Swiss regulator approves Proteus decommissioning plan

The Swiss nuclear safety regulator has said it is satisfied with the plans set out by the Paul Scherrer Institute for decommissioning the Proteus research reactor. The reactor was primarily used for neutron physics experiments with different nuclear fuels.

The Swiss nuclear safety regulator has said it is satisfied with the plans set out by the Paul Scherrer Institute (PSI) for decommissioning the Proteus research reactor. The reactor was primarily used for neutron physics experiments with different nuclear fuels.

The core of the Proteus reactor (Image: PSI)

The PSI submitted an application in April 2013 to the Federal Office of Energy (FOE) for permission to decommission the Proteus reactor, which was shut down in 2011. The Federal Nuclear Safety Inspectorate (ENSI) has a mandate to examine the decommissioning project and to submit an opinion to the FOE.

ENSI has now said it is satisfied that, in drawing up its decommissioning plan for Proteus, the PSI "has taken into account all the relevant provisions of the Nuclear Energy Act, the Nuclear Energy Ordinance, the Radiation Protection Act and the Radiation Protection Ordinance and the guidelines of ENSI and other relevant regulations". In addition, ENSI said it has ensured the decommissioning project complies with international requirements, including those of the International Atomic Energy Agency, the Western European Nuclear Regulators Association and the OECD Nuclear Energy Agency. The project also takes into account the current state of science and technology, it said.

The regulator said it had determined that the PSI had comprehensively explained in the application documents for decommissioning Proteus that "the protection of human health and environment against radiation can be ensured during the dismantling of the plant, that a feasible concept for dismantling exists and that it has been proven for the disposal of waste generated".

ENSI said the conditions for issuing a decommissioning licence for the Proteus reactor have been met. However, it identified eleven conditions that must be met by the PSI.

One of the conditions requires PSI to remove the fuel from the reactor before the start of demolition work. Another conditions calls for PSI to request permission from ENSI to proceed through each of the various phases of decommissioning.

The opinion of ENSI will serve as a basis for the Department of the Environment, Transport, Energy and Communication to decide on whether or not to issue such a licence to the PSI. The department is expected to make a decision by the end of this year.

Proteus is a "zero-power" nuclear research reactor that began operating in 1968. The thermal power of the reactor was limited in operation to a maximum of 1 kilowatt. As the reactor was operated at such a low power, a cooling medium was not required. In April 2011, the PSI decided to permanently shut the reactor, which had hardly been used in the previous two years.

PSI expects Proteus to be dismantled by a small demolition team within two years.

Researched and written
by World Nuclear News