Science Underlying Radioactive Waste Management: Status and Needs-Twenty Years Later

ABSTRACTThe setting of the technical subsystem within the overall socio-political-economic-technical radwaste system will be described and the highly interactive nature of the larger setting emphasized. It will be shown that because of the dominance of the socio-political subsystem, the importance of the technical subsystem is overshadowed. Moreover the key issue in the technical subsystem, whether to put more reliance on the immobilization (via the waste package or engineeered barriers) or the isolation (via the geology) has stayed tilted toward the latter since 1978, when we organized the first symposium on radwaste science (at the Materials Research Society meeting). Now that the isolation strategy is stymied, the opportunity arises again for the materials community to make a compelling case for the waste package's true significance.This review is made mainly from the perspective of one laboratory in one country, the U.S. What is remarkable about the state of research in the technical subsystem is how little the big picture of the science or the technology has changed after some billions spent on R/D. The borosilicate glass (almost unchanged) is still the establishment's choice of reference waste form for HLW Cost, however, is finally forcing cement encapsulated forms to be given a second look. Mineral-modeled ceramics have received a great deal of scientific attention but remain esoteric to managers. It will be shown that in the author's opinion an enormous amount of detailed science has been done but most of it is unlikely to prove to be of any relevance or use. The policy implications for future R/D are discussed.