ML20212H393

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Forwards Rev 1 to Westinghouse Rept, Beaver Valley Unit 2 Failure of Feedwater Control Channel Used for Protection. Time Span for Operator Action Remains Sufficient & Results for Overfill Events Acceptable,Per Westinghouse Analyses
ML20212H393
Person / Time
Site: Beaver Valley
Issue date: 01/15/1987
From: Carey J
DUQUESNE LIGHT CO.
To: Harold Denton, Tam P
Office of Nuclear Reactor Regulation
Shared Package
ML20212H397 List:
References
2NRC-7-008, 2NRC-7-8, TAC-62936, NUDOCS 8701210385
Download: ML20212H393 (2)


Text

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Mr. Harold R. Denton Office of Nuclear Reactor Regulation United States Nuclear Regulatory Conmission Washington, DC 20555 ATTENTION: Mr. Peter Tan, Project Manager Division of PWR Licensing - A Office of Nuclear Reactor Regulation

SUBJECT:

Beaver Valley Power Station - Unit No. 2 i

Docket No. 50-412 i Steam Generator Level Control

REFERENCE:

1) 2NRC-4-076, dated June 8, 1984
2) NUREG/CR-4326, dated August,1985, " Effects of Control Systen l Failures on Transients and Accidents at a 3-Loop Westinghouse Pressurized Water Reactor
3) 2NRC-6-021, dated March 10, 1986 Gentlemen:

Duquesne Light Conpany (DLC) transmitted a response to an ICSB position regarding Stean Generator level control per Reference 1 in 1984. The DLC response included analyses conpleted by Westinghouse which showed that the l

i protection and control systens design for Beaver Valley Unit 2 provides ade-l quate protection against excessive feedwater flow transients frun a stean gene-

rator overfill viewpoint.

Upon reviewing these analyses, Westinghouse discovered that the original results for the limiting event were in error. Westinghouse recently provided DLC with revised analyses, which are attached. These analyses show that the time to stoan generator overfill assuning absolutely no operator action for one specific double-f ailure scenario described in the report, is greater than 6.5 minutes rather than 10 minutes as shown in the original analyses. The conclu-l sion however renains the sane that this one event is not a cunplex transient, is very easily diagnosed, and is of ten a standard malfunction used in reactor operator training courses. Thus the time span for operator action renains l

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r e' I l '. United States Nuclear Regulatory Connission Mr. Harold R. Denton r

l Steam Generator Level Control l

Page 2 l

t sufficient and the results for all overfill events are acceptable considering

the perfonnance of the plant and the other protective functions. These results are consistent with the overall conclusions provided in Reference 2 and as previously noted by DLC in Reference 3.

j DUQUESNE LIGHT COMPANY ,

i l By l J.'d. Chrey ,

Sr. Vice President l

RWF/ljr NR/ STEAM / GEN Attachnent .

l AR/NAR l

l c cc: Mr. P. Tan, Project Manager (w/a)

Mr. J. Beall, NRC Sr. Resident inspector (w/a)

INPO Records Center (w/a) .

NRC Document Control Desk (w/a) i i

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