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Entered date | Event description | |
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ENS 44605 | 27 October 2008 19:21:00 | At approximately 2342 on 10/25/2006, while performing maintenance on the solid state protection system in Mode 5 cold shutdown, Unit 2 received an automatic safety injection signal which resulted in all three ESF Diesel Generators starting and a containment ventilation isolation and containment phase A isolation. All safety injection pumps were in pull-to-lock per plant conditions so that the pumps did not start and no water was discharged into the reactor coolant system. As a result, the ESF Diesel Generators started but did not load as designed. The residual heat removal pumps were stripped from the ESF electrical busses due to the actuation. The first residual heat removal pump was restored within 4 minutes upon the loss of residual heat removal cooling and the second pump was restored within 6 minutes. The residual heat removal system heat exchangers were bypassed at the time of the event and the plant was being allowed to heat up. The cause of the automatic safety injection signal was an inadvertent removal of the block for the low pressurizer pressure safety injection system during the maintenance. Therefore, the signal was a valid signal initiated in response to a parameter satisfying the requirements for initiation of the safety function of the system. Although the actuation was the result of a valid signal, safety injection was not required in this Cold Shutdown Mode of Operation. This notification is being made under 10CFR50.72(b)(3)(iv) as an event that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section. This actuation was initially determined to be due to an invalid signal. Upon further review, it was determined at 1745 on 10/27/08 that the actuation was due of a valid signal. The licensee notified the NRC Resident Inspector. |
ENS 42924 | 21 October 2006 18:26:00 | A contract employee experienced heat exhaustion while working in the Reactor Containment Building in a contaminated area and was considered potentially contaminated because the initial survey for radioactive contamination had not been completed prior to transporting the employee offsite for medical treatment. The licensee notified the NRC Resident Inspector.
At 1758 CDT on 10/21/06, the licensee was notified by their Health Physics Dept. that the contract employee was transported to the Matagorda Hospital in Bay City, TX and was found not to be contaminated. Additionally, all instruments and equipment used in the incident were surveyed and no contamination was found. The licensee notified the NRC Resident Inspector. Notified R4 DO (D. Powers). |