ML14188B242
| ML14188B242 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 10/10/1986 |
| From: | Requa G Office of Nuclear Reactor Regulation |
| To: | Utley E Carolina Power & Light Co |
| References | |
| GL-83-028, GL-85-009 NUDOCS 8610170015 | |
| Download: ML14188B242 (5) | |
Text
October 10, 1936 DISTRIBUTION:
Docket File E. Jordan NRC PDR B. Grimes Docket No. 50-261 Local PDR J. Partlow PAD#2 Rdg N. Thompson T. Novak G. Requa Mr. E. E. Utley, Senior Executive Vice President OGC-Bethesda D. Miller Power Supply and Engineering & Construction ACRS (10)
Tech Branch Carolina Power and Light Company Gray File Post Office Box 1551 Raleigh, North Carolina 27602
Dear Mr. Utley:
SUBJECT:
GENERIC LETTER 85-09 AND ITEM 4.3 OF GENERIC LETTER 83-28, H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 Generic Letter 85-09 presented the NRC staff position with respect to Technical Specification changes related to the Reactor Trip Breaker Design Modifications, Item 4.3 of Generic Letter 83-28. However, by letter dated December 20, 1985, you submitted information to us based on a probabilistic risk analysis by the Westinghouse Owners' Group, and recommended against periodic testing of the bypass breakers and associated Technical Specifications.
The enclosed request for additional information (RAI) reaffirms the staff's position regarding testing of the bypass breakers and submittal of Technical Specifications. The RAI also provides additional detailed guidance pertaining to what the staff requires for review.
Please provide the information within 90 days after receipt of this letter.
The reporting and/or recordkeeping requirements contained in this letter affect fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.
Sincerely, 0
- 0001, 00 Glode Requa, Project Manager DR, DPWR Project Directorate No. 2 Division of PWR Licensino-A Office of Nuclear Reactor Regulation
Enclosure:
As stated cc w/
Enclosure:
See next page L
PM:PA PD.
D er GReq i LRub nstein 10A
/86 10/
10/786
Mr. E. E. Utley Carolina Power & Light Company H. B. Robinson 2 cc:
Thomas A. Baxter, Esquire Mr. Dayne H. Brown, Chief Shaw, Pittman, Potts and Trowbridge Radiation Protection Branch 2300 N Street, N.W.
Division of Facility Services Washington, DC 20037 Department of Human Resources 701 Barbour Drive Raleigh, North Carolina 27603-2008 Mr. McCuen Morrell, Chairman Darlington County Board of Supervisors Mr. Robert P. Gruber County Courthouse Executive Director Darlington, South Carolina 29535 Public Staff - NCUC P.O. Box 29520 Mr. H. A. Cole Raleigh, North Carolina 27626-0520 Special Deputy Attorney General State of North Carolina P.O. Box 629 Raleigh, North Carolina 27602 Mr. D. E. Hollar Associate General Counsel Carolina Power and Light Company P.O. Box 1551 Raleigh, North Carolina 27602 U.S. Nuclear Regulatory Commission Resident Inspector's Office H. B. Robinson Steam Electric Plant Route 5, Box 413 Hartsville, South Carolina 29550 Regional Administrator, Region II U.S. Nuclear Regulatory Commission Suite 2900 101 Marietta Street Atlanta, Georaia 30303 Mr. R. Morgan General Manager H. B. Robinson Steam Electric Plant Post Office Box 790 Hartsville, South Carolina 29550
(1)
E NCLOSURE REQUEST FOR ADDITIONAL INFORMATION IN ACCORDANCE WITH GENERIC LETTER 85-09 AND ITEM 4.3 T.S. (MPA B-90) OF GENERIC LETTER 83-28.
TECHNICAL SPECIFICATION CHANGES H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 DOCKET NO. 50-261 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 positions 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*.
-2
- 2. A different action is permitted (Action 14) if only one of the diverse trip features (i.e., shunt or undervoltage trip) is inoperable.
For Table 4.3-1:
- 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 tbe 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 during 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 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.
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
-3 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 a backup 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.