Neutron and Photon Spectra and Dose Rates Around a Shielding Cask Placed in a Salt Mine to Simulate a Nuclear Waste Package

The dose equivalent rate around a POLLUX storage container with radioactive waste is increased by neutrons and photons backscattered by the host rock when the waste package is transported to its final position in a repository. This was simulated by a smaller shielding cask with a 252 Cf line-source. Neutron spectral fluence and dose equivalent rates were measured with Bonner spheres above ground and underground and compared with MCNP calculations. There may be the same quantity of backscattered neutrons as of the unscattered component. The photon spectra were determined with an NE213 scintillation spectrometer above ground. Photon dose equivalent rates are derived and compared with calculated ones and dosemeter readings.