ML18096A511

LER 92-001-00:on 920107 & 28,SG Blowdown Outlet Isolation Valve Failed to Close.Caused by Dried & Torn Section of Valve Actuator Rubber Diaphragm.Subj Diaphragms Were Replaced.Valves Stroked successfully.W/920206 Ltr

ML18096A511
Person / Time
Site:	Salem
Issue date:	02/06/1992
From:	Pollack M, Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-001-01, LER-92-1-1, NUDOCS 9202110267
Download: ML18096A511 (5)

Text

( ., j \

PSECJ9 Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station February 6, 1992 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 92-001-00 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73(a} (2) (iv}. This report is required to be issued within thirty (30) days of event discovery.

Sincerely yours, C. A Vondra General Manager -

Salem Operations MJP:pc Distribution

~gR02ll0267 920206 S ADOCK 05000272 PDR The Energy People

~

J_ u,-. 0- l...r._, 8 95-2189 (10M) 12-89

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION 16-89) e LICENSEE EVENT REPORT (LERI APPROVED OMB NO. 3150-0104 EXPIRES: 4/30/92 IMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH CP-5301, U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME Ill DOCKET NUMBER 12) I PAGE 13)

Salem Generating Station - Unit 1 TITLE 141 I0 I 5 I 0 I 0 I 0 I 2 I 7 12 I 1 OF 0 I 4 \

I ESF Component Actuation: 12GB4 (Cont. Isol. Valve) Failed Closed Twice Due To Equip. Failu~'

EVENT DATE 15) LER NUMBER 16) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR  ;::SEQUENTIAL!::;:;:;:; REVISION MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERIS)

                                      <*:*:*:*:*    NUMBER   f:'.:'.:'.:'.: NUMBER o11 ol         7 9       2 912        -          olo I1       -             oIo ol 2 o I 6 9 I2 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE Rl:QUIREMENTS OF 10 CFR                     §: (Ch*ck one or more of the following) (11)

MODE (9) POWER I 1 20.402(b) 20.406(*111 )(I) -- 20.406(c) 50.311(cl(1)

                                                                                                                ,_x 50.73(1)(2l(iv) 50.73(11(2)(¥)

73.7llb) 73.71(c) LEVEL 1101 l JO I 0 20.406(*)(111111

                                                                                --   50.38(cl(2)
                                                                                                                ....._   50.73(*H2Hviil                      ,__  OTHER (Spocify in Abstract below and in TBxt, NRC Form 11111mr~11m1111~

20.406(*)(1 )(iii) 60.73(1)(211il 50.73(*)(2)(viiil(A) 366A) 20.406(*)(1 llM 20.408(*)(1 IM - 60.73(*)(2)(ii) 60.73(*l!211iiil LICENSEE CONTACT FOR THIS LER (12) 60.73(*)(2)(viii)(B) 50.73(*1(2l!xl NAME TELEPHONE NUMBER AREA CODE M. J. Pollack - LER Coordinator 6 I o 19 3 I 3 19 I ~ I 2 lo l 2 I 2 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED JN THIS REPORT (131 CAUSE SYSTEM COMPONENT MANUFAC* MANUFAC* TUR ER TUR ER B JIM r1s1v1 M 11 I 210 y I I I I I I I I I I I I I I I I I I I I I SUPPLEMENTAL REPORT EXPECTED 1141 MONTH DAY YEAR EXPECTED n ~NO SUBMISSION DATE 1151 YES (If y~s, comp/et* EXPECTED SUBMISSION DA TE) I I I ABSTRACT (Limit to 1400 spacss, i.e., approximately fifteen singltJ*SJ111Ce typewritten lines) (18) On 1/7/92, the No. 12 Steam Generator (S/G) Blowdown Outlet Isolation Valve (12GB4) (a Containment Isolation Valve) failed closed. Investigation showed that the valve actuator's rubber diaphragm had failed, resulting in air leakage and subsequent valve closure. Inspection of the 1/7/92 failed diaphragm revealed that a section of the diaphragm had dried and tore. The section that dried is located nearest to an uninsulated S/G Blowdown pipe. On 1/8/92, the valve was returned to service. On 1/28/92, the 12GB4 again failed closed. Investigation revealed that the valve actuator's diaphragm again had failed. Inspection revealed that it tore at the same approximate section .as the diaphragm which failed on 1/7/92; however, the diaphragm had not dried. The cause of the 12GB4 valve closure events is equipment failure. A contributing factor to the cause of the 1/7/92 diaphragm failure was premature aging of the diaphragm caused by the prior removal of piping insulation adjacent to the valve actuator. The 1/28/92 valve actuator diaphragm failure was not caused by premature aging. Testing of this failed diaphragm has been initiated to determine why it failed. Assessment of the contributing factors to the 12GB4 valve actuator diaphragm failures is continuing. A review of the maintenance history of the 11-14GB4 valves has been initiated. A review has been initiated to determine the adequacy of the valve actuator diaphragm installation technique. NRC Farm 366 (6-89)

--1~. ~------------- LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 1 5_Q_Q_Q_~7-~__________ 9_~_-:-_Q_Q_!_-:-_Q_Q _____ ------~-_(?~--~-- PLANT AND SYSTEM IDENTIFICATION: Westinghouse - Pressurized Water Reactor Energy Industry Identification System (EIIS} codes are identified in the text as {xxJ IDENTIFICATION OF OCCURRENCE: Engineered Safety Feature equipment operation; Containment Isolation Valve 12GB4 failed closed twice Event Dates: 1/7/92 and 1/28/92 Report Date: 2/6/92 This report was initiated by Incident Report No(s). 92-015 and 92-064. CONDITIONS PRIOR TO OCCURRENCE: January 7, 1992 Mode 1 Reactor Power 100% - Unit Load 1160 MWe January 28, 1992 Mode 1 Reactor Power 90% - Unit Load 1000 MWe DESCRIPTION OF OCCURRENC~: On January 7, 1992, at 0935 hours, the No. 12 Steam Generator Blowdown Outlet Isolation Valve (12GB4) {WI} failed closed. The 12GB4 valve is a Masoneillan International air operated globe valve (model number 38-20761). It takes air to open and is spring loaded to fail close. Investigation showed that the valve actuator's rubber diaphragm had failed, resulting in air leakage and subsequent valve closure. Inspection of the diaphragm revealed that a section of the diaphragm had dried and tore. The section that dried is located nearest to an uninsulated Steam Generator Blowdown pipe. On January 8, 1992, the valve was returned to service after actuator diaphragm replacement and successful functional testing. On January 28, 1992 at 0910 hours, the 12GB4 again failed closed. Investigation revealed that the valve actuator's diaphragm had failed, resulting in closure of the valve. Inspection revealed that it tore at the same approximate section as the diaphragm which failed on January 7, 1992; however, the diaphragm had not dried. It appeared to retain its resiliency. The 12GB4 valve is a Containment Isolation Valve {JM}. Containment isolation is an Engineered Safety Feature (ESF}. Therefore, on January 7, 1992 at 1140 hours and on January 28, 1992 at 1051 hours, respectively, the Nuclear Regulatory Commission (NRC) was notified of the 12GB4 valve closures, in accordance with Code of Federal Regulations 10CFR 50.72(b) (2) (ii). APPARENT CAUSE OF OCCURRENCE: The cause of the 12GB4 valve closure events is equipment failure. In

LICENSEE EVENT REPORT {LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE ~U=n=i~t~l"-~~~~~~~~~~~~~~5000272 92-0_01-QQ__ _ _ 3 o_L_~-- APPARENT CAUSE OF OCCURRENCE: (cont'd) both cases, the valve actuator diaphragm had failed resulting in air leakage and eventual valve closure. A contributing factor to the cause of the January 7, 1992 diaphragm failure was premature aging of the diaphragm caused by the prior removal of insulation on Steam Generator Blowdown piping adjacent to the valve actuator (located a few inches from the valve). The valve actuator diaphragm had dried and failed on the part of the diaphragm closest to the uninsulated pipe. The valve is located in a cramped area approximately 8' off the floor in the Mechanical Penetration Area. The actuator is behind the valve, away from the open work area. The January 28, 1992 valve actuator diaphragm failure was not caused by premature aging, as was the January 7th event. The diaphragm, although found torn in the same location as the January 7th diaphragm failure, was not dry (its resiliency was still intact). Testing of this failed diaphragm has been initiated to determine why it failed. System Engineering has initiated a review of the failure history of the GB4 valves. The 12GB4 valve actuator diaphragm had failed previously on August 23, 1991 (reference LER 272/91-028-00). That failure was also attributed to equipment failure. Review of the 12GB4 Work Order history identified another failed valve actuator diaphragm (which was replaced} in June 1990. ANALYSIS OF OCCURRENCE: The ll-14GB4 valves isolate Steam Generator blowdown in support of normal operations. They also function as containment isolation valves. The operability.of the containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment. In these two (2) events, the 12GB4 valve failed to the safe configuration, as per design. Therefore, there was no affect on the health or safety of the public. However, since containment isolation is an ESF function, the two (2) 12GB4 valve inadvertent closures is reportable in accordance with Code of Federal Regulations 10CFR

50. 73(a) (2) (iv).

CORRECTIVE ACTION: The 12GB4 valve actuator diaphragms were replaced and the valve stroked successfully on January 8, 1992 and January 29, 1992, respectively. The valve was then returned to service after each repair. The uninsulated section of blowdown piping, adjacent to the valve actuator, has been reinsulated. Investigation as to the removal of the adjacent pipe insulation is continuing.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE U-"-=n=i~t-=1~~~~~~~~~~~~~~~5~0~0~0=2=7-=--=2~~~~~~9.2-001-0_0~~~-4_o~f~4-CORRECTIVE ACTION: (cont'd) A faiiure analysis of the January 28, 1992 failed valve actuator diaphragm has been initiated. System Engineering is continuing its assessment as to the contributing factors to the 12GB4 valve actuator diaphragm failures. Upon completion, additional corrective action will be taken as appropriate. As stated previously, a review of the maintenance history {1987 to present) of the 11-14GB4 valves has been initiated. The 12GB4 valve actuator diaphragm had been replaced in August 1991 {reference LER 272/91-028-00) and June 1990 in addition to the two (2) recent events. The 13GB4 valve actuator diaphragm was replaced on January 8, 1991 and again on February 6, 1991. The 11GB4 and 14GB4 valve diaphragms have not been replaced beyond preventive maintenance requirements which include valve actuator maintenance every four (4) years. A review has been initiated to determine the adequacy of the valve actuator diaphragm installation technique and administrative controls. MJP:pc SORC Mtg. 92-014}}