This paper presents the verification procedure for neutron sources installed in U.S.Department of Energy equipment used to measure fissile material flow.The Fissile Mass Flow Monitor(FMFM) equipment determines the ~235 U fissile mass flow of UF_6 gas streams by using ~252 Cf neutron sources for fission activation of the UF_6 gas and by measuring the fission products in the flow.The ~252 Cf sources in each FMFM are typically replaced every 2 to 3 years due to their relatively short half-life (～2.65 years).During installation of the new FMFM sources,the source identity and neutronic characteristics provided by the manufacturer are verified with the following instruments:(1)a remote-control video television(RCTV)camera monitoring system is used to confirm the source identity,and(2)a neutron detection system(NDS)is used for source-strength confirmation.Use of the RCTV and NDS permits remote monitoring of the source replacement process and eliminates unnecessary radiation exposure.The RCTV,NDS,and the confirmation process are described in detail in this paper.
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