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LER 93-007-01:on 930317,automatic Closing of RCIC Sys Turbine Steam Supply Isolation Valves Occurred Due to High Steam Flow Signal.Increased Frequency of Valve Testing from Monthly to weekly.W/930726 Ltr
	ML20046B524
Person / Time
Site:	Pilgrim
Issue date:	07/26/1993
From:	Boulette E, Cannon R; BOSTON EDISON CO.
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	BECO-LTR-93-093, BECO-LTR-93-93, LER-93-007-01, LER-93-7-1, NUDOCS 9308050021
	Download: ML20046B524 (7)
	v • d • e

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- [j 10 CFR 50.73 BOSTON EDISCN Pilgrim Nuclear Power Station Rocky Hdi Road Plymouth, Massachusetts 02360 July 26,1993 BECo Ltr. 93- 093

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E. T. Boulette, PhD 3enior Vice President-Nuclear f U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 '

Docket No. 50-293 j g License No. DPR-35 g SI The enclosed supplemental Licensee Event Report (LER) 93-007-01, " Automatic Closing B-of the RCIC System Turbine Steam Supply Isolation Valves due to High Steam Flow Signal", is submitted in accordance with 10 CFR Part 50.73.

Please do not hesitate to contact me if there are any questions regarding this report.

b (b E. T. Boulette, PhD RLC/bal

Enclosure:

Supplemental LER 93-007-01 cc: Mr. Thomas T. Martin Regional Administrator, Region I y U.S. Nuclear Regulatory Commission i 475 Allendale Rd.

King of Prussia, PA 19403 Mr. R. B. Eaton Div. of Reactor Projects I/II Office of NRR - USNRC One White Flint North - Mail Stop 14D1 11E55 Rockville Pike hockville, MD 20852 Sr. NRC Resident Inspector - Pilgrim Station Standard BEco LER Distrjhution bM

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PlLGRIM NUCLEAR POWER STATION 05000 -293 1 of 6 TITLE (4)

Automatic Closing of the RCIC System Turbine Steam Supply isolation Valves due to High Steam Flow Signal EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

SEQUENT,AL REitSION F ACluTY NAME DOCKET NJMBER MONN DAY YEAR YEAR NUMBE R NUMBER MONTH DAY YEAR N/A 05000 F ACILrrY NAVE [KOET NUMBE R 03 17 93 93 007 01 07 26 93 N/A 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 6: (Check one or more)(11)

ODE p) N X 50.73(aH2>0v) 20.402(b) 20 405fe) 73.71(b)

P R 20.405(a)(110) 50.36(cH1) X 50 73(a)(2Hv) (D) 73.71(c)

LE O) 002 l 20.405(a)(1)Gi) 50.36(c)(2) 50 73(a)(2Hvii) OTHER 20.405(a)(1)6ii) 50.73(aH210) 50.73(a)(2Hviii)(A) 20 405(a)(1) liv) 50.73(a)(2Mii) 50.73(aH2)(viii)(B) Agt;gtg 20.405(a)(1)(v) 50.73(aH2)0ii) 50.73(a)(2)(x) rom. 3%AJ LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER pocbde Area Code)

Robert L Cannon - Senior. Compliance Engineer (508) 747-8321 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSEM COMPONENT MANUF ACTURER S CAUSE SYL cM COMPONENT MANUFACTURER R A BN 20 L200 Yes SUPPLEMENTAL REPORT EXPECTED (14) "" * **

EXPECTED YES NO SUBMISSION I" Y** comp'*e EXPECTED SUBMISSION DA'E)

DATE (15)

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X 3 3 TRACT (Limit to 1400 spaces, i e., approximately *s smgle-spM typewnten knes)(16)

On March 17, 1993, at 0024 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , an automatic Primary Containment Isolation Control System (PCIS) Group 5 actuation occurred while attempting to place the Reactor Core Isolation Cooling (RCIC) System in standby service durmg the performance of Procedure 2.1.1, "Startup from Shutdown". The actuation resulted in the closing of the RCIC turbine steam supply isolation valves M0-1301-16 and -17.

The isolation resulted from a high steam flow isolation signal while attempting to jog open the RCIC turbine steam supply valve M0-1301-16. After several attempts, valve MO-1301-16 was opened. The opening of the valve resulted in a rapid steam line pressurization and actuation of the steam flow sensors upstream of valve M0-1301-16. The inability to open MD-1301-16 on initial attempts was caused by a missing jumper that bypasses tne torque switch in the opening circuit. The missing jumper was installed and M0-1301-16 was satisfactorily tested.

This event occurred during plant startup while at 2 percent reactor power. The reactor mode selector switch was in STARTUP position. The Reactor Vessel (RV) pressure was 130 psig with RV temperature at approximately 360 degrees Fahrenheit. This report is submitted in accordance with 10 CFR 50.73 subpart (a)(2)(iv) and (a)(2)(v)(D). This event posed no threat to public health and safety.

N9C FORM 366A (M12)

NRC F RM 366A ' U.S. NUCLEAR REGULATORY COMMiss10N APPROVEo BY OMB NO. 3150-0104 n-m EXP!RES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WfrH THIS LICENSEE EVENT REPORT (LER) sl?EZ%%"3"JMOX0%"J " '

M TEXT CONTINUATION ^$E"NEsEENGToNIDcN$oN R u-TO THE PAPERWORK REDUCTION PRalECT (3140'041, OFFICE OF MANAGEMt NT AND BUDGET, WASMNGTON. DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3) vtAR *EIP "O$$"R 2 of 6 PILGRIM NUCLEAR POWER STATION 05000-293 93 --007- 01 !

TEXT (tt more space is required, use additional copies of NRC Form 366A)(17) i REASON FOR SUPPLEMENT This supplement updates our root cause and corrective actions as described in our initial report. .

BACKGROUND The Reactor Core Isolation Cooling (RCIC) System turbine steam supply piping is equipped with differential pressure sensors (DPIS 1360-1A and -1B) that provide a steam line break detection function. A high steam flow signal in one or both logic channels functions to .

close the RCIC turbine steam supply piping isolation valves to limit the release of steam -

if a break in the RCIC turbine steam supply piping occurs. The Group 5 portion of the Primary Containment Irlation Control System (PCIS) controls the RCIC turbine steam supply valves (M0-1301-16 and -17) which close on the isolation signal.

EVENT DESCRIPTION On March 17,1993, at 0024 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , an unplanned automatic actuation of the RCIC portion of the PCIS occurred during the performance of Procedure 2.1.1, "Startup from Shutdown".

A startup from cold shutdown was in progress per Procedure 2.1.1. The operating supervisor'was on step 41 of Attachment 1 and instructed the operator to place RCIC into automatic standby mode in accordance with PNPS 2.2.22 (Rev. 39), " Reactor Core Isolation Cooling System", Attachment 7. The operator completed step 1 through 3 and was attempting to jog open M0-1301-16. The sequence consists of the following steps:

1. Verify inboard and outboard isolation valves M0-1301-16 and 1301-17 are shut.

2. Fully open outboard isolation valve M0-1301-17.

3. Crack open inboard isolation valve M0-1301-16.

4. Observe RCIC steam line pressure slowly increase to reactor pressure.

5. Fully open M0-1301-16.

As steps 1 through 3 were performed no increase in RCIC steam line pressure was observed.

The MD-1301-16 valve control switch was then taken to the closed position and this sequence was repeated a number of times in an attempt to pressurize the RCIC steam supply line. During a normal pressurization of the RCIC piping, the M0-1301-16 valve only needs to be cracked off its seat. A full stroke of this valve is approximately 8 seconds.

During each attempt to open the valve, the control switch was held in the open position slightly longer than the previous attempt, with no increase in downstream pressure. When the valve finally opened, it opened further than desired because of the time the control switch was held in the open position. The opening of the valve resulted in'a rapid steam line pressurization and actuation of the steam flow sensors upstream of valve M0-1301-16.

NRC FORM 300A 15 92)

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NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104

< s-m EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THS

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

YEAR BR M 3 of 6 PILGRIM NUCLEAR POWER STATION 05000-293 93 --007- 01 TEXT (if more space is required, use add;tional copies of NRC Form 366A)(17)

M0-1301-16 is a jog valve in the open direction and is normally in the full open position.

MO-1301-16 h;s red and green indicating lights for valve position. Once the valve is ;

throttled (red and green indicating lights), there is no positive means to determine the actual valve position until the valve travels full open. The controls and indication for M0-1301-16 are located in the Control Room on Panel C-904. The RCIC turbine steam inlet pressure is displayed on PI-1340-6 and taps off the RCIC turbine steam piping, down stream of the valve MO-1301-17. :

Problem Report 93.9094 was written to document this event. The NRC Operations Center was notified in accordance with 10 CFR 50.72 at 0105 hours0.00122 days 0.0292 hours 1.736111e-4 weeks 3.99525e-5 months on March 17, 1993. i This event occurred during plant startup while at 2 percent reactor power. The reactor mode switch was in the STARTUP position. The Reactor Vessel pressure was 130 psig with RV ,

temperature at approximately 360 degrees Fahrenheit.

CAUSE !

A Failure Analysis Team (FAT) was established to assist in the collection and review of data regarding the inability of valve M0-1301-16 to initially open on March 16, 1993.

Following review and evaluation of the collected data, several possible causes were evaluated. Based on evaluation of the possible causes, none were considered credible except for possible intermittent operation of the torque switch bypass circuitry which is part of the valve's opening circuitry. Further investigation of the possible cause was ,

scheduled to be conducted during RF0 9.

Subsequent investigation during RF0 9 determined the electrical jumper that bypasses the torque switch in the valve's opening circuit was not installed. Problem Report 93.9213 ;

was written to document the discovery. The missing jumper was the reason valve MD-1301-16 ;

did not open on the initial attempts to open the valve.

During mid-cycle Outage (MCO) 9, MD-1301-16 was overhauled per Maintenance Request (MR) 19203092. To accomplish the overhaul, the actuator was removed from the Drywell to the. '

MOV refurbishment area in the Reactor Building. During the removal, the limit switch housing internals for M0-1301-16 were lost / misplaced. Replacement parts were withdrawn from the warehouse and the valve operator was to have been rewired in accordance with drawing M102B52, " Wiring Diagram Limitorque Motor Operator MD-1301-16". Drawing M102B52 does not show the presence of a jumper in the " standard way" Electrical Maintenance was accustomed. The torque switch bypass jumper was shown installed at the terminal strip rather than installed directly across the contacts of limit switch LS5. Although the correct configuration is also shown on drawing E5016 and MIG 15-9, the jumper was inadvertently ommitted when rewiring was performed during MCO 9. Failure to install the jumper is considered a maintenance preventable functional failure and is attributed to utility non-licensed Electrical Maintenance personnel error resulting from a lack of attention to detail. Also, contributing to the error is the non-standard manner in which this particular torque switch was bypassed and shown on drawing M102B52.

NRC FORM 366A 5 92)

1 NRC FORM 366A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-o104 t s-m EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WrrH THis LICENSEE EVENT REPORT (LER) L"2""' M G %'f "n# # % # L O NrT O 's TEXT CONTINUATION $5u"E*Es's"E'EsING [E[No"$N TO THE PAPETtWORK REDUCTON PROJECT (31500104). OFFICE OF MANAGEMENT AND RUDGET, WASHINGTON,DC 20503 FACILITY NAME (1) oOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR W 4 Of 6 j PILGRIM NUCLEAR POWER STATION 05000-293 93 --007- 01 TEMT (If more space is required, use additional copies of NRC Form 366A)(17)

CORRECTIVE ACTIONS Following the event, valve MD-1301-16 was operated several times and tested in accordance i with procedure 8.5.5.4, "RCIC Motor Operated Valve Operability Test Monthly / Quarterly".

No further abnormal operation was identified.

The frequency of valve M0-1301-16 testing was increased from monthly to weekly during the interval of March 17, 1993, to April 3, 1993 (beginning of Rf0 9).

During RF0 9 the missing electrical jumper was installed (MR19301054) and M0-1301-16 was satisfactorily tested.

Subsequent to installation of the electrical jumper in RF0 9, a review of the completed work determined the jumper had not been installed as shown on drawing M102B52. At the time of jumper installation, drawing M102B52 was reviewed by maintenance personnel and was mistakenly determined to be incorrect in that the drawing did not show the presence of a jumper in the " standard way" Electrical Maintenance was accustomed.

Electrical Maintenance personnel installed the jumper directly across the contacts of limit switch LS5 (" standard way") using schematic diagram E5016, rather than across termination points 3G and llF (electrically equivalent) on the termination strip as shown on drawing M102B52. Although the valve functions properly, the jumper is not installed in accordance with controlled drawing M102852. Problem Report 93.9320 was written to document this condition. Subsequent review by Operations and Engineering determined the operability of M0-1301-16 was not affected. Drawing M102B52 will be revised to reflect the as-wired configuration. This is considered an isolated occurrence. A review of the Problem Report database for similar wiring discrepancies did not identify a trend. A review of Problem Report 93.9213 was conducted with involved personnel, stressing the use of wiring diagrams rather than schematics when available. The Maintenance Section Manager will review this event with Maintenance Section personnel emphasizing the importance of attention to detail when conducting Maintenance activities.

SAFETY CONSE0VENCES This event posed no threat to the public health and safety.

The RCIC high steam flow isolation is designed to mitigate the consequences of a break in the RCIC turbine steam supply piping. The automatic closing of the RCIC turbine steam supply isolation valves prevents excessive loss of reactor coolant and the release of radioactive materials from the nuclear system process barrier if a break occurs. For this event, no break in the RCIC turbine steam line occurred.

Technical Specification 3.5.D.1 requires the RCIC System to be operable when reactor pressure is above 150 psig and temperature is above 360 degrees Fahrenheit. At the time of this event, the RCIC System was not required to be operable.

NHC f ORM 306A (5-921

NRC FORM 366A u.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 is.m EXPlRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS

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LICENSEE EVENT REPORT (LER) 1"0"s"nEMS'BTR2 M ELJ OMRTT2 TEXT CONTINUATION EUN NS ON G 2 0 10 TO THE PAPERWORK REDUCTON PRCUECT [31600104), OFFICE ,

OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503 FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

YEAR W MB R 5 of 6 PILGRIM NUCLEAR POWER STATION 05000-293 93 --007-- 01 TEXT (tf more space as required, use addttional copies of NRC Form 366A)(17)

M0-1301-16 is normally open when RCIC is required to be operable. The safety function of M0-1301-16 is to close upon a Group 5 isolation signal. The ability of M0-1301-16 to close was not affected by the missing jumper.

The Core Standby Cooling Systems (CSCS) consists of the High Pressure Coolant Injection (HPCI) System, Automatic Depressurization System (ADS), Core Spray System, and Residual Heat Removal (RHR) System / Low Pressure Coolant Injection (LPCI) mode. Although not part of the CSCS, the RCIC System is capable of providing water to the RV for high pressure '

core cooling, similar to the HPCI System. In the event the RCIC System were to become inoperable when its operation was necessary, operation of the HPCI System would provide water to the RV for high pressure core cooling. In the unlikely event the RCIC System were to become inoperable and the HPCI System was or were to become inoperable and high pressure core cooling was necessary, automatic (or manual) actuation of the ADS would depressurize the RV for low pressure core cooling provided independently by the Core Spray System and RHR/LPCI mode.

This report is submitted in accordance with 10 CFR 50.73(a)(2)(iv) because the closing of valves M0-1301-16 and -17 was not a planned part of the performance of Procedure 2.1.1 This report is also submitted in accordance with subpart (a)(2)(v)(D) because M0-1301-16, although normally in the open position, may not have opened automatically if an automatic -

initiation signal had occurred with the valve in the closed position.

SIMILARITY TO PREVIOUS EVENTS A review was conducted of Pilgrim Station Licensee Event Reports (LERs) submitted since January 1984. The review was focused on LERs submitted in accordance with 10 CFR 50.73(a)(2)(iv) involving a similar RCIC isolation due to high steam flow signals or 10 CFR 50.73(a)(2)(v)(D) involving similar improper wiring of MOVs. The review identified '

LFR 91-001-00.

For LER 91-001-00, on January 25, 1991, at 0956 hours0.0111 days 0.266 hours 0.00158 weeks 3.63758e-4 months and at 1407 hours0.0163 days 0.391 hours 0.00233 weeks 5.353635e-4 months , an automatic !

closing of valves M0-1301-16 and -17 occurred during a surveillance test. The cause was a !

sensed RCIC turbine steam supply line high flow condition. The high steam flow condition occurred due to a failed transistor in the system's turbine speed control electric governor (EG-M). An exact cause of the transistor failure could not be identified.

However, the signal cable connecting the EG-M to the turbine control valve hydraulic actuator (EG-R) was found to be degraded. This degradation could have led to the transistor failure. The transistor and cable were replaced.

4 NRC FORM 366A &92)

9JRC FORM '}66A U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 t s.m EXPIRES 5/31/95 ESTtMATED BURDEN PER Ff SPONSE TO COMPLY WrrH THIS LICENSEE EVENT REPORT (LER) EE",^J"REa"#S'Eu'Rinr*iMJ '

0,N4%fr*2 AND RFCORDS MANAGEMENT BRANCH (MNBB 7714). U.S. NUCLEAR TE.XT CONTINUATION nEeut4 Tony COMuissm. wAsHiNoTON. oC 205ss.oc,, ANo TO THE F'APERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGE MENT AND BUDGET, WASHINGTON, DC 20503.

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

YEAR R UMB 6 Of 6 PILGRIM NUCLEAR POWER STATION 05000-293 93 --007- g 01 TEXT (if more space is required, use additional coptes of NRC Form 366A)(17)

ENERGY INDUSTRY IDENTIFICATION (EIIS) CODES COMPONENTS CODES Valve, Electrically Operated 20 SYSTEMS Engineered Safety Features Actuation System (PCIS) JE Reactor Core Isolation Cooling System BN l

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ML20046B524

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Enclosure:

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