ML20090H704
| ML20090H704 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 07/17/1984 |
| From: | Larson C NORTHERN STATES POWER CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| IEB-84-02, IEB-84-2, NUDOCS 8407270058 | |
| Download: ML20090H704 (3) | |
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a Northern States Power Company 414 Nicollet Mall Minneapohs, Minnesota 55401 Telephone (612) 330-5500 July 17, 1984 Mr J G Keppler Regional Administrator - Region III U S Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137 MONTICELLO NUCLEAR GENERATING PLAhT Docket No. 50-263 License No. DPR-22 Response to IE Bulletin 84-02, HFA Relav Failure
Dear Mr Keppler:
Ti following is submitted in response to IE Bulletin 84-02:
Replacement Schedule All coils of safety-related General Electric HFA relays containing lexan or nylon coil spools will be replaced with new, Century Series Tefzel, coils.
If replacement coils cannot be obtained, then the entire relay will be replaced.
The coils of the normally energized AC relays have been replaced with Century Series Tef zel coils. The normally energized DC relay coils are scheduled for replacement during the current outage. However, procurement problems may prevent the replacement during this outage of two normally energized DC relays in the reactor protection system. These are unique time delay relays (Model 12HFA65) that provide a delay for resetting the mode switch in shutdown position scram. These coils will be replaced at the first scheduled outage after the replacement coils are available.
Normally de-energized AC and DC relay coils will be replaced during the next refueling outage.
Testing and Inspection The two normally energized DC relays in the reactor protection system with coils that may not be replaced during the current outage cannot be tested without initiating a scram or disabling the mode switch shutdown scram function. Therefore, testing cannot be done during operation.
These relays have been visually inspected and are in good condition. The inspection _will continue on a monthly basis until coil replacement. All other normally energized relay coils will have been replaced prior to startup. Therefore, no additional tests or inspections are required.
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Northem States Power Company Basis for Continuing Operation No' aging degradationyof normally energized DC HEA relays has-been identi-fied at Monticello. The inspections described above for the two normally energized DC relays in.the reactor protection system are sufficient to provide reasonable assurance that _ they will continue to perform their
-intended. function until-the coils are replaced. All other normally energized relay coils will have been replaced prior to startup from the current outage. Therefore, no -additional basis for continuing operation is required.
Failure 'of the.- two normally energized DC relays in the reactor protection system will only affect the mode switch shutdown scram function. Manual-scram and all automatic scram functions are not affected.by failure of these components.
Spare Parts Spare HFA relays with lexan or nylon coils will be replaced with Century Series relays or will have Century Series Tefzel. coil spools installed.
Applicability to Other Relays Failures attributable to aging degradation similar to'those described in the bulletin have not been experienced with other relays at Monticello.
Therefore, no additional corrective actions are required.
If there are any questions related to our response, please contact us.
C E Larson Vice President Nuclear Generation c:
G Charnoff Resident. Inspector, NRC Document Co'ntrol Desk, NRC Attachment-s 5
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UNITED STATES NUCLEAR REGULATORY C0!ctISSION NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATPTG PLANT Docket No. 50-263 RESPONSE TO I.E. BULLETIN 84-02 Northern States Power Company, a Minnesota corporation, by this letter dated July 17, 1984 hereby submits the response to I.E.Bulletin 84-02 for the Monticello Nuclear Generating Plant.
This letter contains no restricted or other defense information.
NORTHERN STATES POWER COMPANY By h
C E LaV%
Vice President Nuclear Generation On this
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day of A e A;
/9ft/ before me a notary public in and forsaidCounty,personalgappcpTredCELarson,VicePresidentNuclearGeneration, and being first duly sworn acknowledged that he is authorized to execute this document on behalf of Northern States Power Company, that he knows the contents thereof and that to the best of his knowledge, information and belief, the state-ments made in it are true and that it is not interposed for de'ay, d>L $ _.&
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