Nuclear Plant Accidents

Mihama Nuclear Power Plant, Japan, 2004

The Mihama Nuclear Power Plant is located in Japan’s Fukui prefecture about 320 km (about 200 miles) west of Tokyo. The plant, which was commissioned in 1976, was the site of several small nuclear-related accidents in 1991 and 2003. On August 9 of 2004, a water pipe in a turbine building adjoining the Mihama 3 reactor burst suddenly as workers prepared to conduct a routine safety inspection. Though no radiation was released, the steam explosion killed 5 plant workers and injured dozens of others. Mihama’s notoriety increased in 2006 when 2 plant workers were injured in an on-site fire.

Davis-Besse Reactor, USA, 2002

located about 10 miles (16km) north of Oak Harbor, Ohio, was commissioned in July of 1978 and is scheduled for final shutdown in April of 2017. The plant has racked up a number of safety problems over its lifetime, including being struck by an F2 tornado in 1998, but the worst of those occurred in March of 2002 when a serious corrosion issue forced the plant to close for roughly 2 years.

During maintenance, plant workers discovered a 6-inch deep corrosion hole in the top of the carbon steel reactor vessel. Only 3/8” of steel cladding remained to prevent a catastrophic pressure explosion and subsequent loss of coolant. If nearby control rod mechanisms would have been damaged in the explosion, shutting down the reactor and avoiding a core meltdown would have been difficult to say the least.

National Reactor Testing Station, USA, 1961

One of the earliest major nuclear power plant accidents occurred on January 3, 1961 when a steam explosion and meltdown killed 3 workers at Stationary Low-Power Reactor Number One (SL-1). The reactor, located at the National Reactor Testing Station roughly 40 miles (60km) west of Idaho Falls, Idaho, was of a now-discontinued design that featured a single large, central control rod.

Jaslovské Bohunice, Czechoslovakia, 1977

Talk about accidents waiting to happen. At the Bohunice Nuclear Power Plant in Jaslovské Bohunice, Czechoslovakia (now Slovakia), all the ingredients for a nuclear disaster were already in place by 1977 when A1, the plant’s oldest reactor, overheated and nearly caused a large-scale environmental disaster. Where to begin? Let’s see… the model KS-150 reactor was of a unique and unproven design from the Soviet Union which was built in Czechoslovakia. Not a good start, and then it gets worse.

Tomsk-7 Reprocessing Complex, USSR, 1993

The Siberian Group of Chemical Enterprises is a group of factories and nuclear power plants located in the Russian city of Seversk. Formerly a Soviet “secret city”, Seversk was until 1992 known as Tomsk-7, which is actually a post office box number. Though former Russian president Boris Yeltsin relaxed some of the restrictions on Seversk (including its name), to this day non-residents are not allowed to visit the city.