Some comments on Australian-obligated plutonium, and more specifically, plutonium produced in power reactors in Japan using Australian uranium. A large quantity of Australian-obligated plutonium is held in Japan and in spent nuclear fuel shipped from Japan to Europe (though the Australian government refuses to reveal exactly how much).

Successive Australian governments have permitted Japanese governments to separate and stockpile Australian-obligated plutonium and to use Australian-obligated plutonium in MOX fuel. There is no question that this plutonium could be used in nuclear weapons; indeed the United States tested a weapon using so-called reactor-grade plutonium in 1962. Nor can we place much faith in the safeguards system of the International Atomic Energy Agency, a system described as "half-blind, toothless and mute" by Professor Jim Falk in his 1983 book ‘Taking Australia Off the Map’.

Concerns over Australian-obligated plutonium are heightened every time Japanese politicians advocate the production of nuclear weapons. On that point I wish to quote from a recent article by retired Australian diplomat Professor Richard Broinowski: “The nuclearisation of Japan and the Korean peninsula would leave Australia’s professed non-nuclear proliferation credentials in tatters. When Australian nuclear diplomats negotiated bilateral safeguards agreements with South Korea in 1979 and Japan in 1982, they did so on the assumption that both countries were unlikely ever to pursue nuclear weapons programs. The proposal was shaky at the time, but has become even less secure in the light of recent developments. As Japan and South Korea themselves approach the nuclear red line, they would no doubt use Australian-origin nuclear fissile material in their nuclear weapons programs. They are after all the second and third largest purchasers of Australian uranium oxide, which in various forms pervades every aspect of their nuclear systems.” (“Going nuclear, Japan?”, The Diplomat, June/July 2003, pp.16-17.)

The Japanese plutonium program, and the Australian government’s willingness to allow the separation and stockpiling of plutonium produced in reactors fuelled by Australian uranium, are fanning regional tensions in north-east Asia. That is one of our many concerns with the Australian uranium mining industry. In addition, the Australian government may further heighten regional tensions if its proposed interdiction of North Korean ships takes place.

The shipment of Australian-obligated plutonium also poses an obvious terrorist target. According to Adam Cobb, a former special director of strategic policy at the Royal Australian Air Force, we should be extremely concerned about the security surrounding enriched uranium and plutonium transports between Europe and Japan. Mr Cobb says: "These shipments are vulnerable targets for terrorist  organisations like Al Qaeda. Part of that radioactive  material is Australian-sourced and in that sense is our responsibility." (Quoted in Australian Financial Review, November 9, 2002.)

Plutonium-239 is the desired isotope for plutonium weapons. As neutron irradiation of uranium-238 proceeds, the
greater the quantity of isotopes such as plutonium-240, plutonium-242 and americium-241, and the greater the quantity
of plutonium-238 formed from uranium-235. These isotopes have unwanted effects such as decreasing the potential yield
of the weapon or increasing the radioactivity of the material thus making it more difficult and dangerous to manufacture
and transport weapons.

Definitions of plutonium usually refer to the level of plutonium-240, which is highly toxic and close in atomic weight to
plutonium-239 (and thus difficult to separate). "Super grade" plutonium contains 2-3% plutonium-240, "weapon grade"
plutonium contains less than 7% plutonium-240, "fuel grade" plutonium contains 7-18% plutonium-240 and "reactor
grade" plutonium contains over 18% plutonium-240.

With the exception of plutonium comprising 80% or more of the isotope plutonium-238, all plutonium is defined by the
IAEA as a "direct use" material, that is, "nuclear material that can be used for the manufacture of nuclear explosives
components without transmutation or further enrichment", and is subject to equal levels of safeguards. (Australian
Safeguards and Non-Proliferation Office, 1998-99, pp.55-59.)

Although plutonium grades with lower percentages of plutonium-240 (and other unwanted isotopes) are more suitable
for weapons manufacture, reactor grade plutonium can still be used for weapons manufacture. (Makhijani and Saleska,
1995, p.48.)

The ease or difficulty of producing a nuclear weapon using reactor grade plutonium is debated. According to the
Australian Safeguards and Non-Proliferation Office, theoretical studies show that reactor grade plutonium could be made
to explode under certain conditions, but characteristics required for a practical nuclear weapon, including reliability,
useful yield, a deliverable size and storage life would be adversely affected by the difficulties associated with reactor
grade plutonium. (Australian Safeguards and Non-Proliferation Office, 1998-99, pp.55-59.)

A report from the US Department of Energy (1997) puts a different view :

"Virtually any combination of plutonium isotopes - the different forms of an element having different numbers of
neutrons in their nuclei - can be used to make a nuclear weapon. ... The only isotopic mix of plutonium which cannot
realistically be used for nuclear weapons is nearly pure plutonium-238, which generates so much heat that the weapon
would not be stable. ... At the lowest level of sophistication, a potential proliferating state or subnational group using
designs and technologies no more sophisticated than those used in first-generation nuclear weapons could build a
nuclear weapon from reactor-grade plutonium that would have an assured, reliable yield of one or a few kilotons (and a
probable yield significantly higher than that). At the other end of the spectrum, advanced nuclear weapon states such as
the United States and Russia, using modern designs, could produce weapons from reactor-grade plutonium having
reliable explosive yields, weight, and other characteristics generally comparable to those of weapons made from
weapons-grade plutonium."

"The disadvantage of reactor-grade plutonium is not so much in the effectiveness of the nuclear weapons that can be
made from it as in the increased complexity in designing, fabricating, and handling them. The possibility that either a
state or a sub-national group would choose to use reactor-grade plutonium, should sufficient stocks of weapon-grade
plutonium not be readily available, cannot be discounted. In short, reactor-grade plutonium is weapons-usable, whether
by unsophisticated proliferators or by advanced nuclear weapon states."

The US government has acknowledged that a successful test using reactor grade plutonium was carried out at the Nevada
Test Site in 1962. The exact isotopic composition of the plutonium remains classified information. It has been suggested
(e.g. by Carlson et al., 1997) that because of changing classification systems, the plutonium used in the 1962 test may
have been weapon grade plutonium using current classifications, not reactor grade plutonium.

The main technical barrier to using plutonium contained in spent fuel for weapons comes not from the plutonium's
different isotopic composition compared to weapon grade plutonium, but from the bulk and the intense radioactivity of
the spent fuel. The bulk and radioactivity make it difficult and dangerous to steal, and a considerable degree of chemical
and engineering sophistication is required to separate the plutonium from the fission products and the uranium while
avoiding lethal radiation doses to workers.

REFERENCES

Australian Safeguards and Non-Proliferation Office, 1998-99, Annual Report.

J. Carlson, J. Bardsley, V. Bragin and J. Hill (Australian Safeguards and Non-Proliferation Office), "Plutonium isotopics - non-proliferation and safeguards issues", Paper presented to the IAEA Symposium on International Safeguards, Vienna, Austria, 13-17 October, 1997, <www.asno.dfat.gov.au/O_9705.html>

Arjun Makhijani and Scott Saleska, "The Production of Nuclear Weapons and Environmental Hazards", in Arjun Makhijani, Howard Hu and Katherine Yih, 1995, Nuclear Wastelands, Cambridge, Mass.: MIT Press, p.48.

US Department of Energy, Office of Arms Control and Nonproliferation, 1997, "Final Nonproliferation and Arms Control Assessment of Weapons-Usable Fissile Material Storage and Excess Plutonium Disposition Alternatives", Washington, DC: DOE, DOE/NN-0007, January, pp.37-39.