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Dictionary

Nuclear Waste

Humans have been exploiting the planet for its minerals and natural systems for millennia. Today, the power of technology and the ambition for highly materialistic lifestyles for an exponentially growing population, has led to a planet showing signs of breaking under the strain. In what ways is land use unsustainable, and what are the consequences?

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.

International Nuclear and Radiological Event Scale INES

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

Chernobyl disaster

Ukraine (formally Soviet Union), 26 April 1986

Level 6: Serious 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, including 3-Mile Island (1979).

Nuclear safety treaties

  • Comprehensive Test Ban Treaty (CTBT) 1996
  • Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (Assistance Convention), Vienna, 1986.
  • Convention on Early Notification of a Nuclear Accident (Notification Convention), Vienna, 1986.
  • Convention on Nuclear Safety, Vienna, 1994.
  • Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water
  • Vienna Convention on Civil Liability for Nuclear Damage, Vienna, 1963.

Flowers Report

The Flower's Report (actual title: Nuclear Power and the Environment) was the 6th report, issued September 1976, of the UK Royal Commission on Environmental Pollution, so-called after its chairman, Sir Brian Flowers.

The report is seen as a landmark change in the UK government's policies regarding nuclear power. Following the leak at Windscale in 1973, in 1975, there was a proposal to develop a nuclear fuel reprocessing plant in Cumbria at the same site (now Sellafield), also as an international service.

Fuel had to date been managed without sufficient regard to the disposal of waste. Spent nuclear fuel was reprocessed, the usable uranium and plutonium returned to the client, but the useless, and highly dangerous, waste that remained was simply dumped in a temporary storage tank.

The Flowers Report forced the reprocessing industry to take responsibility for nuclear waste, and to plan for long-term disposal. The Windscale proposal was consequently cancelled, obliging waste exporting countries, such as Switzerland to take responsibility for the waste they produced in their nuclear reactors.

Countries like Germany and Switzerland are abolishing their nuclear energy industries, for three main reasons.

1. Nuclear Waste

We do not really have a guaranteed long-term system to store the used uranium for the tens of thousands of years necessary before it is sufficiently less dangerous (it will never be completely safe).

For issues concerning nuclear waste management see the article on 'Nuclear Waste' (click and follow link).

2. Nuclear Accidents

Plant safety has not had a clean record. There have been many accidents involving reactor operations and waste management. The radioactive materials from reactors can cause ionising radiation, which is dangerous for health and the environment. Radioactive fall-out plays very much into a primeval fear. There are also the problems of nuclear terrorism and proliferation of nuclear materials and technology, making the world a less safe place.

Fishermen protesting against the construction of the Kudankulam Nuclear Power Plant, March 2002
Fishermen protesting against the construction of the Kudankulam Nuclear Power Plant, March 2002

For accidents and proliferation issues see the article on 'Nuclear Safety' (click and follow link).

3. Economics

On the plus side, nuclear power generation requires the least space of all the energy sources: 0.5 km2/TWh, compared to, say, wind power, 72 km2/TWh.

Energy Returned on Energy Invested, ERoEI: Nuclear = 5-15 (optimised plants up to 24), Photovoltaic (P/V) 3-7, Wind 16-25, Hydro = 10-270 (very dependent on location). Some reports claim the ERoEI for a new generation of nuclear power plant could be in the hundreds, but for now this remains theoretical.

Uranium supply and economic efficiency: far from being 'almost free', as was first touted in the 1950s, the costs of the nuclear industry still outweigh most other forms of electricity production. The high costs of decommissioning aged plants were typically grossly underestimated in original planning, if they were accounted for at all. As Germany is experiencing, there is no way to have the nuclear industry balance its books without the public purse picking up a large part of the tab.

Insight EU provides the following breakdown of energy subsidies in Europe in 2011: Nuclear = 35 billion Euro, Renewable energy = 30 billion Euro, Fossil fuels = 26 billion Euro, Efficiency measures = 15 billion euro. A large part of the subsidies for nuclear power is in the form of liability insurance, which guarantees the state pays for the costs following severe reactor incidents.

Fukushima after the accident
Fukushima nuclear power station, Japan, following the tsunami and resulting fire on March 11, 2011.

The German federal and Länder governments spent between 1956 and 2006 of the order of 50 billion euro on nuclear energy research and technology. This does not include decommissioning costs for installations, which amounted to 2.5 billion Euro, and 6.6 billion Euro for uranium mining redevelopment. Nuclear power stations in Germany in 2009 had an average operational availability of 74.2%.

Nuclear power is expensive and its waste product, depleted uranium fuel, must be stored for tens of thousands of years till it is 'safe'. Accidents can cause leaks of radiative material which leave large areas of land uninhabitable due to contamination, as well as spreading through the groundwater and sea, entering the human foodchain through fish.

Ticino, Switzerland, received a lot of radiation from the Chernobyl nuclear accident in 1986, from a contaminated raincloud. Japan, Russia, Ukraine, and the USA have all suffered serious nuclear accidents, releasing deadly radiation which will contaminate land, water, and food for thousands of years.

It is being phased out in Germany and Switzerland, but France still makes 75% of its electricity from nuclear power. Italy does not use nuclear power at all. Nuclear reactors in 2015 produced 13% of the world's electricity.

Ionisation occurs when electrons are stripped off or added to an atom, leaving a net charge. Ionising radiation is radiation with the energy to achieve the charging of atoms or molecules, such as air.

Ionising Radiation

Ionisation: these radiations strip electrons off molecules in the air, or any media they pass through, so are referred to as ionising radiation. Although short-lived, alpha particles are much more ionising than beta particles, which in turn are much more ionising than gamma radiation.

Alpha radiation Α

Alpha radiation is a stream of particles. These particles consist of two protons and two neutrons - which is the nucleus of a helium atom. Alpha particles therefore have a charge of +2e, and are detectable because their flightpath is curved by a magnetic field.

Alpha particles ionise the material they passes through, and interact with it. After a short distance, called the range, which depends on its energy, an alpha particle will be absorbed by the medium (e.g. air).

AlphaBetaGamma
Mass6.64 × 10-27 kg9.1 × 10-31 kg0
Charge+2e-e0
ParticleHe nucleuselectron (fast)photon
Shielding requiredA few cm of air1-2 cm of paper, thin metalThick lead
Ions per mm of air for 2MeV1041021

Beta radiation Β

Beta (β) radiation consists of a stream of fast electrons (charge -e).

During the decay of an atomic nucleus, three types of radiation are emitted. When they were discovered, it was not known what they were, so they were called 'A', 'B', and 'C' radiations, but scientists being scientists they used Greek letters: α (alpha), β (beta), and γ (gamma).

In 1897, J.J. Thomson ran an experiment which demonstrated the ratio of charge to mass. This was used to identify the -e charge and very low mass of the beta particles. When a neutron decays into a proton, an electron is released. Beta radiation is a stream of fast-moving, and therefore very energetic, electrons.

Electrons are in the lepton class of sub-atomic particles, along with neutrinos and muons. Example of a beta radiation equation:

Thorium-Protactinium β-decay: 23490Th → 23491Pa + 0-1e + 00νe-,

where νe- is the electron antineutrino.

Gamma radiation Γ

Gamma radiation (γ-rays) is the frequency band of the electromagnetic spectrum with the highest frequency (>1019 Hz), and shortest wavelengths (<10-12 m), and particularly high penetrating power. Gamma radiation is high energy (>105 keV), and ionising, so very destructive to living tissue, and requires many centimetres of lead shielding to absorb.

Gamma radiation was discovered by Paul Villard in 1900, who observed them being emitted from radium, and named by Ernest Rutherford in 1903.

Units of Radiation

Bequerel (Bq). The becquerel (Bq, after the French physicist Henri Becquerel, 1852 - 1908) is the S.I. derived unit for radiative activity, and is equal to one nucleus decay per second.