Environmental tritium around a new CANDU nuclear power plant

National Institute of R&D for Physics and Nuclear Engineering-Horia Nulubei, 407 Atomistilor Str., Com. Magurele, Jud. Ilfov, P.O. Box MG-6, 76900 Bucharest, Romania

Abstract

In the routine operation of a nuclear power plant radioactive wastes are generated. Excepting ³H and ¹⁴C, the quantities of radionuclides released during normal operation of CANDU 6, are smaller than emissions of other NPP. The tritium inventory and the tritium releases for classical and future (improved) CANDU 6 were theoretically evaluated and compared with the published data of CANDU 6 reactors with more than 10 years of operation. The tritium releases increases with time and no equilibrium is reached in the 30 years.

The environmental tritium level before and after the start of the Romanian CANDU 6 reactor was determined by analysis of different samples: air, water, soil, and vegetation. During the pre-operational period, the tritium concentration was low and almost uniform (~3 Bq/L), as for an area without local contamination sources other than common atmospheric fallout. In the first years of the reactor activity, the tritium concentration in environment was low, but more variable than pre-operation period. In the vicinity of the reactor, the tritium concentration in air, soil and spontaneous vegetation was till two orders of magnitude higher than the values measured during the pre-operational level. The dose estimation for the maximum exposed individual, consuming local products, is 1.6 µSv/y.