ML20138P108
| ML20138P108 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/19/1985 |
| From: | Cufter A, Cutter A CAROLINA POWER & LIGHT CO. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.2, TASK-TM GL-84-23, NLS-85-442, NUDOCS 8512240300 | |
| Download: ML20138P108 (1) | |
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C9&L Carolina Power & Light Company SERIAL: NLS-85-442 DEC 1 01985 Director of Nuclear Reactor Regulation Attention:
Mr. D. B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 SUPPLEMENTAL RESPONSE TO GENERIC LETTER NO. 84-23 REACTOR VESSEL WATER LEVEL INSTRUMENTATION
Dear Mr. Vassallo:
On December 10,1984, Carolina Power & Light Company (CP&L) responded to Generic Letter No. 84-23. At that time, the Company committed to provide our planned improvements to reduce reactor vessel water level indication errors caused by high drywell temperature by December 31,1985.
Af ter investigating several options designed to reduce level indication errors, CP&L has elected to reduce the length of reference leg vertical drop in the drywell. This will be accomplished by installing two uncompensated condensing chambers in the drywell arid routing the reference leg outside containment through a spare penetration. These instrument lines will replace the temperature compensated reference columns. The existing uncompensated reference legs and chambers will remain as presently installed.
Should the drywell experience the postulated high temperatures associated with flashing, the new reference legs will be relied upon for reactor water level indication. The maximum level error expected is approximately 33 inches, a significant improvement over the existing design. In addition, this modification will provide the inadequate core cooling instrumentation required by NUREG-0737, item II.F.2.
Carolina Power & Light Company will initiate implementation of this work during Reload 6 for Brunswick-1, presently scheduled for April 1989, and Reload 7 for Brunswick-2, presently scheduled for March 1988. Completion of the required modifications will be accomplished during subsequent refueling outages, if necessary.
This completion schedule will be reflected in Schedule B of the Brunswick Long-Range Plan.
Please refer any questions regarding this matter to Mr. Sherwood R. Zimmerman at (919) 336-6242.
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Dr. J. Nelson Grace (NRC-RII)
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