Nuclear plants that can solve a 120-ton waste problem
Russia is attempting to eliminate nuclear waste through an unprecedented international partnership based on fast-reactor technology, which has the potential to win 10 to 15 percent of the world's $ 240 billion nuclear energy market in the near future.
At the Central European Nuclear Industry Forum (Atomex) in Prague last month, Russia’s Rosatom nuclear agency signed a deal to build a fast-neutron nuclear reactor on Russian territory in co-operation with 13 Czech companies. It is called the SVBR-100 project.
Advantages of fast-reactor technology
Chain reaction was key find
The history of bringing fast neutrons under control can be traced back to the Italian physicist Enrico Fermi who, in 1939, speculated that fast neutrons are released during the uranium fission process. He suggested that if the number of neutrons emitted exceeded the number of neutrons absorbed, then a chain reaction could begin. Experiments proved this theory to be correct. The first serious attempts to develop fast-reactor technology were made in the US with the Clinch River Breeder Reactor in 1970, which was closed in 1983. The Soviet Union developed fast-reactor technology as early as the Fifties, successfully testing a number of prototypes until the sodium-cooled BN-600 FBR went into operation at Beloyarsk in April 1980. Russia continues to develop its nuclear reactor technology, with the BN-800 and BN-1200 models currently under construction. The ultimate goal is to produce a commercially successful fast reactor.
Like all nuclear plants, fast-reactor plants to not emit carbon dioxide. But conventional plants produce huge amounts of spent and irradiated fuel that has to be accumulated, stored and monitored as hazardous nuclear waste. This poses a radiological threat for thousands of years. The problem of what to do with it is a major headache for any country that uses atomic energy.
The main advantage of fast-neutron reactor technology over traditional nuclear power plants is that it can utilise this waste product – irradiated or highly-enriched nuclear fuel – in the process of generating energy. Fast reactors also produce far less new nuclear waste than conventional reactors, while some reactors, called fast-breeder reactors, can be used to produce an excess of plutonium, which can then be used in nuclear weapons or recycled to fuel the plant.
According to Leonid Bolshov, professor at the Institute for the Safe Development of Nuclear Energy of the Russian Academy of Sciences, the development of fast nuclear reactors is essential to close the nuclear fuel cycle.“Fast reactors will help us solve one of the most pressing problems connected with atomic energy, and that is what to do with the atomic waste from nuclear power stations that are currently operational.”
In Britain, the Nuclear Decommissioning Authority is considering plans to build two fast reactors at Sellafield in Cumbria to deal with the 120-ton plutonium waste problem there – the world’s largest stock of civilian plutonium. A feasibility study has already been submitted for building the plants, which, if given the go-ahead, could eradicate the British plutonium stockpile by around 2030. This would also have the benefit of generating electricity in the process.
All of the fast reactors tested in the world so far have been experimental models; Russia, the United States and France have considerable experience building and working with experimental fast-neutron reactors.
Russia’s BN-600 reactor, which was operational from 1980 until 2005 in the Ural Mountains, was the most advanced testing ground for the technology. It is now being replaced with the nearby BN-800 reactor, which is close to completion and is based on more advanced development of the same technology.
Powerful sodium unit produces little waste
The BN-600 reactor holds the world record for safely operating fast nuclear reactors that use sodium. It was also the world’s most powerful fast nuclear reactor with a sodium coolant; sodium in a fast reactor does not dissolve amid high levels of radiation. Thus the sodium coolant does not require regular drainage and removal of the dissolved absorber while being refuelled.
Sodium also connects with radioactive iodine during non-volatile chemical reactions, which basically prevents its release from a normal power plant through ventilation systems. Consequently, the reactor produces a small amount of nuclear waste, which has a relatively minor effect on the surrounding environment when compared to the effects of waste produced by traditional reactors.
In 2004, the developer Fedor Mitenkov was awarded the international Global Energy Award for his contribution to fast reactors with the BN-600 project.
The technology has been so successful that Rosatom subsidiary OKBM Afrikantov led the construction consortium for the China Experimental Fast Reactor outside Beijing, which went into operation in July 2011. During a recent visit to China by Vladimir Putin, Rosatom head Sergei Kiriyenko announced active discussions with Chinese partners on the construction of a fully functional (non-experimental) fast reactor in China, similar to the one being constructed in Russia, by Rosatom in the near future.
Prof Bolshov is very excited about the potential of the planned new fast reactor:“We have learnt a great deal from our experience with the BN-600. Russian nuclear scientists spent years perfecting the design of the reactor, and have learnt how to use sodium as a coolant.
“If, after all the discussions and licensing is taken care of, the next project is given the green light, then it has the potential to become the first commercially viable high-powered fast-neutron reactor in the world,” he says.
The coming years
Research and design work on the SVBR-100 reactor will continue until the end of 2014, while operations proper are set to begin in 2017. Potentially, it could take 10 to 15pc of the global nuclear energy market for small and medium-sized power stations.
“Fast reactors are the basis of our [global] competitiveness,” says Kiriyenko. “These include the fast-neutron reactors that already exist at Beloyarsk, lead-bismuthic reactors, lead reactors and other liquid metal coolants. All of these technologies will allow us to utilise the U-238 [highly enriched] isotope in the fuel cycle, which is abundantly available in nature but is currently almost unused.”
According to Kiriyenko, the United States is a key partner for developing new types of reactors for the company. “We can conduct joint R&D to develop a new generation of nuclear reactors; such co-operation should go on between our two countries on a national level and not be restricted to just one company,” he said.