ML20071J693

Clarifies Significance of Thermal Operating Limits Specified in App 6A of Gessar Ii.App 6A Transmitted on 820225 Contains Technical Basis for BWR LOCA Decay Heat Correlation Based on Ansi/Ans 5.1-1979 Revised Decay Heat Std

ML20071J693
Person / Time
Site:	05000447
Issue date:	04/20/1982
From:	Sherwood G GENERAL ELECTRIC CO.
To:	Eisenhut D Office of Nuclear Reactor Regulation
References
MFN-052-82, MFN-52-82, NUDOCS 8204270342
Download: ML20071J693 (2)

Text

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GENER AL h ELECTRIC NUCLEAR POWER SYSTEMS DIVISION GENERAL ELECTRIC COMPANY,175 CURTNER AVE., SAN JOSE, CALIFORNIA 95125 l MC 682, (408) 925-5040

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April 20, 1982 g' REcggyyy , ,

2 APR28 ggg S i "2 7 gym U.S. Nuclear Regulatory Commission b Office of Nuclear Reactor Regulation Washington, DC 20555

• ui Attention: Mr. D. G. Eisenhut, Director Division of Licensing Gentlemen:

SUBJECT:

GESSAR II OPERATING THERMAL LIMITS

Reference:

Letter to D. G. Eisenhut (NRC) from G. G. Sherwood (GE),

"In the Matter of 238 Nuclear Island General Electric Standard Safety Analysis Report (GESSAR II); Docket No. STN 50-447", dated February 25, 1982 The purpose of this letter is to clarify the significance of the thermal operating limits specified in Appendix 6A of GESSAR II. Appendix 6A, which was submitted to the NRC under the referenced cover letter, contains the technical basis for a BWR loss-of-coolant accident (LOCA) decay heat correlation based on the ANSI /ANS 5.1-1979 revised decay heat standard.

The details of Appendix 6A were discussed last year with both the ACRS Subcommittee on Emergency Core Cooling and the NRC regulation staff previous to the document submittal in December 1981. With their con-currence, GE committed to provide upper bound " speed limits" above which the improved decay heat correlation would not be applied to BWR's for j ECCS analysis. The bounding values of 14.4 kW/ft, 57 kW/1, and 28 1 kW/kgU, were chosen to envelope all current BWR product lines, both I foreign and domestic.

The BWR/6 238 Nuclear Island described in GESSAR II is limited to 13.4 l kW/ft and 54.1 kW/l at rated power. These limits are specified in Table 4.4-1 in Chapter 4 of the document and they must be satisfied for any ECCS analysis cerformed using the improved decay heat correlation for a GESSAR II system. The core average specific power for the GESSAR II system is within the envelope value outlined in Appendix 6A.

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GENERAL @ ELECTRIC U.S. Nuclear Regulatory Commission Page 2 If you have any further questions regarding this subject, please contact either J. N. Fox on (408) 925-5039 or D. K. Dennison on (408) 925-3302 of my staff.

Very truly urs,

. erwoo , anager Nuclear Safety and Licensing Operation GGS:hmc:pab/003291

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