Testing And Verifying Information Barrier Methodology On Spent Fuel Assemblies

Testing and verifying information barrier methodology on spent fuel assembliesNaeem Syed1, Styrkaar Husviet1, Tore Ramsøy2, Kjell Johansson21)Norwegian Radiation and Nuclear Safety Authority (DSA), Norway2)Institute of Energy Technology (IFE), NorwayThe UK-Norway initiative (UKNi) [1] has been investigating methodologies and technologies for the future verification of nuclear warhead dismantlement. An important development in this regard is the “Information Barrier” (IB) – an automated gamma-ray detection system to verify two important attributes of the nuclear warhead – presence of plutonium 239Pu, and isotopic ratio of 239Pu / 240Pu. A detailed algorithm of the UKNi method has been published on http://ukni.info.In the present paper, the isotopic ratio of 239Pu / 240Pu has been determined using the UKNi – IB algorithm [2]. The investigation was made on the gamma-ray data from different spent fuel assemblies of varying plutonium content. For the sake of diversity, the same data were analyzed using PC-FRAM code [3].The preliminary results show a good agreement of the results determined by both methods. However, some discrepancies on the deduced results, owned by the presence of other radioactive nuclei and different regions of analysis, have also been observed. These results are important and would help us in dealing with the spoofing the IB results due to the presence of other radionuclides. In the present data a relatively higher radiation background was also tested on the peak fitting methodology of UKNi-IB.The description of the investigation analysis on the UKNi-IB methodology and summary of results will be presented.References:1.http:/UKNi.info2.N. Syed, S. Hustveit, O. Reistad, S. Siem, “Investigating the method of UK-Norway initiative Information Method”, INMM 60th Annual Meeting Proceedings, California USA, 2019. 3.T.E.Sampson, T.A.Kelley, “PC/FRAM: a code for the nondestructive measurement of the isotopic composition of actinides for safeguards applications”, Applied Radiation and Isotopes, vol. 48, issue 10-12, 1997, p. 1543-1548