PLENTIFUL ENERGY

there was no reason to think the waste product would have noteworthy properties
either. So there was little incentive to go much further than noting the reasons why
the original directions were abandoned.
The beginnings of what became the IFR program began in the work done by
Argonne in 1977-79 for the International Nuclear Fuel Cycle Evaluation (INFCE), a
thrust of the Carter administration toward non-proliferation, in an attempt to sharply
constrain reprocessing and limit it to as few nations as possible. To form a sound
technical basis for such an evaluation, Argonne was asked by the Department of
Energy to examine all possible fuels and fuel cycles for all feasible reactor types.
The result turned up a number of very interesting things, useful to the purpose of
the effort, but also very useful in stimulating thought on improving reactor
technology generally. The effort is described in a very complete ANL document,
ANL-80-40. [1] It described in detail what every practical fuel can do. It was this
impetus that caused the first analytical work on metal fuel to be done, apart from
the calculations necessary for routine EBR-II operation, in at least fifteen years.
Thinking began again on safety characteristics of metallic-fueled cores too, and
on metal fuel alloys that would be used in a metal-fueled breeder, and on
reprocessing possibilities. All this was part of the INFCE study. Interesting things
turned up in the look at metallic fuelled reactors in the study. There had been
advances of several kinds since the sixties, particularly in the techniques and
accuracy of calculations. And this new investigation was being done with the
benefit of this new knowledge.
Argonne had done a lot of work on analyzing accidents in CRBR, and in
particular, the phenomena in oxide fuel under severe accident conditions. Metal
fuel, it seemed, might have some surprising advantages over oxide in accidents
whose probability was small, but whose consequences could be substantial. It was
an important insight into the mechanisms of such accidents: with metal fuel, if they
did occur, they would be easily contained—a very significant finding.
The work on the reactor core showed very favorable physics characteristics, the
high breeding held up in uranium-plutonium versions of the lower density
zirconium alloy fuel now being specified for EBR-II operations. Changes
amounting to discoveries in the design of metal fuel pins had for several years been
incorporated into the fuel for EBR-II. The short time in-reactor problem of metal
fuel had been solved—for uranium fuel. Plutonium had not been tried. Plutonium
lowers the melting point, and it mightn‘t make a feasible metal fuel. But data on
alloys and some early experiments suggested that with the new design, metal fuel
containing plutonium could work.
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