Production and release of 14C in nuclear power station with RBMK-reactors

This paper presents the results of experimental estimation of 14C production and release in the RBMK-reactor power station. The results are obtained in five power units, of 1000 MW(e) each. 14C content measured both in its production points in the reactor (the periodic monitoring) and in the points of release to the atmosphere (continuous control). 14C release to the atmosphere is determined by its production in the coolant, in the helium-nitrogen circuit for the reactor space purging, in the nitrogen circuit of the around-reactor metalwork purging /5,2 108 Bq/(MW·year)/ and in the cooling system of the control and protection systems (0,9 108 Bq/(MW·year)). Practically, 14C formed in the fuels and graphite does not enter to the Nuclear Power Station environment. 14C normalized release rate through the ventilation systems to the atmosphere is 108 Bq, and is in good agreement with its production value in the reactor systems. These results are obtained for 10 vol.% nitrogen content in the helium-nitrogen mixture intended for the reactor space purging. (author)