ML20045D309

LER 93-005-00:on 930520,cold Over Pressure Protection Sys Declared Inoperable Due to Inadequate Surveillance Testing. Caused by Mgt Deficiency.Overlap Task Force Will Continue to Review Procedures Associated W/Reactor trip.W/930618 Ltr

ML20045D309
Person / Time
Site:	Millstone
Issue date:	06/18/1993
From:	Scace S, Young J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-93-005-02, LER-93-5-2, MP-93-488, NUDOCS 9306280209
Download: ML20045D309 (6)

Text

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! N^RTHEAST UTILMES a nera' = c a sa'

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• ut I w sfeSNaIsIen s itUbe:$Ec c moUn7 P.O. BOX 270 EoIna**5' IAEIE*'vS* c"o%p,ny liARTFORD. CONNECTICUT 06141-0270 L 'T' Nstheast Nucioar Ene gy Company (203)665-5000 June 18, 1993 MP-93-488 Re: 10CFR50.73(a)(2)(i)

U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555 l

Reference:

Facility Operating License No. NPF-49 i

Docket No. 50-423 Licensee Event Report 93-005-00 Gentlemen: ,

, This letter forwards Licensee Event Report 93-005-00 required to be submitted within l thirty (30) days pursuant to 10CFR50.73(a)(2)(i).

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY F

mw Stephen E. cace Vice President - Millstone Station SES/JSY:dir l i

i

Attachment:

LER 93-005-00 l cc: T. T. Martin, Region 1 Administrator '

P. D. Swetland, Senior Resident Inspector, Millstone Unit Nos.1, 2 and 3 i V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 l

l l PDR 2300.99 9306280209 930618 ADDCK 05000423 r$ ff '

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NRC Form 366 U.S. NUCLEAR REGULATORY COMV:SSION APPROVED OMO NO, 3150-0104 16-89) . ,

EXPi RES. 4/30/92 Estimated burden per response to comply with this

, Information ochection reauest 60.0 nrs. Forward Commeq's regarding buroen estifnate to the Recorcs LICENSEE EVENT REPORT (LER) and Reports Management Branch >$30), U.S Nuclear Reguistory Commission, Wasnington DC 20555 and to ,

. The Paperwork Recucleon Protect (3150-0104), Oftece of Management and Budget Wasnmgtors DC 20503 l DOCNET NUMBER (21 Pa M ' l FACluTY NAME (1)

Millstone Nuclear Power Station Unit 3 ol 51 of ol 01412'l 3 1lOFl0l5 TITLE 44)

Inadequate Overlap Testing EVENT DATE ist M A NUMBF A rei AEPOAT DATE 17) OTHE A F ACluTIE S INVOLVED #8) .

MONTF DAY YEAR YEAR 1 "Y -

MONTH DAY YEAR F AC UTY NAME S of si of of of I- l 0l5 2l0 9 3 9 l3 0l0l5 0l 0 0l6 1l8 9l 3 o,3;o;ogo; ; g.

OPERATING THIS REPORT IS BEING SUBMITTED PURSUANT TO THE REOUIREMENTS OF 10 CFR $: (Check one o' more of the fohowing)(11) t 20 402(b) 20 402(c) 50.73(a)(2iov) 73.71(c)

POWER 20.405(altt)Os 50 36tc)D) 60,73(a)(2)(v) 73 71(c) l LE VE, L

1. 10 1l0l0 20 405(a)(1Heq 50.36(cH2) 50.73. t a)(2)(vtt) _ gyER ISgf in Text, NRC Form 366A) 20.405(alti)(h4 g 50. 731a)(2 H O 50J3(a)(2Hviii)( A) 20 405(aH t)(tv) 50. 73(a H2)(it) 60. 73(a)(2H va0 (B) 20 405Iat tilfiv) 50. 73(a)(2) UiG 60. 73(a H2 H x)

UCENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE Jeffrey S. Young, Engineer, Ext. 6442 2l0]3 4l 4l 7l-l 1l 7l 9l 1 COMPLETE ONE UNE FOR FO COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT hh* m }g l CAUSE SYSTEC COMPONENT NvNf 7y,qos s l I I I I I I 3-- 1 III I I l I II I I I I I II I I I I SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR 1 EXPECTED I SUBMISSION DATE 05)

YES Of yes, complete EXPECTED SUBMISSION DATE) M NO g g g ABSTRACT ILimit to 14DO spaces. Le , approximately fif teen single-space typewritten hnes) (16)

On May 20,1993 at 1400 with the plant in Mode 1 at 100% the Cold Over Pressure Protection System (COPPS) was declared inoperable due to inadequate surveillance testing. The surveillance requirement is a monthly test of the circuit from the sensor up to but not including valve operation, However, only the portion of the circuit from the sensor to the input relays to Solid State Protection System were tested at this frequency.

The discovery was made by the task force reviewing overlap testing issues. This task force was established as a corrective action to Licensee Event Report 93-003. Four other inadequate surveillance tests were discovered in the next twelve days.

The root cause of the event was a management deficiency in that a comprehensive approach to testing was not implemented during procedure development at plant start up. While the exact circumstances of the inadequate tests were different, they all indicate that unusual conditions were not always considered during procedure development. .A broader overview of testing may.have detected these deficiencies.

The immediate correctise action was to declare the affected component or system inoperable and enter the appropriate Limiting Condition for Operation (LCO) Action Statement. All in service components have been tested to confirm operability.

As action to prevent recurrence, the overlap task force will continue to look for other situations where inadequate testing exists. The task force's charter is to review overlap testing for reactor trip and Engineered Safety Features actuations. In addition, the task force will recommend methods for implementing a l comprehensive approach for ct rent test development. l i

NRO Form 356 (6-89)

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N3c FdNn 3%A . U.S NUCLEAR REGULATORY coMM:SSloN APPROVED oMB ND. 3'50-0104 (6-891 EAPiRES : 4/30'92 Estimated buroen per response to compiy with this LICENSEE EVENT REPORT (LER) fg",,*g",gQ'f*75L,6Sf,,h','o ,[,"n*,"lf,o, TEXT CONTINUATION ano Reports Management Branen tp430), u s Nueiear Aepulatory commission. Wastungton DC 205s5. and to ,

tne Faperwork Recuet,o, Project (315G-0104) < o+0ce of -

Management and Buapet. Washington DC 20s03 F AOfLITY NAME I,) DOCK.ET NUMBER [2) i m NuuBFm to PAGE(31 ,

YEAR "M" Ng *"m 6S

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4 51illstone Nuclear Power Station ,

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1. Descretion of Esent On Alay 20,1993 at 1400 with the plant in Atode 1 at 100c1 power (2250 psia and 587 degrees ,

Fahrenheit), the COPPS was declared inoperable due to inadequate surveillance testing. The Instrument  !

& Controls (l&C) department's ANALOG CHANNEL OPERATIONAL TEST (ACOT) covers the circuits between the sensor and input relays to Sohd State Protection System (SSPS). The ACOT is

• performed every 31 days when required. 1&C's operational test of SSPS consists of ACTUATION LOGIC TESTS and A1 ASTER RELAY TESTS on a 62 day schedule. Operations Department performs ^

SLAVE RELAY TESTS which cover slave relays and the circuit up to the actuated device. ~ This test is '

performed quarterly. This is the same method required by Technical Specifications in the Instrumentation Section for Engmeered Safety Features (ESF) functions. However, the Technical . i Specification for the COPPS circuit requires an ACOT up to but excluding valve operation within 31 days i of use and then every 31 days while in use. Therefore, two sections of the circuit were not being tested at the required frequency, On hiay 28,1993 at 1530 with the plant in $1 ode 1 at 100r epower (2250 psia and 587 degrees Fahrenheit), the hiam Steam Line Isolation Engineered Safety Features signal to the hiain Steam isolation Valves (51SIVs) was declared inoperable due to inadequate overlap testing. A slave relay actuates on a hiain Steam Line Isolation signal which causes the interposing relays (see attached drawing) to drop out. This causes the A1SIVs to rapidly close. A block is used to maintain the interposing relay when the slave relay is tested. The interposing relay should be tested on a refuel frequency. This event i was conservatively reported under 10CFR50.72(b)(2)(iii) as a loss of safety function. Further testing demonstrated that a loss of safety function had not occurred. A test was written and performed to I demonstrate operabihty of the Steam Line Isolation signal.

On June 1,1993 at 1400 with the plant in 51 ode 1 at 100ccpower (2250 psia and 587 degrees Fahrenheit) the oserlap task force discovered several loads associated with the Loss Of Power (LOP) load shedding function which were not properly tested. The following conditions were determined to be I inadequately tested:

i the "C" Reactor Plant Component Cooling Water (RPCCW) Pump is a suing pump and can be l powered from either bus. The LOP load shedding function was not tested from either bus during performance of the last 18 month surveillance.

the "C" Service Water Pump (one of two " A" train pumps) load shedding was not tested for an LOP with an ESF actuation during the last 15 month surveillance.

after an actuation signal occurs and is reset with the plant in post Loss of Coolant Accident recirculation to either the hot or cold legs, Charging Pumps in both trains receive a load shed signal and then are sequenced back on. None of these load shedding functions were tested.

In each case, the discovery was made by the task force reviewing overlap testing issues.

11. Cause of Event The root cause of these events was a management deficiency. An integrated approach to testing was not put in place during procedure development at plant start up.

COPPS - The ACOT for COPPS was written based on the methodology used for ESF testing and as described in the FSAR for COPPS. The conflict between the FSAR and Technical Specification requirements was not previously identified.

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Nac Form 366A , U.S NUCLEAR REGULAToAY COMMISSION APPROVED oMB NO. 3150-01D4 t6-89) EXPIRE S. C30/92 Estimated butaen per respor se to comoty with thes LlCENSEE EVENT REPORT (LER) f'o"","ty,co;*c}**

, ,, '*%5,3,0,,"',5, ,l7s*,"cy,c, TEXT CONTINUATION and Reports Management Branch m-530L U S. Nuclear Regulatory Comm:ssion. Wasnington De ?C5Es. and to tne Pawwon Aeduction Pwatt (315".~0104 ; Office of ,

Management anc Buapet. Washincton DC 20503 i F ACILITV N AME (1) DOCKET NUMBER (21 ( F A N(MRrA @ PAGE (3)

YEAA E .

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Niillstone Nuclear Power Station U"" 3 0l 5l 0l 0l 0l4 l2 l3 9l3 0l 0l 5 0l0 0l 3 OF 0l5 TEXT Pf more space es reou' red use and tiona' NRO Form 366A si 117)

MSIVs - the test did not require positionmg of the MSIVs while shutdown during the 18 month surveillance.

LOP load shedding - the test did not ensure that all combinations of load shedding were properly performed.

111. Anah sis of Event These events are being reported in accordance with 10CFR50.73(a)(2)(i) as a condition prohibited by Technical Specifications. In each case, the surveillance procedures did not adecuately implement surveillance requirements. The inadequate surveillance for the MSIVs was conservatively reported under 10CFR50.72(b)(2)(iii) as a loss of safety function. Further testing determined that a loss of safety function had not occurred.

COPPS - Surveillance requirement 4.4.9.3.1 (Overpressure Protection) requires an ACOT on the Power Operated Relief Valve (PORY) actuation channel, but excludmg valve operation within 31 days prior to entenng a condition m which the PORV is required to be OPERABLE. The surveillance procedure was consistent with other ACOTs and therefore, did not include SSPS logic or output relay testing. The remainder of the circuit is properly tested by ACTUATION LOGIC TESTS and SLAVE RELAY TESTS l but not at the required monthly frequency.

This deficiency had minimal safety significance. There have been no test failures of the monthly )

L suneillance as performed. There have been no failures of the bimonthly test of the SSPS circuitry for  ;

the PORVs as part of the COPPS. There have been no failures of the quarterly slave relay testing for l l PORY actuation as part of COPPS. Therefore, the circuit can reasonably be expected to have ,

l functioned properly if challenged. l MSlY - Suneillance requirement 4.3.2.1 (Engineered Safety Features Actuation System - ESFAS) requires CHANNEL CAllBRATION every 18 months of the Main Steam Line Isolation signal. The suneillance procedure covered the circuit from sensor to output of the slave relays but did not test the interposing relay and its associated contacts.

This deficiency had mmimal safety significance. The circuit has an interposing relay from each safety l train, either of which will cause the MSIVs to close. In addition, each relay has two series contacts, l

either of which will cause the MSlVs to close. Finally, several Steam Line Isolation events have occurred on the unit, all MSIVs closed properly. The interposing relays were tested and performed satisfactorily.

l LOP load shedding - Surveillance requirement 4.S.1.1.2 g.4 (AC Sources) requires 18 month verification of load shedding for a simulated LOP and surveillance requirement 4.8.1.1.2.g.6 requires 18 month verification of load shedding for a simulated LOP in conjunction with an ESF actuation.

l l This event has minimal safety significance. The condition for which the Charging Pumps were not tested l

(LOP occurs with the plant in the recirculation mode) is a post accident condition. In addition, all Charging Pumps presently in service have now been tested satisfactorily. The "C" Service Water Pump was tested satisfactorily, and therefore would have been shed if required. The "C" RPCCW pump has been tested satisfactorily on the train to which it is aligned and will be tested on the other train in the near future. Additionally, start up testing demonstrated that the Emergency Diesel Generators were capable of sustaining higher initial loadmg conditions without tripping.

The safety significance of all deficiencies is further minimited by the fact that similar circuitry is used through out the plant and has no record of failures. Therefore, portions of circuits which have not been tested can reasonably be expected to have operated properly if challenged.

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NRC Form 366A

• U S. NUCLEAR REoVLATORY COMMISSION APmROVED OMB fJO. 3160-0104 (6-89) EXPfRE S: 4/30/92

. Estimat d ourcen per respons. to compiy witn this LO O ** F "* *'d LICENSEE EVENT REPORT (LER) c'nt* mater omm.nts r ce*ctan ~5t:

TEXT CONTINUATION ana R. port,egaroing euro.n estimat. to in. Recoras uananment eramn in-sao). u.s Naci r

• Regulatory Commissvin, Wasriangton DC 20556 and to the Paperwork Reduction Prciect (3150-01041 Offic. of Manao.mor.1 ano suco.t wasninoton oc 2osca FActUTY NAME 0) DOCKET NUMBER (2) i rn NUMRf A H;t PAGE (31 YEAR NN asm mam Millstone Nuclear Power Station Unit 3 Oj 4 OF 0l 5l 0l 0l 0l4 l2 l3 9l3 0 l 0l 5 0l0 0l5 TEXT (ff more spac. is reouw.c us. adattional NRC Form 366A s1 (17)

IV. Corrective Action immediate corrective action was to declarc the affected components inoperable and enter the appropriate -l LCO Action Statement, All in semce components were tested and restored to OPERABLE status.  ;

As action to prevent recurrence, the following actions are being taken:

the task force will continue to review procedures associated with reactor trip and ESF to determine >

if any similar conditions exist.

- the task force will make recommendations to unit management on methods to implement a  ;

comprehensive approach to testing.  ;

l The series of tests which satisfies the surveillance requirements for COPPS will be performed prior to

! declaring the system operable. The surveillance procedures are being revised for clarity of -

requirements.

l a change to the FSAR regarding test methodology for COPPS will be investigated.

V. Addinonal Inferm ition l l

l Other Licensee Event Reports (LERs) which have been submitted where portions 01 circuits have not ,

been properly tested due to inadequate procedures are as follows 1 l i LER Number Title 93-003 Inadequate Testmg of Slave Relays93-001 Failure to Verify Testing of NIS Inputs Into Westinghouse 7300 Process Control System Due to Procedural Deficiency 92-031 Failure io Test High Pressure Output Relay for Power Operated Relief Valves Due to Procedural Dehciency 91-025 Failure to Verify De-energitation of Solid State Protection input Relays for Cold Overpressure Protection Due to Procedural Deficiency l

l 91-022 Failure to Adequately Perform Overlap Testing of the Containment l Depressurization Actuation Loops Due to Management Deficiency 90-007 Inadequate Load Shed Verification

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l 87-042 Missed Intermediate Range / Power Range Surveillance Due to Procedural Inadequacy Prior to LER 93-003, procedural deficiencies were addressed as individual events. As a result of LER 93-003 a task force was formed to apply an integrated approach to slave relay testing. The deficiencies noted in the current LER are a result of this review.

Ells codes Systemji Comoonent Engineered Safety Relay - RLY Features Actuation System - JE I$EaI"""

NRC F9rm 366A . U S NUCLEAR REGULATORY COMM:SSION APPROVED OMB NO. 3tSO-0104 (4-89) ,

EXPIRE S: 4/30/92 Estimated buroen per rerponse to comply with this

'n' 'm*'*" co"*ct *" 'covest ; 5 . 0 hrs, Forward LICENSEE EVENT REPORT (LER) Comments regarding bur den estimate to the ROCoros TEXT CONTINUATION and Reporte uan oernent Branen in-530), U S. Nuclear Aeguiatory Commassen. Washington DC 20555. and to the Paperwork Reduction Project (315'J-0104). Oftsce of Manape rent and Buopet Wasntngton. DC 20503 FACIUTY NAME (1) DOCKET NUMBER (2) [F A NUM9gq pp, PAGE (3) l N

YEAR Nmus"ca maEn '

Millstone Nuclear Power Station Unit 3 - -

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r Relay ,, / Steam Line Contact _' Is lation Slave Relay Contact l , . . . . . ' Interposing Relay

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MSIV solenoid Interposing (Typical) j Relay l

Simplified MSIV Circuit ,

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