Abstract: For the design of near surface low-and-intermediate level radioactive waste repository, the principle of multi barriers, which considering both natural and engineered barriers, should be held. From the point of view of radioprotection, the design of a low-and-intermediate level radioactive waste disposal unit is demonstrated. Point kernel integration method QAD and Monte Carlo method MCNP were used to calculate the dose rate outside the walls with different thickness of disposal unit. Based on the calculation, the proper thickness of disposal unit wall was decided, and the application scope of each method was worked out.

Key words: Low-and-intermediate level radioactive waste disposal, Disposal unit, Shielding, QAD, MCNP