*Power Reactor Event Number: 49260 Facility: MILLSTONE Region: 1 State: CT Unit: [ ] [ ] [3] HOT STANDBY AUTOMATIC REACTOR TRIP ON LOW STEAM GENERATOR WATER LEVEL The loss of a non-vital 480v bus resulted in a feedwater transient that caused steam generator water level to lower below the automatic reactor trip setpoint. The reactor trip and plant response was uncomplicated with all rods being inserted into the core. The auxiliary feedwater system automatically actuated and is currently being to used to feed the steam generators. Decay heat is being removed via the steam dumps to the condenser. No relief valves or safeties lifted during the transient. The plant is currently stable in Mode 3 at normal operating pressure and temperature and is in its normal shutdown electrical lineup. There was no impact on Unit 2 which is currently operating at 100% power. *The licensee has notified state and local authorities and the NRC Resident Inspector. Independent Spent Fuel Storage Installation Event Number: 49263 Rep Org: SUSQUEHANNA Licensee: PPL SUSQUEHANNA LLC Region: 1 City: ALLENTOWN State: PA County: LUZERNE DEGRADED NEUTRON SHIELDING FOR A SPENT FUEL CASK "PPL Susquehanna, LLC became aware of a reduction in the effectiveness of a spent fuel confinement system at 0430 [EDT] on Saturday August 10, 2013. One of the safety barriers in a spent fuel cask is the water filled volume of the cask which provides neutron shielding. This volume is normally filled with approximately 670 gal of demineralized water. It has been determined that the neutron shielding volume was not completely filled. The cask neutron shield volume is currently being filled. The loaded spent fuel canister is currently located in the reactor building on the refuel floor and has been located there for the duration of the event. Investigation is currently in progress concerning personnel radiation exposure. The lack of neutron shielding represents a significant reduction in the effectiveness of a spent fuel storage cask confinement system which is an 8 hour reportable condition under 10CFR72.75(c)(2). This also represents a dry fuel storage safety system that was disabled or failed to function which is a 24 hour reportable condition under 10CFR72.75(d)(1)." The cask was a TransNuclear NUHOMS-61BTH. Personnel on the refuel floor were equipped with neutron dosimetry. The licensee notified the NRC Resident Inspector and will notify the Commonwealth of Pennsylvania. nrc.gov/reading-rm/doc-collections/event-status/event/en.html
Posted on: Mon, 12 Aug 2013 11:22:59 +0000
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