The reprocessing of nuclear waste is indeed possible, and some countries have already adopted a recycling strategy. The US is using underground repositories for waste disposal, although some research has begun toward adopting new recycling methods for fission products.
What is Nuclear Waste Reprocessing?
During nuclear reprocessing, the waste of nuclear power plants is chemically reprocessed in order to extract the plutonium and the remaining uranium out of the radioactive fission products.
Reprocessing may take place for several reasons:
- The production of plutonium to be used for nuclear weapons.
- The reprocessed plutonium to be used as a fuel for thermal reactors.
- The reprocessed uranium to be re-used as a fuel, although this is not affordable under certain circumstances.
- All actinides produced during reprocessing to be used as fuel by breeder reactors.
- To significantly reduce the volume and radioactivity of nuclear waste.
Separation Technologies used in Nuclear Waste Recycling
The basic and most prevalent method used for reprocessing nuclear waste is Plutonium and Uranium Recovery by EXtraction or PUREX. It is a liquid-liquid technique that extracts plutonium and uranium independently from the radioactive waste. This basic method has several modifications:
URanium EXtraction or UREX is the process that only extracts uranium instead of plutonium, to produce reprocessed uranium.
TRansUranic EXtraction or TRUEX is a process that removes the transuranic metals from waste by suitable extraction agents.
DIAMide EXtraction or DIAMEX process prevents the formation of organic waste that could end up becoming acid rain.
UNiversal EXtraction or UNEX is used to remove radioisotopes such as strontium (Sr), cesium (Cs), and some actinides.
Arguments against Nuclear Recycling
The recycling of nuclear waste could provide a long-term solution for the energy problem; however there are those who believe waste reprocessing to be a problem itself:
- Nuclear terrorism is a major risk. Separated plutonium, along with other elements such as neptunium, is less radioactive and therefore dangerous, and thus may be an easy target for thieves or terrorists. These elements are used for building nuclear weapons. Only a small quantity of plutonium (~20 pounds) would be enough to build a nuclear weapon.
- One claim is that reprocessing contributes to nuclear proliferation, a strategy that would increase the use and process of weapon usable-materials. This is compounded by the difficulty involved in controlling and keeping track of the quantities used as fuel and the quantities reprocessed and disposed of.
- The recycling process does not eliminate the need for storage and disposal facilities since reprocessing itself produces further waste such as low-level contaminated uranium. This could require the building of new reprocessing facilities to recycle the low-level waste.
- The cost of nuclear waste reprocessing is too high. Recycling and using plutonium for reactor fuel is far more expensive than using the original uranium fuel and then disposing it. Furthermore, the operation of fast reactors that burn up plutonium is more expensive compared to conventional reactors. These reactors run a greater risk of failure or damage, and they are less reliable.
The Situation Today
Nuclear waste recycling is possible. The questions that arise have to deal with the efficiency and the cost of the process.
France for example, employed a nuclear waste reprocessing plan as soon as they started using nuclear energy back in the 1970s. The waste is transferred via train to a recycling facility in La Hague. During these years no terrorist incident or accident has been reported.
Similar plans are adopted by the UK, Russia, Japan, and India, although reprocessing is an expensive procedure. These facilities may cost approximately $20 billion.
In 1977, the United States decided not to follow a recycling strategy. The tactic that the US adopted was to dispose of the nuclear waste in underground facilities for thousands of years, which was considered a viable solution. In 2006, President Bush proposed the revival of the program of constructing large commercial scale reprocessing units and fast neutron reactors. Congress approved the project for basic research only and testing of small scale facilities, thus funding it with $179 million for the year 2008.