ML19275E727

Suppl to Safety Evaluation Supporting Licensee 800125 Response.Peak Containment Pressure Will Remain Below Design Pressure Even W/Addition of Auxiliary Feedwater at run-out Flow

ML19275E727
Person / Time
Site:	05000000, Millstone
Issue date:	05/09/1980
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML093450149	List: ML13319A698 ML14190A386 ML14190A407 ML14190A410 ML15260A018 ML16245A451 ML16245A464 ML16245A519 ML16340B230 ML17208A670 ML17208A671 ML17319A601 ML17340A460 ML18044A564 ML18044A670 ML18044A671 ML18082A762 ML18082A870 ML18082B237 ML18085A271 ML18139A593 ML18139A594 ML19207B142 ML19208A323 ML19254G983 ML19254H090 ML19254H091 ML19262E717 ML19264A126 ML19264B199 ML19271A912 ML19273C792 ML19273D125 ML19275E724 ML19275E727 ML19276J691 ML19281C520 ML19290G036 ML19290G038 ML19294C656 ML19294C857 ML19295B828 ML19295B969 ML19295D087 ML19295D182 ML19295E448 ML19295E739 ML19296E856 ML19296F114 ML19297A101 ... further results
References
FOIA-80-515, FOIA-80-555 TAC-42410, NUDOCS 8005300393
Download: ML19275E727 (1)

Text

-

MILLSTONE NUCLEAR POWER PLANT, UNIT 2 SER Supplement Docket No. 50-336 CONTAINMENT OVERPRESSURIZATION POTENTIAL DUE TO AUXILIARY FEEDWATER PUMP RUN-0UT FLOW FOLLOWING A MAIN STEAM LINE BREAK By letter dated December 21, 1979, the staff requested Northeast Utilities, the licensee for the Millstone Nuclear Plant, Unit 2 to provide certain additional information.

Specifically, the licensee was to assess the potential for contain-ment overpressurization due to the anticipated continuous additon, at pump run-out flow, of auxiliary feedwater to the.affected steam generator following a postulated main steam line break (MSLB) accident.

The staff's interest in this issue resulted from the recommendation of the Three Mile Island, Unit 2 (TMI-2) Lessons Learned Task Force to automat'esinitiation of the auxiliary feedwater systems. Automating the auxiliary feedwater system would cause an increase in energy released to containment after a MSLB; thereby, increasina the containm/ent pressure response to a MS' B.

~

By letter dated January 25, 1980, Northeast Utilities responded to the staff's letter cited above.

In the orf pinal MSLB analysis by Northeast Utilities, no consideration was given to auxiliary feedwater pump run-out. The licensee has since performed an analy-sis that demonstrates that the addition of auxiliary feedwater at the run-out flow condition (2000 gpm) will not cause containment pressure to rise above the initial blowdov4 peak. The auxiliary feedwater pump run-out flow was conserva-tively based on a backpressure of one atmosphere.

The staff concurs with the licensee's conclusion that the peak containment pres-sure will remain below the containment design pressure with the addition of auxiliary feedwater at the run-out flow rate.

8005300 7

.