ML19093B078
| ML19093B078 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/06/1977 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Reid R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19093B078 (3) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY December* 6, Mr. Edson G. Case, Acting Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. Robert W. Reid Operating Reactors Branch 4
Dear Sir:
.__....,...,..~erial No. 540 PO&M/HSM:bep/mc Docket Nos. 50-280 50-281 License No. DPR-32 DPR-37 The purpose of this letter is to submit supplemental information on the High Density Spent Fuel Storage Racks described in our letters of May 27, 1977, August 10, 1977, September 15, 1977, and September 29, 1977.
In our response to question number 8 in our letter of September 29, 1977. we state that the damping values used were four (4) percent for the Operating Basis Earthquake (DBE) and six (6) percent for the Safe Shutdown Earthquake (SSE).
These damping values are two (2) percent greater than the regulatory guide 1.61 valu*es, which are for welded steel structures in air, as the spent fuel racks will be completely submerged in water.
If the regulatory guide damping values are assumed the results of the seismic structural analyses show that the maximum stresses and deflections in the rack are nominal and within the allowable values.
However, the loads which are transmitted to the fuel pool floor embedment pads are slightly greater
(-5 percent) than the a 11 owab 1 e va 1 ues for these pads.
These a 11 owab le values v1ere calculated using the Standard Review Plan~ section 3.8.4 and the American Concrete Institute Standard 318-71 (ACI-318-71).
This method in-herently has about 15 percent of margin due to the use of a capacity reduc-tion factor of O. 85.
Therefore, whi 1 e the 1 oads wi 11 be greater than the allowable values, the loads will not be of sufficient magnitude to cause deformatfon or failure of the fuel pool floor embedment pads.
The applicable codes used in the design of the spent fuel storage racks are discussed in section 6.3.l.l of the spent fuel storage rack submittal forwarded in our letter of May 27, 1977.
The codes used in the design, fabrication, inspection, and installation are listed in attachment 1.
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. VIRGINIA ELECTRIC AND POWER COMPANY TO Mr. Edson G. Case Page 2 If you have any questions or comments on this material or the material submitted in the above mentioned letters, we would be pleased to meet with your staff at their convenience to discuss them.
Attachment Very truly yours,
- zp, >>?. v~ttc~p/
C. M. Stallings Vice President - Power Supply and Production Operations cc:
Mr. James P. 0 1Reilly, Director Office of Inspection and Enforcement Region II
~ ',),....... __...
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ATTACHMENT 1 APPLICABLE CODES USED IN THE DESIGN FABRICATION INSPECTION, AND INSTALLATION OF THE HIGH DENSITY SPENT FUEL STORAGE RACKS FOR SURRY POWER STATION
- 1.
A.I.S.C. Manual of Steel Construction, Seventh Edition, 1970
- 2.
ASME Boiler and Pressure Vessel Code,Section V
- 3.
ASME Boiler and Pressure Vessel Code,Section VIII
- 4.
ASME Boiler and Pressure Vessel Code,Section IX