ML20247J785

Safety Evaluation Supporting Amend 28 to Licenses NPF-37 & NPF-66 & Amend 17 to NPF-72 & NPF-77,respectively

ML20247J785
Person / Time
Site:	05000000, Byron, Braidwood
Issue date:	05/22/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20247J219	List: ML20247J213 ML20247J785
References
GL-85-09, GL-85-9, NUDOCS 8906010131
Download: ML20247J785 (4)

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i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 28 TO FACILITY OPERATING LICENSES NOS. NPF-37 AND NPF-66 i

BYRON STATION, UNITS 1 AND 2 1

_ DOCKET NOS. 50-454 AND 50-455 AND SUPPORTING AMENDMENT NO. 17 TO FACILITY OPERATING LICENSES NOS. NPF-72 AND NPF-77 BRAIDWOOD STATION, UNITS 1 AND,2 i

DOCKET NOS. 50-456 AND 50-457.

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1.0 INTRODUCTION

1 On July 8,1983, the' Nuclear Regulatory Commission (NRC) issued Generic Letter 83-28 which described actions to be taken by licensees to resolve concerns raised by the Salem ATWS events.

Item 4.3 of this letter requested licensees and applicants to modify the reactor trip system on Westinghouse and Babcock &

Wilcox PWRs to automatically actuate the shunt trip attachment of the reactor j

trip breakers.

Based on their review of the proposed Westinghouse design for i

automatically uctuating the shunt trip device, the staff concluded that revisions to the plant technical specifications were needed to provide for surveillance testing of the shunt and undervoltage trip devices during power operation. On May 23, 1985, the staff issued Generic Letter 85-09 to all i

Westinghouse PWR licensees which clarifico the original requireiaent for testing the trip devices by requiring that the shunt ano undervoltage trip devices be tested independently during power operation.

In aodition, i

independent testing of the control' room manual trip switch and wiring to both trip devices and testing of the reactor trip bypass breakers were required.

These changes are considered necessary by the staff to ensure reliable operation of the reactor trip breakers.

l 2.0 EVALUATION l

By letter dated December Edison Company (the licensee 23,)1987, supplemented April 3, 1989, Commonwealth submitted proposed revisions to the Byron /Braidwood i

Technical Specifications based upon the NRC staff evaluation of the Westinghouse shunt trip attachment design and the requirements of Generic Letter 85-09.

In response to the hRC requirements, the following Technical Specification revisions j

were proposed.

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Functional Unit 22 is being added to Technical Specification Table 2.2-1.

This change is being made to be consistent with Technical Specification Tables 3.3-1 and 4.4-1, which also reference the Reactor Trip Bypass Breakers.

2.

Action 9 is being deleted from, and Action 12 is being added to, Functional Unit 20 on Technical Specification Table 3.3-1.

Action 12 is broken down into two independent requirements. Action 12-a invokes the actions stated in Action 14 of Generic Letter 85-09. This action permits continued operation for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> when one of the Reactor Trip Breaker diverse trip features is found to be inoperable. After this 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> period elapses, Action Statement 12-b must be entered. Action Statement 12-b was previously Action 9.

The words " Channel" have been replaced with " Reactor Trip Breaker" for clarity. This Action will require the unit to be placed in Hot Standby within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> for any failure not addressed by Action 12-a.

3.

Functional Unit 22 is being added to Technical Specification Table 3.3-1.

The addition of Functional Unit 22 is necessary to provide both a condition of applicability and action statement for the Reactor Trip Bypass Breakers. The condition of applicability was chosen to be whenever the Reactor Trip Bypass Breaker is racked in and closed for the purpose of bypassing a Reactor Trip Breaker with the Unit in Modes 1 or 2, or in Modes, 3, 4, or 5 with the Control Rods capable of withdrawal.

With a Recctor Trip Bypass Breaker inoperable, Action 13 requires the breaker to be returned to an operable status prior to using the breaker for the purpose of bypassing a Reactor Trip Breaker. The first portion of this Action Statement is stated this way due to the normal mode of discovering an inoperable breaker through the Manual Shunt Trip test, required prior to breaker use in the proposed Note 16 to Technical Specification Table 4.3-1.

If the Bypass Breaker becomes inoperable after being racked in and closed for the purpose of bypassing a Reactor Trip Breaker, then the second portion of Action 13 will require the Unit to be placed in Hot Standby in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, then the breaker must be restored to operable status within the next 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, or the breaker must be opened in the next hour. These actions are based on the present Action Statement 9 and 10 for the Reactor Trip Breakers. The testing i

clause associated with Action 9 was removed from Action 9, due to it not being applicable in this configuration.

4.

Note 14 to Technical Specification Table 4.3-1 for Braidwood Station only is being deleted. This was a one time only change that has expired.

j 5.

Note 14 is being added to the Trip Actuating Device Operational Test for Functional Unit 1 on Technical Specification Table 4.3-1.

Note 14 requires that the appropriate signals reach the undervoltage and shunt trip relays for both the Reactor Trip and Bypass Breakers from the Manual Trip Switches. This note also provides an implementation time frame for this surveillance requirement. The implementation time frame chosen was due to this surveillance requiring the Unit to be in a shutdown condition to perform. The proposed change reflects the intent of Note 11 of Generic Letter 85-09.

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6.

Note 11 on the Trip Actuating Device Operational test for Functional Unit 20 on Technical Specification Table 4.3.1.is being revised. The s

requirements of Note 7 are being incorporated into Note 11 for clarity,

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and Note 7 has been deleted from Functional Unit 20. Note 11 has been-revised to. combine the need to independently verify the operability of both the undervoltage trip and the shunt trip attachment. A requirement to test these functions following maintenance or adjustment has also been incorporated into Note 11.

7.

Functional Unit'22 is being added to Technical Specification Table 4.3-1.

Included with this function unit are Notes 15 and 16 which require manual Shunt Trip testing prior to the Reactor Trip Bypass Breaker being racked in and closed for the purpose of bypassing a' Reactor Trip Breaker.

The monthly frequency designation associated with Note 15 is being deleted.

The requirement to Shunt Trip test the Reactor Trip Bypass Breakers prior to use is-controlled through Note 15 which references bypassing a Reactor.

Trip Breaker.. Bypassing a Reactor Trip Breaker is required monthly in functional Unit 20 and therefore the Reactor Trip Bypass Breaker will be tested monthly.

Including the monthly frequency designation in Functional Unit 22 would be redundant and possibly lead to confusion.

Note 16 requires the Reactor Trip Bypass Breaker to be trip tested from an automatic undervoltage signal once per 18 months. The Surveillance Requirement poses a high potential to cause a unit trip if performed with the unit on line. Due to this potential for a unit trip, this r

surveillance is being viewed as a shutdown item. Therefore, Note 16 also contains an implementation time frame.

On the basis of its review of the above items, the staff concludes that the licensee has provided an acceptable response to these items as addressed in the NRC guidance requiring independent testing of the undervoltage and shunt trip attachments during power operation and independent testing of the control room manual switch contacts during each refueling outage. Therefore, the staff finds that these changes are consistent with the recommendations in Generic Letter 85-09 and are acceptable.

3.0 ENVIRONMENTAL CONSIDERATION

The amendment involves change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.

The staff has determined that the amendment involves no 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 exposures. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9). Pursuant to 10CFR51.22(b),noenvironmentalimpactstatementorenvironmentalassessment need be prepared in connection with the issuance of the amenoment.

a t' :p 4.0., CONCLUSION On the basis of the considerations discussed above, the NRC staff concludes that (1) there is reasonable assurance that the health and safety of'the public will not be endangered by operation in the proposed manner, (2) such

activities will be conducted in compliance with the Commission's regulations,.

and (3) the issuance of.these amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: Don Lasher and Leonard N. 01shan Dated:

May 22, 1989 t'

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