Temperature distribution plays a crucial role in the safety performance assessment and thermal dimensioning design in a deep geological repository for disposing high-level waste. In this study, a two-dimensional axisymmetric model of a single container for heat transfer was created. The fully analytical solution to temperature distribution in the repository was derived by utilizing the methods of separation of variables, impulse theorem, and Fourier transform.

The fully analytical solution was validated by comparing with the existing semi-analytical solution and line heat source solution. The temperature change in the near field around the container was analyzed using the present solution, and the influences of different parameters on the container surface temperature were investigated. Furthermore, the proposed fully analytical solution was used to predict the results of the in situ test.

The findings indicate that the temperature in the buffer layer rapidly increases and reaches its peak value within the first 2 years, then gradually decreases thereafter with time. The thickness of the bentonite pellet layer had a greater effect on the container surface temperature than that of the bentonite block layer. A comparison between the fully analytical solution and the results of the in situ heating test demonstrated that the proposed fully analytical solution can accurately predict the temperature variations in the in situ heating test.