ML20134E690
| ML20134E690 | |
| Person / Time | |
|---|---|
| Issue date: | 05/31/1986 |
| From: | Rossi C Office of Nuclear Reactor Regulation |
| To: | Blaisdell J NORTHEAST UTILITIES SERVICE CO. |
| Shared Package | |
| ML20134B474 | List: |
| References | |
| PROJECT-697 NUDOCS 9702060428 | |
| Download: ML20134E690 (3) | |
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- pa ntauq'og UNITED STATES
!N .
fg NUCLEAR REGULATORY COMMISSION
/ E WASHINGTON, D. C. 20555 1
5% .h, I i % . . . , *# MAY 31,5 Mr. J. A. B,laisdell, chairman UGPA Executive Committee Northeast litilities Service Co.
P. O. Rox 270 Hartford, CT 06141-0?70
Dear Mr. Rlaisdell:
SilRJECT: ACCEPTANCE FOR REFERENCING Or LICENSING TOPICAL REFORT, EPRI
. NP-2511-CCM, "VTPRE-01: A THERMAL-HYORAULIC #FALYSIS CONE FOR
- REACTOR CORES", VOLUFES 1, 2, 3 At
- D 4 4
We have completed our review of the subiert tonical report submi+ted by the Utility Group for Regulatory Applications (llGPA) by letter dated December
! 1:, 1984 We find the report to be acceptable for referencir.n in licence applications to the extent specified and under the limitations delineated in the report and the associated NDC evaluation, which is enclosed. The
- evaluation defines the basis for acceptance of the report, a
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' We do not intend to repeat our review of the matters described in the report and inurd acceptable when the report appears as a reference in license applications, except to assure that the material presented is applicable to the specific olant involved. Our acceptance applies only to the matters described in the report.
In accordance with procedures established ir NilREG-0300, it is rennested that ilGRA publish . accepted versions of this report, proprietary and non-proprietarv, within three months of receipt of this letter. The accepted versions shall incorporate this letter and the enclosed evaluation between the title pace and the abstract. The accepted version shall include an -A (designating accepted) folle, wing the report identification symbol.
Should our criteria or regulations change such that our conclusions as to the acceptability of the report are invalidated, Itr,PA and/or the applicante referencina the topical report will he expected to revise and resubmit their respective documentation, or submit iustification for the contirued effective applicability of the topicel report without revi!. inn of their respectin documentation.
S i nc.er ri v ,
a sh ? - '~7-M Charles F . Rossi, Assistant Director for PWR Licensinq-A Division of PWR Licensinq-A
Enclosure:
as stated 9702060428 970204 PDR PROJ 697 PDR Enclosure 1
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- l 1985). UCCEL then creates copies of the tapes, and distributes them to licensed users."
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We find this quality assurance procedure to be acceptable.
- 3. 0 Summary and Conclusion i
l The staff has reviewed the VIPRE-01 topical report submitted by UGRA. The j review was limited to'PWR applications with heat transfer regimes up to i
critical heat flux. The review consisted primarily of an evaluation of the internal program including the governing conservation equations and
- constitutive equations, the two phase flow and heat transfer models, and the
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numerical solutions techniques. We have also reviewed the VIPRE-01 2
verification and qualification calculations, sensitivity studies on the user's '
input options and code defaults. In addition, an audit calculation was performed with a locked rotor transient using COBRA-IV to compare with the i VIPRE-01_ calculation using the RECIRC solution. Based on this review effort we conclude that the VIPRE-01 computer code.is acceptable for PWR licensing calculations subject to the following conditions: I 1
(1) The application of VIPRE-01 is limited to PWR licensing calculations with heat transfer regime up to CHF. Any use of VIPRE-01 in 9WR calculations )
or post CHF calculations will require prior NRC review and approval. I (2) Use of a steady state CHF correlation with VIPRE-01 is acceptable for reactor transient analysis provided that the CHF correlation and its DNBR limit have been reviewed and approved by NRC and that the application is within the range of applicability of the correlation including fuel assembly geometry, spacer grid design, pressure, coolant mass velocity, ;
quality, etc. Use of any CHF correlation which has not been approved will require the submittal of a separate topical report for staff review and approval. The use of a CHF correlation which has been previously approved for application in connection with another thermal hydraulic code other j than VIPRE-01 uill require an analysis showing that, given the correlation i
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data base, VIPRE-01 gives the same or a conservative safety limit, or a new higher DNBR limit must be used, based on the analysis results. l (3) Each organization using VIPRE-01 for licensing calculations should submit separate documentation describing how they intend to use VIPRE-01 and providing justification for their specific modeling assumptions, choice of particular two phase flow models and correlations, heat transfer correlations, CHF correlation and DNBR limit, input values of plant specific data such as turbulent mixing coefficient, slip ratio, grid loss-coefficient, etc., including defaults.
(4) If a profile fit subcooled boiling model (such as Levy and EPRI models)
- which was developed based on steady state data is used in boiling transients, care should be taken in the time step size used for transient analysis to avoid the Courant number less than 1.
(5) The VIPRE-01 user should abide by the quality assurance procedures i
- described in Section 2.6 of this report.
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