ML20214M548
| ML20214M548 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 09/02/1986 |
| From: | Bailey J GEORGIA POWER CO., SOUTHERN COMPANY SERVICES, INC. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19292F855 | List: |
| References | |
| GN-1066, NUDOCS 8609110167 | |
| Download: ML20214M548 (2) | |
Text
_ _ _ _ _
Georgia Power Company Post Offic] Box 282 Waynesboro, Georgi) 30830 Telephone 404 554-9961 4G4 724-8114 Southern C wnpany Services, Inc.
Post Office Box 2625 Birmingham, Mabama 35202 b
Telephone 205 870-6011 VOgtie Project September 2, 1986 Director cf Nuclear Reactor Regulation File:
X6BK15 Attention:
Mr. B. J. Youngblood Log:
GN-1066 PWR Project Directorate #4 Division of PWR Licensing A U. S. Nuclear Regulatog Commission Washington, D.C.
2055)
NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMBERS CPPR-108 AND CPPR-109 V0GTLE ELECTRIC GENERATING PIANT - UNITS 1 AND 2 SER CONFIRMATORY ITEM 9: STEAM LINE BREAK OUTSIDE CONTAINMENT (PROPRIETARY)
Dear Mr. Denton:
This letter and attachments reconfirm the environmental qualification of ASCO solenoid valves for a main steam line break (MSLB) outside containment.
The attachments document information that we discussed with your staff in meetings on August 27-28.
It is our understanding that the information provided resolved the staff's questions as they pertained to ASCO valves.
On June 25, 1986, Georgia Power Company submitted an analysis of steam line breaks outside containment in response to SER confirmatory item 9.
By letter dated August 12, 1986, your staff requested further information concerning a thermal lag analysis performed by Westinghouse to environmentally qualify certain equipment (including certain ASCO solenoid valve) in main steam isolation valve (MSIV) areas against an MSLB.
As indicated in our letter dated August 21, 1986, one model of ASCO solenoid valve in MSIV areas -- the model NP8321 -- has been qualified by thermal lag analysis. The analysis was applied to four process valves (each of which contains two NP8321 valves) in the Control Building. As discussed in the June 25, 1986 submittal, the thermal lag analysis was based on Bechtel's FLUD code, which determined Vogtle-specific MSLB steam conditions in the locations of the valves. This code, which is proprietary, is provided as.1 The thermal lag analysis demonstrated that the NP8321 valves, which are qualified to a temperature of 346*F, would reach a maximum 1 This proprietary code is submitted under the provisions of 10 CFR $2.790(b). The affidavit required by that section is submitted as Attachment 2.
O 8609110167 860902
'[lj PDR ADOCK 05000424 E
Director of Nuclear Reactor Regulation File: X6BK15 September 2,1986-Log:
GN-1066 Page 2 temperature of 326*F. Other ASCO solenoid valves in MSIV areas are either not subject to ambient temperatures in excess of their qualification temperatures or are not required to function in the event of an MSLB.
In your staff's August 12 request for information, the staff raised six-questions regarding the thermal lag analysis as it applied to equipment (not just ASCO valves) subject to a MSLB environment outside containment.
Questions 1-5 are inapplicable to Westinghouse's thermal lag analysis as applied to the ASCO valves. Questions 1-5 relate to assumptions used to determine a condensing heat transfer rate (for the transitory phase before saturation temperature is reached and convective heat transfer occurs), and to the time the equipment remains in a drying-out stage at saturation temperature. Westinghouse's thermal lag analysis, however, conservatively assumes that the ASCO valves in question start at saturation temperature and are already dry. The analysis applies the forced convection heat transfer coefficient throughout the entire superheat transient. If Westinghouse had chosen to model the condensing heat transfer phase and the drying-out phase, the calculated maximum valve temperature would have been about one degree lower.
Question 6 asked whether Westinghouse's thermal lag analysis conformed to NUREG-0588, Appendix B.
As indicated above, Westinghouse conservatively chose to assume that the ASCO valves would instantaneously rise to saturation temperature and instantaneously dry out. Westinghouse then used the NUREG-0588 Appendix B equation to calculate the forced convection heat transfer coefficient and added an additional temperature increment (1*F) to account for the component surface temperature variation. For these reasons and as discussed more fully in Attachment 3, the Westinghouse analysis conservatively meets the requirements of NUREG-0588.
If your staff requires any additional information on the thermal lag analysis as applied to ASCO valves, please do not hesitate to contact me.
Information pertaining to other types of equipment in MSIV areas will be submitted shortly.
Sincerely,
- 4. A '
J. A. Bailey Project Licensing Manager JAB /sm xet R. E. Conway NRC Regional Administrator R. A. Thomas NRC Resident Inspector J. E. Joiner, Esquire D. C. Teper B. W. Churchill, Esquire W. C. Ramsey M. A. Miller (2)
L. T. Gucwa B. Jones, Esquire Vogtle Project File G. Bockhold, Jr.
0700V