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.
Specific areas of work will be conducted and reported to the Nuclear Science Committee (NSC). They are the following:
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 the Fuel Cycle (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:
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).
The EGIEMAM-II had a kick-off meeting in April 2014 to finalise the mandate of EGIEMAM-II for presentation to NSC (the mandate was agreed at the 25th NSC meeting in June 2014).
The EGIEMAM-II meetings are held approximately every six months. The second meeting took place in April 2015 at the NEA Headquarters, Issy-les-Moulineaux, France.
The expert group critically reviewed integral experiments for validating minor actinide (MA) nuclear data, recommended additional integral experiments needed for validating MA nuclear data and investigated the possibility of establishing an international framework to facilitate integral experiments for MA management.
The NEA's nuclear data evaluation co-operation activities involve the following evaluation projects: ENDF (United States), JENDL (Japan), ROSFOND/BROND (Russia), JEFF (other Data Bank member countries) and CENDL (China) in close co-operation with the Nuclear Data Section of the International Atomic Energy Agency (IAEA).
The Working Party on Scientific Issues and Uncertainty Analysis of Reactor Systems (WPRS) studies the reactor physics, fuel performance, and radiation transport and shielding in present and future nuclear power systems.
The Collaborative International Evaluated Library Organisation (CIELO) Pilot Project, working under the auspices of the WPEC Subgroup 40 (SG40), was established to generate complete evaluations for a selection of the most important isotopes for parameters in nuclear technologies: U-235, U-238, Pu-239, Fe-56, O-16 and H-1 with the aim of improving the accuracy of the data and resolving previous discrepancies in the overall understanding.