ML20127L663
| ML20127L663 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 06/24/1985 |
| From: | Andrews R OMAHA PUBLIC POWER DISTRICT |
| To: | Butcher E Office of Nuclear Reactor Regulation |
| References | |
| GL-83-28, LIC-85-254, NUDOCS 8506280088 | |
| Download: ML20127L663 (2) | |
Text
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Omaha Public Power District 1623 Harney Omaha Nebraska 68102 402/536 4000 June 24, 1985 LIC-85-254 Mr. Edward J. Butcher, Acting Chief Operating Reactors Branch #3 Division of Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, DC 20555
References:
(1) Docket No. 50-285 (2) Letter OPPD (W. C. Jones) to NRC (J. R. Miller) dated November 4, 1983 (LIC-83-267)
(3) Letter NRC (J. R. Miller) to OPPD (R. L. Andrews) dated March 25, 1985
Dear Mr. Butcher:
Generic Letter 83 Request for Additional Information Following Preliminary Staff Review of Licensee Responses The Omaha Public Power District received Reference (3) which requested additional information regarding our Reference (2) submittal. Accordingly, please find at-tached the requested additional information regarding Item 4.5.3 of Generic Letter 83-28.
Sincerely, 1
l R. L. Andrews Division Manager l
Nuclear Production RLA/DJM/dao l
Attachment cc:
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, DC 20036 Mr. E. G. Tourigny, NRC Project Manager h (I 0
Mr. L. A. Yandell, NRC Senior Resident Inspector iq i
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ATTACHMENT NRC Request Item 4.5.3-Incomplete Licensee's response shall present additional information supporting their belief in the adequacy of their on-line testing intervals that addresses the five consi-derations mentioned in this generic letter item.
Generic Letter 83-28 Item 4.5.3
" Existing intervals for on-line functional testing required by Technical Specifi-cations shall be reviewed to determine that the intervals are consistent with achieving high reactor trip system availability when accounting for considerations such as:
1.
uncertainties in component failure rates 2.
uncertainties in coninon mode failure rates 3.
reduced redundancy during testing 4.
operator errors during testing 5.
component " wear-out" caused by the testing Licensees currently not performing periodic on-line testing shall determine appro-priate test intervals as described above.
Changes to existing required intervals for on-line testing as well as the intervals to be determined by the licensees currently not performing on-line testing shall be justified by information on the sensitivity of the reactor trip system availability to parameters such as the test intervals, component failure rates and common mode failure rates."
District Response from Reference (2)
The Omaha Public Power District believes the existing intervals for on-line func-tional testing of the reactor protective system are appropriate.
During ten years of experience using existing test procedures, one instance of trip has occurred.
This occurrence was during testing in which the reactor was tripped due to faulty test switches. These switches were replaced.
The plant has had ten (10) years of reliable operation. This experience coupled with the existing maintenance and surveillance programs provide a high level of assurance for the Fort Calhoun Station reactor protective system.
District's Response to Request for Additional Information The District participated in the Combustion Engineering Owners Group Task on Reactor Protection System Test Interval Evaluation.
The five considerations provided in Generic Letter 83-28 were addressed as part of this work.
Results for the District's
' Fort Calhoun Station demonstrate that the District's current intervals are adequate and conservative.