05000245/LER-1997-002-02, :on 970114,inadvertent Shutdown Cooling Isolation Occurred During Sys Removal from Svc for Maint. Caused by Inadequacy in Preparation of Clearance Required to Perform Maint.Individuals Involved Have Been Counseled

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:on 970114,inadvertent Shutdown Cooling Isolation Occurred During Sys Removal from Svc for Maint. Caused by Inadequacy in Preparation of Clearance Required to Perform Maint.Individuals Involved Have Been Counseled
ML20134M211
Person / Time
Site: Millstone Dominion icon.png
Issue date: 02/13/1997
From: Robert Walpole
NORTHEAST NUCLEAR ENERGY CO.
To:
Shared Package
ML20134M207 List:
References
LER-97-002-02, LER-97-2-2, NUDOCS 9702200144
Download: ML20134M211 (3)
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LER-1997-002, on 970114,inadvertent Shutdown Cooling Isolation Occurred During Sys Removal from Svc for Maint. Caused by Inadequacy in Preparation of Clearance Required to Perform Maint.Individuals Involved Have Been Counseled
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(i)
10 CFR 50.73(a)(2)
10 CFR 50.73(a)(2)(ii)
10 CFR 50.73(a)(2)(x)
10 CFR 50.73(a)(2)(iii)
10 CFR 50.73(a)(2)(iv), System Actuation
10 CFR 50.73(a)(2)(v), Loss of Safety Function
10 CFR 50.73(a)(2)(vii), Common Cause Inoperability
2451997002R02 - NRC Website
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1 NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 g4_g53 EXPIRES 04/30/98 N[oNr cNEc'rSoN REOYSk[0 fS EOUDL t'tc"#9o^"!4&"P"'I'!.n%'c'o,'sim" 42a'.$ ^=

o LICENSEE EVENT REPORT (LER)

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FACIUTY NAME (1)

DOCKET NUMBER (2)

PAGE (3)

Millstone Nuclear Power Station Unit 1 05000245 1 of 3 TITLE (4)

Inadvertant Shutclown Cooling isolation During System Removal from Service for Maintenance i

EVENT DATE (5)

LER NUMBER (6)

REPORT DATE 17)

OTHER FACILITIES INVOLVED (8)

)

MONTH DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR FACluTY NAME DOCKET NUFABER NUMBER 01 14 97 97 002 00 02 13 97 l

)

OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check one or more) (11)

MODE (9)

N 20.2201(b) 20.2203(a)(2)(v) 50.73(a)(2)(i) 50.73(a)(2)tviii) e POWER LEVEL (10) 000 20.2203(a)(1) 20.2203(aH3)(i) 50.73(a)(2)(ii) 50.73(a)(2)(x) 20.2203(aH2)(il 20.2203(a)(3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4>

X 50.73(a)(2)(iv)

OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(v) specify in Abstract below r

or in NRC Form 366A

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20.2203(a)(2)(iv) 50.36(c)(2) 50.73(a)(2)(vii) l LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (include Area Codel Robert W. Walpole, MP1 Nuclear Licensing Manager (860)440-2191 1

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDs TO NPRDS d

b SUPPLEMENTAL REPORT EXPECTED (14)

EXPECTED MONTH DAY YEAR SUBMISSION YES g NO (if yes, complete EXPECTED SUBMISSION DATE).

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

On January 14,1997, at 0010 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> with the plant in cold shutdown condition, an inadvertent Group lli (Shutdown Cooling) isolation occurred while removing the system from service for routine maintenance work on several primary 1

containment isolation system (PCIS) logic system relays. The clearance (tagout) required fuses 595-716 and 595-l 725 to be pulled de-energizing the relays to support the scheduled work. When the first fuse was pulled, valve 1-SD-1 (Shutdown Cooling Suction Valve) went closed due to the containment isolation signal caused by loss of power to ths isolation relay logic power system. An immediate report was made on January 14, 1997, pursuant to 10CFR50.72(b)(2)(ii), "any event or condition that results in manual or automatic actuation of any engineered safety fsature."

Th3 cause of this event was an inadequacy in the preparation and review of the clearance that was required to p!rform maintenance on the isolation logic relays. The individuals involved have been counseled. Further corrective action is to revise the clearance (tagout) procedure and process to require two separate reviews of the clearance (ttgout) procedure prior to release. Also, additional training will be provided in electrical schematic print reading to licensed personnel. No safety consequences resulted from this event. The core was off-loaded in the spent fuel pool with the fuel pool gates installed at the time of the event. Neither shutdown cooling or PCIS was required at the tims.

9702200144 970213 PDR ADOCK 05000245 S

PDR

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t 4U.S. NUCLEAR REGULATORY COMMISSION (4-93)

LICENSEE EVENT REPORT (LER) l TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REVISION Millstone Nuclear Power Station Unit 1 05000245 NUMBER NUMBER 2 of 3 i

97 002 00 TEXT (11more space is required, use additional copies of NRC Form 366A) 111) l.

Descriotion of Event On January 14,1997 at 0010 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> with the plant in cold shutmwn, an inadvertent Group til (Shutdown Cooling) Isolation occurred while removing the system from service for routine maintenance work on

]

several PCIS logic system relays. Clearance (tagout) number 1-0029 97 required fuses 595-716 and 595-725 to be pulled de-energizing the relays to support the scheduled work. When the first fuse was pulled, valve 1-SD-1 (Shutdc un Cooling Suction Valve) went closed due to the containment isolation command

(

caused by loss of power to the isolation relay logic power system.

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A prompt report was made pursuant to 50.72(b)(2)(iii), "any event or condition that results in manual or automatic actuatlon of any Engineered Safety Feature," on January 14,1997.

11.

Cause of Event

i The cause of this event was a personnel error due to an inadequacy in the preparation and review of the i

clearance that was required to perform maintenance on the isolation logic relays. The clearance writer

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reviewed the electrical schematics and thought that de-energizing the relay logic power would cause the 1

valve to lose its capability to isolate as a PCIS boundary. The Unit Supervisor failed to identify this

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condition when he was approving the clearance.

1 111. Analvsis of Event l

This event is reportable pursuant to 10CFR50.73(a)(2)(iv), "any event or condition that resulted in a manual l

or automatic actuation of any Engineered Safety Feature. Since this event did result in a complete isolation 1

of the affected Group 111 PCIS valves, there were no actual safety consequences as a result of this event.

I The core was off-loaded in the spent fuel pool with the fuel poc! gates installed at the time of the event.

i Neither shutdown cooling nor PCIS was required at the time. There are no safety implications since this event does not impact any accident analysis.

4 i

The preparation of the clearance for the scheduled relay work was developed based on recommended clearance (tagout) from the work group performing the routine maintenance. The clearance (tagout) boundary for the scheduled relay work was correct. However, determining that 1-SD-1 would not receive an

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isolation command signal because the power would be lost to the PCIS logic circuit as a result of the fuse removal was in error. The licensed individual authorizing the clearance (tagout) did not review the electrical 4

schematics since he felt that the clearance writer was correct based on the recommended clearance (tagout) provided by the work group.

1 i

IV. Corrective ActiQD The individuals involved have been counseled, e

A second review of all clearance (tagout) has been implemented as an immediate corrective action.

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WRC FORM 366A (4-95)

m t

l lU.S. NUCLEAR REGULATORY COMMISSION (4-95) a LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REVISION l

Millstone Nuclear Power Station Unit 1 05000245 NUMBER NUMBER 3 of 3 97 002 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 1 This immediate corrective action, to require two separate reviews of the clearance (tagout) procedure l

prior to release, will be permanently incorporated through a revision to the clearance (tagout) procedure and process prior to startup for operating Cycle 16.

i Additional training in electrical schematic print reading will be provided to the licensed personnel prior to i

e startup for operating Cycle 16.

I

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V.

Additional information

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Similar Events

There are no other ESF actuations with a similar cause.

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Manufacturer Data Not Applicable 1

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