Embodiments of a radiation shield are disclosed. One non-limiting
embodiment of the radiation shield may comprise a first layer, a second
layer, and a third layer. The first layer may include a neutron
moderating material. The second layer may be adjacent the first layer and
may include a neutron absorbing material. The third layer may be adjacent
the second layer, and may include a photonic radiation attenuating
material. At least the first layer and the second layer may be removable
from the radiation shield.