ML20010J019
| ML20010J019 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/16/1981 |
| From: | Mroczka E NORTHEAST NUCLEAR ENERGY CO. |
| To: | Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| MP-1-1882, RO-81-25-1P, NUDOCS 8109290509 | |
| Download: ML20010J019 (1) | |
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Mr. Ronald C. Haynes Director, Region I September 16, 1981 U.S. Nuclear Regulatory Commission MP-1-1,882-
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REFERENCE:
Docket Number 50-245 Provisional License DPR-21
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Dear Mr. Haynes:
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Occurrence 81-25/1P as required by the Millstone Unit 1 Technical
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Specifications.
On September 15,1981 at 1040 hours0.012 days <br />0.289 hours <br />0.00172 weeks <br />3.9572e-4 months <br />, while operating in the "startup" mode with reactor power at less than one (1) parcent of rated, a voltage fluctuation in the 125 VDC electrical system resulted in spurious isolation of the ATWS System, initiating automatic trip of both reactor recirculation pumps.
Since the pumps were operating at minimum speed at the time of the event, pump coastdown and,matural circulation maintained recirculation loop flow.
Since this condition is not annunciated, Control Room personnel were not alerted to the event.
Subsequently, the Main Steam Isolation Valves were closed to perform turbine testing.
The resulting pressure increase in combination with incertion of colder water due to the recirculation pump trip resulted in higher moderator density and an IRM hi-hi neutron flux scram at 1057 hours0.0122 days <br />0.294 hours <br />0.00175 weeks <br />4.021885e-4 months <br />.
Additional information, including immediate and long-term corrective actions, will be provided in a 14-day followup report.
Yours truly, NORTHEASTNUCLEARENERGYCOMPpNY
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J. Mroczka Station Superintendent Millstone Nuclear Power Station EJM/MJB:sjr cc:
Director, Office of Management Information and Program Control, Washington, D.C. (2)
U.S. Nuclear Regulatory Commission, c/o Document Management Branch, Washington, D.C. 20555 8109290509 810916
{DRADOCK 05000245 PDR
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