ML20042F418

Safety Evaluation Supporting Amends 72 & 56 to Licenses NPF-11 & NPF-18,respectively

ML20042F418
Person / Time
Site:	LaSalle
Issue date:	04/26/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20042F413	List: ML20042F412 ML20042F418
References
GL-84-15, NUDOCS 9005080299
Download: ML20042F418 (4)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMEN 0 MENT NO. 72 TO FACILITY OPERATING LICENSE NO. NPF-11 AND g

MENDMENT NO. 56 TO FACILITY OPERATING LICENSE NO. NPF-18 EI COMMONWEALTH EDISON COMPANY m

LASALLF COUNTY STATION, UNITS 1 AND 2 7g D,0CKET NOS. 50-373 AND 50-374 mt 1.0 Introduction By letter dated July 28, 1987, supplemented March 16 and June 23, 1989, and further clarified July 3 and October 26, 1989 and February 26, 1990, Commonwealth Edison Company (the licensee) requested changes to the Technical Specifications (TS) covering emergency Diesel Generator (EDG) surveillance testing at LaSalle County Station, Units 1 and 2.

The requested changes include: (1) clarification of TS foatuotes which describe 7cceptable methodology b

for EDG testing, and (?) a reduction in the frequency of EDG testing required by TS ACTIONS. These changes were requested so LaSalle Units 1 and 2 TS would reflect current staff pos'.tions with respect to EDG testing as reflected in Generic Letter (GL) 84-15, " Proposed Staff Actions to Improve and Maintain Diesel Generator Reliability."

2.0 Evaluation GL 84-15 describes methods for EDG testing which, if implemented, would mnimize tne impact of testing on EDG reliability. These methods include P

engine prelube, modified or slow starts as applicable, and loading in accordance witn vendor recomendations.

Prior to licensing, a footnote was added to Section 4.8.1.1 2 ef the LaSalle TS for the specific purpose of allowing this methodology to be applied to EDG surveillence testing.

m Subsequently, it was determined that the wording of the footnote was ambiguous, and that clarification was required. The licensee was requested to propose a change to the TS wherein the footnote would be changed to clarify its intent

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and applicability.

In addition, it was suggested that the licensee consider b

deleting the TS requirement to test EDGs at a load " equal to or greater then 2600KW" and substitute a load range.

b The licensee responded to the staff's request and suggestion in their July ?,

1989 letter.

Attachment B to the licensee's letter is a copy of the applicehle b

portions of the LaSalle TS which has been annotated to indicate where E

modified testing is applicable, and where a load range of 2400-2600KW has been l

substituted for " equal to or greater than 2600KW."

In addition te the annotated TS, the licensee provides three, nev. explanatory footnotes.

These footnotes cover; (1) when engine prelube prior to testing is acceptable, 2) when 9005080 m 900426 PDR ADOCK 05000373 P

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2 fast starts and loading are and are not required, and 3) a statement that transients outside the above EDG load range during testing does not invalidate the test.

The staff has reviewed the licensee's submittal and has concluded that the proposed TS changes, with new footnotes, accurately reflect the current staff's position regarding EDG testing methodology as documented in GL 84-15.

The proposed TS changes relative to these footnotes as shown in Attachment B to the licensee's July 3,1989 letter are, therefore, acceptable.

It should be noted that for purposes of this review, the staff interprets "prelube" to mean the deliberate act of pressurizing the entire diesel engine lubricating system for a specified period of time to ensure adequate lubrication to all mot ing parts prior to activating any engine starting mechanism. This is normally accomplished using a separate, motor driven pump.

In addition to the above footnotes, the licensee has proposed a range of 2400-2600KH for EDG surveillance testino.

The staff has noted that current Standard Technical Specifications (STS)' require EDGs to be loaded during test to " equal tt or greater than (continuous duty rating)." In order to comply with TS rmirements, the staff noted that operators routinely operated EDGs under surveillance test at " greater than (continuous duty rating)." This resulted in routine and continuous overloading of EDGs, a practice that is also detrimental to EDG reliability. The current staff position with respect to loading is that by utilizing a load range, operators will be able to meet TS requirements without routinely overloading the EDGs.

A range of 200KW for an EDG rated at 2600KW is considered by the staff to be adequate in terms of de onstrating full load capability. The staff concludes that the licensee's proposed 2400-2600KW range for EDG testing at LaSalle is consistent with current staff position regarding increasing EDG reliability through changes in EDG testing methodology as reflected in GL 84-15 and is, therefore, acceptable.

By letter dated June 23, 1989, the licensee requested changes to the Action Statements in TS Section 3.8.1.1 to reduce the number of EDG tests required when the plant ac power systems (offsite, onsite, or combation) are degraded.

Under current TS, the licensee is required to test all operable EDGs under any condition of inoperable offsite power, onsite power, or combination of both.

Frequency of required testing varies from within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for the initial test, and once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> thereafter until all ac power systems are restored to operable status.

Under current TS, each EDG could be subjected to as many as 10 starts in a typit:a1 ACTION with a 72-hour H me limit.

The licensee's proposal, as detailed in Attachment B to the October 26, 1989 letter, would delete ACTYONS a-f in the existing TSs and substitute new ACTIONS a-1.

The majo: oifferences between existing and proposed TS are the elimination of EDG testing Nce per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> in favor of one test for each operable EDG during any ACTION, and a change in the time to complete the first test from a minimun of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and a maximum of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to a minimum of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and a maximum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

In addition, the proposed TS add clarifications thet eliminhte the requirement for EDG testing if: (1) the remaining operable l

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,' EDG(s) have t a n successfully tested within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or 2) the inoperable F ecame inoperable due to preplanned preventive maintenance.

- Finally, the F. posed TS include additional ACTION g-1 The staff has determined that EDG operability under conditions involving.

degraded ac power systems can be adequately demonstrated by a single test of each operable EDG under any ACTinN of up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Excessive EDG testing with its potential for EDG degratation as reflected in;the current LaSalle TS

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can be eliminated. Therefore, the licensees's proposal to reduce EDG testing j

under degraded ac conditions to one per operable EDG under any ACTION is-acceptable.

(All LaSalle TS ACTIONS in Section 3.8.1.1 are 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or less.).

The staff has-also determined that the time for completing EDG testing will I

vary with the severity of the ACTION, but in no case should the time constraints impede licensee actions to isolate-and commence correction of the degraded ac power condition. Consequently, the licensee's proposal to set this time for EDG testing completion at 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> for the more serious ACTIONS and 24-hours for the less serious ACTIONS is acceptable.

j in the staff's view, a successful test of an EDG within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> satisfies the requirement to demonstrate operability under any ACTION, and the test need not be repeated.

It is also the staff's view that inoperability of an EDG due to preplanned preventive maintenance has no potential for common mode failure, and testing of the remaining EDGs undeFthese conditions is not required. Therefore, the staff finds the licensee's proposed clarifications regarding elimination of-EDG testing as described above to be acceptable.

In the proposed TS, there are more ACTIONS than in the existing TS. This is due to the manner in which the ACTIONS-are presented; i.e., some are combined in the existing TS, but are covered independently in the proposed TS.

The number of variations of inoperable ac sources, however, is the same. Also, the requirements of the ACTION covering these variations is the same. The proposed TS format is easier to read, but does not add or delete any ACTIONS or alter any completion times, except as discussed above. The proposed TS format with additional ACTIONS is, therefore, acceptable.- This.new format necessitated editorial corrections to the footnote for Limiting Conditions for Operation (LCO)3.8.1.1.b. The staff has reviewed these corrections and finds them acceptable.

Based on its review, the staff has concluded that the licensee's proposed changes to TS Section 3.8.1.1,.are consistent with the' objectives of GL 84-15 in terms of reducing EDG testing and are, therefore, acceptable.

The Bases of the affected specification sections have been modified by-the licensee to include the appropriate diesel generator changes.

Based on our review, we conclude that the changes to these Bases are acceptable.

It should be noted that for purposes of this review, preplanned preventive maintenance is considered by the staff to consist of activities which are intended to enhance EDG reliability / availability, and are conducted on a-

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1 3.0 Environmental Consideration These amendments involve changes to the use of the facility components located within the. restricted area as defined in 10 CFR Part 20. The staff has determir,ed that the amendments involve no significant increase-3 tin the amounts and no significant changes in the types of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational exposure. The staff has previously determined that the amendments' involve no significant hazards-i consideration, and there has been no-public ccament on such finding.

Accordingly, the amendments meet the eligibility cri'eria for categorical-exclusion set forth in 10 CFR 51.22(c)(9).- Pursuantto10CFR51'.22(b),

no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.

i 4.0 Conclusion The staff has concluded, based on the considerations discussed.above, that:

(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the proposed manner, and (2) public such i

activities will be conducted-in compliance with the Commission's regulations and iN issuance of these amendments will not be inimical to the common defense and tecurity or to the health and safety of the public.-

Principal Contributor:

Edward Tomlinson, NRR/OSTB j

Jefferey Harold, NRR/PD32 Paul Shemanski, NRR/PD32 4

Robert Pulsifer, NRR/PD32 Dated:

April 26,1990 i

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