ML20247M691

Forwards Staff Review of Rept, Giraffe Sbwr Sys Interactions Test Rept, (NEDC-3254OP,Revision-0).Informs That Review of Sbwr Was Terminated in 1996

ML20247M691
Person / Time
Site:	05200004
Issue date:	05/18/1998
From:	Quay T NRC (Affiliation Not Assigned)
To:	Sawyer C GENERAL ELECTRIC CO.
References
NUDOCS 9805260336
Download: ML20247M691 (3)

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g j UNITED STATES h

• NUCLEAR REOULATORY COMMISSION

• WASHINGTON, D.C. 20066 4001 8

\ ..... f May 18,1998 i l

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Dr. Craig D. Sawyer, Manager Advanced Reactor Programs GE Nuclear Energy 175 Curtner Avenue, M/C 754 San Jose, CA 95125

SUBJECT:

STAFF REVIEW OF GE REPORT " GIRAFFE SBWR SYSTEMS INTERACTIONS TEST REPORT" (NEDC-32540P, REVISION-0)

Dear Dr. Sawyer.

When the design certification review of the Simplified Boiling Water Reactor (SBWR) was terminated in 1996, the Office of Nuclear Reactor Regulation agreed to provide General Electric Nuclear Energy (GE) with a preliminary review of Simplified Boiling Water Reactor (SBWR) testing and analysis program reports. This letter documents the staff's preliminary review of the l GIRAFFE SBWR Systems interactions Test (GIRAFFE / SIT) report. l The Staff agrees in general with the conclusions reported by GE in Section 7 of NEDC-32540P, Revision-0 that: (a) the test results are consistent with and generally indicate expected j performance of the simulated SBWR passive safety systems; (b) there were no notable adverse  !

systems interactions; (c) the test strategy was shown to be appropriate; and (d) that an I acceptable database has been obtained to aid in the validation of the capability of the TRACG computer code to calculate SBWR behavios during the phases of design basis accidents represented in the GIRAFFE / SIT program.

The following additional comments are being provided for consideration by GE in the event that the SBWR design certification review (including the test end analysis program) is restarted at some future time.

The staff recommends that further data analysis be performed to reduce, if possible, the noted errors and uncertainties in some of the data. This includes: (a) correction of the reactor pressure vessel (RPV) level for dynamic effects (discussed on p. 6-2); and (b) conection of DP/ level measurements by using actual fluid temperatures rather than 277K (discussed on P. 6 1).

The emphasis in the report is on demonstrating that there are no adverse systems interactions .

and on test-to-test comparisons of key parameters. The staff agrees that these are important I objectives; however, further consideration of tactual phenomenology during the tests is also valuable, and would be necessary in a more comprehensive review to demonstrate TRACG's ability to represent SPWR phenomena consistent with the SBWR Phenomena identification and Rank!ng Tables. For example, in Fig. 6.2-10, between about 200 and 1000 seconds (the end of the plot), small amplitude oscillations occur in the collapsed liquid level in the chimney during Test GS2. Since the suppression chamber pressure is greater than the drywell pressure during this period (per Fig. 6.2-2), the staff believes that these oscillations may occur as a result of repeated actua*: ions of the we+well-to-drywell vacuum breakers. (This would be consistent with results from the Office of Nuclear Regulatory Commission's confirmatory tests in the PUMA facility.) While this does not appear to cause adverse interactions, it nevertheless demonstrates

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the very close coupling that the staff believes exists between the SBWR containment and RPV dv.,ng accident conditions, and could be an issue in a future review of TRACG modeling capabilities.

A more comprehensive and quantitative error and uncertainty analysis would be expected in a report that was part of an active artification review.'If GE does reopen SBWR certification, the report should be revised to include such an analysis.

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With this letter the staff concludes its review of the GIRAFFE / SIT. If you have any questions regarding this matter, please contact Dino Sca 111 at 301-415-1105.

Sincerely, original signed by:

Theodore R. Quay, Director Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No.52-004 I i

Enclosure:

As stated cc w/enci: See next page 1

i DISTRIBUTION:

Docket File PDST R/F Touay PUBLIC TKenyon WHuffman JSebrosky DScaletti JNWilson ACRS (11) JMoore,0-15 B18 DOCUMENT NAME: A:\ GIRAFFE 1.DCS To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy OFFICE PM:PDST:D_RPJ4 l D:PDST:DRPM l l l NAME DCScalettiff)f4 TRQuay 9

, DATE 05/f7198 V 05/19/98 OFFICIAL RECORD COPY 1

.- ,s Dr. Craig D. Sawyer Docket No.52-004 GE Nuclear Energy cc: Mr. Rob Wallace Mr. Brian McIntire GE Nuclear Energy Westinghouse Electric Corporation 1299 Pennsylvania Avenue, N.W. Energy Systems Business Unit

. Suite 1100 Box 355 Washington, DC 20004 Pittsburgh, PA 15222 Director ".riteria & Standards Division Office of Radiation Programs U.S. Environmental Protection Agency 401 M Street, S.W.

Washington, DC 20460 Mr. Sterling Franks U.S. Department of Energy NE-42 Washington, DC 20585 Mr. Robert H. Buchholz GE Nuclear Energy 175 Curtner Avenue, MC-781 San Jose, CA 95125 Mr. Steven A. Hucik GE Nuclear Energy 175 Curtner Avenue, MC-780 San Jose, CA 95125 Mr. Tom J. Mulford, Manager SBWR Design Certification Electric Power Research Institute 3412 Hillview Avenue Palo Alto, CA 94304-1395 1

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