ML18068A675
| ML18068A675 | |
| Person / Time | |
|---|---|
| Site: | Framatome ANP Richland |
| Issue date: | 05/07/1997 |
| From: | Lyons J NRC (Affiliation Not Assigned) |
| To: | Curet H SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER |
| References | |
| NUDOCS 9705140221 | |
| Download: ML18068A675 (2) | |
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J May 7, 1997 Mr. H. D. Curet, Manager Product Licensing Siemens Power Corporation 2101 Horn Rapids Road P. 0. Box 130 Richland, WA 99352~0130
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION
((RAI) REGARDING REFLOOD HEAT TRANSFER
Dear Mr. Curet:
The inspection team identified two open issues concerning reflood heat transfer during the NRC's inspection at Siemens Power Corporation (SPC) from March 17-21, 1997. Those issues are:
(1) assessment of the scaling methodology used to apply the FCTF 17xl7 PWR reflood heat transfer correlation to non-17xl7 geometries (Inspection Issue 13) and (2) validity of the FCTF reflood heat transfer coefficients derived from the original 17xl7 testing (Inspection Issue 17). Both of these open issues were discussed with you as part of.the ~nspection.
Regarding the first issue, in the NRC staff's Safety Evaluation Report (SER) on Exxon Nuclear's (ENC, now SPC) LBLOCA Evaluation Model, a commitment was confirmed to perform reflood heat transfer testing in 15xl5 bundle geometry to validate ENC's proposed scaling methodolo~y. In correspondence in October 1992 and August 1993, SPC requested and the NRC agreed to a new approach, in which existing data from other tests tould be used instead of data from FCTF 15xl5 tests. While the staff did not request that Siemens *
- submit the scaling evaluation for review in its August 1993 letter, the
- expectation was.that the assessment-would be performed and wou1d *be available for the staff to audit at its discretion. It appears from the results of the inspection that the assessment was not *actually performed until very recently, and the team's initial review of the information provided during the week of March 17, 1997, indicated that the documentation did not meet the staff's expectations.
With respect to the second issue, the team reviewed internal Advanced Nuclear Fuels (ANF, now SPC) correspondence from the period April-June 1987, indicating that concerns had been raised about the correct programming of data analysis algorithms in the XRAD/LEPER code used to derive heat transfer coefficients from the FCTF 17xl7 reflood heat transfer tests. Those heat transfer coefficients were used to develop the original PWR 17x17 reflood heat transfer correlation. A subsequent internal 111emorandum, from March 1989, indicates that some evaluation of the original FCTF data was, in fact, performed using a "controlled" version of the XRAD/LEPER algorithms, and that agreement between the original and "new" analysis was very good.
However, the team has found no evidence that a systematic re-analysis of the 17x17 data was ever performed.
ACN9705140221 ENCLOSURE
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Mr. Curet 2
In order to help resolve these two issues, the staff requests the following:
- 1.
That SPC comp 1 ete the assessment of the app 1 icabil i ty of the re flood
- heat transfer scaling methodology to geometries other than 17xl7, as discussed during the inspection, and submit the results for staff review as part of the overall assessment of the reflood heat transfer correlation; and
- 2.
That SPC provide the staff, as ~oon.as possible, a schedule for a complete reanalysis of temperature data from the original 17xl7 tests used to develop the FCTF reflood heat transfer correlation. The reanalysis should be performed with a computer code that has been verified, validated, and controlled according to the requirements of SPC's quality assurance program.
Upon completion of the reanalysis, the results are to be submitted to the NRC for staff review.
For both (1) and (2), SPC should provide suffici~nt ~vidence to demonstrate that the PWR reflood heat transfer coefficient correlation, as currently implemented in the TOODEE2 code, produces results that are conservative when compared to test data.
Two RAis on these topics are being provided to SPC under separate cover with additional details about what the staff will need to proceed with the.review of the revised FCTF correlation and the scaling methodology.
The staff a 1 so reminds SPC that it may have respon.> i bil it i es with regard to one or both of these issues, pursuant to the requirements of Part 21 of Title 10 of the Code of Federal Regulations (10 CFR 21).
A copy of this letter is being provided to all licensees that-could be affected by either of these issues.
___. ________ -------Sincerely~ -~----- -* - -... -~-=-: __ **-*------*-**-- ---***-***--*----*---*--
Original Signed By:
James E. Lyons, Acting Chief Reactor Systems Branch Division of Systems Safety and Analysis
~ffice of Nuclear Reactor Regulation PISTRIBUTION:
File Center Alevin R/F SRXB R/F PDR AThadani 12G-18 JStaudenmeier Rlandry GThomas EWang OllE-4 JDonohew 013H-3 TPolich 013H-3 LWiens 0148-21 DMcDonald 014C-7 P.l.aufer 013E-21 BMozafari 014H-22 Nle 014H-22
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iiP )81 JHannon 0130-18 MReinhart OllE-22 DOCUMENT NAME:
G:\\SIEMENS.OPN
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- see previous concurrence page
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l OFFICE:
ASC:SRXB:DSSA*
ABC:SRXB:DSSA* *:._.-.ir:COS
- NRR OISP:PSIB*
NAME:
Alevin Jlyons J~GHolahan SMatthews DATE:
4/08/97 4/08/97 4/1',/97 4/09/97 OFFICIAL RECORD COPY /"'