Patent Number: 050892142
Section: abstract

An apparatus for monitoring the pressure within a cask containing radioactive materials is disclosed. The apparatus comprises a differential pressure sensor sealingly connected to a bore that penetrates through the wall of the cask for directly monitoring the pressure of the helium gas contained within the cask and for providing a first barrier between the helium gas and the ambient atmosphere. An evacuated sensor chamber surrounds both the outlet end of the through-wall bore and the differential pressure sensor for providing a second barrier between the helium and the ambient atmosphere as well as a vacuum reference point for the differential pressure sensor. An absolute pressure sensor is connected in parallel to the through-wall bore to allow the system operator to determine whether or not a reduction in the pressure sensed by the differential pressure sensor is the result of a leakage condition in the cask, or in the evacuated sensor chamber. The pressure monitoring apparatus allows direct pressure readings to be taken within the cask itself which are reliably confirmable, and further provides multiple mechanical barriers between the hazardous helium gas contained within such a cask, and the ambient atmosphere.