ML20101C526
| ML20101C526 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 11/26/1984 |
| From: | Cutter A CAROLINA POWER & LIGHT CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| IEB-84-03, IEB-84-3, NLS-84-469, NUDOCS 8412210117 | |
| Download: ML20101C526 (2) | |
Text
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Mr. James P. O'Reilly, Regional Administrator United States Nuclear Regulatory Commission Suite 2900 101 Marietta Street, NW Atlanta, GA 30303 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR -71 & DPR-62 RESPONSE TO IE BULLETIN NO. 84-03 REFUELING CAVITY WATER SEAL
Dear Mr. O'Reilly:
In IE Bulletin No. 84-03, dated August 24, 1984, Carolina Power & Light Company was -requested to evaluate the potential for and consequences of a refueling cavity water seal failure and to provide a summary report of these actions. This letter provides a summary report of the requested evaluation for the Brunswick Steam Electric Plant.
Based on a review of the plant drawings and information received from General Clectric Company, it has been determined that the standard BWR refueling cavity water seal used at Brunswick dif fers significantly from the PWR design. The BWR refueling cavity water seal consists of the refueling bellows seal, the drywell to reactor wall bellows seal, and the reactor wall seal bulkhead plate. This design does not contain any interference fit pneumatic seals, but relies on a welded bellows which requires no outside source of power to maintain seal integrity. Failure of the BWR seal would require structural failure of its welded components. This event is considered to be highly unlikely.
In addition, gross failure of the refueling cavity water seal with the spent fuel storage gate open would not cause active fuel to be uncovered. The design of the fuel storage pool at Brunswick maintains the top of the active fuel below the top of the barrier separating the reactor well and the fuel storage pool. There are no connections to the fuel storage pool which could drain the fuel pool either (1) below the top of the reactor well/ fuel storage pool barrier when the fuel pool gate is removed or (2) below the normal pool level when the gate is in place. Piping entering the fuel storage pool is equipped with a check valve above the pool elevation to prevent water from siphoning out of the pool.
D 411 Fayetteville Street e P. O. Box 1551
- Raleigh. N. C. 27602
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Mr. James P. O'Reilly.-
If a bundle were being tr.ansferred at the time of a cavity seal failure, it could become uncovered if no operator action were taken. However, the combination of a seal design.which limits the rate of water loss and the spent fuel pool water makeup capability would help to mitigate such an event.
The Company believes that, due to design differences between PWR and BWR refueling cavity water seals, gross failure of this seal is not a credible accident for BWRs. Even in the highly unlikely event of such a failure, there 7
- would be no significant increase in risk to the public's health and safety.-
Should you have any questions regarding this matter, please contact Mr. Sherwood R. Zimmerman at (919) 836-6242.
Yours ery truly A. B. Cutter - Vice ident Nuclear Engineering & Licensing A. B. Cutter, having been first duly sworn, did depose and say that the information contained herein is true and correct to the best of his information, knowledge and belief; and the sources of his information are officers, employees, contractors, and agents of Carolina Power & Light Company.
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