The NEA Working Party on International Nuclear Data Evaluation Co-operation (WPEC) held its 38th annual meeting in May 2026 at the NEA headquarters in Boulogne-Billancourt, France. The meeting gathered around 75 experts from laboratories, industry, academia and international organisations to strengthen co-operation on nuclear data for science, technology and nuclear energy applications.
Over the course of the week, participants reviewed progress across WPEC activities and discussed priorities for the continued modernisation of nuclear data. The meeting marked an important mid-point for the current subgroups, providing an opportunity to assess ongoing work, exchange technical results and define next steps for international collaboration.
WPEC brings together international experts from 20 countries and two international organisations to promote the exchange of information on nuclear data evaluation, measurements, nuclear model calculations, validation and related topics. Its work supports the improvement of the quality and completeness of nuclear data and contributes to the efficient use of international expertise and resources.
The discussions covered the latest achievements, the current programme of work and upcoming activities across WPEC’s active subgroups:
- Evaluation, processing and validation in the unresolved resonance region (Subgroup 51);
- Development and application of advanced methodologies to produce application-specific nuclear data libraries (Subgroup 52);
- Stable zirconium evaluations and validation (Subgroup 53); and
- Curated EXFOR: developing an automatically readable, comprehensive and curated experimental reaction database (Subgroup 54).
The meeting also included updates from WPEC’s expert groups: the Expert Group on the High Priority Request List for Nuclear Data and the Expert Group on the Recommended Definition of a General Nuclear Database Structure. These groups support the identification of priority nuclear data needs and the development of standardised approaches for storing and exchanging evaluated nuclear data.
By bringing together evaluation, measurement, modelling, processing and validation communities, WPEC continues to provide an international forum for advancing nuclear data. The annual meeting reaffirmed the value of sustained co-operation in supporting reliable nuclear data for research, innovation and the safe development of nuclear energy systems.
