ML19305A330
| ML19305A330 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/07/1979 |
| From: | Naughton W COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7903130307 | |
| Download: ML19305A330 (14) | |
Text
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Commonwealth Edison One First National Plaza. Chicago, lihnois Address Fleply to Post Office Box 767 Chicago Illinois 60690 March 7, 1979 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
Zion Station Units 1 and 2 Additional Information on Proposed Expansion of Spent Fuel Storage Capacity NRC Docket Nos. 50-295 and 50-304
Dear Mr. Denton:
Recently, the NRC Staff requested Commonwealth Edison Company to provide additional information in support of its request to expand the storage capacity of the Zion Unit 1 and 2 spent fuel pool.
Attachment I to this letter contains Commonwealth Edison's responses to the NRC Staff's requests.
Please address any additional questions that you might have to this office.
One (1) signed original and thirty-nine (39) copies of this letter are provided for your use.
Very truly yours, L :.
William F.
Naugh on Nuclear Licensing Administrator Pressurized Water Reactors attachment 790313030
ZION STATION UNITS 1 AND 2 NRC DOCKET Nos. 50-295 AND 50-304 ATTACHMENT I Additional Information on Proposed Expansion of Spent Fuel Storage Capacity
e 1.
Q.
Describe in detail the I c:rds to be carried over the storage racks.
A.
Fuel handling operations will not be altered by the proposed modification to the fuel storage pool.
No chan;2s are to be made which'would decrease the existing safety factors or introduce any new accident conditions.
Fuel handling tools are suspended from hoists attached to the fuel pool bridge.
The load combinations carried by the hoist are listed in Table 1-1.
Tools are picked up and the throat latched safety hook secured in an area of the pool where there are no storage racks located.
Thus any release of a tool during the tool attachment operation cannot impact the storage racks.
The Spent Fuel Pool Bridge Hoist is rated at one ton capacity, and manufactured in accordance with Hoist Manufacturers Institute specification HMI-100-74.
A design factor of five is employed in the hoist design such that the maxinum static stress will not exceed twenty percent of the material strength of the hoist.
The heavi.est load combination (the assembly / tool) weighs 1782. Ibs., and is well within the capacity of the hoist.
Prior to each refueling outage, the hoist is tested with a 2500 lbs.
load.
In addition, a load cell is utilized in conjunction with the RCC, Burnable Poison and Thimble Plug tools to monitor the forces on the fuel assembly.
The hoist cable is 3/16" diameter 304 stainless steel rated at 10,900 lbs.
The double reeving system on the hook consists of four load bearing strands of the cable, further reducing the possibility of a cable-shear accident.
The reeving system has a design factor of approximately 45:1 when loaded with the RCC tool.
The design factor for the unloaded connection is 12.5:1.
The margin of safety provided by the reeving system and hook latch, is sufficient to preclude,a tool release, as demonstrated by the successful transport and fuel handling experience at Zion Station.
The drop of a fuel assembly onto a rack from a height of two feet has been analyzed and does not af fect the integrity of the rack.
The maximum kinetic energy of dropped fue'. handling tools is tabulated in Table 1-1.
The kinetic energy is maximum for the release of the RCC tool from the maximum possible height.
There is no need, however, to raise any of the tools more than two feet above the storago racks.
Movements of tools over spent fuel will therefore be administrative 1y controlled to keep the tools within two feet of the racks.
This will keep the kinetic energy of any dropped tools within the range analyzed.
The proposed modification will not alter handling operations, or introduce any new conditions in the handling operations not already analyzed in the Zion FSAR.
The fuel assembly drop accident is not altered and is also in accordance with the Zion FSAR.
i
TABLE l-1 SFHT BPT RCC TP Max. Drop of Empty Tool Over Storage Racks (ft) 15.3 14.2 13.2 16.5 Empty Tool Wt. (lbs) 352 800 975 035 Max. Kinatic Energy at Impact ( f t-lbs) 5350 11360 12870 3876 Max. Drop Height Loaded Tool over Racks (ft) 2 2
2 2
Max. Weight Loaded Tool (lbs) 1782 840 1125 275 Max. Kinetic Energy at Impact ( f t-lbs) 2564 1680 2250 550 Unloaded Tool Wire Rope Design Factor 352/43600 800/43600 975/43600 235/43600 Loaded Tool Wire Rope Design Factor 1782/436000 840/43600 1125/43600 275/43600 Design Factor of Tool Connection (loaded) 5:1 5:1 5:1 5:1 Design Factor of Tool Connection (unloaded) 28:1 12.5:1 10.25:1 43:1 SFHT - Spent Fuel Handling Tool BPT
- Burnable Poison Tool RCC
- Thimble Plug
."w
2.
Q.
Provide an evaluation of tensile loads which could be imposed upon the pool liner during postulated seismic events.
A.
Racks in the south and west ends of the spent fuel pool will rest directly on the liner.
During a postulated seismic event, when the racks tend to slide, the liner will be subjected to tenelle stresses.
To determine these stresses the liner was evaluated for combined SSE and dead loads.
Upper bound friction loads were computed from seismic analyses which conservatively assumed maximum friction coefficient between the rack and the liner, i.e., the rack was assumed to be prevented from sliding due to friction.
On the other hand, a low friction coefficient of 0.5 between the liner and the concrete was assumed so that frictional resistance provided by concrete is low.
The maximum principal tensile stress, thus computed for dead loads and SSE loads, was found to be only 6.7 ksi.
- Hence, the liner is adequate to resist the stresses resulting from postulated seismic motion.
2.1
3.
Q.
Provide detailed load and capacity in formation for the years 1982 through 1985.
Provide also your estimate of the source and cost of replacement power in the event that Zion were to be shutdown during any of these years.
A.
The requested information is provided in attached Tables 3-1 through 3.8.
3.1
COMMONWEALTH EDISON COMPANY LOAD AND CAPACITY PRESENT PLAN 1982 1983 1984 1985 Net Summer Capability 21,895 24,093 24,093 24,093 Estimated Peak Load 17,230 18,010 18,820 19,660
% Reserve Margin 27.1%
33.8%
28.0%
22.54 Y
o~
WITHOUT ZION 7
1982 1983 1984 1985 U
w Net Summer Capability 19,815 22,013 22,013 22,013 Estimated Peak Load 17,230 18,010 18,820 19,660 5 Reserve Margin 15.0%
22.2%
17.0%
12.05
SOURCE OF REPLACEMENT ENERGY FOR ZION 1982 1985 Average Average Expected Production Production Class of Plant Contribution Cost Cost Per Day
- Other Nuclear Units 9%
7 mills /kwh
$21,000 High Sulfur Coal Units 8%
10 mills /kwh 27,000 Low Sulfur Coal Units 50%
17 mills /kwh 284,000 Residual Oil Units 29%
25 mills /kwh 242,000 8
Oil Peaking Units 3%
45 mills /kwh 45,000 Purchased Emergency Power 1%
50 mills /kwh 17,000 w
W l
100%
19 mills /kwh
$636,000 Less Zion Production Cost 234,000
$402,000
- at 2,080,000 kw X 24 Hrs. X 67% (expected operating capacity factor) = 33,446,400 kwh's per day
Table 3-3 Zion Replacement-Contribution by Type of Unit (GWH) 1982 1983 1984 1985 Nuclear Units (except Zion) 290 930 980 820 High Sulfur Coal Units 440 840 810 800 Low Sulfur Coal Units 3130 5370 5010 4650
- 6 Oil Units 1430 2860 2850 3360
- 2 Oil Peaking Units 100 260 290 550 Emergency Purchases 30 60 70 140 Total 5420 10320 10010 10320 3.4
Table 3-4 Capacity of Units by Year (MW) 1982 1983 1984 1985 Nuclear
- 11694 11694 11694 11694 High Sulfur Coal Units 1212 1212 1212 1212 Low Sulfur Coal Units 6518 6518 6518 6518
- 6 Oil Units 3141 3141 3141 3141
- 2 Oil Peaking Units 1879 1879 1879 1879 Pumped Hydro **
624 624 312 312 Totalt 25068 25068 24756 24756
- including Zion - Without Zion subtract 2080 MW.
- On 8/7/83 Commonwealth Edisons' share of the Ludington pumped hydro plant is reduced by one half.
System Load Factor (1982-1985)
- 54%
3.5
Table 3-5 Capacity of Nuclear Units 1982 1983 1984 1985 Dresden 1 207 Same Same Same Dresden 2 794 Dresden 3 794 Quad Cities 1*
591 Quad Cities 2*
592 Zion 1**
1040 Zion 2**
1040 LaSalle 1 1078 LaSalle 2 1078 Byron 1 1120 Byron 2 1120 Braidwood 1 1120 Braidwood 2 1120
- Commonwealth Edison share only
- When unit is in service.
3.0
i Table 3-6 Range of mills /kwh*
1982 1983 1984 1985 Nuclear Units 6.8-7.3 6.8-7.4 6.8-7.4 6.8-7.4 High Sulfur Coal Units 9.8 9.9 9.9 9.8 Low Sulfur Coal Units 13.6-17.4 13.6-17.5 13.6-17.5 13.6-17.4
- 6 Oil Units 23.9-26.2 23.9-26.4 24.0-26.4 24.0-26.2
- 2 Peaking Units 47.1-51.0 47.1-51.0 47.1-51.0 47.1-51.0
- Constant 1978 dollars 3.7
9 Table 3-7 Range of Heat Rates (DTU/KWH) 1982 1983 1984 1985 High Sulfur Coal Units 9700 9900 9700 9700 Low Sulfur Coal Units 8500-10900 8500-10900 8500-10900 8500-10900
- 6 Oil Units 9000-10300 9000-10300 9000-10400 9000-10300
- 2 Oil Peaking Units 13100-15000 13100-15000 13100-15000 13100-15000 1.8
Range of Fuel Costs (Q/MMBTU)
Fuel Transp.
Waste Incremental Cost Cost Disposal Mainten9nco*
Total uclear Units 57 9
66
.igh Sulfur Coal Units 96 1
5 102 ow Sulfur Coal Units 78-92 78-83 1-2 3-6 160-175 e
6 Oil Units 218-232 33 2-3 254-267 2 Oil Peaking Units 302-354 7-15 3-5 312-374 m
For fuel handling equipment
.