Wednesday, August 26, 2009

Scientists Release Radioactive Cockroaches Into Phoenix City Sewer

From the "research committee wouldn't approve that nowadays" file:
Approximately 6,500 American roaches, P. americana, were trapped in sewer manholes, tagged with P32, and then released at selected sites. To capture the specimens, a quart jar fitted with a plastic screen cone and baited with over ripe bananas was placed on its side in each of 9 manholes. A total of 18 traps was operated for 12 days to collect the desired number of specimens. Prior to marking, the roaches were maintained in 18-inch square screen cages on a diet of banana and powdered milk.

To tag the roaches, a radioactive casein solution containing 10 microcuries of P32 per milliliter was sprayed upon the specimens under confinement. The spray mixture contained equal parts of a 10 per cent casein solution and a P32 solution, the former being included to assure adhesion of the spray to the integument of the roach. The initial step in the treatment of the roaches was to place 1,000 to 1,500 specimens in a 10 or 20 gallon garbage container which was covered by a transparent plastic lid. The latter was equipped with an exhaust filter and a center hole for nozzle insertion. The spray was then introduced by means of a nasal syringe attached to a small air compressor. A total of 40 to 50 milliliters of spray solution sufficed for each can application, the operation requiring approximately five minutes.

Following the application of the spray, the container was allowed to remain undisturbed for fifteen minutes. At the end of that time, the plastic lid was replaced by the standard garbage can cover. When treatment of all roaches was completed, the contained specimens were transported to the liberation sites which consisted of four manholes one block apart and serving the same trunk line. Release of the specimens occurred at dusk, the container being lowered into the manhole and the lid removed. The opened container remained in the manhole for a 24-hour period.

For recovery of the tagged specimens, 34 traps were located in sewer manholes within a one-mile radius of the four release sites, the majority of the stations being within the 0.5 mile radius (Fig. 1). On the basis of the direction of sewage flow, stations were selected at manholes below and above the release points and at manholes located on secondary lines. In addition to the manhole sites, 10 traps were placed on premises in the blocks immediately adjacent to four liberation sites. Collection of specimens was effected at each station for 8 1/2 weeks following the release of the tagged roaches, a total of 12 samples being procured from each manhole. Radioactive roaches were detected by examining all samples with a laboratory or field count rate meter equipped with a thin-walled Geiger tube.
This is from "The Occurrence and Movement of Periplaneta Americana (L.) Within an Urban Sewerage System," by H.F. Schoof and R.E. Siverly, published in the March, 1954 issue of The American Journal of Tropical Medicine and Hygiene.

What was the logic behind tagging cockroaches with radiophosphorus and releasing them into a municipal sewer? As the authors explained,
These instances coupled with the prevalence and movement of cockroaches in and around food-handling establishments, residences and waste disposal sites have focused further attention upon the importance of these insects as possible vectors of enteric infections. Concurrent with this interest is the renewed effort by communities to control roaches within city sewerage systems (Gary, 1950). The heavy roach infestations within such systems combined with the availability of human wastes are factors which conceivably could constitute a potential hazard to the health of a community.

Since it has been demonstrated that roaches resident within the sewerage systems can become contaminated with pathogenic organisms, the next step in the mode of spread of the pathogens would involve the degree of dispersion of the infected roaches and the contact between the insects and the human population. To obtain information on the dispersion of roaches within and from a sewerage system, a study was conducted at Phoenix, Arizona, in October 1952. Previous surveys of 22 selected manholes in that city for a seven-week period had shown a weekly average of 92 to 143 specimens per manhole with all roaches being P. americana.
Mercifully, it turns out that the radioactive cockroaches didn't go much of anywhere:
The collection data are summarized in Table 1. As is apparent, only one tagged specimen was recovered from sites other than the release point. Despite the absence of marked specimens, all manhole stations yielded P. americana, the average number per collection being 39 specimens. Only one specimen was trapped in the 10 yard stations but this roach was radioactive. Three of the four release sites were trapped to provide a total of 929 roaches in 17 collections or an average of 54 specimens per sample. Of this number, 97.5 per cent were radioactive, thus demonstrating that the method of tagging had been effective. Further substantiation of this aspect was shown by the recovery of tagged roaches throughout the 8 week period. Specimens captured 39 days after release displayed counts of 1,000 to 6,000 per minute.
The authors concluded from these findings that:
The conclusion derived from the experimental evidence is that P. americana does not disperse throughout the urban sewerage system of Phoenix, Arizona. . . .The results reported tend to raise a question as to the relative importance of roaches as a means of disseminating disease pathogens within the sewerage system and from such locations to human habitations. Further evidence discrediting the concept is the finding that the roach populations in sewer manholes are composed of one species, P. americana, whereas the predominant species taken in homes have been Supella supellectilium and Blattella germanica.
Isn't that reassuring?

Friday, August 21, 2009

That Doesn't Even Make Any Sense

I've been eternally mystified by the insistence some arms control types have that restricting the domestic deployment of civilian nuclear technology will somehow forestall proliferation abroad. The classic example of this is the Ford/Carter reprocessing ban. Given that reprocessing continued in the UK, France, Russia, and Japan, it seems that this policy failed to make much of an impression, and given the ability of North Korea to build a basic plutonium extraction plant, it hasn't done anything to halt determined would-be nuclear states. But that doesn't stop certain observers from claiming that this policy was actually a success and should be used as a model for future US nuclear energy policy. The most recent example is James M. Acton's article in the August/September issue of Survival, "Nuclear Power, Disarmament and Technological Restraint." As the author puts it:
The appropriate way to evaluate a strategy of desist and discourage is to ask whether it not only discourages states from taking small-scale research programmes to an industrial level, but leads states to avoid launching new reprocessing programmes in the first place. (Small-scale reprocessing programmes are perhaps even more worrying from a proliferation perspective than their industrial-scale counterparts.) For this reason, the claim from a recent Department of Energy report that 'U.S. opposition [to reprocessing] has not slowed large-scale reprocessing programs in Europe, Japan, and Russia', while true, is also somewhat beside the point. What the Department of Energy's statement really underlines is that, because of the web of political, legal and financial commitments needed to create such multibillion-dollar programmes, it is extremely difficult to stop them once they have been set in motion. This phenomenon, termed 'entrapment' by William Walker, highlights the importance of a policy aimed at stopping such programmes before they have even started. Here, there is evidence that the US moratorium had a positive, albeit modest, effect.
And where were these effects felt?
Most Western nuclear-power programmes prior to the mid 1970s were built around the expectation that power-reactor fuel would be reprocessed. The seminal 1976 study Moving Towards Life in a Nuclear Armed Crowd? observed that, given contemporary plans, 17 states would have reprocessing facilities and enough separated plutonium for between three and six nuclear weapons by 1985; today, just eight or nine states (including North Korea) are reprocessing. Not all of these stoppages were due to the US moratorium. Some programmes, such as South Korea's and Taiwan's (both of which had a clear military dimension), were avoided because of intense US pressure on both the supplier and recipient of reprocessing-technology transfers. Others, however, were influenced by the moratorium.
Acton uses Italy as an example of a state influenced by the moratorium, but ultimately concludes that "the evolution of policy in Italy was driven by a domestic debate about the economics of reprocessing and safety concerns about plutonium," leaving the reader to wonder exactly where it was that the policy had the desired effect. On the whole, it's not at all convincing as a defense of this kind of policy.

The technology which Acton particularly seems to envision for this kind of treatment is Silex laser enrichment:

Realistically, the gas centrifuge is too economically advantageous, and its use too entrenched, to be phased out. The opportunity does exist, however, to forsake enrichment and other nuclear technologies that have not yet been commercialised.

Today, for instance, Global Laser Enrichment (GLE, owned by General Electric Hitachi) is attempting to commercialise a new enrichment process (known as the SILEX process) based on lasers. GLE expects that the SILEX process will be more profitable to enrichment firms than other technologies. However, the economic benefits of cheaper enrichment to electricity consumers are slight because enrichment typically accounts for less than 5% of the total cost of nuclear electricity. Meanwhile, laser enrichment is probably even more worrying from a proliferation perspective than the gas centrifuge because detecting a small, clandestine laser-enrichment plant is likely to be even harder than detecting a secret gas-centrifuge enrichment plant of a similar capacity. Regulators should factor such concerns into licensing decisions for all nuclear technologies and be willing to deny applications if they determine that the costs outweigh the benefits, as is almost certainly the case with GLE, for instance. Forsaking sensitive nuclear technologies on non-proliferation grounds would be controversial, but justifiable.
I'm not sure why this follows. Silex is an extremely challenging technology which is already subject to what are arguably some of the tightest information controls ever applied to a civilian endeavor. Centrifuge technology, however, is much more achievable to would-be nuclear states and information about it has already been widely disseminated thanks to the efforts of A.Q. Kahn and others. Nuclear proliferators would be fools to pursue Silex, so why should we deny it to ourselves?

In general, Acton claims that "policymakers, industry insiders and regulators have usually failed to factor proliferation concerns into decisions about nuclear energy." This is a highly questionable assessment, given not only the history of the reprocessing ban in the US recounted by the author. To read the article, one would not know that such international controls have been in place already for decades. Incredibly, Acton totally ignores the existence of the Nuclear Suppliers Group, which has been working to discourage nuclear proliferation since 1978. Perhaps one could argue that the efforts of the NSG have been utterly inadequate, but a failure to consider its efforts historically in an article making this argument is, to say the very least, an extraordinary oversight.

For all its shortcomings, however, the article does make an important and often-overlooked point:
The proliferation costs of not selling less-sensitive technologies are frequently underplayed. A dramatic example is the US decision to cut the United Kingdom and Canada out of the development of civil nuclear power after the Second World War. Reluctant to rely on the United States as a supplier of enrichment, Britain and Canada decided to focus on reactors that did not use enriched uranium (GCRs and HWRs, respectively). These reactors are, however, more suitable for proliferation than LWRs (which is not to say that LWRs are proliferation proof). Indeed, the Indian nuclear-weapons programme was based on a Canadian-supplied HWR. South Korea tried to acquire an almost identical reactor in the early 1970s, when it was pursuing a nuclear-weapons option. And, as noted above, North Korea produced plutonium for its weapons programme using a GCR based on a British design.
Historically, I think that Acton's example is rather imperfect, but I think the overall point is sound. The UK developed the MAGNOX GCR in order to produce plutonium for its weapons program; it seems unlikely that the US would have provided HEU for weapons use. The Canadians chose HWRs in the 1950s because they determined that developing domestic enrichment capabilities for solely civilian purposes would be prohibitively expensive, and there was no international civilian source for enriched uranium at the time. The US denial wasn't necessarily the issue per se. But it is easy to imagine how an unwillingness to share nuclear technology today could have undesirable consequences. For instance, states denied US reactor technology might turn to India and Russia, which could sell them reactors like the BN-800 that would have less proliferation resistance than conventional LWRs. This is one reason why more sensible arms control wonks have embraced the UAE deal as an example for how nuclear exports should be conducted.

The biggest flaw with Acton's argument, however, is that it is an anachronism in an era when the US dominates the world nuclear field far less than it did thirty years ago. In 1978, the US had much more influence over the civilian nuclear energy field; today, the major American players have been bought out by the Japanese, we have to import critical forgings, and Areva and Rosatom are furiously competing for the export market with offers of financing, fuel cycle services, and other enticements. Acton speaks mysteriously of "a small number of advanced nuclear states," but does this have any bearing on the world situation today? As nations like China and India build up their domestic nuclear industries, US influence continues to shrink, for better or for worse. Any strategy for non-proliferation that is posited on continued American dominance in the nuclear energy field is doomed to failure.