nuclear-news

Emergency shutdown of Nine Mile Point nuclear reactor

Nine Mile Point reactor shut down after primary containment declared inoperable following leak Enformable, 14 Dec 12 The Nine Mile Point Nuclear Station is a two-unit nuclear power plant located in the Town of Scriba, approximately five miles northeast of Oswego, New York, on the shore of Lake Ontario. While both units onsite are General Electric BWRs, the Unit 1 reactor is one of the two oldest nuclear reactors still in service in the United States; New Jersey’s Oyster Creek Nuclear Generating Station is the other.

Event Details

Thursday night, during normal operation, a leakage of nitrogen to maintain Primary Containment pressure within specification was noted at Unit 1 (General Electric BWR Mark 1) in excess of that allowed per Technical Specification 3.3.3.a (An overall integrated leakage rate of less than 1.5% by weight of the containment air per day (La), at 35 psig (Pac).).

This event required the containment system to be declared inoperable, and nuclear reactor to be manually scrammed and shutdown until the utility is able to ensure the safety of the containment system to ensure control of the release of radioactive material.

The primary containment is normally pressurized during reactor operation, and nitrogen used for inerting could leak out of the containment.  An investigation of the containment leakage is in progress.  Decay heat is being removed via shutdown cooling (SDC)…….

Previous containment degradation problems at Oyster Creek Nuclear Power Plant

The NRC has previously noticed that Mark 1 containments are vulnerable to degradation like that which occurred at Oyster Creek Generating Station as a result of water intrusion in the air gap from leakage past the refueling seal and subsequent wetting of the sand cushion at the bottom of the air gap.

Source: NRC Event Notifications    http://enformable.com/2012/12/nine-mile-point-reactor-shut-down-after-primary-containment-declared-inoperable-following-leak/

December 15, 2012 - Posted by Christina Macpherson | general