ML19093B013
| ML19093B013 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 08/10/1977 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Reid R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19093B013 (3) | |
Text
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Vepco VIRGINIA ELECTRIC AND POWER COMPANY, RICHMOND, VIRGINIA 23261 Mr. Edson G. Case, Acting Director Office of Nuclear Reactor Regulation Attn:
Mr. Robert W. Reid, Chief Operating Reactors Branch No. 4 Divisirin of Operating Reactors U.S. Nuclear Regulatory Commission Washington~ D. C.
- 20555
Dear Mr. Case:
August 10, 1977
~
~ Serial No. 314/071977 PO&M/HSM:bep/mc Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37
'RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION
.. HIGH. DENSITY. SPENT FlJEL. STORAGE. RACKS
. SURRY.POWER STATION UNITS l AND 2 The attached information concerning the High Density Spent Fuel Storage Racks for Surry Uni ts l and 2 is being provi de*d in response to your letter of July 19, 1977.
Attachments cc:
Mr. James P. O'Reilly Office of Inspection & Enforcement Region II Very truly yours,
~-fYl, v11-~-~
c.. M. Stallings Vice Presid~nt - Power Supply and Production Operations
Question l:
Question 2:
- e.
In your May 20, 1977 proposal in regard to increasing the capacity for spent fuel storage you state that you per-formed the criticality calculations assuming a uranium-235 enrichment of 3.5 percent.
Please convert this number to the number of grams of uranium-235 per axial centimeter of fuel assembly that was used in the criticality calculations.
We will require this number of grams of uranium~235 per axial centimeter of assembly to be specified a~-a Technical Specification limit on fuel assemblies that are to be placed in these high density storage racks.
Response
A uranium-235 enrichment of 3.5 percent corresponds to 44 grams of uranium-235 per axial centimeter of fuel assem-bly.
This is the vc.lue which should be used as the Technical Specification nominal limit.*
Provide the*:change in the "kx, in this high density storage lattic~ with a small change in the thickness of the stain-less steel.and state the type and composition of the stain-less steel in the racks.
Response
The fuel rack wall thickness will be between 0.090 and
.0.095 inches.
All calculations were performed, however, with a wall thickness of 0.085 inches to ensure a conserva-tive keff value.
Perturbation ~heory analysis of an increase in wall thickness from 0~085,inche~ to 0.090 inches gives a decrease in keff of 0.003.~'It should be noted that due to the assumptions used in these criticality calculations, speci-fically the rack configuration is infinite in all directions, keff is equivalent to k.:,, for these calculations.
Type 304 stainless steel (ASTM A240) will be used in the construction of-these fuei racks.
The nominal composition of this steel used in the criticality calculation is listed below:
Element Iron Nickel Chro'mium Manganese Cobalt Percent 68.18 9.49 21.45 0.20 0.15
- Question 3:
Question 4:
e Provide the change in the ko:, in this high density storage lattice with a small ~h~nge in the urinium-235 enrich~ent.
Response
An increase in the Uranium-235 enrichment of 0.2 w/o*
results in an increase in the keff of 0:012.
Provide the flow rate of the component cooling water through the shell side of the spent fuel pool heat exchanger.
Response
The maximum flow.rate of. the component cooling water throu~h th~ shell side of the spent fuel exchanger is 1322 gpm.
ThE actual flow rate is controlled based on cooling water temperature and the fuel pool water tempe~ature.* Using these methods.the spent fuel pool temperature has been maintained at -95°F.
,./