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| Entered date | Event description | |
|---|---|---|
| ENS 40719 | 2 May 2004 04:09:00 | Operators inserted a manual scram at 0217 (EDT) in anticipation of torus bulk temperature approaching 110 degrees F following an Electromatic Relief Valve (ERV) failing to close during ERV testing. Technical Specification 3.3.2.e requires the insertion of a manual scram prior to torus bulk temperature reaching 110 degrees F. The maximum average torus temperature was 104 degrees F. Operators opened ERV 123 at 0209 for post maintenance testing from approximately 19% power. The ERV subsequently stuck open. Operators performed the off-normal procedure for a stuck open ERV, but this failed to shut the valve. This ported steam from the reactor vessel to the torus resulting in an uncontrolled torus temperature rise. Operators placed torus cooling in service but this did not stop the rising torus temperature. Following the manual scram, cooldown, and depressurization, shutdown cooling is being placed in service. Immediately following the manual scram, a turbine trip signal actuated the logic for high pressure coolant injection. High pressure coolant injection actuated and operators controlled level above 53 inches. With the ERV stuck open, the cooldown rate could not be controlled. The cooldown rate was approximately 190 degrees F during the first hour following the scram. All control rods fully inserted into the core. Decay heat is being removed by shutdown cooling (in service at the time of the report). The operators intend to cooldown to cold shutdown. The electrical buses are stable. Nine Mile Point Unit 2 was not affected. The licensee notified the NRC Resident Inspector. |
| ENS 40478 | 26 January 2004 11:15:00 | This is a notification of a transitory Notification of Unusual Event. Nine Mile Point Unit 1 experienced a transitory low intake bay level due to icing. This condition was resolved by shifting circulating water flow from reverse flow to normal flow. This met Emergency Action Level 8.4.3 for low fore bay level less than 238.8 feet. The duration of this event was from 0941 (EST) to 0943. While returning reactor power to 100%, an unrelated problem (plant computer) halted power ascension at 92.4% (from a stable 90% reactor power). The licensee notified the NRC Resident Inspector and the state and local government through their "warning point" emergency notification system. |