Application of photofission reaction to identify high-enriched uranium by bremsstrahlung photons

Optimal scheme for stimulating photofission of shielded nuclear materials on the Microtron M-30: a combination of theoretical and experimental studies

“…The obtained results complement the existing information on the methods of generating bremsstrahlung beams with specified parameters on electronic accelerators to stimulate the photofission of nuclear materials as unshielded -235 U, 238 U, 239 Pu [2]; 235 U, 238 U [3]; 235 U, 238 U, 239 Pu [4], and shielded, packed in stainless steel containers, -232 Th [5]; 238 U, 239 Pu (additional studies were conducted for the case of a carbon steel container) [6].…”

“…These papers present the results of both theoretical calculations performed using Monte Carlo codes: MCNP6 [2] and combination of PHITS 3/0 and MCNP6 [3] for initial electron energies of 8 and 7, and 13.5 MeV, respectively, and experimental studies conducted on linear accelerators for a wide energy range from 7 to 17.5 MeV (7 and 9 10 [5] and 17.5 [4]) at average peak electron currents on bremsstrahlung converters from 30 mA [5] to 100 mA [4; 6]. Metal plates of tantalum (Ta) with a thickness of 0.5 mm [3] and 2 mm [5] and tungsten (W) with a thickness of 5 mm [4] and 1.8 mm [6] were used as converters for generating bremsstrahlung.…”

“…The weights of the test samples used in the process of stimulating the photofission of nuclear materials for unshielded samples were: 1.5 g -235 U, 2.1 g -238 U, 0.47 g -239 Pu [2]; 1.9 g -235 U + 238 U [3]; 1.0÷1e+2 g -235 U, 1e+2÷1e + 3 g -238 U, 1.0 g -239 Pu [4]; for shielded samples: 15.6 g -232 Th [5]; 241 G -238 U [6]. Their use allowed obtaining statistically accurate and reliable results when analysing the isotopic composition.…”

“…Reliable information about their isotopic composition is required to successfully solve this problem. One of the methods for analysing the isotopic composition of nuclear materials, which is widely used and improved (developed) at the present time, is based on the use of information about gamma and neutron radiation from their decay products formed as a result of the photofission reaction [2][3][4]. As a rule, sealed containers made of stainless steel are used for the storage and transportation of nuclear materials [5; 6].…”