Present Status: Collaboration between NBL and JAEA on Preparation of Pu Reference Material

JAEA has begun collaborative work with NBL for the preparation of Pu reference materials and associated Large Size Dried (LSD) spikes. All accountancy analyses at the Plutonium Fuel Development Center (PFDC) of JAEA are performed by isotope dilution mass spectrometry (IDMS) with well-characterized standard materials, which prepared at PFDC itself from Pu and U reference materials. Currently, Pu reference materials must be obtained from foreign suppliers because there are no facilities in Japan with the capability for preparation and supply of Pu reference materials, and, importing those Pu reference materials is gradually becoming more difficult. Thus, it is important to establish the capability and expertise for the preparation of Pu reference materials and associated LSD spikes in Japan. Therefore, JAEA has started collaborative work with NBL on preparation of Pu reference material. MOX powder which has been stored in JAEA was dissolved and ion-exchange was performed to obtain purified Pu solution at JAEA. Several aliquots had taken from the solution, dried, and sent to NBL for analysis. Pu samples were shipped and have arrived to NBL. NBL will perform coulometry and mass spectrometry for certification analysis. After certification analysis, the Pu nitrate solution will be mixed with a U nitrate solution which prepared from CRMs. Prepared spikes will be analyzed by NBL and JAEA for validation followed by performance test and stability test. The uncertainty of the purified Pu solution and prepared LSD spikes will be evaluated by GUM method. This paper presents the present status and future plans for the collaboration work.