Abstract
Environmental impact of the Yucca Mountain Repository (YMR) has been quantitatively and deterministically evaluated in terms of the radiotoxicity of transuranic (TRU) and fission-product radionuclides existing in the environment after released from failed packages. Inventory abstraction has been made based on the data published in Final Environmental Impact Statement by US Department of Energy (DOE). Mathematical model and computation code have been developed based on analytical solutions. Environmental impact from the commercial spent nuclear fuel (CSNF) packages is about 90% of the total impact including the contribution from defense waste (DW) packages. Impacts due to isotopes of Cm, Am, Pu and Np, and their decay daughters are dominant, compared with those from fission-product nuclides. Numerical results show that reduction of the TRU nuclides by a factor of 100 makes the impact from CSNF smaller than that from DW.