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About 5 years ago, I saw a small blurb in Chemical & Engineering News about some work going on at Los Alamos National Laboratory (LANL) on accelerator-driven transmutation technology (ADTT), which seemed to offer great promise for assisting nuclear waste disposal. I learned that the same technology could be used to generate electricity in a subcritical nuclear reactor and that it also might be used to dispose of weapons-grade plutonium removed from military systems or fueled with denatured thorium in a fission cycle that does not produce material of weapon value. The technology even appeared to be useful for producing tritium required for the periodical refueling of thermonuclear devices.

Accelerator-driven transmutation of waste is based on passing an intense beam of protons from a linear accelerator into a metal target to produce a large flux of spallation neutrons, which pass into a surrounding container filled with long-lived transuranic elements (TRUs), mainly plutonium, and problem fission products such as ⁹⁹Tc and ¹²⁹I. The neutrons induce fission of the TRUs and transmutation of the problem fission products to destroy >99.9% of these elements. The amount of TRUs going to the waste repository is reduced by a factor of 1000 and the mass of fission products by a factor of 20. More importantly, the storage lifetime would be on the order of 300 years rather than 100,000 years.

In a waste-destruction scenario presented to the U.S. Senate Appropriations Subcommittee on Energy and Water Development in May 1998, S. O. Schriber of LANL proposed that the 600 tons of TRUs and 3000 tons of fission products in the 70,000 tons of spent fuel expected to accumulate in the United States by 2015 be burned in 21 units brought on line over a period of 65 years. Products would include 67,000 tons of uranium that could be considered a low-level waste or a resource for future use. Less than 0.3 tons of TRUs and 3000 tons of fission products would go to the repository.

Finally, each of the 21 systems would send 700 MWe to the electricity grid during its 40-year operational life. Depending on the cost of electricity, this might offset the operating costs of the facilities and produce net revenue.

Schriber’s presentation to the subcommittee can be found at www.lanl.gov/orgs/pa/News/schriber0598.html. This scenario is also discussed in a technical paper by Francesco Venneri and co-workers at www.uilondon.org/sym/1999/venneri.htm.

Because this waste conversion process is subcritical and can be shut down by turning the accelerator off, it appears to be inherently safer than other reactor systems. A group at LANL is coordinating U.S. technology development at several national labs, companies, and universities. ADTT is also being pursued actively in other countries with various objectives. The information flow is not unidirectional; much of the technology that allows use of the lead–bismuth eutectic as the target cooling medium seems to have been developed and used in Russia for nuclear submarine propulsion of very fast, deep-diving vessels.

I grew up in a West Virginia coal camp, and my miner father died of black lung disease. I know that scores of miners still are killed in accidents in West Virginia mines alone each year. This has perhaps made me a little more open to the possibility of clean, safe fission power than most.

Images have meanings

Concerning “India’s techno-economic revolution” (August 2000, pp 43–49): I was very glad to read it. However, I think you could have avoided the picture of the temple on the lead page. CSIR is an institution that transcends religious considerations, and the image of a temple in the article isn’t an accurate representation of the brainpower behind this behemoth. It doesn’t behoove a publication of your stature to use such inappropriate images.

Good job, otherwise.

Sathish Kumar Rangarajan
University of Vermont
Burlington, VT
sathish@zoo.uvm.edu

The editors of Chemical Innovation apologize to anyone offended by our use of the temple graphic in the article.—Ed.

For the Record

In the article “Chemical market research goes global” (August 2000, pp 14 –21), Richard Beswick’s correct telephone number is +41-41-711-41-88. Chemical Innovation regrets the error.

In the article “Two reagents in one” (August 2000, pp 31–36), the product molecule in first inline structure should have an aminomethyl, rather than a nitrile, group. We regret the error.