ML17199R342
| ML17199R342 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 08/11/1987 |
| From: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| CAL-RIII-87-14, NUDOCS 8708180226 | |
| Download: ML17199R342 (2) | |
Text
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CONFIRMATORY ACTlON LETTER Docket No. 50-249 Conmonwealth Edison Company ATTN:
Mr. Cordell Reed Senior Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
AUG 11 1987 CAL-RIII-87--014 This letter confirms the telephone conversation between William L. Forney of this office and M. Turbak and N. Kalivianakis of your staff on August 10, 1987, related to the feedwater system problems leading to the manual scram which occurred on August 7, 1987, at Dresden Unit 3. At that time, operators were reducing power due to a unrelated Technical Specification required shut-down.
At around 30% power, operators noticed oscillations in the feedwater system and,evidence of,.possible leaks, and initiated a manual scram.
Two leaks were identified; one where a feedwater flow transmitter root valve had sheared off and another where a drain line on the reactor water cleanup system return line had sheared off. The leaks were believed to be the result of feedwater system oscillations. Similar oscillations also occurred on July 11, 1987, when Unit 3 scrarraned from approximately 25% power when the turbine tripped on high reactor water level. With regard to this event and to our Augmented Investigation Team (AIT) which is being implemented to evaluate the root cause and significance of the event, we understand that you will:
- 1.
Detennine the cause of the pipe breaks which occurred, or plan and submit a course of action to determine the cause through monitoring of systems during return to power operations.
- 2.
Detennine and implement corrective actions to repair the damage from these breaks.
- 3.
Conduct a thorough review and analysis of the recurring feedwater system abnormalities.
- 4.
Based on the results of this review, implement corrective actions to avoid future feedwater system transients similar to those which led to the events on July 11 and August 7, 1987.
CONFIRMATORY ACTION LETTER
Conmonwealth Edison Company 2
AUG 11 1S37 We also understand that startup of Unit 3 will not occur without concurrence of the Regional Administrator or his designee.
Please let us know inmediately if your understanding differs from that set out above.
cc:
D. Butterfield, Nuclear Licensing Manager J. Eenigenburg, Plant Manager DCS/RSB (RIDS)
Licensing Fee Management Branch Resident Inspector, RIII Richard Hubbard J. W. Mccaffrey, Chief, Public
- utilities Division E. L. Jordan, Director, Office for Analysis and Evaluation of
-Operational Data D. M. Crutchfield, Director, Division of Reactor Projects lll/IV/V, NRR J. Lieberman, Director, Office of Enforcement Sincerely,
.Original signed bY.
I..., Ber.t Davis A. Be rt Dav i s.
Regional Administrator
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