The NEA Working Party on Nuclear Criticality Safety (WPNCS) convened during the week of 6-10 July 2026 for its 35th meeting in conjunction with its associated subgroups and the meeting of the International Assay Data of Spent Nuclear Fuel Database (SFCOMPO) Technical Review Group (TRG). The hybrid event gathered approximately 100 experts from 14 countries, including professionals from academia, industry, research institutions and safety authorities.
Participants discussed ongoing and future activities, highlighting several key initiatives:
- an international criticality safety exercise to compare and contrast evaluation methods;
- learning from experience and knowledge transfer;
- nuclear data uncertainty propagation for irradiated fuel inventory calculations;
- definitions and methodologies for calculating burnup;
- neutron noise methods for criticality assay;
- experimental coverage and error recovery; and
- updated publication of a handbook of critical and possibly subcritical values.
The meeting also featured discussions from the two technical review groups within WPNCS: International Criticality Safety Benchmark Evaluation Project Technical Review Group (ICSBEPTRG) and the Spent Fuel Composition Technical Review Group (SFCOMPOTRG).
With a diverse range of topics covered, the meeting facilitated productive discussions and provided a platform for experts to exchange insights on criticality safety challenges and advancements. The next series of meetings will take place virtually in January 2027.
For more information about the working party’s activities, please visit the WPNCS information page.
