Problem May Be Solved

Press, Volume C, Issue 29504, 4 May 1961, Page 20

Problem May Be Solved

[By ROBERT C. COWEN, natural science editor of the "Christian Science Monitor ” Published by arrangement] CAMBRIDGE (Massachusetts). Dr. Rolf Eliassen, professor of sanitary engineering at the Massachusetts Institute of Technology, thinks that, fundamentally, he has the problem of the long-term disposal of “hot” atomic waste solved.

His laboratory has demonstrated that highly radioactive wastes can be made into erosion resisting glass. The specific technology for doing this on an industrial scale has yet to be worked out. But the basic feasibility of this kind of storage now is established. This is just the kind of problem M.I.T. is pre-emin-ently equipped to tackle. It is a tough technical problem arising out of the new age which, if unsolved, would have serious implications for people everywhere. Terms of Far Future As Professor Eliassen explained it. the problem had to be looked at in terms of the distant future. Right now, the dangerously radio active wastes from atomic reactors can safely be stored in tanks. This is only a temporary solution. These tanks are actually complex storage plants which include cooling mechanisms to remove the heat from radioactivity and mechanisms to ensure there are no leaks. Such tanks, in any one case, may be serviceable for 20 years. What is needed. Professor Eliassen said, is a simple, thoroughly reliable method of storage that will be good for .1000 years. This is the method he says he now is convinced he has found in making the wastes into glass. 1000-Year Perspective It often has been noted that waste disposal could become a drag on the development of nuclear electric power unless an effective disposal system could be worked out. This is one way to look at the significance of the problem. However, as a sanitary engineer, Professor Eliassen explained, he hat a different viewpoint. His job is the long-term protection of the public and the environment from contamination by such wastes. This is wnere the 1000year perspective comes into the picture. Moreover, it applies to wastes already produced as well as to the increasing amount of such wastes that will be produced in the future. Responsibility Noted Put in its starkest terms. Professor Eliassen's problem has been to find a way safely to store the wastes so that earthquakes, attacks of water, and other natural processes would not release them to the environment even though the responsible governments which first buried the wastes themselves to disappear and the wastes to be forgotten. He noted that 1000 years is a very long time in human history. The generation that produces such dangerous wastes today has a responsibility to ensure that other generations will not be endangered by them in the remote future. Of all the products made by men, archeologists have found glass to be the most enduring. Obviously glass containers could not be trusted to hold the wastes. But if the wastes could be made a part of the glass itself, they might be very securely locked away from the general environment. Professor Eliassen has

found that, with the addition of a few simple ingredients such as silica which is found in most glasses, atomic wastes make a very stable glass indeed. The wastes are first heat-treated to remove liquids and reduce the radioactive materials to a dry form. Tests at Professor Eliasset)'s laboratory have shown that such "atomic glass” is so highly resistant to erosion that boiling distilled water, the most erosive form of water, would take a million years to reduce the diameter of a glass sphere by two inches. Such glass could easily withstand 1000 years’ exposure below ground without releasing significant radioactivity. But there are still problems to be solved. For example, what is the optimum size of glass block that will offer the smallest possible suface area for erosion while not being so thick it will be unable to get rid of the heat from radioactivity and will melt? Professor Eliassen says he feels confident these are development problems that can be beaten now that the fundamental problem of the kind of storage has been solved. He said that he told the United Nations Scientific Committee on the Effects of Atomic Radiation, which met at Geneva last month, that his work now has demonstrated that the technology of waste disposal can keep ahead of the demands placed upon it by the growth of atomic electric power.