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Nuclear Safety

The very serious, long-range and long-term nature of nuclear accidents makes radioactive fallout and radioactive waste management a global rather than a local issue.

The proliferation of fissile materials, technology, and the rising threat of terrorism, makes the international regulation of the industry a priority for all governments and stakeholders. Nuclear safety has never been a greater polictical issue then it is today.


Although the coal industry is the dirtiest fuel for energy production, and has probably been responsible for more death and suffering in its black and clouded history, the nuclear power generation industry has gained a quasi-pariah status in most countries. This has been due to several landmark accidents, which have led to a general public fear and suspicion of the industry. Gone are the pioneering days of the 1950s and 60s when nuclear development was brandished as an emblem of technological progress, and political power. Although not out, the industry is certainly down.

The IAEA (International Atomic Energy Agency) introduced a logarithmic scale in 1990: the International Nuclear and Radiological Event Scale (INES), which ranks severity of incident or accident from one to seven, where seven is the most severe.

Level 7: Major Accident

Major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures. Only two accidents are classed as the highest level accident:

Fukushima Daiichi nuclear disaster

Japan, 11 March 2011. As the result of an earthquake, a tsunami damaged a series of nuclear reactors, which leaked vast quantities of radioactive materials into the air and sea. The region is now a no-go zone, and the previous residents are, like those of Chernobyl, forever nuclear refugees.

Chernobyl disaster

Ukraine (formally Soviet Union), 26 April 1986. During a test, operators overrode the automatic shut-down mechanism, and removed control rods from the reactor. Without the rods to absorb a high-enough percentage of the neutrons from the fission reactions, a runaway chain reaction resulted, causing a fire, and an explosion. This accident released clouds of radioactive materials which precipitated as far away as north Italy and the UK. The cost in life (at least 9,000 deaths), injury and economics are mounting, and the clean-up solution, a gigantic concrete dome, is still in progress. A true human disaster and a symbol of the dangers inherent in nuclear power.

Level 6: Major Accident

Significant release of radioactive material likely to require implementation of planned countermeasures. There has been only one Level 6 event:

Kyshtym disaster

Soviet Union, 29 September 1957. At the military nuclear waste reprocessing facility, Mayak Chemical Combine (MCC), there was an explosion, which released as much as 80 tonnes of highly radioactive material into the environment. The cause of the explosion was a cooling system malfunction. Due to secrecy around military operations in the Soviet Union, the consequences for the workers at the plant, and inhabitants of the surrounding area, are unknown, but were in all likelihood very serious.

Level 5: Accident with wider consequences

Limited but dangerous release of radioactive material, and several deaths. The reactor core is likely to have been damaged severely.

There have been at least five such incidents:

3-Mile Island

28 March 1979, Harrisburg, Pennsylvania. The core of a reactor overheated due to mechanical failure and human error. The river which provided the cooling water was contaminated by radioactive water from the emergency cooling system. Radioactive steam was released into the atmosphere. A partial meltdown of the core occurred, whereby 1% of the uranium fuel pellet metal cladding melted. Hydrogen gas was generated, which presented the hazard of explosion.

There were no direct deaths or injuries, although long-term health problems from low level exposure to radiation cannot be excluded. A clean-up operation costing billions did little to mitigate the cost to the industry of the loss of public confidence in the nuclear power industry.

Windscale fire

United Kingdom, 10 October 1957. Fire in the core released a cloud of radioactive dust into the environment.

First Chalk River

Ontario, Canada, 12 December 1952. Damaged reactor core.


Switzerland, 21 January 1969. Loss of collant resulted in a partial meltdown. The reactor was in a cavern which could be sealed to prevent wider contamination.


Brazil, 13 September 1987. Caesium chloride radiation source stolen from a disused hospital and sold as scrap. This caused radiation poisoning in hundreds of people.

Since the beginning of the nuclear age, in the 1940s, starting with the deliberate exposure of hundreds of military staff to nuclear weapons testing, there have been scores, if not hundreds, of incidents which have caused deaths and injuries to workers, and contaminated the environment. The long-term effects of radiation to human health and the environment are hard to determine, and epidemiological studies are often the only recourse to link population health to specific events and activities at nuclear sites. These necessarily involve wide bands of uncertainty.

Nuclear Proliferation

The first nuclear bomb was exploded in July 1945 in New Mexiko, USA. Since then the world has added a new nuclear-armed state on average every 9 years, or a nuclear weapon technology-capable state every 5 years.

India nuclear missile
India's nuclear deterrent is a source of national pride. But would Pakistan have developed its weapons if India had stayed non-nuclear?

Nuclear weapons are regulated by the Treaty on the Nonproliferation of Nuclear Weapons (NPT). Under this treaty, states possessing nuclear arsenals prior to 1968 are entitled to maintain their capabilities. Four states have challenged the legitimacy of this principle, and proceeded to acquire weapons. They are not party to the NPL. Another group of countries have developed or inherited (Soviet Bloc) nuclear weapon capabilities.

5 NPL recognised nuclear states: USA, Russia, China, France, UK.

Other states possessing nuclear weapons (not party to the NPL): North Korea, India, Pakistan, Israel.

States possessing weapons technology or formally possessed weapons: Iran, Saudi Arabia, South Africa, Ukraine, Poland, Kazakhstan. The ex-Soviet bloc nations have returned their stockpiles to Russia, and are now officially non-nuclear.

Japan and Iran, and probably several other states, possess what is termed 'breakout capability', meaning they have stockpiled sufficient plutonium and technical capability to fabricate weapons quickly.

Content © Renewable.Media. All rights reserved. Created : December 23, 2015 Last updated :January 15, 2016

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