| 초록 |
Annulus gas system (AGS), which is a space filled by CO2 gas between Calandria tube and pressure tube of CANDU reactor, prevents heat transport from coolant to moderator. Since one of the major radionuclides in AGS is Ar-41, the estimate on radioactivity for this nuclide is important for radiation protection purpose. Thus, we have calculated the theoretical Ar-41 radioactivity (AAr-41) from the content of its target atom Ar-40 (mAr-40) which is introduced into AGS with CO2 gas as impurity. The calculation gives the following relationship; AAr-41 (Bq/year) = 3·1016 x mAr-40 (ppm). Therefore, the Ar-40 content of 40 ppm in CO2 gas, which is a typical case in domestic CANDU reactors, yields the Ar-41 activity of 1.2·1018 Bq/year, showing relatively a good agreement with the experimental one of 1.371·1018 Bq/year. |
