ML20034A537
| ML20034A537 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 04/12/1990 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20034A533 | List: |
| References | |
| NUDOCS 9004230427 | |
| Download: ML20034A537 (8) | |
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ATTACHMENT 1 PEACH BOTTON ATONIC POWER STATION UNIT 3 Docket No. 50-278 License No. DPR-56 TECHNICAL SPECIPICATION CHANGE REQUEST No. 89-20
" Reduction of Snubber Visual Inspection Frequency" Supporting Information for Changes - 8 pages 9004230427 900412 PDR ADOCK 05000278 P
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Dockct No. 50-278 License No. DPR-56 Philadelphia Electric Company, Licensee under facility operating License DPR-56, for Peach Botton Atomic Power Station Unit No. 3, hereby requests that the Technical Specifications contained in Appendix A to the Operating License be amended.
The proposed change to the Technical Specifications is indicated by the vertical bars in the margin of page 234a.
This Technical Specification Change Request (TSCR) involves a one-time increase in the visual inspection interval for inaccessible mechanical and hydraulic shock suppressors (snubbers).
As a result of previous snubber inspections, Peach Botton Atomic Power Station (PBAPS) Unit 3 is currently required by Specification 4.11.D 2 to visually inspect snubbers at an interval of 6 months +
.1 25%.
This TSCR requests that the next inspection due May 26, 1990 be postponed until the scheduled mid-cycle outage in the fourth quarter of 1990.
The subject snubbers are inaccessible during reactor power operation.
Consequently, lasuance of the proposed change is needed before May 26, 1990 to avoid a plant shutdown for l
l performance of the visual inspections, i
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DockOt No. 50-278 License No. DPR-56 Description of Changes The following changes to the Technical Specifications are proposed:
1.
Place an asterisked note on specification 4.11.D.2 page 234a which reads "Those surveillances on inaccessible snubbers which must be performed on or before May 26, 1990 and are required by TS 4.11.D.2 may be delayed for a period not to exceed December 31, 1990."
Safety Assessment Snubbars are installed on piping and components to mitigate the effects of seismic and hydrodynamic events.
Evaluation of the consaquences of extending the visual surveillance interval. includes consideration of the piping and components which the snubbers protect.
In accordance with Technical Specifications (TS), snubbers are categorized into two groups, " accessible" and " inaccessible" based on their accessibility during reactor power operation.
This TSCR concerns only inaccessible snubbers.
Technical Specification 4.ll.D.2 requires that snubbers on safety-related components and piping be visually inspected at various intervals depending upon the snubber failures identified by )
4 Dockct No. 50-278 i
l License No. DPR-56 the previous inspection.
An increase in the number of failures would decrease the inspection interval.
l During a visual inspection in January 1987, three snubbers out of a population of 150 inaccessible snubbers were found with uncovered hydraulic fluid ports.
These three snubbers were declared inoperable and replaced with rebuilt snubbers.
Based on three l
failures, specification 4.ll.D.2 required the inspection interval to be reduced from the previous 18 months i 25% to 4 months i 25%.
A subsequent inaccessible snubber visual inspection allowed the inspection interval to be lengthened to 6 months 1 25%.
During the Period of March 31, 1987 to December 1989, Unit 3 did not operate.
Most recently, in October 1989 prior to startup of Unit 3, 80% of the inaccessible snubbers were functionally tested and verified i
operable and 100% of the inaccessible snubbers were visually inspected and confirmed to be free of discrepancies that could effect operability.
These measures were in excess-of TS requirements, and were undertaken to provide greater assurance that Unit 3 was starting up with an operable snubber population.
However, the 6 month 1 25% inspection interval was not increased due to the unit being shutdown since the last visual inspection.
Therefore, the next visual inspection is due 6 months 1 25% from the previous inspection or no later than May 26, 1990.
Although the-j proposed one-time extension of the visual inspection interval may I
Dockot No. 50-278 l
License No. DPR-56 i
result in a slight increase in the probability of malfunction of the l
i snubbers or in small, localized reductions in safety margins due to l
undetected snubber failures, the overall increase in the probability of a malfunction or reduction in safety margin will not be-significant.
Information Supporting a Finding of No Significant i
Hazards Consideration The proposed change does not constitute a significant hazards consideration in that:
(1)
The proposed change does not involve a significant increase h
in the probability or consequences of any accident previously evaluated.
V This Technical Specification Change Request (TSCR) involves a one-time increase in the inspection interval for l
inaccessible mechanical and hydraulic shock suppressors (snubbers).
Lengthening the inspection interval has no effect on the probability of an accident since a snubber' failure does not initiate an accident.
The short duration
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of this one-time interval extension does not involve a
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l significant increase in the consequences of an accident.
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!Dockst No. 50-276' License ~ No. DPR-56 (2)
The proposed change does not create the possibility 4 of a new or different kind of accident from any previously evaluated.
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The change proposed by this TSCR does not involve any-plant modifications or hardware changes.
Increasing the snubber visual inspection interval does not affect the function, installation, location or cot *1guration of any snubbers nor does it affect the design or function of any piping or systems protected by snubbers.
Additionally, snubber inoperability does not introduce any new failure modes to protected components or piping.
(3)
The proposed change does not result in a significant reduction in the margin of safety.
Prior to startup for the current operating cycle, 80% of the inaccessible snubbers were functionally tested and verified operable and 100% of the inaccessible snubbers were visually inspected and confirmed to:be free of discrepar.cies that could effect operability.
These measures were in excess of Technical Specification requirements, and were undertaken in order to provide-greater assurance that Unit 3 was starting up with an operable snubber population.
Because of the short duration..
'a DockOt No. 50-278 1
'i License No. DPR-56 1
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of this one-time inspection interval extension and the j
results of the most recent visual inspection and functional j
testing, the proposed change does not involve a significant I
i reduction in the margin of safety.
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Environmental Impact Assessment I
I An environmental impact assessment is not required for this proposed change because the change conforms to the criteria for.
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" actions eligible for categorical exclusion" as specified in 10 CPR v
51.22(c)(9).
The proposed change does not involve any systems that
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have a direct relationship with the environment.
This proposed i
l change involves a one-time postponement of snubber visual i
inspections.
This proposed' change involves no significant hazards 0
1 consideration as demonstrated in the preceding section.- This l
proposed chango involves no significant change in'the types or i
l significant increase in the amounts of any effluents that may be released offsite and there will be no significant increase in individual or cumulative occupational radiation exposure.
DockCt No. 50-278 License No. DPR-56 Conclusion i
The Plant Operations Review Committee and the Nuclear Review Board have reviewed this proposed change to the Technical Specifications and have concluded that it does involve an unreviewed safety question, but will not endanger the health and safety of the
. i public.
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