ML17263A637

LER 94-002-02:on 940202,containment Pressure Channels P-947 & P-948 Were Inoperable.Caused by Water Being Trapped in Low Point of Line.Corrective Action:Iron Oxide Scale Was Removed & Sensing Line restored.W/940506 Revised Ltr

ML17263A637
Person / Time
Site:	Ginna
Issue date:	05/06/1994
From:	Mecredy R, St Martin J ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-002, LER-94-2, NUDOCS 9405100227
Download: ML17263A637 (18)

Text

t ACCELERATED DISTRIBUTION DEMOblSj.RA'i'LON 5 Yd l elvi t

REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9405100227 DOC.DATE: 94/05/06 NOTARIZED: NO DOCKET FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G 05000244 AUTH. NAME AUTHOR AFFILIATION ST.MARTIN,J.T. Rochester Gas & Electric Corp.

MECREDY,R.C. Rochester Gas & Electric Corp.

RECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER 94-002-02:on 940202,Containment Pressure channels P-947

& P-948 were inoperable. Caused by water being trapped in a D low point of line. Corrective action:iron oxide scale was removed & sensing line were restored channels.W/940506 ltr.

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

L SIZE:

A NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72). 05000244 D

RECIPIENT COPIES RECIPIENT COPIES D ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD1-3 PD 1 1 JOHNSON,A 1 1 INTERNAL: AEOD/DOA 1 1 AEOD/DSP/TPAB 1 1 AEOD/ROAB/DS P 2 2 NRR/DE/EELB 1 1 NRR/DE/EMEB 1 1 NRR/DORS/OEAB 1 1 NRR/DRCH/HHFB 1 1 NRR/DRCH/HICB 1 1 NRR/DRCH/HOLB 1 1 NRR/DRIL/RPEB 1 1 NRR/DRSS/PRPB 2 2 NRR/j3SGh. SPLB 1 1 NRR/DSSA/SRXB 1 1 BEG FILE 02 1 1 RES/DSIR/EIB 1 1 N1~F LE Ol 1 1 EXTERNAL: EG&G BRYCE,J.H 2 2 L ST LOBBY WARD 1 1 NRC PDR 1 1 NSIC MURPHY,G.A =1 1

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NSIC POORE,W. 1 1 NUDOCS FULL TXT 1 1 R ygoqz g(>Lop.

D D

D NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED: LTTR 27 ENCL 27

Nr ~

c r c 'I x 51acc ROCHESTER GAS AND ELECTRIC CORPORATION 89 EAST AVENUE, ROCHESTER N. Y. 14649-0001 ROBERT C. h<ECREDY TELEottONE Vice Prerident aBEa CODE Pre 546.2700 Crone, Nuclcrrr Production Maj;;:6, 1994 U.S. Nuclear Regulatory Commission Document Control Desk Attn: Allen R. Johnson Project Directorate I-3 Washington, D.C. 20555

Subject:

LER 94-M2, Re@)sigil'.":,.:,':2> Containment Pressure Transmitters Inoperable, Due to Blockage of Sensing Line by Corrosion Products, Causes a Condition Prohibited by Technical Specifications R.E. Ginna Nuclear Power Plant Docket No. 50-244 In accordance with 10 CFR 50.73, Licensee Event Report System, item (a) (2) (i) (B),

which requires a report of, "Any operation or condition prohibited by the plant's Technical Specifications", the attached Licensee Event Report LER 94-002, Revisio'j',':;::,::,':2::;:: r'nMCeMr'rnen w is hereby submitted.

4'c%.(rerggp~pr: ','@c.r++r4 re xggj:,'@AN xenrnr ~~~~rrrccctrcrrnrrn&rrrrruxrrrrCCc@crnrS~xNxa&4 +%re 'r.4. 4>-" ~~~ ." r4n~ r&AxcAN~CeMrt iii'inde'd~i'ii"'Oiisgiiiisi~ii>

This event has in no way affected the public's health and safety.

Very ruly yours, obert C. Mecr y xc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Ginna Senior Resident Inspector

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P P PDR ADOCK 05000244 8 PDR NRC FORM 366 U.S. NUCLEAR REGULATORY CQOIISSIOH PROVED BY Qlg NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. LICENSEE EVENT REPORT (LER) FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.ST NUCLEAR REGULATORY COHHISSION, (See reverse for required number of digits/characters for each block) l}ASHINGIOH, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31/0-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FAGILITY NAME (1) R. E ~ Ginna Nuclear Power Plant DOCKET HQlBER (2) PAGE (3) 05000244 1 OF 14i TITLE (4) ContairN}ent Pressure Transmitters Inoperable, Due to Blockage of Sensing Line by Corrosion Products, Causes a Condition Prohibited by Technical Specifications EVENT DATE 5 LER NllBER 6 REPORT DATE 7 OTHER FACILITIES INVOLVED 8 SEQUENTIAL REVISION FACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR DAY YEAR NUMBER NUHBER 4'ac'ONTH 02 02 94 94 --002-- -'02:: FACILITY NAHE DOCKET NUHBER OPERATING THIS REPORT IS SUBHITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR: Check one or more 11 MQ)E (9) N 20.402(b) 20.405(c) 50.73(a)(2)(iv) 73.71(b) POWER 20.405(a )(1)(i) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) 098 50.36(c)(2) 50.73(a)(2)(vii) LEVEL (10) 20.405(a)(1)(ii) OTHER 20.405(a)(1)(iii) X 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in 20 '05(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) Abstract and in Text, below 20.405(a)(1)(v) 50.73(a)(2)(iii) 50 '3(a)(2)(x) NRC Form 366A LICENSEE CONTACT FOR THIS LER 12 NAME John T. St. Hartin - Director, Operating Experience TELEPHONE NUMBER ( Include Area Code) (315) 524-4446 CQlPLETE ONE LINE FOR EACH CQlPOHEHT FAILURE DESCRIBED IN THIS REPORT '13 REPORTABLE REPORTABLE CAUSE SYSTEM COHPONENT MANUFACTURER CAUSE SYSTEH COMPONENT MANUFACTURER TO NPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED 14 EXPECTED HONTH DAY YEAR YES SUBH I SS I ON (If yes, complete EXPECTED SUBHISSION DATE). X NO DATE (15) ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten tines) (16) On February 2, 1994, at approximately 1642 EST, with the reactor at approximately 989 steady state power, Control Room operators determined that Containment. Pressure channels P-947 and P-948 were inoperable. Based on post-event review of computer data, this condition was in violation of Technical Specification Table 3.5-2 Action Statements. Immediate corrective action was to defeat the inoperable channels by placing the affected bistables in the tripped condition. The underlying cause of the event was an obstruction in the common containment pressure sensing line for P 947 a-nil P-948Fi'i<1'6'sultiri&gjfro'm 4'..:ll":: '"9!i -: *-ll':-'oi':,,:::!!P!:::,,::!!W!ii,:,".:::::ii':-"-i!ilia:::' s -*'-'.ilia',.'i""'i' ii '!E!i'",: -"'"i"'ll'i- "I'i: .: i'i!i i"""-"::i'i'i::ii iiiiii ilia:,**i!'. "4! Corrective action was taken to clear the obstruction from the affected tubing, leak test the penetration piping and transmitter tubing, and verify the proper operation of P-947 and P-948. Corrective action to preclude repetition i is outlined in Section V (B). NRC FORH 366 (5 92) NRC FORM 366A U.S NUCLEAR REGULATORY COWIISSION PROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REGUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEH ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMEHT BRANCH TEXT CONTINUATION (MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, 'WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NNER 2 LER NUMBER 6 PAGE 3 SEQUENTIAL REVISION YEAR R.E. Ginna Nuclear Power Plant 05000244 94 002 2 OF >3 TEXT (If more space is required, use additional copies of HRC Form 366A) (17) PRE-EVENT PLANT CONDITIONS'he plant was at approximately 98'teady state reactor power with no major activities in progress. Instrument and Control (I&C) Department personnel were investigating Containment Pressure channel P-947. This investigation was initiated by a Maintenance Work Request / Trouble Report (MWR/TR) written January 20, 1994 by Control Room operators because the Main Control Board pressure indication for P-947 (PI-947) was observed to be reading slightly lower than the indication for Containment Pressure channels P-945 and P-949 (PI-945 and PI-949), which are also on the Main Control Board. II. DESCRIPTION OF EVENT A. DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES: o June 24, 1992, 1500 EDST: Containment (CNMT) pressure channel P-947 output indication starts to become inconsistent with channels P-945 and P-949, as monitored on the Plant Process Computer System (PPCS). (This is based on post-event review of archived data on the PPCS.) Event date and time. o January 20, 1994: Control Room operators submit MWR/TR on PI-947 Main Control Board indication. o February 2, 1994, 1642 EST: Discovery date and time. o February 4, 1994, 0007 EST: Containment Pressure channel P-947 is restored to operable status. o February 4, 1994, 1536 EST: Containment Pressure channel P-948 is restored to operable status. NRC FORM 366A (5-92) NRC FORM 366A U.S. NUCLEAR REGULATORY CAIIISSION PROVED BY OMB NO. 3150-0'104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO L1CENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140 0104), OFFICE OF MANAGEMENT AHD BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET HIER 2 LER HIHIBER 6 PAGE 3 YEAR SEQUENTIAL REVI SIGH R.E. Ginna Nuclear Power Plant 05000244 94 002-- 02 3 OF 9!4'EXT (If more space is required, use additional copies of NRC Form 366A) (17) B. EVENT: On January 20, 1994, Control Room operators observed that one Main Control Board indication for CNMT pressure, PI-947, was reading slightly lower than the other two indicators, PI-945 and PI-949. They initiated a MWR/TR, for I&C personnel to investigate the difference in readings. On January 21, I&C performed the annual calibration of the channel. The channel (P-947) responded properly to both the electronic checks and to actual pressure signals inserted into the transmitter (PT-947). After reviewing post-calibration trending data and archived PPCS computer traces of CNMT pressure, I&C noticed that channel P-947 was still not tracking consistent with channels P-945 and P-949. Further investigation was conducted on February 2, 1994, to electrical ifproblems identify there could be any possible mechanical and/or with P-947. On February 2, 1994, at approximately 1612 EST, with the reactor at approximately 98% steady state reactor power, Control Room operators declared channel 'P-947 inoperable. The affected bistables were placed in the tripped condition. To verify the operability of the redundant CNMT pressure channels, the operators then caused a small change in CNMT pressure by depressurizing CNMT per operating procedure 0-11, "Control of Mini Purge Exhaust Valves While Depressurizing Containment". I&C personnel monitored test points for CNMT pressure channels P 945 g P 947 P 948 ) and P-94 9 with a digita l multimeter . During this depressurization, at approximately 1642 EST, two channels (P-947 and P-948) did not show any response to the small change in CNMT pressure. The Control Room operators formally declared P-948 inoperable at approximately 1658 EST. The affected bistables were placed in the tripped condition per emergency restoration procedure ER-INST.1, "Reactor Protection Bistable Defeat After Instrumentation Loop Failure". P-947 and P-948 sense CNMT pressure via a common line (CNMT Penetration 203A). A CNMT entry was made to verify that this sensing line for PT-947 and PT-948, (Pen. 203A) was not mechanically blocked. Pen. 203A was visually verified not to be externally obstructed. The valve lineups for the pressure transmitters (PT-947 and PT-948) were verified to be correct. HRC FORM 366A (5-92) NRC FORM 366A U.s. NUcLEAR REGULATDRY cQel lssloN PROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTIOH REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AHD RECORDS MANAGEMENT BRAHCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, TEXT CONTINUATION WASHINGTOH, DC 20555-0001 AHD TO THE PAPERWORK REDUCTION PROJECT (3140 0104), OFFICE OF MANAGEMENT AND BUDGET 'WASHIHGTON DC 20503. FACILITY NAME 1 DOCKET NUMBER 2 LER NINBER 6 PAGE 3 SEQUENTIAL REVI SION YEAR R.E. Ginna Nuclear Power Plant 05000244 94 -- 002-- 02 4 OF .34 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) On February 3, 1994, a work package for troubleshooting and repair of the CNMT penetration line was prepared. A CNMT entry was made and Pen. 203A was pressurized to thirty (30) pounds per square inches above atmospheric pressure (PSIG), using surveillance test procedure PTT-23.17B, "Containment Isolation Valve Leak Rate Testing Containment Pressure Transmitters PT-947 and PT-948 Pen 203A". PT-947 and PT-948 did not respond to this pressure, which indicated a blockage in the piping for Pen. 203A or in the common instrument tubing line. Backflushing with one-hundred-twenty (120) PSIG air supply to clear the blockage was unsuccessful. Pen. 203A was isolated inside CNMT to provide double barrier isolation for CNMT integrity. The instrument tubing was disconnected outside CNMT. The instrument tubing was found to contain water, but this water was not the source of the blockage. The 1/2 inch carbon steel tubing for Pen. 203A was found to be mechanically blocked with a thick sludge. The blockage was removed. The tubing was reassembled and preparations were made to test the tubing. On February 3, 1994, at approximately 2207 EST, Pen. 203A was declared inoperable to perform required Appendix J testing. The Limiting Condition for Operation (LCO) for Technical Specification (TS) 3.6.3.1. was entered. Pen. 203A was tested in accordance with surveillance test procedure PTT-23.17B, "Containment Isolation Valve Leak Rate Testing Containment Pressure Transmitters PT-947 and PT-948 Pen 203A". It was documented in PTT-23.17B that PT-947 and PT-948 now accurately responded when the penetration was pressurized to 60 PSIG. PTT-23.17B was successfully completed at approximately 2336 EST and Pen. 203A was declared operable at approximately 2340 EST. On February 4, 1994, at approximately 0007 EST, P-947 was declared operable. The transmitter and rack calibration procedure for channel P-948 was performed later in the day on February 4, and P-948 was declared operable at approximately 1536 EST on February 4, 1994. HRC FORM 366A (5 92) NRC FORM 366A U S. NUCLEAR REGULATORY CQNIISSIOH PROVED BY OMB NO. 3150-0104 EXP I RES 5/31/95 (5-92) ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATIOH COLLECTION REOUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEHENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION> TEXT CONTINUATION WASHIHGTOH, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NUMBER 2 LER NUMBER 6 PAGE 3 'YEAR SEOUENTIAL REVISION R.E. Ginna Nuclear Power Plant 05000244 94 -- 002 02 '5!.:;:.'OF i:.;":;1'4 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) P,:i.,.': ",:,,",.';,;: q,i'.;;,.:'f; P'; - ~~>>>>>>>>>>mcgrr~~w~XCwO,.~~~X>>X><<>>~>~,a~,.eocevmOW~yXaxc 'i';:;.'. '.;.i:;;.'::;x':".,,~n;".'.; W>>>WZ>ya,. m>>>,<~. >,s .> >~a~m~' yg ~'a. ~>>>>>> ~ HRC FORM 366A (5-92) ~ ~ NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION PROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS IHFORMATIOH COLLECTIOH REQUEST: 50.0 NRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AHD RECORDS MANAGEMEHT BRANCH TEXT CONTINUATION (MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NIMBER 2 LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION R.E. Ginna Nuclear Power Plant 05000244 94 -- 002 02 - ."I."':.-'$~1'-'EXT (If more space is required, use additional copies of HRC Form 366A) (17) C~ INOPERABLE STRUCTURES i COMPONENTS I OR SYSTEMS THAT CONTRI BUTED TO THE EVENT: None D. OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED: Engineered Safety Features that rely on CNMT pressure inputs are Safety Injection Actuation (SI), Steam Line Isolation, and Containment Spray Actuation (CNMT Spray). None of these features was affected by the inoperability of P-947 and P-94 8, because at no time, from June 24, 1992, to February 4, 1994, was CNMT pressure at or near the actuation setpoints (4 PSIG for SI, 18 PSIG for Steam Line Isolation, and 28 PSIG for CNMT Spray ) ~ During this period, the redundant channels (for P-947 the channels are P-945 and P-949; for P-948 the channels are P- 946 and P-950) were in service and were not taken out of service unless the affected bistables were placedP'.".'-':"::." in the ": tripped t """:,',, E".",X.;: 9'8cQmb:eÃ,'l:;:::.'04:.;::::;"':f99,2,:;":~ . V',,';i con d z tz.onj~<e)('0'epr":.;:,,'"'xol-,';::.::.,'aper'axe%'ai'ei:jr,':,,::'sine;>,"::(ji) >jj(i9'),.;!,, i;:,:,:::se'concls': CI ':on;"::":: E. METHOD OF DISCOVERY: This event was first identified due to the astute observation of a Control Room operator on January 20, 1994, who questioned a slight difference in indications for CNMT pressure. The small deviation between redundant channels was within the tolerance of Main Control Board instrumentation channel checks. The monthly Channel Functional Tests and annual Channel Calibrations associated with these channels (as required by TS Table 4.1-1 for units ¹17 and ¹25) did not detect the obstructed tubing line due to the location of the obstruction. The sludge was located between CNMT and the root isolation valves for PT-947 and PT-948. These root isolation valves are closed during performance of the necessary tests and calibrations, in order to pressurize the volume between the valve and the pressure transmitter. This method of testing is consistent with the definition of Channel Functional Testing, as defined in TS 1t7~3 ~a ~ The fact that this event affected both channels P-947 and P-948 was identified as a result of the investigations performed by I&C personnel on February 2, 1994. NRC FORM 366A (5.92) NRC FORH 366A U.S. NUCLEAR REGULATORY CQHISSION PROVED BY OHB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTINATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORNATION COLLECTION REQUEST: 50.0 HRS. FORWARD COHHEHTS REGARDING BURDEN ESTIHATE TO LICENSEE EVENT REPORT (LER) THE INFORHATIOH AND RECORDS HAHAGEHENT BRANCH TEXT CONTINUATION (HNBB 7714), U.S. NUCLEAR REGULATORY COHHISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3110.0104), OFFICE OF NANAGEHEHT AND BUDGET WASHINGTON DC 20503. FACILITY NAHE 1 DOCKET H NBER 2 LER HIHIBER 6 PAGE 3 SEQUENTIAL REVI SIOH YEAR R.E. Ginna Nuclear Power Plant 05000244 94 -- 002-- 02 TEXT (If more space is required, use additional coPIes of NRC Form 366A) (17) A more detailed review 'of the archived PPCS records of CNMT pressure concluded that channel P-947 had not responded to changes in CNMT pressure since June 24, 1992, beginning at approximately 1500 EDST. Note that while CNMT pressure channel P-947 is monitored by the PPCS, channel P-948 is not. In addition, PI-948 (and also PI-946 and PI-950) have a scale of 10 to 200 PSIA (absolute pressure). By comparison, PI-947 (and also PI-945 and PI-949) have a scale of 0 to 60 PSIG. It is assumed that P-948 had not responded to changes in CNMT pressure for the same amount of time as P-947. F. OPERATOR ACTION: The Control Room operators observed that the PI-947 reading was inconsistent on January 20, 1994, and initiated a MWR/TR. After both channels P-947 and P-948 were discovered to be inoperable, the Control Room operators performed emergency restoration procedure ER-INST.1 and placed the affected bistables in the tripped condition. Subsequently, the Control Room operators ensured that higher supervision and the NRC Resident Inspector had been notified of this event. G. SAFETY SYSTEM RESPONSES: None III. CAUSE OF EVENT A. IMMEDIATE CAUSE: The immediate cause of the event was the failure of P-947 and P-948 to respond to changes in CNMT pressure due to obstruction of the common pressure sensing line. NRC FORH 366A (5.92) NRC FORM 366A U.S. NUCLEAR REGULATORY CO}IIISSION PROVED BY QUI NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDIHG BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB 7714)g U ST NUCLEAR REGULATORY COMMISSION>> l}ASHIHGTON, DC 20555-0001 AHD TO THE PAPERWORK REDUCTION PROJECT (3150 0104), OFFICE OF MANAGEMENT AHD BUDGET WASHINGTON DC 20503. FACILITY NA}lE 1 DOCKET NWBER 2 LER NUMBER 6 PAGE 3 SEQUENTIAL REVISION YEAR R.E. Ginna Nuclear Power Plant. 05000244 94 002 02 TEXT (If more space is required, use additional copies of HRC Form 366A) (17) B. INTERMEDIATE CAUSE: The intermediate cause of the obstruction of the common pressure sensing line at Pen. 203A was a buildup of corrosion products in this line, which is 1/2 inch OD, 0.065 inch wall thickness, carbon steel tubing. These corrosion products were visually examined and found to be reddish brown/black in color, visually resembling iron oxide scale. IL'bj,'s;l::.'bu'iaM)j<.,-.".'.e'f.::,.;Cori:.;epiq'ii:.:'.:;'pro'ducts C. ROOT CAUSE: The underlying cause of the ,,",:...,",;g>>e:,,g:":f*,: g,,"::,.: Calibratian f configuration. Z&C personnel have cali.brated these transmitters riO-s',, th>>e:,;:;::,::,".Sp'e'ifi'C SenSing line with a water-filled deadweight tester for many years. The configuration of the transmitter and sensing line forv'~<Pen'".::.'-.::.',:,203A prevented the drainage of all the water after calibration. After the transmitter was unisolated as part of the calibration process, the trapped water traveled down to the low portion of the sensing li enl:ii':.:h>>, >>ea~rlj!R:::i:, st hvg'A} Amvggv>>>>~hggge~>>gg>>hvg~pg 'va>>>>hghvgv'vgseggg~agvug>>vp'uhv>>AYAH%&>>&Ah" v>>gev>>>>frigg:A>>vvrgguhvuhpDg>>hvahug&gsh>>hs YAm>>hhug>>A>>>>va+ggvgasgvger gIhae}::ieav>> eA'~i::,:::.'::::.~~sjMRQ@Perf oihrmanceijlxhn>>rigca'togrp>>'& re grege'0'a HRC FORM 366A (5-92) NRC FORH 366A .S. NUCLEAR REGULATORY CQIIISSION PROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORHATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (HNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (31i0-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NINBER 2 LER NUMBER 6 PAGE 3 SEQUENTIAL REVISION YEAR R.E. Ginna Nuclear Power Plant M 05000244 94 -- 002 02 9;ii,"'OP;:sl%".4I TEXT (If more space is required, use additional copies of NRC Form 366A) (17) Stagnant water hae rema'ined in the carbon steel sensing ~ee 5'hajj'i;:,':,':;4'0'i:.':,:.:Pjyi>><i203)"; for a substantial period of time a,f'5ejgje'ajh col'fbi'i%iixi. Under etteh 'thp'se conditions, significant, corrosion of the carbon steel material 8ecvieid. The corrosion product, hydrated iron oxide (common rust)"'is voluminous, occupying many times the volume of the material lost to the corrosion process. Sufficient corrosion product accumulated to block the sensing line tubing, resulting in the inoperability of P-947 and P-948. IV. ANALYSIS OF EVENT This event is reportable in accordance with 10 CFR 50.73, Licensee Event Report System, item (a) (2) (i) (B), which requires a report of, "Any operation or condition prohibited by the plant's Technical Specifications". CNMT pressure channels P-947 ' and P-948 were inoperable for a considerable length of time, 'co'n~yjj,' ~iBci,':qth Operation prohibited by ei i'is Iragiji'eaM~rei TS. of Ts Table 3. 5-2, units g l.b., 2.b., and f.c. condition since June 24, 1992 is a condition An assessment was performed considering both the safety consequences and implications of this event. The results of this assessment are that there were no operational or safety consequences or implications attributed to the inoperability of P-947 and P-948 because: o A review of plant history and preventive maintenance history files has shown that the redundant CNMT pressure channels (P-945, P-946, P-949, and P-950) have been either operable or placed in the conservative tripped state from the Event date to the Discovery date,-':::,i,.'::except:";,:,:::if i:.,'pri aOp3Xrima'tel y~ii'iiii's .S;:;a!8 8'C end 8!'iOnl iiDrac enb'sr-'."i".25'p .:.i'2:,"'. o A review of PPCS data has shown that the redundant pressure channels have responded to pressurization of the sensing lines and pressure changes in CNMT. IV'i'sualgirn,epgot3cne." O'OCIFSilSC'e'p, '.:4548 to the same failure mode as P-947 and P-948. NRC FORH 366A (5-92) NRC FORM 366A U.S NUCLEAR REGULATORY CQIIISSI ON PROVED BY OMB NO. 3150-0104 (5.92) EXP I RES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AHD RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEMENI'ND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NUMBER 2 LER NUMBER 6 PAGE 3 SEQUENTIAL REVISION YEAR R.E. Ginna Nuclear Power Plant 05000244 94 -- 002 02 '3 0i~O,F,,":::::3'4: TEXT (If more space is required, use additional copies of HRC Form 366A) (17) o The 2 out of 3 logi'c (2/3) required for actuation of SI was reduced to a 2/2 logic with the inoperability of P-947. Thus SI actuation from hkgh CNMT pressure (4 PSIG) would have occurred as assumed in the design basis. 0 The diverse actuation circuitry for SI has three additional means of actuation (steam generator low steam pressure, pressurizer low pressure, and Manual). None of these diverse means was affected by the inoperability of P-947. o The 2/3 logic required for Steam Line Isolation actuation was reduced to a 2/2 logic with the inoperability of P-948. pressure (18 PSIG) would have occurred as assumed in the design basis. o The diverse actuation circuitry for Steam Line Isolation has three additional means of actuation (hi-hi steam flow with safety injection, hi steam flow and 2/4 low Tavg with safety injection, and Manual). None of these diverse means was affected by the inoperability of P-948. o The 2/3 plus 2/3 logic required for CNMT Spray actuation was reduced to a 2/2 plus 2/2 logic with the inoperability of P-947 andwCvWayC... P-948 ;'.Pj.except'or.,':.'.:':,".approx';.mate1y,;".:;nine'!3'(9)j:",.,"second's: V:; 'P'5 mVN'+'.WNNRv..::+9~~"%Xv."VNw."$ "w 'Op'.-:;:(pe'C'ember:;:.:'.;:,:24'j'"::.-,,'-:',1'9924 Thus, CkfMT Spray actuation'from )~ ~h- .Ã>O'4'Wr>.a~v.~&(i:)).,w iw'%4iN5'gN'V'WC CNNT pressuie (28 PSIG) would have occurred as assumed in the design basis. o The alternate actuation circuitry for CNMT Spray (Manual) was not affected by the inoperability of P-947 and P-948. HRC FORM 366A (5-92) NRC FORM 366A U.S NUCLEAR REGULATORY CQBIISSIOH APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES 5/31/95 I ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MANAGEMENT BRANCH TEXT CONTINUATION (MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTOH, DC 20555-0001, AHD TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET 'WASHIHGTOH DC 20503. FACILITY NAME 1 DOCKET NNIBER 2 LER NUMBER 6 PAGE 3 SEQUENTIAL REVISION YEAR R.E. Ginna Nuclear Power Plant 05000244 94 -- 002-- 02 L3~.,:OSCAR,@4c TEXT (If more space is required, use additional copies of NRC Form 366A) (17) ""vyypcCcw ' ~ypyykvcccccccwvcyyy~...CypvrMCtcpyyy ~w~gCvC: 'Cpcvppy ' 'pppyyCpgvyC "CCpycycxwq>w "C vw ".vpw v w, sMw", yy, e>wyc, ypvwy '~sv } vv "vgCyp >wnyyyy yg .~wcyl~" . ne~jSX-N ai.:uaC'i'onjixsta4ie-@xoig~>enanne'i;:-P,; v p c c c y pl p y p paved I 'ccccppy+,,c, ~ p., Cv,av+$ CCRj p&%0p'tcwx Ccvpppyvw xvwypepp?'v'p(%vC'?'v.,wpppw "pwp .. feyY:.., vyvywc '>. yyw A," vcwC,. %,.vyvc '.vpp',r',~yy, '>:;cyA, "v> c i w7 w kine':<:;..'9:::.,".,s'i5~6n'~iiY 8r'vo a'e'I,c()n,'i ':()n:," ' "' "VNSNh~~vccyNQRhfpMc4MxL'(&cvc'Cvykckc@c~ HRC FORM 366A (5-92) NRC FORH 366A U.S. NUCLEAR REGULATORY C(NNISSION PROVED BY INIB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIHATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORHATION COLLECTION REQUEST: 50.0 HRS ~ FORWARD CONHENTS REGARDING BURDEN ESTINATE TO LICENSEE EVENT REPORT (LER) THE INFORHATIOH AND RECORDS HANAGEMEHT BRANCH (HHBB 7714), U.S. NUCLEAR REGULATORY COHHISSIOH, TEXT CONTINUATION WASHINGTON, DC 20555-0001 AND TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF HANAGEHENT AND BUDGET WASHINGTON DC 20503. FACILITY HAHE 1 DOCKET NIMBER 2 LER NlMBER 6) PAGE 3 SEQUENTIAL REVI SI OH YEAR R.E. Ginna Nuclear Power Plant 05000244 94 -- 002-- 02 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) r N:~ ".--: Based on the above, and safety was assured it can be concluded at all times. that the public's health V. CORRECTIVE ACTION A. ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMAL STATUS: o The iron oxide scale-was removed from the obstructed penetration sensing line and P-947 and P-948 were restored to operable status. o The other channels that monitor CNMT pressure were verified to respond to small changes in CNMT pressure. HRC FORH 366A (5-92) NRC FORH 366A .S. NUCLEAR REGULATORY C(HIIISSION PROVED BY QQ NO. 3150-0104 (5-92) EXP I RES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COHPLY WITH THIS INFORMATION COLLECTION REOUEST: 50.0 HRS. FORWARD COHHENTS REGARDIHG BURDEN ESTIHATE TO LICENSEE EVENT REPORT (LER) THE INFORHATIOH AND RECORDS MANAGEHENT BRANCH TEXT CONTINUATION (MHBB 7714), U.S. NUCLEAR REGULATORY COHHISSION, WASHINGTON, DC 20555-0001 AHD TO THE PAPERWORK REDUCTION PROJECT (3140-0104), OFFICE OF MANAGEMENT AHD BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NQIBER 2 LER NIMBER 6 PACE 3 YEAR SEOUENTIAL REVISION R.E. Ginna Nuclear Power Plant 05000244 94 002 02 ljig?'g'OP>:i,'s'.'>g'cg TEXT (If more space is required, use additional copies of HRC Form 366A) (17) B. ACTION TAKEN OR PLANNED'O PREVENT RECURRENCE: o PPCS computer points for CNMT pressure will be archived daily until the 1994 refueling outage to verify channel v v V v I ) o The sensing lines for all CNMT pressure channels will be ins ected and cleaned out during the 1994 refueling outage. o The method of calibration of the CNMT pressure transmitters has been changed to use gas (instead ccQ~w&4~?v'wccggcg~ccc~ of water) as the test ccccv?+wvYp~v?ccw???v?c?vsNvccvc.'i. "(pY."wp&c?vv?v54<r"'v,cvcv g medium. ? "ese::,xe'vms'ea:-:,:;,::proc'e'dUxe's.:;:::'.::vere'..::..u'si'd!-'.'to:;'::,per'for'ia prai~rit'i~i::::;i'IIcm~:rancp';! "'"' * "" '"""' " """ = '"" o Testing these containment penetrations has been enhanced to include formal documentation o'f pressure channel response.>~: e'kaid'~~b8inh"::~ins.i i','.i,""'epC'os't'a3'.: HRC FORH 366A (5-92) NRC FORM 366A U.S. NUCLEAR REGULATORY CQHII SSION APPROVED BY (HLB NO. 3150-0104 (5-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTIOH REQUEST: 50 ' HRS. FORWARD COMMENTS REGARDIHG BURDEN ESTIMATE TO LICENSEE EVENT REPORT (LER) THE INFORMATION AND RECORDS MAHAGEMENI'RANCH TEXT CONTINUATION (MHBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503. FACILITY NAME 1 DOCKET NINBER 2 LER NUMBER 6 PAGE 3 YEAR SEQUENTIAL REVISION R.E. Ginna Nuclear Power Plant 05000244 94 002 02 m~" ~O~~ "~4 TEXT (If more space is required, use additional copies of HRC Form 366A) (17) VI. ADDITIONAL INFORMATION A. FAILED COMPONENTS: There were no failed components. The obstructed sensing line is 1/2 inch OD, 0.065 inch wall thickness, carbon steel tubing. Information about the vendor and manufacturer is not relevant to this event. B. PREVIOUS LERs ON SIMILAR EVENTS: A similar LER event historical search was conducted with the following results: LER 92-003 was also an event caused by an obstructed pressure sensing line. However, the obstruction was caused by buildup of sludge from normal impurities in the process fluid (feedwater). The obstruction referred to in LER 94-002 was caused by corrosion from the interaction of the test medium and the sensing line materials. C. SPECIAL COMMENTS: None HRC FORM 366A (5-92)