ML18005A589

LER 88-023-01:on 880812,reactor Coolant Sys Vent Less than Required by Tech Spec 3.4.9.4 for Low Temp Overpressure Protection.Caused by Failed Valve Gagging Device.Longer Gagging Device installed.W/880913 Ltr

ML18005A589
Person / Time
Site:	Harris
Issue date:	09/13/1988
From:	Howe A, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-880188-(O), LER-88-023, LER-88-23, NUDOCS 8809190333
Download: ML18005A589 (7)

Text

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A.C CELERAYED DISTRIBUTION DEMONSTRATION SYSTEM

~ 3 REGULATORY INFORMATION, DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:8809190333 DOC.DATE: 88/09/13 NOTARIZED: NO DOCKET FACIL:50-400 Shearon Harris Nuclear Power Plant, Unit 1, Carolina 05000400 AUTH. NAME AUTHOR AFFILIATION HOWE,A.J. Carolina Power & Light Co.

WATSON,R.A. Carolina Power & Light Co.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-023-01:on 880812,reactor coolant sys vent less than required due to failure of valve gagging device.

W/8 DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR I ENCL J SIZE:

TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.

NOTES:Application for permit renewal filed. 05000400 8 RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL A PD2-1 LA 1 1 PD2-1 PD 1 1 BUCKLEY,B 1 1 INTERNAL: ACRS MICHELSON 1 1 ACRS MOELLER 2 2 ACRS WYLIE 1 1 AEOD/DOA 1 1 AEOD/DSP/NAS 1- 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 ARM/DCTS/DAB 1 1 DEDRO 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/QAB 10 1 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/RAB 10 1 1 NRR/DREP/RPB 10 2 2 NRR DRIS/SIB 9A 1 1 NUDOCS-ABSTRACT 1 1 R 02 1 1 RES TELFORD,J 1 1 RES7D R DEPY 1 1 RES/DSIR/EIB 1 1 RGN2 FILE 01 1 1 EXTERNAL: EG&G WILLIAMS,S 4 4 FORD BLDG HOY,A 1 1 H ST LOBBY WARD 1 1 LPDR 1 1 NRC PDR '1 1 NSIC HARRIS,J 1 1 NSIC MAYS,G 1' j

A TOTAL NUMBER OF COPIES REQUIRED: LTTR 46 ENCL 45

p 4.

NRC Form 388 U.S. NUCLEAR REGULATOAY COMMISSION (84)3)

APPAOVED OMB NO. 31504104 EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LER)

DOCKE'T NUMBER 12) PAGE 3)

FACILITYNAME (1)

SHEARON HARRIS NUCLEAR PO R PLANT UNIT 1 0 5 0 0 0 4OO 1 OF 04 TECHNICAL SPECIFICATION NON-COMPLIANCE: REACTOR COOLANT SYSTEM VENT LESS THAN RE UIRED DUE TO FAILURE OF VALVE GAGGING'.DEVICE EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

DAY YEAR YEAR SEQUENTIAL yerrp REVrSION MONTH OAY YEAR FACILITYNAMES DOCKET NUMBER(s)

MONTH NUMBER 'S."r: NUMBER 0 5 0 0 0 8 8 1 2 8 8 8 8 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T 0 THE REOUIREMENTS OF 10 CFR (I: IChrch one or morr Of thr fOllorylnP/ (11 OPERATING MODE (0) 20.402(B) 20.405(cl 50.73(cl(2) (lvl 73.71(B)

POWER 20.405( ~ ) (1)(i) 60.38(e) (I ) 50.73(e)(2)(v) 73.71(cl LEVEL (10) 0 20.405( ~ ) (1 l(rll 50.36(e)(2) 60.73(e)(2)(vQ) OTHER ISprclfy ln Aostrrct helovv enrf Fn Tres HRC Form 20.405( ~ l(ll(lii) 50.73(s) (2)(ll 60.73 (e) (2) (vill( (Al 36BA/

20.405(e) (1)(iv) 50.73(eH2)(QI 50.73(c)(2)(villi(B) 20.405(e)(l ) (v) 50.73(c)(2)(lil) 60.73( ~ ) l2) (x)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE J. HOWE SR.

ANDREW ENGINEER 9 19 362 -2 719 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFAC TUAER REPOATABLE TO NPRDS k5)& CAUSE SYSTEM COMPONENT MANUFAC.

TUREA EPOATABLE TO NPRDS I!WN SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SUBMISSION DATE (15)

YES IIIyrs, complete EXPECTED SUB4SISSID/Y DATE/ NO ABSTRACT I(.lmlt ro /400 specn, I ~ ., epprorrlmetrfy fifteen slnple.sneer typevvrltten linn/ (15)

ABSTRACT:

On August 12, 1988, the plant was in Mode 5, 100'F, with the Reactor Coolant System (RCS) drained and vented through a gagged open pressurizer Power Operated Relief Valve (PORV) in compliance with Technical Specification 3.4.9.4 for low temperature overpressure pr'otection. An operator observed a midposition indication on the control board for the gagged open PORV at 1515, and this was locally verified at 1540. Since it was unknown whether the midposition PORV provided the minimum 2.9 square inch vent path required by the Technical Specifications, the remaining two PORVs were returned to operational status and opened at 3620.

O 0l) c2'Cl

~00- An initial evaluation of vent path opening available with a PORV at 0vO

(-O midposition yielded only a 1.25 square inch vent, and a total =of only 1.47 RlD square inches was determined to have existed when taking credit for all other SC7 openings in the RCS. Thus the requirements of Specification 3.4.9.4 were not met.

RD RD Over time, the packing in the PORV was compressed by the valve gag, allowing 0 cX the valve to drift approximately 1/4 inch closed. A longer gagging device was installed on the PORV to ensure it remained fully open until two pressurizer OiCI safety relief valves could be removed to provide an RCS vent. A'ew device which will not be subject to this potential failure mechanism will be designed

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(Y) Q.(A

'for the PORV prior to its next use as a vent. Additional procedural controls for the use of valve gags will be implemented to reduce the potential foy P similar events. Qrr Nnr'nrm 38rl

A NRC FOIm 366A U.S. NUCLEAR REGULATORY COMMISSION I9$ 3I LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO, 3150&106 EXPIRES'/31/88 FACILITY NAME I1I DOCKET NUMBER (2I LER NUMBER (SI PAGE IS)

'<'SI SEQUENTIAL REVISION YEAR NVM ER ;ALII ISrK NUMBER SHEARON HARRIS NUCLEAR POWER PLANT 0 5 0 0 0 OF 1 O TEXT //f IIRYF Z>>CR /f IRSv/RR/, I/>> IRSWOne//YRC FOnn 3SSA'fl I ITI INITIAL CONDITIONS:

The plant was in Mode 5, 100'F, with the Reactor Coolant System (RCS) drained down to approximately four inches below the reactor vessel head flange and vented to the Pressurizer Relief Tank via a gagged open valve.

DESCRIPTION:

On August 12, 1988, at 1515, a control operator observed a midposition indication on valve 1RC-114, Pressurizer Power Operated Relief Valve (PORV)

(EIIS: AB:PCV). This valve had been previously opened and a gag device installed to ensure a minimum 2 9 square inch vent path for the RCS in compliance with Technical Specification 3.4.9.4,.Low Temperature Overpressure Protection. The valve was locally checked and was verified to be approximately midposition at 1540.

Since it was not known whether the midposition PORV provided the minimum required 2.9 square inch vent, the remaining two PORVs were restored to operational status by re-establishing nitrogen to the valve operators, and the two PORVs were opened at 1620, ensuring compliance with Specification 3.4.9.4.

evaluation of the midposition PORV configuration concluded that it An initial had provided only a 1.25 square inch opening'. The existing configuration of the RCS at that time also had two other openings, 3/8 inch pipes for the reactor vessel head vent and reactor vessel level indicator, for a cumulative vent path of 1.47 square inches. This was determined at 1745, and the Shift Foreman reported the situation to the NRC at 1900, as required by 10 CFR 50.72(b)(2)(iii). (Further evaluation based on the increased length of the longer gag subsequently installed on the PORV determined that the actual PORV position provided approximately 2 square inches of vent path.)

CAUSE:

The PORV uses a spring close, nitrogen/air open actuator. The nitrogen/air supply to the actuator had been isolated for outage activities, and without this force acting against the spring, the valve packing was . gradually compressed sufficiently to allow the PORV to move from the fully open position.

The gag was originally installed on the PORV under the control of a work request/authorization (WR6A) to support surveillance test activities.

Although the WRGA provides the administrative control of the use of valve gags, no specific procedure provides guidance on the acceptability of the design of such devices. It was not realized that slight valve movement could result in noncompliance with the Technical Specifications.

NRC FORM 366A R U.S GPO. I 988 0.826 538/655 1943 I

A NRC Form 388A U.S. NUCLEAR REGULATORY COMMISSION (9831 LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMS NO, 3150-OIOC EXP/RES: 8/31/88 FACI LIT Y NAME (11 DOCKET NUMBER (21 LER NUMBER (5) PACE (31 SSOVE NTIAL REVISION PLANT YEAR $g NVMSSII 5 NVMSSA SHEARON HARRIS NUCLEAR POWER UNIT 1 TEXT /// moro Apoce *//v//werE vce CAUSE:

~

(continued)

Hl(C /cocm 355A 3/ I'l) 0 5 0 0 0 OF There have been no previous similar events with failures of valve gags. A pressurizer PORV has been gagged open during previous outages without occurrence of failure. The packing on the PORV had been recently replaced and the compressibility of new packing material contributed to the event. In addition, in previous situations with the PORVs gagged, the nitrogen/air supply was not isolated, so that this was the first time the gagging device alone was holding the valve open against the spring.

ANALYSIS:

Technical Specification 3.4.9.4 requires either two OPERABLE PORVs of the Low Temperature Overpressure Protection System, or a minimum 2.9 square inch vent, which corresponds to the area provided by a single PORV in the fully open position. This ensures protection of the RCS against the overpressure transient associated with either 1) the start of an idle Reactor Coolant Pump (RCP) with secondary side of the steam generators less than,50'F above primary coolant temperature, or 2) the start of an idle charging/safety injection pump (CSIP) and injection into a water-solid RCS. These transients are associated with the 10CFR 50 Appendix G limits based on protecting the reactor vessel

.integrity, assuming a vessel metal irradiation at 4 Effective Full Power Years (EFPY).

With the RCS drained and vented, the RCPs could not be started without violating several prerequisites for pump start. In fact, the RCP breakers were not in service, greatly reducing any potential for inadvertent start-up due to personnel error. One CSIP was in operation during the event, with the other available pump breaker racked out as required by Technical Specifications below 335'F.

During this event, a" 1.47 square inch vent was calculated to be available to relieve any pressure transient, based on the PORV being at midposition.

Additional data obtained shows that the PORV had slipped approximately 1/4 inch from the fully open position, and this would indicate that up to 2 square inches of vent path actually existed.

Since a substantial vent path actually existed, and with the RCPs out of service and the RCS not water-solid, and with vessel irradiation levels not yet at the limiting value of 4 EFPY, the probability of a limiting pressure transient is not likely. The required vent path was unavailable for at least one hour and five minutes, based on the time of discovery until correction.

This event is reportable in accordance with 10 CFR 50.73(a)(2)(v) as a condition that could have prevented the plant from being maintained in a safe shutdown condition due to an equipment failure.

NIIC FORM 355A e U.S GPO 1988.0 824 538/455 (9831

NRC Form 344A U.S. NUCLEAR REGULATORY COMMISSION (983)

LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OMB NO. 3)50M)04 EXPIRES: 8/31/88 FACILI'TY NAME (1) DOCKET NUMSER (2) LER NUMSER (6) PAGE (3)

YEAR SEQUENT/AL rMqr SEV /SKIN SHEARON HARRIS NUCLEAR POVER PLANT- (@ NUMSSR NVMSFR UNIT 1 0 5 0 0 0 OF TEXT /// more 4/rece /r ee/M)her/, rree e//SOS'Mna/ /YRC Fo/rrr 33//AS/ (17)

CORRECTIVE ACTION:

The PORV packing was tightened and a longer gagging device was installed until two of the three pressurizer safety relief valves were removed to provide the required RCS vent.

2 ~ A different device will be designed for installation on the pressurizer PORV which does not risk compression of the valve packing and closure of the valve. This new design will be in place prior to using an open PORV to comply with Specification 3.4.9.4

3. A procedure to control the use of valve gagging devices will be implemented, requiring such devices to be either vendor supplied or designed as a plant modification with appropriate engineering reviews and controls.

NRC FO/IM 344A e U S GPO.(988-0624 538/455 1943)

C~I Carolina Power & Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562 SEp1 5 1988 File Number.'HF/10-13510C Letter Number'HO-880188 (0)

U..S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 88-023-01 Gentlemen.'n accordance with Title 10 to the Code of Federal Regulations, the enclosed Licensee Event Report is submitted. The original report fulfilled the requirement for a written report within thirty (30) days of a reportable occurrence and is in accordance with the format set forth in NUREG-1022, September 1983.

Revision One corrects administrative errors noted in the original regarding the report identification number and supplemental report information.

Very truly yours, R. A. Watson Vice President Harris Nuclear Project AJH:vdj

. Enclosure cc: Dr..J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. W. H. Bradford (NRC SHNPP)

MEM/LER-88-023/1/OS1