ML20137S842
| ML20137S842 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 09/24/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20137S830 | List: |
| References | |
| TAC-57295, TAC-57296, TAC-59278, TAC-59279, NUDOCS 8509300520 | |
| Download: ML20137S842 (4) | |
Text
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SAFETY EVALUATION l
AMENDMENT NO. 33 TO NPF-10 AMENDMENT NO. 22 TO NPF-15 l
SAN ON0FRE NUCLEAR GENERATING STATION, UNITS 2 & 3 DOCKET NOS. 50-361 AND 50-362 Introduction Southern California Edison Ccmpany (SCE), on behalf of itself and the other licensees, San Diego Gas and Electric Company, the City of Riverside, California, i
i and The City of Anaheim, California, has submitted several applications for license amendments for San Onofre Nuclear Generating Station, Units 2 and 3.
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One such request, Proposed Change Number 139, or PCN-139, dated January 23, 1985, involves changes to Technical Specification (T.S.) 3/4.7.6 " Snubbers".
Technical Specification 3/4.7.6 requires that snubbers be operable to ensure the integrity of safety related systems and specifies the frequency and type of periodic inspections required to verify snubber operability. The proposed change would revise T.S. 3.7.6 to more closely conform to the model technical specifications provide by NRC Generic Letter 84-13 " Technical Specifications For Snubbers" dated May 3, 1984 Specifically the following changes were a
proposed.:
1 1.
Delete Snubber Listinos.
2.
Categorize snubbers into accessible and inaccessible groups.
3.
Restrict increases in the visual inspection interval.
4 Eliminate refueling outage inspections for systems which have undergone unexpected transients.
5.
Revise visual test acceptance criteria to further restrict post inspection operability determinations for hydraulic snubbers.
6.
Delete alternate nethod for functional test sample selection.
7.
Differentiate between hydraulic snubber and mechanical snubber functional test acceptance criteria.
The NRC staff has reviewed the proposed changes and has found all the above changes acceptable with the exception of item 4, deletion of inspection of systems which have undergone unexpected transients. Therefore, these amendments incorporate into the tech specs all the proposed changes except i
item 4.
Consequently, the requirement for inspection at each refueling i
outage of snubbers associated with systems which have underqcne unexpected transients will rema.in in the San Onofre 2 and 3 Technical Specifications.
i Evaluation The staff evaluation of each of the changes proposed by the licensees is l
given below:
8509300520 B50924 PDR ADOCK 05000361 P
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. 1.
Delete Snubber Listings Previously, T.S. 3.7.6 required that all snubbers listed in Tables 3.7-4a and 3.7-4b be operable. Tables 3.7-4a and 3.7-4b identified specific numbers of snubbers by size and type associated with each safety-related system. The amendments delete these tables and thus no longer identify specific numbers, sizes and types of snubbers.
Instead, the amended specification requires all snubbers installed on safety related systems or snubbers whose failure could affect safety related systems to be operable and defines criteria to determine if a snubber is subject to this specification.
The amended tech specs continue to require all snubbers installed
.on safety related systems to be operable, and do not reduce any existing operability or surveillance requirement. Therefore, the staff finds 4
change to be acceptable.
2.
Categorize Snubbers.
l This change adds a new provision which allows snubbers to be categorized as either accessible or inaccessible during plant operation for the purpose of scheduling visual inspections. These two groups may be inspected at different times, but are still required to be inspected at the specified interval. This change does not affect the currently specified inspection intervals but allows inspections of accessible and inaccessible snubbers to be scheduled independently.
This change does not reduce any existing requirement, and therefore is acceptable.
3.
Restrict Increases in Visual Inspection Interval.
The visual inspection interval is determined by the number of snubbers found inoperable in the previous inspection. For example if 8 snubbers are found inoperable, the next inspection would be required t
in 31 days.
If this inspection uncovered a generic problem which is identified and corrected and the subsequent inspection found no snubbers inoperable then the existing T.S. allow the inspection interval to be increased by one step to 62 days.
If the next inspection again found no snubbers inoperable then the inspection interval could be increased by two steps to 6 months. The proposed change will no longer allow two step increases in inspection intervals.
l Since the proposed change will allow only one step increases in surveillance intervals, it is an additional restriction. Therefore, this change is acceptable.
4 Eliminate Refueling Outage Inspections.
Currently, in addition to the 100% visual inspection of all snubbers and function:1 testing of a representative sample of snubbers, the technical specifications require a special refueling outage inspection
. of snubbers located on systems identified as having undergone unexpected, potentially damaging transients. The special inspection involves visual inspection of the affected snubbers and verification of freedom of.
movement (i.e., a partial functional test). The licensees proposed to delete this requirement from the technical specifications.
The NRC staff has reviewed this request and the operating history at San Onofre 2 and 3, and has found that dynamic transients such as water hamers have on several occasions caused snubbers to be inoperable.
These inoperable snubbers were found as a result of the inspections of the type required by this technical specification. Because it appears to be performing a useful safety function, the staff has concluded that the requirement for inspection during refueling outages of snubbers that have undergone potentially damaging transients should not be deleted.
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Therefore, the licensees' request for this change is denied.
i 5.
Revise Visual Test Acceptance Criteria.
Previously, snubbers which appear to be inoperable as result of a visual inspection can be determined to be operable for the purposes of determining the next inspection interval provided that the' snubber
. passes a functional test conducted in the as-found condition. This provision applied to both hydraulic and mechanical snubbers. The amended tech specs will no longer allow this provision for hydraulic snubbers found with uncovered fluid ports. Thus, hydraulic snubbers found in this condition will be considered inoperable.
This change is an additional restriction and is therefore acceptable.
l 6.
Delete Alternate Functional Test Sample Selection Criteria i
Sample selection could previously be made by one of two methods.
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One method simply required functional testing of 107, of each type of snubbers. For each type of snubber where one or more functional test failures occur, an. additional 10% must be tested until no more failures are found or all snubbers of that type have been inspected. The alter-nate method required testing of a representative of each type of snubber with retesting based on probabilistic criteria specified in T.S. Figure 4.7-1.
The amendments delete the alternate sampling criteria since it will never be used.
I Further, the amendments specify additional conditions on sample selection. The amendments require that 25% of the snubbers in the representative samole be snubbers from the following categories:
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five feet of heavy equipment; or, 3) snubbers within ten feet of the j
discharge frca a safety relief valve.
The amendments are more restrictive in that they eliminate the alternate sampling method and recuire that the sample include a percentage of snubbers from specific locations. Because this change i
institutes additional restrictions it is acceptable to.the staff.
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7.
. Revise Functional Test Acceptance Criteria J
The' amendments differentiate between the functional test acceptance criteria for mechanical and hydraulic snubbers. Previously, no differen-tiation was made. The amendments more accurately define the functional requirements for each type of snubber.
j Previously, functional testing required verification that fasteners for attachment of the snubber to the component were secure. Visual inspection-also requires verification that snubber attachments are secure. The.
i amendments delete this redundant functional test requirement. Because the proposed change editorially improves clarity and consistency within the technical specifications it is acceptable to the staff.
Contact With State Official The NRC staff has advised the Chief of the Radiological Health Branch, State Department of Health Services, State of California, of the proposed determina-l tions of no significant hazards consideration. No comments were received.
i Environmental Consideration l
These amendments involve changes in the installation or use of facility l
components located within the restricted area. The staff has determined that the amendments involve no significant increase in the amounts of any i
effluents that may be released offsite and that there is no ~significant increase in individual or cumulative occupation radiation exposure. The comission has' previously issued proposed findings that the amendments l
involve no significant hazards consideration, and there has been no public l
comment on such findings. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR Sec. 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environ-1 I
mental assessment need to prepared in connection with the issuance of these amendments.
i Conclusion i
Based upon our evaluation of the proposed changes to the San Onofre Units 2 f
i and 3 Technical Specifications, we have concluded that: except for deletion of the refueling outage inspection, there is reasonable assurance that the j
health and safety of the public will not be endangered by operation in the i
proposed manner, and such activities will be. conducted in compliance with the Commission's regulations and the issuance of the amendment will not be inimical i
to the comon defense and security or to the health and safety of the public.
i We, therefore, conclude' that except for deletion of the refueling outage inspections, the proposed changes are acceptable, and are hereby incorporated
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into the San Onofre 2 and 3 Technical Specifications. The proposed _ deletion of the refueling outage inspection is hereby denied.
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Dated:
September 24, 1985 l
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ISSUANCE OF AMENDMENT NO. 33 TO FACILITY OPERATING LICENSE NPF-10 AND AMENDMENT NO. 22 TO FACILITY OPERATING LICENSE NPF-15 SAN ON0FRE NUCLEAR GENERATING STATION, UNITS 2 AND 3 DISTRIBUTION Docket File 50-361/362~
NRC PDR Local PDR PRC System NSIC LB!3 Reading J. Lee (20)
H. Rood T. Novak J. Saltzman, SAB L. Chandler, OELD
'C. Miles H. Denton J. Rutberg A. Toalston W. Miller, LFMB N. Grace E. Jordan L. Hariron D. Brinkman, SSPB T. Barnhart (4) l