Establishment on safeguards approach


Technical study must be conducted with the relevant parties so that the transparent safeguards approach suitable to the fuel debris handling is formulated before the commencement of fuel debris retrieval.

The operator is required to set the material control and accountancy (MC&A) procedures and report the inventory of nuclear materials and inventory change to the Government. The Government is required to report the physical inventory of nuclear materials to IAEA based on the Japan-IAEA safeguards agreement and to show that undeclared nuclear materials will not be carried out. Also, the operator needs to accept the inspections conducted by the Government and IAEA and to show that they perform appropriate MC&A.

The fuel assemblies in the reactors of Units 1-3 at the Fukushima Daiichi NPS were melted due to the accident. Since those assemblies are estimated to be in a form of fuel debris, it is considered very difficult for nuclear materials to be diverted to nuclear weapons.

Considering such situations, a realistic safeguards approach is required to be formulated so as to correspond to the anticipated fuel debris retrieval method.

Action status and evaluations and issues

  1. Study on the safeguards approach for fuel debris
    • Current status
    • ・Installation of remote-control monitoring cameras and radiation monitors in the periphery of the R/B of Units 1-3 at the Fukushima Daiichi NPS and on-site verification activity with short notice operational supports (SNOS) by the Government and IAEA are allowed.

    • Evaluation and issues
    • ・The fuel debris in Units 1-3 at the Fukushima Daiichi NPS is considered to be difficult to be determined the quantity of nuclear materials by the standard method highly accurately since the heterogeneous mixture of structural materials such as of metal and concrete including the control rod is estimated to have been created.

      ・Therefore, safeguards approach must be drafted considering the fuel debris retrieval method in order for the Government and IAEA to verify that undeclared nuclear materials will not be carried out.

      ・As described above, considering that the quantitative analysis of nuclear materials with a great accuracy is difficult to be performed for the fuel debris in Units 1-3 at the Fukushima Daiichi NPS, the method of MC&A is to be studied so that the Government and IAEA can agree.

      ・Collaborating with the Government and IAEA in a positive and timely manner, identified technological challenges are to be addressed to avoid leaving major issues in the fuel debris retrieval work.

  2. Schedule management for the formulation of safeguards approach
    • Safeguards approach needs to be studied and implemented according to the mid- and long- term Roadmap and actual progress status.