Introduction

The Expert Group on Integral Experiments for Minor Actinide Management (EGIEMAM) has reviewed the existing integral experiments for minor actinide (MA) management and identified a lack of experiments and insufficient accuracies in several areas. In many cases, useful results are not fully available because of proprietary considerations. Moreover, EGIEMAM performed uncertainty analyses and target accuracy assessments and confirmed needs for improvements of nuclear data. After reviewing the integral experiments, EGIEMAM recognized that there exists only a limited number of facilities and limited expertise and resources (materials, manpower and funding). Therefore, there is a need to prepare a concerted effort paving the way for a common experimental program where resources can be optimised towards improving the MA nuclear data knowledge. In conclusion, EGIEMAM has recommended integral measurements, complementary to parallel efforts for differential measurements [to be coordinated by the Working Party on International Nuclear Data Evaluation Co-operation (WPEC)] , for the following nuclides of MA from viewpoints of design of transmutation systems and of fuel cycles: ²³⁷Np, ²⁴¹Am, ^242mAm, ²⁴³Am, ²⁴²Cm, ²⁴³Cm, ²⁴⁴Cm and ²⁴⁵Cm. 

To improve knowledge of MA nuclear data and to support the MA management technology development with reliable accuracy and sufficient anticipation, the expert group pointed out that many additional integral data are still necessary. The first step in this direction requires pooling resources and identifying qualified facilities, personnel, measurement techniques and available supplies of materials to target experiments to meet specific MA data needs. From the lessons learnt, two major categories, reactor physics and irradiation experiments require specific actions through international collaboration.

Objectives

Specific areas of work will be conducted and reported to the Nuclear Science Committee (NSC). They are the following:

• identification of systems of interest and associated target uncertainties
• joint design of reactor physics MA measurements in selected facilities
• selection of reactions and nuclides to be measured including assessment of the new measurement techniques/data, and specifications of the integral experiments including target uncertainties and suitability for benchmarking purposes
• consideration and determination of facilities and required expertise and resources
• development and coordination of the experimental program (including assessment and sharing of resources and results, time schedule and cost).
• international collaboration of irradiation program for MA
• selection of reactions and nuclides to be irradiated including assessment of the new measurement techniques/data, and specifications of the integral experiments including target uncertainties
• selection of irradiation facility
• considering the preparation of the samples and resources for irradiation and time schedule for irradiation
• considering the evaluation of the experiment and potential benchmarking for future studies
• development and coordination of the irradiation program (including assessment and sharing of resources and results, time schedule and cost).

In addition, EGIEMAM recommended that the Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) and the Working Party on Scientific Issues of Advanced Fuel Cycles (WPFC) consider an international comparison of analysis of integral experiments for MA, as well as an independent review of the outcomes of the expert group [cf. International Reactor Physics Experiment Evaluation (IRPhE) Project and International Criticality Safety Benchmark Evaluation Project (ICSBEP)] with the following:

• selection of experiments
• creation of benchmark models
• analysis of benchmark problems
• comparison of the analysis results.

The expert group works in co-ordination with WPRS (including the IRPhE Project), WPFC and WPEC, in particular with WPEC subgroup (SG39) and WPEC subgroup 40  (SG40 CIELO Pilot Project).