Charles Ferguson. . ., a former nuclear submarine officer trained in physics, . . . co-wrote an unclassified report titled “Commercial Radioactive Sources: Surveying the Security Risks.” About two years later, F.B.I. agents . . . asked to meet with him. They brought a document showing that some of his report had been downloaded onto the computer of a British citizen named Dhiren Barot, a Hindu who had converted to Islam. Barot, it turned out, had been communicating with Al Qaeda about a plan to detonate a dirty bomb in Britain, and he had used a highlighting pen on a printout of Ferguson’s study while conducting his research.

The report described how large amounts of certain commercial radioactive materials might pose a danger to a terrorist who tried to handle them. “This seems to have worried him,” Ferguson told me, referring to Barot, “so he decided to look at smoke detectors.” Some detectors contain slivers of americium-241; the isotope’s constant emission of radiation creates a chemical process that screens for smoke. Barot informed his Al Qaeda handlers that he was thinking about buying ten thousand smoke detectors to make his bomb. In fact, to make a device that would be even remotely effective, Ferguson said, he would have had to buy more than a million. “Either his reading comprehension was poor or he was evading the assignment,” Ferguson told me.

The rest of the article is an interesting account of the current efforts by the U.S. government to interdict nuclear-terrorism on U.S. soil. Click here to read it.

The effect of that designation is that certain nuclear materials for which general export licenses are available under NRC rules may now be used to export those materials to Libya. For example, small quantities of americium-241 may now be exported to Libya under the general license provided in § 110.23.

Although exporting americium-241 sounds rather sinister, you should realize that small amounts of americium-241 are used in certain industrial applications such as equipment used to measure the rate of production of oil wells. Tiny amounts (less than 37 kBq) of americium-241 are also used in the ionization chambers of many residential and commercial smoke detectors. Ionization smoke detectors are, in fact, the principal use of americium-241.

People in Tripoli, however, shouldn’t expect to be getting American smoke detectors anytime soon. Under § 110.23 americium-241 can be exported under the general license to restricted countries such as Libya only when “contained in industrial process control equipment or petroleum exploration equipment.” I suppose we are still concerned that Qaddafi might dismantle a hundred million or so smoke detectors, extract the americium-241 and make a dirty bomb or two.

I suppose I should acknowledge that a terrorist cell that couldn’t shoot straight did try to make a dirty bomb from smoke detectors. A recently declassified intelligence report to Congress contained this statement:

British authorities announced the August 2004 arrest of members of an Islamic terrorist cell in the UK that may have attempted to produce an RDD [radiation dispersal device] using a radioactive isotope of americium taken from smoke detectors. The knowledge base and competence of this cell was low.

Uh, yeah. Do the math on how many smoke detectors it would take, at 37 kBq of americium-241 per smoke detector, to make a useful dirty bomb and saying that the competence of this cell was low is an understatement.

In response to these restrictions the Nuclear Control Institute wrote a letter to the NRC in February 2006 complaining that the omission from the public notice of the quantity of nuclear material to be exported deprived the public of meaningful comment on the license application. The NCI letter cited an instance where public comment on an export of HEU to Belgium’s BR-2 reactor revealed that Belgium had no immediate need for the HEU and the license application was withdrawn. According to NCI, limitation of export of excess quantities reduces the risk of diversion of the material to weapons use.

The NRC responded to the NCI letter on August 31 by agreeing to reveal the quantity in future proposed export applications. In a letter to NCI, NRC Chairman Dale Klein noted:

[T]he NRC intends to disclose quantity information for enriched uranium above 6% U-235, mixed oxide materials, and certain other radionuclides absent an NRC determination of a compelling reason for nondisclosure. Federal Register notices for proposed HEU exports will also include quantities requested. However, the NRC will continue to withhold information on projected or actual shipment schedules, delivery dates, date required, mode of transport, storage arrangements, or any other related logistical information provided by either the applicant, the licensee, other parties to the transaction or added by NRC, as this information could be useful to a potential adversary.

“Hat tip” on this item to Secrecy News, a blog maintained by the Federation of American Scientists