROPPED OFF. THE LOSS OF 4e THE PILOT ROD PREVENTED THE WOOOWARO GOVERNOR FROM CONTROLLING THE TUR8INE. THE No. 12 SGFP GOVERNOR WALVE LINKAGE WAS REPAIRED AND NO.

- 11 SGFP GOVERNOR VALVE LINKAGE IN5PECTED WITH NO RELATED PROBLEMS NOTED. ADDITIONAL CORRECTIVE ACTION INCLUDE: 1) MAINTENANCE PROCEDURE M244 WILL BE REVISE 0; 2) A PROCEDURE, TO DEFINE PREVENTIVE 8

MAINTENANCE REQUIREMENTS WILL BE PREPARE 0; 3) RECURRING TASKS WILL BE

, ESTABLISHE0 A5 ADPLICABLE; AND 4) A REVIEW OF SIMILAR PUMP GOVERNOR p

LINEAGE ARRANGEMENTS WITH NO ADDITIONAL PROBLEMS IDENTIFIEO.

1 FORM 98 LER SCS$ DATA 04-18-91 0************************************************e.* ................

' DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE 272 1990 029 0 9009200129 219500 08/17/90

, e .....*** ............*.............e***e..........................

' 485 TRACT POWER LEVEL - 025%. 04 8/17/00, OURING POWER ASCENSION, THE REACTOR TRIPPED DUE TO NO. 14 STEAM GENERATOR (5/G) LOW-LOW LEVEL. THE TRIP OCCURRED OURING THE TRANSFER OF THE FOUR GROUP SUSSES FROM THE STATION POWER TRANSFORMER (SPT) TO THE Aux. 80W!R TRANSFORMER (APT). AFTER SUCCESSFULLY TRANSFERRING THE 1H AND 1E GROUP BUSSES, 1G GROUP BUS WAS BEING TRAN5FERRED. TME OPERATOR INITIATE 0 CLOSURE OF THE 18GGD

' CIRCUIT BREAKER (APT SIDE). THE 12553 BREAKER OPENED; HOWEVER, THE

,, 18GGO BREAKER FAILED TO CLOSE RESULTING IN DEENERGIZATION OF THE 1G GROUP SUS. CONSEQUENTLY THE NO. 14 REACTOR COOLANT Pump (RCP) CIRCUIT BREAKER OPENED 04 UNDERVOLTAGE. THE REACTOR SUBSEQUENTLY TRIPPED ON g' No. 14 $/G LOW-LOW 5/G LEVEL. THE ROOT CAUSE OF THIS EVENT IS

. ATTRISUTED TO EQUIPMENT F AILURE. THE 1 = c r,0 rieruTT an***** **ne' 'a

-vattave PetplutR A55tM3LY WAS m3010 TO SE OUT OF ADJUSTMENTtWORN pt PPEVENTING THE RE3UIRED CLO51NS OF THE BREAKER'S POSITIVE INTERLOCK SWITCH AFTER THE 3REAKER WAS RACKED INT 3 175 NORMAL OPERATING POSITION. THE IBGGD CIRCUIT BREAKER ENCLOSURE POSITIVE INTERLOCK gq ASSEMBLY DEFICIENCIES WERE CORRECTED.

b4 FORM 99 LER SCSS DATA 04-1

,i ;

0****************************************************************8-91 ****

t1 00CKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 272 1990 030 0 9010230119 219705 09/10/90 g4 q, ********************************************************************

A85 TRACT b4 9, POWER LEVEL - 079%. ON 9/10/90 AT 1201 H3URS A REACTOR TRIP ON NO. 13 STEAM GENERATOR (5tG) LOW-LOW LEVEL OCCURRED. PRIOR TO THE EVENT, THE gg PIPE BETWEEN THE NO. 11T0900 VALVE AND THE MAIN STEAM LINE SHEARED PROVIDING A STEAM FLOW PATH TO ATMOSPHERE. TO REOUCE THE STEAM FLOW, U" THE No. 11MS29 VALVE (MS GOVERNOR VALVE) WAS CLOSED. AT $0% POWER, THE 1AMS29 VALVE 15 CLOSED (" PARTIAL ARC CONTROL SCHEME"). SOTH THE 4

b* NOS. 11814M529 VALVES DIRECT STEAM TO THE UPPER HALF OF THE TURSINE.

THEREFORE, WITH BOTH VALVES CLOSED, A SIGNIFICANT DP ACROSS THE HP TUR81NE DEVELOPED. CONTRIBUTING TO THIS OP WAS OPENING THE 11T04 p, VALVE WHICH RESULTED IN BLEEDING STEAM AWAY FROM THE UPPER HALF OF THE HP TURSINE. THE TURSINE SHAFT DEFLECTED CREATING AN ELIPTICAL I' OSCILLATION RESULTING IN DESTRUCTION OF THE AUX. SPEED SENSOR WHICH -

GENERATED AN OVERSPEED SIGNAL CAUSING CLOSURE OF THE MS29 VALVES.

CLOSURE OF THE MS29 VALVES LED TO THE TRIP ON NO. 13 S/G LOW-LOW D1 (EVEL. THE ROOT CAUSE OF THIS EVENT IS ATTRIBUTED TO PERSONNEL ERROR.

OPS. DEP'T. MANAGEMENT DID NOT LAYOUT AN APPROVED PLAN OF ACTION IN

g. ADDRESSING THE PIPE 8REAK ASSOCIATED WITH THE 11T0900 VALVE.

CONTRIBUTING FACTORS WERE PROCEDURAL INADEQUACY AND INADEQUATE b' TRAINING. THIS EVENT HAS BEEN REVIEWED BY SENIOR MANAGEMENT. THOSE INDIVIOUAL5 INVOLVED IN THIS EVENT HAVE BEEN REVISED TO CLEARLY IDENTIFY THE CONCERNS WITH TURBINE VALVE TESTING SELOW 85% POWER.

ta 1

,, FORM 100 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

' 275 1989 009 9103010089 221043 1 10/06/89 f

A85 TRACT

' POWER LEVEL - 100%. ON 10/6/89, AT 1302 PDT, WITH UNIT 1 IN MODE 1 (POWER OPERATION) AT 100% POWER, AN AUTOMATIC SAFETY INJECTION # REACTOR TRIP WAS ACTUATED FROM A STEAM LINE DIFFERENTIAL PRESSURE SIGNAL. AT 1321 POT, 4 1-HOUR EMERGENCY REPORT WAS MADE IN ACCORDANCE WITH 10 CFR 50.72(4)(1)(I). CURING THE REMOVAL FROM SERVICE PROCESS FOR

, CALIBRATION OF A PRESSURE TRANSMITTER FOR AN ATMOSPHERIC STEAM DUMP

, VALVE (ADV) CONTROL, PRES $UWE OSCILLATIONS WERE CREATED IN THE COMMON SENSING LINE WITH A PROTECTION SET STEAM GENERATOR PRES $URE TRANSMITTER. THIS CAUSED REPEATED ACTUATIONS OF A STEAM LINE DIFFERENTIAL PRESSURE SISTA8LE. BISTABLE ACTUATION, COMBINED WITH A PREVIOUILY TRIPPE3 STEAM PRES 5URE 81 STABLE, SATISFIED THE 2t3 COINCIDENCE LOGIC TO GENERATE A STEAM LINE DIFFERENTIAL PRES $URE SI

, SIGNAL. THE IEC REMOVAL FROM SERVICE # CALIBRATION PROCEDURE WAS INADEQUATE IN THAT IT DID NOT VERIFY THE CONDITION OF OTHER CHANNEL 81 STABLES TO ENSURE THAT COINCIDENT LOGIC COULD NOT BE SATISFIED. IRC

, PROCEDURES WERE REVISED TO ASSURE THAT WORK ON EQUIPMENT SHARING &

COMMON PROCESS TAP IS NOT PERFORMED IF ANY OF THE SHARED e

INSTRUMENTATION 15 IN A CONFIGURATION THAT PRODUC E S A PROTECTION g ACTUATION OR CONTROL FUNCTION. ACTIONS FOR ASSOCIATED EVENT 5 INCLUDED DEVELOPING A POLICY FOR GUT n A NC nN YeToorn *Ttts**re 9** arwn ae'~*

Dt FORM 101 LER SCSS DATA 0*****************eese*******e*******************************04-13-91 ******ee g4 00CKET TEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE in 275 1990 002 0 9003270377 217470 02/20/90

- - - - ene .+.**..***een....e******...****ee.***...

DM i 485 TRACT r1 POWER LEVEL - 100%. ON 2/20t90, AT 0530 PST, WITH UNIT 1 OPERATING AT 100I POWER, PLANT OPERATORS INITIATED A MANUAL REACTOR TRIP AFTER 80TH gq yg MAIN FEE 0 WATER PUMPS (MFPS) HAD TRIPPE0. PLANT OPERATORS INITIATED ACTIONS PER PLANT PROCEDURES AND STABILIIED THE UNIT IN MODE 3 (HOT b4 STAN087) At 0600 PST. A DETAILED INVESTIGATION WAS PERFORMED USING INFORMATION FROM ALL EVENT RECORDERS AND INTERVIEWS WITH PERSONNEL INVOLVED. THIS INVESTIGATION CONCLUDED THAT THE IMMEDIATE CAU5E OF De THE EVENT WAS ALL MAIN FEE 0 WATER CONTROL VALVES TRIPPING SHUT WHICH CAUSED BOTH MFPS TO TRIP ON HIGH DISCHARGE PRESSURE. THE

" INVESTIGATION CONCLUDED THAT THE MOST PR08ABLE CAUSE OF THE VALVES TRIPPING CLOSED WAS EITHER A NON-REPEATABLE SOLIO STATE PROTECTION kW SYSTEM (SSPS) CARD FAILURE OR AN INADVERTENT ACTUATION CAUSED ST INSTRJMENTATION AND CONTROLS (IEC) TECHNICIANS WORKING IN THE $$PS RACKS. IMMEDIATE CORRECTIVE ACTIONS INCLUDED EXTENSIVE TESTING AND pg IN$PECTION OF THE S$PS TO DETERMINE THE ROOT CAUSE, REPLACEMENT OF THE TWO SU5PECT SSPS CARDS AND A CAUTIONART T AI',80 ARD OF ISC TECHNICIANS REGARDING THE POTENTIAL HAIARDS ASSOCIATED WITH $5PS TESTING.

R1 FORM 102 LER SCSS DATA 04-18-91 0************e**.****************************************************

g. DOCKET VEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 4

275 1990 005 0 9007200173 218897 06#14/90

....eee*******e.**...e***eens.*** *e.***eeeeeeeee***********ee****

ke ASSTRACT ta POWER LEVEL - 1003. 04 6/14/90, AT 1555 PDT, WITH UNIT 1 IN MODE 1 (POWER OPERATION), UNIT 1 EXPERIENCED A REACTOR TRIP 04 POWER RANGE

HIGH POSITIVE RATE DURING A LOAD REJECTION FROM 100 PERCENT POWER.

THE LOAD REJECTION OCCURRED OUE TO AN OFFSITE 500 KV TRANSMISSION SYSTEM TRANSIENT. UNIT 1 REACTOR TRIPPED DUE TO INCREASING REACTOR COOLANT PUMP (RCP) SPEED AND REACTOR COOLANT FLOW WHICH RESULTED IN LOWER COOLANT TEMPERATURES IN THE UPPER REGIONS OF THE CORE. THE

,, INCREASE IN RCP. SPEED WAS CAUSED ST AN INCREASED 12 KV BUS FREQUENCY THAT WAS CAUSED 87 MAIN TUR81NE $PEEOUP FROM LOAD LOSS. THE RCPS

TRIPPED ON UNDERFREQUENCY AS THE GENERATOR FREQUENCY DECREASED AFTER THE TUR8INE TRIP, PLACING THE REACTOR INTO NATURAL CIRCULATION. A FOUR-HOUR, MON-EMERGENCY REPORT WAS MAGE IN ACCOR0ANCE WITH 10 CFR 8

50.72(8)(2)(II) ON 6/14/90, AT 1756 POT. THE ROOT CAUSE OF THIS EVENT WAS A FALSE RELAY OPERATION AT MIDWAY SUBSTATION WHICH CAUSE0 THE

, OPENING OF THE UNIT 1 OUTPUT BREAKER CAUSING THE LOAD REJECTION AND THE $US$EQUENT REACTOR TRIP. THE UNIT 1 SECONO OUTPUT BREAKER HAD

BEEN CLEAREO FOR 500 KV SWITCHTARD MAI%TENANCE. THE MISOPERATING RELAT WAS FOUND AND ISCLATEO. THE RELAT WILL BE INVESTIGATED AND

, RETURNED TO SERVICE, AND A MEMORANDUM HAS BEEN SENT TO POWER CONTROL ADVISING THEM OF CONDITIONS WHICH MAY PUT THE PLANT AT HIGH RISK OF TRIPPING IF CERTAIN SWITCHTARD WORK IS PERFORME0.

, 1 FORM 103 LER SCSS DATA 04-18-91

,. 0e*******e*********.*+++++**++++++************************.**********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE e 275 1990 014 0 9101100061 220622 12/05/90

..**..* .e ****..........*****.****e....**=****eeeee****.e**********

. =

.. ,..~ w e . . 4 s .4 4 .I JJ4 FJWth, INE U11T CXPFRIENCE3 A REACToc TRIP DOE TO A TUR$1NE TRIP WITH RSACTOR POWER GREATER TMAN 50%. A P -t FOUR-HOUR, NON-EMERGENCY REPORT WAS MADE IN ACCORDANCE WITH 10 CFR 30-72(8)(2)(II) ON 12/6/90, AT 0020 PST. THE TURSINE TRIPPED AS A b4 EE$UL oF A RUNBACK INITIATED BY A FALSE INDICATION OF A LOW STATOR g,

COOLING WATER FLOW CONDITION. THE INDICATED LOW STATOR COOLING WATER Ud FLOW CONDITION RESULTED WHEN A FLOW SWITCH STUCK IN THE LOW FLOW POSITION AFTER STARTING THE STANOBY STATOR COOLING WATER PUMP. THE i

. RUMBACK FAILED TO REDUCE THE GENERATOR LOAD TO SELOW THE SETPOINT OF r1 THE UNIT RUNSACK CHECK RELAT, 51RU. THIS RESULTE0 IN A GENERATOR TRIP, FOLLOWED SY A TURBINE TRIP AND $USSEQUENT REACTOR TRIP. DURING g4 gg THE EVENT, CIRCULATING WATER PUMP 1-2 FAILED TO RESTART ON AUTO TRANSFER TO THE START-UP BUS. THE ROOT CAUSE OF THE EVENT WAS h4 g DETERMINE 0 TO BE INADEQUATE EVALUATION OF THE RUNSACK LIMIT FOR THE DIGITAL ELECTRO-HYDRAULIC CONTROLLER (OEHC). THE RUNBACK LIMIT WAS l NOT SUFFICIENTLT LOW TO ASSURE THAT THE TURSINE WOULD RUNBACK TO A gg POINT SELOW THE RESET POINT OF THE 51RU RELAY. CORRECTIVE ACTIONS FOR i,

THE EVENT INCLUDE: (1) UPGR ADING THE ST ATOR COOL ING WATER FLOW U" SWITCHES; (2) INITIATING A WORK REQUEST TO MODIFY THE SETPOINT FOR THE

' TURBINE VALVE POSITION SOFTWARE; AND (3) ISSUING A MAINTENANCE BULLETIN.

De 1 ye i. FORM 104 LER SCSS DATA 04-1 0*****************************************************************8-91 ***

I4 DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 275 1990 017 0 9101290151 220915 12/24/90 D1 ABSTRACT g, POWER LEVEL - 0882. ON 12/24/90, AT 0318 PST, WITH UNIT'1 IN MODE 1 g (POWER OPERATION) AT 88% POWER, A REACTOR TRIP AND SAFETY INJECTION he OCCURRED DUE TO LOW PRES $URIZER PRESSURE. DURING THE RECOVERY FROM THE TRIP, REACTOR COOLANT SYSTEM (RCS) COOLDOWN EXCEEDED THE ALLOWABLE RATE OF 100F PER HOUR OF TECH $PEC 3.4.9. AN UNUSUAL EVENT WAS te DECLARED AT 0320 PST. A ONE-HOUR EMERGENCT REPORT REQUIRED SY 10 CFR 50.72(A)(1)(I) WAS MADE ON 12/24/90, AT 0342 PST. ON 12/24/90, AN

,, EVENT INVESTIGATION TEAM WAS FORMED TO INVESTIGATE THE EVENT. THE CAUSE OF THE TRIP WAS A PRE 55UPIZER $ PRAY VALVE THAT FAILED OPEN f ee I

TO ITS FEECBACK LINKAGE BECOMING DISCONNECTED. THE FEEDSACK LINKl3E SECAME DISCONNECTED BECAUSE A LOCKING DEVICE Wa$ NOT INSTALLED ON THE SCREW HOLDING THE LINKAGE TO THE VALVE STEM. THE FAILURE OF THr PILOT STEM OF A CONDENSER STEAM DUMP VALVE CONTRIBUTED TO THE OVERCrsLING OP THE RCS. THE ROOT CAUSE FOR THE PILOT VALVE FAILURE IS UNDER

' INVESTIGATION AND WILL 8E REPORTED IN A SUPPLEMENTAL LER. f. o R R E C T IV E ACTIONS FOR THE EVENT INCLUDE REVISING MAINTENANCE PROCEDURt I-2.25-1 TO ADDRES$ THE USE OF APPROPRIATE LOCKING DEVICES ON FEEDSACK

' LINEAGES, REVISING A8 NORMAL OPERATING PROCEDURE AP-13 FOR DEALING WITH FAILED OPEN PRES 5URIZER SPRAY VALVES, REVISING EMERGENCV PROCEDURE

, E-0 04 CLOSING THE MAIN STE AM ISOLATION VALVES, REVISING DESIGN DRAWINGS, AND SENDING A LETTER TO THE VENDOR.

i FORM 105 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

, 27F 1939 012 1 8908180320 215015 05/19/89

, ABSTRACT POWER LEVEL - 0242. AT 0721 CN 5/19/89 WITH UNIT 2 AT 24% THERMAL POWER THE FEEDWATER LEVEL CONTROL SYSTEM WAS TRANSFERRED FROM SINGLE g ELEMENT TO TMREE ELEMENT CONTROL. IMMEDIATELY, THE " REACTOR HI-LO

, LEVEL" ALARM ANNUNCIATED, FOLLOWED BY BOTM "B" ANO "C" ReaCTno secq

. . . . -w.6s 2. =c> east sa:s, Ltvtt CECREASED 3ELOW 0 INCHES RISULTING IN AN AUT0"4 TIC S C R A *1 AND GROUP II AND III ISOLATIONS. THE pq "C" RFP WAS RESTARTEC AND LEVEL 3ECREASE STOPPED A80VE 48 INCHES. AT THIS LEVEL, ALTERNATE ROD INSERTION BACKUP SCRAM INITIATED AND BOTH pq REACTOR RECIRCULATION PUMPS TRIPPED. THE HIGH PRESSURE COOLANT

' INJECTIOM ANO REACTOR CORE ISOLATION COOLING SYSTEMS ALSO RECEIVE bd INITIATION SIGNALS AT THIS LEVEL, SUT DID NOT ACTUATE AS THE LOGIC WAS NOT SATISFIED. REACTOR WATER LEVEL WAS RESTORED 10 < 0 INCHES AND THE e, UNIT STABILIZED IN THE HOT SHUTDOWN CONDITION. THE SCRAM AND GROUP P1 II AND III ISOLATIONS WERE RESET AND ESSENTIAL SYSTEMS RETURNED TO SERVICE. THE ROOT CAUSE OF THIS EVENT WAS FAILURE OF THE FEEDWATER g4 LEVEL CONTROL ELECTOR SWITCH. THE FAILED SWITCH WAS REPLACED, FEEDWATER CONTROL AMPLIFIERS WERE CALIBRATED AND PROCEDURES WERE ENHANCEO. THIS EVENT WILL BE REVIEWED WITH THE APPROPRIATE PLANT 54 g, PERSONNEL. THREE SIMILAR LERS WERE IDENTIFIED.

k0 1

FORM 106 LER SCSS DATA 04-be 0********* ***.....**..**** *.*.**. **.....****......***....*...18-91 DOCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE i, 2?? 1989 015 1 9001250197 2165S1 07/21/89 DM ***************************************.***. ***... *********..***.*

g, , ABSTRACT POWER LEVEL - 0792. AT 2231 ON 7/21/89 WITH UNIT 2 AT 792 THERMAL I' POWER, AN ATTEMPT WAS MADE TO REMOVE A MALFUNCTIONING REACTOR PRESSURE VESSEL (RPV) PRESSURE REGULATOR SET FROM THE ELECTRONIC PORTION OF THE MAIN TUR8INE (MT) ELECTRO-HYDRAULIC CONTROL (EHC) PRESSURE p1 REGULATING SYSTEM. IMMEDIATELY, THE MT BYPAS$ AND CONTROL VALVES

, OPENED, CAUSING MAIN STEAM LINE PRESSURE TO DECREASE TO APPROXIMATELY g, 480 PSIG. AT 850 PSIG MAIN STEAM LINE PRESSURE, A GROUP I ISOLATION l OCCURRED CAUSING THE MAIN STEAM ISCLATION VALVES (MSIV) TO CLOSE. 45

, A RESULT, 4 FULL REACTOR SCRAM OCCURREO. RPV LEVEL DECREASE DUE TO 5HRINK FOLLOWING MSIV CLOSURE RESULTED IN A GROUP II AND III ISOLATION AS LEVEL DECRE ASED 8ELOW 0 INCHES. TWO NAIM STEAM RELIEF WALVES te (MSRV) LIFTED ONCE AUTOMATICALLY, FOLLOWED ST MANUAL OPERATOR CYCLING OF MSRV5 TO CONTROL RPV PRESSURE BETWEEN 930 PSIG AND 1060 PSIG. THE

' HIGH PRESSURE COOLANT INJECTION (HPCI) AND REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM WERE PLACED IN OPERATION TO CONTROL RPV PRESSURE AND LEVEL. THE ROOT CAUSE OF THIS EVENT WAS A MALFUNCTION OF THE a ELECTRONIC PORTION OF THE "A" RPV PRESSURE REGULATOR SET. NO ACTUAL SAFETY CONSEQUENCES OCCURRED AS A RESULT OF THIS EVENT. THE MAJORITY g, OF THE "A" REGULATOR ELECTRONIC COMPONENTS WERE REPLACED. THIS EVENT HAS BEEN REVIEWED WITH APPROPRIATE PLANT PERSONNEL. ONE PREVIOUS t .

SIMILAR LER WAS 10ENTIFIED.

g

, FORM 107 LER SCSS DATA 04-18-91 0********************************************************************

, DOCKET YEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE 277 1989 023 0 5911150135 215543 10/05tS9

,g A85 TRACT i POWER LEVEL - 1002. AT 1806 HOURS ON 10/5/89, WITH UNIT 2 AT 99.52 THERMAL POWER, ST 1.3A-2 "PCIS GROUP I LOGIC SYSTEM FUNCTIONAL TEST"

,; WAS IN PROGRESS. AS PART OF THE TEST, THE OUTBOARD MAIN STEAM ISOLATION VALVE (MSIV) AC SOLENGID PILOT VALVES WERE DE-ENERGIZED, WHICH RESULTED IN THE UNEXPECTED CLOSURE OF THE "O" CUT 80ARD MSIV.

g SUBSEQUENTLT, 44 AUTOMATIC REACTOR SCRAM OCCURRED AT 1806 HOUR 5 DUE TO AN APRM MIGH FLUX $1GNAL UPON THE RESULTANT RAPIO INCREASE IN REACTOR t PRESSURE. A REACTOR WATER CLEAM UP ISCLATION OCCURRED SHORTLY AFTER fj THE SCRAM. OTHER SAFETY ST5TEMS OPERATED AS Of5IGNED. THE CAUSE OF

, THE "0" ?SIV CLOSURE WAS THE SINDING OF ITS DC SOLENGTO Pitor va'we l

l t

--, ....< r6cet itsnN& CAL woltaNLh SUPPLIED BY THE 50LEN010 MANUFACTUREP F3R THE INSTALLATION OF THE PLUNGER SPRING IN THE P1 SOLENOID V3LVE. THE CORRECT TECHNICAL INFORHATION MAS SEEN RECEIVED FROM THE MANUFACTURER AND THE MAINTENANCE PROCEDURE USED TO INSTALL THESE SCLEN3ID YALVES ON THE MSIV'S WILL BE REVISED TO REFLECT THIS q INFORMATION. THE "D" OC SOLENDID VALVE WA5 REPLACEO. ST 1.34-2 WAS b4 COMPLETED SATISFACTORILY PRIOR TO RETURNING UNIT 2 TO SERVICE. THE UNIT 3 50LEN010 VALVES WILL BE INSPECTED PRIOR TO UNIT 3 RESTART.

,g ; 1 FORM 108 LER SCSS DATA 04-18-91 g4 a, 0*..**.a.................................................... ........

i DOCKET TEAR LER NUMBER REVISION OCS NUMSER N5IC EVENT DATE l 277 1959 033 0 9001310025 216582 12/20189

>= y ....................................................................

b, A85 TRACT POWER LEVEL - 100%. ON 12/20/89 AT 1752 HOURS WITH UNIT 2 OPERATING AT 8" 100% POWER, A FULL SCRAM SIGNAL WAS RECEIVED WHEN A TECHNICIAN PERFORMING A SURVEILLANCE ON AVERAGE POWER RANGE MONITOR (APRM) "D" INADVERTENTLY OPERATED 4 SWITCH ON APRM "A" (APRM "D" 4CTUATES A "5" he CHANNEL HALF SCRAM SIGNAL WHILE APRM "A" ACTU4TES AN "A" CHANNEL HALF SCRAM SIGNAL). THE REACTOR FEEDWATER PU4P5 (RFP) TRIPPED FOLLOWING gg ;, THE SCRAM. THE HIGH PRES 5URE COOLANT INJECTION (HPCI) AND THE REACTOR CORE ISOLATION COOLING (RCIC) SYSTEMS ACTUATED A5 DESIGNED TO I8 MAINTAIN REACTOR WATER LEVEL, OTHER SAFETY SYSTEMS OPERATED AS DESIGNE0. CONTROL ROD 33-39 SETTLED TO POSITION 02 SHORTLY FOLLOWING THE SCRAM AND WAS LATER RE-INSERTED. THE ROOT CAUSE OF THE EVENT H45 31 SEEN ATTRIBUTED TO PROCEDURAL DEFICIENCIES AND INATTENTION TO DETAIL SV THE TECHNICIAN PERFORMING THE SURVEILLANCE. THE TECHNICIAN g, INVOLVED IN THIS EVENT WAS COUNSELED AND DISCIPLINE 0. APRM g SURVEILLANCE PROCEDURES WHICH TEST APRM CHANNELS ADJACENT TO OTHER be APRM CHANNELS M4VE SEEN REVISED TO PROVIDE PHYSICAL BARRIERS SETWEEN APRM CHANNELS DURING TESTING AND TO INSTRUCT OPER4 TORS TO 8YPASS ADJACENT APRM CHANNELS WHEN PERMI5518tE. CURRENT PANEL LASELING WILL 3e SE EVALUATED AND IMPROVED A5 APPROPRI4TE. THERE WAS ONE PREVIOUS SIMILAR EVENT.

1 FORM 109 LER SC55 DATA 06-18-91 0.*******************************************************************

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

,, 278 1990 002 1 9005070060 215080 01/28/90 A8STRACT POWER LEVEL - 100%. 04 JANUARY 28, 1990 THE UNIT 3 REACTOR WAS MANUALLY SCRAMMED DUE TO A LEAK OF ELECTR0 HYDRAULIC CONTROL SYSTEM (EHC) FLUID AT THE NUMBER ONE MAIN TURSINE CONTROL VALVE. REACTOR

, COOLANT LEVEL FLUCTUATIONS FOLLOWING THE SCRAM RESULTED IN THREE GROUP II AND III PRIM 4RY CONTAIN4ENT ISCLATION SYSTEM (PCIS) 4CTUATIONS.

+

THE CAUSE OF THE EHC FLUID LEAR WAS FAILURE OF AM 0-RING ON THE FLUID INLET PORT TO THE SERVO VALVE WHICH CONTROLS THE NUM8ER ONE MAIN TUR8INE CONTROL VALVE. THE REACTOR LEVEL FLUCTUATIONS WERE AGGRAVATED ST THE NEE 3 FOR RAPIO DEPRESSUPIIATION VIA THE MAIN TUR8INE 8TPA55 VALVES, IN4BILITT TO RESTART THE "C" REACTOR FEEDWATER PUMP (RFP) AND

, THE SUSSEQUENT 84TCH FEEDING OF REACTOR COOLANT VIA THE HIGH PRES $URE COOLANT INJECTION (HPCI) AND REACTOR CORE ISOLATION COOLING (RCIC)

ST5TEMS. INA81LITT TO RESET THE "C" RFP W45 DUE TO 4 RFP TUREINE

, HTORAULIC CONTROL PRC8LEM. THE CAUSE OF THIS PR08LEM WAS THE LOCK NUT ON THE RFP INTERLOCK DUMP VALVE SETTING ADJUSTMENT SOLT SECOMING

UNSECURED DUE TO SYSTEM VISRATION. NO ACTUAL SAFETT CONSEQUENCES 4

OCCURRED AS A RESULT OF THIS EVENT. THE EHC FLUID LEAK WAS STOPPED

, AN3 THE LEAKING SERVO VALVE WAS REPLACED. T4WESTicAviqw twTn twe

n -. n., .-.,w< -

I .....u-e. -66e scwunn.w, AN N4304=.

i 1 i P1 FORM 110 LER SC55 OATA 04-b4 Deeseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee...18-91 ....

p' OOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 278 1990 003 0 9004170130 217585 03/06/90

kW e............. *....................................................

[ t ;i i g-g 485 TRACT 4 POWER LEVEL - 100%. Og MARCH 6, 1993 AT 0250 HOURS WITH UNIT 3 l

d . OPERATING AT 1003 POWER A REACTOR SCRAM OCCURRED 00E TO A MAIN TUR81NE TRIP. THE 'A' STATOR COOLING PUMP TRIPPED. THE TURBINE TRIPPED WHEN l l A kW THE MAIN GENERATOR LOSS OF STATOR COOLING RUN8ACK TRIP TIMER TIMED ji OUT PREMATURELT. THE STATOR COOLING PUMP TRIPPE0 DUE TO A 3 HARP CORNER OF THE PUMP MOTOR POWER LEAD LUS WEARING THROUGH 175 TAPE gg INSUL ATION AND ARCING FROM THE PUMP MOTOR POWER LEAD TO GROUNO. THE q

TRIP TIMER HAD AN IMPROPER SETTING OUE TO A DEFICIENT TEST PROCEDURE.

U" OURING REACTOR COOLDOWN ON MARCH 7, THE 80TTOM HEAD ORAIN AND RECIRCULATION LOOP TEMPERATURES WERE Mnf LOGGED AS REQUIRED BT

_; TECHNICAL SPECIFICATIONS BECAUSE THE SOTTOM HEAD ORAIN AND h4 RECIRCULATION LOOP TEMPERATURE INDICATIONS WERE NOT CONSIDERED TO 8E REPRESENTATIVE OF ACTUAL REACTOR COOLANT TEMPERATURES. BASED 04 THESE y, TEMPERATURE INDICATIONS ONLY, IT APPEARS THAT THE REACTOR VE5SEL

' PRE 55URE VS. TEMPERATURE LIMIT 5 OF TECHNICAL $PECIFICATIONS WERE j De EXCEEDED. NO ACTUAL SAFETY CONSEQUENCES OCCURRED A5 A RESULT OF THIS

EVENT. THE STATOR COOLING PUMPS HAVE SEEN REPAIRED. THE LOSS OF STATOR COOLANT TRIP TIMER HAS 8EEN PROPERLT SE

T. PROCEDURE

RT 5.40 D1 WILL SE REVISED. AN INVESTIGATION OF THE SOTTON HEAD ORAIN TEMPERATURE INDICATION WILL SE PERFORMED ANO THE RESULTS REPORTED IN A

,, REVISION TO THIS LER.

I 4

48 FORM 111 LER SC55 0ATA 04-18-91 0 **eemenee***************************. e**..ee...e****e****.****e***

e, DOCKET TEAR LER NUMBER REVISION- OCS NUMBER NSIC EVENT DATE 278 1990 008 0 9009040256 219413 07/27/90 eeeeeeee............. ..................ee..e***ee.e.. ***ee........

A85 TRACT I POWER LEVEL - 0802. 04 7/27/90 AT 0350 HOURS, WITH UNIT 3 OPERATING AT i

1005 PoutR, AN OFFGAS RECOMSINER ISOLATION CCCURRED CAU5ING THE MAIN g, CONDEN5ER V A CUU M TO BEGIN DECREASING. A FAST REACTOR POWER REDUCTION WAS INITIATED IN ACCORDANCE WITH THE PROCEDURE FOR A LOSS OF MAIN CONDEN5ER VACUUM. AT 0403 HOURS, WITH UNIT 3 AT APPROXIMATELT 802 POWER, a MANUAL SCRAM WAS INITIATED ST PLACING THE MODE SWITCH IN SHUT 00WN FOLLOWING THE RECEIPT OF AN 'A' CHANNEL REACTOR AUTO HALF

t. . SCRAM SIGNAL. A GROUP II AND III ISOLATION OCCURRED A5 A RESULT OF THE MANUAL SCRAM. OTHER 54*ETT SYSTEMS PERFORMED A5 DE51GNEO. AN

, OFFSITE RAOIDACTIVE GASE0US RELEASE AMOUNTING TO 23.51 0F TECHNICAL SPECIFICATION LIMIT 5 OCCURRED DURING POST SCRAM REC 0 VERT. THERE WERE

NO ADVERSE HEALTH THREATS To ONSITE PERSONNEL OR THE GENERAL PUBLIC.

THE CAUSE OF THE FAILURE APPEARS TO BE A COMPONENT /575 FEM FAILURE IN

,- THE OFFGAS RECOMSINEW CONDENS AT! COOLING WATER PRESSURE CONTROL SYSTEM. THE DESIGN OF THE ST51EM WILL SE EVALUATED TO DETERMINE THE EXACT CAUSE OF THE FAILURE AND THE APP 90PRIATE MEASURES REQUIRED TO

,; CORRECT THE PROSLEM. THERE WAS ONE PREVIOUS SIMILAR EVENT..

3

',' FORM 112 LER SCSS DATA 04-18-91 0.............. **......ee....................* .....................

6 DOCKET TEAR LER NUMOER REVISION OCS NUMBER NSIC EVENT DATE g; 280 1989 026 0 3908140325 214962 07/09/89

, e..................e*...............................................

rueen Lev =L - ve26 UN /t4/e* WITH UNIT 1 AT 63% POWER, INSTRUMENT P1 TECHNICIANS WERE CALI* RATING DOWER RANGE NUCLEAR INSTRUMENT 4 TION (NI)

UHEN A FAILURE 0? THE NI 3CCURCEO. THIS RESULTED IN A SOURIOUS NI DROPPED ROD SIGNAL AND AUTOMATIC INITIATION OF A 30% POWER TUR8IXE pq RU%8%CK. FCLLOWING THE TutSINE RUN8ACK OPERATORS HAD DIFFICULTY

,, i STABILIZING STEAM GENERATOR LEVELS DUE TO INAPPROPRIATE OPERATOR t bd RESPONSE AND EQUIPMENT MALFUNCTION. A TURSINE TRIP / REACTOR TRIP OCCURRED DUE TO A HIGH-HIGH LEVEL CON 3ITION IN THE "3" STEAM GENERATOR t r.

TWO MINUTES AND AS SECONDS AFTER INITIATION OF THE TURSINE RUNSACK.

P1 THE FAILURE OF THE POWER RANGE NI WAS DUE TO A SLOWN CONTROL POWER FUSE CAUSED ST THE USE OF A VOLTMETER WITH AN UNGROUNDED POWER SUPPLY.

g ,

THE PERSONNEL INbOLVED WERE DISCIPLINED. THIS EVENT AND SIMILAR

,4

EVENTS RELATED TO IMPROPER USE OF METERS WILL BE DISCUSSED OURING THE b4 INSTRUMENT TECHNICIANS CONTINUING TRAINING CLASSES. INSTRUMENT

' e TECHNICIANS HAVE BEEN ISSUED INSTRUCTIONS TO USE GROUNDED METERS FOR TESTING UNLF35 SPECIFICALLY DIRECTED OTHERWISE.

kQ 1

't g, FORM 113 LER SCSS DATA 0************************************************************04-18-91 ********

DM 00CKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 280 1989 044 0 9001300204 216587 12/21/89

>t *-

ABSTRACT D4 POWER LEVEL - 100%. ON DECEMSER 21, 1999 AT 2156 HOURS WITH UNIT 1 AT 100% POWER, A MANUAL REACTOR TRIP WAS INITIATED SY THE UNIT 1 LICENSED CONTROL ROOM OPERATOR (CRO). LOSS OF POWER TO A SEMI-VITAL BUS D1 CAUSEC NUMEROUS CONTROL ROOM ALARMS TO ANNUNCIATE AND DE-ENERGIZED THE CONTROL R00 POSITION INDICATION SYSTEM WHICH RESULTED IN E RRONEOUS g, INDICATIONS OF CONTROL RODS INSERTING INTO THE REACTOR. THESE

, INDICATIONS PROMPTED THE OPERATOR TO IMMEDIATELY INITIATE A MANUAL Es REACTOR TRIP /TURSINE TRIP PER APPROVED PROCEDURES. OPERATORS PERFORMED THE APPROPRIATE PLANT PROCEDURES AND QUICKLY STABILIZED THE PLANT FOLLOWING THE TRIP. THE LOSS OF POWER TO THE SEMI-VITAL SUS WAS te CAUSE3 BY A FAULT ON THE "A" RESERVE STATION SERVICE TRANSFORMER THAT ISOLATED THE TRANSFORMER FROM THE STATION'S POWER DISTRIBUTION SYSTEM.

,, THE TRANSFORMER SUPPLIED THE SEMI-VITAL BUS THROUGH THE 1J 4160V EMERGENCY SUS. THE FAULT WAS CAUSED BY MATERIAL BLOWN FROM THE 8

TUR8INE BUILDING ROOF STRIKINS THE PRIMARY LEADS TO THE TRANSFORMER.

THE 83 EMERGENCT DIESEL GENERATOR AUTOMATICALLY RESTORED POWER TO THE EMERGENCY SUS SECONDS AFTER THE EUS WAS DE-ENERGIZED. A FOUR HOUR 3, NON-EMERGENCY REPORT WAS MADE TO THE NUCLEAR REGULATORT COMMISSION PER 10CFR 50.72.

I v.

FORM 114 LER SCSS DATA 04-18-91 Da*******************************************************************

00CKET YEAR LER NUMBER REv!SION DCS NUMBER NSIC EVENT DATE

. 280 1990 004 0 9100000000 220903 05/22/90

~

A8STRACT POWER LEVEL - 100%. ON S/22/90 AT 1150 HOURS WITH UNITS 1 AND 2 AT 100% POWER, 4 FAULT OCCURRED ON THE UNIT 1 "A" MAIN TRANSFORMER AS A RESULT OF AN INADVERTENT ACTUATION OF THE TRANSFORMER *$ DELUGE SYSTEM.

, THE FAULT INITIATED A UNIT 1 GENERATOR DIFFERENTI AL LOCKOUT WHICH IMMEDIATELY INITIATED A TURSINE TRIP / REACTOR TRIP. THE FAULT ALSO

, RESULTED IN THE LOCKOUT OF THE "A" RESERVE STATION SERVICE TRANSFORMER

, (RSST). APPRDI. 10 SECONDS LATER, THE UNIT 2 CONTROL ROOM OPERATOR INITIATED A MANUAL REACTOR TRIP AFTER OSSERVING ERRATIC CONTROL 900 INDIVIDUAL ROD POSITION INDICATIONS (IRPI). OPERATORS PERFORMED THE g APPROPRIATE PLANT PROCEDURES AND QUICKLY STABILIZED THE UNITS

'FOLLOWING THE TRIPS. Tw? ERCATTC 't4 t f 5 toot vaatrav'aae "e** ""- *-

I . . - - -

- -- _ _ _ _ _ J

.. . . . . . . ..., , ... en. -2 -3:*2rNLY UIEi L GinE2AT3R AUTOMATICALLT RESTORED POWip TO THE UNIT 1 "J" EMERGENCT GUS WHICH WAS m4 DE-CNERGIZEC ef THE "A" RSST LCCK00T. A FOUR H3UR NON-E9ERGENCY '

REPORT UA5 HADE TO THE NRC IN ACCORDANCE WITH 10CFa50.72.

b4 FORM 115 LER SC55 OATA 04-18-91 54 0********************************************************************

i g '. DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE eq 280 1990 006 0 9008010066 219029 07/01#90 Ed A85 TRACT POWER LEVEL - 100%. ON 7/1/90 AT 1802 HOURS, WITH UNIT 1 AT 100%

be ., POWER, THE "A" RESERVE STATION SERVICE TRANSFORMER TRIPPED OUE TO ACTUATION OF ITS SUDOEN PRESSURE RELAT. THE TRANSFORMER TRIP ke DEENERGIZE0 THE IJ 4160V EMERGENCY SUS AND THE 83 EMERGENCY DIESEL

, GENERATOR STARTED AND LOADEO ONTO THE TJ BUS A5 DESIGNED IN be APPROXIMATELT NINE SECON05. AN INDIVIDUAL 200 POSITION INDICATION (IRPI) CONTROL R00 STOP AND TURBINE RUNSACK SIGNAL WAS RECEIVE 0, AND i, THE UNIT LOAD WAS AUTOMATICALLY REOUCED TO APPROXIMATELY 95% POWER.

De AFTER THE TUR81NE RUN3ACK, WITH PLANT CONDITIONS STABLE AT 952 POWER, OPERATOR 5 OBSERVED INSTRUMENT AIR (IA) PRES 5URE DECREASING RAPIOLY.

p, 8EFORE INSTRUMENT AIR COULO BE RESTORE 0, THE REACTOR OPERATOR (RO)

RECEIVED INDICATION OF THE "C" MAIN STEAM TRIP VALVE (MSTV3 BEGINNING Be TO CLOSE AND MANUALLY TRIPPED THE REACTOR AT 1807 HOURS. INSTRUMENT AIR W AS RESTORE 3 APPROXIMATELY TWO MINUTES FOLLOWING THE MANUAL TRIP 8V 87PA551NG AND ISOLATING A FAILED IA ORTER. THE UNIT WAS 8ROUGHT TO ye STABLE HOT SHUT 00WN CONDITIONS USING THE "A" AND "C" $TEAN GENERATOR ATMO5PHERIC POWER OPERATED RELIEF WALVES (PORUS). A FOUR HOUR

,. NON-EMERGENCY REPORT WAS MADE TO THE NRC IN ACCORDANCE WITH I

10CFR50.72.

1 Dt FORM 116 LER SC55 CATA 04-13-91

g. 0********************************************************************

DOCKET TEAR LER NUMBER REVISION 0C5 NUM8ER NSIC EVENT DATE 281 1939 007 0 8910170261 215546 09/16t89 I' ********************************************************************

I A85 TRACT

,, POWER LEVEL - 000%. ON SEFTEMBER 16, 1989 AT 1228 HOURS WITH UNIT 2

, , $U8 CRITICAL, OURING A REACTOR STARTUP, A MANUAL REACTOR TRIP WAS l INITIATED WHEN IT WAS DETERMINED THAT IMPROPER 844E OVERLAP EXISTED

' ' ,. BETWEEN T H E " A" AND "B" CONTROL 900 BANKS. THE T? ACTOR TRIP WAS INITIATED TO INSERT ALL CONTROL 4005 AND TO RESEl THE CONTROL 400 STEP COUNTERS TO ZERO. A FOUR HOUR NON-EMERGENCY REPORT WA5 MADE TO THE e NUCLEAR REGULATORT COMMISSION PER 10CF450.72. TROUBLESHOOTING 010 NOT REVEAL THE CAUSE OF THE IMPROPER SANK OVERLAP. DURING THE SUB5EQUENT REACTOR STARTUP, NO PROBLEMS WERE ENCOUNTERED WITH CONTROL 900 SANK

,, OVERLAP.

FORM 117 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET TEAR LER NUMBER REVISION OCS NUMBER 451C EVENT DATE

,i 281 1989 009 0 8910180019 215547 09#18189

, 485 TRACT POWER LEVEL - 0141. ON SEPTEMSER 18, 1989, AY 1042 HOURS, WITH UNIT -

t REACTOR AT 14% POWER AND THE TURSINE AT 1900 RPM UNDER NO LO4 3

gi CONDITIONS, 4 REACTOR TRIP SIGNAL WAS GENERATED. A GENERATC

, DIFFERENTIAL Lor.t0UT RELAY Se BU TPIPPED THE YtJ R i ! M E , AMn st

- . . . .... ass 4 =2*L.Asw an: vlC4 f FOLL34ING THE TRIP. THE St PU D1 GENEPATOR RACKOP LOCK 3UT RELAT TRIP kAS CAUSED BT THE SPURIQU5 ACTUATION OF THE GENERATct SACRUS IMFE0AHCE RELAT (KD- 41). THE EXACT CAUSE OF THE SPURIOUS ACTUATION OF THE RELAY COULO NOT BE DETERMINED

kW M3cEVER FAULTS EERE DISCOVERED IN THE RELAT. THE FAULTED KO-41 RELAY ag WAS REPLACED AND APPROPRIATE TESTING WAS PERFORMED. THE GENERATOR kN STARTUP PROCEDURE MAS BEEN REVISED TO ENSURE THAT REACTOR POWER 15 LESS THAN 101 PRIOR TO CLOSING THE EXCITER FIELO BREAKER. A FOUR HOUR

j NON-EMERGENCY REPORT WAS MADE TO THE NUCLEAR REGULATORY COMMISSION IN P1 ACCORDANCE WITH 10CFR50.72.

1

- FORM 118 LER SCSS DATA h* 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 281 1989 010 0 8910170199 215548 De ************************************************************09/19/89 ********

" A85 TRACT POWER LEVEL - 0251. 04 9/19#89 WITH UNIT 2 REACTOR POWER AT 251, b4 3 SHORTLY AFTER PLACING UNIT 2 ON LINE, AN AUTOMATIC REACTOR TRIP WA5 GENERATED AT 0051 HOUR 5 45 A RESULT OF A LO LO STEAM GENERATOR LEVEL.

A FOUR HOUR NON-EMERGENCY REPORT WA5 h40E TO THE NRC AT 0120 HOURS De PER 10CFR50.72. A RAPID TUPBINE LOAD INCREASE OCCURRED DURING STARTuP WHICH LED TO OSCILLATIONS IN THE STEAM GENEPATOR (StG) WATER LEVEL 5, 81 EVENTUALLY LEADING TO THE LO LO StG WATER LEVEL TRIP. THE CAUSE OF THE RAPID TURBINE LOAD INCREASE WAS THE OPERATOR RAISING.THE GOVERNOR VALVE POSITION LIMITER MORE RAPIOLT TH44 DESIRED. THE OPERATORS D1 PERFORMED THE APPROPRIATE EMERGENCY PROCEDURES, AND QUICKLV STABILIZE 0

,g. THE UNIT FOLLOWING THE REACTOR TRIP. THE LE55045 LEARNED FROM THIS

,, EVENT AND SU55EQUENT UNIT STARTUP HAVE BEEN DISSEMINATED TO ALL g OPERATIONS PERSONNEL.

he FORM 119 LER SCSS OATA 04-1

- , 0****************************************************************8-91 ****

DOCKET TEAR LER NUMBER REVISION DC5 NUM8ER N51C EVENT DATE 7, 281 1990 005 0 9007050105 218702 05/31/90 I ABSTRACT

. POWER LEVEL - 1003. 04 MAY 31, 1990 AT 200$ HOURS WITH UNIT 2 AT 1003

e. POWER, A MANUAL REACTOR TRIP WAS INITIATED ST THE UNIT 2 LICENSED CONTROL ROOM OPERATOR. A MALFUNCTION OF THE "A" MAIN FEEDWATER

, REGULATING VALVE (MFBV) POSITIONER CAUSED THE VALVE TO CLOSE, DECREASING FEE 0 WATER FLOW TO THE "A" 5 TEAM GENERATOR (5/G) TO NEAR '

ZERO. OPERATORS PERFORMED THE APPROPRIATE PLANT PROCEDURES AND QUICKLT STABILIZED THE PLANT FCLLOWING THE TRIP. 5AFETT SYSTEMS FUNCTIONED AS DESIGNED WITH THE EXCEPTION THAT ONE INDIVIDUAL ROD POSITION INDICATOR (IRPI) 200 BOTTOM BISTABLE LIGHT FAILE0 TO ,

ILLUMINATE ANO SEVERAL OTHERS DID NOT ILLUMINATE IMMEDIATELT. THE

FAILURE OF THE MFRV WAS CAUSED ST ELOCKADE OF THE POSITIONER AIR

'5UPPLY INLET FILTER / ORIFICE ASSEMBLY. THE FAILURE OF THE RCD 807T04

,,, LIGHT TO ILLUMINATE WAS CAUSED ST A FAULTY LIGHT SULB. THE DELATED ILLUMINATION OF THE OTHER ROD 80TTOM LIGHTS WAS THE RESULT OF A .

SEMI-VITAL BUS VOLTAGE FLUCTUATION. THE MAINTENANCE PROCEDURE WILL

, BE REVISED TO REQUIRE REPLACEMENT OF YME FILTER /0RIFICE ASSEMBLIES OURING EACH REFUELING. OPERATION OF THE LOAD TAP CHANGER FOR THE "C"

' RESERVE STATION SERVICE TRANSFORMER (415T) 15 UNDER EVALUATION. A

, FOUR HOUR NON-EMERGENCT REPORT WAS MADE TO THE NUCLEAR REGULATORY COMMI55 ION PER 10CFR 50.72.8.2.11.

t. 1 I"

.- FORM 120 LER SC55 DATA AA-18-o*

... a.,a wc4 u 9010100211 Z19655 p1

- - - - 0F/27/90 ABSTRACT g4 POMER LEVEL - 1002. ON 8/27/90 AT 0925 HOURS, WITH UNIT 2 CPERATING AT ej 100% POWER, THE "A" MAIN FEE 0 WATER REGULATING VALVE (MFRV) CLOSED DW FOLLOWING THE INADVERTENT GROUNDING OF ITS CONTROL SIGNAL DURING PERI 001C SURVEILLANCE TESTING. CLOSURE OF THE "A" MFRV RESULTED IN A

, ,, MISMATCH SETWEEN "A" STEAM GENERATOR (S/G) FEE 0 WATER FLOW AND STEAM pq FLOW CAUSING SEVERAL ANNUNCIATOR 5 70 ALARM. THE REACTOR OPERATOR i

IMME0!ATELY ATTEMPTED TO REOPEN THE "A" MFRV 8T INCREASING THE O CONTROLLER DEMAND IN MANUAL GUT THE VALVE DID NOT RESPONO. SINCE A LOW S/G LEVEL COINCIDENT WITH STEAM FLOW-FEE 0 WATER FLOW MISMATCH be REACTOR TRIP WAS IMMINENT, THE REACTOR OPERATOR MANUALLY TRIPPED THE

,. REACTOR AT APPROXIMATELT 27% LEVEL IN THE "A" 5/G. THE OPERATORS Dq FOLLOWE0 APPROPRIATE PLANT PROCEDURES AND QUICKLY $7A81LIIED THE UNIT FOLLOWING THE MANUAL TRIP. A FOUR HOUR NON-EMERGENCY REPORT WAS MADE i-1 TO THE NUCLEAR REGULATORY COMMISSION IN ACCORDANCE WITH 10CFR50.72.

he FORM 121 LER SCSS DATA be 0************************************************************04-18-91********

DOCKET YEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE y, 2S2 1989 010 0 8908280290 215124

- - - - 07/21/89 D'8 AS$ TRACT POWER LEVEL - 1003. ON JULY 21, 19E9 UNIT 1 WAS AT 1002 POWER. DuRING R1 THE AFTERNOON, A " MOT L ACQUER" SMELL W AS NOTICEO COMING FROM 4160V BUS 11. 4160V 8US 11 SUPPLIES No. 11 REACTOR COOLANT PUMP AND NO. 11 g, FEE 0 WATER 8 UMP. THE PROSLEM WAS INVESTIGATED AND DETERMINED TO BE OF NO IMMEDIATE CONCERN BUT WORTNT OF INCREASE 0 AWARENESS. AN E' "0PER*TIONS NOTE" WAS ISSUED TO ALERT OPERATOR $ OF THE PROBLEM.

OURING A $U8 SEQUENT INVESTIGATION FOR THE SOURCE OF THE SMELL, AN OPERATOR PULLED OPEN THE POTENTIAL FUSE ORAWER FOR 4160V SUS 11, ee CAU$ING UNDERVOLTAGE RELAYS TO TRIP. AFTER A 5 SECOND TIME DELAY TIMED OUT, THE BREAKER FOR NO. 11 REACTOR COOLANT PUMP TRIPPED AND THE I' REACTOR TRIPPED AT 2345 ON JULT 21, 1989 OUE TO $1NGLE LOOP LOSS OF FLOW REACTOR TRIP SIGNAL. THE UNIT WAS RETURNED TO SERVICE AT 2204 ON JULY 22, 1989. 4160V SUS 000R$ H AVE BEEN L AI ELED, CAUTIONING I

PERSONNEL OF THE CONSEQUENCES OF OPENING THE POTENTIAL FUSE DRAWERS.

POTENTIAL FUSE ORAWER FRONTS WILL ALSO SE LASELEO.

p. 1 FORM 122 LER SCSS DATA 0************************************************************04-15-91 DOCKET TEAR LER NUMBER REVISIGN OCS NUMBER N5IC EVENT DATE

' 282 1990 01F 0 9012260256 220525

,, 11/21/90

,1 485 TRACT POWER LEVEL - 100I. 04 NOVEMBER 21, 1990, UNIT 1 WAS AT 1003 POWER.

AT A80UT 1540 AN OPERATOR MAKING ROUNOS OF THE TUR8INE BUILDING

,; NOTICE 0 THAT NO. 11 SUS OUCT COOLING FAN WAS NOT RUNNING AND THAT ITS SUPPLY 8 REARER HAD TRIP 8ED. HE NOTIFIED TH7 CONTROL ROOM OF HIS FINDINGS, AND HE WAS THEN INSTRUCTED TO $ TART NO. 12 Sus DUCT COOLING

,, FAN TO RE-ESTASLI$M THE FLOW OF COOLING AIR THROUGH THE GENERATOR SUS DUCTS. WHEN NO. 12 SU5 OUCT COOLING FAN WAS STARTED AT 1545, THE MAIN GENERATOR TRIPPED, RESULTING IN A YURSINE TRIP / REACTOR TRIP. THE I

gi TURBINE BUILDING OPERATOR HAD DETERMINED THAT THERE WAS NO BUS DUCT COOLING FAN RUNNING, SUT SUS OUCT TEMPERATURE APPEARED NORMAL. ACTUAL t Sus DUCT TEMPERATURE WAS MIGHLY ELEVATED, BUT THE TEMPERATURE SENSORS

g. ARE LOCATED IN THE SUS DUCT COOLER SUC TION 00CT SUCH THAT REPRESENTATIVE SUS 00CT TEMPERATURE Y$ NOT 58N58n is a saw it wov

.o.un 6

in.n v .aa=s:3 A 4: ret t A T OR TRIF 3N HIGH TE9FERATURE OF '5C. AN INVESTIGATION WAS SEGUN 443 THE CAUSE OF THE TRIP WAS DETERMINED. THE P1 UNIT WAS RETURNEC T3 SEPVICE AT 1$41 THE N!XT DAY.

1

. FORM 123 LER SC55 OATA bd 0*********************************************************ee.04-19-91 ********

DOCKET TEAR' LER NUMBER REVI5!ON DC5 NUMBER N5IC EVENT DATE '

t !>

285 1989 019 0 6911010208 215697 09/24/ 89 pq e............................................................**.. ..

, ABSTRACT I4 POWER LEVEL - 006%. ON 9/24/89, FORT CALHOUN STATION UNIT 1 WAS OPERATING AT APPROXIMATELY 70% POWER IN MODE 1. AT 1259 HOURS

b4 INDICATION OF HIGH TEMPERATURE FOR REACTOR COOLANT PUMP RC-34 UPPER MOTOR THRUST 83ARING WAS RECEIVED IN THE CONTROL ROOM. AFTER gg MARIM!!ATION OF 80TH THE COOLING WATER FLOW TO THE OIL COOLERS AND THE 93 DIL FLOW TO THE BEARING FAILED TO REOUCE THE INDICATED TEMPERATURE, U" THE SHIFT SUPERVISOR INITIATED A CONTROLLED PLANT SH"YDOWN AT 1320 HOUR 5. AT 1518 HOURS, WITH REACTOR POWER BETWEEN 5 ANO 6 PERCENT, bM RC-3A THRUST BE ARING TEMPER ATURE INDICATION SPIKED TO 26? PEGREES.

THE REACTOR WAS IMMEDIATELY MANUALLY TRIPPED AND RC-3A WAS 1.:9T DOWN.

3 THIS TRIP !$ REPORTA8LE PUR5UANT TO 10 CFR 50.73(A)(2)(IV).

b4 7, INVESTIGATION REVEALED THE CAUSE OF THE INDICATED HIGH TEMPERATURE TO 8E DAMAGEO CABLE FOR THE BEARING RESISTIVE TEMPERATURE DEVICE (Rio),

88 ALTHOUGH CAUSE OF THE DAMAGE COULD NOT SE DETERMINED. THERE WAS NO EVIDENCE OF ACTUAL EXCESSIVE BEARING TEMPERATURE. THE DAMAGED CABLE AND THE RTD WERE REPLACED. OTHER 5!MILAR RTO WIRING WILL SE INSPECTED 4 31 AND INVESTIGATION INTO THE CAUSE OF THE CA9LE DAMAGE WILL BE ;

t COMPLETED DURING THE 1990 REFUELING OUTAGE.

, be I I

FORM 124 LER SC55 DATA 1 .. 0.... ............................................ ............. 04-1 3-91....

DOCKET YEAR LER NUMBER REVISION DC5 NUMSER N5IC EVENT DATE

a. 285 1990 026 1 9101110004 220652 11/19190

.........................................eeeeeeeeee....... .........

, A85 TRACT POWER LEVEL - 100%. ON NOVEM8ER 19, 1990 WHILE THE PLANT WAS OPERATING t AT 1002 POWER, A PIPE JOINT AT AN ISOLATION VALVE IN THE TUR8INE

, BUILDING INSTRUMENT AIR HEADER FAILED. THE RESULTING LO55 0F g, INSTRUMENT AIR PRES 5URE CAUSED 4 FEE 0 WATER TRAN5IENT WHICH ULTIMATELY RESULTED IN MANUAL TRIPPING OF THE REACTOR. THE ROOT CAUSE FOR THIS

' EVENT WAS IMPR3PER INSTALLATION OF THE ISCLATION VALVE (INADEQUATE JOINT INSERTION COUPLED WITH POOR SOLDERING TECHNIQUE) UNDER &

MODIFICATION IN 1984 THE CONTRIBUTING CAUSE WAS INADEQUATE CONTROL

OF THE INSTALLATION PROCESS. THE COMPLETED CORRECTIVE ACTIONS FOR THIS EVENT INCLUDED REPAIRING THE FAILED JOINT INSTALLING BRACES

, AROUND ALL APPLICA8LE HEADER ISOLATION VALVES, CHECKING THE TURBINE SUILDING HEADER FOR LEAKS, AND REPAIRING ONE ADDITIONAL LEAK. THE

' ADMINISTRATIVE CONTROLS OVER MODIFICATIONS HAVE BEEN IMPROVED $1NCE 1984. THE LONG TERM CORRECTIVE ACTIONS FOR THIS EVENT INCLUDE REIMSTALLING THE ISOLATION VALVE 5 U5!NG SETTER TECHNIQUES PROVIDING BETTER TRAINING ON SOLDERED JOINTS, AND DISCUS $1NG THIS EVENT IN

,' LICENSED AND NON-LICENSED CPERATING PERSONNEL REQUALIFICATION

,a '

TRAINING.

1 I FORM 125 g ,' LER SCS$ DATA 04-18-91 Oe*************eeeeee.**********ee**e*** *** **ee****ee********e.. e*

.e bOCEET TEAR LER NUMBER REVISION DCS MUM 8ER N5IC EVENT DATE g ;' 286 1989 004 0 8903150504 213198 02/04/89

, ..................................................... .*........**.e L

. m

.... ..... asw.. v. etowu==v *, Iv4f wilH THE U41T ! R! ACTOR SU9 CRITICAL AT LESS TMAN E-10 AMPS IN THE INTE1 MEDIATE RANGE, A P1 REACTOR TRIP WAS INITIATED ST AH IEC TECHNICIAN TRouSLESH00 TING NUMBER 32 SOURCE RANGE. ALL FLANT ST5TEMS FUNCTIONED PROPERLY. IT UA5 g4 DETERINEO THAT Am I4C TECHNICI AM REMOVED INSTRUMENT FUSES FOR THE

[; SOURCE RANGE RESULTING IN A LOSS OF VOLTAGE TO THE HIGH FLUX TRIP SISTABLE. THE SOURCE RANGE HAS BEEN REPAIRED AND PLACEO SACK IN DW SERVICE.

, g 1 P1 FORM 126 LER SC55 DATA Id .

0*****************************************e******************04-19-91 **e **** r DOCKET VEAR LER NUM8ER REVISION DCS NUMBER N5IC EVENT DATE i

286 1999 015 0 8911300071 216004 he 10/19189 gg eeeeeee*.......................................e** ......... ........

gg ABSTRACT h POWER LEVEL - 100%. ON OCT09ER 19, 1939, WITH THE REACTOR AT 100 U" PERCENT POWER, CONTROL ROOM OPERATORS INITIATED A NANUAL REACTOR TRIP WHEN THEY OSSERVED 12 CONTROL RODS FULLY INSERT INTO THE REACTOR CORE.

INSTRUMENTATION AND CONTROLS TECHNICIAN 5 WERE PERFORMING be SURVEILLANCE TEST 3PT-M62, "480 VOLT UNDERVOLTAGE AND DEGRADED GRID" AT THE TIME OF THE EVENT. ALL SYSTEMS FUNCTIONED PROPERLY FOLLOWING pg

THE TRIP WITH THESE EXCEPTIONS: THE COMPUTER GENERATED "5EQUENCE OF EVENT 5" RECORD WAS LOST; THE STATION AUXILIART TRANSFORMER TAP CHANGER D8 RESPONDED SLUGGISHLT; OPERATOR $ ENCOUNTERED OIFFICULTY IN RESTARTING g, CONTROL ROD DRIVE MECHANISM COOLING FAN 831 ; THE CONDENSATE POLISHER 91 FACILITY STP455 VALVE DID NOT OPEN! A LEAK OEVELOPE0 04 A PRE 55URIIER SAFETY VALVE LOOP DRAIN VALVE. WHILE THE PLANT STAFF WAS UN48LE TO q, DETERMINE THE EAACT ROOT CAUSE OF THE EVENT, THE INITIATING OCCURRENCE

' WAS A "NON-SI 3 LACK 0UT" ACTUATION ON 450 VOLT SUS 54 IT HAS BEEN CONCLUDED THAT THIS RESULTED FROM A PERSONNEL ERROR SU5TAINED DURING p THE PERFORMANCE OF SURVEILLANCE TEST 3 P T- M 6 2. FOLLOWING A SAFETY b9 REVIEW 8T THE PLANT OPERATIONS REVIEW COMMITTEE AND APPRORIMATELY 110 HOURS OF PLANNED CCRRECTIVE MAINTENANCE, PLANT OPERATORS BROUGHT THE y, p REACTOR CRITICAL ON OCT08ER 23, 1987, SYNCHRONIZED THE GENERATOR TO THE 805 ON OCTOBER 24, 1989, AND REACHED FULL POWER ON OCTOSER 25, 1989.

I FORM 127 LER SC55 DATA

0************************************************************04-15-91 ********

g DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 296 1990 003 0 9005040247 218081 03/31/90

..een..............................e*****eeeeeeeeen.................

485 TRACT I ,; POWER LEVEL - 100%. ON MARCH 29, 1990, THE AUTHORITT DISCOVERED THAT A NON-C ATEGOR Y I, SEISMIC CLASS III NITROGEN SUPPLY LINE HAD EEEN

) INSTALLED IN A $4FETT-RELATED, CATEGORY I, SEISMIC CLASS I LINE i

,, BETWEEN TWO CONTAINMENT ISOLATION VALVES. ALTHOUGH THE NITROGEN

$UPPLY LINE WAS NON-CATEGORY I, IT HAS'8EEN SUCCES$ FULLY TESTED IN ACCORDANCE WITH THE CONTAINMENT ISOLATION LEAK TEST PROCEDURE ON A

,. PERIDOIC 84515 SINCE IT WAS ORIGINALLY INSTALLED. THE AUTHORITT HAS IDENTIFIED THE ROOT CAUSE OF THIS EVENT 70 SE A LESS THAN ADEQUAYE 2

ENGINEERING REVIEW 08 THE MODIFICATION THAT ORIGINALLY INSTALLED THE

, NITROGEN SUPPLT LINE. THE PR09 TEM WAS CORRECTED SV REMOVING THE PIPE CONNECTION Ago THE RESTORATION OF THE LINE TO ITS ORIGINAL CLASSIFICATION.-

t '

s FORN' 128 LER SC55 CATA 04-18-91

., 0****e.......*......*....................................... ........

. DOCKET TEAR LER NUMSER REVISION OCS NUMSER NSIC EVENT ARTE

^~

ABSTRACT F4 POWER LEVEL - 100%. ON JUNE 21, 1990 WITN THE REACTOR AT 100 PERCENT P02ER, A UNIT TRIP WAS INITIATED AS THE RESULT OF ACTUATION OF THE i bg MAIM GENERATOR LOCK 0UT RELAYS. ALL PLANT SYSTEMS FUNCTIONED PROPERLY

,i '

FOLLOWING THE TRIP. IT WAS DETERMINED THAT THE ACTUATION OF THE DM GENERATOR LOCKOUT RELAYS RESULTED FROM THC MECHANICAL FAILURE OF PROTECTIVE RELAY, MCT1, WHICH PROVIDES EXPANDED BREAKER PROTECTION FOR

g THE 345KV E LE CT R IC A L OUTPUT SREAKERS. THIS RELAY WAS REPLACED AND r1 ' TESTED SUCCESSFULLY. THE REACTOR WAS BROUGHT CRITICAL ON JUNE 30, 1990 AT 1852 HOURS AND FULL POWER OPERATIONS REACHED ON JULY 2, 1990 g4 y AT 0515 HOURS.

Da ,. FORM 129 LER SCSS DATA

04-18-91 0***.**.............................***...**................ ........

pc 00CKET Y!AR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE h

257 1989 002 0 8904180103 213557 03/06/89 We *************************.a..**********.*********.****** ****.****.*

j, ABSTRACT be POWER LEVEL - 100%. ON MARCH 6, 1959 AT 0657 HOURS WHILE OPERATING AT 1001 REACTOR POWER, THE UNIT 3 MAIN TUR81NE (MT) TRIPPEO, RESULTING IN g4 gg AN ANTICIPATORY REACTOR TRIP. THE MT TRIP WAS INITIATED 8V A GENERATOR LOCKOUT WHICH WAS OUE TO A LOSS OF GENERATOR EXCITATION.

THE REASON FOR THE LOSS OF EXCITATION COULD NOT BE DETERMINED.

t,

' ADDITIONALLY, THREE PIPE SUPPORTS WERE DAMAGED FOLLOWING THE TRIP AS A RESULT OF A WATER HAMMER IN THE MAIN STEAM TUR81NE 8vPASS LINE. THE P1 IMMEDIATE CORR!CTIVE ACTION WAS TO STABILIZE THE UNIT AT HOT SHUTDOWN.

.i, SUBSEQUENT CORRECTIVE ACTIONS INCLUDED DETERMINING THE CAUSE OF THE g, TRIP AND IMPLEMENTING A PLAN FOR THE REPAIR OF THE THREE PIPE I

SUPPORTS. THE ACTUAL ROOT CAUSE OF THE TRIP COULO NOT SE DETERMINED,

,i THEREFORE THIS EVENT IS CLASSIFIED AS UNKNOWN.

he 1

. FORM 130 LER SCSS DATA 04-18-91 0.*****************************************************************.*

00CKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 257 1959 004 0 8909270141 215304 08/18189 8

A85 TRACT

, , POWER LEVEL - 100%. ON 811S/89 AT 1233 HOURS, OCONEE UNIT 3 TRIPPED FROM 100% FULL POWER. THE REACTOR TRIP WAS AN ANTICIPATORT TRIP

' ' RESULTING FROM A FALSE ELECTROHYOPAULIC 00mTROL (EHC) SYSTEM LOW HYDRAULIC PRESSURE TRIP $1GNAL. THE VALSE SIGNAL WAS GENERATED WHEH WATER OROPS MADE MOMENTARY CONTACT #40055 THE TERMINAL STRIP t ASSOCIATED WITH THE LOW HTORAULIC f* ESSURE TRIP CIRCUIT. THE STATION JANITORIAL SERVICE VENDOR AND OPERATZ?"; PtASONNEL HAD WASHED THE

,, FLOOR AROUND THE EHC HTORAULIC POWER UNIT CABINET PRIOR TO THE UNIT

, TRIP. THE CABINET 0004 WAS INADEQUATELY SHUT, POTENTIALLY ALLOWING MOISTURE TO ENTER THE HYDRAULIC POWER UNIT CA8INET. PLANT RESPONSE TO THE TRIP WAS MORMAL WITH NO RADIOLOGICAL RELEASES OR ENGINEERED

, SAFEGUARD ACTUATIONS. THE ROOT CAUSE OF THIS INCIDENT IS CLAS$1FIED AS AN INAPPROPRIATE ACTION, POOR WORK PRACTICE. IMMEDIATE CORRECTIVE ACTIONS WERE TO STABLIllE THE UNIT AT HOT SHUTDOWN CONDITIONS.

, 1 FORM 1 31 LER SCSS DATA 04-18-91

' 0**********************.*******************..************************

DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE p 287 1970 001 1 9003370007 217079 01/19190 4

6

... . , .. ,,

nou=> raLL>=th, a 24PIO RECUCTION IN POWER

ROM 100% FP AFTER CONTROL R03 GROUP $ ORODPED INTO THE COR*. A TEST WAS p1 IN PROGRESS AT THE TIME TO VERIST PROPER OPERATION CF THE CONTROL ROD POMER SUPPLIES. DURING THE TESTING OF GROUP 6 POWER SUPPLT, TRANSFER gq OF POWER TO THE AUXILIARY POWER SUPFLT WAS INITIATED. THE NORMAL g; POWER SUPPLT APPARENTLY FAILED TO DISENGAGE PROPERLY AND LATER D4 TECHNICIAN ACTIONS RESULTED IN OPPOSING PHASES BEING ENERGIZED. THE RESULTING OPPOSING ELECTROMAGNETIC FIELOS CAUSED THE R005 IN GROUP 6

, ;. TO FALL INTO THE CORE. OPERATORS PEALIIED THE ROD GROUP HAD DROPPED pq ' FROM CONTROL ROOM INDICATOR 5, SUT WERE NOT ASLE TO MANUALLY TRIP THE REACTOR BEFORE THE REACTOR PROTECTIVE SYSTEM AUTOMATICALLY TRIPPED THE "4 i' UNIT 04 LOW REACTOR COOLANT SYSTEM PRES 5URE. IN SPIT

OF SEVERAL f POST-TRIP FAILURES AND ABNORMAL PROBLEMS THE UNIT WAS STABILI2ED AT j

HOT SHUTDOWN CONDITIONS. AN IMMEDIATE INVESTIGATION WAS INITIATED TO

! De g ASSESS THE CAUSES AND EFFECTS OF THE TRIP. THE ROOT CAUSE OF THIS EVENT IS CLASSIFIED A5 UNKN3WN, POSSISLE EQUIPMENT MALFUNCTION. THE gg MAJOR CORRECTIVE ACTIONS WEPE TO PROVIDE MORE INSTRUCTIONS IN i,

PROCEDURES 10 CORRECT A CONTRIBUTING CAUSE OF MANAGEMENT DEFICIENCV.

1 DM FORM 132 LER SC55 OATA 04-

>= O e * * * * *

e . . . e e . . . e e . * * * * . . e e . . . . e *

e . . . . * * * * * * * * * * . .*..e. . . * * . . * * . * * *1 5 - 9 1 DOCKET TEAR LER NUMBER REVISION DCS NUMBER N5IC EVENT DATE D , 237 1990 002 0 9004200276 217794 03/07/90 R4 ABSTRACT POWER LEVEL - 100%. AT 1406 HOURS ON MARCH 7,1990, OCONEE UNIT 3 km EXPERIENCE 0 A REACTOR TRIP FROM 100% FULL POWER DUE TO HIGH REACTOR COOLANT SYSTEM (RCS) PRESSURE. A VALVE LIMIT SWITCH LINKAGE ARM MAD

' ** BECOME DISCONNECTED, PR0945LT DUE TO VISRATION DURING START-UP, I CAUSING A CLO550 INDICATION WHICH 5AT!5FIE0 PART OF THE CONTROL LOGIC FOR AUTOMATIC CLOSURE OF A FEEDWATER SLOCK WALVE. THE REST OF THE k*

LOGIC WAS SATISFIED WHEN A ROUTINE TEST SUPPLIED A LOW REACTOR POWER INPUT TO THE CONTROL LOGIC. THE BLOCK VALVE CLOSED, RESULTING IN A g, ; PARTIAL LOSS OF FEEDWATER AND, SUBSEQUENTLT THE REACTOR PROTECTIVE ST5 TEM TRIPPED ON HIGH RCS PRES 5URE. TRIP RESPONSE WAS NORMAL EXCEPT I' THAT ONE CONTROL R0D ORIVE BREAKER EXCEEDED ITS EXPECTED TRIP TIME AND WAS REPLACEO. THE LIMIT SWITCH LINKAGE WAS RECONNECTED AND THE UNIT WAS RESTARTED. THE ROOT CAUSE IS IDENTIFIED AS EQUIPMENT FAILURE.

a 1

,, FORM 135 LER SC55 OATA 04-18-91 Oe*******************************************************************

' DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

' 287 1990 003 0 0012260225 220528 11/13/90

.** ee...... *********************** *****************************

9 ASSTRACT POWER LEVEL - 1003. 04 NOVEMBER 13, 1990, AT APPP0XIMATELT 2256 HOURS,

, WHILE AT 1003 FULL POWER, OCONEE UNIT 3 CONTROL RCD GROUP 7 OROPPED INTO THE CORE. FROM CONTROL ROOM INDICATORS OPERATIONS PERSONNEL

' RECOGNIZED THAT THE RCD GROUP HAD OROPPED AND WERE ASLE TO TRIP THE REACTOR FROM 603 FULL POWER BEFORE THE REACTOR PROTECTIVE SYSTEM COULD i AUTOMATICALLY TRIP THE REACTOR ON LOW REACTOR COOLANT ST5 FEM PRES 5URE. THE POST TRIP RESPONSE WAS NORMAL. INVESTIGATION OP THE

, DROPPED CONTROL ROD GROUP REVEALED A "4IL50 SOLIO STATE PROGRAMMER, WHICH CONTROLS POWER TO THE CONTROL R00 DRIVE STATOR 5. THE PROGRAMMER WAS REPLACED AND THE UNIT WAS RETURNED TO CRITICAL AT 0435 hours0.00503 days 0.121 hours 7.19246e-4 weeks 1.655175e-4 months ON I NOVEMBER 14, 1990. THE ROOT CAUSE OF THIS EVENT IS IDENTIFIED 45 g.

EQUIPMENT FAILURE.

i 1

, FORM 134 LER SCSS DATA AA-**-*'

- . . i<c. .9) J 341?270266 21c2$1 pt

- - - - .*********11/27td9 *******

ABSTRACT PCLER LEVEL - 100t* AT APP 30XINATE1T 0506 HOU 5 ON NOVEM8ER 29, 1989, i.

A RAPID REQUCTION IN TURBINE LOAD OCCURRED. THIS R4PID REDUCTION IN D4 LOAD RESUL)ED IN INCREASING TEMPERATURE AND PRESSURE IN THE REACTOR COOLANT SYSTEM CAUSING TH! REACTOR TO TRIP ON HIGH RCS PRESSURE WITHIN

, ABOUT 4 SECON05. THE REACTOP PROTECTION SYSTEM FUNCTIONED CORRECTLY pq AND OPERATOR RESPONSE WAS APPROPRI4TE. THE POST TRIP RESPONSE WAS NORMAL.

MAIN STEAM HEADER PRES 5URE W45 REDUCE 0 TO RESEAT a MAIN STEAM "O 5AFETY WALVE (MS-V-21A). LEVEL CONTROL FOR 6 OT5G WAS CONSIDERED SLUGGISH AND THE FEEDWATER VALV! WAS CONTROLLED MANUALLY. THESE k4 ACTIONS ARE IN ACCORDANCE WITH PROCEDURES AND TRAINING. THE RAPID

. LOAD REDUCTION W45 THE RESULT OF EHC 4CTION. THE POWER LOAD UN84 LANCE CIRCUIT THAT PROTECTS THE TURBINE FROM OVERSPEED AND THE SPEED ERROR by CIRCUIT WERE SUSPECTED SINCE EITHER OF THESE CIRCUITS CAN RESULT IN RAPID CONTROL VALVE CLO5URE. THE FUNCTION AND CALIBRATION OF THESE be CIRCUIT 5 WERE CHECKED. MINOR CALIPRATION DRIFT W45 FOUND. THE ORIFT WAS NOT A8 NORM 4L AND WOULD NOT HAVE CAUSEO THE TRANSIENT. A LOOSE bg SHIELD WIRE W AS FOUND ON THE INPUT TO THE SPEED ERROR CIRCUIT FROM THE

' TURBINE PRIMART SPEED SENSOR. IT 15 POSTULATED THAT THE LOOSE CONNECTION WAS DISTURSED SY OPENING AND CLOSING THE CABINET 00095.

,, THIS W45 DETERMINED TO BE THE PROBABLE CAUSE.

E8 FORM 135 LER SC55 DATA pe 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 289 1990 004 0 9004100364 217733 03/

g ***************************************************************04/90 *****

A85 TRACT

>* POWER LEVEL - 0004. ON THE MORNING OF 3/4/90, ALL THE L*STS AND ME4SUREMENTS FOR ZERO POWER PHYSICS TESTING WERE COMPLETEC AND THE ge REACTOR CONTROL PARAMETERS WERE EEING ADJUSTED TO PREPARE l'OR POWER ESCALATION. THE DESIRED ROD POSITION TO BEGIN POWER ESCALATION WAS

' 60% WITHDRAWN ON GROUP 6. BORON WA5 ADDED TO THE RCS TO SALANCE THE ROD WITHDRAWAL NECE554RT TO ACHIEVE THIS R00 CONFIGURATION. THE 0

OPERATOR W45 MAINTAINING REACTOR POWER AT 3X10EXP(-8) DURIdG THE 80RON ADDITION BY WITHDRAWING CONTROL R005 45 NECE554RT. DURING THIS EVOLUTION GROUP 5 W45 WITHDRAWN TO ITS "OUT LIMIT." THE OPERATOR NOTED THAT NOT ALL RODS H40 NOT REACNED THE FULL OUT POSITION AND THAT FURTHER ROD TRAVEL WA5 PREVENTED SECAUSE OF THE " GROUP" OUT LIMIT.

' TO CORRECT THIS PR08LEM THE OPERATOR PLACE 0 THE R005 WHICH M40 REACHED THEIR INDIVIDUAL FULL OUT LIMIT ON THE AUXILIARY POWER SUPPLY. THESE e

ROD 5 WERE THEN INSERTED TO ALIGN THEM SETTER WITH THE REMAINDER OF THE GROUP AND TO CLEAR THE "SROUP" OUT LIMIT. THE OPERATOR THEN WITHOREW GROUP 5 TO THE FULL OUT POSITION, NOT REALIZING THAT GROUP 6

, , WAS ALSO BEING WITHDRAWN. THE OPERATOR NOTED POWER WAS INCREASING AND BEGAN TO INSERT RODS AT APPROXIMATELY THE SAME TI4E (02:25) RP5 CHANNELS "4" AND "O" RE4CHED THE HI FLUX TRIP SETPOINT OF 0.5I 0F FULL POWER AND THE REACTOR TRIPPED.

1 FORM 136 LER SC55 OATA 04-19-91 0********************************************************************

DOCKET TEAR L!R NUMBER REVI5!04 DCS NUMBER NSIC EVENT DATE 293 1999 011 0 8904060007 2?3499 03/04tS9 A85 TRACT t: POWER LEVEL - 0102. ON 314/S9 AT 1740 hours0.0201 days 0.483 hours 0.00288 weeks 6.6207e-4 months , AN AUTOMATIC ACTUATION OF A PORTION OF THE PRIMARY CONTAINMENT ISOLATION C O N T R 0 t- %V%T84 for?ti l

...rres su la v.ubal10N ;NJILtTIONS OF TWO SEARING 5. TH2 PCIS ACTUATION INCLU3EJ THE AUTOMATIC CLOSING OF THE MAIN STEAM ISOLATION Pe WALVE5 (MSIWS). THE RPS AC TU AT 2 0'1 A P:0 REACTOR SCRAM OCCUREE3 A5 DESIGNEO SECAUSE THE M31VS W8RE CLOSING. THE PCIS ACTUATION OCCU2 RED DM SECAUSE THE MAIN STEAM SYSTEM /RiACTOR VESSEL (RV) LOW PRES $URE TRIP

g SETPOINT (900 PSIG) WAS REACHED WHILE TH* REACTOR MODE $ ELECTOR SWITCH WAS IN THE RUN POSITION. THE PRESSURE DECREASE WAS OUE TO THE bd AUTOMATIC CLOh!NG AND RE-OPENING OF THE TUR8INE SYPASS VALVES THAT e

ti OCCURRED BECAUSE OF A BTP455 VALVES VACUUM TRIP AND AN UNEXPLAINED P1 RESET OF THE v4CUUM TRIP. THE CAUSE FOR THE VACUUM TRIP AND RESET OF THE TRIP COULO NOT BE DETERMINED DURING EXTENSIVE INVESTIGATION.

"4 $USSEQUENT CONTROLLEO TESTING, ATTEMPTING TO DUPLICATE THE 3/4/89 CONDITIONS, WAS PERFORMED WITH SATISFACTORY RESULTS. UNRELATED TO THE

! CAUSE FOR THE EVENT WA$ THE FAILURE (SPURIOU$ UPSCALE TRIP) 0F A De g DIFFERENTIAL PRESSURE TRANSMITTER (ROSEMOUNT INCORPORATED MODEL 1153 087RCN3012) TH4T WAS REPLACE 0 AND SENT TO THE MANUFACTURER FOR go EXAMINATION.

U" FORM 137 LER SCSS DATA 04-18-91 q; Oe**e****e*******************e*****e.*e***ee........*eae ..* ........

b4 00CKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 293 1989 015 0 $906140112 214265 05/03/89 g,q, eseeeeeeeeee**eaeeeeeeeeeeeeeeeeeee e.eeeeeeeeee.eemeneeeee**eeeeeee ABSTRACT D1 POWER LEVEL - 0241 ON 5/3#89 AT 0326 HOURS, A HIGH REACTOR VESSEL

, q (RV) WATER LEVEL OCCURRED THAT RESULTE0 IN AN AUTOM4 TIC TUR8INE TRIP, D -e GENERATOR TRIP, AND REACTOR SCRAM AT 24% REACTOR POWER. THE EVENT 4

,,.'; .i INCLUDE 0 A DESIGNED AUTOMATIC TRANSFER OF THE POWER SOURCE FOR THE 4160 VAC AUR. POWER DISTRIBUTION SYSTEM (APOS). DURING THE EVENT 1

( INBOARD MAIN STEAM ISOLATION VALVE (MSIV) AND 4 5AMPLING SYSTEM

,, ISOLATION VALVES CLOSED AUTOMATICALLY. THE HIGH RV WATER LEVEL WAS b9 PRIMARILY CAUSED WHILE TROUBLESHOOTING THE ACTUATOR CONTROLS OF A l FEEDWATER SYSTEM REGULATING VALVE. THE S4MPLING SYSTEM ISOLATION e VALVES CLOSED BECAUSE OF 4 TRANSIENT VOLTAGE DECREASE (APDS TRANSFER)

THAT 120 VAC COILS OF RELATED RELAYS. A RANDOM FAILURE OF THE DC i

(* PILOT (125 VOC) FOR THE MSIV AND THE EFFECTS OF THE APOS TRANSFER TO THE MSIV's AC PILOT $0LEN010 CONTROL RELAY, CAUSED THE MSIV TO CLOSE.

CORRECTIVE ACTIONS INCLUDE RESTRICTED USE OF THE TROUBLE 5 HOOTING l PROCEDURES, REPLACEMENT OF SOME ACTUATOR COMPONENTS FOR BOTH REGULATING VALVES, REPLACEMENT OF THE FAILEO OC PILOT SOLEN 0IO i , ASSEM8LV AND ADJUSTMENT OF THE COIL OROP OUT WOLT4GE (OR COIL REPLACEMENT) FOR APPROPRIATE CONTROL RELAYS. THE OC PILOT SOLEN 0ID

' A5$EMBLY (MODEL 6910-020) WAS EXAMINED BY THE MANUFACTURER (AUTOM4 TIC VALVE CORPORATION). THIS EVENT OCCURRED WITH THE RE4CTOR MODE SELECTOR SWITCH IN THE RUN POSITION WITH THE FEE 0 WATER SYSTEM IN SINGLE ELEMENT (RV WATER LEVEL) CONTROL).

1

, FORM 138 LER SCSS DATA 04-18-91 0****************e******ee *** ************************************e*

00CKET TEAR LER NUMBER REVISION DC$ NUMSER NSIC EVENT DATE

, 293 1989 023 0 8908230283 215018 07/18189

.e...e.........ee....e.e...ee......e..e....e......e...........e.....

ABSTRACT

' POWER LEVEL - 035%. ON JULY 15, 1999 AT 1038 HOURS, 4 MANUALLY INITIATED REACTOR PROTECTION SYSTEM (RPS) SCRAM SIGNAL AND REACTOR g SCRAM OCCURRED. THE SCRAM SIGNAL RESULTED IN AN AUTOMATIC SEQUENCE OF EXPECTED DESIGNEO RESPONSES THAT INCLUCED A TURBINE-GENERATOR TRIP, 9 AUTOMATIC OPENING OF TW3 345 KV SWITCHT4RD AIR CIRCUIT BREAKERS, AND g; AN AUTOM4 TIC TRANSFER OF STATION ELECTRICAL LOADS. THE DIRECT CAUSE

, FOR THE SCRAM was THE DELISER4TE MOVEMENT na Tus neartno wone ceservac

su uc42en ==Loun. Int d41**RT CAUS? FOR THC DFCRE A SI'G VACUUM WAS ATTRIBUTED T 3 41 InACEOUACT IN THE APPROVED PROCEDURS THAT WAS PEING W4 USED TO RECONFIGU2E THE STEAM JET AIR EJECTOR $ OF THE MAIN CONDENSER GAS REMOVAL SYSTEM. CO2RECTIVE ACTIONS TAKEN INCLUDED THE FOLLOWING:

gq REVISION OF THE PROCEDURE TO INCLUO! SPECIFIC STE85 FOR INTERCHANGING g, A STEAM JET' AIR EJECTOR 5 00 RING OPERATION, AND CLEANING THE SALTWATER W4 PORTIONS OF THE CIRCULATING WATER SYSTEM TO REMOVE MACRO-FOULING DUE TO MARINE ORGANISMS. THE UNIT WAS RETURNED TO COMMERCIAL SERVICE ON 9g JULT 26, 1989 AT 0936 HOURS. THIS EVENT OCCURRED WHEN THE REACTOR

' P1 VESSEL (RV) PRESSURE WAS 950 05IG AND THE RV WATER TEMPERATURE WAS 520 DEGREES FAHRENHEIT. THIS REPORT 15 $UEMITTED IN ACCORDANCE WITH 10 g4 g- CFR 50.73(4)(2)(IV).

D8 p FORM 139 LER SC55 OATA 0************************************************************04-18-91

^'

be OOCKET TEAR L!R NUMSER REVISION 0C5 NUM8E4 NSIC EVENT DATE p 293 1989 026 0 5919060191 215354 08/30/89 i ABSTRACT 54 POWER LEVEL - 065X. ON 8/30189 AT 1917 HOURS, AN AUTOMATIC REACTOR PROTECTION SYSTEM (RPS) SCRAM SIGNAL ANO REACTOR SCRAM OCCURRED WHILE ya ,

AT 652 REACTOR POWER. 45 EXPECTED, THE SCRAM SIGNAL RESULTED IN AN AUTOMATIC SEQUENCE OF DESIGNER RESPONSES THAT INCLUDED A E' TURBINE-GENERATOR TRIP, AUTOMATIC OPENING OF TWO 345 KV SWITCMYARD AIR CIRCUIT SREAEERS, AND AN AUTOMATIC TRANSFER OF STATION ELECTRICAL LOADS. THE DIRECT CAUSE FOR THE SCRAM SIGNAL WAS HIGH REACTOR

>-4 WESSELIMAIN STEAM SYSTEM PRESSURE (1069 PSIG) THAT OCCURRED 45 A RESULT OF AN AUTOMATIC TURBINE RUNBACE. THE TUR8INE RUN8 ACE WAS

,, CAUSED BY THE FAILURE 08 A NONSAFETY-RELATED 24 KV POTENTIAL

, TRANSFORMER (PT) IN CONJUNCTION WITH A NONSAFETT-RELATED VOLTAGE Di SALANCE RELAY THAT WAS WIRED IN ACCORDANCE WITH AN ARCHITECT-ENGINEER (BECHTEL) DRAWING THAT CONTAINED AN ERROR SINCE 041GINAL CONSTRUCTION (C.1971). THE PT (177LE EE02553, A SERIAL NUM8ER 70F3376) WA5 te MANUFACTURED BY THE WESTIN5 HOUSE ELECTRIC CORPORATION. THE PT WAS REPLACED, THE DRAWING ERROR WA5 COPR!CTED AND THE VOLTAGE SALANCE

'* RELAY WA5 REWIRED IN ACCORDANCE WITH THE REVISED DRAWING. THE PROCEDURE USED TO FUNCTIONALLY TEST THE VOLTAGE BALANCE RELAY WA5 8

STRENGTHENED. APPLICABLE PORTIONS OF THE STATION ELECTRICAL SYSTEM WERE TESTED ANDt0R EVALUATED FOR IMPACT OF OVERVOLTAGE WITH 5ATISFACTORT RESULTS. THIS REPORT IS SU8MITTED IN ACCORDANCE WITH

e. 10CFR50.73(A)(2)(IV).

1

' FORM 140 LER SC55 DATA 04-18-91

-0********************************************************************

00CEET TEAR LER NUMBER REVISION DCS NUMSER N5IC EVENT DATE ,

293 1989 035 0 9001180124 216387 12/08/89 A85 TRACT POWER LEVEL - 0952. ON DECEM5ER S, 1999 AT 0305 HOURS, AN UNPLANNED AUTOMATIC REACTOR PROTECTION SYSTEM (RPS) SCRAM SIGNAL AND REACTOR SCRAM OCCURRED at 95 PERCENT REACTOR POWER. THE SCRAM SIGNAL RESULTED IN RESPONSES THAT INCLUDED A TURSINE-GENERATOR TRIF. THE DIRECT CAUSE FOR THE SCRAM SIGNAL WA5 A (FALSE) LOW REACTOR VESSEL (RV) WATER >

LEVEL SIGNAL THAT OCCURRED WHILE RETURNING A LOCAL RV WATER LEVEL i IMOICATOR (0!FFERENTIAL *RE55URE TTPE) TO SERVICE FOLLOWING A

, SATISPACTORV CALISRATION PERFORMED BY A QUALIFIED TECHNICIAN. THE CAUSE FOR TME EVENT WA5 A MINOR Mf0RAULIC TRANSIENT THAT OCCURRED WHILE CAREFULLY AND SLOWLT OPENING A LOW SIDE (ACTIVE LEG) NEEDLE TYPE g, -MANIFOLD VALVE IN ACCORDANCE WITH THE APPROVED PROCEDURE. THE LEVEL

. INDICATOR SHARES 5ENSIMS LIN85 C04u04 TO ADJAC*gf est sews:

I i

. . . . ...m%. ... -.a.eea .t a ao :ArLU4tu aph IMPR0VEMENil FOR l CALIBRATING THE LOCAL LEVEL INCICATORI INCLUCING POSSIBLE CMANGE OF

' pq THE MANIFOLD VALVE M8NOLE(5) OR REPLACEMENT OF THE RELATED NEEOLE TYPE l MANIFOLO VALVES WITH HETERING TYPE VALVES. THE CALI5 RATION PROCE302E IS BEIKG QEVISED TO BE PERFORMED WHILE $ HUT 00WN. THIS EVENT OCCURRED I g, DURING POWER OPERATION WITH THE REACTOR MODE SELECTOR SWITCH IN THE 54 RUN POSITION. THE RV PRE 55URE WAS 1027 PSIG WITH THE RV WATER TEMPERATURE At 547F.

, y 1 P1 FORM 141 LER SC55 DATA 04-15-91 g4 g 0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 293 1990 008 0 9006200183 213515 05/13/90 he 9: ********************************************************************

gg A85 TRACT t POWER LEVEL - 100%. ON MAY 13, 1990 AT 1603 HOURS, AN AUTOMATIC SCRAM D" RESULTING FROM A LOAD REJECTION OCCURRED WHILE AT 100 PERCENT REACTOR POWER. THE LO4D REJECTION INCLUDED A TRIP OF THE GENERATOR FIELD

'i BREAKER, ACTUATION OF THE TUR81NE MECHANICAL HYDR 4ULIC CONTROL $ PEED bg ' GOVERNOR, CLOSURE OF THE FOUR TUR6INE CONTROL VALVES AND OPENING OF THE THREE STPA55 WALVE$, AND THE BRIEF 4CTUATION OF THE MAIN gg ; STEAMtTARGET ROCK TWO-STAGE RELIEF VALVES AT APPROXIMATELY 1100 PSIG (LOW END OF THE 1115 PSIG SETPOINT RANGE INCLUDING TOLERANCE). THE I8 LOAD REJECTION WAS CAUSED BY A MOMENTARY FAULT 04 THE OFFSITE 345 KV

~

TRANSMISSION SYSTEM. THE GENERATOR *5 LD55-OF-FIELO REL4Y (240)

DETECTED THE FAULT AND IMMEDIATELY TRIPPED THE GENERATOR WITHOUT AN pe EXPECTED (INHERENT) 15 CTCLE TIME DELAY BECAUSE ONE OF IT'S COMPCNENTS, THE TELEPHONE RELAY ('X') COIL, WAS OEFECTIVE. THE RELAY

"' (240) WAS LAST CALI5 RATED AND FUNCTIONALLY TESTED ON OCTOBER 26, 1989 AT THAT TIME, THE OPERATION OF THE (*E') COIL WAS TESTED IN I

ACCORDANCI WITH THE VENDOR MANUAL. THE RELav's TIME DELAY WAS be SUILT-IN AND NOT ADJUST 45LE, AND WAS NOT REQUIRED TO SE TIMEO. THE RELAY WAS INSTALLED DURING PL ANT CONSTRUCTION (C. 1972). THE CAUSE

g. FOR THE OPEN COIL IS BEING INVESTIGATED SUT IS BELIEVED TO BE RANDOM OR AGE RELATEC FAILURE. THE RELAY IS THE ONLY ONE OF IT5 TYPE I' (WESTINGHOUSE TYPE KLF-1) INSTALLED AT PILGRIM STATION AND WAS REPLACED WITH ANOTHER KLF-1 RELAY HAVING AN ADJUSTABLE TIME DELAY. '

1 9

FORM 142 LER SC55 04T4 04-18-91

, 0********************************************************************

00CKEY YEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 293 1990 013 0 9010160047 219716 09/02/90 8* ********************************************************************

t

485 TRACT POWER LEVEL - 0601. CM 9/2/90 At 2233 HOURS, AN UNPL ANNED M ANUAL

, REACTOR SCRAM WA5 INITI4TED WITH REACTOR POWER AT 60%. OPERATORS

, MANUALLY SCRAM 9EO THE REACTOR DUE TO DIFFICULTIES EXPERIENCE 0 IN CONTROLLING REACTOR VE5SEL (RV) WATER LEVEL. A FUSE BLEW IN A FEE 0 WATER CONTROL CIRCUIT power SUPPLY CAUSING S0TH FEE 0 WATER

, REGULATING VALVE 5 (FRVS) TO LOCKUP WITHOUT CONTROL ROOM INDICATION. A i MODIFICATION WAS IMPLEMENTED WHILE SHUTOOWN WHICH IMPR3VE5 YHE RELIABILITY OF THE POWER SUPPLY AND PROVIDES CONTROL ROOM INDICATION

' OF A FRV LOCKUP FPOM A LOSS OF CONTROL POWER. AFTER THE SHUTDOWN OTHER EQUIPMENT PROSLEMS WERE EXPERIENCE 0. STARTUa FRV FAILE0 CPEN OUE TO AIR LEAK 5 AND FAILURE OF ITS AIR BOOSTER RELAY THAT WAS LATER 1

I' REPLACED. RCICS WAS DECLARED INOPERABLE DUE TO THE TURSINE TRIPPING ON THREE START ATTEMPTS. TURSIME TRIPS WERE ATTRISUTED TO AN IMPROPER

, MANUAL START SEQUENCE SPECIFIED IN RCICS OPERATING PROCEDURE AND/OR g LOOSENESS OF THE MECHANICAL QVERSPEED TRIP LINEAGE. THE RCICS SUCTION e IIPGE3 pef!ENCEg4. PRE 55URE TRENSIENT DUE TO THE INJECTION CHECK

                 ...... ..        .nor,     wautu :4 u 6 uc utIERM14cD. A RESIOUAL HEAT REMOVAL SYSTEw/ SHUT 00WN C00LI4G SUCTION ISOLATION WALVE WOULD NOT OPEN y,              NO2MALLY.

I CAUSE WAS CONTACT FAILURE 04 THE VALVE'S SEAL-IN RELAT. UN ;; FORM 143 LER SCSS DATA t WW 0************************************************************04-18-91 ******** DOCKET TEAR LER NUMBER REv!$ ION DCS NUMBER NSIC EVENT DATE

 ,                295         1989           002               0     3903080477 213200         01/27/

pq ******************************************************************89 ** ABSTRACT Id POWER LEVEL - 099%. WHILE INVESTIGATING FAILURE OF A SAFEGUARDS TEST LIGHT, THE UNIT 1 TURSINE TRIPPED WHICH RESULTED IN A REACTOR TRIP. b4 ALL SAFETY RELATED EQUIPMENT CPERATED AS EXPECTED. AS THE OPERATOR WAS H3LDING A TEST PUSHSUTTON AND DEPRESSING THE TEST LIGHT, A bg TECHNICIAN PLACED LEADS ACROSS TWO ADJACENT TERMINALS IN THE CIRCUIT TO SIMULATE THE COIL OF THE CIRCUIT. WHEN THE TEST LEADS WERE PLACED he IN THE CIRCUIT, A TURSINE TRIP SIGNAL WAS DEVELOPED AND TRIPPED THE TURSINE. INVESTIGATION INDICATED THAT THE MOST LIKELY C AUSE OF THE EVENT WAS THE TECHNICIAN PLACING THE LEADS ACROSS INCORRECT TERMINAL be POINTS. THE CAUSE OF THE TEST LIGHT FAILING TO LIGHT WAS 4 SLOWN BUL5 AND FAULTT SOCKET. THE SUL5 AND FAULTY SOCKET WERE REPLACED. THE

     '           CIRCUIT WAS TESTE3 AND VERIFIED OPERATING CORRECTLY PRIOR TO STARTUP 0F THE REACTOR.             THE ELECTRICAL MAINTENANCE DEPARTMENT WILL REVIEW De THIS EVENT AND STRESS THE IMPORTANCE OF AWARENE5S DURING TROUSLESH00 TING.

1 N

         ,     FORM       144                            LER SCSS DATA
   ,,       0******************************+*****************************04-18-91              ********

i DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 295 1990 004 0 9003050301 217044 01/27/90 D* ******************************************************************** g, A85 TRACT POWER LEVEL - 039%. UNIT 1 WAS IN MODE 1 AT APPROXIMATELY 39% POWER.

              THE NUC. EAR STATION OPERATOR (NS0) PLACED THE LEVEL CONTROL VALVE FOR THE 10 STEAM GENERATOR (S/G) INTO MANUAL CONTROL FOR TROUBLESHOOTING ON THE CONTROLLING S/G LEVEL CHANNEL. THE NSO CONTINUED TO PERFORM i            OTHER DUTIES, INCLUDING A $0 GALLON DILUTION OF THE REACTOR COOLANT SYSTEM (RCS) 80R04 CONCENTRATION, AND WITHORAWAL OF CCNTROL 9005 ONE
   ,            HALF STEP FOR TEMPERATURE CONTROL.                    APPROXIMATELY 35 MINUTES AFTER PLACING THE 1D S/G LEVEL CONTROL VALVE INTO MANUAL, AT 0516. UNIT 1
   '            EXPERIENCED A TUR5INE TRIP / REACTOR TRIP RESULTING FROM HIGH WATER LEVEL ON 10 $/G.                   THE CAUSE OF THE EVENT WAS PERSONNEL ERROR. THERE WAS NO SAFETY SIGNIFICANCE TO THIS EVENT, AS ALL SAFEGUARDS AND i      i REACTOR PROTECTION EQUIPMENT OPERATED AS DESIGNE0. STANDING ORDER 90-04 WAS ISSUED WHICH REQUIRES A NSO TO BE STATIONED CONTINUQUSLY AT
   ,            THE S/G CONTROL PANEL WHENEVER A MAIN FEEDWATER REGULATING VALVE IS IN MANUAL CONTROL.

1 FORM 145 LER SCSS DATA 04-18-91 0****************************************************************++** DOCKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 295 1993 017 0 9009190081 219465 08/13/90

       ,       ASSTRACT POWER LEVEL - 095%. UNIT 1 WAS AT STEADY STATE AT 1030 MWE. UNIT 2
   ,            WAS IN HOT SHUTDOWN, WITH PERIGOIC TEST (PT)-54, " REACTOR PROTECTION g        LOGIC REACTOR AT NOT SHUTOOWN" IN PROGRESS. DUE TO DIFFICULTIES ENCOUNTERED IN T! STING, THE NEE 3 AROSE TO TRIP UNTT 2 i nc ai s v .                ew

                  . . . . . ...   ..s.s. 46L 2attoV assitPs JJtWATED %$ 055!GN50.        THERE WAS THEREFORE NO SAFETY $1SNICICANCE T9 Td!S EVENT. CORRECTIVE ACTIONS p1            INCLUDE TAILGATE SESSIONS, BETTER LASELING AT THE TUR3INE PEDESTALS, REPAIRING THE TURBINE STOP VALVE SYOA55 VALVES, AND AN INVESTIGATION TO DETERMI2E THE FESSIBILITY OF BYP4551NG THE TUR8INE BEARING LIFT OIL gg      PUMP SPEED SWITCH TRIP AT LOW TURBINE SPEED.

1 h4 , , ,p FORM 146 LER SC' 04TA ! pq 0*******************************-****************************04-13-91 ******** 00CKET YEAR LER HUMBER REVISION DCS NUMBER NSIC EVENT DATE bd ,I t 298 1989 001 0 8903030463 213143 01/25/89 De q A85 TRACT POWER LEVEL - 1001. ON 1/25/89, AT 6:53 A.M., AN AUTOMATIC REACTOR b6 SCRAM OUE TO HIGH NEUTRON FLUX OCCURRED WMILE AT 100% POWER UNDER

        ,p      NORMAL STEADY STATE CONDITIONS. THE ENSUING REACTOR PRESSURE VESSEL WATER LEVEL TRANSIENT RESULTED IN ACTUATION OF GROUPS 2, 3, AND 6 b8            ISOLATIONS (PRIMARY CONTAINMENT, REACTOR WATER CLEANUP, AND SECONDARY bg CONTAINMENT INCLUDING STANOBY GAS TREATMENT SYSTEM INITIATION). WATER LEVEL WAS IMMEDIATELY RESTORED AND MAINTAINED BY THE CONDENSATE / FEE 0 WATER SYSTEM; NO AUTOMATIC OR MANUAL ECCS SYSTEM gg     g. ACTUATIONS WERE REQUIRED.           IT WAS INITIALLY THEORIIED, BASED ON i

9 AVAILABLE PLANT DATA, THAT THE NEUTRON FLUE TRANSIENT WAS DUE EITHER D3 TO ELECTRONIC N0!$E IN THE NEUTRON MONITORING SYSTEM OR A PRESSURE SPIKE AS A RESULT OF A MAIN TUD8INE PRESSURE CONTROL SYSTEM MALFUNCTION. SUBSEQUENTLY, PROBLEMS WERE EXPERIENCE 0 WHEN STTEMPTING p4 TO EQUALIZE THROUGH THE IN80ARD MAIN STEAM ISCLATION VALVE (MSIV) ON THE "A" MAIN STEAM LI5E. UPON DISASSEMBLY OF THE IN80ARD VALVE, IT

   "'           WAS DETERMINED THAT THE STEM OISC HAD SEPARATED FROM THE STEM OURING OPERATION, AND THa! THE MAIN DISC SEATED, CAUSING A PRESSURE SPIKE AND THE RESULTING FLUX TRANSIENT. THE SAFETY SIGNIFICANCE OF THIS EVENT D*           15 CONSIDERED TO BE MINIMAL. THE TRANSIENT RESPONSE OF THE PLANT WAS VERY SIMILAR TO THE RESPONSE RECORDED FOR AN OVERSEAS BWR WHICH g,           SUFFERED 4 SIMILAR FAILURE.

1

             FORM         147                  LER SCSS DATA                           04-18-91 0********************************************************************

i DOCKET YEAR LER NUMBER REVISION OCS NUMBER N5IC EVENT DATE

       ,         298          1989       025          0     8911020271 215747            09/28/89
   ,           ....** ....es ......................................................

ABSTRACT

   '            POWER LEVEL - 1001. ON SEPTEMBER 28, 1989, AT 11:36 AM, A MAIN TURBINE TRIP OCCURRED. FOLLOWED IMMEDIATELY SY A REACTOR SCRAM.                THE REACTOR e
      ,         VES5EL WATER LEVEL TRANSIENT THAT RESULTED FROM THE SCRAM CAUSED CONTAINMENT ISOLATION GROUPS 2 (PRIMARY CONTAINMENT), 3 (REACTOR WATER

CLEANUP) AND 6 (SECONDARY CONTAINMENT) TO OCCUR. THE TUR8INE TRIP g: SIGNAL THAT INITIATED THE EVENT WAS TURBINE HYDRAULIC CONTROL OIL RESERVOIR LOW LEVEL, WHICH OCCURRED APPROIIMATELY TWO MINUTES AFTER

   '            THE CONTROL OIL PUMPS WERE SHIFTED.               IT WAS LATER VERIFIED THAT

g. RESERVOIR LEVEL HAD REMAINED IN THE NORMAL RANGE THROUGHOUT THE EVENT.

THE EXACT CAUSE FOR THE TURSTNE HYDRAULIC CONTROL CIL RESERVOIR LOW LEVEL TRIP SIGNAL COULO NOT BE POSITIVELY IDENTIFIED. IT WAS CONCLUDED g THE TRIP SIGNAL WAS CAUSE0 SY SPURIOUS ACTUATION OF THE LEVEL SWITCH DUE 10 EQUI? MENT VIBRATION A5 A RESULT OF 5HIFTING CONTROL OIL PUMPS. THE IMMEDIATE ACTIONS TAKEN WERE TO STABILIZE TME PLANT FOLLOWING THE

   '                            TO MINIMIZE THE POSSIBILITY OF RECURRENCE, A 1EMPORARY q;        SCRAM.

INSTRUCTION WAS ISSUED TO LIMIT CONTROL OIL PU4P SHIFTING, AND A e CONTROL OIL ST5 FEM FLUSH WAS SCHEDULED FOR THE NEIT CUTAGE. g ADDITIONALLYe SEVERAL SYSTEM R EE .' ABILITY IMPROVEMENTS WILL BE EVALUATED.

                   .       .,.                        sc4  .t

aata 0*****************************************************-******04-19-91 ********

p1 DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 295 1960 026 0 9001050082 216288 11/25/89

   ,q           eeeeeeeeeeee****eeeeeeee****+************++*************************

q! A85 TRACT WW POWER LEVEL - 100%. ON 11/25/39, AT 10:15 P.M., WITH THE PLANT AT FULL

g. POWER, A REACTOR SCRAM OCCURRED WHEN THE OUT80ARD MAIN STEAM pq ISOLATION VALVES (MSIVS) CLOSED AS A RESULT OF DEPRESSURIZATION OF THE INSTRUMENT AIR (IA) SYSTEM. THE DECREASE IN IA SYSTEM PRESSURE "4 g; OCCURRED WHEN THE AIR ORYER POST FILTER ASSEMSLT RUPTURED.

INVESTIGATION REVEALED THAT THE POST FILTER MEDIA (PAPER CARTRIDGES) HAD SEEN IGNITED BY EITHER HOLE AIR OR HOT PARTICLES FROM THE ORYER. D4 3; 8URNING CARTRIOGES RESULTED IN OVERHEATING OF THE FILTER ASSEMBLY HOUSING. THE ASSOCIATED HEAT INDUCEO STRESS, COUPLED WITH INTERNAL De ($YSTEM) AIR PRESSURE, CAUSED THE HOUSING TO DEFORM AND RUPTURE. CORRECTIVE ACTIONS TAKEN INCLUDED COMPLETE DISASSEMBLY, INSPECTION AND REFURBISHMENT OF THE "8" AIR DRYER, INCLUDING REPLACEMENT OF THE POST U" FILTER ASSEM5LY, AS WELL 45 AN EXTENSIVE INSPECTION OF THE "A" AIR DRYER. FILTER CARTRIDGES CAPA8LE OF WITHSTANDING HIGH TEMPERATURE

    >=           CONDITIONS WERE INSTALLED IN BOTH POST FILTER ASSEMBLIES.

APPROXIMATELY FIFTEEN FEET OF PIPING 00WNSTREAM OF THE POST FILTER WAS 1 yg REPLACED DUE TO CONCERNS ABOUT THE POSSISLE EFFECTS OF OVERHEATING. CHECKS WERE MADE OF THE IA SYSTEM COWNSTREAM OF THE POST FILTERS TO VERIFT SYSTEM CLEANLINESS. ADDITIONALLY, COMPONENTS IN THE VICINITY 88 0F THE RUPTURED POST FILTER ASSEMELY WERE INSPECTED TO ENSURE THAT DEBRIS FROM THE EVENT WAS NOT PRESENT. R$ 1 FORM .149 LER SCSS DATA 04-13-91 b' 0******************************************************************** 00CKET YEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE b' 298 1990 011 0 9011260132 2200?1 10/17/90 Re ABSTRACT POWER LEVEL - 100%. ON 10/17/90, AT 1:49 PM, WITH THE PLANY IN OPERATION AT FULL POWER, A REACTOR SCRAM AND SEVERAL ESF ACTUATIONS, INCLUDING GROUP ISOLATIONS AND EMERGENCY CORE COOLING SYSTEM e ACTUATIONS, CCCURRED DUE TO A GROUND FAULT ON THE 345 KV PHASE A TRANSMISSION LINE, CAUSING THE 345 KV OUTPUT BREAKERS TO OPEN. THE

     ,,          GROUND FAULT OCCURRED WHEN GUSTING WIND CONDITIONS CAUSED A POWER CABLE (5/C-s10) TO A TEMPORARY CONSTRUCTION ELEVATOR WHICH WAS INSTALLED TO FACILITATE REFURBISHMENT OF THE REACTOR BUILDING ROOF, 70 COME INTO CONTACT WITH THE 34$ KV A PHASE TRANSMISSION LINE AND THE TRANSMISSION TOWER SHIELO LINE. POWER TO THE STATION WAS IMMEDIATELY t           RESTORED THROUGH THE STARTUP TRANSFORMER.                       THIS POWER SOURCE, HOWEVER, WAS INTERRUPTED WITHIN THREE SECONOS 05 THE INITIAL GROUND FAULT WHEN
     ,           A PIECE OF THE POWER CASLE MADE CONTACT SETWEEN THE 345 KV PHASE C
         ,       TRAN5 MISSION LINE AND THE 161 KV PHASE A TRANSMISSION LINE. UPON SENSING LOSS OF VOLTAGE ON THE 4160 VAC CRITICAL SUSE5, SUPPLY BREAKERS FdOM THE EMERGENCY TRANSFORMER CLOSED, REPOWERING THE 4160
         ,       VAC CRITICAL SWITCHGEAR. THE ROOT CAUSE OF THIS EVENT IS FAILURE TO ESTAsLISH AND IMPLEMENT SUFFICIENT WORK CONTROL MEASURES FOR THE REACTOR SUILDING ROOF REFURSISHMENT ACTIVITY, CONSIDERING THE LOCATION
         ,       SELECTED FOR STAGING OF THE WORK.

1 1 g F0RN 150 LER SCSS DATA 04-15-91 0********************************************************************

     .          DOCKET YEAR LER NUMBER REVISION OCS NUMSER                             NSIC         EVENT DATE g           301    1959         002                0     5905030409 213730                           03/29/59

                            ...- 6.. 26    ess.. ee a s c e s 2., AT 034! MOURS, UNIT 2 EXPERIENCED A

, MAIM STEP-UP TRANSFORMER LOCLOUT "AIN GENERATOR 1pfAKst TRIP AND p1 CONCURRENT TURBINi AND RE3CTOR TRIPS. THE UNIT HAD SEEN OPERATING AT 1003 POWER. TME LOCKOUT OCCURRED SHCRTLY AFTER THE SPU2IOUS ACTUATION be OF THE UNIT 2 x01C PHASE FIRE DELUGE SPRAY SYSTEM. THE DELUGE SPRAY APPARENTLY INDUCEO A FLASH 0VER FROM THE TRANSFORMER TO GROUND, WHICH WAS DETECTED BT TRANSFORMER DIFFERENTIAL PROTECTIVE RELAYS. THE SPRAY l kW SYSTEM ACTUATED WHILE TROUBLESHOOTING A WIRING PROBLEM OISCOVEREO t.

                '         OURING MODIFICATION WORK WHICH REPLACED THE TRANSFORMER DELUGE HEAT pq                 ACTUATION DEVICES WITH NEW ELECTRONIC DETECTOR $.           THE EMERGENCY DIESELS AUTOMATICALLY STARTED SECAUSE OF SUS UNDERVOLTAGE.                              THE
                ;.        UNDERVOLTAGE CONDITION WAS THE RESULT OF THE PR! MATURE ACTUATION OF Ld                 THE GENERATOR STUCK BREAKER PROTECTION RELAY, WHICH ISOLATED A UNIT 1 SUS SECTION CROSS-CONNECTION. THE VOLTAGE DECREASED ON THE REMAINING kJ      i:        TRANSMISSION LIN! TO UNIT 2 OUE TO A MAINTENANCE OUTAGE AT 4 NEARSY PLANT AND THE LINE LOSSES ASSOCIATED LITH TRANSMISSION FROM OTHER gg                DISTANT SUPPLIES. AN UNUSUAL EVENT WAS DECLARED AT 0854 HOURS. THE
                ;;        EVENT WAS TERMINATED AT 1205 HOURS. REPAIRS WERE EFFECTED AND THE De UNIT RETURNED TO SERVICE 04 APRIL 2.

g bg FORM 151 LER SCSS DATA 04-13-91 0******************************************************************** DOCKET TEAR LER NUM*ER REVISION DCS NUMBER NSIC EVENT 04TE 301 1959 004 0 8909270169 215305 08/20#89

                         ***********+********************************************************

3 485 TRACT p -, POWER LEVEL - 000%. ON E/20/S9, AT 1631, UNIT 2 EXPERIENCE 0 A MAIN STEP-UP TRANSFORMER LOCKOUT, PAIN GENERATOR BREAKER TRIP, AND

         ".               CONCURRENT TURSINE AND REACTOR TRIPS. THE UNIT HA0 BEEN OPERATING AT 1003 POWER. THE LCCK0UT OCCURRED SHORTLY AFTER WATER SPRAY HAD BEEN I

INITIATED TO THE TRANSFORMER OIL COOLERS TO REDUCE TEMPERATURES ON THE 6* x01 TRANSFORMERS. THE UNIT TRANSFORMER LOCK 0UT WAS INITIATED BY THE APPARENTLY RANDOM ACTUATION OF THE 2x0T "B" PHASE " SUDDEN PRESSURE" g, TRIP SYSTEM. THE UNIT RESPONDED IN A NORMAL MANNER TO THE TRIP WITH SEVERAL MINOR PROSLEPS. AN UNUSUAL EVENT WAS DECLARED AT 1644 DUE TO I' LOSS OF ELECTRICAL LOAD. THE UNUSUAL EVENT WAS TERMINATED AT 1856. AFTER EXTENSIVE INVESTIGATION AND THOROUGH CHECKOUT AND TESTING OF THE 2x02 "B" PHASE TRANSFORMER, THE UNIT WAS RETURNED TO SERV!CE ON 4 8/21/89. 1 FORM 152 LER SCSS DATA 04-18-91 0******************************************************************** 00CKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT OATE I 302 1989 020 0 8907150161 214624 06/14159 J

          ,              A85 TRACT
              ,           POWER LEVEL - 000%. 04 JUNE 14, 19E9, CRYSTAL RIVER UNIT 3 WAS SU8 CRITICAL IN MODE 3 (HOT STANOBY3. A REACTOR COOLANT SYSTEM HEATUP WAS IN PROGRESS AND SAFETY CONTROL ROD GROUP ONE WAS FULLY WITHORAWN.

AT 1054 THE "S" CONTROL ROD ORIVE (CRO) AC BREAKER OPENED SPURIOUSLY. AT 1100, WHILE TROUBLESHOOTING THE "E" CR0 AC SREAKER, A PLANT OPERATOR (REACTOR OPERATOR LICENSED) INADVERTENTLY CONTACTED THE

              ,           MANUAL SHUNT TRIP LEVER FOR THE "A" CRO AC BREAKER. THIS ACTION OPENED THE "A" CRO AC SREAKER AND RESULTED IN A REACTOR TRIP.                               SAFETY CONTROL ROD GROUP ONE INSERTED INTO THE CORE AND THE PLANT WAS
              ,           ST481LIZ80 USING PLANT ASNORMAL PROCEDURES. THE CAUSE OF THE EVENT WAS PERSONNEL ERROR IN MANUALLY CONTACTING THE "A" CR0 AC SREAKER

MANUAL SHUNT TRIP LEVER. CONTRIBUTING CAUSES INCLUDED THE FACT THAT

g. THE LEVER PROTRUDE 0 FROM THE CASINET A40 WAS UNPROTECTED, AS WELL AS THE SPURIOUS OPENING OF THE "B" Con AC *R*AuSR. To ooereune

                                                                                               . . .m. . __= _-- __ - _ _ - _ _ _
                   ....  .- ....... %.s.' e        i SEQUENCING, ADDITION OF SUS DUCT LIGHTNING ARRESTER 5, AND ADDITION OF P1               A SEPARATE SUS DUCT GROUND CASLE.

1 FORM 158 LER SC55 DATA DO 0************************************************************04-13-91 ******** DOCKET TEAR LER NUMSER REVISION DC5 NUMSER NSIC EVENT DATE 304 1990 013 0 9012140064 220137 11111/90 De ******************************************************************** 8 t A85 TRACT U" POWER LEVEL - 0993. ON 11/11/90 AT 1014 ZION UNIT 2 TRIPPED DUE TO A SENSED LOSS OF MAIN TURSINE BEARING OIL PRESSURE. THE DIAPHRAGM IN b4 THE SEARING OIL SECTION OF THE TUREINE TRIP OEVICE (TTD) HAD RUPTURED. THIS SENSED LOSS OF SEARING OIL PRESSURE ACTUATED THE TTD WHICH bs TRIPPE0 THE TUR8INE. THE TURBINE SEARINGS WERE NOT DAMAGED, AS THEY OID NOT LOSE DIL PRES 5URE. THE ROOT CAUSE ANALYSIS DETERMINED THAT THE

                  DIAPHRAGM HAD BEEN IN SERVICE PAST ITS SERVICE LIFE EXPECTANCV.

SIGNS OF CRACKING AND HARDNESS WERE VIStaLE. FOLLOWING VERIFICATION OF THE NEW DIAPHRAGM SHELF LIFE, IT NAS PLACED INTO THE TTD. AFTER pe PERFORMING PT-101 " MAIN TUR3INE PROTECTIVE DEVICE TRIP TEST", SECTION 5.2 " LOW BEARING OIL PRES 5URE TRIP TEST", THE UNIT WAS RETURNED TO b, SERVICE. CURRENTLY A PREVENTIVE MAINTENANCE PROCEDURE 15 BEING

    ;               CREATED TO ENSURE THAT THE TfD 15 PROPERLY MAINTAINED AT EACH REFUEL OUTAGE.

be I

t. FORM 159 LER SC55 04T4 04-18-91 0*********++++++*****************************************************

                 DOCKET YEAR LER NUMBER REVISION DCS NUMBER                   N5IC             EVENT DATE 305      1989      016           0      9001310373 216627                    12/27/89 5

485 TRACT POWER LEVEL - 1002. AT 1658 CST ON DECENSER 27, 1999, WITH THE REACTOR AT 100% POWER, THE PLANT EXPERIENCED A TUR81NE/ REACTOR TRIP. THE

     '   ,          REACTOR TRIP WA5 CAUSE0 87 BOTH TUR8INE STOP VALVES CLO5ING COINCIDENT WITH THE PLANT POWER LEVEL GREATER THAN 10%. THE TURBINE STOP VALVES CLOSED AS A RESULT OF A DECREASE IN ELECTRO-HYDRAULIC (EM) TRIP FLUID 8
         ,          HEADER PRES 5URE.      THE DECREASE IN EH PRES 5URE COULD DE CAUSED BY EITHER OF TW3 VALVES OPENING IN RESPONSE T3 SIGNALS ALLOWING THE EH
     ,              FLUID TO BE 00MPEO. .THE ROOT CAUSE OF THE DECREASE IN EH TRIP FLUID
          ,         HEADER PRES $URE COULD NGT SE DETERMINE 0. A MULTI-DISCIPLINED COMMITTEE WAS FORMED TO REVIEW THE EVENT USING FORMAL ROOT CAUSE ANALYSIS TECHNIQUES. SASED ON THE REVIEW OF ALL APPLICAELE PLANT PARAMETER DATA, THE TEAM GENE #ATED SEVERAL POSSISLE SCENARIOS THAT MAT HAVE OCCURRED. A SPECIFIC SCENARIO HMICH WAS THE INITIATING EVENT COULD NOT BE CONCLUSIVELY DETERMINED. THE REPORT GENERATED BY THE
         ,          COMMITTEE INCLU3E0 5!VERAL RECOMMENDATIONS FOR FOLLOW-UP INSPECTIONS AND MAINTENANCE DUPING THE NEXT REFUELING OUTAGE (SCHECULED FOR MARCH OF 1990). THE PLANT WAS STASILIIED IN THE HOT SHUTDOWN CONDITION.                       A5 g

EXPECTED, THE AURILIARY FEE 0 WATER PUMPS STARTED, WHICH 15 AN ESF ACTUATION, IN RESPONSE TO THE TRIP. THIS EVENT IS SEING REPORTED A5

REQUIRED ST 10 CFR 50.73(A)(2)(IV).

1 f _ ~, _._ . , . _

                                                                                                  ,                      .              mm

_.m... ...n m.e . m .3 c- .cvA>&cN JLs NUMBEP NSIC EVENT DATE 306 1963 002 0 3007050374 214521 05/26/S9 pq eeeeeeeeeeeeeeeeeee* eeeeeeeeeeeeeeeee*ene*eeeeeeeeeeeeeeeeeeeeeeeen g4 A85 TRACT p* POWER LEVEL - 100%. ON $/26/$9, UNIT 2 WAS AT 100% POWER. AT 0605 UNIT 2 TRIPPED ON STEAM GENERATOR LOW LEVEL. INVESTIGATION OF PLANT bW DATA REVEALEO THAT THE TURSINE CONTROL VALVES HAD CLOSED JUST PRIOR TO

 }       p'      THE TRIP. INVESTIGATION OF THE TUR8INE CONTROL SYSTEM LED TO THE pq              POWER SUPPLY ORAWERS, WHERE SAILED COM*0NENTS WERE FOUND ON A SPEED I

ERROR AMPLIFIER CARD. TME FAILED COMPONENTS WERE AN ELECTROLYTIC

         ,       CAPACITOR AND AN INDUCTOR.          THE SPEED ERROR AMPLIFIER CARD WAS fd ~            REPLACED AND INSPECTION OF ALL OTHER CIRCUIT CARDS WAS COMPLETED.            THE SPEED ERROR AMPLIFIER WAS TESTED AND THE CONTROL SYSTEM RETURNED TO b4 n     '

SERVICE. UNIT 2 WAS RETURNED TO $5RVICE AT 0353 ON MAY 27, 1989. l CAUSE OF THE EVENT WAS FAILURE OF AN ELECTROLYYIC CAPACITOR. THE go CAPACITOR FAILURE SHORTED THE CONTROL SYSTEM POWER SUPPLY TO GROUND, CAUSING LOSS OF ELECTRONIC CONTROL POWsR TO THE TURBINE CONTROL VALVES. THIS CAUSED THE CONTROL VALVES TO CLOSE. THE SHORT CIRCUIT U" CLEARED ABOUT 7 SECONDS LATER, ALLOWING THE CONTROL VALVES TO REOPEN, I

;)

BUT THE LOW STEAM GENERATOR LEVEL TRIP SETPOINT HAD BEEN REACHED AND kN UNIT 2 TRIPPED. THE SPEED ERROR AMPLIFIER CARD WAS REPLACED. OTHER CIRCUIT CARDS WERE INSPECTED.

he t- I FORM 161 LER SCSS DATA D' 0************************************************************04-18-91 ******** DOCKET Y t' A R LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE p1 306 1959 004 1 9003270415 217460 12/21/89 e.......e**ee.**ne...************..** ..... ********************eee* b' ABSTRACT POWER LEVEL - 100%. UNIT 2 TRIPPED ON 12/21/59, FROM WHAT APPEARED TO h4 BE FAULTY VCLTAGE REGULATION SY ONE OF THE CONTROL ROD ORIVE MECHANISM MOTOR-GENERATOR SETS. ONE SUBSTATION CIRCUIT 8REAKER DIO NOT OPERATE ga PROPERLY AND POWER WAS LOST TO NON-SAFEGUARDS 4KV BUSES, WHICH $UPPLT THE REACTOR COOLANT PUMPS. THE REACTOR WAS COOLED BY NATURAL ' CIRCULATION FOR 4800T 3 HOURS. THE VOLTAGE REGULATOR FOR THE MG SET

            ,    WAS REPLAC50 AND TESTED.         SINCE THE CUTDOOR TEMPERATURE AT THE TIME OF THE TRIP WAS -22F, THE COLD WAS BLAMED FOR THE 8REAKER MALFUNCTION.

8 HEATING WAS APPLIEC TO THE SUBSTATION SREAKERS ANO TESTING SHOWED PROPER OPERATION. THE UNIT WAS RESTARTED. ON 12/26/59, A NEARLY

  ,              IDENTICAL TRIP AND LOSS OF NON-SAFEGUARDS 4KW BUSES OCCURRED.

EKTENSIVE INVESTIGATION UNCOVERED MALFUNCTIONS IN THE MG SETS, IN THE ROD CONTROL SYSTEM, AND IN THE SUBSTATION BREAKER CONTROL SYSTEM. AFTER REPAIRS AND ENTENSIVE TESTING, UNIT 2 WAS RETURNE0 TO SERVICE ON 1/10/90. e 1

   ,            FORM    162                     LER SCSS DATA                       04-18-91
       ,      0************************************+*******************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 306 1990 001 0 9004130289 217795 03/08/90

                .*....***e****e*     **...     *****e**............e*********....***** ....

AS$YRACT POWER LEVEL - 100%. ON MARCH 8, 1990, UNIT 2 WAS AT 100% POWER. AN OPERATIONS INSTRUCTOR AND A TRAINEE WERE MAKING OPERATOR ROUNDS IN THE TUR8INE BUILDING. THE BUS OUCT COOLER LOCAL PANEL TEST WAS TO SE fy DEMONSTRATED TO THE TRAINEE. WHEN THE TEST BUTTON WAS DEPRESSED, A RELAY FAILE0 TO OPERATE PROPERLY AND A GENERATOR LOCKOUT SIGNAL WAS e PRODUCED, RESULTING IN A TURBINE TRIP AND REACTOR TRIP AT 1104. PLANT

      ,          RESPONSE TO THE TRIP WAS AS EXPECTED FOR A SECONDARY-SIDE INITIATED REACTOR TRIP; SOME WATER HAMMER OCCURREO IN SecoN7Anv tT9s o'e'=e i

e . ec2s asL4: aJ 9ethalt PROPERLV, ALLOWING A TRIP SI5NAL TO 9E GENERATED. THE CIRCUIT !$ 3E513NED 51 THAT WHEN THE TEST SUTTON IS P1 DEPRESSED, RELAY K3 CE!NERGIZES, PEMOVING THE TRID RELAY (23-X) FROM THE CISCUIT PRIOR TO $1HULATING A HIGH TEMPERATURE CONDITION. THE K3 kW QELAY CCNTACTS FAILED TO OPEN A5 DESIGNED. THUS, WHEN THE HIGH q; TEMPERATURE CONDITION WAS SIMULATED, A TRIP SIGNAL WAS GENERATED, , DW PRODUCING A GENERATOR LOCKOUT AND RESULTING IN A TURBINE TRIP AND REACTOR TRIP. 1 li I I P1 FORN 163 LER SC55 OATA 5 4 . 0******************************.*******..********************04-18-91 ******** 00CKET YEAR LER NUMSER REVISION 005 NUM8ER NSIC EVENT DATE 306 1990 002 0 9004190017 217799 03/09/90

>$ 9 ; ..................................** ...............................

gg 485 TRACT i: POWER LEVEL - 006T. ON MARCH 9, 1990, UNIT 2 WAS BEING RESTARTED U" FOLLOWING THE UNIT TRIP 04 MARCH S (UNIT 2 LER 90-001). REACTOR POWER WAS ABOUT 6% AND THE TUR81NE HAD JUST SEEN TRIPPED AS PART OF TURSINE bg

           ;;            CONTROL SYSTEM TESTING THAT IS PERFORME0 AT EACH STARTUP.                              WHEN THE i

TUR8INE WAS RELATCHED, AT 0128, THE REACTOR TRIPPED. CAUSE OF THE } TRIP WAS DETERMINED TO SE A FAILED RELAY, WHICH WAS THEN REPLACED. I yg j, LOGIC TESTING THEN TOOK PLACE TO PROVE OPERASILITY OF THE NEW RELAY. 1 ' AFTER THE LOGIC TESTING, VISUAL OSSERVATION OF SOME PERMIS$1VE RELAYS De SHOWED THAT TWO RELAYS, ONE IN EACH TRAIN, WERE NOT IN THEIR PROPER

              ,          POSITIONS. THESE TWO RELAYS WERE REPLACED AND TESTED FOR PROPER OPERATION.                THE UNIT WAS RESTARTED AND RETURNED TO SERVICE AT 0928 ON p .g                  MARCH 10, 1990. CAUSE OF THE EVENT WAS FAILURE OF A WESTINGHOUSE NSFO

i. RELAT. THE FAILED RELAYS WERE REPLACED.

bi I I FORM 164 LER SCSS DATA 04-19-91 he 0.................................................................... DOCKET YEAR LER NUMEER REVISION DCS NUMBER NSIC EVENT DATE ge 306 1990 003 1 9009250190 219540 03/16/90 ) .................................................................... 485 TRACT A POWER LEVEL - 100%. ON MARCH 16, 1990, UNIT 2 WAS OPERATING AT 100% 8 POWFR. AT 0921 A REACTOR TRIP OCCURRED FOLLOWING THE RESETTING OF A ROD CONTROL SYSTEM URGENT FAILURE ALARM WHICH HAD SEEN GENERATED ST g, COMNECTING TEST EQUIPMENT TO THE ROD CONTROL SYSTEM. ELECTRONIC NOISE HAD SEEN OBSERVED ON TEMPORARY MONITORING EQUIPMENT INSTALLE0 ON UNIT

     3                 2 ROD CONTROL SYSTEM. IN AN ATTEMPT TO IDENTIFY OR ELIMINATE POSSIBLE SOURCES OF THIS NOISE, AN IEC TECHNICIAN PLANNED TO DISCONNECT AND RECONNECT VARIOUS INPUTS TO A RECORDER.                 THE TECHNICIAN CONNECTED AN
   '     ,;              OSCILLOSCOPE TO A POINT IN THE ROD CONTROL SYSTEM. WHEN THE 05CILLOSCOPE WAS CONNECTED, THE "V-REF" CONTROL SIGNAL WAS FORCED TO A
    ,                    LOW VALUE 87 THE LOW INPUT IMPEDANCE OF THE OSCILLOSCOPE. THE 3-
                         "V-REF" SIGNAL FOR ONLY TWO ROCS, E-03 AND I-11, WAS AFFECTED AND THEY
   '                     DROPPED APPR0x!MATELY 10 STEPS INTO THE CORE AS THE URGENT FAILURE CIRCUITRY RESPONDED TO PREVENT ROD MOTION ST (PPLYING " NOLO" CURRENT n*

TO THE ROD MECHANISMS. APPR0xIMATELY 10 SECONOS LATER, THE URGENT F AILURE AL ARM W.5 RESET. WHILE THE RESET PUSHSUTTON WAS DEPRESSED, THE " HOLO" CURRENT WAS REMOVED FROM RODS E-03 AND I-11, AND THEY SEGAN , g TO 040P INTO THE CORE, RESULTING IN A HIGH NEGATIVE FLUX RATE REACTOR TRIP. RESPONSE TO THE TRIP WAS NORMAL AND CORRECT. AFTER EVALUATION OF THE EVENT, THE UNIT WAS RETURN!O TO SERVICE AT 0128 THE NEXT DAY. ft I

 , 9                    FORM    165                            LER SC55 DATA                                    04-18-91 4;           0....................................................................

00CKET YEAR LER NUMBER aEVISION DCS NUMSER NSIC

    ,                                                                                                        sys4Y nave

4357RACT

                >t                   POWER LEVEL - 333%. ON 3CT33ER 7,      1990 UNIT 2 WAS CRITICAL AT ZERO POWER AFTER REFUELING.       ZERO POWER PHT5!CS TESTING HAD JUST BEEN pq                  COMPLETED. THE REACTIVITY COMPUTER USED FOR PHYSICS TESTING Was TO BE g       DISCONNECTED FROM NUCLEAR INSTRUMENTATION (NIS) POWER RANGE CHANNEL N41. AN INSTRUMENT AND CONTROL TECHNICIAN, WHEN ASKED TO 00 THE WORK, D4 REVIEWED THE PROCEDURE AND THE L0GIC DIAGRAMS TO DETERMINE WHAT HIS r        ACTIONS SHOULD SE. WITH PROCEDURE IN HAND, HE PROCEEDED TO REMOVE THE P1                  CONTROL POWER AND INSTRUMENT POWER FUSES FROM THE FRONT PANEL OF THE NIS DRAWER, CAUSING A UNIT 2 REACTOR TRIP AT 1712 BECAUSE HE HAD g4 ,;                INADVERTENTLY REMOVED THE FUSES PROM NIS INTERMEDIATE RANGE CHANNEL N35 INSTEAD OF POWER RANGE CHANNEL N41. THE TRIP AND RECOVERT FROM THE TRIP WERE UNEVENTFUL. CAUSE OF THE EVENT WAS PERSONNEL ERROR IN b4            ,     REMOVING FU5ES FROM THE WRONG NIS CHANNEL DRAWER. CHANNEL N35 Is IMMEDIATELT ABOVE CHANNEL N41 ON THE NIS RACK. THE TECHNICIAN FAILED go                    TO USE SELF-CHECKING WHEN REMOVING THE FU5ES.

1 U" FORM 166 LER SCSS DATA 04-1 0****************************************************************8-91 **** DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 306 1990 012 0 9101310104 220872 12/29/90 y , ABSTRACT I' POWER LEVEL - 100%. ON 12/29/90, UNIT 2 WAS AT 100% POWER, AT 2234, UNIT 2 TRIPPED. CONTROL ROOM ANNUNCIATOR $, AND THE SEQUENCE OF EVENTS 9e GENERATED ST THE PLANT PROCESS COMPUTER, INDICATED THAT THE CAUSE OF THE REACT 0k TRIP WAS A NEGATIVE FLUX RATE TRIP FROM THE REACTOR g, PROTECTION ST57EM. AN INVESTIGATION INTO THE CAUSE OF THE NEGATIVE

                , '                 FLUX RATE TRIP REVEALED THAT TWO CIRCUIT CARDS IN THE ROD CONTROL SYSTEM POWER CABINET 150 HAD FAILEO. THE FIRST FAILURE WAS OF A Bi TRAN5!STOR IN THE URGENT FAILURE ALARM CIRCUIT. THE SECOND FAILURE WAS THE OPENING OF A SOLDER CONNECTION ON THE STATIONART GRIPPER e             REGULATION CARD, CAUSING THE REFERENCE VOLTAGE TO GO TO IERO. IN RESPONSE TO THE REFERENCE VOLTAGE GOING TO ZERO, THE URGENT FAILURE
                                  ALARM CIRCUIT SHOULD HAVE GENERATED AN URGENT FAILURE ALARM AND A
                                    " MOLD" CURRENT THAT WOULD BE APPLIED TO THE $fATIONART GRIPPERS FOR ALL THE RODS SUPPLIED ST THAT POWER CABINET. THIS HOLD CURRENT WOULD 8

HAVE PREVENTED THE ROD 5 FROM DROPPING INTO THE REACTOR. BUT SINCE THE URGENT FAILURE ALARM CIRCUIT HAD ALSO FAILED, NO CURRENT WAS SUPPLIED , e. TO THE STATIONART GRIPPER 5 IN CONTROL R0D BANK D AND THEY FELL INTO THE CORE, CAUSING THE NEGATIVE FLUX RATE TRIP. THE FAILED CARDS IN THE 400 CONTROL SYSTEM WERE REPLACED. UNIT 2 WAS RETURNED TO SERVICE AT 1330 ON 12/30/90. 1 e . FORM 167 LER SC55 DATA 04-18-91

                ,               0********************************************************************

DOCKET TEAR LER NUM8ER REVISION OCS NUMSER NSIC EVENT DATE 309 1989 001 0 8902210346 213055 01/10/89 A85 TRACT POWER LEVEL - 100%. AT 2019 ON 1/10/89, TME REACTOR A UTOM ATIC ALL Y TRIPPED FROM 100% POWER ON LOSS OF LOAD DUE TO A TURSINE TRIP. THE TURBINE TRIPPE3 DUE TO A SPURIOUS LOW VOLTAGE CONDITION 04 A CONTROL POWER SUS FOR THE ELECTRO-HYDRAULIC CONTROL (EHC) SYSTEM. THE EHC

                        ,           SYSTEn FG IYIn45 THE TURBINE CONTROL VALVE 5. CONTROL POWER FOR EHC 15 PROVIDED FROM FIVE DL ;G !* suSSES. LOSS OF YOLTAGE ON ANT ONE OF

THESE BUSSES ACTUATE 5 4 RELAY THAT TE!?! THE MAIN TURSINE. A g WESTINGHOUSE TECHNICAL REPRESENTAT!vE (THE EHC 5T57CM VENDOR)

PHYSICALLY INSPECTED THE POWER DISTRI5UTION PANFL sNm sereven staeev

as c eacLauf!cy.av ME1507f, 55V'R4L 83fENTI4LLY SUSPECT ELECTR355C COMP 0hf4TS WIPE RIPLACEC. 4 Tr4334&RV STRIP CHART RECORDEC WAS Bt CONNECTED TO THREE OF THE SUSSI5 TO ASSIST FURTHER TROUSLESH00 TING EFFORTS IN THE EVENT OF 4 REPEAT OCCURRENCE. THE OTHER TWO SUSSES ARE h4 NOT EXTERNALLY 4CCES$18LE FOR RECORDING. b4 FORM 163 LER SC55 OATA 04-15-9 0********************************************************************1 P1 DOCKET YEAR LER NUMSER REVISION OCS NUMSER NSIC EVENT DATE 309 1959 003 0 5905110271 213957 04/05159 g4 , ABSTRACT b0 POWER LEVEL - 100X. ON 4/5/S9, 4 PLANT TRIP OCCURRED WHEN GENERATOR gg PROTECTIVE REL4Y5 56P AND 868U ACTU4TED ON A LOSS OF LOAD CONDITION TO TRIP THE REACTOR AND TURSINE. THE CAUSE OF THE PLANT TRIP WAS ATTRIBUTED TO 4 CENTRAL MAINE POWER COMPANY (CMP) REL4Y INSPECTOR

,,            RETURNING A 345 KV 8REAKER FAILURE RELAY TO SERVICE. 4FTER TESTING THE RELAY, THE INSPECTOR 010 NOT CLOSE THE RELAY INPUT SWITCHES BEFORE CLO5ING THE OUTPUT (TRIP) SWITCHES. WITH ALL OUTPUT SWITCHES CLOSED, A D4             CHARGE 0 INPUT CABLE W45 RECONNECTED TO THE RELAY, CAUSING IT TO ACTUATE. THE RELAY IN TURN TRIPPED ONIT TIE 8REAKERS WHICH ISOLATED y

THE PLANT FROM THE GRID RESULTING IN THE LOS$ OF LOAD CONDITION. ALL PLANT SYSTEMS RESPONDE0 NORMALLY TO THE PLANT TRIP. A CAUTION HAS 8EEN

            ADDED TO THE ASSOCIATED CMP TEST INSTRUCTION ENSURING THE OUTPUT (TRIP) SWITCHES ARE CLOSE0 LAST WHEN RESTORING THE RELAY TO SERVICE.

1 P4 FORM 169 LER SC$$ DATA 04-18-91

>,       0****************+++++***********************************************
,           DOCKET YEAR LER NugeER REv!SION OC$ NUMBER                 NSIC        EVENT DATE 311    1989        003           0        8903140524 213206           02/05/S9 Be         A85 TRACT POWER LEVEL - 060%. ON 215159, FOLLOWING POWER REDUCTION FROM 90% TO
,,            601, THE UNIT EXPERIENCE 0 4 REACTOR TRIP DN NO. 23 STEAM GENERATOR (SIG) LOW LEVEL CONCURRENT WITH STEAM FLOWIFEED FLOW MISM4TCH. AT THE TIME 05 THE EVENT, NOS. 23A AND 235 CIRCULATING WATER PUMP 5 AND NO.

23 HEATER OR414 PUMP WERE OUT OF SERVICE. FOUR MINUTES PRIOR TO THE UNIT TRIP, NO. 22 5/G FEED PUMP (SGFP) HAD TRIPPED OUE TO LOW $UCTION e PRES 5URE. IT WAS FOUND TH4T THE LOW SUCTION TRIP SET POINT FOR THE 822 SGFP RESPONDED HIGH DUE TO FAILURE OF THE LOW SUCTION PRES 5URE

            SWITCH. THE ROOT CAUSE OF THIS EVENT HAS SEEN ATTRIBUTED TO INADEQUATE P10CEDURES ASSOCIATED WITH OPERATING THE PLANT WITH CIRC.

WATER SYSTEM RE00CEO CAPACITY CONCURRENT WITH AN INOPERASLE HEATER DRAIN PUM

P. PROCEDURE

40P-CONO-2 H45 SEEN REVISED TO CLARIFT OPERATOR ACTIONS WITH INOPERABLE CIRC. PUMP 5 AND HEATER OR4IN PUMPS. THE SGFP LOW SUCTION PRESSURE FIRST OUT ANNUNCIATOR RELAY Was INSTALLED AND TESTED. THE $ PEED CONTROL AND ELECTRIC OVERSPEED WERE ALSO CHECKE0 FOR SOTH SGFPS. THE NO. 22 $GFP LOW SUCTION PRES 5URE SWITCH WAS REPAIRED AND THE NO. 21 5GFP SWITCH W45 CHECKED AND FOUND SATI$ FACTORY. THE #21 SGFP MECHANICAL OVERSPEED DEVICE Was CHECKED AN3 THE PUMP W45 OPERATED TO SIMULATE 4 TRANSIENT PRIOR TO IT BEING PLACEO IN SERVICE. THE 234515 V4LVE WAS ADJUSTED AND TESTED SUCCES5 FULLY. 1 FORM 170 LER SC55 OATA 04-15-91 0**********************.***.***************************************** ' OOCKET YEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE

    .-          311    1959        005           0       5934180055 213562            03/12/89
            *************e****************         * *******   a.. * ............. ..

es :< L:vtt - luu;. UN H 12/ d 3, SOTH STES* GENERATOR FEED DUMPS (SGFPS) DECUCEJ THEIR TU211NE SPEEG TO ICLE. THE REACTOR SUBSEQUINTLY P9 TRIPPED ON NO. 23 STEAM GENERSTOR (S/G) FEED FLOW / STEAM FLOW HISMATCH WITH LOW S/G LEVEL. AFTER THE REACTOR TRIPPE0, A SAFETY INJECTION gy (SI) OCCURRED ON HIGH STEAMLINE FLOW COINCIDENT WITH LOW STEAMLINE

        ,         PRESSURE.      THE ROOT CAUSE OF THIS EVENT HAS BEEN ATTRIBUTED TO AN EQUIPMENT FAILURE. A CONTROL POWER FUSE, IN THE "0" VITAL INSTRUMENT b4                INVERTER LOW VOLTAGE POWER SOURCE, CAME OUT OF ITS FUSE HOLDER l      i,'        RESULTING IN INVERTER FAILURE AND DEENERGIZATION OF "D" VITAL by                INSTRUMENT SUS.      INVESTIGATIONS CONCLUDED THE FUSE MORE THAN LIKELY HAD COME OUT OF THE FUSF HOLDER DUE TO IMPROPER INSTALLATION AT SOME g      ,i         POINT IN THE PAST. THE FUSE ASSEMBLY DID NOT SHOW ANT SIGN OF DAMAGE
 ,4               OR IMPAIRMENT WHICH WOULO CAUSE THE FUSE TO DISLODGE. SUBSEQUENTLY, 58                THE INVERTER FUSE WAS REINSTALLED AND SUCCESSFULLY CHECKED FOR CONTINUITY AND TIGHTNESS. THE STATIC INVERTER WAS STARTED, TESTED SATISFACTORILY AND RETURNED TO SERVICE. ENGINEERING IS INVESTIGATING go                THE FEASISILITY OF SEPARATING THE PRES $URE CHANNELS TO OTHER VITAL INVERTERS THERESY ELIMINATING THE FOSSISILITY 05 THE OCCURRENCE OF A U"               SIMILARLY CAUSED SI. NEW VITAL INVERTERS ARE SCHEDULED TO BE INSTALLED DURING THE NEXT UNIT 2 REFUELING OUTAGE.

! 1 kw FORM 171 LER SCSS DATA 04-1 y, 0****************************************************************8-91 **** DOCKET YEAR LER NUMEER REVISION OCS NUMBER NSIC EVENT DATE 311 1989 006 0 8905040171 213816 03/29/89 88 , ********************************************************************

  >9             ABSTRACT POWER LEVEL - 0003. ON 3/29/59 A UNIT SHUTDOWN WAS 4EQUIRED TO COMPLY bi              WITH TECH SPEC ACTION STATEMENT 3.7.7.8. THIS ACTION STATEMENT WAS
  '               FIRST ENTERE3 ON 3/28/89 At 0900 HOURS IN SUPPORT OF REPLACEMENT OF b'              THE AUX. BLOG. VENTILATION SYSTEM (ASVS) (VF) CHARCOAL FILTER ADSORSER BANK. CHARC0AL BANK TEST RESULTS, CONDUCTED IN ACCORDANCE WITH TECH SPEC SURVEILLANCE 4.7.7.8,         SHOWED THE EFFICIENCY OF THE BANK 70 NOT ge              MEET TECH SPEC SURVEILLANCE 4.7.7.F. WITH THE UNIT IN MODE 3, HOT STAND 87, A REACTOR TRIP SIGNAL ON No. 21 STEAM GENERATOR (S/G) " STEAM
                FLOW / FEED FLOW MISMATCH COINCIDENT WITH LOW S/G LEVEL" OCCURRED. THE ROOT CAUSE OF THE REQUIRED SHUTDOWN HAS BEEN ATTRIBUTED TO EQUIPMENT PROBLEMS.      THE ROOT CAUSE OF THE REACTOR TRIP SIGNAL ACTUATION HAS 8

SEEN ATTRISUTED ALSO TO AN EQUIPMENT PROSLEM. PSESG SYSTEM ENGINEERING WILL RE-REVIEW THE VENTILATION SYSTEM PREVENTIVE

  , .             MAINTENANCE REQUIREMENTS TO ENSURE THEY ARE ADEQUATE.           A DETAILED INVESTIGATION OF THE CIRCUMSTANCES SURROUNDING THIS EVENT 87 PSEEG MANAGEMENT HAS BEEh C3MPLETED.         THE No. 21 S/G STEAMLINE FLOW CHANNEL I TRANSMITTER WAS SUCCESSFULLY RECALI644TED.

1 i FORM 172 LER SCSS DATA 04-18-91

  ,            0********************************************************************

DOCKET TEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE 311 1989 003 0 8905170078 213860 04/11/89

                 *****************+**************************************************

A85 TRACT POWER LEVEL - 100%. ON 4/11/S9 AT 2043 HOURS, A REACTOR TRIP ON No. 24 STEAM GENERATOR (SIG) " LOW-LOW LEVEL" OCCURRED. THE NO. 24 MAIN STEAMLINE ISOLATION VALVE, 24M5167, HAD CLOSED. AT THE TIME OF THE EVENT, THE REQUIRED TECH SPEC SURVEILLANCE 4.0.5-V FOR THE 21M518 M AIN

      ,.          STEAMLINE STPASS STOP VALVE WAS IN PROGRESS.           THE ROOT C AUSE OF THIS EVENT HAS BEEN ATTRIBUTED TO AN EQUIPMENT FAILURE. AN "0PERATE RESET" i               LATCHING RELAY (74-4&), ASSOCIATED WITN THE SOLIO STATE PROTECTION g           SYSTEM ($$PS), FAILED DURIN3 THE 21MS13 $URVEILLANCE RESULTING IN CLOSURE OF THE 2AM5167 VALVE. THE FAILED "74-AA" #FL Av wat orestren.

2 satm< re t u n e N a t . L Jce:LTS ARE PRESENT. FOLL0 DIN 3 THE REACTOR TPIP, THE 24M515, MAIN STfA"LINE SA5ETY VALVE, L187ED TWICE. THE VALVE

, P4                REMAINED PARTIALLY OPiN FOR APPROXIMATELT ONE HOUR. INVESTIGATION REVEALED THAT THE AS FOUND LIFT SET PRE 55U2E WAS 901 PSIG (AFTER THE pq                SECCND LIFT).         A PROPER LIFT SETFOINT OF 1070 PSIG COULD NOT BE g:       ACHIEVED. THE VALVE WAS SUBSEQUENTLY REPLACED WITH A SPARE VALVE. IT UN                APPEARS THAT THE VALVE SEATING SURFACE DURING THE FIRST LIFT BEC AME DAMAGED ALLOWING INCREASED LEAKAGE. THE REPLACEO 24M515 V ALVE H AS e
;          [.       SEEN SHIPPED TO CRO5BY VALVE & GAGE CO. FOR INSPECTION AND REPAIR.

P1 1 g4 ;. FORM 173 LER SC55 OATA 0************************************************************04-18-91 ******** D4 00CKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE g; 311 1989 013 1 8909180326 215254 06/10/89 DC r.' 4857RACT

     "              POWER LEVEL - 100%. ON 6/10/$9, A REACTOR TRIP WAS MANUALLY INITIATED FROM 15% REACTOR POWER DUE TO THE LOSS OF THE MAIN CONDEN5ER ON HIGH 1,      8ACK PRESSURE. AT 2306 HOUR 5, THE "$CREENW45H TROUBLE" OVERHEAD b4 '

ANNUNCIATOR IN CONTROL ROOM ALARMED DUE TO HIGH DIFF. LEVEL (OL) ACROSS SEVERAL CIRCULATING WATER SYSTEM (CWS) SCREENS. A POWER

  >s                RUNBACK WAS INITIATED. WITHIN 5 MIN. OF THE ALARM, 5 0F THE 6 CIRCULATING PUMP 5 TRIPPED ON HIGH OL ACROSS THEIR ASSOCIATED SCREENS.
     '             TUR8INE WAS MANUALLY TRIPPED WITH THE REACTOR AT 48% POWER.                       THE g,      FUNCTIONAL TURBINE BTPASS VALVE 5 (5 TEAM DUMP) WERE ARMEO AND OPENED.

CONDEN5ER BACK PRESSURE INCREASED TO WHERE THE PERMISSIVE TO USE STEAM D4 DUMP 5 WAS EXCEEDED. THE STfAM DUMP VALVES CLOSED AND THE FIRST MAIN STEAM SAFETY VALVE IN EACH STEAMLINE LIFTED. DIRECTION WA5 GIVEN TO g, MANUALLY TRIP THE REACTOR. ROOT CAUSE HA5 SEEN ATTRIBUTED 10 EXTERNAL

  ;                CAUSES AND INADEQUATE CORRECTIVE ACTION FROM A SIMILAR PRIOR EVENT.

bi

              '    LARGE ACCUMULATIONS OF GRASS AND DEBRIS ON THE SCREENS CAUSED THE HIGH DL.       ON 8/11183, A SIMILAR EVENT OCCURRED.          CORRECTIVE ACTION FROM THE PRIOR EVENT DID NOT REQUIRE ANY LONG TERM ACTIONS. A REVIEW OF t1 j,           PREVENTIVE MAINTENANCE (PM) HISTORY FOR CLEANING TRASH RACK 5 WAS CONDUCTED. IT WAS FOUND TH4T NO SPECIFIC PM REQUIREMENT EXISTED. A
  ,,               PM TASK FOR SPECIAL CLEANING OF TRASH RACKS EVERY REFUELING OUTAGE HAS i

SEEN ESTA8LISHEO. 1 0

        .; ,      FORM           174                    LER SCSS DATA                         04-18-91
     ,          0.**..*...*****.*****.***************.*******.e.**.a..*.*******..****

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

  '                   311         1990      029              1     9102080111 220939          06/28190 i I               ABSTRACT POWER LEVEL - 075%. AT 0032 HOUR $ ON 6/25190, OURING SALEM UNIT 2
  ,                POWER ASCENSION OPERATIONS, A REACTOR TRIP OCCURRED FOLLOWING THE LOS$

9 0F 80TH STEAM GENERATOR FEEDWATER PUMP 5 (SGFPS) RESULTING FROM

  '                FAILURE OF 2F 4160-480/277 VOLT TRANSFORMER. DUE TO THE LOSS OF SOTH SGFP's

LOW STEAM GENERATOR LEVEL COINCIDENT WITH STEAM FLOW / FEED FLOW i ' MISMATCH" HAD OCCURRE3 CAUSING THE REACTOR TRIP. A MAIN STEAMLINE ISOLATION WAS MANUALLY INITIATED TO REQUCE AN EXCESSIVE C00LDOWN RATE FOLLOWING THE REACTOR TRIP. MAIN STEAM ISOLATION VALVES (MSIv5) 21 g AND 2AM5167 DID NOT CLOSE 04 THE INITIAL ATTEMPT! HOWEVER, THE OPERATOR AGAIN DEPRE55ED THE MAIN STEAMLINE ISCLATION PUSH 8UTTONS (THIS TIME FOR AN EXTENDED PERIOD) AND THE VALVE 5 CLOSED. THE UNIT g; WAS STABILIZED IN MODE 3 (HOT STAND 87). THE ROOT CAUSE OF THE TRANSFORMER FAILURE WAS INADEQU4TE PREVENT!vE MAINTENANCE. THE
PREVENTIVE MAINTENANCE PROGRAM 15 BEING REVISE 0 TO PROVIDE ROUTINE, g, DOCUMENTED INSPECTION AND CLEANING OF TRANSFORMER COILS. AL50, THE

   ,               ROUTINE ELECTRICAL TRANSPORMER TESTING T5 PEING RFvitsa vn tureuns enu l

. ... ..... . .~..4 . <t.c.L:u to: f:21W 15ULATION LOGIC DID NOT MEET DEST 3N BASIS Al PER *ESE STAN3ARO 270 THE MSIV CIRCUITRT WAS I D '9 MODIFIED ON SALEM UNITS 1 AH3 2 TO RESOLVE THE IDENTIFIED CONCERNS. 1 FORM 175 LER SC55 DATA 04-18-91 0******************************************************************** kN DOCKET TEAR LER NUM8ER REVISION 0C5 NUMBER NSIC EVENT DATE i + g 311 1990 036 0 9010120193 219722 09/04/90 pq ******************************************************************** g4 9 ABSTRACT POWER LEVEL - 060%. 04 9/4/90 AT 0226 HOURS, DURING NORMAL POWER OPERATION, NO. 21 STEAM GENERATOR FEED PUMP (SGFP) TRIPPED ON LOW be ; . SUCTION PRES $URE. A TUR8INE RUMBACK TO 60E POWER AT 15%/ MIN WAS INITIATED. AT THE COMPLETION OF THE RUN8ACK, STEAM GENERATOR (S/G) kg LEVEL BEGAN INCREA51NG. 45 PER PROCEDURE, THE FOUR SF19 VALVES (5/G t FEEDWATER CONTROL VALVES) WERE PLACED IN MANUAL MODE TO GAIN CONTROL be OF S/G LEVEL. HOWEVER, JUST AFTER THE 248F19 VALVE WAS PUT IN MANUAL CONTROL, No. 24 S/G REACHED ITS HIGH LEVEL SETPOINT INITIATING A

             ,       TUR8INE TRIP AT 0231 HOUR $ ON 9/4/90.                            WITH REACTOR POWER 480VE h4               PERMISSIVE P-9 (50% POWER), A REACTOR TRIP FOLLOWED. THE ROOT CAUSE OF THE REACTOR TRIP IS ATTRIBUTED TO EQUIPMENT FAILURE. THE 218F19 yg i.             AUT0/ MAN CONTROLLER FAILED, CAUSING VALVE CLOSURE DURING THE RECOVERT OPERATION AFTER THE No. 21 SGFP HAD TRIPPEO. THE SETPOINT FOR THE SUCTIC1 PRES 5URE SWITCH HAD ORIFTED HIGH. WHEN THE 23HD15 VALVE
      '   t          (HEATER DRAIN PUMP DISCHARGE CONTROL VALVE) FAILED CLOSED (RUPTURED DIAPHRAGM) A SIGNIFICANT SGFP SUCTION PRESSURE DROP OCCURRED. THIS D1               COUPLED WITH THE HIGH SETPOINT RESULTED IN THE No. 21 SGFP TRIP.

PRECEDING THE RUPTURE OF THE VALVE DIAPHRAGM, THE VALVE CONTROLLER

    ,,               FAILED.        THE FAILED PRES 5URE SWITCH, THE 23HD15 VALVE DIAPHRAGM, AND g                THE 23HD15 VALVE CONTROLLER'S PNEUMATIC RELAY WERE REPLACED. THE Ae 218F19 VALVE AUT0/ MAN CONTROLLER WA$ REPLACED.

1 e . FORM 176 LER SC55 DATA 04-18-91 , 0****************************************e***************************

                  DOCKET TEAR LER NUMBER REVISION DCS NUM8ER                                    N5IC                  EVENT OATE 312         1989          001                 1        8908020059 214S82                            01/31/89 e

ABSTRACT

      ,              POWER LEVEL - 093%. AT 1725 HOURS ON 1/31/89, A POST MAINTENANCE TEST OF AUXILIART FEEDWATER (AFW) PUMP P-315 WAS IN PROGRESS. DURING THE PERFORMANCE OF THIS TEST, THE PUMP REACHED AN OVERSPEED CONDITION RESULTING IN AN OVERPRESSURIIATION OF SOTH AFW TRAINS.                                            AT 2156 HR5, 80TH AFW TRAINS WERE DECLARE 0 IN0PERA8LE. CONTROL ROOM OPERATORS BEGAN A PLANT SHUTDOWN AT 2212 Hour $ AND TRANSITION TO DECAT HEAT COOLING. THE REACTOR WAS IN HOT STANDST AT 0146 HOURS ON 2/1/89.                                                AT
    ,                0155 HRS, THE REACTOR WAS MANUALLY TRIPPED TO ASSURE THAT A GREATER THAN tt SHUTDOWN MARGIN WA5 ACHIEVED WITHIN THE TECHNICAL SPECIFICATION (TS) IMPOSED 4 HR TIME LIMIT. AT 1554 HRS, CONTROL ROOM OPERATOR $ ESTABLISHED DECAT HEAT COOLING 1 HR AND 59 MIN AFTER THE SPECIFIED T5 TIME REQUIREMENT. THE MANDATORY SHUTOOWN OF THE PLANT As t

REQUIRED ST TS IS REPORTA8LE PUR5UANT TO 10 CFR 50.73(a)(2)(1)(A). THE FAILURE TO ESTABLISH DECAT HEAT COOLING WITHIN 12 HRS SU8 SEQUENT

        ,.           TO THE REACTOR TRIP AS REQUIRED ST T5 15 REPORTABLE PUR5UANT TO 10 CFR 50.73(4)(2)(I)(B). A SITE TEAM CONDUCTED A ROOT CAUSE INVESTIGATION OF THE PUMP OVERSPEED AND ASSOCIATED OVERPRESSURIZATION OF THE'AFW g :-         SYSTEM. THE INVESTIGATION DISCLOSED THAT THE TURSINE GOVERNOR FAILED TO CONTROL TURSINE SPEED AND THE MECHANICAL OVERSPEED TRIP MECHANISM t                FAILED TO CLOSE THE TUR81NE STEAM INLET VALVE.
        ,.        1
               -_      =        v       -            = , - , -         .        - - , -                . -                                                                                                                                    --
                                                                                                                                                                                                                ,                        ,. r    ,

                            . . . . .   ...s  6s                     aus:tw           s:4&2&J9  JL s 74UMSE D                                                    NSIC EVENT 0175 312  1931                       UO4                     0     9035010106 213732                                                       03/28/99 P,

h4 A8STRACT POWER LEVEL - 093%. ON MARCH 25, 1989, AT 1516 HOURS, WHILE OPERATING AT 93% POWER, THE PLANT'S MAIN FEEDWATER PUMPS (MFPS) EXPERIENCED Dd SPEED CONTROL PROBLEMS. THIS RESULTE0 IN 4 RAPID LOSS OF FEEDWATER t FLOW TO THE STEAM GENERATORS. THE CORRESPONDING INCREASE IN REACTOR P1 COOLANT SYSTEM (RCS) PRESSURE CAUSED THE PLANT TO AUTOMATICALLY SHUT 00WN. SECAUSE OF THE MFP CONTROLLER PROSLEMS, T HE INTEGRATED CONTROL i g4 SYSTEM (ICS) RESPONSE TO THE PRE-TRIP UNDERFEED CAUSED THE POST-TRIP FEEDWATER REFEED TO THE RCS 70 SE GREATER THAN EXPECTED. THIS b4 RESULTED IN A PRESSURIZER LEVEL DROP TO THE ELEVATION OF THE LEVEL INDICATOR TAP. THE PLANT DID NOT EXIT THE POST-TRIP WINDOW, AND NORMAL POST-TRIP LEVELS WERE ESTABLISHED 14 MINUTES AFTER THE TRIP. be 1 D" FORM 175 LER SCSS DATA 0************************************************************04-18-91 ******** 00CKET YEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE hw 313 1989 002 0 8904120107 213465 01/20159 D4 A8STRACT

                         POWER LEVEL - 100%. ON 1#20#89 A REACTOR TRIP OCCURRED DUE TO A FAILURE IN THE MAIN GENERATOR EXCITER. FOLLOWING THE TRIP, TWO REACTOR C00LANY PUMPS (RCPS) TRIPPE0 04 UNDERVOLTAGE WHEN BUS H1 D4                        FAILED TO FAST TRANSFER TO OFFSITE POWERJ THE MAIN FEEDWATER (MFW)

STARTUP V4LVES AND LOW LO4D CONTROL VALVES FOR SOTH 'A' AND '88 MFW

,,                         TRAINS F4ILED TO CLOSE DUE TO MISWIRING IN THE INTEGRATED CONTROL j                          SYSTEMJ THE 'S' MFW BLOCK VALVE FAILED TO CLOSE DUE TO AW INCORRECT TORQUE SWITCH SETTING; MFW PUMP P18 FAILED TO RUN BACK TO THE DESIGNED D'

POST-TRIP MINIMUM SPEED DUE TO AN UNDETERMINED CAUSEJ AND MFW PUMP P1A POST-TRIP MINIMUM SPEED WAS HIGHER THAN DESIGNES MINIMUM SPEED DUE se TO AVAILABILITT OF STEAM FROM A MOISTURE SEPARATOR REMEATER. THE MFW SYSTEM COMPONENT FAILURES CAUSED AN OVERFILL OF THE 'B' ONCE-THROUGH

,,                         STEAM GENERATOR (SG). CURING THE TRANSIENT, OPERATORS INITIATED HIGH PRESSURE INJECTION (HPI) TO COMPENSATE FOR REACTOR COOLAMT SYSTEM I

(RCS) SHRINKAGE CAUSED SV OVERC00 LING CUE TO OVERFEEDING THE SGS. AFTER SECURING HPI THE COM81 NATION OF A PARTIALLY FAILED OPEN CHECK VALVE AND THE RCP OPERATING CONFIGURATION ALLCWtD SACKLEAKAGE OF t . REACTOR COOLANT INTO HPI SYSTEM PIPING OUTSIDE CONTAINMENT. DURING REC 0VEkT FROM THE TRANSIENT, THE EMERGENCY FEE 0 WATER SYSTEM

'           ,             AUTOMATICALLY ACTU4TED ON 'B' SG LOW LEVEL.

1 I

FORM 179 LER SCSS DAT4 04-18-91 0********************************************************************

i DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 313 1959 018 0 5906050380 214112 0$101/89 ABSTRACT POWER LEVEL - 050%. ON $ #1/ S 9, THE REACTOR TRIPPED ON A TURBINE TRIP CAUSED BY MAINTENANCE PERSONNEL INADVERTENTLY JARRING A TURBINE CONTROL PANEL CONTAINING MERC010 SWITCHES FOR TURBINE TRIP FUNCTIONS. MAINTENANCE PERSONNEL M40 GONE INSIDE THE MAIN TURSINE HOUSING TO I REPLACE AN ELECTRO-HTDRAULIC FLUID FILTER FOR A TURBINE THROTTLE VALVE. AS PERSONNEL EXITED THE WORK AREA ST CLIMSING DOWN FROM A CATWALK TO THE TOP OF A LADDER APPROXIMATEL't FIVE FEET BELOW, THE t CONTROL PANEL WAS 8EING USED As AN INTERMEDIATE STEPPING PLACE WITHOUT g INCIDENT. HOWEVER, AT 1556 HOURS, THE UNIT TRIPPED WHEN SWITCHES FOR

.                        THE TUR8INE SOLENOID TRIP FUNCTION CHANGEO STATE As Yns e a N e t. wet

                                                                                                     . m 4..u...,

a r e a s o, Lbu i te IHL LUNTROL SYSTEM. ALSO, 4 MAIM STEAM SAFETY F1 VALVE (MSSU) FAILE3 TO C39PLETFLY RESEAT AFTER LIFTING OUE TO A MISSING COTTER PIN. THE MISSIN3 PIN ALLOWED a NUT VC UI5 RATE D0dN THE CALWE STEM DHILE THE WALVE WAS ret;IEVING STEAM, PREVENTING THE VALVE gq PROM FULLY CLO3INGo THE TUDGINE CONTROL PANEL HAS BEEN LABELED WITH A

        ;'     CAUTION THAT IT IS A UNIT TRIP HAZARD. THE ISOLATED SENSING LINE HAS b4             BEEN UNISOLATED. THE MSSV MISSING COTTER PIN WAS REPLACED AND COTTER PINS WERE WERIFIED INSTALLED ON THE OTHER MSSV.

i - 1 P1 FORM 180 LER SCSS DATA g) ~ . 0*e***************e ** .e*****.+e* ..+**********************04-18-91 DOCKET YEAR LER NUMBER REVISION DC$ NUMBER NSIC EVENT DATE 313 1989 037 0 8912180061 216191 11/10/89 he ,

             ********..******** ** . ***...****** ........*****e....e*** ....**ee go            ABSTRACT POWER LEVEL - 074%. ON 11/10/89 AT APPROX. 2255, A REACTOR TRIP U"             OCCURRED AS A RESULT OF THE INADVERTENT GROUNDING OF A REACTOR PROTECTION SYSTEM (RPS) POWER SUPPLY OURING SURVEILLANCE TESTING.                 THE
>4 GROUNDING RESULTED IN THE LOSS OF THE RPS POWER SUPPLT AND OEENERGIZED THE REACTOR POWER AUCTIONEERING CIRCUIT FOR THE INTEGRATED CONTROL SYSTEN (ICS) WHICH RESULTED IN A REACTOR POWERIFEEDWATER FLOW y,    ,        MISMATCH.

THE ICS AUTOMATIC RESPONSE TO THIS MISMATCH WAS TO REQUCE FEE 0 WATER FLOW To THE STEAM GENER ATORS AND TO WITHORAW CONTROL RODS. E8 THESE ACTIONS RESULTED IN A RISE IN REACTOR COOLANT SYSTEM (ECS) TEMPERATURE AND PRESSURE AND A REACTOR TRIP AT 2355 PSIG. THE INITIAL PLANT RESPONSE FOLLOWING THE TRIP WAS AS EXPECTED, WITH ALL POST TRIP R1 PAR AMETER S SEING NORMAL. HOWEVER, DUE TO VARIOUS STEAM LEAKAGE PATHS IN THE SECONDARY SYSTEM, THE STEAM GENERATOR PRESSURES GR ADUALLY

b. DECAYED 10 APPR0x!MATELY $60 PSIG AND RCS TEMPERATURE OECREASED TO 535 g DEGREES. THE CAUSE OF THIS EVENT WAS AN INADEQUATE PROCEDURE WHICH hi REQUIRED CONNECTING A TEST LEAD TO A SOLDEREO CONNECTION IN THE SACK 0F THE RPS CA8INET. THIS CONNECTION WAS WITHIN ONE EIGHTH INCH OF THE CONNECTION WHICH WAS INADVERTENTLY GROUNDEO. THE RPS CALIBRATION

t. PROCEDURE WAS REVISED TO SPECIFY TAKING THE REQUIRED READING FROM A MORE SUITABLE LOCATION.

te FORM 181 LER SCSS DATA 04-18 91 e o........... .....ee*.***......*.....**..***..e***e.e.e...... .*..**e. DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE , 313 1989 039 0 8912270264 216193 11/14/89

             ........................e**ese***e.** ******.****.e*******ee****eee.

A85 TRACT POWER LEVEL - 0741. ON 11/14#89 AT APPR0x. 2323, A REACTOR TRIP ' ,a OCCURRED AS A RESULT OF THE INADVERTENT CLOSURE OF A MAIN FEEDWATER ISOLATION VALVE. WHILE ATTEMPTING TO CLOSE THE SUCTION ISOLATION WALVE FROM THE CONDENSATE STORAGE TANK TO THE STEAM DRIVEN EMERGENCY FEED PUMP OURING MCVATS TESTING, A LICENSED PLANT OPERATOR INADVERTENTLY CLOSED THE MAIN FEEDWATER ISOLATION VALVE FOR THE "B" STEAN GENERATOR. THIS ACTION CAUSE0 THE "8" MAIN FEE 0 WATER PUMP TO TRIP ON HIGH DISCHARGE PRESSURE AND RESULTED IN A REACTOR TRIP OUF TO A HIGH REACTOR COOLANT SYSTEM (RCS) PRESSURE OF 2355 PSIG. THE INITIAL PLANT RESPONSE FOLLOWING THE TRIP WAS NORMAL. HOWEVE2, OUE TO VARIOUS STE44 LEAKAGE PATHS IN TME SECONDARY SYSTEM, STEAM Gf.NERATOR PRESSutES GRADUALLY DECAYED TO 935 PSIG AND 891 PSIG FOR THE "A" AND "8" GENERATORS RESPECTIVELY. RCS TEMPERATURE CECREASED TO 540.2 DEGREES. THESE VALUES ARE SLIGHTLY BELOW THOSE NORMALLY ANTICIPATED OURING POST TRIP CONDITIONS. THE ROOT CAUSE OF THIS EVENT WAS t PERSONNEL ERROR IN THAT THE OPERATOR FAILED TO EMSURE THAT HE WAS g'y LIANIPULATING THE CORRECT VALVE. DISCIPLIN4RT ACTION WAS TAKEN AGAINST . THE OPERATOR. Resp 0NSISLE FOR MANIPULATING WRONG vatV8 As t a. 9

Pg FORM 182 LE9 SCSS 04TA 04-19-9 0*e***eeeeee***......eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee.1 DOCKET YEA 1 LER NUMEER REv!SION OCS NUT.8ER NSIC EVENT DATE 313 1989 043 0 9002060392 216630 12/28/89 D4 , ,, ABSTRACT pq ' POWER LEVEL - 0423. ON 12/28/89, AT APPR0xIMATELY 1529, AN AUTOHATIC REACTOR TRIP AND ACTUATION OF THE EMERGENCY FEEDWATER SYSTEM (EFW) L4

OCCURRED AS A RESULT OF THE LOSS OF ALL MAIN FEEDWATER FLOW WHICH RESULTED FROM THE INADVERTENT TRIPPING OF A MAIN FEEDWATER PUMP (MFP).

EARLIER IN THE DAY, THE 'A' MFP HAD TRIPPED ON OVERSPEE0 OUE TO A bl g, MALFUNCTION IN THE PUMP CONTROL CIRCUITRY. ANOTHER MALFUNCTION IN THE TRIP OIL SYSTEM HAD CAUSED AN 11 SECOND DELAY IN THE SENSING OF THE go TRIP BY THE INTEGRATED CONTROL SYSTEM (ICS). AT THE TIME OF THE f EVENT, TROUSLESH00 TING WAS IN PROGRESS TO DETERMINE THE CAUSE OF THE DELAY. OPERATIONS PERSONNEL HAD LATCHED, AND THEN TRIPPED THE 'A' MFP

#9 WITH NO OSSERVED DELAY IN TRIP INDICATION SY THE ICS. DURING THE y,       PERFORMANCE OF A SECOND TEST, AN OPERATOR MISTAKENLY TRIPPED THE be              OPERATING MFP ('8').      THIS ACTION RESULTED IN A TOTAL LOSS OF FEEDWATER FLOW WHICH INITIATED AN AUTOMATIC REACTOR TRIP AND ACTUATION
,, q,           OF THE EFW SYSTEM. THE ENGINEERED SAFETY FEATURES ACTUATED, AS DESIGNED, AND PRIMARY AND SECONDARY PARAMETERS WERE MAINTAINED WITHIN ACCEPTA8LE LIMITS. THE ROOT CAUSE OF THIS EVENT WAS DETERMINED TO BE B'             PERSONNEL ERROR. DISCIPLINARY ACTION WAS TAKEN AGAINST THE OPERATOR WHO TRIPPED THE WRONG MFP. ADDITIONAL ACTIONS ARE ALSO 8EING TAKEN To pg              MINIMIIE THE OCCURRENCE OF PERSONNEL ERRORS.

1 f' FORM 183 LER SCSS DATA 04-18-91 o.................................................................... be DOCKET YEAR LER NUMEER REVISION DCS NUMBER NSIC EVENT DATE 313 1990 022 0 9101230196 220515 12/13/90 485 TRACT POWER LEVEL - 000%. ON DECEMBER 18, 1990, WHILE CONDUCTING A PLANT HEATUP IN PREPARATION FOR STARTUP, AN AUTOMATIC REACTOR TRIP WAS 9 INITIATED BY THE REACTOR PROTECTION SYSTEM (RPS) UPON SENSING NO I REACTOR COOLANT PUMPS (RCPS) RUNNING IN THE "B" REACTOR COOLANT SYSTEM

 ,,             (RCS) LOOP. AT THE TIME OF THE TRIP, RCPS P-32C AND P-320 WERE RUNNIN3 IN RCS LOOP 'A' AND P-324 WAS RUNNING IN LOOP '8'. RCPS WERE
 '              BEING BALANCED TO REDUCE VIBRATION IN ACCORDANCE WITH AN APPROVED PROCEDURE. THE OPERATORS WERE REQUESTED TO SHIFT FROM P-32A TO P-328 IN RCS LOOP '8'. AFTER REVIEWING THE RCP OPERATING PROCEDURE, THE INVOLVED OPERATORS ASKED THE SHIFT SUPERVISOR (SS) IF HE WISHED TO STOP P-32A AND START P-328. THE SS GAVE AN AFFIRMATIVE RESPONSE. AT
 ,              THAT TIME, A TRAINEE UNDER THE SUPERVISION OF A SENIOR REACTOR OPERATOR, STOPPED P-32A.      A REACTOR TRIP THEN OCCURRED DUE TO IERO PUMPS RUNNING IN THE 'B' RCS LOOP. THE ROOT CAUSE OF THIS EVENT WAS PERSONNEL ERROR. AN INADEQUATE PROCEDURE WAS A CONTRI8UTING F ACTOR.
     ,          THE RCP OPERATING PROCEDURE CONTAINED NO CAUTIONS REGARDING THE POSSI8ILITT OF INITIATING TRIP WHEN STOPPING FCPS. A CREW SRIEFING WAS HELD WITH THE CREW INVOLVED TO DISCUSS THIS EVENT AND ITS
    ,           SIGNIFICANCE. THE RCP OPERATING PROCEDURE WILL SE REVISED TO INCLUDE ADDITIONAL GUIDANCE REGARDING SHIFTING RCPS.

1 I FORM 186 LER SCSS DATA 04-18-91

0.*******.***********************************************************

g DOCKET YEAR LER NUM9ER REVISION DCS NUMSER NSIC EVENT DATE

 ,               315     1989      001           0     8903010413 213165        nitiateo

__ _ , .~ _

pe POWER LEVEL - 071%. ON 01/16/30 THE FLANT HEATING SOILER (PHS) WAS Si!NG OPER4TED FOR TESTING FURDOSES AFTER MAINTENANCE. THE UNIT SUPERVISOR GAVE INSTRUCTIONS TO A REACTOR OPERATOR (RO) F02 FLACING g4 CUXILI42T STEAM LOAD ON THE PHS. THESE INSTRUCTIONS INCLUDED OPENING THE STEAM SUPPLT TO THE START-UP AIR EJECTOR $ IF THE NORMAL STEAM LO4DS WERE NOT ENOUGH. AFTER PLACING THE NORMAL STEAM LO4DS ON THE

>9                                     PHS, THE RO IDENTIFIED THE CONTROL SWITCH FOR THE STEAM SUPPLY TO THE START-UP AIR EJECTORS. A FEW MINUTES LATER THE CONTROL ROOM WAS P1                                     NOTIFIED THAT THE PHS NEEDED MORE LOAD. THE RO PROCEEDED TO OPEN THE STEAM SUPPLY TO THE START-UP AIR EJECTORS. BUT HE ERR 0NEOUSLT OPERATED THE CONTROL SWITCH FOR THE CONDENSER AIR OFF-T4KES TO THE START-UP AIR EJECTORS DUE TO INADEQUATE SELF CHECKING. THIS CAUSED 4 RAPIO b4                                     DECREASE IN CONDENSER WACUUM WHICH RESULTED IN 4 UNIT TRIP. PREVENTIVE p.

ACTION WILL INCLUDE OPERATOR TRAINING TO EMPHASIIE THE IMPORTANCE OF SELF CHECKING. THE LABELING OF THE INVOLVED CONTROL SWITCHES WILL SE g4 ENHANCED FOR HUMAN FACT 3R CONCERNS. APPROPRIATE ADMINISTRATIVE ACTION WAS TAKEN WITH THE INVOLVED OPERATOR. h4 FORM 185 LER SCSS DATA

 >=                                0**********************************.***************..********04-18-91 DOCKET TEAR LER NUMBER REVISION DCS NUMBER           NSIC    EVENT DATE
 ,,                                      315   1939      003             U   8904230195 213734      03/18#89 88                                  *85 TRACT OWER LEVEL - 010%. ON MARCH 18, 1959 AT 0611 HOURS WHILE UNIT ONE WAS pe                                    SHUTTING DOWN IN PREPARATION FOR REFUELING, AN ENGINEERED SAFETY FEATURES (ESF) 4CTUATION (REACTOR TRIS SEQUENCE) OCCURRED. THE
 '                                     REACTOR TRIP W45 00E 70 & STANDING HIGH FLUX TRIP 04 THE INTERMEDIATE RANGE (IR) NUCLEAR INSTRUMENTATION CHANNEL I (N-35) WHICH HAD NOT 8*                                    RESET PRIOR TO POWER DROPPING SELOW PERMISSIVE P-10 (APPROMIMATELT 9 PERCENT) WMICH AUTOMATICALLY UNBLOCKS THE IR HIGH FLUX REACTOR TRIP.

THE LOW VALUE FOR THE TRIP RESET SETPOINT WAS DUE TO IME METH000LOGT

3. USED TO DETERMINE THE CURRENT EQUIVALENT v4 LUES OF THE TRIP SETPOINT WHICH RESULTED IN A CONSERVATIVELY LOW SETPOINT FOR BOTH THE REACTOR

                                     TRIP AND THE TRIP RESET. TO PREVENT RECURRENCE, CHANGES ARE BEING MADE IN THE METHOD USED TO DETERMINE THE CURRENT EQUIVALENT VALUES FOR THE TRIP AND TRIP RESET SETPOINTS THAT WILL ENSURE THE TRIP SETPOINT IS CONSERVATIVE AND WILL ALSO ENSURE THE RESET SETPOINT WILL SE ABOVE P-10. THESE CH4NGES WILL BE IN EFFECT PRIOR TO UNIT ONE GOING A80VE
 ,                                     P-10.

1

 '                                            186 FORM                        LER SCS$ DAT4                      04-13-91 0*****************++*******************************************.*****

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 316 1989 014 0 5909220109 215257 08/14/89 485 TRACT POWER LEVEL - 1001. ON 8/14/$9 AT 1601 HOURS, A REACTOR PROTECTION SYSTEM (RPS) ACTU4 TION (REACTOR TRIP) QCCURRED WHEN OPERATORS TRANSFERRED THE CONTROL ROOM INSTRUMENTATION DISTRIBUTION (CRID) IV (VITAL OUS) INVERTER TO ITS MORMAL CLASS 1E POWER SUPPLY AND THE

                ,                      INVERTER FAILEO. WHEN THE CRID IV INVERTER FAILED, A REACTOR TRIP SIGNAL WAS INITI4TED OUE TO THE REACTOR COOLANT PUMP (RCP) CIRCUIT SREAKER POSITION INDICATION OPEN (FED FROM CRIC IV). PRIOR TO THE TRIP (AT APPROXI44TELT 1540 HOURS), THE CRID INVERTER HAD TRANSFERRED TO ITS ALTERNATE NON-CLASS 1E POWER SUPPLY AT THE SAME TIME Thai A 6

CONTROL POWER FUSE MAD BLOWN ON POWER RANGE NUCLEAR INSTRUMENT 4 TION g' SYSTEM (NIS) CHANNEL IV (N-44). SUS $52UENT INVESTIGATION DETERMINED

  .                                    THAT THE CRIO INVERTER F4ILURE WAS DUE To a FAILED SILICnN CnNTom e en

               . .,... . . . .. 6..,    as      , , -:6 Late AND THf CRI3 INUERTER DECLAAED GPERA3LE.         ALL C h.      .T S FED FROM THE C#10 hERE INS *ECTED P4           AND, CHERE NECESSARY, FUSES a%s/OR POWEP SUPPLIES WERE REPLACEO.

1 FORM 187 LER SCSs CaTA 0**********************;*************************************04-18-91 ******** b4 DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 316 1990 004 0 9007200197 218599 06/11/90 P1 ******************************************************************** A85 TRACT C POWER LEVEL - 086%. ON #dN t II, 1990 AT 1417 HOURS, THE UNIT 2 REACTOR TRIPPED FROM A POWER RANGE, NEbfRON FLUX, HIGH NEGATIVE RATE SIGNAL. b4 THIS SIGNAL REQUIRES A 2 OUT OF 4 (2#4) LOGIC TO INITIATE A TRIP. i ALTHOUGH THE CAUSE OF THE TRIP IS NOT CONCLUSIVELY KNOWN, IT IS gg 8ELIEVED THA) 4 DROP OF MORf THAN ONE (1) CONTROL R00 CAUSE0 THE

     ,      REACTOR TO TRID. AT THE TIME OF THE REACTOR TRIP, A TECHNICIAN WAS

"" WALEING ON TOP OF THE ROD CONTPOL SYSTEM POWER CABINETS. IT COULO NOT 8E DETERMINED WHETHER THE PRESENCE OF THE TECHNICIAN CONTRIBUTED 10 THE POSTULATED R03 CONTROL SYSTEM FAILURE. NO HARDWARE FAILURE THAT 54 WOULO HAVE RESULTED IN THE DROPPING OF CONTROL RODS WAS IDENTIFIED. PRIOR TO UNIT RESTART, Als CONTROL RODS WERE SUCCESSFULLY EXERCISED. ,, FOLLOWING THE REACTOR TRIP, NO MALFUNCTIONS OF SAFETV-RELATED SYSTEMS OR COMPONENTS OCCURREO. IN ADDITION, ALL SAFETY EQUIPMENT RESPONDED

' AS DESIGNED. THE NRC WAS NOTIFIED WIA THE EMERGENCY NOTIFICATION SYSTEM (ENS) AT APPROXIMATELY 1537 HOURS ON JUNE 11, 1990.

1 D-4 FORM 18S LER SCSS DATA 04-1 ,, 0****************************************************************8-91 **** ' DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 316 1990 012 0 9101160001 220661 12/12/90 b' ge ABSTRACT POWER LEVEL - 100%. ON DECEMBER 12, 1990 AT 0316 HOURS, THE UNIT 2

 '         REACTOR TRIPPED AS A RESULT OF STEAM-TO-FEEDWATER FLOW MISMATCH (DIFFERENCE SETWEEN STEAM AND FEED FLOWS ON ONE OF TWO MEASURED CHANNELS OF EACH PARAMETER FOR A STEAM GENERATOR (SG)) IN COINCIDENCE D

WITH LOW SG LEVEL (ONE OF TWO SG NARROW RANGE CHANNELS FOR A SG) CONDITIONS IN THE NUMBER 4 SG. THESE CONDITIONS AROSE FOLLOWING A e; TRIP GF ONE OF TME TWO TUR8INE ORIVEN MAIN FEEDWATER PUMPS (TO-MFWP) DUE TO AN ERR 0NEOUS ACTUATION OF THE TURBINE THRUST BEARING WEARISHAFT '* POSITION DETECTION ALARM AND TRIP DEVICE. NO MALFUNCTIONS OF SAFETT-RELATED SYSTEMS OR COMPONENTS OCCURRED. THE TUR8INE THRUST SEARING WEARtSHAFT POSITION DETECTION DEVICE WAS REMOVED FROM THE MFWP ' TUR81NE DRIVER AND INSPECTED. THIS DEVICE, AND THE SIMILAR DEVICE ON THE OTHER TURBINE DRIVER, WERE SENCH CALIBRATED AND PROPERLY SET-UP e ON THE MFWP TURBINES AT TURNING GEAR AND NO-LOAD OPERATING SPEEDS. 1 ' FORM 189 LER SCSS DATA 04-18-91 0******************************************************************** DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 316 1990 013 0 9101150352 220662 12/15t90 ABSTRACT

   ,       POWER LEVEL - 100%. ON DECEMBER 15, 1990, AT 0540 HOURS DURING A TECHNICAL SPECIFICATION (TS) SURVEILLANCE, THE 2-48 PLANT BATTERT WAS DECLARED INOPERASLE WHEN A SINGLE CELL'S VOLTAGE DECREASED EELOW A 4       TEST LIMIT. EFFORTS TAKEN TO RESTORE THE CELL WOLTAGE WERE

, UNSUCCESSFUL AND A REACTOR SHUTOOWN WAS INITTAT8n. "H*'*C Two

               ....... 22-=s     ativ.iasa ur 6ec ANIILIPATiO TRANSIENT CITNOUT SCRAM MITIGATION SYSTE9 QCTUATICN CIRCUIVAT COMSAC). ALL ECUIPMENT p -g            PERF03MEO AS EXPECTED AND THERE WERE NO COMPONENT PAILUQE5 FOLLOWING THE TREPO THE REACT 00 ENTERED MODE 5 AT 0600 HouG5 ON 12-16-90 TO EXIT 9          THE BATTERY T5 ACTION STATEMENT AND THE BATTERT CELL OF CONCERN WAS g;     REMOVED FROM SERVICE VIA A JUMPER. A PROPOSED T5 AMENOMENT !$ BEING PREPARED TO REQUEST CHANGING THE SURVEILLANCE TO ALIGN WITH INDUSTRY bd              STANDARDS AND CONFORM TO STANDARD T5. THE AMSAC ACTUATION OCCURRED OUE
        ,g     TO AN IMPROPER SETPOINT. ALL AMSAC INPUT SETPOINTS WERE VERIFIED AND pq              CORRECTED A5 NEEDED.

1 d FORM 190 LER SCSS DATA 04-18-91 0******************************************************************** h4 .,

        '     DOCKET YEAR LER NUMBER REVISION DCS NUMBER                  NSIC      EVENT OATE 321     1990         012             0       9007160174 218813       06/10/90 gg             *******************************************************************

ABSTRACT hm POWER LEVEL - 025%. ON 6/10/90 AT APPROX. 0826 COT, UNIT 1 WAS IN THE RUN MODE AT AN APPROX. POWER LEVEL OF 609 CMWT. AT THAT TIME, 4 kg PROCEDURALLY CONTROLLEO MANUAL SCRAM WAS DIRECTED BY MANAGEMENT TO ALLOW FOR TERMINATION OF 05FGA5 SYSTEM FLOW TO FACILITATE FULL y, INVESTIGATION AND RESOLUTION OF OFFG45 OPERATIONAL PROBLEMS. THE GROUP 2 PRIMARY CONTAINMENT ISOLATION SYSTEM VALVES ISOLATED AND AN AUTOMATIC REACTOR PROTECTION SYSTEM ACTUATION WAS RECEIVED ON LOW I8 LEVEL DUE TO THE EXPECTED VOIO COLLAPSE A5 A RESULT OF THE MANUAL SCRAM. LEVEL WAS RESTORED USING THE "B" REACTOR FEEDWATER PUMP. THE

 >e            OFFGAS SYSTEM PROSLEMS RESULTED IN A REDUCTION OF HTOROGEN AND OXYGEN RECOM81 NATION AND AN EVENTUAL HTOROGEN IGNITION IN THE CAR 80M A050RBER BEOS. AT 1331 COT, IT WAS CONFIRMED COMBUSTION WAS TAKING PLACE AND, AT 1338 COT, A NOTIFICATION OF UNU50AL EVENT (NUE) WAS DECLARED FOR A I             FIRE LASTING LONGER THAN 10 MINUTES (AFTER DISCOVERY). THE OFFGAS ke            SYSTEM WAS PURGE 0 WITH NITROGEN FOR SEVERAL DAYS. EXHAU$TIVE TESTING WAS COMPLETED AT APPROX. 1315 COT ON 6/16t90 DEMONSTRATING THE FIRE y,            WAS EXTINGUISHED AND THE NUE WAS TERMINATED AT 1325 EDT. THE CAUSE OF THE FIRE IN THE OFFGA5 SYSTEM WAS COMPONENT MALFUNCTION DUE TO A COM8INATION OF COMPONENT FAILURE, DISCREPANCIES IN AS-BUILT EQUIPMENT I'            CONFIGURATION, AND LESS THAN ADEQUATE SYSTEM OPERATING PROCEDURES.

1 i FORM 191 LER SC55 DATA 04-18-91

 ,,         0********************************************************************

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 321 1990 013 0 9007240074 218855 06/20/90 e A85 TRACT POWER LEVEL - 025%. ON 6/20/90 AT APPROXIMATELY 0245 COT, UNIT 1 WAS

 ,             IN THE RUN MODE AT AN APPROXIMATE POWER LEVEL OF 600 CMWT
          +

(APPROXIMATELY 24.6% RATED THERMAL POWER). AT THAT TIME, THE REACTOR SCR AMMEO ON LOW REACTOR VESSEL WATER LEVEL. WATER LEVEL DECREASED TO THE SCRAM SETPOINT WHEN THE 18 REACTOR FEE 0 WATER PUMP (RFP) FAILE0 TO 1 RESPOND TO AN INCREASING DEMAND SIGNAL FROM THE MASTER FEE 0 WATER CONTROL UNIT OR THE 18 RFP CONTROL UNIT (THE 1A RFP HAD BEEN REMOVE 0 FROM SERVICE EARLIER). GROUP 2 AND 5 PRIMARY CONTAINMENT ISOLATION

      ,3       SYSTEM (PCIS) SIGNALS WERE RECEIVED AND ALL GROUP 2 AND THE INSOARD GROUP 5 PRIMARY CONTAINMENT I SOL ATION VALVE 5 (PCIVS) CLOSED. THE HIGH PRES 5URE COOLANT INJECTION (HPCI) AND REACTOR CORE ISOLATION COOLING
      ,        (RCIC) SYSTEMS AUTOMATICALLY INITIAYED AND INJECTED PER DESIGN. UNIT 1 AND UNIT 2 STANDST GAS TREATMENT (55GT) SYSTEMS RECEIVED AUTOMATIC e            INTIATION SIGNALS AND THE 1A TRAIN STARTED (THE 2A TRAIN WAS ALREADY g:       RUNNING AT THE TIME OF THE EVENT.) THE CAUSE OF THIS EVENT IS
  ,            UNRNOWN.      THE 18 RFP RESPONDE0 AS IF HIGM pees %Uns %vFam vn tus        1*  ese

                                                                                                                                                                                                                           --------------------------------------------------------g-,
                                                                                      .n.                        u,.o.

ss4.;LI.w: ALTICNS F9R THIS EVENT INCLUDED TESTING OF THE MASTER AND 13 RFP CONTROL LOOPS, Visual INSPECTION AND TESTING OF THE

,              >1                                                                    1E RFP TUR91NE CONTROLS, AND TESTING Oc THE IS EFP DURING UNIT STARTuP.
               >4                                                      I FORM                                             192                                           LER 5C55 DATA WM 0************************************************************04-18-91 t

t q, ' DOCKET. TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT OATE P1 321 1990 020 0 9011070036 219860 10/

                                                                              ***************************************************************06/90                                                                   *****

d I ABSTRACT POWER LEVEL - 0223. ON 10/6/90, AT APPROXIM4TELT 0337 CDT, UNIT 1 WAS b4 .p' IN THE RUN M005 AT APPROXIMATELY 536 CMWT (APPROX!MATELY 22 PERCENT OF RATED THERMAL POWER) AND DECREASING AS PART OF A SCHEDULED SHUTOOWN Do TO SUPPORT MAINTENANCE ON A RECIRCULATION PUMP SEAL. AT THAT TIME, A

q. MAIN TURSINE TRIP OCCURRED ON HIGH VISR4 TION AND 4 FULL REACTOR g, PROTECTION SYSTEM ACTUATION AND RECIRCULATION PUMP TRIP WERE INITI4TED ON TUR8INE STOP VALVE (TSV) CLUSURE. A SECOND RPS ACTUATION AND A q' i PRIMARY CONTAINMENT ISOLATION SYSTEM GROUP 2 ISOLATION OCCURRED PER kW DESIGN WHEN REACTOR VESSEL WATER LEVEL DECREASED TO REACTGR LOW WATER LEVEL 3. REACTOR FEEDWATER PUMPS RESTORED AND MAINTAINED mEACTOR p e q; VESSEL WATER LEVEL AND THE TUR8INE STPASS VALVES AUTOMATICALLY CONTROLLED REACTOR PRESSURE. CAUSES OF THE EVENT INCLUDE A JALVE De MALFUNCTION, A LESS THAN OPTIMAL DESIGN OF TSV CLOSURE SCRAM STPASS

PRESSURE SWITCHES, AND A FJILEO CENTRAL PROCESSING UNIT (CPU) SO4RD.

CORRECTIVE ACTIONS INCLUDE CHANGING A VALVE MOTOR OPERATOR TORQUE ft SWITCH SETTING, REPLACING A CPU SOARD, AND EVALUATING REPLACEMENT OF i THE PRESSURE SWITCHES.

                ,,                                                    1 i

FORM 193 LER 5C55 DATA 04-0*************.******.******e*..********..*****.***.****** **.***13-91 00CEET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE Ae 321 1990 021 0 9011200001 220053 10/15/90 ABSTRACT

                '                                                                  POWER LEVEL - 070%. ON 10/15/90 AT APPR0x!MATELY 1507 CDT, UNIT 1 WAS IN THE RUN MODE AT AN APPROXIMATE POWER OF 1698 CMWT (APPROXIMATELY 70% RATED THERMAL POWER). AT THAT TIME, THE UNIT WAS MANUALLY

i. SCRAMMED DUE TO HIGH VISRATION 08 THE MAIN TUR8INE (EIIS CODE TA).

FOLLOWING THE MANUAL SCRAM, REACTOR VESSEL WATER LEVEL DECREASED AS

               ,                                                                  EXPECTED DUE TO VOIO COLLAPSE CAUSED SV THE RAPIO POWER REDUCTION.

THIS RESULTED IN 4 REDUNOANT REACTOR PROTECTION STSTEM (EIIS CODE JC) ACTUATION, A GROUP 2 PRIMARY CONTAINMENT ISOLATION SYSTEM (PCIS, EIIS CODE JM) ISOLATION SIGNAL ON LOW WATER LEVEL (LEVEL 3), AND CLOSURE OF GROUP 2 PRIMART CONTAINMENT ISOLATION VALVES (PCIVS). THE REACTOR

               ,                                                                  FEEDWATER PUMPS (RFPS, EIIS CODE SJ) AND THE REACTOR CORE ISOL4 TION COOLING (RCIC, EIIS CODE SN) SYSTEM WERE USED TO RESTORE AND MAINTAIN

REACTOR VESSEL WATER LEVEL. REACTOR PRESSURE WAS CONTROLLED BT THE TUR8INE STPASS VALVES (EIIS CODE JI). THE CAUSE OF THE MAIN TURBINE

                                   ,                                              MIGH VI884 TION M45 NOT SEEN DETERMINE 0. A POTENTIAL CAUSE WAS THE CLOSURE OF REHEAT STEAM SOURCE VALVES (RSSVS, EIIS CODE 58) 1N38-F1014 AND 8 TO THE SECOND STAGE MOISTURE SEPARATOR REMEATER (MSR, EIIS CODE
                                   ,.                                             SB).                                     CLOSURE OF THE RSSWS WOULO CAUSE 4 RAPIO DROP IN THE TEMPERATURE OF THE LOW PRESSURE TUR8INE INLET STEAM AND COULD RESULT
               '                                                                  IN MOVEMENT OF THE LOW PRESSURE TURBINE ROTOR IN RELATION TO THE g,                                             TUR8INE SHELL AS THE TWO SODIES OF METAL COOLED AT DIFFERENT RATES.

THE CAUSE FOR RSSV CLOSURE MAS NOT BEEN DETERMINE 0. 1

               .                                                          FORM                                            194                                              LER SCS$ DATA                        **  **-9*

s. a aws- vu) > 3935230175 213907 04/16199 P1 ABSTRACT g4 F0WER LEVEL - 0522. ON APRIL 16, 1989, AT 2004 PDT, 4 REACTOR TRIP OUE q, TO LOW LOW STEAM GENERATOR (SG) WATER LEVEL OCCURRED FOLLOWING A MAIN b4 GENERATOR TRIP AND TRANSFER OF ALL ELECTRICAL BUSES. AT 2056 PDT, A 4-HOUR NON-EMERGENCY REPORT WAS MADE TO THE NRC IN ACCORDANCE WITH 10 i; CFR 50.72. AN EVENT INSPECTION TEAM (EIT) WAS ESTAELISHED TO P1 INVESTIGATE THE EVENT. SASED ON INSPECTIONS, TESTS PERFORMED AND A REVIEW OF AVAILABLE INFORMATION, THE EIT DETERMINED THAT ACTUATION OF g4 i: THE GENERATC 34CKUP PROTECTIVE RELAY CAUSED THE MAIN GENERATOR TRIP.

COINCIDENT hilH THE GENERATOR BREAKERS OPENING, ALL VITAL SUSES TRANSFERRED TO STAN087 POWER. A CIRCULATING WATER PUMP FAILED To b4 s RESTART ON THIS TRANSFER PREVENTING THE ACTUATION OF THE CONDENSER STEAM DUMPS. SG PRESSURE INCREASED CAUSING SG LEVEL TO SHRINK TO THE b4 LOW LOW SG WATER LEVEL REACTOR TRIP SETPOINT. ADDITIONAL INSTRUMENTATION WAS INSTALLED FOR THE UNIT REST ART. NO ABNORMALITIES

    "            WERE 08 SERVED DURING THE RESTART OF THE UNIT.                                        THE GENERATOR BACKUP RELAY ACTUATION WAS CAUSED BY A TEMPORARY VOLTAGE TRANSIENT. THE b4     3 '. CIRCULATING WATER PUMP FAILURE TO RESTART WAS CAUSED BY A FAILURE TO i

ADEQUATELY CONTROL EQUIPMENT REMOVED FROM SERVICE. APPLICABLE PROCEDURES ARE BEING REVISED, AND OPERATIONS ISSUED AN INCIDENT yq SUMM4RT TO ALL APPLICABLE PERSONNEL. 1 I' FORM 195 LER SCSS DATA 0************************************************************04-18-91 ******** D1 DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 323 1989 007 0 8903230428 215069 07/16/89 ] >, ********************************************************************

 '.be          ABSTRACT POWER LEVEL - 027%. ON 7/16189, 47 0258 PDT, DI ABLO C ANYON POWER PLANT (DCPP) UNIT 2 WAS MANUALLY TRIPPED IN ACCORDANCE WITH DCPP ABNORMAL
 &e              OPERATING PROCEDURE AP-20, " CONDENSER TU8E LEAK." A 4 HOUR NON-EMERGENCY REPORT WAS MADE TO THE NRC AT 0358 PDT ON 7/16189, IN

, ,, ACCORDANCE WITH 10 CFR 50.72(8)(2)(11). DCPP UNIT 2 WAS IN A PLANNED MAINTENANCE CURTAILMENT AT ASOUT 50 PERCENT POWER FOR CLEANING MAIN CONDENSER TUBE SHEETS. ON 7/16/89 A SHORT TIME AFTER RESTARTING 8 CIRCUL4 TING WATER PUMP 2-1, A CONDENS4TE PUMP DISCHARGE HIGH CATION CONOUCTIVITY ALARM ANNUNCIATED IN THE CONTROL ROOM. THE SHIFT FOREMAN e DIRECTED THE CONTROL ROOM OPERATOR $ TO ENTER PROCEDURE AP-20, WHICH' REQUIRES POWER TO BE REQUCED. AT 27 PERCENT POWER, FEEDW4TER

 '               CONOUCTIVITY INCREASED AND THE REACTOR WAS MANUALLY TRIPPED PER PROCEDURE.              THE CAUSE OF THIS EVENT WAS FAILURE OF A CONDENSER TUBE SHEET PLUG.                  THE PLUG WAS NOT RECOVERABLE FOR EX4MINATION, AND THEREFORE THE REASON FOR FAILURE COULO NOT BE DETERMINED. THE MOST LIKELT ROOT CAUSE FOR THE FAILURE WAS EITHER IMPROPER PLUG INSTALLATION OR USE OF A MATERIAL SUSCEPTIBLE TO CORROSION. OTHER TUBE SHEET PLUGS WERE INSPECTED AND FOUND TO BE INSTALLE0 CORRECTLY

AND OF THE PROPER MATERIAL. A NEW PLUG WAS INSTALLED IN THE TUBE SHEET.

1 FORM 196 LER SCSS DATA 04-18-91

      ,      De*******************************************************************

DOCKET TEAR LER NUMBER REVISION OC3 NUMBER NSIC EVENT DATE 323 1989 009 0 8910030097 215359 08/28/89 ABSTRACT

      ,          POWER LEVEL - 1001. CN 8/28/99, AT 2057 PDT, WITH UNIT 2 IN MODE 1 AT 100% POWER, OPERATORS INITIATED 4 4440st erarYno Yevo esveo a*eeaw*ve
                      ,                                                                                           . _ _      m , _ .         ._ .       . __ _ . , - - - - - .

  .-                                   .       - - -                        ~---   .      ,     .                            .
                       ....ocsancs,      mas eL:valto, FlutTUATING 40 TOR C U R R E '4 T FOR RCP 2-1.

OPERATORS TRIPPE0 THE REACTOR A 'I D THEN TRIPPED RCP 2-1. FEEDER GROUND P1 ALARMS FOR RCP 2-1 AND SOTH CkP5 CLEAaEo. AT 2115 PDT, THE UNIT WAS STA81LIIED IN MODE 3 WITH AN RCS TEMPERATURE OF APPROXIMATELY 525F. g4 IN ACCORDANCE WITH 10 CFR 50.72(8)(2)(II) A 4-HOUR NON-EMERGENCT q; REPORT WAS COMPLETED AY 2205 POT ON 8/28/89 THE EVENT WAS CAUSED ST AN INADEQUATE ELECTRICAL CONNEC TION 04 RCP 2-1. ALL 12KV ELECTRICAL b4 CONNECTOR 5, INCLUDING THE FAILE0 CONNECTOR, WERE REPLACED ON RCP 2-1. l i gr ALL OTHER 12KV CONNECTORS FOR UNIT 2 RCPS WERE EXAMINED TO THE EXTENT eq PRACTICA8LE WITH NO ABNORMALITIES FOUNO. 1 Ed b FORM 197 LER SCSS DATA 04-18-91 0******************************************************************** I DW i' DOCKET TEAR LER NUMBER REVISION DCS MUMBER NSIC EVENT DATE 323 1989 010 0 8912040049 215962 10#27/89 . gg ******************************************************************** A85 TRACT U" 3 POWER LEVEL - 100%. ON 10/27/89, AT 0655 PDT, THE UNIT 2 TURSINE AND p REACTOR WERE MANUALLY TRIPPED AND THE FIRE AL ARM SOUNDED FOLLOWING b4 CONFIRMED REPORTS OF SMOKE AND ARCING IN THE MAIN ELECTRICAL GENERATOR i EXCITER HOUSING. A5 4 PRECAUTION, OPERATORS REQUESTED SACKUP pg f, FIREFIGHTING ASSISTANCE FROM THE CALIFORNIA DEPARTMENT OF FORESTRT. PLANT OPERATORS ALSO VENTED THE HTOR0 GEN FROM THE GENERATOR AND 88 EVACUATED THE TURBINE BUILDING OF ALL NONESSENTIAL PERSONNEL. PGRE

              ;.       DECLARED AN UNUSUAL EVENT AT 0703 PDT, 10/27/89                              THE PG8E FIRE BRIGADE RESPONDED, ENTERED THE EICITER HOUSING AND VENTILATED THE D1               ENCLOSURE OF SMcKE. NO FURTHER ACTION WAS REQUIRED. AT 0828 PDT, 10/27/89, WITH UNIT 2 IN MODE 3 (HOT STANDST) THE UNU5UAL EVENT WAS bt              TERMINATED. THE SMORE WAS CAUSED ST AN EXCITER 8 EARING FAILURE THAT RESULTED IN DAMAGE TO THE PERMANENT MAGNET GENERATOR. TO PREVENT I                RECURRENCE, THE ANNUNCIATOR RESPONSE MANUAL WA$ CHANGE 3 TO REQUIRE AN k'              IMMEDIATE UNIT TRIP UPON ANT GENERATOR RADIO FREQUENCY MONITOR ALARM COINCIDENT WITH A CHANGE IN SEARING TEMPERATURE OR SEARING II54ATION.

te AL50, THE EXCITER BEARING TEMPERATURE INDICATOR WAS REMOVED. ALL , CONTROL OPERATORS WILL RECEIVE TRAINING REGARDING THIS EVENT AND THE

       ,,              NEW ANNUNCIATOR RESPONSE REQUIREMENT 5.

I FORM 198 LER SC55 OATA 04-18-91 0******************************************************************** g . DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 324 1989 009 1 9001020123 216243 06/17tS9 A85 TRACT e POWER LEVEL - 0763. AT 2047 HOURS ON JUNE 17, 1989, A MANUAL REACTOR 3 SCRAM WAS INITIATED ON UNIT 2, IN ACCORDANCE WITH 18E SULLETIN 88-07, !' , DUE TO A LOSS OF SOTH REACTOR RECIRCULATION PUMPS. BOTH PUMPS WERE OEENERGIZED WHEN TROU8LE5H00 TING ON UNIT 2 STARTUP ALXILIARY TRANSFORMER (SAT), WHICH SUPPLIES POWER TO THE PUMP 3, CAUSED THE SAT TO TRIP ON A HIGH RESISTANCE GROUND FAULT. A PLANNED POWER DECREASE WAS IN PROGRESS PRIOR TO THE LOSS OF THE SAT AND THE POWER LEVEL AT i THE TIME OF THE SCRAM WAS 76%. AS A RESULT OF THE REACTOR SCRAM AND THE LOSS OF THE SAT, UNIT 2 EXPERIENCED A LOSS OF OFF-SITE POWER. THE

            ,          DIESEL GENERATORS AUTOMATICALLY STARTED AND POWERED THE UNIT 2 EMERGENCY (E) SUSES PER DESIGN. DUE TO THE MOMENTART LOSS OF POWER 04

THE E-8USES AN0/OR VE5SEL LOW LEVEL *(45 APPLICA5LE), CONTAINMENT

       '               150LATION GROUPS 1, 2, 3, AND 6 AUTOMATICALLT ISOLATED.                                     REACTOR PRESSURE WAS CONTROLLED BT THE SAFETT RELIEF VALVES, MIGH PRESSURE 4       t               C00LANY INJECTION SYSTEM, AND THE REACTOR CORE ISOLATION COOLING
           .g,         SYSTEM.      THE INVESTIGATION DETERNINED THAT THE CAUSE WAS PERSONNEL
       ,               ERROR ST THE TECHNICIAN PERFORMING TROUBLE 5M00TIgg om Tw= t47                                      vue

                  *4
                          = rust-eeA.L l<Cear141:3 ANJ TMi R E S'JL T IN3 HIGH CURRENT CAUSED THE SAT TO TRIP.

j P4 1 gq FORM 199 LER SC55 OATA p 0************************************************************04-18-91 ******** i

   >4            DOCKET YEAR LER NUMBER REVISION DC5 NUMBER                                      NSIC              EVENT DATE 324             1990       004               2    9010090209 219636                                     03/13/90 I r1 ABSTRACT i   g4 g:          POWER LEVEL - 0072. AT 0536 ON MARCH 13, 1990, A MANUAL SCRAM WAS INITIATED DUE TO THE FAILURE OF $4FETYtRELIEF VALVE (5RV) 821-F013G TO i

b4 CLOSE DURING STARTUP TESTINGJ REACTOR POWER WAS APPROMIMATELT 7% AND

             '    REACTOR PRESSURE WAS APPP0x. 250 P5IG. THE 11 UNIT 5RV'S WERE 8EING CTCLED IN ACCORDANCE WITH PLANT PROCEDURES 70 WERIFV OPERASILITY PER l go              TECH SPEC 3.5.2. TEN OF THE ELEVEN SRV's HAD SEEN SUCCES5 FULLY TESTED PRIOR TO THIS FAILURE.                 A NORMAL SCRAM RECOVERY WAS CONDUCTED PER
   ""             PLANT PROCEDURES AND NO AUTOMATIC SAFETT ACTUATION 5 OR ISOLATION 5 OCCURRED.              REACTOR VE5SEL LEVEL WAS MAINTAIN USING THE FEE 0 WATER SYSTEM.             THE INVESTIGATION DETERMINED THAT THE SOLEN 0ID VALVE WHICH b4             ALLOWS REMOTE MANUAL OPERATION OF 821-F013G WAS INOPERABLE. THE

' 50LEN010 WOULD ALLOW THE $RV 70 SE OPENE0, SUT WOULD NOT ALLOW TIMELV y ,7 CLO5URE OF THE SRV. THE SOLENOID VALVE WAS REPLACED. THE UNIT RETURNED TO THE REQUIRED TESTING CONDITIONS AND THE SRV WA5 88 5UCCES5 FULLY TESTED. THE SOLENDID VALVE WAS SENT TO WYLE LA80RATORY AND THE ROOT CAUSE WAS DETERMINED TO 8E FAILURE OF THE SOLENGID DISC TO PROPERLV REALIGN WITM ITS SEAT AFTER DE-ENERGIZATION. A POTENTIAL

   >t             CAUSE OF THE FAILURE TO RFSEAT IS " DIRT" WHICH WA5 EMBEDDED IN THE 3        RUS8ER PAD LOCATED ON THE 8ACK5 EAT. AN INVESTIGATION INTO THE SOURCE
   ,,             OF THE MATERIAL 15 CONTINUING. A SUPPLEMENT WILL SE !$5UED SY MARCH 19 1991, TO PROVIDE THE RESULTS OF THIS INVESTIGATION.

1 mo FORM 200 LER SCSS DATA 04-18-91 e 0******************************************************************** DOCKET TEAR LER NUMBER REVISION DCS NUM8ER N5IC EVENT DATE

                  324             1990       008               1    9012210115 220537                                     08/16/90 e*....e*******.................. ............e** ...... ........eene i

t AB5 TRACT i POWER LEVEL - 100%. ON 8116190, UNIT 2 REACTOR WAS AT 1001 POLER.

   , ,            REACTOR LEVEL CONTROL SYSTEM WAS OPERATING IN AUTOMATIC, AT 0942, REACTOR AUTOMATICALLY SHUTOOWN ON A "T5V FAST CLOSURE" '4P5 TRIP SIGNAL
   '              CAUSED BY A TURSINE TRIP 04 REACTOR HIGH WATER LEVEL. THE HPCI TURSINE STOP VALVE CYCLED CLO5ED AND THEN OPEN, WATER INTRUSION INTO THE HPCI OIL WAS NOTEO, THE RCIC BAROMETRIC CONDENSER VACUUM PUMP
   '              EXPERIENCED AN ELECTRICAL FAULT, AND A LOSS OF THE RECIRCULATION PUMP 5 RESULTED IN TEMPERATURE TRAN5IENTS IN THE VE5SEL. HPCI AND RCIC
   ,              OPERASILITT WERE NOT AFFECTED.                   THE RECIRCULATION PUMP 5 ARE NOW SEING POWERED FROM THE START UP AURILIARY TRANSFORMER TO PREVENT THEIR LOS5 00 RING FUTURE REACTOR TRIPS. THE CAUSE OF THIS EVENT WAS FAILURE OF PRIMARY POWER FUSE C32-F5, WHICH SUPPLIED POWER TO THE STEAM FLOW INPUTS OF THE THREE ELEMENT FEEDWATER CONTROL LOGIC. LOSS OF THE STEAM FLOW INPUTS RESULTED IN A MAKIMUM DEMAND SIGNAL TO THE RFPS AND A RAPID INCREASE IN REACTOR LEVEL UP TO THE HIGH LEVEL TUR8INE TRIP 4

POINT WHICH, IN TURN, CAUSED A REACTOR SCRAM ON TSV POSITION. PRIMARY POWER FU5E C32-F5 AND ITS ASSOCIATED CIRCUIT WERE EVALUATED. THE Fil5E HAS BEEN REPLACEO. THE FAILED FUSE WAS ANALYZE 0 SV THE HEREC I W IT H THE INITIAL CONCLUSION THAT THE FUSE FAILED OUE TO SHORT DURATION EXPOSURE TO A CURRENT IN EXCESS OF 20 AMPS. SIMILAR EVENTS:

2-88-018, 1-88-023, AND 2-90-005.

(I U rw., ~v,,,,-r yv e ,7 - ,w , , w = - - - - - , - , - r----- - ,,---w-r-<,---.=,,-<% .- m --- . , ,-. v = - --- - y

ow.m.. s.-s Le< .auds=d < = v i s 10' 9C5 NUMBER NSIC EVENT DATE 324 1990 003 0 9003250252 219542 03/19190 yq ,

eeeeeeeeeeee*eneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee g4 ABSTRACT q POWER LEVEL - 100%. WHILE TESTING THE MAIN CONDENSER LOW VACUUM INSTRUMENTATION AND ISOLATION LOGIC, AN ISOLATION $1GNAL WAS GENERATED b4 WHICH CLOSED THE MAIN STEAM ISOLATION VALVES. CLOSURE OF THE MAIN , , q; STEAM ISOLATION VALVES INITIATED A UN11 2 REACTOR SCRAM AT 21)A ON pq 8/19190. REACTOR PRESSURE PEAKED AT APPROMIMATELY 1133 PSIG AND THE MINIMUM WATER LEVEL REACHED WAS APPROXIMATELY 112 INCHES. NO SAFETY g4 q LIMITS WERE EXCEEDED IN THE PLANT RESPONSE TO THE LEVEL AND PRES $URE TRANSIENTS. THE OPERATING CREW WAS ASLE TO CONTdui THE PLANT SY USING REDUNDANT EQUIPMENT OR ALTERNATE METH005. THE SAFETY RELIEF VALVE D4 ,;; OPENING SEQUENCE AND ACTUATION PATTERN WERE QUESTIONED. THE ACTUATION 4 PATTERN IS NOT A CONCERN. HOWEVER, $4FETT RELIEF VALVE, 821-F013C gg (5ETP0 INT 1105 PSIG) DID NOT OPEN. THE PILOT VALVE A55EM8 LIES WERE I ' qi REPLACED ON SAFETY RELIEF VALVES 821-F0134, 821-F013C, 821-F013G, 821-F013H, AND 82L-F013K. SIMILAR PROBLEMS ENCOUNTERED DURING THIS U" SCRAM HAVE BEEN REPORTED IN LERS 2-88-005, 2-88-019, 2-87-004, q' 1-87-011, 2-86-001, 2-86-013, 2-86-017, 2-85-003, 2-85-011, AND be 1-85-033. 1 ht lt FORM 202 LER SC55 DATA 04-18-91 0***ee **** .ae***e**e ****** meas ******e***e******e******** *eme**** I' i, DOCKET YEAR LER NUM8ER REVISION DCS MUMBER N51C EVENT DATE 324 1990 012 1 9011080128 219862 08/30/90 39 *eme eee***ee..............e*e*******eeeeeeme**e** ..eeeeee***e *e**

,,             A85 TRACT POWER LEVEL - 0083. ON AUGUST 30, 1990, UNIT 2 REACTOR START-UP WAS IN PROGRESS. THE REACTOR WAS AT APPR0x!MATELY 81 POWER AND 300 PSIG.

D8 THE EMERGENCY CORE COOLING SYSTEMS WERE OPERABLE IN STAND 8Y LINE UP EXCEPT FOR THE HIGH PRE 55URE COOLANT INJECTION SYSTEM WHICH WA5 e IMOPER48LE AWAITING THE PERFORMANCE OF THE HPCI SYSTEM OPERASILITY TEST. AT 1656 THE START-UP LEVEL CONTROL VALVE (SULCV) FAILED CLOSED RESULTING IN A LEVEL TRANSIENT. AT 1657 THE REACTOR PROTECTION SYSTEM (RPS) LOW LEVEL 81 SETPOINT (165") WAS REACHED CAUSING A REACTOR SCRAM. PRIMARY CONTAINMENT ISOLATION SYSTEM GROUPS 2, 6 AND 8 ALSO

 '              RECEIVED AN !$0LATION $1GNAL AND ACTUATED PER DESIGN. SCRAM RECOVERY WAS IN ACCORDANCE WITH THE EMERGENCY FLOWCHARTS AND PROCEDURES.

t . APPROMIMATELY 20 MINUTES AFTER THE SCRAM, LEVEL WAS STABILIZED. THE CAUSE OF THE SULCV FAILURE IS BELIEVE0 TO BE WORN 0-RING SEALS. THE

 '*             SEALS HAVE BEEN REPLACED AND THE SULCV IS OPERATING PROPERLY. THE WORM SEALS ARE 8EING ANALVIED TO DETERMINE THE CAUSE OF THE FAILURE.

THE SAFETY SIGNIFICANCE OF THIS EVENT IS MINIMAL. LEVEL WAs RECOVERED t 4 3 WITHOUT THE NEED FOR SAFETY SYSTEM INJECTION AND THE UNIT 15 DESIGNED FOR A LEVEL TRANSIENT FROM FULL POWER.

 .           I l'

FORM 203 LER SCSS DATA 04-18-91 0**ee*****e****e**e****eeeee***********ee*****e*************e***e****

       ,       DOCKET TEAR LER NUMBER REVISION DCS MUMSER                   NSIC       EVENT DATE 324    1990        015               0      9011020052 219863          09/27/90
               ****e*********eee*****       ee***    e****    .e******eeeeee. e********ee*****

A85 TRACT POWER LEVEL - 1003. ON 9/27t90, WHILE OPERATING AT 100% POWER UNIT 2

     ,          EXPERIENCED GENERATOR VOLTAGE OSCILLATIONS WHICH RESULTED IN A LOSS OF THE MAIN GENERATOR DUE 10 LOSS OF EXCITATION. THIS RESULTED IN A 6              REACTOR SCRAM DUE TO CONTROL VALVE FAST CLO5URE SIGNAL.                THE PRIMARY

p. CAUSE OF THE SCRAM WAS A VOLTAGE REGULATOR THAT HAD BECOME~POTENTIALLY

 ,              UN5 TABLE DUE TO PAST IMPROPER ADJUSTMENTS. SYSTEMS SUNCYT6Nen at

           ._ -.            ._.       _ _ _ , _ _ - . _            -_- -- - .                    _ _ - - _ _ - _ _ _ .                -                      . ~   . .

v4 va r>IV. LAUSt OF TME SCRAM WAS IN1Di2UATE CONFIGU?ATION CbMTR D9 ON THE VOLTAGE REGULATOR ACJUSTMINTS AND URAL CIRCUIT 3ETTINGS. POTENTIALLY CONTRIBUTINC TO THE EVENT WAS THE GRIO SYSTEM CONFIGURATION ON THAT DATE, THE SYSTEM VOLTAGE SCHEDULE, AND PROCEDU2E

 >q                 CONTROLS FOR MAINTAINING GENERATOR EXCITATION. CORRECTIVE ACTIONS INCLUDE ADJUSTMENTS OF THE VOLTAGE REGULATOR, UPDATING THE VENDOR b9                 TECHNICAL MANUAL TO ENSURE PROPER FUTURE ST5 FEM PERFORMANCE, AND EVALUATIONS OF THE GRIO STABILITY REGUIREMENTS AND DESIGN BASIS
        ;;          RELATIVE TO SYSTEM CAPACIT4NCE VALUES. THE EVENT $4FETT SIGNIFICANCE P1 '                IS CONSIDERED MINIMAL. TRANSIENT PARAMETERS EXPERIENCED WERE WELL WITHIN ANALTZED TRANSIENT PARAMETERS FOR THIS TYPE EVENT.

1 L4 FORM 204 LER SC55 DATA CH3 0************************************************************04-15-91 ******** DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE Ee 324 1990 016 0 9011150240 220154 10/12/90 A85 TRACT POWER LEVEL - 100%. 04 OCTOBER 12, 1990, THE UNIT 2 REACTOR was AT De 100% POWER AND 1005 PSI. THE EMERGENCf CORE COOLING SYSTEMS WERE OPER4BLE IN STAND 8T READINESS. 4 FUNCTIONAL CHECK WAS IN ON 4 bI THERMOCOUPLE MVII MODULE IN THE FEEDW4TER CONTROL CASINET, H12-P612, LOCATED IN THE CONTROL ROOM 8ACK-PANELS. FUSE 2-C32-F3 15 PART OF THE De CIRCUITRT WHICH POWERS THE REFERENCE 0 MODULE. AT 14:01:52 4 HIGH REACTOR LEVEL W AS DETECTED. THIS RESULTED IN A REACTOR SCRAM ON TUR8INE STOP VALVE FAST CLOSURE, PER 3ESIGN. THE CONTROL R005

 #*                 INSERTED AND TURSINE SYP455 VALVES ACTED TO CONTROL REACTOR PRES $URE At 1005 PSI. THE SCRAM WAS CAUSED BT 4 FAILURE OF THE GOULD SHAWMUT
 ,,                 FUSE 2-C32-F3 IN THE FWCS. THE FAILURE RESULTEO IN A FAL5E LOW LEVEL
 ,                  SIGNAL TO THE 8 TUR81NE DRIVEN REACTOR FEED PUMP (TDRFP) CONTROL CIRCUITRY WHICH, IN RESPONSE, INCREASED THE 8 TORFP OUTPUT AND RESULTED IN A MAIN TURBINE TRIP ON REACTOR HIGH WATER LEVEL.                                              THE REASON THE FUSE SLEW IN THE FWC5 MAS NOT BEEN DETERMINED.                                             THE GOULO L*                 SH4WMUT FUSES HAVE BEEN SENT TO THE CPSL HARRIS ENERGY 8 ENVIRONMENTAL CENTER FOR FURTHER TESTING AND EXAMINATION. IN ADDITION, AN EVENT
 ,,                 RECORDER IS CURRENTLY MONITORING THE POWER SUPPLY CIRCUITRY TO THE 2-C32-F3 FUSE. PAST SIMILAR EVENTS INCLUDE LERS 2-90-08, 2-88-018 AND 1-88-023.        THE 55FETY SIGNIFICANCE OF THIS EVENT IS MINIMat.

1

 , .               FORM    205                              LER 5C55 04T4                                                 04-18-91 0********************************************************************
 '                 DOCKET TEAR LER NUMBER REVISION OCS NUMBER                                 NSIC                     EVENT DATE 325      1989                     002      1            8906300259 214456                           02/07/59 485 TRACT POWER LEVEL - 000%. UNIT 1 WAS IN THE 1988/1989 REFUEL / MAINTENANCE OUTAGE.       ON FEBRUARY 7 AT 1305, FEBRUART S At 2327 AND FESRUARY 11 AT 0051 AND 0320 HOURS, FULL REACTOR PROTECTION SYSTEM (RPS) TRIPS WERE RECEIVED OUE TO SUSPECTED ELECTRICAL NOISE IN THE INTERMEDIATE RANGE
      ,             NEUTRON MONITORING (IRM) CIRCUITRY.                         THE 5HORTING LINKS WERE REMOVED PER THE SPECIAL PROCEDURE (SP) "CRD DATA COLLECTION" (SP-89-001),

WHICH ALLOWS A FULL RPS TRIP GIVEN 4 SINGLE RPS CH ANNEL TRIP. NO

      ,             ACTIVITIES WERE IN PROGRESS WHICH WOULD ADD POSITIVE REACTIVITY TO THE CORE. PAST $1MILAR EVENTS WERE REPORTED IN LERS 1-35-031, 1-86-014, 1-8F-013 AND 1-88-009                   IN 1937, GE DETERMINED THAT EXISTING CABLE ROUTIN3 MAD RESULTE3 IN ELECTRICAL NOISE SEING INDUCE 0 IN THE IRM CABLES.       MODIFIC ATIONS WERE PERFORMED TO REQUCE THE AMOUNT OF NOISE EXPERIENCED ST THE IRMS. ANOTHER INVESTIGATION ST GE M45 RESULTED IN
      ,             THE INSTALLATION OF 8 ADDITIONAL ELECTRICAL NOISE SUPPRESSION CIRCUITS ON UNIT 1. AN INVESTICATTnM in neyse.,we ve                           ev.n,-              c.       o.+e   ---- --

_ - _ . . ~ ,_ ,m .. _ _ __ ..

                 .u ....e.a.2     c.2 L:u au in: int 4EAlto ELECTRICAL NO!3E EXPERIENCE 0 IN F -g THE IRH CABLING. THESE EVENTS HAD N3 $1FETY SIGNIFICANCE $1NCE THE SYSTEM FUNCTIONED IN ITS DESIGNED HANN!R.

1

         ;;    FORM       206                  LER SC55 DATA b4 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 325 1970 017 0 9011020102 219865 pq g,

               .................................................................. 0 09/27/9

A85 TRACT POWER LEVEL - 022%. DURING A SCHEDULED UNIT 1 $ HUT 00WN FOR A REFUEL / MAINTENANCE OUTAGE ON SEPTEM5ER 27, 1990, THE REACTOR SCRAMMED B4 i; ON HIGH PRESSURE AT 0348, OURING THE PERFORMANCE OF PERIODIC TEST (PT) 40.2.10, TURBINE CONTROL /STOP VALVES (TCV/TSW) LEAK TIGHTNESS go TESTING. PRIOR TO THE EVENT, THE REACTOR WAS AT APPROXIMATELT 22%

POWER AND THE EMERGENCY CORE COOLING SYSTEMS (ECCS) WERE OPERABLE IN U" STAND 8Y READINESS. EVENT RECOVERT WAS IN ACCORDANCE WITH SITE EMERGENCY OPERATING PROCEOURES, NO ECCS OR ENGINEERED SAFETT FEATURE ACTUATION 5 OR ISOLATIONS OTHER THAN SCRAM SIGNALS OCCURRED. THE EVENT b4 WAS OCCURRED BT ERRONEOUS PROCEDURAL GUIDANCE, INCORPORATED INTO THE PT FROM A VENCOR 00CUMENT, AND DEFECTIVE SWITCHES ON THE TSV5 WHICH p, ALLOWE0 THE TCVS TO OPEN WHEN THE TSV5 WERE CLOSING. THIS RESULTED IN THE TUR81NE BTPASS VALVES (8PV) OPEN DEMAND SIGNAL BEING LIMITED 87 be THE MAKIMUM COMBINE FLOW CIRCUITRY OF THE TURBINE CONTROL SYSTEM. THE CLOSURE OF THE 78v5 OCCURRED REACTOR PRESSURE TO INCREASE TO THE SCRAM SETPOINT. max! MUM POWER ATTAINED OURiNG THE SCRAM WAS 28%. Pe THIS EVENT HAD MINIMAL SAFETT SIGNIFICANCE AS THE REACTOR !$ ANALTIED FOR A HIGH PRES 5URE SCRAM FROM FULL POWER. PAST HIGH PRE 55URE SCRAM

   ,,           EVENTS WERE REVIEWED AND FOUND NOT TO BE RELATED TO THIS EVENT. THE I             PROCEDURE WILL BE REWRITTEN AND THE SWITCHES WILL SE REPAIRED.

1 ke FORM 207 LER SC55 OATA 04-18-91

s. 0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER N5IC EVENT DATE 327 1999 005 1 8906270186 214406 02/10/89

A85 TRACT POWER LEVEL - 100%. 04 2/10/89 WITH UNIT 1 IN MODE 1, A REACTOR TRIP i, OCCURRED AT 2036 EST. THE TRIP SIGNAL WAS A RESULT OF A STEAM GENERATOR (5G) STEAM FLOW 70 SEE0 WATER FLOW MISMATCH OF GREATER THAN

              40% OF THE NOMINAL VALUE OF STEAM FLOW AT FULL POWER COINCIDENT WITH A LOW SG LEVEL (25%) SIGNAL ON SG LOOP 3. TWO INSTRUMENT MAINTENANCE (IM) TECHNICIAN 5 WERE IMPLEMENTING WORK REQUEST (WR)-8235429 04 FLOW RECORDER (FR)-2-200/201, " CONDENSER 8TPA55/ MAKEUP FLOW." THE RECORDER PEN NEEDED TO BE RESTRUNG WHICH REQUIRED IT TO BE REMOVED F ROM THE
   ,            CASE. THE TECHNICIANS FULLY REMOVED THE RECORDER IN 175 CASE WHICH REQUIRED LIFTING THE POWER SUPPLY LEADS. AFTER REINSTALL 4 TION, THE TECHNICIANS RETERMINATED THE POWER SUPPLT LEADS, AT WHICH TIME ONE TECHNICIAN DETERMINED THE TERMINATING LEADS WERE 700 CLO5E TO EACH OTHER. THE TECHNICIAN INADVERTENTLY SH3RTED A SCREWORIVER BETWEEN THE TERMINALS, TRIPPING OPEN SREAKER NO. 39 ON 120-VAC v!TAL INSTRUMENT BOARD I-II WHICH IS THE POWER SUPPLT TO A PLUG MOLD SUPPLTING THE RECORDER.       THE PLUG MOLD IS AL50 THE COMMON POWER SUPPLY TO THE FLOW INDICATING CONTROLLERS (FIC)-3-35, -90, AND -103 WHICH CONTROL MAIN FEEDWATER REGULATING VALVE 5 (MFWRVS) FCV-3-35, -90, AND -103 FOR SG
       ,        LOOPS 1, 3, AND 4. ROOT CAUSE OF THE REACTOR TRIP SIGNAL WAS PERSONNEL ERROR, IN THAT, APPROPRIATE PRECAUTIONS WERE h0T TAKEN IN PERFORMING e

TERMINATIONS 08 ENERGIZED EQUIPMENT. g- 1

wwsn: n s.=- L:< avant4 4 : V I 5 ! Cl4 305 NUM3ER N5IL EVENT DATE 327 1897 035 0 9001170353 216451 12/10/99 ya g4 A85 TRACT POWER LEVEL - 1001. ON DECEMSER 10, 1939, AT 1051 EASTERN STANDARD TIME (EST) WITH UNIT 1 IN MODE 1, A TURBINE TRIP / REACTOR TRIP

  >4 OCCURRED. THE TRIP RESULTED FROM A HIGH-HIGH FEE 0 WATER LEVEL OF 75 i

PERCENT IN THE NO. 3 STEAM GENERATOR (S/G). THE TRIP WAS PRECEDED ST eq A SECONDARY SIDE TRANSIENT AND TUR81NE RUMBACK TO APPR0x!MATELY 80-PERCENT LOAD AS A RESULY OF A HIGH LEVEL IN THE NO. 3 HEATER DRAIN N i; TANK (HOT). OURING THE RUNSACK, A LOW FEEDWATER FLOW WAS OBSERVED, AND MAIN FEEDWATER PUMP (MFP) 1A WAS PLACED IN MANUAL TO 800ST

' FEEDWATER FLOW TO MATCH STEAM FLOW. HOWEVER, AS THE S/G LEVELS b4 , RECOVERED, NO. 3 LOOP OID NOT ISOLATE UNTIL AFTER THE 60-PERCENT SETPOINT, AND THE TUR81NE/ REACTOR TRIP OCCURRED AS THE NO. 3 S/G LEVEL ga REACHED 75 PERCENT. PLANT SHUTDOWN PROCEEDED IN AN ORDERLY MANNER i

g. CONSISTENT WITH PROCEDURES. A POSTTRIP REVIEW TEAM CONCLUDED THAT THE U" TRIP WAS CAUSED ST A FAILURE OF $/G Loop 3 MAIN FEEDWATER REGULATING VALVE TO CLOSE AND MAINTAIN LOOP 3 S/G AT A 60-PERCENT LEVEL, A be i.

CONTRISUTING CAUSE WAS THE INABILITT OF THE MFP 1A TO ADEQUATELT RESPOND TO CHANGING FEEDWATER DEMANDS. THE INITIATING EVENT WAS THE FAILUR! 0F LEVEL CONTROL VALVES TO MAINTAIN PROPER LEVELS IN THE No. 3 , gg HDT. CORRECTIVE ACTIONS TAKEN CONSISTED OF TROJ8LESH00 TING, REPAIR, AND/OR ADJUSTMENTS TO MALFUNCTIONING EQUIPMENT. LONGER-TERM D4 . CORRECTIVE ACTIONS INCLUDE EAGLE 21 INSTALLATION TO IMPROVE OPERATING gagggys, 1 P4 FORM 209 LER SCSS DATA 04-18-91

   ,,         0********************************************************************
   '             DOCKET TEAR LER NUMBER REVISION DCS NUMBER                    NSIC     EVENT DATE 327    1990      012             0         9007100034 218792          06/02/90 A'

g, ABSTRACT POWER LEVEL - 011%. ON JUNE 2, 1990, WITH UNITS 1 AND 2 AT

   ,,              APPRONIMATELY 11 AND 100 PERCENT POWER RESPECTIVELT, A REACTOR TRIP OCCURRED ON UNIT 1 480UT 17 MINUTES AFTER A GENERATOR / TURBINE TRIP HAD OCCURRED AS A RESULT OF ELECTRICAL PROSLEMS. CONTROL ROOM OPERATORS D

REOUCED REACTOR POWER AND ANNOUNCEO THE TURBINE TRIP ON THE PLANT PUBLIC ACCESS (PA) SYSTEM. THE PLANT WAS STABILIZING AS REACTOR POWER REACHED APPROXIMATELT 15 PERCENT WHEN MAIN FEEDWATER (MFW) FLOW WAS LOST. TWO AUXILIARY UNIT OPERATORS (AUDS) MAD MISHEARD THE PA

    .    '       ANNDUNCE4ENT AS " UNIT TRIP" RATHER THAN "TUR81NE TRIP" AND HAD ISOLATED THE STEAM SUPPLIES TO THE MFW PUMPS. OPERATORS STARTED THE AUXILIART FEE 0 WATER PUMPS WHILE CONTINUING TO REOUCE REACTOR POWER, e

SUT THE REACTOR TRIPPED ON LOW-LOW STEAM GENERATOR LEVEL. THE ROOT CAUSE OF THE REACTOR TRIP HAS BEEN ATTRIBUTED TO INADEQUATE

   ,               COMMUNIC ATION S ET WEEN CONTEDL ROOM OPERATORS AND A005.           AS CORRECTIVE 7

ACTION, OPERATIONS MANAGEMENT HAS ISSUED A NIGHT ORDER CLARIFTING WHAT SPECIFIC ACTIONS SHOULD BE TAKEN SY 2005 FOLLOWING A REACTOR OR TUR8INE TRIP ONLT WITH UNIT OPERATOR GUIDANCE. A RELATED WEAKNESS IN AUO TRAINING REGARDING ACTIONS TO BE TAKEN FOLLOWING A TUR81NE TRIP OR REACTOR TRIP WAS IDENTIFIED AND CORRECTED DURING THE INVESTIGATION OF THIS EVENT. t 1 FORM 210 LER SCSS DATA 04-18-91 g 0******************************************************************** COCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE 327 1990 021 0 9010230284 219736 09/14/90 gg ********************************************************************

st...vs agar e.vu<.:s di 1o11 E 45T! AN 34YLIGHT TIME. THE TRIP WA5 i pq GENERATED FROM A LOW-LDW STIAM GENERATOR WATER LEVEL SIGNAL IN LOOP 2. THE LOW LEVEL dA5 THE RESULT OF 4 FEE 0 WATER TRANSIENT INITIATED ST i THE FAILURE OF A VITAL INVERTER. THE INVERTER FAILURE OCCURRED AFTER f a; THE C0%7LETION OF MAINTENANCE ACTIVITIES GN THE INVERTER AND DURING THE TRANSFER OF THE INVERTER FROM ITS MAINTENANCE POWER SUPPLY TO ITS NORMAL POWER SUPPLY. DURING THE TRANSFER, THE INVERTER OUTPUT VOLTAGE b4 OROPPED TO ZERO BECAUSE OF THE RANDOM FAILURE OF THE INVERTER'S 5

         ;.        SILICON-CONTROLLEO RECTIFIERS.              THIS DEENERGIZED THE 1-II VITAL pq               INSTRUMENT POWER BOARD. THE LOSS OF POWER RESULTED IN THE MAIN FEEDWATER REGULATOR VALVES CLOSING AND THE MAIN FEE 0 WATER PUMP 5 N              DROPPING TO MINIMUM SPEED.            THIS REDUCED FEEDWATER FLOW TO ALL FOUR STEAM GENERATOR $.         PLANT SYSTEMS RESPONDED PROPERLY AND THE S HUT DOWie DQ               POSED NO DANGER TO PLANT EMPLOYEES OR THE GENERAL PUBLIC.                  THE UNIT i

WA$ $TABILIZE0 IN ACCORDANCE WITH PLANT PROCEDURES. THE v!TAL INVERTER WAS REPAIRED AND RETURNED TO SERVICE ON SEPTEMBER 15, 1990. ke 1 FORM 211 LER SCSS DATA De 0************************************************************04-18-91 ******** DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE , b4 327 1990 022 0 9010290176 219869

                 ********************** *****************              *******************09/19/90 AB5 TRACT I'              POWER LEVEL - 060%. ON SEPTEM8ER 19, 1990, WITH UNIT 1 OPERATING AT APPROXIMATELY 60 PERCENT REACTOR POWER, 2235 POUNDS PER SQUARE INCH GAUGE (PSIG), AND 564 DEGREES FAHRENHEIT (F), A TURBINE TRIP FOLLOWED p-e 87 A REACTOR TRIP OCCURRED AT 0357 EASTERN DATLIGHT TIME. THE TUR8INE TRIPPED AS A RESULT OF "A" PHASE MAIN TRANSFORMER DIFFERENTIAL RELAY
  >,.              (5UDDEN PRE $$URE) OPERATION CAUSED FROM CORRODED AND SHORTED TERMINAL $

g ON THE TRANSFORMER GA5 RELAY. SECAUSE THE REACTOR POWER WAS GREATER b5 THAN THE REACTOR TRIP INTERLOCK FOR AUTOMATIC BLOCK OF REACTOR TRIP DN TUR8INE TRIP PERMISSIVE (P-9), A REACTOR TRIP OCCURRED AS A RESULT OF THE TURBINE TRIP. OPERATORS RESPONDED TO THE TRIP USING EMERGENCY ge OPERATING PROCEDURE 1-E-0, " REACTOR TRIP OR SAFETT INJECTION," AND STABILIZE 0 THE REACTOR AT HOT STAND 8Y CONDITIONS (MODE 3) At 547

                DEGREES F AND 223$ PSIG. ALL REACTOR PROTECTION SYSTEMS OPERATED A5 DESIGNED, AND NO ANOMALIES OCCURRED. THE SUDOEN PRES 5URE RELAY WAS REPLACED, AND THE EQUIP 4ENT'WAS RETURNE0 70 SERVICE.

8 1

  , ,           FORM        212                     LER SC55 DATA                             04-18-91 0********************************************************************
  '             DOCKET TEAR LER NUM8ER REVISION DCS NUMBER                         N51C    EVENT DATE 328     1989         005             0      8905190516 213886            04/15/89 AS$ TRACT POWER LEVEL - 030E. THIS REPORT DETAILS 3 UNIT 2 REACTOR TRIPS WHICH OCCURRED ON APRIL 15, 16, AND 19, 1939 FOLLOWING THE COMPLETION OF THE UNIT 2 CTCLE 3 REFUELING OUTAGE. FOR ALL 3 EVENTS OPERATOR ACTIONS (PERFORMED IN ACCORDANCE WITH PLANT PROCEDURES) CAUSED STEAM GENERATOR

($G) WATER LEVELS TO BEGIN FLUCTUATING AND, A REACTOR TRIP DUE TO LOW-LOW WATER LEVEL IN ONE OF THE SGS. FOR THE 4/15 EVENT, UNIT 2 WAS AT 301 REACTOR POWER AND IN THE PROCESS OF PERFORMING A MAIN TURBINE OVERSPEED TEST WHEN THE REACTOR TRIPP!3 OUE TO LOW-LOW WATER LEVEL IN 3G No. 4. FOR THE 4/16 EVENT, OPERATIONS WAS PERFORMING A SWAPOWER FROM AURILIART FEEDWATER (AFW) TO MAIN FEE 0 WATER (MFW) SUPPLY TO THE

       ,          SGS WHEN THE REACTOR TRIPPED OUE TO LOW-LOW WATER LEVEL IN SG NO. 1.

FOR THE 4/19 EVENT, DURING NORMAL POWER ESCALATION (18% REACTOR POWER), OPERATIONS WAS SWAPPING OVER FROM THE MFW BYPASS VALVES TO 4, n2 MFW MAIN REGULATING VALVES WHEN THE REACTOR TRIPPED CUE TO LOW-LOW WATER LEVEL IN SG NO. 2. THE 4/15 CAUSE Was ALLOWING %G tevFt

L usc .4% eN OJI-J5-CAL 13aATION CONOTTION ON 2-PT-3-1 (MFW PUMP p q DISCHARGE PRES $URY). THE CAUSE FOR THE 6/19 TRIP WS$ OP(44 TING LOOPS i 152 STP455 UALUES IN MAMUAL 8MD NOT ALLOGING SUFFICIENT TIME FOR THE SYSTEM TO STABILIIE AFTEQ EACH TRONSIENTo ' } D4 FORM 213 LER SC55 OATA 04-18-91

  ==          0...............................................*........... ........

DOCKET YEAR LER NUMBER ' REVISION OCS MUM 8ER N51C EVENT DATE

pq 328 1989 008 0 8903140121 214994 07/10/89 a

! "d ABSTRACT POWER LEVEL - 100E. ON 7/10/$9, AT 1134 EDT, WITH UNIT 2 IN MODE 1 kN (100X REACTOR POWER, APPROX. 2,235 PSIG, AND TAVG AT 578F), 4 REACTOR i i TRIP OCCURRED. THE TRIP OCCURRED ON HIGH NEGATIVE FLUK AS NOTED ON THE gj FIRST-0UT-ANNUNCI4 TOR. PLANT SHUTDOWN PROCEEDED IN AN ORDERLY MANNER CONSISTENT WITH PROCEDURES WITH NO CVERC00 LING TRANSIENT. A POSTTRIP i U" REVIEd TEAM WAS FORMED THAT CONOUCTED PERSONNEL INTERVIEWS AND 4

'                DEVELOPED RECOMMENDATIONS FOR IMMEDIATE CORRECTIVE / INVESTIGATIVE o

ACTIONS. THESE ACTIONS ARE DETAILED IN THE REPORT AND INCLUDE

CN TROU8LE5H00 TING 04 THE ROD CONTROL SYSTEM 45 WELL AS OTHER DEFICIENCIE5 NOTED 8Y THE OPERATOR $. PERSONNEL STATEMENTS, STRIP CHART gg RECORDERS, TROUBLESHOOTING WORK REQUESTS, PREVIOUS TRIP REPORTS, j WESTINGHOUSE OWNER'S GROUP TRIP DATA 945E, AND A TRIP MODELING ROUTINE 3

t EI 0F THE WATT 5 BAR SIMULATOR WERE PART OF THE RESOURCES UTILIZED IN THE ' TEAM *5 EVALU4 TION. AL50, PLANT MANAGEMENT REQUESTED WESTINGHOUSE TO ASSIST IN PROVIDING EXPERTISE IN TROUSE5H00 TING THE R0D CONTROL Pe SYSTEM. THE TE4M*5 CONCLUSION IS THAT THE TRIP WAS A DROPPED ROD EVENT BECauSE OF A SPURIOUS CONTROL SIGNAL FAULT. NEITHER THE TRIP

ITSELF NOR THE TEAM *5 RECOMMENDED RESTART PLAN POSE ANT COMPROMISE TO

  '              THE SAFE OPERATION OF THE UNIT. AT 1857 WITH UNIT 2 IN MODE 3 (OE REACTOR POWER, 2235 PSIG, AND 547F), A SECOND REACTOR TRIP SIGNAL W45                                                                       '

] #* GENER ATED BY A SOURCE RANGE SPIKE APPROX. 7 HR$ AFTER THE HIGH FLUX TRIF. -SOURCE RANGE CHANNEL HAD NOT BEEN BYPASSED. , s. 1 i j

              FORM     214                               LER SCSS DATA                                                      04-18-91 0*.*..... *.*.*****...**..*.****..... *.**..*....***..*.*.*..** **.**

) DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE e 328 1990 003 0 9005160103 215169 04/10/90 1 AB5 TRACT

   '             POWER LEVEL - 1003. ON APRIL 10, 1990, WITH UNIT 1 DEFUELED AND UNIT 2                                                                      '

l IN MODE 1 AT 100 PERCENT POWER, A REACTOR TRIP OCCURRED 04 UNIT 2 AT 0134 EASTERN DAYLIGHT TIME. THE TRIP RESULTED FROM A GENERAL WARNING ' ALARM ON BOTH TRAINS OF THE SOLID STATE PROTECTION SYSTEM (55PS) AND , WAS CAUSED BY SURVEILLANCE TEST STEP 5 SEING PERFORMED OUT OF SEQUENCE

   ,             DURING A MONTHLV 55P5 TRAIN "B" FUNCTIONAL TEST. WHEN THE OUT-OF-5EQUENCE SITUATION WAS DISCOVERED, THE PROCESS USED TO EVALUATE 1

THE SITUATION WA5 NOT 45 SPECIFIED IN PLANT INSTRUCTIONS. AS 4 CONSEQUENCE WHEN THE OMITTED STEPS WERE PERFORMED OUT OF SEQUENCE, A i

        ,-       REACTOR TRIP OCCURRED. PLANT SYSTEMS RESPONDED PROPERLY AND THE SHUT 00WN POSED NO D4NGER TO PLANT EMPLOYEES OR THE GENERAL PU8LIC.
                'THE ROOT CAUSE OF THE EVENT HAS BEEN ATTRIBUTED TO PERSONNEL ERROR 04
        ,        THE PART OF THE TEST DIRECTOR AND HIS SUPERVISOR IN NOT FOLLOWING PROCEDURES ADDRESSING AN OU T- 0F- S E GUE NC E SITUATION. 45 CORRECTIVE ACTION, APPROPRI4TE DISCIPLINARY ACTION HA5 BEEN GIVEN TO 80TH THE

g. TEST DIRECTOR AND THE SUPERVISOR. IN ADDITION, 4 SITE WIDE MESSAGE HAS SEEN DISTRIBUTED TO PROVIDE (555045 LE ARNED FROM THE EVENT AND TO j i- EMPMASIZE THE PROPER RESPONSE TO PROBLEMS ENCOUNTERED DURING W'1E.

,/!

I l

                                                                                                 , . ==
                 . . . . . . . . . . 6.s  .uwsca  ,=V121oN   UL5 NUMaER   NSIC       EVENT DATE 329      1993       017            0    9012230292 2295S8         11/23/9 pq                *************************************:eee********* a***************0*

g4 A85T%ACT

         !.        POWER LEVEL - 0101. ON NOVEMBER 23, 1990, AT 0431 EASTERN STANDARD TIME WITH UNIT 2 IN MODE 1, A REACTOR TRIP OCCURRED A5 4 RESULT OF D4                 LOW-PRE 55URIZER PRES $URE.        TWO MINUTES E ARLIER, THE 6.9KV UNIT BOARD j                   20 HAD DEENERGIZED, LEADING TO THE LOSS OF THE No. 4 REACTOR COOLANT pq                 PUMP (RCP). THE LOS5 OF THE UNIT BOARD HAS BEEN DETERMINED TO HAVE BEEN CAUSED BY STICKING CONTACTS ON THE FAST TRANSFER 62-224 RELAY.

WHEN THE RCP TRIPPED, OPERATION 5' PERSONNEL IMME0!aTELY BEGAN TO TAKE ACTION TO REOUCE POWER. THE SHIFT OPERATING SUPERVISOR BEGAN

>$ SEARCHING FOR A PROCEDURE COVERING THE LOS$ OF AN RCP. OPERATION 5' PERSONNEL DID NOT ASSUME THEIR NORMALLf ASSIGNED TASK, AND THEY DID NOT COMMUNICATE EFFECTIVELY WITH CNE ANOTHER WHILE PERFOR9ING THE gg TASKS THEY ASSUMED. THE LEAD REACTOR OPERATOR (LRO) MANUALLY BEGAN REDUCING POWER FASTER THAN THE TURBINE WAS BEING RUN SACK BECAUSE OF A 89 PERCEIVED URGENCY TO SHUT THE UNIT DOWNI THIS RESULTED IN 4 POWER MISMATCH, THE AVERAGE TEMPERATURE AND REFERENCE TEMPERATURE AND, SUBSEQUENTLY, LOW-PRE 55URIZER PRES 5URE. THE CAUSE OF THE REACTOR TRIP

>4 WAS 4 MI5 UNDERSTANDING OF THE CONSEQUENCES OF LOSING ONE RCP SELOW 35 PERCENT POWER SV THE LRO, AND SUB5EQUENT POOR COMMUNICATION AND b                 COMMAND AND CONTROL ST OPERATION 5' PERSONNEL.

I' FORM 216 LER SC55 DATA 0************************************************************04-18-91 ******** Pe DOCKET YEAR LER NUMBER REVISION DC5 NUMBER N5IC EVENT DATE 331 1989 001 0 8903020553 213152 01/18/89 I A85 TRACT' D9 POWER LEVEL - 100%. ON 1/18/99 AT 0337 HOURS AN ELECTRO HTDRAULIC CONTROL (EHC) RESERv0!R LOW LEVEL ALARM WAS RECEIVED IN THE CONTROL Le ROOM. THE AUI. OPERATOR WA5 SENT TO INVESTIGATE THE LOW LEVEL ALARM. THE EHC RESERVOIR WAS LOW AND THERE WAS A LEAK ON A HIGH PRESSURE

' '               SUPPLY LINE TO THE TUR8INE CONTROL VALVE 83 (CV-3) WHICH COULO NOT BE ISOLATED. CONTROL ROOM PERSONNEL SEGAN LOWERING REACTOR POWER BY REOUCING RECIRCULATION FLOW AND INSERTING CONTROL RODS. WITH REACTOR t

POWER AT 41% AND EHC RESERVOIR LEVEL DECREASING, THE REACTOR WAS MANUALLY SCRAMMED AT 0352 HOURf. THERE WERE NO COMPONENT OR SYSTEM

,                 FAILURES OTHER THAN THE LEAK IN THE EHC PIPING. THE LEAK WA5 IN A FLEXIBLE HOSE INSTALLED DURING THE CYCLE 9/10 REFUELING OUTAGE. THIS
'                 HOSE WAS REMOVED AND EXAMINED FOR CRACKS USING A LIQUID PENETRANT INSPECTION. A 1/2" CIRCUMFERENTIAL CRACE IN THE TUBING WAS IDENTIFIED. A REPRESENTATIVE OF THE H35E MANUPACTURER WAS CONSULTED
       ,.         AND ALL OF THE FLEXIBLE HIGH PRESSURE EHC TUBING THAT WAS INSTALLED DURING THE CYCLE 9/10 REFUELING WAS REPLACED.
 .           1 FORM        217                  LER SC55 DATA                        04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS MUMEER N5IC EVENT DATE 331 1989 003 0 3903150444 213210 02/02/89

                **************************************************************s*****

ABSTRACT POWER LEVEL - 1001. ON 2/2/89, WITH THE PLANT OPERATING AT 100% POWER,

       '          OURING THE PRELIMINARY STEP 5 0F A HYDROGEN INJECTION SPECIAL TEST PROCEDURE, A REACTOR SCRAM OCCURRED.          THE CAUSE OF THIS SCRAM WAS HIGH
+

MAIN STEAM LINE RADIATION LEVEL 5 CAUSED BY A LARGER THAN EXPECTED g QUANTITT OP HYDROGEN SEING INJECTED INT 3 THE FEE 0 WATER SYSTEM. THE

 .                ROOT CAUSE OF THIS EVENT WA S F AILURE 70 RE-VERIFY 78tY # f "-

                    .. ... .... .,             <*..c.s    : con ==NLt ur THI5 TYPE 05 EVENT WILL BE p e A REVISION CF THE SPECIAL TEST ADMINISTRATIVE CotTROL *ROCEDURE. THE REVISION WILL INCLUDE THE REQUIREMENT FOR INDEPEN3ENT VERIFICATION OF TEST RIG 5 AND SPECIAL VALVE LINEUPS MAICH UILL BE USED DU21NG SPECIAL TESTS. THIS REQUIREMENT WILL BE SPPLIED TO SP!CIAL TESTS, EXCEPT bi ,,

THOSE WHICH HAVE NO POTENTIAL FOR AFFECTING SAFETY-RELATED SYSTEMS OR WM STRUCTURES. THE REACTOR SCRAM OCCURRED 45 DESIGNE0 UPON RECEIPT OF MULTIPLE MAIN STEAM LINE HIGH RADISTION SIGNALS. ALL RODS INSERTED TO THE FULL-IN POSITION. THROUGHOUT THE EVENT, VESSEL LEVEL AND PRESSURE gg WERE MAINTAINED WITHIN 5AFE OPERATING LIMITS VIA PROPER RESPONSE OF FEEDWATER LEVEL CONTROL AND THE SAFETY RELIEF VALVES A$ WELL AS APPROPRIATE RESPONSE SY OPERATIONS PERSONNEL. DQ g FORM 218 LER SCSS DATA 0************************************************************04-1S-91 ******** 3, DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 331 1989 008 0 8904170217 213580 03/0 D4 ****************************************************************5/89 **** 3 A85 TRACT be POWER LEVEL - 100%. ON MARCH 5, 1989 WITH THE REACTOR OPERATING AT 100% POWER, CALIBRATION OF THE MAIN STEAM LINE R40!aT10N MONITORS WA$

   '          IN PROGRE55 WHEN THE 'B' OUT50ARD MAIN STEAM LINE ISOLATION VALVE (MSIV) UNEXPECTEDLY CLOSED DUE TO A FAILED DC SOLENOID. THE ISOL4 TION OF THE '8' MAIN STEAM LINE (MSL) RESULTED IN FLOW IN THE REMAINING

6 THREE MAIN STEAM LINES EXCEEDING THE HIGH FLOW LIMIT OF 40%. IN ACCORDANCE WITM OESIGN THIS RESULTED IN ISOLATION OF ALL MAIN STEAM p, LINES. WHEN MSIV'S REACHED THE LESS THAN 90% OPEN POSITION, AN AUTOMATIC REACTOR SCRAM OCCURRED. REACTOR PRESSURE PEAEED AT b APPROXIMATELY 1126 PSIG ANO WA5 CONTROLLED WITH THE USE OF FOUR PRES $URE RELIEF VALVES. ALL SAFETY SYSTEMS PERFORMED A5 EXPECTED AND OPERATOR RESPONSE WAS APPROPRIATE. THE CAUSE CF THE FAILED SOLENOID 8* COIL WA5 M0!$TURE INTRU510N. THE SOURCE FOR THE MOISTURE WA5 CONDENSATION FROM A NEAR8V MINOR STEAM LEAE. THE SULENOID ENCLOSURE g, WAS SUSCEPTIBLE TO MOISTURE INTRUSION A5 A RESULT OF INADEQUATE TORQUING OF 4 THREADED COVER FOR THE ENCLOSURE DURING PREVIOUS

           MAINTENANCE ACTIVITIES IN DECEMBER 1985. THE LACE OF PROPER TORQUING
        '    W45 OUE TO AN INADEQUATE MAINTENANCE REPAIR PROCEDURE. THE FAILED 50LENotD W45 REPLACED. OTHER MSIV FAST CLOSURE SOLENOIDS WERE a

INSPECTED FOR MOISTURE INTRU510N AND THE ENCLOSURES WERE PROPERLY TORQUED. THE REPAIR PROCEDURE HAS SEEN REVISED.

 ,        1 FORM        219                       LER SC55 DATA                                    04-18-91
 '        0********************************************************************

DOCKET YEAR LER NUMBER REVISION OCS NUMBER M5IC EVENT DATE

,              331         1989           009           0       5937190295 214636                  06/12159 A85 TRACT POWER LEVEL - 100%. ON 6/12/89, WHILE AT FULL POWER A REACTOR PROTECTION $YSTEM (RPS) ACTUATION AND REACTOR SCRAM OCCURRED. TWO ITT BARTON M30EL 764 FLOW TRANSMITTERS WHICH HELP To DETERMINE THE AVERAGE POWER RANGE MONITOR UPSCALE SETPOINT WERE AFFECTED 87 HAND-MELD RADIO FREQUENCY INTERFERENCE. PRIMARY CONTAINMENT !$0LATION
     ,       SYSTEM GROUPS II THROUGH V ISOLATED AND THE STAND 8Y GAS TREATMENT SYSTEM INITI4TED AS EXPECTED ON LOW LEVEL POLLOWING VOID COLLAP5E.

SOME FEEDWATER CONTROL PR05LEMS DURING RECOVE4Y RESULTED IN VESSEL

     ,.      LEVEL APPROACHING THE LOW LEVEL SETPOINT 33 41 NUT ES AFTER THE REACTOR SCRAM.          DUE TO CONSERVATIVE INSTRUMENT SETPOINTS, AN RPS TRIP AND THE AFOREMENTIONED $AFETY SYSTEMS WERE INITIATED. THE ROOT CAUSE OF THE g       SCRAM WAS THE UNANTICIPATED RESPONSE OF THE FLOW TRAN5MITTERS TO HAND-HELD RADIO FREQUENCIES. THE TRANSMITTERS WERE IN A LOW TRAFFIC

                      ..... . ....-. c. SAL-ean A sa in: LONTROL ROOM. A LOOSE 43JUSTMENT SPRING LOCKNUT 04 A FEE 0 WATER VALVE PNEUMATIC POSITIONER AL50 D1 CONTRIBUTED. CORRECTIVE ACTIONS k_2E TO PLACE FURTHER RESTRICTIONS ON HAND-HELO RADIO USE SHORTEN THE CALIDRATION FREQUENCY 07 THE POSITION kW                IU3ICATCR, AND REQUIRE THE USE OF LOCTITE WHEn ADJUSTING THE PNEUMATIC c;

POSITIONER. 1 kW

            ,:      FORM      220                  LER SCSS DATA P1            0************************************************************04-18-91        ********

DOCKET YEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE g4 , 331 1989 011 1 8911070016 215750 08/

                    ***************************************************************26/89           *****

b4 ,

               ,    A85 TRACT POWER LEVEL - 100%. ON AUGUST 26, 1989, AT 1642 HOURS WITH THE PLANT

, gg OPERATING AT 100% POWER, OPERATIONS PROCEDURE, " POWER /LOAO UNBALANCE

               '     AND RELAY CIRCUITS TEST" WAS IN PROGRESS. THIS TEST 15 PERFORME0 FOR

CONTINUED RELIABLE OPERATION OF THF MAIN TUR8INE. CONTRARY TO WHAT

] WAS EXPECTED, A TRIP OF THE MAIN TUR8INE CONTROL VALVES AND SUB5EQUENT s; 54 ' REACTOR SCRAM OCCURRED AT 1643 HOUR 5. SUB5EQUENT DETAILED .I INVESTIGATIONS IDENTIFIE0 8 RIDGING OF A MERCURV-WETTED RELAY IN THE POWER / LOA 0 UNBALANCE CIRCUITRT A5 THE MOST PROBASLE ROOT CAUSE FOR THE TUR8INE TRIP ANO SUBSEQUENT REACTOR SCRAM. APPROXIMATELY FIVE MINUTES FOLLOWING THE SCRAM, PROBLEMS WERE ENCOUNTEREO ON THE "8" I' ESSENTIAL AND NON-ESSENTIAL 8055ES. SUBSEQUENT INVESTIGATION REVEALEO THE ROOT CAUSE TO 8E A FAILE0 TRIP COIL ON AN ASSOCIATED BREAKER. THE PLANT WAS BROUGHT TO A NORMAL SAFE SHUT 00WN CONDITION AND THE D6 APPROPRIATE NOTIFICATIONS WERE MADE. THERE WAS NO EFFECT ON THE SAFE OPERATION OF THE PLANT.

    ,            1 FORM      221                 LER 3C55 OATA                               04-18-91 b'

0******************************************************************** 00CKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE te 331 1990 002 0 9005070103 218017 03/29/90 A85 TRACT POWER LEVEL - 1001. ON MARCH 29, 1990 WITH THE REACTOR OPERATING AT 1001 POWER, 4 MANUAL REACTOR SCRAM WAS INITIATED AT 0407 HOUR 5 IN 1 RESPONSE TO A RISING REACTOR WATER LEVEL. THE RISING WATER WAS OUE TO

    ,                FEED REGULATING VALVE LOCK-UP. AT APPROXIMATELY 0245 HOURS ON MARCH 29, 1990, OPERATING AIR WAS ISOLATED TO AN INSTRUMENT AIR HEADER
    '

ISOLATION VALVE DUE TO A PERSONNEL ERROR MADE IN THE TAGOUT PREPARATION PROCESS. AS THIS OPERATING AIR PRESSURE SLOWLY BLED OFF, THE AIR HEADER ISOLATION VALVE FAILEO SHUT. THIS LOSS OF INSTRUMENT

    '                AIR CAUSE0 THE FEED REGULATING VALVES TO LOCK-UP.                REACTOR LEVEL SLOWLT INCREASED TO THE 195" HIGH LEVEL ALARM POINT AT 0605 HOUR $. 45 ACTIONS TO LOWER REACTOR LEVEL TO WITHIN THE NORMAL OPERATING RANGE WERE UNSUCCESSFUL AND WARIOUS OTHER CONTROL VALVES 8EGAN TO FAIL DUE

TO THE LOSS OF INSTRUMENT AIR, THE OPERATIONS SHIFT SUPERVISOR CONSERVATIVELT ELECTED TO DIRECT INITIATION OF A MANUAL SCRAM.

FOLLOWING THE REACTOR SCRAM, ALL AUTOMATIC FUNCTIONS AND MANUAL ACTIONS WERE COMPLETED SATI5FACTORILT. CORRECTIVE ACTIONS FOR THIS EVENT INCLUDE A REQUIRED INDEPENDENT REVIEW OF INSTRUMENT AND SERVICE

          ,-         AIR TAGOUTS, COMPLETION OF DRAWING UPDATES, AND A REVIEW OF THE DESIGN

, DOCUMENT CHANGE PROCESS FOCUSING ON POTENTIAL PROCESS IMPROVEMENTS. FORM 222 LER SC55 DATA 04-18-91 0********************************************************************

g. DOCKET VEAR LER NU98ER REVISION 0C5 NUMBER NSIC EVENT DATE

    ,                  331     1993      004            0       9005010072 219010             nasntion t

                           -. ass.se POWER LEVEL - 0051. ON 4/1/93 AT 0532 MOURS, OURING REACTOR STARTU#, A P1 MOMENTARY INCREASE IN INDICATED 5 Lux 01 AVERAGE P0btR RANGE MONITOR

{ (APRM) CHANNELS "C" AND "O" 10 GREATER THAN 15% OF RATED POWER ' D4 CESULTED'IU AN AUTOMATIC REACTOR SCRAM. THE PLANT WAS AT l

          'i'                 APPROXIMATELT SE THERMAL POWER.                                        THE APRM 3 CRAM WAS ORIGINATED FROM

, W4 LOCAL POWER RANGE MONITOR (LPRM) 32-09C, hMICH FEEDS IT5 OUTPUT SIGNAL TO APRM CHANNELS "C" 440 "0". THESE APRM CHANNELS FEED OPPOSITE j 6 ; SIDES OF THE REACTOR PROTECTION SYSTEM (RPS) LOGIC. eq ~ THE MOST PROBABLE CAUSE WAS METALLIC PARTICLES PORMED IN THE LPRM DETECTOR, WHICH 5HORTED THE AN00E TO THE CATHODE. THIS RESULTED IN A MOMENTARY SPIKE l g4 q WHICH WAS SENSED A5 A POWER INCREASE SV THE APRMS, AND SUBSEQUENTLY I THE RPS LOGIC. WHEN THE SWITCH 15 IN STARTUP MODE, THE UPSCALE TRIP h4 SETPOINT 15 SET AT 15E OF RATED POWER. THE PLANT RESPONDED TO THE , p~ SCRAM As DESIGNED WITH NO 085ERVED EQUIPMENT FAILURES. FOLLOWING THE j SCRAM, A REVIEW OF THE EVENT AND TROUBLESHOOTING OF THE FAILED LPRM t go WERE PERFORME0. -THE LPRM WAS STPASSED AND REACTOR STARTUP COMMENCE 0 WITHOUT FURTHER COMPLICATIONS. THIS EVENT 15 BEING REPORTED PURSUANT

     ,q                       10 10CFR 50.73(A)(2)(IV).

bg FORM 223 LER SCSS DATA 0*************e************e*********************************04-18-91 ******** pg , 00CKET TEAR LER NUM8ER REVISION OCS MUM 8ER NSIC EVENT DATE 4 331 1990 014 0 9010170065 219739 09/ , Be e...................................e** e.** ee........ ee.....10/90 .... ABSTRACT D1 POWER LEVEL - 0273. ON SEPTEMBER 10, 1990 WITH THE REACTOR AT APPRONIMATELT 2TI POWER, A TUR8INE TRIP OCCURRED A5 A RESULT OF A

,, SENSE 0 HIGH LEVEL IN A M0ISTURE SEPARATOR REHEATER. REACTOR STEAM
, PRODUCTION AT THE TIME OF THE TUR8INE TRIP WAS SLIGHTLY IN EXCESS OF

,    be                       THE STPASS VALVE. CAPACITY, RESULTING IN A RISING REACTOR PRES $URE, AND A REACTOR SCRAM APPRONIMATELY ONE MINUTE LATER. - PL ANT RESPONSE TO THE CONDITIONS PRESENT OCCURRED APPROPRIATELY. PRIMART CONTAINMENT te   >

ISOLATION GROUPS 2-5 RESPONDED IN ACCORDANCE WITH OESIGN WHEN REACTOR WATER LEVEL DECREASEO AS A RESULT OF V010 REQUCTION IN RESPONSE TO THE

                          REACTOR SCRAM.                     THE ROOT CAUSE OF THE EVENT WAS VALVE MISALIGNMENT

FOLLOWING MAINTEN ANC E. THE CORRECTIVE ACTIONS INCLUDED AN IMMEDIATE

'                            VALVE LINEUP VERIFICATION AND ENHANCEMENTS TO THE VALVE LINEUP 8

PROCEDURE. 1

,    e+

FORM 224 -LER SCSS DATA 04-1 1

     '                0*****************************************************************8-91                                                                                ***

DOCKET TEAR LER NUMBER REVISION DCS NUMSER M51C EVENT DATE 331 1990 015 0 9010220256 219740 09/13/96

, eeeeeeeeeee

eeeeeeeeeeee.......eeeeeeeeeeeeeeeeeeeee.. eeeeee ...e l , A85 TRACT i

         ,p                  POWER LEVEL - 05F2. 04 SEPTEM8EP 13,1990, WITH THE REACTOR AT APPROMIMATELY 373 POWER, OPERATIONS PERSONNEL MANUALLY SCRAMMED THE REACTOR (REACTOR PROTECTION SYSTEM INITIATION) WHEN RAPIOLT 0ECREA51NG
        ,'                   INSTRUMENT AIR PRESSURE RESULTED IN REACTOR VESSEL LEVEL CONTROL
     #                      OIFFICULTIES. THE FEEDWATER REGULATING VALVES, WHICM RECEIVE THEIR

MOTIVE POWER FROM INSTRUMENT AIR, " LOCKED UP" IN THEIR CURRENT i

        ,.                  POSITION, RESULTING IN A GRADUAL INCREASING TREMO IN REACTOR VE5SEL

' i LEVEL. PRIMART CONTAINMENT ISOLATION SYSTEM GROUPS TWO THROUGH FIVE INITIATED AS DESIGNEO 04 RE00CEO LEVEL FOLLOWING THE SCRAM. THE PLANT i ' , WA5 RETURNED TO A STABLE CONDITION WITH NO FURTHER PRC5LEMS. THE

                          'CAUSE OF THE INSTRUMENT AIR PRESSURE LOS$ WA5 THE FAILURE OF A t                      THREE-INCH SOLDERED COPPER FITTING JOINT AT AN AIR ORTER INLET.

4 EMARINATION OF THE JOINT FOUND INADEQUATE SOLDER COVERAGE. LARGER

     .                      JOINTS ARE DIFFICULT TO SOLDER, 410 C00 5-88 0'eT * ** w ? t"9'                                                          ***"'"**'*"

                                    ...it   rca.us *:st th artli c J AND REPAIRED AS NECESSART, AND A SAMPLING INSPECTION OF STHER 53LDERED J0!NTS IS ONGOING.              INSPECTION CRITERI A P e                          FOR CERTAIN OI*FICULY JOINTS IS BEING MODIFIED TO INCLUDE ULTRA $0NIC TESTING.

b4 FORM 225 LER SCSS DATA 04-18-91 kW 0******************************************************************** i g5 DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE r1 331 199U 016 0 9010220257 219741 09/18/90

                                   **********************....***...*... ..*.****....**.e.***...*.....*.

i *3 ' ABSTRACT POWER LEVEL - 0501. 04 SEPTEMSER 18, 1990, WITH THE PLANT OPERATING af b4 g *, APPROXIMATELY $0% POWER, A REACTOR SCRAM OCCURRED WHEN THREE INBOARD MAIN STEAM ISCLATION VALVES (MSIWS) CLOSED UNEXPECTEDLY. JUST PRIOR gg TO THE MSIVS CLOSING, THE 'A' $1DE OF THE MAIN STEAM LINE RADIATION

                      ;,            MONITOR (MSLRM) SURVEILLANCE TEST HAD SEEN SATISFACTORILY COMPLETED U"                           WITH ISOLATION SIGNALS RESET. UPON INITIATING THE                'B' SIDE TEST, THE
                                    '8', 'C',    AND 'O'  IN80ARD MSIVS CLOSED RESULTING IN THE SCRAM. THE
                      '             CAUSE OF THIS EVENT Wa$ 4 LOOSE WIRING CONNECTION IN THE IN80ARD MSIV
       >=                           CONTROL LOGIC WHICH EFFECTIVELY PUT THE 'B', 'C', AND 'O' INBOARD MSIVS IN A HALF (A SIDE) TRIPPED CONDITION (AC $0LEN0105 DE-ENERGIIED) yg                           EVEN THOUGH THE LOGIC WAS RESET.            CURING PERFORMANCE OF THE MSLRM SURVEILLANCE, WHEN THE           '8' LOGIC TRIP WAS INSERTED, THE DC SOLENOIDS I'                           ON THE INBOARD MSIVS DE-ENERGIZED CAUSING THE '8', 'C' AND 'D' IN80ARD VALVES TO G0 CLOSED. IMMEDIATE CORRECTIVE ACTIONS WERE TO REPAIR THE CONNECTION ANL PERFORM AN EXTENSIVE INSPECTION OF APPROPRIATE CONTROL Pe                          ROOM PANELS FOR *D0!TIONAL LOOSE CONNECTIONS. LONG TERM CORRECTIVE ACTION WILL INWLLVE PERIODIC INSPECTIONS OF APPROPRIATE PANEL 5. THIS
        ,,                          EVENT HAD NO EFFECT ON THE SAFE OPERATION OF THE PLANT. SAFETY SYSTEM 3
        '                           RESPONDED AS DESIGNED IN RESPONSE TO THE SCRAM SIGNAL AND THE PLANT WAS QUICKLY BROUGHT TO A STABLE CONDITION.

Ae j i ae FORM 226 LER SCSS DATA 04-18-91 0***********w*******************************************************

                                 DOCKET YE82      6ER NUM8ER REVISION DCS NUMBER             NSIC                                        EVENT DATE 331      199c       019               0       9011280139 220158                                                  10/19/90 e

ABSTRACT

s. POWER LEVEL - 065%. ON OCTOBER 19, 1990 THE REACTOR WAS IN SINGLE LOOP OPERATION AT APPROXIMATELV 651 POWER, TWO NIGHT $HIFT ELECTRICIAN $

ASSIGNED TO THE TASK OF (ROUBLESH00 TING THE SOURCE OF AM APPARENT FAULT 04 THE '8' RECIRCULATION MG SYSTEM DRIVE MOTOR PULLED WHAT THEY PERCEIVED TO BE THE PDTENTIAL TRANSFORMER FOR THE CIRCUIT. THE

POTENTIAL TRANSFORMER ACTUALLY SENSES THE AVAILABLE SUPPLY VOLTAGE FROM ONE WINDING OF THE STARTUP TRANSFORMER TO ONE OF THE ESSENTIAL

        ,                           ELECTRICAL BUSSES. THIS CAUSED THE SUS 10 SENSE AN UNDERVOLTAGE CONDITION AND AUTOMATICALLY INITIATED A DEAD BUS TRANSFER FROH THE STARTUP TRANSFORMER TO THE STANDSV TRANSFORMER. WHEN POWER WAS RESTORED TO 144, LOSS-OF-POWER RELAYS IN THE CONDENSATE DEMIMERALIIER SYSTEM (EEIS CODE SG), CAUSED 3 CUT OF 4 INSERVICE DEMINERALIIER BEDS (FUNCTION COMPONENT FDM) TO ISOLATE. THIS RESULTED IN THE LOSS OF FEEDWATER AND A REACTOR SCRAM 04 LOW REACTOP VESSEL LEVEL. THE i           INITIATING EVENT, Removal 0F THE *0TENTIAL TRANSFORMER, WAS CAUSED ST PERSONNEL ERROR.      THE RDOT CAUSE OF THE SCRAM WAS AN UNDESIRA8LE DESIGN FEATURE OF THE CONDENSATE DEMINERALIZER CONTROL LOGIC.

g. 1 o FORM 227 LER SCSS DATA 04-18-91 g>, 0********************************************************************

4%Tc syrut nave DOCKET TEAR LER NUMBER REVISION DCS NUMBER

485 TRACT P1 POWER LEVEL - 1002. A REACTOR SCRAM CCCURRED FROM FULL POWER AT 3:23 g P.M. 03 11/5/89. AN UNIDENTIFIE0 FAILURE IN An ELECTRONIC C0% TROL but C ARD OF THE ELECTRO-HTOR AULIC CONT AOL (EHC)(JJ) SYSTEM FOR THE MAIN gg TUR8INE (TA) IS SELIEVED TO HAVE OPENED THE SVPA55 VALVES AND CLO5ED THE INTERCEPT AND CONTROL VALVES. THIS REDUCTION IN STEAM FLOW CAUSED WW 4 PRES 5URE TRANSIENT RESULTING IN A REACTOR HIGH FLUX SCRAM SIGNAL

    *g           FROM THE AVERAGE POWER RANGE MONITOR (APRM)(IG). THE HIGH PRESSURE P1                COOLANT INIECTION (HPCI)(8J) SYSTEM WAS INOPERA8LE PRIOR TO THE SCAAM.

THE AUTOMATIC FEATURES OF THE PLANT RESPONDED NORMALLY TO THE SCRAM g ,g q EXCEPT THAT 1 SAFETY RELIEF VALVE PASSED A SMALL AMOUNT OF STEAM AT A PRESSURE 5% SELOW ITS DESIGN LIFTING PRESSURE. THE REACTOR CORE DW q ISOLA TION COOLING (RCIC)(SN) SYSTEM WAS USED TO RESTORE REACTOR WATER LEVEL. 1 CONTROL ROD WA5 NOT FULLY INSERTED, REQUIRING MANUAL INSERTION FROM POSITION 02. SELECTED ELECTRONIC CONTROL CARDS WERE b4 REPLACE 0 IN THE EHC SYSTEM. THE PLANT WAS RESTARTED 11/10f89, AND ji 5 CRAMMED 11/12/89 (LER-89-023) FOR UNRELATED REASONS. THE PLANT WAS RESTARTED 11/13/89 AND RUN AT 25% POWER TO 085ERVE THE EHC SYSTEM. IT WA5 SHUTDOWN 11/20/89 FOR FURTHER WORK ON THE EHC SYSTEM. FOLLOWING p TESTING AND REPLACEMENT OF ELECTRONIC CIRCUIT 50AR05, THE PLANT WAS b4 R55 TARTED ON 11/22/89. 1 FORM 228 LER SC55 OATA. 04-18-91 0.................................................................... 8d g.* DOCKET VEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 333 1989 023 0 8912200361 216204 11/12/89 pq .................................................................... gg A05 TRACT g POWER LEVEL - 0101. AT 5:34 P.M. ON 11/12/89, A REACTOR SCRAM k4 g OCCURRED OURING A SCHEDULE 0 SURVEILLANCE TEST OF SAFETY RELIEF VALVES (SRV)(AD).'IM PREPARATION FOR THE TEST, INDICATED REACTOR POWER WA5 AT APPR0x!MATELY 10% AND PRES $URE WAS BEING CONTROLLED AT 575 PSIG USING t1 g THE MAIN STPA55 VALVES. THE FIRST SRV WAS OPENED IN ACCORDANCE WITH PROCEDURE. UPON CLOSING THE WALVE, THE RE ACTOR SCR AMMED OUE TO A

 ,,              PRES 5URE TRANSIENT WHICH RESULTED IN A HIGH FLUM 15X AVERAGE POWER g;       RANGE MONITOR,(APRM)(IG) TRIP. IN THE START-UP/ MOT STAND 87 MODE, THE APRM TRIP POINT 15 SET AT A NOMINAL 155. ACTUAL TRIP POINT SETTINGS
               RANGED FROM 13.5E TO 14.5% TO ALLOW FOR INSTRUMENT ORIFT. THIS LEFT A 4,       MARGIN OF ONLY 3.52 SETWEEN INDICATED REACTOR POWER OF 10I AND THE g,               TRIP POINT. THE SMALL PRES $URE TRANSIENT CAUSED 87 OPENING AND THEN CLOSING THE VALVE WAS SUFFICIENT TO CAUSE A NEUTRON FLUX _ SPIKE AND
'   'g<       SCRAM THE REACTOR. THE SURVEILLANCE TEST PROCEDURE DIO NOT PROVIDE                                                                                  ,

INSTRUCTION CONCERNING AN APPROPRIATE MARGIN, NOR DID IT PROVIDE A CAUTION TO THE OPERATOR CONCERNING THE POSSISLE PRESSURE TRANSIENT AND ei i' THE NEED FOR AN ADEQUATE MARGIN. CORRECTIVE ACTION REVISE 0 THE PROCEQUEE TO PROVIDE FOR V ALVE TESTING AT 940 PSIG WHEN THE RE ACTOR

 ,,              MODE SWITCH WILL BE IN THE RUN MODE. IN THE RUN MODE, THE FLOW SIASEO
         .       SCRAM WILL SE IN EFFECT. THE APRM MIGH FLUM TRIP POINT OP 1203 WILL SE IN SERVICE.

1 FORM 229 LER SC55 DATA 04-18-91 0****.*..............................................................

    , . . ,     DOCKET TEAR LER NUM8ER REVISION DCS MUM 8ER                        45IC                         EVENT DATE 333     1990         001          0    9002260448 216910                                         01/19/90
                ..........................................        2........................

I A85 TRACT

 *'              POWER LEVEL - 1003. A REACTOR SCRAM FRod PULL POWER OCCURRED AT 10:45 gg         4.M. 04 JANUARY 19, 1990 DURING THE CALIBRATION OF REACTOR WATER LEVEL
 ,               INSTRUMENT ATION.       THE I45TRUMENT WHICM WAS Sf!NG CalfaceTen tunost

m_-. esa e a.ak4, e 'A.mm 4L g <s3 A+4 --- 2 a .,w L4 - -,. --ab m,.1,1 h O 9 W W Y W f n

                                                                                                  .     .       .       .        .      .        .

A . 4 d . . . ..

k l O d O d l . o O.m = e Dem .. andenMmwww-nwenMMw,a e oeC ee-m 2e->OsM,,wano,e e O eO =>Mn1-e- ! mouZezmmmesonme12now eunem MmZerOOmsmm2mmemosom eunem mamOO1mo m O w D sn m m m m w c a z m o en n m E M dmN eun 4 Z<mmwCnns zemmmme s* eumea r u n m < rn u v j mmp<3M MmOO m>mm ewmo mm nO2MorMCmem>nMuma ewme

Tam m.

Od@mmMM N@ 20@@mM Rm> e M e e1M M RH Z>m@ OAMa%m= 0 Me MmEm3m% %

.          b      %C          2nCEnMCe M >r3                              n       e          o         >     mmMMgommrMCm                                     OOd                n         o           e        mmMnmv

!' U M 4 W D 2 M m 2 Wem W P Z M M fu r M e eN W M en M Z g m en M MnZM arerM e DN OTnH2e<> OOOm2m2 m Mt mCm omMOm od4 ew mon OummMO2mm2 %m edM ew DMM Me p mOMDM2 mMOO 4 4 eemed MOEmn 2 anDO OMgncc semeO FMac Pa i i uomo a nMEem 200 mm eene ~zproMmm m en n M > mom eene mm2mm < w meCa 4mmswOwmmmMme eOme N>M xamOn>mOONMMme e eOme a M 4Mme MOummnEmgMe m on e e NemOM> MO3proppmn. e e MO4 m 1 ( On 4100mMn MenOM@ R l e e e = mane R MPP 4mC l e O ** m OMM V* m2Mus zMZ O=12Cn e re 1 OnFm2*EO4 dom Ma e re CW2wn . CDU MO@ U M m m9 peg e me e PCM wwOm2 d on o r M d e me en n M an M% 1 9CC3mmnO2EspKM D sH u e e 2 e O m#m MWe m e ae muoO nsm> 3 M ris Z 10 NCu 2 N C D Q fle 2 M Jnr> u e e e 2COEmmmm no Mw=^bo e e WCOzmp pr

          'm m M 2 4 e m m F C                  MMO4mMN                           eQ2e                    m en        MOOO4mo                    M OgmLPH                                  0 04 e                4M 2pwrM A

,1 mut C2mm erwC=mO me O NCe o enMOCcw22522 c o me eOC e OmM inwMo we m m a s M 4 G n Z m en r o M m ew2 e zw m2<e M O w en M w ra eese O d 2 2 M r ia C 2

                 '@r          MO          mC              M t2nm                  O      we               Pnm           momeomemOCm                                         M              e      me            NmOrc                        26 Mn        OZmH2w2                      mmM               e      me            Zhopp                     b 940Mn                  mOMPz                            e     en e                 2         r,      r MEMOM m>M >mCNCOn                                   Z              e      ae            m22M             M E Z C m e M Me4 W r 2 Ora                                        e      mo            pHOPMORP P2Mnmas                  MSKNMH                    MnMW                 e         e          M M M en M Z an o m m e MM MMrnt                                                    e        .e          2           mcmL mo J m E m en n M 9 9 tn             r3           EmM         G           e          er        n     30M           Omn@                OOngOm                        M             e          ee        OM              On           GM we      GmmCemm                 OrMnanmMd                               e      aem           2KO            OMO           1M         3 3 m m E rn a m                            e      2 e en              1 M en 1 r e ,*
            - O M R Z r m o r 1 M 4 en > M C n U N                                e      mem               Or>EZtnEmOn                                4      m>mm                          e     meM            w>Z                   g en m
          #Mme m > O n an n W                   21mPCE                            o      <*            NM             mmOMMI                   eMMMUekn                                    e     ( e            NMmmw<OU Lmm           e Me NGOme=naprmO                                        e      m eM          M     nur                MmAgon                    A      mnw                       e     M e@            l             mom nm              M    O     <mpZn                 MhmE                 eOW en               % MMI             3 Le rn O         ONemoWOMO                                       eOmen                OM64Mrp<

e n-n rn O M Z COM manMMM d e M ee mmOrmmm ruswMO14 Om e M eW NDOMD -4 Mmm2 MOM mCOmemM22M Dd 6 09@ MMnsM MM d4Ee ma mm e OeM Or2m2M ur ANmmZ HDmanFme gMOdeo e 2e CCCMmpgrQ m 3 <>m M e 3 e e. m2g apO 9 2 Mr FMO4 D O- % e eO wmM mrmm Mr mm men e 4 0 CC Duru 1 Mrm@ =K 2 MO @MK Nd e em OZMn mt41 ZnceMChm e e> 22Om2@ lb OMMP MMOMmhmpnmmE e e606 4 e m M O b 2 m rn m g D J O C C Mp e@CO M cM h m e en 8s r>2>2m em prW W Man % eOne> Ommzz em e n 9 C en m T m 2 eon *> MM mm o p r in g ra m mMn m e m e rn M O c ede* 2n DMe me>Mn WCm3 eOM D M> M o rn r d' wMn MM ZrbM Z ah n m en 2 O ed e MOCMP3 M an 2 M OOM 2 en ed e OMZmzG wie m w m n en d m e M 2 m me eN2e O M Z M an EMMwerzgro *NJe JMM zMLu n mwCnw m m w en t mM eaCe aMmm mno 2 OQm m eeC e mOwM C nm an M 3 msn 2 M M D 4 mppm2 4 03 6 M Mg OunbmMM ptm O O .E e O2 - 2LL M "whMM DMZDMMn E 2 0 4 4 sn eNee ra D M m m m O O m O m m e C M g m m eNW e mop pH 3MTCMMMnMcCnMDe wp eNme mDOOMM2w onbrmmmr0 e e re e OM4 ww2 KC4m> <r > eame

>42 MMC 3M MMMm eNme Z en M r w w a m M on R C 4 rn M en d mm2Mame Mmm2 m m en M m e e MMDmmM $O2OM M DOM e e mw22np 3 m o rn rn m 4 m> CEOmm2

r M C en 2 eN e m e uGC MggrOm> Oc eN e 2m Cr1 eM a wMMMMFDEMw M M eN2e rH e DMZZ m2WZMZr od2O O 2 E < e m aa n2MMM OZ2ODMO mmEO eOwe EOZ o m 2 eu EmewCZpr *Nue M m e .c < Ow>O2m mnZmM Owmmmm edM e M Een MMm n> c e Mr emwe M M M P 43 m n aMM fnaamm 200m404m e@ne M M2Mmm NOMGM kW 9 eOne 1OZ4 r en Emmw Omm O 2M CmmK e4 e 3m>msnm@wr OEOC MO eQ

m mm 0 AC- ne 4 1 .E Om> awrnrCm e e mr mC Mmen6 eMNZK e e ma 4 M u o R@NO 091 2 0 m m m n9 M m m e e Mmra MHmmOCQMrom m e e MPPZ OG en M < gMcM 10 2 O m p O Z en e e Z O m en C M 2 M 3gZd2 EMMm e o mM r>m 2 e d m Mentn m g M O M44 O 2 e e IN M O M p ngsmMOmMmC2 e e m3 g u te g fMDnam m3CMMMMmd OM e me O CMWZ POMw 4 M r rn > e me .zMMM i m en JDWm 44 -mrn2OnwCMC2 e de AmerIO ogo 2 ZwMM M e d e wZesM M WM EO M mmgm momC edmeO m mMmp32 CmMMnmm eOmeO M >nCOwM eM 4pmnOZOZm m m > eO2ee 2EOMmmm>O anEOm Omu ew2 ee en M eg o t O > M o on 424 C Coma OMM% 2m 12MmMr O O O ne O r emM e e ed ed m>CE m4ZHF OMmm40012m DM 2 mmMOu mu e%M e e ed ed Zm M

. cM># ><C M 4 mOnMm1 sx m 2 4 eocow mmO mer MmCO b2Ce e40*w e 2 MrstI $2 eMO mO2p> r u o% >e 8 Mm MZ I mz n > e%> e 4 O OdOM IpsdM M m>pM > e eewee O O Om mnMm MZMT ecM eo M gm v. tMMWO Z 032 M e O sn e d m Z M m2 OMme eOmed M w w n1 rn 2 en M en e4 > CD2 mom 3 rn e 4 t EO Z O I2 w O 3 e % 4 2 O 2 m m O 1 l i e 1 l l l l l l I 1 al I i w - - __ - FOPM 232 LER SC55 OATA 04-13-91

i O*** *************+******************************.=**.**********.****

DOCKET YEAR LER NU15ER REVISION OCS Nue5ER NSIC EVENT DATE , g 333 1990 026 0 9101160153 220665 12/12/90 I I ABSTRACT POWER LEVEL - 130%. A REACT 3R SCR AM FROM FULL POWER OCCURRED AT 1352 t 4 ON 12/12/70 OURING CALIsRATION OF REACTOR WATER LEVEL INSTRUMENTATION. THE INSTRUMENT BEING CALISRATED SMaREO COMMON REFERENCE AND VARIABLE g g LEVEL LEGS WITH INSTRUMENTS OF THE REACTOR PROTECTION SYSTEM (JC). THE REACTOR SCRAMMEO AS THE INSTRUMENT HIGH PRESSURE ISOLATION VALVE WAS SEING CRACKE3 OPEN DURING RETURN TO SERVICE. THE SCRAM RESULTED I 1 FROM A FALSE LOW REACTOR WATER LEVEL SIGNAL. DURING THE ACTUAL LEVEL TRANSIENT FOLLOWING THE SCRAM O!FFICULTY WAS EXPERIENCE 3 WITH g 1 RESTARTING THE REACTOR FEEDWATER PUMPS AND 4 FAILu?E OF THE REACTOR FEECWATER LOW " LOW CONTROL VALVE OCCURRE3. A SECOND SCRAM OCCURRED , OUE TO AN ACTUAL LOW REACTOR WATER LEVEL AT 1416 DUE TO FAILURE OF THE REACTOR FEE 0 WATER LOW FLCW CONTROL VALVE AIR OPERATCR DIAPHRAGM. THE D4 PLANT RETURNED TO SERVICE AT 0658 CN 12/17/90 AFTER GEING OFF LINE FOR 4 DAYS, 17 HOURS, AN3 6 MINUTES. A GOOT CAUSE INVESTIGATION 08 THIS SCRAM IS IN PROGRESS AND !$ EXPECTED TO BE COMPLETED PRIOR TO THE I END OF THE FALL 1991 R! FUELING OUTAGE. UNTIL THEN, FUTURE CALIBRATIONS WILL BE CONOUCTED DURING SCHEDULED OUTAGES. RELATED LERS: , 90-001 AND 90-027 I I FORM 233 LER SCSS DATA 04-19-91 0+++++++++****+++++++**+******************+++++++++****************** , , DOCKET YEAR LER NUMPER REVISION DCS NUMBER NSIC EVENT DATE 333 1970 027 0 9101180175 220817 12#15/90 ...............+................................***......** ........ e t 485 TRACT POWER LEVEL - 00$3. A REACTOR SCRAM FROM SIX PERCENT POWER OCCURRED DURING A START-UP ON DECEMBER 15, 1990 AT 2140. THE CAUSE WAS A , , FAILURE OF A FASRIC-WCVEN SUNF-N DIAPHRAGM WHICM HAD SEEN IN SERVICE FOR 15 YEARS IN THE AIR OPERAluR FCR THE REACTOR FEEDWATER LOW FLOW CONTROL VALVE AND AIR LEAKAGE FROM THE OPERATOR STEM PACKING GLAND. THE FAILURE OF THE VALVE TO STROKE FULL OPEN RESULTED IN AN INABILITY to SUPPLV $UFFICIENT FEE 0 WATER FLOW TO THE REACTOR. THIS RESULTED IN DECREASING REACTOR WATER LEVEL AND THE NECESSITY TO USE THE REACTOR FEED PUMP (RFP) DISCHARGE VALVE TO CONTROL WATER LEVEL. AFTER SEVERAL CONTROLLED J0GS IN THE OPEN DIRECTION OF THE RFP OISCHARGE VALVE, THE INCREASE IN JATER FLOW RESULTED IN A MIGH NEUTRON Flux SCRAM OF THE REACTOR DUE TO EXCEEDING THE 15 PEPCENT POWER LIMIT WHILE THE MODE SWITCH WAS IN THE START-UP MODE POSITION. CORRECTIVE ACTIONS INCLUCED REPAIRING THE REACTOR FEECWATER LOW FLOW CONTROL VALVE OPERATOR, REVISING THE START-UP PROCEDURE TO VERIFY FULL STROKE CAPASILITY OF , THE VALVE, AND 400ING A CAUTION LIMITING THE ACCEPTABLE OPEN DEMAND SIGNAL FOR THE VALVE TO 70 PEECENT. THE PLANT WAS RESTORED TO SERVICE AT 0653 DN 12/17#90. RELATED LER: 93-026. 1 FORM 234 LER SCSS DATA 04-13-91 0.**.******************.**+++.**..**+++.*.+..***+++++.a..+++......**. DOCKET TEAR LER HUMSER REVISION DCS NUMSER NSIC EVENT DATE 33A 1939 001 0 890?23301A 213095 01/17/59

ASSTRACT POWER LEVEL - 070%. ON 1#17/87, POST-MAINTENANCE TESTING OF THE "C" SYpASS FEE 0 WATER REGUL A TT NG W at ve firev) wat .= eversete nr -- - --

y ,, a u a x _-u u. ._ n u . . n n - - - - - - . . . . . . g p y M - = . , , ,w - - . . . . s e e a d a m a 4 O d O e > e com > e ce1 9MMMME22CMMwhDEC4aDe e 000 DMNOOmmepMecm42W e 0 0 0 u m n M &s e m 2 0 m m V en222pOOM224 > MNmOOM eunem 2 2 m C D F m m C m m z em > O m *weem m 4 0 m M 2 m > g an d er S w D > s e r C M M b w e F 2 M u m D E *e awp e2 p g ,g M enen e 2 m M 2pwFEM ewse2 O m 2 M an a m m m a m 4MF2 m FmMMQm2NMmma eeme FFMe 201mM1mCC4mm eeme 42 ODD O22OM F emM 22pMWMO #n e r o mmm> e Me MMO MMOmF mnFmme e M e MMm 2mL M 2G $2nmm MNMn2M C2M W O e e MnD 222mMn>OM O e

Os mm C>mMON "O M F W O D D He M D* EMunMFM e DN MDMMouwMDCMmmmFM e *N 2 EmOMemMA MM Om22 OOC Op C p w en ed d ew eMn2 emommouC2m *d d aw M w e m w en m e e j ewMwmeQU ZwO,meM=*24 eomea
M ammi m* me m4 eemeu d2232Fmo OmW l

OMwM mM en nuM Om *we* Or m230 M mMmm pame eMOOmM E*voa , s> 20@DM4 2@CmMNm% O F eGme Sarm4ma mOFC24r ewme a w 2m*MOImMM M2 am en M 2Ce> 22 *

Ped MOCO m en F w e e d MwkmOMMmov }

*2 MM mM OWMmO24 O f e e O D2 2 M O ta m C F D i e e e m 2 rn 4 4 mep 2OMP2020m2 2mM gmo e F e wOnMOpmmumm4 e e F e m4M O Mm M v ve a 2 0 M e m po v 2 p F O M O st en n tn o e no t WC2M MOmEmr n*O e me % mM4m22 mOMM * - Mm20nMFG Em> c 4 e me in M O N M C 2 5 0 kmaG e me 2 me m m E m m eh m eMMM mM Nmm EWm2MmrdQ e e O 22@hn9M%OMMOO e e FMm0 En mm% 9 % > ZOCnMDOM M M LFCwH 4020 240 M res e m e m M O M M 002 e Q COMO SOC * *mmO 2MmMm2Mr#MFemM e eOC* OmMe we OmwnmEme eOCe e m m en Z E > C F 7 p S on 2mmUM20MW24wOM O 4 %2 e 2 V 2 m inm2MO eN2 . @ @ 2 O fn > SFMOMW *MgM 22 2n m29 MOMO e we OMO > w > m en g e O e ee MC

mmM ZO 1 04 CmMODO4WD CO2m2 2 e me 22CmM2M n 2 p M in g 2 e sn o Owe momWMUmm l 9 WOD4M 2OFDMM @ e me 2MMm2W2MM M en s b e m* no envm4M C w AAFFMe 20m CMrnwnEOM e e em 4 rp O 4 M c i sn o DN
e CMem en 2 M NZ mHwM UC 9 M F 2 98 2 M MO % e @F F MH Cm>>FG mM% e er 22Ze m4>O2M Fu

#Fn OMWOm>Mg enOFeed e som rn Z M 4 ro m w 4 0 MFMd e # ** O U en WC2 T p a. DD M22denmO2WDOD m ee e ne e a 24mM m m M Men E M O O m w e me2 mmmMM2 4 M m 2 e si I M D2 MO DMM me MMM m% e C e in en M 2 D m M P O O LF%

4
2OrnZOwpp2 Mu i Pmmone wMO 4 en MC2mm e M oM m2mO2 OM 2 2%Fe e M oM > mmmmFmm eO mM ZwwmD>w 23 me eOpen DM M2DNDMM meM w DOp en PSE e 24 AOT ,

o DDmOOe 2 MFMMO9929 e M ee Ce M M O h Men 2 M M 2 M % e M oM dmM MmmMM U ps I am m O rte c OMm4CZ FmM e Dee p mMCOM OO2mCmn e O*e m m2eMm 2pm2 j 8 M22Cnm m utn m M M 4 0 C e 2e M >Wn O p p>FM e 2e m e en 4 M p p a p p t < .nmOMMwp 4MMMmM4 Omn e 3 0 mM2 an m 2 M mMFF302 e 60 em m OpmM20mp e M M en M O s EngC* w w m an d e ey m2pgm> TmnOF pm e ep Op2FmMOm4 Met JCC22M O% = M F M a rn > Z *WO4 M S M O m w M u ta m 2 E d m an eWO O M C404Mmmmm One I gr44m Cn m>MommMn een*D % MCm Fm 4 PO 3 ecoep pm eg r o t em24 8 M 2 H 2 8m p 2 0 ke 2 p W M M D OMe M40m*90nFmo e *Oe* MMMUM wMC V *4 O402GOMmU2@ Me 01 e9 e w m m en 2 0 ta r m o m e EO 3 ew e tn y N>me sen z a m O O n o d sm u c p > m en m e re ONZ e in 4 2 2 % MDmM 40 C *N2

M42Om2m 2Wmu

- 2 CmOMFFOMM eNCe nmwMD 22O2m12m2 edce e p en v u C w M M m a n 64 2 3E e m m N en c MM ODC DO2 e M20 MFDM M OFmMM p eO2 e FMm C2 meJew # 2M2Dporew KM CMCO2 ewwe MM 4F22 F*e ZeZM edee F4mMmFmo u , en2mmeO unmO9mOmEM emm. O m mmCmom 202 eeme m > 2mW mM MC a M W en M an d Om 04 M in M eum* 2M 4 M40memmMy epse 4M w en u n 3 822m -mMO M WO22MMgMMZM e e M 2 2 2 en Mm242M9m o e 20 M2mm mm en e Monm O u 2 2 en O 3 0 % M e e d m > m 2 4 2 F M v m 6 0 en e e Cwm900 324 % , e>N 22 h 2 M C m e m 5 2 en 2 eN e emmMmMZO O 2Cm oN e MFwF u mle 04 mmCMMm2 MD *d 2e e Om2mM D MEM44 mO ed 2 e wM pmM 3mp MM

M 8n d mM WWWMMMOD2 9 eeM e dC M 2HM2M 2h ME DWM e M O 2 2 O 2 'n O M as 4 6 0 2 2 M O ne E m o ** MOM 2M*O t eM e e 2Em20 2 MMPO > owM e m>>M mm 29 a m M en 2 M WM M m in mMVmE ewhe N U rn t 2 MmM2 410M edOe M4 FN4HH ft 4 # EgmmeF mppanM rn m ew e e map MM2 2 OmmDm ed e MMmCm DMM 4 1 mCOO M MO222Cnt >m e e om242mmmM >e mme e e 90 @ d N O M in 2 9%

4 F MON 2 MMMMM e e n@m m 2C Om e e 22@wmmPM Mu4 OMEw& m sn m M r O O M 9 2 M O e e @2m 3p Sen t M p2 e e mwen2P900 MM M 2mm4MM DMCOmkM mW e e 40 ECOOM M SO4m e e M me n m 2 m n en 1 en m m ZFMOm22 4MM m e me gm> 3M 3F2OmMO e me 402 MMm 2kT n in92M p 2 D en m D s in M F m * ** CMmmP O 00 SWOC e 4 e C MOOOOOM M M b mommmmM maOn>>

O *n e O m > O rn 4 2 m w E ZF eOmeO pmO2 mt i en F .

M E 2 rn o m m4Dnem pmW euzee Mme mm M De e a eN2 ee Z O sn 4 EQ4 J OMo&sMmO9p NOC2MMmM e%4 e e mmmO mMmF M M *%4

8 DMC 2 M M e rn 29 @ 14 FM m2FMmMFG ed ee a49214mWMmm M ed ee F O 2 m en a M 2 2 e2 9 n w C 4 em p > O eMMp POME emO ew 43pm M 2 4 en a M2 ewoew 4 wm mom *4 0 DmM 242m u m en n 2 2 2 e%> e 8 M 20 D mm2 20 e%p e 8 edme agr M m in 2 4 MM COOwW% O eWH ee D MOX FO M eNM eG M 2FObe > SMM 2d an 'O O mF M ecmed 1 C on e M M eemed MMmM 3 WMOEM M NM m M fn m m O O MOO M 3 sn M '

4 w2 e 2 2M M m m 2 2 l M *8 4 O sn l l 1 l l < l l A 6 J l FCRM 237 lea 5C51 OATA 04-13-91 - t 1 0*************e== ===e*****e***************************************** 00CKCT YEA: LER NUMBE2 REVISION OCS NUX9ER NSIC EVENT DATE >1 334 1909 008 0 8910060216 215520 09/01/89 e................ **............e***** ........e**e.**e .**** *****e " r ASSTRACT POWER LEVEL - 000%. ON 9/1/39, UNIT 1 WAS PERFORMING A PLANNED l' 1 SHUTDOWN IN PREPARATION FOR THE1R SEVENTH REFUELING OUTAGE. THE ' REACTOR WAS SU5 CRITICAL WITH CONTROL R3D INSERTION IN PROGRESS. At t t 2210 HOURS, THE "A" MAIN FEEDWATER REGULATING VALVE, WHICH HAD BEEN CLOSED EARLIER DURING THE SHUTCOWN, WAS 055ERVED TO BE OPEN. DESPITE , I' OPERATOR ACTIONS (SHUTTING DOWN THE MAIN FEEDWATER PUMP), AT 2211 HOUR 5, "A" $ TEAM GENERATOR LEVEL INCREA$10 TO ITS HIGH-HIGH LEVEL SETPOINT, INITIATING AN AUTOMATIC FEEDWATER ISOLATION (FWI). L1 OPERATORS VERIFIED ALL REQUIRED FWI VALVES CLOSED. AT 2213 HOURS, A REACTOR TRIP WAS INITIATE 0 DUE TO SOURCE RANGE HIGH FLUE. OPERATORS b-4 HAD NOT INSTALLE0 THE SOURCE RANGE INSTRUMENT POWER FU$55 ON CHANNEL N32 DURING THE SHUTDOWN AS THE DETECTOR WAS OUT OF SERVICE DUE TO AN D4 EXPIRE 3 CALIBRATION. WHEN INTERMEDIATE RANGE Flux OECREASED TO THE o0!NT WHERE THE SOURCE RANGES AUTOMATICALLY ENERGIZED, CHANNEL N32 INITIATED A TRIP SIGNAL DUE TO LACK OF INSTRUMENT POWER. ALL CONTROL -t i RODS FULLY INSERTED IN RESPONSE TO THE TRIP $IGNAL. THERE WERE NOT SAFETY IMPLICATIONS DUE TO THIS EVENT. ALL REQUIRED SAFETY FUNCTIONS , , ACTUATED A5 DESIGNED. ' 1 THIS SESSION HAS USED 4.93 SECONDS OF CPU TIME AND HAS BEEN ACTIVE FOR 2'.5.58 SECONDS 6 s THE ESTIMATED COST OF THE RUN 15 S 1.85 9 4 t 4 4 1 t t 6 i + w mwg ~ , m THIS SESSION 15 READY TO BEGIN. >-1

buy LER GROU7 SPUILIC2 15 t0W " ACTIVE" UITH 255 Leas tl

! b"I THE ' 255 KETS IN THE CURRENT ACTIVE GROUP WILL 8E SORTED i ,; * , ti CURRENT OPTIONS FOR LIST COMMAND g4 ;; N000CK NOCOMM NOMAT bel ;: ' NOWATCH NOREF kg N00EC g] A85 TRACT h0TP0 U9 NOFLOW .i b4 ~ YOU HAVE REQUESTE0 LISTING 255 RECORDS, ARE YOU SURET D4 i y F8 FORM . 1 LER SC55 OATA 0************************************************************04-18-91 ******** P4 DOCKET TEAR LER NUMBER REVISION OC5 NUMBER NSIC EVENT DATE

334 1939 018 0 9002020077 216653 12/27/

,, ******************************************************************89 ** A85 TRACT b4 POWER LEVEL - 0292. ON 12/27/89, AT 0001 HOURS, THE UNIT WAS IN POWER OPERATION (OPERATING MODE 1) AT 29% POWER, FOLLOWING THE INITIAL yq ;; STARTUP FROM TH5 REFUELING OUTAGE. THE 1A R00 ORIVE MOTOR GENERATOR (ROMG) SET WA5 IN OPERATION AND THE 18 ROMG SET WAS OUT OF SERVICE '* AWAITING POST MAINTENANCE TESTING. OUTAGE MAINTENANCE ACTIVITIES ON ;; THE 18 ROMG SET INCLUDED BEARING REPLACEMENT AND BREAKER. TRIP CHECK 5. A CAUTION TAG HAD BEEN PLACEO ON THE IS ROMG SET OUTPUT BREAKER 6 STATING THAT TRIP CHECKS WERE STILL REQUIRED. AT 0121 HOURS, A REACTOR TRIP OCCURRED ON POWER RANGE HIGH NEGATIVE RATE FLUX TRIP. , , THE OPERATORS STABILIZED THE PLANT IN HOT SHUTOOWN (OPERATING MODE 3) UTILIZING EMERGENCY OPERATING PROCEDURES E-0 AND E5-0.1. THE CAUSE '

FOR THE TRIP WAS DUE TO A TRIP OF THE 480 VOLT AC FEEDER BREAKER (145)

TO THE 14 ROMG SET 5. UPON A LOSS OF POWER TO THE 14 NOMG SET, THE CONTROL R005 DROPPE0 INTO THE CORE CAUSING A NEGATIVE RATE REACTOR t - ' TRIP. ' ELECTRICAL MAINTENANCE WAS REQUESTED TO INVESTIGATE THE CAUSE 0F THE FEEDER BREAKER TRIP. THERE WERE NO SAFETT IMPLICATIONS A5 A , RESULY OF THIS EVENT. THE UPDATE 0 FINAL SAFETT ANALYSIS REPORT 4 .. DISCUSSE5 SIMILAR EVENTS OF THIS TYPE IN SECTION 14.1.3 " ROD CLUSTER CONTROL ASSEMBLT MISALIGNMENT". 1 FORM 2 LER SC55 OATA 04-18-91 0******************************************************************** ,; DOCKET TEAR LER NUMBER REVISION OCS NURSER NSIC EVENT DATE 334 1990 007 0 9005030270 218021 03130/90 1 *****************************.****************a********************* ! AB5 TRACT

POWER LEVEL - 100I. 04 3130/90 AT 1541 HOURS, WITH THE UNIT IN POWER y OPERATION AT 1002 REACTOR POWER, ALARMS INDICATING A LOOP "C" STEAM

, FLOW # FEE 0 WATER FLOW MISMATCM, FOLLOWED ST 4 "C" Steam c Mroevne ftc) ....... . e. .. r..u, nonce:w, TH: VALVE W)ULO NOT RISPONO. AT ! 15%4 HOURS, A REACTOR TRIP ON "SG "C" LOW LEVEL L FEE 0 WATER FLOW LOW" p1 GCCURRED. CONTROL ROOM PERSONNEL ENTERED EMERGENCY OPERATING PROCEDURES, E-0 AND ES-0.1, To STABILIZE THE PLANT IN HOT STAND 8Y. i THE CAUSE PCR THE REACT 02 TRIP WAS THE CLOSU:E OF FCV-FW-498, IM og RESPONSE TO INSUFFICIENT INSTRUMENT AIR PRESSURE SUPPLYING THE VALVE POSITIONER. AIR PRES 5URE M AD DEGR ADED DUE TO MDISTURE IN THE FILTER l b4 ' IN THE INSTRUMENT AIR REGULATOR FOR THE VALVE POSITIONER. HIGH MOISTURE WAS PRESENT DUE TO THE INSTRUMENT AIR ORTER BEING i pq UNAVAILABLE. THE MOISTURE IN THE INSTRUMENT AIR SYSTEM MAS BEEN + REMOVED AND THE INSTRUMENT AIR ORYER HAS BEEN RETURNED TO SERVICE. ' 4 ' '; THERE WERE NO SAFETY IMPLICATIONS AS A RESULT OF THIS EVENT. THE PLANT SYSTEMS RESPONDED A5 DESIGNED (ALL RODS INSERTED, TUR8INE TRIP OCCURRING AND AUXILIARY FEEDWATEA INITIATING ON LOW SG LEVEL), WITH j De r THE EXCEPTION OF FCV-FW-498, TO PLACE THE PLANT IN HOT STAN08Y. THIS ! EVENT 15 8OUNDED 8V UFSAR, SECTION 14.1.8. 3, 1

FORM 3 LER SCSS DATA D"

0****************************************.*******************04-18-91 9 DOCKET YEAR LER NUMBER REVISION DCS MUM 8ER NSIC EVENT DATE be 335 1989 003 0 8903220241 215024 ......e*..........................................................89 07/17/ ABSTRACT 1 I' POWER LEVEL - 004%. ON 7/17/89, ST. LUCIE UNIT 1 WAS IN MODE 2 AND !

e. PERFORMTNG A TUR8INE STARTUP. STEAM GENERATOR (SG) LEVELS WERE MAINTAIPED WITH THE 1A AND 18 AURILIARY FEEDWATER ( AFW) PUMPS. AT p1 0254, ThE IS MAIN FEE 0 WATER (HFW) PUMP WAS STARTED, AFW WAS SECURED

;, AND THE TUR8INE WAS ROLLED SHORTLY THEREAFTER SG LEVELS WERE OBSERVED ,, TO SE OECREASING, AND AFW WAS RESTORED. THE UNIT AUTOMATICALLY k TRIPPED AT 0300 ON LOW SG LEVEL DUE TO MI5 MATCHES 8ETWEEN STEAM LOADS AND FEED FLOW RATES. THE AUDISLE ANNUNCIATOR FOR THE LOW SG LEVELS h8 PRE-TRIP ALARMS FAILED BEFORE THE TRIP. STANDARD POST TRIP ACTIONS WERE PERFORMED AND THE UNIT WAS STABILIZED IN MODE 3. MFW FLOW TO THE ' ' se SGS WA5 P2*wENTED SECAUSE THE MFW 8 LOCK VALVES HAD NOT 8EEN OPENED. PROCEDURES WILL SE CHANGE 0 TO VERIFY THEIR PROPER LINE UP BEFORE , STARTING THE TUR8INE. AFFECTED AUDIBLE ANNUNCI ATORS WERE RETURNED TO SERVICE. A COGNITIVE PERSONNEL ERROR AMONG THE UTILITY LICENSED ' OPERATORS LED TO THE AUTOMATIC REACTOR TRIP.

1

,, FORM 4 LER SC55 DATA 04-18-91 1 0******************************************************************** DOCKET TEAR LER NUNSER REVISION DCS NUM8ER NSIC EVENT DATE 335 1989 005 0 8910180338 215565 09/13/89 ... *......e** ...................**................................ t

A85744CT i

, POWER LEVEL - 095X. ON SEPTEMBER 13, 1989, AT 1409, WHILE IN MODE 1 AT 981 POWER, UNIT 1 TRIPPED 04 LOSS OF LOAD. PRIOR TO THE TRIP, THERE WERE TW3 NUCLEAR PLANT WDRE ORDERS (NPWO) OEING WORKED CONCURRENTLT ON I 8 THE REACTOR PLANT PROTECTION SYSTEM (RPS). ONE OF THE NPWO'S INVOLVED REMOVING TCS-1 FOR MAINTENANCE WHILE THE OTHER NPWO WAS FOR

REPLACING A "C" CHANNEL POWER SUSPLY IN THE RPS CASINET.' IN ORDER TO REPLACE THE POWER SUPPLT, BREARER CS-3 INSIDE THE RPS CA8INET WAS

, OPENED.- WHEN THIS WAS DONE, TCS-7 AND TCB-3 OPENED AND WITH TCS-1 ' ALREADY OPEN, A TUR8INE AND REACTOR TRIP OCCURRED. THE ROOT CAU5E OF THE REACTOR TRIP WAS DETERMINED TO 8E AN INADEQUATE NPWO WORK ,- DESCRIPTION, IMADEQUATE COMMUNICATIONS TO OPERATIONS SY 18C AND THE PROCEDURE FOR UNIT RELIABILITT-SENSITIVE SYSTEMS DID NOT CLEARLY SHOW THAT ITS USE WAS REQUIRED. CORRECTIVE ACTIONS REVIEW / REVISE SENSITIVE g SYSTEMS PR3CEDURES, WRITE STANDARD WORE DESCRIPTIONS TO BE ATTACHED , 70,NPWO',5 FOR RPS POWER SUPPLY REPLACEMENTS, ADD CAUTION STATEMENTS TO w -w- w iw .- e 3w.- m7 --g-9*W + ' - ' * * --PT"'-- $1T7 -"-P'-* W"-'--** M &M+ *"'94'-'* w'N D ers %' e mW '91 4P - ' * **C r'T'" ' ' * " - 1 ' h- "N'-"2 1" 4 T pq FORM 5 LER SC55 DATA 0************************************************************04-18-91 ******** g, DOCKET TEA 2 LER NUMBER REVISION DCS EUKBER NSIC EVENT DATE l: 335 1990 007 0 9006260003 218762 he .................................................................. 0 05/24/9 , A8STRACT pq POWER LEVEL - 0912. ON 5/24/90 ST. LUCIE UNIT 1 WA$ IN MODE 1 AT 91% POWER PERFORMING MAIN TURBINE MAINTENANCE ON A HYDRAULIC CONTROL VALVE ' Ed i- (MOOG) IN THE DIGITAL ELECTRO-HYDRAULIC (DEM) CONTROL SYSTEM 04 THE #3 GOVERNOR VALVE. WHEN DEH FLUID WAS RE-ESTASLISHED TO THE VALVE, AN I be EXCESSIVE UNISOLABLE LEAR DEVELOPED. THE ASSISTANT NUCLEAR PLANT SUPERVISOR INSTRUCTED THE REACTOR CONTROL OPERATOR $ TO MANUALLY TRIP THE REACTOR AND TURBINE AT 0452. TME STANDARD POST TRIP ACTIONS WERE y3 PERFORMED AND THE UNIT WAS STABILI!ED IN MODE 3, HOT STAND 8T. THE INITIATOR OF THIS EVENT WAS THE SEVERE LEAKAGE OF DEH FLUID FROM THE U" ASSOCIATED MOOG VALVE OF THE #3 GOVERNOR VALVE. AN INVESTIGATION REVEALED THE 0-RINGS INSIDE THE BASE OF THE MOOG VALVE WHICH SEAL THIS , VALVE TO THE 83 GOVERNOR VALVE MOUNTING PLATE HAD RUPTURED. THE De CAUSE OF THE RUPTURE WAS DUE TO THE INSTALLATION OF IMPROPERLY SIZED 0-RINGS. THE PARTS LIST USED TO OBTAIN REPLACEMENT 0-RINGS FOR g, MAINTENANCE HAD THE INCORRECT PART NUMs2R LISTED FOR THESE 0-RINGS. THE ROOT CAUSE FOR THIS EVENT IS INADEQUATE TECH MANUALS AND ORAWINGS #4 FOR THE DEH SYSTEM WHICH LACK TME PART NUMBERS FOR REPLACEMENT PARTS. AN OFFICIAL PARTS LIST WAS REGuiSTED FROM THE VENDOR FOR ALL 0-RINGS USED ON THE TURSINE/ GENERATOR $ET, AS WELL AS ALL OTHER SUPPORTING p1 WESTINGHOUSE SYSTEMS. 1 FORM 6 LER $C55 DATA 04-18-91 6 0******************************************************************** to DOCKET TEAR LER NUMBER REVISION DC$ NUMBER NSIC EVENT DATE 336 1990 006 0 9006180193 215570 05/05/90 ABSTRACT POWER LEVEL - 1003. CN 5/5/90 AT 00:49 HOURS WITH THE UNIT IN MODE 1 AT 100% POWER, PLANT OPERATORS MANUALLY TRIPPED THE REACTOR DUE TO e DECRE ASING LEVELS IN THE #1 STEAM GENERATOR. THE SECONDART PLANT OPERATOR OBSERVED A RAPIOLT DECREASING LEVEL IN THE 81 STEAM , GENERATOR, WITH THE FEE 0 WATER REGULATING VALVE, 2-FW-51A, INDICATING FULL OPEN. WITH CONTROL OF MAIN FEED FLOW TO #1 STEAM GENERATOR APPARENTLY LOST AND SINCE STEAM GENERATOR LEVEL WAS DECREASING, THE UNIT WA$ MANUALLY TRIPPED. OPERATORS THEN PERFORMED E0P 2525, "5TANDARD POST TRIP ACTION 5" AND E0P 2526, " REACTOR TRIP REC 0 VERT". e , ALL EQUIPMENT RESPONDED A5 EXPECTED AND THE UNIT WAS PLACED IN 4 STABLE CONDITION. MAIN FEED FLOW TO THE 81 STEAM GENERATOR WAS , RESTORED AND CONTROLLED WITH THE FEEDWATER REGULATING STP455 VALVE, ,, 2-FW-414 THE 81 FEEDWATER REGULATING VALVE, 2-FW-51A, WAS ' DISA55EMSLED AND INSPECTED. CURING THE DISA$$EMBLY IT WAS DISCOVERED THAT THE STEN MAD SEPARATED FROM THE PLUG. THIS EVENT 15 BEING ,, REPORTED PURSUANT TO THE REQUIREMENTS OF PARAGRAPH 50.73(4)(2)(IV) DUE TO THE MANUAL REACTOR TRIP ON DECREASING STEAM GENERATOR LEVEL. SIMILAR LER's: 37-009. 1 FORM 7 LER SCSS DATA 04-18-91 I 0**************************** ..*******************************.***** g DOCKET TEAR LER NUMBER REVISION DC5 NUMBER NSIC EVENT DATE t 336 1990 012 0 9010040140 219657 05/27/90 4 , -. . . - - . , , , ., ., -e , y q v m._ . ..... .s..se ,eer, 4*:s ,3163, WHILc PERFORMI?G SURVEILLANCE I t PR3CEDURE SP 2601D " POWER RANSE SAFETT CHANNEL AN3 DELTA T POWER P4 CHANNEL CALIBR&T!3N" WITH 'A' RPS CHANNEL INOPERASLE (TRIPPED), THE l i PLANT OPERATOR DID NOT SYP455 THE SECOND CHANNEL BEFORE TESTING IT, " WHICH CAUSED A4 AUTOMATIC PLANT TRIP. OPERAT025 THEN PERFORMED ,. EMERGENCY OPERATING PROCEDURE E0P 2525. ALL EQUIPMENT RESPONDED AS b8 EXPECTED AND THE UNIT WAS PLACED IN A STABLE CONDITION. THE CAUSE OF , THE EVENT WAS OPERATOR ERROR IN Thai THE OPERATOR FAILED TO PERFORM ! g THE PRESCRIBED STEPS WHEN INITIATING THE DAILY POWER RANGE SAFETY pq CHANNEL AND DELT4 Y POWER CHANNEL CALIBR4 TION. THE LICENSED REACTOR OPERATOR INVOLVED HAS 8EEN INSTRUCTED IN THE PROPER SEQUENCE OF BYPASS 4 SWITCH OPERATIONS AND THE ENTIPE OPERATIONS DEPARTMENT HAS DISCUSSED THE IMPORTANCE OF EVALUATING PLANT CONDITIONS AND SELF-VERIFICATION AT SUBSEQUENT DEPARTMENT MEETINGS. IN ADDITION, PROCEDURE SP 26010 HAS be ;. BEEN REVISED TO INCORPORATE A SEPARATE SECTION ON PERFORMING THE CALIBR4TIONS WITH ONE RPS CHANNEL INOPERA8LE, INCLUDING A SIGNATURE gg REQUIREMENT FOR VERIFICATION THAT THE BTPASS LIGHTS ARE ENERGIZED ON THE CHANNEL TO BE TESTED. THIS EVENT IS BEING REPORTED PUR5UANT TO be THE REQUIREMENT 5 OF PARAGRAPH 50.73(4)(2)(IV), REPORTING ANY EVENT OR CONDITION THAT RESULTED IN MANUAL OR AUTOMATIC ACTUATION OF ANY ENGINEERED SAFETY FEATURE SYSTEM. We 1 g, FORM 8 LER SCSS DATA 0************************************************************04-13-91 ******** 8' DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 338 1989 005 0 8903290172 213377 02/25/S9 Pt ABSTRACT ,, POWER LEVEL - 0762. AT 1407 HOURS ON 2125/89, UNIT 1 AUTOMATICALLY ' TRIPPED FROM 761 POWER (MODE 1). THE INITIATING SIGNAL FOR THE , REACTOR TRIP W45 "C" STEAM GENERATOR STEAM FLOW GREATER THAN FEE 0 WATER ea FLOW MISM4TCH COINCIDENT WITH A LOW STEAM GENERATOR LEVEL. THE STEAM FLOW GREATER THAN FEE 0W4TER FLOW MISMATCH WAS CAUSED 87 THE CLOSURE

g. OF THE "C" MAIN FEEOW4TER REGULATING VALVE ON THE LOSS OF CONTROL AIR.

THIS EVENT IS REPORTASLE PUR5UANT TO 10CFR$0.73(4)(2)(IV). FOLLOWING THE REACTOR TRIP, INDICATIONS OF PRIMARY TO SECONDARY LEAKAGE WERE DETECTED. "C" STEAM GENERATOR WAS IDENTIFIED AS THE SOURCE OF THE LE4EAGE. THE EMERGENCY PLAN W45 ENTERED AND AN ALERT 8 WAS DECLARED. THE PLANT WAS SUBSEQUENTLY COOLED DOWN AND DEPRES5URIZED TO MODE 5 AND THE ALERT W45 TERMINATED. DURING THE , C00LDOWN, A PR38LEM WAS ENCOUNTERED PLACING THE RESIOUAL HEAT REMOVAL SYSTEM IN SERVICE DUE TO A F4ULTY AUTO-CLOSURE RELAY ON THE RHR SUCTION ISOLATION VALVE (1-RH-MOV-1701). THIS IS REPORTABLE PURSUANT TO 10 CFR50.73(A)(2)(v). FOLLOWING THE EVENT, CALCULATIONS WERE MADE THAT IMOICATED THAT PRIMARY THE SECONDARY LERK4GE WAS 74 GPM. THIS I5 ' s REPORT 48LE PUR5uaNT TO 10CFR50.73(A)(2)(I)(A). THIS EVENT POSED NO SIGNIFICANT SAFETY IMPLICATIONS SECAUSE SAFETV EQUIPMENT FUNCTIONED AS ., DESIGNED. RADIOLOGICAL RELEASES WERE WELL SELOW TECH SPEC LIMITS. 1 '- FORM 9 LER SCSS DATA 04-18-91 0******************************************************************** 00CRET YEAR LER NUMBER REv!5 ION DCS NUMBER NSIC EVENT DATE 338 1989 014 0 8905160218 214996 07/19/89 ...eeeeeeeeee.......................................e**............. 485 TRACT ' POWER LEVEL - 0901. AT 1740 HOURS, ON 7/19/ 8P, UNIT 1 EXPERIENCED AN AUTOMATIC REACTOR TRIP FROM 90% POWER. THE REACTOR TRIP SIGNAL t OCCURRED OUE TO A LOSS OF ELECTRO HYDR 4ULIC CONTROL (EHC) SYSTEM g: PRES $URE WHICH GENERATED 4 TUR8INE TRIP AND A SU65EQUENT REACTOR TRIP . SINCE POWER WAS GREATER THAN 102. THIS EVENT IS REPORTA8t* *URSuaNT .... . 4. . . . ,. . .. .o=-6.ec e=*r sul04010 UPERATED UGLUE (500) 20-ET. THE LOSS 05 EHC SYSTEM PRESSURE RESULTE3 IN THE CLOSURE OF THE pq TUR8INE STOP UALVE5 WM3CM GENERATED THE TUQG3NE TREP SIGNALo A QEACTOR TRIP SIGNAL WQS AUTOMOTICALLY 2NITIATED, AS DESIGOEO, SINCE g4 POWER CAS GRECTER THAN 103. NO SAFETT INJECTION SIGNAL (MANUAL OR q AUTOMATIC) W45 INITIATED AS REQUIRED OURING THIS EVENT. UNIT 1 W45 kW PLACED ON LINE at 2136 HOURS ON 7/20/89 A ROOT CAUSE EVALU4 TION 15 BEING PERFORMED TO DETERMINE THE ROOT CAUSE OF THE TURSINE TRIP . gi SOLENOID OPERATED VALVE 20-ET 0-RING FAILURE. RECOMMENDATIONS pq RESULTING FROM THE ROOT CAUSE EVALU4 TION ON THE 0-RING FAILURE WILL BE EVALUATED AND IMPLEMENTED AS NECESSARY. THIS EVENT POSED NO # *g SIGNIFICANT SAFETY IMPLICATIONS SECAUSE SAFETY RELATED EQUIPMENT FUNCTIONED A5 OESIGNED AND KEY RE AC TOR PAR AMETERS ST ASILIZ E0 FO'. LOWING THE REACTOR TRIP. De q 1 gg FORM 10 LER SC55 DATA 04-18-91 0........................................................... ........ he DOCKET YEAR LER NUMBER REVISION OCS NUM8ER NSIC EVENT DATE 333 g939 017 0 9000000000 218824 12/05/89 >= A85 TRACT p,e POWER LEVEL - 007%. AT 2236 HOURS ON 12/5/89, UNIT 1 EXPERIENCED AN AUTOMATIC REACTOR TRIP FROM APPROXIMATELY 73 POWER. THE REACTOR TRIP OCCURRED OUE TO 4 LOW LOW LEVEL IN THE "B" STEAM GENERATOR (5/G). R4 q, THIS EVENT IS REPORTABLE PURSUANT TO 10CFR50.73(A)(2)(IV). PRIOR TO THE REACTOR TRIP, REACTOR POWER WAS SEING REOUCEO OUE TO ELECTRO 31 HTORAULIC CONTROL (EHC) SYSTEM PRESSURE TRANSIENTS. APPROXIMATELY 16 ,i MINUTES BEFORE THE REACTOR TRIP, THE MAIN GENERATOR OUTPUT BREAKER WAS

OPENED AND THE TUR81NE WAS MANUALLY REMOVED FROM SERVICE. THE EHC I SYSTEM PRESSURE TRANSIENT W45 CAUSED SY LE4 KING TUR81NE OVERSPEED g, PROTECTION CIRCUITRY (OPC) VALVES. THE OPC VALVES WERE REPLACED ANO k8 OTHER EHC SYSTEM MODIFICATIONS / REPLACEMENTS WERE IMPLEMENTED. AN EVENT INVESTIGATION 15 SEING PERFORMED TO DETERMINE ADDITIONAL EHC 3 g SYSTEM UPGRADES. UNIT 1 WAS PLACED ON LINE AT 0434 HOURS ON 12/21/89 THIS EVENT POSED NO SIGNIFICANT SAFETY IMPLICATIONS BECAUSE SAFETY

RELATED EQUIPMENT FUNCTIONED 45 EXPECTED AND KEY REACTOR PARAMETERS ,i STABILIZED FOLLOWING THE REACTOR TRIP. THE HEALTH AND SAFETY OF THE GENERAL PU8LIC WERE NOT AFFECTED. 6 1 ,. FORM 11 LER SC55 04TA 04-19-91 0....**.*.......**...*** *****.**.*...*********..*.*.*.****.**..***** ,3 00CKET YEAR LER NUM8ER REVISION OCS NUMSER NSIC EVENT DATE 338 1990 001 0 9032220365 216914 01/23/90 t 485 TRACT g POWER LEVEL - 1004. AT 1522 HOURS ON JANUARY 23, 1990, UNIT 1 , EXPERIENCED AN AUTOMATIC TRIP FROM 100 PERCENT POWER. THE INITIATING

SIGNAL FOR THE REACTOR TRIP WAS A LOW LEVEL IN THE "C" STEAM GENERATOR WITH A STEAM FLOW GREATER THAN FEE 0 WATER FLOW MI5 MATCH. THE MISMATCH q RESULTED FROM CLO5URE OF THE "C" MAIN FEEDWATER REGULATING VALVE.

THE CLO5URE WAS CAUSED ST A FAILED PRINTED CIRCUIT DRIVER CARD IN THE VALVE CONTROLLER. AFTER EVENT INVESTIGATION AND CORRECTIVE ACTION,

g. UNIT 1 W45 RETURNED TO CRITICAL ON JANUARY 24, 1990 at 0241 HOUR 5.

THIS EVENT CONSTITUTES AN AUTCMATIC ACTUATION OF THE REACTOR PROTECTION SYSTEM AND 15 REPORT ABLE PURSUANT TO 10 CFR 50.73 g (A)(2)(IV). NO SIGNIFICANT SAFETY CONSEQUENCES RESULTED FROM THE REACTOR TRIP 8ECAUSE PLANT SAFETY SYSTEMS FUNCTIONED A5 DESIGNE0. THE i REACTOR COOLANT SYSTEM PARAMETERS STABILIZED AT THEIR NORMAL POST g TRIP VALUES. THERE WAS NO RELEASE OF RADIDACTIVE MATERIALS CUE TO THE , TRIP. THE HEALTH AND SAFETY OF THE PUBLIC WERE NOT AFFfCTED AY aNY FORH 12 LER SCSS DATA 04-p1 0*******************=*****************************eeeeeeeeeeeeee.15-91 .... DOCKEY TEAR LER NUMBER REVISION DCS NUMSER N5IC EVENT DATE 339 1990 010 0 f012030131 220163 11 ,b4 qg e*eneeeeeeene.............................eeeeeeeeeeee.**eneee/02/90 eemene b4 ABSTRACT qg POWER LEVEL - 0095. AT 1741 HOURS, ON NOVEMBER 2, 1990, UNIT 2 pg EXPERIENCED AN AUTOMATIC REACTOR TRIP FROM APPROXIMATELY 9 PERCENT POWER. THE REACTOR TRIP WAS CAUSED 87 4 LOW LOW LEVEL IN "A" STEAM 'i, 4 GENERATOR. THE REACTOR TRIP OCCMRRED APPROXIMATELY EIGHT MINUTES FOLLOWING AN AUTOMATIC TRIP OF THE TURBINE FROM APPROXIMATELY 15 PERCENT POWER. THIS EVENT 15 REPORTABLE PUR3UANT To be ,g 10CFR50.73(A)(2)(IV). A FOUR HOUR REPORT WA5 MADE IN ACCORDANCE WITH 10CFR50.72(8)(2)(II). THE CAUSE OF TH! EVENT WAS PERSONNEL ERROR g, SINCE FAILURE TO RESET THE FEE 0 WATER REGULATING STPA55 WALVES AFTER .i. REINITIATION OF MAIN FEEDWATER RESULTED IN THE LOW LOW STEAM GENERATOR E" LEVEL AND THE SUB5EQUENT REACTOR TRIP. A CONTRIBUTING CAUSE OF THE EVENT WAS THAT A SPECIFIC PROCEDURE FOR RESPONDING TO A TURSINE TRIP ,; WITHOUT A REACTOR TRIP WAS NOT AVAILABLE. AS AN IMMEDIATE CORRECTIVE be ACTION, EMERGENCY PROCEDURE 2-E-0, REACTOR TRIP OR SAFETT INJECTION, WAS ENTERED AND THE PLANT WA5 STASILIZED. IN ADDITION, A ROOT CAUSE y , ,;. EVALUATION 15 SEING PERFORMED. FURTHER CORRECTIVE ACTIONS WILL BE IMPLEMENTED, AS REQUIRED, BASED ON THE RESULTS OF THE ROOT CAUSE EVALUATION. THIS EVENT POSED NO SIGNIFICANT SAFETY IMPLICATIONS 84 . SECAUSE SAFETT RELATED EQUIPMENT FUNCTIONED AS DESIGNED ANO KET PARAMETERS STABILIZEC FOLLOWING TME REACTOR TRIP. THERE WA5 ND p, RELEASE OF RADIDACTIVE MATER'*tt DUE TO THE REACTOR TRIP. THE HEALTH AND SAFETT OF THE PUBLIC W7dE NOT AFFECTED. I be FORM 13 LER SC55 047. **c 0************************************************************04-18-91 ******** DOCKET TEAR LER NUMBER 2EV!510N DCS NUMBER NSIC EVENT DATE e,, 341 1959 006 0 8904050121 213477 02/26159 a......................................... ......................... ,: ABSTRACT POWER L E V E L - 1001. ON FESRUARY 26, 1989, A TUR8INE TRIP AND REACTOR 6 5 CRAM OCCURRED DURING OPERATION OF A RESET PUSH 8UTTON FOR THE MAIN , TUR8INE MECHANICAL OVERSPEED TEST. THE OPERATOR HAD NOT RECEIVED THE ,, EXPECTED INDICATION AT ONE POINT IN THE TEST AND WANTED TO VERIFY THAT THE LOGIC WAS RESET. WHEN THE RESET PUSHSUTTON WAS DEPRESSED A , SECOND TIME, A TURBINE TRIP OCCURRED FOLLOWED ST A REACTOR SCRAM. THE CAUSE OF THE TUR31NE TRIP WAS A POOR DESIGN OF THE MAIN TUR8INE OVERSPEED TRIP LINEAGE, A5 RECOGNIZED SV THE MANUFACTURER. t , ADDITIDNALLY, THE LACK OF KNOWLEDGE OF THE CONSEQUENCES OF USING THIS RESET PUSHSUTTON OUT OF SEQUENCE CONTRIBUTED TO THE EV!NT. THE TRAINING DEPARTMENT HA5 INCORPORATED A DISCUSSION OF THE LINEAGE OPERATION INTO THE TURBINE CONTROLS LECTURE. THE OPERATOR HAS BEEN COUN5ELLED. ALSO, A CRITIQUE OF THIS EVENT IS BEING GIVEN IN LICENSED OPERATOR TRAINING. AN EVALUSTION OF THE NECE551TV FOR A DESIGN CHANGE TO IMPROVE THE HUMAN FACTOR $ CONSIDERATIONS OF THIS RESET WILL SE PERFORMED. 1 I FORM 14 LER 3C15 DATA 04-18-91 0******************************************************************** , DOCKET TEAR LER NUM8ER REVISIO4 DCS NUMBER M51C EVENT DATE 341 1989 007 0 8904140432 213586 03/07/89 , ................................ee.......ee...... eeeeeeeeeeeee ... , 4851RACT . . . . . . . . se u .sv=. dee via la vtcuC: TMt VIERaTION SY QEDUCING THE TURSINE LOAD WERE UNSUCCESSFUL. TMEREFORE, TME REACT 00 045 $ CRAMMED p1 AND THE TURSINE SHUT 00WN IN ACCORDANCE WITH THE SITE PROCEDURES. ALL SYSTEMS RESPON3E0 PER THEIR DiSIGN DURIN6 THE SCOAQo THE TUCBINE CA5 ,q BALANCED OURIO6 THE SUBSEQUENT OUTAGE. DUDING THE FIRST REFUELING OUTAGE, PARTS OF THE TUR8INE WILL mE DISA55EM8 LEO AND/OR INSPECTED. 1 kg i FORM 15 LER SCSS DATA 04-r1 0***************************************************************18-91 ***** DOCKET YEAR LER NUMBER REVISION 0C5 NUMBER N51C EVENT DATE EG 341 1989 036 0 9001300245 216604 12/18/89 DO i ABSTRACT POWER LEVEL - 0201. ON 12/18/89, INSTRUMENT & CONTROLS (ILC) PERSONNEL go SIGNED 04 $URVEILLANCE 44.020.151, "N5555 - REACTOR WATER CLEANUP DIFFERENTIAL FLOW FUNCTIONAL TEST". AN IRC TECHNICIAN STATIONED IN ' U" THE CONTROL ROOM REQUESTED THE CONTROL ROOM CPERATOR TO RESET NUCLEAR 5TEf' SUPPLY 5HUTOFF SYSTEM (NS$55) DIVISION I AND II MAIN STEAM 150t1T104 WALVE (MSIV) LOGIC, 45 DIRECTED SV THE PROCEDURE. AT 2230 DO HOUR 2, THE CONTROL ROOM OPERATOR INADVERTENTLY DEPRESSED THE CLOSED PUSH 8UTTONS 04 THE A, 8 AND C INSCARD MSIV's AND A REACTOR SCRAM y RESULTED. THE IMMEDIATE ACTIONS OF THE REACTOR SCRAM A8 NORMAL OPERATING PROCEDURE (20.000.21) WERE PERFORMED AND THE PLANT WAS IN A 8' STABLE CONDITION AT 2240 HOURS. THE CAUSE OF THIS EVENT WA5 OPERATOR ERROR. NUCLEAR TRAINING IS REVIEWING RESETTING THE NUCLEAR STEAM SUPPLY SYSTEM ISOLATION LOGIC WITH CONTROL ROOM PERSONNEL. THE Pe OPERATOR INVOLVED WAS REMOVED FROM LICENSED DUTIES AND PARTICIPATED IN AN ACCELER ATED REQUALIFICATION TRAINING PROGRAM. A CRITIQUE OF THIS EVENT WILL BE ISSUED AS REQUIRED READING. D* FORM 16 LER SC55 DATA 04-18-91 0********************************************************************

g. DOCKET VEAR LER NUMBER REVISION DC5 NUMBER N5IC EVENT DATE 341 1989 038 1 9009050391 219392 12/23/89 A85 TRACT I POWER LEVEL - 0421. CN DECEMBER 23, 1989, SMOKE WAS DISCOVERED IN THE VICINITV 0F THE HIGH PRES 5URE TUR8INE. THE FIRE BRIGADE WAS

, DISPATCHED, AND REACTOR WAS MANUALLY 5 CRAMMED. THE BRIGADE DISCOVERED THE LAGGING INSULATION PA05 WERE BURNING AND EXTINGUISHED THE FIRE. INVESTIGATION Md5 DETERMINED THAT THE INSULATION PADS WERE SO AKED WITH OIL AND THE TURBINE CA5ING MAD HEATED UP TO THE OIL's FLASH POINT. AN DIL $ PILL HAD OCCURRED SEVERAL WEEKS EARLIER DURING A FLUSH OF THE e TURBINE LUBE OIL SYSTEM DURING TUREINE REASSEMBLY. APPAAENTLY, THE SPILL WA5 NOT ADEQUATELY CLEANED UP. THE DAMAGED INSULATION PADS WERE , REPLACED AND AN INSPECTION F00 OTHER DAMAGE PERFORMED. 40 OTHER , DAMAGE WAS NOTED. AN ACCOUNTa5ILITY MEETING WAS HELD SETWEEN MANAGEMENT AND THE PERSONNEL INVOLVED IN THE MAINTENANCE ON THE TURSIN

E. PROCEDURE

S HAVE 8EEN REVISED TO ASSURE THAT OIL LEAK 5 ARE OETECTED/ CLEANED UP AND TO PRESCRISE APPROPRIATE INSPECTIONS. THIS t INCIDENT COUPLED WITH OTHER INCIDENT 5 WHICH OCCURRED DURING STARTUP FROM THE FIRST REFUELING OUTAGE LED TO FERMI 2 DEVELOPING AN

        ,       ACCOUNTABILITY ACTION PLAN. THE ACCOUNTABILITY ACTION PLAN WAS IMPLEMENTED ST SITE ORGANIZATIONS AND ! VALUATED SY CUALITT ASSURANCE AS COMMITTED TO IN DETROIT EDISON LETTER NRC-89-0300, DATED DECEMBER
   !            26, 1989.

1 e g FORM 17. LER SCSS DATA 04-18-91

   ,        0********************************************************************

                                                            ~~
                          --........................**e...*.............................

p3 ABSTRACT POWER LEVEL - 1001. ON APRIL 10, 1990 AT 0156 HOU25, THE REACTOR 4 P30TECTION SYSTEM (RP5) MOTOR-GENERAT02 (MG) SET "A" TRIPPED OUE TO A p' COIL FAILURE IN THE K1 RELAY. THE APPROPRIATE ISOLATIONS AND ACTUATION 5 OCCURRED A5 A RESULT OF THIS. WHILE THE OPERATORS WERE bd VERIFYING PLANT RESPONSE AND PREPARINS TO RESTORE POWER, THE INBOARD MAIN STEAM ISOLATION WALVES (451WS) CLOSE3. THIS RESULTED IN A pq REACTOR SCRAM AND SUBSEQUENT TURBINE TRIP. THE RPS MG SET RELAT FAILED WHEN ITS COIL TERMINATION FAILEO. CLOSURE OF THE MSIVS IS ATTRIBUTED TO LOSS OF PNEUMATIC PRES 5URE QUE TO PNUEMATIC SUPPLY 150LATIONS. Id LEAKAGE WITHIN THE ISOLATED SYSTEM WAS TRACE 0 TO TWO SOURCES LEAKAGE

  >4                 THROUGH THE TRAVERSING IN-CORE PROSE (TIP) INDEXER BORES AND ADDITIONAL LEAKAGE THROUGH THE TIP PURGE SYSTEM WHICH HAD BEEN ADDED TO THE ORTWELL PNEUMATIC SYSTEM LOADS OURING THE FIRST REFUELING sg OUTAGE. A5 CORRECTIVE ACTION, THE FAILEO RELAY AND THE IDENTICAL

, RELAT ON MG SET "5" WERE REPLACEO. THE FAILED RELAY WAS FURTHER ( D* ANALYZED TO CONFIRM ITS FAILURE MECHANISM. FIVE OF THE SIX RELIEF VALVE 5 04 THE TIP PURGE SYSTEM WERE GAGGED. ALSO THE PRES 5URE bg REGULATOR OF THE PURGE ST5 TEM WAS SET LOWER TO ALLOW MORE THAN FIFTEEN MINUTES FOR OPERATORS TO RESTORE THE PNEUMATIC SUPPLY FOLLOWING ITS ISOLATION. De FORM 18 LER SCS$ DATA

  >8              0******** ***************************************************04-18-91   ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER M51C EVENT DATE pg 341 1990 011 0 9011090342 220062 10106/90

                    **enee   ***ee..  *********   *****.e********.e**e... *****...........e*.

A85 TRACT I POWER LEVEL - 001X. ON OCTOSER 6, 1990, FERMI 2 WAS IN STARTUP AND E8 HOLDING WHILE PLANT PERSONNEL WERE INVESTIGATING REACTOR WATER LEVEL IND'. CATION DISCREPANCIES. THE 015CREPANCY WAS NOTED OURING A CHANNEL

r. CHLCK PRIOR TO HEAT-UP. INSTRUMENTATION 8 CONTROLS TECHNICIANS L3MOUCTING TROUBLESHOOTING ON THE LEVEL CIFFERENCE NOTICE 0 AT THE REMOTE LOCATION THAT THE "B" REFERENCE LEG INSTRUMENTS INDICATED APPROEIMATELT 20 INCHES LOWER THAN THE EQUIVALENT RPS INSTRUMENTATION ASSOCIATED WITH "A" REFERENCE LEG AT APPROEIMATELY 1750 HOURS. THE

IRC TECHNICIANS WERE IN THE PROCESS OF NOTIFTING THE CONTROL ROOM WHEN AT 1754 HOURS, A REACTOR SCRAM 04 LOW REACTOR WATER LEVEL OCCURRED.

  ,                  THE CAUSE OF THIS EVENT WAS ATTRIBUTED TO AIR VOIOS IN THE "A" REFERENCE LEG. INITIAL TROUSLESH00 TING WAS PERFORME0 AS CLOSE TO PRE-SCRAM CON 0!TIONS A5 POSSIBLE AND, BASED ON THE RESULTS, THE PLANT WAS PLACED IN COLD SHUT 00WN AND THE ORTWELL WAS DEINERTED FOR FURTHER INVESTIGATION FOLLOWING THE REACTOR SCRAM.          THE SOURCES OF LEVEL e       ,          INDICATION DIFFERENCE WERE INVESTIGATED AND CORRECTIVE ACTIONS WERE FORMULATED. THE CORRECTIVE ACTIONS, THE ROOT CAUSE Ev4LUATION, AND
  ,                  THE STARTUP PLAN WERE REVIEWED ST THE ON-SITE SAFETT REVIEW ORGANIZATION PRIOR TO STARTUP.

1 FORM 19 LER SCSS DATA 04-15-91 0********* ********************************************************** DOCKET TEAR LER NUMBER REVISION OCS NUMSER N5IC EVENT DATE 346 1989 017 1 5912260001 216209 09/09/99

                    ....e*   e.*****e.a   **  *.*****..*****a**************************       ****

i ABSTRACT POWER LEVEL - 0503. ON St9tSo AT 1220 HOURS THE PLANT WAS OPERATING AT e 50X POWER WHEN 4 REACTOR TRIP SIGNAL WAS GENERATED. THE REACTOR

        ,            TRIPPED WHCN THE LOGIC FOR OVER TEMPERATURE DELTA TEMPERATURE (OT
  ,                  DELTA T) WAS SATI5FIED FROM A SPURIOUS SIGNAL. THE OtwFe %TCNas

e m

                  ...... .... .... - . . s.. swo 4:24 tt1L33 11-1. "h0 CLEAR INSTRUMENTATION, PCWER RANGE".          ThF TRIP WAS CAUSE3 SV RECEIPT OF A Pe                 SPURIOUS SIGNAL, APPARENTLY FROM CHANN!L 4 0F THE OT DELTA T CIRCUIT.

THE SIGNAL WAS CONSIDERED SPUDIOUS SECAUSE REACTOR COOLANT SYSTEM b4 CONDITIC35 WEGE ACCEPTABLE WHEN THE TRIP OCCURRED. A COMPREHENSIVE

         ;j       INVESTIGATION WAS CONOUCTED WITH NO EXACT CAUSE IDENTIFIED. THE b4                CONTINUED INVESTIGATION DID IDENTIFY CONDITIONS WHICH COULO HAVE CAUSED A SPURIOUS SIGNAL. THESE CONDITIONS INCLUDED INTERMITTENT FAILURE OF A COMPARATOR MODULE OR AN INTERMITTENT OPEN IN A pq                 IERMINATION CONNECTION WHICH GENERATE 3 A TRANSITORY SIGNAL LARGE ENOUGH TO CAUSE THE BISTABLE TO TRIP. A POTENTIAL CONTRIBUTING FACTOR y         WAS A LOWER OT DELTA Y SETPOINT THAN IN PREVIOUS OPERATING CYCLES.

IMMEDIATE CORRECTIVE ACTIONS PRIOR TO RETURN TO POWER INCLUDED b4 q; REPLACEMENT OF 3 CHANNEL 4 Of DELTA T MODULES (EVEN THOUGH NO INDICATION OF FAILURE EXISTED) AND PERFORMANCE OF PICTS FOR INPUTS INTO ALL 4 0F THE OT DELTA T CHANNEL 5. he 1 FORM 20 LER SC55 OATA km 0*************,**********************************************04-18-91 ******** q.

              DOCKET TEAR LER NUMBER REVISION DCS NUMBER                NSIC      EVENT DATE
>=                 344       1990        034          0      9009130189 219455        08/09/90 ABSTRACT POWER LEVEL - 1002. ON AUGUST 9,          1990, THE TROJAN NUCLkAR PLANT ht5 D'       ,4 OPERATING IN MODE 1 (POWER OPERATION) AT 100 PERCENT RATED THCRMAL POWER. THE GENERATOR LOA 0 WAS APPROMIMATELY 1135 MW. AT 1648 THE "B" p1 FEE 0 WATER PUMP TRIPPED ON INDICATION OF HIGH THRUST BEARING WEAR. IN i,      RESPONSE TO THE LOSS OF THE FEE 0 WATER PUMP, THE MAIN TUR8INE BEGAN AN

g. AUTOMATIC RUN8 ACE AND THE CONTROL ROOS BEGAN AUTOMATICALLY STEPPING IN I TO REQUCE REACTOR POWER. THE TUR81NE RUNSACK CONTINUED FOR ONE MINUTE, TWENTT SECONDSI THEN THE REACTOR AUTOMATICALLY TRIPPED ON k' LOW-LOW LEVEL IN THE "0" STEAM GENERATOR. FOLLOWING THE REACTOR TRIP, AUTOMATIC FEE 0 WATER ISOLATION AND AURILIARY FEE 0 WATER INITIATION

g. OCCURRED. THE "6" FEE 0 WATER PUMP TRIP WAS INITIATED BV PROTECTIVE INSTRUMENTATION WHICH RECEIVED INDICATION OF EXCESSIVE THRUST SEARING WEAR IN THE PUMP's TUR81NE ORIVER. THE EXCESSIVE BEARING WEAR

[* INDICATION WAS THE RESULT OF INCORRECTLY SET INSTRUMENTATION, NOT ACTUAL WEAR. THE THRUST BEARING WEAR INDICATING INSTRUMENT 5 WERE e RECALISRATED AND THE PUMP WAS REASSEMSLED. THE PLANT WAS RETURNED TO POWER OPERA'*-JN ON AUGUST 11, 1990. THIS EVENT HAD NO EFFECT UPON

 ,               PUBLIC HEALTH AND SAFETY. THE REACTOR PROTECTIVE SYSTEM AND ENGINEERED SAFETY FEATURES ACTUATION SYSTEM FUNCTIONED AS REQUIRED.
'                THE PLANT RESPONDED AS EXPECTED TO THE TRIP.

1 i FORM 21 LER SC55 CATA 04-18-91 De*******************************************************************

,               DOCKET TEAR LER NUMBER REVISION OCS NUMSER                NSIC      EVENT DATE 346       1989        003          1      8903220199 213378        01/18/89
      ,         ABSTRACT POWER LEVEL - 1001. 04 1/18/89, AT 1344 HOURS, WI TH CONTROL ROD ORIVE (CRO) TRIP SREAEER TESTING IN PROGRESS, THE REACTOR TRIPPED FROM 100%
      ,          RATED THERMAL POWER (RTP).          THE TRIP WA5 INITIATED BY A SPURIQUS CR0 TRIP CONFIRM SIGNAL WHICH CAUSED THE INTEGR ATED CONTROL ST5 TEM (ICS)

TO INITIATE THE RAPIO FEE 0 WATER REDUCTION (RFR). THIS RESULTED IN

      ,          FEE 0 WATER FLOW SEING REQUCEO TO A800T 6% WHILE THE REACTOR WA5 STILL AT 1001. THIS CAUSED THE REACTOR COOLANT SYSTEM (RCS) PRES 5URE TO 9                INCREASE RAPIDLY UNTIL IT REACHED THE HIGH PRESSURE TRIP SETPOINT OF g;         2300 PSIG WHERE THE REACTOR PROTECTION SYSTEM (RPS) TRIPPED THE
 ,               REACTOR.        THE POST-TRIP RESPONSE 9F THE PLAMT WAS MOR*RL WITH No wA.ine

                                     ~
                                                                                                                . -~
              - - . . . w - w e. . e   4v. i. ine suAdvs WILL 3E RETURNED TO THE VENDOR FOR TROUBLESHOOTING.               IF ANYTHING OTHER THAN A RANDOM COMPONENT FAILURE 15 P1           DETERMINED, A REVISION TO THIS REPORT WILL BE 155UEO.                     THIS EVENT 15 REP 02 TABLE PER 10CFR50.73(A)(2)(IV) A5 AN AUTOMATIC ACTUATION OF RPS.

I b4 FORM 22 LER SC55 OATA 04-1 8-91

 >(        0.****..*...*..**.**.**........****.*.a.******.****..***.a...**. ****

i

  >q jj   00CKET TEAR LER NUM9ER REVISION DCS NUMBER                         NSIC      EVENT DATE 346       1989             005            0       8907050105 214461         05/30f89
             *******.********e******* ***** ***** **********************.e.******
  "d A85 TRACT POWER LEVEL - 100%. ON 5!30/89, DAVI5-8 ESSE EXPERIENCE 0 4 REACTOR TRIP DG , g      FROM 100% POWER.              THE EVENT BEGAN A5 A TRIP OF THE MAIN TUR8INE QUE TO LO55 0F CONDENSER WACUUM WHEN THE CIRCULATING WATER (CW) PUMP 5 2 gg          AND 4 TRIPPED ON HIGH PHASE O!FFERENTIAL CURRENT. THE POST-TRIP q;      RESPONSE OF THE PLANT WAS G000                    THE CAUSE OF THE HIGH OIFFERENTIAL U"          CURRENT WAS IN A FAILEO SPLICE IN ONE PHASE OF A 13.8KV FEEDER CABLE

+ WHICH WAS SENSED ST THE PROTECTIVE RELATING FOR THE CV PUMPS. THE

      ,;;     FAILED SPLICE WAS REMOVED FOR DETERMINATION OF CAUSE. THE FAILURE OF be          THE SPLICE WAS DETERMINED TO BE CAUSED ST IMPROPER INSTALLATION. WITH THE FAULTT LOAD CABLE ISOLATED FROM THE 13.8KV SUS, THE PLANT WAS gj ,i,      RESTARTED AND 8ROUGHT BACK ON LINE BT 1530 HOURS ON MAY 31, 1989.

Ed FORM

      ,j,                 23                        LER SC55 DATA                           04-18-91 0********************************************************************

kw 00CKET TEAR LER NUMBER REVISION OC5 NUM8ER N11C EVENT DATE

         .      346       1990             002            1       9007180022 218867         01/26/90
      ,,     ABSTRACT b8         POWER LEVEL - 073%. 04 1/26/90, AT 0846 HOURS, DURING PERFORMANCE OF SURVEILLANCE TEST 08-MI-03205, RCP CURRENT MONITOR INPUTS TO 5FRCS se         ACH1 AND RPS CHANNEL 1, THE STATICN EXPERIENCED A REACTOR TRIP FROM 73% FULL POWER.              PRIOR TO THE TRIP, THE STATION HAD SEEN OPERATING
            WITH 3 0F THE 4 RCPS RUNNING. PLANT RESPONSE TO THE TRIP WAS NORMAL WITH RET PARAMETERS REMAINING IN THE NORMAL POST-TRIP SAND. STEAM GENERATOR HEADER PRESSURE WAS INTENTIONALLY REDUCEO YO APPR02 970 6

PSIG TO 410 IN FULLY RESEATING TWO NAIN STEAM SAFETV VALVES 50LIOLT.

      ,       AFTER STABILIZATION OF THE PLANT, THE LETOOWN ISOLATION VALVE, MU28, g,         WOULO h0T REOPEN.               THE INABILITY TO RESTORE THE LETOOWN FLOW RESULTED IN SLOWER THAN NORMAL PLANT COOLDOWN AND MODE 5 WAS ACHIEVED OF 1/27/90, AT 0345 HOURS. IMMEDIATE NOTIFICATION WAS MADE PER 10CFR50.72(8)(2)(II) ON 1/26/90, AT 1007 HOURS.                    THE REACTOR TRIP IS

REPORTABLE AS AN LER PER 10CFR50.73(A)(2)(IV). AN ACTION PLAN

   *  ,       IMPLEMENTED TO DETERMINE THE CAUSE OF THE RCP CURRENT MONITOR CIRCUIT TRANSIENT CONCLUDED THAT THERE WERE 2 MAJOR FACTORS.                     THET WERE THE
   ..         INADEQUACT OF THE TEST SWITCHES TO PROVIDE CURRENT ISOLATION AND THE
      ,       USE OF A STANDARD ISOLATION PLUG WHICH RESULTS IN UNINTENDEO FORCES ON
  '           THE KNIFE SWITCH WHICH CARRIES THE STP455 CURRENT.                     THE CAUSE OF MU28 FAILURE WAS DETERMINED TO BE THERMAL SINDING OF THE DISC IN THE VALVE
      .i'     SEAT. THE VALVE WAS REPLACED WITH A FULLY FLERIBLE WEDGE GATE VALVE UNDER MWO 2-59-0053-00.

1 FORM 24 LER SC55 DATA 04-18-91 0********************************************************************

      ,      DOCKET TEAR LER NUMSER REVISION DC5 NUMBER                         N5IC      EVENT DATE 346        1990             016            0       9101180056 220711         12/13190
             *************.******.***********.*********.e.**************.***.e***

I'

   ,         ABSTRACT

                                                                                                     . ~
                    . . . . . . - . ... . .. st...wa     sveeti1GN ht5TtH (RFS) CHAhMEL 1 p,

REACTOR TRIP M3DULE LOSIC AND REACTOR TRID BREAKER S WAS IN Po3GRESS WHEN THE TRIP OCCURRE3. REACTOR TRIP 3REAKER 8 H AD B EEN PREVIOUSLY TRIPPED AS PART OF THE RPS FUNCTIONAL TEST. SEVEN OF EIGHT CONTROL

    "            RODS I*4 ROD GROU7 7 DROPPED INTO THE CORE CAUSING REACTOR POWER TO INITIALLY DECREASE TO APPR0XIMATELY 45 PERCENT.                RCS PRESSURE AND kW               TEMPERATURE DECREASED DUE TO A RESULTING MI5 HATCH 8ETWEEN REACTOR POWER AND FEE 0 WATER FLOW.            RPS SUSSEQUENTLY TRIPPED THE REACTOR ON LOW RCS PRES 5URE.        PLANT RESPONSE TO THE REACTOR TRIP WAS NORMAL WITH KET pq              PARAMETERS REMAINING IN THE NORMAL POST-TRIP BAND. THE APPARENT CAUSE OF THE GROUP ROD DROP WAS A DEGRADATION IN THE "A" SIDE POWER E8               TRAIN OF THE CONTROL ROD ORIVE (CRD) ST! TEM SUCH THAT WITH THE "B" SIDE REACTOR TRIP 8REAKER OPEN, THE CURRENT SUPPLIED TO THE CR0 MOTOR km STATORS WAS NOT SUFFICIENT TO SUPPORT MOTION OF THE GROUP 7 CONTROL
         ,       RODS.

AN ACTION PLAN WAS DEVELOPED TO IDENTIFT THE SPECIFIC CAUSE. ACTION PLAN IMPLEMENTATION 15 CURRENTLT IN PROGRESS. IMMEDIATE be NOTIFICATION WAS MADE PER 10CFR50.72(8)(2)(II) ON DECEMBER 13, 1990, AT 0944 HOURS. THE REACTOR TRIP IS BEING REPORTED PURSUANT TO THE he REQUIREMENT S OF 10CFR50.73(A)(2)(IV). A REVISION TO THIS LER WILL BE SUSMITTED WHEN THE ROOT CAU5E IS DETERMINED. 1 kg FORM 25 LER SCSS DATA g, 0************************************************************04-13-91 ******** DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 348 1989 006 0 8912130377 216086 11/12/89 BL p3 A85 TRACT 3 POWER LEVEL - 034%. AT 1658 ON 11/12/$9, WITH THE UNIT OPER ATING AT

  ,,             34% POWER, A SAFETY INJECTION AND REACTOR TRIP WERE INITIATED DUE TO I               LOW STEAM LINE PRESSURE. TROUBLE 5 HOOTING OF AN OSCILLATION IN THE #3 TURBINE-GENERATOR GOVERNOR VALVE WAS IN PROGRESS. AS PART OF
  >e             TROUBLESHOOTING THIS PROBLEM, A CIRCUIT CARD THAT CONTROL 5 THE #3 GOVERNOR VALVE WA5 REPLACED WITH AN IMPROPERLY CONFIGURED CARD. THIS

g. CAUSED THE DIGITAL ELECTRO-HYORAULIC CONTROL (DEHC) SYSTEM TO OPEN ALL THREE OF THE OTHER GOVERNOR VALVES. THIS IN TURN RESULTED IN A I'

DECREASE IN STEAM LINE PRESSURE. THE RATE OF DECREASE CAUSED THE RATE SENSITIVE FEATURE OF THE LOW STEAM LINE PRESSURE SAFETT INJECTION AND REACTOR TRIP. A NOTIFICATION OF UNUSUAL EVENT WAS DECLARED AT 1658. I e THE NOTIFICATION OF UNUSUAL EVENT WAS TERMINATED AT 1900. THIS EVENT W AS C AJSED ST COSNITIVE PERSONNEL ERROR. THE CIRCUIT CARD THAT WAS

  ,              INSTALLED FOR THE 83 GOVERNOR VALVE HAD BEEN CONFIGURED FOR THE #4 GOVERNOR VALVE.           THE PERSON INVOLVED HAS BEEN COUNSELED. AS A FURTHER ENHANCEMENT, WHEN TROUBLESHOOTING THE DEHC SYSTEM DURING POWER
  '              OPERATION, THE GOVERNOR VALVE POSITION LIMITER WILL SE RESTRICTED TO LIMIT THE AMOUNT OF VALVE OPENING. THIS LER ALSO PROVIDES THE SPECIAL e
       ,         REPORT INFORMATION REQUIRED SY TECH SPECS 3.5.2.

FORM 26 LER SCSS DATA 04-18-91 0******************************************************************** DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 348 1990 005 0 9008089256 219041 07/20/90

                *****************************************<~*************************

ABSTRACT POWER LEVEL - 100%. AT 2218 ON 07-20-90, WITH THE UNIT OPERATING AT 1U0% POWER, THE REACT 0a WAS TRIPPED MANUALLY FOLLOWING THE AUTOMATIC

      ,          TRIP OF THE 1A STEAM GENERATOR FEED PUMP (SGFP). THE 14 SGFP TURSINE TRIPPED 04 OVERSPEE3 OUE TO THE FAILURE OF THE SPEED SENSOR CONVERTER.

THE REACTOR WAS TRIPPED MANUALLY IN ANTICIPATION OF AN AUTOMATIC g REACTOR TRIP. THE UNIT WAS STABILIZE 0 IN MODE 3 (HOT STAND 87). THE

             . UNIT RETURNED TO POWER OPERATION AT 0446 04 07-24-90.

                      .           ..                  6;s asia vata                                         04-13-91 0.*.**.**..*.e......***...e..*.e..****....**.******..ees...** .e***.e.

p3 00CEET YEAR LER NUMBER REVISION DCS NUM3ER N5IC EVENT DATE 353 1989 013 0 8912190009 216215 11/10/89 eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeen.ee

11 A8STRACT ] De POWER LEVEL - 098%. ON 11/10/59, a UNIT 2 REACTOR SCRAM OCCURRED

   ,       i FOLLOWING A MAIN TURSINE TRIP. ALL CONTROL RODS FULLY INSERTED A5

, pq DESIGNE0. THE.TUR8INE TRIP RESULTED FROM A UNIT 2 GENERATOR TRIP CAUSEO ST ACTUATION OF THE A-PH&$E OVERALL DIFFERENTIAL CURRENT RELAV.

    "O FOLLOWING THE SCRAM, REACTDR VESSEL PRESSURE INCREASED TO 1125 PSIG AND LEVEL DECREASED To APPROXIMATELY 0 INCHES INSTRUMENT LEVEL.

OPERATORS RESTORED NORMAL OPERATING VESSEL LEVEL AND PRES 5URE. THE 4 he . ; HIGH PRE 35URE COOLANT INJECTION (HPCI) AND REACTOR CORE ISOLATION i ' COOLING (RCIC) SYSTEM 5 RECEIVEC M0MENTARY INITIATION SIGNALS DUE TO g, SPIKING OF LEVEL TRANSMITTEPS. THE RCIC SYSTEM DIO NOT INITIATE AND l THE HPCI 575 TEM PARTIALLY INITIATED DUE TO THE SHORT DURATION OF THE , b" INITIATION $1GNALS. BOTH SYSTEMS WERE OPERABLE AND A8LE TO RESPOND TO A VALID INITIATION SIGNAL THROUGHOUT THE EVENT. BOTH SYSTEMS WERE SECURED AND ALL INITIATION LOGICS WERE RESET. AM " UNUSUAL EVENT"

     >=              EMERGENCY CLASSIFICATION WA5 DECLARED AND ALL APPROPRIATE NOTIPICATIONS WERE MADE. THE CAUSE OF THE OVERALL DIFFERENTIAL g,               CURRENT RELAT ACTUATION WAS A MISCALCULATION OF THE TRIP SETPOINT PERFORMED DURING THE ORIGINAL UNIT 2 DESIGN. THE CALCULATION WAS D4 CORRECTED AND THE AFFECTED RELAYS' SETPOINTS WERE ADJUSTED.                                 THE MISCALCULATION WAS VERIFIED To BE AN ISOLATED EVENT AND NO FURTHER ACTIONS TO PREVENT RECURRENCE ARE PLANNED.                      OPERATORS RESTARTED UNIT 2 p3              ON 11/14/89.

1 b' FORM 28 LER SC55 04TA 04-18-91 i

          .,      0...........................*........................................

ke DOCKET TEAR LER NUMSER REVISION DC5 NUM8ER NSIC EVENT DATE 353 1990 012 0 9008160188 219284 07/15/90 A85 TRACT I* POWER LEVEL - 0653. 04 JULY 15, 1990, 4 UNIT 2 REACTOR SCRAM OCCURRED FOLLOWING A MAIN TURSIME STOP VALVE (TSV) CLOSURE, A REACTOR e PROTECTION SYSTEM (RPS) ACTUATION. THE TSV CLOSURE RESULTED FROM A LOSS OF MAIN CONDENSER V4CUUM DUE TO 4 FAILEO LOW PRESSURE TURSINE , , SEARING CAVITY WASTE OIL ORAIN PIPE. REACTOR PRESSURE VESSEL (RPV) PRES $URE INCREASED 10 1005 PSIG AND LEVEL DECREASED FROM A NORMAL

     '               OPERATING LEVEL'0F +35 INCHES TO +6 INCHES INSTRUMENT LEVEL. PRIMARY CONTAINMENT AND REACTOR VESSEL ISOLATION CONTROL SYSTEM (PCRv!CS), AN ENGINEERED SAFETV FEATURE (ESP), ACTUATION SIGNALS WERE RECEIVED AND e               NO VALVE MOTION OCCURRED, AS EXPECTED, DUE TO PLANT CONDITIONS.

+ OPERATOR $ RESTORED RPV PRES 5URE AhD LEVEL TO NORMAL POST SCRAM

                   OPERATING LEVELS. AN "UNU$UAL EVENT" EMERGENCT CLAS$IFICATION WA5
         '           DECLARED AND ALL APPROPRIATE NOTIFICATIONS WERE MADE IN ACC0404NCE WITH 1DCFR50.72(4)(3) AND 10CFR50.72(8)(2)(II). THE PIPE F4ILURE W45 DETERMINED TO 8E CAUSE0 ST INSUFFICIENT PIPE SUPPORT RESULTING IN
         ,:          VISRATION INDUCED METAL FATIGUE. THE F4ILED PIPE WA5 REPLtCED AND THE REMAINING FIVE SIMILAR PIPES WERE INSPECTED. PIPE SUPP04t$ WERE ADDED TO ALL SIR LOW PRES 5URE TUR8tNE SEARING CAVITV WASTE OIL ORAIN
         ,           WIPES. NUCLEAR ENGINEERING AND SERVICES DEPARTMENT PERSONNEL ARE EVALUATING THE NEED FOR FURTHER CORRECTIVE ACTIONS 04 UNIT 2 AND ANY SIMILAR ACTIONS 04 UNIT 1.

1

     ,              FORM         29                   LER SCSS DATA                                         04-18-91 g

0*.************.......*...*..*.............****..*.**.*..*..**......*

.i   .

DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT OATS l' r - , ,,,~,,,v < -e,a, - v , , - -, ---.v-,- ,,-,v, , ,, , , v- r < - ,,,, , - ,-,-

                                                                                                                                    . . j ABSTRACT p3                    POWER LEVEL - 1004. ON SEPTEMBER 10, 1990, A UNIT 2 REACTOR PROTECTION SYSTEM (RPS) ACTUATION OCCU2 RED RESULTING FROM AN ACTUATION OF THE
      "                 PRIMART CONTAINMENT AND RE ACT02 VESSEL ISCLATION CONTROL SYSTEM q;            (PCRVICS) ENGINEERED SAFETY FEATURE (ESP) ACTUATION 5. A PtRv!CS GROUP D4                   I MAIN STEAM ISOLATION VALVE (MSIV) ISOLATION SIGNAL OCCURRED DUE TO A SPURIOUS TRIP SIGNAL ON THE 'O' CHANNEL OF THE STEAM LEAK OETECTION
  ,       q,            SYSTEM (SLOS) WHEN A TEMPERATURE SWITCH MOMENTARILY SPIKED WHEN AM pq                   OPERATOR REPOSITIONED THE SWITCH WHILE INSTRUMENTATION AND CONTROL

' TECHNICIAN 5 WERE SIMULTANEOU5LY TESTING THE 'A' CHANNEL OF THE SLDS. p". REACTOR PRES 5URE WESSEL (RPV) PRES 5URE INCREASED TO 1120 PSIG AND RPV L4 LEVEL DECREASED FROM A NORMAL OPERATING LEVEL OF +35 INCHES TO -48 INCHES INSTRUMENT LEVEL. ADDITIONAL PCRVICS ACTUATION SIGNALS WERE De q , RECEIVED AND APPROPRIATE VALVE AND DAMPER MOTION OCCURRED. THE i REACTOR CORE ISOL ATION COOLING (RCIC) SYSTEM RECEIVED AN INITIATION b2 SIGNAL 04 LOW LOW RPV LEVEL AND INJECTED INTO THE RPV. OPERATORS

           .; ,        RESTORED RPW PRESSURE AND LEVEL TO NORMAL POST SCRAM OPERATING LEVELS SY 0941 HOURS. THE CAUSE OF THE EVENT WAS A SPURIOUS TRIP SIGNAL FROM De A STEAM LEAK DETECTION SYSTEM TEMPERATURE SWITCH. THE ISOLATION
          .),           SIGNALS WERE RESET ST 0948 HOURS. THE TEMPERATURE SWITCH WA5 REPLACED be                  AND THE FAILURE MECHANISM OF THE TEMPERATURE SWITCH 15 UNDER INVESTIGATION.

I I pe it FORM 30 LER SC55 DATA 04-1 D4 ,, De**********=*********************************eae*****************8-91 *** h, ' 00CKET TEAR LER NUMBER REVISION DCS NUM8ER 354 1989 017 0 8910050397 215369 NSIC EVENT DATE 08/30/89

         ,          eeeeeeeeeeeeeeeeeeeeeeeeeeee...... eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee b'

485 TRACT I POWER LEVEL - 0823. ON 8/30189 AT 0112, A REACTOR SCRAM OCCURRED 45 A be RESULT OF A LOW REACTOR PRES 5URE VE5SEL (RPV) WATER LEVEL (+12.5") SIGNAL. TMF TRANSIENT WAS INITIATED SY THE PAILURE OP A 1/2" SOLDERED ' ! g, , CONNECTION WHERE THE SCRAM PILOT AIR LINE FROM CONTROL ROD DRIVE (CRO) HTOR8ULIC CONTROL UNIT (HCU) 34-59 JOINED A 1-1/2" AIR HEADER

                     INTERCONNECTING A 8ANK OF HCU'S ON THE SOUTH SIDE OF THE REACTOR
         ,             SUILDING. THIS FAILURE RESULTED IN THE RAPID DEPRE55URIZATION OF THE SCRAM AIR HEADER, AND IN RESPONSE, CONTROL RODS SEGAN TO INSERT. THE

ENSUING V010 COLLAP5E RESULTED IN AN UNRECOVERAELE LOW LEVEL TRANSIENT

         ,            AND THE SUB5EQUENT SCRAM. FAILURE ANALYSIS FOLLOWING THE SCRAM
    ,,                DETERMINED THE RO3T CAUSE OF THE INITIAL AIR LINE. FAILURE TO BE

, DEFICIENCIES IN INITIAL INSTALLATION OF THE AIR LINE 00 RING PLANT , , CONSTRUCTION. IMMEDIATE CORRECTIVE ACTIONS INCLUDE 0 RADIOGRAPHY OF 4 ' SIMILAR JOINTS PRIOR TO RESTARTING THE PLANT, LEAK CHECKING ALL I SOLDEREO CONNECTIONS AT ALL 185 SCRAM PILOT AIR HEADER RISERS, AND l PULL TESTING ALL 185 TEE JOINTS TO DEMONSTRATE THE A81LITV 0F THE l JOINTS TO WITH5TAND NORMAL OPERATING STRESSES. LONG TERM CORRECTIVE

    ,                 ACTIONS INCLUO! COMPLETION OF AN ONGOING TESTING PROGRAM FOR 4*            INSTRUMENT AIR PIPING PRIOR TO THE END OF THE CURRENT REFUELING OUTAGE.

4 . y FORM 31 LER SC55 OATA 04-18-91 . 0********************ee******e***************************************

        ,           DOCKET TEAR LER NUMBER REVISION DC5 NUMBER                        NSIC                  EVENT DATE 354   1989           025            0 9002080103 216683                            12/30/89 e...........      eeeeeeeeeeeeeeeeeeeeeeeeeeeeeee......             ee............eee I'

ABSTRACT

    ,                 POWER LEVEL - 1001. 04 12/30/S9 AT 1947, OURING THE PERFORM ANCE OF THE g;            T8WO SECTION OF THE MAIN TUR8INE MONTHLT FUNCTIONAL TEST PROCEOURE, A 1
    -                 TURSINE TRIP OCCURRED. THIS TRIP WAS FOLLOWED IMMEDIAT?LY 97 4
                -     .,_,                           _ - - , ,    ,     . - - ~ . _ _       _--,n                , , -         c.--

                . . . . . . .   ....o...,   42 tar:wses, WilH MINGR EXCEPTIONS 45 NOTED IN THE TEXT OF THIS REPORT. INVESTIG4 TION SJ9 SEQUENT TO THE EVENT DETERMINED y,             THAT A 78dC LIMIT SWITCH HAD MALFUNCTIONED OURING THE TEST, RESULTING IN THE TURBINE TRIP CIRCUITRY SENSING THAT THE TURBINE END THRUST BEARIKG MAO ACTUALLY FAILEO. WHILE THE INITIATIRG CAUSE OF THIS EVENT U" , g ,      WAS THE 78WO LIMIT SWITCH FAILURE, THE ROOT CAU5E OF THIS EVENT WA5 DM            THE INADEQUATE PRIORITIZATION OF A DESIGN CHANGE WHICH HAD BEEN PENDING SINCE 198!. THIS DESIGN CHANGE WOULO HAVE MOO!FIED THE T8WD
      .g.      CIRCUITRY TO PREVENT A TURBINE TRIP SIGNAL WHILE TESTING THE T8WD.

p3 ' CORRECTIVE ACTIONS INCLUDED IMPLEMENTING THIS DESIGN CHANGE, REPAIRING THE 78WO LIMIT SWITCH, REVIEWING ALL OTHER "5 CRAM REOUCTION" OESIGN E8 ' CHANGES FOR ADEQUATE PRIORITIZATION, REVIEWING OTHER TUR8INE TRIP TEST ' PROCEDURES FOR ADMINISTRATIVE ADEQUACT, AND INCORPORATING THIS EVENT INTO APPROPRIATE TRAINING PROGRAMS. DM ,, 1 b, FORM 32 LER SC55 OATA q- De***********************************************************04-18-91 ******** bM DOCKET TEAR LER NUMBER REVISION OCS NUMBER N5IC EVENT OATE 354 1990 001 0 9002130341 216700 he

     ,,     ************************************************************01/06/90     ********

A85 TRACT .

 ,, ,          POWER LEVEL - 097T. ON 1/6/90 at 0120, OURING PERFORMANCE OF A SURVEILLANCE PROCEDURE WHICH TESTS THE MAIN TURBINE COM81NED INTERMEDIATE VALVES (CIV), THE "A" M0ISTURE SEPARATOR EXPERIENCE 0 4 b* ,          HIGH LEVEL CONDITION. IN RESPONSE TO THIS HIGH LEVEL CONDITION, THE ASSOCIATED DUMP VALVE OPENE0, BUT NOT IN TIME TO PREVENT A TUR8INE y,

TRIP ON MOISTURE SEPARATOR HIGH LEVEL. IMMEDIATELY FOLLOWING THE TURBINE TRIP, THE REACTOR SCRAMMED ON 4 TURBINE CONTROL VALVE CLOSURE

 **            SIGNAL FROM THE REACTOR PROTECTION SYSTEM. ALL CONTROL R005 WERE I

VERIFIEC TO 8E INSERTED, AND PLANT 575TEMS RESPONDE0 AS EXPECTED, WITH

     ,         MINOR EXCEPTIONS A5 NOTED IN THE TEXT OF THIS REPORT. INVESTIGATION be SU65EQUENT TO THE SCRAM DETERMINED THAT MULTIPLE CAUSES COMBINED TO RESULT IN THE SCRAM - MOISTURE SEPARATOR LEVEL CONTROLLERS WHICH WERE p ,           NOT OPTIMALLY TUNED AND THE CTCLING OF A CIV PRIOR TO STABILIZATION OF MOISTURE SEPARATOR LEVEL AFTER CYCLING A PREVIOUS CIV. CORRECTIVE b             ACTIONS INCLUDED TUNING OF THE MOISTURE SEPARATOR ORAIN CONTROL
     ,         INSTRUMENTATION LOOPS, PROCEDURALLY INCREASING THE TIME SETWEEN CTCLING OF CIV's DURING THE SUBJECT SURVEILL ANCE, COUNSELLING THE 6

NUCLEAR CONTROL OPERATOR (NCO, R0 LICENSED) WHO PERFORMED THE

     ,         SURVEILLANCE, AND INCLUDING A REVIEW OF THE EVENT DURING THE NEXT
 ,            LICENSED OPEAATOR REQUALIFICATION CTCLE.

FORM 33 LER SC55 OATA Da***********************************************************04-18-91 ******** e g 00CEET TEAR LER NUM8ER REVISION 0C5 NUM8ER NSIC EVENT DATE 354 1990 003 0 9004260078 218025 03/19/90 485 TRACT POWER LEVEL - 0993. ON MARCH 19, 1990 AT 1850, A REACTOR SCRAM g OCCURRED ON LOW REACTOR VESSEL LEVEL (*12.5") WHEN ALL FEE 0 WATER PUMPS TRIPPED IN RESPONSE TO A LOS5 OF THE PRIMARY AND SECONDART CONDENSATE PUMPS. FOLLOWING THE SCRAM, REACTOR VESSEL LEVEL OtCREASED TO SELOW g: THE HIGH PRES 5URE COOLANT INJECTION (HPCI) AND REACTOR CORE !$0LATION CCOLING (RCIC) ST5TEMS INITIATION SETPOINT (VESSEL LEVEL 2, -38"). 8 THE HPCI AND RCIC SYSTEMS AUTOMATICALLY INITIATED AND WERE UTILIZED TO g, RESTORE WE5SEL INVENTORY TO NORMAL LEVEL. INVESTIGATION SU85EQUENT TO TME EVENT DETERMINED THAT THE PRIMARY AND SEC040 ART CONDENSATE PUMPS t- TRIPPED Im RESPONSE TO A P E R T UR S A T ION IN THE STATION ELECTRICAL ge ' DISTRIBUTION SYSTEM CAUSED ST AN ELECTRICAL FAULT IN OFF-SITE 500AV

 ,            TRANSMISSION LINE. THIS ELECTRICAL fault WAS CAUSED ST FLA%wnWre

                                                                                                        . =
                    ........ ....     .s  snu r.uLI, 4.W C U R 1 *4 ; IMIS PROCESS, 4 VOLTAGE REDUCTION WAS PRO

AGATE 3 THP1 UGH ALL STATION ELECTRICAL DISTRIBUTION p, SYSTEMS. INV85TIGATION AND TESTING 97 PSERG NUCLEAR ELECTRIC ENGINEERING DEPARTMENT CONCLUDED THAT THE VOLTAGE REDUCTION SENSED AT h4 THE 120VAC (CONTROL PO*JER) LEVEL WAS OF SUFFICIENT MAGNITUDE AND DURATION TO CAUSE THE TRIPPING OF THE CONDENSATE SYSTEM, WHICH 54 1 ULTIMATELY RESULTED IN THE TRIPPING OF THE OPERATING FEEDWATER PUMPS.

i pq FORM 34 LER SCSS DATA 0**********************************************************e.04-18-91 ........ E4 DOCKEY YEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE 354 1990 024 0 9012110224 220472 De ;.

               ........................................................... 11/04/90     ........

485 TRACT g, POWER LEVEL - 100%. ON 11/4/90 AT 0042, A REACTOR SCRAM OCCURRED DUE TO AVERAGE POWER RANGE MONITOR (APRM) FIXED NEUTRON FLUX UPSCALE (118 hm POWER), WHICH WAS INITIATED BY CLOSURE OF THE 3 IN80ARD MAIN STEAM ISOL4 TION VALVE (MSIV). THE 8 MSIV CLOSURE RESULTED FROM FAILEO kg FITTING ON A PRIMARY CONTAINMENT INSTRUMENT GAS (PCIG) SUPPLY LINE TO THE MSIV, CAUSING IT TO CLOSE. THE REACTOR PROTECTION SYSTEM FUNCTIONED NORMALLY TO SHUT 00WN THE REACTOR. SECOND SLRAM SIGNAL y,,, OCCURREO ON LOW LEVEL (12.5") IN THE REACTOR VESSEL WHEN A NUCLEAR CONTROL OPERATOR (NCO, RO LICENSED) PLACE 0 THE C FEEDPUMP IN THE POSITIONER MODE, AND DID NOT ADEQUATELY MONITOR REACTOR VESSEL WATER D8 LEVEL. ALSO, DURING THE COURSE OF RECOVERY FROM THE SCRAM, THE a CONDENSER MECHANICAL VACUUM PUMPS WERE STARTED TO MAINTAIN VACUUM IN p, THE MAIN CONDENSER DUE TO UNAVAILABILITY OF THE STEAM SEAL SYSTEM. THE SYSTEM ALIGNMENT RESULTED IN C040ENSER GAS 8EING RELEASED VIA THE

   '            SOUTH PLANT VENT (SPV) WITHOUT THE NORMAL OFFGAS TREATMENT (ND HOLOUP I

TIME), AND INITIATED AN SPV RADIATION ALARM. CORRECTIVE ACTIONS INCLUDE PERFORHING DESIGN ENHANCEMENTS ON THE IN8OARD MSIV PIPING, D8 EVALUATING POTENTIAL DESIGN CHANGES FOR THIS PIPE CONFIGURATION, REPAIRING OEFECTIVE EQUIPMENT, PROCEDURAL ENHANCEMENT ADDITIONAL g, , ADMINISTRATIVE GUIDANCE, LICENSE 0 CPERATOR TRAINING ON THE EVENT, AND COUNSELLING FOR THE NCO INWOLVED IN THE SECOND SCRAM. 1

t. ,

FORM 35 LER SCSS DATA 04-18-91 a 0********************************************************************

      ,        DOCKET YEAR LER NU48ER REVISION DCS NUMBER                  NSIC      EVENT OATE
,                 354      1990        028           0         9012210101 220544       11/17/90 8

ABSTRACT POWER LEVEL - 100%. ON 11/17/90 AT 0352, OURING PERFORMANCE OF A e , SURVEILLANCE PROCEDURE WHICH TESTS THE MAIN TUR8INE COMSINED INTERMEDIATE VALVES (CIV), THE 'A' MOISTURE SEPARATOR EXPERIENCED A

,               HIGH LEVEL CONDITION. IN RESPONSE TO THIS HIGH LEVEL CONDITION, THE
     ,          ASSOCIATED DUMP VALVE SEGAN TO OPEN, SUT LEVEL CONTINUED TO RISE, AND THE MAIN TURSINE TRIPPED ON M0!$TURE SEPARATOR HIGH LEVEL. IMMEDIATELY FOLLOWING THE TUR81NE TRIP, THE REACTOR SCRAMMED ON A TURSINE CONTROL g          VALVE CLOSURE SIGNAL FROM THE REACTOR PROTECTION SYSTEM. ALL CONTROLS R005 WERE VERIFIED 'O 8E INSERTED, AND PLANT SYSTEMS RESPONDE0 AS EXPECTED.        INVESTIG4 TION SUSSEQUENT TO THE SCRAM DETERMINED THAT THE
     ,          INITIATING CAUSE OF THIS EVENT 70 SE A MALFUNCTION OF THE LEVEL CONTROL SYSTEM FOR THE "A" MOISTURE SEPARATOR.             SEVERAL FACTORS APPEAR TO HAVE CONTRISUTED TO THIS PALFUNCTION: SLUGGISH OPERATION 08 THE 1

g EMERGENCY DUMP VALVE, MISOPERATION OF MOISTURE SEPARATOR LEVEL SWITCHES, POTENTIALLY LEAKING CHECK WALVES ON THE NORMAL DRAIN LINE, e AND A POSSIBLE CSSTRUCTION IN EITHER THE NORMAL DRAIN OR EMERGENCY g OURING PATHS. INTERIM CORRECTIVE ACTIONS CONSISTED OF TROUSLESHOOTING OF THE LEVEL CONTROL SYSTEM, R8W!EWIN3 *0!$TURs tspa o uno e ewri

                            ..  -,-.e.

1 p, 1 FORM 36 LER SCSS DATA U4 0************************************************************04-18-91 ******** DOCKET TEAR LER NUM8ER REVISION DCS NUMBER NSIC EVENT DATE 361 1989 004 0 8903220427 213316 km

                          ................................................................9/89    02/0 pq                      A8STRACT POWER LEVEL - 000%. ON 2/9/89, UNIT 2 ENTERED MODE 2 AT 0405 AND EG t          ATT4INED CRITICALITY AT 0455, WITH GROUP 4 CONTROL ELEMENT ASSEMBLIES (CEAS) AT 135 INCHES WITHDRAWN. JUST PRIOR TO 0505, THE OPERATORS be                       PERCEIVED ALL 4 CHANNELS OF THE CORE PROTECTION CALCULATORS (CPCS) TO BE INOPERA8LE BASED UPON 4 M!$ UNDERSTANDING OF THE FUNCTION OF THE CPC ALARM AND ANNUNCIATOR LIGHTS. 45 A RESULT, THE OPERATORS CONSIDERED g,                        TH4T TECHNICAL SPECIFICATION (TS) 3.0.3 NAD SEEN INV0KED AT 0405, UPON ENTRY INTO MODE 2, AND THAT A CONTROLLED REACTOR SHUT 00WN WAS REQUIRED.        AT 0505, INSERTION OF GROUP 4 CEAS WAS INITIATED, TAKING be THE REACTOR SUSCRITICAL. AT 0509, WITH POWER AT 2.0 E-41 AND GROUP 4
            ,,              CEAS AT 102 INCHES, A CPG-GENERATED REACTOR TRIP OCCURRED. THE be                       STANDARD POST-TRIP ACTION PROCEDURE WAS IMPLEMENTED, AND THE PLANT WAS STABILIIE0 IN MODE 3 4T 0515. THERE W45 NO SAFETT SIGNIFICANCE i
      '                     ASSOCIATED WITH THE REACTOR TRIP SINCE ALL PROTECTIVE SYSTEMS OPERATED IN ACCORDANCE WITH DESIGN. THE OPERATORS PERCEPTION OF CPC OPERASILITY PRIOR TO CRITICALITY AND INOPERASILITY AFTER CRITICALITY, D4             ,

RESULTED FROM FAILURE TO CORRECTLY RESOLVE THE DIFFERENCE BETWEEN TWO SETS OF CPC ALARM LIGHTS! ONE OF WHICH WAS EXTINGUISHED INDICATING CPC y, OPERASILITY, AND THE OTHER WAS ILLUMIN41EO INDICATING CPC INOPERASILITY. b i FORM 37 LER SCSS DATA be 0*******.**********.*.***************.***.*******************04-18-91 ******** DOCEET TEAR LER NUMBER REVISION OCS NUM8ER NSIC EVENT OATE g,, 361 1989 019 0 8910120066 215512 09/02/89 f* ABSTR4CT POWER LEVEL - 02F1. AT 0534 ON 9/2/89, 1989, OURING A PLANNED SHUTDOWN a CF UNIT 2 AT THE END OF CYCLE 4, 4 MANUAL TRIP W45 INITIATED 00E TO

            ,              THE APPROACH OF 4x!AL SHAPE INDEX (ASI) TO THE CORE PROTECTION
    ,.                     CALCULATOR (CPC) AUXILIARY TRIP SETPOINT. ASI DESCRISES THE Ax!AL POWER DISTRIBUTION OF THE REACTOR CORE.          THERE IS NO SAFETY
   '       ,               SIGNIFICANCE TO THIS EVENT SINCE THE REACTOR PROTECTION SYSTEM FUNCTIONED IN ACCORDANCE WITH DESIGN.          AT THE END OF A FUEL CYCLE, THE EFFECT OF A DECREASE IN PLANT POWER ON ASI IS GREATER THAN AT ANY s
           ,               OTHER TIME IN THE CTCLE. AS A RESULT, STRICT CONTROLS MUST BE EMPLOYED TO MAINTAIN ASI WITHIN LIMITS AND PREVENT & TRIP. ALTHOUGH
    '                      ACTION WAS TAKEN 70 CONTROL ASI, IT W45 NOT SUFFICIENT TO MAINTAIN ASI
           ,               WITHIN ITS LIMITS. THE GUIO4NCE IN THE OPERATING PROCEDURE GOVERNING I

PLANT SHUTDOWN W45 NOT SUFFICIENTLY SPECIFIC TO PROVIDE ASSURANCE THAT THE OPERATORS COULO SUCCESSFULLY CONTROL ASI OURING A PLANT

           ,.              SHUTOOWN AT END-OF-CTCLE. AN EVALU4 TION OF THIS EVENT WAS PERFORMED SY THE CORE ANALYSIS ENGINEERING GROUP. AS A RESULT OF THIS EVALUATION, THE ABOVE CAUSES WERE DETERMINED AND A PROPER STRATEGY FOR g               END-OF-CYCLE PLANT SHUT 00WNS WAS DEVELOPED, WHICH WILL 8E INCORPORATED INTO THE PLANT SHUTOOWN PROCEDURE.            THIS EVENT WILL SE DISCUSSED WITH APPROPRIATE OPERATIONS PERSONNEL AND ADDITIONAL ASI 1

g, TRAININ's WILL BE INCLUDED. s g; FORM 38 LER SCSS DATA 04-18-91

    ,                  0....................................................................

 .       -       -        ,      .-. -- . . ~ . - . .                                   .-~      . . - . . -                - . . -   - . . . - -                - --

L .

                                                                        .....................................ee..

pg , ASSTR4CT PO'EQ J LEVEL - 100I. AT 2200 ON DECEMBER 6, 1990, UNIT 2 AUTOMATIC ALLY

   *U4                  T2IPPED FROM 100E POEER ON A REACTOR PROTECTION ST5 TEM LOSS OF LOAD
           ,9           (LOL) SIGNAL. THE LOL SIGNAL WAS CAUSED BY A TUR8INE TRIP, WHICH l                        OCCURRED A5 A RESULT OF A MOMENTARY LOSS OF POWER FROM THE MON-1E i DN                    UNINTERRUPTIBLE POWER SYSTEM (UPS), MOMENTARILY DE-ENERGIZING BUS l j         rp           Q-069. EMERGENCY FEE 0 WATER ACTUATION SYSTEM (EFAS) 1 AND EFAS 2 l pq                     ACTUATIONS PROPERLY OCCURRED.                        ONE 6.9 KV 8US 0I0 NOT AUTOMATICALLY                                 ,

e ' TRANSFER TO OFFSITE POWER FOLLOWING THE TRIP, DE-ENERGIZING 2 REACTOR ! b8 1 ' COOLANT PUMP 5 (RCPS), TWO OTHER RCP5 CONTINUED TO PROVIDE FORCEO I CIRCULATION. APPROXIMATELY 1 10 2 MINUTES FOLLOWING THE TRIP, & COMPLETE LOSS OF POWER 04 Q-069 OCCURRED. APPROPRIATE ACTIONS WERE DN 3; INITIATED IN ACCORDANCE WITH PROCEDURES TO COMPENSATE FOR THE !-1 ' OPERATION OF CONTROL SYSTEMS WHICH WERE AFFECTED ST THE LOSS OF POWER

ON 0-069 ONE MAIN STEAM SAFETY VALVE FOR EACH STEAM GENERATOR MAY

} . ' ,'. HAVE LIFTED FOR A SHORT TIME AND PROPERLV RESEATEO. BUS Q-069 POWER WAS RESTORED AT 2220 VIA THE MANUAL 8?PA55 SWITCH. RECOVERY OF THE ! DE PLANT OTHERWISE PROCEEDED NORMALLY. IT IS POSTULATED THAT FAILURE OF

1) A CAPACITOR IN THE NON-1E UPS INVERTER DUTPUT AND 2) A TRANSISTOR be IN THE STATIC SWITCH TRANSFER LOGIC CONTROL CIRCUIT C0481NED TO CAUSE THE LOSS OF POWER 04 8US 3-069 (SOTH AT THE ONSET OF THE EVENT AND AT p, b 1-2 MINUTES POST-TRIP). THE ROOT CAUSE EVALUATION IS CONTINUING.

84 ,., FORM 39 LER SC55 OATA 04-18-91 Ge****e****************e*e******e*********ene............*... ........ p, 00CKET TEAR LER NUM8ER REVISION OCS NUMSER NSIC EVENT DATE

          ...            362          1989                  001            3     8912260017 216246                   01/06/89 bI                 e....eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee***ee..

5

          ,          485 TRACT Ee                  POWER LEVEL - 100E. AT 2335 ON 1/6/89 WITH UNIT 3 AT 98E POWER, REACTOR TRIPPED ON LOW SG LEVEL AFTER A PARTIAL LOSS OF NON-1E g,     ,

UNINTERRUPTI8LE POWER SUPPLY (UPS) POWER OCCURRED WHICH CAUSED FEEDWATER REGUL ATING VALVES TO REDUCE FLOW TO SG E089 AND RESULTED IN

                     ACTUATIO1 0F EMERGENCY FEE 0 WATER TO 53 EOS9.                          EMERGENCY FEE 0 WATER TO                                                                              '
          ,            SG E088 AL50 ACTUATED DUE TO THE RESULTING LEVEL "5HRINK" IN SG E088, WHICH IS EXPECTED FOLLOWING A TRIP FROM HIGH POWER.                                    SINCE STEAM e                   SVPAss CONTROL SYSTEM WAS IN MANUAL TO PERFORM TUR8INE VALVE TESTING, g            HEAT REMOVAL FROM YME 5G5 WAS GREATER THAN NORMAL.                                    AT 2336, A5 A
   ,,                  RESULT OF LOWER SG TEMPERATURE, RCS PRES 5URE DECREASED BELOW SIAS SETPOINT (1806 PSIA), RESULTING IN AN SIAS ACTUATION. THERE WAS NO
   '     6             5AFETV INJECTION FLOW INTO RCS SINCE RC5 PRES $URE REMAINE0 A80VE SNUTOFF MEAD OF INJECTION PUMPS. 2 0F 3 NON-1E UPS PHASES WERE LOST SECAUSE OF A COMMON FAULT IN THE ASSOCIATED INVERTER *5 CONSTANT e     g             VOLTAGE TRANSFORMER (CVT) OUTPUT WINDINGS. A TEMPORARY JUMPER, WHICH HAD NOT BEEN PROPERLY REMOVED OURING PREVIOUS MAINTENANCE, WAS FOUNO
   '                   BETWEEN UPS UNGROUNDEO NEUTRAL ANO GROUNO.                            THERE WERE 2 PRIOR
         '             FAILURES OF A CVT IN THE SA9E INVERTER AFTER INSTALLATION OF THE TEMPORARY JUMPER, BUT NEITHER RESULTED IN A SAFETY SYSTEM ACTUATION.

CAUSE OF TRANSFORMER FAILURE WAS THE BREAEDOWN OF INSULATION BETWEEN

         ,.'           ENERGIZED WINDINGS ANO GROU40E0 IRON CORE.

r 1 g, FORM- 40 LER SC55 OATA 04-15-91 0***ee**eeeeeeeee*****eme=eeeeeeeen*******eeeeeenae*******e ********* DOCRET TEAR LER NUMSER REVISION OCS NUM8ER 451C EVENT DATE

t-

        .g.              362         1989                  006            1      39120F0086 216094                  04/07/89
                     ......e............                        e..e..e......ee.................................

445 TRACT-n POWE..R

                       .m.      . . L.E. VEL....1001. At 0535 ON 4/7189, WITH UNIT 3 AT 1001 POWER, Am
                                                                                                                                                    ,_,_,,,.-.---.,-4 .-, -,- , - ~ ~ ~ - - - '~-- -

                   ... . . . . . . . . ,s  ..6  2: s e <. e. : vit 2 3 dUi UNJERV3LTAGE (UV)    R* lay 5.

PL1%T CONDITIOJi WERJ STASILI!tD, AND RECDVERY PROCEEDED NORMALLY. pS THE EMERGENCY F8E3 WATER ACTUATION SVSTEM (EFAS) FOR BOTH STEAM GENERATOR 5 (5G5) ACTUATED 45 A RESULT OF THE EXPECTED DECREASE IN SG bg LEVEL SELOW THE ACTUATION SETPOINT. AT 0630, LEVEL 5 OF BOTH SGS WERE VERIFIED 10 BE ABOVE THE R! SET SETPOINT, AND EFAS WAS RESET. THE RPS

  #4 OPERATED IN ACCORDANCE WITH OESIGN, AND ALL EFAS COMPONENTS WERE VERIFIED TO HAVE ACTUATED AS REQUIRED. FOLLOWING THE TRIP, THE CEDMCS MOTOR-GENERATOR (MG) SET 81 LOAD CONTACTOR WAS FOUND TO SE OPEN, pq            CONTRART TO ITS NORMAL, EXPECTED P051T!0N.

i THE CEDMC S SUS IS POWERED BY TWO PARALLEL ANO FULLY REDUNDANT MG SET 5, VIA OUTPUT CIRCUIT EO BREARERS AND LOAD CONTACTOR5. SUBSEQUENT TESTING DEMONSTRATED THAT UNDER CERTAIN CONDITIONS, THE OPENING OF ONE MG SET LOAD CONTACTOR b4 COULO RESULT IN A DROP IN CEDMC5 SUS WOLTAGE OF SUFFICIENT MAGNITUOE TO CAUSE THE CEOMCS BUS UNDERVOLTAGE (UV) RELAYS TO DEENERGIZE. MONITORING EQUIPMENT WAS INSTALLED ON THE MG SETS TO ESTABLISH be POS5IBLE CAUSE AND CORRECTIVE ACTIONS FOR THE SPURIOUS OPENING OF THE MG SET LOAD CONTACTOR. pm FORM 41 LER SC55 DATA De 0************************************************************04-18-91 ******** DOCKET VEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE g, 362 1990 002 1 9011080154 219905 02#23/9

              *******************************************************************0*

te ABSTRACT POWER LEVEL - 100%. AT 2257 ON FEBRUARY 23, 1990, WITH UNIT 3 At 100% p, POWER, DURING THE PERFORMANCE OF MAIN STEAM ISOLATION SYSTEM (MSIS) SUBGROUP RELAY TESTING, A SPURIOUS M515 ACTUATION OCCURRED. THIS M515

  ,            ACTUATION INITIATED CLOSURE OF THE MAIN STEAM ISOLATION VALVES
  *             (MSIVS) AND RELATED IN A REACTOR TRIP 04 HIGH PRE 55URIZER PRES 5URE.

Et THE PLANT TRANSIENT INCLUDED: 1) LIFTING OF THE MAIN STEAM SAFETY VALVES (M55VS); (2) INITIATION OF THE EMERGENCY FEE 0 WATER ACTUATION SYSTEM (EFAS); AND 3) THE BRIEF OPENING OF A PRE 55URIZER $4FETY VALVE

g. (PSV). HOWEVER, OURING THE TRANSIENT, RC5 PRES 5URE NEVER EXCEEDED THE MINIMUM PSV SET POINT VALUE ALLOWED BY TECHNICAL SPECIFICATION (TS) 3.4.2. OPERATORS STABILIZED THE PLANT IN MODE 3. FOLLOWING THIS EVENT, IT WA5 DETERMINED THAT THE LIFT SET Po!NTS FOR THE UNITS 2 AND 3 PSV5 WERE OUTSIDE THE 75 REQUIREMENT 5. THERE IS NO SAFETY e

SIGNIFICANCE TO THIS EVENT SINCE: 1) ALL REACTOR PROTECTION SYSTEM, M515, AND EFA5 COMPONENTS WERE VERIFIED TO ACTUATE IN ACCORDANCE WITH

  ,            DESIGN; AND 2) THE PLANT RESPONSE WITH THE AS-FOUNO PSV LIFT SET POINTS WAS DETERMINED 70 SE ACCEPTABLE.                  CONTACTS ON THE MSIS MANUAL ACTUATION PUSHSUTTON (PS) WERE FOUND TO BE DEGRADED SUCH THAT ONE TRIP LEG OF MSIS DID NOT RESET DURING THE SUBGROUP RELAY TESTING.

1 e FORM 42 LER SC55 CATA 04-1

  ,         0****************************************************************8-91                ****
     ,        DOCKET YEAR LER NUM8ER REVISION DCS NUMBER                        NSIC     EVENT DATE 364       1989         007            0        8906280019 214412           05#22#89 A85 TRACT POWER LEVEL - 035%. AT 1019 ON 5#22189, WITH THE UNIT OPERATING AT

g. APPROI. 35I POWER, THE REACTOR TRIPPED DUE TO LO-LO STEAM GENERATOR LEVEL. THE LO-Lo STEAM GENERATOR LEVEL OCCURRED BECAUSE THE 24 STEAM GENERATOR FE!D PUMP (SGFP), WHICH WAS PROVIDING FEE 0 WATER FLOW TO THE g- STEAM GENERATOR 5, TRIPPED. THE UNIT WAS STASILIZE0 IN MODE 3 (HOT STANDST). THE SGFP TRIP WAS CAUSED BY & LOOSE ELECTRICAL CONNECTOR ON .

  .            THE 24 SGFP THRUST BEARING WEAR DEVICE. A L T H OUGH THE EIACT CAUSE g         COULO NOT BE DETERMINE 0, 17 15 SELIEVED THAT THE CONNECTOR WAS NOT
  ,            FULLY TIGHTENED FOLLOWING MAINTENANCE P*RFORmED OURING TM8 R*C*NY

                 ..mo,.  ..-s...  .t4=     amit s is *a al TO SE Gif4ERATEO. THUS, THE 2A SGFP TRIPPED WHICH CAUSED THE LO-LQ STEAM GENERATOR LEVEL AND AN AUTOMATIC p4            REACTOR TRIP RCSULTED.          T3 PREVENT RECURRENCE CF THIS PROSLEM, A PREVENTIVE MAINTENANCE TASE UILL BE DEVELOPED TO INSPECT SGFP ICSTRUMENTATICN CONNECTIONS FOR TIGHTNESS FOLLOTING MAJ22 UNIT OR SGFP q;      OUTAGES. THE UNIT RETURNED TO POWER OPERATION ON 5/22/89 AT 2234.

1 , he

  ,     ,p     FORM     43                      LER SC55 DATA p,        0************************************************************04-18-91        ********

DOCKET YEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 364 1989 008 0 8906270168 214413 y q; ........**...........................*.........*........... 05/27/89 ......*. { hw i, ABSTRACT POWER LEVEL - 088%. AT 0906 ON 3-27-89, WITH THE UNIT OPERATING AT 88% g, POWER AND A THREE PERCENT PER HOUR POWER INCREASE IN PROGRESS, THE q i, REACTOR TRIPPED DUE TO A TURSINE TRIP. THE TURBINE TRIP RESULTED FROM hm 4 GENERATOR TRIP CAUSED BV LOSS OF EXCITATION. THE LOSS OF EXCITATION WAS CAUSED ST THE FAILURE OF THE 89 EXCITER BEARING WHICH RESULTED IN THE FAILURE OF THE SHAFT DRIVEN PERMANENT HAGNET GENERATOR

b. (PMG). THE #9 BEARING FAILED WHEN CONTRACT PERSONNEL FAILED To IN5 TALL AN INSULATING WASHER ON ONE OF THE FOUR BOLT 5 ON A BEARING OIL y, i LINE FLANGE. THIS EVENT WAS CAUSED BT AN INADEQUATE PROCEDURE.

ALTHOUGH A PROCEDURE DID EXIST FOR THE REASSEMBLY OF THE BEARING OIL PIPING, THERE WAS NO METHOD FOR VERIFYING PROPER INSULATION CAPABILITY b4 ,, FOLLOWING REASSEMBLY. SECAUSE THE BE ARING OIL LINE FLANGE BOLT INSULATING WASHER WAS NOT INSTALLED AS REQUIRED, THE 89 EXCITER p, BEARING EVENTUALLY FAILED. A NEW BEARING AND PMG STATOR HAVE SEEN INSTALLED. A PROCEDURE (FNP-0-EMP-1171.02, GENERATOR SHAFT / PEDESTAL

   "*           INSULATION VERIFICATION) H45 BEEN DEVELOPED TO VERIFY PROPER I            INSULATION OF THE 89 BEARING. THE UNIT RETURNED TO POWER OPERATION ON 5-31-89 AT 2021.

ha 1 g, FORM 44 LER SC55 DATA 04-18-91 0*****************************************************.************** DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

   .            364   1989         010               0       8910190282 215672        09/20/89 I
      ,        ABSTRACT
   ,,           POWER LEVEL - 061%. AT 0722 ON 9/20/89, WITH THE UNIT OPERATING AT APPRONIMATELY 61% POWER, THE REACTOR W AS TRIPPE D M ANU ALLY FOLLOWING
   '  ,         THE LOSS OF THE OPERATING STEAM GENERATOR FEED PUMP ($GFP). THE 24 SGFP TURBINE TRIPPED OUE TO A LOW AUTO-STOP OIL PRESSURE SIGNAL. THE SHIFT SUPERVISOR DIRECTED A MANUAL REACTOR TRIP IN ORDER TO PREVENT AN

,. UNNECESSARY CHALLENGE TO THE REACTOR PROTECTION SYSTEM. THE UNIT WAS STABILIIED IN MODE 3 (HOT STAND 87). THE LOW AUTO-STOP OIL SIGNAL WA5

   ,_           CAU5ED BT THE INADVERTENT OPENING OF THE OVER5 PEED TRIP TEST VALVE.
      ,         OPENING THIS VALVE LOWERED AUTO-STOP OIL PRES $URE 8Y DIVERTING AUTO-STOP OIL TO THE OVERSPEED TEST CEVICE. AUTO-STOP OIL PRE 55URE DROPPED SELOW THE AS-FOUND TRIP SET POINT OF THE LOW AUTO-STOP OIL
      ,         PRES $URE SWITCH CAUSING A SGFP TRIP. THE TRIP 5ETPOINT WAS FOUND TO SE HIGHER THAM IT SHOULD HAVE BEEN. THE UNIT RETURNED TO POWER OPERATION AT 2003 ON 9/26/89 1

4. FORM 45 LER SC55 3ATA 04-18-91 i g. 0******************************************************************** 00CEET YEAR LER NUMBER REVISION DCS NUMBER 45IC EVENT DATE

   ,              364   1989        012                0       5911220017 215888        10/18189

g. ..*...*....**.......*........*...*...*........**...*.****.**.**.a..*

e.- m ~ - - e , , ,-

                              .... ....,, . . . s..  ... i<4-ecs I                                                                     0 - I) LO-Lo STEAR GENERATOR LEVEL.

THE LO-LO STEAM GENEPATOR LEUEL

URRED WHEN THE TUPBINE GENERATOR p1 GOVERN 00 VALVES CLCSED. THIS f SRE RESULTED F20M A DIGITAL

' ELECTRO-HTORAULIC CONTROL (DEN SYSTEM OESIGN FEATURE ENHANCEMENT h4 WHICH CAUSES THE GOVERNOR VAll POSITION LIQITEQ TO LOWER TO ZERO AS A 8ACKUP TO CLOSING THE GOVERNO VALVES WHEN BOTH OVERSPEED PROTECTION CHANNEL (OPC) POWER SUPPLIES I '. THIS EVENT WAS CAUSE0 SY A DESIGN I bN ERROR IN THE DEHC SYSTEM. THI 'OR ALLOWED A MOMENTARY OATA LOSS TO

                  , 9 ,'      8E CREATED WHEN THE OPERATOR RL               *? THE "RE-ENASLE HIGHWAV" pq                FUNCTION AT THE DEHC OPERATORS /                 CONSOLE. THIS RESULTED IN THE SAME SYSTEM CONTROL ACTION THAT                KEN WHEN BOTH OPC POWER SUPPLIES Ld g,              FAIL. THE VALVE POSITION LIMITER               1RE WHICH LOWERS TO ZERO AS A 8ACKUP TO CLOSING THE GOVERNOR VALs.              MHEN THE OPC POWER SUPPLIES FAIL DN                HAS 8EEN REMOVED FROM THE Uh!T 1 AND UNIT 2 DEHC SYSTEMS.
                  ,;,        WESTINGHOUSE HAS BEEN DIRECTED TO DETERMINE IF THERE ARE OTHER DEHC
           +

FEATURES AVAILABLE TO THE OPERATOR WHICH MAY CAUSE A TUR8INE TRIP OR CO TUR81NE VALVE CLOSURE. U" FORM 46 LER SCSS DATA be 0**********************************************************.*04-18-91 ******** DOCKET TERR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE 364 1989 013 0 8911220055 215889

            , , , ,         ........................................................... 10/19189          ..e*e...

485 TRACT 83 . POWER LEVEL - 002I. AT 1823 ON 10-19-89, WITH THE UNIT OPERATING AT APPROKIMATELV TWO PERCENT POWER, THE REACTOR TRIPPED DUE TO LO-LO tw LEVEL IN THE 2C STEAM GENERATOR. THE UNIT OPERATOR IMPROPERLT i TRANSFERRED FROM AUXILIARY FEE 0 WATER (AFW) TO MAIN FEE 0 WATER (MFW)

              '              DURING A PLANT STARTUP. THIS EVENT WAS (AUSED SY PERSONNEL ERROR IN I                 THAT THE UNIT OPERATOR INCORRECTLY TRANSFERRED STEAM GENERATOR LEVEL he               CONTROL FROM AFW TO MFW. A CONTRIBUTIN3 CAUSE WAS THAT THE PERSONNEL INVOLVED FAILEO TO PROPERLY RESTORE AIR TO THE 2C MFW SYPASS VALVE.

THE PERSONNEL INVOLVED HAVE BEEN COUNSELED CONCERNING IMPROPER t* FEE 0 WATER TRANSFER AND RESTORATION OF AIR TO FEE 0 WATER WALVES. A TRAINING CHANGE NOTICE DESCRIBING THIS EVENT WILL BE ISSUED TO ALL

              ,              LICENSED PERSONNEL.

4 FORM 47 LER SCSS DATA 0*****.******************************************************04-18-91 ********

           ,               DOCKET VEAR LER NUMSER REVISION OCS NUM8ER                    NSIC          EVENT DATE 364       1939    015              0      8912280001 216216               11/18189
                      )    ....................................*...............................

ABSTRACT i 9 POWER LEVEL - 1002. AT 0433 ON 11-18-99, WITH THE UNIT OPERATING AT 1001 POVER, THE REACTOR TRIPPED DUE TO A TURSINE TRIP. THE TUR81NE

           ,                 TRIP IS ATTRISUTED TO A VOLTAGE TRANSIENT IN THE POWER CIRCUIT TO THE
                 ,,          DEHC SYSTEM. A VOLTAGE TRANSIENT IN THIS CIRCUIT IS SUSPECTED 70 HavE
           '                 CAUSED THE DENC SYSTEM TO ERRONEOUSLY SENSE A LOSS OF DC POWER.                     THE VOLTAGE TRANSIENT IS ATTRIBUTED TO THE FAILURE OF THE DEHC INVERTER.
                 ,g          THE UNIT RETURNED TO POWER OPERATION At 0455 ON 11-19-89 USING THE ALTERNATE POWER SUPPLY.         THE INVERTER WAS REPAIRED AND RETURNE0 TO SERVICE.

1 r) FORM 45 LER SCSS DATA 1

                , :~     0************************************************************04-18-91           ********

DOCKET YEAR LER NUMSER REVISION OCS NUMBER NSIC EVENT DATE 364 1990 001 0 9006140214 218568 05/12/90

g. ....................................................................

                  ^
                                                                                                 . ca
                .....e   .. rts .u; ev L J a - L t.

WaltR LEVEL IN THE 2A ST*AM GENERATOR. THE LOW-LOW WATER LEVEL CCCURRED WHEN THE STEAM SUPPLT VALVE 5 FOR THE Pg 04-55RVICE STEA1 GENERATOR FEE 3h&TER PUMP (SGFP) CLOSED. TESTING SEING PERFORME3 IN ACCORD 4NCE WITH FNP-2*5TP-151.4 (M4IN TURBINE PROTECTIVE DEVICE TEST) RESULTED IN LOW ELECTRO-HTORAULIC (EH) FLUID PRES 5URE WHICH CAUSED THE SGFP VALVES TO CLO5E. THIS EVENT W AS L AUSE0 i BY PROCEDURAL INADEQUACY. FNP-2-STP-151.4 OID NOT PROVIDE ADEQUATE b4 GUIDANCE CONCERNING THE INITIAL CONDITIONS REQUIRED TO PERFORM THE

. PROCEDURE. TESTING PERFORMED SUBSEQUENT TO THE REACTOR TRIP 5HOWED pq THAT IT 15 NOT APPROPRIATE TO PERFORM THIS PROCEDURE WHILE FEEDWATER

' IS BEING PROVIDED BY A SGFP. FNP-2-51P-151.4 HAS BEEN REVISED TO E4 ' PROVIDE ADDITIONAL INITIAL CONDITIONS TO PREVENT PERFORMING THE PROCEDURE WHEN AN SGFP 15 IN SERVICE. 1 M FORM 49 LER SC55 DATA gg 0************************************************************04-18-91 ******** DOCKEY YEAR LER NUMBER REVISION DC5 NUMBER NSIC EVENT DATE 366 1989 005 0 8910040395 215373 09/03/89 DM bg 4857 TACT POWER LEVEL - 070%. 04 9/3189 AT APPROEIMATELY 2239 CDT, UNIT 2 WAS IN

   ,,          THE RUN MODE AT AN APPROEIMATE POWER LEVEL OF 1695 CMWT (APPROXIMATELY 701 0F R4TED THERMAL POWER). AT THAT TIME, LICENSED R'          OPERATIONS PERSONNEL WERE CHANGING REACTOR VE5SEL WATER LEVEL CONTROL FROM SINGLE ELEMENT TO THREE ELEMENT CONTROL FOLLOWING COMPLETION OF PROCEDURE 575v-5UV-004-25, " EXCESS FLOW CHECK VALVE OPERABILITY," FOR pg          THE MAIN STEAM LINE FLOW INSTRUMENT 5' EXCESS FLOW CHECK VALVES. WHEN THE MASTER CONTROLLER WAS PLACED IN AUTOMATIC FOLLOWING THE CHANGE
   "'          FROM SIN 5LE ELEMENT TO THREE ELEMENT CONTROL, THE CONTROLLER'S OUTPUT SIGNAL SUDDENLY WENT TO IERO. BOTH REACTOR FEED PUMPS DECREASE 0 FEEDW4TER FLOW TO THE REACTOR VE5SEL IN RESPONSE TO THE CONTROLLER'S b*          ZERO OUTPUT SIGNAL. REACTOR VESSEL WATER LEVEL DECREASED AND THE REACTOR SCRAMMED ON LOW WATER LEVEL.            THE ROOT CAUSE OF THIS EVENT IS

g. COMPGNENT FAILURE. THE SELF SYNCHRON!!ED CONTROL UNIT, THE MAIN OPERATING UNIT OF THE MASTER CONTROLLER, FAILED WH5N THE MASTER CONTROLLER WAS PLACED IN AUTOMATIC. THE F4ILURE OF THE SELF I SYNCHRONIZED CONTROL UNIT C AUSED THE M45TER CONTROLLER'S OUTPUT SIGNAL TO GO TO ZERO. CORRECTIVE ACTIONS FOR THIS EVENT INCLUDED REPLACING e

THE SELF SYNCHRONIZED CONTROL UNIT. 1 i FORM 50 LER 5C55 0474 04-18-91 0******************************************************************** OOCKET TEAR LER NUMBER REVISION OC5 NUMBER N5IC EVENT DATE 366 1990 001 1 9006210099 215530 01/12/90

   ,          ABSTRACT
      ,,       POWER LEVEL - 1001. CN 1112/90 AT APPROIIMATELV 1610 CST, UNIT 2 WAS IN THE RUN MODE AT AN APPROXIMATE POWER OF 2436 CMWT (APPROXIMATELY 100X OF RATED THERMAL POWER). AT THAT TIME, THE REACTOR SCRAMMED
      ,        BECAUSE THE MAIN STEAMLINE ISOLATION VALVES (MSIVS) WERE LESS THAN 90%

OPEN. THE MSIVS HAD ISOLATED ON A GROUP 1 PRIMART CONTAINMENT ISOLATION ST5 TEM (PCIS) SIGNAL WHICH RESULTED FROM A FALSE LOW

      ,        CONDEN5ER VACUUM SIGNAL. HIGH PRESSURE COOLANT INJECTION (HPCI)

SYSTEM AUTOMATICALLY INITIATED AND INJECTED ON LOW REACTOR WATER LEVEL AS REQUIRE 0. FOLLOWING WATER LEVEL RECOVERT, HPCI INJECTION VALVE t 2E41-F006 CLOSED AUTOMATICALLY ON HIGH WATER LEVEL. HOWEVER, IT COULD g NOT BE RE-0PENED WHEN OPERATIONS PERSONNEL SUB5EQUENTLY ATTEMPTED 10 START HPCI MANUALLT. THE REACTOR CORE ISOLATION COOLING SYSTEM AND g TWO CONTROL ROD ORIVE SYSTEM PUMP 5 WERE USED TO CONTROL WATER LEVEL

   ,           FOLLOWING THE FAILURE OF VALVE 2E41-F036 TO OPEN. TMF 000T C atsts t es

                                              ..s.. c..se e23:o ave 4*tto r3CM ITS STEM ISOLATIN3 THE COMMON SENSING LINE F3R VACUU1 SWITCHES 2E21-NOSec AND 0. CONSEQUENTLY, THESE P4                         SWITCHES THEN SENSED A LOW CONDENSER VACUUM ANO, SECAUSE THEY INPUT TO THE A AND 8 TRIP SYSTEMS RESPECTIVELY OF THE ISOLATION LOGIC, THE
                   >4                        MSIVS ISOLATED. THE CAUSE OF VALVE 2E41-F006 FAILING TO OPEN IS 4

COMPONENT FAILURE.

>=

FORM St LER SCSS DATA 04-e, 0****************************************************************13-91 **** DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE E4

                                        .      366     1990        003           0      9004300271 218027            03/28/90 i                    b4                      ABSTRACT POWER LEVEL - 100%. ON 3/2S/90 AT APPRON. 0815 CST, UNIT 2 WAS IN THE

. gg RUN MODE AT AN APPROX. POWER LEVEL OF 2436 CMWT (APPROX. 100% OF RATED l ., THERMAL POWER). AT THAT TIME, A PLANT IRC TECHNICIAN WAS VALVING-IN U" PRESSURE TRANSMITTER 2E32-NOSO FOLLOWING A ROUTINE CALIBRATION PER PROCEDURE $7CP-CAL-103-25, "ITT SARTON MODEL 764 01FFERENTIAL PRES $URE TRANSMITTER." VALVING-IN THE PRESSURE TRANSMITTER, WHICH SHARES A be COMMON SENSING LINE WITH REACTOR PROTECTION SYSTEM (RPS) AND PRIMARY CONTAINMENT ISOLATION SYSTEM (PCIS) WATER LEVEL TRANSMITTERS p, 2821-N080C AND 0, CAUSED A PRESSURE PERTURBATION IN THE SENSING LINE WHICH CAUSE0 WATER LEVEL TRANSMITTERS 2821-N080C AND D TO SPIKE DOWNSCALE. THIS RESULTED IN A FALSE LOW WATER LEVEL SIGNAL BEING SENT Da TO THE A2 AND B2 TRIP CHANNELS IN THE RPS AND THE PCIS. FULL SCRAM AND PARTIAL GROUP II PCIS ISOLATION $1GNALS WERE GENERATED PER DESIGN, DS THE UNIT SCRAMMED AND THE OUT50ARD GROUP II PRIMARY CONTAINMENT ISOLATION VALVES (PCIVS) CLOSED. THE CAUSE OF THIS EVENT IS AN ' "' INADEQUATE PROCEDURE. PROC EDURE $ 7CP-C AL-103-25 DID NOT PROVIDE

                    '                        ADEQUATE INSTRUCTIONS TO PREVENT THE PRESSURE PERTURBATION THAT RESULTED WHEN PRES $URE TRANSMITTER 2E32-NOSO WA$ VALVED-IN.

8* FURTHERMORE, THE PRDCEDURE DID NOT PROVIDE ADEQUATE RETURN TO SERVICE INSTRUCTIONS (E.G., OPEN LINES, INSTALL JUMPERS, LIFT LEAD $) NECESSARY

g. TO PREVENT A SCRAM AND PCIS ACTUATION IN 1HE EVENT OF A PERTURBATION IN THE COMMON SENSING LINE.

t. FORM $2 LER SCSS OSTA 04-18-91 b 0******************************************************************** DOCKET TEAR LER HUMBER REVISION DCS NUM8ER NSIC EVENT DATE

                     ,                         368     1989        006           0      8905300012 214001            04/18/89
                     '                      ABSTRACT POWER LEVEL - 100%. ON 4/18/89, A 14 INCH, HIGH PRESSURE TURBINE e

EXTRACTION STEAM LINE RUPTURED RESULTING IN A REACTOR TRIP ON HIGH REACTOR COOLANT SYSTEM (RCS) PRESSURE. CURING THE TRANSIENT, THE

                     ,                       STEAM TURBINE ORIVEN EMERGENCY FEEchATER (EFW) PUMP TRIPPED ON OVERSPEED AFTER RECEIVING AN AUTOMATIC START SIGNAL. THE 'A' TRAIN FEE 0 WATER CONTROL SYSTEM (FWCS) MALFUNCTIONED CAUSING A SLIGHT OVERFILL OF 'A' STEAM GENERATOR (SG). ONE OF TWO ATMOSPHERIC STEAM OUMP WALVES (ADVS), LOCATED DOWNSTREAM OF THE SG MAIN STEAM ISOLATION VALVES (MSIVS), COULO NOT SE OPENED FR3M THE CONTROL ROOM. QUE TO THE LOSS OF CONDENSER VACUUM, THE MSIv5 WERE MANUALLY CLOSE0 AND UPSTREAM
                                 ,           ADVS WERE USED FOR DECAY HEAT REMOVAL.          ONE OF THE UPSTREAM ADVS APPARENTLY FAILED OPEN, RESULTING IN A MINOR UNEXPECTED RCS COOLDOWN.

THE PLANT WAS STABILIZED AND A COOLDOWN WAS PERFORMED. THE FAILED a

g. LINE WAS INSPECTED AND THE ROOT CAUSE WAS PIPE WALL THINNING DUE TO EROSION-CORROSION. ADDITIONAL EXTRACTION STEAM PIPING WAS INSPECTED e RESULTING IN SEVERAL AREAS SEING REPLACED. A DEGRADED RAMP GENERATOR I 6. THE GOVEPNOR SPEED CONTROL CIRCUIT OF THE STEAM TURBINE ORIVEN EFW PUMP WAS REPLACEO. THE 'A' TRAIN FWCS WAS FOUND TO wave Snus wvert

P1 FORM $3 LER SCSS DATA 0************************************************************04-13-91 ******** 64 00CKET TEAR LER NUZ8EQ REVISION DCS NUMBER NSIC EVENT DATE is 368 1989 024 0 9002080162 216686 bW ...............................................................31/89 12/ g i. A857RACT p5 POWER LEVEL - 100%. ON 12/31/89, A REACTOR TRIP OCCURRED FROM 100% OF RATED THERMAL POWER WHEN '8' STEAM GENERATOR (SG) WATER LEVEL REACHED 4 t A HIGH LEVEL SETPOINT AND THE REACTOR PROTECTION SYSTEM GENERATED A REACTOR TRIP SIGNAL. DURING THE TRANSIENT ONE OF THE RUNNING

                     >4                                  CONDENSATE PUMPS WHICH WAS EXPECTED TO TRIP DID NOT TRIP. OTHERWISE, j i l       THE PLANT RESPONDED PROPERLY WHEN THE REACTOR TRIP OCCURRED. THE OPERATIONS STAFF RESPONDED APPROPRIATELY AND IN A TIMELY MANNER TO THE kg                                   REACTOR TRIP. OF PRIMARY CONCERN WAS THE POTENTIAL FOR REACTOR COOLANT SYSTEM OVERC00 LING OR A SG OVERFILL EVENT, HOWEVER, PROPER
                              "                           SYSTEM OPERATION PREVENTED EITHER FROM OCCURRING. NO SIGNIFICANT SAFETY CONCERNS WERE IDENTIFIED. THE ROOT CAU ;E OF THIS EVENT IS be                                  BELIEVED TO 8E A LOOSE TERMINAL ON AN ELECTRICAL MODULE IN THE '8' FEE 0 WATER CONTROL SYSTEM (FWCS) CABINET. THE TERMINAL WAS NOT PROPERLY RETERMINATED WHEN MAINTENANCE ACTIVITIES WERE PERFORMED pg                                   OURING 2RT REFUELING OUTAGE. THE LODSE TERMINAL WAS ON AN ELECTRICAL MODULE IN THE '8' MAIN FEE 0 WATER (MFW) FLOW LOOP TO THE *B' FWCS. TO Be                                  VERIFY THAT THE LOOSE TERMINAL COULO CAUSE A TRANSIENT SIMILAR TO THIS EVENT, SIMULATED SIGNALS FOR 100% POWER CONDITIONS FOR THE INPUTS TO THE 'B'   FWCS WERE INPUT AND THE CONNECTION ON THE TERMINAL LOOSENED.

91 A VERY SIMILAR RESPONSE TO THE TRANSIENT WHICH INITIATED THE REACTOR TRIP OCCURRED.

                     ,,                              1 FORM     54                                                     LER SCSS DATA                                          04-18-91 0....................................................................

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

t. 368 1990 005 0 9004170065 217598 03/04/90 1

I' ABSTRACT POWER LEVEL - 000%. ON 3/4/90, WHILE TRANS;f!ONING FROM MODE 2 e (STARTUP) TO MODE 3 (HOT STANc87), THREE OF THE FOUR LOGARITHMIC (LOG) POWER LEVEL INSTRUMENTATION CHANNELS WERE DECLARED INOPERABLE DUE TO

y. ABNORMAL NOISE INDICATIONS AND ERRATIC SEMAVIOR. TO COMPLY WITH TECH SPECS THE REACTOR TRIP CIRCUIT BREAKERS WERE OPENED RESULTING IN A

                                                       MANUAL REACTOR TRIP. FOLLOWING THE TRIP IT WAS OSSERVED THAT THE CONTROL ELEMENT ASSEMBLY (CEA) 861 HAD NOT FULLY INSERTED AND INDICATED APPR0x!MATELY ELEVEN INCHES WITHDRAWN.                                                            THE REACTOR SHUT 00WN
                                               ,         MARGIN (SDM) WAS VERIFIED TO BE ADEQUATE AS REQUIRED BY TECH SPECS.

A LOOSE CONNECTION ASSOCIATED WITH A SURGE CAPACITOR ON THE 6900 VOLT

                     ,                                   'O' REACTOR CO3LANY PUMP (RCP) MOTOR WAS FOUND TO BE ARCING AND
                                               ,         INDUCING ELECTRICAL NOISE INTO THE INSTRUMENTATION CIRCUITS. WHEN 'O'
                     '                                   RCP WAS SECURED THE INSTRUMENT CHANNELS INDICATIONS RETURNED 10 NORMAL. THE CAUSE OF CEA 861 NOT FULLY INSERTING WAS NOT CONCLUSIVELY 0*TERMINE0. HOWEVER, EVALUATIONS INDICATED THE MOST LIKELY CAUSE WAS OUE TO SOME TYPE OF FOREIGN MATERIAL SECOMING WEDGED BETWEEN A CEA FINGER AND FUEL GUIDE TUBE INSIDE DIAMETER. THE SURGE CAPACITOR ON
                                                         'O' RCP MOTOR WAS REPLACE 0 AND THE LOOSE CONNECTION REPAIRED. CEA 861 WAS SUCCE55 FULLY FREED AND TESTED.

1 i FORM 55 LER SCSS DATA 04-15-91

0***************************.****************************************

g; DOCKET TEAR LER NUMBER REVISION OCS NUMBER 'NSIC EVENT DATE

                     .                                     368   1990                                               006      0     900&140707 7177A*                          "**"****

l

POWER LEVEL - 0031. 04 3/5#90, WHILE PERFORMING THE LOGARITHMIC (LOG) i P1 POUER LEVEL NUCLEAR INSTRUMENTATION CHANNEL FUNCTIONAL TEST COP 4 2105.015) IN PREPARATION FOR A REACTOR STARTUP, TWO OF THE CHANNELS j b4 OIO COT SATISFY THE REQUIREMENTS OF THE TEST PCOCEDURE AND WERE 4 q;. DECLARED IMOPER48LE. WITH THESE CONDITIONS THE MINIMUM NUMBER OF OPERA 8LE CHANNELS REQUIRED BY TECH SPECS WAS NOT MET. CONTROL ROOM 4 j D4 OPERATORS MANUALLY INITIATE 0 A REACTOR TRIP Bf OPENING THE REACTOR t p TRIP CIRCUIT 8REAKERS. A SANK OF OPERATORS MANUALLY INITIATED A i pq REACTOR TRIP ST OPENING THE REACTOR TRIP CIRCUIT BREAKERS. A SANK OF l CONTROL ELEMENT ASSEMSLIES, WHICH HAD BEEN WITHORAWN A FEW INCHES FOR 4 qi TESTING, FULLY INSERTEO. ON 3/6/90, AFTER A REVIEW OF OP 2105.015, IT WAS DETERMINED THAT THE ACCEPTANCE CRITERIA WAS INCORRECT. IT WAS D8 ALSO DETERMINED THAT OP 2105.015 0I0 NOT ADEQUATELT PERFORM A CHANNEL

           ,[r       FUNCTIONAL TEST AS DEFINED ST TECH SPECS. MONTHLY TEST PROCEDURES pq              PERFORMED 81 INSTRUMENTATION AND CONTROLS (ISC) TECHNICIANS USING DIFFERENT PROCEDURES (OP 2304 SERIES) HAVE THE CORRECT VALUES FOR p        CHANNEL INDICATIONS AND 00 SATISFV THE REQUIREMENTS OF A CHANNEL U"              FUNCTIONAL TEST. FUNCTIONAL TESTS OF THE LOG POWER LEVEL CHANNELS WERE SATISFACTORILY PERFORMED PRIOR TO REACTOR STARTUP 0N 3/7#90, i            s i i      USING THE ISC PROCEDURES.

l De i 1 pg ,, FORM 56 LER SCSS DATA 04-18-91 0*****eeee*********e***************e*********************e*** ******** 8' DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 368 1990 014 1 9011210263 220075 06/26/9 i e***eeee****e****e**********eee*** *ee **eeeeeee**e*****eme.*eme*0* P1 A85 TRACT g, POWER LEVEL - 030%. AT ABOUT 2348 HOURS ON 6126/90, A REACTOR TRIP g OCCURRED FROM APPROM. 30E OF RATED THERMAL POWER ON LOW DEPARTURE FROM b' NUCLEATE 8 OILING RATIO. THE CAUSE OF THE REACTOR TRIP WAS ATTRI6UTED TO AN ERRONEOUS INDICATION RECEIVE 0 BY CONTROL ELEMENT ASSEM8LV i' CALCULATOR (CEAC) 81 FROM REED SWITCH POSITION TRANSMITTER (RSPT) 81 te g ON A PART LENGTH CONTROL ELEMENT ASSEMBLY (CEA 29). A LARGE PENALTT j FACTOR WAS CALCULATED 87 CEAC #1 AND RESULTED IN THE GENERATION OF A REACTOR TRIP SIGNAL FROM THE CORE PROTECTION CALCULATORS (CPCS). THE j ,; ROOT CAUSE OF THE HIGH IN01 CATION HAS NOT SEEN DETERMINED. A TEMPORARY MODIFICATION WAS INSTALLED FOR CEA 29, RSPT #1 WHICH I PROVIDED A FIXE 0 SIGNAL FOR THE CEA AT A FULL OUT VALUE. THE SAFETV

          ,g        FUNCTION OF THE CEA WAS UNAFFECTED WITH THE TEMPORARY MODIFICATION

p. INSTALLE0. TRAINING WAS PROVIDED TO THE OPERATIONS STAFF RESPONSIBLE -

FOR THE APPROACH TO CRITICALITY. ADDITIONALLY, APPROPRIATE PROCEDURE i . ' ' .; REVISIONS WERE MADE AND A CAUTION CARD INSTALLE0 ON THE CONTROL PANEL TO ADDRESS PLACING CEAC 81 IN AN IMOPERA8LE CONDITION IF THE PARY 4 .t LENGTH CEAS WERE GOING TO SE INSERTED. PLACING CEAC 81 IN AN l'

         ,i  '      INOPERASLE CONDITION BLOCKS ANT CEA POSITION SIGNALS SENT TO THE CPCS AND THEREST, PREVENTS 44 UNNECESSARY REACTOR TRIP. THE CEAC/CPC
    ,               SYSTEMS FUNCTIONED AS DESIGNED.

l I i FORM 57 LER SCSS DATA 04-19-91

         ,,     De***********************************************e************e******

OOCKET VEAR LER NUM8ER REVISION OCS NUMBER 4 ' NSIC EVENT DATE 368 1990 019 0 9010010100 219614 03/21/90

, ,

eeee**********ene*e**e***ee.**e******eee****e****** ease **** ease ***

ASSTRACT I p POWER LEVEL - 100I. ON AUGUST 21, 1990 AT 0216 HOURS, WHILE OPERATING

   .j               AT FULL POWER THE '8' STEAM GENERATOR (SIG) MAIN STEAM ISOLATION VALVE t

, (MSIV) CLOSED FULLY RESULTING IN AN AUTOMATIC REACTOR TRIP GENERATED (* ST THE CORE PROTECTION CALCULATORS (CPCS). THE CPC TRIP WAS INITIATED

     ,,             DUE,TO A SENSE 0 TEMPERATURE DIFFERENCE SETWEEN THE REACTOR C00LANY L

                ...s...cs   r os a:v.s n:43 W:Mov&L. THI 'd' 3/G MAIN STIAM 5AFETY VALVES ODENED TO LIMIT SIG SEC0 HOARY PRESSURE AND RESEATED PROPERLV p1 FOLLOWING THE REACTOR TRIP. OTHIR PLANT SYSTEMS RESPONDED PROPERLY TO THE TRANSIENT. SUBSEQUENT INVESTIGATIONS REVEALED THE M51V CLOSURE
  ,,            USS DUE TO THE FAILURE OF A NORMALLY ENERGIZED, 125 VOLT OC 50LEN010
        ,j      ON AN AIR SUPPLY VALVE TO THE MSIV. THE ROOT CAUSE OF THE SOLEN 0ID FAILURE COULD NOT BE DETERMINE 0. THE SOLENOID WAS REPLACE 0 AND THE WW MSIV WAS STROKE TESTED FOR OPERASILITY. APPROXIMATELY ONE HOUR AFTER THE TRIP THE INDICATION ON THE 'A' 5/G SLOWDOWN LINE RADIATION MONITOR pq            WAS NOTED TO BE SLIGHTLY ELEVATED. ANALYSIS OF 5/G SECONDARY WATER CONFIRMED THAT A VERY SMALL PRIMARY TO SECONDARY LEAK EKISTED. THE LEAK RATE STA81LIZED AT THIS VALUE AN3 HAS NOT INCREASED. THERE WAS IN NO ACTUAL SAFETY SIGNIFICANCE AS THE RESULT OF THIS EVENT.

1 D1 , FORM 58 LER SC55 DATA i be 0************************************************************04-18-91 ******** DOCKET VEAR LER NUMBER REVISION rJCS NUMB ER NSIC EVENT DATE 368 1990 020 0 1011020140 219912 09/28190 D" 1

              *************************************e******************************
; hw          AB5 TRACT POWER LEVEL - 082%. AT 2142 HOURS uM 9/20190, DURIMG A PLANNED POWER y,            REDUCTION FROM FULL POWER, MAIN CONDEMSCR CIRCULATING WATER PUMP 2P-38 WAS SECURED. THE PUMP OISCHARGE VALW! FAILED TO AUTOMATICALLY CLOSE De            ALLOWING A FLOWPATH FOR CIRCULATING WATER FLOW TO STPA55 THE MAIN i      CONDEN5ER. AT 2143 HOURS AN AUTOMATIC MAIN TURBINE TRIP ON HIGH CONDENSER PRES $URE OCCURRED AND CONTROL ROOM PERSONNEL MANUALLY D4            TRIPPE0 THE REACTOR IN ANTICIPATION OF AN AUTOMATIC REACTOR TRIP.             THE EMERGENCY FEE 0 WATER SYSTEM, ACTUATED AUTOMATICALLY AND WAS USED TO RESTORE AN3 MAINTAIN NORMAL STEAM GENERATOR WATER LEVELS. THE PLANT WAS SU85EQUENTLY STABILIZE 0 IN MODE 3 (HOT STAN08Y) CONDITIONS.

INVESTIGATIONS REVEALEO THAT THE VALVE FAILED TO CLOSE QUE TO A 8i MECHANICAL KEY WHICH 015 ENGAGED FROM THE MOTOR SHAFT ALLOWING THE MOTOR PINION GE AR TO TURN FREELY ON THE SHAFT. V!8 RATION CAUSED 4

s. SETSCREW USED TO SECURE THE KEY TO LOOSEN. THE ROOT CAUSE WAS DETERMINE 0 70 SE INADE00 ATE WORK INSTRUCTIONS LEADING TO THE PREVIOUS

              INSTALLATION OF A SETSCREW THAT WAS TOO SMALL TO ALLOW PROPER LOCKWIRING. THE PROCEDURE FOR MOTOR PINION GEAR INSTALLATION HAS BEEN CHANGED TO INCLUDE DETAILED INSTRUCTIONS ON MOTOR PINION GEAR e            INSTALLATION. HOWEVER, THE PROCEDURE WILL SE EVALUATED TO DETERMINE IF A00!TIONAL GUIDANCE CONCERNING THE SELECTION OF SETSCREWS IS
  ,,           WARRANTED.

i

  '                     59 FORM                          LER SCSS DATA                           04-18-91 0*********'**********************************************************

DOCKET YL 1 LER NUMBER REVISION 0C5 NUM8ER NSIC EVENT DATE 369 1989 004 0 8905020429 213752 03/07/89 A85 TRACT POWER LEVEL - 1005. 04 MARCM 7, 1989 AT 2345, AN ALERT CONDITION WA5 DECLARED ON UNIT 1 SECAUSE OF INDICATION OF PRIMARY TO SECONOARY LEAKAGE IN EXCESS OF 50 GP4 AT 2346, UNIT 1 WAS MANUALLY TRIPPED FROM MODE 1, POWER OPERATION, APPROXIMATELY 83% POWER SECAUSE OF

     ,         INDICATIONS OF A STEAM GENERATOR TU8E LEAK IN THE 8 STEAM GENERATOR.

ALL MAJOR PLANT EQUIPMENT FUNCTIONED PROPERLY, AND THE UNIT WAS STASILIZED IN ACCORDANCE WITH STATION 48MORMAL OPERATING PROCEDURES.

     ,         THE INITIAL NOTIFICATIONS 70 THE STATE, LOCAL COUNTY AUTHORITIES AND THE RESIDENT NRC INSPECTOR WERE MADE AT 2353. THE MRC REGION II
  ,-           CFFICE WAS NOTIFIED AT 0344 04 MARCH 8,        1989. THE TECHNICAL SUPPORT
     ,         CENTER AND OPERATIONAL SUPPORT CENTER WERE FULLY STAFFED AND ACTIVATED SY 0132. THE CRISIS MANAGEgENT CENTER WAS STAFF?n ann erTTveten av

                                                                                              . ==

mv . ... L e m a s a .- int IJs '%ILURd KILL 3E SODRESSED IN AN A30EN3UM TO THIS LER. 91 1 g4 FORM 60 LER SCSS DATA 0**++********************************************************04-18-91 ******** DW DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 369 1989 022 1 9006110089 218401 08/26/89 P1 ABSTRACT d POWER LEVEL - 1001. ON AUGUST 26, 1989 AT 0934, A UNIT 1 REACTOR TRIP OCCURRED 8ECAUSE OF A REACTOR COOLANT (NC) LOW FLOW SIGNAL THAT IS be INTERLOCKED WITH A PERMISSIVE SIGNAL WHICH BLOCKS A REACTOR TRIP WHEN THE UNIT IS LESS THAN 48 PERCENT POWER (P-8 PERMISSIVE). UNIT 1 WAS OPERATING IN MODE 1, POWER OPERATION, AT 100 PERCENT POWER PRIOR TO gg THE TRIP. A LOW NC FLOW SIGNAL WITH P-8 PERMISSIVE CAUSED REACTOR TRIP BREAKER "A" TO TRIP THE UNIT. THE SIGNAL WAS CAUSED BY A FAILED U" UNIVERSAL BOARD IN THE SOLID STATE PROTECTION SYSTEM (SSPS) CASINET FOR TRAIN "A". THE TUR8INE GENERATOR AUTOMATICALLY TRIPPED SECAUSE OF THE REACTOR TRIP. ALL SYSTEMS AND EQUIPMENT RESPONDED AS EXPECTED be FOLLOWING THE TRIP WITH ONE EXCEPTION. OPERATIONS PERSONNEL IMPLEMENTED THE REACTOR TRIP RECOVERY PROCEDURE TO RECOVER FROM THE be TRANSIENT. AT ABOUT 1000, OPERATIONS PERSONNEL MADE THE REQUIRED NOTIFICATION TO THE NRC. AT 2220, INSTRUMENTATION AND ELECTRICAL De PERSONNEL DISCOVERED THE FAILED UNIVERSAL BOARD AND REPLACED IT. THE SSPS CASINET WAS TESTED AFTER THE SOARD WAS REPLACED TO ENSURE THE TRAIN WOULD OPERATE PROPERLY. UNIT 1 WAS RETURNED TO MODE 1, POWER R1 OPERATION, ON AUGUST 29, 1989 AT 1230. THIS EVENT IS ASSIGNED A CAUSE OF EQUIPMENT FAILURE / MALFUNCTION. THIS EVENT IS NUCLEAR PLANT l b RELIA 81LITY DATA SYSTEM REPORTABLE. THE BOARD WILL BE SENT TO

 '          WESTINGHOUSE FOR REPAIR AND FAILURE ANALYSIS.

1 Ae FORM 61 LER SCSS DATA 04-1

s. 0****************************************************************8-91 ****

DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE

369 1990 001 0 900214004S 216921 01/08/90 4 ABSTRACT POWER LEVEL - 1001. ON 1/5/90, AT 1015, A UNIT 1 TURBINE TRIP / REACTOR TRIP OCCURRED WHEN BOTH MAIN FE!0 WATER PUMPS TRIPPED ON LOW SUCTION PRES $URE. UNIT 1 WAS OPERATING IN MODE 1 AT 1001 POWER PRIOR TO THE l TRIP. A T30UBLE ALARM WAS RECEIVED FOR CFP "A" SPEED CONTROLLER AND IMMEDIATELY CFP "A" STARTE3 RECUCING SPEED. OPERATIONS PERSONNEL INITIATED A MANUAL TURSINE RUNBACK TO COMPENSATE FOR THE LOSS OF FEEDWATER FLOW FROM CFP "A". THEN CFP "A" SPEED CONTROLLER WITHIN MINUTES STARTED INCREASING SPEED. THIS ATTRIBUTED TO THE LOW SUCTION PRESSURE THAT TRIPPED SOTH CFP "A" AND "8". SPEED CONTROLLER MALFUNCTION WAS DUE TO THE STRAINER IN THE CONTROLLER SECOMING CLOGGED WITH SLUDGE. SPEED CONTROLLER CONTROL OIL IS SUPPLIED BY THE FEE 0 WATER PUMP TURSINE LUBE AND HTDRAULIC OIL (LF/LP) SYSTEM WHICH
,. SHARE THE CIL PURIFIER IN THE MAIN TURSINE LUBRICATING AND PURIFICATION OIL (LT) SYSTEM. THERE WERE SEVERAL ANOMALIES AS PLANT EQUIPMENT RESPONDED TO THE TURBINE TRIP / REACTOR TRIP. OPERATIONS
, PERSONNEL IMPLEMENTED REACTOR TRIP RECOVERY PROCEDURE TO RECOVER FROM THE TRANSIENT. AT 1148, OPERATIONS PERSONNEL MADE THE REQUIRED I NOTIFICATION TO THE NRC. UNIT 1 THEN ENTERED A REFUELING OUTAGE FOR
, TURSINE REPAIR. CAUSE IS OTHER/ UNKNOWN SECAUSE IT COULD NOT BE DETERMINED H3W EXCESSIVE WATER IN THE LT AND LF SYSTEM RESULTED IN I SLUDGE COLLECTING IN THE STRAINER.

g 1

              . . . . .     .... ... 4..m e .   =cv424ul  uts muMotR    hilC       EVENT JATE 369     1999         027             0    90111902:9 220077          10/13/90 y,           eeeeeeeeeee.....eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee........eeeee y,           ABSTRACT j;     POWER LEVEL - 1003. ON OCTOBER 13, 1990, AT 1033, UNIT 1 EXPERIENCED A i              REACTOR TRIP /TUR81NE TRIP. UNIT 1 WAS IN MODE 1, POWER OPERATION, AT WW             100 PERCENT POWER AT THE TIME OF THIS EVENT. THE FIRST OUT (FO) g       ti     ANNUNCIATOR INDICATED AN "SSPS GENERAL WARNING - RX TRIP."                 PRIOR TO eq ~           THE REACTOR TRIP, INSTRUMENTATION AND ELECTRICAL (IAE) PERSONNEL WERE PERFORMING THE 81-MONTHLY PERIODIC TEST ON THE SOLID STATE PROTECTION SYSTEM (SSPS) TRAIN 8. THE " GENERAL WARNING" SIGNAL WAS GENERATED h4             SECAUSE OF THE FAILURE / MALFUNCTION OF A REACTOR TRIP BREAKER CELL SWITCH.       THE ONLY SAFETY SYSTEM ACTUATION THAT OCCURRED 45 A RESULT OF b4     ,,

THE TRIP WAS THE START OF THE AUEILIARY FEE 0 WATER (CA) PUMPS. OPERATIONS (OPS) PERSONNEL IMPLEMENTED THE REACTOR TRIP / SAFETY gg INJECTION PROCEDURE AND THEN ENTERED THE REACTOR TRIP PROCEDURE. OPS PERSONNEL IMPLEMENTED THE UNIT FAST RECOVERY PROCEDURE TO RECOVER FROM hm THE REACTOR TRIP. AT 1200, OPS PERSONNEL MADE THE REQUIRED NOTIFICATION TO THE NUCLEAR REGULATORY COMMISSION (NRC). IAE PERSONNEL REPLACED THE FAILE0 CELL SWITCH. OPS CONTROL ROOM PERSONNEL I bg RETURNED UNIT 1 TO MODE 1 (POWER OPERATION) ON OCTOBER 14, 1990, AT i 1825. THIS EVENT HAS SEEN ASSIGNED A CAUSE EQUIPMENT g, FAILURE / MALFUNCTION BECAUSE OF THE FAILED CELL S WI TC H. THIS EVENT IS NUCLEAR PLANT RELIABILITY DATA SYSTEM REPORTA8LE AND PART 21 REPORTABLE. THE SWITCH WILL BE SENT OFFSITE FOR FURTHER FAILURE 83 ANALYSIS. 1 D1 FORM 63 LER SCSS DATA 04-1

     '      0****************************************************************8-91            ****

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 369 1990 032 0 9012210150 220547 11/17/90 As enea ....e** .................................**.................... g, A85 TRACT POWER LEVEL - 100%. ON NOVEM8ER 17, 1990, AT 0319, UNIT 1 EXPERIENCE 0

   ,,           A TUR8INE TRIP, FOLLOWED ST A REACTOR TRIP. THE TRIP WAS INITIATED ST THE 8 LOW PRESSURE (LP) TURSINE HIGH EXHAUST N000 TEMPERATURE SIGNAL.

PRIOR TO THE EVENT, UNIT 1 WAS OPERATING IN MODE 1 (POWER OPERATION) t AT 100 PERCENT POWER. OPERATIONS (OPS) CONTROL ROOM PERSONNEL IMPLEMENTED PROCEDURE EP/1/A/5000/01, REACTOR TRIP OR SAFETY INJECTION, AND THEN ENTERED PROCEDURE EP/1/A/5000/1.3, REACTOR TRIP. OPS PERSONNEL MADE THE REQUIRED NOTIFICATION TO THE NRC PER PROCEDURE

   '          'RP/0/4/5700/10, NRC IMMEDIATE NOTIFICATION REQUIREMENTS. THE MOTOR DRIVEN AUXILIARY FEEDWATER PUMPS STARTED AS REQUIRED, DUE TO A LOW LOW STEAM GENERATOR (S/G) WATER LEVEL. THERE WERE NO OTHER SAFETT SYSTEM t            ACTUATIONS. OPS CONTROL ROOM PERSONNEL ENTERED PROCEDURE OP/1/4/6100/05, UNIT FAST RECOVERY.            ON NOVEM8ER 17, 1990, AT 1821,
   ,            UNIT 1 ENTERED MODE 1            IT WAS DETERMINED BY INSTRUMENT AND ELECTRICAL (IAE) PERSONNEL THAT THE TRIP SIGNAL WAS RECEIVED BECAUSE OF A DAMACED LP TURSINE EXHAUST HOOD TEMPERATURE INSTRUMENT. T3 PREVENT RECURRENCE OF THIS EVENT, MAINTENANCE ENGINEERING SERVICES (MES)

PERSONNEL WILL EVALUATE THE USE OF A DUAL ELEMENT THERMOCOUPLE OR POSSIBLE USE OF A TWO CUT OF TWO LOGIC FOR THE TEMPERATURE SIGNAL. THIS EVENT HAS BEEN ASSIGNED A CAUSE OF UNKNOWN SINCE IT CANNOT BE

       ,        DETERMINED WH AT CAUSED THE TEMPERATURE INSTRUMENT TO SECOME DAMAGED.
   '          FORM         64                    LER SCSS DATA
       ,,                                                                               04-18-91 0**************************=.*...**+a********************************

DOCKET TERR LER NUM8ER REVISION DCS NUM5ER NSIC EVENT DATE g 370 1959 001 0 8904180249 213676 03/03/89

ev.=% tsutt - l uu t. os 3/ 5/ s95 AT US14, WHILE OPERATION S PERSONNEL WERE PERFOR41Ni A ROUTINE 200 CLUSTER CONTROL ASSEMBLT MOVEMENT TEST i p1 ON THE UNIT 2 ROD CONTROL STSTEM, A HIGM NEGATIVE NEUTRON FLUX RATE REACTOR TRIP GCCURRED SECAUSE OF CONTROL R005 OROPPING INTO THE CORE. gq THE TU181!!E GENERATOR AUTOMATICALLY TRIPPED BECAUSE OF THE REACTOR TRIP. OPERATIONS PERSONNEL IMPLEMENTED THE REACTOR TRIP RECOVERY PROCEDURE TO RECOVER FROM THE TRANSIENT. AT 0855, OPERATIONS WW PERSONNEL MADE THE REQUIRE 0 NOTIFICATION TO THE NRC. SINCE IT COULO 99 NOT BE DETERMINED WHAT CAUSED THE CONTROL R005 TO OROP, AN INDEPENDENT eq TECHNICAL REVIEW WAS PERFORMED ON THE EVENTJ CONSEQUENTLY, A DECISION WAS MADE SV STATION MANAGEMENT PERSONNEL AT APPR0xIMATELY 0230 ON

         ,,        MARCH 4,    1989 TO RESTART THE REACTOR. UNIT 2 Was RETURNED TO POWER Ed '              OPERATION ON MARCH 4,       1989 AT 0555. THIS EVENT IS ASSIGNED A CAUSE OF UNKNOWN SECAUSS IT COULO NOT BE DETERMINE 0 OURING THE COURSE OF THIS De      i,        INVESTIGATION WHAT CAUSED THE CONTROL R005 TO OROP INTO THE CORE.

1 ka

              ,   FORM      65                    LER SCSS DATA                           04-18-91
  ""            0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE i. I 370 1989 002 0 8904200281 213596 03/14/89 kg ...................................................**............... g,f A85 TRACT POWER LEVEL - 09S1. ON MARCH 14, 1989 AT 0412, THE UNIT 2 TRAIN 8 MAIN FEE 0 WATER PUMP TURBINE (CFPT) TRIPPEO. A UNIT 2 RUNSACK RESULTED D8

        .g         BECAUSE OF THE LOSS OF THE 28 CFPT. OPERATIONS PERSONNEL IMPLEMENTED PROCEDURE AP/2/A/5500/03, LOAD REJECTION, AND HAD COMPLETED ALL P1              IMMEDIATE ACTIONS WHEN VALVE 2CM-420, GENERATOR LOAD REJECTION BYPASS, i
           '       FAILE0 TO OPEN AS REQUIRED ON A RUNBACK SIGNAL. THE FAILURE OF VALVE 1
   ,,              2CM-420 TO OPEN PREVENTED ADDITIONAL SUCTION FLOW TO BE PROVIDEO FOR I

THE 2A CFPT, AND CONSEQUENTLY, LEVELS IN 8 AND C STEAM GENERATORS

           .       (SGS) 8EGAN TO DECREASE". AT 0415, THE UNIT 2 REACTOR TRIPPE0 BECAUSE D'              0F A LOW-LOW LEVEL IN 28 SG. THE MAIN TURBINE TRIPPED BECAUSE OF THE REACTOR TRIP. ALL THREE AURILIARY FEE 0 WATER PUMPS AUTOMATICALLY

t. ,i STARTED AS REQUIRED TO RECOVER SG LEVELS. UNIT 2 WAS IN MODE 1, POWER OPERATION, AT 981 POWER AT THE TIME THIS INCIDENT OCCURREO. THIS EVENT HAS BEEN ASSIGNED A CAUSE OF OTHER, EQUIPMENT

       ,,          FAILURE / MALFUNCTION BECAUSE OF A FAILURE OF SUCTION PRESSURE SWITCHES ON 28 CFPT AND A SROKEN AIR SUPPLY LINE TO VALVE 2CM-420.

I 1

   ,,             FORM      66                   LER SCSS DATA                            04-18-91 0**************. ************. ..***+*****************************.*.
   '   ,.         DOCKET TEAR LER NUMSER REVISION OCS NUMSER                  NSIC      EVENT DATE 370     1959       003             1      8912140098 216150          04/06/89
    '  e ASSTRACT g              POWER LEVEL - 1003. ON APRIL 6,          1989 AT 0503, a UNIT 2 REACTOR TRIP
       ..          OCCURREO SECAUSE OF LOW-LOW LEVEL IN STEAM GENERATOR 2C.              THE UNIT WAS OPERATING IN MODE 1 (POWER OPERATION) AT 1001 POWER PRIOR TO THE TRIP. THE LOW-LOW LEVEL CONDITION WAS CAUSED BY THE FAILURE OF THE
       ,           BELLOWS IN THE POSITIONER FOR VALVE 2CF-20, STEAM GENERATOR 2C MAIN FEE 0 WATER (CF) REGULATING VALVE. THE TURSINE GENERATOR AUTOMATICALLY TRIPPED BECAUSE OF THE REACTOR TRIP. OPERATIONS PERSONNEL IMPLEMENTED
       ,           THE REACTOR TRIP REC 0 VERT PROCEDURE TO RECOVER FROM THE TRANSIENT.            AT 0542, CPERATION$ PERSONNEL MADE THE REQUIRED NOTIFICATION TO THE NRC.

INSTRUMENTATION AND ELECTRICAL PERSONNEL COMPLETED THE REPLACEMENT g 0F THE FAILED FEEDSACK SELLOWS IN THE POSITIONER FOR VALVE 2CF-20 AND THE OTHER 3 UNIT 2 S/G CF FLOW CONTROL VALVES AT 1459. THE FAILEO e OELLOWS WAS SENT TO THE DUKE POWER COMPANY METALLURGY LABORATORY FOR g ANALYSIS. THE REFUELING OUTAGE PREVENTIVE MAINTENANCE (PM) FOR THE CF REGULATING VALVES WILL 48 RSVT%F4 To eco, arc vac esca. e, ne..~..

e..... .. ,ua_ or eat r atu<c 06 TME FEiO3ACK eELLOWS IN THE POSITIONER FOR VALVE 2CF-20. P1 1 g4 FORM 67 LER SCSS OSTA qg 0************************************************************04-18-91 ******** h4 DOCKET TEAR LER NUMBER REVISION OCS NUM8ER NSIC EVENT DATE 370 1990 008 0 9101310207 220S45

 ,       a,       ************************************************************12/27/90   ********

P1 A85 TRACT 4 qi' POWER LEVEL - 000%. ON 12/27/90 OPERATIONS (OPS) AND PERFORMARCE (PRF) REACTOR GROUP PERSONNEL WERE PERFORMING ROUTINE ROD MOVEMENT TESTING WM ASSOCIATED WITH ZERO POWER PHYSICS TESTING (ZPPT). OPS PERSONNEL g; ATTEMPTED TO INSERT SHUTDOWN BANK E FROM THE FULLY WITHDRAWN POSITION. SHUTDOWN SANK E FELL INTO THE CORE AT 0141:25, TAKING THE REACTOR gn SU8 CRITICAL. AT 0142:15, OPS PERSONNEL INITIATED A MANUAL REACTOR g, TRIP. OPS PERSONNEL THEN IMPLEMENTED THE REACTOR TRIP AND UNIT FAST U" RECOVERT PROCEDURES TO RECOVER FROM THE TRANSIENT. AT 0225, OPS PERSONNEL MADE THE REQUIRED NOTIFICATION TO THE NRC. SINCE IT COULO

           ;.       NOT SE DETERMINED WHAT CAUSED SHUTOOWN SANK E TO DROP, AN INDEPENDENT be                 TECHNICAL REVIEW WAS PERFORMED ON THE EVENT AND, CONSEQUENTLY, ON 12/28/90 AT 0918, A DECISION WAS MADE ST STATION MANAGEMENT PERSONNEL 3, , a             TO RESTART THE PEACTOR.         UNIT 2 WAS RETURNE0 TO MODE 2 (STARTUP)

OPERATION ON 12/23/90, AT APPROXIMATELY 1234 THIS EVENT IS ASSIGNED Ds A CAUSE OF POSSISLE EQUIPMENT FAILURE / MALFUNCTION BECAUSE IT COULD NOT BE DETERMINED OURING THE COURSE OF THIS INVESTIGATION WHAT CAUSED THE SHUTDOWN SANK E TO OROP INTO TH! CORE. MAINTENANCE ENGINEERING Pw SUPPORT (ME$) PERSONNEL WILL DEVELOP A PLAN TO PERFORM FURTHER TESTING p IN AN ATTEMPT TO FIND A CAUSE.

 ,,            1 I

FORM 68 LER SCSS DATA h6 0************************************************************04-18-91 ******** DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE y, , 373 1989 009 1 8907110299 214561 03/02/89 1

      ,,         A85 TRACT POWER LEVEL - 086E. ON 3/2/$9, AT 2302 HR$ A PHASE TO GROUND FAULT I                 OCCURRED AT "C" PHASE LIGHTNING ARRESTOR ON THE PRIMARY SIDE OF THE UNIT 2 SYSTEM AUI. TRANSFORMER. FAULT WAS AUTOMATICALLY ISOLATED ST
 ,                  THE TRIPPING OF SWITCHTARD OIL CIRCUIT BREAKERS (OCS) 4-6 AND 6-1 ANO UNIT 2 FEEDER BREAKERS. ALL LOADS BEING FED FROM THE SAT TRANSFERRED TO UNIT 2 UNIT AUE. TRANSFORMER EXCEPT FOR BUS 243 WHICH WAS SUPPLIED 8Y 25 OIESEL GENERATOR WHICH SATISFACTORILY AUTC-STARTED ON UNDERVOLTAGE. UNIT 2 REMAINED ON-LINE AFTER THE INCIDENT. AS A e
      ,            RESULT OF TRANSIENT ON THE 345 KV SYSTEM, UNIT 1 GENERATOR PROTECTIVE RELATING SENSED A HIGH GENERATOR OIFFERENTIAL CURRENT ON PHASE A AND
 ,                 ISOLATED UNIT 1 GENERATOR. UNIT 1 TUR8INE TRIPPED 04 LOAD REJECTION RESULTING IN A REACTOR SCRAM FROM TURSIME CONTROL VALVE FAST CLOSURE.

UNIT 1 PROCEEDED INTO NORMAL POST-SCRAM CONDITIONS WITH THE EXCEPTION 0F TEMPORARY LOSS OF THE SERVICE AIR COMPRESSOR AND PLANT P40 CESS

     ,             COMPUTER.      PR08LEMS WERE ALSO ENCOUNTERED WITH THE RESETTING OF THE SCRAM LOGIC. CAUSE OF THIS EVENT WAS THE PHASE TO GROUND FAULT THAT OCCURRED FROM THE LIGHTNING ARRESTOR TOP CAP TO A SPARGER HEAD ON THE TRANSFORMER DELU;E SYSTEM.          THIS WAS EVIDENT FROM ARC SURNING IDENTIFIED AT TOP OF LIGHTNING ARRESTGR AND AT SPARGER HEAD. FAULT WAS CAUSED BY DESRIS THAT HAD BLOWN ONTO THE LIGHTNING ARRESTOR LEAD.

q 1 g FORM 69 LER SCSS DATA 04-18-9 g 0********************************************************************1

 ,              00CKEY TEAR LER NUM8ER REVISION DCS NUMBER                 NSIC       EVENT SATs

ASSTROCT y4 P3dtR LEVEL - 100%. ON 3/23/93 At 0337 MOURS UNIV 1 eAS 2N OPERATIONAL CONDITION 1 (RUN) AT 100% #0 dero AT THIS TIME THE "B" PHASE b4 INSULATOR QETCEEN THE UCIT 1 EAST / WEST MAIN POWER TRANSFORMERS AND THE i SWITCHYARD, FAILED AND FLASHED OVER TO GROUND. AS A RESULT OF THIS FLASH 0VER, THE "B" AND "C" W4 PHASE DIFFERENTIAL CURRENT RELAYS 80TH TRIPPED CAUSING THE UNIT 1 MAIN GENERATOR TO LOCKOUT, WHICH RESULTED , , IN A MAIN TURSINE TRIP. THIS IMMEDIATELY CAUSED THE UNIT 1 REACTOR 70 pq SCRAM. THREE SAFETY RELIEF WALVES ACTUATED TO CONTROL REACTOR PRESSURE. THE "B" PHASE INSULATOR WAS REPLACEO ON 3/29/90. THE b4 t.* REMAINING INSULATORS WERE INSPECTED AND NO SIGNIFICANT PROBLEMS WERE NOTED. ONE ADDITIONAL INSULATOR WAS REPLACED OUE TO MINOR CHIPPING. UNIT 1 WAS STARTE0 8ACK UP AND THE GENERATOR SYNCHRONIZE 0 TO THE GRID pq ; AT 0310 HOURS ON 3/31/90. THIS EVENT IS REPORTA8LE PURSUANT TO THE REQUIREMENTS OF 10CFR50.73(A)(2)(IV) DUE TO THE ACTUATION OF AN ENGINEERED SAFETY FEATURE SYSTEM. DR. , 1 D" FORM 70 LER SCSS DATA

      ,,  0************************************************************04-18-91 ********
>=           DOCKET TEAR LER NUMBER REVISION DCS MUMSER            NSIC       EVENT DATE 373    1990       010          0     9005010023 219070         06/26/90 D'     8'     ********************************************************************

ABSTRACT ts, POWER LEVEL - 0751 ON 6/26/90 AT 0453 HOURS WITH UNIT 1 IN OPERATIONAL CONDITION 1 (RUN) AT 75% POWER, A REACTOR SCRAM OCCURRED pq DURING THE PERFORMANCE OF LA5ALLE LIMITED PROCEDURE LLP-90-027, " UNIT 1 TUR81NE STOP VALVE (TSV) SCRAM FUNCTIONAL TEST". THE SCRAM OCCURRED

"'              AS DESIGNE0, DUE TO THE CLOSING OF TURSINE STOP VALVES 1, 3, AND 4 I              AFTER 82 TSV WAS CYCLED AND ITS OPEN LIMIT SWITCH FAILED. IT WAS DISCOVERED DURING THE SCRAM INVESTIGATION THAT THE s2 TSV OPEN LIMIT to             SWITCH (SV05-2, NON REACTOR PROTECTION SYSTEM LIMIT SWITCH) HAD FAILED TO THE NOT OPEN POSITION. THIS FAILURE OCCURRED 5/22/90 AT 0359 g4 ,i          HOURS, THE LAST TIME THIS PROCEDURE WAS PERFORMED.       AT THIS TIME, THE VALVE TEST LOGIC OF TURBINE ELECTRO HTORAULIC CONTROL SYSTEM (EHC)

SEALE0 IN THE MASTER / SLAVE INTERLOCK. THIS PREVENTS THE OTHER TSYS

,:           FROM CLOSING WHILE 82 TSV 15 TESTED. ON 6/26/90 AT 0453 HOURS, 82 TSV WAS TESTED AND CLOSED TO A80UT 901 OPEN. WHEN THE VALVE FULLY OPENED, e

LIMIT SWITCH SWOS-2 TOGGLED TO THE OPEN POSITION (DUE TO A LOOSE

    ,,         MOUNTING OF THE SWITCH, CAUSED BY VIBRATIONS). THIS BROKE THE SEAL-IN
,,             INTERLOCK. A SECONO LATER, IT TOGGLED BACK TO GIVE A NOT OPEN ALARM AND COMMANDED THE OTHER TSVS TO Go FULL CLOSE. THE EMERGENCY CORE I
    ,         COOLING SYSTEMS (ECCS) AND THE REACTOR CORE ISOLATION COOLING SYSTEM WERE AvaILABLE DURING THE EVENT. THE 18 TORFP WAS TESTED AND FUNCTIONED AS DESIGNED.

I e 6 FORM 71 LER SCSS DATA 04-18-91

   ,,     0********************************************************************

DOCKET TEAR LER NUM8ER REVISION DCS NUM8ER NSIC EVENT DATE

'                374    1989       011          1     9001090077 216355         08/26/a9 i

1 A85 TRACT POWER LEVEL - 010%. ON S/26/89, A CONTROLLED SHUTDOWN WAS IN PROGRESS ON UNIT 2. WHILE CONDUCTING LOS-TG-SA2, "TUR81NE VALVE LEAK TIGHTNESS ! SURVEILLANCE," 4 REACTOR PROTECTION SYSTEM (RPS) ACTUATION OCCURREO t g. AT 0414 HOURS. WHEN THE ACTUATION SIGNAL WAS RECEIVED, TWO OF THE FOUR SCRAM GROUP LIGHTS OF THE RPS BUS "A" A REMAINED ENERGIZED. THIS 9 PREVENTED SOME OF THE RODS FROM RECEIVING THE NORMAL AUTOMATIC SCRAM

,  g.         ACTUATION. ROD MOTION APPEARS TO HAVE INITIATED FOR THESE RODS DUE TO

, THE CHANNEL "A" 84CKUP SCRAM ACTUATION WHICH OCCURRED AT THF %AMC

t

                   .. 4.n-.. esa.i_useuna. as s112 lime ALL THE REMAINING SCRAM VALVES OEENERGIZED, IN3ICATING THAT THE SCRAM MAD OCCURRE3. SEFORE THE P1                TURBINE VALVE TEST uAS STARTEC, THE HATHAWAY SECUENCE OF EVENTS ALARM TYPER WAS TU2NEO OFF QUE TO ITS CONSTANT PRINTING CAUSED BT ALARM bg               KELAY CHATTERI%G. A5 A CESULT, THE MAIN SOUICE OF INFORMATION TO CE i.

USED IN ANALYZING THE REACTOR TRIP WAS NOT AVAILA8LE. AT THE TIME OF THE TRIP, MO PLANT PARAMETERS EXCEEDED THEIR TRIP SETPOINTS. A5 A he RESULT OF THE MISSING INFORMATION, SEVERAL SCENARIOS WERE DEVELOPE 0

 ,        i:

USING AVAILABLE INFORMATION IN AN ATTEMPT TO DETERMINE THE CAUSE OF p, THE REACTOR TRIP. AT THIS TIME 4 DEFINITE CAUSE FOR THE TRIP HAS NOT SEEN DETERMINE 0. kG FORM 72 LER SCSS DATA he . 0************************************************************04-18-91 ******** DOCKET ~ TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE g4 374 1990 001 0 9003150291 217392 02/

                 .******.******.******.*.a.*..**....***.***.***..*.*****.*..***.06/90               .***.

b" A85 TRACT POWER LEVEL - 1001. ON 2/6/90 AT 0926 HOURS, WHILE UNIT 2 WAS IN

  >=              OPERATIONAL CONDITION 1 (RUN) AT 99.8% POWER, OURING THE PERFORMANCE OF LASALLE INSTRUMENT SURVEILLANCE LIS-NR-403, " UNIT 2 AVERAGE POWER p,,i            RANGE MONITOR (APRM) ROD SLOCK AND SCRAM FUNCTIONAL TEST," A FULL REACTOR SCRAM OCCURRED. NORMALLY THE SURVEILLANCE ONLY CAUSES HALF-SCRAMS. AT THE TIME OF THE OCCURRENCE, F APRM WAS TRIPPE0, PER D8    ,         THE PROCEDURE, WHICH TRIPPE0 REACTOR PROTECTION STSTEM (RPS) CHANNEL
                  " A" . WHILE THE RPS CHANNEL "A" HALF SCRAM CONDITION WAS IN EFFECT, E pq              APRM SPIKED SPURIOUSLT, CAUSING RPS CHANNEL "B" TO TRIP AND A FULL
       ,.         REACTOR SCR AM OCCURRED. ADDITIONALLY, IT WAS ALSO DETERMINED TH AT ALL
  ,,              OTHER EXPECTED AUTOMATIC ACTIONS OCCURRED AS EXPECTED INCLUDING I               PRIMART CONTAINMENT ISOLATION $1GNALS WHEN REACTOR WATER LEVEL REACHED 12.5 INCHES DECREASING. INITIATION OF THE EVENT WAS NOT DUE TO AM be              ACTUAL TRAN5IENT ON A PARAMETER WHICH IS MONITORED TO PROTECT T;'E REACTOR CORE SUT DUE TO SPURIOUS SPIKE OF APRM E. TROUSLESH00 TING E 3,              APRM WILL CONTINUE UNDER WORK REQUEST L96857 IN AN ATTEMPT TO DETERMINE THE CAUSE OF THE SPURIOUS SPIKES. UNIT 1 WAS NOT AFFECTED ST THIS EVENT. THIS EVENT IS REPORTABLE PURSUANT TO 10CFR50.73(A)(2)(IV) DUE TO AN ACTUATION OF AN ENGINEERED SAFETY FEATURE.

e 1

  ,,             FORM            73                    LER SCS5 DATA                            04-18-91 0********************************************************************

DOCKET TEAR LER NUM8ER REVISION OC5 NUMSER NSIC EVENT DATE 374 1990 010 0 9010170178 219755 09/12/90 t

A85 TRACT

  ,               POWER LEVEL - 100%. 04 9/12/90 AT 0305 hours, WITH UNIT 2 IN
      ,,          OPERATIONAL CONDITION 1 (RUN) AT 99.9% POWER, THE UNIT 2 NUCLEAR STATION OPERATOR (N50, LICENSED REACTOR OPERATOR) WAS PERFORMING TH!

TUR8INE GENERATOR WEEKLY SURVEILLANCE (LOS-TG-W13. AFTER THE N50 MAD

      ,.          PERFORMED THE GENERATOR REGULATOR MODE TRANSFER SWITCH PORTION OF THIS SURVEILLANCE, HE NOTICE 0 A SEVERE TRANSIENT ON SEVERAL GENERATOR OUTPUT INDICATIONS. A FEW SECONOS AFTER THIS, THE 2E MAIN POWER t,          TRANSFORMER "8" PHASE DIFFERENTIAL RELAY ACTUATED WHEN THE CURRENT TRANSFORMER FEEDING THIS RELAY SHORTED OUT TO GROUNO. AS A RESULT,
  '               THE UNIT 2 MAIN GENERATOR LOCKED OUT C AUSING THE MAIN TURBINE TO TRIP.

g THIS IMMEDI ATELY CAUSED THE UNIT 2 REACTOR TO 3 CRAM. FIVE SAFETY RELIEF WALVES ACTUATED TO CONTROL REACTOR PRESSURE. THE INITIAL CAUSE

OF THE TRANSIENT COULO NOT SE DETERMINED. THE "5" PHASE CURRENT

g. TRANSFORMER THAT FEEDS THE "B" PHASE O!FFERENTIAL RELAY SCMEME WA5

  ,               REPLACEO.           ALL AFFECTED CIRCUITS A550CI ATED WITH TME GENsaAToost

                    ... 62..$,ts    c.s
                                           .we w:Ne<4luu WA5 SYNCH 90NIZE0 TO THE GRID AT 0410 40025 04 9/21/23.        THIS EVENT !$ REPCRTABLE PURSUANT TO THE pi REQUIREMENTS OF 13CFR$0.73(A)(2)(IV) DUE T3 THE ACTUATION OF AN ENGINEERED SAFETY FEATURE SYSTEM.

h4 *, FORM 74 LER SCSS DATA b4 0************************************************************04-18-91 ********

   ,             DOCKET YEAR LER NUMSER REVISION OCS NUMBER NSIC     EVENT OATE r,                382        1989     013             0             8938170315 215030        07/15/89 E8            A85 TRACT POWER LEVEL - 1002. ON JULY 19, 1989, WATERFORD STEAM ELECTRIC STATION h4       g,     UNIT 3 WAS OPERATING AT 100% POWER WHEN A RAPIOLY DECREASING LEVEL WAS OBSERVED IN STEAM GENERATOR NUMBER 1.                   THE MAIN FEEDWATER g,              REGULATING VALVE FOR THIS STEAM GENERATOR WAS FOUND CLOSED. THE CONTROLLER FOR THE VALVE WAS SWITCHED TO MANUAL AND THE VALVE WAS b"             OPENED IN AN ATTEMPT TO RESTORE THE STEAM GENERATOR LEVEL. WHEN IT BEC AME APP ARENT THAT THE LEVEL COULD NOT BE RESTORED BEFORE RECEIVING A LOW STEAM GENERATOR LEVEL REACTOR TRIP, 4 MANUAL REACTOR TRIP WAS be INITIATED. THE ROOT CAUSE FOR THE EVENT WAS ATTRIBUTED TO A CIRCUIT FAILURE IN THE POSITION CONTROL CIRCUITRY FOR THE MAIN ANO STARTUP
    ,,,g           FEEDWATER REGULATING VALVES FOR STEAM GENERATOR NUMBER 1. THE CIRCUIT CARD CONTAINING THE FAILED COMPONENT WAS REPLACE 0 AND THE SYSTEM RESTORED TO NORMAL. DURING THE COURSE OF THIS EVENT NO THREAT TO THE Il    ,

HEALTH OR SAFETY OF THE PUBLIC OR PLANT PERSONNEL EXISTED. I l e

          ,,     FORM          75                  LER SCSS DATA
    "'         0************************************************************04-18-91           ********

3 00CKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 382 1989 017 1 9001030256 216334 08/19189

s. ********************************************************************

g. 485 TRACT PUWER LEVEL - 0231. AT 1319 hours ON AUGUST 19, 1989, AN AUTOMATIC REACTOR TRIP OF WATERFORD STEAM ELECTRIC STATION UNIT 3 OCCURRED WHILE f*, OPERATING AT 23% POWER. THE TRIP WAS INITIATED BY THE PLANT I

PROTECTION SYSTEM (PPS) IN RESPONSE TO VARIATIONS IN CORE ARIAL SHAPE INDEM (ASI), A MEASURE OF CORE POWED DISTRIBUTION, INDUCED BY THE DOWN POWER REQUIRED FOR AN A8 NORMAL CONTROL ELEMENT ASSEMBLY (CEA)

     ,             CONFIGURATION. THIS EVENT IS REPORTABLE AS AN AUTOMATIC REACTOR PROTECTION SYSTEM ACTUATION. THE ROOT CAUSE OF THIS EVENT IS
     ' ' ,         EQUIPMENT MALFUNCTION. CURING ROUTINE CEA OPERASILITY TESTING, CEA 18 WOULO NOT MOVE IN EITHER DIRECTION. AFTER REPAIRS WERE MADE TO CEA CONTROL CIRCUITRY, CEA 18 WAS INSERTED BELOW THE TECHNICAL e
         ,         SPECIFICATION (TS) LIMIT OF 145 INCHES WHILE VERIFYING RESPONSE. CEA 18 WOULO NOT WITHDRAW, NECESSITATING A REACTOR POWER REQUCTION PER
     ,             TSS. WHILE ATTEMPTING TO CONTROL ASI SUSSEQUENT TO THE POWER g         REDUCTION, THE REACTOR TRIPPED.           THE DEFECTIVE EQUIPMENT HAS 8EEN REPLACE 0 AND TESTED SATISFACTORILV. SECAUSE PROTECTIVE FEATURES FUNCTIONED AS DESIGNED, THE HEALTH AND SAFETY OF THE GENERAL PUBLIC 09
         ,         PLANT PERSONNEL WAS NOT ADVERSELY AFFECTED BY THIS EVENT.

1 g FORM 76 LER SCSS DATA 04-18-91 0**************************++**************************************** DOCKET TEAR LER NUMSER REVISION OCS NUMBER NSIC EVENT DATE g 332 1989 024 0 9001250231 216495 12/23/89 9 g' A8STRACT POWER LEVEL - 100T. AT 1109 HOURS 04 3?CEMBER 23, tomo, rantone annu

_ . . _ ___ - _ _ = _ , =-- . - .__ _ _ 7 . _

                                                         - . . . . . . . . . w.. 6 .. 46.4'       wcretn*lON (su) 51 AFTER MAIN
                                         *EED RtGULATINr, VALVE (M'pV) 81 UNExDECTEDLY FAIL 53 SHUT.                         SHORTLY y,

AFTER THE REACTOR TRIP M:RV s1 OPENE0 INACVERTENTLY. A REACTOR COOLANT SYSTEM (RCS) COOLDOUN AND A CORRESPONDING RCS PRESSURE DROP TO

                          "              APPC3XIMATELY 1640 PSIA RESULTED, GENEGATING A SAFETY INJECTION p    ACTUATION SIGNAL (SIAS). AN EMERGENCY FEEDWATER ACTUATION SIGNAL (EFAS) WAS ALSO GENERATED OURING THE POST-TRIP TRANSIENT.                          THE ROOT b4 CAUSE OF THIS EVENT APPEARS TO BE AN ANOMALY IN THE MFRV PNEUMATIC
                ,                 je '

CONTROL SYSTEM 8ROUGHT ABOUT 8V COLD WEATHER EFFECTS ON SYSTEM y, COMPONENTS. A VENDOR DIAGNOSTIC TEAM WILL BE CONTRACTED TO PROVIDE AN INDEPTH INVESTIGATION TO AID IN ROOT CAUSE DETERMINATION. IF THE b4 q ROOT CAUSE CAN SE POSITIVELY IDENTIFIED IT WILL BE DESCRIBED IN A REVISION TO THIS REPORT. ALL SAFETY SYSTEMS FUNCTIONED AS DESIGNE01 THEREFORE, THIS EVENT DID NOT THREATEN THE HEALTH AND SAFETT OF THE be 9: GENERAL PUBLIC OR PLANT PERSONNEL. FORM 77 LER SCSS DATA b" 0************************************************************04-18-91 ******** DOCKET YEAR LER NUMBER REVISION 0C5 NUM8ER NSIC EVENT DATE

                                  .,       382    1990           002                0       9004270164 218033               03/22/90 kg                    ********************************************************************

ABSTRACT POWER LEVEL - 1001. AT 2133 HOURS ON MARCH 22, 1990, AN AUTOMATIC D-i REACTOR TRIP OCCURRED AT WATERFORD STEAM ELECTRIC STATION UNIT 3 WHILE THE PLANT WAS OPERATING AT 100% POWER. THE REACTOR TRIP WAS INITIATED SY THE PLANT PROTECTION SYSTEM WHEN TWO CONTROL ELEMENT y, ASSEM8 LIES (CEAS) DROPPED TO THE FULLY INSERTED POSITION WHILE THEIR

                                 ..      DRIVE MECHANISMS WERE 8EING TRANSFERRED FROM THEIR NORMAL POWER SUPPLY E'                    TO THE CONTROL ELEMENT DRIVE MECHANISM SYSTEM (CEDMCS) HOLD BUS.

I THIS EVENT IS REPORTABLE SV REASON OF THE OCCURRENCE OF AN AUTOMATIC

                                 ,:      REACTOR PROTECTION SYSTEM ACTUATION.                   THE ROOT CAUSE OF THIS EVENT WAS be                    AN EQUIP 9ENT MALFUNCTION.               INSPECTIONS SUBSEQUENT TO THE TRIP REVEALED THAT SEVERAL ELECTRICAL CONNECTORS USED TO TRANSMIT POWER g, ,                  FROM THE CEOMCS PANELS TO A CEA ORIVE MECHANISM WERE DAMAGED FROM MISALIGNMENT DURING PREVIOUSLY PERFORME D M AINTENANCE.                        THIS CONDITION .

DISRUPTED THE POWER SUPPLY CIRCUITRY OF THE CEA DRIVE MOTORS AFFECTED, L'

                                 ,       CAUSING DISENGAGEMENT OF THE ORIVE MECHANISMS FOR THESE CEAS.                           THE LAMAGED COMPONENTS IN THE POWER SUPPLY CIRCUITRY WERE REPLACED ANO e                     OPERATIONALLY CHECKED TO BE SATISFACTORY. ALL PLANT PROTECTIVE
                                 ,       FEATURES FUNCTIONED AS DESIGNED AND NO THREAT WAS POSED TO THE HEALTH
                   ,,                    OR SAFETY OF THE GENERAL PUBLIC OR PLANT PERSONNEL DURING THIS EVENT.

8- FORM 78 LER SCSS DATA 04-18-91 0********************************************************************

                                ,       DOCKET TEAR LER NUM8ER REVISION OCS NUMSER                                 NSIC   EVENT DATE 382    1990           003                1       9010240411 219916               03/29/90 ABSTRACT

POWER LEVEL - 1003. At 0730 HOURS ON MARCH 29, 1990, WITH WATERFORD STEAM ELECTRIC STATION UNIT 3 AT 99.9% POV'A, A SEVERE TRANSIENT ON 4

THE 230 KV POWER 79ANSMISSION GRID AT TAFT, LOUISIANA, RESULTED IN A REACTOR TRIP. THE TRANSIENT WAS INITIATED WHEN AN OCCIDENTAL CHEMICAL

g. COMPANY EMPLOYEE CAUSED A FAULT AT THE 230 KV SUBSTATION OWNED SY THE CHEMICAL COMPANY. THE REACTOR COOLANT pumps SLOWED TO LESS THAN 96.5

                                         % OF NORMAL SPEED AS VOLTAGE OROPPED. THIS GENERATED A LOW I

g MULTIPLIER IN TME CORE PdOTECTION CALCULATORS AND A REACTOR TRIP OCCURRED OUE TO AN ANTICIPATORY DEPARTURE FROM NUCLEATE 80! LING RATIO

                    ,,                   TRIP SIGNAL. THIS EVENT IS REPORTA*LE AS AN AUTOMATIC REACTOR g         PROTECTION SYSTEM ACTUATION.                 THIS SUPPLEMENT IS SUSMITTED FOR
                    ,                    POTENTIAL GENERIC INTEREST WITH RESPECT TO OFF-SITE GRID CONDITIONS.

l .... =J6a.. t=LLt aN1Ln Or-i4dEGIIED THE 'B' 5AFETT 505. EMERGENCY CIESEL GENERATOR 'O' 5 T AR TED AND RE-t'45 RGIIED THE 'S' 5AFETT 905 A5 i p, DESIGNED. t THE ROOT CAUSE OF THIS EVENT WAS A GRID WOLTAGE DROP ON THE ' LOUISIAN4 POWER AND LIGHT COMPANT 230 KV SYSTEM CAUSED ST A FAULT AT

      "              OCCIDENTAL CHEMICAL COM7 ANT. SECAUSE PLANT PROTECTIVE FEATURES i;      FUNCTIONED AS DESIGNED, THIS EVENT DID NOT THREATEN THE HEALTH OR I

SAFETT OF THE GENERAL PUBLIC OR PLANT PERSONNEL. l De 1

   '        qi pq              FORM          79                         LER SCSS DATA 0************************************************************04-18-91 58 ;.           DOCKET TEAR LER NUMBER REVISION DC5 NUMBER                         NSIC                   EVENT DATE 382    1990              012                0  9010030251 219647                     08/25/90 D4 s.

A85 TRACT g, POWER LEVEL - 1003. AT 1802 HOURS ON AUGUST 25, 1990, WITH WATERFORD STEAN ELECTRIC STATION UNIT 3 AT 1003 POWER, 4 SEVERE VOLTAGE ' W" TRANSIENT ON THE SOUTHEASTERN LOUISIANA 230 KV POWER TRANSMISSION GRID RESULTED IN A REACTOR TRIP. THE TRANSIENT WAS IMITIATED WHEN & FAULT ATTRI8UTED TO 4 LIGHTNING STRIKE OCCURRED AT THc WATERFORD 230 KV be SWITCHTARD. ONE CIRCUIT BRE AKER EXPLODED AND SURNED. THE RAPID REDUCTION IN LO40 ON THE MAIN GENERATOR, COM8INED WITH AN INOPERABLE

    , , , ,          STEAM SYP455 CONTROL SYSTEH CAUSED REACTOR C OOL AN T ST5 TEM TEMPERATURE AND PRES $URE TO INCREASE. A REACTOR TRIP OCCURRED DUE TO HIGH
! DI                PRE 55URIZER PRESSURE. THIS EVENT 15 REPORTA8LE AS AN AUTOMATIC
          ,         REACTOR PROTECTION ST5 FEM ACTUATION. AS A RESULT OF THIS ST5 TEM TRANSIENT, VOLTAGE ON THE WATERFORO 230KV SWITCHTARD DECATED TO 33 KV

) 31 i OVER A TWO SECOND PERIOD. AN INVESTIGATION CONCLUDED THAT THE

          ,'         IN-PLANT SAFETY SUS WOLTAGE LEVEL DID NOT DROP LOW ENOUGH FOR A bi               SUFFICIENT DURATION 10 ACTUATE THE UNDERVOLTAGE REL4YS ASSOCIATED WITH 1
' I                 THE EMERGENCY DIESEL GENERATORS.                    THE ROOT CAUSE OF THIS EVENT W45 h*,-            THE SEVERE GRID DISTUR$ANCE, WHICH 15 4TTRIBUTED TO A LIGHTNING STRIKE. SECAUSE PLANT PROTECTIVE FEATURES FUNCTIONEO AS DESIGNED, THIS EVENT DID NOT THREATEN THE HEALTH OR SAFETT OF THE GENERAL PUBLIC g,,             OR PLANT PERSONNEL.

1 I', FORM 80 LER SC55 DATA 04-18-91 5 0******************************************************************** . 6 DOCKET TEAR LER NUMBER REVISION DCS NUMBER N5IC EVENT DATE ( , 3ST 1989 001 0 8002070150 212951 01/04/89

          ,        A85TR4CT
    '               POWER LEVEL - 0603. AT 0240 HOURS ON J4NUART 4,                   1989, UNIT 1 EXPERIENCED AN AUTOMATIC SHUT 00WN FDLLOWING A REACTOR PROTECTION p
          ,         SYSTEM ACTUATION.                  IN ANTICIPATION OF THE SCRAM, OPERATIONS REDUCED POWER FROM 100% TO 60% 10 MINIMIZE THE EFFECT OF THE ANTICIPATED
   ,                TRANSIENT. OPERATIONS INADVERTENTLT ISOLATED INSTRUMENT AIR TO
         ,          INSTRUMENTATION WHICH EVENTUALLY RESULTED IN A LOSS OF MAIN CONDENSER I                    VACUUM, A MAIN TURSINE TRIP, AND AN ENSUING REACTOR SHUTDOWN.                                     ALL EQUIPMENT OPERATED PER DESIGN DURING THE TRANSIENT AND E5F ST5TEMS WERE NOT CHALLENGEC.                  THE EVENT HAS SEEN DETERMINED TO BE REPORTABLE PER 10CFR50.73(A)(2)(YV), IN THAT AN UNPLANNED RPS ACTUATION OCCURRED.

A CONT 118UTING FACTOR LEADING INTO THIS EVENT WAS THE REDUCEO

         ,          RELIABILITY OF THE UNIT 1 I/A ST5 FEM DUE TO PLANNED MAINTENANCE ACTIVITIES. LOSS OF STATUS CON 7EOL AN3 OMISSIONS FROM THE UNIT 1 I/A OPERATING PROCEDURE ARE CONSIDERED THE ROOT CAUSES. CORRECTIVE g          ACTIONS WILL CONSIST OF IMPLEMENTING PROGRAMMATIC CHANGES TO PPOVIDE AN IMPROVEMENT IN THE SYSTEM OF TRACKING EQUIPMENT AND WALVE STATUS.

e THE UNIT 1 It4 OPERATING PROCEDURE WILL SE REVISED TO INCLUDE THE g OMITTED SECTION.

                                                                                                                                                                                                     ,n. - .-
                                                                                                                                                                                                              , - a. ~ . --
                     ,,                     ------            - - . ,            .,,      ,. , , . - , . . -              n      .. ,,v,.,,.-                                      , ,   ,n.,.. ---w

DOCKET YEAR LER NUM!ER REVISIW4 OCS MUM 3ER NSIC EVENT DATE , P3 397 1989 002 1 5911220127 215911 01/12/89 eeeeeeeeeeeeeeee.....eeeee.e.ee..eeeeeeeeeeeeeeeeeeeeeeee.eeeeeemene ABSTRACT POWER LEVEL - 0201. AT 0415 HOURS ON 1/12/89, WITH UNIT 1 OPERATING AT kW APPROXIMATELY 20% POWER, A REACTOR SCRAM OCCURRED DUE TO ACTUATION OF

     ,         i:       THE REACTOR PROTECTION SYSTEM (RPS). OPERATIONS WAS IN THE PROCESS pq                 OF TRANSFERRING FROM STARTUP LEVEL CONTROL TO AUTO FEEDW4TER LEVEL CONTROL WHEN CONTROL OF LEVEL WAS LOST DUE TO A RAPIO INCREASE IN FEE 0 WATER FLOW RATE. THE REACTOR LEVEL REACHED THE +54" LEVEL WHICH EO RESULTS IN A TRIP OF THE MAIN TUR8INE. THE LARGE COLD WATER ADDITION CAUSED REACTOR POWER TO INCREASE PAST 243, WHICH RESULTED IN THE RPS ha       j        ACTUATION UPON TURBINE TRIP. THE REQUIRED PLANT EQUIPMENT RESPONSE DURING THE TRANSIENT WAS PER DESIGN. THE CAUSE OF THE EVENT WAS g,                 ATTRIBUTED TO COGNITIVE OPERATOR ERROR. A C00LOOWN OF 101F Was EXPERIENCE 0 OVER THE FIRST HOUR FOLLOWING THE SCRAM. THIS EXCEEDED b"                THE TECH SPEC MAXIMUM C00LOOWN RATE OF 100F PER HOUR DURING A ONE HOUR PER100, BUT WAS NOT IMMEDIATELY IDENTIFIEO. AS A RESULT, TECH SPEC ACTION REQUIREMENTS WERE NOT PROPERLY IMPLEMENTED. AN ENGINEERING be                ANALYSIS CONCLUDED THAT NO ADVE9SE EFFECTS ON THE REACTOR COOLANT SYSTEM STRUCTURAL INTEGRITY OCCURRED AS A RESULT OF THE TEMPERATURE be               OEVIATION. TRAINING WAS CONDUCTED FOR ALL LICENSED OPERATORS PRIOR TO ASSUMING $HIFT DUTIES SEFORE THE NEXT STARTUP. ENHANCEMENTS FOR CLARITY PURPOSES WERE MADE TO THE OPERATING PROCEDURE.

B4 1 p, FORM 82 LER SCSS DATA 04-18-91 0.**.**.*............***.**....**..**..*.*...**......*..*****.*..*..*

       "'              00CKET TEAR LER NUMBER REVISION DCS MUM 8ER            NSIC      EVENT DATE 387    1989         005         0      8903160019 213318         02/07/89 I

Se ASSTDACT

g. POWER LEVEL - 000%. ON 2/7/89 WITH UNIT 1 IN CONDITION 2 AND WITH 4 NORMAL STARTUP EVOLUTION IN PROGRESS, THE 'A' CONDENSATE PUMP WAS STARTED AND AN EXTENSION ELECTRICAL TRANSIENT OCCURRED. SOTH REACTOR RECIRCULai10N PUMPS TRIPPED AND THE UNIT WAS MANU4LLY SCRAMMED PER PROCEDVAE OUE TO LOSS OF RECIRCULATION. RECIRCULATION WAS RESTORED t AND PLANT RECOVERY WA S COMPLETE WITHIN ABOUT TWO HOURS. THE EVENT HAS SEEN OETERMINED REPORTA8LE PER 10CFR50.73(A)(2)(IV) IN THAT THE

        ,               REACTOR WAS MANUALLY SCR AMMED AND WARIOUS CONTAINMENT ISOL ATION VALVES CLOSED. THE PLANT RESPONDED TO THE ELECTRICAL TRANSIENT PER DESIGN AND THERE WAS NO COMPROMISE TO PUBLIC HEALTH OR SAFETY. EQUIPMENT FAILURE CAUSED THE ELECTRICAL TRANSIENT WHEN AN ELECTRICAL FAULT OCCURRED AT THE TERMINALS FOR THE 'A' CONDENSATE PUMP MOTOR. UNIT 1 t               WAS PLACEO IN COLD SHuTOOWN, THE FAILED ELECTRICAL COMPONENTS WERE REPLACEO, AND THE      'A' CONDENSATE PUMP WAS RETURNED TO SERVICE. THE
        ,               CONNECTIONS ON THE REMAINING THREE CONDENS4TE PUMP MOTORS ON UNIT 1
            ,,          WERE INSPECTED AND FOUND TO BE S4TISFACTORT.

1

                  ,    FORM      83                  LER SCSS DATA                         0'-18-91 0.....****** *.......................................................

DOCKET TEAR LER NUMBER REVISION OCS NUM8ER NSIC EVENT DATE

            ,:            387    1989         027         0      9001250354 216614         12/24/89 485 TRACT POWER LEVEL - 1001. AT 0824 Houes ON 12124/89, UNIT 1 EXPERIENCE 0 A e               REACTOR PROTECTION SYSTEM (RPS) ACTUATION RESULTING IN AN AUT044 TIC g           SCRAM FROM 1001 POWER. A LOSS OF ELECTRICAL POWER SUPPLY (PRIMARY AND BACKUP) TO THE 230KV SWITCMTARD SERVICES RESULTED IN T*IPPING OF "4TN

1

                      . . . . . a usw o   wusegut whLWe PA51 CLuiU4E AS PER DESIGN. ALL HAJOR p1 EQUIPMENT OPERATED DURING THE TRANSIENT PER DESIGN AND NO ADDITIONAL ENGINEERED SAFETT FEATURE (ESP) SYSTEMS WERE CHALLENGED. THIS EVENT HAS BEEN DET!RMINEO 10 SE REPORT 48LE PER 10CFR50.73(A)(2)(IV), IN THAT gg                   AM UXPLANZE0 ESF ACTUATION OCCURRED. 80TH POWER SUPPLIES TO THE 19        230KV SWITCHTARD WERE LOST DUE TO UNRELATED EVENTS. THE PRIMARY DW                   SOURCE WA5 LOST BY A VEHICLE HITTING A POWER LINE POLE. THE SACKUP SOURCE WAS LOST DUE TO AN ELECTRICAL COMPONENT FAILURE IN THE BACKUP g
            ,p        GENERATOR EXCITSR FIELD CIRCUIT. BOTH POWER SUPPLIES WERE RESTORED TO pq                   SERVICE. A TASK FORCE IS EVALUATING THE EXISTING 230KV SWITCHTARD STATION SERVICES POWER SUPPLIES FOR RELIA 8ILITY AND FOR CONSIDERATION g4 ,g                0F P05518LE IMPROVEMENTS.

Da q, FORM 84 LER SC55 DATA 0*****ee**************************************ee*************04-18-91 ******** be DOCKET TEAR LER NUMBER REVISION DCS NUM8ER 451C EVENT DATE 3, 383 1989 003 0 8904040282 213452 02/27/89

                    *********************************** e*******************************

i. A85 TRACT DM POWER LEVEL - 100X. AT 0612 ON 2-27-89, UNIT 2, OPERATING AT 100X POWER, EXPERIENCED UNPLANNED ENGINEERED SAFETY FEATURE ACTUATION 5 A5 A bt , RESUL T OF THE LOSS OF NORMAL POWER TO THE *8" REACTOR PROTECTION SYSTEN (RPS) BUS. THIS INTERRUPTION OF POWER, PER DESIGN, CAUSED THE De STAN08T GA5 TREATMENT SYSTEM AND CONTROL ROOM EMERGENCY OUTSIDE AIR SUPPLY SYSTEM TO INITIATE. ALL OTHER EQUIPMENT FUNCTIONED PER DESIGN

{ WITH THE EXCEPTION OF THE REACTOR RECIRC PUMP "A" CHILLEO WATER RETURN b1 IN80ARD PRIMARY CONTAINMENT ISOLATION VALVE, MV-2879282, WHICH FAILED

                ,     TO CLOSE.         INSTEAD OF ENERCISING THE OPTION OF CONTINUED OPERATION AT g,                 A REDUCED POWER LEVEL WITH THE ASSOCIATED OUT80ARD CHILLED WATER g                   ISOLATION WALVE CLOSED, THE DECISION WAS MADE TO SHUT THE UNIT DOWN he AND REPAIR THE IN80ARD VALVE. A CONTROLLED SHUTDOWN WAS INITIATED AT 1410 AND COMPLETED AT 2126 ON 2/27/89            THE CAUSE OF THE POWER INTERRUPTION TO THE "B" RP5 8US WAS AN INTERNAL SHORT CIRCUIY TO s.,                GROUND IN THE "B" RP5 MOTOR / GENERATOR SET MOTOR WHICH CAUSED ITS FEEDER BREAKER TO TRIP. THE POTOR W AS REPLACED ANO NORMAL. POWER TO
                    THE SUS WAS RESTORED. IN A8!! !T V OF THE AIR OPERATED CHILLED WATER
          .           ISOLATION WALVE TO CLOSE HA5 EEEN ATTRIBUTED TO A FAILURE OF ITS OPERATING AIR SOLEN 0ID CONTROL VALVE, 5V-2879282. THE 50LEN010 VALVE 8
                     'W45 REPLACED AND THE CHILLED WATER ISOLATION VALVE, HV-279282, WAS
          ,           TESTED SATISFACTORILT.
  ,               1 8
          ,         PORM         85                  LER SC55 DATA                           04-18-91 Oeeeeeen....e*******ese,ee.eeee................s....e*********e..

DOCKET TEAR LER NUMBER REVISION DCS NL'M8ER NSIC EVENT OATE e

          ,            388       1990         002         0   . 9003070116 217094            02/06/90 eeeeeeeeee***************eeeeeeeeeee*******************e***ee*******

e. 485 TRACT

                     ?OWER LEVEL - 100X. AT 0906 HOUR 5 ON FE8RUART 6,           1990, WITH UNIT 2 06* RATING AT 100X POWER, 4 MAIN GENERATOR POWER / LOAD UNBALANCE SIGNAL,
       .,            CRETTED HMEN THE 500 KV SWITCHTARD MAIN DISTRIBUTION BREAKER OPENED, CAU550 4 MAIN.TUR8INE Tw!P.          IN ACCOR04NCE WITM PLANT DESIGN, THE TURB14E CONTROL V ALVES CLOSED AND AN AUTOMATIC R! ACTOR SCRAM OCCURRED.
         ,           ALL MAJOR EQUIPMENT OPERATED PER DESIGN DURING THE TRAN5IENT, ECC5 SYSTEMS WERE N3T CHALLENGED AND NO ABNORMAL OPERATOR ACTIONS WERE REQUIRED TO PLACE THE UNIT IN A STA8LE CONDITION. THE CAUSE OF THIS 4'          EVENT WAS ATTRISUTED TO A LOOSE "5 TATE 5" LINK IN THE DIFFERENTIAL CURRENT RELAY CIRCUIT OF THE 500 KV SWITCHTARD CIRCUIT 84E4aER WHICH e                  CONNECTS UNIT 2 TO THE POWER GRID. HIGH CIRCUIT RESISTANCE CAUSED ST g            THE LDOSE CONNECTION RESULTED IN PROTECTIVE RELAT OPERATION WHICH
  ,                  OPENE0 THE 500 KV CIRCUIT BREAKER, ISOLATING'TwE MatN cswsoevne sea.

                                                                                                     . ==~
                    ..u.. ....waa . . ,

as.aca' LINRS JN 4LL RELATED ACCESSISLE R! LAY A t40 pq CONTROL PANELS TO C]t.*IPM THAT THE C0tNECVIOMS ARE PROPER IN ORDEQ TO PRECLUDE A RECURRIHCEo 1 b" FORM

          ;.                86                   LER SC55 DATA                           04-18-91 0........................................................... ........

WW DOCKET TEAR LER NUMBER REVI510N OCS NUMBER NSIC EVENT DATE i, 338 1990 005 0 9007020128 215769 05/28/9 pq ******enee.**.eeeeeeee.... ee****......*******e......*.*******ee***0*

i. ABSTRACT

'O

POWER LEVEL - 1001. AT 0256 HOURS ON 5/28/90, AN AUTOMATIC ACTUATION OF THE RPS OCCURRED ON UNIT 2. THE UNIT HAD SEEN OPERATING AT 100% b4 RATED POWER PRIOR TO THE ACTUATION. FEE 0 WATER CONTROL SYSTEM TRAN5MITTER PD.-C32-2N0048 FAILED 00WNSCALE WHICH RESULTED IN THE b, FEE 0 WATER MASTER CONTROLLER INCREASING TO 100% DEMAND. a, REACTOR WATER

          '        LEVEL INCRE ASED FROM THE STEADY STATE LEVEL OF +35 INCHES TO +54 he               INCHES. WHEN VESSEL LEVEL REACHED +54 INCHES, THE MAIN AND PEED PUMP TURSINES TRIPPED. TRIPPING OF THE MAIN TUR8INE RESULTED IN A FAST bg CLOSURE OF THE TUR8INE STOP AND CONTROL VALVES. FAST CLOSURE OF THE TURBINE STOP AND CONTROL VALVES RESULTED IN A REACTOR SCRAM. THE LOWEST VE5SEL LEVEL OBSERVED OURING THE TRANSIENT WAS APPROXIMATELT De               -26 INCHES. THE RCIC SYSTEM WAS MANUALLY INITIATED TO RESTORE REACTOR VESSEL LEVEL TO AN ACCEPTABLE VALUE. A COMPONENT FAILURE IN THE R4               AMPLIFIER CIRCUIT CARD FOR FEE 0 WATER CONTROL SYSTEM TRANSMITTER PDT-C32-2N0048 CAUSED THE TRANSMITTER TO FAIL DOWNSCALE WHICH IN TURN

<pa RESULTED IN THE FEE 0 WATER HASTER CONTROLLER INCREASING TO 1003 DEMAND. THE EVENT HAS SEEN DETERMINED TO BE REPORTABLE PER 10CFR50.73(A)(2)(IV), IN THAT AN AUTOMATIC ACTUATION OF THE RPS

    '             OCCURRED WHEN THE FEE 0 WATER LEVEL TRANSMITTER FAILEO.           THE FAILED
  '               AMPLIFIER CIRCUIT CARD 15 SEING SENT TO ROSEMOUNT TO PERFORM A FAILURE As ANALYSIS TO DETERMINE EXACT CAUSE OF FAILURE.

1 g, FORM 87 LER SC55 DATA De***********************************************************04-18-91 ********

  '*             DOCKET TEAR LER NUMSER REVISION DCS NUMBER                  N5IC     EVENT DATE 389    1989        005           0      3909010387 214894           06/26/89
                 .........**e............................... ................e*.....e A8STRACT
  ,               POWER LEVEL - 022X. ON JUNE 26, 1989 AT 2347 Houas, ST. LUCIE UNIT 2 REACTOR TRIPPE0 ON LOSS OF LOAD PROM 22% POWER DURING TUR8INE STARTUP.
  '               THE LOS$ 05 LOAD REACTOR TRIP WAS A RESULT OF A TUR81NE TRIP DUE TO HIGH STEAM GENERATOR LEVEL IN THE 24 STEAM GENERATOR.             THE TRIP WAS UNCOMPLICATED AND THE UNIT WAS QUICKLT ST48ILIZED IN MODE 3, HOT e     ,

STAN087. THE ROOT CAUSE OF THE EVENT WAS COGNITIVE PERSONNEL ERROR ST UTILITY- LICENSED OPERATORS DUE TO LESS THAN ADEQUATE COMMUNICATION

  ,               SETWEEN THE SHIFT CREW PERFORMING THE TUR8INE STARTUP EVOLUTION.               THE UTILITY-LICENSED OPERATORS WERE COUNSELED ON THE NEED FOR WELL

CONTROLLED EVOLUTIONSe IN WHICH GOOD COMMUNICATION IS OF THE UTMOST IMPORTANCE ST ALL PARTICIPANTS, 45 A SHORT TERM CORRECTIVE ACTION.

THE PLANT TRAINING GROUP WILL EVALUATE THIS EVENT TO DETERMIME APPROPRIATE TRAINING REQUIREMENTS AND METHODS. 1

      '         FORM       88                   LER SCSS DATA                           04-18-91 0....................................................e**...... **e...

i y DOCKET TEAR LER NUMBER REVISION OCS NUM5ER N51C EVENT DATE 389 1959 007 0 3910310177 215708 09/23t89 e..................................................*****eeeeee.e**** I A85 TRACT l

                             .... ... .. .. ... aevut.: 4%. oduuF    1. THE REACTOR CONTROL pg             OPERATUR (RCO) MANUALLY REDUCEO MAIN TUR8IN! LCAD TO MATCH REACTOR POWER. AT 0$13, AS THE CONTROL P005 WERI SEING INSERTED, FOUR CE45 IN REGULATING GROUP 5, THE LEAD 8ANK, DROPPED IN THE CORE. THE RCO

IMMEDIATELY TRIPPED THE REACTOR FEOM 963 POWER DUE TO THE MULTIPLE qg OROP CEAS.

THE STANDARD POST TRIP ACTIONS WERE COMPLETED AND THE UNIT WAS QUICKLT STABILIZED IN HOT STAND 8T, MODE 3. THE MOST PROBA8LE h4 CAUSE OF THE EVENT WAS A SLOWN FUSE CAU5ING THE INITIAL DROPPED CEA. pq

         ,ll THE APPARENT CAUSE FOR THE FOUR CEAS TO DROP WAS DUE TO THE TRIPPING OF THE CEA SUSGR3UP BREAKER. THE ROOT CAUSE FOR THE SUSGROUP SREAKER TRIP HAS NOT BEEN CONCLUSIVELT IDENTIFIED: HOWEVER, TESTING THE Id .i'  '      SUSGROUP BREAKER REVEALED THAT THE BREAKER TRIPPED AT A CURRENT LESS THAN DESIGNE0. THE FOLLOWING CORRECTIVE ACTIONS HAVE BEEN IMPLEMENTED: REPLACED THE 8 LOWN FUSE AND REPLACE 0 THE CEA SU8 GROUP by , g        SREAKER.
     ! ,;,     FORM       89                   LER SC55 DATA 0************************************************************04-16-91 D"                                                                                 ********

DOCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE

         ,i         389   1990         001            0     9002230298 21692          01/14/90 kg      '
                *****************************************************3         ***************

ABSTRACT

  -f'.i          POWER LEVEL - 0501. ON 1/14/90, ST. LUCIE UNIT 2 WAS IN MODE 1 AND PERFORMING POWER ASCENSION TOWARDS 1001 POWER FOLLOWING A REACTOR Sa,           STARTUP FROM A MAINTENANCE OUTAGE. TURSINE STARTUP PROCEDURE WAS 1

y, BEING UTILIZED. THE 28 STEAM GENERATOR FEED PUMP AND 28 CONDENSATE PUMP WERE IN SERVICE. REACTOR POWER WAS APPROACHING 50% WITH THE TURBINE POWER INCREASING AT 4.0 MEGAWATTS PER MINUTE WHEN THE 28 STEAM

   "*            GENERATOR FEED PUMP LOW SUCTION PRESSURE ALARM WA5 RECEIVED. UTILITY b              LICENSED OPERATORS ATTEMPTED TO START THE 2A CONDENSATE PUMP BUT IT WOULD NOT START.       THE 28 STEAM GENERATOR FEED PUMP TRIPPE0 ON LOW h*            $UCTION PRESSURE. PUMP WAS UNA8LE TO BE RESTARTED. THE STEAM GENERATOR WATER LEVELS DECREASED TO THE AUTOMATIC TRIP SETPOINT AND

t. . THE UNIT AUTOMATICALLY TRIPPED AT 23c' THE 2C AFW PUMP TRIPPED ON OVERSPEED UPON RECEIVING AN AFW ACTUATION SIGNAL. STANDARD POST TRIP

               ACTIONS WERE PERFORMED AND THE UNIT WA5 STABILIIED IN MODE 3. THE SECOND CONDENSATE PUMP COULD NOT BE STARTED PRIOR TO THE TRIP 8ECAUSE ITS CONTROL FUSES HAD NOT BEEN RE-INSTALLED FOLLOWING OUTAGE WORK.

t PROCEDURES HAVE SEEN CHANGED TO ENSURE THE AVAILABILITY OF THE SECOND CONDENSATE AND FEEDWATER PUMP FURTHER IN ADV ANC E OF SEING NEEDED AND

   ,,            TO CLARIFT THE POWER A5CENSION PROCEDURE. A COGNITIVE PERSONNEL ERROR ST UTILITV LICENSED OPERATORS LED TO THE AUTOMATIC REACTOR TRIP.
       ,     1 t  :

FORM 90 LER SC55 DATA 04-18-91

   ,   ,     0********************************************************************

DOCKET TEAR LER NUM8ER REVISION 0C5 NUM8ER NSIC EVENT DATE

  ,                395    1989        006            0      3905100159 213964         04/01/89
  '            ABSTRACT POWER LEVEL - 030%. ON 411/89 AT 0447 HOURS WITH THE PLANT OPERATING e              AT APPR04. 303 POWER, A YURBINE TRIP OCCURRED A5 A RESULT OF HIGH MOISTURE SEPARATOR REHEATER LEVEL.           FEEDWATER TEMPERATURE DROPPED g        SELOW THE FEEDWATER ISOLATION SETPOINT 04 ALL 3 STEAM GENERATORS OUE TO THE LOSS OF FEEDWATER HEATING RESULTING FROM THE TURSINE TRIP.

APPRORIMATELY 30 MINUTES AFTER THE TUR81NE TRIP, WITH ACTUAL FEEDWATER I FLOW A5 EXPECTED FOR 303 POWER, INDICATED FLOW 70 "C" STEAM GENERATOR g SEGAN DRIFTING DOWN. WHEN THE TRANSMITTER INDICATED FEEDWATER FLOW

  ,             WA5 8ELOW THE ISOLATION SETPOINT, THE *C" FEE 0 WATER ISOLATION VALVE

g. CLOSED 04 LOW FLOW COINCIDENT WITH LOW TEMPERATURE SIGNALS. STEAM

  ,             GENERATOR WATER LEVEL SEGAN DECREASING AN3 APPR0x!MATELY TWO m!NUTFt

                          ...   . . . . . . . . a...ia-6   =c=4 a Je misleM ikDICAI!ONS, ALARMS AND

' PLANT RCSPONSES FOR THAT TRIP INDICATE 3 THE TRIP WAS THE RESULT OF y, SEVERAL ERR 0NE305 INSTRUMENTATION SIGt14L$ AN3 NOT THE RESULT OF ACTUAL HOISTU1E SEPARATOR REHEATER (MSR) HIGM LEVEL CONDITIONS. SU3 SEQUENT U" TO THE 4/1 REACTOR TRIP, SEVERAL IMPRO?ERLY FUNCTIONING MS2 AND MS2 ORAIN TANK LEVEL SWITCHES, ALARMS AND CONTROLLERS WERE DISCOVERED AND DN REPAIRED. THESE MALFUNCTIONS WERE RESPONSISLE FOR THE CONFLICTS SEEN BETWEEN ACTUAL PLANT CON 3ITIONS AND INDICATED DATA DURING EACH TURBINE

             ,      TRIP.

p, 1 1 FORM 91 LER SCSS DATA E4 0************************************************************04-18-91 ******** DOCKET YEAR LER NUM8ER REVISION DCS MUM 8ER NSIC EVENT DATE km 395 1989 011 1 9002010227 216654 05/2

                  ****************************************************************8/89               ****

be ABSTRACT be POWER LEVEL - 100%. AT 0252 HOURS, $/29/89, A MANUAL REACTOR TRIP WAS INITIATED FOLLOWING THE FAILURE OF A PRESSURIZER SAFETY VALVE. THE bg VALVE (XVS-E010-C) 8ECAME UNSEATED CAUSING A RAPID DEPRESSURIZATION OF THE REACTOR COOLANT SYSTEM. THE MANUAL REACTOR TRIP WAS INITIATED AT APPROXIMATELY 2000 PSIG AND THE SAFETV VALVE RESEATED PRIOR TO

   ,,      4 REACHING THE SAFETY INJECTION SETPOINT OF 1850 PSIG. THE REACTOR COOLANT SYSTEM PRES $URE RECOVERED AND WAS STASILIZED AT APPROXIMATELV 2000 PSIG. DURING THE TRANSIENT, A CONDENSER STEAM DUMP VALVE FAILED D8 TO CLOSE AND AN OPERATOR HAD TO FAIL THE AIR 10 THE VALVE FOR CLOSURE.

PRESSURIIER SAFETT VALVES (XVS-8010-8 AND C) WERE REPLACED AND THE p ., REACTOR WAS RESTARTED AT 0049 HOURS, JUNE 11, 1989 NOTE: VALVE 8010

          ,e        8 WAS REPLACE 0 DUE TO MINOR LEAKAGE PAST THE SEAT. THE LICENSEE HAS DETERMINED THAT THE REASON FOR THE MISOPERATION OF XVS-8010-C IS THAT I'               THE EXPECTED MARGIN SETWEEN NORMAL OPERATING PRESSURE AND THE I

6e PRESSURIZER SAFETY VALVE RELIEF SETPOINT PRESSURE WAS REDUCE 0 TO ZERO. IT WAS ALSO DETERMINED THAT THE MOST PREVALENT FACTOR IN THIS MARGIN REDUCTION WAS A LOOP SEAL DISCHARGE. THIS DISCHARGE RESULTED IN A g, REDUCEO VALVE SETPOINT SECAUSE OF THE STEAM MEDIUM IMPOSED ON THE VALVE. AS SUCH, THE LICENSEE IS FOCUSING THE CORRECTIVE ACTION PLAN

   '*              ON THE ELIMINATION OF LOOP SEAL CAPABILITY FOR THE PRESSURIZER SAFETY V AL VE S. SIMIL AR EVENT: 395/89-015.

1 FORM 92 LER SCSS DATA 04-18-91

   ,           0********************************************************************

DOCKET YEAR LER NUM8ER REVISION DCS NUM8ER NSIC EVENT DATE 395 1939 012 0 S*0S140351 215002 07/11/S9 i APSTRACT POWER LEVEL - 100%. 04 JULY 11, 1989, A TUR8INE TRIP / REACTOR TRIP

   ,               OCCURREO WHILE OPERATING AT 100% REACTOR POWER.                   TECHNICIANS WORKING
        '          INSIDE THE " GENERATOR STATOR COOLING WATER" CABINET INADVERTENTLY SHORTED THE POWER LEADS ON THE TEMPERATURE CONVERTER CAUSING THE AC POWER FUSE TO BLOW.                 THIS GAVE A FALSE INDICATION OF LOSS OF GENERATOR
        ,;         STATOR COOLING WATER WHICH CAUSED A TJRSINE TRIP AND A REACTOR TRID DUE TO THE TURSINE TRIPPING A80VE 50% REACTOR POWER. IN ADDITION TO THE AFOREMENTIONED LOSS, THREE OTHER GENERATING STATIONS TRIPPED WHILE g          ATTEMPTING TO COMPEN$ ATE FOR THE VARS LOST ON THE GRID WITH THE TUR6INE TRIP / REACTOR TRIP. AS A RESULT OF THE LOSS OF FOUR GENERATING STATIONS, THE OFFSITE VOLTAGE TO THE ENGINEERING SAFETY FEATURE (ESP)

I

        ,,         BUSSES DECRE ASED BELOW THE MINIMUM ACCEPTABLE VALUE AND A NOTIFICATION OF UNUSUAL EVENT (NUE) Was DECLARED AT 1510 HOURS. THE LICENSEE'S DISPATCHERS IMMEDIATELY TOOK ACTION TO PLACE ADDITIONAL GENERATING g9         UNITS ON-LINE. SOTH EMERGENCY DIESEL GENERATORS CAME ON-LINE AND
   ,               SU',PLI!D THEIR RESPECTIVE ESF SUSSES. THE OFFSITE VOLTAGE TO THF 558

                    *. s reaaw+e:L A4JU41th Uk 4tLEASES 05 RADI0 ACTIVE HATERIALS A5 A RESULT OF THIS EVENT.
   >1          1 kg            FCRM        93                 LER SCSS DATA qq    0************************************************************04-18-91
! b4             DOCKET TEAR LER NUMBER REVISION DCS NUMSER             NSIC     EVENT DATE 395    1989      015           2     8912270294 216225       05/25/89 9     ,p      ********************************************************************

k1 A851RACT

, g POWER LEVEL - 1002. AT 1000 HOURS ON AUGUST 25, 1989, THE "A" PRESSURIZER SAFETY WALVE 50DY INLET TEMPERATURE INCREASED TO GREATER kW q, THAM 450F AND A PLANT SHUT 00WN WAS INITIATED. SHORTLY AFTER THE LOAD REDUCTION WAS STARTED, THE "A" PRES $URIZER SAFETY VALVE OPENE0 AT A SYSTEM PRES $URE OF APPROXIMATELY 2260 PSIG. AT 1003 HOURS, THE gg ACOUSTIC LEAK MONITOR ALARME0, THE REACTOR COOLANT SYSTEM (RCS) BEGAN i
' TO RAPIOLY DEPRESSURIZE AND AT APPROXIMATELY 1004 HOURS THE SHIFT
"" SUPERVISOR DIRECTED A MANUAL REACTOR TRIP. THE PRESSURIZER SAFETY VALVE RESEATED PRIOR TO REACHING THE SAFETY INJECTION SETPOINT OF 1850 PSIG. ALL PLANT PARAMETERS RECOVERED TO THEIR EXPECTED POST TRIP be VALUES EXCEPT RCS PRESSURE WHICH WAS CONTROLLED AROUND 2000 PSIG TO AVOID LIFTING THE SAFETY VALVE AGAIN. THE PLANT WAS TAKEN TO COLO y, 4
, SHUT 00WN, THE "A" PRESSURIZER SAFETY VALVE REPLACED, AND THE REACTOR WAS RESTARTED at 0635 HOURS ON SEPTEMBER 1, 1989 FURTHER 84 INVESTIGATION SY THE LICENSEE HAS SHOWN THAT A LOSS OF LOOP SEAL OM
,, THE "A" PRESSURIZER SAFETY WALVE WAS THE CAUSE OF THE VALVE'S MISOPERATION. LER 89-011, DATED JUNE 27, 1989, DOCUMENTS A SIMILAR p, EVENT INVOLVING THE "C" PRESSURIZER SAFETY VALVE. THE LICENSEE HAS DETERMINED THAT A LOSS OF LOOP SEAL WAS & CONTRIBUTING FACTOR IN THE
"' EVENT AND WILL SUBMIT THIS FINDING IN A SUPPLEMENTAL REPORT. THE
\ EXPECTED SU8 MISSION DATE OF THIS REPORT IS JANUARY 3, 1990.
, 1 Aa

, FORM 96 LER SCSS DATA 04-18-91

r. 0********************************************************************

DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

    ,,               395     1989      020           0     9001100063 216412       12/02/89 g:       ********************************************************************

i 485 TRACT

        ,          POWER LEVEL - 1005. CN 12/2/89, AT APPROX. 2202 HOURS, OPERATIONS

, PERSONNEL STARTED A LOAD REDUCTION TO 901 POWER FOR THE MONTHLY

+ TURBINE CONTROL VALVE TESTING. WHEN THE OPERATOR PUSHED THE LOAD

    ' ' ,          SELECTOR DECREASE BUTTON FOR THE SECOND 21 REDUCTION IN POWER THE TUREINE COMMENCED A RAPID POWER DECREASE (2209 HOURS). OPERATIONS PERSONNEL ATTEMPTED TO COUNTER LOSS OF-LOAD BY SELECTING MANUAL i   ,;       'INCREASEI HOWEVER, TURBINE CONTROLS FAILED TO RESPOND AND THE TUR8INE WAS MANUALLY TRIPPED WHEN TURBINE POWER DECREASED BELOW P-9 (POWER
    ,             PERNISSIVE < $0% RATED THERMAL POWER). THE EXCITER FIELD BREAKER
        ,          INITIALLY FAILED TO CPEN FROM THE MAIN CONTROL BOARD (MCS). AN
    '             OPERATOR WAS IMMEDIATELY DI3 PATCHED TO LOCALLV OPEN THE BREAKER . THE BREAKER FINALLY OPENED AFTER SEVERAL ATTEMPTS TO CTCLE THE 8tEAKER
        .:        FROM THE MCS. MAIN FEEDWATER WAS MANUALLY SECURED AT 2220 HOURS WHEN THE TUR81NE RUN84CK TRANS IENT CAUSED A HIGH LEVEL IN THE DEAREATER.

WHEN MAIN FEEDWATER WAS RESTORED AT 2221 HOURS, THE ADDITION OF COOLER

        ,;        (290F) WATER CAUJED A RAPIO RCS COOLDOWN AND STEAM GENERATOR LEVELS 4

TO SHRINK TO SELOW TME L0k LOW STEAM GENERATOR LEVEL REACTOR TRIP SETPOINTS. A REACTOR TRIP OCCURRED AT 2222 HOURS ON "C" STEAM g- GENERATOR LOW-LOW LEVEL. WITH THE EXCEPTION OF THE PREVIOUSLY MENTIONED PROBLEMS THE PLANT RESPONSE WAS NORMAL. A FAILED TUR8INE e CONTROL CIRCUIT BOARD WAS REPLACEO AND THE EXCITER FIELO BREAKER PM'D g- PRIOR TO AUTHORIZING THE PLANT RESTART. 1

                                            ....................eeeeeeeeeeee..............

DOCKET TEAR LER HUMBER 4CVISION DC5 NUM3ER N5IC EVENT DATE pg 397 19B9 002 0 8903130165 213225 01/30#39 eseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee U"

         .p      A85 TRACT POWER LEVEL - 100%. ON 1/30/89, AT 0514 HRS, A REACTOR SCRAM OCCURRED be DUE TO TUR8INE CONTROL VALVE FAST CLOSURE ACTUATION OF THE REACTOR i,

PROTECTIVE SYSTEM LOGIC. THIS LOGIC WAS ACTUATED WHEN THE MAIN pq GENERATOR 500KV OUTPUT BREAKERS TRIPPED A5 A RESULT OF HIGH CURRENTS CREATED WHEN A PORCELAIN INSULATOR ON THE OUTPUT SIDE OF 25/500KV MAIN Ed TRANSFORMER TR-M1 SHORTED TO GROUND. PLANT OPERATORS RESPONDED TO MANEUVER THE PLANT TO A SAFE SHUTDOWN CONDITION. THE DAMAGED 500KV be g INSULATOR STACK WAS REPLACED. ALL OTHER 500KV AND 115KV INSULATOR 5 IN THE TRANSFORMER YARD WERE CLEANED AND INSPECTED. TRANSFORMER TR-M1 WAS TESTED TO DETERMINE ITS ACCEPTABILITT FOR CONTINUED USE. THE bg IMMEDIATE CAUSE OF THE INSULATOR FAILURE WAS THE SUILD UP OF A CHEMICAL RESIDUE DEPOSITED BY THE VAPOR PLUME FROM THE CIRCULATING E' WATER SYSTEM COOLING TOWERS. THIS RESIOUE WAS FOUND TO SE CONDUCTIVE WHEN WET. THE RESIOUE CONSISTED OF RIVER WATER MINERALS AND SULFATE bg COMPOUNOS GENERATED BY SULFURIC ACID ADDITION USED TO CONTROL THE PH OF CIRCULATING WATER. TWO ROOT CAUSES WERE IDENTIFIED: 1) EQUIPMENT DESIGN DEFICIENCV (PROSLEM NOT ANTICIPATED). THE INSULATORS USED AT WNP-2 ARE NOT OF THE TYPE OR NUMBER RECOMMENDED FOR CONTAINMENTED ENVIRONMENTS. 2) EQUIPMENT MAINTENANCE DCPICIENCV. NO FORMAL D4 NAINTENANCE/ INSPECTION PROGRAM EXISTED WHICH IDENTIFIED THIS EQUIPMENT. 1 D1

            ,    FORM      96                  LER SCSS DATA bi         0***********ce***********************************************04-18-91                ********

I 00CKET YEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE 397 1989 028 0 8905080199 214963 06/29/89 he ....e**ee........................... .......................... eene g, , 485 TRACT POWER LEVEL - 025%. 6/29/89, AT 0020 HOURS, DURING TE STING OF THE MAIN TURSINE OVERSPEED PROTECTION TROLLER (OPC), A TURBINE THROTTLE VALVE

   ,            CLOSURE REACTOR SCRAM OCCURRED.       AT THE TIME OF THE SCRAM, THE TUR8INE WA5 OPERATING IN THROTTLE VALVE CONTROL COASTING DOWN FROM IHE

ACTUATION SETPOINT OF 1854 RPM. AFTER 3 UN50CCES$FUL ATTEMPTS TO

       ,          INPUT AN 1800 SPEED DEMAND, THE OPERATOR DECIDED TO WAIT UNTIL ACTUAL
   ,,             TUPBINE SPEED HAD DROPPE0 SELOW 1800 RPM TO TRY AGAIN. AFTER TURBINE SPEED OR3PPED BELOW 1800 RPM, THE OPERATOR KEYED IN ANOTHER 1800 RPM
   '   ,          REFERENCE DEMAND AT 50 RPM PER MINUTE AS SPECIFIED IN THE PROCEDURE.

THIS INPUT WAS ACCEPTED BT THE TURBINE CONTROL SYSTEM. THE OPERATOR, AS EXPECTED ST THE PROCEDURE, THEN RETURNE0 TUR8INE CONTROL TO THE "IN i e SERVICE" F051 TION WITH THE OPC KETLOCK SWITCH. THIS RESULTED IN RAPID OPENING OF THE TURSINE GOVERNOR AND THROTYLE VALVES AND

   '              $USSEQUENT PRESSURIZATION OF THE TUR81NE FIRST STAGE CHAMBER SINCE
      ,           THROTTLE VALVES WERE LESS THAN 95% OPEN AT THIS POINT, THIS CAUSED ACTUATION OF TME TURBINE FIRST STAGE PRES 5URE SWITCHES CAUSING THE SCRAM LOGIC TO BE MET RESULTING IN A TURBINE THROTTLE VALVE CL35URE
      ,           REACTOR SCRAM.      THE ROOT CAUSE OF THE EVENT WAS AN INADEQUATE PROCEDURE IN THAT THE TUR8INE OPERATING PROCEDURE DID NOT PREVENT THE OPC TEST FROM BEING DONE WITH THE TURSIME IN THE THROTTLE VALVE
      ,4          CONTROL MODE. CORRECTIVE ACTIONS TAKEN CONSIST OF DEVIATION OF THE OPERATING PROCEDURE.

1 I' FORM 97 LER SC55 DATA 04-18-91

   ,          0******e**************************************e**********************

(, DOCKET TEAR LER NUMSER REVISION DCS NUMBER N11C EVENT DATE , , 397 1989 031 0 5909190149 215274 03/06t**

P0eER LEVEL - 100%. AT 2027 HOURS ON 810#S0o O LOW REACTOR ORE 55URE pq VESSEL (RPV) LiUEL REOCTOR SCRA!1 WAS IMITIATED 3Y VHE REACTOR PROTECTIVE SYSTEM ZN RESPONSE TO AN ACTUAL LOW WATER LEVEL CONDITIOC he CAUSE0 SV AN UNDLANNED TRID OF REACT 00 FEEDWATEQ DUMP 18 (CFW-P-18).

            ;     SCRAM OCCURRED OURING SURVEILLANCE TESTING OF THE AUXILIARY AND he                 EMERGENCY LUBE DIL PUMP 5 FOR REACTOR FEE 0 WATER TURBINE 18 (RFW-0T-18)

WITH THE PLANT AT 100% POWER. WHEN A $0LEN010 OPERATE 0 ORAIN VALVE WAS , l, ACTUATED TO DEPRESSURIZE ONLY THE AUTO START PRESSURE SWITCH FOR THE p, AUXILIARY LUBE OIL PUMP, THE ENTIRE "S" FEE 0 WATER PUMP LUBE OIL SYSTEM WAS SUBJECTED TO A LOW LUEE OIL PRE 55URE TRANSIENT SUFFICIENT TO CAUSE A LOW LUBE DIL TRIP OF RFW-P-18. REMAINING PEE 0 WATER PUMP WA5 hO ; , ' UNA8LE TO SUPPLY ENOUGH CAPACITY TO MAINTAIN RPV LEVEL ABOVE THE 6 REACTOR SCRAM SETPOINT. ROOT CAUSE INVESTIGATION IS STILL IN be , ; PROGRESS. TWO MAJOR AREA $ HAVE BEEN IDENTIFIED: 1) INAPPROPRIATE RRC FCV RUNBACE SETPOINT COUPLED WITH THE CHANGE IN FEE 0 WATER PUMP g, GOVERNOR MAXIMUM $ PEED C AP ABILITY; 2) INADVERTENT TRIP OF RFW-P-18 ON

       ,1 LOW LUBE PRES $URE DURING TESTING OF THE AUXILIARY AND EMERGENCY OIL b"                PUMPS. CORRECTIVE ACTION CONSISTS OF REVISION OF THE OPERATING PROCEDURE FOR REACTOR FEE 0 WATER PUMPS TO INCORPORATE INSTRUCTION TO ENSURE THAT TEST PUSMBUTTON 15 DEPRESSED FOR A SUFFICIENT LENGTH OF be                TIME DURING FEE 0 WATER TURSINE STARTUP.

1 FORM 95 LER SC55 CATA D1 , 0************************************************************04-18-91 ******** DOCKET YEAR LER NUMBER REv!sION OCS NUMBER N51C EVENT DATE 397 1989 035 0 8909220118 215277 08/17/89 p, *************************.********..** *******...**** ************** ABSTRACT b' POWER LEVEL - 067%. AT 3319 HOURS, ON 8#17/89, A REACTOR SCRAM I OCCURRED DURING A $URVEILLANCE SEING PERFORMED ON A REACTOR LEVEL be INSTRUMENT ASSOCIATED WITH THE AUTOMATIC DEPRE55URIIATION SYSTEM (A05). THE SCRAM OCCURRED WHEN AN 18C TECHNICIAN PREMATURELY OPENED y, THE ISOLATION VALVE FROM THE REFERENCE INSTRUMENT LEG OF THE DEVICE BEING TESTED. THIS CAUSED A PRE 55URE TRANSIENT IN THE REFERENCE AND

               VARIABLE INSTRUMENT LINES WHICH INITIATED A REACTOR SCRAM SY THE REACTOR PROTECTION SYSTEM (RPS) ON REACTOR WATER LEVEL LOW - LEVEL 3.

THE ROOT CAUSE OF THIS EVENT WAS A PERSONNEL ERROR AND EQUIPMENT e DESIGN DEFICIENCV. IMMEDIATE CORRECTIVE ACTION INCLUDE 0 PLANT SHUT DOWN TO HOT STAN08Y AND A MEMO FROM THE PLANT MAINTENANCE MANAGER

 ,,              SUMMARIZING IMMEDIATE CORRECTIVE ACTIONS. FURTHER CORRECTIVE ACTION INCLUDES IMPROVED TRAINING AND INCREASED VISIBILITY FOR " CRITICAL"
      ,          SURVEILLANCE 5.           4 DESIGN STUDY WILL AL50 SE INITIATED TO EVALUATE THE OESIGN OF THE LEVEL TRIP SYSTEM AND ITS INTERFACING INSTRUMENTATION.

SINCE ALL SAFETY SYSTEMS OPERATED AS DESIGNED AND PLANT OPERATORS g ACTED PROMPTLV TO PLACE THE PLANT IN A SAFE SHUTOOWN CONDITION, THIS EVENT POSED NO THREAT TO THE HEALTH AND SAFETT OF THE PLANT PERSONNEL

 ,               OR THE PU8LIC.

FORM 99 LER SCSS DATA 04-18-91

      ,       0********************************************************************

DOCKET TEAR LER NUMBER REVISION 0C5 NUM8ER NSIC EVENT DATE 397 1990 021 0 9011060294 219924 09/25/90 ABSTRACT 4 g POWER LEVEL - 0452. AT 0557 HOURS ON SEPTEMBER 25, 1990 PLANT OPERATORS MANUALLY CRAMMED THE REACTOR AFTER EXPERIENCING MAIN

  ,              TURSINE HTORAULIC C0hTROL OIL PRES 5URE PROBLEMS IN THE DIGITAL

{ ELECTRO-HTORAULIC (DEN) SYSTEM. THE DEN SYSTEM PROVICES AUTOMATIC AND s MANUAL CONTROL OF iME MAIN TURBINE GENERATOR 87 POSITIONING THE

                                                                                                             . mas i
                       .... -. . _.. .. - oass:. vorc NIFeLi IN THE AUTO STOP OIL HEADER PORTION OF THE TURBINE LU3E CIL (TO) SYSTEM.                 THIS RESULTE3 IN A p,                 DECREASE IN PRES $URE IN THE DEH SYSTEH. THE PRELIMINARY ROOT CAUSE OF THE EVENT WAS TRACED TO THE IMPROPER INSTALLATION OF A STABILIIER i

i U" STRAP THAT M47 HAVE CONTRIBUTED TO THE FAILUXE. THE IQSTALLATION COMBINED WITH THE UNANTICIPATED VIBRATION IN THE AREA 0F THE PIPE NIPPLE LED TO FATIGUE FAILURE. IMMEDIATE CORRECTIVE ACTION WAS TAREN be TO PLACE THE. PLANT IN A COLD SHUTDOWN CONDITION. ALL SYSTEMS AHO

    ,     .j,          COMPONENTS PERFORMED AS DESIGNED. PLANT MAINTENANCE PERSONNEL pq REPLACED STABILIZERTHE      BROKEN NIPPLE AND REINSTALLED THE RELIEF VALVE AND THE STRAP.

' THE EVENT POSED NO THREAT TO THE HEALTH AND SAFETY i te d' 0F EITHER THE PUBLIC OR PLANT PERSONNEL. 1 ! DN , FORM 100 LER DATA

0*****************************SCSS 04-18-91 g,

                                                            *********++****************************

{ ' DOCKET TEAR LER NUMBER REVISION DCS WUM8ER NSIC EVENT DATE q, 397 1990 031 0 9101160184 12/07/90 DM

                     ************************************************220683          ********************
           ;,       ABSTR4CT i

De POWER LEVEL - 100%. ON DECEMBER 7, 1990 At 1010 HOURS, A REACTOR SCRAM OCCURRED DUE TO ACTUATION OF THE REACTOR PROTECTION SYSTEM (RPS) g,, LOGIC. THE INITIATING SCRAM SIGNAL WAS " TURBINE G0bERNOR VALVE FAST CLOSURE" DUE TO A MAIN TUR8INE/ GENERATOR TRIP WITH REACTOR POWER GREATER THAN 30 PERCENT. THE LOGIC W45 ACTUATED WHEN THE MAIN Sa , GENERATOR 500 KV OUTPUT BRE AKERS TRIPPED AS A RESULT OF HIGH CURRENTS pe CREATED GROUND. WHEN A PROCEL4IN INSULATOR IN THE TRANSFORMER YARD SHORTED 10 THE INSULATOR IS ON THE OUTPUT SIDE OF 25/500 KV MAIN TRANSFORMER TR-M2 ("B" PHASE). THE ELECTRICAL FAULT (FLASH 0VER) W O' OUE TO CIRCULATING WATER (CW) SYSTEM COOLING TOWER WATER CHEMICAL ! I DEPOSITS HAVING BUILT UP 04 THE INSULATOR, WITH WET AND ICING 49 CONDITIONS CONTRIBUTING TO PROVIDE A CONDUCTIVE PATH OVER THE SURFACE l 0F THE INSULATOR. 47 1019 HOURS, AN " UNUSUAL EVENT" WAS DECL4REO AS DIRECTED 87 THE EMERGENCY CLASSIFICATION PROCEDURE DUE TO THE

t. RESULTING FAULT-CAUSE0 EXPLOSION WITHIN THE PROTECTED AREA (TRANSPORMER VARD) AT 1030 HOURS, THE REACTOR SCRAM WAS RESET AND* AT I*

1100 HOURS, THE " UNUSUAL EVENT W45 TERMINATED. THE ROOT CAUSES OF THIS EVENT WERE: 1) A LESS THAN ADEQUATE CORRECTIVE ACTION PLAN

e PERTAINING TO THE SCHEDULE AND SCOPE FOR INSPECTING AND CLEANING THE 500 KV INSULATOR $, AND 2) A LESS THAN ADEQUATE PLANT DESIGN.

1 FORM 101 LER SCSS DATA

   '   'A        0************************************************************04-18-91              ********

DOCKET YEAR LER NUMSER REVISION OCS NUM8ER NSIC EVENT DATE 400 1989 001 2 8903270363 213384

   ,   ,y           me****************e*****************************************01/16/89            ********

485 TRACT

       ,,            POWER LEVEL - 100%. THE PLANT WAS OPERATING IN MODE 1, POWER OPERATION, AT 100% REACTOR POWER ON 1/16/$9                   PLANT PERSONNEL WERE IN THE PROCESS OF REMOVING A CLEARANCE 04 4 VALVE IN THE AUX. STEAM

g. CONDENSATE TANE VENT LINE SYSTEM TO TME MAIN COMDINSER. DURING THE

' COURSE OF THE RESTORATION A DIRECT VENT PATH TO THE ATMOSPHERE FROM THE MAIN CONDENSER WAS ESTA5LISHED DUE TO A MISPOSITIONED VALVE AND g, RESULTED IN A RAPIO LOSS OF CONDENSER VACUUM. A REDUCTION OF TUR81NE LO AD ENSUE 0 AND A TURSINE TRIP OCCURRED AT 1518 HOURS DUE TO LOW COMOENSER VACUUM. THE TUR81NE TRIP WAS IMMEDI ATELT FOLLOWED BY AN 1 g, AUTOMATIC REACTOR TRIP AND A PLANT SHUT 00WN. -THE AUX. FEEDWATER SYSTEM ACTUATED 04 STEAM GENERATOR LO-LO LEVEL TO MAINTAIN WATER LEVELS AND THE MAIN STEAM ISOLATION VALVES WERE CLOSED TO LIMIT PLANT

g. 'COOLODWN AND THE PLANT WAS STASILIIE0 IN MODE 3, NOT STAN087. THE CAUSE OF THE EVENT WAS PERSONNEL ERROR IN NOT HAVING A $MTFT FOO*44#

                   . . . . . 6.c  to.tur.

LahmeLlatt ALTIONS INCLUDE: TN! APFROPRISTE PERSONNEL HAUE BEEN COUN5 ELL 50, THE EVENV NAS SEEN DISCUSSED p. STRESSING THE NEED FOR GOOD WOUKING PRACTICE 50 A SHIFT FOREMAN CLEARONCE PLACE 3 ON THE Q4NUAL VALVEo AND REDAIR TO THE MOTOR ODERATED , , VALVE WILL 8E COMDLETED. j dl b4 FORM 102 LER SC55 DATA pq p' Da***********************************************************04-18-91 ******** 00CKET YEAR LER NUMBER REVISION OC5 NUMSER NSIC EVENT DATE 400 1989 003 0 3903210164 213320 q, ************************************************************02/06/89 ******** ABSTRACT De g, POWER LEVEL - 100%. 04 2/6/89, WITH THE PLANT OPERATING AT 100% POWER, AT 0005 THE SH4FT OF THE 4 MAIN FEE 0 WATER PUMP (MFP) SHEARED, CAUSING gg A SUDDEN REOUCTION IN FEEDW4TER FLOW TO THE STEAM GENERATORS. WITHIN q, SECONDS THE MPP TRIPPE0, CAUSING A TUR8INE RUN8ACK. THE OPERATORS E" TOOK MANUAL CONTROL OF THE FEEDW4TER REGULATING VALVE 5 AND ATTEMPTED TO RAISE STEAM GENERATOR LEVELS, BUT THE REACTOR TRIPPED 04 LOW STE4M

       .-       GENERATOR L! VEL APPROEIMATELY ONE MINUTE AFTER THE TRANSIENT BEGAN.

bg THE PLANT RESPONSE TO THE REACTOR TRIP W45 NORMAL, WITH ALL AUXILIARY FEE 0W4TER PUMPS SUTOMATICALLY STARTING TO MAINTAIN STEAM GENERATOR De f- LEVELS, AND THE OPERATOR MANUALLY CLO5ING THE MAIN STEAM ISOLATION VALVES TO CONTROL THE PRIMARY PLANT C00LOQWN. THE MAIN GENERATOR Da EXCITER FIELO 8REAKER DID NOT TRIP OPEN, AND WA5 OBSERVED TO BE g SMOKING. THE BREAKER WA5 LOCALLY CPENED AND AN EXTINGUISHER USED ON THE 8REEP.ER TO PREVENT IGNITION. THE EXCITER FIELD BREAKER WAS FOUNO D, 10 NAVE 4 SURNED 007 TRIP COIL WHICH W AS SUBSEQUE NTLY REPAIRED. THE g; MFP SH4FT WAS FOUND 10 BE SHEARED NEAR THE COUPLING BETWEEN THE PUMP b* AND THE COUPLING. THE DAMAGED SHAFT W45 SENT TO A COMPANY LA8 ORATORY, k AND THE PRELIMINARY CAUSE WAS DETERMINED TO BE LONG TERM CYCLIC 8 FATIGUE. THE EVENT CAUSED INTERNAL DAMAGE TO THE PUMP MOTOR, 45 WELL hs AS MINOR MISSILE DAMAGE TO COMPONENTS IN THE NEAR VICINITT. 1 FORM 103 LER SCSS DATA 0************************************************************04-18-91 ********

  ,.        DOCKET YEAR LER NUMEER REVISION DCS NUM8ER                NSIC     EVENT DATE 400      1989         004          0      3903160060 213321       02/07/89
  ,           A8STRACT POWER LEVEL - 047%. THE PLANT W45 OPERATING.IN MODE 1, POWER
      ,.       OPERATION, WITH MAIN FEEDWATER TRAIN "8 " IN SERVICE AT 472 REACTOR POWER.       AT 1055 ON 2/7/89, THE SU3 DEN LOSS OF ALL 3 CIRCULATING WATER PUMPS (CWPS) RESULTED IN THE LOSS OF ALL FLOW TO'THE MAIN CONDENSER.

e , THE PLANT TRIPPED AT 1058 A5 A RESULT OF A SUDOEN LOSS OF WACUG4 IN THE MAIN CONDENSER. THE LOW PRESSURE TURSINE RUPTURE DISKS RUPTURED

  ,            AS DESIGNED, A RESULT OF THE LOSS OF v4CUUM IN THE MAIN CONDENSER.

g7 THE AURILI4RY FEE 0 WATER SYSTEM 4CTUATED SUSSEQUENT TO THE REACTOR TRIP A5 & RESULT OF TRIP OF THE ONLY OPERATING MAIN FEEDWATER PUMP. MAIN STEAM ISOLATION VALVE 5 WERE CLOSE0 TO LIMIT PLANT COOLDOWN AND THE

      ,        PLANT STABILIZED IN HOT STAN08Y (MODE 3). THIS EVENT W45 CAUSED BY AIR ENTERING THE CWP'5 SEAL WATER SYSTEM AND CAUSING THE PUMP 5 TO TRIP ON LOSS OF SEAL FLOW. AIR ENTERED THE SEAL WATER SYSTEM OUE TO A g,       FAILURE IN THE LEVEL CONTROL SYSTEM FOR THE POTABLE WATER HTOROPHEUM4 TIC TANK. CORRECTIVE ACTIONS INCLUDED REPAIRING FAILED COMPONENTS IN THE POTASLE WATER SYSTEM, REPLACING THE RUPTURE DISES g:       FOR THE TURFINE, IDENTIFYING ADDITIONAL MODIFICATIONS FOR THE SEAL WATER SYSTEM AND THE POTABLE WATER SYSTEM. ALL SYSTEMS FUNCTIONS A5
  ,-           EIPECTEO. THIS EVENT 15 REPORTED IN ACC040ANCE WITH g>       10CFR50.73(A)(2)(IV) A5 AN ENGINEERED SAFETY FEATURE ACTUATION AND A
  ,            REACTOR PROTECTION SYSTEM 4CTUATION.

                                                        .w, ten 4Lsa UATA
!                   pm 0**..e***********.*******************************************04-19-91                                                   ********

I DOCKET TEAR lea NUMBER REVISION DCS NUMBER NSIC EVENT DATE 400 1999 005 0 8903280293 113385 kW ************************************************************02/22/S9 ******** ABSTRACT b4 POWER LEVEL - 1001. 04 2/22/89, AT 1314, WITH THE PLANT AT 1001 POWER

p AND STS NET MWE, A REACTOR TRIP ON LOW STEAM GENERATOR LEVEL pq COINCIDENT WITH STEAM / FEE 0 WATER FLOW MISMATCH OCCURRED DURING THE PERFORMANCE OF A CALIBRATION TEST PROCEDURE FOR STEAM GENERATOR LEVEL b4 H CHANNEL L-474. THE SECTION OF THE PROCEDURE SEING PERFORMED CAUSED AN ' ISOLATION OF FEE 0 WATER TO A STEAM GENERATOR, CAUSING THE STEAM / FEED FLOW MISMATCH. A LOW LEVEL SIGNAL WAS ALREADY PRESENT WHEN THE DG *; 4 CHANNEL WAS REMOVED FROM SERVICE FOR THE TEST, 50 THE TRIP SIGNAL I OCCURRED ALMOST IMMEDIATELY AFTER THE ISOLATION VALVES CLOSEO. THE 4 pq PLANT WAS STA81LIZED IN HOT STAND 8Y AT 557F AFTER THE TRIP, WITH ALL 3

q AUX. FEEDWATER PUMPS AUTOMATICALLY STARTING DUE TO LOW STEAM U" GENERATOR LEVELS. THE CAUSE OF THE TRIP WAS PERFORMANCE OF A SECTION 4

' 0F THE PROCEDURE INTENDED TO SE CONDUCTED DURING SHUTDOWN. CAUTIONS l i IN THE PROCEDURE, INTENDED TO ALERT PERSONNEL OF THE IMPACT ON PLANT be OPERATION, WERE REVIEWE0 87 THE TECHNICIANS, AND SY THE OPERATORS ON 4

'                                    SHIFT INCLUDING THE SHIFT FOREMAN, SUT THE CAUTIONS WERE NOT g,     ;

SUFFICIENTLY EEPLICIT TO BE UNDERSTOOD ST THESE INDIVIDUALS. THE PLANT WAS RETURNED TO SERVICE AT 2255 0F THE SAME DAY. THE PROCEDURES I I4 WHICH TEST THE FEEDWATER CONTROL LOGIC WILL SE REVISED TO ENSURE EMPLICIT INSTRUCTIONS ARE PROVIDE 0 AS TO THE EFFECT ON PERFORMANCE OF THE TEST ON THE FEEDWATER VALVE LINEUP.

                     >1          1 g,             FORM                105                                           LER SCSS DATA E

0.*******************************.***************************04-18-91 *...**** l k' DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 400 1989 006 0 8904240141 213680 03/14189 ke A85 TRACT 7, POWER LEVEL - 100%. THE PLANT WAS OPERATING AT FULL POWER PRODUCING

                         ,           890 NET MWE 04 3/14/89 FIRE PROTECTION TECHNICIANS HAD DIFFICULTY IN RESETTLING THE FIRE SYSTEM DELUGE VALVE THAT SUPPLIES THE SPRINKLER i                    i                SYSTEM OVER THE MAIN FEEDWATER PUMPS (MFPS). THEIR SUBSEQUENT ACTIONS
                        ,            RESULTED IN A SMALL AMOUNT OF WATER BEING SPRATED ON THE "B" MFP.

i. SHORTLY AFTERWARD, AN INTERNAL SHORT OCCURRED IN THE MOTOR JUNCTION 80E. THE ENERGT FROM THE SHORT SLEW THE DOOR FROM JU NCT ION B04. THE

                    '   +

PLANT CONTROLS AUTOMATICALLY RESPONDED AS DESIGNED BUT THE REACTOR TRIPPED ON LOW LEVEL IN THE "A" STEAM GENERATOR APPROE. 71 SECONDS AFTER THE "B" MFP TRIP. DAMAGE WAS CONFINED TO THE MOTOR LEAD 9 4 CONNECTIONS AND STEAM PLAN? PERFORMANCE INSTRUMENT TU8ING IN THE TRAJECTORY OF THE .tUNCTION BOX D004 THE PLANT TRIP WAS CAUSED ST

                     ,               PLANT DESIGN CONSIDERATIONS. THE SHORTING OF "8" MFP MOTOR LEAD WA$

g, DUE TO GAPS IN THE ELECTRICAL ENCLOSURE FOR THE '8' MFP MOTOR THAT

                    '               ALLOWED WATER TO ENTER THE JUNCTION 80X. PREVIOUS EXPOSURE OF THE JUNCTION 80X INTERNALS 70 WATER SPRAY CAUSED THE DETERIORATION OF
                        ,;          WIRING INSULATION. THE DAMAGE 10 "B" MFP WAS REPAIRED AND THE WATER

TIGHTNESS OF THE "A" MPP ENCLOSURE CORRECTED. THE PROCEDURES USED SY FIRE PROTECTION PERSONNEL WILL SE REVISED AND APPLICA8LE PERSONNEL i

g.' RETRAINED. 1 I PORM 106 LER SCS$ DATA 04-18-91

g. '

3 0.**********..............................................e..........

l' 00CKET TEAR LER NUMBER REVISION DCS MUM 8ER NSIC EVENT DATE gg 400 19t9 017 1 S912130259 216106 10/09/89

                                    .....        . . . . . . . . eve,eav,   *e cas>, 4 ututkAT05 ANu NAIN POWER TRANSFORMER OPa5E DIFFERENTIAL RELAY TRIPPED THE LOC 40UT RELAY OF THE p3 Malta GENERAT03o VRIPPIMG THE G ENE RA TOR AND CAUSING A TURSINE AN3 REACTOR TRIP FCOM 1001 POWER. THE REACTOR WAS STABILIZE 0. ACTUATION 0F THE EECECAT00 AND MAIN POWER TRANSP00MER DIFFERENTIAL RELAY AND f*                       SUBSEQUENT GENERATOR TRIP WAS CAUSED af MULTIPLE GROUND FAULTS.                        THE he                      GROUND FAULTS DESTROYED THE NEUTRAL GROUNDING BUS AND CAUSED THREE FIRES: AN OIL FIRE AT THE "8" MAIN P0 DER TRANSFORMER, A HYDROGEN FIRE UNDERNEATH THE MG AND A THIRD SMALL CIL FIRE IN THE GENERATOR p,                      HOUSING. AN ALERT WAS DECLARED, AND THE SITE FIRE BRIGADE RESPONDED TO THE FIRES, ASSISTED LATER SY OFF SITE FIRE DEPARTMENTS. ALL FIRES 58                       APPEARED CUT 8Y 0145. THE INITIATOR OF THE GROUND FAULTS HAS BEEN IDENTIFIED A$ ALUMINUM DE84IS IN THE ISOLATED PHASE SUS OuCT, WHICH
    >g                     WAS DEPOSITED IN THE BUS DUCT FROM PREVIOUS FAILURES OF THE DUCT COOLING SYSTEM OAMPERS.                 ARCING FROM THE ALUMINUM DEBRIS IN THE BUS LED TO A DOUBLE PHASE TO GROUND FAULT AT THE "B" MAIN POWER g,                       TRANSFORMER. MAGNETIC FORCES FROM THIS FAULT BROKE INSULATOR $ IN "A" PHA5E AND "B" PHASE OF THE ISOLATEC PHASE BUS DUCT. THE "A" PHASE bm                     CONDUCTOR CONTACTED THE BUS ENCLOSURE CREATING ANOTHER GROUND FAULT.

THE TUR8INE-ORIVEN AUXILIARY FEE 0 WATER PUMP STARTED AFTER REACTOR TRIP, BUT THE PUMP TRIPPED SHORTLY THEREAFTER. me 1 4 D' FORM 107 LER SCSS DATA 0************************************************************04-18-91 ******** i DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE = Ri 400 1999 018 0 9001110187 216413 12/07/89 i I P4 A8STRACT

     *'                    POWER LEVEL - 000T. THE PLANT WAS IN COLD SHUTOOWN, MODE 5, ON 12/7/89, CONTROL ROD BANK                 "A" WAS BEINS WITHORAWN FOR SURVEILLANCE I
    >e TESTING OF THE DIGITAL ROD POSITION INDICATOR (DRPI) PER-PROCEDURE OST-1112 AND ROD OROP TESTS PER PROCEDURE EST-704 TO 5ATISFY TECHNICAL SPECIFICATION SURVEILLANCE REQUIREMENTS 4.3.3.3 AND 4.1.3.4 g,                    RESPECTIVELY. AN OPERATOR MONITORING THE ORPI NOTICEO THAT R0D 8-10 WAS INDICATING 6 STEPS WITHORAWN WHEN THE REST OF CONTROL BANK "A" INDICATED 12 STEPS WITHORAWN. THE CONTROL BANK WAS WITHDRAWN A FEW MORE STEPS AND THIS SAME OP!RATOR NOTICED THAT 200 5-10 INDICATED IT WAS AT THE BOTTOM, WHILE THE REST OF THE CONTROL BANK INDICATED 18 i e                         STEPS ON DRPI. THE OPERATOR INFORME0 THE REACTOR OPERATOR WHO IMMEDIATELY OPENED THE REACTOR TRIP BREAKERS AS REQUIRED PER 05T-1112
     ,                     FOR ABNORMAL ROD MOVEMENT. ALL RODS INSERTED AND ALL SYSTEMS 1                           RESPONDE0 45 REQUIRED. THE CAUSE OF THE EVENT WAS DUE TO A CABLE FAILURE ON ORPI DATA TRAIN "B" FOR ROD 8-10.
    '                 1
        ,               FORM        108                          LER SCSS DATA                          04-18-91 0********************************************************************

DOCKET TEAR LER NUMBER REVISION OCS NUMBER N51C EVENT DATE 410 1989 009 0 8906020268 214170 04/22/89

        ,               ABSTRACT POWER LEVEL - 100%. ON APRIL 22, 1959 AT 1941 HOURS, NINE MILE POINT UNIT 2 (NMP2) EXPERIENCED A REACTOR SCRAM AS A RESULT OF A NEUTRON
        ,                 MONITORING SYSTEM TRIP. SPECIFICALLY, WMEN PREPARING TO PERFORM WEEKLV TUR8INE 8ACKUP OVERSPEED TRIP TESTING AN OPERATOR KETED A RADIO WITHIN THE VICIMITY OF THE ELECTRO HYDRAULIC CONTROL (EHC) CABINET.
        ,                 THIS ACTION CAUSED EHC SYSTEM OISTURBANCES RESULTING IN INADVERTENT MOVEMENTS OF THE TUR8INE CONTROL AND STPASS Valves. TMIS MALFUNCTION CREATED A PR!55URE SPIKE WHICH CAUSED ALL SIR AVERAGE POWER RANGE g                 MONITORS (APRMS) TO EXCEED THEIR UPSCALE TRIP SETPOINT. AT THE TIME OF                                                                               TH8 4097

_THE_ EVENT REACTOR POWER WAS AT 1003 RATED THERMAL POWER.

m.. stas aw csaut: av"*0P<1 Air P E R i CN'4 E L ARE AWARE OF POTENTIAL PROSLE*1 WITH RADIO USE; (2) INSTALLnTION OF PER"&NENT y, CAUTION SIGNS AT EACH ENTRANCE TO THE RELAY ROOMI AN3 (3) ISSU4NCE OF 4 MEMO 2ANDUM FROM THE STATION SUPERINTENDENT TO ALL STATION PERSONNEL U" COICERNIEG USE OF RADIOS /SEEPERS. IO 400!TIO2, OTHER 42EAS OF THE g STATION WHICH HAVE SEEN IDENTIFIED AS RADIO TRANSMISSION SENSITIVE HAVE BEEN POSTED. DW 1 h, FORM 109 LER SC55 OATA 04-18-91 0........................................................... ........ k* :q

       '       DOCKET TEAR LER NUMBER REVISION DCS NUM8ER                                                                 MSIC       EVENT DATE 410          1989                     014                           0        8905300041 214009                        04113/89 84 -}.

ABSTRACT g, POWER LEVEL - 100T. ON APRIL 13, 1989 4T 1101 HOURS WITH THE RE4CTOR j, MODE SWITCH IN RUN, AND THE REACTOR AT 1001 RATED THERMAL POWER, NINE 8" MILE POINT UNIT 2 EXPERIENCED A REACTOR SCRAM. THIS EVENT WA$ A RESULT OF A TUR81NE TRIP CUE TO THE ACTUATION OF THE GENERATOR pg 7 PROTECTION CIRCUITRT. THE GENERATOR PROTECTION CIRCUITRY INITIATED A FAST TRANSFER OF HOUSE SERVICE LOADS 70 THE STATION RESERVE TRANSFORMERS. ONE OF THE 13.8KV ELECTRICAL BUSES FAILED TO TRANSFER g, WHICH CAUSED A LOS$ OF FEE 0 WATER. REACTOR WATER LEVEL DECREASED 45 THE TURSINE CONTROL BTP455 VALVES MODULATED 10 CONTROL REACTOR PRESSURE, WHICH CAUSED THE AUTOMATIC ACTUATION OF THE HIGH PRESSURE B4 , CORE SPRAY (C5H) AND REACTOR CORE ISOLATION COOLING (ICS) SYSTEMS. THE CAUSE FOR THE TURBINE TRIP W45 DETERMINED TO BE A DISCONNECTED pg WIRE LOCATED IN THE MAIN GENERATOR POTENTIAL TRANSFORM!R CUBICAL. THIS CREATED A SIGNAL TO THE TRIPPING AND ALARM RELAYS C AUSING A TUR8INE TRIP. THE CAUSE 80R THE 13.8KV BU$ FAST TRANSFER FAILURE W45 I OETERMINED TO BE THE POSITIVE INTERLOCKING ROLLER FOR TH! SREAKER NOT FULLY ENG4GED. CORRECTIVE ACTIONS INCLUDE: (1) RELANDED THE Es DISCONNECTED WIRE AND TIGHTENED OTHER POTENTIAL TRANSFORMER CONNECTIONS; (2) REVISING THE ELECTRICAL MAINTENANCE PROCEDURE g, , (N2-EPM-GMS-R693) To CHECK CONNECTION INTEGRITY IN HIGH VIBRATION AREAS. 1 B* FORM 110 LER SC$$ 04TA 04-18-91 6 0********************************************************************

     ,;        DOCKET TEAR LER NUMBER REVISION OCS NUMBER                                                                 NSIC       EVENT DATE
  ,,              410          1939                     024                           0        8910120144 215577                        09/08/59
               ...e ...............................................................
  #' 'I A85 TRACT POWER LEVEL - 0881. AT 15:00:45 HOURS ON SEPTEMBER 8, 1939, WITH THE

e ,g REACTOR MODE SWITCH IN "RUN" AND THE REACTOR AT 882 RATED THERM 4L POWER (930 MWE), NINE MILE POINT 82 EXPERIENCE 0 A DOWNSHIFT OF REACTOR

  ,             RECIRCULATION PUMPS TO SLOW $ PEED. THIS PLACED THE UNIT ABOVE THE
     ,;         100X ROD LINE WITH CORE FLOW <45% (RESTRICTED AREA 0F OPERATION). THE CONTROL ROOM ANNUNCIATORS NOTIFIED THE OPERATIONS PERSONNEL OF THE DOWN$NIFT. OPERATIONS PERSONNEL IMMEDIATELY PERFORMED THE REQUIRE 0
     ,.         ACTIONS PER N2-OP-29, REACTOR RECIRCUL4 TION SYSTEM, BT PLACING THE
  ,             REACTOR MODE $ WITCH TO "$HUTOOWN", INITISTING A REACTOR SCRAM.

OPERATIONS PERSONNEL PROCEEDED WITH SCRAM RECOVERY PER M2-0P-101C, gj PLANT SHUT 00WN. 10CFR50.72 NOTIFICATION WAS MADE ON SEPTEMBER 8, 1989, af 2013. THE ROOT CAUSE FOR RECIRCULATION PUMP TRIP IS 4 FAILURE OP A 24 VOLT OC POWER SUPPLY (C334-K613) WITHIN THE FEEDW4TER CONTROL t SYSTEM. CORRECTIVE ACTION W45 TO REPLACE THE FAULTT POWER SUPPLT. I-l 1

g. FORM 111 LER sCss DATA 04-18-91 0....................................................................

                                   . _ _ . _ , _ _ _ _ _ . , ,. - _ _ . . _ _ _ _       _,-_.,m       _ . , , - .__          , , . _  ,,, ,                  . . _ . _ . , _ _ , _ , _ . , ,    m .   . -.                                  _. , , , -

        .        .. - - . - - . - ~ - - - - - -                       -  . - . - - - . - - - - - - . . . . . . .                                -- - - - - - - -

pq ABSTRACT ' POWER LEVEL - 0543. ON OCT0aER 13, 1989, AT 0949 HOURS NINE MILE

POINT U:IT 2 (NMP2) EXPERIENCED f4 ACTUATION OF AM EEGINEERED 54FETT ag FEATURE (ESP), SPECIFICALLV AN AUTOMATIC REACTOR SCRAM 45 4 RESULT OF A MAIN TURBINE TRIP. AT THE TIME OF THE EVENT, THE REACTOR WAS

] h4 OPERATING AT 54E RATED POWER WITH THE MODE SWITCH IN "RUN" i pq (OPER ATIONAL CONDITION 13. THE ROOT CAUSE WA5 DETERMINED TO 8E PERSONNEL ERROR IN THAT AN ADEOUATE EVALUATION OF PLANT IMPACT WAS NOT PERFORMED. A CONTPIBUTING CAUSE WAS F4ILURE OF 4DMINISTRATIVE kd PROCEDURES TO ADDRESS A COMPREHENSIVE PLANT IMPACT REVIEW. CONTROL ROOM OPERATORS CARRIED OUT IMMEDIATE CORRECTIVE ACTIONS. OTHER ) CORRECTIVE ACTIONS INCLUDE REVISION OF PLANT IMPACT EV4LU4 TION FORM DN pg

AND REPAIR OF MOTOR GENERATOR LOGIC CIRCUIT. THE RESPONSISLE CHIEF SHIFT OPERATOR (C50) WAS DIRECTED TO WRITE 4 SPECIAL REPORT CONCERNING s

   "e                         THIS EVENT. M!ETINGS WERE HELD TO STRESS THE IMPORTANCE OF Pla4T a              IMPACT EVALUATIONS. ADMINISTRATIVE PROCEDURES WILL 8E REVISED. A t                              LE55045 LEARNED TRANSMITTAL WILL BE 155UEO.

Du g 4:i 3 he ' FORM 112 LER SC55 DATA , 0e*****....*.......................... ..................... 04-18-91

    ,,p,                  DOCKET TEAR LER NUMBER REVISION DCS NUMBER                                                          NSIC      EVENT DATE 410             1989       036          0                             8911220160 215896 D- 8
                          ......................................... ..................... 10/1                                             5/S9....

i A85 TRACT ' p1 POWER LEVEL - 001%. ON OCTOBER 18, 1959, AT 06:15:41 HOU45, NINE MILE

POINT UNIT 2 (NMP2) EXPERIENCED AN UPSCALE TRIP OF THE INTERMEDIATE RANGE MONITORS (IRMS) RESULTING IN AN AUTOMATIC ACTUATION OP THE fi REACTOR PROTECTION SYSTEM (RP5) AND A FULL REACTOR SCRAM.

OF THE EVENT, THE REACTOR MODE SWITCH W45 IN THE START / HOT STANDST AT THE TIME Es POSITION.WITH REACTOR POWER IN THE INTERMEDIATE RANGE (1%). THE ROOT { CAUSE FOR THIS EVENT W45 DETERMINED TO BE INADEQUATE CONTROL OF 1 ge 1 ACTIVITIES ASSOCIATED WITH THE PLANT SHUTDOWN ON THE PART OF CONTROL

ROOM PERSONNEL. 4 CONTRIBUTING FACTOR WA5 A PROCEDUR AL DEFICIENCT.

                           CORRECTIVE ACTIONS INCLUDE (1) INSTRUCTING OPERATING SHIFT PERSONNEL
           ,                 ON THIS EVENT, (2) REVISING THE OPERATIONS TRAINING PROGRAM, AND (3)

REVISING PLANT SHUTDOWN PROCEDURE N2-OP-101C. i e 1

   ,                     FORM                   113                LER SC55 DATA                                                          04-1 0**********************.***.*************************************8-91                                                      ****
                     DOCKET TEAR LER NUMBER REVISION DC5 NUMBER                                                            NSIC      EVENT DATE A10              1989       0A0          0                            900112000F 216414                   12/01/89
                         ..****.e.**.ee*******..**..**..*************************************

9 ABSTR4CT

   ,.                       POWER LEVEL - 097E. ON 12/1/99, NINE MILE POINT UNIT 2 (MMP2) WAS
          .i                OPERATING AT APPROM. 9FE RATED THERMAL POWER WITH THE MODE SWITCH IN THE "RUN" POSITION (OPERATIONAL CONDITION 1). 4T 1310 HOURS, NMP2
                         -EMPERIENCED AN AUTOMATIC REACTOR SCRAM CAUSED SV AVERAGE POWER RANGE
          ,                 M ON IT OR (4PRM) HIGN NEUTROM FLUE SIGN 4LS ON SOTH OIVISIONS OF THE REACTOR PROTECTION ST5 TEM (RPs). AT 1313 HOURS, THE TUR8INE WAS TRIPPED ON REVERSE POWER 87 THE MAIN GENERATOR ANTIMOTORING DEVICE.
          ,                 IMMEDIATE CORRECTIVE ACTIONS WERE TAKEN 8T OPERATIONS TO CARRT OUT ALL SCRAM REC 0VERV ACTIONS AND TO PLACE THE PLANT IN A STABLE "NOT SHUTOOWN" N00E (OPERATIONAL. CONDITION 3). OPERATIONS THEN INITIATED AN 1

g. INVESTIGATION OF THE EVENT. THE IMME3IATE CAUSE WAS 4 M4LFUNCTION OF

, , THE ELECTRONTDRAULIC CONTROL ST57EM (EHC) WHICH RESULTED IN THE POWER i t TRANSIENT THAT CAUSED THE scram. CORRECTIVE ACTION WAS TO REPLACE 3 g- RELAY 804R05 IN THE EHC CONTROL CIRCUIT AND CORRECT A GROUND LOOP IN

   ,                , THE TURBINE SPEED SEN5ING CIRCUIT.

                                                                                          -- '1
                 -     ...                L.h  >L o b4TA                      04-13-91 0...............................**...................................

P1 DOCKET YEAR LER HUMSER REVISION 0C5 NUMBER f45IC EVENT DATE 410 1990 009 0 9006220191 215539 05/14/90 kg ******************************************************************** A85 TRACT h4 POWER LEVEL - 045%. ON May 14, 1990, AT APPROXIMATELY 2052 HOUR 5, WITH l e ; THE REACTOR MODE SWITCM IN THE "RUN" POSITION AND THE Rett;gg r3 OPERATING AT 100% RATED THERMAL POWER, NINE MILE POINT UNIT 2 (NMP2) WAS EXPERIENCING NUMEROUS OFF-NORMAL PLANT CONDITIONS. OPERATIONS g4 PERSONNEL WERE RESPONDING TO SEVERAL A8 NORMAL OFFGAS SYSTEM (OFG) INDICATIONS AND ALARMS, AND MAIN CON 3fNSER VACUUM WAS DECREASING. AT APPROXIMATELY 205S HOURS, OPERATORS INITIATED REACTOR POWER RE00CTION D8 . IN RESPONSE TO DECREASING CONDENSER VACUUM. AT 2119 HOURS WITH REACTOR POWER AT APPROXIMATELT 45% RATED THERMAL POWER, THE REACTOR kg MODE SWITCH WAS PLACED IN THE "5 HUT 00dN" POSITION, INITIATING A REACTOR SCRAM. THE CAUSE OF THIS EVENT WAS THE PARTIAL LOSS OF THE

'  U"           INSTRUMENT AIR SYSTEM (IAS) DUE TO PIPE FAILURE INDUCED BY l

5TRE55-CORR 0513N CRACKING. IMMEDIATE CORRECTIVE ACTIONS INCLUDED: b4 PERFORMING A WALK 00WN OF THE SUSPECTED SR ANCH OF THE IAS TO LOCATE SOURCE OF AIR LOSSI GENERATING A WORK REQUEST TO REPLACE THE FAILED l AIR LINEI AND REQUESTING A FAILURE ANALYSIS SE PERFORMED TO IDENTIFY

y, CAUSE OF PIPE FAILURE.

, 1 8' FORM 115 4 LER SC55 DATA 1 0************************************************************04-18-91 De DOCKET YEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE 410 1990 D13 0 9010160051 219760 09/05/90 l A8STRACT be POWER LEVEL - 064%. 04 SEPTEMEER 5, 1990, 47 0400 HOURS, WITH THE REACTOR MODE SWITCH IN "RUN" AND AT APPROXIMATELV 64% RATED THERMAL g, POWER (645 MWE), NINE MILE POINT UNIT 2 EXPERIENCED AN ENGINEERED SAFETY FEATURE ACTUATION. SPECI*ICALLY, AN AUTOMATIC REACTOR SCRAM

              CAUSE0 SY & TUR8INE GENERATOR TRIP WHICH WAS INITIATED BY A GENERATOR FIELD GROUND. THE ROOT CAUSE OF THE TUR8INE GENERATOR FIELO GROUND IS BEING INVESTIGATED. THE IMMEDIATE CORRECTIVE ACTION WAS TO RESPOND i

70 THE REACTOR SCRAM AND TURBINE TRIP IN ACCORDANCE WITH PLANT PROCEDURES. A WORK REQUEST WAS !$5UED TO INVESTIGATE THE TURBINE

, GENERATOR FIELD GROUND. THE ROOT CAUSE AND THE LONG TERM CORRECTIVE ACTIONS WILL BE SU8MITTED A5 A SUPPLEMENT TO THIS REPORT.

1 i+ FORM 116 LER SC55 DATA 04-18-91 i De******************.************************************************ DOCKET TEAR LER NUMBER REVISION DCS NUMBER M5IC EVENT DATE

   ,              412    1989     003           0     8003220424 213272       02/12#89 ABSTRACT POWER LEVEL - 055%. ON 2/12/89, WITH THE UNIT IN POWER OPERATION, A POWER REDUCTION PROM 905 REACTOR POWER TO SOE REACTOR POWER WAS IN PROGRESS 45 PART OF END OF CORE LIFE PROGRAM 5. AT 004S HOURS,
   ,  ,-        CPERATOR5 NOTICED ERRATIC OPERATION OF THE "C" MAIN FEEDWATER REGULATING VALVE (PFRV). THE OPERATORS PLACED THE "C" MFRV IN MANUAL TO CONTROL STEAM GENERATOR LEVEL. AT 0108 HOURS AT APPROX. 55%

8 g REACTOR POWER, THE "A" MAIN FEEDWATER PUMP WAS SHUTOOWN TO R EDUC E THE PRESSURE DIFFERENTI AL ACROSS THE VALVE ALLOWING EASIER VALVE MOVEMENT I AND CONTROL. AT 0120 HOURS, A TUR8INE TRIPIREACTOR TRIP OCCURRED DUE

      ,         TO 4 HIGH WATER LEVEL IN THE "C" STEAM GENERATOR. THE OPERATORS STABILIZED THE PLANT IN HDT 5MUTDOWN UTILIZING THE EMERGs4rv nosestTMr.

1

                           ...sw%.          ..a ...m.austu    as ntu4AUL1L FORCES AND WI5 PAT!0M ACTINS OVER TIME.           THE MFRv5 WERE ALL DISASSEMBLEO, INSPECTED At4D REPAIRED AS PM                     MECE554RT.             THIS EVENT WAS REPORTED TO THE NUCLEAR R?GULATORY COMMISSION AT 0300 HOURS, IN ACCORDANCE WITH 10CFR50.72.8.2.II. THERE y4                     WERE to SAFETY IRPLICATIONS TO THE PUBLIC AS A RESULT 0F THIS EVENT.

g' THIS TTPE OF EVENT HAS PREVIOUSLY BEEN ANALVIED AS STATED IN THE

' l b4 UPDATED FINAL SAFETY ANALYSIS REPORT, SECTION 15.1.2, " FEE 0W4TER SYSTEM MALFUNCTIONS CAUSING AN INCREASE IN FEE 0 WATER FLOW".

i : 1 P1 FORM 117 LER SCSS DATA 04-18-91 g4 , 0*******************.************************************************ 00CKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 412 1989 018 0 8906100033 214477 05t27/89 he ......*e.........................e *e.......**e****.e*..$...... **.. gg 485 TRACT POWER LEVEL - 000%. 04 5/27/89, THE PLANT WAS IN HOT STAN08Y, U" PREPARING TO ENTER THE STARTUP MODE. THE REACTOR TRIP SREAKERS WERE CLOSED IN PREPARATION FOR THE MODE CHANGE. REACTOR PRESSURE WAS 1300 be P5IG AND INCREASING TOW 4R05 ITS NORMAL OPERATING VALUE OF 2235 PSIG. TUR8INE IMPULSE PRES 5URE PROTECTION CHANNEL III TESTING WAS IN PROGRE5S. PERSONNEL PERFORMING lHE TEST REMOVED THE CHANNEL FROM

      >g                   SERVICE, IN ACCORDANCE WITH PROCEDURE. WHEN THE CHANNEL WAS REMOVED FROM SERVICE, ITS IMPUT TO THE SOLIO STATE PROTECTION SYSTE9 (55PS)

WAS PUT IN THE TRIPPED CONDITION, A5 DESIGNE0. SSPS RESPONDED TO THIS I' HIGH TURBINE POWER SIGNAL SY UN8 LOCKING THE LOW PRESSURE REACTOR TRIP (5ETPOINT 1945 PSIG). A LOW PRE 55UPE REACTOR TRIP OCCURRED P1 IMMEDIATELY, OPENING THE REACTOR TRIP ORE 4KERS. THIS EVENT W45 OUE TO PERSONNEL ERROR AND A LACK OF PROCEDURAL GUIDENCE. ALTHOUGH THE

      ,,                   PROCEDURE HAD THE TECHNICIANS VERIFY THE LOW PRES 5URE REACTOR TRIP
      ,                    BISTABLES WERE OFF PRIOR TO REMOVING THE CHANNEL FROM SERVICE, THEIR FOREMAN INSTNUCTED THEM TO PROCEED. THIS PROCEDURE IS BEING REVISED 8'

TO CLARIFY THE ACTIONS TO BE TAKEN IN RESPONSE TO DEVIATIONS FROM THE TEST *5 ANTICIP4TED PLANT 5T4705. THIS EVENT 15 SEING INCLUDE 0 IN te PERSONNEL TRAINING. REVIEW OF THE STATION RECORDS SHOWED 2 PREVIOUS SIMILAR EVENTS. REACTOR TRIPS 00E TO LOW PRESSURE ARE O!5 CUSSED IN

      ,,                   SEAVER v4LLET UNIT 2 UFSAR SECTION 7.2.

4 FORM 118 LER SCSS DATA 04-18-91 0********************************************************************

         .               DOCKET TEAR LER NUMBER REVISION OC5 NUMBER                             NSIC         EVENT DATE 412           1990         008          0     9003060114 219056                   07#02/90

, s. ASSTRACT t POWER LEVEL - 0902. ON 7102/90 AT 0700 HOURS, WITH THE UNIT IN POWER OPERATION AT 87% REACTOR POWER, 4 POWER INCREASE TO 90% WAS INITIATED.

      ,                    4T APPROI. 0800 HOURS, REL4V PERSONNEL SEGAN CLEARING THE 345 KV 8US SACKUP TIMER PROTECTION ASSOCIATED WITH THE MAIN TRANSFORMER TO PERFORM 4 CALISR4 TION OF PRIMART 345 KV LEADS SECONDARY BACKUP FAULT UNIT (58FU) PROTECTION RELAY, 50-J3202.                RELAY 50-J3202 15 WITHIN 4 CURRENT LOOP INPUTTING A SIGNAL TO O!FFERENTIAL PROTECTION RELAY 87-204            RELAT 57-204 COMPARES SIGNALS FROM THE 345 KV OISTRIBUTION LINES 440 THE OUTPUT OF THE MAIN TRANSFORMER. AT 0915 HOURS, WITH THE UNIT AT 90% REACTOR POWER, A REACTOR TRIP OCCURREO. THE REACTOR TRIP WAS THE RESULT OF AN IMMEDIATE TUR81NE/ GENERATOR TRIP. OPERATIONS PERSONNEL UTILIZE 0 THE ENERGENCT OPERATION PROCEDURES TO STABLILIZE THE UNIT IN HOT STAN087. THE CAU5E FOR THE TURSINE/ GENERATOR TRIP WAS ACTU4 TION OF RELAT 57-204. THIS RELAT ACTUATED 45 A RESULT OF 4 i                   PERSONNEL ERROR DURING THE CALIBRATION OF RELAY 50-J3202. THE RELAY
             ,             TECHNICIAN OPENEO A 4-POLE SHORTING SWITCH, DE-ENERGIZING 1 INPUT TO RELAY 87-204, CAUSI4G 4CTU4 TION.              THE 4-POLE SH O R T I N r. iWTTcw wat me n

                                                                                                  . --~
                  .   ... . .      ..<.so  .,   ..m.n, at:4 L Y SI S REPORT, SECTIO 1 3.0.
                                                          .4  in  un:Ati) *INAL SM E T T
 , ,        1 1
 ,4           FORM     119                    LER SCS$ DATA j; 0************************************************************04-15-91     ********

DOCKET YEAR LER NUMBER REVISION DC5 NUM8ER NSIC EVENT DATE kW 413 1989 008 1 3905240498 214010 03/05/89 P1 ABSTRACT LC Ig POWER LEVEL - 100%. ON 3/5/S9, AT 2140 HOURS, A UNIT 1 REACTOR TRIP OCCURRED AFTER EXCEEDING THE OVER POWER DELTA TEMPERATURE SETPOINT. b4 IN PREPARATION FOR AUI. SAFEGUARDS TESTING OF STEAM LINE ISOLATION

        ;g     VALVES, THE OPERATOR AT THE CONTROLS MISTAKENLT DEPRESSED THE CLOSE PUSH 8UTTON FOR THE MAIN STEAM LOOP 4 ISOLATION VALVE WHILE ATTEMPTING b,

TO CLOSE THE STEAM GENERATOR 1A POWER OPERATED RELIEF ISOLATION VALVE. THE TWO PUSH 8UTTONS ARE 40JACENTLY LOCATED. THE POWER OPERATED D4 RELIEF ISOLATION VALVE HAD FAILED TO CLOSE ON TWO PREVIOUS PUSH 8UTTON ACTUATION 5 DURING THIS TEST. THE MAIN STEAM ISOLATION VALVE WAS i IMMEDIATELT REOPENED, SUT AS OTHER RELIEF VALVES HAD ALSO CPENED, Di SAFETT INJECTION SUS SE QUE NTLY ACTUATED ON LOW RATE COMPEN5ATED STEAM PRES 5URE. UNIT RESPONSE TO THE TRIP AND $AFETY INJECTION WAS 45 g,f DESIGNED. CONTROL ROOM PERSONNEL ENTERED THE APPROPRIATE EMERGENCY PROCEDURES 70 STASILIZE THE UNIT AND RECOVER FROM THE SAFETY D3 INJECTION. THE APPLICATION OF PROTECTIVE COVERS TO CERTAIN CONTROL g, DEVICES HAS SEEN REVIEWEO. THE POWER OPERATED RELIEF ISOLATION VALVE ACTUATOR DEVICES HAS SEEN REVIEWEO. THE POWER OPERATED RELIEF p, ISOLATION VALVE ACTUATOR WAS FOUND TO HAVE 4 WORN STEM NUT WHICH WA$ i, SUSSEQUENTLY REPLACED. THE UNIT WAS OPERATING IN MOD E 1, POWER

  ,,           OPERATION, AT 1002 POWER AT THE TIME OF THE TRIP.

I be FORM 120 LER SC55 04TA 0************************************************************04-18-91 ******** t, DOCKET YEAR LER NUMBER REVISION DCS NUMSER N5IC EVENT DATE 413 1989 017 0 8903010458 214899 06/26/89 ABSTRACT e POWER LEVEL - 100%. ON JUNE 26, 1989, AT APPR0xIMATELY 0635 HOURS, WITH UNIT 1 IN MODE 1, POWER OPERATION, AT 100% POWER, 1CF28, STEAM

  ,            GENERATOR (S/G) 1A MAIN FEEDWATER (CF) CONTROL VALVE, SLOWLY BEG 4N CLOSING, CAUSING 5/G 14 LEVEL TO DECRE4SE. THE 5/G 14 LEVEL DEVIATION
  '            ALARM WAS RECEIVED AND ICF30 $/G 1A CONTROL SYP45$ VALVE, WAS OPENED TO SUPPLY ADDITIONAL CF FLOW. AN OPERATOR WA5 OISP4TCHED AND DISCOVERED THAT AIR WAS LEAKING FROM THE 1CF28 CONTROL AIR MANIFOLD.

e A WORK REQUEST WAS ISSUED TO INVESTIGATE AND REPAIR THE AIR LEAR AS 5/G 1A LEVEL CONTINUED TO DECREASE. 1CF28 EVENTUALLT CLO5ED AND { REACTOR POWER WAS REDUCED IN AN ATTEMPT TO MATCH CF FLOW WITh DEMAND.

      .        A M ANUAL RE ACTOR TRIP WAS INITIATED AT 0718 HOURS, FROM 85% REACTOR POWER, JUST PRIOR TO A 5/G LOW LOW LEVEL REACTOR TRIP SIGNAL.

EMERGENCV PROCEDURE EP/1/4/5000/01, REACTOR TRIP OR $45ETY INJECTION,

     ,         WA5 ENTERED.        THE TURBINE TRIPPED DUE TO THE REACTOR TRIP AND aux!LIARY FEEDWATER ACTUATION OCCURRED.           A G45KET IN THE VALVE'S CONTROL AIR MANIFOLD WAS FOUND TO SE TORN, WHICH APPARENTLY OCCURRED
     ,         DURING INSTALLATION OF THE GASKET, DUE TO INAPPROPRIATE ACTIONS.               THE TORM GASKET W45 REPLACED AND ALL OTHER UNIT 1 S/G CF CONTROL VALVE 5 WERE INSPECTED FOR SIR LE4KS.

f

   .         FORN      121                    LER SCSS DAT4                         04-18-91 g     0********************************************************************
   .         DOCKET Y E, A R LER NUMBER REVISION DC5 NUMBER NSIC     EVENT OATE

_--------------------.----------------am--- ABSTRACT i e -g PCWER LEVEL - 100%. ON 9/24/59, UNIT 1 USS IN MODE 1, POWER OPERATION, AT 100% POWER, AT 1930 HOURS, 1CF28, STEAM GENERATOR (S/G) 1A MAIN FEEDATER (CF) CONTROL VALVE, BEGAN CLOSING, CAUSING A STEAM GENERATOR qq 1A LEVEL DEVIATION ALARM. THE CONTROL ROOM OPERATORS (CROS) ' RESPONDED BY OPENING 1CF30, S/G 1A CF CONTROL SYP455 VALVE, AND 54 DISPATCHING OPERATIONS PERSONNEL AND INSTRUMENTATION AND ELECTRICAL qg (IAE) PERSONNEL TO INVESTIGATE THE PR03LEM. THE CR0 SEGAN POWER pq REQUCTION TO COMPENSATE FOR THE REDUCED CF FLOW 70 S/G 14. AT 1944 HOURS, S/G 14 LEVEL BEGAN OROPDING RAPIOLY. THE CR0 THEN INITISTED 4

      " gg       MANUAL REACTOR TRIP AND ENTERED EMERGENCY PROCEDURE EP/1/4/5000/01, REACTOR TRIP OR SAFETY INJECTION. BY 2110 HOURS, S/G 1A WAS RETURNED                                                                                                  ,

TO THE NORMAL OPERATING LEVEL. 1CF28 MALFUNCTIONED DUE TO A FAILED DN , ; GASKET IN THE POSITIONER CONT 70L AIR MANIFOLD. THE GASKET APPEARED TO HAVE FAILEO DUE TO IMPROPER DESIGN AND/OR INSTALLATION DEFICIENCY. 34 THE POSITIONER WAS REPLACEO ON 1CF28 AND ON THE REMAINING THREE UNIT 1 qi CONTROL VALVES BEFORE UNIT 1 RETURNED TO MODE 1, POWER OPERATION, AT U" 0753 HOURS ON 8/25/89. THE CF CONTROL VALVE POSITIONERS ARE BEING INSPECTED WEEKLV FOR AIR LE4KS, AND AN IMPROVED GASKET DESIGN HAS BEEN , qi IMPLEMENTED ON UNIT 1. be '!, FORM 122 LER SCSS DATA 04-18-91 0******************************************************************** 84 a, DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 414 1989 001 0 8902240116 213115 01/12/89 D1

          ,,. ABSTRACT g,           POWER LEVEL - 0943. ON 1/12/89, At 0943 HOURS, 4 BUS $MANN FN4 FUSE
    '            FAILEO IN 4 MAIN FEE 0 WATER CONTROL VALVE CIRCUIT CAUSING THE VALVE To y,    FAIL CLOSED. CONTROL ROOM OPERATORS OPENED THE MAIN FEEDW4TER SYP455 k'

VALVE IN AN ATTEMPT TO PROVIDE ADDITIONAL FEE 0 WATER. THE UNEXPECTED CLOSURE ISOL4TED FEE 0 WATER FLOW 70 STEAM GENERATOR 20 AND QUICKLY ae RESULTED IN AN AUTOMATIC REACTOR TRIP. UNIT 2 WAS IN MODE 1, POWER OPERATION, AT 94% POWER WHEN THIS INCIDENT OCCURREO. PREVIOUS

    "'           MECHANICAL F4ILURES OF BUSSMANN FN4 FUSES IN 1986 AT MCGUIRE AND
         ,,,     CATAW84 PROMPTED DESIGN ENGINEERING TO IDENTIFY SUITABLE REDLACEMENTS 8

FOR ALL CLASS 1E APPLICATIONS. SCHEDULING OF NON-SAFETT FNA FUSE REPLACENENT WAS DECIDED TO BE LEFT TO THE DISCRETION OF THE STATION AS THAT WAS CONSIDERED TO SE A RELIABILITY ISSUE. THIS INCIDENT HAS 3 BEEN ATTRIBUTED TO A MANUFACTURING DEFICIENCY. THE FUSE WHICH CLOSEO THE MAIN FEEDWATER CONTROL VALVE FAILED MECHANICALLY. THIS ALSO BEEN

    '*           ATTRISUTED TO A NAN 4GEMENT DEFICIENCY. ALTHOUGH THE MECHANICAL FAILURES ON THE BUSSMANN FNS FUSE HAD SEEN PREVIOUSLY IDENTIFIED, NON-SAFETY APPLICATIONS AND SUITABLE REPLACEMENTS WERE NOT IMPLEMENTED

IN 4 TIMELY MANNER. FOLLOWING THIS INCIDENT, ALL SUSSMANN FNA FUSES ON SOTH UNITS, MAIN FEEDWATER CONTROL AND SYPASS CONTROL VALVES WERE

    ,            REPLACED WITH LITTELFUSE FLQ FUSES.

1

    '           FORM     123                    LER SCSS DATA                        04-18-91
         ,    0********************************************************************

DOCKET YEAR LER MUMBER REVISION OCS NUMBER NSIC EVENT DATE 414 1989 002 0 8903060032 213157 01/21159 ASSTRACT

    '            POWER LEVEL - 021%. 04 1/21/89, AT 1845:40 HOURS, THE UNIT 2 REACTOR g

WAS MANUALLY TRIPPEO OUE TO DECREASING LEVEL IN STEAM GENERATOR (SIG) t 8. THIS TRANSIENT WAS INITIATE 0 BT TH! MECHANICAL MALFUNCTION OF A g- TEMPERATURE TRANSMITTER FOR THE GENERATOR STATOR COOLING WATER (KG)

    ,            SYSTEM. THE FAILED TRANSMITTER CAUSED 2tGS, GENERATOs STATea CnniTgG

_ -. ~

            --          - . . -                 .       ~                . . .         -.            . _ ._. - - -
                           . ......, - a . . - . . .o . : s .us+we. tall at Appa0x. 13 3 3 M1UR 5.

DURING THE SUB5ECUENT TRANSIENT, THE $1G LEVELS SEGaN A LaRGE i Pg 05CILLATION. THE MAIN FEEDWATER PUMP TUR3INE (CFPT) DISCHARGE l PRESSURES SEG4N RISIN3 DUE TO CP REGULATING VALVES CLOSING IN RESPONSE TO INCRE451NG 5/G LEVEL 5. TO GAIN QUICKER GESPONSE OP CFPT 2A 57EED CONTROL, THE 8ALANCE OF PLANT OPERATOR SWAPPED FROM THE WESTINGHOUSE 59 TO THE GE CONTROLLER. THIS SWAP W45 PERFORME0 WITH A DEVIATION BETWEEN THE TWO CONTROLLERS. CFPT 24 AND CFPT 28 TRIPPED ON HI DISCHARGE PRESSURES. CONTROL OF THE CFPTS COULO NOT BE REGAINED. 45 + pq 5/G 8 LEVEL WA5 DECREASING TOWARDS THE LO LO LEVEL SETPOINT, THE REACTOR WAS MANU4LLY TRIPPED AT APPROX. 21X POWER. PRIOR TO THIS E9 INCIDENT, THE UNIT W45 OPERATING AT APPROX. 951 POWER. THIS INCIDENT HA5 BEEN ATTRIBUTED TO AN EQUIPMENT M4LFUNCTION. 1 k2 FORM 124 LER SC55 DATA he 0***************************.********************************04-18-91 ******** DOCKET VEAR LER NUMBER REVISION 0C5 NUMBER N5IC EVENT DATE 414 1989 003 1 3905010063 213763 DM

             .....*................** .................................. 02/21189           ........

bg A85 TRACT POWER LEVEL - 094X. ON FEBRUARY 21, 1989, si 0112 HOURS, IAE

 ,,              TECHNICIANS PLACEO 4 JUMPER TO CH2CK RELAY CONTACTS WHILE INVESTIGATING THE FAILURE OF THE "90 PERCENT OPEN" LIGHT TO ILLUMINATE 88            OURING THE MAIN STE4M ISOL4 TION WALVE MOVEMENT TEST.               THIS JUMPER RESULTED IN A SHORT CIRCUIT, CLOSING 25M3, STEAM GENERATOR (SIG) 2C MAIN STEAM ISOLATION VALVE. THE RESULTING PRE 55URE INCREASE IN 5/G 2C P.           CAUSED 4 REACTOR TRIP 04 SIG Lo LO LEVEL, AND C4USED 25V7, SIG 2C PORW, AND THREE 5/G 2C CODE SAFETY RELIEF VALVES TO OPEN. THE OPENING
  "             OF THESE VALVES RESULTED IN A RAPID DECREASE IN STEAM LINE PRESSURE,
 '              WHICH RESULTED IN A SAFETY INJECTION 04 LOW STEAM LINE PRESSURE (RATE l'           COMPENSATED). THIS INCIDENT 15 CLASSIFIED AS M4N4GEMENT DEFICIENCY DUE TO THE LACK OF A POLICY FOR AN INDEPENDENT ASSESSMENT OF 4CTIONS TO SE TAKEN UNDER TROUBLESHOOTING PROC 50URES, WITH CONTRIBUTING CAUSES OF EQUIP 4ENT MALFUNCTION DUE TO THE OPENING SETPOINT FOR 25VT SEING FOUND TO BE T00 HIGH, AND LACK OF ATTENTION TO DETAIL PRIOR TO JUMPER I'

PLACEMENT. CORRECTIVE AC1 IONS WILL INCLUDE PROVIDING 4 TROUBLESM00 TING REVIEW GUIDELINE. THE OPEN SETPOINT FOR 25V7 WAS R E C AL IBR ATE D. UNIT 2 WAS IN MODE 1, POWER OPERATION, 47 94% POWER AT e THE TIME OF THIS INCIDENT. 1 FORM 125 LER SC55 OATA 04-1

  '       0**************.**************************************************5-91                 ***

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 414 1990 013 0 9011150259 220036 1010?t90

  ,         .............................. ** ...............***e.........e*****
 ,          485 TRACT POWER LEVEL - 0953. ON OCTOBER 7,           1990, A T A PPROXIM ATELY 1659 HOURS, WITH UNIT 2 IN MODE 1, POWER OPERATION, AND OPERATING AT 95% REACTOR POWER LEVEL, A REACTOR (RX) TRIP GCCURREO QUE TO LOW-LOW LEVEL IN THE 2D STEAM GENERATOR EstG). THE REACTOR TRIP OCCURRED AFTER THE 24 MAIN FEEDWATER PUMP TUR8INE (CFPT-2A) TRIPPED ON INDICATED HIGH DISCHARGE PRE S5URE WHICH INITIATED 4 TURSINE RUNSACK. THE P41N TURSIME RAN SACK
        ,      PAST ITS SETPOINT OF 701 LOADJ TERMIN4 TING AT APPROIIMATELY 60% WHEN THE RX TRIPPED. SUSSEQUENT INVESTIGATION OF THE EVENT REVEALEO THAT THE CFPT-2A TRIP OCCURRED DUE TO AN ERROMEOUS HIGH DISCHARGE PRESSURE
       ,       SIGNAL WHICH RESULTED FROM F4ILED DI4PHRAGM5 IN TWO 0F THE THREE FEE 0 WATER PUMP OI5 CHARGE PRES 5URE SWITCHES.          SUSSEQUENT CORRECTIVE ACTIONS INCLUDED STABILIZING THE UNIT AND REPLACING THE DEFECTIVE g       PRE 55URE SWITCHES. THIS INCIDENT IS ATTRIBUTED TO AN EQUIPMENT FAILURE. ADDITIONAL CORRECTIVE ACTIONS INCLUDED REVIEW AND

            .t.- atevai,  .4. 4:vLAL:9:N! O' THE Fa! LED PRESiURE SWITCHES.

1 p. FORM ?26 LER SCSS DATA 0*****e****ese***eeeeeeeeee.*** .eeeeeeeeeeeeeeeee.......... 04-18-91........ DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 416 1989 006 0 8906050397 214130 05/05/39 he .................................................................... 3 ABSTRACT POWER LEVEL - 005%. ON MAY 5, 1939 AT 0945 HOURS, THE REACTOR TRIPPED ON LOW REACTOR WATER LEVEL. A CONTROLLED PLANT SHUTDOWN W AS IN PROGRESS WHEN OPERATORS EXPERIENCED LEVEL CONTROL PROBLEMS. ATTEMPTS b4 TO CONTROL THE VESSEL OVERFEED CONDITION WERE UNSUCCESSFUL AND THE ' OPERATING REACTOR FEED PUMP TURBINE (RFPT) TRIPPED ON HIGH WATER LEVEL. SUBSEQUENT ATTEMPTS TO RESTART THE TRIPPED RFPT AND RESTORE gg LEVEL WERE UNSUCCESSFUL. THE CAUSE OF TME VESSEL OVERFEED WAS DETERMINED TO BE THE FEEDWATER HEATER OUTLET VALVES INDICATING CLOSED U" WHEN IN FACT THEY WERE SLIGHTLY OPEN. THE RFPT TRIP RESET LOGIC MISLED THE OPERATORS WHEN THEY ATTEMPTED TO RESTART THE TRIPPED RFPT. DESIGN E9 CHANGES TO THE FEEDWATER CONTROL LOGIC ARE 8EING EVALUATED TO PREVENT RECURRENCE. ALSO TRAINING ON THE EVENT WILL BE CONOUCTED 10 MAKE OPERATORS AWARE OF THE LESSONS LEARNED. ALL PLANT SAFETY SYSTEMS p, PERFORMED AS EXPECTED. THE MINIMUM WATER LEVEL REACHED WAS APPROXIMATELY 14 FEET A80VE THE TOP OF SCTIVE FUEL. ALL EMERGENCY CORE COOLING SYSTEMS WERE OPERASLE AND AVAILABLE TO RESPOND IF I', NECESSARY. 1

 >1 FORM     127                LER SCSS DATA                         04-15-91
 ,,    0********.***********************************************************

i

 ;        DOCKET YEAR LER NUMBER REVISION DCS NUMBER            NSIC      EVENT DATE 416    1989      010           0     8905280005 215076         07/22/89 As       ....................................................................

g. A85 TRACT POWER LEVEL - 1003. ON JULY 22, 1989, A SEVERE ELECTRICAL STORM PASSED OVER GRAND GULF NUCLEAR STATION. DURING THE STORM, THE REACTOR AUTOMATICALLY SCRAMMED DUE TO A HIGH NEUTRON FLUX SIGNAL ON THE AVERAGE POWER RANGE MONITORS (APRMS). ADDITIONALLY, A SPIKE TO THE I

REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM LOGIC CAUSED RCIC TO AUTOMATICALLY ACTUATE AND INJECT INTO THE REACTOR VESSEL. REACTOR

 ,         WATER LEVEL DECREASED TO -15 INCHES AND WAS RAISE 0 TO THE LEVEL 8 HIGH LEVEL TRIP (*53.5 INCHES) IN APPR0xIMATELY 2 MINUTES.       A CHANNEL
 '         CHECK OF APRM INDICATIONS WAS PERFORME3 DURING PLANT RESTART 04 JULY 2 3, 1989 TO CON *IRM PROPER RESPONSE.      NO AENORMALITIES WERE OBSERVED.

SYSTEM ENERGY REQUISITIONED A SPECIALIST IN LIGHTNING PROTECTION TO t PERFORM A PLANT SURVEY AND STUDY OF THE EXISTING PLANT LIGHTNING PROTECTION SYSTEM. THE CONTRACTOR HAS SU5MITTED PROPOSALS TO PROVIDE

 ,         LIGHTNING OIS$1PATION ARRAYS ON VULNERABLE STRUCTURES. SYSTEM ENERGY IS PRESENTLY EVALUATING IMPLEMENTATION METHODS A40 CONSTRUCTING A SCHEDULE FOR IMPLEMENTATION .      CURRENT PROGRESS INDICATES THAT IMPLEMENTATION WILL LIKELY SE COMPLETE 3 SY OECEMBER 31, 1989.        IN ANY CASE, IMPLEMENTATION WILL SE COMPLETED NO LATFR ' ': 4 THE STARTUP FROM THC FOURTH REFUELING OUTAGE (RF04).

1 FORM 12S LER SCSS DATA 04-15-91 0**.................................................*.*****.a.*..****

     ,   DOCKET YEAR LER NUMSER REVISION DCS NUMBER             NSIC     EVENT DATE 416    1959      012           0     8909210080 215283         08/14tS9 I

485 TRACT

             -      ~
                 . . . %#.stn2;=

Lua v4LbuM <c2ULTING IN A R! ACTOR 3 CRAM CUE TO THE 8457 i CLOSURE OF THE HAIN TURSINE STop AND CONTROL VALVES. DURING THE I pg COURSE OF THE EVENT TWO SUBSEQUENT RPS ACTUATION $ OCCURRED ON LOW i REACTOR WATER LEVEL SIG24LS. A MAIN STEAM ISOLATION VALVE (MSIV) b4 ISOLATICN SIGNAL WAS ACTUATED ON LOW CON 0ENSER VACUUM. THE RE4CTOR

         ;       CORE !$0L ATION COOLING SYSTEM WAS MANU4LLY INITIATED TO CONTROL REACTOR WATER LEVEL.          NO ECCS WERE INITIATED MANUALLY OR bW 4

AUTOMATICALLY. ALL CONTROL R005 FULLY INSERTED WITH THE EXCEPTION OF i eq ' 1 CONTROL R00 32-45 WHICH STOPPED AT POSITION 08. ALL MSIVS PROPERLY CLOSE0 WITH THE EXCEPTION OF 821-F0223 WHICH CLOSE0 APPROXIMATELY 35 MINUTES FOLLOWING A MANUAL CLOSURE SIGNAL. COMPONENTS IN THE CONTROL E4 ROO HYORAULIC CONTROL UNIT WERE REPLACE 0 TO CORRECT THE CONTROL R00 MALFUNCTION. THE FAILURE MECHANISM OF THE MSIV WAS DETER 4INED TO BE DW GENERIC TO OTHER INSTALLEO MSIVS AND IS REPORTED SEPARATELY IN LER y 59-013. A 3 FOOT SECTION OF THE CONDENSER EXP4NSION BELT H40 TORN HORIIONTALLY NEAR THE LOWER RETAINING CLAMPS. THE HEMP REINFORCEMENT , gg FISERS HAD APPARENTLY DEGR40E0 OUE TO MOISTURE INTRUSION THROUGH THE y RU88ER. THE BELTS ON ALL 3 CONDENSER SECTIONS WERE REPLACE 0 WITH De j BELTS USING A POLYESTER REINFORCE 4ENT FISER.

  >=           FORM         129                   LER SCSS DATA 0************************************************************04-18-91     ********

b4 1 DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 414 1989 016 0 8912140405 216155 11/07/89 to ABSTRACT p1 POWER LEVEL - 1005. ON NOVEMBER 7, 1959, A SEVERE THUNDER STORN WAS IN PROGRESS IN THE SITE VICINITY. DURING THE STORM, LIGHTNINQ STRUCK

  ,,             THE SITE CAUSINQ 4 SPIKE ON PLANT INSTRUMENTATION. THE REACTOR I             AUTOMATICALLY SCRAMMED DUE TO THE SPIKE SIMULATING A HIGH FLUX SIGNAL ON THE AVERAGE POWER RANGE MONITORS (APRMS). THE SPIKE CAUSED TWO b8 HIGH PRESSURE CORE SPRAY (HPCS) LOW W4TER LEVEL CHANNELS TO TRIP.

HPCS 010 NOT INITIATE DUE TO THE SHORT DURATION OF THE SPIKE. ALSO,

y. REACTOR CORE ISOLATION COOLING (RCIC) RECEIVED AN INITIATION SIGNAL, BUT 010 NOT INJECT DUE TO THE TRIP THROTTLE VALVE BEING IN THE CLOSED POSITION IN PREPARATION FOR AN 18C SURVEILLANCE. RE4CTOR W4TER LEVEL I* OECREASED TO -18 INCHES AND WAS $USSE3UENTLY RAISED TO 51 INCHES SY THE FEEDWATER SYSTEM. A FUNCTIONAL CHECK OF APRM IN3ICATIONS AND HPCS e

TRIP UNITS WAS PERFORMED PRIOR TO PLANT STARTUp. NO ADVERSE EFFECTS

       ,        WERE OBSERVED.           A DESIGN CHANGE PACKAGE WAS ISSUE 0 TO INSTALL 4
   ,            LIGHTNING OISSIPATION SYSTEM ON VOLNER48LE STRUCTURES. IMPLEMENTasION OF THE SYSTEM IS OUE TO BE COMPLETED BY STARTUP FROM THE FOURTH
   ' ,          REFUELING OUTAGE (RF04).

1

       ,       FORM         130                  LER SCSS DATA                        04-18-91 0********************************************************************
   ,           DOCKET YEAR LER NUM8ER REVISION DCS NUMSER                  NSIC    EVENT DATE
       .          416        1989         019          0     9002060019 2166S6        12/30/59
               *** **.*****.*................***......**** .*******...*******.e***.
       ,       ABSTRACT POWER LEVEL - OS35. CN DECEMSER 30, 1989, A TOTAL LOSS OF PLANT SERVICE WATER (PSW) WAS EXPERIENCE 0 00E TO A LOSS OF POWER TO THE SUPPLY WELLS.           REACTOR POWER W45 REDUCEO SY DECRE ASING RECIRCUL ATION FLOW THROUGH THE REACTOR CORE ANO 4 REACTOR SHUTOOWN SEQUENCE WAS COMMENCE 0.         WHILE REQUCING REACTOR POWER, THE OPERATORS DETERMINED y         THAT PSW WOULO NOT BE READILY RESTORED AND THE REACTOR W45 MANUALLY SCRAMMEO.          THE REACTOR CORE ISCLATION COOLING (RCIC) SYSTEM WAS INITIATED FOR REACTOR VESSEL LEVEL CONTROL.' THE MAIN STEAM LINE g         ISOLATION VALVES WERE CLOSED IN ACCORDANCE WITH PROCEDURES. THIS ACTION CAUSED 4 MIG 4 PRES $URE scram SIGMat 4wn AM AYutterv est

                                                                                             . ==
                   . .. 66   .6scs.. an; 224 saalN Liytt 1C]FPED afLOW THE TECH. SPEC.

i LIMIT DUI TO lea % AGE OF $5W INTO PSW. EVENTUALLY, PSW WAS RESTORED y, AND $$W EA31N INVENTORY WAS RECOVERED. THE PCdER LOSS TO THE SUPPLY WELLS WAS DUE TO A MALFUNCTION OF THE MICROUAVE INFORMATION AND

    "             CONTROL SYSTEMS. PE210DIC MICROWAVE OPERATIONAL CHECKS ARE BEING l:'       ESTABLISHED.

1 M

         ;;      FORM      131                LER SCSS DATA pq           0**********.*******.****************+++******************+++.04-18-91********

00L%ET VEAR LER NUMBER REVISION DCS NUMBER HSIC EVENT DATE 416 1990 011 0 9005250383 219375 07/24/90 L.

                 .*.*..**.....*....*.....*....*.*....*...*....*........**....*......a De     p       ABSTRACT POWER LEVEL - 100%. ON JULY 24, 1990 AT 1355, THE REACTOR TRIPPED ON gg              HIGH REACTOR WATER LEVEL. REACTOR POWER WAS IN THE PROCESS OF BEING p,       REDUCED IN AN ATTEMPT TO CONTROL "B" REACTOR FEED PUMP TURSINE (RFPT)

U" OSCILLATIONS CAUSED BY A MALFUNCTION OF THE "3" RFPT CONTROLLER. THE CAUSE OF THE MALFUNCTIONING "B" RFPT CONTROLLER WAS DETERMINE 0 TO BE AN INTERMITTENT FAILURE OF THE LINEAR VARIABLE DIFFERENTIAL De TRANSFORMER (Lv07) AND THE ASSOCIATED CIRCUIT BOARD TO THE ELECTRONIC AUTOMATIC POSITIONER (EAP). THE EAP 04HL CONTROLLER WAS CALIBRATED IN

  ,,               ACCORDANCE WITH THE VENDOR RECOMMENDED SETTING.        THE CALISRATION PROCEDURE FOR THE REACTOR FEED PUMP TURBINE "A" AND "B" EAP OAHL RI              CONTROL CIRCUIT MAS BEEN IMPROVED AND THE CALIBRATION FREQUENCY HAS
      ,           8EEN INCREASED. ALL PLANT SAFETY SYSTEMS PERFORMED AS EXPECTED. THE MINIMUM WATER LEVEL REACHED WAS APPROKIMATELY 126.7 INCHES A50VE THE p,

TOP OF ACTIVE FUEL. THE RCIC WAS MANUALLY STARTED AND FUNCTIONED A5 1 DESIGNE0.

  ,,           1 FORM      132                LER SCSS DATA                         04-15-91 ee           0.*********************.*********************************************

DOCKET YEAR LER NUMEER REVISION DCS MUMSER NSIC EVENT DATE 3, 416 1990 017 1 9010260079 219932 09/16/90

             ,   *****************+************************.*************************

I' ABSTRACT POWER LEVEL - 100%. A DIVISION I LOAD SHEDDING AND SEQUENCING SYSTEM s MALFUNCTION CAUSED A SALANCE OF PLANT (BOP) LOAD SHED ON SEPTEMBER 16, 1990. THE LOSS OF MAJOR PLANT EQUIPMENT, WHICH RECEIVED POWER FROM

  ,               THE SHEDDED 80p SUSSES, RESULTED IN A REACTOR SCRAM, DUE TO MAIN TUR5INE CONTROL VALVE FAST CLOSURE. $USSEQUENT TO THE SCRAM, REACTOR
  '   ,           WATER LEVEL DECRE45!0 70 -41.6 INCHES WHERE AN AUTOMATIC HIGH PRES 5URE CORE SPRAT SYSTEM ACTUATION OCCURRED. OURIN3 RESTORATION OF MAIN STEAM ISOLATION VALVES, AS A PART OF SCRAM SUBSEQUENT ACTIONS, A e
       ,          SECOND REACTOR SCRAM OCCURRED DUE TO LOW REACTOR WATER LEVEL.         THE LOAD SHED IS ATTRIBUTED TO A DEFECTIVE LIGHT BULB REING PLACED IN THE
  ,               LOAD SHED PANEL.      THE SHORTED LIGHT BULB CAUSED AN OVERCURRENT WHICH
      ,           SUBSEQUENTLY CAUSED DEGRADATION OF A COMPUTER CHIP WHICH INITIATED THE LOAD SHED. THE CARDS WHICH CONT AINED OEGRADED COMPUTER CHIPS, OUE TO THE OVERCURRENT, WERE REPLACEO.       THE DIVISION I LOAD SHED PANEL WAS
      ,           TESTED SATISFACTORILY AND OPERASILITY WAS VERIFIED. ALL SAFETY SYSTEMS FUNCTIONE3 AS DESIGNEO. THE MINIMUM WATER LEVEL REACHED WAS
                  -54.1 INCHES WHICH WAS APPROKIMATELY 112 INCHES ABOVE THE TOP OF
      ,           ACTaVE FUEL.

1

      ,          FORM      133                LER SCSS DATA                         04-18-91 0********************************************************************
               -DOCKET TEAR LER NUMBER REVISION OCS NUMBER               NSIC     EVENT DATE g             416     1990      026          0      9101030322 220609         11/24/90

                  . .....          . . . . . . s s . .. , 4    - = L l ;d alauluP CN NOUE"bER 24o 13300 4 MANUAL SCRAM WAS !?45E RTE 3 70LL961NG 4 LOCRUP OF TM! 203 82TTERN tw             CONTROL STSTEM (RPCI). THE LOCQUP W45 C4USED ST PULTIPLE CONTROL R005 0 RIFTING CUT OF SEQUENCE 005 TO THE EXCESSIVE DIFFERENTIAL PRESSURE OF THE COOTOOL ROD ORIVE (COD) COOLING WATERo COO SYSTEM C00LICG
       ;i WATER FLOW WAS MAEIMIZED TO INCREASE REACTOR WATER LEVEL. OPERATORS DW             WERE AWARE THAT AN ELEVATED CR0 COOLING WATER DIFFERENTIAL PRESSURE COULO CAUSE RODS TO DRIFT. THE TR4NSIENT OF REACTOR WATER LEVEL HAS BEEN ATTRIBUTED TO OPEN DRAIN VALVES IN THE MAIN STEAM LINES COUPLED pq             WITH VACUUM ESTASLISHED IN THE MAIN CONDENSER. A CONTRISUTING FACTOR TO THE TRAN51ENT WAS THE UN4VAILABILITY OF CONDENSATE DURING THE I4 ..          REACTOR STARTUP SEQUENCE QUE TO DEPRESSED CONDENSATE TEMPERATURE. THE STARTUP PROCEDURE WAS JUDGED TO BE IN4DEQUATE. THE STARTUP PROCEDURE b4             HAS SEEN AMENDED TO SPECIFT MAIN STEAM LINE DRAIN VALVE LINEUPS AND THE MINIMUM HOTWELL TEMPERATURE REQUIREMENT. REACTOR CONTROL SYSTEMS FUNCTIONED PROPERLVI No EQUIPMENT WAS OBSERVED 45 HAVING bG             MALFUNCTIONED. THE LOCKUP OF THE RPCS 45 4 CONSEQUENCE OF THE DRIFTING CONTROL R005 OCCURRED AS DESIGNED.

1 De FORM 134 LER SCSS DATA 04-18-91 >= 0**..******..****************************************e...... ........ DOCKET YEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE y, 416 1990 028 0 9101140227 220688 12/10/90

             ........................................................e ..........

BI 485 TRACT pe POWER LEVEL - 100%. ACTUATION OF ENGINEERED SAFETY FEATURES OCCURRED ON DECEMBER 10, 1990, INCLUDING THE REACTOR PROTECTION SYSTEM (RPS) AND THE EMERGENCY CORE COOLING SYSTEM (ECCS) HIGH PRESSURE CORE SDRAY

  '           (HPCS) SYSTEM. THE SUBSEQUENT REACTOR SCRAM FROM FULL POWER W45 I              CAUSED INDIRECTLY 57 A FAILEO SOLDER JOINT IN THE INSTRUMENT 41R SYSTEM.        THIS REPORT IS SEING SUSMITTED PUR$UANT TO D*

10CFR50.73(A)(2)(IV) AND PLANT TECHNICAL SPECIFICATION 3.5.1 ACTION ITEM H. THE FAILED PIPE JOINT WAS INVESTIGATED. 4 LEAKING ROOT VALVE 'g , APPARENTLT CAUSED A SLIGHT PRESSURE DIFFERENTI AL ACROSS THE JOINT AND PRECLUDED OPTIMUM CAPILLARY ACTION DURING THE SOLDERING PROCESS. IT I' IS BELIEVED THAT VIBRATIONS IN COMSINATION WITH STSTEM PRESSURE CAUSED THE RESULTANT SEPARATION 0* THIS INADEQU4TELY SOLDERED JOINT. THIS JOINT HAD SEEN SOLDERED ON NOVEMBER 9, 1990. APPLICABLE PLANT e 40MINISTRATIVE PROCEDURES WILL SE REVISED TO PRECLUDE INEDEQUATE WELDING AND SIMILAR FAILURES. THE ACTUATION OF THE RPS AND THE , RESULTANT AUTOM4 TIC SCRAM OCCURRED AS DESIGNED. ACTUATION OF THE ECCS INITIATED 45 DESIGNED 8Y INJECTING CONDENSATE FROM THE CONDENS ATE ' STORAGE TANK INTO THE REACTOR VESSEL V!4 HPCs. THE SAFETY OF THE GENERAL PUSLIC W45 NOT COMPROMISED BY THIS EVENT. 1 4 FORM 135 LER SCSS 04T4 04-1S-91 , 0..******.*************.*******.******+++++*********************+++** DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 416 1990 029 0 9101240010 220E27 12#18/90

            ..................e.................................................

485 TRACT POWER LEVEL - 017%. ON DECEMSER 18, 1990, DURING A CONTROLLED SHUTOOWN, A REACTOR PROTECTION SYSTEM ACTUETION OCCURRED RESULTING IN AN AUTOMATIC PLANT SMUTDOWN. THE ACTUATION OCCURRED OUE To LOW REACTOR WATER LEVEL WHICH WAS CAUSED BY a REACTOR FEEDWATER PUMP TRIP. THE HIGH OISCHARG5 PRE 55URE TRIP OF THE FEEDWATER PUMP WAS A RESULT OF THE INTERACTION SETWEEN THE STARTUP LEVEL CONTROL SYSTEM AND THE t MASTER FEEDWATER CONTROL SYSTEM. THE INVESTIGATION, WMICH FOLLOWED g THE SCRAM, IDENTIFIED THE AIR SUPPLY V4LVE FOR THE STARTUP LEVEL , CONTROL VALVE NOT SEING FULLY OPEN AND THE 'A' ELECTRIC AUTn=ATIr

                   .  .. . . . . ,~nu6.      s-a,   ve  t"t   :V NI. ALL 54FETT SYSTEMS PERFORMED 45 dei!GNED 09 RING TH: T R a tis I E N T . THE MINIMUN WATER LEVEL P1            REACHED WAS -25 INCHES AS INDICATED ON THE WICE RANGE LEVEL INSTRUMENTATION. THE MINIKUM LEVEL WAS APPROXIMATELY 142 INCHES ABOVE b4             THE TCP OF ACTIVE FUEL.

NN FORM 136 LER SC55 OATA 04-0****************************************************************18-91 **** pq DOCKET YEAR LER NUMBER REVI510N DCS NUMSER NSIC EVENT DATE 4I3 1989 008 0 8906140205 214240 05/06/89 A85 TRACT ! h4 4 POWER LEVEL - 090%. ON 5/6/59 AT 0810 HOURS, WITH THE PLANT AT 901 POWER IN MODE 1, A MANUAL REACTOR TRIP WA5 INITIATED OUE TO AN ANTICIPATED TUR8INE TRIP. PRIOR TO THE TRIP, THE PLANT WAS 4 gg EXPERIENCING FOULING OF THE TRAVELING SCREENS DUE TO LARGE AMOUNTS OF U" SEAWEED AT THE INTAKE. ROOT CAUSE OF THIS EVENT WAS DESIGN DEFICIENCY IN THAT THE TRAVELING SCREEN CAPACITY WAS INADEQUATE. RECENT CHANGES i TO THE FISH RETURN SYSTEM TO BRING IT INTO COMPLIANCE WITH STATE kN REGULATIONS HAVE INCREASED THE SEAWEED LOADINGS ON ALL BAYS, ESPECIALLY "A" AND "B" BAYS. 45 CORRECTIVE ACTION, A PROCEDURE CHANGE gg HAS BEEN IMPEMENTED WHICH ALLOWS FOR THE ISOLATION OF THE FISH SPRAY SYSTEM WHEN SE4 WEED RECIRCULATION 15 A CONCERN. RECOMMENDATIONS OF AN 8' INTERNAL TASK FORCE ADDRESSING OPERATIONAL PR05LEMS WITH THE TRAVELING SCREENS WILL BE IMPLEMENTED OVER THE NEXT TWO YEARS. 1 H FORM 137 LER SC55 DATA 04-18-91

 ,,         0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 423 1989 009 1 9001040124 216352 05/11/89

 &4           ********************************************************************

to ABSTRACT POWER LEVEL - 100%. AT 1514 ON 5/11/89 WHILE OPERATING IN MODE 1, 100E

             REACTOR POWER, 557 DEGREES AND 2250 PSIA, A REACTOR TRIP OCCURRED DUE TO A POWER RANGE NEUTRON FLUX HIGH NEGATIVE RATE SIGNAL. UPON DEENERGIZING A R00 DROP TIME RECORDING ST5 TEM CONNECTED TO THE CONTROL e             ROD ORIVE SYSTEM, THE CONTROL R005 UNLATCHED.              THE RECORDING Sf5 TEM HAD SEEN CONNECTED IN PREPARATION FOR TESTS DURING THE SECOND
 ,             REFUELING OUTAGE, SCHEDULED TO START 5/12189, ROOT CAUSE OF THE REACTOR TRIP WAS PROCEDURAL INADEQUACY IN THAT THE PROCEDURE DIO NOT
 '*            SPECIFT THAT CONTROL R005 MUST BE UNLATCHED PRIOR TO CONNECTING THE ROD OROP TIME RECORDING SYSTEM. SPURIOUS ROD OROP SIGNALS WERE GENERATED BY THE ROD OROP TIME RECORDING SYSTEM WHILE SEING 8

DEENERGIZED. THIS CONDITION 00E5 NOT OCCUR EVERY TIME THE SYSTEM IS DEENRGIZED. TO PREVENT RECURRENCE PLANT PROCEDURES WERE CHANGED TO

 ,             REQUIRE R005 TO BE UNLATCHED SEFORE CONNECTING THE R0D OROP TIME i       RECORDING SYSTEM.          SINCE THIS EVENT OCCURRED WITHIN 49 HOURS OF THE SCHEDULED START OF THE SECOND REFUELING OUTAGE, THE REFUELING OUTAGE COMMENCED IMMEDIATELY AFTER THE TRIP.

1 FORM 138 LER SC55 DATA 04-18-91 De******************************************************************* DOCKET TEAR LER NUMSER REVISION DCS NUMSEE NSIC EVENT DATE 423 1990 005 0 9002270006 216966 01/18/90 i A85 TRACT

    ,          POWER LEVEL - 1001. ON 1/18190, AT 0805 HOURS, WHILE OPERATING IN MODE
 ,             1 AT 1003 POWER, 2250 PSIA AND 597F, A MANUAt PLANY TRIP vat
                                                      ,     -     .       -           -   -    c--. . - - ... - -. , , - -   .-

i ctas rLan aAE441Lo ALA4M C4NUNCIATED FJR 3LL FOUt STEA1 GENERATORS, FOLLOWED BY STE3M GENERATOR LOW LEVIL 4LARM5. TME MOTOR-0 RIVEN P1 FEE 0 WATER P U 1P, 3FWS-PI, 013 NOT AUTOMATICALLY START BECAUSE TME FEE 0 WATER PUMP DISCHARGE HEADER PRES 5URE DIO NOT DECREASE TO THE , gq AUTCM4 TIC START SETPOINT. THE THIRO CONDEn5 ATE PUMP, 3CNM-P18, WAS q; STARTED PRIOR TO STARTING 3FWS-P1. BY THE TIME 3FWS-P1 WAS MANU4LLY STARTED, THE STEAM GENERATOR LEVELS WERE TOO LOW AND AN AUTOMATIC TRIP DN ON LOW LOW STEAM GENERATOR TRIP WAS IMMINENT. THE ROOT CAUSE OF THE q; EVENT WAS THE FAILURE OF THE TUR81NEtPUMP COUPLING OF 3FW5-P28 00E To i r1 LOSS OF PRELOAD ON THE COUPLING BOLTS OUE TO PERSONNEL AND PROCEDURAL - ERRORS. CONTRISUTING CAUSES WERE THE PUMP AND TUR8tNE MISALIGNMENT, g4 q; AND INADEQUATE COUPLING LUBRICAT!0N. IN ORDER TO PREVENT A RECURRENCE OF FEEDWATER PUMP COUPLING FAILURE, CHANGES HAVE BEEN MADE TO THE

  >8 q,         COUPLING INSTALLATION PROCEDURE AND THE VI5 RATION ALARM SETPOINT WILL SE LOWERED.

b4

         .p    FORM     139                       LER SCSS DATA                                                                                                  04-18-91 U"        0........................................................... ........

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT 04TE

          ;;      423    1990                 009                                0                                                      9004200305 217843        03/09/90 kg
               ...***............................................**e...............

g,g A8STRACT POWER LEVEL - 100%. ON 3/9/90, 4T 1653 HOURS, WHILE OPERATING IN MODE 88 1 AT 1001 POWER, 2250 PSIA AND 597F, 44 AUTOMATIC TUR$1NE TRIP WITH 3 SUBSEQUENT REACTOR TRIP OCCURRED OUE TO HIGH STATOR COOLING WATER

  }             TEMPERATURE.      THE CAUSE OF THE EVENT WAS THE FAILURE OF THE MECHANICAL p4 LINEAGE 04 THE FISCHER S PORTER CONTROLLER FOR THE STATOR COOLING WATER TEMPERATURE CONTROL VALVE DUE TO WEAR AT THE LINEAGE
<   ,,          CONNECTIONS. THE ROOT CAUSE OF THE EVENT W45 INADEQUATE DESIGM, IN t            THAT THE TEMPERATURE CONTROLLER IS MOUNTED DIRECTLY ON THE TEMPERATURE CONTROL VALVE. THE WEAR FOUNO ON THE MECHANICAL LINKAGE OF THE 8'

CONTROLLER W45 INDUCEO FROM VIBR4 TION OF THE TEMPERATURE CONTROL VALVE. A5 SHORT TERM CORRECTIVE ACTION, THE AILEO CONTROLLER WAS ee REPLACED WITH A SPARE OF THE SAME MODEL. THE ACTIONS TO PREVENT RECURRENCE INCLUDE REPLACING THE ORIGINAL MODEL CONTROLLER WITH A MORE

    "'          RELIASLE CONTROLLER WITH MANUAL OVER-RIDE CAPABILITIES, AND RELOCATING THE NEW CONTROLLER TO AN AREA 0F LOW VI8 RATION.

1 I FORM 140 LER SC55 OATA 04-18-91

    ,        0**** **********************************************************. .**

DOCKET TEAR LER NUMBER REVISION DC5 NUMBER NSIC EVENT DATE i

      ,        423     1990                 011                               0                                                      9005090083 218139         03/30/90

A85 TRACT POWER LEVEL - 0303. ON 3/30190 AT 1328 HOURS WITH THE PLANT AT S0%

    ,           POWER IN MODE 1, A MANU4L REACTOR TRIP WAS INITIATED OUE TO AN
       ,,       ANTICIP ATED TUR BINE TRIP FROM A LOSS OF CONDENSER VACUUM.                                                                                      PRIOR TO THE TRIP, THE INTAKE STRUCTURE SCREEN W A S.N SYSTEM WAS REMOVED FROM SERVICE TO INSTALL 4 REPAIRE0 EL80W. THE INSTALLATION WAS PLANNED FOR
       ,        THREE HOUR $. THE INSTALLATIONS WOULO HAVE RESTORED THE SECONO 1003 SCREENWASH PUMP TO SERVICE BEFORE THE SEASONAL (1.E., 4/15-5/30) HIGH SEAkEED LOA 0!N3 SEGAN. HOWEVER, TME EFFORT TO MANUALLY CLEAR THE
       ,        SCREENS WAS NOT ENOUGH TO *REVENT TWO CIRCULATION WATER PUMP 5 FROM TRIPPING. THE 4007 CAUSE Wa5 THE FAILURE TO COLLECT THE O!8RIS FROM THE MANUAL SCREEN W45HING.                             THE DEBRIS RECIRCULATED INTO THE INTAKE
       ,f  ~

STREAM 04 THE TIOE CHANGE. ALSO, A MAJOR FACTOR THAT PREVENTE0 CLEARING THE SCREENS R4PIOLY WAS THE IN481LITT OF OPERATORS TO t M4NU4LLY RUN THE SCREENS AT ANY SPEE0 OTHER THAN SLOW. IN THE FUTURE, gi ANT TEMPORARY SYSTEMS USED IN PLACE OF THE SCREEN WASH WILL INCLUDE

    ,           DE8RIS COLLECTION. OTHERWISE, mAINTENANrs esouTotwe vwn tres                                                                                         u.eu .-

FORM 141 LER SC55 DATA p e 0************************************************************04-13-91 **.***** DOCKET TEAR LER NUM3ER REVISION DCS NUMBE0 NSIC EVENT DATE g4 423 1990 013 1 9008240193 219378 04/16/90 M AB$ TRACT

       ;      POWER LEVit - 049%. ON APRIL 16, 1990, AT 1201 HOURS WITH THE PLANT AT pq           48% POWER IN MODE 1, A MANU4L REACTOR TRIP WAS INITIATED SEC AUSE OF AN ANTICIPATED TURSINE TRIP DUE TO LOSS OF CONDENSER VACUUM.

I4 CIRCULATING WATER PUMP 3CW5-P18 WAS PROVIDING COOLING WATER FOR CONDEN5ER WATER 50XE5 "A" ANO "B". A RAPID BUILDUP OF SE4 WEED ON "B" b4 TRAVELING SCREEN RESULTED IN AN AUTOMATIC TRIP OF 3CWS-P18 DUE TO HIGH ' SCREEN DIFFERENTIAL LEVEL. AS THE LOSS OF COOLING TO TWO CONDENSER BATS WOULO HAVE RESULTED IN A LOW CONDEN5ER VACUUM, A REACTOR TRIP WAS gg INITIATED. THE REACTOR TRIP CAUSED A MAIN TURBINE AND GENERATOR TRIP g, IN ACCORDANCE WITH DESIGN. THE ROOT CAUSE OF THE EVENT W45

 **           INADEQUATE ADMINISTRATIVE GUIDANCE IN THAT DE8RIS W45 ALLOWED TO COLLECT ON THE TRASH RACK. DURING TRASH RACK RAKING, SEAWEED BROKE FREE AND CLOGGED "B" TRAVELING SCREEN.      HIGHER THAN NORMAL SEAWEED b4 INFLUX AND 130% FLOW DUE TO CROSS CONNECTING A 8 8 WATERBOXE5 CONTRIBUTED TO THE HIGH WATER PUMP TO SUPPLY ONLY THE ASSOCIATED p,           WATER 80X OURING SEVERE WE4THER. FOR CORRECTIVE ACTION, THE TRASH RACKS HIGH DIFFERENTIAL LEVEL ALARM POINT HA5 BEEN LOWERED FROM 15 INCHE5 TO 6 INCHES. PERSONNEL HAVE BEEN INSTRUCTED TO CLOSELY MONITOR De THE  TR4$H RACK WATER LEVEL $ AND CLEAN THE RACKS BEFORE LEVEL 5 EXCEED 4 INCHES, p1       1
 ,,         FORM     142                LER SCSS DATA
 ',       0************************************************************04-18-91********

D9 DOCKET TEAR LER NUMBER REVISION DC5 NUMBER NSIC EVENT DATE 423 1990 014 0 9036200233 218564 05/10/90 te 485 TRACT

            POWER LEVEL - 060%. ON 5/19/90 AT 2033 HOURS WITH THE PLANT IN MODE 1 AT 60% POWER, A MANUAL REACTOR TRIP WAS INITIATED SECAUSE OF AN e

ANTICIPATED TUR8INE TRIP OUE TO LOSS OF CONDENSER VACUUM. CIRCULATING WATER PUMP 3CWS-819 WAS PROVIDING COOLING WATER FOR CONDENSER WATER 80tES "A" AND "B". A RAPIO BUILOUP OF SEAWEED ON "B" TRAVELING

 ,.           SCREEN RESULTED IN AN AUTOMATIC TRIP OF 3CWS-P18.       THE PLANT WAS IN THE PROCESS OF DOWNPOWERING AS A RESULT OF WEATHER EFFECTS ON
 '            CONDEN5ER COOLING W4TER EQUIPMENT IN THE INTAKE STRUCTURE.           AS THE LOSS OF COOLING TO TWO CONDENSER 8475 WOULO HAVE RESULTED IN A LOW CONDENSER WACUUM, A REACTOR TRIP WAS INITISTED.       THE REACTOR TRIP CAUSED A MAIN TUR8INE AND GENERATOR TRIP IN ACCORD 4NCE WITH DESIGN.

ROOT CAUSE 08 THIS EVENT WAS DESIGN DEFICIENCT IN THAT THE TRAVELING

 ,            SCREEN CAPACITY WAS INADEQUATE. 4 CONTRIBUTING CAUSE WAS THE PEAK SEAWEED SEASON. 45 CORRECTIVE ACTION, THE TRAVELING SCREEN UNITS IN A

NUM8ER OF SATS WILL BE REDESIGNED AND MODIFIED PER THE RECOMMENDATIONS OF AN INTERNAL TASK FORCE. TWO OF THESE UNITS WILL BE MODIFIED IN THE NEXT TEAR. PERSONNEL HAVE SEEN INSTRUCTED TO EVALU4TE INTAKE STRUCTURE CONDITIONS MORE FREQUENTLY AND PROCEDURES MODIFIED TO ALLOW POWER REDUCTIONS AT 4 FASTER RATE.

1 FORM 143 LER SC55 OATA 04-18-91

     '    0***********************************+++++++++++**********************

DOCKET TEAR LER NUMBER REVISION DC5 NUMSER N51C EVENT DATE

 .             423     1990     019          1      9101070169 220616         06/06/90
            ....*.*...****..*.a....*.*.*........*....*.*.........*********.e....

                                                                                                                                              ._= - - - - - . - - - = =
                                         -e tuv4 ra.:<,     21/F AND 225) 8514, A4 AUTOMATIC REACTOR TRIO FROM A NEGATIWE Flut RATE sis 1al OCCURREC CUE TO A OR3PPE0 CONTROL ROD. THE F 9 CAUSE OF THIS EVENT WAS A SROKEN CONNECTI3N IN THE STATIONART GRIPPER COIL POWER CABLE F02 R03 G13. THIS SINGLE DROFPED ROD RESULTED In A pq                           NEGATIVE FLUX RATE SIG%AL ON TWO F0WER RA%GE DETECTORS, THERE8Y ii     RESULTING IN A REACTOR TRIP SIGNAL. THE ROOT CAUSE OF THE BROKEN D4                           CONNECTION WAS CORROSION AT THE CONDUCTOR / PIN INTERFACE. 220616EDIATE CORRECTIVE ACTION CONTROL ROOM OPERATORS *ERFORME3 THE ACTIONS i

REQUIRED BY THE APPLICABLE EMERGENCY OPERATING PROCEDURE. THE BROKEN eq CONNECTOR WAS REPLACED. A FUNCTIONAL TEST WAS PERFORMED BY FULLY WITHDRAWING AND THEN INSERTING THE AFFECTED ROD. LONG TERM CORRECTIVE O . ACTION WILL SE TO INSPECT AND REPLACE CONNECTORS AS NECESSARY OURING THE THIRD REFUELING OUTAGE. 1 54 g, FORM 144 LER SCS$ DATA b, 0************************************************************04-18-91 ********

                                  ;i DOCKET YEAR LER NUMBER REVISION DCS MUMSER                 NSIC       EVENT DATE 423    1990        030            0      9102070051 220935           12/31/90 he EM                         A857RACT POWER LEVEL - OS6%. 04 12/31/90, AT 1636 HOURS WITH THE PLANT IN MODE y,                      i    1 AT 863 POWER, 580F AND 2250 PSIA, 8 MANUAL REACTOR TRIP WA$

INITIATED DUE TO TWO SIN INCH MOISTURE SEPARATOR ORAIN LINE (DSM) I' PIPING BREAKS IN THE TURBINE BLOG. FOLLOWING THE TRIP A MAIN STEAM LINE ISOLATION WAS INITIATED TO MINIMIIE THE RELEASE OF STEAM INTO THE TURSIME SLDG. CAUSE OF THE EVENT WAS FAILURE OF THE 2 DSM LINES pe DOWNSTREAM OF THE RESPECTIVE LEVEL CONTROL VALVES. SOTH LINES APPEARED TO BURST, FAIL LONGITUDINALLT, THEN UNIIP CIRCUMFERENTIALLY

             ,                           AT THE MINIMUM WALL THICKNESS LOCATION. THE WALL THICKNESS AT THE g                            RUPTURE WAS APPROX. 0.020 INCHES.           THE CAUSE OF THE SEVERE WALL LOSS WAS SINGLE PHASE EROSION / CORROSION.        THE COMBINATION OF TEMPERATURE, b8 HIGH FLUID VELOCITT AND EXTREMELT LOW 0xTGEN CONTENT ARE THE CAUSATIVE FACTORS. THE WALL LOSS W AS LOC ALI!ED. THE MINIMUM THICKNESS re                          OCCURRED ADJACENT TO THE CONTROL VALVE (S) AND INCREASED AT 9.011 INCHES PER INCH DOWNSTREAM FROM THE VALVE (S).           THE ROOT CAUSE ANALYSIS
                                       OF THE EVENT HAS NOT SEEN COMPLETED. AS IMMEDIATE CORRECTIVE ACTION CONTROL ROOM OPERATORS PERFORMED THE ACTIONS REQUIRED BY THE APPLICABLE EMERGENCY OPERATING PROCEDURES. THE RUPTURED PIPES WERE I                           CAPPED PENDING REPAIRS DURING THE UPCOMING OUTAGE. THE DSM PUMPS AND PIPING WERE ISOLATED. POTENTIAL LONG TERM CORRECTIVE ACTIONS WILL SE
             ,                           EVALUATED WHEN THE ROOT CAUSE ANALYSIS IS COMPLETE.

1

             '                                  145 FORM                           LER SCSS DATA                            04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 424 1989 005 0 8903170282 213275 02/10/89

                                        **.*...**..**    *****..**.a....*****.**      .. .**.....+...****..... ****.

ABSTRACT 4 POWER LEVEL - 100%. ON 2-10-89, AT APPR0x. 0050 CST, CONTROL ROOM OPERATORS RECEIVED MAIN FEE 0 WATER PUMP TUR8INE (MFPT)" A" HIGH

VISRATION ALARMS. A CHECK OF THE VISRATION MONITOR SYSTEM SHOWED A VISRATION OF ONLY 1.2 MILS. (THE VISRATION SYSTEM ALARMS AT 3 MILS

                                ,        AND TRIPS AT $ MILS). AT APPROX. 0051 CST MFP "A" TRIPPED.

STEAM /FEEDWATER FLOW MISMATCH ALARMS WERE RECEIVED ON ALL 4 STEAM GENERATORS (SG). TURSINE LOAD WAS MANUALLT REDUCE 0 TO APPROIIMATELY

                                ,        700 MWE AND CONTROL R005 PLACED IN AUTO TO FOLLOW LOAD. STEAM DUMP VALVE CONTROLLERS WERE MANUALLY OPERATED TO ATTEMPT TO MATCH
             +

STEAM / FEED FLOW. AT APPR0x!MATELY 0053 C ST, SG s4 REACHED 20% LEVEL g AND THE SHIFT SUPERVISOR DIRECTED THE REACTOR 70 SE MANUALLY TRIPPED. FEEDWATER ISOLATION AND START OF AurILIaRY PrenWaTeo ca=Ws seiwo e __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ~ . - .

v Aswallore TRIP CANNOT BE P33ITIVELY IDENTIFIEC. THE CAUSE OF THE T04FW PU4P CVERSPEED TRIO, ALTH0ur.H NOT POSIT!bELY IDENTIFIED, MAY , p1 HAVE BEEN CAUSED SY PARTICULATE CONT 4MINATION OF THE LUSE OIL, WHICH SERVES AS THE CONTROL SYSTEM HTORAULIC FLUID. CORRECTIVE ACTIONS l bg IECLUDE TEMPORARILY INSTALLING WISR4 TION INSTRUMENTATION TO COLLECT

                  MFP VIBRATION DATA. ADDITIONAL SURVEILLANCES WERE ALSO PERFORMED ON THE TDAFW PUMP TO ENSURE OPERABILITY.

DM 1 i 1: pq FORM 146 LER SCSS DATA 0************************************************************04-15-91 ******** DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 424 1959 012 0 8900000000 216366 05/ De

               *************+a************************************************09/89                                 *****

ABSTRACT ge POWER LEVEL - 100%. ON 519159, nr APPRot. 0905 CDT, THE UNIT BEGAN EXPERIENCING MAIN FEE 0 WATER PUMP (MFP) '8' HIGH VIBR4 TION ALARMS (6 U" ALARMS IN 15 SECON05), WHICH WOULO IMMEDIATELY CLEAR. THE TURSINE BUILDING OPERATOR (TBO) REPORTED NO Ui!USU AL NOISE AT THE PUMP. THE bg

        .i, ADV4NCED TURSINE SUPERVISORY INSTRUMENTATION (ATSI) WAS CHECKED AND READINGS WERE FOUND TO BE SELOW ALARM LEVELS. AT THIS TIME IT WAS THOUGHT THAT PAINTERS, WORKING IN THE AREA, HAD MOVE 0 CASLES CAUSING g,               THE ALARM. ALARMS WERE AGAIN RECEIVED AT 1013 CDT AND A CHECK OF THE ATSI AND A REPORT FROM THE TSO DID NOT IN0!CATE ANYTHING ABNORMAL.

I' SEARING METAL AND LUBE OIL TEMPERATURES WERE CHECKED 04 THE MAIN

          ;        COMPUTER, AND THE READINGS WERE ACCEPTABLE. ASSISTANCE WAS REQUESTED FROM MAINTENANCE AND ENGINEERING.      ADDITIONAL ALARMS WERE RECEIVED P1              SETWEEN 1029 AND 1040 CDT. THE IN0!VIDUALS INVESTIG4 TING THE PROSLEM
'                  DID NOT DETECT ANY UNUSUAL VIBRATION OF THE MFP. AT 1040 CDT, MFP                                      'B'
   ,,            ' TRIPPED ON HIGH WIBRATION. CONTROL ROOM OPERATORS ATTEMPTED RECOVERY
   '               FROM THE PUMP TRIP, SUT WERE NOT ABLE TO PREVENT A REACTOR TRIP AT b*

1042 CDT DUE TO STEAM GENERATOR 84 LOW-LOW LEVEL. THE CAUSE OF THE FEE 0 WATER PUMP TRIP WAS 4 BROKEN SOLDER CONNECTION ON 4 TEST JACK IN THE ATSI VIBRATION CARD FOR Th! LOW PRES $URE SEARING. A CONTRIBUTING g, , CAUSE TO THE REACTOR TRIP WAS A F4ILED SISTABLE IN THE CONTROL R00 DRIVE CIRCUITRT. te FORM 147 LER SCSS DATA 04-18-91 e 0******************************************************************** 00CKET TEAR LER NUMBER REVISION DCS NGMBER NSIC EVENT DATE

   ,                   424  1959       016          1     8909081090 215175                                     07/03/59
   '           A8STRACT POWER LEVEL - 100%. ON 7/9/S9, 4T 0327 CDT, 4 M4NU4LLY INITIATED e

REACTOR TRIP OCCURRED ON UNIT 1 WITH THE REACTOR AT 10JE OF DATED THERMAL POWER. THE MANUAL TRIP WAS INITIATED BECAUSE THE LOOP 4 MAIN

  ,               FEE 0 WATER ISOLATION VALVE (MFIV) FAILED CLOSED RESULTING IN A DECREASE IN THE NO. 4 STEAM GENERATOR LEVEL. THE PLANT WAS STASILIZE0 TN MODE
   '              3 FOLLOWING THE REACTOR TRIP. TROUBLESHOOTING FOLLOWING THE #1NU4L TRIP F4ILED TO IDENTIFT THE EIACT CAUSE OF THE SPURIOUS CLOSL';;
          ,      HOWEVER, 2 POTENTIAL FAILURE MECHANISMS WERE EVALUATED; SOLENDID FAILURE AND AUXILIARY REL4Y FAILURE. CORRECTIVE ACTIONS FOR THE 715/S9 i                  EVENT INCLUDED TROU5LESH00 TING OF THE VALVE CONTROL CIRCUITRY, REP 41R 0F THE ASSOCIATED MANDSWITCH FOR A PR3BLEM NOTED OURING TROUBLESHOOTING BUT UNRELATED TO THE FAILURE, AND CONTINUED CONTROL I

LOOP MONITORING WITH A MULTI-CHANNEL RECORDER. ON S/3/89, THE LOOP 4 g3 MFiv SPURIOUSLY CLOSED AND THE RESULTING DECREASE IN FEEDWATER LEO THE OPERATOR TO TRIP THE REACTOR af 1445 CDT. CONTROL R001 OPERA 10RS i ACHIEVED ST ABLE PL ANT CONDITIONS SY 1505 CDT. CORRECTIVE ACTION FOR

p; THIS EVENT CONSISTED OF REPLACING A FAILED SOLENOID WALVE AND RETURNING THE VALVE TO TME VENr9' une mattence ***e****

                                                .vs-     e:                            L:4 5055 DATA                                          04-19-91 Pt 0******.**e*********.e*.****..****************eee***..**e****                                   ** ***.

DOCKET TEAP LEE NUN 3ER REVISION QC5 NUMSER N51C EVENT DATE 424 1989 015 0 8911070020 215754 1 b4 *************************************************************0#02/89 *******

                                        .p A85 TRACT b4 POWER LEVEL - 0871. ON 10-2-89, AT APPROXIMATELY 0136 COT, THE NO. 1 1                       4 ,'     STEAM GENERATOR (SG) TRAIN "A" MAIN STEAM I SOL A TION VALVE (MSIV) t1                             FAILED CLOSED. AT 0137 COT, AN AUTOMATIC REACTOR TRIP OCCURRED DUE TO SG MO. 1 REACHING ITS LOW-LOW WATER LEVEL SETPOINT. 4 TURBINE TRIP, d it                 MAIN FEE 0 WATER ISOLATION AND AUXILI4RT FEE 0 WATER ACTUATION OCCURRED AS DESIGNED FOLLOWING THE TRIP. THE MSIV CLOSED OUE TO A SLOWN FUSE IN
                  >8                             THE CONTROL LOGIC POWER SUPPLT. INVESTICATIONS REVEALED THAT GROUNDING
                                        ,j ,     PROBLEMS EXISTED IN THE 125VOC CONTPOL POWER DIsiRIBUTION PANEL AND bg                              INDICATED THAT A GROUND COULO HAVE EXISTED IN A M5IV LIMIT $ WITCH WHICH SHOWED SIGN 5 OF INTERNAL MOISTURE REL4TED DETERIORATION AND ARCING. THE COMBINATION.OF THE GROUNDS IN THE CONTROL POWER
                             "                   DISTRIBUTION PANEL AND THE SU5PECT GROUND IN THE MSIV LIMIT 5 WITCH LIKELT CAUSED THE FU5E TO BLOW. THE GROUNDING PROSLEMS WERE CORRECTED b4
                                               AND THE MSIV LIMIT SWITCH AND PU5E REPLACEO. CORRECTIVE ACTION TO PREVENT RECURRENCE INCLUDES COMPLETING 4 PREVIOUSLT IDENTIFIED TASK OF SEALING THE MSIV LIMIT SWITCHES DURING THE NEXT REFUELING OUTAGE T0 be                     1 PREVENT WATER INTRU$ ION.

1

                                              FORM     149                           LER SC55 OATA 0**********.**************************************e .***.****04-18-91                           ********

p4 OOCKET TEAR LER NUM5ER REVISION OCS NUMBER NSIC EVENT DATE 424 1990 001 0 9003060244 217056 01/24/90

                    ,                           * *****e**    .... ******* ***e.**.e** .**.**a.********                              ....*ea.**e.*    .

A85 TRACT S' POWER LEVEL - 090%. ON 1-24-90, PARTIAL STROKE TESTING" 0F A M41N STEAM ISOLATION VALVE (MSIV) WAS IN PROGRESS. CURING A PREVIOUS TEST, ei THE V ALVE HAD FAILED TO REOPEN AUTOMATICALLY AT THE 101 CLOSED POSITION AS DESIGNED. 45 A RESULT, PLANT PERSONNEL WERE PREPARED 10

                    ,,                            INSTALL A JUMPER TO REOPEN THE WALVE IF IT FAILED TO REOPEN AUTOMATICALLT. THE TEST SEG4N AND AN INDICATOR ILLUMINATED AT APPROMIM4TELT 101 CLOSEDI HOWEVER, UNKNOWN TO THE PERSONNEL INVOLVED, 8

THERE WERE TWO LIMIT 5WITCHE5 WHICH WERE NOT ADJUSTED TO ACTUATE CONCURRENTLT. CONSEQUENTLT, WHEN THE INDICATOR ILLUMINATED, THE OTHER g . LIMIT SWITCH HAD NOT TET ACTUATED AND IT APPEARED THAT THE VALVE WOULO NOT REOPEN AUTOMATICALLT. THE JUMPER WAS INSTALLE0 TO INITIATE

                                              VALVE REOPENINGI HOWEVER, POSITION INDICATION W45 LOST AND THE MSIV WENT FULLT CLOSED. MSIV CLD5URE RESULTED IN A RAPIO DECRESSE IN WATER LEVEL IN STE4M GENERATOR (5G) 84 TO THE LOW-LOW LEVEL SETPOINT AND AN 8
                                       ,         AUTOMATIC REACTOR TRIP OCCURRED AT 0133 CST. AN INVESTIGATION OETERMINED THAT WHEN THE JUMPER W45 INSTALLE0, THE MSIV CONTROL FUSES
                    .                            FAILED, WHICH CAUSED THE V4LVE TO CLOSE. CORRECTIVE ACTIONS INCLUDET A) FUSE REPLACEMENT, 8) PROCEDURE REVISION TO INCLUDE A CAUTION THAT

THE INDICATOR M4T LIGHT PRIOR TO THE VALVE RECEIVING THE REOPEN SIGN 4L, AND, C) LIMIT SWITCH ADJUSTMENT TO OSTAIN CONrURRENT

                                       ,,        ACTUATION.
                                       ,3       FORM    150                           LER SC55 0A74                                          04-18-91 0********************************.*************** *******************
                     '                          00CAET VEAR LER NUNBER REVISION OC5 NUMBER                                     N51C        EVENT DATE
                                       ,.          424    1990       011                                  0       9005290001 218322          04/25/90 e************e*.    *..***..*e.....**...**..******e.*.                              *...****** ****.

g- A85 TRACT POWER LEVEL - 047t. og A-24-on, er siti rav, eu- . - - * . -- *--- --

                                                                                                                                                               . _ . . __      _   .~     ._

                                                                                                   . ==
                     =+.uasa=eus maa av.cIv=C ahC FEE 0 WATER

LOW TC SG f4 0. 2 WAS OSSECVED TO SE DECREASING 4APIDLY. THI SALANCE OF PLANT QPERATOR ATTEMDTED TO

, P -t INCREASE THE FEE 3 WATER SLOW ST INCREASING THE DEMAND $1GNALS TO MAIN FEEDWATER RCGULATING-WALVE (MFav) No. 2 AND BTPASS FEE 0gATER gy CEGULATIEG VALVE 40. 2. H03EVER, SG MO. 2 LEVEL CONTINUED TO FALL go' WHICH FORCEO INITIATION OF THE REACTOR TRIP. THE AUXILIARY FEE 0 WATER i SYSTEM ACTUATED AS DESIGNE0 FOLLOWING THE REACTOR TRIP TO MAINTAIN SG i WW LEVELS. BT 1310 COT, THE UNIT WAS STA81LIZED IN MOD E 3. SUBSEQUENT i i ,, INVESTIGATION IN0!CATED THAT MFRV NO. 2 HAD CLOSED AND CAUSED THE , r1 EVENT. THE MFRV APPARENTLY CLOSED WHEN WORKERS INSTALLING INSULATION ON THE MFRV INADVERTENTLY BUMPED INTO AND MISPOSITIONED THE LOCAL ' O CONTROL LEVERS LOCATED ON THE SIDE OF THE VALVE POSITIONER. MISPOSITIONING OF THE LOCAL CONTROL LEVERS INTERRUPTED THE CONTROL AIR SUPPLY TO THE VALVE POSITIONER. SINCE THE LOCAL CONTROL LEVERS ARE DN NOT USED FOR NORMAL OPERATIONS, CORRECTIVE ACTION 10 PREVENT i i RECURRENCE HAS BEEN TAKEN TO REMOVE THESE LEVERS FROM SOTH THE UNIT 1 be AND UNIT 2 MFRVS. l 1 i ' "" FORM 151 LER SCSS DATA 04-1 8-91 i

              ,   0........ee**ne* ....e*****      ...* .....**......ee...*......=*eee. ....

l he DOCKET VEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE l 424 1990 016 0 9003280290 219379 07/23/90 p, ******************************************************************** 4 ABSTRACT U' , POWER LEVEL - 1008. ON 7-23-90 AT 0600 COT, UNIT 1 WAS OPERATING IN MODE 1 AT 1002 POWER WHEN A 41601480 VOLT NON-1E TRANSFORMER (1N801) D1 EXPERIENCED AN INTERNAL FAULT, CAUSING A TRIP OF THE ASSOCIATED FEEDER BREAKER. THIS TRANSFORMER WAS SUPPLTING POWER TO THE SPEED CONTROL

    ,.               CIRCUITRY FOR 90TH OF THE MAIN FFE0 WATER PUMP (MF P) TUR8INES. THE

(. MFPS TRIPPED, THE STEAM GEMERATOR (SG) WATER LEVELS DECREASED 70 242, MARROW RANGE LEVEL, AND THE REACTOR OPERATOR INITIATED A MANUAL 6a REACTOR TRIP AT 0602 COT. THE MAIN FEEDWATER SYSTEM ISOLATED AND THE 4 MOTOR-DRIVEN AUXILIARY FEEDW4TER (AFW) PUMPS STARTED, AS EXPECTED, l te WHEN THE REACTOR TRIP CCLURRCD. THE TUR8INE ORIVEN AFW PUMP' STARTED WHEN TWO OF THF FOUR SG*E RFLCHED THEIR LOW-LOW LEVEL SETPOINT. NORMAL PLAN 1 LONb!?ILT* is,32 ESTABLISHED IN MODE 3 (NOT STAND 8T) AT I* 0656 COT. THE CAUSE OF THE EVENT WAS AN INTERNAL FAULT IN THE IN801 TRANSFORMER. FURTHER INVESTIGATION OF THE CAUSE OF THE FAULT IS IN 8 . PP0GRESS. I 1 i . ! FORM 152 LER SCSS DATA 04-18-91 1 0******************************************************************** j DOCKET Y!AR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

!                     424    1990       023            0     9101220420 220828           12/18190 1    9               ........***ee.....e---.....**.... **...*******e        *e .e* ......e   *****
    ,               ABSTRACT POWER LEVEL

1003. 04 12-18-90 AT 1936 CST, UNIT WAS PPERATING AT 1002 POWER WHEN A 4160/480 VOLT NON-1E TRANSFORMER (1NB10I)

                    'EMPERIENCED AN INTERNAL FAULT. THIS SAILURE RESULTED IN A LOSS OF POWER FOR THE SPEED CONTROL CIRCUITRY FOR THE 18 MAIN FEEDWATER PUMP (MFP) YUR8INE AND CERTAIN SUPPORT SYSTEMS FOR EMERGENCY DIESEL GENERATOR 18. FEE 0 WATER PUMP SPEEO, FEE 0 WATER FLOW, AND STEAM
         ,,          GENERATOR (SG) LEVELS DECREASED. THE REACTOR OPERATOR INITIATED 4 MANUAL REACTOR TRIP AT 1937 CST AFTER EFFORTS TO MAINTAIN SG LEVELS WERE UNSUCCESSFUL. ALL SAFETV RELATED FUNCTIONS OCCURRED PER DESIGN FOLLOWING THE REACTOR TRIP; HOWEVER, 4 NON-1E 4160 VOLT SUS FAILE0 TO AUTOMATIC ALLT TR ANSFER TO THE RESERVE AUXILIARY TRANSFORMERS CAUSING A 9               .TEMPOR4RT LOSS OF W ARIOUS NON-1 E HOUSE LO ADS.      TRANSFER OF THE 4160 9

VOLT SUS WAS COMPLETED MANUALLY AND NORMAL PLANT CONDITIONS WERE ESTABLISHED FOR MOT STANogy nT 1958 e t T, vus enar r .e c e was vu-

)

              ,, ,.....,,      ..s,.    .n. 4evutuLe lwar6-URMcRS A4: GE Cl4SS AA/FA, THREE PHASEo DRV TVPE TRAN550RMERS. THE 8&ILED TQANSFORMER HAS .EEN Py REPLACED AND FURTKER STJ3T OF POSSI3LE FACTORS UNICH HAT HADE LED TO TH2 FAILURE IS IN D30GRESS.

b4 li FORM 153 LER SCSS DATA 04-18-91 kW 0.*..**.........*.**......***.*.*.........*****...*......**. ........ t p 00CKET TEAR LER HUMBER REVISION OCS NUMBER NSIC EVENT DATE em 425 1959 019 0 5906050216 214183 05/02/89 EO A85 TRACT A POWER LEVEL - 063%. ON 5-2-89, PERSONNEL WERE PERFORMING A CHECK OF be ii TURSINE TRIP OEVICES PER PROCEDURE 14256-2, " WEEKLY TURSINE TRIP r OEVICE OPERASILITY TEST", PRIOR TO PLACING THE TURBINE IN STAN08T. AN hO OVERSPEED TRIP DEVICE TEST M ALFUNCTIONED AND, AFTER CONSULTING THE TUR81NE VENDOR REPRESENTATIVE, THE OPERATOR ATTEMPTED TO RESET THE

  ""         MALFUNCTION USING THE "STOP/GO NORMAL" BUTTON. WHEN THIS SUTTON WAS PUSHED AND RELEASE 0, AT 1102 COT, THE TURSINE TRIPPED WHICH RESULTED IN A REACTOR TRIP. PRIOR TO THE TURSINE TRIP, A DEFECTIVE WELO IN A be ONE INCH STEAM LINE WAS RELEASING STEAM INTO AN AREA UNDER THE TURBINE FRONT STANDARD WHERE THE TURSINE TRIP DEVICE CONTROLS ARE LOCATED.

p, THE CAUSE OF THE TUR8INE TRIP HAS NOT BEEN DETERMINE 0 DESPITE EXTENSIVE TROUSLESH00 TING. HOWEVER, IT COULO BE POSTULATED THAT THE I D8 STEAM LEAK AFFECTED MECHANICAL OR ELECTRICAL COMPONENTS TO PRODUCE THE TRIP. FOLLOWING THE TRIP, THE WELO WAS REPAIRED AND THE TRIP DEVICE OPERASILITY TESTS WERE REPEATED SEVERAL TIMES BUT THE TURSINE TRIP P1 DEVICE MALFUNCTION COULD NOT SE OUPLICATED. 1 I' FORM 154 LER SCSS DATA 04-15-91 s 0.................................................................... D' 00CKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE , 425 1989 020 0 8906130270 214295 05/12/89 A8STRACT I' POWER LEVEL - 078%. 04 5-12-89, WHILE PERSONNEL WERE PERFORMING SURVEILLANCE OF NUCLEAR INSTRUMENT CHANNEL N64, A 2 OUT OF 4 HI FLUX a RATE TRIP COINCIDENCE $1GNAL WAS RECEIVED, CAUSING AN AUTOMATIC REACTOR TRIP. POWER RANGE CHANNEL N43 EXPERIENCE 0 A MOMENTARY LOSS OF

  ,,         POWER, WHICH TRIPPED THE RATE TRIP SISTABLE ON N43.             THE CONTROL ROOM OPERATOR ACKNOWLEDGED THE ALARM FOR THE TRIPPED SISTALLE, SUY FAILED
  '          TO NOTICE THAT THE WRONG BISTABLE M40 TRIPPED FOR THE WORK SEING PERFORME0.        A STEP OF THE SURVEILLANCE PROCEDURE, WHICH WAS SEING PERFORME3 FOR N64, REQUIRES THE FUSES TO SE PULLEO.             THIS TRIPPE0 THE RATE TRIP BISTASLE FOR N44. THE N43 AND N64 BISTABLES SATISFIED THE 2 CUT OF 4 LOGIC FOR A POWER RANGE TRIP. THE REACTOR TRIP SREAKERS
  ,          OPENE0, TRIPPING THE REACTOR AT 1429 COT.           ALL AUTOMATIC SYSTEMS FUNCTIONED AS DESIGNE0. THE CONTROL ROOM OPERATOR $ BROUGHT THE PLANT TO STABLE CONDITIONS IN MODE 3 (HOT STA408V). THE CAUSES OF TNIS EVENT WERE THE LOSS OF POWER TO CHANNEL N43 AND THE FAILURE OF CONTROL ROOM OPERATORS TO NOTICE THAT THE WRONG SISTASLE M40 TRIPPE0.

TROUBLESHOOTING CHANNEL N43 OIO NOT REVE AL THE CAUSE FOR THE LOSS OF POWER. A COPY OF THIS LER WILL SE PLACEO IN THE OPERATION REQUIRED READING 800K. 1 FORM 155 LER SCSS DATA 04-18-91 0**.*****..** **..****............**..*...*.**.....*..*..************

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE g 425 1939 021 1 8905140002 215006 05/22/89

                . . . . -. ..... s.... se 2 c: s ee          v=t#444T10NS wfRE U'4 D E t W a i TO START UP THE MAIN TUR3INE.          AT A*PR04TMATELY 1547 CCT, STEPS WERE IN TO P -t             eRING THE TUR3INF SPEED UP TO 130 AT 1605 COT, Iq3ICATIONS O' A STEAM / FEED MISMATCH PROSLEM WERE SEEN ON STEAM GENERATOR (SG) 82 A20 gg               THE REACTOR OPERATOR (RO) 08SERvfD A DECREASE IN TAVE GREATER THAN
      ^

EXPECTED. BECAUSE SG LEVELS AND PRESSURE WERE DECREASING, THE BALANCE b4 OF PLANT OPERATOR TRIPPED THE TUR8INE AT 1606 COT. FEED TO THE STEAM GENERATORS WAS INCREASED AND THE STEAM DUMPS WERE MANUALLY CLOSED. 1 i '. HOWEVER, AT 1607 CDT, AN AUTOMATIC REACTOR TRIP OCCURRED ON LOW-LOW LEVEL IN SG 82. CONTROL ROOM OPERATORS TOOK APPROPRIATE ACTIONS TO P1 STABILIZE THE UNIT IN MODE 3 (HOT STAND 8Y). THE DIRECT CAUSE OF THE g4 3, EVENT WAS THE FAILURE OF THE INTERCEPT. VALVES To OPEN AND A CONTRIBUTING CAUSE WAS OPERATOR OVERSIGHT IN NOT RECOGNIZING THE b4 INTERCEPT VALVES

FAILURE TO OPEN AS TUR8INE SPEED WAS INCREASED.

     ,,=
              WHEN THE MAIN TURBINE REACHED 1800 RPM, THE CONTROL VALVES OPENED FURTHER TO MAINTAIN A CONSTANT TURBINE SPEED CREATING A LARGE STEAM bg               LOAD. THIS CAUSED PRESSURIZATION OF THE HIGH PRES $URE TURBINE AND 13        MOISTURE SEPARATOR REHEATERS (MSR), EVENTUALLY L"FTING THE "S" MSR U"               RELIEF WALVE. THE OPERATOR TRIPPED THE MAIN TUR8INE, SG WATER LEVELS LOWERED AND A REACTOR TRIP OCCURRED. CORRECTIVE ACTIONS INCLUDED t.

b4 ADJUSTMENT OF THE CLOSING 8145 VOLTAGE ON THE INTERCEPT VALVE CIRCUIT CARDS. 1 >I [. FORM 156 LER SCSS DATA 8' 0******************.***.******.**....***********.*********.**04-18-91 ******** OOCKET YEAR LER NUMSER REVISION DCS NUMSER NSIC EVENT DATE 425 1989 024 0 8908280268 215149 07/26/39 p -e

              ......*.*........*.*...................*.****............. *.a.***..

,, 485 TRACT

POWER LEVEL - 100I. ON 7-26-89, AT 0136 COT, WHILE PERSONNEL WERE n' PERFORMING CORRECTIVE MAINTENANCE ON POWER RANGE NUCLEAR INSTRUMENTATION CHANNE*. 2N43, a 2 OUT OF 4 OVERTEMPERATURE DELTA-7 (OTOT) TRIP SIGNAL WA5 RECEIVED AND CAUSED AN AUTOMATIC REACTOR TRIP te FOR VEGP UNIT 2. THE CORRECTIVE MAINTENANCE 04 2N43 REQUIRED THE CHANNEL 111 OTDT REACTOR TRIP BISTABLE TO BE TRIPPED AS A PART OF THE

,, REMOVAL FROM SERVICE PROCESS. A LOS$ OF INPUT FROM PRES $URIZER PRESSURE CHANNEL 2P455 THEN OCCURRED AND CAUSED THE CHANNEL IV OTOT REACTOR TRIP BISTABLE TO TRIP. THIS COMPLETED THE 2 OUT OF 4 LOGIC ' REQUIRED FOR REACTOR TRIP 04 0T07. BT 0156 CDT, THE PLANT HAD SEEN STABILIZED IN MODE 3. THE FAILURE OF CHANNEL 2P455 WAS CAUSED ST THE

t. FAILURE OF AN OPERATIONAL AMPLIFIER IN THE NON-ISOLATED SECTION OF AN NLP2 PROCESS CARD. THIS CHANNEL HAD SPIKED LOW 04 TWO SEPARATE

, , gy OCCASIONS SEVERAL DAYS EARLIER BUT TROUSLESH00 TING FAILED TO IDENTIFY THE EXACT CAUSE OF THE PROSLEM UNTIL AFTER THE REACTOR TRIP. AN ADDITIONAL SPIKING PROSLEM HAD ALSO BEEN EXPERIENCED ON CHANNEL 2N43

       ^       AND WAS STILL 3EING INVESTIGATED AT THE TIME OF THE EVENT.                          CORRECTIVE ACTION CONSISTED OF REPLACING THE DEFECTIVE NLP2 CARD FOR CHANNEL 2P455 AND REPLACING A SUSPECT CARD FOR CHAMNEL 2N43.

1 el FORM 157 LER SCSS DATA 04-19-91

    ,;     0*************.**********.*.**.*************.**********.*************

DOCKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 425 1989 027 0 8911090270 215919 10/11/89

              **.a     *e.*.....*.........*.......*.....*.........*...........*......

AeSteACT

    ,,'        POWER LEVEL - OSSI. ON 10/11/89, AT 2333 CDT, AN AUTOMATIC REACTOR TRIP OCCURRED WITH THE REACTOR IN STABLE OPERATION AT SSI 0F RATED t               THERMAL POWER.         ALL AUTOMATIC SAFETT FEATURES FUNCTIONEO AS REQUIRED g:         AND THE REACTOR WAS STASILIZED IN MODE 3 WITHOUT INCIDENT. NO

, ANNuMCIATOR OR OTHER WARNING 08 A PROSLEM PRECEDED THE RrarToo voto,

. =

4 ...........o.. ar==a3AL111 I t iT ING OF THE CONTDOL ROOS THEN p1 INDICATED THAT 4 PROPLEM EXISTED WITH 400 E-2 IN CONTROL 8ANK S. INVESTIGATICN OF THE CONTROL R3D CIRCUITRY ICENTIFIED 4 FAILE0 OIODE WHICH HAD APPARENTLY RESULTED IN A LOSS OF CURRENT TO THE STATIONARY GRIPPER COIL. THIS ALLO 350 THE R00 TO OROP INTO THE CO2E AND INITIATE f" g A NEGATIVE FLUX RATE TRIP. CORRECTIVE ACTION INCLUDED REPLACING THE DIODE FOR ROD K-2. DM 1 r1 FORM 158 LER SCSS DATA 0************************************************************04-18-91 ******** Ed i' - DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 425 1989 029 0 8912120165 216109 11/05/89 e ee ee een. .............. ...................... **e..... . .... . bal A85 TRACT De POWER LEVEL - 1004. ON 11-5-89, PLANT PERSONNEL WERE RETURNING A g; HEATER ORAIN TANK HIGH LEVEL DUMP VALVE, 2LV-4333, TO SERVICE

   ""              FOLLOWING REPLACEMENT OF VALVE PACKING AND GASKETS.              THE VALVE WAS ISOLATED FROM THE HEATER ORAIN TANK AND OPERATORS NOTICEO IT INDICATED 301 OPEN. TO CHECK OPERASILITY, THE OPERATORS ISOLATED THE AIR LINE bg TO THE VALVE, WHEREUPON IT WENT FULL OPEN, 45 EXPECTED. ATTRIBUTING THE 301 OPENING TO A VALID DEMAND SIGNAL, OPERATORS BEGAN TO OPEN THE b4               VALVES WHICH HAD ISOLATED 2LV-4333. AT THIS POINT, THE OPERATORS NOTICED STEAM AND WATER COMING FROM THE PACKING.              THE 30% OPEN VALVE II               CAUSED THE HEATER ORAIN TANK TO CUMP TO THE MAIN CONDENSER. THIS RESULTED IN LOW MAIN FEE 0 WATER DUMP SUCTION PRESSURE WHICH CAUSED THE PUMP TO TRIP.      IN ADDITION, THE STANDST CONDENSATE PUMP FAILED 70 te              START 00 LOW FEEDWATER PUMP SUCTION PRESSURE. THE RE00CEO FEEDWATER FLOW RESULTED IN A RAPID DECREASE IN STEAM GENERATOR WATER LEVELS.

g, ANTICIPATING AN AUTOMATIC REACTOR TRIP, CONTROL ROOM OPERATORS

  ;                INITIATED A MANUAL REACTOR TRIP WITH STEAM GENERATOR LEVELS AT 19%

b' (NARROW RANGE INDICATOR) AT 1223 CST. VALVE 2LV-4333 MOVED TO THE 30% OPEN POSITION DUE TO A DEFECTIVE 0-RING (WHICH WAS REPLACED) IN THE VALVE ACTUATOR. THE STANDBY CONDENSATE PUMP FAILURE TO START WAS DUE , n. TO ITS 8REAKER SEING IMPROPERLY RACKED IN. THE BREAKER WAS RACKED IN PROPERLY AND THE PUMP TESTED SUCCESSFULLT. te FORM 159 LER SCSS DATA 04-8 0****************************************************************18-91 **** DOCKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 425 1959 031 0 9001020207 21 6251 12/02/89

  '              ABSTRACT POWER LEVEL - 100I. ON 12-2-89, PLANT PERSONNEL WERE RELEASING A s

CLEARANCE ON HEATER DRAIN TANK (HDT) HIGH LEVEL DUMP VALVE 2LV-4334. THE HIGH LEVEL DUMP VALVE FOR M3ISTURE SEPARATOR REHEATER (MSR)"D",

  ,               2LV-4525, Wa$ IN A 50% JACKED-OPENED POSITION DUE TO 2LV-4334 SEING ISOLATED. UPON OPENING THE VALVE WHICH ISOLATED 2LV-4334, IT BECAME EVIDENT THAT 2LV-4334 WAS NOT CLOSED. THE HDT LEVEL DECREASED AND THE NORMAL LEVEL CONTROL VALVE, 2LV-4332, CLOSED. THE ISOLATION VALVE
       ,          WAS RECLOSED AND HDT LEVEL ROSE; HOWEVER, 2LV-4332 FAILED TO REOPEN RESULTING IN RISING FEEDWATER HEATER LEVELS AND, OUE To THE CONFIGURATION OF 2LV-4525, MSR 0 LEVEL ROSE AS WELL. AT 0341 CST, MSR
       ,          D LEVEL REACHED THE HIGH LEVEL SETPOINT GIVING A TURSINE/ REACTOR TRIP. THE ROOT CAUSE FOR THE EVENT WAS COGNITIVE PERSONNEL ERROR
  '               INVOLVING REASSEMBLY OF 2LV-4334. THE VALVE WAS REASSEMSLED SUCH THAT
      ,           ITS POSITION INDICATION SHOWED CLOSED WMEN IT WAS ACTUALLY FULL CPEN.

FOR 2LV-4332, THE LEVEL CONTROL SENSING LINES WERE DISCOVERED TO BE CLOGGEO WHICH RESULTED IN ITS MALFUNCTION. ACTIONS TO PREVENT

      ,           RECURRENCE INCLUDE DISCUSSING THIS EVENT IN MAINTENANCE SHOP MEETINGS, IMPLEMENTATION OF A PERIODIC TASK TO 9 LOWDOWN THE LEVFs re4 Tom L

i P1 FORM 163 LER SCSS DATA 0************************************************************04-13-91 ********

      >q         ECCKET TEA 2 LER NUMBER REVISION DCS NUM3ER           NSIC                 EVENT DATE 425    1990      002          0      9004260305 218045                   03/20/90 A85 TRACT P1           POWER LEVEL - 1001. ON 3-20-90, at 0820 CST, A UNIT 2 GENERATOR PRIMARY DIFFERENTIAL RELAY ENERGIZED CAUSING A GENERATOR TRIP, TUR8INE g4   ,

TRIP, AND REACTOR TRIP. THE RELAY ENERGI!EO U*0N A PHASE TO GROUND FAULT WHICH OCCURRED WHEN 4 TRUCK OPER4 TOR SACKED INTO 4 SUPPORT POLE FOR A 230KV PHASE "C" "5WITCHER" FEEDER LINE FOR UNIT 1 RESERVE b4 AURILIARY TRANSFORMER (RAT) "A". THE 230KV LINE CAME IN CONTACT WITH THE GROUND CAUSING A F4 ULT WHICH AL50 TRI* PED UNIT 1 RAT "A" AND UNIT be 2 RAT "8". DIESEL GENERATOR 25 STARTED AUTOMATICALLY AND RESTORED POWER TO EHERGENCY SUS 28403. A LOSS OF POWER TO CERTAIN NON-!E

      ,,           BUSSES RESULTED IN A TRIP OF REACTOR COOLANT PUMPS 2 AND 4. AT 1035 CST, NORMAL OPERATING PROCEDURES WERE ENTERED AFTER THE UNIT W45 be           STASILIZED IN MODE 3. ALTHOUGH TME INITIATING EVENT WAS THE TRUCK SACKING INTO THE 230KV $UPPORT POLE, CAU5ING A PHASE TO GROUND FAULY, THE UNIT SHOULD NOT HAVE TR1PPED ON THE GROUND FAULT CURRENT RECORDED pe           DURING THIS EVENT. INVESTIGATION DETERMINED THE CAUSE FOR THE ACTU4 TION OF THE GENERATOR PRIMARY DIFFERENTIAL RELAY W45 INCORRECT I'           TAP SETTINGS FOR VARIABLE RATIO CURRENT TRANSFORMERS LOCATE 0 ON THE GENERATOR MAIN OUTPUT BREAKERS. A CONTRIBUTING CAUSE WAS THE FAILURE P4 TO TEST THE RELAY TO VERIFY THAT IT WAS RECEIVING THE PROPER VOLTAGE AND CURRENT SIGNALS FROM THE CURRENT TRANSFORMERS.       THE TAP SETYINGS FOR THE CURRENT TRANSFORMERS WERE CORRECTED AND THE REMAINING g,           PROTECTIVE RELAYS WILL BE TESTED.

i '

      "'         FORM     161                LER SC55 DATA                                    04-15-91 0********************************************************************

E* DOCKET YEAR LER NUMBER REVISION DCS NUMSER N5IC EVENT DATE 425 1990 007 0 9006190115 218543 05/06/90 ABSTRACT 8 POWER LEVEL - 100%. ON 5-6-90, af 2039 CDT, CONTROL ROOM OPERATORS RECEIVE TROUBLE ALARMS INDICATING CLOSURE OF MAIN STEAM ISOLATION VALVE (MSIV) 2HV-3026A AND STEAM GENERATOR ($G) 83 LOW-LOW WATER LEVEL. AN AUTOR4 TIC REACTOR TRI* ENSUEO. THE MAIN FEEDWATER SYSTEM

  , ,              !$0 LATED AND THE AUXILIARY FEEDWATER SYSTEM STARTED 45 DESIGNED. UNIT CONDITIONS WERE STABILIZED IN MODE 3 AT 2050 CDT. THE DIRECT CAUSE OF THIS EVENT WAS THE CLO5URE OF THE MSIV, WHICH RESULTED IN THE REACTOR TRIP WHEN SG #3 REACHED ITS LOW-LOW WATER LEVEL SETPOINT. AN INVESTIG4 TION OF THE MSIV CONTROLS FOUND THAT THE AIR SOLENCID TO THE e            VALVE'S HTDR4ULIC PUMP WAS NOT ENERGIZED 50 THAT SIR PRESSURE WAS NOT
         ,         AvaILABLE TO DRIVE THE PUMP MOTOR. FURTHER INVESTIGATION REVEALED

THAT THE AX1 REL4Y HAD F41 LEO. THE AX1 RELAT ENERGIZE $ SOTH THE AIR SUPPLY SOLENCID AND THE HTDRAULIC DUMP SOLENOID TO HOLD THE MSIV OPEN.

WHEN THE AX1 RELAT FAILED, THE LOSS OF HYDRAULIC FLUID PRESSURE TO THE VALVE CAUSED THE M5IV TO CLOSE. THE FAILURE OF THE RELAY W45 THE ROOT CAUSE FOR THIS EVENT. THE FAILED REL4y WAS REPLACED AND THE MSIV

         ,         WAS TESTED AND VERIFIED TO OPERATE 5ATI5FACTORILY. THE FAILED relay MAS BEEN RETURNED TO THE VENDOR FOR ANALYSIS.

1 t FORM 162 LER SCSS DAT4 04-19-91

      '      0********************************************************************

g!. DOCKET TEAR LER NUMBER REVISION DCS NUM6ER N5IC EVENT DATE

      ,             425    1990      005          0      0099n20151   *****^                  "o*

POWER LEVEL - 037%. ON 6-26-90, INOICATION WAS RECEIVED IN THE CONTROL p t RO3M THAT MAIN STEAM ISOLATION VALVE (MSIV) 2HV-3026A WAS CLOSING. OPERAT025 WHO WERE DISPATCHED TO INVESTIGATE FOUND HYDRAULIC FLUID SFRAYING FGOM THE VALVE. AFTER AN UNSUCCESSFUL ATTEMPT TO KEEP THE

         ,;     VALVE OPEN, A MANUAL REACTOR TRIP WAS INITIATED AT 1906 CDT OUE TO DECREASING LEVEL IN STEAM GENERATOR NO. 3. A FEEDWATER ISOLATION AND WW             AN AUXILIARY FEEDWATER ACTUATION OCCURRED PER DESIGN. SV 1947 CDT,
 ,              THE UNIT HAD SEEN STASILIZED IN MODE 3 WITHOUT INCIDENT.           THE CAUSE pq             FOR THE MSIV CLOSURE WAS THE FAILURE OF AN 0-RING WHICH SEALS THE CONNECTION OF THE "NON-PUMP SICE" MANIFOLD ASSEM5LY TO A 50$$ ON THE ACTUATOR CYLINDER. FACTORS WHICH COULO HAVE CONTRIEUTED TO THE 0-RING h4 -'          FAILURE INCLUDED A SLIGHT MISALIGNMENT OF THE CYLINDER BOSS AND MANIFOLD ASSEMSLY, A SMALL LOW SPOT AT THE EDGE OF THE ACTUATOR
 .58     j;     CYLINDER 8055, AND EVIDENCE THAT THE 0-RING MAY HAVE BEEN PINCHED ON INSTALLATION. AS a TEMPORARY M0blFICATION, A SPACER AND A SMALLER 7

ga DIAMETER 0-RING HAVE BEEN INSTALLED TO ENSURE THE 0-RING SEATING i SURFACE IS NOT TOO CLOSE TO THE OUTSIDE DIAMETER OF THE 8055. THE he PROPOSED PERMANENT MODIFICATION IS TO MACHINE THE 80$$ TO PROVIDE A OETTER SEATING SURFACE. 1 I

>=

FORM 163 LER SCSS DATA 04-18-91 p, 0******************************************************************** DOCKET YEAR LER NUMBER REVISION DCS NUM8ER WSIC EVENT DATE 425 1990 000 0 900$060053 219061 06/30/90 t8 *................................................................... p1 ABSTRACT POWER LEVEL - 0182. ON 6-30-90, A PROLONGED DELAY WAS EXPERIENCED IN ROLLING THE UNIT 2 TUR8INE AND SYNCHRONIZING THE GENERATOR TO THE I' GRID. DURING THIS DELAT, REACTOR POWER WAS ALLOWED TO INCREASE I STEADILY CUE TO MENON SURNOUT. SINCE SYNCHRON!!A TION APPEARED ke IMMINENT AND TO AVOID PRODUCTION OF LIQUID RA0 WASTE, THE SHIFT SUPERINTENDENT (SS) DECIDED NOT TO BORATE TO HOLD POWER WITHIN THE g, NORMAL RANGE FOR SYNCHRONIZATION SUT RATHER TO PROCEED WITH THE TRANSFER OF STEAM GENERATOR (SG) LEVEL CONTROL TO THE MAIN FEEDWATER REGULATING VALVES (MFRV's). THIS ACTION DID NOT FOLLOW THE NORMAL SEQUENCE PROVIDED FOR 87 THE UNIT OPERATING PROCEDURE (UOP) AND, DUE TO A FURTHER DELAY IN SYNCHRONIZATION, SG LEVEL CONTROL BECAME I DIFFICULT. SUSSEQUENTLY, 4 FEEDWATER ISOLATION AND A TUR8INE TRIP OCCURRED WHEN A SG REACHED ITS HIGH-HIGH LEVEL SETPOINT. SG LEVELS

   ,,           THEN FELL RAPIDLY AND FORCED INITIATION OF A MANUAL REACTOR TRIP AT 1150 CDT. ALL SYSTEMS RESPONDED APPROPRI ATELT AND SY 1204 COT THE

' '* UNIT HAD BEEN STABILIZED IN MODE 3. THE ROOT CAUSE FOR THE EVENT WAS A COGNITIVE PERSONNEL ERROR 87 THE SS. THE SS WAS AWARE OF THE DIFFICULTY THAT COULO BE EXPECTED IN CONTROLLING SG LEVELS WITH THE

TUR81NE UNLOADED AND REACTOR POWER CONTINUING TO RISE. HOWEVER, HE ELECTED TO OPERATE IN THIS CONFIGURATION AND AUTHORIZE 0 THE SEQUENCE

   ,            DEVIATION INVOLVING THE TRANSFER TO THE MFRV'S.
       ,     1
   '                   164 FORM                        LER SCSS DATA                            04-16-91 0***************************************.**********.*******ee........

DOCKET YEAR LER NUMBER REVISION DCS MUMSER NSIC EVENT DATE 440 1990 001 0 9002000006 216695 01/07/00

               .eemenee.................................................e**e......

ABSTRACT

   '            POWER LEVEL - 1001. ON JANUARY 7,      1990, AT 1132, A REACTOR SCRAM OCCURRED OUE TO A REACTOR WATER LEVEL OF LESS THAN LEVEL 3 (+177.7 INCHES ABOVE TME TOP OF ACTIVE FUEL). THE LOW WATER LEVEL OCCURRED AFTER AN IMPROPER TRANSFER OF 430 WOLT AC POWER SUPPLIES RESULTED IN A
   ,            MOMENTART POWER INTERRUPTION TO THE FEE 3 WATER CONTROL CIRCUITRY AND A

                        ..#   .w,,a,   ...s  i *: 2utets 44     I"t    .) WCLT 005 BEING CEEHERGIZED WHEN THE SUS TRANSFER W A S *1 A D E . TO PREVENT R E C UR R E NC E, THE OPERATOR HAS Ps                 SEEN COUNSELED ON THE IMPORTANCE OF PATING CLCSE ATTENTION TO DETAIL MHEN OPERATING PLANT EQUIPMENT. THE SYSTEM OPERATING INSTRUCTION WAS g,                 REVISED AND SUPPLEMENTAL TRAINING OM LIVE-8U5 TRANSFERS WAS DEVELOPED.

4 INVESTIGATION IS BEING PERFORMED INTO POSSIBLE DESIGN CHANGES TO

  >4                  INCREASE FEE 0 WATER CONTROL SYSTEM AVAILASILITY IN THE EVENT OF LOSS 08 NON-ESSENTIAL BUSSES. AS PART OF THE ESTABLISHED REQUALIFICATION
                '    TRAINING PROGRAM, ALL PLANT LICENSED OPERATORS WILL BE INSTRUCTED ON eq                 THE LESSONS LEARNED FROM THIS EVENT. SUSMITTAL OF THIS REPORT ALSO MEETS THE REQUIREMENTS FOR TECHNICAL SPECIFICATION 3.5.1 ACTION G 8
                =

WHICH REQUIRES A SPECIAL REPORT FOLL0 DING ANY EMERGENCY CORE COOLING SYSTEM ACTUATION AND INJECTION INTO THE REACTOR COOLANT SYSTEM. 1

  >S FORM      165                      LER SCSS DATA g,              0**************************************************.*********04-18-91                             ********

00CKEY YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 443 1989 008 0 8907310204 2149G3 06/22/89 km D4 ABSTRACT POWER LEVEL - 003%. ON 6/22/59, 4 MANUAL REACTOR TPIP WAS INITIATED p, WHILE CONOUCTING A NATURAL CIRCULATION TEST. SHORTLY AFTER TRIPPING THE REACTOR COOLANT PUMPS, AS PER THE NATURAL CIRCULATION TEST 8' PROCEDURE. ONE OF THE CONDENSER STEAM OUMP VALVES BEING USED TO CONTROL TEMPERATURE FAILED TO THE FULL OPEN POSITION. THIS OPEN VALVE CAUSED AN INCREASED STEAM DEMAND WHICH INITIATED AN UNPL ANNED PLANT pe C00LDOWN. THIS COOLDOWN CAUSED THE PRESSURIZER LEVEL TO DECREASE SELOW THE 17% MANUAL TRIP CRITERIA SPECIFIED IN THE STARTUP TEST PROCEDURE. DUE TO THE UNIT SHIFT SUPERVISOR'S MISINTERPRETATION OF

   '                 THE TEST PROCEDURE TRIP CRITERIA. THE PLANT WAS NOT MANUALLT TRIPPED AT THAT TIME. WHEN THE STEAM DUMP VALVE, MS-PV-3011. WAS CLOSED, THE D8 PREVIOUSLY DECREASING PRESSURIZER PRESSURE AND PRES $URIZER LEVEL BEGAN INCREASING.      BOTH PRESSURIZER PRESSURE AND LEVEL CONTINUED TO

g. INCREASE UNTIL THE PRESSURIZER PRESSURE, AT 2310 PSIG, APPROACHED THE TEST PROCEDURE MANUAL TRIP CRITERION OF 2340 PSIG AND A MANUAL REACTOR TRIP WAS INITIATED AT 12:36PM. THE CAUSE OF MS-PV-3011 FAILING TO THE FULL OPEN POSITION HAS SEEN DETERMINED TO BE THE POSITIONER i

FEEDSACK LINKAGE WHICH SECAME DISCONNECTED OURING THE TEST. 8 CORRECTIVE ACTION FOR THIS VALVE AND SIMILAR VALVES IS BEING , SCHEDULED. THE STARTUP TEST PROGRAM WILL BE REVISED TO REQUIRE THAT A

    ,                MORE COMPREHENSIVE PRE-TEST BRIEFING BE PROVIDED AND A DETERMINATION BE MADE OF WHICH TESTS REQUIRE SPECIAL CLASSR004 AND REVIEWED.

1 e FORM 166 LER SCSS DATA 04-18-91 a 0******************************************************************** DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE

    ,                  443      1990        315               1        9011050112 219937                            06/20/90
                    **********************+*********************************************

ABSTRACT POWER LEVEL - 0301. 04 6/20/90, AT 4: 30 P.M., WHILE IN MODE 1 AT 30% REACTOR POWER AND INCREASING, A TURSINE-GENERATOR TRIP WITH REACTOR TRIP OCCURRED. THE TRIP WAS INITIATED SY THE ACTUATION OF A MAIN

          ..         GENERATOR GROUND FAULT RELAT DESIGNED TO PROTECT THE LAST 5% OF GENERATOR WINDINGS FROM A GROUND FAULT. AN EMERGENCY FEEDWATER (EFW)

ACTUATION ALSO OCCURRED OUE TO LOW-LOW STEAM GENERATOR NARROW RANGE

 'j       ,          LEVEL. STEAM GENERATOR "A" EFW ISOLATED DUE TO HIGH EFW FLOW ONE MINUTE INTO THE EVENT. THE TUR91NE GENERATOR TRIPPED DUE TO THE i                GROUND FAULT RELAY ACTUATING. ALL THE APPLICABLE TRIPS AND INTERLOCKS g           ASSOCIATED WITM & TUR5INE GENERATOR, REACTOR TRIP AND FEEDWATER
    ,                ISOLATION FUNCTIONED AS DESIGNED.                 PARAMETERS ASSOCIATED WITH THE

                                                                                             . -=

s-o; u. au rutt s'ttu, IMU5 CREATING A SITUATION WHERE SOTH EFW PUMPS WERE SUPPLTING sc20 WATER SIMULTANEOUTLY. THE ROOT CAUSE FOR THE F9 ACTUATION OF THE GROUN3 FAULT RELAY HAS SEEN DETERMINED TO SE INCORRECT RELAT SETTINGS PROVIDED BY THE VENDOR. A HINOR MODIFICATION g4 - (MMOD) WILL BE ISSUED To REVISE THE RELAT SETTINGS AND BYPASS THE I TRIP FUNCTION OF THE RELAY. ADDITIONAL CORRECTIVE ACTIONS INCLUDE b4 REVISING THE EFW ISOLATION SETPOINT AS WELL AS REVIEWING AND UPDATING EMERGENCY OPERATING PROCEDUR55. 1 P1 FORM 167 LER SCSS DATA 4 0************************************************************04-15-91******** DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 443 1990 019 0 9005090069 219073 07/0 he :,

              *****************************************************************5/90     ***

i bg A8Sfd4CT POWER LEVEL - 075%. CN 715190, AT 4:29 P.M., WHILE IN MODE 1 AT 751 U" REACTOR POWER, A REACTOR TRIP WITH TURSINE TRIP OCCURRED. THE TRIP WAS INITIATED ST 4 MAIN STEAM LOW ELECTROHTORAULIC CONTROL IEHC) OIL PRESSURE SIGNAL. A MAIN FEE 0 WATER !$0LATION ALSO OCCURRED DUE TO THE kW SENSITIVITY OF THE STEAM GENERATOR LEVEL TRIP SIGNALS TO PRESSURE PULSES. THE REACTOR TRIPPED DUE 10 CONTACT CLOSURE OF THE EHC OIL

 >g            PRESSURE SWITCHES SATISFTING THE TWO OUT OF THREE LOGIC FOR REACTOR TRIP ON LOW EHC OIL PRESSURE. ALL APPLICA8LE TRIPS AND INTERLOCKS II            ASSOCIATED WITH THE REACTOR TRIP AND FEE 0 WATER ISOLATION FUNCTIONED AS
        '      DESIGNE0. ALL OPERATOR ACTIONS WERE DETERMINED TO BE APPROPRIATE.

THE ROOT CAUSE HAS BEEN DETERMINED TO BE EXCESSIVE VIBRATION OF THE D1 EHC PRESSURE SWITCHES DUE TO THEIR MOUNTING LOCATION. THIS VIBRATION CAUSED THE SWITCHES TO CLOSE EVEN THOUGH ADEQUATE EHC OIL PRESSURE bi EXISTED. CORRECTIVE ACTIONS INCLUDE RELOCATION OF THE PRESSURE g SWITCHES TO AN AREA WITH LESS VIBRATION As WELL AS MONITORING THE

 &'            PRESSURE SWITCHES IN THEIR NEW LOCATIONS UPON THE PLANT'S RETURN TO POWER OPERATIONS. 400!TIONALLT, A DESIGN CHANGE TO ELIMINATE THE EFFECTS OF THE PRESSURE PULSES 04 THE STEAM GENERATOR LEVEL TRIP te            SIGNALS WILL SE EVALUATED. THIS IS THE FIRST EVENT OF THIS TYPE AT SEA 8400K STATION.

Ie FORM 168 LER SCSS DATA 04-18-91 a 0******************************************************************** DOCKET TEAR L*R NUMBER REv!$ ION OCS NUMBER NSIC EVENT DATE

 ,               443    1990          022       0      9010020286 219624         08/22/90 ABSTRACT POWER LEVEL - 100%. 04 8/22190 AT 9:19      A.M.,  EDT, WHILE IN MODE 1 AT 1001 REACTOR POWER, A TURBINE-GENERATOR TRIP WITH REACTOR TRIP OCCURRED. THE TRIP WAS INITIATED ST AN APPARENT LOSS OF VOLTAGE ON
 ,             THE ELECTROHTORAULIC CONTROL (EHC) 24 VOLT OC SUS OURING TROUBLESHOOTING ACT!v1 TIES. A MAIN FEE 0 WATER ISOLATION ALSO OCCURRED SUBSEQUENT TO THE REACTOR TRIP. A WORK REQUEST WAS INITIATED TO PERFORN CIRCUIT CHECKS IN THE EARLY VALVE ACTUATION (EVA) CIRCUITRY OUE TO INCONSISTENT OPERATION OF THE EVA'S TEST INTERLOCK L IGHT LOCATED ON THE MAIN CONTROL E0ARD (MCB). SUSSEQUENT TO INITIAL TESTING AT THE MCS, IT WAS DECIDED TO CONTINUE THE TESTING LOCALLY AT THE EHC
      '        CA8INET. TWO TEST LEADS WERE USED TO SINULATE THE TEST SIGNAL AND 70 SU* PLT 24 VOLT OC POWER TO THE EVA CIRCUIT. AFTER THE SECOND APPLICATION OF THE TEST LEADS, A VOLTAGE OROP OCCURRED UN THE 24 VOLT
     ,         DC TRIP BUS RESULTING IN A TUR8INE-GENERATOR TRIP WITH REACTOR TRIP.

THE ROOT CAUSE FOR THE LOSS OF VOLTAGE ON THE EHC 24 VOLT OC SUS COULO t NOT BE CONCLUSIV8LY OETERMINED, ALTHOUGH A CONTRIBUTING FACTOR WhS

     ,         THE TROUBLESHOOTING ACTIVITY ASSOCIAT*O WITH THE EVA CIRCUIT.

PERSONNEL ERROR IN APPLTING THE TEST L* ADS Mat 40T assw em 8" m' T env

                        . . . wewon su 414AMal: wNALLENGES TU PLANT SYSTEMS.

1 P1 FORM 149 LER SCSS DATA 04-g4 0 e * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

e a e * * * * *
e e * * * * * * *****

                                                                                                                       * * * * * * * *

e e e e e *1 8 - 9 1 9; DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 443 1990 025 0 9012120168 220497 kW t .i

                      ...................................................................0                      11/09/9 i P1                  ABSTRACT POWER LEVEL - 1001. ON 11/9/90, AT 2: 31                     P.M. EJT, WHILE IN MODE 1 AT kd    +               100% POWER, A REACTOR TRIP WITH TUR8INE-GENERATOR TRIP CCCURRED. THE TRIP WAS INITIATED SV A STEAM GENERATOR LOW-LOW NARROW RANGE LEVEL SIGNAL. THE INITIATING EVENT WA5 CAUSED ST FATIGUE FAILURE OF A WW    g;             CONTROL AIR PIPE N!PPLE. THIS NIPPLE CONNECTS THE AIR 80057ER RELAY TO THE VALVE ACTUATOR FOR FEE 0 WATER FLOW CONTROL VALVE, 1-FW-FCV-520.

gg FOLLOWING THE FAILURE OF THE NIPPLE, VALVE 1-FW-FCV-520, FAILED CLOSED AS DESIGNED, DUE TO A LOSS OF CONTROL AIR. THE VALVE CLOSURE De RESULTED IN A LOSS OF FEE 0 WATER TO THE "5" STEAM GENERATOR. A REACTOR TRIP OCCURRED AS DESIGNED, WHEN THE STEAM GENERATOR WATER LEtEL j be OROPPED BELOW THE LOW-LOW NARROW RANGE LEVEL SETPOINT. SUSSEQUENT TO THE REACTOR TRIP, A MAIN FEEDWATER ISOLATION OCCURRED DUE TO HIGH-HIGH STEAM GENERATOR WATER LEVEL SIGNAL $ PIKES. IN AOCITION, AN EMERGENCY y, FEE 0 WATER ACTUATION OCCURRED A5 OESIGNED, DUE TO THE LOS$ OF FEE 0 WATER TO A STEAM GENERATOR. THE ROOT CAUSE OF THE EVENT HA5 BEEN Be DETERMINED TO SE VIBRATION INDUCE 0 FATIGUE FAILURE OF THE PIPE FITTING OUE TO A LESS THAN OPTIMAL DESIGN LOCATION. CORRECTIVE ACTIONS l INCLUDE RELOCATION OF THE AIR 80057ER RELAYS FOR ALL FOUR FEEDWATER ' D1 FLOW CONTROL AND BYPASS VALVES. IN *DDITION, A WALKDOWN OF THE SECONDARY SIDE WILL 8E PERFORMED OURING 100% POWER OPERATION TO

  ,,                   IDENTIFY SIMILAR CONTROL AIR ARRANGEMENTS THAT MAT 8E AFFECTED SY I

EXCESSIVE VIBRATION. 1 ke FORM 170 LER SC55 DATA 04-18-91 si 0**************************************************************** *** DOCKET TEAR LER NUM8ER REVISION DCS NUMBER N5IC EVENT OATE

  ,,                      445      1990         002                  0      9004170049 217600                  03/05/90
                     . *..+............. *..........***** ****. **ee.... ***********e....

8 4857RACT POWER LEVEL - 000t. At 0155 CST ON 3/5/90, WHILE CONDUCTING COLO R00

  ,                    OROP YESTING, A BLOWN FUSE IN INVERTER IV1PC1 RESULTED IN A REACTOR TRIP AND A SOURCE RANGE FLUX DOUSLING (SRFD) SIGNAL. THE DISTRIBUTION
  '

PANEL 50ARD WAS RE-ENERGIIED ON ALTERNATE POWER. THIS RE-ENERGIIATION CAUSED A MOMENTARY SPIKE ON A WIDE RANGE REACTOR COOLANT SYSTEM (RCS)

PRESSURE CHANNEL WHICH CLOSED THE RESIOUAL HEAT REMOVAL (RHR) NOT LEG SUCTION VALVE, RESULTING IN THE TEMPORART LOSS OF $HUTOOWN COOLING. 5HUTOOWN COOLING WAS RESTORED AT 0228 CST ON 3/5/90. AT APPROEIMATELY

  ,                    0248 CST, AFTER VERIFTING THAT INDICATION WAS APPROPRIATE FOR PLANT CONDITIONS, THE SRF0 $1GNAL WAS RESET AND AFFECTED COMPONENTS RESTORED
  '                    TO THEIR ORIGINAL POSITION. THE ROOT CAUSE FOR THE FUSE FAILURE HAS NOT BEEN DETERMINED. THE POSSISLE CAUSE5 IDENTIFIED INCLUDE FAILURE OF THE FERRO-RES3NANT TRANSFORMER, AND LOOSE CONNECTIONS IN THE GATING CIRCUIT. CORRECT!YE ACTIONS INCLUCED THE REPLACEMENT OF THE FERRO-RE$0NANT TRANSFORMER AND A REWORK OF ALL LOOSE CONNECTIONS IN
      ,                THE INVERTER. A DETAILED v!SUAL INSPECTION OF THE THREE OTHER SIMILAR INVERTERS WILL SE PERFORME0 DURING THE NEXT COLD SHUTDOWN OF SUFFICIENT CURATION. THIS INSPECTION WILL INCLUDE THE VERIFICATION OF
      ,                ALL 80LTED AND SOLDERED CONNECTIONS IN THE INVERTERS.

t g FORM 171 LER SC55 04TA 04-18-91 0*****************+**++.******+=***++ ********+.****+++++++++++++++++

p4 ADSTRACT POWER LEVEL - 0073. AT APPROXIMATELY 1715 CST ON 4/21/90, WHILE g4 OUSTING THE MAIN C0HT20L 80420, THE #EACTOR OPERATOR ACCIDENTALLY SUMPE0 SWITCH 1/1-N-338 AND RESET SOURCE RANGE CHANNEL N31 WHICH HAD

   >*         8EEN PREVIOUSLY STPA5550 FOR POWER OPERATION. RE-ENERGIZING THE SOURCE RANGE HIGH VOLTAGE POWER SUPPLY WHILE OPERATING AT 7X POWER i          EXCEEDED THE REACTOR TRIP SETPOINT AND GENERATED A REACTOR TRIP

,' eq SIGNAL. THE REACTOR TRIP COINCIDENT WITH A LOW-AVERAGE REACTOR COOLANT SYSTEM (RCS) TEMPERATURE GENERATED A FEEDWATER ISOLATION L4 SIGNAL. DURING REACTOR TRIP RECOVERY, THE AUXILIARY BOILER FAILED TO START DUE TO A FAULTY IGNITER ASSEMBLY AND RESULTED IN A SLIGHT ! b4 DECREASE IN RCS TEMPERATURE PRIOR TO THE PLANT SEING STABILIZED IN MODE 3. CORRECTIVE ACTIONS FOR THIS EVENT INCLUDED THE REMOWAL OF CLEANING 8 RUSHES FROM THE CONTROL ROOM AND THE SUSPENSION OF ALL be CONTROL 80ARD CLEANING UNTIL AN ALTERNATIVE METHOD IS IMPLEMENTED. ADDITIONALLY, A PLEXIGLASS COVER HAS SEEN PLACED OVER THE INVOLVED U" SWITCH UNTIL AN EVALUATION IS COMPLETED TO DETERMINE IF THE SWITCH IS OVERLY SENSITIVE AND WHY SUMPING THE SWITCH CAUSED THE SOURCE RANGE CHANNEL TO RESET. b4 1 p, FORM 172 LER SC55 OATA 0************************************************************04-18-91******** 88 00CAET TEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 445 1990 013 0 9006140199 218559 05/09/90 R1 i ABSTRACT

' ,          POWER LEVEL - 04St. AT APPROX. 1504 COT ON 5/9/90, WHILE USING A g        PROCEDURE, WRITTEN FOR MODE 5 COLD SHuTOOWN, OR MODE 6 REFUELING, TO CALIBRATE A FEEDWATER PUMP OISCHARGE PRES $Uk* TRANSMITTER, JUMPERS
 '  D' WERE INSTALLE0 ACROSS THE FEE 0 WATER PUMP SPLEO CONTROLLERS WHILE THEY WERE SEING USE0 TO MAINTAIN FEE 0 WATER PUMP SPEED OURING MODE 1 POWER se       OPERATION. INSTALLATI04 0F THE JUMPERS CAUSED A COAST 00WN OF THE FEE 0 WATER PUMPS, RESULTING IN A LOSS OF FEE 0 WATER FLOW AND REDUCTION
           OF STEAM GENERATOR WATER LEVELS.       AN AUTOMATIC REACTOR TRIP OCCURRED WHEN THE STEAM GENERATOR WATER LEVEL LOW-LOW TRIP SETPOINT WAS REACHEO. PLANT RECOVERY WAS COMPLETED WITHOUT FURTHER INCIDENT OR D

UNEAPECTED FINDINGS. THE ROOT CAUSE OF THE EVENT HAS SEEN DETERMINED TO SE AN INADEQUATE REVIEW AND APPROVAL PROCESS FOR CERTAIN PROCEDURE

    ,        CHANGES. AS CORRECTIVE ACTIONS FOR TMIS EVENT, A PROCEDURE REVISION WILL ENSURE TECHNICAL REVIEWS AND OPERATIONAL IMPACT ASSESSMENTS ARE
    '        PERFORME3 FOR MODE APPLICA8ILITY INTERPRETATIONS. GENERIC CORRECTIVE 4

ACTIONS WILL INCREA5E SENSITIVITY TO THE IMPACT THAT NON-5AFETT COMPONENTS CAN HAVE ON AN OPERATING PLANT. THE SINGLE POINT FAILURE t ANALYSIS, WHICH IDENTIFIES THESE COMPONENTS, WILL SE UTILIIED PROGRAMMATICALLY.

    . 1 FORM    173                  LER SCSS DATA                         04-18-91 0********************************************************************

00CAET VEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE 445 1990 017 0 9006290113 218774 05/27/90 AB5 TRACT POWER LEVEL - 0433. ON 5/27/90, AT 0126 WHILE PERFORMING STEAM i GENERATOR ATMOSPHERIC RELIEF VALVE (ARV) CAPACITY TESTING, A MAIN g; FEE 0 WATER FLOW CONTROL VALVE (FCV) FAILED CLOSEO. THIS RESULTED IN

REOUCED FEE 0 WATER FLOW AND DECREASING STEAM GENERATOR (SG) NO. 3 WATER g LEVEL. THE OPERATOR CLOSED THE ARV, WHICH WAS OPEN FOR TEST

    .        PURPOSES, AND STARTED TO MANUALLY RAMP 00WN TME mATN vnentwe vn eenore

                  .. ots . 2.. ei ascs, wn;S Nu. 3 SG DATER LEVEL RE&CNED APPROXIMATELY 30% (AUTOMATIC REACTOR TRID 15 A T 291 SG WATER LEVEL), TH! 09ERATOR P1              MANUALLY TRIPPED THE REACTOR. ALL OTHER OLANT SYSTEMS OPERATED PROPERLY.        THE CAUSE OF THE EVENT WAS THE FAILURE OF A SOLEN 0ID VALVE C0IL, ASSOCIATED WITH NO. 3 SG FCV, 002 TO RAIN WATER INYCUSIOM (FCW'S li' ARE LOCATED OUTSIDE).        A TEMPORARILY REMOVED COVER ALLOWED WATER TO 54 ENTER A JUNCTION 80x THEN ORAIN VIA CONOUIT TO THE 50LEN010 COIL i

HOUSING. CORRECTIVE ACTION INCLUDED THE REPLACEMENT OF THE FAILED

 ,        3,      50LEN010 COIL AND INSPECTION OF THE OTHER SOLEN 0 IDS FOR WATER / MOISTURE pq               INTRUSION. AN EVALUATION WILL DETERMINE IF ADDITIONAL CRITICAL COMPONENTS EXIST IN A SIMILAR CONFIGURATION. GUIDANCE FOR THE CONDUCT i;

0F OUYD00R MAINTENANCE ACTIVITIES WILL BE ADDRESSED PR0 GRAMMATICALLY. be :, FORM 174 LER SCSS DATA 0************************************************************04-18-91 ******** ke DOCKET TEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE

          .,       445      1990         023          0     9009100049 220895              08/08/90 he            ********************************************************************

i, ASSTRACT kg POWER LEVEL - 017%. ON 8/9/90, COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 WAS IN MODE 1, POWER OPERATIONS, WITH REACTOR POWER AT 171. A p,f LOOSE FUSE IN THE MAIN FEEDWATER CONTROL POWER CIRCUIT CAUSED CLOSURE OF A VALVE IN THE FEE 0 WATER FLOW PATH TO STEAM GENERATOR NUMBER 4 88 WATER LEVEL IN STEAM GENERATOR NUMBER 4 DECREASED TO THE LO-LO LEVEL q, SETPOINT, INITIATING A REACTOR TRIP SIGNAL. CORRECTIVE ACTIONS INCLUDED INSPECTION OF SIMILAR COMPONENTS IN OTHER APPLICATIONS, p1 MAINTENANCE ON THE MALFUNCTIONING COMPONENT, AND PERSONNEL TRAINING.

          ;,  1 FORM       175                  LER SCSS DATA                              04-18-91 I
          ;,  0********************************************************************
  >*            DOCKET TEAR LER NUMBER REVISION DCS NUMBER              NSIC            EVENT DATE 445      1990         025          0     9010010186 219626              08/25/90 g,      3     ********************************************************************

A85 TRACT POWER LEVEL - 0974. AT APPR0xEMATELY 0037 ON 8/25/90, STEAM GENERATOR (SG) NUM8ER 2 FEEDWATER FLOW CONTROL VALVE (FCV) FAILED FULL OPEN. 4 8 REACTOR OPERATOR ATTEMP1ED TO CLOSE THE VALVE FROM THE MAIN CONTROL 80ARD 87 REDUCING THE DEMAND SIGNAL / HOWEVER, AT 0038, A TUR8INE TRIP

  ,              $1GNAL AND FEE 3 WATER ISOLATION SIGNAL WAS GENERATED DUE TO PROTECTION SYSTEM INTERLOCK P-14, HI-HI LEVEL IN SG NUMBER 2.           THE REACTOR
  '              TRIPPED AT G038 DUE TO THE TUR8INE TRIP SINCE REACTOR POWER WAS ABOVE THE P-9 SETPOINT OF 50%. THE CAUSE OF THE FEE 0 WATER FCV FAILURE IS ATTRIBUTED TO THE FEE 08ACK LINEAGE ARM FROM THE VALVE STEM TO THE 8

VALVE POSITIONER SEPARATING OUE TO FLOW INDUCED OSCILLATIONS.

  ;              CORRECTIVE ACTIONS INCLUDE THE INSTALLATION OF A LOCK WASHER 04 THE i              FEED 8ACK LINKAGE ARM AND A DESIGN MODIFICATION TO MODIFY THE VALVE
        ,        INTERNALS 70 REDUCE FLOW INDUCED OSCILLATIONS.

1

        ,       FORM       176                  LER SCSS DATA                              04-18-91 0********************************************************************

DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

       ,           445      1990         027          0    9010300042 219940               09/07/90
       ,        A85 TRACT POWER LEVEL - 100%. 04 9/7/90, AT 0033, COMANCHE PEAK STEAM ELECTRIC STATICN (CPSES) UNIT 1 STEAM GENERATOR (SG) NUMBER (No.) 2 FEEDWATER f         FLOW CONTROL VALVE (FCV) FAILED FULL OPEN DUE To SHEARING OF THE
   ,             POSITIONER FEED 9ACK LINEAGE ARM. THE FAILE0 VaLVS OVERSEE 0 SG No. 2

                                                                                                                      . ==.

asao.La*Lu at JugJ IN MJut 5. af 0130, 4 94 LANCE Oc PLtNT REACTOR OPERAT3R (RO) DECREASED sut!tIART FEEDWATER FLOW TO SG NO. 4 SINCE THE y1 LEVEL WAS INCREASING FASTER THAN THE OTHER THREE. AT 0232, A RELIEF RO NOTED THAT SG NO. 4 LEVEL WAS APPROACHING THE LO-LO LEVEL SETPOINT h4 Ar0 IECREASED AUXILIARY FEEDWATER FLOW. THE LOW LEVEL COMSINED WITH qg THE INCREASED FLOW WHICH CAU5ED A "5HRINK AND SWELL" EFFECT IM SG NO. h8 4 RESULTED IN LO-LO LEVEL SIGNAL WHICH GENERATED AN AUTOMATIC START

                     $IGNAL FOR THE AUXILIARY FEE 0 WATER SYSTEM. THE CAUSE OF THE LINEAGE i
             ).      ARM FAILURE 15 ATTRIBUTED TO FATIGUE RESULTING FROM FLOW INDICED pq                 OSCILLATIONS. CORRECTIVE ACTIONS INCLUDE REPAIR OF SG NO. 2 FCV AND A DESIGN MODIFICATION TO MODIFY THE VALVE INTERNALS TO REDUCE FLOW g g;         INDUCED OSCILLATIONS.

he ;: FORM 177 LER SC55 OATA 0************************************************************04-15-91 ******** b, 00CKET TEAR LER NUMBER REv!5 ION OCS NUMBER NSIC EVENT DATE i, 445 1990 028 0 9010220016 219779 09/05/90 his ********************************************************************

             ..'"   ABSTRACT be               POWER LEVEL - 0352. AT 1428 ON SEPTEMSER E, 1990, COMANCHE PEAK STEAM ELECTRIC STATION UNIT 1 WAS AUTOMATICALLY TRIPPED FROM 38 PERCENT g,        ,'      POWER. A LIGHTNING STRIKE IS BELIEVED TO HAVE CAUSED A SURGE IN THE INPUT POWER RESULTING IN THE DE-ENE:CIIATION OF POWER SUPPLIES IN THE ROD ORIVE SYSTEM, CAUSING THE R005 CONTROLLED ST ONE R00 CONTROL D4               CASINET TO OROP INTO THE CORE. THIS RESULTED IN THE REACTOR TRIP FORM HIGH NEGATIVE FLUX RATE. NO SPECIFIC COMPONENT OR SYSTEM FAILURES p1               WERE IDENTIFIED AS THE CAUSE OF THIS EVENT. THE INSTALLATION OF SURGE SUPPRESSORS IN THE INPUT SUPPLY TO ROD DRIVE POWER SUPPLIES WILL
    ,,               PROVIDE ADDITIONAL AS5URANCE THAT POWER SUPPLIES REMAIN AVAILABLE DURING LIGHTNING STRIKES.

1 4e FORM 178 LER SC55 DATA 04-1E-91

c. 0********************************************************************

DOCKET TEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE 445 1990 029 0 9010160286 219780 09/10/90 I 4857aACT POWER LEVEL - 0921. ON SEPTEMBER 10, 1990, AT 0917 COT, C0HANCHE PEAK

    ,                STEAM ELECTRIC STATION UNIT 1 EXPERIENCE 0 A REACTOR TRIP FROM MODE 1, POWER OPERATIONS.          THE REACTOR TRIP WAS CAUSED BY A TUR5INE TRIP WHICH RESULTED FROM A HIGH LEVEL CONDITION IN THE B MOISTURE SEPARATOR REMEATER (MSR). THE HIGH LEVEL IN THE MSR OCCURRED WHEN AN OPERATOR ATTEMPTED TO RESTORE A SEPARATOR ORAIN TANK DRAIN VALVE TO SERVICE
           ,         WHILE THE DRAIN VALVE WAS STILL ISOLATED.            THE EVENT WAS CAUSED ST THE FAILURE OF OPERATORS TO ADEQUATELY VERIFT COMPONENT STATUS PRIOR 70 i
     ,               RETURNING THE COMPONENT 10 SERVICE. CORRECTIVE ACTIONS TAKEN INCLUDE
           ,         REVIEW OF THE LESSONS LEARNED PACKAGE ST OPERATOR 5 AND INDIVIOUAL COUNSELING.
    '             1 FORM     179                     LER SCSS DATA                         04-15-91 0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 445 1990 033 0 9010260117 219941 09/15190 ABSTRACT

e POWER LEVEL - 0541. CN 9/15190, COMANCHE PEAK STEAM ELECTRIC STATION g UNIT 1 WAS IN MODE 1, POWER OPERATION, WITH REACTOR POWER AT 54t.

OPERATIONS PERSONNEL WERE PREPAeING TO RAT 5F erarToo onwee va o'**a**

r otu==sta euw IkirPcJ. 45 4 RESULT OF OECREASING STES" GENERATOR LEVELS, A MANUAL REACTOR TRIP WAS INITIATED. THE CAUSE 0" THE EVENT P -4 WAS AN IMPROPERLY ROUIED MEAT 0R414 PUMP SHIELD GROUNC LEAD WHICH CAUSED A FALSE GROUNO 07ERCURRENT SIGNAL. CORRECTIVE ACTION INCLUDED g4 REUCRK OF THE AFFECTED C0KPONENT AND REVIEW OF SIMILAR COMPONENTS FOR g THE SAME PROBLEM. 1 kW

  .             FORM       180                  LER SCSS DATA eq          0************************************************************04-18-91  ********

DOCKET TEAR LER NUMSER REVISION OCS NUMBER NSIC EVENT DATE g, ,; 454 1989 002 0 8903100242 213279 01131/

                ******************************************************************89        **

kW . ' ABSTRACT

POWER LEVEL - 099%. UNIT 1 WAS OPERATING AT 99% POWER AT 0956 ON gn 1#31189, WHEN THE REACTOR TRIPPED MANUALLY. LEVEL IN STEAM GENERATOR 1C WA5 INCREASING BECAUSE ITS FEEDWATER REGULATING VALVE (1FW530) HAD

  ""              FAILED FULLY OPEN. THE VALVE WOULD NOT RESPOND TO AUTOMATIC OR MANUAL CONTROLS.       THE REACTOR TRIP WAS PRUDENT BECAUSE STEAM GENERATOR 1C bg             LEVEL WAS RAPIOLT APPROACHING ITS HIGH-LEVEL AUTOMATIC FEEDWATER ISOLATION SETPOINT (P-14). ALL SAFETY SYSTEMS FUNCTIONEO 45 DESIGNED.

THE UNIT WAS STASILIZED IN HOT STANOST AT APPROEIMATELT 1114. De i. FEE 0 WATER REGULATING VALVE 1F2530 WAS FOUND TO HAVE IT$ VALVE POSITIONER FEED 8ACK ARM DISENGAGED FROM THE VALVE FOLLOWER. NEITHER 88 MANUAL NOR AUTOMATIC CONTROL WAS POS$1SLE WITH THE VALVE IN THIS CONDITION. THE WALVE POSITIONER WAS RECONNECTED USING LOCETITE AND A STAR WASHER TO PREVENT FUTURE FAILURES. SIMILAR PREVENTATIVE ACTION 31 WAS PERFORMED ON THE REMAINING REGULATING VALVES ON BOTH UNITS. 1

   '            FORM       181                 LER SCSS DATA                         04-18-91 0********************************************************************

be 00CKEY TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 454 1990 002 0 9006100463 217602 03/01/90 t, ******************************************************************** A85 TRACT POWER LEVEL - 000%. 04 3/1/90, AT 0939, WHILE IN MODE 2, A UNIT 1 I REACTOR TRIP OCCURRED WHEN THE 2 OUT OF 4 COINCIDENCE WAS SATISFIED ON OVER TEMPERATURE DELTA TEMPERATURE (OT OELTA T). THE FAILURE OF THE LOOP 15 REACTOR COOLANT RESISTANCE TEM *ERATURE DETECTOR AMPLIFIER CARD CONCURRENT WITH THE PREVIOUSLY TRIPPED LOOP 14 815 TABLES, WHICH WAS NECESSART TO ACCOMMODATE LOW POWER PHYSICS TESTING, SATISFIED THE TRIP LOGIC. THE FAILED CARD WAS REPLACE 0 SUT THE ROOT CAUSE OF THE I ' FAILURE IS INDETERMINATE. ALL SYSTEMS RESPONDED AS REQUIRE 0, AND THE UNIT WAS STABILIZED IN MODE 3. THIS EVENT IS REPORTA8LE PER 10CFR 8 50.73(A)(2)(IV) FOR AN EVENT THAT RESULTED IN AUTOMATIC ACTUATION OF AN ENGINEERED SAFETY FEATURE INCLUDING THE REACTOR PROTECTION SYSTEM.

   ,          1 FORM      182                  LER SCSS OATA                         04-13-91 0********************************************************************

DOCKET TEAR LER NUMBER REv!SION DC1 NUMBER NSIC EVENT DATE r 454 1990 006 0 9006030273 219397 05/03/90

   ,            A85 TRACT POWER LEVEL - 0792. ON 5#03/90, AT 0300, WITH UNIT 1 OPERATING ST 791 I
        ,        POWER, THE OPERATING OEPARTMENT BEGAN SURVEILLANCE ISOS 3.4.2.4-1,
  +
                 "TUR8INE THROTTLE, GOVERNOR, REHEAT, AND INTERCEPT VALVE MONTHLT 4             SURVEILLANCE." AT 0359, THE SURVEILLANCE WAS HELO 10 ACCOMMODATE 4        TROU8LESH00 TING ON THE TURBINE DIGITAL ELECTRO-HTDRAULIC COMPUTER
   ,             (DEHC).       QUE TO THE REPEATED sAILURE OF A 2 AMPEo? s 'l t s og 1 as &

_ . _ ~_ ___ - _____-___ _ _ _ _ _ _ _ - _ _ _ _ _ - _ _ _ _ _ _ _ _ - - - _ - _ _ _ _ _ . _ - - _ _ _ - - _ - _ . _ - - _ - __ - - . - _ _ _ . 5

                 .. ......-    .s. w.   :4 Lcn* -44cL w.S L0ST. THE 3 AMPER: FUSE 0 '4 THE j               SAHE CARD WAS ELOWN.           AS A DEPLACEMENT FUSE WAS INSERTED, A 103

, Pt PEGAWATT POW!R EXCURSION 3CCURRED, FOLLOWED BY A COMPLETE LO4D REJECTION. At 0651, A REACTOR TRIP OCCURRED ON LOW-2 STE44 GENERATOR gg LEVEL. THE 2 AMPERE FUSE FAILED DUE TO A SHORT CIRCUIT IN THE PUSH 90TTON. THE BUTTON WAS EQUIPPED WITH 4 GROUNDED COPPER SCREEN. WHEN THE BUTTON W45 MOVED INSIDE THE SOCKET, THE SCREEN CAME IN b4 CONTACT WITH THE PUSHSUTTON LIGHT'S POWER SUPPLY WHICH INDUCEO A SHORT

  ?     ,

AND SLEW THE FUSE. ROOT CAUSE FOR THE 5 AMPERE FUSE FAILURE AND P1 SUB5EQUENT REACTOR TRIP REMAIN INDETERMINATE. AS CORRECTIVE ACTION, SCREENS IN ALL THE PU5HBUTTONS WERE REMOVED. LIGHTING CIRCUIT W45 gq : ALSO REWIRED TO SE MADE SEPAR4TE FROM THE RUN8ACK CIRCUITRY 50 A LOSS OF INDICATION WILL NOT EFFECT A RUNBACK $IGNAL. 1 ha ; FORM 183 LER SC55 OATA

                                                 ............ .................... 04-18-91 be        0...............ee.......e                                                                ........

DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 1 454 1990 011 1 9103010259 221135 08/19190 D* e................................................................... bw ABSTRACT POWER LEVEL - 075%. AT 0425 ON AUGUST 19, 1990, WITH SEVERE LIGHTNING g: ACTIVITY NEAR SYRON STATION, A UNIT 1 REACTOR TRIP OCCURRED FROM 78% POWER. A LIGHTNING STRIKE INDUCED A VOLTAGE SURGE THAT ACTIVATED MINE

             OUT OF TEN OVER-WOLTAGE PROTECTION DEVICES INSTALLED ON POWER SUPPLIES 4

IN THE ROD ORIVE (RD) (A4) POWER CASINETS. THIS ACTIVATION RELEASED TWELVE OUT OF FIFTEEN ROD CONTROL CLUSTER ASSEMBLT GROUPS INTO THE t4 CORE AND RESULTED IN A HIGH NEGATIVE FLUX RATE REACTOR TRIP. DUE TO SEVERAL COMMONWEALTH EDISON AND INDUSTRY WIDE LIGHTNING INDUCED

   ,           REACTOR TRIPS, SEVERAL MODIFICATIONS HAVE PREVIOU5LY SEEN MADE TO BOTH

THE CONTAINMENT LIGHTNING PROTECTION SYSTEM AND THE ROD DRIVE OVER VOLTAGE PROTECTOR 5. THE ROD DRIVE SYSTEM WILL BE FURTHER M00TFIED 8'

WITH A NEW MODEL OF POWER SUPPLY TH4T 15 LESS LIKELY TO CAUSE REACTOR TRIP AFTER A TRANSIENT CAUSED BY LIGHTNING. THIS EVENT 15 REPORTABLE

t. PURSU4NT TO 10CFR50.73 ( A)(2)(IV) A5 4 RESULT OF THE AUTOMATIC ACTUATION OF THE REACTOR PROTECTION SYSTEM.

pe ' FORM 184 LER SC55 DATA 04-18-91 o 0..........................*** ...................................... DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

   ,            454       1990          014          0         9101090154 220634                      12/03/90 eeeeeeen.......eeeeeeeeee.....e***.**.ee               ..e***e.eeeeeeeeee e.eeen.

ABSTRACT POWER LEVEL - 0983. ON 12/3/90, AT 1240 WHILE PERFORMING SCHEDULED SLAVE RELAY SURVEILLANCE 1805 3.2.1-950 " UNIT ONE ENGINEERED SAFEGUARO FEATURES ACTUATION SYSTEM INSTRUMENTATION SLAVE RELAY SURVEILLANCE

   ,           (TRAIN A FEE 0W4TER ISOLATION, REACTOR TRIP K637)" 4N ACTUAL FEEDW4TER (FW) (5J) ISCL4 TION SIGNAL (FWI) WAS GENERATED CAUSING A LOSS 08 FEE 0 WATER. A REACTOR TRIP ON LOW-2 STEAM GENERATOR LEVEL IN THE 10 STEAM GENERATOR ENSUED. ALL COMPONENTS ASSOCIATED WITH A FWI/ REACTOR TRIP RESPONDED AS EXPECTED WITH THE EXCEPTION OF VALVE 1FWO39A WHICH HAD Duel POSITION INDICATION. DURING PERFORMANCE OF THE SURVEILLANCE, SWITCH 5817 15 PLACED IN A " PUSH TO TEST" POSITION. AFTER PUSHING IN THE SWITCH AND WERIFYING INDICATIONS, THE SYSTEM MUST BE RESTORED BY RESETTING THRE! SWITCHES IN SEQUENCE. 5817 IS ONE OF THE THREE SWITCHES AND SHOULD BE THE LAST TO BE RESTORED TO ITS NORMAL POSITION.

CONTRARY TO THE PROCEDURE, THE 5817 SWITCH WAS RESTORED TO 175 NORMAL POSITION FIRST IMMEDIATELY AFTER THE " PUSH TO TEST" STEP WAS

   *.          PERFORMED. THE FEEDW4TER ISOLATION CCCURRED SEVERAL STEPS LATER WHEN
      ,        THE SWITCH THAT IS NORMALLT FIRST TO BE RESET WAS RESET SEC040. THE FW ISOLATION AUEILIARY REL4Y5 ARE A L4TCHING TYPE 449 Han Not es*4 l

t

pe FORM 185 LIE SCSS DATA 04-1E-91 De*eeeeeeeeeeeeeeeeeeeeeeeeeeee..ee**eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeen

CCCKET TEA 2 LER NUMBE2 REv!SIOU DCS NUMBER 455 1990 001 NSIC EVENT OATE

       .g                                       0      9002220074 216934          0

>n

             ................e**    ...... ** .........**......... ....**ee..1/18190 ......

A85 TRACT pq POWER LEVEL - 0991. ON 1/18/90, UNIT 2 WAS OPERATING AT 99% POWER. AN INSTRUMENT MAINTENANCE TECHNICIAN WAS PERFORMING A FUNCTIONAL b" N SURVEILLANCE ON STEAM PRESSURE CHANNEL 526 WHEN CHANNEL $25 SPIKED LOW. A REACTOR TRIP AND SAFETT INJECTION FOLLOWED. THE MOST PROSABLE be CAUSE OF THE EVENT WAS THE FAILURE OF THE 525 PRESSURE TRANSMITTER. y; THE TRANSMITTER WAS REPLACED, AND THE So! KING HAS NOT RECURRED. THIS IS THE FIRST TIME THE COINCIDENCE WAS SATISFIED DURING A PRESSURE ke TRANSMITIER FAILURE AND RESULTED IN A REACTOR TRIP. THIS EVENT IS 33 REPORT 48LE PER 10CFR50.73(A)(2)(IV) FOR ANT EVENT OR CONDITION THAT be RESULTED IN MANUAL OR AUTOMATIC ACTUATION OF ANT ENGINEERED SAFETT FEATURE, INCLUDING THE REACTOR PROTECTION SYSTEM.

,,    l' FORM     186                  LER SCSS DATA p,q.       0************************************************************04-18-91   ********

DOCKEY TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 655 1993 010 0 9101220502 220832 12/20/90 84 ;, .................................................................... 31 A85 TRACT POWER LEVEL - 072%. 04 DECEMBER 20, 1990 AT 0400, A SEVERE STEAM LEAK ,, WAS REPORTED IN THE UNIT 2 MAIN STEAM TUNNEL. AFTER VERIFYING THE ' SIZE OF THE LEAK, THE REACTOR WAS MANUALLY TRIPPED. BT ELIMINATING STEAM GENERATOR BLOWOOWN AND FEE 0 WATER AS CAUSES, IT WAS DETERMINED bi THAT THE LEAK WAS ON THE MAIN STEAM SIDE. THE MAIN STEnd ISOLATION VALVES WERE THEN CLOSED WHICH ISCLATED THE LEAK. THE MAIN STEAM DUMPS

y. WERE OPENED TO DEPRESSURIZE THE MAIN STEAM HEADER. UPON ENTRT INTO THE MAIN STEAM TUNNEL, THE 2C MAIN STEAM SAMPLE PROBE WAS FOUND LYING ON THE FLOOR. THE WELD FOR THE PROSE HAD 8EEN IMPROPERLT REPAIRED I'

DURING THE PREVIOUS REFUELING OUTAGE CAUSING THE PROSE AND ITS ISOLATION VALVE TO BE EJECTED LEAVING A ONE INCH HOLE IN THE MAIN 6 STEAM LINE. SINCE THIS PROSE WAS NEE 9ED ONLY FOR INITIAL START-UP TESTING, TME N31ZLE WAS CAPPED. THIS EVENT IS REPORTA8LE PURSUENT TO

,,            10CFR53.73(A)(2)(IV) ANY EVENT THAT RESULTS IN A MANUAL OR AUTOMATIC ACTUATIO4 0F THE ENGINEERING SAFETT FEATURES INCLUDING REACTOR PROTECTION SYSTEM.

1 e FORM 187 LER SCSS DATA 04-18-91 0************************************************************.*******

,           DOCKET TEAR LER NUMBER REVISION DCS NUMBER               NSIC       EVENT DATE
    ,           456   1989       004           0      8904130103 213621           03/06/59
    ,       ABSTRACT POWER LEVEL - 097%. AT 0100 04 3#6189 A SURVEILLANCE WAS IN PROGRESS TO TEST TRAIN 5 TUR81NE TRIP RELAY K640. CURING THE INITIAL
    ,        PREPARATION STEPS OF THE PROCECURE THE INTERFACE DIAPHRAGM VALVE TEST VALVE CONTROL SWITCH, CS/Dvi, IS TAKEN FROM THE NORM (NORMAL) TO THE PERM (PERMISSIVE) POSITION. THE PERM SET (TEST PERMISSIVE ENABLEO) g        LIGHT IS VERIFIED ILLU4INATED ON THE CONTROL PANEL. THIS INITIAL SETUP PROVIDES FOR TESTING WITHOUT TRIPPING THE MAIN TURBINE. AY e-            0154, A NUCLEAR STATION OPERATOR DEPRESSED THE RELAY TEST SWITCH. THE gy       GOVERNOR VALVES DRIFTED TO THE CLOSED POSITION, THE CLOSURE OF THE

, GOVERNOR WALVES RESULTED IN A DECFEASE IN STEA= FLOW AND AN TNC#8ste

                     ....c.nw      sa sa: Luw Lud L:Vit 3EACTOR TOID SETPOINT AND THE REACTOR TRIPPE0, TUR31NE TRIPP!0, AND YHT AUXILIARY *E!]WAT*P PUMPS AUTO
   >g                 STARTE3. THE CAUSE 08 THIS EVENT WAS A DEFECTIVE TEST SWITCH, C5#0VT.

THE FAILURE OF THE SUITCH RESULTED IN THE CONTROL SYSTEM REDUCING 4 kW THE GOVE:%0R VALVE POSITION LIMITS TO ZERO. THE SWITCH WILL 8E p REPLACEO. EVENT. PREVIOUS EVENT CORRECTIVE ACTION WAS NOT APPLICABLE TO THIS , b4 1 l eq PORM 188 LER SC55 DATA 04-18-91 0........................................................... ........ g4 gi ' DOCKET YEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 456 1989 006 0 8909220405 215050 i UU

                  ************************************************************07/18/89        ********

2 ll i ABSTRACT tm POWER LEVEL - 056%. AT 2020 AND 2026 ON 7/18/89 THE STATION l! EXPERIENCED LIGHTNING INDUCEO YOLTAGE TRANSIENTS CAUSING MULTIPLE ROD h4 ORIVE OVERVOLTAGE PROTECTION DEVICES TO ACTUATE ON UNIT 1 AND 2, RESPECTIVELY. ON UNIT 1 TEN OUT OF TEN OVERVOLTAGE PROTECTORS 3, bg ACTUATED. ON UNIT 2 SEVEN OUT OF TEN OVERVOLTAGE PROTECTORS ACTUATE 0. THIS REMOVED POWER TO W ARIOUS R00 ORIVE CONTROL C ARDS AND ALLOWED NUMEROUS CONTROL R005 70 OROP. 80TH REACTORS TRIPPED 00E TO NEGATIVE gg RATE TRIP ON THE POWER RANGE. IMMEDIATE CORRECTIVE ACTIONS WERE TO STASILIIE THE PLANT, RESET THE OVERVOLTAGE PROTECTORS, AND VERIFY ROD I' CONTROL OPERASILITY. THE EXACT LOCATION OF THE LIGHTNING STRIKES ARE r UNKNOWN. THE ROOT CAUSE 15 INADEQUATE PROTECTION AND ISOLATION OF THE ROD CONTROL SYSTEM FROM LIGHTNING INDUCE 0 TRAN5IENTS. THE IMMEDIATE D1 CORRECTIVE ACTIONS WERE TO RESET THE OVERVOLTAGE PROTECTOR 5. NO DAMAGE OCCURREO TO THE ROD CONTROL SYSTEM. THERE HAS SEEN ONE

   ,,                PREVIOUS OCCURRENCE OF A LIGHTNING INDUCEO VOLTAGE TRAN5IENT RESULTING g                 IN A REACTOR TRIP. CORRECTIVE ACTIONS WERE IMPLEMENTED ADDRESSING b'                80TH ROOT AND CONTRIBUTING CAUSES FOR THE ABOVE EVENT. THE PREVIOUS CORRECTIVE ACTIONS ARE NOT APPLICABLE TO THIS EVENT.

1 t4 FORM 189 LER SCSS DATA 04-18-91

0********************************************************************

DOCKET YEAR LER NUMBER REv!SION DCS NUM8ER NSIC EVENT OATE 456 1990 001 0 9002230074 216935 01/12/90 t

                  ...................*.. * ..........**** ........*................ e
   , ,            A85 TRACT POWER LEVEL - 099X. A DC GROUND INVESTIGATION WAS IN PROGRESS ON 125V
   ' '              DC BUS 114 IN ACCORDANCE WITH PROCEDURE. AN EQUI

MENT OPERATOR (EO)

AND A SHIFT FOREMAN WERE SYSTEMATICALLY ISOLATING AND RESTORING LOADS TO IDENTIFY THE GROUNO. CIRCUIT NUMSER 19 WAS IDENTIFIED A5 THE PEED ' ' TO THE GENERATOR RELAY NORMAL POWER. THE PROCEDURE SPECIFIED TRANSFERRING TO RESERVE POWER USING A DE AD BUS TR ANSFER PROCEDURE. AT 1324 THE EO OPENED CIRCUIT NUMBER 19 PER PROCEDURE. WHEN THE CIRCUIT WAS OPENED AN AUXILIARY RELAY WA5 DE!NERGIZED WHICH PROVIDED INPUT TO ELECTRO-HYORAULIC CONTROL SYSTEM (DEHC). WHEN TH8 RELAY DEENERGIIED THE DEHC SYSTEM SENSED THAT THE MAIN GENERATOR WAS DISCONNECTED FROM THE TRAN5 MISSION SYSTEM WITH TURSINE LOAD ABOVE 303. THIS INITIATED A LOAD OROP ANTICIPATION (LOA) SEQUENCE CAUSING THE TURSINE GOVERNOR VALVES TO CLOSE. THIS CAUSED STEAM PR*$5URE TO INCREASE AND STEAM

         ,          PLOW TO DECREASE RESULTING IN A LOW LOW STEAM GENERATOR WATER LEVEL REACTOR TRIP FROM THE $4 RINK EFFECTS 04 LEVEL INDICATION. THE CAUSE OF THE EVENT WAS A PROCEDURAL DEFICIENCY. THE PROCEDURE DID NOT CAUTION THAT A4 LDA WOULO OCCUR IF TUR5INE POWER WA5 ABOVE 302. THE DC GROUND 0154PPEARED SMORTLY AFTER THE REACTOR TRIP ANO DID NOT 4

' RETURN WHEN THE UNIT RETURNED TO POWER. THE PROCEDURE H A5 SEEN f TEMPORARILY REVISED. AN EVALUATION OF THE METHODOLOGY AND CONTENT OF

  ,                 THE PROCE3URE WILL SE CONDUCTED. 40 PR*VIOUS OCCU#t*NC8%.
       .           - . . ~       .         ,-- -         _             _      -   , , - . .       _    _    ,             .         . .-.                 _ _ .. ,, _ . _

                                                                                                                                         . am
                       .      .,,                     L:s  at>> uala 0************************************************************04-1E-91                ********

^l r -9 00CKET TEAR LER HUM 5ER REVISION DCS NUM3ER NSIC EVENT DATE 456 1990 ODS 0 9007093202 218808

    ,               eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee**06/08/90               ********

A85 TRACT . b4 POWER LEVEL - 1002. ON 6/8/90 THERE WAS HEAVY THUNDERSTORM ACTIVITY IN

               ~      THE BRAIDWOOD STATION AREA. AT 0615 A REACTOR TRIP OCCURRED ON UNIT-P1                1 DUE TO A HIGH FLUX RATE TRIP SIGNAL FROM THE POWER RANGE NUCLEAR INSTRUMENTATION. THE REACTOR OPERATORS VERIFIED ALL AUTOMATIC

ACTIONS. ALL SYSTEMS FUNCTIONED AS DESIGNED. STABLE PLANT CONDITIONS WERE IMME01ATELY ESTABLISHEO. AN EXAMINATION OF THE R00 ORIVE (RO) b4 POWER CASINETS INDICATED THE POWER SUPPLY OVER WOLTAGE PROTECTORS (P50VP) HAD TRIPPED IN THREE OF THE RD CA8INETS. THERE WERE NO BLOWN FUSES IDENTIFIED IN ANT OF THE C ABINETS. THE PSOVP'S WERE RESET AND be ALL VOLTAGES WERE CHECKEO. THE ROOT CAUSE OF THIS EVENT WAS A VOLTAGE TRANSIENT. IT IS BELIEVED THAT LIGHTNING STRUCK THE UNIT 1 U" CONTAINMENT AND CAUSED A VOLTAGE SURGE IN THE STATION GROUND STSTEM.

THIS CAUSED TH! ACTIVATION OF P50VPS IN THE 3 RD POWER CASINETS. THIS

    >=               SHU T OFF THE CURRENT TO THE STATIONART GRIPPER COILS OF THE R005 POWERED 57 THE CABINETS,.AND CAUSED THEM TO DROP, RESULTING IN A NEGATIVE FLUX RATE. THE NEGATIVE FLUM RATE WAS OF SUFFICIENT g,     i MAGNITUDE TO ACTIVATE THE REACTOR TRIP SIGNAL FROM THE POWER RANGE
'                    NUCLEAR INSTRUMENTATION. NO CAMAGE OCCURRED TO THE RD STSTEM. A 88               REVIEW OF THE STATION LIGHTNING PROTECTION SYSTEM IS BEING CONOUCTED.

THE STATION HA0 MADE MODIFICATIONS TO THE RD POWER SUPPLY SYSTEM AND ye THE STATION GROUNDING SYSTEM AS CORRECTIVE MEASURES FROM P R!v1005 EVENTS. 1 FORM 191 LER SCSS DATA E D' 0************************************************************04-18-91 ******** 00CKET TEAR LER NU4BER REv!SION CCS NUMBER NSIC EVENT DATE AS6 1990 018 0 9011010038 219947 09/29/90

g. ********************************************************************

                 ABSTRACT POWER LEVEL - 092%. AT 0345 04 9/29/90 THE TRAIN 8 SOLID STATE PROTECTION SYSTEM (SSPS) INITIATED A CONTAINMENT VENTILATION ISOLATION a

SIGNAL. NO COMPONENTS REPOSITIONED AS ALL WERE IN THEIR REQUIRED STATE. AT 1735 A SPURIOUS TRAIN 8 SAFETY INJECTION SIGNAL (SI)

OCCueRED CAUSING A REACTOR TRIP AND CONTAINMENT ISOLATION TO OCCUR AS WELL AS STARTING TRAIN 8 ECCS COMPONENTS. THE B TRAIN OF SSPS WAS

    '                DECLARED INOPERABLE AND A PLANT C00LDOWN WAS INITIATED.                        AT 0013 ON 9/30/90 A REACTOR OPERATOR WAS PERFORMING AN $$PS TEST PROCEDURE WHEN THE TRAIN 5 S$PS MEMORIES TEST SWITCH WAS IMADVERTENTLT ROTATED FROM
,   s                CFF TO POSITION 23. THIS ENABLED THE PRES $URIIER AND STEAMLINE LOW PRES $URE SI AND STEAMLINE ISOLATION CIRCUITS WHICH HAD BEEN BLOCKED.
    ,                WITH BOTH PRESSURES SELOW THEIR RESPECTIVE SETPOINTS, a TRAIN 8 SI AND A STEAMLINE ISOLATION OCCURRED. DUE TO THE STEAMLINE ISOLATION, THE

RCS TEMPERATURE INCREASED ABOUT 12 DEGREES FROM 340 TO 352 F OVER THE NENT 14 MINUTES UNTIL COOLING WAS RE-ESTABLISHED. 350F IS THE LOWER j LIMIT OF MODE 3 OPERATION. AT 1020 04 10/3/90 4 SPURICUS TRAIN 8 i

FEE 0 WATER ISOLATION OCCURRED WITH THE UNIT IN COLD SHUTDOWN. THE CAUSES OF THE EVENT WERE COMPONENT FAILURE, PERSONNEL ERROR, AND COMPONENT DESIGN INTERFACE. TRAIN 8 $$PS WAS REPAIRED, TRAINING WILL SE PROVIDED, AND THE MEMORIES TEST SWITCH WAS RE-ORIENTED. 1 i FORM 192 LER SCS$ DATA 04-15-91 t 0******************************************************************** g- DOCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT CATE

   .                   456    1993      021                 0     9'.01020162 221nor                  t>sntion

POWER LEVEL - 0901. AT 1545 ON 12/1/90 THE 1B FEEDwaTER PUMP (FW), ONE Pt OF THE Tuo C4 LINE FW PUMPS, TRiop!D. THE NUCLEAR STATION OPERATOR (NS0) INITIATED A TUR$1NE RUNSACK TO 60% PO%ER IN ACCORDANCE WITH g4 PROCEDURE. STEAM GENERAT02 (SG) LEVELS DEC2 EASED DUE TO BOTH THE gi REDUCTION IN FW FLOW FROM THE LOSS OF THE FW PUMP AND THE " SHRINK" kW EFFECT ON THE SG LEVEL INSTRUMENTATION FROM THE REDUCTION IN STEAM FLOW AS A RESULT OF THE TUR8INE RUNSACK. AT 1647 THE LEVEL IN THE IS i

SG REACHED THE LO-2 REACTOR TRIP SETPOINT AND A REACTOR TRIP, TURBINE pq TRIP, FEE 0 WATER ISOLATION, AND AUX. FW AUTOMATIC INITIATION OCCURRED AS DESIGNED. ALL COMPONENTS ASSOCIATED WITH THESE ACTUATIONS ,

d ' FUNCTIONED AS DESIGNED. THE CAUSE OF THE FW PUMP TRIP WAS LOW OIL PRES $URE. IT IS BELIEVED THAT THE SUCTION OF THE HIGH PRESSURE OIL PUMP BECAME PARTIALLY PLUGGED FROM A SLUDGE SURST. THE STAN08T OIL D4 i PUMP STARTED BUT THE LOW PRES $URE "0IP" THAT OCCURRED WAS OF SUFFICIENT HAGNITUDE TO REACH THE LOW OIL PRESSURE TRIP SETPOINT. THE gg TUR8INE RUNSACK WAS INITIATED, SUT EQUILISRIUM FW FLOW / STEAM FLOW WAS NOT ACHIEVED PRIOR TO REACHING THE REACTOR TRIP SETPOINT. A U" CONTRIBUTING CAUSE TO THE EVENT WAS A PROCEDURAL DEFICIENCT. THE PROCEDURE DID NOT ADDRESS CLOSING THE RECIRCULATION VALVE ON THE TRIPPED FW PUMP. THE DIL SYSTEM HAS BEEN CLEANED AND IS 8EING kg HONITORED. THE PROCEDURE HAS BEEN REVISED. NO PREVIOUS OCCURRENCES. 1 FORM 193 LER SCSS DATA 04-R' 0****************************************************************19-91 **** 00CKET TEAR LER NUMBER REVISION DCS MUMSER NSIC EVENT DATE 456 1990 023 0 9101310179 220853 12/30/90 P1 ********************************************************************

    ,,           A85 TRACT g              POWER LEVEL - 095%. ON 12/30/90, UNIT 1 WAS LOAD FOLLOWING TO b'
            ;      ACCOMODATE SYSTEM DEMAND FOR THE COMMONWEALTH EDIS0N COMPANT SYSTEM LOAD DISPATCHER.            AT 0515 THE UNIT COMPLETED A POWER ASCENSION TO FULL CAPABIL1TY. AT 0521 A GENERATOR NEUTRAL GROUND OVERCURRENT te             PROTECTIVE RELAT ACTUATED AND TRIPPED THE UNIT 1 MAIN GENERATOR. A TUR8INE AND REACTOR TRIP FOLLOWED A S DE SIGNED. HEGGER TESTING
                 REVEALED A GROUND ON THE "C" PHASE OF THE MAIN GENERATOR. THE CAUSE OF THE GROUND WAS AN INTERNAL GENERATOR DEFECT.             UPON APPLICATION OF HI POTENTIAL ALTERNATING CURRENT TO THE 'C" PHASE, OSSERVATION OF 6

SMOKE AND ELECTRICAL ARCING REVEALED THAT THE F AULT WAS IN THE BOTTOM COIL IN SLOT 29 0F THE STATOR. DAMAGE TO THE COIL WAS ATTRIBUTED TO A

    ,              VENT SPACER THAT CAME LOOSE. VIBRATION OURING NORMAL OPERATION ALLOWED THE SPACER TO RUS AND WE AR DOWN INSULATION PROTECTING THE COIL.         THE GROUND WAS CREATED AS A RESULT OF INSULATION BREAK 00WN.

THE COIL WAS REMOVED FROM THE STATOR AND SENT TO THE VENDOR. THIS COMPONENT FAILURE IS CONSIDERED TO BE AN ISOLATED EVENT. THERE HAVE BEEN PREVIOUS DCCURRENCES OF A REACTOR TRIP CAUSED ST A GENERATOR TRIP. PREVIOUS CORRECTIVE ACTIONS AND CONTRIBUTING ROOT CAUSE ARE NOT

    ,             APPLICABLE TO THIS EVENT.

1 FORM 194 LER SCSS DATA 04-18-91 0******************************************************************** DOCEET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 457 1959 002 0 8906140299 214241 05/11/59 ASSYRACT POWER LEVEL - 067%. AT 0447 04 5111189, SRAIDWOOO 345 KV sus 11 RECEIVED A TRIP SIGNAL FROM TRANSMISSION SUS STATION (TSS) 177. THE A

    >             PHASE OF EUS TIE (STC8) 10-11 OPENED MORE SLOWLT THAN THE "B" AND "C" t        PHASES.          A LOCAL SREAKER SACKUP (L89) SIGNAL WAS INITIATED. THIS SENT A TRIP SIGNAL TO UNIT 2 MAIN GENEeAT0o L eC u mj r e n e v t .      Twit

                  - .. a....:s. meaat:   -L*NI   suNJ1TIONi WERE IMMEDIATELY ESTABLISHED.

pg AT 0540 THE FL3W CouTROL VALVE FROM Tif 24 AF PU4P TO THE 2A SG WOULO NOT GO FULL OP 1. THE INSTRUMENT AIR TO THE VALVE WAS ISOLATED AND IT F AILED OPEN. FLOW WAS CONTROLLED BY TMROTTLING THE MOTOR OPERATED h4 ISOLATION VALVE. THE ROOT CAUSE OF THIS EVENT WAS A DEFECTIVE TRIP 49 COIL FOR THE A PHASE OF STCS 10-11. TME CAUSE OF THC LEVEL SPIKE ON 54 THE 2C SG WAS A PRES $URE SPIKE FROM SUDOEN LOSS OF STEAM FLOW. THE CAUSE OF THE AF WALVE FAILURE WAS DEFECTIVE CONTROL CARD. THE CAUSE i

        .[ ,     OF THE TRIP SIGNAL FROM TSS 177 WAS NOISE ON THE MICROWAVE CHANNELS.

pq THE A PHASE TRIP COIL HAS BEEN REPAIRED. THE MICROWAVE UNIT AT TSS 177 WILL BE REPLACED. THERE WAS A PREVIOUS OCCURRENCE OF A LOSS OF A Ed I; SWITCHTARD BUS CUE TO AN L88 INITIATION. PREVIOUS CORRECTIVE ACTIONS WERE NOT APPLICA8LE TO THIS EVENT. 1 he q, FORM 195 LER SCSS DATA b5 0************************************************************04-18-91 ********

q. DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT OATE 457 1987 004 0 8910160019 215593 b4 09/07/89

  >=            ABSTRACT POWER LEVEL - 0903. AT APPROXIMATELY 2000 HOURS, 9/7/89 A SEVERE g,        ,

THUNDERSTORM WAS IN THE AREA 0F SRAIDW300 STATION. A VIDEO RECORDER HAD SEEN SET UP TO MONITOR THE EFFECTS OF ATMOSPHERIC EVENTS. FROM D: 2029 TO 2036 SIXTY-THREE LIGHTNING FLASHES WERE RECORDED BY THE

i. CAMERA. FOUR OF THESE LIGHTNING STRIKES HIT STATION STRUCTURES. THE

  !              UNIT 2 AUX. SLDG. VENT STACK WAS STRUCK TWICE. THE BRAIDWOOD STATION De            SWITCHYARC WAS STRUCK.         AT 2031:44 THE UNIT 2 CONTAINMENT WAS STRUCK.

AT 2032 ALL TEN ROD CONTROL SYSTEM (RO) POWER CASINET OVERVOLTAGE

g. PROTECTION DEVICES ACTUATED. THIS CAUSED THE STATIONARY GRIPPER COILS

   ,             OF THE CONTROL RODS TO DEENERGIZE AND THE RODS OROPPED INTO THE CORE.

E' THE RAPID FLUX DECREASE WAS SENSED BY THE NUCLEAR INSTRUMENTATION WHICH GENERATED A POWER RANGE FLUXRATE HIGH REALTOR TRIP. THE REACTOR TRIP SREAKERS OPENED, THE TUR81NE TRIPPED, AND F3EDWATER ISOLATION e OCCURRED. THE SHRINK EFFECT ON STEAM GENERATOR LEVEL INSTRUMENTATION RESULTED IN AN AUTO START OF THE AUXILIARY FEEDWATER PUMPS ON LOW

               WATER LEVEL. THE CAUSE OF THIS EVENT WAS A LIGHTNING INDUCED VOLTAGE TRANSIENT.      THE RD OVERVOLTAGE PROTECTION DEVICES WERE RESET. THE R0 SYSTEN WAS TESTED.        A TIME DELAY HAS SEEN ADDED TO THE OVERVOLTAGE e

PROTECTION DEVICES. RECOMMENDAT!ONS ON ADDITIONAL CORRECTIVE MEASURES

       ,         ARE 8EING EVALUATED. THERE HAVE BEEN TWO PREVIOUS OCCURRENCES.
   ,             PRE VIOUS CORRECTIVE ACTIONS WERE NOT APPLICA8LE.

1 FORM 196 LER SCSS DATA 04-18-91 0******************************************************************** DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 457 1990 010 0 9007100186 218211 06/09/90 A857RACT POWER LEVEL - 015%. A UNIT START Up WAS IN PROGRESS. FEEDWATER (FW)

       .         FLOW WAS 8EING CONTROLLED IN AUTOMATIC BY THE STPASS FW REGULATING VALVES (SFRV). STEAMLINE HEADER PRESSURE WAS BEING CONTROLLED IN AUTOMATIC ST THE STEAM DUMPS. AT 0030 ON 6/9/90 A REACTOR OPERATOR
       ,         (RO), WHO WAS MONITORING THE FW PANEL, 05 SERVED THAT INDICATED LEVEL ON THE 28 STEAM GENERATOR (SG) HAD DECREASED TO 353. THIS WAS SELOW THE SET POINT OF 50%. TME R0 PLACED THE CONTROLLER IN MANUAL AND
       ,,        INCREASED THE OUTPUT TO RAISE SG LEVEL.            28 SG LEVEL CONTINUED TO DECREASE FROM THE ' SHRINK' EFFECT OF THE COLO F W. THE SUPERVISOR i             (SRO) DIRECTED THE RO WHO WAS MONITORING REACTOR CONTROL PANEL, TO

, g, WITHORAW CONTROL RODS TO INCREASE TEMPERATURE AND "$WELL" THE LEVEL.

   ,             SG LEVEL INCREASED FRom AN INITIAL VALUE or 20% TO 241. AT 0939 THE

u n . u s _ . e a v.a anaLa t*U)LU IHi LEVEL IN TME 29 SG TO DECREASE pg *ELOW THE REACTOR TRIO SET POINT 08 17% AND A REACTOR TRIP CCCURRED. THE CAUSE OF THE EVENT WAS A MALFUNCTIONIN", SFRV WHICH uGUL3 STICK OU2ING OPERATION IN THE LOWER THIRD OF VALVE TRAVEL. THE VALVE g, PCCKING WAS LOOSENED AND WALVE TRAVEL WAS SKOOTH AND ACCEPTABLE. yt OPERATOR TRAINING WILL BE PROVIDED. PREVIOUS CORRECTIVE ACTIONS ARE i NOT APPLICA8LE.

   >W         1 f

pq ' FORM 197 LER SCSS DATA 0************************************************************04-18-91 ******** Ed DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 458 1989 007 0 8903290026 213393 bug

                ************************************************************02/20/89         ********

ABSTRACT ks POWER LEVEL - 0023. AT 0153 ON 2/20169 WITH THE UNIT IN OPERATIONAL q; CONDITION 2 WITH REACTOR POWER IN THE IRM RANGE AND DURING A REACTOR DM STARTUP FROM A CONTROLLED SHUTDOWN, A REACTOR SCRAM OCCURRED DUE TO AN INTERMEDIATE RANGE MONITOR (IRM) UPSCALE TRIP. THE IRH UPSCALE WAS bg CAUSED ST EXCESSIVE FEEDWATER WHICH OECREASED THE MODERATOR ' TEMPERATURE AND INDUCED POSITIVE REACTIVITT. CONTRIBUTING TO THIS EVENT WAS THE PLACING OF STEAM DR4tNS IN SERVICE BY OPERATIONS. AS yy EACH ORAIN WAS PLACED IN SERVICE, OPERATIONS WAS ALLOWING REACTOR PRESSURE AND LEVEL TO STASILIZE. AFTER OPENING THE FOURTH ORAIN IN A 8I SERIES OF FOUR, A FEEDWATER TRANSIENT OCCURRED CAUSING THE REACTOR SCRAM. UPON INVESTIGATION IT WAS DISCOVERED THAT DURING THIS TIME pg FRAME THE STARTUP FEED WATER REGULATOR VALVE WAS NOT RESPONDING PROPERLY DUE TO NUMEROUS AIR LEAKS IN THE VALVE OPERATOR. THE AIR LEAKS CAUSED THE VALVE TO HAVE A SLUGGISH RESPONSE. REACTOR STARTUP

   "'            OPERATING PROCEDURE GOP-001 HAS SEEN CHANGED TO NOW REQUIRE A STEAM I             BTPESS VALVE TO SE OPEN APPROXIMATELT 50% PRIOR TO PLACING STEAM l            ,

DRAINS IN SERVICE. THIS WILL ALLOW ADDITIONAL MARGIN TO COMPENSATE he FOR THE CECREASE IN REACTOR PRESSURE IP A RAPID INCREASE IN FEEDWATER FLOW OCCURS. THERE WAS NO IM*ACT ON THE SAFE OPERATIONS OF THE PLANT

t. OR TO THE HEALTH AND SAFETY OF THE PUSLIC.

1 FORM 198 LER SCSS DATA 0************************************************************04-18-91 ******** DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE 458 1989 008 0 8904070151 213430 02/25/S9 ABSTRACT POWER LEVEL - 078%. AT 0041 04 2#25189 WITH THE UNIT AT ?$1 POWER (OPERATIONAL CONDITION 1), THE REACTOR AUTOMATICALLY SCRAM 9ED WHILE e PERFORMING A ROUTINE UPPER THRUST SEARING WEAR DETECTOR TEST IN ACCORDANCE WITH OPERATIONS SECTION PROCEDURE (OSP3-0101. THE SCRAM OCCURRED AS A RESULT OF A TURBINE TRIP CAUSED ST A DEFECTIVE STPASS

        ,        RELAY. THE RELAT FAILED TO OPEN THE " TRIP SUS" CIRCUIT AS DESIGNED TO PREVENT A TURSINE TRIP WHILE TESTING THE THRUST BEARING WEAR OETECTOR.         IMMEDIATELY FOLLOWING THE TURBINE TRIP, THE REACTOR CORE ISOLATION COOLING (RCIC) SYSTEM INJECTED OUE TO A SPURIOUS LOW REACTOR WATER LEVEL 2 SIGNAL. THE S*URIOUS SIGNAL RESULTED FROM A PRESSURE PERTURBATION, CAUSED ST THE FAST CLOSURE OF THE TUR5INE CONTROL
       ,         VALVES, SEING SENSE 0 SY THE REACTOR WATER LEVEL INSTRUMENTATION.

REACTOR WATER LEVEL INCREASED TO LEVEL 8 AND THE RCIC STEAM SUPPLY VALVE CLOSED PER DESIGM. AS COReECTIVE ACTION, A TUR5IME TRIP STPASS

       ,         SWITCH WILL BE INSTALLED TO SE UTILIZED DURING THE WEEKLY TURBINE TESTING TO TEMPORARILY STPASS TUR5INE TRIPS WHICH MAY SE INADVERTENTLY e

CAUSED 8T SPURIOUS RELAY ACTUATIONS WITHIN THE MAIN TURSINE g ELECTRO-HTDRAULIC CONTROL PANEL. 40DITIONAL CORRECTIVE ACTION IS BEING IMPLEMENTED DURING THE SECOND REFUELING OUTAGE T9 **8Veuf

FORM 199 LER SCSS PSTA

 ,,       0..........................***..............................34-16-91    ........

DOCKET VEAR LER r4UMSER REVISION DCS NUMSER NSIC EVEN* DATE

 ,,            458     1959        035           0     8911080205 215783         09130/89 b4         ABSTRACT 6

POWER LEVEL - 078%. AT 0340 ON 9/30180 WITH THE UNIT AT 75% em POWER (OPERATIONAL 13, THE REACTOR AUTOMATICALLY SCRAMMED DURING THE PERFORMANCE OF A ROUTINE REACTOR PROTECTION SYSTEM (RPS) - MAIN STEAM 4 LINE ISOLATION VALVE CLOSURE MONTHLY SURVEILLANCE TEST. THE CAUSE OF THE SCRAM WAS DETERMINED TO BE A DEFECTIVE TEST SWITCH IN THE REACTOR PROTECTION SYSTEM. THE DEFECTIVE GENERAL ELECTRIC SWITCH (MODEL CR b6 2940) HAD INADVERTENTLY PLACED THE SYSTEM IN A CONSERVATIVE STATE ALLOWING A SCRAM TO OCCUR AFTER A HALF SCRAM $1GNAL WAS INITIATED 45 g, REQUIRED BY THE SURVEILLANCE TEST. THE TEST SWITCH WAS REPLACEO VIA A PROMPT MAINTENANCE WORK ORDER. PRIOR TO SUCCESSFULLY COMPLETING THE b4 SURVEILLANCE TEST, THE PROCEDURE WAS REVISED TO REQUIRE VERIFICATION 0F PROPER SWITCH POSITION PRIOR To PERFORMING THE SURVEILLANCE AND UPON RESTORATION. THE RPS SYSTEM WAS RETURNED TO SERVICE. THE RPS kw SYSTEM ACTUATED PER DESIGN IN RESPONSE TO THE DEFECTIVE TEST SWITCH CONDITION AND THE REACTOR SCRAM PLACED THE UNIT IN A SAFE SHUTDOWN p, CONDITION. THERE WAS NO ADVERSE IMPACT ON THE $4FE OPERATION OF THE PLANT NOR TO THE HEALTH AND SAFETY OF THE PUBLIC AS A RESULT OF THIS EVENT. 9 1 p, FORM 200 LER Sc55 OATA 04-18-91 0.****..*.*****+***..** **.**e******.**..*********. **..*.e.***.***.*

  ,         DOCKET TEAR LER NUMBER REVISION DCS NUMBER              NSIC       EVENT DATE 458     1989        042          0      9001110176 216420         12/01/89 I

te A85 TRACT

. POWER LEVEL - 0972. AT 062P ON 12/1tP9 WITH THE UNIT AT 97 PERCENT POWER (OPERATIONAL CONDITION 1), THE MAIN TURBINE GENERATOR TRIPPE0,

            RESULTING IN A REACTOR SCRAM. THE GENERATOR TRIPPE0 DUE TO THE MAIN GENERATOR PROTECTION BREAKERS TRIPPING AS A RESULT OF SENSING A FAULT ON AN OFFSITE 230KV LINE. THE FAULT FAILED TO CLEAR AT THE 230KV e

SWITCHYARD 00E TO A FAILE0 RELAY AND SLOW BREAKER RESPONSE TIME FOLLOWING THE SIGNAL FROM A SACKUP REtav. IMMEDIATELY FOLLOWING THE

  ,           GENERATOR TRIP, THE STATION 4.15KV NORMAL SWITCHGEAR (INNS-SWG14)

FAILE0 70 SUCCESSFULLY TRANSFER TO OFFSITE POWER. THIS CAUSED AN

  '           UNDERVOLTAGE CONDITION WHICH INITIRTED AN AUTOMATIC START OF THE DIVISION III HIGH PRESSURE CORE SPRAY (HPCS) EMERGENCY DIESEL GENERATOR. INITIATION OF THE O! VISION III STANOBY SERVICE WATER PUNP e

15WP*P2C ALSO OCCURRED OUE TO A MOMENTARY LOSS OF POWER TO THE INITIATING TR18 UNITS. THE DIVISION III EMERGENCY DIESEL GENERATOR

 ,            RESTORE 0 POWER TO THE SUS PER DESIGN. THE REACTOR SCRAM PLACED THE UNIT IN THE SAFE SHUT 03WN CONDITION. SINCE ALL SAFETY SYSTEMS FUNCTIONED AS DESIGNED, THERE WAS NO IMPACT ON THE SAFE OPERATION OF THE PLANT OR TO THE HEALTH AND SAFETY OF THE PUSLIC AS A RESULT OF THIS EVENT.

1 FORM 201 LER SC55 OATA 04-18-91 0..*.*********.*********..*.**..********.*******.******************** 00CKEY TEAR LER NUMBER REVIS!ON DCS NUMSER NSIC EVENT DATE

      ,        458     1990        003          0     9004230336 217836          03/15/90 g            .*..........*..........................**................**...*..**.

g AB5 TRACT

  ,           POWER LEVEL - 0421. AT 2140 MOURS ON 3115/90 WITH THE UNIT AT 47

easecs ave m:L4 OrtwAIIJ1 Cut TO A LOSS OF FIELD. THIS RESULTED IN i p, TRIP SIGNALS BEING SENT TO MAIN GENERAT3R PROTECTION 3REAKERS AT THE 230 KV SWITCHTARD. GSU'S INVESTIGATION REVEALEO A MALFUNCTION OF THE ZONE 1 LOSS OF FIELD RELAT (40G KLF). THIS RELAY WAS REWO2KED Ato

b4
ETU2%ED TO SERVICE. PROCEDU2ES HAVE BEEN UPGRADED TO IKCLUDE STATE OF THE ART THREE-PHASE TESTING METHODS AND TO CLEARLY IDENTIFY THOSE b4 CONDITIONS THAT INITIATE 4 GENERATOR TRIP. THE REACTOR SCRAM PLACED

' THE UNIT IN A SAFE SHUT 00WN CONDITION. SINCE ALL SAFETT SYSTEMS

  ,       I, FUNCTIONED AS DESIGNED, THERE WAS NO IMPACT ON THE SAFE OPERATION OF pq '               THE PLANT THIS  EVENT.OR TO THE HEALTH AND SAFETT OF THE PUBLIC 45 A RESULT OF
  ,       !;     1 FORM      202                  LER SCSS DATA he     .

0************************************************************04-18-91 ******** DOCKET YEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE DG 458 1990 014 0 9005140251 218190

                   ************************************************************04/07/90********

U" ABSTRACT 43 POWER LEVEL - 079%. AT 0154 ON 04/07190 WITH THE REACTOR AT 79% POWER be (OPERATIONAL CONDITION 1), A REACTOR SCRAM OCCURRED WHILE TESTING THE MAIN TUR81NE COM8INED INTERMEDIATE VALVES (CIVS) (*V*). THE SCRAM g,n: OCCURRED ON LOW TUR8INE ELECTRONTDRAULIC CONTROL (EHC) SYSTEM PRES $URE. THIS LOW PRESSURE APPEARS TO HAVE SEEN DUE TO MULTIPLE CIv5 I'8 STROKING WHEN THE 24 CIV WAS BEING TESTED. HOWEVER, REPEATED TESTING I. FAILED TO BRING A80UT A REPETITION OF THE EVENT WHICH CAUSED THE SCRAM. CORRECTIVE ACTION INCLUDED REPLACEMENT OF TWO SOLENOID VALVES, 31 FIVE RELAYS, AND THE ELECTRICAL TRIP VALVE. A MODIFICATION HAS SEEN INSTALLdD TO PROVIDE ADDITIONAL RELAY CONTACTS SETWEEN THE CIVS AND

     '               THE TEST CIRCUIT. IN ADDITION, THE VALVE TESTING PROCEOURE MAS 8EEN I                  REVISED TO REQUIRE INCREASED MONITORING OF VALVE POSITION. THIS EVENT hi                 RESULTED IN THE ACTUATION OF THE REACTOR PROTECTION SYSTEM (RPS).

THEREFORE, TH15 REPORT IS SUSMITTED PURSUANT TO 10CFR50.73(A)(2)(IV). THIS EVENT CAUSED NO ADVERSE IMPACT ON THE HEALTH AND SAFETY OF THE j g. PUBLIC. 1 FORM 203 LER SCSS DATA I 0************************************************************04-18-91 ******** DOCKET YEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE 458 1990 047 0 9101180156 220715 12/12/90 A85 TRACT POWER LEVEL - 050%. AT 0032 HOURS ON 12/12190, WHILE PERFORMING TURBINE OVERSPEED PROTECTION WEEKLY OPERASILITY TESTING e (STP-110-0101), A REACTOR SCRAM OCCURRED AS A RESULT OF A TUR8INE CONTROL VALVE (TCV) FAST CLOSURE SIGNAL. AT THE TIME OF THE SCRAM,

 ,                  THE REACTOR WAS AT A REDUCE 0 POWER OF SG PERCENT TO PERFORM THE SUBJECT TESTING. THE CAUSE OF THE TURSINE CONTROL VALVE FAST CLOSURE
 '                  SIGNAL WAS DUE TO A LOW ELECTRO-HTORAULIC TRIP SYSTEM (ETS) PRESSURE TRANSIENT THAT OCCURRED DURING SCHEDULED SURVEILLANCE TESTING OF THE
       ,g           COMBINED INTERCEPT WALVES (CIVS). CORRECTIVE ACTIONS INCLUDED THE i

INSTALLATION OF ORIFICES ON ALL ETS SUPPLY PORTS TO THE TCVS, TUR81NE STOP VALVES (TSVS), AND CIVS. IN ADDITION, A TRANSMITTER WAS y INSTALLED ON THE TUR8INE FRONT STANDARO 70 WERIFY ETS PRESSURE. ALL

SYSTEMS RESPONDE3 TO THE REACTOR SCRAM PER DESIGN. THE RPS RESPONDED CORRECTLY TO THE TCW FAST CLOSURE IN ANTICIPATION OF THE LOSS OF THE 1

gg TURBINE GENERATOR. REACTOR WATER LEVEL AT NO TIME REACHED A LEVEL REQUIRING THE USE OF ALTERNATE SOURCES OF WATER INJECTION TO MAKE UP t FOR LOST INVENTORY. THEREFORE, THE REACTOR WAS NOT PLACED IN A g, CONDITION WHICH THREATENED THE HEALTH AND SAFETT OF THE PU8LIC.

             .............................       ....ee..*........ee..............ee....

DOCKET TEAR LER NUMSER REVISION DCS NUMSER NSIC EVENT DATE P1 p. 461 1989 022 0 8907053489 214580 05/26/89 eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees A qg ABSTRACT bd POWER LEVEL - 019%. THIS REPORT DOCUMENTS THE INSERTION OF A MANUAL SCRAM SIGNAL ON MAY 26, 1989 AND AGAIN ON JUNE 1, 1989. ON MAY 26, , q; 1989, REACTOR WATER LEVEL BEGAN DROPPING. THE MOTOR DRIVEN REACTOR pq FEE 0 WATER PUMP (MDRFP) REGULATING VALVE IFWOO4 DID NOT OPEN IN RESPONSE TO THE DECREASING LEVEL. WHEN INDICATED REACTOR WATER LEVEL

   " ',         OROPPED TO APPROXIMATLY TEN INCHES, 4 MANUAL SCRAM SIGNAL WAS INSERTED. THE FAILURE OF VALVE IFWOO4 WA5 DETERMINED TO BE CAUSED BY A FAULTV SERVO-AMPLIFIER BOARD.       THE 804RD WAS REPLACED. THE PLANT D4      q,       ENTERED MODE 2 (STARTUP) IN MAY 27, 1999         ON JUNE 1, 1989, POWER WAS SEING REDUCED IN ORDER To SHUT THE REACTOR DOWN TO REPAIR THE SEAL ON L.               REACTOR RECIRCULATION PUMP 8. AFTER SWITCHING FEEDWATER CONTROL FROM
       ,p       THE TUR8INE ORIVEN REACTOR FEEDWATER PUMP TO TH MORFP, VALVE IFWOO4 U"              FAILED TO SHUT IN RESPONSE TO ITS CONTROL SIGNAL. REACTOR WATER LEVEL SEGAN IN RAISING. WHEN INDICATED REACTOR WATER LEVEL REACHED g' ,     FORTY-FIVE INCHES, A MANUAL SCRAM SIGNAL WAS INSERTED. THE CAUSE OF he THESE EVENTS WAS THE FAILURE OF VALVE IFWOO4 TO R ESPOND TO ITS CONTROL SIGNAL. TROUBLESHOOTING IDENTIFIED TWO PROSA8LE CAUSES: VI8 RATIONS g,q,            CAUSED LOOSE ELECTRICAL CONNECTIONS ON THE SERVO-AMPLIFIER 804ROJ
                $1LICOM-CONTROLLED RECTIFIERS ON THE BOARD HAD FAILED. THE 80420 HAS BEEN REPLACED AND RELOCATED.

84 1 g, Pg FORM 205 LER SCSS DATA n, 0************************************************************04-15-91******** g, DOCKET TEAR LER NUM8ER REVISION OCS NUMBER NSIC EVENT DATE 461 1989 02S 0 8907310365 214906 06/28/89

              ................... **       ee..........................................

ke 485 TRACT e,, POWER LEVEL - 100%. ON JUNE 28, 1989, WITH THE PLANT IN MODE 1 (POWER OPERATION), THE "C" PHASE MAIN POWER TRANSFORMER (MPT) SUDOEM PRESSURE

SENSOR RELAY MALFUNCTIONED CAUSING A TRIP 0F THE MAIN GENERATOR. THE

      ,.        TRIP OF THE MAIN GENERATOR RESULTED IN A TUR8INE TRIP AND AN AUTOMATIC REACTOR SCRAM BECAUSE OF THE TUR81NE CONTROL V ALVE F AST 4

CLOSURE SIGNAL. THE CAUSE OF THIS EVENT IS ATTRIBUTED TO A SPURIOUS

      ,         SIGNAL FROM THE MALFUNCTIONING SUDDEN PRES 5URE SENSOR RELAT. THE
,               SUDDEN PRESSURE SENSOR RELAY MALFUNCTIONED BECAUSE OF INTERNAL CORROSION RESULTING FROM WATER INTRUSION INTO THE RELAY. THE SUDDEN
, ,             PRESSURE SENSOR RELAY WAS REPLACED WITH A SENSOR RELAV WHICH HAS AN AIR VENT TO PREVENT MOISTURE 8UILDUP INSIDE THE RELAY. THE SUDDEN PRESSURE SENSOR RELAYS WERE REPLACED IN THE OTHER TWO MAIN POWER
'     ,         TRANSFORMERS AND AL50 IN THE RESERVE AUXILIART TRANSFORMER AND THE EMERGENCY RESERVE AUNILIARY TRANSFORMER.
..          1
            , FORM     236                  LER SC55 DATA                        04-18-91 0********************************************************************
      .-      00CAET TEAR LER NUMBER REVISION OCS NUMBER               N51C    EVENT DATE 461    1989        029           0     8909150263 215007        07/14/89
              ................................ .. *.e*********e***.***.eee*******

ABSTRACT POWER LEVEL - 039%. ON JULY 14, 1989, WITH THE PLANT AT THIRYT-NINE

'               PERCENT REACTOR POWER, A MANUAL REACTOR SCRAM WAS INITIATED IN 41 ANTICIPATION OF AN AUTOMATIC SCRAM THAT WAS INMINENT BECAUSE MAIN

CONDEN5ER VACUUM WAS DELdEA5ING. (A LOSS OF MAIN CONDENSER VACUUM g )~ CAUSES A TUR8INE TRIP AND RESULT 5 IN AN AUTCMATIC REACTOR SCRAM.) THE

.               REACTOR HAD BEEN OPERATING AT 100 PERCENT REACTOR POWFR Wwsw

                         , ,               .... .-..~ ..          6.

nuve e bJ19aAk%cti ISCLATION OALUES WERE MANUALLY CLOSED IN ANTICIPATION OF THE EUTOMATIC ISOLETION THAT 00ULO D1 OCCUR BECAUSE OF LCW C3NDENSER USCUUM. THE CAUSE OF THIS EVENT IS ATTRIBUTED TO A MECHANICAL FAILURE OF THE GUS8E3 EXPANSION JOINT LOCATED BETWEEN THE "A" LOW PRESSURO TUQ8INE AND THE MAIN COCDENSEO. b4 , THE EXPANSION JOINT FAILED 8ECAUSE OF AGE, OVERTORQUING OF THE ' ATTACHMENT NUTS OF THE EXPANSION JOINT CLAMP ASSEMBLY, AND STEAM 94 EXPOSURE THAT RESULTED FROM A DETACHED PROTECTIVE COVER. CORRECTIVE l '- ACTION FOR THIS EVENT INCLUDE 0 REPLACING THE RUSSER EXPANSION JOINTS , pq BETWEEN SOTH THE "A" AND "B" LOW PRESSURE TURBINES AND THE MAIN CONDENSER, TORQUING THE ATTACHMENT NUTS OF THE CLAMP ASSEM8LY TO Ed VENDOR RECOMMENDED VALUES, AND REINFORCING THE WELOS OF THE PROTECTIVE CGVER.

1 he a

. FORM 207 LER SCSS DATA gg 0************************************************************04-18-91 ******** i t, 00CEET YEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE 461 1989 032 0 8909060289 215152 07/31/89 DM e. De A85 TRACT POWER LEVEL - 0251. ON JULY 31, 1989, WITH THE PLANT AT APPROXIMATELY Dt 25 PERCENT POWER, OPERATORS INITIATED A MANUAL SCRAM OF THE REACTOR. PRIOR TO THE SCRAMS THE PLANT HAD BEEN OPERATING AT 100 PERCENT POWER R8 WHEN DIFFICULTIES WERE EXPERIENCE 0 WITH THE MOISTURE SEPARATOR REHEATER (MSR) AND THE HIGH PRESSLRE FEEDWATER HEATER SYSTEMS AND THEIR VENT AND DRAIN SYSTEM. IN RESPONSE TO THESE DIFFICULTIES, pg OPERATORS SEGAN REDUCING POWER TO REMOVE THE MSR$ FROM SERVICE. AT THIS POINT OPERATORS NOTED AN INCREASE IN WATER LEVEL IN THE REHEATER

   "'              ORAIN TANE, AN INCREASE IN OFF-GAS SYSTEM FLOW, AND A DECREASE IN T"E i

MAIN CONDENSER VACUUM. IN RESPONSE OPERATORS CONTINUED TO DECRE42E I REACTOR POWER. AT APPROXIMATELY TWENTY-FIVE PERCENT REACTOR POWER, l 44 WHILE REMOVING ONE OF THE TURSINE DRIVEN REACTOR FEEDWATER PUMPS FROM SERVICE, AN OPERATOR FAILED TO HATCH THE MANUAL FEE 0 WATER CONTROL To to THE AUTOMATIC FEE 0 WATER CONTROL PRIOR TO TRANSFERRING THE PUMP TO MANUAL. THIS CAUSE0 REACTOR WATER LEVEL TO INCREASE AND APPROACH THE

                HIGH WATER LEVEL SCRAM SETPOINT THEREFORE. OPERATORS INITIATED A
      ,           MANUAL SCRAM.                   THE CAUSE OF THIS EVENT IS ATTRIBUTED TO OPERATOR ERROR DURING THE TRANSFER OF FEEDWATER PUMP CONTROL. SECAUSE THE OPERATOR e               RECOGNIIED HIS ERROR AND IDENTIFIED IT TO HIS SUPERVISION, NO
      ,           CORRECTIVE ACTION IS REQUIRED.

FORM 208 LER SCSS DATA 04-18-91 e, 0 ......... ** ...e*.................... ***ee............... *...... DOCKET TEAR LER NUMBER REVISION OCS NUM8ER NSIC EVENT DATE

      ,             461         1990                 012                0      9036270079 218744                 05/17/90
                 ....e*.aea............... * ...... * .......... *.... **** ......**e
      ,,        485 TRACT POWER LEVEL - 043T. 04 MAY 17, 1990, WITH THE PLANT IN POWER OPERATION
   '              AT 43 PERCENT REACTOR POWER, AND SOTH REACTOR RECIRCULATION (RR)

g. PUMPS IN FAST TPEEO, REACTOR FEE 0 WATER SYSTEM (FW) FLOW CHANNEL "B" FAILEO AND CAUSE0 INSTRUMENTATION TO INCORRECTLY SENSE TOTAL FW FLOW AS LOW. 45 A RESULT OF THIS, THE LOGIC INITIATED AN AUTOMATIC 4: TRANSFER 0F THE "A" ANO "B" RR PUMPS TO SLOW SPEED. 14 RESPONSE TO THE RR PUMP TRANSFERS, THE CONTROL ROOM OPERATOR INITIATED A MANUAL REACTOR SCRAM IM ACCORDANCE WITH THE OFF-NORMAL PROCEDURE.

gi ' ADDITIONALLY, GROUPS 2, 3 AND 20 CONTAINMENT ISCLATION VALVES ACTUATED AS A REACTOR VESSEL WATER LOW-LEVEL TRIP OCCURREO. TROUBLESHOOTING

p. DETERMINE 0 THAT A POWER CONVERTER FOR THE FW CONTROL SYSTEM FAILE0 DUE g, TO NORMAL END OF LIFE AM5 CAUSED THE "B" FW FLOW CHANNEL TO FAIL.

THE CAUSE OF THIS EVEkT IS ATTRIBUTED TO THE NORMAL END-OF-LIFE

           -  .~          ,          - - - -             , - ---     ,w                        . . . . , . - , .     --   , . , , ,   - -                             -   ,

                 . ....... s      .ns 4-96 MoacLa INIitaTING A PREVENTIVE MAINTENANCE (PM) pq               TASK TO PERI 00!CALLY QE* LACE THE DOWER CONVERTER ANC ANOTHER CONVERTER OF THE SAME HOLEL; AN3 DETERMINING IF OTHER FW CONTROL SYSTEM POWER SUPPLIES / CONVERTERS MAY NEED PM TASKS FOR PE2103IC REPLACEMENT.

b4 FORM 209 LER SCSS DATA

b. 04-18-91 0........................................................... ........

t 41 DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT OATE pq 461 1990 013 0 9003140018 219257

               ........................................................... 07/09/90 4*           ABSTRACT I                 POWER LEVEL - 091X. ON JULY 9, 1990, WITH THE PLANT IN POWER OPERATION b ,,,            AT 91 PERCENT REACTOR POWER, MAIN CENERATOR OVERVOLTAGE/HERTI

, PROTECTION RELAY $9/S1-1 ACTUATED. AFTER A DESIGNED 45-SECOND TIME be DELAY, THE MAIN TUR8INE GENERATOR TRIPPED VIA TURSINE CONTROL V ALVE FAST CLOSURE WHICH CAUSED AN AUTOMATIC REACTOR SCRAM. ADDITIONALLY, GROUPS 2, 3, AND 20 CONTAINMENT ISOLATION VALVES ACTUATED AS A REACTOR U" a VESSEL WATER LOW-LEVEL TRIP OCCURRED. INVESTIGATION DETERMINED THAT be RELAY $9/81-1 HAD ACTUATED PRIOR TO EXCEEDING ITS DESIGN SETPOINT SECAUSE IT WAS OUT OF CALISRATION. THE CAUSE OF THE RELAY BEING OUT OF CALIBRATION CANNOT BE DETERMINED. PR08ASLE CAUSES ARE PERSONNEL y,, ERROR IN READING THE TEST INSTRUMENT OURING CALIBRATION AND/OR TEST INSTRUMENT ERROR DURING CALIBRATION CAUSED BY A FLUCTUATING VOLTAGE SOURCE. Di,: CORRECTIVE ACTIONS INCLUDE: RECALIBRATING TWO RELAYS ANO VERIFYING SETPOINTS OF A SAMPLE OF OTHER RELAYS CALIBRATED OURING THE SAME PERIOD; ISSUING DETAILED PROCEDURES FOR CALIBRATING PROTECTIVE y, VOLTAGE RELAYS; INVESTIGATING QUALIFYING A CLINTON POWER STATION TECHNICIAN TO PERFORM RELAY TESTING; RECENTLY PURCHASING NEW DIGITAL TEST EQUIPMENT; AND BRIEFING EACH OPERATIONS CREW ON GENERATOR I' LIMITATIONS AND ABNORMAL VOLTAGES. I 1 to FORM 210 LER SCSS DATA

g. 0************************************************************04-18-91 ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 482 1989 002 0 8902280362 213119 01/23/89 t A85 TRACT POWER LEVEL - 100%. ON JANUARY 23, 1959, AT 1322 CST, A REACTOR TRIP

,               OCCURRED *% A RESULT OF A HIGH BEARING VIBRATION MAIN TUR8INE TRIP. A FEE 0 WATER IS6LATION SIGNAL, AN AUXILIARY FEE 0 WATER ACTUATION SIGNAL, AND A STEAM GENERATOR SLOWDOWN AND SAMPLE ISOLATION SIGNAL OCCURRED AS OESIGNED FOLLOWING THE REACTOR TRIP. THE REQUIRE 0 SAFETY RELATED
               ' EQUIPMENT PERFORMED AS DESIGNE0. PRIOR TO THE EVENT, THE UNIT WAS IN
     ,          MODE 1, POWER OPERATION, AT 100 PERCENT POWER. THE CAUSE OF THE TRIP WAS DETERMINED TO BE A SPURIOUS SIGNAL IN THE VI8 RATION MONITORING CIRCUITRY WHICH INCORRECTLY INDICATED HIGH VIBRATION ON THE MAIN
     ,          TUR8INE MUMBER 7 8 EARING.      TO PREVENT ADDITIONAL UNNECESSARY CHALLENGES OF REACTOR PROTECTION SYSTEMS, THE TUR8INE HIGH VIBRATION TRIP CIRCUITRY HAS BEEN MODIFIED FROM A TRIP FUNCTION TO AN ALARM
     ,          FUNCTION. FURTHER EVALUATION OF THE TUR8INE VISRATION TRIP CIRCUITRY IS SEING CONOUCTED TO DETERMINE IF INSTALLATION OF MULTI-COINCIDENCE LOGIC IS FEASISLE FOR THE TRIP CIRCUITRY. THERE WAS NO DAMAGE TO I           PLAN EQUIPMENT OR RELEASE OF RADICACTIVITY AS A RESULT 0* THIS EVENT.

AT NO TIME DID CONDITIONS DEVELOP THAT MAY HAVE POSED A THREAT TO THE HEALTH OR SAFETY OF THE PUBLIC. 1

r. FORM- 211 LER SCSS DATA 04-1 g 0**** **..* *.******... ... *******.******.. ...*.a.*************8-91 .a..

DOCKET VEAR LER NUMBER REVISION DCS NU=SEE NSTC zwrwt ante

AeSTRaCT i p, POWER LEVEL - 100%. 04 212180, AT APPR0tIHATELY 1321 CST, A REACTOR ' TRIP OCCURRED FR0a 100% POWER AS A RESULY OF STEAM GENERATOR (SIG) 'C' U9 CEPCHI%G THE LO-LO LEVEL TRIP SETPOINT FOLLOWING CLOSU1E OF S/G 'C' q; MAIN STEAM ISOLATION VALVE (MSIV 'C'). IN ADDITION, A FEEDWATER ISOLATION SIGNAL, AN AUX. FEE 0 WATER ACTUATION SIGNAL, AND A STEAM DW GENERATOR SLOWOOWN AND SAMPLE ISOLATION SIGNAL ACTUATIONS OCCURRED AS

                  .                             .g,                                                        DESIGNED.       THE CAUSE OF THE REACTOR TRIP HAS BEEN DETERMINED TO BE A pq                                                                                     LOOSE SCREW ON 4 TERMINAL STRIP IN THE SOLID STATE PROTECTION SYSTEM (SSPS). DURING UNRELATED MAINTENANCE, THIS LOOSE TERMINATION WAS b4 q.'                                                                                  BUMPED RESULTING IN A FAST CLOSE SIGNAL TO MSIV 'C'. EFFORTS TO IDENTIFY THE ROOT CAUSE OF THE LOOSE TERMINAL CONNECTIONS HAVE BEEN UNSUCCESSFUL. OTHER TERMINATIONS IN THE SSPS AND OTHER CONTROL ROOM De q i                                                                                 PROCESS CA81 NETS WERE CHECKED AND TIGHTENED AS NECESSART. IN ORDER TO PREVENT RECURRENCE OF THIS EVENT, A CHECK OF SCREWS IN THESE pg                                                                                     APPLICATIONS WILL SE ADDED TO THE INSTRUMENTATION AND CONTROLS q,    '

PREVENTATIVE MAINTENANCE PROGRAM. 1 Sus FORM 212 LER SCSS DATA 0***e.** .e** e*****e****e ***e**********************e***e*** 04-18-91 g, kg ******** DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

                   ,, p                                                                                          482  1990       001         0      9093140392 217397                                               02/0 emeneeeeeee.................................***eeeeee........                                                        e*6/90
                                                                                                                                                                                                                         **ee ta                                ;                                           ABSTRACT POWER LEVEL - 1002. ON 2/6/90, AT APPROX. 0906 CST, A REACTOR TRIP e,

OCCURRED FROM 100% POWER AS A RESULT OF A LOOP LOW FLOW CONDITION

                                               .:                                                        FOLLOWING A TRIP OF REACTOR COOLANT PUMP (RCP) "A".                                                 IN ADDITION, A
                                '                                                                        FEEDWATER ISOLATION SIGNAL, AN AUXILIARY FEEDWATER ACTUATION SIGNAL, I                                                                                      AND A STEAM GENERATOR BLOWOOWN AND SAMPLE ISOLATION SIGNAL ACTUATIONS OCCURRED AS DESIGNED. ALL REQUIRED SAFETY RELATED EQUIPMENT PERFORMED he                                                                                   AS DESIGNED. THE TRIP OF RCP "A" WAS CAUSED BY AN INDICATED HIGH DIFFERENTIAL CURRENT 04 THE "A" PHASE. THE DIFFERENTIAL CURRENT RELAY g,                                ,

WAS TESTED AND No ABNORMALITIES WERE DETECTED. EXTENSIVE TROUSLESHOOTING EFFORTS WERE UNSUCCESSFUL IN IDENTIFYING THE ROOT I' CAUSE FOR THE RELAY ACTUATION. FOLLOWING INSTALLATION OF TEMPORARY RECORDERS TO MONITOR INPUTS TO THE RELAT, RCP "A" WAS RESTARTED AT APPROX. 1630 CST. NO SIGNIFICANT A8 NORMALITIES ASSOCIATED WITH PUMP a OPERATION WERE DETECTED AND THE NEXT DAY, 04 217/90, THE UNIT WAS

                                             ,;                                                          RESTARTED, ENTERING MODE 2, STARTUP, AT 1631 CST.
                                                       .                                       FORM                  213                LER SCSS DATA                                                               04-18-91 0e......................** ...............eee.eee............e**..een DOCKET YEAR LER NUMBER REVISION OCS NUM8ER                                                               MSIC     EVENT DATE t-                     gg                                                                    482  1990      011          0     9006190024 213551                                                05/14/90
                                           ','                                                485 TRACT POWER LEVEL - 0052. A S/14190, AT 2136 CDT, DURING PERF01A ANCE OF THE 8

MAIN TUR81NE OVERSPEED TRIP TEST, A FEEDWATER ISOLATION SIGNAL (FWIS) pg AND MAIN TURSINE TRIP SIGNAL OCCUR *ED WHEN STEAM GENERA 10R '8' REACHED i THE HIGH-HIGH LEVEL SETPOINT. SHORTLY THEREAFTER, A REACTOR TRIP AND AUXILIARY FEEDWATER ACTUATION SIGNAL (AF45), AND STEAM GEWERATOR g) SLOWOOWN AND SAMPLE ISOLATICN $1GNAL (SGSSIS) OCCURRED WHEN STEAM GENERATOR "C" REACHED THE LOW-LOW LEVEL SE1 POINT. ALL ENGINEERED SAFETY FEATURES AND REACTOR PROTECTION SYSTEM EQUIPMENT RESPONDED

(, PROPERLY TO THE ACTUATION SIGNALS. EARLIER IN THE DAT ON S/14190, FEEDWATER PREHEATING USING MAIN STEAM HAD SEEN REMOVED FROM SERVICE. t WHEN THE MAIN TURSINE WAS TAKEN OFFLINE IN ACCORDANCE WITH THE gj OVERSPEED TRIP TEST, FEEDWATER HEATING USING EXTRACTION STEAM WAS

                   ,                                                                                 LOST. AS A RESULT OF THE COLDER FEEDWATER EEING Sup* LIED To Twc tream

                 . . . . . . . . . ~ . . ..- .** ossa ec.t uN>uwLt>>&UL I '4 DRIVENTING THE HIGH-HIGH ANO LOW-LOW LEVEL CONDITIONS.            THE P40CEDUR? FOR PERFORMING y,

THE OVERSPEED TRIP TEST HAS SEEN REVISED TO REQUIRE FEECUSTER HEATING TO BE INSERVICE PRIO3 TO CONDUCTING THE TEST, THE C'V*SEO TEST WAS COT.PLETED SutCE55 FULLY ON 5/16/90 AT 0002 COT.

 >4            FORM     214                   LER SC$$ 0474 pq
       .j,  0************************************************************04-18-91              ********

DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE 482 1990 012 0 9036260355 218775 05/17/9 g *******************************************************************0* 485 TRACT be , i , POWER LEVEL - 0013. ON 5/17/90, 4T 2305 COT, WITF THE UNIT AT 0.51 POWER, A REACTOR TRIP SIGNAL, MAIN TURSINE (TA-Tk3) TRIP SIGNAL, gg AUXILIARV FEE 0 WATER ACTUATION SIGNAL (4FAS), FEE 0htTER ISOLATION g, SIGNAL (FWIS) AND STEAM GENERATOR BLOWOOWN ANS SAM 6 tE ISOLATION SIGNAL D" (5G8515) OCCURRED AS A RESULT OF A LOW-LOW WATER LEVEL IN STEAM GENERATOR 'C'. PRIOR TO THIS EVENT, THE UNIT M40 SEs*N TAKEN OFF LINE bg AND THE STE4M GENERATOR ATMOSPHERIC RELIEF VALVh$ (45 V's) WERE BEING USED TO MAINTAIN REACTOR COOLANT SYSTEM TEMPERATURE. AT APPRORIMATELY 2300 COT, IT W45 OI5 COVERED THAT THE 'C' 4RV WAS STUCL OPEN. EFFORTS p,, TO CLOSE THE ARV FROM THE CONTROL ROOM WERE UNSUCCESS7UL, AND OPERATORS WERE DISPATCHED TO PANUALLY ISOLATE THE VALWE. THI$ VALVE WA5 ISOLATED AT 2310 COT, AND PL4NT CONDITIONS WERE SfABILIZEO. II, OURING SUBSEQUENT TROUSLE5H00 TING, A CURRENT-TO-PNEUMATIC CONVERTER IN THE ARV POSITIONER CIRCUITRY WAS REPLACEO. THE ARV W45 VERIFIED TO 33 8E OPERATING PROPERLY AND WAS RESTORED TO SERVICE AT 0716 COT ON

       ,,'      5/18/90. IT IS BELIEVED THAT THE FAILURE OCCURRED AS A RESULT OF A
 "*             PRES $URE REGULATING BALL IN THE AIR BLEED OFF LINE OF THE CONVERTER BEING RESTRICTED FROM FREE MOVEMENT.           THIS CONDITION CAUSED THE ARV TO REMAIN IN THE OPEN POSITION.

4e' I a... FORM 215 LER SC$$ DATA 0************************************************************04-18-91 ******** DOCKET TE4R LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE

  ,             432    1990         013           0       9006220084 218550               05/19/90 O
      ,,      ABSTR4CT
 ,              POWER LEVEL - 0972. ON 5/19/90, AT 2353 COT, A MAIN TUR8INE (14-TR8)

TRIP 3CCURRED AS A RESULT OF HIGH-HIGH AOISTURE SEPARATOR REHEATER LEVEL. SECAUSE THE UNIT WAS OPERATING AT GREATER THAN 501 POWER, THE MAIN TUR31NE TRIP CAUSED A REACTOR TRIP. AS EXPECTED, AN AUXILI4RY FEE 0 WATER ACTU4 TION SIGNat, A FEE 0 WATER ISOLATION SIGNAL AND A STE4M e

      ,.        GENERATOR BLOWDOWN AND SAMPLE ISOLATION SIGNAL ALSO OCCURRED. ALL REACTOR PROTECTION SYSTEM AND ENGINEERED SAFETY FEATURES EQUIPMENT
 ,              FUNCTIONED PROPERLY. FOLLOWING THIS EVENT, EXTENSIVE TROJBLESH00 TING g         ACTIVITIES WERE CONDUCTED. 4 LEVEL SWITCH ON MOISTURE SEPARATOR OR4IN TANK (MSOT) 'A' WAS FOUND TO !NITIALLY BE STUCK THUS PREVENTING A MAIN CONTROL ROON ALARM ON HlGH LEVEL.            THE SWITCH WAS REPLACEO.            THE
      ,<        REMAINDER OF THE LEVEL CONTROL CIRCUITRY FOR MSOT 'A' W45 FOUND TO BE OPERATING PROPERLY. NO ABNORMALITIES kERE IDENTIFIED IN THE OUMP VALVE TO THE CONDENSER, THE NORMAL LEVEL CONTROL VALVE, OR ITS g          UPSTREAM CHECK VALVE.       No SIGNIFICANT 48 NORMALITIES COULO BE IDENTIFIED OURING THE TROUBLESHOOTING. THE UNIT WAS RESTARTED ON L*20/*C, ans LEVELS WERE CLOSELT MONITOREO. NO FURTHER O!FFICULTIES 8

g WERE ENCOUNTEk'O IN THE LEVEL CONTROL SYSTEM. e-g: FORM 216 LER SCSS Data 04-18-91

 ,         0********************************************************************

l -

                                          ..............+.***.a.****en...*............

p, A85 TRACT POWER LEVEL - 0972. ON 5/29/57 AT 1051 CDT, A REACTOR TRIP OCCU%REO ON "4 4 PO%ER RANGE NEUTRON FLUX RATE TRIP SIGNAL. THE PLANT WAS IN MODE 1

             - POWER OPERATIONS, AT 97 PERCENT REACTOR POWER. THE REACTOR COOLANT SYSTEM (RCS) TEMPERATURE WAS 5STF (4VERAGE). RCS PRESSURE WAS 2235
 >=

PSIG. THE POWER FLUX RATE TRIP SIGNAL WAS RECEIVED DURING THE [ p, PERFORMANCE OF A SURVEILLANCE PROCEDURE FOR INCOPE/EXCORE CALIBRATION. A CHANGE IN METER LOCATION OF THE MEASURING & TEST EQUIPMENT (METE) INSTALLED FOR THE SURVEILLANCE WAS REQUESTED 87 A UTILITY REACTOR

       ,     ENGINEER. THE TECHNICIAN REMOVED THE LEADS FROM THE METE THAT W4S E8 CONNECTED TO POWER PANGE CHANNELS N41 AND N42. WHEN RECONNECTING, THE TECHNICIAN OROPPED THE N42 LEADS CAUSING A GROUNO. A GROUND IN ONE b4          CF THE N41 LEADS ALSO OCCURRED, WHICH LE4D TO THE TRIP SIGNAL AND SUBSEQUENT UNIT TRIP /TURSINE TRIP. THIS EVENT WAS CAUSED SY THE LACK g,

' OF OETAIL PROVIDEO IN PLANT PROCEDURES WHICH RESULTED IN PERSONNEL SEING UNAWARE OF POTENTIAL CONSEQUENCES. NEITHER THE TECHNICIAN NOR E" THE REACTOR ENGINEER REALIZED THE RISK ASSOCIATED WITH THE CONFIGLRATION DUE TO THE MULTIPLE CHANNEL ARRANGEMENT AND NON-ISOL4TED TEST POINT

S. PROCEDURE

ESP-ZZ-00006 INCORE/EXCORE CALIBRATION HAS kg BEEN REVISED TO INCORPORATE SPECIFIC PRECAUTIONS CONCERNING PLACEMENT,

             ,ow-srYION AND REMOVAL OF THE MSTE.           THE EVENT WILL SE DISCUSSED WITH
 ,,          THE !*CHN) wl ANS AND ENGINEER S INVOLVED.

1 Bs FORM 217 LER SCSS DATA p. 0************************************************************04-18-91 ******** DOCKET YEAR LER NUM8ER REVISION 0C5 NUMBER NSIC EVENT DATE 453 1939 003 0 3907280187 214908 06/23/89 485 TRACT D* POWER LEVEL - 1001. 4T 0840 COT ON 6#23/89, CONTROL R00 SANK '8* FAILED TO MOVE AND WAS DECLARED INOPERABLE IN MODE 1 - POWER OPER4 TION g, 4T 100% REACTOR POWER. AT 1102, A PLANT SHUT 00WN WAS COMMENCED PER TECHNICAL SPECIFICATION (T/5) 3.1.3.1 ACTION 8. AT 1418 AT

           APPROXIM4TELY 3% REACTOR POWER, THE M4IN TURBINE WAS TRIPPED. A PROTECTIVE RELAY FOR GENERATOR OUTPUT BREAKER ERR 3NEOUSLT SENSED A FL ASH 0VER AND CLEARED THE 345 KV SWITCHTARD BUS '8'. THIS RESULTED IN

A COMPLETE LOSS OF POWER TO THE 4.16 LV SAFEGUARDS SUS M801. THIS RESULTED IN AN ENGINEERED SAFETT FEATURE ACTUATION OF THE TUR8INE

 ,           ORIVEN AUXILIART FEE 0 WATER PUMP. AT 1419, THE REACTOR W45 MANUALLY TRIPPED AT 2% REACTOR POWER.          THE PLANT WAS STABILIZED IN MODE 3 - HOT STAN087. THE LOSS OF M801 HAD CAUSED RADIATION MONITORS, GK-RE-05
 '           AND GG-RE-27, T0 8ECOME INOPER48LE. Tis 3.3.3.1 ACTIONS 27 AND 30 WERE NOT COMPLETED WITHIN THE 1 HOUR TIME LIMIT. THE PLANT WAS e

RESTARTED AT 0210 ON 6/24/E9 AND REACHED 100% REACTOR POWER AT 480UT 1500 ON 6/25/89 TWO CIRCUIT 804R05 IN THE ROD CONTROL LOGIC CASINET

 '           WERE REPLACED. THE CAUSE OF THE LOSS OF N801 WAS THE F4ILURE OF A
    ,        FL4 SHOWER RELAY DUE TO 4 LOOSE SET SCREW.          THE RELAY WAS REPAIRED.

THE CAUSE OF THE LATE COMPLETION OF T/S 3.3.3.1 8CTIONS 27 aND 30 WAS ATTRIBUTABLE TO COGNITIVE PERSONNEL ERROR $. THESE WERE IDENTIFIED SUT

    ,        WERE NOT COMPLETED WITHIN THE TIME REMAINING.

1

g. FORM 218 LER SCSS DATA 04-18-91 0********************************************************************

DOCKET TEAR LER NUMBER REVISION OCS Num8ER NSIC- EVENT DATE

    ,         433    1990         005           0       9006010187 213374         05/01/90
           ********************************************************+++*********

g' A85 TRACT POWER LEVEL - 100%. 04 5#1/90 A T 13 31 COT, a eEACTOR Trio, aun

                           ~ , v-  s                                                        -

                  .....      .....so  ......  *v4  enc *L4NI MAS IN MODE 1 - POWER OoERATIONS, 100 PERCENT REACTOR POWER, AT NORMAL OPERATING DRESSURE AND y3              TEMPERATU4E.          THE SCW LOW 5 LOW TURBINE TRIP SIGNAL AND SUSSEQUENT REACTOR TRIP SIGNAL uERE RECEIVED DURING THE CALIBRATION OF THE Stu INLET CC DUCTIVITY RETER. DURING RESTORATICM OF P3 E2 TO THE

', k" . g'. CONDUCTIVITY METER, A CONDUCTIVE FOREIGN PARTICLE CREATED A DEAD SHORT ACROSS THE POWER SUPPLY LEADS OF THE METER ASSEMBLY. THE SUBSEQUENT , h4 TRANSIENT CAUSED THE FAILURE OF A 10 AMP FUSE RESULTING IN A LOSS OF lg ;; MAIN GENERATOR SCW INSTRUMENTATION POWER. THE LOSS OF INSTRUMENTATION ! pq POWER INITIATED A TURSINE RUNBACK A T 132 8. WITH THE " LOSS OF SCW l I 4 FLOW" SIGNAL STILL PRESENT, THE MAIN GENERATOR PROTECTION CIRCUITRY Id g INITIATED A TURBINE TRIP AT 1331 SEVERAL GENERATOR PROTECTION SCW RUN8ACK MODIFICATIONS ARE BEING IMPLEMENTED TO ALLEVIATE FALSE ACTIVATIONS AND ENHANCE THE RELIABILITT OF THE SYSTEM. g, FORM 219 LER 5055 DATA 0************************************************************04-18-91 ****ca** i DM DOCKET TEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE 483 1990 007 0 9007160378 218823 06/11/90 be ABSTRACT g, POWER LEVEL - 100%. ON 6/11/90, AT 1016 COT, A REACTOR PROTECTION SYSTEM (RPS) REACTOR TRIP, A FEEDWATER ISOLATION (FWIS), AND AN I4 AUKILIARY FEEDWATER ACTUATION OCCURRED FOLLOWING SIMULTANEOUS CLOSURE OF ALL FOUR MAIN STEAM ISOLATION VALVES (MSIVS). THE PLANT WAS IN MODE 1 - POWER OPERATIONS AT 100 PERCENT REACTOR POWER. THE NSIVS CLOSED 31 DUE TO A FAILED INPUT SUFFER CARD IN THE MSIV MANUAL FAST CLOSE CIRCUITRY IN THE MAIN STEAM AND FEE 0 WATER ISOLATION SYSTEM CONTROL

    "'           CABINET. THE FAILED INPUT SUFFER CARD WAS REPLACED. ON 6/12/90, AT 0$01 CDT, WHILE SUSCRITICAL DURING REACTOR STARTUP, FOUR SANK 'B' ROD I  ,.        CONTROL CLUSTER ASSEM8 LIES DROPPED. OPTIONS WERE EVALUATED AND AT ke           0545, THE REACTOR TRIP BREAKERS WERE OPENED, MANUALLY TRIPPING THE REACTOR.          A FWIS WAS RECEIVED AS ANTICIPATED. THE PLa4? Wra :4 MODE 2 g, ,         - STARTUP ($U8 CRITICAL). A FAULTV R00 CONTROL SLAVE CTCLER COUNi?1 CARD FOR THE 150 CONTROL R03 POWER CABINET WAS IDENTIFIED AND REPLACED.          DURING STARTUP OF THE PLANT ON 6/12/90, OPERATIONS I*
       ,         SURVEILLANCE PROCEDURE, " MAIN TUR81NE TRIP TESTS" (0$P-AC-00004), WAS NOT PERFORMED. THIS EVENT WAS DISCOVERED ON 6118/90. THE PLANT WAS I            IN MODE 2 - STARTUP AT IS PERCENT REACTCR POWER. THIS EVENT WAS
       ,         CAUSED ST THE SHIFT TECHNICAL ADVISOR MISTAKENLY READING THE
    ,            SURVEILLANCE SCHEDULE E00K. 0$P-AC-00004 WAS PERFORMED SATISFACTORILY ON 6/18190.
       ,      1 FORM        220                   LER SCSS DATA                        04-18-91 e  ,      0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 483 1990 016 0 9012270013 220506 11/24/90 ABSTRACT

       ,         POWER LEVEL - 048%. ON 11/2A/90 AT 0051 CST, WITH POWER BEING REDUCED AT 20% PER HOUR, A TURSINE TRIP OCCURRED ON A HIGH MOISTURE SEPARATOR REHEATER (MSR) HIGH LEVEL SIGNAL. A REACTOR TRIP OCCURRED WITHIN TEN g         SECONDS DUE TO LOW STEAM GENERATOR LEVELS WHICH HAD RESULTED DUE TO THE TUR8tNE TRIP. ENGINEERED SAFETT FEATURES FEEDWATER ISOLATION AND Auz!LIARY FEEDWATER ACTUATION WERE GENERATED PER DESIGN. THE LICENSED
       ,         OPERATORS IMMEDIATELY STA81LIZED THE PLANT IN ACCORDANCE WITH PLANT PROCEDURES. THE PLANT WAS AT 45% REACTOR POWER AT THE TIME OF THE
    ,            TRIP, WITH REACTOR COOLANT SYSTEM TEMPERATURE AT $71F AND PRESSURE AT 2235 PSIG. ONE MSR LEVEL DEVICE WAS INADVERTENTLY INSTALLED UPSIDE 43        DOWN,
                 ...~.... -- .

CAUSING ONE HIGH LEVEL SIGNAL TO LOCK IN. THE SPURICUS n

                                                                                                           .        .         cz 6.*4   rv% en: ma< Levct IRIP 21 Gnat. DUE TO NARROW TRIP AND RESET TOLERANCE, THE MSR LEVEL OEv!CES hERE VERT SENSITIVE TO VIBRATION.         AN P1                 ACTUAL HIGH MSR LEVEL HAD NOT OCCURRED.      THE INCORRECTLY INSTALLED MSR LEVEL SUITCH WAS INVERTED AND ALL 12 Su1TCHES WERE ADJUSTED 10 b4                MAKE THEM LESS SUSCEPTI8LE TO VISRATION-INDUCEO SPURIOUS ACTU4TIONS.
          }g       OTHER SIMILAR LEVEL SWITCHES IN THE PLANT ARE BEING EV4LU4TED FOR b4                 POTENTIAL SET-UP PROBLEMS DUE TO TIGHT CALIBRATION TOLERANCES.

1 lr eq FORM 221 LER SCSS DATA 0***** .......*****.************* * **** ************ ******04-18-91 . *.a... i,

          '       DOCKET TEAR LER NUMBER REVISION DCS NUMSER             NSIC    EVENT DATE 483    1990       017          0    9101280180 220729          12/30/90
                  ..............****.e..**...*****..*****.***...* ****.***..... *.***.

WW y A85 TRACT t gg POWER LEVEL - 100%. ON 12/30/90, AT 1152 CST, A REACTOR TRIP OCCURRED

i. QUE TO THE FAILURE OF A CONTROLLER / DRIVER CARD FOR THE 'B' FEEDWATER

     "             REGULATING VALVE (FRV). THE FRV FAILED CLOSED AND COULO NOT SE RE-OPENED BY THE LICENSED OPERATORS FROM THE MAIN CONTROL BO ARD IN EITHER THE AUTOMATIC OR MANUAL MODE. THE SU8 SEQUENT 'B' STEAM

! be ' GENERATOR LOW WATER LEVEL ACTUATED THE REACTOR TRIP SIGNAL. AS 4 RESULT OF THE RPS ACTUATION, A FEEDWATER ISOLATION (FWIS) AND AN i bg ., AUXILIARY FEEDWATER ACTUATION (4FAS) WERE GENERATED 8V DESIGN. THE PLANT WAS IN MODE 1 - POWER OPERATIONS AT 100 PERCENT REACTOR POWER. i E8 THE REACTOR COOLANT SYSTEM TEMPER 4TURE WAS 588 DEGREES F AND THE 3, PRES $URE WAS 2235 PSIG. THE LICENSED OPERATORS RECOVERED FROM THE TRIP AND ENGINEERED SAFETY FEATURE (ESF) ACTUATIONS VIA PLANT PROCEDURES. p-e THE FRV CONTROLLER / DRIVER C4RD WAS REPLACED AT 1330 ON 12#30/90. THE MANUFACTURER OF THE CARD IS WESTINGHOUSE (COMPONENT 823 37416G03) . THE g, PL ANT W AS RETURNED TO MODE 1 - POWER OPERATIONS AT 0134 ON 12/31/90. A g CAPACITOR IN THE POWER $UPPLY SECTION OF THE CARD WAS THE CAUSE OF THE CARD FAILURE. THE FAILURE OF THE CAPACITOR IS INDETERMINATE. CORRECTIVE ACTIONS INCLUDt THE FAILURE HISTORY AND OTHER APPLICATIONS OF THE USE OF THIS CAPACITOR WILL BE EVALUATEDI AND AN EVALUATION WILL te ' SE PERFORMED TO DETERMINE THE FEASIBILITY OF ADDING A REOUNDANT CONTROLLER / DRIVER CARD TO THE CIRCUIT FOR THE FRV'S. te FORM 222 LER SCSS DATA 04-18-91 0 0********************************************************************

         ,,       00C8ET VEAR LER NUM8ER REVISION DCS NUMBER            NSIC     EVENT DATE 498    1989
      .                                001          0    8902070184 212969         01/03/89
                  ***ee***************************************************************

e 4BSTRACT POWER LEVEL - 100%. AT 1317 HOURS ON JANUART 3, 1989 WITH UNIT 1 IN t ,. MODE 1 AT 100% POWER, A REACTOR TRIP OCCURRED ON OVER TEMPERATUREt0 ELTA TEMPERATURE 45 4 RESULT OF A F4ILURE IN THE MAIN

   ,               TURBINE GENERATOR ELECTRO-HTDRAULIC CONTROL (EHC) SYSTEM WHICH CLOSED
        ,;         THE TUR8INE GOVERNOR VALVES. THE MOST PROBABLE CAUSE OF THIS EVENT WAS DETERMINED TO SE A POORLY CRIMPE0 LUG ON AN INTERCONNECTING WIRE WHICH SUPPLIED POWER TO SEVERAL FRAMES OF PRINTED CIRCUIT CARDS IN THE
        ,          EHC CABINET. THIS RESULTED IN 4 HIGH RESISTANCE CONNECTION WHICH OROPPED THE POWER SUPPLY VOLTAGE TO SEVERAL CARDS WHICH CONT 4IN DIGITAL AND ANALOG CIRCUITS RESPONSISLE FOR CONTROL OF TUR81NE VALdES,
        ,;         TUR8INE PROTECTION AND OPERATOR INTER 74CE. CORRECTIVE ACTIONS INCLUDE REPLACEMENT OF THE DEFECTIVE WIRE AND CHECK OF OTHER SIMILAR WIRES FOR EXCES$1VE VOLTAGE DROP.

ls 1

FORM 223 LER SCSS DATA 04-15-91 g, 0********************************************************************

   ,              DOCKET TEAR LER NU98ER REVISION DCS NuM9Fo            MtTr    event aav=

ABSTRACT p1 POWER LEVEL - 100%. 01 JANUARY 20, 1937, UNIT 1 WAS IN MODE 1 AT 100% POWER. AT 1017 HOURS, ALARMS WERE RECEIVED IN THE CONTROL ROOM F02 pq TUR81NE GENERATOR HIGH VISRATION, AND SEARING 8 AND 9 HIGH i TEMPERATURE. A FIRE WAS SUBSEQUENTLT REPORTED AT BEARING 9. THE DELUGE SYSTEM WAS ACTUATED, THE TURBINE WAS MANUALLY TRIPPED AND THE

> D8            REACTOR AUTOMATICALLY TRIPPED AT 1123 HOURS. THE FIRE WAS                                                                                              -

! EXTINGUISHED IN 14 MINUTES. THE CAUSE OF THE EVENT WAS LOSS OF , pq COOLING OF THE GENERATOR HYDROGEN. THE RESULTING INCREASE IN HYDROGEN TEMPERATURE AND PRESSURE CAUSED LEAKAGE FROM THE BEARING SEALS. THE g4 , LOSS OF COOLING OF THE HTOROGEN IS BELIEVED TO HAVE BEEN CAUSED BY A ' LOOSE TEMPERATURE SENSOR CONNECTION T3 THE HTOROGEN GAS TEMPERATURE b8 CONTROLLER. THE EFFECTS OF THE LOSS OF COOLING WERE NOT IMMEDI ATELY

        ,       DETECTED DUE TO THE FAILURE OF TWO INPUTS TO THE HYDROGEN SYSTEM COMMON TROUBLE ALARM IN THE CONTROL ROOM. CORRECTIVE ACTIONS INCLUDE be             INSPECTION OF THE GENERATOR, REPAIR OF THE SEARING SEALS, REPAIR OF THE HTOR0 GEN CONTROLLER, M00!FICATION OF THE CONTROLLER DESIGN AND REPAIR OF THE INPUTS TO THE CONTROL ROOM ANNUNICATOR.

b1 FORM 224 LER SCSS DATA 04-18-91 0************e*** ********************************* *************.

y,, DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 498 1989 015 1 9004200670 217791 07/04/89

               ****    **ee*******...* ...*.e            .....********************** ***********

3a ABSTRACT ti POWER LEVEL - 1004. ON 7/4/99, UNIT 1 WAS IN MODE 1 AT 100% POWER. AT 1915 HOURS, THE MAIN GENERATOR OUTPUT CIRCUIT BREAKER OPENE0. THE

   ,,           MAIN TURBINE GOVERN 3R VALVES CLOSED TO LIMIT YUR8INE OVERSPEED AND 4 REACTOR TRIP SYSTEMS RESPONDED AS DESIGNED AND NO UNIXPECTED POST-TRIP TRANSIENTS OCCURRED. THE CAUSE OF THIS EVENT WAS THE L41 LURE OF A 125 D'           VDC RATED AUXILIARY RELAY WHICH WAS ERR 0NEOUSLT USED IN THE 250 VDC GENERATOR CIRCUIT BREAKER TRIP CIRCUIT. IT HAS SEEN DETERMINED THAT

g. THE INCORRECT RELAY WAS $UPPLIED TO HLSP BY THE VENDOR. AN ERROR WAS MADE IN TRANSPOSING THE HL&P PURCHASE ORDER REQUIREMENTS TO THE

   '*           VENDOR'S PURCHASE ORDER WITH THE RELAY SUS-SUPPLIER. SINCE THE VENDOR j     ,         TAGGED THE RELAVS CORRECTLY, THE ERROR WAS NOT DETECTED DURING RECEIVING VERIFICATION. THE FAILEO RELAY AND ONE OTHER 125 VDC RELAY 4

HAVE 8EEN REPLACED WITH THE CORRECT MODEL. 250 VDC CONTROL CIRCUITS

      ,         IN UNIT 2 HAVE SEEN INSPECTED FOR SIMILAR RELAYS WHICH ARE NOT OF THE
   ,            CORRECT RATING.       NO OTHERS WERE FOUND.

1

FORM 225 LER SCSS DATA 04-18-91 0********************************************************************

   '  .        DOCKEY VEAR LER NUMSER REVISION DCS NUMSER                                               MSIC EVENT DATE 498    1990         005                 0      9035050001 215100                                03/29/90 e**  ea **e...    ********e..   ***        e....*...     ****** ******* .***********

ABSTRACT

   '            POWER LEVEL - 100I. 04 MARCH 29, 1990, UNIT 1 WAS IN MODE 1 AT 100
      ,         PERCENT POWER. AT APPROXIMATELY 1443 HOURS, FEE 0 WATER BOOSTER PUMP (FBP) 11 TRIPPED UPON ACTUATION OF A GROUND FAULT RELAY. THE STAND 8Y PUMP, F8P 13, AUTOMATICALLY STARTEDI SUT DID ROT DELIVER SUFFICIENT
      ,         FLOW T3 PREVENT STEAM GENERATOR FEEDWATER PUMP 12 FROM TRIPPING ON LOW SUCTION PRESSURE.       ATTEMPTS TO MAINTAIN STEAM GENERATOR LEVEL WERE UNSUCCESSFUL AND THE REACTOR TRIPPED 04 LOW STEAM GENERATOR LEVEL.

f THE PLANT WAS SROUGHT TO A STABLE SHUTDOWN IN MODE 3. THE CAUSE OF THE F8P 11 TRIP HAS NOT TET 8EEN IDENTIFIE0I HOWEVER, IT IS BELIEVED THAT e A WEARNESS OF THE FBP 11 WINDINGS OR FEEDER CASLES AGGRAVATED BT g MOISTURE INTRUSION AND DIRT DUE TO CLOGGED AIR INLET FILTERS RESULTED

   ,            IN THE GROUND FAULT. CORRECTIVE ACTION IS SEING TAueN To nTeattruesc.

                           . - , ss..   ...saco ev eLg.Jw1LaLLY IhiPiCT AND CLEAN THE COOLING AIR

' FILTERS. SACKUP FBP 13 0I0 NOT PROVIDE ADEQUATE FLOW SECAUSE THE pq RECIRCULATION VALVE HA0 SEEN MANUALLY SET IN THE CPEN POSITION UNTIL THE VALVE CONTROLLER COULO BE REPAIRED. REPAIR TO THE F8P 13 RECIRCULATION VALVE CONTROLLER WILL GE COMPLETED DURING THE CURRENT ii* REFUELING OUTAGE. , 1

; he i   ,                  FORM          226                LER SCSS DATA pq              0************************************************************04+WO-923       ********

00CKET TEAR LER NUMBER REVISION DCS MUMSER NSIC EVENT.DATE 498 1990 006 0 9009060070 219444

   ==
                      .....................................................*......... 0?#3      0#90....

DW ABSTRACT POWER LEVEL - 100%. ON 7/30/90, UNIT 1 WAS IN MODE 1 AT 100% POWER. j g. AT APPROMIMATELY 1946, FEEDWATER ISOLATION VALVE 1A FULLY CLOSED

               ;         DURING A PARTIAL STROKE SURVEILLANCE TEST. THE RESULTANT LOSS OF D"                    FEE 0 WATER FLOW CAUSE0 A DECREASE IN STEAM GENERATOR LEVEL AND THE i

REACTOR WAS MANUALLY TRIPPEO. THE UNIT WAS STASILIZED WITH THE EXCEPTION OF LEVEL IN STEAM GENERATOR 1A WHICH DIO NOT RECOVER DUE 10 j be A MISPOSITIONED RECIRCULATION TEST VALVE IN THE TRAIN 4 AUMILIARY

FEEDWATER ST5 TEM (AFW). THE RECIRCULATION TEST VALVE WAS RETURNED TO

! y, THE REQUIRE 0 POSITION AND STEAM GENERATOR 14 LEVEL WAS RECOVERED. THE

F E E DW AT E R ISOLATION VALVE CLO5URE WAS CAUSED ST A TECHNICIAN R8 INADVERTENTLT CONTACTING THE WRONG TERMINAL WITH A TEST JUMPER. THE 4

CAUSE OF THE MISPOSITIONED RECIRCULATION TEST WALVE COULO NOT BE CONCLU$1VELT ESTABLISHE0; HOWEVER, IT IS LIKELY THAT THE WALVE WAS NOT pg CORRECTLY REPOSITIONED DURING A SURVEILLANCE TEST PRIOR TO THE EVENT, 1 4 AND THIS E RROR WAS NOT DISCOVERED OUE TO A LACK OF ADEQUATE

    "'                   INDEPENDENT VERIFICATION. CORRECTIVE ACTIONS INC LUD E: ISSUANCE OF i

TRAINING SULLETINS CONCERNING USE OF JUMPER $; EVALUATION OF ALTERNATIVE DESIGNS TO OSVIATE THE NEED TO PERFORM THE PARTIAL STROKE 8* TEST WITH JUMPER $; AND, ISSUANCE OF A ME MO R A NDUM TO OPERATIONS PERSONNEL TO REENFORCE THE REQUIREMENTS PERTAINING TO INDEPENDENT g, VERIFICATION. 1 FORM 227 LER SC55 DATA 04-18-91 0************************.*******+++*********************..********** i e 00CKET TEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 498 1990 014 0 9007240018 218885 06/2Lf90

    ,                 ...........................e*.....................................s.

A851RACT

' '                      POWER LEVEL - 0151. 04 JUNE 20, 1990 AT 0410 HOURS WITH UNIT 1 IN MODE 1 AT ISE POWER WHILE PERFORMING SYNCHRONIZATION OF THE MAIN GENERATOR j e        ,              TO THE GRID, A REACTOR TRIP - TUR8INE TRIP OCCURRED OUE TO i

UNDERVOLTAGE TO THE REACTOR COOLANT PUMPS. DURING THE EVENT

    ,                    ELECTRICAL POWER WAS LOST TO THE DIGITAL ROD POSITION IN0! CATION
          ,              (DRPI) ST5 TEM, NECESSITATING A MANUAL EMERGENCY 80 RATION SINCE IT 1

COULO NOT BE VERIFIED THAT ALL R005 WERE ON 80TTOM. THE REACTOR TRIP i

WAS INITIATED SV 4 GENERATOR BREAKER LOCK 0UT WHICH WAS CAUSED ST THE

,         ,-             SPURIOUS ACTUATION OF A GENERATOR BREAKER POLE FAILURE RELAT. THIS GENERATOR BREARER LOCKOUT LED TO THE LOSS OF POWER TO THE UNIT AUMILIART TRANSFORMER WITH RESULTING LOS$ OF POWER TO THE REACTOR
^         ,             COOLANT PUMP 5 AND SUBSEQUENT REACTOR TRIP. CORRECTIVE ACTIONS INCLUDF CALIBRATING THE RELAY AND INCLUDING IT IN THE PREVENTATIVE MAINTENANCE PROGRAM.         IN ADDITIch, CORRECTIVE ACTIONS ARE BEING t                   CONSIDERED TO MINIMIZE THE POSSIBILITY OF LOS$ OF POWER EVENTS DURING 4

i GENERATOR SYNCHRONIZATION.

    ,              1 I

FORM 225 LER SCSS DATA nA-to-ot

                                           . .        .,..                  u.,            a                   *v>313Jdeo      210233     06/23/90 P1 ASSTRACT kW                              P3YER LEVEL - 0762. AT 0554 HOU25 ON JUNE 28, 1990 WITH UNIT 1 IN MODE j

1 AT 76 PERCENT POWER A REACTOR TRIP OCCURRED OUE TO A TUR8INE TRIP

        !                                WHICH WAS CAUSED BY LOW ELECTR0 HYDRAULIC CONTROL (EHC) SYSTEN FLUID b4                             PRESSURE. THE PLANT WA5 BROUGHT TO A STASLE CONDITION IN MODE 3. THE
                       ;;                CAUSE OF THIS EVENT WAS F4ILURE OF AN EHC SUPPLY LINE TO 4 MAIN pq                              TUR8INE GENERATOR THROTTLE VALVE.                                     THE LINE FAILED DUE TO EXCESSIVE i                                         VIBRATION INDUCED EV OSCILLATION IN A MAIN TUR81NE GENERATOR GOVERNOR
                       ;'               VALVE. THE OSCILLATIONS WERE CAUSED 8Y A LOOSE CONNECTION IN THE pd                               CONTROL CIRCUIT. INVESTIG4 TION REVEALED THAT THE EHC SYSTEM PIPING CONTAINED A NUM8ER OF LESS THAN ADEQUATE SUPPORTS AND THAT PORTIONS OF DW , * -                        THE PIPING HAD LESS THAN THE SPECIFIED WALL THICENESS. CORRECTIVE                                                                                                                                  .

ACTIONS INCLUDE REPAIRING THE LOOSE CONNECTION AND REPLACING THE LESS b1 THAN ADEQU4TE PIPING AND SUPPORTS. y D4 FORM 229 LER SC55 04T4 04-18-91

                       ,,          0********************************************************************

pg DOCKET VEAR LER NUMBER REVISION OCS NUMSER NSIC EVENT DATE 498 1990 016 0 9003070019 219066 07/02/90

          ,4           ,,              ********************************************************************

485 TRACT B4 , POWER LEVEL - 000%. ON JULY 2, 1990, UNIT 1 WAS IN MODE 1 AT ABOUT 100 i PERCENT POWER. AT 1803 HOUR $ 4 REACTOR TRIP WAS INITIATED WHEN 2 OUT ]' p3 0F 4 COINCIDENCE WAS SATISFIED ON OVER TEMPERATURE / DELTA TEMPERATURE

                    ,                    (OT DELTA T). UNIT 1 WAS IN POWER ASCENSION AND LOOP 4 DELTA b'                             TEMPERATURE AND T AVERAGE SISTABLES WERE IN A TRIP CONDITION TO E

SUPPORT THE SURVEILLANCE IN PROGRESS. DUE TO A DECREASE IN RE4CTOR

                    ,                   COOLANT SYSTEM (RCS) PRESSURE, LOOP 3 OT DELTA T TRIPPED WHEN THE
          &*                             SETPOINT REACHED THE ACTUAL DELT4 T. TWO OF THE FOUR CHANNELS IN A TRIPPED CON 0! TION SATISFIED THE TRIP LOGIC AND INITISTED THE REACTOR g,         ,:                  TRIP.       A FEEDWATER ISOLATION OCCURRED ON LOW AVERAGE REACTOR COOLANT SYSTEM TEMPERATURE AND AN AUXILIART FEEDWATER SYSTEM ACTU4 TION OCCURRED ON LOW STEAM GENERATOR LEVEL 45 EXPECTED. THE MAIN STEAM L'

ISOLATION VALVES WERE MANUALLY CLOSED TO LINIT THE COOLDOWN AND THE PLANT WAS STABILIZED IN MODE 3. NO UNEXPECTED POST TRIP TRAN5IENTS e WERE OBSERVED. CORRECTIVE ACTIONS TO PREVENT THIS INCIDENT INCLUDE

                     ,                  LOGGING OT DE LT A T AND ACTUAL DELTA T EVERT SHIFT AND REQUIRING THAT
          ,,                            POWER NOT SE INCREASED WHEN A80VE 90 PERCENT UNLESS ALL CHANNELS OF OT DELTA T ARE OPERABLE DURING POWER ASCENSION.

1

I-FORM 230 LER SC55 OATA 04-15-91

, e                               0********************************************************************

t DOCKEY TEAR LER NUMBER REVISION OCS NUMSER N5IC EVENT DATE

          ,,                              498        1990                   020            0                   9005240175 219381          07/16/90
 ,         t                           4)STRACT
                    ,,                  PUWER LEVEL - 1003. AT 0236, ON JULY 15, 1990 WITH UNIT 1 AT 100%
<                                       POWER, A REACTOR TRIP OCCURRED DURING PERFORMANCE OF A SOLIO STATE

PROTECTION SYSTEM (55PS) SURVEILLANCE TEST. THE TRIP WA5 CAUSED SY A l ,, MALFUNCTION IN A TEST SWITCH WHICH RESULT!O IN ONE TRAIN OF 55P5 REMAINING IN THE URGENT ALARM CONDITION, COUPLED WITH COMPLETION OF A SU65EQUENT PROCEDURAL STEP THAT PLACED THE OTHER 55P5 TRAIN IN THE

,          I g;                  URGENT ALARM CONDITION. THE SSPS IS DESIGNEC SUCH TMAT IF S0TH LOGIC TRAINS ARE PLACEO IN THE URGENT ALARM CONDITION, A REACTOR TRIP i                            OCCURS.           THE TEST SWITCH WILL EE REPLACED PRIOR TO STARTUP FROM THE g                   NERT REFUELING OUTAGE.                    IN ADDITION, TEST PROCEDURES HAVE BEEN REVISED T

e .O. . E.

                                               . .N
                                                  . -5U.R
                                                     .      E . T H A T. UR G E N T ALARM CONDITIONS ARE SATI5FACTORILY CLEARED
                                             -              ,...- - -~          -,-,,..v,. _ . . . . , , , ,           , , ,       ,

I p, FORM 231 LER SCSS DATA 04-IS-91 i 0........................................................... ........ ' b4 03CKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EV!NT DATE li 498 1990 023 0 9011070028 219955

      >=
                                .................*............................................ 29/90            09/

l A85 TRACT

     ,              y I

pq POWER LEVEL - 100%. 04 SEPTEMBER 29, 1990, UNIT 1 WAS IN MODE 1 AT 100% POWER. AT 0232 HOURS, FEEDWATER !$0LATION VALVE 14 FULLY CLOSED i "4 g; OURING AN " ALTERNATE" PARTIAL STROKE SURVEILLANCE TEST. THE RESULTANT LOSS OF FEEDWATER FLOW CAUSED A DECREASE IN STEAM GENERATOR LEVEL AND THE REACTOR WAS MANUALLY TRIPPED. DURING RECOVERY, A STEAM GENERATOR , NW ;; POWER OPERATED RELIEF VALVE (PORW) WAS MANUALLY OPENED TO APPROXIMATELY 30% WHILE INDICATING APPROXIMATELY 5% OPEN. AT 0345 l be HOURS, AN AUXILIARY FEEDWATER (AFW) ACTUATION OCCURRED 04 LOW-LOW i i STEAM GENERATOR (SG) LEVEL. THE SG PORV WAS CLOSED AND THE PLANT WAS STABILIZED. THE FEEDWATER ISOLATION VALVE CLOSURE WAS CAUSED BY A ! h4 TECHNICIAN INADVERTENTLY CONTACTING THE WRONG TERMINAL WITH A TEST i g, JUMPER. THE CAUSE OF THE AFW ACTUATION DURING RECOVERY WAS FAILURE OF l bg A REACTOR OPERATOR TO CONFIRM THE POSITION OF THE SG PORV BY ' NONITORING SG LEVEL AND PRES $URE INDICATIONS WHEN THE VALVE POSITION

      ,4 g                        INDICATOR OISPLATED SOME UNCERTAINTY. CORRECTIVE ACTIONS INCLUDE:

ADDITION OF SPECIAL CONNECTORS ON THE TERMINALS IDENTIFIED IN THE

      #8                          " ALTERNATE" PARTIAL STROKE TEST PROCEDUREJ THE USE OF SPECIAL

g. INSULATED JUMPERS OURING PERFORMANCE OF THE STROKE TESTJ PERFORMANCE OF THE PARTIAL STROKE TEST ON A MONTHLY BASIS v!CE WEEKLY.

33 1 FORM 232 LER SCSS DATA 04-18-91 l >' 0*****************************************.2************************* l I 9, DOCKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE l >e 498 1990 025 0 9012280111 220614 11/24/90 , ... e* .................................... *ee..................... te t ABSTRACT POWER LEVEL - 1001. 04 NOVEMBER 24, 1990, UNIT 1 W3" IN MODE 1 AT 100% I' POWER. AT 1443 HOURS, THE GENERAT02 RUNNING GROUND FAULT RELAY *

                  ,i ACTUATED DUE TO A ST AT OR COIL END TURN FAILURE WHICH INITIATED AN AUTOMATIC REACTOR TRIP. ALL SYSTEMS RESPONDED AS EXPECTED WITH NO
                  ,;              ENGINEERED SAFETY FEATURES ACTUATIONS.                  INITIAL INTERNAL INSPECTION OF
       ,                          THE GENERATOR REVEALED DAMAGE TO THE END TURN OF STATOR COIL #20 AT THE TURSINE END. THE GROUNO FAULT RELAY ACTUATION WAS OUE TO ELECTRICAL ARCING FROM THE FAILED STATOR COIL END TURN TO THE STATOR 8

COOLING WATER SYSTEM MANIFOLD. FURTHER TESTING AND INSPECTIONS ARE PLANNED TO IDENTIFY THE CAUSE OF THE FAILURE AND APPROPRIATE e , CORRECTIVE ACTIONS. A SUPPLEMENTAL REPORT WILL BE SUBMITTED FOLLOWING i RETURN OF THE GENERATOR TO OPERATION AND COMPLETION OF ASSOCIATED (( I TESTING. ( 4 FORM 233 LER SCSS DATA 04-18-91 $

                 ,.           0****************************************************.***************

DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 409 1959 009 0 3905110063 213547 04/05/89 g, .eeeeeeeeeeeee............ *e...........**.......................... 485 TRACT POWER LEVEL - 011%. 04 4#05/89, UNIT 2 WAS IN MODE 1 AT 11% POWER 4 PERFORMING INITIAL SYNCHRONIZATION TO THE GRID. AT 0729 hours,

       .                         APPROXIMATELY FOUR SECONDS AFTER CLOSURE OF THE GENERATOR BREAKER, A g,               REACTOR TRIP AND LOSS OF 0FFSITE POWER 04 THE AUX. SUSSES AND THE e

4.16KV,,,,......ENGI.NEERE.D TRAIN A . ... . .. .. SAFETT FEATURES SUS OCCURRED. ONCE THE

_.. . .. .. .... 4 . cu. eau % ar 40x. Fid0w116R. THE CEUSE 05 THIS EUet.T WAS I"P50p!R INSTALLATION 38 4 WIRING CHANGE TO THE p9 G2NERATOR PR3TECTIUE RILETING Bf STARTU* TECHNICIANS PRIOS TO SYSTEH TU3NOVER TO PLANT OPERATIONS. THE CAUSE OF THE INA00ERTENT RCP 20 kg CE3TAQT Was A 5ROKEN LUG IN THE TR!p CIRCUIT DUE TO ITS ASSOCIATED WIRE CATCHING 04 THE BREAKER ENCLOSURE WHEN THE SREAKER WAS RACKED IN

            >4                     LAST. CORRECTIVE ACTIONS INCLUDE CORRECTION OF THE GENERATOR PROTECTIVE RELAY WIRING, TESTING OF OTHER PROTECTIVE CIRCUITRY, REPLACEMENT OF THE RCP 20 BREAKER LUG AND CHECKING THE OTHER UNIT 2 pq                      RCP SREAKERS.

1 LO FORM 234 LER SCSS DATA 0**************************************************+*********04-18-91 ******** i ka i DOCKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 499 1989 013 0 9905300038 214015 04/15189 he ******************************************************************** A85 TRACT

             ""                     POWER LEVEL - 0243. ON APRIL 15, 1999, UNIT 2 WAS IN NODE 1 AT 24
                           .t       PERCENT POWER.                 AT 0517 HOURS A REACTOR TRIP OCCURRED WHEN THE TRAIN 5 bg                                                                                                                        .

REACTOR TRIP BREAKER OPENED UNEXPECTEDLY. A REACTOR TRIP SYSTEM ACTUATION SUSSEQUENTLY OCCURRED ON " POWER RANGE NEG4TIVE RATE". THE b,, REACTOR WAS BROUGHT TO AN ORDERLY SHUTOOWN AND NO UNEXPECTED POST-TRIP

TRANSIENTS OCCURRED. THE CAUSE OF THIS EVENT IS UNKNOWN. THE II REACTOR TRIP BREAKERS AND ASSOCIATED CIRCUITRY WERE TESTED.

                           ,        ADDITIONAL DIAGNOSTIC 4CTIVITIES WERE A TTEMPTED, HOWEVER NO PROBLEMS WERE FOUND.

i pg 1 I

             , .                  FORM        235                           LER SCSS DATA                           04-18-91 0********************************************************************
                           ,      DOCKET TE4R LER NUMBER REVISION DCS NUMSER                               NSIC   EVENT DATE D'                     499       1959                 916            0       8907100202 214534        06/02/89 s..

ABSTRACT POWER LEVEL - 0763. 04 JUNE 2, 1959. UNIT 2 WAS IN MODE 1 AT 76

                           ,       PERCENT POWER. AT 0354 HOURS, DURING THE PERFORMANCE OF THE MAIN TURBINE STEAM INLET VALVE 08ERASILITY TEST, A REACTOR TRIP AND TURBINE e

TRIP OCCURRED ON COMPLETION OF TWO OUT OF FOUR LOGIC FOR CLOSE0 TURBINE INLET THROTTLE VALVES. THE PL4NT WAS BROUGHT TO AN ORDERLY SHUTDOWN WITH NO UNEXPECTED TRANSIENTS. THE EVENT OCCURRED AFTER A LIMIT SWITCH 04 TURBINE INLET V4LVE TV-1 STUCK. WHEN THE VALVE W45 CLOSED AND REOPENED DURING THE PERFORMANCE OF THE TEST, THE LIMIT SWITCH STUCK IN THE VALVE-CtOSED 80SITION WHICH PREVENTED CLEARING OF THE TRIP SISTABLE. THIS CONDITION WAS NOT RECOGNIZED 45 4 RESULT OF A

              '            ,       DEFICIENT TEST PROCEDURE. WHEN A SECOND VALVE WAS TESTED AND STROKED CLOSED, THE MINIMUM TRIP LOGIC WAS SATISFIED AND THE REACTOR TRIP
              ,                    OCCURRED. THE DEFECTIVE LIMIT SWITCH HAS SEEN REPLACED. CORRECTIVE ACTIONS INCLUDE A REVISION TO THE TURBINE INLET VALVE YEST PROCEDURES AND REVIEW O' OTHER SURV!ILLANCE PROCEDURES FOR SIMILAR WEAKNESSES.

4DDITIONALLY, THE TURSINE INLET THROTTLE VALVE LIMIT SWITCHES, THE ONLY SIMILAR SWITCHES SROM THIS MANUF4CTURER WHICH PERFORM A SAFETT-RELATED ACTUATION, WILL SE REPLACED. 1 FORM 236 LER SCSS 04T4 04-18-01 0************************** ***.*************************************

                          ,       00CKEY TEAR LER NUMBER REVISION DCS NUMSER                               NSIC   EVENT DATE 499       1989                 017            0       9903210249 215037        07/13/89
               .                  485 TRACT

                      .       . . . . . ,         ~-.e,-    .s  4 4m: *=JI:LIIV: 4ELAYS TRioDED THE TUR8INE AND ACTUATED THE SWITCHiARC A40 GENERATOR BREAKERS TO CLEAR pq                   THE FAULT.             THE REACTOR TRIPPED ON THE TURBINE TRIP. THE *LANT WAS CROUGHT TO AN ORDERLT COOLDOWN WITH NO UNEXPECTED PRIMARY SYSTEM P03T b4                   TRIP TRANSIENTS. THE INVESTIGATION OF THE TRANSFORMER FAILURE IS ONGOING.             THE MOST PROBA8tE CAUSE WAS *AILURE OF THE NIGH SIDE, PHASE A SUSHING. THE TRANSFORMER WILL SE RETURNED TO THE MANUFACTURER FOR WW REPAIR AND THE SUSHING AND TRANSFORMER WILL BE ANALYZED FURTHER TO
         ;            DETERMINE THE CAUSE OF THIS EVENT.

I P1 i FORM 237 LER SCSS DATA bl 0************************************************************04-18-91 ******** DOCKET YEAR LER NUMSER REVISION DCS NUMBER NSIC EVENT DATE he , 499 1989 019 0 8910030051 216367 08/23/89 i 485 TRACT I he POWER LEVEL - 100%. ON $/23/89, UNIT 2 WAS IN MODE 1 AT 1003 POWER. AT 0119 HOURS, FEEDWATER ISOLATION VALVE C CLOSED FULLY DURING A PARTIAL STROKE SURVEILLANCE TEST. THE RESULTANT LOSS OF FEEDWATER be ' FLOW AND DECREASE IN STEAM GENERATOR LEVEL CAUSED A REACTOR TRIP. THE UNIT WAS STASILIZED IN MODE 3 WITH NO UNEXPECTED POST TRIP

 ,,       i TRANSIENTS.              THE CAUSE OF THIS EVENT WAS A FAILURE IN THE FEEDWATER ISCLATION VALVE CONTROL CIRCUIT WHICH ALLOWED IT TO STROKE FULLY CLOSED.             THE SPECIFIC COMPONENT WHICH FAILED IS UNKNOWN AT THIS TIME.

R-a THE FAILURE DID NOT AFFECT THE ABILITY OF THE VALVE TO PERFORM ITS SAFETY FUNCTION. FURTHER TROUSLESH00 TING OF THE VALVE CONTROL y, CIRCUITS WILL DE PERFORMED DURING THE NEXT SCHEDULED MAINTENANCE OUTAGE. THE FEE 0 WATER VALVE CONTROL CIRCUITS ARE SEING REVIEWED TO

 "'                  DETERMINE IF MODIFICATIONS CAN BE PERFORMED TO REDUCE THE POTENTIAL I

FOR FULL CLOSURE OF THE VALVES DURING TESTING.

          +
             , 1 be FORM            238                      LER SCSS DATA                                   04-18-91 t,            0***************************************+****************************

DOCKET YEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 499 1989 020 0 8910040297 215393 OS/29ts9 e ABSTRACT POWER LEVEL - 100X. ON S/29/59, UNIT 2 WAS IN MOD E 1 AT 100% POWER.

 ,                    AT 1400 HOURS ALL THREE OPEPATING TURSINE DRIVEN FEEDWATER PUMPS TRIPPED. THE LICENSED CONTROL ROOM OPERATOR IMMEDIATELY TRIPPED THE
       ,              REACTOR IN ANTICIPATION OF LOW STEAM GENERATOR LEVEL. AN AUXILIARY I

FEEDWATER ACTUATION SUBSEQUENTLY OCCURRED ON LOW STEAM GENERATOR LEVEL. THE UNIT WAS STABILIZED IN MODE 3 WITH NO UNEXPECTED PD$T-TRIP e , TRANSIENTS. TH! CAUSE OF THIS EVENT WAS A MOMENTARY INTERRUPTION OF CONTROL POWER TO THE FEEDWATER PUMP OVERSPEED PROTECTION CIRCUITS DUE

 '                   TO THE FAILURE OF AN INVERTEP. A CONTRISUTING CAUSE WAS THE DESIGN OF
       ,,            THE FEEDWATER PUMP OVER5 PEED PROTECTION CIRCUITS WHICH COULO NOT TOLERATE THE MGMENTART LOSS OF CONTRCL POWER WITHOUT TRIPPING THE PUMPS.             THE INVERTER HAS SEEN REPAIRED AND RETURNED TO SERV!CE. THE
     .,             DESIGN OF THE FEEDWATER PUMP OVERSPEED *ROTECTION HAS SEEN MODIFIED TO AN

ENERGIZE TO TRIP" SCHEME ON UNIT 2 AND WILL SE MODIFIED ON UNIT 1 PRIOR TO STARTUP FROM THE FIRST REFUELING OUTAGE.

1 FORM 239 LER SCSS DATA 04-18-91

      ,        0********************************************************************

DOCKET TEAR LER NUMBER REVISION DCS NUMSER NSIC EVENT DATE 499 1989 021 0 5910160050 215583 09/05/89 g

                    ,    e- 1                 -4e        -          '-    --- - - - ' ' 4      m 6 w --      - ' - - -                      --                     -w

                                                                                                   , . .       m
                  . . . _ . .  ....s.  -.   *ressa;M41 LT 1adi nJU45, CONTROL ROJM GPERATORS OBSERVED SPEED OSCILLATIONS 04 VME TUR3INE OSIUEN STEAM GENERATOR p1              FEEDWATER PURP ($GFP) 21o THE OPEPAT3RS ATTEAPTED TO REGAIN SPEED CONTROL 3 HOWEVER, THE DUMP OID HOT RESPOND ONO SUBSEQUENTLY TRIPPQD ON bd              OVERSPEED. THE RESULTANT LOSS OF STEA4 GENERATOR LEVEL CAUSED &

ti' REACTOR TRIP AND AUXILIARY FEE 0 WATER SYSTEM ACTUATION. NO SAFETT INJECTION ACTUATION OCCURRED. THE PLANT WAS STASILIZED IN MODE 3. bW THE CAUSE OF THIS EVENT WAS A DEFECTIVE SGFP 21 SPEED CONTROLLER CARD

' eq p EDGE CONNECTOR WHICH WAS DISTURSEO 8T A MAINTENANCE TECHNICIAN DURING TROUBLESHOOTING OF A CARD ASSOCIATED WITH SGFP 22 IN THE SAME CARD i FRAME. THE DEFECTIVE CONNECTOR WAS RE*AIREO, THE CARD FRAME ALIGNMENT CHECKE0, THE REMAINING PRINTED CIRCUIT C ARDS AND EDGE CONNECTORS WERE Ed: INSPECTED AND THE CONTACT SURFACES WERE CLEANED. THE PRINTED CIRCUIT CARDS IN THE SPEED CONTROLLER CIRCUITS ON UNIT 1 WERE ALSO INSPECTED be q, AND CLEANEO.

           ,,    FORM       240                  LER SCSS DATA                        04-18-91 0********************************************************************

D" 00CKET TEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

         .,         499       1989       022           0      8910270113 215716       09/19/89 he           ********************************************************************

gg ., A85 TRACT POWER LEVEL - 100%. ON SEPTEMBER 19, 1989, UNIT 2 WAS IN MODE 1 AT 100 PERCENT POWER. AT 1237 HOURS DURING THE CROSS CALIBRATION OF THE D8 INCORE AND EXCORE NUCLEAR INSTRUMENTATION, AN OVERTEMPERATURE DELTA TEMPERATURE (OTOT) TUR81NE RUNSACK OCCURRED RESULTING IN AN OTDT p1 REACTOR TRIP. THE TURSINE TRIPPED ON THE REACTOR TRIP AND AN AUXILIARY FEE 0 WATER ACTUATION OCCURRED ON LOW STEAM GENERATOR LEVEL. THE MAIN STEAM ISOLATION VALVES WERE CLOSE0 TO PREVENT EXCESSIVE I' REACTOR COOLANT SYSTEM COOLDOWN. THE ENGINEERED SAFETT FEATURES FUNCTIONED AS DESIGNED. THE CAUSE OF THIS EVENT WAS THAT THE TURSINE b4 RUMBACK SETPOINT DESIGN DID NOT PROVIDE SUFFICIENT OPERATING MARGIN TO ALLOW FOR SMALL DEv!ATIONS IN RCS AVERAGE TEMPERATURE. .THE OTOT ge RUN8ACK FEATURE HAS BEEN DISABLE 0 AND ANALYSIS IS BEING PERFORMED TO DETERNINE IF IT CAN SE RESTORED WITHOUT CAUSING UNWANTED PLANT TRANSIENTS. 4 FORM 241 LER SCSS DATA 04-15-91

         , *i 0********************************************************************
    ,            DOCKET TEAR LER NUMBER REVISION OCS NUMBER                NSIC     EVENT DATE 499       1989        023          0      8911010105 215717       09/22/89 ABSTRACT t             POWER LEVEL - 0941. ON 9/22/E9, UNIT 2 WAS IN MODE 1 AT 94% POWER.            AT 0201 HOURS & TURSINE TRIP OCCURRED ON LOS$ OF POWER TO THE FOUR MAIN
    ,             TUR81NE AUTO STOP SOLEN 0 IDS.         THE REACTOR TRIPPED 04 THE TURSINE TRIP.

A MAIN FEEDWATER ISOLATION AND aux!LIART FEEDWATER ACTUATION OCCURRED ON LOW AVERAGE REACTOR COOLANT SYSTEM TEMPERATURE AS EXPECTED. THE UNIT WAS STABILIZE 0 IN MODE 3 WITH NO UNEXPECTED

             . POST-TRIP TRANSIENTS. THE CAUSE OF THIS EVENT WAS FAILURE OF A NON-SAFETT-RELATED INVERTER WHICH INTERRUPTED POWER TO THE MAIN TURBINE AUTO STOP SOLENDIDS. A CONTRIBUTING CAUSE WAS THAT THE DESIGN
         .;       DID NOT PROVIDE FOR THE SINGLE FAILURE OF A POWER FEED. THE INVERTER

, NAS 8EEN REPAIRED AND RETURNED TO SERVICE. THE POWER FEED DESIGN hAS SEEN CHANGED 70 ADO AN ADDITIONAL POWER SOURCE. 1 i FORM 242 LER SCSS DATA 04-13-91 g- 0********************************************************************

     .           DOCKET TEAR .LER NUMBER REVISION 3CS NU'RER               NtTC     *v5=?  '878 l                                                                                                         ... -

. =

ABSTRACT P1 DOWER LEVEL - 130%. ON OCT03E7 13, 1937, UNIT 2 WAS IN MODE 1 AT 100% POWER. AT 1745 HOURS, A REACTOR TRIP OCCURRED DUE TO THE DETECTION OF gq HIGH NEUTRON FLUX NEGAT!vE RATE ON 2 0F 4 POWER RANGE NEUTRON

          .i       MONITORING CHANNELS. THE PLANT WAS BROUGHT TO 4 STABLE CONDITION IN bd               MODE 3 WITH NO UNEXPECTED POST-TRIP TRANSIENTS. THE CAUSE OF THE                  '

EVENT IS 8ELIEVED TO BE AN INTERMITTENT HIGH RESISTANCE CONNECTION ON eq A STATIONARY GRIPPER 0100E IN THE ROD CONTROL SYSTEM WHICH CAUSED ROD ' F-8 IN CONTROL BANK A TO DROP. THE DIODE HAS BEEN REPLACED. THE REMAINING STATIONARY GRIPPER DIODES ON BOTH UNITS WILL SE INSPECTED g OURING THE NEXT SCHEDULED MAINTENANCE OUTAGE ON ESCH UNIT. i 44 l; FORM 243 LER SCS$ DATA 04-18-91 0..............**.....*.*...****.*....*..**.***...*..**..... ........ ' DC DOCKET T!AR LER NUMBER REVISION CCS NUMBER NSIC EVENT DATE g, 499 1990 002 0 9003140403 217385

                  .........*....**..*a ee.........**.***********e.*******..e**02/02/90 *....***

i qg A85 TRACT D4 POWER LEVEL - 100%. ON FEBRUAPT 2, 1990, UNIT 2 W45 IN MODE 1 AT 100 PERCENT POWER. AT 0259 HOURS THE TRAIN "S" RE4CTOR TRIP BREAKER b di SPURIOUSLT OPENE0. THIS INITIATED A TURBINE TRIP AND SUSSEQUENT REACTOR TRIP. FEEDWATER ISOLATION OCCURRED ON LOW AVER 4GE REACTOR I8 q, COOLANT SYSTEM TEMPERATURE AND AN AUXILIART FEEDW4TER SYSTEM ACTUATION OCCURRED ON LOW STEAM GENERATOR LEVEL 45 EXPECTED. THE PLANT WAS STABILIZED IN MODE 3. NO UNEXPECTED POST TRIP TRANSIENTS OCCURRED. p -e EXTENSIVE TROUBLESHOOTING OF THE SOLID STATE PROTECTION STSTEM AND THE a.

REACTOR TRIP SRE4KER WAS PERFOPMEDI H3 WEVER, THE CAUSE OF THE

  ,,               SPURIOUS BREAKER OPENING IS UNKNOWN. AS A CONSERVATIVE MEASURE, THE
  ;                FIFTEEN UNIVERSAL LOGIC CARDS ASSOCIATED WITH THE REACTOR TRIP FUNCTION IN TRAIN "S" 0F THE SOLID STATE PROTECTION SYSTEM HAVE SEEN D'

REPLACED. INSTRU1ENTATION HAS 8EEN INSTALLED ON THE REACTOR TRIP BREAKER IN AN ATTEMPT TO ISOLATE THE SOURCE OF THE SPURIOUS TRIP ge SIGNAL SHOULD IT RECUR. 1

  !*              FORM     244                  LER SCSS DATA                          04-1 0***.*********************************************************.**8-91       ****

e DOCKET YEAR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE 499 1990 004 0 9005020166 218052 03/26/o0

   ,,             .......*.e    ....* . *........****.    *.e**.**..e**e.....**.......... **

ABSTRACT POWER LEVEL - 100%. ON MARCH 26, 1990, UNIT 2 WAS IN MODE 1 AT 100 PERCENT POWER. AT 0721 HOURS, 4 STEAM FLOW / FEED FLOW MISMATCH ALARM e WAS RECEIVED ON STEAM GENERATOR 2 C. FEE 0 WATER FLOW TO STEAM GENERATOR 2 C H4D DECREASED TO 50 PERCENT OF FULL POWER FLOW. ATTEMPTS TO

  ,                MANUALLY CONTROL THE STEAM GENERATOR 2 C FEEDW4TER REGULATING VALVE TO
            .      RESTORE FEE 0 WATER FLOW WERE UNSUCCESSFUL. THE REACTOR SUSSEQUENTLY TRIPPED ON LOW STEAM GENERATOR LEVEL.        THE PLANT WAS OROUGHT TO A STABLE CONDITION IN MODE 3 WITH NO UNEXPECTED POST TRIP TRANSIENTS.

THE CAUSE OF THIS EVENT WAS SEPARATIDN OF THE FEEDWATER REGULATING VALVE STEM FROM THE PLUS WHICH ALLOWED THE PLUG TO LCDGE IN THE FEE 0 WATER FLOW STREAM RESTRICTING FLOW TO APPROXIMATELT 50 PERCENT.

       ,           THE UNIT 2 FEE 0 WATER REGULATING VALVE STEMS HAVE BEEN WELCED TO THE PLUGS TO PREVENT SEPARATION. THE UNIT 1 FEEDW4TER REGULATING WALVE
  '                STEMS WILL SE WELDED DURING THE CURRENT REFUELING OUTAGE.

1 e.

FORM 245 LER SCSS DAT4 04 .3-91

g. 0.******.*********************.**************************************

  ,               DOCKET TEAR LER NUMEER REVISION OCS NUMPER             NSTC       *v**Y   9878

i ASSTR4CT , P1 POWER LEVEL - 1001. ON A*RIL 14, 1G00, UNIT 2 WAS IN =03E 1 AT 100 PERCENT POWER. AT 1704 HOURS, A SIMULTANEOUS REACTOR AND TUR8INE TRIP b4 OCCURRED ON LOW TU18INE ELECTR0 HYDRAULIC CONTROL (EHC) FLUID j; PRES 5URE. THE PLANT WAS BROUGHT TO 4 STABLE SHUTOOWN IN MODE 3 WITH UN NO UNEXPECTED POST-TRIP TRANSIENTS. THE CAUSE OF THIS EVENT WAS FAILURE OF THE EHC SUPPLY LINE TO A MAIN YUR81NE GOVERNOR VALVE. THE PM q LINE FAILED DUE TO FATIGUE STRESS OF 4 WELO CAUSED SY GOVERNOR VALVE-INDUCED VI8 RATION. THE VALVE VISRATION WAS CAUSED BY VALVE PLUG ROTATION. INTERIM CORRECTIVE ACTION M45 BEEN TAKEN TO REPAIR THE EHC , gq p' ' SUPPLY PIPING AND ADO ADDITIONAL SUPPORTS. THE V4LVE USED TO THROTTLE FLOW DURING FULL POWER OPERATION WILL SE MODIFIED TO 400 ANTI b4 SWIRL SAFFLES AND ANTI ROTATION PINS ON THE PLUG TO STEM CONNECTION

                     ,*.            DURING THE FIRST REFUELING OUTAGE.

1 be

                     ;,            FORN    246                      LER SCSS DATA
   ,,                            0************************************************************04-18-91                        ********

DOCKET TEAR LER NUMBER REVISION DCS NUM8ER NSIC EVENT DATE

. 499 1990 013 0 9010260121 219948 09/17/90 b4 *******************o ***********************************************

i

   >g                ;,            485 TRACT POWER LEVEL - 100%. ON 9/17/90, UNIT 2 WAS IN 100% POWER, at 0330 g,                               HOURS, A REACTOR TRIP OCCURRED DURING PERFORMANCE OF THE TRAIN 5 REACTOR TRIP 8REAKER TRIP ACTUATING DEVICE OPERATIONAL TEST. A MAIN Dt                               FEE 0 WATER ISOLATION OCCURRED ON LOW REACTOR COOLANT SYSTEM AVERAGE TEMPERATURE AND THE AUXILI4RT FEEDWATER SYSTEM ACTU4TED ON LOW STEAM GENERATOR LEVEL. CONTRDL ROOM PERSONNEL RESPONDED IN ACCORDANCE WITH g,                               PROCEDURES AND STABLIZED THE PLANT. ALL SYSTEMS RESPONDED AS

, ; EXPECTED. THE CAUSE OF THE EVENT WAS FAILURE OF A NON-LICENSED

   "'                               OPERATOR TO SELF VERIFT THAT HE WAS IN POSITION TO OPEN THE CORRECT REACTOR TRIP BREAKER PANEL PRIOR TO MANIPULAf!ON OF THE AUTO SHUNT TRIP TEST PUSH 5UTTON. THE NON-LICENSED OPERATOR WAS COUNSELEO AND

' t4 RECEIVED DISCIPLINARY ACTION, IN ADDITION A TRAINING MODULE EMPHAS!!ING THE IMPORTANCE OF ATTENTION TO DETAIL AND

   ,,                               SELF-VERIFICATION WAS DEVELOPE 0 AND PRESENTED TO EMPLOTEES ENG4GED IN OPERATIONS AND MAINTENANCE OF THE PLANT.

1 9 FORM 247 LER SCSS DATA 04-18-91

   , .                           0********************************************************************

DOCKET VEAR LER NUMBER REVISION 0C5 NUMBER NSIC EVENT DATE

   , ,                                528    1959           004          0      8904180201 213609                             03/05/89
   **                              ASSTRACT POWER LEVEL - 100%. ON MARCH 5, 1989, PALO VERDE UNIT 1 WAS OPERATING i                                AT APPROKIMATELY 100 PERCENT POWER WHEN, AT APPR0rIMATELT 1001 MST A REACTOR TRIP OCCURRED ON DEPARTURE FROM NUCLE 4TE SOILING RATIO (DN8R)
   '                                DUE TO A CONTROL ELEMENT ASSEMBLY CALCULATOR (CEAC) FAILURE. OURING THE ENSUING TURBINE / GENERATOR TRIP, POWER W45 LOST TO ONE OF THE TWO 13.8 KV NON- CLASS ELECTRICAL BUSSES WHEN THE SU5'S NORMAL FEEDER BREAKER DID NOT TRIP AS REQUIRED. A SMALL FIRE WAS DESERVED AND SUB5EQUENTLY EXTINGUISHED ON THE FEEDER SREAKER TRIP COIL. THE CAUSE OF THE TRIP WAS 4 F4ILURE OF THE CEAC 82 PROCESSOR 804RD.                                 THE PROCESSOR 804RD WAS REPLACED.

1 FORM 245 LER SC55 DATA 04-18-91

                               0********************************************************************

00CKET TEAR LER NUM8ER REVISION DC5 NUMSER NSIC EVENT DATE i 525 1990 006 0 9009250128 210529 nestas=a

                           -a.-       ..

I POWcR LEVEL - 100%. ON */14/90 DALO VERGE UNIT 1 WAS 00EqaTING IN "0DE 'pq 1 AT 100% POWER. AT APPROXIMATELY 2159 HST IT WAS DISCOVERED THAT THE '88 PHASE OF THE MAIN TRANSFORMER MAO LOST FORCED COOLING. A l RAPID F01ER REDUCTION MAS INITI4TED IN ORDER TO UNLOAD THE TRANSFORMER i had, ,;

        '                  WITHIN 30 MINUTES AS REQUIRED BY THE ALARM RESPONSE PROCEDURE FOR 4 had                    LOSS CF TRANSFORMER COOLING AND TO MINIMIZE THE TRANSIENT ON THE PLANT. THE MAIN TURBINE WA$ MANUALLY TRIPPED AT APPROXIMATELY 2223 1          ,;               WITH THE REACTOR AT APPROXIMATELY 65% POWER. APPROXIM4TELY 30 SECONDS

t-g AFTER THE MAIN TURBINE TRIP, THE REACTOR TRIPPED ON HIGH PRE 55URIZER l

PRESSURE. ALL SYSTEMS FUNCTIONEO AS DESIGNED AND THE PLANT WAS l g,g g ' STABILIZED IN MODE 3 (HOT STAN08v). THE LOS$ OF COOLING TO THE MAIN TRANSFORMER WAS CAUSED BY THE FAILURE OF A CONTROL POWER TRANSFORMER. THE REACTOR TRIP HAS SEEN DETERMINED TO SE THE EXPECTED RESULT OF A bud , g LOAD REJECT WITH THE REACTOR AT 65% POWER WITH STEAM SYPASS CONTROL CONFIGURED FOR NORMAL (100% POWER) OPERATION. THE CONTROL POWER gq TRANSFORMER WAS REPLACED. THE ALARM RESPONSE PROCEDURE FOR THE MAIN

          ,,               TRANSFORMER WILL SE REVISED TO ENHANCE DIRECTIONS FOR THE "NO VOLTAGE U"4 ALARM". ENHANCEMENTS TO THE STEAM BYP45$ CONTROL SYSTEM ARE CURRENTLY UNDER EVALU4 TION.
          ,;        1 kW FORM            249                LER SC55 DATA                             04-1 p4g             0****************************************************************8-91                 ****

DOCKET TEAR LER NUMBER REVISION OC$ NUM8ER NSIC EVENT DATE 529 1989 003 1 8912190264 216205 02/16/89 84 g .................................................................... by A8STRACT 7; POWER LEVEL - 100%. AT APPROXIMATELY 0345 MST ON FEBRUARY 16, 1989, gg PALO VERDE UNIT 2 WAS IN MODE 1 (POWER OPERATION) AT APPROXIMATELY 100 e g PERCENT POWER WHEN A FEEDWATER CONTROL SYSTEM (FWCS) MALFUNCTION E4

ii RESULTED IN A REACTOR TRIP OUE TO LOW LEVEL IN STEAM GENERATOR (SG)

NUMSER 1. IMMEDIATELY PRIOR TO THE TRIP THE CONTROL ROOM STAFF OBSERVED BOTH SG LEVELS DECREASING. 80TM MASTER CONTROLLER OUTPUTS E1 , WERE CYCLING FULL SCALE. SG NUMBER 1 ECON 0MIZER VALVE WAS FULLY SHUT AND $G NUMBER 2 ECONOMIZER VALVE WAS 10 PERCENT OPEN. A CONTROL ROOM

'                        OPERATOR PLACED SG NUMBER 1 ECONOMIZER VALVE IN MANUAL AND INSERTED APPROXIMATELY 17 PERCENT OPEN DEMAND WHEN THE REACTOR TRIPPED.

IMMEDIATELY FOLLOWING THE TRIP AN AUXILI4RY FEEDWATER ACTU4 TION $1GNAL 8 8 WAS INITIATED. AT APPROXIMATELY 0345 MST 4 5AFETY INJECTION ACTU4 TION SIGNAL (SIAS)/ CONTAINMENT ISOLATION ACTUATION $1GNAL (CIAS) t , WAS GENERATED DUE TO THE OVERC00 LING OF THE REACTOR COOLANT SYSTEM. SG NUMBER 1 LEVEL CONTINUED TO INCREASE AND AT APPROMIM4TELY 0347 MST A MAIN STEAM ISOLATION SIGNAL WAS RECEIVED AND TERMINATED THE C00LOOWN. THE CAUSE OF THE EVENT WAS A SMALL AMOUNT OF DEBRIS IN THE RESTRICTOR ON THE WERTICAL RELAY WITHIN THE ECONOMIZER VALVE PNEUMATIC , I

POSITIONER. IMMEDIATE CORRECTIVE ACTION TAKEN WAS TO REPLACE THE PNEUM ATIC REL AYS IN E0TH FWC585. THIS SU8MITTAL ALSO PROVIDES SPECIAL

,   n.                     REPORT 2-5R-89-003 IN ACCORDANCE WITH TECHNICAL $PECIFICATION 3.5.2 ACTION B.

1 e . FORM 250 LER SCSS DATA 04-18-91

0********************************************************************

OOCKET YEAR LER NUMBER REVISION DCS MUMSER NSIC EVENT DATE 529 1989 009 1 8912130271 216113 07/12/89 485 TRACT POWER LEVEL - 1002. 04 JULY 12, 1989 AT APPROXIMATELY 2212 MST PALO

    *1                     VERDE UNIT 2 W45 OPERATING AT APPROXIMATELY 100 PERCENT POWER WHEN 2 0F THE 4 REACTOR COOLANT PUMPS WERE LDAD SHED FROM THEIR POWER SUPPLY e                    (8US 2E-MAN-502), RESULTING IN A ReaCY0s YeTo cM r ee rne s ten e av            au=,

m . _ _ -. _ - , -. ._ - , - . - _ __ , . _ _ _ _ _ . , _ . , _ , . _ , . _ - , _ _ . . ._ ,_ _ ,, - - - .

                                                                                                     . . m
                 .......w. 2.,m=L tstan :C,1N:tks0 SA:ETT FEATURES OCCURRED ON Lcw REACTOR CO3LANT SYST!M (RCS) PRESSURE. FOLLOWING THE EVENT, AT D"1             APPROXIMATELY 1527 MST 04 JULY 13, 1991, A PORTION OF THE MAIN FEEDWATEQ SYSTEM (MFWS) WAS OVERPRESSURIZE0* THE CAUSE OF THE LOAD had            SHED WAS A FAILED FUSE IN THE ouS POTENTIAL TRANSFORMER. THE CAUSE OF g ,r THE SIAS/CIAS WAS RCS DEPRES$URIZATION 00E TO IMPROPER STE AM 8YPASS b=(            CONTROL SYSTEM (58CS) RESPONSE AND LEAKING PRESSURIZER SPRAY VALVES.
      '          THE CAUSE OF THE MFWS OVERPRESSURIZATION WAS A FAILED CHECK VALVE.

IMMEDIATE CORRECTIVE ACTION TAKEN WAS TO REPLACE THE FUSE. THIS t-1 SU8MITTAL ALSO PROVIDES A SPECIAL REP 3RT IN ACCORDANCE WITH TECHNICAL i SPECIFICATION 3.5.2 ACTION S. I E ei FORM 251 LER SCSS DATA b"4 , 0************************************************************04-18-91 ******** 00CKET TEAR LER NUMBER REVISION OCS NUMBER NSIC EVENT DATE j D4 529 1959 010 0 59120$0090 216110 10/31/

        ,,     ******************************************************************89         **

U"4 ABSTRACT POWER LEVEL - 067%. AT APPROXIMATELY 1646 MST ON OCTOBER 31, 1989, bwl PALO VERDE UNIT 2 WAS IN MODE 1 (POWER OPERATION), OPERATING AT APPROXIMATELT 67% POWER WHEN A REACTOR TRIP OCCURRED WHICH RESULTED

 >q             FROM A LOW OEPARTURE FROM NUCLEATE BOILING RATIO (ON8R) TRIP SIGNAL.

THE ONBR TRIP SIGhAL WAS CAUSED BY AN ERRONEOUS POWER LEVEL INPUT FROM 81 THE MIDDLE EXCORE DETECTOR TO THE CHANNEL "8" CORE PROTECTION CALCULATOR. THE TRIP WAS UNCOMPLICATED AND SECONDARY PLANT RESPONSES OCCURRED ANO NONE WERE REQUIRED. AT APPRO11MATELY 1656 MST ON OCTOBER D4 31, 1989, THE PLANT WAS STASILIZED IN MODE 3 (HOT STANOST) AT NORMAL TEMPERATURE AND PRESSURE. THE CAUSE OF THE ERRONEOUS MIDDLE EXCORE

 ,g             DETECTOR INPUT POWER LEVEL SIGNAL TO THE CHANNEL "B" CORE PROTECTION CALCULATOR IS SUSPECTED TO BE AN INTERMITTENT MALFUNCTION OF THE CHANNEL "B" EXCORE LINEAR CALISRATE SWITCH.           AS INTERIM CORRECTIVE k4             ACTION, A TEMPORARY MODIFICATION HAS SEEN INSTALLE0 TO BYPASS THE NORMAL OPERATING FUNCTIONS OF THE LINEAR CALIBRATE SWITCH. A$

t4 CORRECTIVE ACTION TO PREVENT RECURRENCE, ENGINEERING IS DEVELOPING A PERMANENT SOLUTION. THERE HAVE BEEN NO PREVIOUS SIMILAR OCCURRENCES

 ,,             REPORTED PURSUANT TO 10CFm50.73.
 ' '           FORM      252                   LER SCSS DATA                         04-18-91 0********************************************************************

i, DOCKET YEAR LER NUMBER REv!SION DCS NUMBER NSIC EVENT DATE 529 1990 001 0 90040A0165 217577 02/23/90 A85 TRACT

 '*             POWER LEVEL - 024%. AT APPROXIMATELY 2301 MST 09 FEBRUARY 23, 1990, PALO VER3E UNIT 2 WAS IN MODE 1 (P3WER OPERATION) AT APPROXIMATELY 24
 ,,             PERCENT POWER DURING A PLANNED SHUTCOWN FOR A REFUELING OUTAGE WHEN THE REACTOR WAS MANUALLY TRIPPED BY A REACTOR OPERATOR SECAUSE THE
 *

EXIAL SHAPE INDEX WAS APPROACHING ITS TRIP SETPOINT ON THE CORE PROTECTION CALCULATOR. THE REACTOR TRIP WAS DIAGNOSED AS AN

          ,     UNCOMPLICATED REACTOR TRIP. NO OTHER SAFETY SYSTEM RESPONSES OCCURREO AND NONE WERE REQUIRED.         AT APPROXIMATELY 2311 MST ON FEBRUARY 23, 1990, THE PLANT WAS STABILIZED IN MODE 3 (HOT STAND 8Y) AT NORMAL
    . ,         TEMPERATURE ANO PRES $URE.        THE CAUSE OF THE MANUAL REACTOR TRIP WAS THAT THE AXIAL SHAPE INDEX WAS APPROACHING ITS TRIP SETPOINT CURING AN END OF CORE LIFE SHUTOOWN. THE COREECTIVE ACTION WAS TO TRIP THE REACTOR AND ENSURE THE AXIAL SHAPE IN3EX REMAINED WITMIN LIMITS. A PREVIOUS $1MILAR EVENT WAS REPORTED IN LER 528/87-018-01.

t ? I

 , .           FORM     253                    LER SCSS DATA                         ns-to-os

250 1439 J01 1 3092120163 21cs34 Ob05/kh i i P 1 ******************************************************************** A85 TRACT but P02E2 LEVEL - 0981. ON KARCH 3, 1989 47 APPROXIMATELY 0102 MST PALO

                     .g       YERDE UNIT 3 WAS OPERATING AT APPROKIMATELY 98 PERCENT POWER WHEN 4N b=4                        ELECTRICAL GRIO DISTURBANCE RESULTED IN THE M&IN GENERATOR OUTPUT SREAKERS OPENING. THIS RESULTED IN A REACTOR POWER CUTS 4CK (RPCS) AND I'1 . g                     STEAM SYP455 CONTROL SYSTEM (SSCS) ACTUATION. AN $$CS M4LFUNCTION RESULTED IN A STEAM GENERATOR (S/G) NUMBER 2 LOW PRESSURE REACTOR TRIP, TUR8INE TRIP, M414 STEAM ISOLATION SIGNAL, AND CONTAINMENT k g ,{                      ISOLATION ACTUATION SIGNAL AT A*PRONIMATELY 0103 MST. APPROXIMATELY 3

SIX SECON05 L ATER, A SAFETY INJECTION ACTU4 TION SIGNAL OCCURRED AS A

    "                          RESULT OF LOW PRESSURIZER PRESSURE. CONTROL ROOM PERSONNEL ATTEMPTED

, g TO REMOVE DECAT HEAT AND CONTROL S/G PRES $URE UTILIZING THE ATMOSPHERIC DUMP VALVES (ADV'S). CONTROL ROOM PERSONNEL COULD NOT b4 REMOTELY OPERATE THE ADV'S FROM THE CONTROL ROOM OR REMOTE SHUT 00WN 1

                     ,i       PANEL. HEAT REMOVAL WAS SUSSEQUENTLY ESTABLISHED BY MANUALLY OPENING gmq                       THE ADV*S. IN THE INTERIM, ONE M41N STEAM SAFETY VALVE CYCLE 0 TO REMOVE DECAY HEAT AND CONTROL S/G PRES $URE.        THE CAUSE OF THE REACTOR i

b N ',' TRIP WAS A M4LFUNCTION IN THE $8CS. AN INDEPENDENT INVESTIGATION HAS BEEN CONDUCTED TO DETERMINE THE CAUSES OF THE PROBLEMS OCCURRING DURING THE EVENT. SASED UPON THE INVESTIGATION, APPROPRIATE D 4 ,> CORRECTIVE MEASURES HAVE SEEN DEVELOPED. THIS SU6MITTAL ALSO PROVIDES A SPECIAL REPORT IN RCCORDANCE WITH TECH SPEC 3.5.2 ACTION 8. yq 1 FORM 254 LER SCSS DATA 04-18-91 04 0******************************************************************** DOCKET Y!AR LER NUMBER REVISION DCS NUMBER NSIC EVENT DATE

    >4                          530    1990        004          0      9005100254 218103          04/14/90 A85 TRACT POWER LEVEL - 0811. 04 APRIL 14, 1000, AT APPROXIMATELY 0355 MST, PALO 84                        WERDE UNIT 3 Wa$ IN MobE 1 (POWER OPERATION) AT APPROXIMATELY 51 PERCENT POWER WHEN A REACTOR TRIP OCCURRED WHICH RESULTED FROM A

( OROPPED $HUTOOWN GROUP CONTROL ELEMENT ASSEM8LY (CE4). NO OTHER SAFETY SYSTEM RESPONSES OCCURRED AND NONE WERE RECUIRED. THE EVENT

    ' '                       WAS DIAGNOSED AS AN UNCDMPLICATED REACTOR TRIP. AT APPROXIMATELY 0413 4

MST ON APRIL 14, 1990, THE PLANT WAS ST481LIZE0 IN MODE 3 (HOT STAND 8Y) AT NORMAL TEMPERATURE AND PRESSURE. THE CAUSE OF THE CEA

    '1                        OROPPING INTO THE CORE WAS AN QPTICAL ISOLATOR CARD MALFUNCTION.           THE i

MALFUNCTION WAS DETERMINED TO BE A RANDOM FAILURE OF 4 MICROCHIP 04

    ,,                        THE CARD. AS CORRECTIVE ACTION, THE OPTICAL ISOLATOR CARD WAS REPLACED AND SUCCESSFULLY RETESTED. 4 SIMILAR EVENT W45 REPORTED IN UNIT 1 LER 528/85-088.
   **                        FORM     255                 LER SCSS DATA                           04-18-91 0********************************************************************
   , ,                       00CRET YEAR LER NUMBER REVISION OCS NUMBER              NSIC       EVENT DATE 530    1990       007           0      9011270126 220217          10/20/90 485 TRACT 4      3 POWER LEVEL - 1005. 04 10/20/90, AT APPR0x. 1230 MST, PALO VERDE UNIT 3 WAS IN MODE 1 (POWER OPERATION) AT APPROR. 100%-POWER WHEN A REACTOR
                ,             TRIP OCCURRED. A FALSE STEAM HEADER PRESSURE SIGNAL CAUSED THE
                     ,        IN-SERVICE (I.E. 7 0F S VALVES) STEAM 8YPASS CONTROL VALVES (58CVS) 70
          ~

OPEN CAUSING AN EXCESS STEAM DEMAND AND TME REACTOR TRIP. THE

   'l                         RESULTING RE ACTOR POWER TRANSIENT W45 TERMINATED BY THE CORE
                     ,=       PROTECTION CALCULATOR (CPC). NO OTHER SAFETY SYSTEM RESPONSES OCCURRED
   +*                         AND NONE WERE REQUIRE 0. TMF ?V*Nt Wat nTar.Nnten oc = = uwe a = = = 'ravca

                                                                                                                                                                                                .q vutssu4E. SU55?JUENTLT, 3k1C/22/90, APS ENGIN!TRING OETERMINED THAT
 #~4 UNIT 3 UA$ IN AN UNANALTZED CON 3ITION THAT WAS JUTSIDE ITS DESIGN
           '              8 ASIS. THE UPDATED FIN &L SAFETY ANALYSIS REP 02r CHAPTER 15 "ACCIO!NT A%ALYSIS" ASSUMED THAT OILY 0%3 58CV ECULO CPEA DUE TO A FAILU2E OF bg                       THE CONTR!L SYSTEM. THE FALSE PRES $URE $IGNAL Wh!CH CAUSED THE $8CVS q              TO OPEN WAS DETERMINED TO BE A RESULT OF A POWER OISTRIBUTION N00ULE g4                       FAILURE IN A BALANCE OF PLANT ANALOG INSTRUMENT CABINET. THE ROOT CAUSE OF THE POWER DISTRIBUTION MODULE FAILURE WAS OETERMINEO TO BE A DMI g                    FAULTV DIODE. THE MODULE HA5 BEEN REPLACED. THE FAILURE OF THE 0100E WAS A RANDOM, LOW FREQUENCT COMPONENT FAILURE. SIMILAR EVENTS: UNIT 1, j                 86-006 AND 86-053, AND UNIT 3 89-001. ACTUATION OF AN ENGINEEREO had tl                  SAFETY FEATURE.

a t U"

        ' ,g            THIS SESSION HAS USED                              5.26 SECONOS OF CPU TIME AND HAS SEEN ACTIVE FOR 309.74 SECON05 bel lq              THE ESTIMATED COST OF THE RUN I$ S                              2.04

but b4 Ik

 *i ;

ne l m4 i kW :i t4 i E. 4

        . 'l iI e 4

4 it

 *41          .                                                                                                                                                                                   ,'

I4

i 4 - (}

       'au.                                                                                                                                                                                     lf t l' p'

g 9

-}}

ML20134Q044

Contents

Text

Dear Dave:

Enclosure:

SUMMARY

T. PROCEDURE

P. PROCEDURE

E. PROCEDURE

S. PROCEDURE

Navigation menu