ML19326E096
| ML19326E096 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/27/1980 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-05, IEB-80-5, NUDOCS 8007250662 | |
| Download: ML19326E096 (2) | |
Text
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BALTIMORE GAS AND ELECTRIC COMPANY P. O. BOX 1475 BALTIMORE. MARYLAN D 21203 June 27,1980 ARTHUR E. LUNDVALL,i)R.
VICE PmessognT Su pety Mr. Boyce H. Grier, Director Region I, Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19h06
Subject:
Calvert Cliffs Nuclear Power Plant Units Nos.1 & 2, Dockets Nos. 50-317 & 50-318 IE Bulletin 80-05 j
Reference:
BG&E letter dated 6/h/80 from A. E. Lundvall, Jr.
to B. H. Grier, same subject.
Dear Mr. Grier:
The referenced letter provided our response to the subject bulletin.
In that response, ve identified the Reactor Coolant Drain Tank as being one tank which was calculated to possibly experience a negative pressure below its design collapse pressure if it was pumped without sufficient backfill gas. However, operating experience has shown that even if the tank is pumped at maximum flovrate, tank pressure remains greater than atmospheric. Additionally, sines the Reactor Coolant Drain Tank is located inside of containment, no outside release to atmosphere vould occur. As an extra precaution, we stated in our previous letter that we would increase the setpoint of the nitrogen supply control valve to ensure a greater nitrogen backflow into the tank. However, operationally, it has been determined that nitrogen backflow into the Reactor Coolant Drain Tank significantly increases the volume of vaste gas which our Vaste Gas system must process and is not consistent with the provisions of "as lov as reasonably achievable" (ALARA). Consequently, normal plant operating procedures call for the isolation of nitrogen to that tank during routine operations.
Since the Reactor Coolant Drain Tank pressure does not drop below atmospheric pressure during routine pumping operations and remains well above the minimum design pressure (vacuum), and since the restriction of nitrogen flov into the tank is consistent with the ALARA guidelines, we have determined that operation of the tank in this mode is acceptable.
Additionally, since the tank is located within containment such that a rupture of the tank would not lead directly to radioactive releases to the environment, we have determined that operation of the tank described herein does not present an undue risk to the health and safety of the public.
Very truly -
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..r Mr. B. H. Gricr
.2-Junn 27, 1980 cc:
J. A. Biddison, Esquire G. F. Trowbridge, Esquire Messrs. E. L. Conner, Jr. - NRC J. W. Brothers - Bechtel Division of Reactor Construction Inspection Office of Inspection and Enforcement Washington, D. C.
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