Examination of (α,n) Signatures as a Means of Plutonium Quantification in Electrochemical Reprocessing

In this paper, we investigate the possibility of plutonium quantification within the electrorefiner vessel of an electrochemical separation facility via the use of the (α,n) neutron signature from dissolved actinides. As a potential alternative means to traditional spontaneous fission tracking, such an analysis may provide a more reliable tracking capability of plutonium within systems that produce a mixed matrix sample that yields a large (α,n) source term relative to that of spontaneous fission. This assessment includes an evaluation and breakdown of nuclides within the refining unit to differentiate the source of neutrons and then the ratio between (α,n) emissions to total neutron emissions given a range of fuel parameters. Next, we provide an assessment of the origin of (α,n) neutrons in relation to multiple isotopes of plutonium to determine the potential of a direct tracking method. Preliminary results indicate that the (α,n) contribution for electrochemical systems is much higher than in its aqueous counterpart and rivals spontaneous fission yield in terms of magnitude. Furthermore, ²³⁸Pu is shown to be a main contributor to the (α,n) yield for the fuel examined in this study.