ML18107A235

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LER 99-001-00:on 990330,MSSV Failed Lift Set Test.Caused by Setpoint Variance Which Is Result of Aging.Valves Were Adjusted & Retested to Ensure TS Tolerance.With 990423 Ltr
ML18107A235
Person / Time
Site: Salem PSEG icon.png
Issue date: 04/23/1999
From: Garchow D, Enrique Villar
Public Service Enterprise Group
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-99-001-03, LER-99-1-3, LR-N990199, NUDOCS 9905030062
Download: ML18107A235 (5)
v • d • e


Text

e OPS~G Public S~rvice El~ctric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit APR 131999 LR-N990199 U.S. Nuclear Regulatory Commission Document Control Desk -

Washington, DC 20555 Gentlemen:

General anager -

Salem Operations Attachment

/EHV C Distribution LER File 3.7 9905030062 990423 PDR ADOCK 05000311 S PDR The pCMer is in µtr hands.

95-2168 REV. 6/94

    • J..NRC FORM 366 U.S.NU R REGULA TORY COMMISSION .aaoveo BY OMB NO. 3150-0104 (4-95) W EXPIRES 04/30/98 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS.

REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T-6 F33l. U.S. NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555-0001, AND TO (See reverse for required number of THE PAPERWORK REDUCTION PROJECT di its/characters for each block Generating Station - Unit 2 1 OF 4 Main Steam Safety Valves Failed Lift.set.Test 1::::::: OTHER FAc1on*s '"F::

VIII OTHER n---r..,...,..,..,.,.=.....,,,,.,...-----r-.........,,,..,=~-----r-~""""'=7"m'-'""------rt!:p~ecifv in Abstract below or lt--t-.r............= . . . .~----1--m..,,,..,r.:t7R"'""-----t--!y.""""'=7"m:T.'\-----i in NRC Form 366A spaces, 1.e., approximate y During the period from March 30 through March 31, 1999 with the Salem Unit 2 in Mode 1 at 75% reactor power and steam pressure at >804 psig, in place lift assist testing of the main steam s~fety valves (MSSV) was* performed.

Because the testing of the MSSV was performed at end of life conditions, when power related xenon transients have greater effects, Public Service Electric and Gas reduced power to 75% and the high flux trip setpoint to 87%, thus meeting the Technical Specifications requirements for one inoperable MSSV. When a MSSV valve was determined to be inoperable, the MSSV valve was adjusted and subsequently retested to meet the table 4;7-1 tolerance prior to continuing with the test. The cause of this event was consistent with AEOD/S92-20 study, which classified these failures as "setpoint variance." Setpoint variance, as discussed in this report, is a result of aging. Aging is the effects see'n by a component that remained unexercised for an extended period of time at extreme temperatures.

Lubrication dries out due to high temperature, and due to component design,

  • there is no lubricity provided by system fluid. The valves were adjusted and retested to ensure compliance with the +/- 1% Technical Specification ol rior to continuin with the test.

'<Jt. lf,N;=;;R;;;C~FO~R;';M:=;;3;';;6;;6A;==========~ U.S. NUCLEAR REGULA TORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET II LER NUMBER (6) II PAGE (3)

Salem Generating Station - Unit 2 0 5 0 0 0 311 II YEAR  :;~iurv\'~d~AL NU~~ER II 2 OF 4 99 - 001 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Main Steam I Safety Valves {SB/RV}*

  • Energ¥ Industry Identification System (EIIS) codes and component function identifier codes appear in the text as {SS/CCC}.

IDENTIFICATION OF OCCURRENCE Event Date: March 30, 1999 (first occurrence)

CONDITIONS PRIOR TO OCCURRENCE Mode 1 - 75 % reactor power DESCRIPTION OF OCCURRENCE During the period from March 30 through March 31, 1999 with the Salem Unit 2 in Mode 1 at 75% reactor power and steam pressure at >804 psig, in place lift assist testing of the main steam safety valves (MSSV) was performed.

This testing was performed to satisfy Technical Specification Section 4.0.5.

Technical Specification 3.7.1.1 Table 3.7-4 specifies the test acceptance criteria, including a +/- 1% tolerance. Technical Specifications also require that with one inoperable MSSV (per loop)~ the inoperable MSSV is to be restored to'operable within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or the power range neutron high flux trip setpoint is to be r~duced to 87%. Because testin~ of the MSSV wa~

performed at end of life (EOL) conditions, when power related xenon

~ransients have greater reactivity effects, Public Service Electric and Gas reduced power to 75% and the high flux trip setpoint to 87%, thus meeting the Technical specifications requirements for one inoperable MSSV.

When a MSSV valve was determined to be inoperable, the MSSV valve was adjusted and subsequently retested to meet the table 4.7-1 tolerance prior to continuing with the test.

In total, seven MSSV valve~ failed to meet the required'+/- 1% setpoint tolerance. The test results for valves failing to meet the required lift set tolerances are presented below:

NRC FORM 366A (4-95)

  • ,_,;, NRC FORM 366A .S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION

'n===========================================;;:::===========rr========:c;:=::::==:==:=:=====;r======:==::~===il FACILITY NAME (1) DOCKET LER NUMBER (6) PAGE (3)

Salem Generating Station - Unit 2 0 5 0 0 0 311 YEAR I <>CNUMBER"~ I NU~;ER 3 OF 4 9 9 -- 0 0 1 -- 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

Valve Id. As found TS Setpoint Acceptable band 51-a Difference Setpoint(psig) (psig) (psig) 21MS14 1086 1100 1089.0 - 1111. 0 - 1. 27 21MS12 1105.8 1120 1108.8 - 1131. 2 - 1.26 22MS13 1082.5 1110 1098.8 - 1121.1 - 1. 59 23MS13 1124.8 1110 1098.8 - 1121.1 + 1. 33 23MS12 1140.7 1120 1108.8 - 1131. 2 + 1. 84 23MS11 li50.2 1125 1113.8 - 1136.3 + 2.24 24MS14 1088.3 1100 1089.0 - 1111. 0 - 1. 06 CAUSE OF OCCURRENCE EPRI/NMAC TR-105872* (Safety Relief Valve Testing and Maintenance Guide) and special report AEOD/S92-20 were consulted to aid in determining the cause of failure. The AEOD study looked specifically at MSSV failures throughout the industry. The study noted that most failures were outside the +/- 1%

alldwable but within a +/- 3% tolerance. The AEOD study classified these failures as "setpoint variance." Setpoint variance, as discussed in this report, is a result of aging*. Aging is the effects seen by a component that remained unexercised for an extended period of time at extreme temperatures.

Lubrication dries out due to_ high temperature, and due to component design, there is no lubricity provided by system fluid.

The results of this study are also applicable to the Salem testing. Seven valves failed to meet the required +/- 1% setpoint tolerance in plant The failed valves would have passed the as found testing with a +/- 3% tolerance, and in fact most valves displayed a decreasing trend in setpoint. That is, as the *valve was exercised, the setpoints would drop to within *the +/- 1%

tolerance.

From a process point of view, there were no processes or program deviations that could have contributed to this event. Processes that could have an effect on these valves are the PM program, correcti v_e maintenance program, and surveillance test program. The accuracy of the Crosby SPVD" (Set Pressure Verification Device) testing has.been verified through laboratory testing.

NRC FORM 366A (4-95)

\;. NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSEE EVENT REPORT (LER)

., TEXT CONTINUATION l?=======================F=A=~=1L=1TY===N=A=M=E=(1=)=======================;;======0~0~cK~E~T=====rr=======~LE~R~NU~M~B~E~R~(~6):-======;;====~p~A~G=e7.(3~)==91 Salem Generating Station - Unit 2 05000311 YEAR I I

""N'1.i'iiB'ER"L Nu~;ER 4 OF 4 99 -- 001 -- 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PRIOR SIMILAR OCCURRENCES Because Salem Unit 1 and 2 were in an extended shutdown for almost 3 years, there has been no LERs issued over the last .two years addressing safety valve testing at Salem. However, a review over the last 5 years identified one LER (272/95-026) addressing MSSV testing.

The identified causes of LER 272/95-026 were ring setting adjustments without post adjustment lift setpoint testing, and the use of the Furmanite Trevitest equipment. The corrective actions taken for this event were appropriate for the identified root cause and would not have prevented this event.

SAFETY CONSEQUENCES AND IMPLICATIONS There were no safety consequences associated with this event. The Salem licensing basis UFSAR Chapter 15 accident analyses has been recently re-analyzed in.support of a Fuel Upgrade/Margin Recovery Program (FUMRP). The FUMRP analyses bound. the as found condition of the valves. Therefore, the valves would have performed their intended safety function although their setpoints were found to be outside the Technical Specification tolerances.

CORRECTIVE ACTIONS

1. The valves were adjusted and retested to ensure compliance with the +/- 1%

Technical Specification tolerance prior to continuing with the test.

2. As required in 10CFR50.55a testing frequency of the MSSV will be modified in accordance with the new ASME Operational and Maintenance Code. The new Code will require staggered testing of the MSSV. It is expected that these requirements will go into effect during 2Rll and 1R14.

NRC FORM 366A (4-95)

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