Benchmark on Dose Rate Calculations for Irradiated Assembly

The radiation dose rate emitted by spent fuel assemblies is a crucial parameter within the framework of proliferation resistance, and its accurate determination is hence of paramount importance. Recent calculations have shown some discrepancies with historical results for pressurised water reactor spent fuel assemblies. To verify these discrepancies and help define a reference calculation, an international benchmark was carried out under the framework of the Nuclear Energy Agency (NEA) Expert Group on Advanced Fuel Cycle Scenarios (EGAFCS). The benchmark aimed to verify updated dose rate calculation procedures (new modelling approaches, new nuclear data, new versions of calculation codes) and share the benchmark results at the international level. The benchmark, including code-to-code verification and validation against experimental data, has shown and validated a methodology for the adequate estimation of the radiation dose rate from pressurised water reactor spent fuel assemblies (UOX and MOX) after certain periods of decay, confirming also the self-resistance of the simulated assemblies. This report outlines the exercise, its results and a series of recommendations for calculations.

19 Sept 2023 178 pages English

https://doi.org/10.1787/3dbcca5e-en 9789264654860 (PDF)

Author(s): Nuclear Energy Agency