ML080940495
| ML080940495 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 03/28/2008 |
| From: | Duncan R Progress Energy Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| GL-04-002, HNP-08-037, TAC MC4688 | |
| Download: ML080940495 (4) | |
Text
Robert J. Duncan, 11 Progress Energy Vice President Harris Nuclear Plant Progress Energy Carolinas, Inc.
MAR 2 8'2008 Serial: HNP-08-037 10 CFR 50.54(f)
U.S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT NO. 1 DOCKET NO. 50-400/LICENSE NO. NPF-63 SECOND SUPPLEMENTAL RESPONSE TO NRC GENERIC LETTER 2004-02, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN BASIS ACCIDENTS AT PRESSURIZED-WATER REACTORS"
References:
- 1. Generic Letter 2004-02,."Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,"
dated September 13, 2004
- 2. Letter from J. Scarola, to the Nuclear Regulatory Commission (Serial: HNP 101), "Response to NRC Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,"' dated September 01, 2005
- 3. Letter from R. J. Duncan, II, to the Nuclear Regulatory Commission (Serial:
HNP-08-015), "Supplemental Response to NRC Generic Letter 2004-02,
'Potential Impact of Debris Blockage on Emergency Recirculation During Design Bases Accidents at Pressurized-Water Reactors,"' dated February 29, 2008
- 4. Letter from T. H. Boyce, Nuclear Regulatory Commission to R. J. Duncan II, "Shearon Harris Nuclear Power Plant, Unit I - Generic Letter 2004-02, 'Potential Impact of Debris Blockage on Emergency Recirculation During Design-Basis Accidents at Pressurized-Water Reactors,' Extension Request Evaluation (TAC NO. MC4688)" dated December 28, 2007 Ladies and Gentlemen:
NRC Generic Letter (GL) 2004-02 (Reference 1), issued September 13, 2004, requests that addressees perform an evaluation of the emergency core cooling system (ECCS) and containment spray system (CSS) recirculation functions in light of the information provided in the GL and, if appropriate, take additional actions to ensure system function. Carolina Power & Light Company (CP&L) doing business as Progress Energy Carolinas, Inc., provided its requested written response to the NRC in accordance with 10 CFR 50.54(f) on September.01, 2005 (Reference 2).
P.O. Box 165 New Hill, NC 27562 T> 919.362.2502 F> 919.362.2095 A
HNP-08-037 Page 2 Harris Nuclear Plant (HNP) has completed its modification to the containment sump as presented in our February 29, 2008, response (Reference 3). Since some internal reviews were not completed at the time of that submittal, HNP received a "Case 1" extension (Reference 4) which allowed a March 31, 2008, date for submittal of the results of these remaining reviews. Therefore, with this current submittal containing these final results, HNPs Supplemental Response to Generic Letter 2004-02 is complete.
This document contains no new regulatory commitment.
Please refer any questions regarding this submittal to Mr. Dave Corlett at (919) 362-3137.
I declare, under penalty of perjury, that the foregoing is true and correct Executed on [
MAR 2 8 2008
]"
Sincerely, R. J. Duncan, II Vice President Harris Nuclear Plant RJD/kms
Attachment:
Supplemental Response Technical Input cc:
Mr. P. B. O'Bryan, NRC Sr. Resident Inspector Mr. V. M. McCree, NRC Acting Regional Administrator, Region II Ms. M. G. Vaaler, NRC Project Manager
Attachment to SERIAL: HNP-08-037 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 SECOND SUPPLEMENTAL RESPONSE TO NRC GENERIC LETTER 2004-02, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN BASIS ACCIDENTS AT PRESSURIZED-WATER REACTORS" Harris Nuclear Plant (HNP) has completed its internal reviews of the Chemical Model spreadsheet developed by Westinghouse in conjunction with WCAP-16530-NP, "Evaluation of Post-Accident Chemical Effects in Containment Sump Fluids to Support GSI-191," revision 0.
The species and quantities of chemical precipitates that HNP reported in section 3.o of our Supplemental Response to Generic Letter 2004-02 (Serial: HNP-08-015) did not change as a result of completing the internal reviews.
HNP has also completed its internal reviews of the Loss-of-Coolant Accident Deposition Analysis Model (LOCADM). The results of the LOCADM modeling have been finalized.
Figure 1 shows the fuel temperature and the scale thickness profiles with respect to time. The peak fuel temperature is approximately 395'F, which occurs at the onset of recirculation. The fuel temperature monotonically decreases to a value of approximately 150'F at the end of thirty days. This temperature profile is well below the acceptance criterion of 800'F mentioned in Appendix A of WCAP-16793-NP, "Evaluation of Long-Term Cooling Considering Particulate, Fibrous, and Chemical Debris in the Recirculating Fluid," revision 0. The maximum scale thickness is determined to be approximately 50 microns.
Figure 1 LOCADM results for HNP 450 400 Maximum LOCA scale thickness (microns)
E 350
-UE-Fuel Cladding Temp at Max Thickness (F)
J300 3250 200 150 S100 0
0 100 200 300 400 500 600 700 800 Time (hrs)
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Attachment to SERIAL: HNP-08-037 SHEARON HARRIS NUCLEAR POWER PLANT DOCKET NO. 50-400/LICENSE NO. NPF-63 SECOND SUPPLEMENTAL RESPONSE TO NRC GENERIC LETTER 2004-02, "POTENTIAL IMPACT OF DEBRIS BLOCKAGE ON EMERGENCY RECIRCULATION DURING DESIGN BASIS ACCIDENTS AT PRESSURIZED-WATER REACTORS" Four inputs to the LOCADM model that had a large impact on cladding temperature are sump pH, spray mass flow, containment temperature, and upper plenum pressure. Higher sump pH, lower spray flow, higher containment temperature, and lower upper plenum pressure result in higher cladding temperature. The inputs for HNP were biased such that these quantities were set conservatively. A LOCA deposit thermal conductivity of 0.2 W/m-K was used, which is consistent with WCAP-16793-NP. A maximum crud thickness of 140 microns and a maximum oxide thickness of 130 microns were used.
No plant-specific refinements were made to the WCAP-16530-NP base model. The values of aluminum release from the WCAP-16530-NP spreadsheet were adjusted in accordance with the guidance contained in Westinghouse letter LTR-SEE-I-08-30, "LOCADM Guidance for Modification to Aluminum Release," to account for higher aluminum corrosion rates at the beginning of the accident. Additionally, LOCADM was run with increased quantities of debris in accordance with the "bump-up factor" methodology in Pressurized Water Reactor Owners Group (PWROG) letter OG-07-534, "Additional Guidance for LOCADM."
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