Chinese collaboration for accelerator-driven systems

11 March 2016

A strategic cooperation agreement to develop accelerator-driven systems has been signed between China General Nuclear (CGN) and the Chinese Academy of Sciences (CAS). Such systems could be used to transmutate used nuclear fuel or run subcritical nuclear reactors powered by thorium.

CGN-CAS ADANES signing ceremony - 460 (CAS)
The signing of the ADANES agreement (Image: CAS)

The agreement on Accelerator-Driven Advanced Nuclear Energy Systems (ADANES) was signed in Beijing on 9 March by CGN deputy general manager Zheng Dongshan and CAS deputy secretary general Tan Tieniu following a forum between the two organizations.

CGN said the agreement would be based on "complementary advantages, win-win cooperation and common development" in the research and development of accelerator-driven systems. "By signing this agreement, the two sides will further establish long-term strategic alliances and partnerships to accelerate the development of advanced nuclear energy systems," it said.

The transmutation of long-lived radioactive waste can be carried out in an accelerator-driven system, where neutrons produced by an accelerator are directed at a blanket assembly containing the waste along with fissionable fuel. Following neutron capture, the heavy isotopes in the blanket assembly subsequently fission, producing energy in doing so. Such systems could also be used to generate power from the abundant element thorium.

An accelerator-driven system can only run when neutrons are supplied to it because it burns material which does not have a high enough fission-to-capture ratio for neutrons to maintain a fission chain reaction. Such a reactor, therefore, could be turned off simply by stopping the proton beam, rather than needing to insert control rods to absorb neutrons and make the fuel assembly subcritical. Because they stop when the input current is switched off, accelerator-driven systems are seen as safer than normal fission reactors.

Cooperation between CGN and CAS goes back many years. In September 2006, they signed a framework agreement on scientific and technical cooperation, as well as an agreement on the Daya Bay reactor neutrino experiment project.

Researched and written
by World Nuclear News