Patent Number: 048779695
Section: description

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to FIG. 1, a transport flask for radioactive material comprises a hollow cylindrical body 1 provided with cooling fins 2 and lifting trunnions 3. In use the open end of the body is closed by a lid (not shown) which can be bolted to the body. The interior of the body accommodates a plurality of substantially identical members 4 which cooperate to define channels 5 to receive radioactive waste containers. In the example of FIG. 1 the members 4 define seven such channels 5. With reference to FIGS. 2 and 3, each member 4 comprises an elongate aluminium body having concave longitudinally extending surfaces 6 and 7 which each define substantially a half of channel 5. Radially outer surface 8 of the member is curved to conform to the curvature of the interior of the body 1. Radially inner surface 9 of the member 4 is curved to define a portion of a central channel 5. A stepped groove 10, which extends the length of the member 4 is formed in the surface 8. A plurality of T-shaped keys 11 are fixedly secured to the flask body at regular intervals about the interior thereof, the keys 11 extending the length of the body. The keys 11 are dimensioned to slidably receive the stepped grooves in the members 4. A clamping bar 12 cooperates with each key 11 to clamp the member 4 in position, the clamping bar being secured to the T-piece by bolts 13, conveniently three in number, spaced at equal intervals along the length of the bar. During assembly, each member 4 slides along its locating T-shaped key 11 into its required position within the flask body. The member 4 is then clamped securely to the wall of the flask body by tightening the bolts 13 to a predetermined torque. The stepped groove opens into an enlarged passage 14 which can receive a tool for applying the required torque to the bolts. The member 4 is so shaped that initially contact is made against the flask wall at the longitudinal edges of the member. Upon tightening the bolts the member deforms elastically until contact is made along the full extent of the radially outer surface of the member. This ensures good thermal contact between the member and the flask body. The individual members 4 cooperate to define the channels 5 within the flask body. Containers containing radioactive material can be accommodated in the channels and the members 4 provide for the conduction of heat generated within the containers to the flask body. As the structure within the flask is formed from a plurality of individual and substantially indentical separate members 4, the cost of manufacture can be less than that of a single monolithic support. The build-up of stresses or distortion is minimised as a result of the separate members. A further advantage lies in the recovery of containers which might become jammed or stuck within the channels as it is possible to remotely release the members 4 to thereby free the containers.