In view of the experimental activities with a portable D-T neutron generator, which produces 14 MeV neutron beam, the characterization of the emission of the generator was carried out for ensuring adequate safety conditions in terms of operational radiation protection. The neutron generator is used for inspection of samples in which is suspected the presence of fissile or fertile material or explosives. Its use implies the operation to be conducted in an open field, where the radiological protection of workers and public has to be provided with distance-from-the-source and light shielding systems only. In the current study the minimum requirements for the shielding and the distance of workers and other people are assessed, considering the actual operation parameters in terms of neutron yield, energy, working load and so on. This study is the basis for initiating the licensing process in Italy. The safety assessment is performed using the standard method of calculation indicated by the US NCRP publications and the results are validated by comparison to simulations obtained by means of the stochastic code for radiation transport MCNPX 2.5.0, which reproduces the operational conditions the neutron generator should operate in. The simulation model allows the user to reproduce the emission of the generator according to different settings of the accelerator voltage, beam current, pulse frequency and duty factor. The related results include the dose rates for different shielding geometries and compositions. Radiation protection indications for workers and population will be provided. A practical field application of the generator will be described and discussed.
Using a portable Neutron Generator in an open field: the radiation protection assessment
G. M. Contessa
;N. Cherubini;A. Dodaro;L. Lepore;G. A. Marzo;S. Sandri
2016-01-01
Abstract
In view of the experimental activities with a portable D-T neutron generator, which produces 14 MeV neutron beam, the characterization of the emission of the generator was carried out for ensuring adequate safety conditions in terms of operational radiation protection. The neutron generator is used for inspection of samples in which is suspected the presence of fissile or fertile material or explosives. Its use implies the operation to be conducted in an open field, where the radiological protection of workers and public has to be provided with distance-from-the-source and light shielding systems only. In the current study the minimum requirements for the shielding and the distance of workers and other people are assessed, considering the actual operation parameters in terms of neutron yield, energy, working load and so on. This study is the basis for initiating the licensing process in Italy. The safety assessment is performed using the standard method of calculation indicated by the US NCRP publications and the results are validated by comparison to simulations obtained by means of the stochastic code for radiation transport MCNPX 2.5.0, which reproduces the operational conditions the neutron generator should operate in. The simulation model allows the user to reproduce the emission of the generator according to different settings of the accelerator voltage, beam current, pulse frequency and duty factor. The related results include the dose rates for different shielding geometries and compositions. Radiation protection indications for workers and population will be provided. A practical field application of the generator will be described and discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
