ML17285B183

LER 90-006-00:on 900308,10CFR50 App R Cable Fire Protection Review Identified 12 New Cables in Fire Areas Vulnerable to Design Basis Fire.Caused by Equipment Design Deficiency. Items Placed on Hourly Fire watch.W/900409 Ltr

ML17285B183
Person / Time
Site:	Columbia
Issue date:	04/09/1990
From:	Fies C, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-90-006, LER-90-6, NUDOCS 9004200459
Download: ML17285B183 (7)

Text

I '

r il ACCELERATED DEMONSTlTION SYSTEM 1

l" AS DISTRIBUTION REGULATORY INFORMATION:".DISTRIBUTION SYSTEM-'=('RI'DS)"---

ACCESSION NBR: 9004200459 DOC. DATE: 90/~/09 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION FIES,C.L. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 90-006-00:on 900308,10CFR App R cable fire protection.ltr.

W/9 DISTRIBUTION CODE: IE22T COPIES RECEIVED: LTR TITLE: 50.73/50.9 Licensee Event Report (LER), IncidenMRpt, etc.

J ENCL,J SIZE:

NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5'PD 1 1 SAMWORTH,R .1' INTERNAL: ACNW 2 2 ACRS 2 2 AEOD/DOA 1 1 AEOD/DSP/TPAB '1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 NRR/DET/ECMB 9H 1 1 NRR/DET/EMEB9H3 1 1 NRR/DET/ESGB 8D 1 1 NRR/DLPQ/LHFB11 1 1 NRR/DLPQ/LPEB10 1 1 NRR/DOEA/OEAB11 1 1 NRR/DREP/PRPB11 2 2 NRR/DST/SELB 8D 1 1 NRR/DST/SICB 7E 1 1 NRR DS SPLB8D1 1 1 NRR/DST/SRXB 8E 1 1 REG 'F LE 02 1 1 RES/DSIR/EIB 1 1 CN . ILE 01 1 1 EXTERNAL: EGGG STUART,V.A 4 4 L ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 NUDOCS FULL TXT 1 1 NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASIZl CORI'ACI'HE,DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISIRIBUTION LISIS FOR DOCUMEKIS YOU DON'T NEEDl FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 37 ENCL 37

'.WMHIiN&TOb~&UBLICPOWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George lVashington iVay ' Richland, lVashington 99352 April 9, 1990 Docket No. 50-397 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.90-006

Dear Sir:

Transmitted herewith is Licensee Event Report No. 9t)-006 for the WNP-2 Plant.

This report is submitted in response to the report requirements of 10CFR50.73 and discusses the items of reportability, corrective action taken, and action taken to preclude recurrence.

Very truly yours, C. H. Powers (H/D 927M)

WNP-2 Plant Manager WSD:lr

Enclosure:

Licensee Event Report No.90-006 cc: Mr. John B. Hartin, NRC Region V Hr. C. J. Bosted, NRC Site (M/D 901A)

INPO Records Center Atlanta, GA Hs. Dottie Sherman, ANI Mr. D. L. Williams, BPA (H/D 399)

$ 004200~ ~

r9 900409 00039'7 . I PDR ADO jP pDC

'f

NAC FORM 365 V.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 31504)104 (54)9)

EXPIRES: 4/30/92 ESTIMATED BURDEN PEA RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST/ 50.0 HRS. FORWAAO LICENSEE EVENT REPORT ILER) COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS ANO AEPORTS MANAGEMENT BRANCH (P530). U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROÃCT l31600104), OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON, DC 20503.

DOCKET NUMBER (2) PA E FACILITY NAME HI Washington Nuclear Plant - Unit 2 0 5 0 oeo 39 7i oF04 TITLE ls) 10CFR50 Appendix RRR Cable Fire Protection EVENT DATE (5) LER NUMBER (6) AEPOAT DATE LTI OTHER FACILITIES INVOLVED (SI SEQUENTIAL:)rp RBV~ OAY YEAR FACILITYNAMES DOCKET NUMBER(SI MONTH DAY YEAR YEAR NUMBEil @c: NUMBER MQNTH 0 5 0 0 0 03 089 0 9 0 0 0 6 000 4 0 9 9 0 0 5 0 0 0 THIS REPOAT IS SUBMITTED PURSUANT TO THE RLQUIREMENTB oF 10 cFR (I: le/recit one or morr ol tnr fol/ow/npl (11)

OPERATING MODE (9) 20.402(bl )0.405(c) 60.73(el (2) Dvl 73.7)(II)

POWER 20.405( ~ ) (1)(il 5046(cl((l 50.73(e I (2) (r) 73.71(cl

~ LEYEL (10) 9 9 20.405(el() I(BI 50.35(cl(21 60.73(s l(2)(viil QTHER /spec/fy In ABNrrct Below rntf in Trxt. NRC Form 20.405(sl(1 I()BI 50.73(el(2)(i) 60 73(e) (2) (riii) (Al 3FEAI 20.405(e) l1)(ivl 50,73(el(2)(BI 50.73(s)(2)(riB)(BI 20AOS(el II)(vl 50.734)(2 I IIIII 50.73( ~ l(2) (el LICFNSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE'UMBER AREA CODE C. i. Fies, Compliance Engineer 5 09 77 -25 01 COMPLETE ONE LINE FOR EACH COMPONENT FAILUAE OESCAIBEO IN THIS REPORT (13)

CAUSE SYSTFM COMPONENT MANUFAC.

TVRER EPORTABLE TO NPRDS CAUSE SYSTEM COMPONENT MANUFAC.

TURER EPORTABLE TO NPROS:p

)r.. >> ~

m m

IW~!:>> 4 SUPPLEMENTAL REPORT EXPECTED (14) MONTH OAY YEAR EXPECTED SV 6 MISSION DATE (16) ~

YES Ilfyrr. comp/ere EXPECTED SUBst/$ $ /ON DATE/ NO ABSTRACT ILlmit ro f400 rpecer, lr., epproxlmrtrly fifrern rfnplerpece typewritten /inrr/ I'16)

On March 8, 1990 the expanded 10CFR50 Appendix R analysis was completed which systematically evaluated shutdown path components and their electrical circuits.

This analysis identified twelve problem cables that could prevent an orderly plant shutdown in the unlikely event of a Design Basis Fire.

The root cause of this event was equipment design deficiency caused by the Architect-Engineer/Supply System who failed to thoroughly implement Appendix R requirements.

Immediate corrective action was taken to place these items on an hourly fire watch.

Plant procedures were changed to eliminate the problem associated with two cables.

In addition, an urgent Plant Modification Request was issued to provide design for a permanent correction of the remaining items.

The event posed no threat to the health and safety of either the public or plant personnel.

NRC Form 365 (64)9)

0 I"

II

NRC FORM 35SA LLS. NUCLEAR REGULATORY COMMISSION (54)9) APPROVED 0M B NO. 31500104 E XP I R ES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT ILERI INFORMATION COLLECTION REOUESTI 50JI HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TD THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P4)30), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555, AND TO 1ME PAPERWORK REDUCTION PROJECT (31504))04). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, OC 20503.

FACILITYNAME (ll DOCKET NUMBER (2) LER NUMBER (5) PAGE (3)

REVOION jwa SEOVCNTIAL NVM 4R ..% rrVM84ll Washington Nuclear Plant - Unit 2 0 s 0 0 o 3 9 7 9 0 0 0 6 00 02 0 4 TEXT N more 4/>>ce /4 rer/rrke4 oee erf45we/NRC form 3SSA'4/ (IT)

Plant Conditions Power Level - 99K Plant Mode - 1 Event Descri tion On March 8, 1990 an expansion of the previously completed 10CFR50 Appendix R Fire Protection review identified twelve new cables in four fire areas vulnerable to a Design Basis Fire (DBF). This expanded analysis adds the guidance provided in Generic Letter 86-10 and includes spurious signal analysis and computerization techniques. The analysis methodology uncovered additional problems not previously identified by the original AE methodology.

The first fire area involved a postulated DBF in the Main Control Room (Area RC-X).

A DBF could result in a worst case failure of cables 2DG2-26, 2DG2-33, 2DG2-44, 2DG2-45, and BSYNC-9028. This could cause spurious actuatiop of the local protective relays which could cause the Division II Diesel Generator (E- DG-2) to become disconnected from the associated 4160 VAC Safety Related Bus (E-SM-8). One additional cable, 2D12D-4, .during the DBF, could cause a loss of power to safety related circuit breakers E-CB-8/81 and E-CB-8/83. Loss of this power supply would result in the loss of the two Division II 480 Volt Safety Related buses (E-SL-81 and E-SL-83).

The second fire area where a DBF could cause a loss of shutdown capability was the chiller area in the Radwaste/Control Building (Area RC-XIII). A DBF in this area could result in the worst case failure of cables lSM7-121 and 2SMB- 131.

Specifically, a short to ground would cause the potential transformer fuses to open and the undervoltage relays on the 4160 Volt Safety related buses for Division I (E-SM-7) and Division II (E-SM-8) would deenergize. This would cause the loss of both buses.

The third fire area involved the Reactor Building (Area R-I) where two cables (2MSBA-145 and 2MSBB-210) were impacted by the analysis. The first cable is a control cable to a Residual Meat Removal Lower Drywell Spray Inboard Isolation Valve (RHR-V-17B). A DBF could result in 120 VAC power being applied to this cable which is connected to the control circuitry for the RHR Lower Drywell Spray Outboard Isolation Valve (RHR-V-16B). As a result, the DBF could cause both RHR-V-16B and RHR-V-17B to open diverting shutdown cooling flow. The second cable provided power to a valve associated with the RHR Steam Condensing mode of operation (RHR-V-87B).

This mode of operation has been deactivated for WNP-2 but the power cable remains connected to the valve. Inadvertent valve operation could possibly occur during a DBF violating Emergency Core Cooling System (ECCS) high-to-low pressure interface requirements.

NRC Form 35SA (54)9)

NRC FORM 368A US. NUCLEAR REGULATORY COMMISSION (649) APPROVEO 0MB NO. 31500104 EXPIRES: 8/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REQUEST: 50A) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (P430), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, OC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT-(31500)OS). OFFICE OF MANAGEMENTANO BUDGET, WASHINGTON;OC 20503.

FACILITY NAME ( 1 I DOCKET NUMBER (2) LER NUMBER PAGE (3)

(6)'EQUENTIAL YEAR REVOION NUMBER NUMBEII Washington Nuclear Plant - Unit 2 o s o o o 3 9 7 9 0 0 0 6 0 0 03 oFO 4 TEXT /I//INso soscs /o sN/v/sod. vss ahfh/ons//IRC %%dms 386A'sl ()T)

The fourth fire area involved a postulated fire in a cable chase in the Reactor Building (Area RC-III) which could impact cables 2CHB-15 and 2SL81-70. The loss of these cables could cause Control Room Chiller 1B (CCH-CR-lB) to fail which would, in turn, cause the loss of chiller cooling capability to the control room. Safety related .Standby Service Water Cooling would still be available.

Immediate Corrective Action Immediate corrective action was taken to place these items on an hourly fire watch.

In addition an urgent Plant Modification Request was issued to provide design for a permanent correction to these items.

Further Evaluation and Corrective Action A. Further Evaluation

1. This event is being reported per the requirements of 10CFR50. 73(a)(2)(v) as "Any event or condition that alone could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A)

"'hut down the reactor and maintain it in a safe shutdown condition...."

2. The root cause of this event was inadequate analysis methodology by the Architect-Engineer (AE) in response to Appendix R requirements. The Supply System revised the AE's original methodology which resulted in deficiency identification.

3. There were no structures, components or systems that were inoperable prior to the start of this event which contributed to the event.

B. Further Corrective Action

l. Plant procedures will be evaluated to assure the loss of the HB" chiller (CCH-CR-1B) is adequately addressed in response to a fire in the Reactor Building (Area RC-III).

2. A plant modification will be implemented during an outage of sufficient duration to execute the completed design. It will correct the deficiencies identified as a result of a DBF in the Main Control Room (Area RC-X), Chiller Area RC-XIII and Reactor Building Area R-I. The modification will provide isolation of the problem cables in the event of a DBF.

NRC Form 368A (689)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (64)9) "m 'I APPROVED OMB NO. 3(500104 1 e EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS LICENSEE EVENT REPORT (LER) INFORMATION COLLECTION REOUESTI 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS TEXT CONTINUATION AND REPORTS MANAGEMENT BRANCH (F630), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO

'1)HE PAPERWOHIL REDUCTION PROJECT-(31504)104). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (11 DOCKET-NUMBER (2) LER NUMBER LS) PAGE (3)

YEAR:@ SEQUENTIAL Pg: REVISION NUMBER NUMBER Washington Nuclear Plant - Unit 2 o s o o o 39 7 9 0 0 0 6 0 0 04 OF 0. 4 TEXT illmore SOsco /sos/Vtrod. vso srfdldoos/HRC FonII 3664'sl (IT)

Safet Si nificance No fires were experienced in the areas associated with the identified cables. The fire detection systems remained operable and fire watch tours were performed on a routine basis. The health and safety of the publ.ic and plant personnel was not affected by this event.

Similar Events LERs84-031 (Revisions 0, 1, 2, 3, 4, 5 and 6),85-043, 88-022, and 88-026 have previously been written on this subject. These LERs re~orted a variety of problems discovered during the initial review of the Appendix "R'nalysis and installation performed by the Architect-Engineer for WNP-2, Burns and Roe. In addition, other RRR Appendix associated issues Were also reported.

EIIS Information Text Reference EIIS Reference tern ~Com onent

'Ss EDG-2 (Division II Diesel Generator) EB GEN E-SM-8 (Division II 4160 VAC Bus) EB BU E-SL-81 (Division II 480 VAC Bus) EB BU E-SL-83 (Division II 480 VAC Bus) EB BU E-SM-7 (Division I 4160 VAC Bus) EB BU RHR-V-17B (Residual Heat Removal Valve 17B) SO V RHR-V-16B (Residual Meat Removal Valve 16B) SO V CCM-CR-1B (Control Room Chiller 1B) VH CHU WN-CC-51B-1 (t/Iixed Air Cooling Coil 51B-1) VH CCL NRC FornI 366A (669)