Monitoring of the 14C concentration in the stack air of the nuclear power plant VVER Jaslovske Bohunice

C-14 releases in the stack air of the NPPs V1 and V2, Jaslovske Bohunice was determined during the year 2004-2010. Radioactivity concentration of C-14 in the stack air was determined in the forms of inorganic (CO2)-C-14 and C-14 (n) H (m) . The annual average activity concentration in the stacks air samples varies between 12 and 121 Bq m(-3). NPP V1, starting with 45 Bq m(-3) in 2005 is decreasing due to the shutting down of the reactors (the first reactor was shut down in December 2006 and the second reactor in December 2008). The average value of radioactivity concentration for power unit V2 was 32 Bq m(-3) in 2004 and reached the value of 102 Bq m(-3) in the first-quarter of the 2010. The average normalized yearly discharge rates were between 0.39 and 0.64 TBq GW (e) (-1) year(-1) (2005-2008), NPP V1 and 0.19-0.61 TBq GW (e) (-1) year(-1) (2004-first-quarter 2010) for NPP V2, Jaslovske Bohunice. Most of the discharged C-14 is in a hydrocarbon form, (95% for Jaslovske Bohunice NPP V2), but the CO2 fraction may reach 37% in the air stack for Jaslovske Bohunice V1.