Reprocessing involves dissolving spent nuclear fuel in acid and separating the unused uranium (about 96% of the mass), plutonium (1%) and high level wastes (3%). Most commercial reprocessing takes place in the UK (Sellafield) and France (La Hague). There are smaller plants in India, Russia and Japan. Japan plans to begin large-scale reprocessing at the Rokkasho plant. (In addition, a number of countries have military reprocessing plants.)
Reprocessing is arguably the most dangerous and dirty phase of the nuclear fuel chain. Reprocessing generates large waste streams with no management solution and it separates weapons-useable plutonium from spent fuel.
Proponents of reprocessing give the following four justifications:
1. Reducing the volume and facilitating the management of high level radioactive waste.
However reprocessing does nothing to reduce radioactivity or toxicity, and the overall waste volume, including low and intermediate level waste, is increased by reprocessing. Steve Kidd (2004) from the World Nuclear Association states: “It is true that the current Purex reprocessing technology (used at Sellafield and La Hague) is less than satisfactory. Environmentally dirty, it produces significant quantities of lower level wastes.”
2. ‘Recycling’ uranium to reduce reliance on natural reserves.
However, only an improbably large expansion of nuclear power would result in any problems with uranium supply this century. A very large majority of the uranium separated from spent fuel at reprocessing plants is not reused, but is stockpiled. Uranium from reprocessing is used only in France and Russia and accounts for only 1% of global uranium usage (IAEA, 2006). It contains isotopes such as uranium-232 which complicate its use as a reactor fuel.
3. Separating plutonium for use as nuclear fuel.
However there is very little demand for plutonium as a nuclear fuel. It is used in ‘MOX’ reactor fuel (mixed uranium-plutonium oxide), which accounts for 2−5% of worldwide nuclear fuel, and in a small number of fast neutron reactors.
4. Using plutonium as a fuel so that it can no longer be used in nuclear weapons.
However, reactors which can use plutonium as fuel can produce more plutonium than they consume. Moreover, since there is so little demand for plutonium as a reactor fuel, stockpiles of separated plutonium continually grow and now amount to about 250 tonnes (enough for 25,000 nuclear weapons). Reprocessing has clearly worsened rather than reduced proliferation risks. Addressing the problem of growing stockpiles of separated plutonium could hardly be simpler – it only requires that reprocessing be slowed, suspended, or stopped altogether.
The main reason reprocessing proceeds is that reprocessing plants act as long-term, de facto storage facilities for spent nuclear fuel. Unfortunately this sets up a series of events which has been likened to the old woman who swallowed a fly – every solution is worse than the problem it was supposed to solve:
1. The perceived need to do something about growing spent fuel stockpiles at reactor sites (not least to maintain or obtain reactor operating licences), coupled with the lack of repositories for permanent disposal, encourages nuclear utilities to send spent fuel to commercial reprocessing plants, which act as long-term, de facto storage sites.
2. Eventually the spent fuel must be reprocessed, which brings with it serious proliferation, public health and environmental risks.
3. Reprocessing has led to a large and growing stockpile of separated plutonium, which is an unacceptable and unnecessary proliferation risk.
4. Reprocessing creates the ‘need’ to develop mixed uranium-plutonium fuel (MOX) or fast neutron reactors to make use of the plutonium separated by reprocessing.
5. All of the above necessitates a global pattern of transportation of spent fuel, high level waste, separated plutonium and MOX, with the attendant risks of accidents, terrorist strikes and theft leading to the production of nuclear weapons.
None of this is logical or justifiable on non-proliferation, environmental, public health or economic grounds but it suits the short-term political and commercial objectives of those involved.
(See Friends of the Earth, 2008, for more information on reprocessing.)