Certification of the decommissioning project for the PROTEUS research reactor at the Paul Scherrer Institute

The Paul Scherrer Institute (PSI) revised the documents concerning the decommissioning of the PROTEUS research reactor. This report presents the results of the evaluation by the Swiss Federal Nuclear Safety Inspectorate (ENSI). PSI considered all relevant stipulations of nuclear energy legislation, the law on radiation protection, as well as ENSI directives. Moreover, ENSI made sure that the PROTEUS decommissioning project corresponds to the IAEA, WENRA and OECD/NEA international requirements, and corresponds to current state of science and technology. ENSI ascertained some facts that have to be looked at more deeply. Before beginning with the decommissioning work, all the fuel must be taken out of the PROTEUS facility. For each step an authorization has to be requested from ENSI with a detailed description of the work foreseen. Personal dosimetry has to be performed with calibrated dosimeters. By the use of mechanical, thermal or chemical methods to partition radioactive components, the air on the working place has to be continuously checked for radioactive aerosols. The dose limit of 0.3 mSv per year must be respected. The surveillance of the release of radioactive materials has to be done according to the PSI release regulations. By large material quantities like barite concrete blocks, graphite reflector and steel components, PSI has to describe the process used to declare the materials as inactive. For the radioactive materials expected, the containers specified have to be approved by ENSI. Before the first dismantling phase, the organization plan for all participating persons and their responsibilities have to be presented to ENSI. In its request for the decommissioning of the PROTEUS research reactor, PSI consistently demonstrates that the protection of persons and environment against radioactive radiation can be guaranteed during the dismantling of the facility and that the wastes produced can be safely managed. In consequence, all required conditions for delivering the decommissioning authorization are fulfilled