A consortium of organisations that are part of Russian state nuclear corporation Rosatom has completed the initial phase of a project to investigate the ageing properties of nuclear fuel debris, the results of which will be used in clean-up work at the Japan’s crippled Fukushima Daiichi NPP. The project is being managed by Japan's Mitsubishi Research Institute (MRI) and is subsidised by the Japanese government.

The Russian consortium, led by RosRAO, includes JSC Techsnabexport (Tenex), Tenex-JapanCo, the AI Leipunsky Institute of Physics and Power Engineering (scientific project manager) and the Scientific Research Institute of Technical Physics and Automation  (responsible for developing and manufacturing neutron detectors). The work has already resulted in the development of methods allowing the creation of model active samples of Fukushima Daiichi fuel debris, RosRAO said on 22 August.

MRI selected the RosRAO-led consortium in spring 2017 to carry out a feasibility study of the project to eliminate the consequences of the accident at the Fukushima-1 nuclear power plant. The aim of the project is to develop a method for the most accurate search and identification of fuel fragments at Fukushima Daiichi. During the first stage, industrial neutron detectors were tested to work in conditions of very strong gamma radiation, and approaches for creating neutron counters with sizes smaller than a matchbox and a communication line of up to 60 metres were developed and tested.

Now the second phase of the project is underway. "The decision on the continuation of the project was made following the results of a competitive selection, where the results of Japanese and French colleagues were also presented," RosRAO said. The second phase is aimed at developing an automated system for measuring neutron and gamma fields with a small corona counter. The new system will have to accumulate the results obtained in the database, as well as build three-dimensional maps of the power density of gamma and neutron radiation, and determine the presence of fuel fragments to be extracted during the dismantling of the emergency power units of the Fukushima NPP.  Rosatom plans to test the   automated system in the autumn. "Completion of the development and testing of the system is planned in September 2018," RosRAO said.