ML18059A409
| ML18059A409 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 09/29/1993 |
| From: | Slade G CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9310060145 | |
| Download: ML18059A409 (2) | |
Text
consumers Power POWERINli
/llllCHlliAN'S PIUlliRESS Palisades Nuclear Plant:
27780 Blue Star Memorial Highway, Covert. Ml 49043 September 29, 1993 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 G BSlada General Manager.
DOCKET 50-255 - LICENSE DPR~20 - PALISADES PLANT - CONSUMERS POWER COMPANY
. COMMITMENTS RESULTING FROM A PCS THROUGH WALL LEAK AND EXCEEDING THE PLANT.
COOLDOWN RATE LIMIT Consumers Power Company is providing our committed actions as a*result of recent events ~t Palisades. These events involved:
A through wall leak in a safe end to pipe weld in the pressurizer power operated relief valve line; and exceeding the T~chnical Specifications cooldown rate of 20 degrees per hour when the primary system cold leg temperature was less than 170 degr~es. As a result. of these occurrences we will perform the following action~:
Pressurizer Line
- 1. An investigation to determine the root cause of initiation and development of the through wall crack will be conducted.
Documentation of the investigatirin and corrective actions will be maintained and made available to the NRC.
- 2. A re-evaluation of the pipe stresses, including those from periodic -
maintenance.and other potential causes of stress, on each line on top of.
the pressurizer with an lnconel 600 safe end~ The evaluation will be made available to the NRC.
- 3. Determine why the June 1993 NOE inspection did not identify, characterize, and size the indication. The results of this determination will be made*
available to the NRC.
- 4. A draft copy of the fracture mechanics flaw evaluation by Sargent and Lundy that was conducted following the weld indication in June 1993 was provided to the NRC.
This evaluation was never finalized because the failure that occurred was due to stress corrosion cracking which is different from that postulated in the flaw evaluation.
O 4.. l 1. L 9310060145 930929 PDR ADOCK 05000255 S
PDR A CM5 ENERGY COMPANY
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- 5. Consumers Power Company will evaluate the potential for similar cracks in*
the remaining safe ends including the following:
- a.
Performing NOE on the remaining safe end welds for the PORV, spray, and relief valve lines.
- b. Justifying the surge line and other Inconel s.afe ends for operation.
- 6. The NRC will be provided with a crack tip sample for independent sample analysis.
- 7. All identified cracks and defects resulting from the inspections in item 5 above will be repaired within Code requirements.
- 8. Consumers Power Company will implement changes to the plant inspection program to address deficiencies in 3 above.
Cooldown Rate
- 9. Consumers Power Company will determine the root cause and corrective action of the apparent violation that occurred during the plant cooldown on September 17, 1993.
Documentation will be available for NRC review..
- 10. An engineering evaluation to determine the possibl~.effects on the reactor vessel from exceeding cooldown rate will be completed and be available.for
. NRC review.
Meeting
- 11. A meeting with the NRC will be held prior to returning the reactor to a critical condition.
/~~/~
Gerald B Slade General Manager CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades Attachment I