ML042290626
| ML042290626 | |
| Person / Time | |
|---|---|
| Issue date: | 08/25/2004 |
| From: | Sheron B W NRC/NRR/ADPT |
| To: | Pietrangelo A R Nuclear Energy Institute |
| Solorio, D L, NRR, 415-0149 | |
| References | |
| Download: ML042290626 (3) | |
Text
August 25, 2004 Anthony R. Pietrangelo Senior Director, Risk Regulation Nuclear Generation
Nuclear Energy Institute
1776 I Street, N.W., Suite 400
Washington, D.C. 20006-3708
SUBJECT:
INDUSTRY PROGRESS ON EFFECT OF CHEMICAL REACTIONS ON PWR SUMP PERFORMANCE
Dear Mr. Pietrangelo:
By letter dated May 28, 2004, the Nuclear Energy Institute (NEI) submitted the outstanding sections and appendices to NEI report on sump performance evaluation methodology. The
methodology is intended to help the industry and the Nuclear Regulatory Commission (NRC)
resolve generic safety issue (GSI) 191, Pressurized-Water Reactor (PWR) Sump
Performance. As noted in the executive summary and Section 7.4 of the methodology, NEI
does not provide any guidance on the assessment of chemical effects on PWR sump
performance. In the NEI sump performance evaluation methodology, NEI states that:
"Guidance to address the effects of corrosion products on head loss is deferred until the [planned] testing is completed and the data have been appropriately
evaluated.
At several public meetings on the results from NRC-sponsored research and the development of NEI sump performance evaluation methodology, NRC management has identified the need
for the industry to address the uncertainties associated with the effect of chemical reactions on
PWR sump performance in a proactive manner. Since the ongoing test program to address
these uncertainties may not be completed prior to the time that PWR licensees are expected to
evaluate the performance of containment sumps and, if necessary, design solutions, NRC
management has stated that it may be prudent to introduce a reasonable amount of margin in
the NEI sump performance evaluation methodology to account for these uncertainties and to
avoid the potential to have to make additional design changes to the sumps once the ongoing
test program is complete. In correspondence to the staff, dated, July 12, 2004, (ADAMS Accession Number ML042290564),NEI stated support for this position and mentioned that NEI is currently looking into a process to facilitate the introduction of margin to address uncertainties associated with the effect of chemical reactions on PWR sump performance. We would appreciate it if you would keep the staff informed of your ongoing activities to introduce an appropriate amount of margin into the NEI sump
performance evaluation methodology.
A. Pietrangelo I appreciate your continued attention to this important matter. If you have any questions concerning this letter, please contact Mr. David Solorio at 301-415-0149.
Sincerely,
//RA// Brian W. Sheron Associate Director for Project Licensing
and Technical Analysis
Office of Nuclear Reactor Regulation
ML042290626OFFICESPLB:DSSASPLB:DSSASPLB:DSSANRR:DENRR:DSSA NRR/ADPT NAMEMGilesDSolorio JHannonLLundSBlackBSheron DATE08/20/0408/20/0408/20/0408/20/0408/20/0408/25/04