ML20214P801
| ML20214P801 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/28/1986 |
| From: | Adensam E Office of Nuclear Reactor Regulation |
| To: | Farrar D COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8612040380 | |
| Download: ML20214P801 (5) | |
Text
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November 28, 1986 N4:
Docket No. 50-374 NRC PDR Local-PDR BWD-3 r/f EAdensam Mr. Dennis L. Farrar EHylton Director of Nuclear Licensing ABournia Connonwealth Edison Company RBernero P.O. Box 767 Attorney, 0GC Chicago,-Illinois 60690 EJordan JPartlow
Dear Mr. Farrar:
BGrimes ACRS(10)
Subject:
Additional Information on Re-Racking of Spent Fuel Pool - La Salle County Station, Unit 2 By letter dated September 19, 1986, you submitted a request for approval of proposed re-racking of the spent fuel pool at la Salle County Station, Unit 2.
As a result of our review of your submittal, we find that we need additional information in order to continue our review. Enclosed please find the addi-tional information requested.
If you shoald have any questions, please contact Anthony Bournia, Project Manager, at (301) 492-8698.
Sincerely,
/S/
Elinor G. Adensam, Director BWR Project Directorate No. 3 Division of BWR Licensing-
Enclosure:
As stated cc: See next page 8612040380 861128 ~
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Mr. Dennis L. Farrar la Salle County Nuclear Power Station Commonwealth Edison Company Units 1 & 2 cc: -
Philip P. Steptoe, Esquire John W. McCaffrey Suite 4200 Chief, Public Utilities Division One First National Plaza 160 North La Salle Street, Room 900 Chicago, Illinois 60603 Chicago, Illinois 60601 Assistant Attorney General 188 West Randolph Street Suite 2315 Chicago, Illinois 60601 Resident Inspector /LaSalle, NPS U.S. Nuclear Regulatory Commission Rural Route No. 1 P.O. Box 224 Marseilles, Illinois 61341 Chairman La Salle County Board of Supervisors La Salle County Courthouse Ottawa, Illinois 61350 Attorney General 500 South 2nd Street Springfield, Illinois 62701 Chairman Illinois Connerce Commission Leland Building 527 East Capitol Avenue Springfield, Illinois 62706 i
Mr. Gary N. Wright, Manager Nuclear Facility Safety Illinois Department of Nuclear Safety 1035 Outer Park Drive, 5th Floor Springfield, Illinois 62704 Regional Administrator, Region III U. S. Nuclear Regulatory Commission 799 Rossevelt Road Glen Ellyn, Illinois 60137 4
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RE00EST FOR ADDITTONAL INFORMATION REGARDING LASALLE COUNTY STATION UNIT 2 SPENT FUEL POOL RERACK MODIFICATION 1.
Describe, in some detail, the procedure that will be used for (1) removal of the fuel assemblies from the present racks, (21 removal and disposal of the racks, (3) installation of the new high density racks and (AT loading the new racks with the presently stored spent fuel assemblies.
The description should include, step by(step, the number of people involved in each step of the procedure including divers if they are found to be necessary), the estimated dose rates they will be exposed to, the times spent in the radiation fields and the estimated man-rem associated with each step of the operation.
2.
Identify the radiation monitoring systems that will be used, and indicate their locations in the spent fuel pool area. The monitoring systems in question are those which are to provide a warning to the personnel whenever the area radiation levels increase inadvertently to preset alarm trigger levels.
3.
It may be possible that the space between the spent fuel and inside concrete shield wall is reduced due to the proposed modification. If this is the case, provide an estimate of the potential increase in the dose rate in occupied areas outside the spent fuel pool concrete shield wall.
4.
Provide a summary estimate of the pro,iected changes in environmental doses resulting from the spent fuel pool modification. The estimates should include annual, as well as total plant life doses. Also include an estimate of the potential amount of K-85 and H-3 released due to additional fuel being stored in the spent fuel pool.
I l
5.
Indicate the depth of the spent fuel pool water which'normally will cover the stored-in-place fuel elements, and provide the resulting pool surface dose rates for this condition.
6.
Provide the spent fuel pool heat exchanger tube surface area (square feet).
7.
Verify that the reactor building bridge crane, the lifting and handling i
rigs, and all special handling tools are single failure proof.
f 8.
Verify that the method of attaching the lifting device to the new and existing racks are single failure proof.
r;,,..
l 9.
For every item which has not been identified as single failure proof,
, provide the following information.
a)
Detailed drawings of the component and the method and location of attachment (s);
b)
The design and actual stress factors to be applied during re-racking operations; c)
A discussion as to the purpose (s) and use(s) of the component;
-d)
A discussion of the component testing, inspection, and frequency of each; e)
A discussion of the results and effects of the failure of the component at the most adverse time and the protective actions which will be taken to prevent fuel damage or damage to safety-related structures, systems and components; and f)
Provide a discussion of the proposed methods to verify that the failure of this component does not lead to the damage of the pool liner, the fuel storage racks, or other safety-related structures, systems, or components.
- 10. Provide drawings which show:
a)
The arrangement of the spent fuel in the pool when each' existing rack is being removed and each new rack is being installed; b)
The secuence of each rack removal and installation of each new rack; c)
The path which each rack will follow within the pool, within the reactor building, and within any other area until the rack is i
outside of all safety-related structures; d)
The maximum height that each rack will be lifted above any surface below; and e)
The physical relationship of each load path to 1) other safety-related systems and components, and 2) embedded structural beams within each surface over which the rack will pass.
l
- 11. Provide the results of an analysis of dropping the rack into the spent fuel pool, and any other body of water over which the racks may pass, assuming the rack is at its maximum carrying height. The results should address the effects of splashing water out of the pool (both in terms of a potential personnel hazard and in terms of the loss of water and potential loss of NPSH for the spent fuel pool cooling system pumps), and pool impact effects 1) on the pool liner at its weakest point (at the leakage
,m
w.
. detection traces), 2) on other fuel storage racks, and 31 on other safety related structures, systems, and components.
- 12. ' Verify that o fuel would be impacted if the rack were to fall on its side, or m vide a discussion of your procedures which will prevent the rack from ialling on its side given that the rack is dropped by failing one yoke'at a time.
- 13. Verify that all operator training, load handling procedures, and eye testing of operators will be in confonnance with NUREG-0612. " Control of Feavy Loads at Nuclear Power Plants."
- 14. In Section 4 of the spent fuel storage capacity modification safety analysis report, the seismic analysis of the modification is referenced to various portions of the Sargent & Lundy specification T-3758.
Indicate where this specification can be found, or provide a copy.
- 15. Describe the physical configuration of the pertinent components of the fuel rack assemblies which corresponds to the finite element represen-tation shown in Fig. 4.1.6-1.
Please provide c simple isometric figure showing the major structural features of the assemblies.
16 In Section 4.1.7 it is indicated that a central pedestal was added in order to raise the natural frequency of vibration in the vertical direction. Indicate how this is accomplished.
It is realized that the addition of the central pedestal increases the stiffness of the steel plate on which the fuel assemblies rest. However, since the rack is basically supported on the four adjustable pedestals, most.likely the natural frequency of the fuel assemblies and that of the rack will be different. In view of this observation, describe the safety significance if the rack's natural frequency is not raised as currently designed.
- 17. From the analytical model shown in Fig. 4.1.6-1 it appears that torsional vibration has not been considered for either the fuel assembly or the l
rack. Discuss your rationale.
- 18. Please discuss the possibility of resonant vibration, since the fuel assemblies and racks in the pool are identical in design and construction, and have about the same natural frequencies.
19.
In Section 5.3.1, it is claimed that structural integrity of the pool has been taken into consideration. However, the report does not provide the basis for this claim. Specifically, there is no discussion in the report of the potential effects that the proposed modification may have on the pool. Provide the pertinent information in this respect.
- 20. In Section 5, References 9 to 12 are mentioned, but they are not listed in subsection 5.4.
Provide the missing references.
- 21. In Table 5.3.4.2-3, a multiplier of 1.33 is applied to the stress limit factors shown in Table NF-3523.2-1 for service levels B and D.
Provide the bases for such increases since the service levels B and D therein are already 331/3% and 100% higher than service level A.
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