ML14191A316
| ML14191A316 | |
| Person / Time | |
|---|---|
| Site: | San Onofre, Robinson  |
| Issue date: | 02/04/1988 |
| From: | Medford M Southern California Edison Co |
| To: | NRC Office of Administration & Resources Management (ARM) |
| Shared Package | |
| ML14191A319 | List: |
| References | |
| RTR-NUREG-0612, RTR-NUREG-612 NUDOCS 8802090285 | |
| Download: ML14191A316 (10) | |
Text
REGULATOY INFORMATION DISTRIBUTIO YSTEM (RIDS)
ACCESSION NBR:8802090285 DOC.DATE: 88/02/04 NOTARIZED: NO DOCKET #
FACIL:50-261 H.B. Robinson Plant, Unit 21 Carolina Power & Light C 05000261 AUTH.NAME AUTHOR AFFILIATION MEDFORDM.O.
Southern California Edison Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Application for amend to License DPR-13,revising License Condition 3.C & deleting Tech Spec 4.13 "Turbine Deck Load Bearing Test & Visual Insp."
DISTRIBUTION CODE: A0O1D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal: General Distribution NOTES:
RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-1 LA 1
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1 INTERNAL: ARM/DAF/LFMB 1
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i TOTAL NUMBER OF COPIES REQUIRED: LTTR 20 ENCL 17
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 M. 0 MEDFORD TELEPHONE MANAGER OF NUCLEAR ENGINEERING February 4, 1988 18181 302-1749 AND LICENSING U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Spent Fuel Transshipment San Onofre Nuclear Generating Station Unit 1 By letter dated December 24, 1987, SCE requested that the NRC review and approve SCE's proposed methodology for transshipment of spent fuel from San Onofre Unit 1 to San Onofre Units 2 and 3. Subsequently, the NRC requested that a license amendment be submitted to supplement the December 24, 1987 submittal.
Therefore, provided as an enclosure is Proposed Change No. 181 which is a request to revise the license and technical specifications for San Onofre Unit 1 in conjunction with the previous submittal.
The formal amendment application submittal will be provided at a later date.
The proposed method for transshipment as described in the December 24, 1987 submittal involves the lift of a 70 ton cask over the cask handling area of the spent fuel pool and the decontamination pad area at San Onofre Unit 1.
This was concluded to be acceptable based on the heavy loads program at San Onofre, the results of the NRC's review of the handling of heavy loads and the NUREG-0612 guidelines. In addition a steel plate is being installed in the cask handling area to mitigate the effects of a postulated cask drop on the spent fuel pool structure and liner. This information has been discussed in detail in the December 24, 1987 submittal.
Subsequent, to the December 24, 1987 submittal, further investigation of the postulated drop of the spent fuel cask in the area of the decontamination pad indicates that the continued operation of San Onofre Unit 1 could be significantly impacted if this drop were to occur. The conclusions of maintaining the plant in a safe shutdown condition are still applicable.
However, in order to provide even greater assurance of the prevention of substantial physical damage, an impact limiter will be used for the lifts of the 70 ton cask in the area of the decontamination pad. This impact limiter 8802090285 88020W PDR ADOCK 05000206 1
P PDR
Document Control Desk February 4, 1988 will absorb the forces resulting from the drop of the 70 ton cask preventing it from penetrating the turbine deck or decontamination pad. The evaluation of the significant hazards consideration documented in Proposed Change 181 is based on the December 24, 1987 submittal and the use of an impact limiter in the decontamination pad area.
Due to the reasons stated in the December 24, 1987 submittal, it is SCE's intention to transship fuel as soon as possible. Movement of fuel was planned to occur during the midcycle outage which is scheduled to begin February 14, 1988. Therefore, it is respectfully requested that the NRC staff urgently review and approve the proposed methodology for shipment of fuel.
Notwithstanding the fact that the enclosed license amendment application is submitted for NRC approval, it continues to be our conclusion that transshipment of spent fuel from San Onofre Unit 1 to San Onofre Units 2 and 3 does not require an amendment of the San Onofre Unit 1 license. This conclusion is based on the fact that handling of the spent fuel cask in accordance with the existing San Onofre Unit 1 heavy load handling program and procedures is consistent with the NRC's previous review and resolution of heavy loads issues.
In order to resolve all issues associated with spent fuel transshipment as soon as possible, we would like to meet with you at your earliest convenience.
Very truly yours, Enclosure cc:
J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3
00 DESCRIPTION AND SAFETY ANALYSIS OF PROPOSED CHANGE NO. 181 TO PROVISIONAL OPERATING LICENSE DPR-13 AND TECHNICAL SPECIFICATIONS This is a request to revise License Condition 3.C. and delete Technical Specification 4.13, "TURBINE DECK LOAD BEARING TEST AND VISUAL INSPECTION,"
for San Onofre Nuclear Generating Station, Unit 1.
DESCRIPTION License Condition 3.C refers to the shipment of spent fuel casks utilizing the air pallet system as described in SCE's March 21, 1975 report. The purpose of this license condition was to ensure that the modifications as described in the March 21, 1975 report were implemented prior to use of the air pallet.
system and that a turbine deck load bearing test was conducted prior to the first shipment of spent fuel.
This license condition has been satisfied.
SCE has requested the NRC to review a new method for shipment of spent fuel at San Onofre Unit 1 in conjunction with the transshipment of Unit 1 spent fuel to San Onofre Units 2 and 3. The details of this method were transmitted to the NRC by letter dated December 24, 1987. Since the existing license condition has no relation to the proposed method of shipment it will be revised to indicate that the shipment of spent fuel will continue in accordance with the methodology as described in the December 24, 1987 report, "Transshipment of San Onofre Unit 1 Spent Fuel."
Technical Specification 4.13, "TURBINE DECK LOAD BEARING TEST AND VISUAL INSPECTION," requires that a turbine deck load bearing test be performed every four years.
This test assured the structural integrity of the turbine deck and supporting structure for shipment of spent fuel with the air pallet system. Since a new method for shipment of spent fuel has been proposed in SCE's December 24, 1987 submittal which does not use the air pallet system, this technical specification would no longer be applicable. Therefore, the Technical Specification 4.13 will be deleted.
The heavy loads issues associated with the movement of a spent fuel cask at San Onofre Unit 1 were reviewed relative to the seven guidelines of Phase I of NUREG-0612, "Control of Heavy Loads at Nuclear Power Plants" and the results of this review were presented in Section F of SCE's December 24, 1987 submittal.
The review concluded, in a manner similar to the approach used by the NRC in their review of other San Onofre Unit 1 heavy load handling operations documented in the Safety Evaluation Report (SER) enclosed with their November 5, 1985 letter to SCE, that the heavy load handling operations associated with the shipment of spent fuel from San Onofre Unit 1 satisfy the Phase I guidelines of NUREG-0612. In addition, it is the conclusion of the NRC, as documented in their letter to All Licensees of Operating Reactors dated June 28, 1985, that the NUREG-0612 Phase I guidelines are adequately providing the intended level of protection against load drop accidents and that Phase II of NUREG-0612 is an unnecessary addition to the Phase I actions. Specifically, the NRC concluded that "the risks associated with damage to safe shutdown systems are relatively small because: 1) nearly all
-2 load paths avoid this equipment, 2) most equipment is protected by an intervening floor, 3) of the general independence between crane failure probability and safety-related systems which has been observed, and 4) redundancy of components". The NRC also determined that "the greatest risk is associated with carrying heavy loads over or in a location where spent fuel could be damaged. The single most important example of this concerns loads handled over the open reactor vessel during refueling (such as the reactor vessel head).
However, as previously mentioned, this is limited to the extent practical and where necessary, is performed with a specifically implemented program in conformance with the Phase I guidelines." It is noted that specific information was provided in SCE's December 24, 1987 submittal regarding SCE's special program and procedure requirements for the handling of the spent fuel cask at San Onofre Unit 1. Therefore, it is concluded that handling of the San Onofre Unit 1 spent fuel cask in accordance with the existing San Onofre Unit I heavy load handling program and procedures is consistent with the NRC's previous review and resolution of heavy loads issues.
Notwithstanding this conclusion, in the December 24, 1987 submittal SCE has performed Phase II of NUREG-0612 type analyses of the consequence of a spent fuel cask drop to determine the effect on San Onofre Unit I systems and structures. As previously stated in SCE's July 6, 1982 submittal to the NRC of Phase II of NUREG-0612 analyses for San Onofre Unit 1, the probability of a load drop scenario is greatest during the initial lift of the heavy load.
During the remaining phases of a load handling operation, the probability of a load drop is two to four orders of magnitude lower and, therefore, not considered to be credible events. Using this conclusion and the information presented in the December 24, 1987 submittal, the two areas of concern for the shipment of spent fuel at San Onofre Unit 1 are in the cask handling area of the spent fuel pool and the decontamination pad area. These are the same two areas of concern when using the air pallet for spent fuel cask movement, as these two lifts are necessary to use the cask in the cask handling area of the spent fuel pool and to move the cask onto or from the air pallet. It is noted that during this initial lift the load drop probability increases slightly with increased load due to the fact that the turbine gantry crane structural failure probability increases with the increased loads. However, SCE heavy load checkout requirements will ensure a verification of a secure load, after the initial lift, but prior to any transverse or vertical movement. Since there are no adverse consequences from a cask drop during the initial lift (less than a foot or so), even in the event of a failure there is no change in the probability of an accident for the two cask handling methods.
For the case of the cask handling area in the spent fuel pool, the structure, the liner plate and the stainless steel plate to be installed, will withstand the effects of a postulated load drop as discussed in Section I of the December 24, 1987 submittal.
For the case of the decontamination pad area, the December 24, 1987 submittal indicates cable trays are located beneath the lift area and would be affected in the event of a postulated drop. It further indicates that redundant equipment would still be available to maintain the plant in a safe shutdown condition. In specific cases, local starting of equipment may be necessary. Therefore, it is concluded that the handling of the spent fuel cask at San Onofre Unit 1 meets the guidelines of NUREG-0612, Phase II and accordingly, is an operation that meets criteria more stringent than currently required by the regulations.
-3 Subsequent to the December 24 submittal, it has been determined that the use of an impact limiter is possible and will provide an additional level of protection. The impact limiter would absorb the forces resulting from the postulated drop of the 70 ton cask such that the cask would not cause substantial physical damage. Even though the December 24, 1987 submittal indicated the results of a cask drop on the decontamination pad were acceptable, use of an impact limiter will provide even greater assurance.
EXISTING LICENSE CONDITION AND TECHNICAL SPECIFICATION See Attachment 1 PROPOSED LICENSE CONDITION See Attachment 2 SAFETY EVALUATION The proposed change as discussed above shall be deemed to constitute a significant hazard consideration if positive findings are made in any of the following areas:
- 1. Will operation of the facility in accordance with this proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No Operation of the facility in accordance with this proposed change will allow the shipment of spent fuel from San Onofre Unit 1 in accordance with the methodology described in SCE's December 24, 1987 submittal. As previously indicated, the new methodology involves the use of a multi-element spent fuel cask weighing 70 or 100 tons instead of the 30 ton single element cask previously used to transport the spent fuel and will not use the air pallet for movement on the turbine deck. As discussed in the description above, the highest probability of a load drop is during the initial lift. Accordingly, the probability of a postulated load drop scenario increases slightly for the increased load of the 70 to 100 ton spent fuel cask during this initial lift. However, the increase in probability of this previously evaluated scenario does not increase significantly (i.e., from a probability of occurrence of approximately.5 x 10-5 to approximately 1 x 10-5 as indicated in SCE's July 6, 1982 submittal). Furthermore, since there are no adverse consequences from a cask drop during the initial lift, the probability of an accident is not increased with the new method of fuel handling.
-4 In addition, as part of the December 24, 1987 submittal the areas that could be affected by the postulated drop of the spent fuel cask were evaluated. In the case of the cask handling area a steel plate is being installed which would mitigate the effects of a cask drop in this area.
In the case of the decontamination pad area, an impact limiter will be used during the lifts to mitigate the effects of a potential cask drop.
Therefore, even if a cask drop is postulated, it would not affect spent fuel, systems, equipment or plant operation.
In summary, while the new methodology involves the use of a heavier spent fuel cask, as stated in the SCE's December 24, 1987 submittal and further supported by the information discussed in the description above, the load drop scenario is not heavily dependent upon the weight of the cask and a postulated load drop scenario does not affect plant operation.
Therefore, there are no accidents which have been previously evaluated which will be affected by this shipment and operation of the facility in accordance with this proposed change does not involve a significant increase in the probability or consequences of an accident.
- 2. Will operation of the facility in accordance with this proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No Operation of the facility in accordance with this proposed change will allow the shipment of spent fuel in accordance with the methodology described in SCE's December 24, 1987 submittal.
This method of shipment involves the use of a multi-element spent fuel cask weighing from 70 to 100 tons.
The information presented in the description to this proposed change indicates that the new method of handling a larger spent fuel cask will be in accordance with existing San Onofre Unit 1 heavy load handling programs and procedures, which have been previously reviewed as part of the NRC actions in the area of heavy load handling issues for San Onofre Unit 1. Therefore, it is concluded that operation of the facility in accordance with this proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Will operation of the facility in accordance with this proposed change involve a significant reduction in a margin of safety?
Response: No Operation of the facility in accordance with this proposed change will allow shipment of spent fuel in accordance with the methodology described in SCE's December 24, 1987 submittal.
As stated in the submittal, SCE has implemented a heavy loads handling program which the NRC found acceptable by letter dated November 5, 1985. Accordingly, compliance with the San Onofre Unit 1 heavy loads program and procedures with regards to the control and handling of the cask and the fact that a postulated drop scenario does not impact spent fuel, systems, equipment or plant operations assures that there is no significant reduction of overall plant safety. Therefore, operation of the facility in accordance with this proposed change will not involve a significant reduction in the margin of safety.
-5 The Commission has provided guidance concerning the application of the standards for determining whether a significant hazards consideration exists by providing certain examples (48 FR 14870) of amendments that are considered to involve or not likely to involve significant hazards considerations.
This proposed change is not similar to those examples. The change will allow the transshipment of spent fuel from San Onofre Unit 1 to San Onofre Units 2 and 3 in accordance with the methodology described in SCE's December 24, 1987 submittal. It is acknowledged that use of the larger cask results in an increase in the probability of load drop, however the accident probabilities are not affected. In addition, in the event of a postulated cask drop, spent fuel, systems, equipment or plant operation is not affected. Therefore, it can be concluded that operation of the facility in accordance with this proposed change does not involve a significant hazards consideration.
SAFETY AND SIGNIFICANT HAZARDS DETERMINATION Based on the safety evaluation, it is concluded that: (1) the proposed change does not involve a significant hazards consideration as defined by 10 CFR 50.92; and (2) there is reasonable assurance that the health and safety of the public will not be endangered by the proposed change; and (3) this action will not result in a condition which significantly alters the impact of the station on the environment as described in the NRC Environmental Statement.
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- 3. This license shall be deemed to contain and is subject to the conditions as specified in the following Commission regulations (Title 10, CFR, Chapter 1):
Part 20, Sections 50.54 and 50.59 of Part 50, Section 70.32 of Part 70, Section 40.41 of Part 40 and Section 30.34 of Part 30; is subject to all applicable provisions of the Act and rules, regulations and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified below:
A. Maximum Power Level Edison is authorized to operate the reactor at steady state power levels up to a maximum of 1347 megawatts thermal.
B. Technical Specifications The Technical Specifications contained in Appendix A as revised through Amendment No. 99 are hereby incorporated in the license. Southern California Edison Company shall operate the facility in accordance with the Technical Specifications.
C.
Fuel Shipments shall not be resumed (except during cold shutdown condition of the reactor) until the modifications described in the licensee's March 21, 1975 report entitled "Spend Fuel Shipping Cask Handling, San Onofre Nuclear Generating Station, Unit 1," and the initial turbine deck load bearing test and visual inspection have been satisfactorily completed.
- 0. The facility may be modified by implementing the "Sphere Enclosure Project" as described in Amendment 52 to the Final Safety Analysis for the San Onofre Nuclear Generating Station, Unit 1, submitted December 3, 1975; Supplement to the Sphere Enclosure Project Report, submitted March 1, 1976; Second Supplement to the Sphere Enclosure Report submitted March 25, 1978; additional information submitted by letter dated March 25, 1976 (withheld from public disclosure pursuant to 10 CFR Part 2, Section 2.790(d)).
E. Steam Generator Inspections During the refueling outage scheduled to begin no later than November 30, 1985, Southern California Edison shall perform an inspection of the steam generators. The inspection program shall be submitted to the Commission at least 45 days prior to the scheduled shutdown. Commission approval shall be obtained before resuming power operation following this inspection.