Method for calculating short-half-life daughter nucleus bank deposit external irradiation dose of long-lived radioactive nuclide

Abstract

The invention relates to a method for calculating the short-half-life daughter nucleus bank deposit external irradiation dose of long-lived radioactive nuclide. The method includes the steps of judging a balance relationship built by a mother nucleus and a daughter nucleus according to an emission source item of a liquid effluent of a nuclear facility, determining a radioactivity factor A and a decay constant factor lambda of the daughter nucleus on a deposit site and a surface deposit external irradiation dose conversion factor DCF of the daughter nucleus, and calculating the surface bank deposit external irradiation dose of the deposit site. The method can be used for calculation of various kinds of surface deposit external irradiation caused by discharge of the liquid effluent of the nuclear facility, and solves the technical problem in relevant evaluation calculation in the prior art.

Description

technical field [0001] The invention belongs to nuclear radiation environmental impact assessment technology, in particular to a method for calculating the external exposure dose of long-lived radionuclides with short half-life daughter nuclei deposited on shore. Background technique [0002] In the liquid effluent of nuclear facilities, long-lived nuclides generally have a long-term equilibrium relationship with their short-lived daughter nuclei. Since the migration rules of daughter nuclides in the environment are different from those of the parent nuclei, and the amount of nuclides in the environment generally depends on There are certain difficulties in the evaluation of the amount of its mother core. In the general models and procedures used in the current radiation environmental impact assessment of nuclear facilities, the external exposure of shore deposition of short-lived daughter nuclei of long-lived nuclides is either not considered or the calculation is not perfe...

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Problems solved by technology

[0002] In the liquid effluent of nuclear facilities, long-lived nuclides generally have a long-term equilibrium relationship with their short-lived daughter nuclei. Since the migration rules of daughter nuclides in the environment are different from those of the parent nuclei, and the amount of nuclides in the environment generally depends on There are certain difficulties in the evaluation of the amount of its mother core

In the general models and procedures used in the current radiation environmental impact assessment of nuclear facilities, the external exposure of shore deposition of short-lived daughter nuclei of long-lived nuclides is either not considered or the calculation is not perfect enough, and for some radionuclides , the dose contribution of its sub-nuclei may be very large, which makes the calculation of the external irradiation of shore sediments in the radiation impact assessment a certain unconservative situation

[0003] In the current radiation impact assessment process of nuclear facilities, the external exposure of long-lived nuclide nuclei discharged from the liquid route is generally not considered in the calculation. However, for some long-lived nuclides, although their daughter nuclei The half-life is very short, but because the daughter nucleus is continuously produced with the decay of the mother nucleus, after the mother nucleus is deposited on the shore, the daughter nucleus will establish a long-term equilibrium or transitional equilibrium state with the mother nucleus at the place where the mother nucleus is deposited. The activity should not be ignored. At the same time, due to the high external radiation dose conversion factor of some daughter nuclei, the external radiation dose contribution caused by it is often higher than that of the parent nucleus. It is unreasonable to ignore its radiation effect

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