Method for obtaining three-dimensional neutron flux density distribution in reactor core transient process of fast neutron reactor

Abstract

The invention discloses a method for obtaining three-dimensional neutron flux density distribution in a reactor core transient process of a fast neutron reactor. A polygonal prism grid is adopted for the anisotropic neutron flux density of the reactor core of the fast neutron reactor to carry out fully-three-dimensional transportation space dispersion, a semi-spherical surface of a sixty-degree region is taken as a unit to carry out alternate scanning, and iterative format degradation in an angle parallel process is weakened; and the characteristics of the weak local effect and the global space coupling of the neutron flux density of the reactor core of the fast neutron reactor are considered, an estimated correction quasi-static strategy is adopted for neutron flux density change in a transient process to carry out time dispersion, ingredients of different change rates along with time in the neutron flux density can be decomposed, separated solution is carried out on different time scales, meanwhile, nonlinear iteration among above ingredients is avoided, and calculation efficiency is improved. The method for obtaining the three-dimensional neutron flux density distribution in the reactor core transient process of the fast neutron reactor has the advantages of being high in calculation accuracy and reasonable in calculated amount.

Description

technical field [0001] The invention relates to the technical field of fast neutron reactor core operation and safety, in particular to a method for obtaining the three-dimensional neutron flux density distribution in the transient process of the fast neutron reactor core. Background technique [0002] Fast neutron reactor is the main reactor type in the fourth-generation nuclear energy system. The average neutron energy of the core is more than one million times higher than that of the traditional thermal neutron fission-dominated pressurized water reactor. more neutrons. Excess neutrons can not only multiply nuclear fuel and improve the utilization rate of uranium resources; they can also be used to transmute highly radioactive and long-lived minor actinide nuclides (isotopes of neptunium, americium, curium, etc.) in nuclear waste, which can greatly shorten the time spent on nuclear waste. The required number of years for geological storage. Therefore, the development of...

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Problems solved by technology

[0005] In order to overcome the difficulties of the above-mentioned physical phenomena and solve the problems in the prior art, the present invention provides a method for obtaining the three-dimensional neutron flux density distribution in the transient process of the fast neutron reactor core, by decomposing the neutron flux density over time Components with different rates of change, and separate solutions on different time scales, reducing the amount of calculation

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