ML062650230

Vermont Yankee Hearing - Staff Exhibit 17, Letter from Cecil O. Thomas to J. S. Charnley Re Acceptance for Referencing of Licensing Topical Report NEDE-24011-P-A Rev. 6 Amendment 11

ML062650230
Person / Time
Site:	Vermont Yankee
Issue date:	11/05/1985
From:	Thomas C Office of Nuclear Reactor Regulation
To:	Charnley J General Electric Co
Byrdsong A T
References
50-271-OLA, Entergy-Staff-17, RAS 12304
Download: ML062650230 (3)

Text

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NUCLEAR REGULATORY COMMISSION OFFICE OF SECRETARY Washington, D. C. 20555 RULEMAKINGS AND November 5, 1985 ADJUDICATIONS STAFF MFN 141-85 Ms.J.S. Charnley, Manager Fuel Licensing General Electric Company 175 Curtner Avenue SanJose, California 95125 DOCKET NUMBER PROD. &UTIL FAC. 50-97/-0 1.4

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SUBJECT:

Acceptance for Referencing of Licensing Topical Report NEDE-2401 1-P-A Rev. 6, Amendment 11, "General Electric Standard Application For Reactor Fuel" (GESTAR II)

We have completed our review of the subject topical report submitted by the General Electric Company (GE) letter dated Fcbruary 27, 1985. We find the report to be acceptable for referencing in license applications to the extent specified and under the limitations delineated in the report and the associated NRC evaluation pertaining to treatment of uncertainties in the calculation of Operating limit MCPR values, which is enclosed. The evaluation defincs the basis for acceptance of the report.

We do not intend to repeat our review of the matters described in the report and found acceptable when the report appears as a reference in license applications, except to assure that the,- aterial presented is applicable to the specific plant involved. Our acceptance applies only to tl-e matters described in the report.

In accordance with procedures established in NUREG-0390, it is requested that GE publish accepted versions of this report, proprietary and non-proprietary, within three months of receipt of this letter. The accepted versions shall incorporate this letter and the enclosed evaluation between the tide page and the abstract. The accepted versions shall include an -A (designating accepted) following the report identification symbol.

Should our criteria or regulations change such that our conclusions as to the acceptability of the report are invalidated, GE and/or the applicants referencing the topical report will be expected to revise and resubmit their respective documentation, or submitjustification for the continued effective applicability of the topical report without revision of their respective documentation.

Sincerely, Cecil 0. Thomas, Chief Standardization and Special Projects Branch Division of Licensing US. NUCLEAR RE6JLATJ

Enclosure:

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GESTAR i NEDE-2401 1-P-A-I 1-US ENCLOSURE EVALUATION OF AMENDMENT 11 TO NEDE-2401 1-P-A By letter dated February 28, 1985 (Reference 1) General Electric Company (GE) submitted Amendment 1I to the GE Licensing Topical Report NEDE-2401 1-P-A, "General Electric Standard Application for Reactor Fuel" (GESTAR II). Additional information was submitted in a meeting on June 21, 1985 and subsequently in Reference 2 in response to a request from the staff (Reference 5). The Core Performance Branch and the Reactor Systems Branch have reviewed the information submitted and prepared the following evaluation.

Amendment II to GESTAR II alters the document to include an updated version of the ODYN code among the calculational techniques used for plant transient analyses and alters the manner in which calculational uncertainties arc treated in obtaining core operating limits. A description and justification of the code revisions were included in References I and 2. The changes to the ODYN calculational model include:

1. Improved Neutronics Methods These methods are described in Reference 4, which has been reviewed and approved by the staff (Reference 5).

2. Inclusion of GESTR-M Fuel Performance Model This model has been approved by the staff as part of the approval ofAmendment 7 to GESTAR-iI (Reference 6).

3. Improved Bulkwater Model Improvements include more detailed nodalization, use of a drift flux rather than a homogeneous formulation in the void correlation and use of a void profile and feedwater quenching. Reference 2 presents comparisons of both the new and current void correlations with experiments and demonstrates the superiority of the new correlation.

4. Improved Upper Plenum Model The improved model uses a drift flux rather than a homogeneous model and an improved calculation of the mass holdup.

5. Improved Separator Mass Storage Model The improved model uses a transient, homogeneous mass balance rather that a quasi steady-state mass balance.

Data were provided in Reference 2 on the results of comparisons of the old and new ODYN calculations to the Peach Bottom turbine trip tests.*These data showed that the new ODYN results provided generally better agreement with the test data than did the old ODYN calculations.

Breakdown of the calculations to separate out the effects of the various improvements showed that most of the improvement occurred from the inclusion of the previously approved methods in the calculations. Based on improved agreement with experiments and the refinement of the calculational models as described above we conclude that the improvement to the ODYN code are acceptable.

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• Ig I DW In addition to implementing the new model, GE intends to continue use of the current model for appropriate non-limiting calculations. We find this acceptable.

Amendment 11 also revised the manner in which code uncertainties are handled in obtaining the Option A and Option B MCPR operating limits. However insufficientjustification has been provided for this change and we conclude that thc currently used treatment of uncertainties must continue to be used. This has been discussed with GE and they concur in this condition to the staff approval of this amendment.

REFERENCES

1. LetterJ.S. Charnley (GE) to C.O. Thomas (NRC), "Amendment 11 to GE LTR NEDE 2401 1-P-A', February 27, 1985.

2. LetterJ.S. Qharnley (GE) to C.O. Thomas, (NRC), "Response to Request No. I for Additional Information on NEDE-24011 Rev. 6, Amendment 11,"July 18,1985.

S. Letter, CO. Thomas, (NRC) toJ.S. Charnley (GE), "Request Number I forAddidonal Information on NEDE-24011 Rev. 6, Amendment 11", May 9, 1.985.

4. NEDE-S01 30-A, "Steady State Nuclear Methods", May, 1985.

5. Letter, C.O. Thomas (NRC) toJ.S. Charnley (GE), "Acceptance for Referencing of JLccnsing Topical Report NEDE-SO 30, 'Stead)-State Nuclear Methods' December 22, 1983". (See also page following thc tide page of the approved report).

6. Approval letter, C.O. Thomas (NRC) toJ.S. Charnley (GE), dated March 1, 1985.

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