Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Peculiarities of residual radiation formation of disperse micro encapsulated nuclear fuel

9/20/2018 2018 - #03 Physics in nuclear power engineering

Bedenko S.V. Shamanin I.V.

DOI: https://doi.org/10.26583/npe.2018.3.07

UDC: 621.039.5

Researches in the field of physics of nuclear fuel of new generation are being carried out at present at National research Tomsk polytechnic university. The fuel being developed is a graphite matrix with micro encapsulated fuel (microfuel) of spherical shape in it. The main technological application of these researches is creation of low-power high temperature gas-cooled thorium reactor unit. The researchers are of great significance and are generally paid much attention to.

In the present paper a calculated analysis of different configurations of thorium reactor core loading is described. Neutron-physical researches and fuel isotopic composition calculation were made. Alpha-emitters, sources of neutron and photon radiation were analyzed. A calculation instrument which allows evaluating radiation characteristics of nuclear fuel at the reactor designing stage was developed. It also makes it possible to reconsider usual procedures of handling new and irradiated nuclear fuel in a nuclear fuel cycle of new generation.

The main attention in the research was paid to the calculation of neutron yield and spectrum formed as a result of (alpha, n)-reactions on light nuclei of microfuel, as the concentration of various alpha-emitters resulting from irradiation is directly dependent on the fuel burn-up, while the concentration of (alpha, n)-neutrons depends on the configuration of microfuel, graphite matrix, concentration of light elements, and modifies the pattern of neutron diffusion flux.

To calculate the neutron yield, an analytical model and verified calculation codes were used. At the stage of calculation evaluation the use of an analytical model is considered a more preferable research method, as it allows calculating alpha-particles transport, when a corresponding code is not available. Besides, such approach can be used to prepare a file with input data for tasks of neutron-activation analysis, to calculate dosimetric characteristics of neutron isotopic sources and media, containing discrete particles of different shape, size and composition.

The researched were performed to create an effective calculation instrument used for initial evaluation of radiation characteristics of nuclear fuel in a nuclear fuel cycle of new generation.

An analytical model and verified calculation codes of the programs WIMS-D5B, SCALE 6.0, SOURCES-4C and SRIM-2013 were used.

The work was supported by Russian Science Foundation № 18-19-00136 of April 18, 2018. The subject: Scientific basis development of oxide compositions plasma-chemical synthesis technology for perspective nuclear fuel types.


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thorium reactor isotopic composition disperse nuclear fuel alpha-particles transport radiation sources spectrum