ML17285A631

LER 89-026-00:on 890619,testing Confirmed That Selected Steam Tunnel Penetrations Could Fail to Perform as Pressure Boundary Following Design Basis Main Steamline Break.Caused by Inadequate Design Mgt.Part 21 related.W/890719 Ltr

ML17285A631
Person / Time
Site:	Columbia
Issue date:	07/19/1989
From:	Fuller R, Powers C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-89-127-000 LER-89-026, LER-89-26, PT21-89-127, PT21-89-127-000, NUDOCS 8907280223
Download: ML17285A631 (6)

Text

AC CELE RATED QFI'RIB U'n ON DEMON +RATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8907280223 DOC.DATE: 89/07/19 NOTARIZED: NO DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397

'AUTH. NAME AUTHOR AFFILIATION FULLER,R.E. Washington Public Power Supply System POWERS,C.M. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 89-026-00:on 890619,potential failure of penetration seals could cause failure of safety equipment.

W/8 ltr.

DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR g ENCL I TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.

SIZE:

r NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME 'TTR ENCL ID CODE/NAME LTTR ENCL PD5 LA 1 1 PD5 PD 1 1 SAMWORTH,R 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DS P/TPAB 1 1 AEOD/ROAB/DSP 2 2 DEDRO 1 1 IRM/DCTS/DAB 1 1 NRR/DEST/ADE 8H 1 1 NRR/DEST/ADS 7E 1 0 NRR/DEST/CEB 8H 1 1 NRR/DEST/ESB 8D 1 1 NRR/DEST/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEST/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEST/RSB 8E 1 . 1 NRR/DEST/SGB 8D 1 1 NRR/DLPQ/HFB 10 1 1 NRR/DLPQ/PEB 10 1 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/RPB 10 2 2 NUDOCS-ABSTRACT 1 1 1 1 RES/DSIR/EIB 1 1 1 1 RGN5 FILE 01 1 1 EXTERNAL EG&G WILLIAMSP S 4 4 FORD BLDG HOY,A 1 1 L ST LOBBY WARD 1 1 LPDR 1 1 I NRC PDR 1 1 NSIC MAYS,G 1 1 NSIC MURPHY,G.A 1 1 D S

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Box 968 ~ 3000 George Washington Way ~ Richland, Washington 99352 Docket No. 50-397 July 19, 1989 Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555,

Subject:

NUCLEAR PLANT NO. 2 LICENSEE EVENT REPORT NO.89-026

Dear Sir:

Transmitted herewith is Licensee Event Report No.89-026 for the WNP-2 Plant.

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

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

WNP-2 Plant Manager ChiP:lg

Enclosure:

Licensee Event Report No.89-026 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)

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PDR ADOCK 0'6000397 PDC

~ ",ww ww NRC perm 356 U.S. NUCLEAR REGULATORY COMMISSION (9.63) APPROVED OMB NO. 31504)04 EXPIRES: SI31IBB LICENSEE EVENT REPORT (LER)

DOCKET NUMBER (2( PAGE 3)

FACILITY NAME (1)

Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 7 1 OF P 4

'"""'OTENTIAL FAILURE PF PENETRATION SEALS COULD CAUSE FAILURE OF SAFETY E(}UIPMENT IN SECONDARY CONTAINMENT FOLLOWING POSTULATED DESIGN BASIS STEAMLINE BREAK IN STEAM TUNNEL EVENT DATE (SI LER NUMBER (6) REPORT DATE 17) OTHER FACILITIES INVOLVED (SI 9+9'SEQVENTtAL 4EvtsroN OAY YEAR FACILITYNAMES DOCKET NUMBER(S)

MONTH DAY YEAR YEAR a4 NVMSER ?9?? NVMBER MONTH 0 5 0 0 0 0 6 1 9 8 9 8 9 0 2 6 0 0 071 9 8 9 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REGVIREMENTS OF 10 CFR (): (Check one or more of the lOllowinpl (11)

OPERATING MODE (9) 5 20.402(b) 20AOS(cl 60.73( ~ I (2)(iv) 73.71(6)

POWER 20.406(el(1)(i) 50.36(e) Ill 60.73(el(2) (vl 73.71(c)

LEVEL DTHER (speclly In Aortrect p p p 20.40S( ~ l(11(9 I 50.35 (c) 12) 50.73(e) LT)(viO Oelow end In Tert, NRC Form 20.406( ~ l(I ) (>i)) 50.73( ~ )(2)II) 60,73(e l(2)(viii)(Al 36SAI 20.405( ~ l(IIBvl 50,73( ~ l(2)(ii) 50.73(e) (2)(viii)IS) 1 OCFR Part 21 20.406(el(I ) (v) 60.734) (2)((ill 50,73( ~ ) 12) (el LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE R.E. Fuller Com liance En ineer 5 0 3 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPOR'T (13) r ORL By r MANUFAC. r~oavasu CAUSE SYSTEM COMPONENT MANUFAC-TURER Tree@%~I'Sr 44%'..,,6 MS SYSTEM COMPONENT TURER ig<~g(~

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? o SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES ill yn, complete EXPECTED SUBMISSION OATEI X NO ABSTRACT (Limit to tc00 rpecet, in., epprommetely lrlteen rinple rpece typrwritren li nNI (16)

On June 19, 1989 testing confirmed that selected penetrations in the Steam Tunnel could fail to perform as a pressure boundary following a design basis Main Steamline break in the Steam Tunnel. As a result, qualification limits could be exceeded for safety equipment in the Reactor Building (Secondary Containment). Review and identification of this condition occurred as part of by the current review process of Plant design changes. Also, this event is reportable per 10CFR Part 21 as a deficiency in the seal design of the Steam Tunnel Penetrations by the Plant Architect/Engineer Burns & Roe, Inc.

During review of a design change to core drill and seal two new 2 and 1/2-inch diameter penetrations from -the Steam Tunnel to the Reactor Building, it was determined that the proposed sealant was not pressure rated for diameters greater than 3/4-inch. Existing penetrations in the Steam Tunnel were inspected and representative sample testing was performed on the sealant. The inspection and testing determined eleven existing penetrations in the Steam Tunnel required modification to resist the postulated design basis pressures.

An urgent Plant Modification Request was initiated to modify the eleven penetrations prior to Plant startup.

The root causes of inadequate pressure boundaries in the Steam Tunnel include 1) less than adequate design, and 2) management programs, of the Architect/Engineer (i.e., Burns &

Roe, Inc.) did not ensure the seal designs were compatible with the design basis requirements.

NRC Farm 366

NRC Form 3ddA US. NUCLEAR REOULATORY COMMISSION

(%331 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150-0104 EXPIRES: B/31/BB FACILITY NAME (11 DOCKET NUMBER (ll I.ER NUMBER (d) PACE (31

~3 SEOUSNTIAL @s Rf vrsroN NUMSER ....I NUMSSR Mashin ton Nuclear Plant - Unit 2 0 s 0 0 o 397 89 0 60 0 2 oF0 4 TEXT lllmore s/rose /s rterr/red, Use edde'orre/ NRC Form 3ddA'sl (IT/

Abstract (cont'd),

The corrective actions include 1) revision of appropriate drawings to include pressure requirements on Steam Tunnel penetrations, and 2) the Architect/Engineer (Burns 8 Roe, Inc.) will be notified of the deficiency per 10CFR Part 21.

The actual safety significance of the postulated event is unknown because the severity of the environmental conditions in the Reactor Building and corresponding equipment operability was not determined for a design basis steamline break in the Steam Tunnel and corresponding loss of the 'pressure boundary of the eleven penetrations. There was no actual safety significant event associated with this discovery, since a Main Steamli ne break did not occur during the event period.

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

Event Descri tion On June 19, 1989 testing confirmed that selected penetrations in the Steam Tunnel could fail to perform as a pressure boundary following a design basis Main Steamline break in the Steam Tunnel. As a result, qualification limits could be exceeded for safety equipment in the Reactor Building (Secondary Containment). Review and identification of this condition occurred as part of the current review process of Plant design changes.

A design change was proposed to core drill and seal two new 2 and 1/2-inch diameter spare penetrations from the Steam Tunnel to the Reactor Building on the 501-foot elevation. The penetration sealant specified in the design change was Dow-Corning Silicone Foam DC3-6548. During the review of the design, a Design Engineer determined that a maximum Steam Tunnel internal pressure of 26 psia for 0.2 second and 20 psia continuous pressure for several seconds (FSAR Figure 3.6-130) would occur following an FSAR design basis accident of a Main Steamline break inside of the Steam Tunnel at 100K of rated reactor power. The Design Engineer discovered the proposed sealant was not pressure tested for penetrations greater than 3/4-inch in diameter. This discovery resulted in inspection of existing penetrations in the Steam Tunnel an(l representative sample testing of a 4-inch diameter penetration sealed with DC3-6548.

The inspection found 65 penetrations from the Steam Tunnel to the Reactor Building where the Dow Corning Silicone Foam was used as a pressure boundary. The representative sample testing qualified the sealant for penetrations up to 4 inches inside diameter and a maximum internal pressure of 27.7 psia without restraint.

Eleven of the 65 penetrations required modification to satisfy the design requirements. Identification of the eleven penetrations are R310-4001, -4002,

-4025, -4028, -4038, -4039 and -4040, and, R308-4005, -4007, -4009, and -4024.

NRC Form 366A U.S. NUCLEAR REOULATORY COMMISSION (0%3)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMB NO. 3150-0)04 EXPIRES: 8/31/88 FACILITY NAME ()) DOCKET NUMBER (3) PAGE (3)

LER NUMBER (8)

SEQUENTIAL AP REVISION NUMSER NUMSEII Washin ton Nuclear Plant - Unit 2 0 5 0 0 0 3 9 OF TEXT /I!more spese /s recur) ed, use sddi)/orrs////I C Form 3684's/ (17)

Immediate Corrective Action An urgent Plant Modification Request (PMR) was initiated to modify the eleven penetrations. All eleven penetrations were modified prior to Plant restart (July 2, 1989) from the refueling outage.

Further Evaluation and Corrective Action A. Further Evaluation

1. This event is reportable per 10CFR 50.73(a)(2)(ii)(B) as a condition outside of the Plant design basis. A design basis of the Steam Tunnel is to channel steam from a Main Steamline break in the Steam Tunnel to the Turbine Building through blowout panels. The condition cited in this report would have allowed steam from a postulated break to enter areas of the Reactor Building.

Reportability per 10CFR 50.-73(a)(2)(ii)(A) and 10CFR 50.73(a)(2)(v) would require a significant number of manhours to analyze the effect of this postulated event on Plant equipment with no improvement in Plant Safety.

Some of the Reactor Building areas adjacent to the Steam Tunnel through which steam from the postulated event would have leaked contain Plant equipment which may not be qualified for the post event environment.

This event is also reportable per 10CFR Part 21 as a deficiency in the seal design of the Steam Tunnel penetrations by the Plant Architect/Engineer Burns & Roe, Inc. The deficiency resulted in a major reduction of the containment system to perform its design function.

2. There were no structures, components, or systems inoperable prior to the event which contributed to the event.

3. The root causes of inadequate pressure boundaries in the Steam Tunnel include 1) less than adequate design, and 2) management programs of the Architect/Engineer (i.e., Burns 8 Roe, Inc.) did not ensure the seal designs were compatible with the design basis requirements.

a) Three blowout'anels in the Steam Tunnel are designed to open and vent into the Turbine Building at a pressure of 0;5 psig. As a result, pressure requirements of penetration fire 'seals in the Steam Tunnel were not thought to be required.

b) The Plant Architect/Engineer Burns 8 Roe, Inc., designed the penetration seals. The management programs Burns 8 Roe, Inc. had in effect at the time of the seal design are unknown.

AU.S. CPOI 1988 530 5S9r00010

NRC Form 388A U2L NUCLEAR REOULATORY COMMISSION (043)

LICENSEE EVENT REPORT {LER) TEXT CONTINUATION APPROVEO OMB NO. 3)50-0104 EXPIRES: 6/31/BB FACILITY NAME (1) OOCKET NUMBER (2) LER NUMBER (6) PACE (3)

YEAR @Ii SEQUENTIAL NUMBE4 REVISION NUMBE4 Washington Nuclear Plant - Unit 2 o s o o o3 97 8 9 0 2 6 000 4 OF 0 4 TEXT /// moro srrsso /s rsr/o/rsd, oss sddidorM///RC Form 36SA's/ (17)

B. Further Corrective Action

l. Appropriate Plant drawings were revised to include pressure requirements on Steam Tunnel penetrations.

2. The Architect/Engineer (Burns & Roe, Inc.) will be notified of the 10CFR Part 21 determination.

3. Other areas of the Plant with the potential for pressurization will be reviewed to identify and modify penetration seals that do not satisfy the design basis requirements.

Safety Si nificance Tne actual safety significance of the postulated event is unknown because the severity of the environmental conditions in the Reactor Building and corresponding equipment operability was not determined with failure of the eleven penetrations following a design basis steamline break in the Steam Tunnel. There was no actual safety significant event associated with this discovery, since a Main Steamline break did not occur during the event period.

Also, the FSAR analyses were performed with the conservative assumption that only the ceiling panel in the Steam Tunnel blew out and the two .wall blowout panels remainea in place. This conservatism was included to maximize the predicted radionuclide release to the environment from this event and not establish a pressure requirement for the Steam Tunnel penetration seals.

the Steam Tunnel depressurization rate would be greater than predicted in the FSAR However, it is postulated that with all three blowout panels releasing at the designed pressure of 0.5 psig.

Therefore, the severity of the environmental conditions in the Reactor Building would be decreased because of a lower average driving pressure in the Steam Tunnel, reducing -the probability of equipment failure.

Since this condition did not actually occur, this condition did not threaten the health and safety of the public or Plant personnel.

Similar Events None EIIS Information Text Reference E I IS Reference System Component Main Steam System SB Reactor Building NG Turbine Building NM NRC FORM 388A ~ U.S. CPOI )988-520-589/00010,