ML18089A273
| ML18089A273 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/28/1983 |
| From: | Houston R Office of Nuclear Reactor Regulation |
| To: | Lainas G Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML18089A274 | List: |
| References | |
| NUDOCS 8308080734 | |
| Download: ML18089A273 (2) | |
Text
/
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 JUL 2 I 1983 DISTRIBUTION Docket file (50-?Z?)
NRG PDR (50-272)
Local PDR (50-272)
MEMORANDUM FOR:
Gus Lainas, Assistant Director for Operating Reactors Division of Licensing FROM:
R. Wayne Houston, Assistant Director for Reactor Safety Division of Systems Integration
SUBJECT:
SAFETY EVALUATION, GENERIC WESTINGHOUSE DESIGN MODIFICATION FOR AUTOMATIC REACTOR TRIP USING SHUNT COIL TRIP ATTACHMENTS The Instrumentation & Control Systems Branch (ICSB) has reviewed the Westinghouse Owners Group (WOG) generic design modification to provide automatic reactor trip system (RTS) actuation of the breaker shunt trip attachments.
The details of this modification were provided to the NRG by letter dated June 14, 1983 from J. J. Sheppard (WOG Chairman) to D. G. Eisenhut (Director, DL).
The staff considers automatic actuation of the reactor trip breaker shunt coil trip attachment to be a safety related function.
Therefore, the circuitry used to implement this function must be Class lE.
Our review consisted of an evaluation of the WOG design modification for conformance to the criteria of IEEE Standard 279-1971 11Criteria for Protection Systems for Nuclear Power Generating Stations.
11 Based on our review, we con.elude that the design is acceptable with the following exceptions:
- 1.
A test procedure has not been developed to verify the oper-ability of the control room manual reactor trip switch con-tacts and wiring.
The WOG has committed to develop a generic test procedure applicable to most Westinghouse plants.
Upon completion of a test procedure acceptable to the staff, each 1 i censee should verify that they are using this procedure *or justify any deviations. This procedure should be available within the next month.
- 2.
The shunt trip attachments and the associated actuation circuitry have not been seismically qualified.
The WOG is currently developing a test plan to seismically qualify these components.
Guidance for the qualification testing is given in Regulatory Guide 1.100, Revision 1 which en-dorses IEEE Standard 344.
Installation of the automatic shunt trip modification need not be delayed pending com-pletion of the seismic qualification testing program.
The WOG believes this testing may take several months.
- 3.
The independence/isolation provided between the safety related shunt trip actuation circuits and non-safety related circuits (e.g~, breaker closing circuits and aux-iliary relays) is not acceptable.
The automatic shunt trip
Contact:
R. Kendall, ICSB X29451
modification must be implemented in accordance with the independence/separation criteria of IEEE Standard 279-1971.
Further guidance is provided in Regulatory Guides 1.32, Revision 2 and 1.75, Revision 2 which endorse IEEE Stan-dards 308 and 384 respectively. Since the wiring of the existing shunt trip circuits varies from plant to plant, this concern will be resolved on a plant specific basis.
Although the proposed design is applicable to most Westinghouse plants, specific design information will be required for each individual plant incorporating the automatic shunt trip modification.
The required in-formation is identified in the enclosed Safety Evaluation and summarized in an attachment to the evaluation. It is anticipated that the enclosed generic evaluation coupled with an evaluation of the information required on a plant specific basis will be sufficient to resolve this issue.
- 7
\\ /'J/
I
.. '1 //(_ f \\t.. J!Jj,g._(AA---.Ci..r.._____
1_/ (./ v
--.r-~
~
R. Wayne Houston, Assistant Director for Reactor Safety Division of Systems Integration
Enclosure:
As stated cc:
R. Mattson E. Jordan
- 1
- Novak
. M. Srinivasan J. T. Beard M. Chiramal G. Meyers P. Shemanski
- v. Noonan G. Holahan A. Thadani D. Thatcher
- w. Lanning P. Baranowski K. Murphy D. Pyatt I. Villalva F. Miraglia E. Adens am D. Eisenhut