Earthquake

Plant Status

  • Sustained nuclear fission did not occur at the Fukushima Daiichi nuclear energy facility last week, Japan’s Nuclear and Industrial Safety Agency said, confirming earlier reports from Tokyo Electric Power Co. Plant employees detected a trace amount of radioactive xenon-135 gas in the reactor 2 containment vessel last week, which led to initial concerns there might have been an ongoing nuclear reaction in the vessel. After investigation, TEPCO said the xenon was produced through spontaneous fission, a form of radioactive decay. NISA said the density of the xenon did not change when a boric acid solution was injected into the reactor, demonstrating that criticality was not occurring.
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Monitoring Used Nuclear Fuel Pools

Responding to Fukushima: Part 3 of a 5-Part Series

The events at Fukushima unveiled an important lesson to the nuclear industry on the need to remotely monitor water temperature and levels in used fuel storage pools during an extended loss of power. In particular, when power was lost at Japan’s Fukushima Daiichi reactors, the systems the plant relied on to monitor the used fuel pools were inoperable. That loss led some to erroneously conclude that there was no water in the spent fuel pool at reactor 4—a conclusion that was later proven to be false.

The industry supports the Nuclear Regulatory Commission’s (NRC) recommendation that U.S. nuclear energy facilities enhance used fuel pool monitoring instrumentation. The storage pools protect used fuel rods under 40 feet of water to allow radioactivity in the fuel to safely decrease. Adding backup monitoring equipment enables operators to know when they need to take action to maintain water level and temperature of used fuel storage pools in the unlikely event that installed systems have been disabled.
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Plant Status

  • Workers at the Fukushima Daiichi nuclear energy facility have taken steps to halt the possibility of localized fission reactions in reactor 2 after detecting trace amounts radioactive xenon in the reactor’s containment vessel, NHK World reports. Xenon is a byproduct of fission. Tokyo Electric Power Co., which operates the facility, reports no significant changes in temperature, pressure and other data from the reactor.
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Emergency Diesel Generator

Responding to Fukushima: Part 2 of a 5-Part Series

Nearly all of the events that occurred at Japan’s Fukushima Daiichi nuclear energy facility following the massive March 11 earthquake and tsunami can be traced to the complete loss of electricity, including backup generators and emergency batteries, that was needed to power reactor cooling systems.

In response to the Fukushima accident, the U.S. Nuclear Regulatory Commission (NRC) is re-evaluating the agency’s “station blackout” requirements for dealing with power outages. U.S. nuclear plants are required to have a minimum of four hours of emergency power; many plants exceed that requirement. That’s in addition to the several locomotive-sized diesel generators that provide layer upon layer of backup power for systems to safely shut down and maintain a reactor should electricity from the grid be disturbed.
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Flood Protection Dike

Responding to Fukushima: Part 1 of a 5-Part Series

U.S. nuclear energy facilities are highly unlikely to experience the devastating combination of a massive earthquake and tsunami that crippled the Fukushima Daiichi power plant in Japan, but the events there underscored the need to guard against even very unlikely combinations of extreme natural forces.

The nuclear energy industry agrees with most issues the U.S. Nuclear Regulatory Commission has identified since Fukushima to complement existing seismic and flood protection programs.
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Activity ID: 1002943 Activity Name: NEI Remarketing Safety Activity Group Name: Remarketing Safety First