To demonstrate that true catalysis had occurred, Mango and coworkers conducted additional experiments un der identical conditions with alkene and hydrogen (with no rock), with hy drogen and rock (no alkene), and with alkene and rock (no hydrogen). In each case, only trace amounts of hydrocar bons were detected. The addition of small amounts of water increased cata lytic activity and selectivity to methane. Above about 2.5% by weight of water, catalytic activity remained unaffected, but selectivity to methane dropped in favor of increased conversion to C5 and higher hydrocarbons. Since the source rock does not con tribute material to the reaction, but is essential for it to proceed, the research ers reason, the reaction must be catalyt ic. As additional evidence, the reaction rate is fairly constant over time— consistent with catalytic reactions and inconsistent with thermal cracking. Scientists may question, however,
whether the experimental conditions correspond to conditions in geologic formations. Mango responds by noting that the experimental temperature range is well within that suggested for gas generation in sedimentary basins, and below some temperatures mea sured in actual reservoirs and deep gas deposits. Similarly, hydrogen condi tions in the experiments are well with in the limits encountered in nature. The researchers also tried the reaction with a sample of commercial cracking catalyst (Si0 2 /Al 2 0 3 ). At the reaction temperature, the catalyst was active with π-octadecene-l, but the products were more typical of acid catalysis and totally unlike those produced with the source rock catalyst. Mango has not identified the specific catalysts in the source rock, but the principal candidates are nickel and va nadium compounds. He is now work ing on more precise identification. Joseph Haggin
North Korea suspected of hiding plutonium The International Atomic Energy Agen cy (IAEA) says several types of isotopic tests lead it to believe North Korea may have produced far more plutonium than it has declared. However, evidence obtained so far is somewhat sketchy and circumstantial. North Korea has blocked IAEA from conducting further tests and inspections needed to prove that that nation is un derstating its plutonium production. The U.S. Central Intelligence Agency and the Department of Defense fear that North Korea is extracting plutoni um from spent fuel to build nuclear weapons, and that it is developing nu clear facilities to enable it to sell nucle ar technologies to nations like Iraq. North Korea now operates a 5-MW nuclear reactor, and is rapidly complet ing a 50-MW reactor. Construction of a 200-MW reactor also is well under way. All are Calder Hall reactors, used in the U.K. in the 1950s and ideally suited for producing weapons-grade plutonium (mostly Pu) from natural uranium ore. North Korea has one reprocessing line for extracting plutonium from spent fuel and is completing a second line, which will double its capacity for plutonium production. It also has a plant that manufactures fuel for its re actors. All the nuclear facilities are lo
cated at Yongbyong, 60 miles north of the capital, Pyongyang. North Korea claims it has produced less than 100 g of plutonium in one re processing run. But IAEA says it may be hiding as much as 10 kg. About 5 kg are needed to make a crude bomb. When IAEA tested three samples of plutonium provided by North Korea, it found the samples had different isoto pic compositions of americium-240 and -241, says David R. Kyd, director of public information at the agency's headquarters in Vienna. When plutoni um is extracted from spent fuel, americium is also extracted. The longer the fuel stays in the reactor, the more americium develops. So if one sample of plutonium has a different level of americium than another, it was probably extracted at a different time. Another way to test whether North Korea is hiding plutonium is to deter mine whether the isotopic ratios of 239Pu to 240Pu in the extracted plutonium sam ples are the same as the ratios in the waste from reprocessing this plutonium. The 239Pu/240Pu ratios in the samples do not match the ratios in the waste IAEA inspectors had access to, says Kyd. IAEA tests indicate that the 239Pu/240Pu ratios in the waste differ from those in the samples by about 0.5 to 1%.
This leads IAEA to suspect North Korea is hiding waste. But that nation has barred IAEA from conducting fur ther tests to confirm this. "We have reason to believe there is a great deal of concealed waste material at their facilities because we have satellite photos of facilities that were camou flaged before our inspections began," Kyd tells C&EN. "We believe waste is hidden below ground at the site. If we could get into that, we would be able to see whether the volume of waste is such as to make us believe a good deal more plutonium has been produced than North Korea claims. They have refused to let us into those sites on the grounds that they are militarily related." A third way to test North Korea's ve racity is to check the fuel rods in July when the core is removed from the 5-MW reactor for refueling. IAEA is demanding it be allowed to test these rods to see if they are the original ones installed in 1986, or whether more rods were removed in 1989 for plutonium reprocessing than North Korea ac knowledges. North Korea claims it withdrew only a few damaged rods at one time in 1989, and experimentally reprocessed a rod to produce a few ounces of plutonium. North Korea denies it is building nu clear reactors and setting up reprocess ing facilities to build nuclear weapons. It
Yongbyon is site of North Korean nuclear facilities China North Korea YQNGBYOM Korea Bay
Sea of Japan P'yongyang
* Seoul
Yellow Sea
South Korea
APRIL 11,1994 C&EN
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NEWS OF THE WEEK says it wants to gain experience with tional Institute on Drug Abuse's Adplutonium production so it can eventudiction Research Center. Henningfield ally manufacture mixed oxide fuel (a says the paper's withdrawal "set the mixture of plutonium and uranium oxfield back at least six years," until Caides) to use in breeder reactors for elecnadian researchers could duplicate and tric power production. Until recently, its publish the findings. operating reactor produced no electriciLast week, William Steiner, a Philip Nicotine ty, but one transmission line was hastily Morris shareholder, filed a class action installed before the last IAEA inspection. suit against the company and its top ofSerious questions have been raised ficers. The suit alleges, among other about North Korea's claims. Currently, company does not comment on the pa- things, that the "Defendants engaged in mixed oxide fuel is about five to six per in question, but states that DeNo- a course of conduct that was designed times as expensive as ordinary urani- ble has published dozens of papers, to, and did, deceive the investing public um fuel and is expected to remain so "including five based on his nicotine- concerning the then current and future for many decades to come. Breeders re- related research conducted while at profitability of the company's tobacco quire much more sophisticated tech- Philip Morris." operations. Defendants' scheme was nology than the nuclear reactors comThe existence of the 1983 paper was rooted in their public statements ... that mercially used in most of the Western revealed by Food & Drug Administra- cigarettes were not addictive, despite the world, and they are a much more ex- tion head David A. Kessler during ques- company's own undisclosed evidence to pensive way to produce nuclear power. tioning at a hearing Waxman held last the contrary." Philip Morris had no comBette Hileman month (C&EN, April 4, page 5). But he ment on the suit at press time. Steiner's suit appears to be the first refused to name the researcher or his company. FDA is considering whether against Philip Morris on the issue of regulate nicotine in tobacco as a drug. nicotine's addictive nature. Other suits Suppression of nicotine to Kessler was made aware of the study are expected to follow as debate continaddiction data charged by Jack E. Henningfield, chief of clini- ues in Congress and at FDA. Lois Ember cal pharmacology research at the NaTobacco companies continue to deny that nicotine is addictive. But nicotine's habit-fonning nature in test animals was Chemical stocks follow rest of the market down shown in an industry-sponsored study completed in 1983 that was kept "secret" The stock market plunge of the past (1992 = 100), indicating that the larger by a tobacco company, charges Rep. two weeks—brought on by inflation chemical firms were less affected by the Henry A. Waxman (D.-Calif.), who has fears and rising interest rates—also af- drop and gave some protection to the made the study available to the public. broader index. fected chemical stocks. C&EN's index of 11 biotechnology The study on nicotine addiction in rats Chemical stock prices dropped sigwas accepted for publication five years nificantly. However, whether these company stocks, usually more volatile, before a landmark 1988 Surgeon Gener- stocks performed better or worse than behaved more moderately during the peal's report concluded that "nicotine is the Dow Jones industrial average de- riod, dropping 5.6% to 182.2 (1990 = 100). the drug in tobacco that causes addic- pends on the breadth of the chemical During the two-and-a-half week perition." The research was conducted by stock index used. od, all the stock indexes peaked on Victor J. DeNoble and colleagues at the At the New York Stock ExPhilip Morris Research Center, and ap- change close on April 6, the proved for publication in Psychopharma-Dow Jones average was Chemical stock index fell 7% cology, a peer-reviewed journal. DeNoble down to 3679.73, off 185 from peak to valley withdrew the paper, explaining it was points, or 4.8%, from its "due to factors beyond my control," and March 21 level. But C&EN's C&EN chemical stock index, 1954 = 100a 740 f left the company shortly thereafter. market value index of seven chemical stocks was down DeNoble tried to publish a revised 720 version in 1986. But according to the just 2.6% in the same period journal's editor at that time, Philip Mor- to 693.8 (1954 = 100). The sevris obtained a court injunction against en companies are Air Prod700 publication. Waxman, chairman of the ucts & Chemicals (replacing House Subcommittee on Health & the American Cyanamid after it Environment that is examining possible spun off its chemical opera680 regulation of nicotine in cigarettes, says tions), Dow Chemical, W. R. "Philip Morris closed the laboratory Grace, Hercules, Monsanto, 660 4 5 6 Rohm and Haas, and Union 21 22 23 24 25 28 29 30 where the research was conducted." L-April J L_ March In a written statement, Philip Morris Carbide. a Based on closing stock prices for Air Products, Dow Chemical, denies seeking an injunction, "legal or But a broader C&EN index W. R. Grace, Hercules, Monsanto, Rohm and Haas, and Union otherwise, against the publication of of 30 chemical stocks fell Carbide, weighted by number of shares. any of Dr. DeNoble's research." The 7.8% in that period to 110.6 6
APRIL 11,1994 C&EN
