EXPERIMENTAL STUDIES ON DEVELOPMENT OF THE METHOD FOR DETERMINING THE AMOUNT OF IMPURITATED GASES IN NUCLEAR FUEL

The article is devoted to an issue of estimating the impurity gas amount in nuclear fuel in the aspect of the distracting contribution from released gases to the total pressure inside ampoule of the device in the simulating a severe accident with core melting. The paper presents a method based on measuring the pressure and temperature of gas in a closed values of the fuel elements during the fuel melting. The correctness of the developed methodology is confirmed by the results of experiments on the melting of fuel in a pulsed graphite reactor IGR with the implementation of a controlled neutron pulse.

Research on the Neutron Multiplicity Pulse Trains Computer Simulation

Neutron multiplicity counting (NMC) is one of the most advanced Non-Destructive Assay (NDA) techniques. In this paper, the principle and method of generation of neutron pulse trains is studied. A model of 4π cube counter is established for 238Pu sample, the capture time of neutrons is gained by simulation code, then output the neutron pulse trains for post dispose from generated fissile initial-times. The result from post dispose of this neutron pulse trains show a small bias compared with input value, it’s an evidence for the validity of simulation in this paper.

Modelling of ionization effects and the effects of displacement in digital chips for CAD

The methods of design of digital fault-tolerant bipolar integrated circuits to exposure to radiations such as gamma, x-ray and neutron radiation are considered, as well as the impact of the neutron pulse, which af-fect largely on the gain of the transistor. The operating mode of integrated circuits with change in the ini-tial values of voltages, as well as currents of the emitter and of the base is presented. Numerical calcula-tions of the ionization current in the base-collector junction are considered which allow pre-calculate dose rate of gamma, x-ray and neutron radiation.