ML20151B382

Safety Evaluation Supporting Amend 139 to License NPF-1

ML20151B382
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	03/31/1988
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20151B361	List: ML20151B358 ML20151B375 ML20151B382
References
NUDOCS 8804080199
Download: ML20151B382 (3)

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UNITED STATES NUCLEAR REGULATORY COMMISSION 3,

j WASHING TON, D. C. 20555 e

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0.139 TO FACILITY OPERATIhG LICENSE NO. NPF-1 PORTLAND GENERAL ELECTRIC COMPANY THE CITY OF EUGENE, OREGON PACIFIC POWER AND LIGHT COMPANY TROJAN NUCLEAR PLANT DOCKET NO. 50-344

1.0 INTRODUCTION

By letter cated November 13, 1988, Pertland General Electric Company (PGE) proposed changes to Trojan Technical Specification (TS) Section 3/4.10 "Special Test Exceptions" which would extend the surveillance time period for verifying control rod insertability during control rod worth and shutdown margin tests from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days.

TS Surveillance Requirement 4.10.1.2 currently requires that each full length rod not fully inserted be demonstrated operable by verifying its rod drop time to be no greater than 2.2 seconds within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reducing the shutdown margin to less than the normal operating limits of  ;

TS Section 3.1.1.1. The proposed change would enable low power physics 1 tests to be accomplished without an additional trip to verify rod cluster l control assembly (RCCA) insertability. The startup test program includes  !

a RCCA trip test before criticality in order to measure drop times and demonstrate RCCA insertability. Criticality is then achieved and low power physics tests are perfonned. Measurements of RCCA worths are made later and may involve the reduction of shutdown margin as permitted by i TS Section 3.10.1. Since RCCA worth measurements are performed several

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days after the performance of insertability tests, the reactor would have to be tripped again to demonstrate RCCA insertion capability and satisfy i the current 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> criterion. The requested revision would eliminate I the necessity for an additional trip during physics tests by requiring a RCCA insertability to be verified within seven days prior to reducing shutdown margin instead of within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

2.0 DISCUSSION AND EVALUATION The primary concern in extending the surveillance time period for veri-fying control and insertability is whether or not there could be an increase in the probability of a stuck RCCA over a seven day period of J BOCdOE;0199 800331 l gDR ADrscK0500g j l

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time as compared to the present 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time period. Consideration of the configuration of the components that are used in RCCA insertion indicate that there is nothing which could cause a signiff:. ant increase in th probability of a RCCA to become untrippable since there is no significant change in the geonotry of these components over the seven day period of low power physics testing. The components considered include the fuel assembly (including foreign material buildup in the gap between the RCCA and the guide plates within the guide tube), the drive rod assembly, and the control rod drive mechanism. Also, since the control rod clusters will insert by gravity upon loss of power, the probability of a stuck RCCA is not increased due to an electrical malfunction, if cne were to occur during rod worth testing.

Since the proposed change continues to provide assurance that all RCCAs are trippable during low power physics testing and does not affect the amount by which shutdown margin may be reduced during the testing period, we find that the extension of the surveillance period from 24 hcurs to 7 days, with respect to the shutdown margin special test exception, is acceptable.

3.0 CONTACT WITH STATE OFFICIAL The NRC staff has notified the Oregon Departnent of Energy of the proposed issuance of this amendment along with the proposed determination of no significant hazards consideration. No coments were received.

4.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change in surveillance requirements for a facility component located within the restricted area as defined in 10 CFR Part

20. The staff has determined that the amendment involves ro significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.

The Comission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment reets the eligibility criteria for categorical exclusion set forth in 10 CFR 651.22(c)(9). Pursuant to 10 CFR 551.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendrent.

5.0 CONCLtlSION Wehaveconcluded,basedontheconsiderationsdiscussedabove,that(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such

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activities will be conducted in compliance with the Commission's regu-lations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the  :

public.

PRINCIPAL CONTRIBUTOR:

i T. Chan Dated: March 31.1988 <

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