ML15223A500
| ML15223A500 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/27/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Parker W DUKE POWER CO. |
| References | |
| NUDOCS 7904190248 | |
| Download: ML15223A500 (6) | |
Text
DISTRIBUTION:
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NRC PDR (3)
MARCH 2 7 1979 L PDR ORB#4 Rdg Dockets Nos.
50-269vK NRR Rdg 50-270 VStello and" 50-287 BGrimes TJCarter DEisenhut WRussell RReid Mr. William 0. Parker, Jr.
MFairtile Vice President -
Steam Production RIngram Duke Power Company RVollmer P. 0. Box 2178 Attorney, OELD 422 South Church Street OI&E (5)
Charlotte, North Carolina 28242 TERA a.JRBuchanan
Dear Mr. Parker:
ACRS (16)
-Gray File In order to complete our review of your submittal of February 2, 1979, in regard to the increase in storage capacity of the Oconee Units Nos. 1 and 2 Spent Fuel Storage Pool, we find that we need additional information. These requests relate to both structural information and the environmental aspects of our review.
Kindly provide the information requested in the enclosure to enable us to complete our review. Submit three signed originals and 37 additional copies in a time frame that will not delay your proposed work schedule.
Sincerely, Robert W. Reid, Chief Operating Reactors Branch #4 Division of Operating Reactors
Enclosure:
Second Request for Additional Information j
cc w/enclosure:
See next page 7904190 a2q ORB#4:DOR OR sunNAus MFairtile: rf,
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OCONEE NUCLEAR STATION UNITS NOS. 1/2 SPENT FUEL POOL MODIFICATION SECOND REQUEST FOR ADDITIONAL INFORMATION Structural Information
- 3. Verify that all provisions of the NRC guidance on spent fuel pool modifications, entitled "Review and Acceptance of Spent Fuel Storage and Handltng Applications" (including errata), regarding the use of ASME Code, Subsection NF are met. Justify any deviations.
- 4.
(page 2-2) Provide a more detailed sketch of typical module than
- p. 8. 2.2-2.
Include details of "chevron grid structure",supporting "U" channels,connections between various elements. Provide dimensions, thicknesses, size of gaps and in general all the information needed to evaluate strength of elements.
Make clear how the modules are supported
- 5. (page 2-2 & 2-3) It is stated that non-linear time history method of seismic analysis has been used for two horizontal directions. and the response spectrum method for the vertical direction-, also that these methods represent the response of the pool structure to the specified ground motion. Clarify this statement. Explain, step by step, the method used.to introduce as input the response of the -pool. Justify.
the compatibility of two different methods (time history and response spectrum) used for the same structure.
- 6. You state (page 2-3) that first an analysis was performed assuming an empty rack module, that from this a dynamically equivalent model of the module was determined, and used in the final analysis of the rack con taining fuel assemblies, and including the effects of water jnside and.outside of the module. Explain with precision the transition from one model to the other.
- 7. You indicate that the SAP and the CESHOCK computer codes have been used.
Explain what steps have been taken to insure that the inputs were checked.
also the results. Did you comply with the requirements of Standard Review Plan 3.8.1 Section 1I. 4.e?
- 8. (page 2-4)
You do not provide details of the base of the module.
Provide a sketch and explain in detail the path along which the forces are transmitted to the bottom of the pool.
- 9. Discuss the effect of increased vertical and horizontal loads on the liner and on the concrete structure (walls and bottom) of the pool.
Duke Power Company cC:
Mr. William L. Porter Duke Power Comoany Post Office Box 2178 422 South Church Street Charlotte, North Carolina 28242 J. Michael McGarry, III, Esquire DeBevoise & Liberman 700 Shoreham Building 806 '15th Street,.N.W.
Washington, D. C. 20005 U. S. Nuclear Regulatory Commission Region II Office of Inspection and Enforcement ATTN:
Mr. Francis Jape P. O. Box 85 Seneca, South Carolina 29678 Mr. Robert B.. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 420, 7735 Old Georgetown Road Bethesda, Maryland 20014 Manager, LIS NUS Corporation 2536 Countryside Boulevard Clearwater, Florida 33515 Oconee Public Library 201 South Spring Street Walhalla, South Carolina 29691
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- 10.
Most of the published studies on hydrodynamic effects discuss uni directional motion only. The present problem involves two-directional even tri-directional motion.
Since the principle of superposition is not applicable to non-linear systems, your analysis is only approximation.
Therefore justify your approach to this problem, and establish that it offers reliable results.
- 11.
Describe the planned inservice inspection and surveillance of the new racks and liner supporting them. On page 3-1 you indicate that the pool liner is constructed from 1/4" stainless steel clad plates. Discuss the potential for corrosion of the liner, after miscellaneous dynamic and thermal loads occurring during operation of the plant (including earthquakes) initiate some defects in the cladding.
- 12. Provide Figure 4.2-1 referred to on page 4-1.
- 13.
(page 4-1)
You state that "... Underwater divers will be used to cut the pipe supports of the existing racks approximately 1" above the embedded floor plate to which they are welded. Connecting angles will
'then be cut...
Provtde sketches explaining this operation.
- 14. On same page (4-1) you state that you will avoid transporting new rack modules above stored fuel.
Indicate the procedure which will enforce this requirement.
- 15.
On same page (4-1) you also refer to "acceptable" tolerances on module verticality, levelness and positioning.
List these tolerances and describe the means of enforcement.
- 16.
On page 4-2 you refer to "bearing pads".
Provide a sketch of typical pad and its connections to the module and to the liner if any.
- 17.
On page 4-3 you refer to "bent plates" supporting the old racks and and weldid to the liner.
Sketch these bent plates, indicate their relationship to the "pipes" mentioned in our question (13) above and describe the method of removal of these bent plates if required.
- 18. On page 4-3 you refer to a "temporary construction crane."
Describe protection against drop of a heavy load such as proposed in Question
- 31.
- 19. There will be a time interval during which old and new racks will be in place simultaneously. Indicate that a sufficient physical separ ation will be provided to avoid interaction.
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- 20. Figure 2.3-2, describe the properties of the spring element between the bottom lumped mass and the fixed base used in the vertical direction analysis.
- 21.
Page 4-2, verify that during installation of the new storage modules, a drop of a module will not damage the spent fuel pool liner. Provide the maximum module drop height and worst case module drop orientation.
Environmental Information
- 22.
You stated in your February 2, 1979, submittal that the dose rates above the spent fuel pool are expected to be 5 to 10 mrem/hour at times other than refueling. Justify why this radiation field will be as low as reasonable achievable (ALARA) during the proposed pool modification. Your response should consider increased purification system operation, increased filter and demineralizer change out frequency or relocating tools and components stored in the pool.
- 23. In accordance with Table 5.2-1 of the aforementioned submittal, the occupational exposure expected for the spent fuel pool modification is estimated to be 125.5 man-rem. Provide the data showing the derivation of this estimation. The data should include the expected dose rate to workers during each phase of the operation, the number of people involved and their occupancy times. Include the exposure that will be received from removal, decontamination and disposal of miscellaneous equipment presently stored in the pool.
- 24.
Based on the concentrations of the radionuclides given in Table 5.2-2, the dose rates from the SFP water indicated in Section 5.2.2.3 appear to be too high. Notably missing from this table are 134Cs, 137Cs, and 60Co concentrations which normally provide the major fraction of dose rate from the SFP water. Provide the data for these radionuclides for this table. Also, provide the concentrations of 134Cs, 137Cs, 58Co and 60Co following a refueling when the SFP water clean-up system is in equilibrium with the SFP water. Compare the calculated dose rates based on the total concentration in the pool with the 5 to 20 mrem/hr at the perimeter and pool center given in Section 5.2.2.3.
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- 25.
Justify that the exposure received by the method that will be used to dispose of the present racks (i.e., cutting and packaging),
as compared to.crating the intact racks for disposal, will pro vide as low as is reasonably achievable (ALARA) exposure to personnel.
Provide your considerations of costs,disposal volume and estimated exposure received for your proposed method and the alternative disposal methods. The estimated exposure should include the estimated dose rates, the number of people involved and their occupancy times. Explain in your discussion why the "fast cutting" torch to cut up the racks will only be used to minimize exposure above some minimum dose levels.
- 26. Discuss in some detail the impact of the proposed SFP modification on radioactive liquid effluents from the plant, including leakage of water from.the pool.
Discuss the spent fuel pool leak collection system, including the disposition of leakage if it should occur, and the magnitude of leakage from the pool in the past.
- 27. Provide the average failed fuel fraction for the station since operation began.
- 28. Provide the volume of a solid waste shipment from the replace able pool filter and the frequency of its replacement under normal pool operation.
- 29. Discuss the capability of the SFP cooling system to keep the expected, not design, SFP bulk water temperature at or below the FSAR design of 125 0F during normal refuelings until the modified pool is filled. If the bulk water temperature is expected to be above the FSAR design value, discuss when this will occur and for what period of time. Includein this discussion, the effect of these higher temperatures on releases of tritium and radioiodine from the pool.
- 30. Discuss the instrumentation to indicate the SFP water temper ature. Include the capability of the instrumentation to alarm and the location of the alarms.
- 31.
Propose a technical specification which prohibits carrying loads greater than the weight of a fuel assembly over spent fuel in the storage pool.