ML20034G552
| ML20034G552 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 03/02/1993 |
| From: | Depuydt M COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20034G553 | List: |
| References | |
| GL-90-09, GL-90-9, NUDOCS 9303100076 | |
| Download: ML20034G552 (6) | |
Text
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Ccmmenw:alth Edisen 10CFR50.90 y1j 1400 Opus Place i
W Downers Grove, !!!inois 60515 i
9 March 2, 1993 Dr. Thomas E. Murley, Director i
Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission i
Washington, D.C. 20555
)
l Attn:
Document Control Desk l
1
Subject:
LaSalle County Station Units 1 and 2 i
Application for Amendments to Facility Operating l
Licenses NPF-11 and NPF-18 Appendix A, Technical Specifications l
Snubber Visual Inspection Intervals l
EC Docket Nos. 50-373 and 50-374
Reference:
Generic Letter 90-09, " Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions", dated l
December 11, 1990.
I
Dear Dr. Murley:
In accordance with 10 CFR 50.90, Commonwealth Edison (CECO) proposes to amend Appendix A, Technical Specifications, of Facility Operating Licenses t
The proposed amendment requests changes to Technical Specification surveillance requirements 4.7.9.b and 4.7.9.c, which deals with i
snubber visual inspection intervals and corrective actions.
The amendment request would change the Snubber Visual Inspection Intervals and Corrective Actions in 4.7.9.b. and 4.7.9.c to the alternative requirements provided in Generic Letter 90-09, " Alternative Visual Inspection Intervals and l
Corrective Actions".
i In addition to the changes to the snubber visual inspection schedule, minor changes are requested to Section 4.7.9.e of both Unit 1 and 2 Technical l
Specifications. Wording related to the first refueling shutdown is removed from the specification of both units, since the current surveillance frequency is at least once per 18 months. Also Footnote
- is being removed from Section 4.7.9.e of Unit 1 Technical Specifications, because Unit 1 is past Cycle 2, currently in Cycle 6.
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050041 i
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2 ZNLD/2510/17 9303100076 930302 I
DR ADOCK 0500 3
1
Dr. Murley March 2, 1993 l
i The amendment request is subdivided as follows:
i 1.
Attachment A provides a description of the proposed changes to the Technical Speci cations.
l 1
2.
Attachment B includes the marked-up Technical Specification page with the requested changes indicated.
l 3.
Attachment C describes CECO's evaluation performed in accordance with 10CFR50.92(c), which confirms that no significant hazards consideration is involved.
4.
Attachment D provides the Environmental Assessment.
l This proposed amendment has been reviewed and approved by both CECO On-Site and Off-Site Review in accordance with Commonwealth Edison procedure.
l Commonwealth Edison is notifying the State of Illinois of this application for amendment by transmitting a copy of this letter and its attachments to the j
designated State Official.
To the best of my knowled5 and belief, the statements contained above are true and correct.
In som respects, these statements are not based on my personnel knowledge, but upon information furnished by other Commonwealth Edison and contractor employees. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
Please direct any questions you may have concerning this amendment request to this office.
l l
Respectfully, M! county of be j
s w e of WM/%',"?,*[
?
W10bpagdh Notary Public j i6 Mary Beth Depuydt
/
' Nuclear Licensing Administrator l
i Attachments:
A.
Description and Evaluation of the Proposed Changes l
B.
Marked-up Technical Specification Pages l
C.
Evaluation of Significant Hazards Consideration t
D.
Environmental Assessment j
cc: A.B. Davis, Regional Administrator - RIII.
D. Hills, Senior Resident Inspector - LSCS l
R.L. Stransky, Project Manager - NRR Office of Nuclear Safety - IDNS
,, OFFICI A L SEA '
I SANDRA C L NOTARY pDBUC. STAif 0['h ojg 3.DjSiON EXP;RES C/25/94 ZNLD/2510/18
l j
i l
ATTACHMENT A i
DESCRIPTION OF SAFETY ANALYSIS OF THE PROPOSEQ_QWLNGES A.
DESCRIPTION OF THE PROPOSED CHANGE The proposed Technical Specification Amendment would change the Snubber Visual Inspection Intervals and Corrective Actions, contained in Surveillance Requirement 4.7.9.b. and 4.7.9.c., to the Alternative Requirements Provided in Generic Letter 90-09, " Alternative Visual Inspection Intervals and Corrective Actions".
B.
DESCRIPTION OF THE CURRENT REQUIREKEN]
The current Technical Specification Surveillance 4.7.9 deals with the r
l surveillance requirements for the augmented inservice inspection program for snubbers.
Section 4.7.9.b desr.ribed the method by which visual inspection intervals i
are determined.
Sertion 4.7.9.c defines the visual inspection acceptance criteria to which tLe snubbers surveillance is performed. The current visual inspection schedule is based on the number of inoperable snubbers found during the previous visual inspection and assumes that refueling l
intervals will not exceed 18 months.
Depending on the number of l
inoperable snubbers found per inspection period and the previous occurrences, the inspection interval may change.
1 C.
.B6SES FOR THE CURRENT REOUIRR EMI The visual inspection frequency is based upon maintaining a constant t
level of snubber protection to each safety-related system. Therefore, i
the required inspection interval varies inversely with the observed snubber failures on a given system and is determined by the number of inoperable snubbers found during an inspection of each system.
In order to establish the inspection frequency for each type of snubber on a safety-related system, it was assumed that the frequency of snubber failures and initiating events is constant with time and that the failure of any snubber on that system could cause the system to be unprotected j
and to result in failure during an assumed initiating event.
Inspections i
performed before that interval has elapsed may be used as a new reference point to determine the next inspection. However, the results of such early inspections performed before the original required time interval has elapsed (nominal time less 250 may not be used to lengthen the required inspection interval. Any inspection whose results require a shorter inspection interval will override the previous schedule.
The acceptance criteria are to be used in the visual inspection to determine OPERABILITY of the snubbers.
For example, if'a fluid port of a hydraulic snubber is found to be uncovered, the snubber shall be declared inoperable and shall not be determined OPERABLE via functional testing.
ZNLO/2510/19
ATTACHMENT A
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DESCRIEJ10ll OF SAFETY ANALYSIS OF THE PROPOSED CHAl!GES D.
DESCRIPTION OF THE NEED FOR AMENDING THE TECHNICAL SPECIFICATIONS Generic Letter 90-09 presents the NRC Staff alternative requirements for snubber visual inspection intervals and corrective actions.
LaSalle I
County Station (LaSalle) has a large number of snubbers (greater than 400) and there have not been any recent failures which would reduce the current inspection frequency.
l The current Technical Specification 4.7.9 snubber visual inspection schedule could become restrictive, requiring plant shutdowns due to increased inspection frequencies as well as a significant increase in radiological exposure to plant personnel.
Basing the snubber visual inspection frequency on the number of unacceptable snubbers found during the previous inspection in proportion to the sizes of the various snubber populations or categories should allow inspections and corrective actions i
l to coincide with plant outages.
The ability to extend the visual r
inspection surveillance interval to up to 48 months would reduce the i
resources spent on inspections and reduce adiological exposure to plant l
personnel.
i l
E.
DESCRIPTION OF THE AMENDED TECHNICAL SPEC.FICATION REQUIREl!EMI These changes include recommended changes to the text of the surveillance requirements for Visual Inspections and Visual Inspection Acceptance l
Criteria. As stated in the Generic Letter, the new visual inspection schedule maintains the same confidence level as the existing schedule.
The proposed inspection schedule is based on the number of unacceptable j
snubbers found during the previous inspection in proportion to the sizes of various snubber populations or categories.
The snubbers may be categorized, based on their accessibility during power operation, as i
accessible or inaccessible.
These snubbers may be examined separately or i
jointly.
LaSalle will make and document that decision before any i
inspection and shall use that decision as the basis upon which to determine the next inspection interval for that category. A snubber is considered unacceptable if it fails to meet the acceptance criteria of the visual inspection.
The inspection schedule provided in the Generic Letter is based on a fuel cycle of up to 24 months and may be as long as two fuel cycles, or 48 months for plants with other fuel cycles, depending on the number of unacceptable snubbers found during the previous visual inspection.
LaSalle currently has an 18 month fuel cycle and therefore proposes to incorporate the 48 month option, which would allow up to a three cycle frequency depending on the number of unacceptable snubbers found during the previous inspection period.
If a review and evaluation can not justify continued operation with an unacceptable snubber, the snubber will be declared inoperable and the action requirements will be met.
To j
determine the next surveillance interval, an unacceptable snubber may be reclassified as acceptable if it can be demonstrated that the snubber is operable in its as-found condition by performance of a. functional test and if it satisfies the acceptance criteria for functional testing.
ZNLD/2510/20
ATTACHMENT A f
DESCRIPTION OF SAFE 1Y ANALYSIS OF THE PB0 POSED CHANGES 1
E.
DESCRIPTION OF THE AMENDED TECHkICALS_P_ECIFICATION REQUIREMENT (continued)
All snubbers found connected to an inoperable common hydraulic fluid i
reservoir shall be counted as unacceptable for determining the next i
inspection interval.
For instance, if a fluid port of a hydraulic snubber is found to be uncovered, the snubber is to be declared 2
unacceptable and shall not be determined acceptable by functional testing.
4 The next visual inspection interval may be twice, the same, or reduced to as much as two-thirds of the previous inspection interval.
The inspection interval depends on the number of unacceptable snubbers found in proportion to the size of the population or category for each type of snubber included in the previous inspection interval.
Table 4.7.9-1, Snubber Visual Inspection Interval, duplicates Table 4.7-2 in enclosure B of the Generic Letter. As stated in the notes f*' lowing the table, interpolation is permitted between population or cate33ry sizes and the number of unacceptable snubbers.
Interpolation is conservative, because any rounding is done to the next lower integer for the value of unacceptable snubbers in Columns A, B, or C if that integer includes a fractional value of unacceptable snubbers as determined by interpolation.
If the number of unacceptable snubbers is equal to or less than the number in Column A of Table 4.7.9-1, the next inspection interval may be twice the previous interval but not greater than 48 months.
If the number of unacceptable snubbers is equal to or less than the number in Column B of Table 4.7.9-1, the next inspection interval shall be the same as the previous interval.
If the number of unacceptable snubbers is equal to or greater than the number in Column C of Table 4.7.9-1, the next inspection interval shall be two-thirds of the previous interval.
However, if th: r.urber of unacceptable snubbers is less than the number in Column C, but greater than the number in Column B, the next interval shall be reduced proportionately by interpolation, that is,.the previous interval shall be reduced by a factor that is one-third of the ratio of the difference between the number of unacceptable snubbers found during the previous interval and the number in Column B to the difference in the numbers in Columns B and C.
The provisions of Specification 4.0.2 are applicable for all inspection intervals up to and including 48 months.
The flexibility provided by 4.0.2 allows reasonable planning of unit outages and surveillance scheduling.
In addition to the changes to the visual inspection surveillance requirements, minor. changes were made to section 4.7.9.e of both Unit 1 and 2 Technical Specifications. Wording related to the first refueling shutdown is removed from the specification of both Units, since the current syrveillance frequency is at least once per 18 months. Also, Footnote is being removed from specification 4.7.9.e of Unit 1 Technical Specifications, because Unit 1 is past cycle 2.
ZNLD/2510/21
ATTACMENT A
{
DESCRIPTION OF SAFETY ANALYSIS OF THE PROPOSED CHANGES i
F.
IIMES FOR THE AMElEID TECHNICAL SfECIFICATION REQUEST 1
l The Bases for Section 4.7.9 of the Technical Specification have been i
changed to agree with the changes to the specification. The visual inspection. frequency will be based on maintaining a constant level of snubber protection to the safety related system, as given in Generic Letter 90-09, " Alternative Visual Inspection Intervals and Corrective Actions". Therefore, the new schedule is based on the number of unacceptable snubbers found during.the previous inspection in proportion l
to the sizes of various snubber population or categories.
l
!i LaSalle has not had any failures determined by snubber visual j
inspections, so the Snubber Visual Inspection Period has been maintained at an 18 month schedule.
The new inspection schedule maintains assurance of snubber operability by basing future inspection periods on the number of failures of a given snubber type and manufacturer. As stated in j
Generic Letter 90-09, the new schedule of inspections maintains the same i
confidence level as the existing schedule.
l l
i G.
SCHEDULE i
i CECO requests that this proposed amendment be approved prior to the start of the Unit 2 fifth refuel outage, L2R05, which is preseritly scheduled to 4
begin in September of 1993.
It is also requested that this amendment be made effective on the date of issuance, j
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ZNLD/2510/22
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