ML20204G042
| ML20204G042 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/28/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20204G030 | List: |
| References | |
| GL-85-09, NUDOCS 8608070049 | |
| Download: ML20204G042 (4) | |
Text
,
l SAFETY EVALUATION REPORT TECHNICAL SPECIFICATION CHANGES (MPA B-90)
SEQUOYAH NUCLEAR STATION, UNIT 5 1 AND 2 INTRODUCTION By letter dated May 23, 1986, TVA proposed changes to the Sequoyah' Technical Specifications pertaining to Reactor Trip System Instrumentation add Surveillance in response to Generic Letter 85-09 (MPA B-90). Generic Letter 85-09 concluded that Technical Specification changes should be proposed by licensees to explicitly require independent testing of the undervoltage 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 l
and wiring during each refueling outage.
EVALUATION TVA's proposed Technical Specification changes are consistent with those specified in Generic Letter 85-09, except as indicated below by items 1,2 and 3.
1.
A different Action than that indicated is needed for Modes 3*,4* and 5*
(asterisk means with the reactor trip system breakers in the closed posi-tion, the control rod drive system capable of rod withdrawal, and fuel in the reactor vessel) for Functional Units 20 and 21 of Table 3.3-1.
2.
No provision is included for testing of the Reactor Trip Bypass Breaker prior to each time it is put into service.
3.
No provision is included for verifying the operability of the Bypass Breaker trip circuits each refueling outage.
G600070049 060728 DR ADOCK 05000327 PDR
,o,-
The proposed Technical Specification changes for Functional Units 20 (Reactor Trip Breakers) and 21 (Automatic Trip Logic) apply the same Actiont12 to all Applicable Modes. Action 12,whichrequiresgoingtoHotStandbybndercertain conditions, is not appropriate for Modes 3*,4* and 5*.
For Modes 3*,4* and 5*,
tha-reactor trip breakers should be opened if the condition is not remedied within a given time period as specified in Action 13 of Generic Letter 85-09.
TVA has declined to provide Technical Specification changes for surveillance testing of the reactor trip bypass breakers on the basis that Westinghouse Owners Group (WOG)calculationshaveshownnosignificantreliabilityimprovementfrom including periodic surveillance tests of the bypass breakers in the technical specifications. This is not acceptable to the NRC staff. When a reactor trip breaker is tested, the reactor trip bypass breaker is put into service in its place. The Generic Letter 85-09 Technical Specifications specify (Table Notation 13) a manual test of the bypass breaker (either a local shunt trip or remote undervoltage trip) prior to putting it into service. This testing is a simple procedure and it is prudent to do this test before relying on the breaker.
The Generic Letter 85-09 Technical Specifications (Table Notation 11) also re-quires a manual trip function test to independently verify the Operability of the undervoltage and shunt trip circuits of the Bypass Breakers each refueling outage. This test is important to assure that the bypass breaker can be manu-ally tripped from the control panel.
r 5
l 4
CONCLUSION t
i The licensee should amend its proposed Technical Specification chahges by 1.
proposing a different Action than that indicated for Modes 3*,4* and 5* for Functional Units 20 and 21 of Table 3.3-1, 2.
including provisions for testing the Reactor Trip Bypass Breaker prior to each time it is put into service, and 3.
including a provision for verifying the operability of the Bypass Breaker trip circuits each refueling cutage.
Each of the above changes should be in accordance with Generic Letter 85-09.
G
DISTRIBUTION:
Docket File NRC PDR Local POR PRC. System NSIC PWR#4 Rdg.
MDuncan BJYoungblood Rdg.
JHolonich TVA)G (3) S. Richardson AR 5029 HDenton JTaylor BHayes GZech NGrace LSpessard SWeise, RII SAConnelly DMuller TNovak BJYoungblood CStahle TKenyon WLong TAlexion BKSingh KHooks ACRS (10) 0 ELD JPartlow BGrimes EJordan