With the progress of reactor modelling and computer simulations, the use of zero-power facilities progressively shifted from studying engineering mock-ups to producing benchmark-quality experimental information for nuclear data and computer code validation. Today, nearly all of the original zero power reactors have been permanently shut down leading to a drastic reduction in experimental capability.
In this context, the NEA organised a workshop entitled The demise of zero power reactors: From concern to action on 22-23 June 2023. Hosted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in Fontenay-aux-Roses, France, this hybrid event gathered 109 experts from 16 countries, the European Commission and the International Atomic Energy Agency. Participants from research centres, national laboratories, technical support organisations, industry, regulatory and academic institutions discussed the needs for new reactor physics validation data and provided recommendations for acquiring such data, including minimal functional specifications of the needed facilities and expertise.
The workshop also focused on lessons learnt from the operation of zero power reactors, the status, gaps and needs for critical and shielding experiments and thoroughly evaluated benchmark data for validation of nuclear data and codes, as well as the challenges related to data preservation. Participants exchanged views on the future needs for zero power reactors data, experimental capabilities, and operation and business models for new zero power reactors.
This workshop was initiated by the NEA Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) Task Force on Zero Power Reactors which was established to analyse the current state and challenges in this area. A report containing the Task Force findings and recommendations is expected to be released in early 2024.