ML18067A746

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LER 97-009-00:on 970923,discovered Procedure Weakness Re Implementation of App R Shutdown Methodology.Caused by Human Error.Revised Off-Normal Procedure ONP-25.2, Alternate Safe Shutdown Procedure.
ML18067A746
Person / Time
Site: Palisades Entergy icon.png
Issue date: 10/23/1997
From: Roberts W
CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18067A745 List:
References
LER-97-009, LER-97-9, NUDOCS 9710300112
Download: ML18067A746 (5)


Text

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150..0104 (4195) EXPIRES 4130/98 ESTIMATED BlJIOO< PER RESPONSE TO COMPLY WllH THIS MANDATORY INFORMATION COLLECTION REQUEST: SO.O HRS. REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT LICENSEE EVENT REPORT (LER) BRANCH (T-8 FJJ), U.S. MJCLEAR REGULATORY COMMISSION, WASHINGTON, DC 2055S-0001, AND TO THE PAPERWORK REDUCTION PROJECT (31~11M, OFFICE OF' MANAGEMENT AND BUDGET, WASHINGTON, DC 20503 (See reverse for required number of digits/characters for each block)

DOCKET NUMBER (2) Page (3)

FACILITY NAME (1) CONSUMERS ENERGY COMPANY PALISADES NUCLEAR PLANT 05000255 1 of 5 TITLE (4) LICENSEE EVENT REPORT 97-009- PROCEDURE WEAKNESS IN IMPLEMENTING APPENDIX R SHUTDOWN METHODOLOGY EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR I* SEQUENTIAL NUMBER REVISION NUMBER MONTH DAY YEAR FACILITY NAME DOCKET NUMBER 05000 FACILITY NAME DOCKET NUMBER 09 23 97 97 - 009 - 00 10 23 97 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS *oF 10 CFR§: (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)(iii)

POWER 20.2203(a)(1) 20.2203(a)(3)(i) x 50.73(a)(2)(ii) 50. 73(a)(2)(x)

LEVEL (10) 100 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50. 73(a)(2)(iii) 73.71 I',::r ..

I 20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(ivl 20.2203(a)(4) 50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(iv)

50. 73(a)(2)(v) 50.73(a)(2)(viil OTHER Specify in Abstract below or in NRC Form 366A LICENSEE CONTACT FOR THIS LER (12)

NAME William L. Roberts, Licensing Engineer TELEPHONE NUMBER (Include Area Code)

(616) 764,.2976 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS TONPRDS D

SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR I YES If ves COMPLETE EXPECTED COMPLETION DATE x I NO EXPECTED SUBMISSION DATE 115)

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

On September 23, 1997, at 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br /> with the plant at approximately 100% power, it was

  • recognized that an operator action to support an Appendix R program analysis had not been implemented in the appropriate Off-Normal Procedure (ONP). Specifieally ONP 25.2, "Alternate Safe Shutdown.Procedure" did not include the action to trip all four primary coolant pumps if the control room had to be evacuated. Instead, the procedure directed the control room operators to

"... trip two primary coolant pumps and leave two operating ... ". Once the control room is evacuated, no instrumentation is identified to provide the operational status of the primary coolant pumps or the status of the component cooling water to the primary coolant pump motor and seals.

It has been identified that a fire-initiated hot short could cause one of the component cooling water containment isolation valves to spuriously close, isolating cooling flow to the primary coolant pumps. Palisad~s' J?rifl1ary coolant pump operat_ion_ has_ not been analyzecj for operati_on without - .

seal or motor bearing cooling. The manufacturer indicates that no damage to the seal or pump motor will occur if operated without cooling for no more than ten minutes. ONP 25.2 has been revised to require tripping of all four primary coolant pumps when evacuating of the control room.

Having not implemented the action to support the analysis is contrary to 10 CFR 50 Appendix R direction that during post fire shutdown, ... the fission product barrier shall not be affected, i.e ... there shall be no ... rupture of primary coolant boundary. This is reported as a condition outside of the plant's design basis.

9710300112 971023 5 PDR ADOCK 0500025 s PDR

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT {LER)

TEXT CONTINUATION FACILITY NAME 111 DOCKET12l LER NUMBER 51 PAGE

_CONSUMERS ENERGY COMPANY PALISADES NUCLEAR PLANT 05000255 YEAR I SEQUENTIAL NUMBER REVISION NUMBER 2 OF 5 97 - 00 9 - 00 TEXT (If more space 1s required, use add1t1onal copies of NRC Form 366A) (17)

EVENT DESCRIPTION On September 23, 1997, at 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br /> with the plant at approximately 100% power, it was recognized that an operator action to support an Appendix R program analysis had not been implemented in the appropriate Off-Normal Procedure (ONP). Specifically, ONP 25.2, "Alternate Safe Shutdown Procedure" did not include the action to trip all four primary coolant pumps if the control room had to be evacuated. Instead, the procedure directed the control room operators to

"... trip two primary coolant pumps and leave two operating ... ".

There is no instrumentation external to the control room identified or analyzed to provide the operational status of the primary coolant pumps or the status of the component cooling water to the primary coolant pump motors and seals. It has been identified that a fire-initiated hot short could cause one of the component cooling water contai.nment isolation valves to close, isolating cooling flow to the primary coolant pumps. Palisades primary coolant pump operation has not .

been analyzed for operation without seal or motor bearing cooling beyond the ten-minute period cited by the manufacturer. A revision to ONP 25.2 was initiated and the procedure change reflecting the tripping of all four primary coolant pumps was issued the next day.

  • ANALYSIS OF EVENT The Palisades Plant is a pressurized water reactor with two steam generators and four primary coolant pumps. Water from the component cooling water (CCW) system flows into the containment and provides cooling for each primary coolant pump seal and motor bearing oil.

Beginning in 1994, an Appendix R Enhancement Plan was established to reconstitute the Appendix R analyses and correct identified problems. Rather than recreating or revising existing Appendix R documents, the Enhancement Plan created new analyses to assess and document compliance with requirements.

New analyses were performed based on the assumptions that loss of offsite power may not be the most limiting event. These analyses recognized that if offsite power was not lost, the potential existed for the primary coolant pumps to rerr~in operating. If two of the four primary coolant

. pumpswere-allowed--to remain inoperation following a fire, then component cooling water: pump.

power, control circuitry, and system flow instrumentation would also have to be reviewed to determine what affect the fire had on their operation. These functions would need to be verified as operating once the control room was evacuated to support the continued operation of the primary coolant pumps or the two operating pumps would have to be tripped.

It was decided that if evacuation of the control room was required, then the appropriate action for Palisades would be to trip all four primary coolant pumps rather than trip two and leave two running. Without the pumps operating, a natural circulation cool down is achievable for the

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION J

4195

. LICENSEE EVENT REPORT (LER) g TEXT CONTINUATION FACILITY NAME 11 l DOCKET12l LER NUMBER 16l CONSUMERS ENERGY COMPANY PALISADES NUCLEAR PLANT 05000255 YEAR I SEQUENTIAL NUMBER REVISION NUMBER 5

97 - 00 9 - 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) postulated event.

Tripping all four primary coolant pumps and other conclusions reached as a result of the Appendix R Enhancement Plan reviews were documented in a number of new analyses. It was recognized

.that revisions would be needed to Off Normal Procedure (ONP) 25.2, " Alternate Safe Shutdown Procedure" as a result of these conclusions. These revisions were identified and presented to the ONP 25.2 procedure sponsor in the form of a marked-up version of the procedure. Review of ~~e proposed revision containing the recommended changes to ONP 25.2 determined that the guidance to trip all four prima*ry coolant pumps when evacuating the control room, as prescribed by analysis, was not included. It was also determined that an independent technical review of the proposed revision was not completed; thus, it was never verified that all of the required revisions were included in the document submitted to the procedure sponsor.

Subsequently, Revision 8 to ONP 25.2, a comprehensive revision intended to incorporate the results of the Appendix R Enhancement Plan analyses, was issued in March of 1996. This revision maintained its original direction to trip two and leave two primary coolant pumps running when evacuating the control room. Without indication of the status of CCW flow to the containment being required by procedure, it could be assumed that following evacuation of the control room a hot short could cause one of the three CCW containment isolation valves to close, t~ereby isolating cooling flow to the primary coolant pump seals and motor bearings without operator knowledge.

SAFETY SIGNIFICANCE Without cooling flow, it is assumed that the pump seal would eventually fail in such a way as to create a primary coolant system leak in the area of the pump shaft and seal. This is contrary to the 10 CFR Part 50 Appendix R direction that during post fire shutdown, ... the fission product barrier shall not be affected, i.e .... there shall be no ... rupture of the primary coolant boundary.

For this event to occur, a fire would have to (a) result in evacuation of the control room, (b) result in a hot short that would cause closure of one of the component cooling water valves to the

__containment, (c).notresultin a loss-of offsite power-and (d) not result in a manual or automatic trip of the primary coolant pumps. Our reviews have determined that this event is highly unlikely to occur. The overall impact on plantrisk, resultant from the absence of specific direction to "trip all four primary coolant pumps when evacuating the control room" is, therefore, considered minimal.

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION

~I 4195 LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION r;J FACILITY NAME 11 l DOCKETl2l LER NUMBER 6l CONSUMERS ENERGY COMPANY PALISADES NUCLEAR PLANT 05000255 YEAR I SEQUENTIAL NUMBER REVISION NUMBER 5

97 - 00 9 - 00 TEXT (If more space 1s required, use add1t1onal copies of NRC Form 366A) (17)

CAUSE OF THE EVENT The cause of the event is a human error. The engineer identifying and transmitting requested changes to the procedure sponsor failed to properly communicate the requirement for tripping all four primary coolant pumps prior to evacuation of the control room.

A contributing cause for this event is that the process for compiling information from the Appendix R analyses does not require a formal. technical review prior to the information being sent to the procedure sponsor.

CORRECTIVE ACTION ACTIONS COMPLETED:

Remedial

1. Off Normal Procedure ONP-25.2, "Alternate Safe Shutdown Procedure" was revised to provide guidance for tripping all four primary coolant. pumps.

PROPOSED CORRECTIVE ACTIONS:

Prevent Recurrence

1. All Appendix R engineering analyses will be finalized and a review of the engineering*

analyses'will be completed to ensure consistency in their assumptions and conclusions. It will also be verified that the appropriate procedure changes recommended by the analyses have been made.

2. The engineering analysis process will be enhanced to require appropriate technical reviews of transmittal documents utilized for procedure development or revisions.

RELATED CORRECTIVE ACTIONS:

LER 97-008 entitled "Spurious Valve Operation Could Result In Loss of Shutdown Capabilities Per 10 CFR 50, Appendix R, Section 111.L" was transmitted to the NRC in a letter dated October 10, 1997. One of the corrective actions committed in response to that event is applicable to preventing recurrence of the condition described in this event report and is restated here as follows.

NRC FORM 366a U.S. NUCLEAR REGULATORY COMMISSION 4195 LICENSEE EVENT REPORT (LER) g

- TEXT CONTINUATION I

FACILITY NAME 11 l DOCKETl2l LER NUMBER *61 YEAR SEQUENTIAL REVISION CONSUMERS ENERGY COMPANY NUMBER NUMBER 05000255 5 PALISADES NUCLEAR PLANT 97 - 00 9 - 00 TEXT (If more space 1s required, use additional copies of NRC Form 366A) (17)

"A method will be developed or enhanced to screen Palisades changes, both physical and procedural, whereby areas potentially affected by the change can be identified so that appropriate Appendix R reviews are performed. Change types to be screened include the following: modifications, Operating Procedure changes, Surveillance Procedure changes, Engineering Analyses which change design basis inputs, and FSAR changes."

ADDITIONAL INFORMATION A similar condition was reported under LER 97-008.