| dc.description.abstract | The following report is a study of various aspects of the
relationship between heavy water and the development of the
civilian and military uses of atomic energy. It begins with
a historical sketch which traces the heavy water storyfrom
its discovery by Harold Urey in 1932 through its coming of
age from scientific curiosity to strategic nuclear material
at the eve of World War II and finally into the post-war
period, where the military and civilian strands have some-
times seemed inextricably entangled. The report next assesses
the nonproliferation implications of the use of heavy water-
moderated power reactors; several different reactor types
are discussed, but the focus in on the natural uranium, on-
power fueled, pressure tube reactor developed in Canada, the
CANDU. The need for and development of on-power fueling safe-
guards is discussed in some detail. Also considered is the
use of heavy water in plutonium production reactors as well
as the broader issue of the relative nuclear leverage that
suppliers can bring to bear on countries with natural ura-
nium-fueled reactors as compared to those using enriched
designs. The final chapter reviews heavy water production
methods and analyzes the difficulties involved in implemen-
ting these on both a large and a small scale. It concludes with an overview of proprietary and nonproliferation constraints
on heavy water technology transfer.
Our major conclusions are as follows:
1. On-power fueling of CANDU reactors leads to special,
well recognized safeguarding problems. These have been addres-
sed by a safeguards development program, encompassing both
systems analysis and hardware development, jointly sponsored
by Atomic Energy of Canada, Ltd. (AECL), the Canadian Atomic
Energy Control Board (AECB), and the International Atomic
Energy Agency (IAEA). The approach involves surveillance,
containment, and item-counting of irradiated fuel bundles.
Although the complete system has not as yet been tested on
an operating reactor, it appears to be a good example of
"proliferation resistance engineering." The major problem
may be the political one of obtaining agreement to incorporate
the system in operating reactors and those under construction.
2. The question of relative leverage on natural uranium
vs. enriched uranium fuel cycles does not have a neat answer.
At the moment, most of the countries of proliferation concern
have neither large amounts of uranium ore nor the ability to
enrich it. (There are, of course, some significant excep-
tions, the most obvious being South Africa which has both.)
In the near term, the chances of achieving a consensus among
current suppliers of separative work, all of whom belong to
the London Club, not to supply it in the event of violations
of nonproliferation agreements, also seems greater than the prospects of reaching a similar agreement among all countries
who might be able to supply uranium ore. If we assume in ad-
dition that the malefactor also can produce heavy water--no
small matter--the potential leverage advantage would seem to
lie with enriched reactors. On the other hand, the spread of
enrichment technology--which is easier to rationalize on civil-
ian grounds if enriched reactors are in place--could tip the
scales the other way. In general, however, this weighing of
enriched vs. natural uranium fuel cycles is unnecessarily
restrictive. Experience has shown that there are many poten-
tial levers--nuclear and non-nuclear--which can be used to
persuade countries to adhere to nonproliferation norms. The
heart of the matter is the political will to use these in the
face of conflicting policy objectives.
3. Unlike uranium enrichment via gaseous diffusion and
the gas centrifuge, key aspects of which are closely held on
nonproliferation grounds, techniques for heavy water produc-
tion, particularly by hydrogen sulfide-water exchange (the GS
process), have been extensively documented in the open liter-
ature. Nevertheless, construction and operation of large
plants are difficult, and thus there is good reason to believe
that the technology will not spread rapidly through the indig-
enous efforts of developing countries. Unlike uranium enrich-
ment and fuel reprocessing, heavy water production does not
provide a direct route from civilian fuel cycle to weapons-
usable materials; on these grounds a logical quid pro quo forits transfer would be adherence to the Non-Proliferation
Treaty (NPT) or acceptance of the principle of full-scope
safeguards by the recipient. | en |
