ML20080A157

Confirms 830627 Telcon Re Results of Heat Balance Calculations of Containment Atmosphere Temp Calculations. Post-accident Containment Sampling Procedure Will Be Modified to Include 10 Minute Sampling Period

ML20080A157
Person / Time
Site:	Point Beach
Issue date:	07/12/1983
From:	Fay C WISCONSIN ELECTRIC POWER CO.
To:	Clark R, Harold Denton Office of Nuclear Reactor Regulation
References
TAC-57058, TAC-57059, NUDOCS 8307250157
Download: ML20080A157 (2)

Text

lHsconsin Electnc rowca couesur 231 W. MICHIGAN, P.O. BOX 2046, MILWAUMEE, WI 53201 July 12, 1983 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. NUCLEAR REGULATORY COMMISSION Washington, D. C. 20555 Attention: Mr. R. A. Clark, Chief Operating Reactors Branch 3 Gentlemen:

DOCKETS 50-266 AND 50-301 CONTAINMENT ATMOSPHERE SAMPLING POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Early in June 1983 Mr. F. Witt of your staff called Wisconsin Electric Power Company, licensee for the Point Beach Nuclear Plant, with several questions concerning the sampling systems and procedures for the containment atmosphere post accident sampling. These questions primarily concerned sampling recirculation and assurances that the gas sample taken would be representative of the actual containment atmos-phere. Mr. Witt was particularly concerned with the potential for moisture condensation in the sample lines and requested Wisconsin Electric to calculate a heat balance on the sample line to confirm that condensation would not take place during the actual drawing of the sample.

Dr. E. J. Lipke and Mr. C. W. Krause of my staff returned Mr. Witt's call on June 27, 1983 with the results of our heat balance calculations. These calculations were done for several assumed containment atmosphere temperatures. A sample line length of approxi-mately 40 feet of one-inch schedule 40 stainless steel pipe from the l containment to the sample cubicle was assumed. This pipe is insulated I

with a nominal one inch of insulation and heat traced for freeze protection with a setpoint of 40 F. The ambient temperature around the j sample pipe was assumed to be O'F. Our calculations for containment l saturated steam atmosphere temperatures of 300'F and 212*F showed i that a five-minute recirculation of the containment atmosphere at l 10 cubic feet / minute was more than sufficient to warm the sampling pipe to essential containment temperature and account for heat losses to ambient thus ensuring no significant condensation during the actual sampling. A third calculation at containment conditions of 190'F l

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(o Mr. H. R. Denton July 12, 1983 indicated that a five-minute. recirculation would not be sufficient to fully warm.the sample lines; however, a ten-minute recirculation would be acceptable. Accordingly, we are modifying the post accident containment sampling procedure to include a ten-minute sampling recirculation period.

Very truly yours, ff, Vice President-Nuclear Power C. W. Fay Copy to NRC Resident Inspector

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