Field Test of Nuclide Migration in Bentonite-based Materials at Aerated Zone --- Cooperative Research Program on Field Migration Test between CIRP and JAERI ---

摘要

A field test was jointly conducted by China Institute for Radiation Protection (CIRP) and Japan Atomic Energy Research Institute (JAERI) to explore moisture movement with Br and migration of radioactive tracer ~(237)Np, ~(238)Pu and ~(90)Sr in bentonite-based materials at aerated zone. The test ran under two rainfall conditions, the artificial rainfall with sprinkling density of 15 mm/d and 5 mm/hr, and the natural rainfall. Tracing test of Br~- implies that there does have water going through the bentonite specimen. However, the curves are very complex and further work need be conducted to quantify this movement. ~(238)Pu has no observable movement during the test period under either rainfall conditions, and ~(237)Np has very short movement dominated by diffusion. Bentonite-based materials are effective to retard nuclide migration.