Nuclear reactors are very safe! The likelihood of a nuclear accident is remote. However, if one happens, it is likely to make a really big hole in the ground and to cover a huge area with fallout. That’s what happened on April 1986 at Chernobyl.* The fallout traveled to Wales, Norway, Germany, and left part of Ukraine too radioactive (apparently) for human habitation, although – in the absence of humans – wildlife seems to be thriving in the area.

Lest one think such things only happen at poorly run Russian/Soviet power plants, a serious incident also occurred in Unit 2 at Three Mile Island, an American nuclear power plant. The reactor vessel was destroyed with the release of a substantial amount of radioactive material. Unit 2 cost US$700 million to build and had been generating electricity for just 3 months prior to March 1979 incident. One billion dollars was spent on the initial site clean up, but it has not been restored to “greenfield” standards.* No nuclear plant has been built in the USA since then.
* & & others

Other serious nuclear accidents – some were termed “meltdowns” – have occurred at the following: Chalk River NRX, 1952; EBR-1, Idaho; Windscale England, 1957; Santa Susana, Simi Hills, California, 1959; SL-1, Idaho, 1961; Enrico Fermi, Michigan, 1966; Chapelcross, Scotland, 1967; Jaslovske Bohunice, and Czechoslovakia, 1977.* Apparently, “meltdown” incidents have also occurred aboard Soviet nuclear submarines.

Odd scenarios with terrorists crashing jumbo jets onto a nuclear power plant have been suggested. Engineers claim that this would not damage super-thick ferroconcrete structures. Nevertheless, one wonders how confident we should be in such statements. Clearly, there will never be a test!

The number of quite minor incidents with nuclear power are unsettling. In July of 2007, two made the news. An earthquake in Japan caused minor damage to a nuclear reactor, which leaked “a small amount” of tritiated water. How much water leaked; where did it go? Several days later, plant operators admitted the leaked water was 50% more radioactive than first reported. They admitted that 400 drums of radioactive waste had toppled, and that 40 of these had spilled! Meanwhile, a fire at a nuclear reactor (Krummel) in north Germany and failure of backup power in another German reactor (Brunsbuttel) were understated by the operator, Vattenfall, causing concern among Germans and outrage among Vattenfall employees, who were forbidden to talk about either incident!

While these cannot be termed “serious”, neither are they trivial. They illustrate the difference between a nuclear reactor and a coal-fired power plant of similar size. Had spills or fires occurred at coal plants, they would not have been newsworthy. That is simply because coal-fired power plants cannot explode disastrously or cause radioactive fallout. If a coal-fired power plant has a leak, plumbers are dispatched to fix it. At a nuclear plant, the plumbers must wear protective suits and may only be permitted on site for (say) 20 minutes, after which a new crew must take over. The area, now contaminated with radioactive material, must be carefully decontaminated so that workers without protective clothing can access it. Each work crew involved may receive several months worth of radiation in their brief exposure. They are then forbidden further exposure to radiation for (perhaps) a year. The incident becomes far more serious and far more costly to bring under control.

The first British nuclear reactor – also the world’s first commercial reactor – Calder Hall was built at Windscale. This was originally designed to produce plutonium for the British nuclear deterrent. In 1957, one of the units was destroyed by fire and released a huge quantity of radioactive material requiring products from neighbouring farms to be destroyed. In 1981, the facility was renamed Sellafield – possibly to “whitewash” its poor reputation. For many years afterwards people have protested the facility, which indeed seems to have been plagued with releases (21 between 1950 and 2000) of radioactivity – the most recent in 2004. This latter incident was not reported until its occurrence had been leaked!

The bottom line appears to be that accidents (incidents) do occur at nuclear facilities. These have often been covered up by authorities, ensuring that the public may be more suspicious of nuclear power than they need to be.