ML17290A903

Application for Amend to License NPF-21,requesting Continued Plant Operation W/Eccs Functional,But Not in Strict Compliance W/Requirements for Demonstrating That Response Time within Limits of TS 3/4.3.3, ECCS Instrumentation.

ML17290A903
Person / Time
Site:	Columbia
Issue date:	01/13/1994
From:	Parrish J WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML17290A904	List: ML17290A903 ML17290A905
References
GO2-94-011, GO2-94-11, NUDOCS 9401240296
Download: ML17290A903 (17)

Text

ACCELERATED DI UTION DEMONST TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9401240296 DOC.DATE: 94/01/13 NOTARIZED: YES DOCKET FACIL:50-397 WPPSS Nuclear Project, Unit 2, Washington Public Powe 05000397 AUTH. NAME AUTHOR AFFILIATION PARRISH,J.V. Washington Public Power Supply System RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Application for amend to License NPF-2l,requesting continued plant operation w/ECCS functional,but not in strict compliance w/requirements for demonstrating that response time within limits of TS 3/4. 3. 3, "ECCS Instrumentation. " D DISTRIBUTION CODE: AOOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution J ENCL j SIZE: ~+2 NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PDV LA 1 1 PDV PD 1 1 CLIFFORD,J 2 2 D

INTERNAL: ACRS 6 6 NRR/DE/EELB 1 1 NRR/DORS/OTSB 1 1 NRR/DRCH/HICB 1 1 NRR/DRPW 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 1 0 OGC/HDS1 1 0 1 1 EXTERNAL: NRC PDR 1 1 NSIC D

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL 20

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM P.O. Bax'968 ~ 3000 George Wasbtngton Way ~ Rtcbland, lWashfngton 99352W96'8 ~ (509) 372-5000 January 13, 1994 G02-94-011 Docket No. 50-397 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555 Gentlemen:

Subject:

WNP-2, OPERATING LICENSE NPF-21 REQUEST FOR AlVKÃDMENTTO TECHNICALSPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION

References:

1) Letter G02-91-159, dated August 29, 1991, JW Baker (SS) to NRC, "Licensee Event Report No. 91-013-02"

2) Letter G02-93-266, dated November 9, 1993, JV Parrish (SS) to NRC, "Licensee Event Report No.'93-010-05"

3) Letter G02-94-010, dated January 13, 1994, JV Parrish (SS) to NRC, "Request for Discretionary Enforcement for Technical Specification 3/4.3.3, ECCS Instrumentation" In accordance with the Code of Federal Regulations, Title 10 Parts 50.90 and 2.101, the Supply System is requesting an amendment to the WNP-2 Technical Specifications on an emergency basis as provided for in the regulations. Specifically, the Supply System is requesting continued plant operation with Emergency Core Cooling System (ECCS) instrumentation functional, but not in strict compliance with the requirements for demonstrating that the response time is within the limits specified in Technical Specification (TS) 3/4.3.3, "Emergency Core Cooling System Actuation Instrumentation." As reported in Reference 3, on January 10, 1994, the condition of noncompliance with the WNP-2 Technical Specifications was identified as part of the ongoing Technical Specification Surveillance Improvement Project (TSSIP). It was identified that the

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Page'2 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION

~0 procedures performed to satisfy Surveillance Requirement (SR) 4.3.3.3 did not adequately measure the total response time of two in-series relays in the logic string for the opening of the injection valve in the Low Pressure Core Spray (LPCS) and Residual Heat Removal (RHR) B and C low pressure ECCS loops and three in-series relays in the logic string for the injection valve in the RHR A low pressure ECCS loop. On January 12, 1994 it was identified that similar inadequacies existed in the total response time testing of the logic strings for the start of the associated pumps, specifically, in one relay in the logic string to the LPCS and RHR B/C pumps and in two relays in the logic string for the RHR A pump.

The Supply System is requesting as an emergency Technical Specification change to add a note to the surveillance requirements in TS 3/4.3.3. This note, added to SR 4.3.3.3, will allow the delay of the response time testing for the low pressure ECCS systems until startup following the next COLD SHUTDOWN, but no later than the startup following completion of the Spring 1994 Refueling Outage.

Failure to satisfy the response time testing specified in SR 4.3.3.3 requires that the applicable systems be declared inoperable, This involves all four low pressure ECCS systems and would require that the plant be taken to COLD SHUTDOWN. The Supply System believes there is less risk in relying on the existing functional testing than in testing at power or forcing an unnecessary plant transient by taking the plant to COLD SHUTDOWN to perform an additional response time test on each of the four loops.

D cri ion f n iion On January 10, 1994, a condition of noncompliance with the WNP-2 Technical Specifications was identified as part of the TSSIP. The TSSIP is an ongoing project that was recommended by a Supply System Quality Action Team formed as a corrective action of LER 91-013-02 (Reference 1). The TSSIP revises and broadens the scope of the Surveillance Procedure Verification Program completed in May 1991. Additional details of this program and previous findings are provided in LER 93-010-05 (Reference 2).

During the performance of the TSSIP review for compliance with the requirements associated with SR 4.3.3.3 and Table 3.3.3-3, it was noted that response time testing procedures did not measure the entire response time from sensor actuation until the ECCS equipment is capable of performing its safety function (i,e., valves travel to their required position and pump discharge pressures reach required values). Specifically, the interval not measured is the time from logic relay coil energization to contact operation in the injection valve control circuit. This affects Division I and II low pressure ECCS. The existing response time testing procedures measure the system response time from the sensed parameter to the energization of the first logic relay and from the injection valve hand switches until the injection valves are open. The testing does not measure the interval from the logic relay coil pickup to injection valve control circuit contact

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Page'3 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION closure. At the time of the verbal request for discretionary enforcement, the review of response time testing for Division I and II ECCS was continuing and was expanded to include HPCS response time testing. The review raised a question on the HPCS system which resulted in the determination that the testing of the initiation logic for the LPCS and RHR pumps was also not completely adequate.

Specifically, for the ECCS low pressure pumps, actual testing initiation signals were measured at a point in the logic string which did not include certain logic components. These include one relay in the logic string to the LPCS and RHR B/C pumps and two relays in the logic string for the RHR A pump. The response time testing does include pump initiation until stable pump discharge pressure is achieved. Logic System Functional Testing has been performed which establishes that the circuits are functional including both pumps and associated injection valves; however, these tests did not require that the timing of the function be measured.

Because the inadequate testing was not identified by TSSIP until January 10, 1994, it was not possible to submit this request on a more timely basis. The additional details of the inadequate response time testing for the pump logic strings were not identified until January 12, 1994. This letter was delayed one day until the Supply System was able to more clearly define the extent of the testing deficiencies.

li In summary, the Supply System is requesting the NRC approve an emergency change to the WNP-2 Technical Specifications. The Supply System requests the ECCS RESPONSE TIME testing of the low pressure ECCS injection valves and pump start logic be delayed until startup following the next COLD SHUTDOWN, but no later than the startup following completion of the Spring 1994 Refueling Outage. It is the Supply System's belief that continued operation without full compliance with the response time testing is acceptable because testing has demonstrated that the ECCS loops will function as designed and it is expected that the testing of the relays will not challenge the acceptance criteria specified in the Technical Specifications.

It should be noted that, because the TSSIP is an in-depth technical review of the surveillance procedures to ensure they meet the Technical Specification surveillance requirements, other conditions of noncompliance with the WNP-2 Technical Specifications may be identified in the future.

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Page'4 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION om ensat Mea ur The Technical Specification acceptance criteria for the applicable response times require that the time be less than or equal to 43 seconds. Of the four ECCS systems, the most limiting margin as established by the acceptance criteria of the surveillance procedures for the response of the opening of the injection valves is 11 seconds. The response time of the portion of the logic circuits not measured is expected to be less than 0.5 seconds. The corresponding remaining margin to the TS acceptance criteria will therefore be in excess of 10 seconds. Also, the time that is expected to be added to the response time in each case is small when compared to the allowable response time or the measured response time.

The most limiting margin to the Technical Specification limit of 43 seconds established by testing from sensor initiation through achieving adequate pump discharge pressure is 20.6 seconds. The response time for the portion of the logic circuits not yet measured is expected to be less than 0.5 seconds. The corresponding margin to the TS acceptance criteria will therefore be in excess of 20 seconds. As discussed above, the time to be added to the measured time is small when compared to the allowable response time or the measured response time.

The relays which have not been response time tested are located in the Main Control Room where they are under control of the Shift Manager. This limits possible environmental degradation as well as access to the cabinets, making them less susceptible to inadvertent damage.

The affected relays are GE HMA or HFA types which do not have any time delay features, i.e.,

a dash pot or other dampening of the armature which would automatically delay the pick up time. Degradation of this type of relay is typically evidenced by failure to function, rather than degraded response times. Since no mechanism has been identified for degrading pickup times, it can be concluded that the actuated relay willperform its function consistent with existing data.

Qualification data for HFA and HMA relays indicates expected pickup times of less than 100 milliseconds. This data has been subsequently confirmed by response time testing at WNP-2.

Based upon the reasons stated above, compensatory actions are not necessary.

Safet Basi f r theR ues Logic System Functional Testing (LSFT) is performed each annual refueling outage. The applicable series of LSFTs were completed during the Spring 1993 Refueling Outage. The LSFT provides testing of the instrumentation and logic string from the sensor through the

Page 5 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION injection valves through an overlapping series of channel functional tests (CFT) and specific component tests. The LSFTs provide periodic assurance that each of the circuits, including relays and contacts, will operate as required to perform their safety functions through the actuated component.

The Supply System has performed industry event reviews of HMA and HFA relays. A search of the WNP-2 Operating Events Review files, Nuclear Plant Reliability Data System (NPRDS) database and INPO Operating Experience was performed. There were some failures of the early HFA relays. We have replaced our HFA relay coils with the new Century series relay coils and there is no indication that these relays with these coils have experienced the same type of failures. No information indicating any other generic failure mechanisms applicable to the pickup times of the HMA or HFA relays was discovered. Further, a review of Supply System maintenance history did not identify any concerns with these HMA and HFA relays that would impact their response time.

The Supply System has evaluated these relay designs and their applications at WNP-2 and has concluded that the relays will perform their intended safety function within specified time requirements. Therefore, a plant shutdown for response time testing would not provide significant additional assurance that the relays would actuate within specified time requirements.

Additionally, in order to support the response time testing of each low pressure ECCS system during power operation, an entire division (two ECCS loops and the associated emergency diesel generator) would have to be disabled during the performance of the test.

Justification for the Period of A licabilit Based upon the observed failure modes of these relays, the scope of the testing currently performed, the results of the testing, and the limited added assurance that would be provided by the response time testing in evaluating the ability of these relays to perform their safety function, the Supply System believes that granting the requested emergency change to the Technical Specifications does not represent a significant safety issue.

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The Supply System has evaluated this request for an emergency Technical Specification change to defer the ECCS response time testing for the low pressure ECCS systems until startup following the next COLD SHUTDOWN, but no later than the startup following completion of the Spring 1994 Refueling Outage. The Supply System has determined that the granting of this request will not represent a significant hazards consideration because it will not:

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Page'6 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRVMI<22ITATION

1) Involve a significant increase in the probability or consequences of an accident previously evaluated. The only components that have not been adequately response time tested are relay coils and contacts. The relays are accident mitigating features and are not considered in the initiating sequences, for any accidents previously evaluated. Hence, the probability of evaluated accidents will not be increased upon approval of this request.

Design and industry experience leads to the conclusion that the overall system response time will be within the Technical Specification requirements. There is no observed mechanism that would cause deterioration of the response time of these relays. The LSPTs performed to date have demonstrated that the relays function as designed. Thus, the relays and logic strings when tested are expected to yield response time results well within the assumptions in the accident analysis. Therefore, approval of the request will not result in a significant increase in the consequences of an accident previously evaluated.

2) Create the possibility of a new or different kind of accident from any accident previously evaluated. No new modes of operation of any equipment, system configuration or initial conditions result from, or are necessary to compensate for, the lack of complete response time testing of the relays. Granting of the request will not affect initial conditions or introduce new system configurations and thus, will not create the possibility of a new or different kind of accident.

3) Involve a significant reduction in a margin of safety. As discussed above, the LSFTs performed to date have demonstrated functionality of the relays. Design and industry experience lead to the conclusion that the response time of the circuits will be within the expected overall system response limit. There is no observed mechanism that has caused deterioration of the response time of these relays. With no identified mechanism for degradation and design specifications supporting appropriate interval time response, there is reasonable confidence that the relays will perform within the required limits and the design basis for the low pressure emergency core cooling systems will be maintained.

Hence, there is no significant increase in the ECCS response time and the margin of safety provided by the response time specified in the Technical Specifications is not significantly decreased.

Because the logic strings are considered to be capable of performing their safety function within the response times listed in the Technical Specifications, granting of this request does not represent a significant hazards consideration.

C' Page 7 REQUEST FOR AMENDMENTTO TECHNICAL SPECIFICATION 3/4.3.3, ECCS INSTRUMENTATION Environmen 1 n ide i n As previously discussed, the Supply System concludes that this request does not involve a significant hazards consideration, nor is there a potential for a significant change in the types or significant increase in the amount of any effluent that may be released offsite, nor does the request involve a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed change meets the eligibilitycriteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and, therefore, per 10 CFR 51.22(b), an environmental assessment of this change is not required.

The Supply System concludes that granting this request will involve minimum or no safety impact and represents a reduced risk to public health and safety over that associated with a potential plant shutdown.

This change has been approved by the WNP-2 Plant Operating Committee and the Supply System Corporate Nuclear Safety Review Board. In accordance with 10 CFR 50.91, the State of Washington has been provided a copy of this letter.

Sincerely,

. V. Parrish (Mail Drop 1023)

Assistant Managing Director, Operations MGE/bk Attachments CC: KE Perkins - NRC RV NS Reynolds - Winston & Strawn JW Clifford NRC DL Williams - BPA/399 NRC Site Inspector - 927N W Bishop - EFSEC

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STATE OF WASHINGTON )

Subject:

Request for Amend to Tech Spec

) 4 E In rumentation COUNTY OF BENTON )

I. J. V. PARRISH, being duly sworn, subscribe to and say that I am the Assistant Managing Director, Operations for the WASHINGTON PUBLIC POWER SUPPLY SYSTEM, the applicant herein; that I have the full authority to execute this oath; that I have reviewed the foregoing; and that to the best of my knowledge, information, and belief the statements made in it are true.

DA~ /3y~u , 1994 J.. Parrish, Assistant Managing Director perations On this date personally appeared before me J. V. PARRISH, to me known to be the individual who executed the foregoing instrument, and acknowledged that he signed the same as his free act and deed for the uses and purposes herein mentioned.

GIVEN under my hand and seal this QQ day of 1994.

Notary Public in and for t Q((:yhlgp. STATE OF WASHINGTON

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