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| Entered date | Event description | |
|---|---|---|
| ENS 52682 | 15 April 2017 13:03:00 | During shutdown activities with the reactor subcritical, actions were being taken to remove 11 Reactor Feed Pump from service in support of a scheduled refueling outage. Reactor Water Level on Safeguards level instrumentation dropped below +9 inches, which resulted in a valid Reactor Protection System (RPS) Scram signal and Partial Group 2 Primary Containment Isolation System (PCIS) signal. All systems functioned as required. Reactor Water Level on Safeguards instrumentation was restored to greater than +9 inches immediately. RPS and PCIS logic was reset. There was no impact to the health and safety of the public as a result of this event. This actuation of these systems is being reported per 10 CFR 50.72(b)(3)(iv)(A) as an event that resulted in a valid actuation of any of the systems listed in 10 CFR 50.72(b)(3)(iv)(B). The NRC Resident Inspector has been notified. |
| ENS 50364 | 14 August 2014 08:58:00 | The service water radiation monitor system will be rendered nonfunctional during planned preventive maintenance. As a result, this represents a loss of emergency assessment capability and is reportable per 10CFR50.72(b)(3)(xiii). The planned maintenance is expected to last 4 hours. During this time, plant parameters will be monitored and sampling will be performed which will support sustaining the health and safety of the public during this planned maintenance activity. The NRC Resident Inspector will be notified prior to removing the service water radiation monitor from service. |
| ENS 49819 | 11 February 2014 20:35:00 | While cycling AO-2382A (TORUS-DW VAC BREAKER) for required surveillance testing, (the vacuum breaker) did not indicate fully closed on all available indicators. The procedure for this condition was utilized to continue to cycle the vacuum breaker to achieve closed indication on all available indicators. The vacuum breaker was cycled a total of four (4) times and dual indications were present for approximately six (6) minutes. During the six (6) minutes that the vacuum breaker indications did not show fully closed, the Technical Specification Limiting Condition for Operation (TS LCO) requirement was not met. The Monticello Safety Analysis assumes all eight (B) vacuum breakers are closed, therefore this condition is being reported per 10CFR50.72(b)(3)(ii)(B) and per 10CFR50.72(b)(3)(v)(D). The vacuum breakers are all capable of performing their design function and all safety related equipment is operable." The NRC Resident Inspector has been notified. The same vacuum breaker failed its surveillance test in a similar fashion on February 7, 2014 (See EN #49808). The surveillance test for this vacuum breaker is due again on February 18, 2014. |