ML20198N947
| ML20198N947 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/02/1986 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| CAL-RIII-86-03, CAL-RIII-86-3, NUDOCS 8606060207 | |
| Download: ML20198N947 (3) | |
Text
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,S m 3 CONFIRMATORY ACTION LETTER CAL-RIII-86-003 June 2, 1986 Docket No. 50-373 Docket No. 50-374 Consonwealth Edison Company ATIN: Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL CC690 Gentlemen:
This letter confirms the telephone conversation between Charles E. Norelius of this office and L. DelGeorge of your staff on June 2,1986, related to the apparently irrproper response of the reactcr protection system (RPS) at LaSalle Unit 2 cr June 1. 1986. At that time with the reactor operating at about 83%
power and with a feedwater surveillance test in progress, one of the reactor feedwater purrps increased speed and locked up, causing reactor water level to increase.
Upen reaching the high water level set point both pumps then automatically tripped, causing reactor water level to decrease.
There are indications that reactar water level ',>y have decreased to nominal plus six inches (which is bclow the scram set point of 12.5 inches) but the reactor did not scram. hhen the anomaly was discovered several hours after the event the operating staff initiated a controlled shutdcwn in lieu of manually scramming the reactor and declared an alert. The alert was teminated when hot shutdown Was reachea at alcut 9:30 a.m., June 2.
With regard to this event and to our Augmented Investigation Team (AIT) which is being implemented to evaluate the rcot cause and significance of the event, we understand that ycu will:
1.
Cetermine the cause of the feedwater purap transient.
2.
Conduct a thorough review to determine if water level decreased to or below the scral;i set point.
3.
If water level decreased below the scram level, determine if a scram signal was received by the reactor protection system (RPS).
4.
If such a signal was received, detennine why the reactor did not scram.
5.
If such a signal was not received, or if water level did rot decrease below the scrcn level, determine why the narrow range instrumentation indicated a Icw water level.
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CONFTRMATORY ACTION LETTER Conmonwealth Edison Ccmpany 2
June 2, 1986 6.
Maintain all affected equipment related to the event, including the RPS, in such a manner that it can easily be kept or placed in the "as found" condition. Therefore, minimize any actions which would destroy or cause to be lost (other than necessary to protect the health and safety of the public) any eviderce which would be needed to investigate or reconstruct the event.
7.
Advise the AIT team leader, Mr. Geoffrey Wright, of this office prior to cerductir.g any troubleshooting activities.
Such notification will be soon enough to allow tine for the team leader to assign an inspcctor to observe the activities.
8.
Make available to the AIT all relevant written material related to the installation, testing, and/or modifications to the reactor level switches eric the RPS.
9.
Review operator and shift personnel actions following the event and determine if these actions were in accordance with your procedures and policies. Specifically, determine:
What actions the on-duty operations stoff took following the event.
a.
b.
khen and by whom the event was first identified.
If the event was identified during shift turnover reviews or by c.
scme cther r.ethod.
d.
Why event classification and notification took about 12 hcurs.
- 10. Determine if this problem is unique to Unit 2 or if similar problems could cccur on Unit 1.
- 11. Submit a foimal report of your findings and conclusions to the Region III office within 30 days.
We also understand that startup of Unit 2 will not occur without concurrence of the Regional Adn.inistrator or his designee. Such centurruice will also be obtained for Unit 1 should it be determined thc.t Unit 1 is affected by this event.
CONFIPPATORY ACTION LETTER
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CONFIRMATORY ACTION LETTER Contrenwealth Edison Company 3
June 2, 1986 Please let us know imediately if your understanding differs from that set out above.
Sincerely,
' L,,
s.
Jarites G. Keppler Regional Administrator cc w/ enclosure:
D. L. Farrar, Director of f;uclear Licensing G. J. Diederich, Plant Manager DCS/ESo (RIDS)
Licensing Fee Manager.ent Branch Resident Inspector, RIII Phyllis Dunton, Attorney General's Office, Envircr. mental Control Division
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