RBG-21-423, Forwards River Bend Station Preliminary Equipment Survivability Rept, as Further Evidence to Support Interim Operation at Full Power Until Final Analysis Re Equipment Response to Hydrogen Burn Event Completed
| ML20128H452 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 07/01/1985 |
| From: | Booker J GULF STATES UTILITIES CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20128H455 | List: |
| References | |
| RBG-21-423, NUDOCS 8507100004 | |
| Download: ML20128H452 (2) | |
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x o-GULF STATES UTILITIES COMPANY July 1, 1985 RBG-21,423 File No. G9.5 Mr. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Ccrrmission Washington D.C. 20555
Dear Mr. Denton:
River Bend Station Unit 1 Docket No. 50-458 Gulf States Utilities Ccrapany (GSU) has performed an analysis to determine the River Bend Station equipnent response to deflagration type hydrogen burns resulting frm a degraded core accident. khile not explicitly required as part of a preliminary analysis under 10CFR50.44,
" Standards for Combustible Gas Control Systs in Light-Water-Cooled Power Reactors," this report is provided as further evidence to support interim operation at full power until GSU's final analysis is cmpleted.
Enclosed is a copy of GSU's report entitled, " River Bend Station Preliminary Equignent Survivability Report."
'Ihis analysis was based on tmperature profiles obtained frm the GSU report on containment pressure and tmperature response to hydrogen cmbustion (CLASIX-3 Analysis) previously submitted to the NRC on June 7, 1985. Also included in this report is a revised listing of equignent required to survive a hydrogen burn event along with "as-built" locations of this equipnent. This listing should replace previously supplied equipnent. lists and locations.
The approach used in this analysis was to show that either 1) the equipnent surface (casing) taperature was within the equipmnt qualification tmperature or 2) that the most thermally sensitive cmponent reached a tmperature below the equignent qualification tmperature.
All equipmnt analyzed was shown to meet this acceptance criteria with the exception of the transfonmr of the hydrogen igniter located in the wetwell volume. The predicted tmperature for the most thermally limiting cmponent of the hydrogen igniter (the internal transformer) was above the predicted equignent qualification tmperature. However, for the following reasons it is felt that the hf 0
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s analysis is overly conservative.
First, the hydrogen release rates used in our CIASIX-3 analysis are well above the threshold for diffusion flames for a considerable period of time. This produces higher than expected equipnent teroperatures. Second, the hydrogen burn parameters overly conservative ccmpared to results from previous hydrogen burn are tests.
If as a result of final analysis and ccanpletion of the Hydrogen Control Owners Group program it is shown that equipnent protection should be provided, GSU will provide this information at the first refueling outage or other schedule agreed to with your staff.
Very truly yours,
~
~
J. E. Booker Manager -
Engineering, Licensing &
Nuclear Fuels River Bend Nuclear Group JMG/FJZ/MAM/rg Attachment L