Attributes and templates from active measurements with {sup 252}Cf

Mihalczo, J.T. ; Mattingly, J.K.

Oak Ridge Y-12 Plant

关键词: Fission;    Y-12 Plant;    43 Particle Accelerators;    37 Inorganic, Organic, Physical And Analytical Chemistry;    Nuclear Explosives;   

DOI  :  10.2172/751985
RP-ID  :  Y/LB--16,052
RP-ID  :  AC05-84OR21400
RP-ID  :  751985

美国|英语

来源: UNT Digital Library

【 摘 要 】

Active neutron interrogation is useful for the detection of shielded HEU and could also be used for Pu. In an active technique, fissile material is stimulated by an external neutron source to produce fission with the emanation of neutrons and gamma rays. The time distribution of particles leaving the fissile material is measured with respect to the source emission in a variety of ways. A variety of accelerator and radioactive sources can be used. Active interrogation of nuclear weapons/components can be used in two ways: template matching or attribute estimation. Template matching compares radiation signatures with known reference signatures and for treaty applications has the problem of authentication of the reference signatures along with storage and retrieval of templates. Attribute estimation determines, for example, the fissile mass from various features of the radiation signatures and does not require storage of radiation signatures but does require calibration, which can be repeated as necessary. A nuclear materials identification system (NMIS) has been in use at the Oak Ridge Y-12 Plant for verification of weapons components being received and in storage by template matching and has been used with calibrations for attribute (fissile mass) estimation for HEU metal. NMIS employs a {sup 252}Cf source of low intensity (< 2 x 10{sup 6} n/sec) such that the dose at 1 m is approximately twice that on a commercial airline at altitude. The use of such a source presents no significant safety concerns either for personnel or nuclear explosive safety, and has been approved for use at the Pantex Plant on fully assembled weapons systems.