ML20207F654

Summary of 880816 Operating Reactors Events Meeting 88-33 in Rockville,Md Re Briefing of Senior Managers from Nrr,Osp, AEOD & Regional Ofcs on Events Which Occurred Since Last Meeting on 880809.List of Attendees Encl

ML20207F654
Person / Time
Site:	Maine Yankee
Issue date:	08/17/1988
From:	Lanning W Office of Nuclear Reactor Regulation
To:	Rossi C Office of Nuclear Reactor Regulation
References
OREM-88-033, OREM-88-33, NUDOCS 8808230151
Download: ML20207F654 (11)

Text

-

AUG 171998 MEMORANDUM FOR: Charles E. Rossi, Director Division of Operational Events Assessment Of fice of Nuclear Reactor Regulation FROM: Wayne Lanning, Chief Events Assessment Branch Division of Operational Events Assessment Office of Nuclear Reactor Regulation

SUBJECT:

THE OPERATING REACTORS EVENTS MEETING August 16, 1988 - MEETING 88-33 On August 16, 1988 an Operating Reactors Events meeting (88-331 was held to brief senior managers from NRR, OSP, AE00, Commission Staff, and Regional Offices on events which occurred since our last meeting on August 9, 1988. The list of attendees is included as Enclosure 1.

The events discussed and the significant elements of these events are presented in Enclosure 2. Enclosure 3 presents a summary of reactor scrams. No signif-icant events were identified for input to NRC's Performance Indicator Program.

Mtinal Signert th-Pd W. Bwa nows ky fw Wayne Lanning, Chief Events Assessment Branch Division of Operational Events Assessment Of fice of Nuclear Reactor Regulation

Enclosures:

As stated cc w/Enclo.:

See Next Page DISTRIBUTION Central. File

[

EAB Reading File ,, j Circulating Copy EAB Staff MLReardon, EAB [ /

00udinot, EAB LXilgore, SECY l .Kf:) U' j

~

POR ,( 8808230151 880017 PDR ORG NRRB

[ [Y Ql b

h,,h. (f l l[Li PNV ~

DFC :EAB: :C:EAB: p  :  :  :  :  :

.....:. ...:...... .f(....:............:............:............:............:.....Q......

NAME :M rdon :Wlanning  :  :  :  :

.....:............:............:............:............:............:..........~.:...........

^  :

DATF :08/ / 7/88 :08/ /88  :  :  :  :

0FFICIAL RECORD COPY

2 ENCLOSURE 1 b

LIST OF ATTENDEES OPERATING PEACTORS EVENTS BRIEFING (88-33-)

August 16, 1988 NAME ORGANIZATION NAME ORGANIZATION R. Scholl NRR/00EA A. Vietti-Cook OCM/LZ

0. Crutchfield NRR/0RSP M.L. Reardon NRR/00EA 0.C. Fischer NRR/00EA J. Kelly , OSP/TVA S. Israel AE00 P. Baranowsky NRR/00EA V. Benaroya AE00/DSP P. Sears NRR/P01-3 W.E. Holland SRI (Surry) C. Patel NRR/ORP W. Hodges NRR/ DEST C. Thomas NRR/PMAS H.N. Pastis NRR/P02-3 0.B. Matthews NRR/P02-3 B. Boger NRR/ADR-1 T. Martin NRR/ADT S. Varga NRR/ORP W. Minners RES/0RPS C.J. Haughney NRR/ORIS J. Sniezek 00:NRR o

• - - , - . - -- , - - - - , , - - - , - . , - . . , , - - . --- - , _ . . - - , , - - - , - - ,,, . ,.,,y.,- - -e--,,,-.,, n --mm-,y

- - ENCLOSURE 2 OPERATING REACTORS EVENTS BRIEFING 88-33 EVENTS ASSESSMENT BRANCH LOCATION: 12-B-11 WHITE FLINT TUESDAY, AUGUST 16, 1988, 11:00 A.M.

MAINE YANKEE GENERATOR / REACTOR' TRIP AND FAILURE TO CLOSE "RESERVE" BREAKERS GENERIC ISSUE INADE00 ATE NET POSITIVE SUCTION HEAD IN THE HIGH/ LOW PRESSURE SAFETY SYSTEMS

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

88-33 MAINE YANKEE GENERATOR / REACTOR TRIP AND FAILURE TO CLOSE "RESERVE" BREAKERS AUGUST 13, 1988 PROBLEM FAILURE TO AUTOMATICALLY TRANSFER STATION AUXILIARY LOADS (6.9KV AND 4.16KV BUSES) FROM THE MAIN GENERATOR TO THE "RESERVE" 0FFSITE SOURCES FOLLOWING MAIN GENERATOR, TURBINE AND REACTOR TRIP DUE TO MAIN TRANSFORMER FAULT.

CAUSE '

TRANSFER TO THE "RESERVE" SOURCES WILL NOT OCCUR IF RESERVE SOURCE LOW V0LTAGE IS SENSED, IT IS SUSPECTED THAT THE MAIN TRANSFORMER FAULT CAUSED A M0MENTARY GRID DISTURBANCE (LOW VOLTAGE) THAT PREVENTED TRANSFER.

SAFETY SIGNIFICANCE o FAILURE TO AUTOMATICALLY TRANSFER POWER TO 6.9KV BUSES RESULTS IN LOSS OF REACTOR COOLANT PUMPS (RCP) AND CONDENSER CIRCULATING WATER PUMPS (CCWP),

o LOSS OF POWER TO THE 4.16KV BUSES REQUIRES DIESEL GENERATOR AUTOMATIC START TO PROVIDE POWER TO SAFETY-RELATED LOADS.

DISCUSSION o ON AUGUST 13, 1988, WHILE OPERATING AT 98% POWER, A FAULT OCCURRED ON MAIN TRANSFORMER X1A (SEE FIGURE 1, ATTACHED) CAUSING 4 MAIN GENERATOR, TURBINE AND REACTOR TRIP.

o GENERATOR TRIP RESULTED IN THE LOSS OF THE NORMAL SOURCE OF POWER TO 6.9KV BUSES 1 8 2 AND 4.16KV BUSES 3, 4, 5, 8 6 (SEE FIGURE 2, ATTACHED),

o FAILURE TO AUTOMATICALLY TRANSFER 6.9KV AND 4.16KV LOADS TO THE "RESERVE" (OFFSITE) SOURCES PER DESIGN RESULT,ED IN LOSS OF THE RCPs AND CCWPs, o DIESEL GENERATOR (DG) BACKED BUSES WERE ISOLATED AND THE DGs AUTOMATICALLY STARTED AND SUPPLIED BUS LOADS AS DESIGNED.

CONTACT: R. KENDALL

REFERENCE:

50.72 # 13187

.- MAINE-YANKEE 88-33 o PRIMARY SYSTEM WAS COOLED VIA NATURAL CIRCULATION FOR 20-25 MINUTES UNTil "RESERVE" POWER WAS MANUALLY RESTORED TO ONE 6.9KV BUS, ALLOWING RESTART OF ONE RCP, o LOSS OF CCWPs RESULTED IN CONDENSER OVERPRESSURE AND RUPTURE OF A LOW PRESSURE TURBINE RUPTURE DISC, ADDITIONAL CONCERNS o GROUP 5B RODS ("NON-TRIPPABLE" GROUP; 4 RODS) COULD NOT BE MANUALLY INSERTED BY THE OPERATORS FOLLOWING REACTOR TRIP DUE TO PCWER SUPPLY PROBLEMS.

o ONE MAIN STEAM LINE EXCESS FLOW CHECK VALVE FAILED TO CLOSE MANUALLY DUE TO FAILED SOLEN 01D (STEAM LINE #3), MAIN YANKEE IS A 3-LOOP CE PLANT, o ONE SERVICE WATER PUMP FAILED TO AUTOMATICALLY START CONCURRENT WITH '

THE DG AUTOMATIC START / LOAD SEQUENCE, FOLLOWUP REGION I HAS SENT ADDITIONAL INSPECTORS TO THE SITE AND IS CONTINUING TO FOLLOWUP,

l _

V. -

C

. " _ Y R .

MT =

' AILTH J,

S MTW AU I I Y

C ld k

. 6RY h v 1I E

X A

[e 5 5~ 2.D DSE E NNK

. r 4 8 AON .

M . ' e e

4 3 6 3 .N T YA I

igL N C I

s 4

3 i

h T '

D FEI CSNI OEE NSN N _

,. AOA t

t CM SR N E a qT# '.

A r.

TI TN I

r a.

m A

e 1l . ,

t

• c ,l_

u r -

a s

=A _

u n r a' a i mm s

_ u C 1 r o

c s

s "w C 1 s e

.'"T C C _

n e

'w s

.eno S _

C C R

r t 4

_ .e u r _

u R .- .

a O O l .

n r . C N

A T.s.. _

R T

' :3 1 E '

C I

=~ E

]

[

W e

t s

=T . _ ' '

R U

G I

F m .

0 '

s I T

A . e , ' ,!

7 4 _

$ e.

_ . x

]

[

i s

"T

" I C_

[

E I i 8 i ' _

=

N

. S

[

,3 S _

} :. -D _

l ,

]

[ -

C C

_ C u

=

]

p p

o y

C

{ _

[

u o -

s n

u l t 1 , ,

e j

Y

'A

- P 2

1 r

4 4 O I

x C

" O C C

{ V K

5 1

1

]

[

N

]

[

N

• g N

JI 2

1 S

U B

MO EP R

E W

C V T C 4 N S I 0 Y C S 8 SM U 4 M O N B ART I

C O REA Q lV N N GW E

)

l l AO E 0 D P K I

I l 6 1 S 1 1 U YN 6

4 3 x

B 1E RA

- N A Y l

C V I s O N~ 3.

8 L I L E V N ) 0 N I

8 IXI K MW A #y 4 G. E I NUA 5

1 AN FOAM 1

C C N N 4 1

l )I S 2

U S 4 B U 1 B 4 V 6 x V S 0 8

0 U 4 0 B 9 V C C 6 N N 0 8 6 ] I

) I C 1

[ 5 N 4 B1 1

- 8 B' i

O G 0 N D 6 V a 0 h 8 4

O

a. O O l i N N N 7

O N

I I

]

[

]

[ h A

I 7

0 5

I

) I S

U B 2 C - x C E 5 N G N V R S D 0 U U I )1 8 G B 4 I F

I V O S 0 N U 6 )

3 B 1 l 1

4 3 S V 1 U

0 3 B 0 C x C 9 N N V 6 )I 0 6 i 8

2 4 a C V N C K g N 0 1

)

2 u l I S

2 U 0 B C 1 V

3 N 4 m 0 O S 8 N BU 4 l

C O V N N 9

0 9 I

) 1 6 S 4 0 U 2 41 3 B a C C a C N N N V V 0 K1N 2

M )

[

]

[ [g )I 8 4

^. 2

. 88-33 GENERIC ISSUE INADEQUATE NET POSITIVE SUCTION HEAD IN THE HIGH/ LOW PRESSURE SAFETY SYSTEMS MAY 12, 1988 PROBLEM .

THE NPSH FOR THE HIGH PRESSURE INJECTION PUMPS COULD BE INADEQUATE DURING THE RECIRCULATION MODE FOLLOWING A SMALL BREAK LOCA, CAUSE FLAWED DESIGN ANALYSIS LED TO UNDERSIZED PIPING. TYPICAL LOCA ANALYSIS DOES NOT ANALYZE ECCS FLOW SCENARIOS FOR THE RECIRCULATION PHASE, SAFETY SIGNIFICANCE CAVITATION CAUSED BY INADEQl' ATE NPSH COULD RESULT IN PUMP FAILURE AND LOSS OF LONG TERM COOLING FOR CERTAIN SMALL BREAK LOCAs, O

DISCUSSION o TURKEY PT, - MAY 12, 1988 - LICENSEE DISCOVERED A THROTTLE VALVE IN THE RHR DISCHARGE LINE IS NORMALLY 30% OPENED, EVALUATION SHOWED THAT THE VALVE SHOULD BE IN THE FULLY OPEN POSITION, o OCONEE 1, 2, AND 3 - MAY 19, 1988 - DURING A ECCS DESIGN REVIEW, THE LICENSEE DISCOVERED THAT A CERTAIN SET OF CONDITIONS COUPLED WITH INADE00 ATE GUIDANCE TO THE OPERATORS COULD CAUSE THE HPSI PUMPS TO HAVE INADEQUATE NPSH FOLLOWING A SMALL BREAK LOCA, o CONTAINMENT SPRAY AND HIGH PRESSURE INJECTION ARE BOTH PIGGYBACKED OFF THE LPSI (RHR) PUMPS IN THE RECIRCULATION MODE FOLLOWING A SMALL BREAK LOCA (PROCEDURES ALLOWED SIMULTANE0US USE OF LPSl/HPSI AND CS PUMPS, o ORIGINAL 6 INCH LINE TO CROSSTIE LPSI TO HPSI WAS REDUCED TO 3 INCHES BASED ON B8W CALCULATIONS BACK IN THE SIXTIES (OCONEE),

o EMERGENCY PROCEDURES REVISED AT OCONEE TO REDUCE FLOW AND MAINTAIN PRESSURE IN THE HPSI TRAINS AND/0R THE CONTAINMENT SPRAY TRAINS TO ACHIEVE ADEQUATE NPSH CONDITIONS DURING THE RECIRCULATION PHASE, CONTACT: J, THOMPSON

REFERENCE:

50,72 # 12326 AND MORNING REPORT 08/00"

GENERIC.lSSUE 88-33 o THIS PROBLEM POTENTIALLY EXISTS FOR OTHER PWR's.

FOLLOWUP o AEOD ENGINEERING EVALUATION REPORT (AUGUST 1988) SUGGESTED A SUPPLEMENT TO AN EARLIER INFORMATION NOTICE ON INJDEQUATE NPSH IN LPSI IN PWRs (IN 87-63, INADEQUATE NET POSITION SUCTION HEAD IN LOW PRESSURE SAFETY SYSTEMS),

o B&W IS LOOKING AT GENERIC IMPl? CATIONS TO OTHER B8W PLANTS, o EAB IS WORKING WITH RSB AND AEOD TO FACillTATE PROPER GENERIC REGULATORY RESPONSE (1.E., INFORMATION NOTICE OR BULLETIN),

O r .

l l

l

,, ll i

N

• ~ nCi 3 O

I d 2

• 2 T

F

=. .D F

g.

C

r. , . ON A o

. s i_

t S OT )2

= DT I S i

s e r w

1. . a 8

O - . RC Rf o 8

~

a

. 1

F t

a AE UT A es ~ (

3 FCO E 1 V

.e

~ A n e

P, OER L (

a MAF P CU f

g ~ c~

a 1 t

A~ AS C - e g- O a -

R CI lD. N 0 t a

.. O a I*

l ACB I N E E6 d p O g

. e.

1

• DE& G N ER U O

i e =

1 e

r *O WREOU ERC C 8 6

r  :

=...

. t O.

FE M C O OFI 8 t 9

4 5

- e - sn 8 ' I 1

-icra 7 r 9 N ( m c,

8 n-@ e.

'- ]@

8*

, 0 4 E ,

T5 2 m

h

, 8, l

, y . -

n -%* 1 .,

s g

g g

. K t

e. 9 e. * ,

o.. be.g r F

s. a .

c, ,N r i Sl .

1*': g j, i >

) c

,. <V .

I 2 . as

..'yg Q m-T . 5

= -

' i

" g S D

• . p

,M"' M C "

i i w

.<3n .

. m t

[

4- 9 i -- . ,5

.  ;. ,. G D

7 .

• 1+ =

T.

P

't o

1.m%'A'.

L- _-

m ,

. I.,'

.WN";

b I

O .

?

, 4 . Il

.i y P

,: d' :3 L 2

_'i.

,: f 4.,.dp4,g 0

.. . 81

q1!l .}l

c. c .' _p  :

_ : 3 :

t

. , t~l,' f_ - I.

,l  :[ti i y IP .:. . : 3 :

I.t Itb t u

L

:t i o _

l

., ~ "t u ,,

g g

< <d ,,,

,a .

=

ng,-,= e g ."

. ' c i

I ~- -

g,.2 . = , " " ,'

e I '- a f,, 1 c."'

~ cF- 0 g

' .=

=

n.

e _.

.. e

. c..=

(.-

e. m t r . .

e u I e, u. =t T. -

_ 3 r t

.. n'M G..

e=

a ,

. , y:: .

_ "-."* __ ==

e.= -

.'*m _.

'i

.p _

n..

u. - _

1'

, j,j ll'

. , ENCLOSURE 3 REACTOR SCRAM

SUMMARY

NEEKENDING 08/14/88 ,

l. PLANT SPECIFIC DATA DATE SITE UNIT PONER SIGNI4 CAUSE COMPL1- YTD fiD YTD CATIONS ABOVE DELON TOTAL 151 151 08/11/88 BRAIDN000 1 100 A PERSONNEL No 1 0 1 08/12/88 TURKEY POINT 4 0A EQUIPMENT NO 0 1 1 08/13/88 MINE YANKEE 1 98 A E00!PMENT YES 2 0 2 SUMARY OF COMPLICAi!ONS SITE UNIT COMPLICAi!DNS MINE YANKEE 1 SERVICE NATER PUMP FAILED TO START AUTOMTICALLY AND LOAD ONTO D/6 AS EIPECTED .

ONE MIN STEAM LINE EICESS FLON CHECK VALVE CollLD NOT BE CLOSED MNUALLY FROM THE CCNTROL R00M .

4 I

l i

. .._ __ . _ _ , _ _ _ _ _ __ . . - _ . . ___ ___ _ _ _ . _ _ _ . _ _ . . . _ _ - . _ _ . _ . _ , _ _ _ _ _ . _ _ _ . . _ . , _ _ _ _ . . _ _ _ _ _ . _ . _ _ , _