ML20137L858

Amends Responses to Insp Repts 50-373/83-34,50-373/85-17 & 50-374/85-17.Completion Dates for Issuance of Supplemental Engineering Change Notices Revised to 851231,as Result of Deferral of Certain Unit 1 First Refueling Outage Mods

ML20137L858
Person / Time
Site:	LaSalle
Issue date:	10/24/1985
From:	Massin H COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
0811K, 811K, NUDOCS 8601280115
Download: ML20137L858 (3)

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( U ' J Address Reply to: Post Office Box 767 (f Chicago, Illinois 60690 October 24, 1985

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Mr. James G. Keppler i Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

LaSalle County Station Units 1 and 2 Amended Responses to Inspection Report No. 50-373/83-34 and Nos. 50-373/85-017

& 50-374/85-017 References (a): Cordell Reed letter to J. G. Keppler dated November 18, 1983.

(b): L. O. De1 George letter to J. G. Keppler dated August 16, 1985.

Dear. Mr. Keppler:

1 This letter amends the responses to two inspection reports (References (a) and (b)) by revising two completion dates identified in these responses. These revisions are associated with the deferral of >

certain Unit 1 outage modifications in order to make the first refueling outage more manageable.

IR 50-373/83-34 1 Page 2 of Reference (a) is amended to read "second refueling outage" instead of "first refueling outage" in the fourth line from the bottom of the page.

I JUSTIFICATION i

1. Subject' ir'spection report documented a non-compliance for an unscheduled heat up of LaSalle Unit 1 during Cold Shutdown conditions.

2. Among the corrective actions specified in the' Station's response was the installation of a temperature sensor on the Shutdown Cooling coninon suction header to unambigucusly indicate reactor water temperature when Shutdown Cooling is in operation. The scheduled ccmpletion of the <

installation was to have been first refuel.

3. As part of an aggressive station program to maintain better control of plant activities during unit outages, much work scheduled for the first

> refuel is being deferred to second refuel. This job, installation of the temperature sensor, is among those which will be deferred.

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.. C J. G. Keppler . October 24, 1985

4. Deferral of this work will not increase the likelihood of another unexpected heat-up for several reasons:

The event in question occurred due to the fact that both normal means (clean-up and recirc) for determining reactor coolant temperature were unavailable ~and as a result the currently installed RHR inlet sensor is located such that it is not reliable under all conditions.

The event in question took place as a result' of using the currently installeo RHR inlet temperature instrumentation to monitor reactor coolant temperature. As currently installed this sensor may (did) become unreliable during certain flow conditions of the Shutdown Cooling system.

5. The deferral of this work will not increase the' likelihood of a recurrence for.several reasons:

a) The conditions under which the currently iristalled sensor is unreliable have been investigated and appropriate cautions are in all applicable procedures.

b) The practice of having both normal means of determining reactor coolant temperature unavailable has been discontinued.

c) All other corrective actions required for subject non-compliance have been completed.

6. The installation of the temperature loop will provide a third, reliable means of determining reactor coolant temperature during shutdown conditions. The availability of a third means will increase outage rescheduling flexibility.

IR 50-373/85-017 and 50-374/85-017 Page 9 of Reference (b) is amended to read " December 1,1985" instead of " October 1,1985" in the third line.

JUSTIFICATICN Reference (b) transmitted CECO's response to a Notice of Violation on three items. The third item concerned discrepancies between schematics and associated wiring diagrams in Engineering Change Notices (ECNs). In our response, we indicated that supplemental ECNs would be issued by October 1,1985 to correct a similar error in drawings lE-1-4656AC (ENC.

ED-87) and lE-2-4656AC (ED-61). The revised date for completing this action is December 1, 1985.

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J. G. Keppler _3- October 24, 1985 The ECNs in question support modifications associated with the ATWS Rule. The original target date of October 1 was consistent.with supporting the Unit 1 installation during the first refueling outage, which began this month. Because that work was deferred to the second outage, the priority for revising the ECN was changed in. favor of outage-related work. This delay is acceptable because of.the corresponding delay in the installation scheoule.

The revised date is well in aovance of the proposed start of physical work such that plant installation will not be affected.

If you have any further questions regarding this matter, please direct them to this office.

Very truly yours, H.-Ll. Massin Nuclear Licensing Administrator 1m cc: NRC Resident Inspector - LSCS A. Bournia - tRR l

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