ML20033G634
| ML20033G634 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/23/1990 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20033G630 | List: |
| References | |
| GL-89-14, NUDOCS 9004100432 | |
| Download: ML20033G634 (9) | |
Text
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l LIMERICK GENERATING STATION UNITS 1 and 2 i
i Docket Nos.
50-352 t
50-353 License Nos. WPF-39 NPF-85 i
t TECHNICAL SPECIFICATIONS CRANGE RDQUEST
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No. 89-14 i
" Proposed Change to the Technical Specifications 3
to Remove the 3.25 Limit on Extending Surveillance Intervals" I
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1 Supporting Information for Changes - 9 pages i
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I 9004100432 900323 6
FDR ADOCK 05000,352 p
FDC l
DockCt Nos. 50-352 50-353 Philadelphia Electric Company (PECo), Licensee under Pacility Operating License Nos. NPP-39 and NPP-85 for Limerick Generating Station (LCS), Units 1 and 2, respectively, hereby requests that the Technical Specifications (TS) contained in Appendix A to the operating Licenses be amended as proposed herein.
The proposed change to the TS are indicated by the vertical bars in the margins of the pages contained in Attachment 2.
The pages to be changed are 3/4 0-2 and B 3/4 0-4 for Units 1 and 2.
We request the changes proposed herein to be effective upon issuance of the Amendments.
This change request provides a discussion and description of the proposed TS changes, a safety assessment of the proposed TS changes, information supporting a finding of No Significant Hazards Consideration, and information supporting an Environmental Assessment.
Discussion and Description of,the Proposed Changes The proposed changes affect the Surveillance Requirements (SR) of the Applicability Section of the LGS TS.
The proposed changen involve the removal of the 3.25 limit on extending surveillance intervals.
Currently, LGS SR 4.0.2 permits surveillance intervals to be extended up to 25 percent of the specified surveillance interval.
The purpose of this extension is to facilitate the scheduling of.
Dockot No3. 50-352 50-353 surveillance activities and to allow surveillances to be postponed when plant conditions are not suitable for conducting a surveillance, for example, under transient conditions or other ongoing surveillance or maintenance activities.
SR 4.0.2 also limits extending surveillances so that the combined time interval for any three consecutive surveillance intervals shall not exceed 3.25 times the specified surveillance interval.
The intent of the 3.25 limit is to preclude the routine use of the provision for extending a surveillance interval by 25 percent.
Connonwealth Edison Company (CBCo) submitted a lead-plant proposal for the LaSalle County stat;on TS to remove the 3.25 limit for surveillances that are performed during a refueling outage and are specified with an 18-month surveillance interval.
After discussions with the NRC, CBCo amended the proposal to remove the 3.25 limitation for all surveillance intervals.
The amended proposal was approved by the NRC on a lead-plant basis.
As a result of these efforts, NRC Generic Letter (GL) 89-14, "Line-Item Improvements in Technical Specifications - Removal of the 3.25 Limit on Extending Surveillance Intervals," was issued on August 21, 1989.
This GL encourages licensees and applicants to propose changes to their TS to remove the 3.25 limit on extending autveillance intervals.
Based upon the guidance provided in GL 89-14, we propose to 4
revise SR 4.0.2 as follows. )
l DockCt No3. 50-352 50-353 "4.0.2 Each Surveillance Requirement shall be performed within the specified surveillance interval with a maximo.m allowable extension not to exceed 25 percent of the specified surveillance interval."
In addition, changes to the Bases for this SR are proposed which reflect the removal of the 3.25 limit on extending surveillances.
5 The proposed changes to the Bases state that the provision for extending surveillances is not intended to be used repeatedly as a convenience to extend surveillance intervals beyond that specified for surveillances that are not performed during refueling outages.
Safety Assessment Experience has shown that the 18-month surveillance interval, with provision to extend it by 25 percent, is usually sufficient to accommodate normal variations in the length of a fuel cycle.
Ilowever, the NRC has routinely granted requests for one-time exceptions to the 3.25 limit on extending refueling surveillances because the risk to safety is low in contrast to the alternative of a forced shutdown to perform these surveillances.
Therefore, the 3.25 limitation on extending surveillances has not been a practical limit on the use of the 25-percent allowance for extending surveillances that are performed on a refueling outage basis.
The use of the allowance to extend surveillance intervals by 25 percent can also result in a significant safety benefit for surveillances that are performed on a routine basis during plant -
DockCt No]. 50-352 50-353 4
operation.
This safety benefit is realized when a surveillance I
interval la extended at a time when conditions are not suitable for performing the surveillance.
Examples of this include transient plant operating conditions or conditions in which safety systems are out of service because of ongoing surveillance or maintenance i
activities.
In such cases, the safety benefit of allowing the use i
of the 25-percent allowance to extend a surveillance interval would i
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outweigh any benefit derived by limiting three consecutive surveillance intervals to the 3.25 limit.
Also, there is the
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administrative burden associated with tracking the use of the 25-1 pe: cent allowance to ensure compliance with the 3.25 limit.
This additional administrative burden could remove resources from items 1
more important to safety.
On the basis of these considerations, we t
have concluded that removal of the 3,25 limit will have an overall i
positive impact on safety.
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Information Supporting a Pinding of No Significant i
Hazards Consideration i
We hac9 concluded that the proposed change to the LGS TS, which remove the 3.25 limit on extending surveillance intervals, does not constitute a significant hazards consideration.
In support of this determination, an evaluation of each of the three (3) standards set forth in 10 CPR 50.92 is provided below.
DockCt No]. 50-352 50-353 1)
The proposed change does not involve a significant increase in i
the probability or consequences of an accident previously evaluated.
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i The limit of 3.25 times the specified surveillance interval for l
any three consecutive surveillance intervals is intended to j
preclude routine use of the provision for extending a i
I surveillance interval by 25 percent.
However, many TS i
surveillance tests can only be performed during a plant shutdown and the situation may arise when a forced plant shutdown is the f
f i
only alternative to exceeding the allowable surveillance Interval limit.
Additionally, conditions can exist that are not suitable for performing a surveillance test, e.g.,
during transient plant operating conditions or conditions in which safety systems are out of service because of ongoing i
surveillance or maintenance activities.
During these situations, the proposed removal of the limit of 3.25 times the f
specified surveillance interval for three consecutive intervals results in a greater benefit to safety than limiting the use of the 25-percent allowance on extending surveillance intervals, as l
discussed in GL 89-14.
i This proposed change will not adversely affect any plant hardware, plant design, safety limit settings, or plant system operation.
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Dock;t No3. 50-352 50-353 4
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Therefore, this proposed change does not modify or add any 1
initiating parameters that would increase the probability or the consequences of an accident previously evaluated.
j 2)
The proposed change does.not create the possibility of a new or different kind of accident from any accident previously i
evaluated.
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i The proposed change only involves the removal of the 3.25 limit for extending surveillance intervals and does not involve any 1
change to safety-related equipment.
There is no change to operational configurations nor are any new accident precursors or scenarios created which could result in a malfunction or accident of a different type.
As such, the plant initial conditions ut111:ed in the Final Safety Analysis Report (FSAR) for the Design Basis Accident analyses remain valid and the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
3)
The proposed change does not involve a significant reduction in a margin of safety.
The margin of safety is currently based on an allowable extension of 25 percent to the specified surveillance interval with the combined time interval for any three (3) consecutive surveillance intervals not to exceed 3.25 times the specified _
Dockct No3. 50-352 50-353 I
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interval.
The proposed removal of the limit of 3.25 times the j
specified surveillance interval does not result in a reduction in a margin of a safety.
This proposed change has been determined to result in a net safety benefit.
This safety benefit is realised when a surveillance interval is extended at a time when conditions are not suitable for performing the surveillance or a forced shutdown is required to comply with the i
surveillance limit.
Therefore, the safety benefit of allowing the unrestricted use of the 25-percent extension to surveillance t
intervals outweighs any benefit derived by limiting three (3)
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consecutive surveillance intervals to the 3.25 limit.
Therefore, this proposed change does not reduce a margin of safety.
Information Supporting an Environmental Assessment An environmental assessment is not required for the changes proposed by this Change Request because the requested changes i
conform to the criteria for ' actions eligible for categorical exclusion" as specified in 10 CPR 51.22(c)(9).
The requested changes will have no impact on the environment.
This Change Request does not involve a significant hazards consideration as discussed in I
the preceding section.
This Change Request does not involve a significant change in the types or significant increase in the amounts of any effluents that may be released offsite.
In addition, i
this Change Request does not involve a significant increase in individual or cumulative occupational radiation exposure..
Dock;t NoJ. 50-352 50-353 Conclusion The Plant Operations Review Committee and the Nuclear Review Board have reviewed these proposed changes to the TS and have concluded that they do not involve an unreviewed safety question nor a significant hazards consideration, and will not endanger the health and safety of the public,..
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