ML20214H125

Forwards Request for Addl Info on Tech Spec Changes in Response to Generic Ltr 85-09 & Generic Ltr 83-28,Item 4.3 Re Reactor Trip Breaker Design Mods.Request Should Be Transmitted,Along W/Generic Ltr 85-09,to Licensee

ML20214H125
Person / Time
Site:	Vogtle, Robinson, 05000000
Issue date:	07/30/1986
From:	Rosa F Office of Nuclear Reactor Regulation
To:	Requa B Office of Nuclear Reactor Regulation
Shared Package
ML20213E629	List: ML20213E625 ML20213F117 ML20214G397 ML20214H017 ML20214H085 ML20214H125 ML20215A123 ML20215A344 ML20215A593 ML20215A752 ML20215A782 ML20215A967
References
GL-83-28, GL-85-09, GL-85-9, TAC-55373, NUDOCS 8608050107
Download: ML20214H125 (4)

Text

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Docket No.: 50-261 MEMORANDUM FOR: B. Requa, Project Manager, Project Directorate #2 Division of PWR Licensing-A FROM: Faust Rosa, Chief Electrical, Instrumentation and Control Systems Branch Division of PWR Licens~ing-A

SUBJECT:

RE0 VEST FOR ADDITIONAL INFORMATION, TECHNICAL SPECIFICATION CHANGES, GENERIC LETTER 85-09 AND ITEM 4.3 T.S. (MPA-R90) 0F GENERIC LETTER 83-28 ,

Plant Name: Robinson 2 Utility: Carolina Power and Light Company ce si tatus: E #'b Resp. Directorate: PD #2/DPA Project Manager: B. Requa Review Branch: EICSB/DPA Review Status: Incomplete

Reference:

Carolina Power and Light Company letter, S.

R. Zinnennan to Steven A. Varga,

--- Response to Generic Letter 85-09",

December 20, 1985.

Generic Letter 85-09 presented the NRC staff positions with respect to Technical Specification changes (Item 4.3 T.S., MPA B-90) related to the Reactor Trip Breaker design modifications of Item 4.3 of Generic Letter 83-28. We understand that the Carolina Power and Light Company has not submitted these proposed Technical Specifi-cation changes as yet for staff review. However, the company by letter dated December 20, 1985, recomended against periodic testing of the bypass breakers, based on a probablistic risk analysis by the Westinghouse Owners Group. The enclosed request for additional infonnatt testing of the bypass breakers. pn The(RAI) reaffinns RAI also providesthedetailed staff's position regarding additional guidance as to what the staff requires for; review. Please transnit the RAI, along with a

. copy of Generic Letter 85-09, to the licensee.

ISl Faust Rosa, Chief Electrical, Instrumentation and Control Systems Branch Division of PWR Licensing-A

Enclosure:

N As stated

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REQUEST FOR ADDITIONAL INFORMATION <

IN ACCORDANCE WITH GENERIC LETTER 85-09 I AND ITEM 4.3 T.S. (MPA B-90) 0F l GENERIC LETTER 83-28. '

TECHNICAL SPECIFICATION CHANGES  !

H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 1 DOCKET NO. 50-261 r

INTRODUCTION Generic Letter 85-09 contains staff positions regarding proposed Technical Specification changes pertaining to reactor trip breaker (RTB) design changes (Item 4.3 of Generic Letter 83-28).

Generic Letter 85-09 concluded that Technical Specification changes should be proposed by licensees to explicitly require independent testing of the under-voltage and shunt trip attachments of the reactor trip breakers during power operation, testing of bypass breakers prior to use, and independent testing of the control room manual switch contacts and wiring during each refueling ' outage.

Staff positions You are requested to submit proposed Technical Specification changes, noting particularly the following posi ions of Generic Letter 85-09.

For Table 3.3-1: ,

1. For the reactor trip breakers (RTBs) and for the automatic trip logic, different actions are specified for Modes 1 and 2 as compared to Modes 3*, 4*, and 5* (asterisk means with the reactor trip system breakers closed and the control rod drive system capable of rod withdrawal).

Action 12 applies to Modes 1 and 2, whereas Action 13 applies to Modes 3*, 4*, and 5*.

l 1

2.

A different action is pemitted (Action 14) if only one of the diverse trip features (i.e., shunt or undervoltage trip) is inoperable.

For Table 4.3-1: .i

. .. . . . - . . - . . - -- ~

1.

The manual reactor trip tests at refueling intervals specify testing of the bypass breaker trip circuits as well as the RTB trip circuits.

Independent testing of the undervoltage (UV) and shunt trip attachment (STA) of each RTB and bypass breaker is specified (Action 11).

2.

Each RTB is to be tested at least every 62 days on a staggered basis (Action 7). Independent testing of the UV and STA is specified (Action 12) as part of this RTB test.

3.

Each automatic trip logic train is to be tested at least every 62 days on a staggered basis (Action 7).

4 The reactor trip bypass breakers are to be manually tested prior to placing the breaker in service (Action 13). Also an automatic UV trip test is to be made durkng each refueling outage (Action 14).

Some licensees or applicants have declined to provide Technical Specification changes for testing of the bypass breaker prior to each time it is put into l service.

The reason cited is that a study by Westinghouse for the Westinghouse Owners Group (WOG) has shown only marginal reliability improvement by such testing, i

i The NRC staff finds this basis for not testing to be unacceptable. When a reactor trip breaker (RTB) is tested, the reactor trip bypass breaker is put I

l

into service as a backup to the remaining RTB. The Generic Letter 85-09 Tech-nical Specifications specify a manual trip test of the bypass breaker prior to putting it into service. This testing'is a simple procedure and it is prudent to do this test before relying on this breaker as asbackup to the remaining RTB.

Although the probabilistic risk analyses have shown that the testing of the bypass breaker only marginally improves overall reliability, no claim is made that the reliability is decreased or that the bypass breaker is not safety related. Accordingly, the NRC staff concludes that this test should be made as specified in Generic Letter 85-09.

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