ML18102B604

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LER 97-013-00:on 970902,unplanned Entry Into TS 3.0.3 Was Noted Due to Two Inoperable Pressurizer Level Channels. Caused by Error in RCS P&ID Drawing.Pressurizer Channel I Was Restored within Six Minutes of event.W/971002 Ltr
ML18102B604
Person / Time
Site: Salem PSEG icon.png
Issue date: 10/02/1997
From: Bakken A, Mel Gray
Public Service Enterprise Group
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-97-013-01, LER-97-13-1, LR-N970641, NUDOCS 9710100130
Download: ML18102B604 (5)
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'I Publio Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236 Nuclear Business Unit OCT 2-eJ7 LR-N970641 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 LER 311/97-013-00 SALEM GENERATING STATION - UNIT 2 FACILITY OPERATING LICENSE NO. DPR-75 DOCKET NO. 50-311 Gentlemen:

This Licensee Event Report entitled."Unplanned Entry into 3.0.3 Due to Two Inoperable Pressurizer Level Channels" is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR50. 73 (a) (2) (i) (B).

Sincerely, General Manager Salem Operations Attachment MKG/tcp c Distribution LER File 3.7 9710100130 971002 PDR ADOCK 05000311 S PDR 111111111111111111111111111111111

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Ill llll The pov,:er is in your hands.

95-2168 REV. 6/94

bNRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSIO APPROVED BY DMB NO. 3150-0104 (4-96) EXPIRES 04/30/98 ESTlllATED BURDElll PER RESPONSE TD COllPLY WITH THIS llANOATDRY INFDRllATIDN CDLLECTIDll REDDEST: 50.D HRS. Rll'DRTED LESSONS LEARNED ARE llllCDRPDRATED INTO THE UCElllSIJIG PROCESS AND FED BACK TD INDUSTRY. FORWARD CDllllElllTS REGARDING BURDEN ESTlllATE TD THE INFDRllATIOll AND RECORDS llANAGEllElllT BRANCH IT*6 F33),

LICENSEE EVENT REPORT (LER) U.S. NUCLEAR REGULATORY CDlllllSSION. WASHINGTON. DC ZD55!HIDD1. AND TO THE PAPERWORK REDUCTION PROJECT (3150.0104}, OFFICE OF llANAGEllElllT AND BUDGET, WASHINGTON. DC 20503.

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FACILITY NAME 111 DOCKET NUMBER 121 PAGE 131 SALEM GENERATING STATION, UNIT 2 05000311 1 of 4 TITLE 141 UNPLANNED ENTRY INTO 3.0.3 DUE TO TWO INOPERABLE PRESSURIZER LEVEL CHANNELS EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MOllTII DAY YEAR YEAR I BEOUHllAL NUMilBl I REVISION llUMllBl MOllTII DAY YEAR FACIUll' NAME DOCKET NUMBER FACl!JlY llAME DOCKET NUMBER 09 02 97 97 - 013 - 00 10 02 97 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or morel 1111 MODE(DJ 1 ZO.ZZ01(b) ZO.ZZ03(a)(Z)(v) x 50.73(a)(2lfll 50.731aK2llviiil POWER 39% ZD.ZZ03(aK1l ZO.ZZ03(a)(3)(i) 50.73(a)(Zlflil 50.731eKZJ(x)

LEVEL (10) 20.2Z03(a)(Z)(i) ZO.Z203(a)(3)(iiJ 50.73(a)(Z)(iiil 73.71

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ZD.ZZ03(a)(2)(iv) 50.36(c)(Zl 50.73(a)(ZKviil LICENSEE CONTACT FDR THIS LER (1ZJ NAME TilEPHOME NUMBER (lnoludo Aruo Code)

Mel Gray, Licensing Engineer 609-339-2191 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) 11---CA-U-SE--+--SY-STEM _ _ _ _C_OMP_O_N_ENT--t--MA-llU-FA_ClU_RER

___ R_~_o,.._RTR_":S_LE--t:l+---CA-US_E_+---9-ySTEM--+--CO-MP-ON-ENT--+--MA-llll-F-AClU_R_ER R_~_o:_R_":'"_nE- l SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR YES SUBMISSION (If yH, complete EXPECTED SUBMISSION DATE).

x IND DATE (15)

ABSTRACT (Limit to 1400 spaces, i.e .. approximately 15 single-spaced typewritten lines) (16)

At the time of occurrence Salem Unit 2 was in Mode 1 at 39% Reactor Power.

On August 29, 1997, Salem Unit 2 pressurizer level channel III exceeded the level deviation between channels and was declared inoperable. Channel III was placed in a tripped condition in accordance with Technical Specifications. On September 2, 1997, Maintenance personnel prepared to isolate channel III at the root valve to support troubleshqoting. Root valve 2PS9 was shut at 0548 hours0.00634 days <br />0.152 hours <br />9.060847e-4 weeks <br />2.08514e-4 months <br /> and immediately pressurizer level channel I failed low. Since channel I was selected as a controlling channel, pressurizer heaters tripped off, letdown isolation valves closed and maximum charging flow was initiated. TS 3.0.3 was entered for two inoperable pressurizer level channels (I & III). The pressurizer heaters were restored and valve 2PS9 was reopened within approximately 3 minutes.

Following a satisfactory channel check, channel I was restored and TS 3.0.3 exited at 0554 hours0.00641 days <br />0.154 hours <br />9.160053e-4 weeks <br />2.10797e-4 months <br />. Subsequent investigation identified an error in the controlled drawing used to identify the root valve. Corrective actions include revision of drawings to remove this error.

This event is reportable in accordance with 10CFR50. 73 (a) (2) (i) (B) as a condition prohibited by plant Technical Specifications.

llRC FORM 366 (4-96)

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-96)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEQUENTIAL NUMBER I REVISllN llllMBBI 2 OF 4 97 - 013 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PLANT AND SYSTEM IDENTIFICATION Westinghouse - Pressurized Water Reactor Reactor Coolant System {AB/LT}

  • Energy Industry Identification System (EIIS) codes and component function identifier codes appear as {SS/CC}

CONDITIONS PRIOR TO OCCURRENCE At the time of occurrence Salem Unit 2 was in Mode 1 at 39% Reactor Power.

At 0650 hours0.00752 days <br />0.181 hours <br />0.00107 weeks <br />2.47325e-4 months <br /> on August 29, 1997, Salem Unit 2 pressurizer level channel III exceeded the 3% level deviation between channels and was declared inoperable. Technical Specification (TS) 3.3.1.1 Action 6 was entered.

TS 3.3.1.1 requires the reactor trip system instrumentation channels and interlocks of Table 3.3-1 to be OPERABLE. The three (3) Pressurizer Water Level channels are identified in Table 3.3-1 with Action #6 applicable.

Action #6 allows continued plant operation with one inoperable pressurizer level channel that is placed in the tripped condition. At 0746 hours0.00863 days <br />0.207 hours <br />0.00123 weeks <br />2.83853e-4 months <br /> on August 29, 1997, pressurizer level channel III was placed in the tripped condition as required by TS 3.3.1.1, Action 6.

DESCRIPTION OF OCCURRENCE Three pressurizer liquid level transmitters {AB/LT} provide signals for use in the Reactor Control and Protection System and the Chemical and Volume Control Systems. Each transmitter provides an independent high water level signal that is used to actuate an alarm and, upon two out of the three transmitter signals, will cause a reactor trip. Two of the three transmitters may be selected to provide an alarm when the liquid level falls to the fixed low level setpoint. The same signal will trip the pressurizer heaters "off" and close the letdown isolation valves. Two transmitters are similarly selected to supply a signal to the liquid level setpoint controller.

On September 2, 1997, Maintenance personnel were preparing to backfill the pressurizer level channel III transmitter (2LT-461) sensing leg in order to restore the channel to within tolerance. The level transmitters are typically isolated by the cabinet isolation valves. For backfilling the lines, the root valves were to be closed to provide isolation.

NRC FORM 366A (4-95))

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-961 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (2) LEH NUMBER (6) PAGE (31 SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEOUENTlAL NUMBER I REVISION NUltllER 3 OF 4 97 - 013 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (171 The Reactor Coolant System (RCS) piping and instrumentation (P&ID) drawing, the MMIS computer component identification system and a figure in the applicable I&C procedure indicated that valve 2PS9 was the instrument root valve for the variable leg to pressurizer level channel III transmitter 2LT-461.

Valve 2PS9 was shut at 0548 hours0.00634 days <br />0.152 hours <br />9.060847e-4 weeks <br />2.08514e-4 months <br /> on September 2, 1997 and immediately pressurizer level channel I failed low. Since channel I was selected as a controlling channel, this caused pressurizer heaters to trip off, letdown isolation valves to close and initiated maximum charging flow. TS 3.0.3 was entered for two inoperable pressurizer level channels (I & III) and the pressurizer heaters were restored. Valve 2PS9 was reopened within approximately 3 minutes of closure. Following completion of a satisfactory channel check, pressurizer level channel I was declared OPERABLE, and TS 3.0.3 was exited at 0554 hours0.00641 days <br />0.154 hours <br />9.160053e-4 weeks <br />2.10797e-4 months <br />. Letdown was restored at 0559 hours0.00647 days <br />0.155 hours <br />9.242725e-4 weeks <br />2.126995e-4 months <br />.

This event is reportable in accordance with 10CFR50. 73 (a) (2) (i) (B) as a condition prohibited by plant Technical Specifications.

CAUSE OF OCCURRENCE Subsequent investigation identified that the cause of occurrence was an error in the Reactor Coolant System P&ID drawing. The drawing shows 2PS9 as the root valve to pressurizer channel level III transmitter 2LT-461; however 2PS9 is the instrument root valve for pressurizer level channel I transmitter 2LT-459. 2PS11 is the correct instrument root valve for 2LT-461. When the operator closed 2PS9,* the pressurizer level channel I variable leg was isolated and the channel failed low.

The channel I and channel III instrument root valves (2PS9 and 2PS11) were incorrectly swapped on Salem Unit 2 Reactor Coolant P&ID drawing 205301.

Salem Unit 2 arrangement drawings show the correct configuration~ This error was introduced over a series of revisions to P&ID drawing 205301 from 1982 to 1986. These revisions incorrectly incorporated the root valve data from instrumentation schematics. A contributing factor may have been that the Salem Unit 1 design has these valves swapped from the Salem Unit 2 design. In 1986, personnel involved may have assumed the Unit 2 configuration was identical to the Unit 1 configuration. It appears that subsequently utilizing the P&ID drawing, the Unit 2 drawing error was propagated to the MMIS database and a figure that appears in an I&C procedure. Discovery of this error was delayed because these instrument root valves are rarely used. As stated previously, the subject transmitters are normally isolated using cabinet isolation valves. This P&ID drawing error is considered to be an isolated configuration issue on the pressurizer instrumentation.

NRC FORM 366A (4-95))

NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION (4-96)

LICENSEE EVENT REPORT !LERI TEXT CONTINUATION FACILITY NAME (1) DOCKET NUMBER (Z) LER NUMBER (6) PAGE (31 SALEM GENERATING STATION UNIT 2 05000311 YEAR I SEQUENTIAL NUMBER I REVISllN NUl\1IER 4 OF 4 97 - 013 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

PRIOR SIMILAR OCCURRENCES A review of LERs for the past two years did not identify any prior similar occurrences of components rendered inoperable due to drawing deficiencies.

SAFETY SIGNIFICANCE This event reduced the redundancy in the pressurizer level - high circuit from one out of two to one out of one logic. The event resulted in isolation of letdown flow, shutdown of pressurizer heaters, and initiation of maximum charging, and therefore placed additional thermal and mechanical stresses on primary coolant system components. The pressurizer high level signal and corresponding reactor trip provides protection against RCS overpressurization by limiting pressurizer water level to a volume sufficient to retain a steam bubble and prevent water relief through the pressurizer safety valves. No credit is taken for the operation of this trip in accident analyses. Its functional capability enhances the overall reliability of the reactor protection.system. Decreasing the redundancy in the pressurizer - high level signal to one out of one logic decreased the overall reliability of this trip. However considering the prompt operator action taken to stabilize plant conditions and the defense in depth designed into the overall reactor protection system, this event did not impact the health and safety of the public.

CORRECTIVE ACTIONS

1. Pressurizer Channel I was restored within six minutes of the event.
2. Pressurizer Channel III was returned to service on September 17, 1997.
3. PSE&G has reviewed Salem Unit 1 arrangement, I&C, mechanical piping drawings and I&C procedure figures and verified them to be consistent with regard to pressurizer root valve to transmitter configuration.
4. PSE&G has revised the Salem Unit 2 drawings to indicate the correct root valve to transmitter configuration. The MMIS database has also been corrected.
5. PSE&G will revise the figure in the applicable I&C procedure to correct this error by November 15, 1997.

NRG FORM 366A (4-95))

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