Assessing the safety of spent fuel pools during a loss of cooling accident

Photo credit Large scale MIDI facility at IRSN

New NEA nuclear safety joint project 'Pool during Loss of Cooling Accident' (POLCA) launched during a meeting of 40 international experts on 9-10 April, 2024. (Photo: Large scale MIDI facility at IRSN)

A new NEA nuclear safety joint project, the entitled Pool during Loss of Cooling Accident (POLCA), was launched during a meeting of 40 international experts on 9-10 April 2024. The two-day meeting was organised to finalise the project’s experimental and analytical programme.

The POLCA project will examine the behaviour of spent fuel pools (SFPs) during situations of loss of cooling through experimental analysis. This four-year project brings together experts from eight NEA countries: Belgium, Canada, Czechia, France, Germany, Spain, Sweden, the United States and non-member the United Arab Emirates. 

The objectives of the POLCA project are to:

  • Enhance knowledge of SFPs in an accident scenario
  • Improve the physical understanding of large-scale pools to provide thermal hydraulics data;
  • Support the thermo-hydraulics model development and validation for SFP during a loss of cooling accidents;
  • Evaluate some mitigation strategies for fuel assembly management.

The POLCA project will contribute to the enrichment of an experimental database, used to improve thermohydraulic numerical tools in pool conditions. The project will utilise the facilities of the French Institute of Radiological Protection and Nuclear Safety (IRSN) which provide dedicated instrumentation for measuring thermohydraulic behaviour.

Following the Fukushima Daiichi nuclear power plant accident, the international nuclear community initiated a deep assessment of the safety of spent fuel pools, which store spent fuel from nuclear reactors.

In April 2023, around 30 experts from 10 countries met at the IRSN in Cadarache, France, to discuss how to advance the understanding of SFP phenomena during a loss of cooling accident. As a result of this meeting, the POLCA (Pool during Loss of Cooling Accident) joint project was established.

The next POLCA meeting is scheduled to take place in France in November 2024.

You can read more about the NEA’s work on nuclear power plant accident management on the WGAMA webpage.

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