KAKUJOHO (Nuclear Information)


Japanese ZEN approach to proliferation

May 15, 2005

Japanese ZEN approach to proliferation

"Separated plutonium is more proliferation resistant than plutonium in spent fuel"

Did you get it?

If so, you are already a ZEN master. Apply for a job with the Japan Atomic Energy Commission.

If not, you have a lot to learn. Ask the Japanese Ambassador for explanation.

The New Nuclear Policy-Planning Council of the Japan Atomic Energy Commission says in its 12 November 2004 interim report:

"In regard to 'non-proliferation', when conducting reprocessing, in order to avoid giving rise to international concerns about nuclear proliferation and nuclear terror, it is necessary to create strict, internationally agreed safeguards and measures for the protection of nuclear materials. In the case of scenario 1[reprocessing all spent fuel], so that pure plutonium oxide doesn't exist at the reprocessing plant, uranium nitrate and plutonium nitrate solutions are combined to make MOX powder (mixed oxide powder). This is to implement Japan's promise to the international community and is done in accordance with technical procedures agreed with the US. In the case of scenario 3 [direct disposal of all spent fuel], the temptation for diversion of this material will increase in the period between hundreds and tens of thousands of years after disposal, so it will be necessary to develop and implement an efficient and effective internationally agreed monitoring and physical protection system. When these things are taken into account, there is no significant difference between the scenarios on the issue of non-proliferation." [Translation by CNIC]

Is Ambassador more worried about what might happen thousands of years from now than about what's happening right now with the NPT regime?

Professor Steve Fetter at School of Public Affairs, University of Maryland, who is a more earthly person, says:

1.About clear and present danger vs. future danger

Yes, plutonium would be easier to recover from spent fuel thousands of years hence, but...(1) the price for decreasing the very-long-term risks is to increase the near-term risks; we should give far more attention to the risks over the next few decades because we know these will be dangerous times; human society a thousand years from now is likely to pose far smaller proliferation risks--because otherwise it is unlikely that humanity will make it that far; (2) spent fuel in geologic repositories will be highly inaccessible, and it is not clear that the recovery of Pu from this spent fuel would be easier or more attractive than the production of fresh Pu or HEU with the technology of the future; (3) this risk can be eliminated only if Japan separates and continuously recycles all of the fissile isotopes--not just Pu, but Np, Am, etc.--which is doesn't plan to do; and (4) if this is a serious concern, then other disposal options can be investigated that would make the spent fuel or waste much less accessible, such as disposal in subduction zones or in deep sea beds.

2.About the method to produce mixture of uranium and plutonium

First, a mixture of U and Pu oxides (MOX) is somewhat less attractive for bomb-building purposes than pure Pu oxide, but any group that can build an implosion device can easily separate the Pu from MOX. The chemistry involved is much simpler than reprocessing. For a description, see http//www.oxfordresearchgroup.org.uk/nuclear/plutonium/EnergyReviewSubmission0901.htm

Second, the use of MOX does not eliminate plutonium. Much of the plutonium in fresh MOX is burned, but some remains unburned and more is produced from U238 in the fuel. The plutonium in spent MOX is less desirable but still usable in a nuclear weapon. Indeed, no country is planning to reprocess spent MOX fuel, so that fuel must either be stored for permanent disposal, or reprocessed for use in future breeder reactors. Thus, the net effect of MOX use is clearly an increase in proliferation risk, because otherwise the Pu in the spent LEU fuel would never be in circulation; it would be stored for disposal or stored for later reprocessing to provide start-up fuel for breeder reactors--just like spent MOX fuel.

*For more information on the Rokkasho reprocessing plant:

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