Nuclear Accident

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Nuclear Accident


a situation in which an uncontrollable chain reaction arises in a nuclear reactor.

The possibility of an uncontrollable chain reaction occurring throughout the entire core of a nuclear reactor is virtually impossible, since the reactor control and protection system would prevent such a situation from ever arising. However, with the considerable sizes of the modern power reactors, localized brief sources of criticality may arise, which may lead to undesirable consequences, such as damage to the reactor or its core as a result of the rise in heat beyond the permissible level. Such a heat flare-up may be caused, for example, by the shifting of the fuel elements or the erroneous removal of a regulating rod.

A nuclear accident may also be caused by the formation of a critical mass in vessels or devices containing fissionable materials. The possibility that such a nuclear accident will ever arise has been virtually eliminated by the strict observance of safety rules when working with fissionable materials.


References in periodicals archive ?
This is the story of how the worst natural disaster in the history of Japan became buried beneath an avalanche of popular Press exploiting apocalyptic nuclear accident scenarios and radiation fears.
The mission recognized the "huge effort and enormous resources" that Japan is devoting to its remediation strategies and activities, with the aim of improving living conditions for people affected by the nuclear accident and enabling evacuees to return home, the IAEA said in a news release.
They stressed the need to undertake all necessary measures to ensure the efficient of any pre-emptive contingency plan to avert any nuclear accident.
A nuclear accident would hit exports of French delicacies and the tourism industry, the world's biggest in terms of visitors, costing France about 160 billion euro ($126 billion), the study said.
In the light of the natural disaster that took place on March 11, 2011, resulting in the Fukushima Daiichi nuclear accident, the UAE places utmost emphasis on nuclear safety as we take stern and progressive steps towards the development of a peaceful nuclear energy programme," Al Kbi said.
Although it is only a few years ago that sites that had witnessed major nuclear accidents were considered places to be avoided, increasing numbers of tourists are now being attracted to sites like Pripyat and Chernobyl, both of which have been the victim of major nuclear accidents in Russia.
This new liability regime provides a clear and predictable process for the public and nuclear industry to deal with compensation for damages that may arise in the case of a nuclear accident," said H.
7DAYS asked if the decision to go beyond international requirements reflects global reaction against nuclear power after the tsunami-led nuclear accident in Japan in March 2011.
The accident in Fukushima (Prefecture) made it clear that a nuclear accident can occur anytime in our country.
THE nuclear accident at Fukushima was a "man-made disaster" and not entirely caused by the tsunami, it has been revealed.
In case of a new serious nuclear accident in Western Europe, around 28 million people on average would be affected by contamination, while in densely populated South Asia, the risk is even greater and it is estimated that radiation will infect about 34 million people, while in East Asia and the US this would be 14 to 21 million people, '' Head of the research team Professor Jos Lelieveld said.
There is a lack of advanced facilities to analyse and mitigate a nuclear accident.