Authors & Affiliations

Mukhamadeev R.I., Peregudova O.O., Seliverstov I.N., Tsikunov A.G.

A.I. Leypunsky Institute for Physics and Power, Obninsk, Russia

Abstract

This paper is concerned with the computational algorithm study and upgrade aimed to take into account sodium aerosol size distribution. The fast reactor coolant temperature is known to be well above 473 0K (ignition temperature), therefore any leaks and further interaction with air oxygen result in the spontaneous ignition and radioactive combustion products generation, accompanied by equipment contamination and their subsequent potential escape into the environment with the impact on the living organisms. The hazard level depends on the leak size and location, pressure in the system, radioactivity values and sodium temperature, the state of the ambient atmosphere etc. The behavior of suspended combustion products in the room atmosphere obeys conventional laws of agglomeration, diffusion, settling. Depending on the amount of discharged mass and discharge time either one or the other mechanism will prevail. By now in Russia and other countries considerable studies have been carried out on the development of calculation methods for the assessment of sodium burning parameters, which are still underway. Therefore the calculations should take into account this information as the initial data for the analytical assessment of radioactive contamination of the lowest atmospheric layer and a ground surface, as well as dose functionals caused by these factors. Based on the materials of ICRP No. 68, 72 publications, using the ICRP Dose Coefficients software the new library of dose coefficients for the assessment of public internal exposure doses due to inhalation intake of radionuclides with account of the mean radiodynamic diameter of aerosols was prepared aimed at a more accurate record of public internal exposure doses. The new library data prepared can be used in several different models of aerosol dispersion account in case of their dry deposition, which are presented in the applicable regulations of Rostekhnadzor.

Key words
BN reactor, radioactivity, radioactive discharge, radioactive contamination, radionuclide, size distri-bution, sodium aerosol, exposure dose, library of dose coefficients, dose functional, Radiation Safety Standards (RSS-99/2009)

Article Text (PDF, in Russian)

References

UDC 614.876:621.039.5

Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, issue 1:10, 2015