ML19341C248

Forwards Clinch River Breeder Reactor Project Circulation Verification Program Pretest Predictions for Fftf Natural Circulation Tests Initiated at 100% & 75% Power/Flow Conditions.

ML19341C248
Person / Time
Site:	Clinch River
Issue date:	02/26/1981
From:	Copeland R ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT
To:	Eisenhut D Office of Nuclear Reactor Regulation
Shared Package
ML19341C249	List: ML19341C248 ML19341C252
References
NUDOCS 8103020529
Download: ML19341C248 (2)

Text

*.

9Jp**%,;

r$ $

%f Department of Energy Cinch River Breeder Reacter ..

Plant Project Office , J.

RO. Box U  ;;

Oak Ridge, Tennessee 37830 W Docket No. 50-537 .

February 26, 1981 )'

2 ",

Mr. Darrell G. Eisenhut, Director U t Division of Project Management '"

Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Eisenhut:

PRE-TEST PREDICTION OF FFTF NATURAL CIRCULATION TESTS

References:

(1) Letter PS:80:359, R. L. Copeland to D. G. Eisenhut,

" Pre-Test Prediction of FFTF Natural Circulation,"

dated November 28, 1980.

(2) Letter, S:L:1195, A. R. Buhl to R. S. Boyd, " Natural Circulation Decay Heat Removal Verification Plan,"

dated June 21, 1976.

This letter transmits information concerning the pre-test prediction of the results of the natural circulation tests scheduled for early March 1981 at the Fast Flux Test Facility (FFTF). These pre-test predictions and those previously transmitted in Reference (1) are being supplied to establish a basis for demonstrating that the methodology and the computer l codes, as discussed in Reference (2), are capable to reasonably characterize i

the phenomena controlling natural circulation. These pre-test predictions are provided to clearly document that the data and methodology which will be used in the post-test analyses were selected prior to the test. $OO}

~ 5 These pre-test predictions assume reactor scram and trip of the sodium j circulating pumps from pre-existing conditions of 1) 100% of full power f//

and 100% of full flow, and 2) 75% of full power and 75% of full flow. fi Pre-test predictions utilizing CRBRP methodology and computer codes for 5 &D Gd./s!

tests from 35% power and 75% of flow were transmitted in Reference (1). g gy /,

Following completion of all three natural circulation tests, post-test 2G4 Rs / 40 sit '

analyses will be performed utilizing the actual test boundary conditions. 94, The pre-test predictions are, of necessity, based on boundary conditions (e.g., power history and heat sink temperature) selected by the analysts.

It is unlikely that these boundary conditions will be duplicated during the actual tests. Accordingly, the post-test analyses will be used for comparison with experimental data. A report will be compiled to consol-idate all of the pre-test predictions and post-test analyses and discuss any differences between those analytical results and the test data.

8103020CJi A

o ,o 1

Mr. Darrell G. Eisenhut Fch uary 26, 1981 The pre-test predictions and post-test analyses will be considered successful if they demonstrate 1) that the Project methodology provides a reasonable characterization of the phenomena controlling natural circulation flow and heat transfer in both the reactor and the heat transport loops and 2) that use of the methodology results in a conserva-tive prediction of the critical plant parameters (e.g., core hot channel sodium temperature arid heat transport system flow rates). Included with the predictions are acceptance boundary curves for the pre-test predic-tions. The methodology used to generate these acceptance curves are similar to those used in Reference (1) and will be the same methodology to generate acceptance boundary curves for the post-test analyses. The prediction methodology will be cons'iered acceptable if the measured flows for the tests are equal to or greater than the acceptance boundary Curves.

Included as an attachment to this letter is "CRBRP Natural Circulation Verification Program Pre-Test Predictions for FFTF Natural Circulation Tests Initiated at 100% and 75% Power / Flow Conditions," WAPO'D-0281, dated February 1981. Appendices A, B, and C, of this report, which contain an archival listing of data used by the computer codes, are being provided to the addressee only.

We would be pleased to answer any questions you may have on the attach-ments or to discuss the analyses at your convenience.

Sincerely,

. p s Rhond _ . I d PS:81:080  : tin Assis recto for Public Safety Attachments:

As stated cc: Standard Distribution Service List Licensing Distribution k