Science: Night Burial

The gates of Canada's Chalk River atomic energy project, usually heavily guarded, were deliberately left deserted one recent evening. In lonely majesty a big road grader with a lead-shielded cab lumbered slowly out, towing a skid with a bulky, canvas-wrapped burden. As the skid scraped past, radiation detection devices went wildly off scale. Inside the canvas was a 2½-ton aluminum tank, probably the most troublesome radioactive object that man has ever handled.

Last December, Chalk River's nuclear reactor had to be shut down because of leakage of radioactive material. The aluminum jackets around several of its uranium "fuel" rods had corroded and permitted "hot" products of the nuclear reaction to escape into the heavy water surrounding the rods. Thus the whole reactor, including the big tank that held the heavy water, was contaminated. The reactor could not be rebuilt until the tank had been properly taken care cf. With an announcer barking orders over a public-address system, men in gas masks and protective clothing started the ticklish operation of jockeying the dangerous tank out of the reactor's concrete shield. The crane that lifted it had a shielded cab to protect its operator. In 30 minutes the tank was lowered into its canvas shroud, to be towed to a deserted spot and covered with sand. Not until last week, with the tank safely in its grave, did the scientists reveal that its radioactivity was half as strong as that of all the radium which the world has produced.