A radiation detection assembly includes an ionization chamber for detecting radiation. The ionization chamber includes a volume of pressurized gas. An exterior enclosure houses the ionization chamber within an interior volume. The exterior enclosure includes a frangible section. A relief assembly defines a gas flow path from the ionization chamber to the frangible section of the exterior enclosure. The frangible section releases pressure from within the ionization chamber when the pressurized gas within the ionization chamber exceeds a predetermined pressure such that at least some of the pressurized gas flows through the relief assembly and through the frangible section of the exterior enclosure. The pressurized gas is then released to an exterior of the exterior enclosure. A method of reducing pressure within a radiation detection assembly is also provided.