ML20034B435

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

ML20034B435
Person / Time
Site:	LaSalle
Issue date:	03/15/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20034B433	List: ML20034B432 ML20034B435
References
GL-84-15, NUDOCS 9004270152
Download: ML20034B435 (4)

Text

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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION-SUPPORTING AMENDMENT NO. 72 TO FACILITY OPERATING LICENSE NO. NPF-11 AND' AMENDMENT tio. 56 TO FACILITY OPERATING LICENSE NO. NPF-18 i

COMMONWEALTH EDISON COMPANY LASALLE COUNTY STATION UNITS 1 AND 2 l

DOCKET N05. 50-373 AND 50-374 1.0 Introduction I

By letter dated July 28,1987, supplemented March 16 and June 23, 1989, and f

further clarified July 3 and October 26 1989 and February 26, 1990, Co monwealth Edison Company (the license,e) requested changes to the Technical Specifications (TS) covering emergency Diesel Generator (EDG) surveillance 4

testing at LaSalle-County Station, Units 1 and 2.

The requested changes i

include 1) clarification of TS footnotes which describe acceptable methodology for EDG testing, and 2) a reduction in the frequency of EDG testing required by i

TS ACTIONS.

These changes were requested so'LaSalle Units 1 and 2 TS would reflect current staff positions with respect to EDG testing as reflected in Generic Letter GL 84-15, " Proposed Staff Actions to Improve and Haintain Diesel Generator Reliability."

2.0 Evaluation Gl. B4-15 describes r'ethods for EDG testin minimizetheimpactoftestingonEDGreikability.which, if implemented, would These methods include engine prelube, modified or slow starts as applicable, and loading in accordance with vendor recommendations. Prior to licensing, a. footnote was aoded to Section 4.8.1.1.2 of the LaSalle TS for the specific purpose of i

allowing this methodology to be applied to EDG surveillance testing.

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 i

and applicability.

In addition, it was suggested that the licensee consider deleting the TS requirement to test EDGs at a load " equal to or greater than i

2600KW" and substitute a load range.

t The licensee responded to the staff's request and suggesHon in their J 1989 letter. Attachment B to the licensee's letter is a copy of the applicab portions of the LaSalle TS which has been annotated te indicate where inodified testing is applicable, and where a load range of 2400-2600KW has been substituted for " equal to or greater than 2600KW."

In addition to the i

- annotated TS, the licensee provides three, new, explanatory footnotes.

These footnotescover1)whenengineprelubepriortotestingisacceptable,2)when f

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9004270152 900315 DR ADOCK 0500 i

2 faststartsandloadingareandarenotrequired,and3)astatementthat I

transients cutside 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 foctnotes, accurately reflect the current staff's position regarding EDG testing methodology ts documented in GL 84-15.

The proposed TS changes relative to these footnotes as shown in Attachment B to i

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 deliberste act of press'rizing the entire diesel engine u

lubricating system for a specified period of time to ensure adequate lubrication to all moving 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 2400-2600KW for EDG surveillance testing. The staff has noted that current.

Standard Technical Specifications (STS) require EDGs to be loaded during test to " equal to or greater than (continuous duty rating)."

In order to comily with TS requirements, the staff noted that opetators routinely operated RDGs 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 loac'ing is that by utilizing a load range, operators will be able to meet TS l

requirements wittout routinely overloading tie EDGs. A range of 200KW for an EDG rated at 2600KW is considered by the staff to be adequate in terms of demonstrating full load capability. The staff concludes that the licensee's l

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 chenges to the Action Statements in TS Section 3.8.1.1 to reduce the number of EDG tests required den the plar.t ac power systems (offsite, onsite, or combination) are depraded.

Under current TS the licensee is required to test all operable EDGs under any condition of inope,rable offsite power, onsite power, or combination i

of both.

Frequency of required testing varies from within-1 hour to within 8 i

l hours 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 'ntil all ac power syttems are restored to operable status. Under current TS, each EDG could be subjected to as many as 10 starts in a typical ACTION with a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> time limit.

The licensee's proposal, as detailed in Attachment 8 to the October 26,1989 letter, would delete ACTIONS a-f in the existing TS, and substitute new ACTIONS a-1.

ThemajordifferencesbetweenexistingandproposedTSare the elimination of EDG testing once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> in 1avor of one test for each

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operable EDG during any ACTION, and a change in the time to complete the first test from a minimum of I hour and a maximum of 8 hotws 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 proposea TS add clarifications that eliminate the requirement for EDG testing if 1) the remaining operable s

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3 EDG(s)havebeensuccessfullytettedwithinthepast24 hours,or2)the inoperable EDG became inoperable due to preplanned preventive maintenance.

Finally, the proposed 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 ACTION 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 degradation as reflected in the current LaSalle TS can be eliminated.

under degraded ec conditions to one per operable E06 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 vary with the severity of the ACTION, but in no case should the time constraints impode licensee actions to isolate and commence correction of the degraded ac power condition.

Consequently, the_licenste's proposal to set this time for EDG testing completion at B hours for the more serieus ACTIONS and 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the less serious ACTIONS is acceptable.

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.

Itisalsothestaff'sviewthatinoperabIlityof an EDG due in preplanned preventive maintenance has no potential for common mode failure, and testing of the remaining EDGs utde Fthese 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 mon ACTIONS than irr 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 propcsed TS format is easier to read, but does not add or delete any ACTIONS or aher any completion tines, except as discussed above.

The proposed TS format with e.dditional ACTIONS is, therefore, acceptable. This new format necessiteted editorial corrections to the footnote for Limiting Conditions for Operation (LCO) 3.B.1.1.b.

them acceptable.

The staff has reviewed these corrections and finds 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 tie chinges to these bases are acceptable.

it shculd be noted that for purposes of this review preplanned preventive maintenance is considered by the staff to consist of activities that are conducted on a repetitive basis at scheduled intervals, the purpose of which is to enhance EDG reliebility/ availability, it includes such things as l, II

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i lubrication, fluid replacement, minor adjustments, monitoring activities, Such items as major component replacement or periodic engine etc.

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inspection / teardown are not considered to be preplanned preventive maintenance.

l 3.0 Environmental tensideration 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 determined that the amendments involve no significant increase in the amounts and no significant changes in the types of any effluents thet 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 consideration, and there has been no public coment on such finding.

Acccrdingly, the amendments meet the eligibility criteria for categorical exclusionsetforthin10CFR51.22(c)(9). Pursuantto10CFR51.22(b),

no environmental impact statement or environmental assessment need be

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prepared in connection with the issuance of these amendments.

4.0 tonclusion The staff has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the willnotbeendangeredbyoperationintheproposedmanner,and(2)public such activities will be conducted in compliance with the Comission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor:

Edward Tomlinson, NRR/0STE Jefferey Harold, NRR/PD32 Paul Shemanski, NRR/PD32 Robert Fulsifer, NRR/ru32 Dated: March 15, 1990 1

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