ML17279B097

LER 88-012-00:on 880606,potential Existence of Unmonitored Radiological Effluent Release Path During Certain Emergency Conditions Determined.Cause Unknown.Fan Disabled.Part 21 related.W/880606 Ltr

ML17279B097
Person / Time
Site:	Columbia
Issue date:	06/06/1988
From:	Powers C, Washington S WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
REF-PT21-88, REF-PT21-88-084-000, RTR-REGGD-01.097, RTR-REGGD-1.097 LER-88-012, LER-88-12, PT21-88-084-000, PT21-88-84, NUDOCS 8806160090
Download: ML17279B097 (7)

Text

REGi I AT . INFORMATION DISIP. IBVTIOI~J~YSTEN (RIDBl i

ACCESSION NBR 880616009<a DOC. DATE 88/06/06 NOTARIZED: NO DOC wE"-

FAC IL: 50-397 WPPSB Nuclear P" object Unit 2r Wa hington Public Pore 050CO3'"

AUTH. NAME AUTHOR AFF ILIATION WASHINGTON> S L.'ashington Pub lie Poeer Supply System PQWERSr C. M. Washing ton Pub lie Poeer Supp irr System REC IP. NANE RECIP IENT AFF ILIA"IQN SUB JFCT.'FR 88-012-00: on 88060'.r potential ex zstence o& unmoni t oned radiolnqi cal eI:fluer<t release path due ing certain emer gencg conditions determined. Cause unI'noen, Fan disabled.

W/880606 Itv.

DISTRIBUTION CODE. IF22D COPIES RECEIVED: LTR ENCL SIZE:

TITLE: 50. 73 Licensee Event Report (LER) r Inc ident Rptr etc.

NOTES:

REC IP IENT COP IES REC IP IENT CQP IEB ID CODE/NAI'IE LTTP. ENCL ID CODE/MANE LTTR ENCL PD5 LA 1 PD5 PD 1 1 S*NWORTHr R 1 1 INTERNAL: ACRS NICHELSON 1 1 ACRS NOELLER AEOD/DOA 1 AEOD/DSP/NAS 1 1 AEQD/DSP/ROAD 2 AEOD/DBP/TPAB 1 1 ARN/DCTS/DAB 1 DEDRQ 1 NRR/DFST/ADS 7E 0, NRR/DEBT/CEB 8H 1 NRP/DEST/EBB 8D 1 1 NRR/DEST/ ICSB 7 1 1 NRR/DEBT/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEBTtPSB 8D 1 NRR/DEST/RSB 8E 1 1 NRR/DEBT/SGB 8D NRR/DLPG/HFB 10 NRR/DLPG/GAB NRR/DREP/RAB 10 10 1

1 1

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NRR/DOEA/EAB NRR/DREP/RPB 10 il 1 2

1 2

NRR/DR IS/SI B 9A 1 1 NUDOCS-ABSTRACT 1 02 1 1 RES TELFORDr J 1 1 REB/DE/EIB 1' RES/DRPB DEPY 1 RGN5 FILE 01 1 1 FXTERNAL: EGkG WILLIAMS B 4 4 FORD BLDG HOY, A H ST LOBBY WARD 1 1 LPDR NRC PDR 1 1 NSIC HARB ISr J NBIC NAYBr G 1 1 TQTAL NUNBER OF CQP IFS REQUIRED: LTTR 45 ENCL 44

NRC Form 388 U.S. NUCLEAR REGULATORY COMMISSION (9 83)

APPROVED OMB NO 31500101 EXPIRESI 8'3li88 LICENSEE EVENT REPORT (LER)

FACILITY NAME (II DOCKE'T NUMBER (2) PAGE 13i Washin ton Nuclear Plant Unit 2 0 5 0 0 0 9 7 1 OFO 5

"'"('I Potentia Unmonitore uent Re ease Path Due To Design Error By Architect/Engineer Cause Unknown EVENT DATE I5) LE A NUMBER (5) REPOR'T DATE It) OTHER FACILITIES INVOLVED (81 MONTH OAY YEAR YEAR sEQUENTtAL .:.x svEvtss0rs MONTH OAY YEAR FACILITYrsAMES DOCKE'T NUMBER(SI NUMSER P StUMSESV 0 5 0 0 0 0 5 0 68 88 0 1 0 0 0 6 0 5 0 0 0 THIS REPORT IS SUBMITTED PUASUANT TO THE REQUIREMENTS OF 10 CFA II: (Check one or more ol the Ionoivinpl (11)

OPERATING MODE (0) 20.402(b) 20.405(cl 50,73(el(2Hiv) 73.71(ts) 5 POWER 20AOS I ~ I (I ) I I) 50.38(c)(ll 50.7 3 I ~ I(2) I v) 73.71(cl LEYEL 0 0 20.405 (~ Ill) (i( ) 50. 35 (c I (2) 50.73(r)(2)(veil OTHER ISpecity in Aostrrct orloivrndin Tert, IIRc form 20.405( ~ Ill)(iii) 50.73( ~ )(2)(il 50,73( ~ ) I 2 I ( iiil (A) v 366AI 20.405( ~ )(l)(ivl 50.7 3(c) (2) (Ii) 50,73( ~ l(2) lviiil(BI OCFR Part 21 20,405(el(1) Iv) 50.73(c)(2) Iiiil 50.73( ~ II2I(x)

I.ICENSEE CONTACT FOR THIS LER (12I NAME 'TELEPHONE NUMBER AREA CODE Steven L. Washin ton Com liance En ineer 5 93 7- 0 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBEO IN THIS REPORT (13)

MANUFAC. REPORTABLE MANUFAC.

CAUSE SYSTEIIA COMPONENT TO NPRDS CAUSE SYSTEM COMPONENT TURER TURER

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SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR EXPECTED SU 8 M I SS I 0 N DATE (15)

YE'5 III yncompirte fXPECFED SVBMISSIOrY DATEI NO ABsTRAcT /Limit to lr00 sprees, ir,, rpprovimrtrry fistrrn sinpre specs typewnttrn Iinesl (18)

On May 6, 1988 a Plant Design Engineer determined that under certain emergency conditions an unmonitored radiological effluent release path from the Turbine Building through Diesel Generator Corridor (D104) to the atmosphere could exist. The cause of this event is design error. Fan DEA-FN-51, which exhausts directly to the atmosphere during both normal and emergency operation, was part of the original Plant design done by Burns 8 Roe Inc. The effluent path through DEA-FN-51 should have been evaluated for effluent monitoring instrumentation in accordance with Regulatory Guide 1.97. WNP-2 committed to monitor noble gas effluents in Appendices B and C of the Final Safety Analysis Report (FSAR). The root cause of this event is unknown. During normal and most emergency operations there is no effect since DEA-FN-51 is supplied clean outside air by the Turbine Building HVAC System, or during some emergencies by the DG Area Cable Cooling System. However, during some postulated post-accident conditions it is possible that DEA-FN-51 could pull air from the Turbine Building and exhaust it directly to the atmosphere. The most severe accident (radiologically) in the turbine building is a main steamline break which could generate a source term concentration of 3.312 x 10 4uCi/cc.

The above concentration is within the range specified in Regulatory Guide 1.97 for which effluent monitoring is required. The effects of a main steamline break in the Turbine Building, with a total release to the environment, have been analyzed and the consequences of this potential event reviewed and accepted. The immediate corrective actions taken included: an engineering assessment which determined that DEA-FN-51 was not required for cable cooling during normal or emergency conditions, disabling the fan by pulling its power fuses, and closing the back draft damper. Corrective actions to be taken include: removal of fan DEA-FN-51 and its accessories, sealing the opening created by the removal of the fan, and a design review to ensure that no other potential Regulatory Guide 1.97 unmonitored leakage paths exist. x'22 BBObi60090 BB0606 >li P DR ADOCI4'I 050003'))7 NRC Form 388 5 PDR (9 83 I

NAC Form 35CA U.S, NUCLEAR REGULATORY COMMISSION (943)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPAOVEO OM8 NO 3(50&104 EXPIRES: 8/31/88 FACILITYNAME (1) LER NUMBER LC)

IO(~ SCCVCNTIAL Ir.A IICYISION NVM Cll I<v NVMCCR Washington Nuclear Plant - Unit 2 o s o o o3 788 0 1 0 0 2 QF TEXT N moro t/Mco /I coy/I'or/, oto ~ SASO'onM//YRC Form 35EA't/((T)

Plant Conditions a) Power Level Oi b) Plant Mode - 5 (Refueling)

Event Descri tion On May 6, 1988 a Plant Design Engineer determined that under certain emergency conditions an unmonitored radiological effluent release path from the diesel generator corridor to the atmosphere could exist. The Plant Design Basis includes an FSAR Appendix B II.F.1.1 commitment to monitor noble gas effluent and an Appendix C FSAR commitment to meet the intent of Regulatory Guide 1.97, This potential release path was being investigated due to a concern raised by a Plant System Engineer.

The Diesel Generator Area Cable Cooling System is designed to cool critical electrical cabling during normal and emergency conditions, The system cools cabling which runs between the emergency diesel generators and the main control room and critical switchgear room. The System is comprised of two independent and separ ate systems which cool areas containing both Division 1 and Division 2 cable. The failure of one system will not affect the operational functions of the other cooling system. The cable cooling system, which is shown in Figure 1, is comprised of two exhaust fans (DEA-FN-51 and DEA-FN-52) powered from the Division 1 emergency power bus and one supply air handling unit (DMA-AH-51) powered from the Division 2 emergency power bus. During normal Plant operation DEA-FN-51 runs continuously and exhausts directly to the atmosphere. DEA-FN-52 also runs continuously and discharges to the Radwaste Building. DMA-AH-51 is normally in standby. When DMA-AH-51, is r unning it draws air from the outside when the outside temperature is above 40'F or recirculates room air if the temperature is below 40'F. If not already in service, both DEA-FN-51 and ,DEA-,FN-52 auto start when the Division 1 diesel generator is started and DMA-AH-51 auto starts when the Division 2 diesel generator is started.

During normal Plant operations DEA-FN-51 draws clean air down the diesel generator corridor (D104) which is supplied by the Turbine Building HVAC System. During some emergency conditions DEA-FN-51 and DEA-FN-52 are supplied outside air by the supply air handling unit4DMA-AH-51) when the outside air temperature is greater than 40'F or recirculated room air when the temperature is less than 40'F. However, these emergency conditions DMA-AH-51 is not operable, air from the Turbine Building if during could be drawn in by DEA-FN-51 and exhausted to the atmosphere. A main steamline break in the Turbine Building would result in a source whose maximum concentration is 3.312 x 10-4 uCi/cc. (The source concentration was calculated by dividing the total main steamline break source by 10% of the volume of the Turbine Building.) The above concentration level is within the range specified in Regulatory Guide 1.97 Table 2 (between,10-6 uCi/cc and 102 uCi/cc) and, therefore, this release path should have been monitored.

NRC FORM SCCA o U.S GPO:)988 0 824 538/455 194)3)

NRC Form 308A U.S, NUCLEAR REGULATORY COMMISSION I943)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMB NO 3150&IOO EXPIRES: 8/31/88 FACILITY NAME 11) I DOCKET NUMBER LTI PAGE 13I LER NUMBER IS>

>>>vr SEQVENT/AL >or. REVISION So>> NUMSER  :~: NVM ER Washington Nuclear Plant - Unit 2 39 788 012 0 0 03 05 TEXT /// //rod o/roco /I nrRriorE rroo ///o/oo/ N//C %%dnrr 3RLI 3/ 1 1 Tl Immediate Corrective Actions An Engineering Assessment determined that DEA-FN-51 was not required for cable cooling during normal or emergency conditions. The fan was disabled by removing its power fuses and by closing the back draft damper.

Further Evaluation There were no Plant structures, components, or systems inoperable at the start of this event that contributed to this event.

The cause of this event is a design error. This fan was part of the original Plant design done by Burns 8 Roe Inc., the Architect/Engineer for WNP-2, and should have been evaluated in accordance with Regulatory Guide 1.97. The root cause of this event can not be determined.

This event is reportable per 10CFR50.73(a)(2)(ii)(B) and 10CFR Part 21. The Plant was in a condition outside its design basis.

Further Corrective Actions to be Taken A Plant Modification Request is being processed to remove DEA-FN-51 and its associated accessories and to seal the opening created by the removal of the fan.

A Plant Design Review will be performed to verify that no other potential unmonitored release paths requiring monitoring by Regulatory Guide 1.97 exist. Burns 8 Roe, Inc.

will be notified of the 10CFR Part 21 determination.

Safety Si nificance The maximum potential release through this path would be the entire source generated by a main steamline break. This release has been analyzed (FSAR, Chapter 15, Section 15.6.4 ) and found acceptable even if all the activity is released directly to the environment. Therefore, the consequences of this potential event have been previously reviewsd and accepted. Since an actual emergency condition did not occur during the ev'ent period, this event posed not threat to the health and safety of the public or Plant personnel.

Similar Events Hone EIIS Information Text Reference EIIS Reference System Component Diesel Generator Corridor NRC FO/IM SSSA o U S GPO.1980.0.024.538/O55 1903 I

NRC Form 348A U 8 NUCLEAR REQULATO/IY COMMISSION 184/31 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVEO OM8 NO 3150 0/04 EXPIRES/8/3I/88 FACILITY NAME III OOCKET, NUMSER 12l LER NUMEER IS) PAGE 13>

4T~/ ssavsNr/*L g,;0 Sr:x AEY/s/0//

NVM Ell NVM ER Washington Nuclear Plant - Unit 2 o s o o o 012 00 0 4 OF TEXT /// /tu/ff fpfcf /4 /Pquiu/t. u44 aAto'anal HRC Fo//n 38SA'4/ I I TI EI IS Information Text Reference EIIS Reference System Component Diesel Generator Area Cable Cooling System exhaust fan (DEA-FN-51) VJ FAN Turbine Building HVAC VK Diesel Generator Area Cable Cooling System Supply air Handling Unit (DMA-AH-51) VJ AHU Turbine Building NM Main Steamline SB PSP Diesel Generator Area Cable Cooling System VJ Division 1 Diesel Generator EL DG Division 2 Diesel Generator EL DG Main Control Room NE Critical Switchgear Room NE Diesel Generator Area Cable Cooling System exhaust fan (DEA-FN-52) VJ FAN Division 1 emergency power bus EL BU Divison 2 emergency power bus EL BU Radwaste Building NE Reactor Building . NG N/IC fa/IM 3444 uU 8 GPO 1888 0 824.538/455 18831

NRC Form 3ddA .U.S. NUCLEAR REGULA'TORY COMMISSIOr/

(983)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO OM8 NO 3I SOW(04 EXPIRES: 8/3l/88 FACILITY NAME (II OOCKET NUMSER (2l LER NUMSER (d( PAGE (3)

Yt*R SEOUENT/AL ' NI 4EVISION

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NUM t4 NUMdt4 Washington Nuc1ear Plant Unit 2 p p p p p 3 9 7 8 8 0 1 2 0 0 0 5 oF 0 5 TEXT /// more <<>>oe>> /e//Iie/L rr>> ////O 'o>>/ H/IC form 3//SAOI II 7) lJ I-SERVICE BUILDING <<C DEA"FN"51 Cl I

DIESEL REACTOR CL GENERATOR BUILDING a A BUILDING l2!

a D A-AH"5i IAI A

TURBINE BUILDING I-N

'D DAMPER TURBINE BLDG HVAC SUPPLY RADWASTE BUILDING FIGURE 1 N/IC FORM SddA 4 U.S GPO. (988 0.82 ~ 538/4 55 (983(

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George 1Vashington 1Vay ~ Richland, 1Vashington 99352 Docket No. 50-397 June 6, 1988 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.88-012

Dear Sir:

Transmitted herewith is Licensee Event Report No.88-012 for the WNP-2 Plant.

This report is submitted in respons'e to the report requirements of 10CFR50.73 and 10CFR Part 21. The report discusses the items of reportability, corrective action taken, and action taken to preclude recurrence.

Very truly yours,

, &de C.M. Powers (M/D 927M)

WNP-2 Plant Manager CMP:lg

Enclosure:

Licensee Event Report No.88-012 cc: Mr. John B. Martin, NRC - Region V Mr. C.J . Bosted, NRC Site (M/D 901A )

INPO Records Center - Atlanta, GA Ms. Dottie Sherman, ANI Mr. D.L. Williams, BPA (M/D 399)