ML19344A925
| ML19344A925 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 07/31/1978 |
| From: | Naughton W COMMONWEALTH EDISON CO. |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19344A926 | List: |
| References | |
| REF-GTECI-A-36, REF-GTECI-SF, TASK-A-36, TASK-OR NUDOCS 8008220593 | |
| Download: ML19344A925 (7) | |
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Commonwealth Edison One Fast Natenai Plaza Chicago llhnois Address Re::ly to Post Office Box 767 Chicago libriots 60690 July 31, 1978 Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Response to NRC Request for Additional Information on Control of Heavy Loads near Spent Fuel at Zion Station Units 1 & 2 NRC Docket Nos. 50-295 and 50-304 References (a) :
May 17, 1978 letter from Victor Stello, Jr.
to All Licensees for Power Reactors requesting additional information on control of heavy loads near spent fuel.
(b) :
July 13, 1978 letter from W.
F. Naughton to Director of Nuclear Reactor Regulation entitled " Response to NRC request for Additional Information on Control of Heavy Loads near Spent Fuel at Zion Station Units 1 and 2" Dear Sir-Per Reference (a), the NRC Staff requested all power reactor licensees to provide the Staff with additional informa-tion on control of heavy loads near spent fuel.
Reference (b) contained Commonwealth Edison Company's response to the requested information for Zion Station Units 1 and 2.
However, a complete discussion of the degree to which Zion Station complies with the eight (8) regulatory positions delineated in Regulatory Guide 1.13 (Revision 1, December 1975) was not included in the Company's response to Item 9 of Reference (a).
This discussion is included in the attachment to this letter.
One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.
Very truly yours,
{
W. F. Naug on Nuclear Licensing Administrator Pressurized Water Reactors 1
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Comemnwe:Mh Edison NRC Dockot Noa. 50-295 50-304 A_TTACEMENT Response to Item 9 of NRC Recuested Information on Control of Heavy Loads Near Spent Fuel 9.
The design of Zion's spent fuel storage facility complies with the eight (8) regulatory positions delineated in Regulatory Guide 1.13 (Revision 1, December 1975) as discussed below in the order presented in that guide.
Regulatory Position 1 As described in Section 9.7 of the Zion FSAR, the reactor cavity, the refueling canal and spent fuel storage pit are reinforced structures with seam-welded steinless steel plate liners.
These are Seismic Class I structures as identified in the response to FSAR Question 4.23.
Regulatory Position 2 The spent fuel building is a Seismic class I structure.
An analysis of the effects of tornados and tornado generated missiles is documented in the response to FSAR Questions 5.11 and 5.12.
Regulatory Position 3 Heavy load movement over the spent fuel pool is restricted by mechanical and electrical interlocks on the Zion fuel building crane operation as described in the response to FSAR Question 14.10.
Further information has been provided in the letters referenced in the response to Item 4 Regulatory Position 4 As described in Section 9.7 of the Zion FSAR, all fuel storage facilities are contained and equipment designed so that accidental releases of radioactivity directly to the atmosphere are monitored and will not exceed the guidelines of 10 CFR 100.
The ventilation and filtration ecuipment is described in Section 9.10 of the FSAR.
The ventilation system is designed to maintain the building pressure slightly below atmospheric pressure so that leakage is always inward.
Section 14.2.1 of the FSAR contains the results of an analysis of the releases resulting from the rupture of all rods in one fuel bundle in the spent fuel pit.
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Commonwealth Edison NRC Dockst Noa. 50-295 50-304 Regulatory Position 5 control of heavy load movement near the spent fuel pool is accomplished by use of electrical and mechanical interlocks on the fuel building crane and administrative controls described in responses to Items 5, 6 and 8.
Regulatory Position 6 There are no drains, permanently connected mechanical or hydraulic systems, or other features of the spent fuel pool that could cause the fuel to become uncovered.
The cooling system is equipped to prevent syphoning of the coolant.
Further design information is provided in Section 9.5 of the FSAR.
Regulatory Position 7 Fuel pool level is continuously monitored by a level switch which alarms in the main control room.
Filtration and domineralization is controlled manually.
Regulatory Position 8 Makeup for the spent fuel pool cooling system is normally supplied from the Seismic Class I Refueling Water Storage Tanks.
Backup is available from the Seismic Class I Service Water System via temporary connections,
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Accress Repsy to Post Othee Box 767 Chicago. lihnois 60690 July 13, 1978 U
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Director of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555 T'
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Subject:
ResponsetoNRCRequestforAdhitional
.)
Information on Control of Heavy Loads" near Spent Fuel at Zion Station Units 1 and 2 NRC Docket Nos. 50-295 and 50-304 Reference (a):
May 17, 1978 letter from Victor Stello, Jr.
to All Licensees for Power Reactors requesting additiont.1 information on control of heavy loads near spent fuel
Dear Sir:
Per Reference (a), the NRC Staff has requested all power reactor licensees to provide the Staff with additional information on control of heavy loads near spent fuel.
Attached are commonwealth Edison Company's responses to the requested information for Zion Station Units 1 and 2.
As the response to Item 9 indicates, Zion Station meets the intent of Regulatory Guide 1.13 including the eight regulatory positions.
However, a discussion of the degree to which Zion Station complies with the eight (8) regulatory positions delineated in Regulatory Guide 1.13 (Revision 1, December, 1975) is not available at this time.
A more complete response to this item will be forthcoming in about two weeks.
One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.
Very truly yours, W. F. Naught Nuclear Licensing Administrator Pressurized Water Reactors attachment O'g 78201017o I
Commonwealth Edison NRC Docket Nos. 50-295 50-304 No equipment required for the safe shutdown of the plant is 5.
in the spent fuel building.
Movement of heavy loads either in the containment or the fuel building is presently pro-hibited.
Any required movement of heavy loads will be reviewed on a case by case basis.
6.
No heavy loads are required to be moved over the fuel pool, with the exception of the spent fuel cask.
Heavy load and cask drop accidents have been analyzed per the references listed in Response 4 above.
There are no required moves of heavy loads over the fuel transfer canal.
7.
Design features which affect the potential for a heavy load handling accident involving spent fuel are described in FSAR Amendment 32, dated May 1, 1974, and are also discussed in the submittals referenced in Response 4 above.
8.
Administrative control precludes the movement of heavy loads over the spent fuel pool and reactor core during refueling; therefore, no procedures exist for moving heavy loads.
Any required movements of heavy loads will be evaluated on a case by case basis and a special procedure for the move will then be written and be subject to the onsite review process.
9.
The design of the Zion spent fuel storage facility has been reviewed inhouse and meets the intent of Regulatory Guide 1.13 including the eight (8) regulatory positions.
A discussion of the degree to which Zion Station complies with the eight (8) regulatory positions delineated in Regulatory Guide 1.13 (Revision 1, December,1975) is currently being formulated and will be forwarded as soon as possible.
I 1
NRC Dockat Nos. 50-295 l
50-304 TABLE 1 WEIGHTS AND SPACE REQUIREMENTS FOR RAIL CASK SYSTEM COMPONENTS Approx.
Cowenent Weight _
Approx. Space outer closure head 2460 lbs.
64 1/2" Diam.
Inner closure head 8120 lbs.
58 3/4" Diam.
Cask Body (water in neutron shield) w/o closures or internals 150280 lbs.
88 '
- Diam x 17 ' high PWR Basket 15 750 lbs.
140 lbs.
PWR Spacer PWR Fuel variable Impact Structure 'Ibp 12600 lbs.
108" Max Diam. x 4' Long Impact Structure Bottom 11350 lbs.
108" Max Diam. x 4 ' Long Lif ting Yoke A 2600 lbs.
50 1/2" x 9 3" x 120" High Lifting Yoke B 2170 lbs.
50 1/2" x 93" x 79" High 90000 lbs.
Car Tie downs 9000 lbs.
Neutron Shield Expansion Tanks 2300 lbs.
Cooling System 12900 lbs.
P3rsonnel Barrier, Movable section 1600 lbs.
10' x 16' x 4" High Personnel Barrier, Fixed Section 2000 lbs.
- Future versions to be 94" dian.
Commonwealth Edison NRC Docket Nos. 50-295 50-304 ATTACHMENT RESPONSE TO NRC REQUESTED INFORMATION ON CONTROL OF HEAVY LOADS NEAR SPENT FUEL 1.
Diagrams of the physical relation of fuel pool, transfer canal, receiving and storage areas for cask movements in the fuel building are attached to the March 3, 1978 letter from Mr. D. E. O'Brien to Mr. Albert Schwencer, Chief Operating Reactors - Branch 1.
NRC Docket Nos. 50-295 and 50-304.
2.
After removal of the head, there are no objects that are required to be moved over the reactor core during refueling operations.
In the Fuel Building, no objects are required to be moved over the spent fuel pool.
However, the missile blocks at the containment entrances, when removed each refueling, are carried along a corridor approximately 15 ft, wide to the north of the fuel pool, but not over the pool.
These concrete blocks weigh approxinately 17 tons each and are carried at a height of about 3 ft. above the floor.
This limits the possibility of the blocks falling into the pool in the event of crane failure.
3.
To date, no spent fuel casks have ever been used.
The cask used in the safety analysis is the NLI 10/24 rail cask.
The dimensions and weights are listed in Table 1.
4.
Heavy load and cask drop analyses have been sulunitted by the following letters:
G. J. Plial to Mr. Robert A. Purple, Chief Operating Reactors - Branch 1, dated April 8, 1976 R. L. Bolger to Mr. Albert Schwencer, Chief Operating Reactors - Branch 1, dated September 14, 1976 D. E. O'Brien to Mr. Albert Schwencer, dated August 9, 1977.
D. E. O'Brien to Mr. Albert Schwencer, dated March 3, i
1978.
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