ML20197D674
| ML20197D674 | |
| Person / Time | |
|---|---|
| Site: | 07002623 |
| Issue date: | 11/03/1978 |
| From: | Spitalny B NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Rouse L NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| NUDOCS 7811280374 | |
| Download: ML20197D674 (9) | |
Text
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/# 4r UNITED STATES g'% . WUCLEAR REGULATORY COMMISslON
< I 0 WASHINGTON, D. C. 20555
% h) !
%f***** / November 3, 1978 Docket 70-2623 b MEMORANDUM FOR: L. C. Rouse, Acting Chief Fuel Reprocessing and Recycle Branch FROM: Brett S. Spitalny Fuel Reprocessing and Recycle Branch
SUBJECT:
SUMMARY
OF MEETING HELD WITH DUKE POWER COMPANY (DPC) TO DISCUSS THE AGE (DECAY) 0F SPENT FUEL TO BE SHIPPED FROM OCONEE TO McGUIRE Date/ Place: 6/2/78 - Willste Building Silver Spring, Md.
Attendees: Duke Power Co. NRC G. Pollak R. Starostecki G. Copp B. Spitalny M. Glover P. Loysen V. Leung R. Birkel
Purpose:
To discuss the issue of decay time required prior to the shipment of spent fuel. DPC has proposed to ship 120-day old fuel
'. tith respect to this licensing action.
Background:
By letter dated March 9, 1978, DPC filed an application for the amendment of Materials License SNM-1773. This amendment, if approved, would allow the storage of Oconee Nuclear Station spent fuel at the McGuire Nuclear Station. The application requested the transfer of fuel that had decayed for a period of 120 days. NMSS is proposing regulations that would require fuel to age for the period of one year for the licensing of an Independent Spent Fuel Storage Installation (ISFSI). DPC has stated that it is economically advantageous and additionally minimizes exposure if allowed to ship the lower aged fuel. Duke was requested to justify this statement and discuss the topic at NRC.
7811280 37'(
L. C. Rouse
- Discussion:
Duke presented a paper for discussion of the spent fuel decay time which analyzed the cost and exposure of shipping 120 day vs. one year old fuel. The study examined the spent fuel situation at Oconee through the year 1982. The paper presented by Duke is attached as an enclosure to this summary. This paper states their position and constitutes the majority of the discussion at the meeting.
One other area of concern raised by Duke Power was briefly discussed at this meeting. This was the need for evaluating the consequences of pre-noticing this licensing action in light of the fact that intervention is anticipated.
Conclusion:
It was determined that Duke would prefer to see the youngest decayed fuel shipped that would be acceptable, and that as requirements for age increase, so do the disadvantages of greater cost and exposure.
i , _
Duke's argument of the greater exposure is due to having to shuffle the younger fuel within the Oconee pools a number of times to obtain access to older fuel. The reason for the staff selecting the one-year requirement is to ease the requirements to cope with the thernal and radioactive considerations on ISFSI applicants.
The staff agreed that it would allow Duke to ship 9-month old fuel if ,
calculations showed that it was safe with respect to cooling require-ments, and that danger of clad rupture or melt down was not a severe problem as wi th freshly discharged fuel .
Sandia Laboratory and Oak Ridge flational Laboratory would be contacted to evaluate this problem.
The staff also agreed to pursue the topic of noticing this action with OELD, and determine the best course of action.
Sett S QEka <
Brett S. Spitalny Fuel Reprocessing and 1 Recycle Branch Division of Fuel Cycle and flaterial Safety
/
SPENT FUEL COOLING REQUIREMENTS PRIOR TO TRANSPORTATION PRESENTED BY DUKE POWER CO. TO NRC 6/2/78 Various Case Studies Assumptions:
- 1) The discharges and transfers required are based on refueling schedules from System Planning and transfer schedules from Nuclear' Fuel Services.
- 2) In our planning for transfers, when possible, we ship the last dis-charged fuel first. Because of this the fuel that is transferred, is handled one time and then stored until the AFR or government repository is available. This eliminates costly double-handling.
- 3) In calculating costs and exposure we have used the following unit values:
a) workers required for intrastation transfers -5; interstation transfers 10 b) hours to transfer 1 assembly intrastation -8; interstation -32 c) average man-rem for intrastation transfer -0.10; interstation
-0.30 d) transfer costs per hour:
Year Intrastation Interstation 1979 $53/hr. $106/hr.
1980 57 114 1981 61 122 1982 65 130 cac c
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. . e) Approximate shipping charges per assembly:
s Year Interstation 1979 963 1980 1030 1981 1103 1982 1180 Reasoning Behind Duke Policy:
- 1) Duke has chosen the 2/3, 1/3 split of its station FCR capacity at its Oconee 01, 02 and Oconee 3 Pools for 3 reasons:
a) The probability of the need for a full core discharge into the Oconee 1, 2 pool is greater than that for unit 3 as there are two reactors feeding into it.
b) When inservice inspections are required in 1982 and 1983 for oconee 1 and 2, respectively, the 2/3 FCR capacity in the Oconee 1, 2 pool will require fewer transfers to allow the inspections to take place. ,
c) The use of an 18 month cycle on Oconee 1 and 2 beginning in 1979-1980 will require the discharge of 34 more assemblies (between the two units) than those spaces reserved by the nominal 2/3 FCR capacity. This cycle plan will be less costly to the public than the annual cycle and the additional transfers will be spread out over a longer period of time.
d) The PIE program requires more space at times than now in use.
I
Case By Case Analysis: (See slide #1)
' Case 1. 2/3 FCR in Oconee 1, 2 1/3 FCR in Oconee 3 120 day cooling The important aspects of this case are:
- 1) The average age of all fuel transferred during 1979-1982 is 1.07 years.
- 2) The range of ages is from a low of 180 days to a high of 92 assemblies at greater than 1.5 years.
- 3) 300 assemblies of the 775 total are in the range 180 days to slightly less than one year cooled.
- 4) With even a 180 day cooling requirement we could make the required transfers and still enjoy the benefits of our 2/3, 1/3 split at Oconee.
Case 2. 2/3 FCR in Oconee 1, 2 1/3 FCR in Oconee 3 1 year cooling The important differences between this case and case #1 are:
- 1) The average age is now 1.43 years
- 2) 107 extra assemblies must be transferred to meet the require-ments of 1 year cooling
- 3) To meet the one year requirement, 176 assemblies have been delayed in their planned transfer periods to meet 1 year cooling. These delays coupled with any problems in our transfer rate of one per day would cause the loss of a FCR capacity at Oconce for extended periods of time, espec-ially during 1981-1982.
Case 3. O FCR in Oconee 1, 2 1 FCR in Oconee 3 1 year cooling The important results here are:
- 1) slightly more assemblies are transfened than in our pre-ferred case 1.
- 2) The average age of all transferred assemblies is 1.78 years.
- 3) 160 assemblies are delayed in their transfer periods to meet the one year cooling requirement. -
Problems we have with this case:
- 1) As expressed earlier in our reasoning behind 2/3, 1/3. (2 units discharge there, inservice inspections require more 1
transfers, the 18 month cycle discharge requirements, and the PIE program at times requiring more space).
- 2) Even though there would be fewer transfers in 1979; in 1981, l 1982, and beyond when the number of transfers becomes much larger, the number of required transfers with this split would be larger than case 1.
e Exposure, Time, and Cost Considerations (See slide #2): ,
Conclusions:
- 1) In terms of transfer costs for labor and freight, case 1 saves Duke and its customers approximately $ 150,000 over the four years.
- 2) According to our assumptions on exposure, case 1 involves a dose 10 man-rem less than case 3.
- 3) Time restrictions are the largest problem, especially in 1981, 1982 and thereafter. Even in case 1 we will be requiring some transters in and out of pools during their refueling outages. During cases 2 and 3, where some transfer period delays are occurring to allow for one year cooling, we will face even tougher problems. In our Oconee 1,2 pool we would
be forced to either wait out the one year period to begin transfers to another station or begin double handling fuel to Oconee 3 as in 1979 and hope to be able to regain our FCR capacity there when time permits.
- 4) We believe these time restrictions to be the overriding con-cern not only for Duke but for other utilities. If the transportation of spent fuel becomes the problem that many are predicting it will be, then many utilities with a small pool will lose FCR capability and/or be forced into extensive doubic-handling to meet the one year restriction.
- 5) A more realistic 180 day cooling period when the I-131 levels have subsided to 4.2 million times less than that at dis-charge could well serve the utilities and the public in l
effectively handling spent fuel.
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SUMMARY
OF CASE STUDIES -
Case 1. A 2/3 Full Core Discharge Capability in Oconee 1,2 Spent Fuel Fool '
and a 1/3 Full Core Discharge Capability in Oconee 3. All Fuel Trans-ferred is Cooled 120 Days or Longer.
Case 2. The Same As Case 1 But With a 1 Year Cooling Requirement.
Case 3. The Entire Full Core Discharge Capability Maintained in Oconee 3 and a One Year Cooling Requirement.
\i. ~
No. of Assemblies No. of Assemblies Handled Other Transferred Than the First Time j Year Case 1 Case 2 Case 3 Case 1 Case 2 Case 3 1
1979 207 314 151 0 107 0 1980 40 40 100 0 5 0 1981 256 256 260 20 87 87 1982 272 272 297 0 0 0 l
Total 775 882 808 20 199 87 V
Average Age of Transferred Assemblies (Years)
Year Case 1 Case 2 Case 3 l 1979 0.93 107@0.50 207@l.91 2.00 l 1980 0.93 1.01 1.07 1981 1.34 1,67 1.56 1982 0.93 1.28 2.09 Total 1.07 1.43 1.78 6
(
Slide No. 1 f.
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T ____________E-"~___________________~-
120 DAYS VS. l' YEAR FUEL '
~. .
Cost of Total of Case Exposure Shipments Refueling Days Transfer Days Transfer 6 Year # Man-Rem $ During Year During Year Refueling Days 1979 1 62.1 725900 103 207 310 2 72.8 771300 103 314 417 3 45.3 529600 103 151 ,
254 1980 1 12.0 150600 121 40 161 2 12.0 150600 121 40 161 3 30.0 376600 121 100 221 1981 1 76.8 1031900 224 256 480 2 76.8 1031900 224 256 480 3 78.0 1048100 224 260 484 1982 1 81.6 1169600 183 272 '455 2 81.6 1169600 183 272 455 3 89.1 1277100 183 297 480 Total 1 232.5 3078000 - - -
2 243.2 3123400 - - -
3 242.4 3231400 - - -
l Slide No. 2 l
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