Germany is plagued by an unusually large number per capita of pathologically pious zealots of the type who like to strike heroic poses as saviors of humanity. The number may even approach the levels found in the USA. They definitely take the cake when it comes to the subspecies of the tribe whose tastes run to nuclear alarmism. They came out of the woodwork in droves the last time an attempt was made to move radioactive waste via rail to the storage facility in Gorleben, tearing up the tracks, peacefully smearing a police vehicle with tar and setting it on fire, and generally making a nuisance of themselves. Now, in keeping with that tradition, an article just appeared in the German version of New Scientist, according to which those evil Americans are actually planning to restart the production of (shudder) plutonium.
Entitled The Return of Plutonium and written by one Helmut Broeg, the article assumes a remarkable level of stupidity on the part of its readers. Mimicking Der Spiegel, Germany’s number one news magazine, its byline is more sensational than the article that follows, based on the (probably accurate) assumption that that’s as far as most consumers of online content will read. Here’s the translation:
The USA stopped producing plutonium 25 years ago. In order to preserve the ability to launch deep space missions, they will resume the production of the highly poisonous and radioactive material.
Only in the body of the article do we learn that the particular isotope that will be produced is plutonium 238, which, unlike plutonium 239, is useless for making nuclear explosives. As it happens, Pu-238 is the ideal material for powering thermoelectric generators such as that used on the Curiosity Mars rover because it decays primarily via emission of alpha particles (helium nuclei) and has a half life of 87.7 years. That means that its decay products are mostly stopped in the material itself, generating a lot of heat in the process (because of the short half life, or time it take half of the material to decay), which can be converted to electricity using devices with no moving parts. The world supply of the material is currently very short, and more is urgently needed to power future deep space missions.
All this is very sinister, according to Broeg. He quotes Heinz Smital, who, we are informed, is an “atomic expert” at Greenpeace, that, “the crash of such a satellite could contaminate large areas with radioactivity. Don’t look now, Mr. Smital, but if you’re really worried about radioactive contamination by alpha emitters like Pu-238, you might want to reconsider building all the coal plants that Germany is currently planning to replace the nuclear facilities it has decided to shut down. Coal typically contains several parts per million of radioactive uranium and thorium. A good-sized plant will release 5 tons of uranium and 10 tons of thorium into the environment each year. Estimated releases in 1982 from worldwide combustion of 2800 million tons of coal totaled 3640 tons of uranium (containing 51,700 pounds of uranium-235) and 8960 tons of thorium. That amount has gone up considerably in the intervening years. The cumulative radiation now covering the earth from these sources dwarfs anything that might conceivably result from the crash of a rocket with a Pu-238 power source, no matter what implausible assumptions one chose to make about how its containment would fail, how it would somehow enter the atmosphere at hypersonic speed so as to (optimize) its dispersion, etc. Of course, the radioactive isotopes released from burning coal will also be with us for billions of years, not just the few hundred it takes for Pu-238 to decay.
But wait! Dispersal of Pu-238 isn’t the only problem. There’s also (drum roll) the BOMB! Broeg drags in another “expert,” Moritz Kütt, a physicist at the Technical University of Darmstadt, who assures us that, “In the production of Pu-238, some Pu-239 is produced as well. As a matter of principle, that means the US is resuming the production of weapons-useful material.” Kütt goes on to ask what the world community would have to say if Iran announced that it would produce Pu-238 for a space mission?
To appreciate the level of gullibility it takes to swallow such “warnings,” one must spend a few minutes to check on how Pu-238 is actually produced. Generally, it is done by irradiating neptunium 237 from spent nuclear fuel with neutrons in a reactor. Occasionally the Np-237 captures a neutron, becoming Np-238. This, in turn emits a beta particle (electron), and is transmuted to Pu-238. It’s quite true that some of the Pu-238 will also capture a neutron, and become Pu-239. However, the amounts produced in this way would be vanishingly small compared to the amounts that could be produced in the same reactor by simply removing some of the fuel rods after a few months and chemically extracting the nearly pure Pu-239, which would not then have to be somehow separated from far greater quantities of highly radioactive Pu-238. In other words, if the world community learned that Iran had a nefarious plan to produce bomb material in the way suggested by Kütt, the reasonable immediate reaction would be a horse laugh, perhaps followed by sympathy for a people who were sufficiently stupid to adopt such a plan. As for the US deciding to replentish its stocks of bomb material in this way, the idea is more implausible than anything those good Germans, the brothers Grimm ever came up with. It only takes 4 kilos of Pu-239 to make a bomb, and we have tons of it on hand. In the unlikely event we wanted more, we would simply extract it from reactor fuel rods. The idea that we would ever prefer to attempt the separation of Pu-239 from Pu-238 instead is one that could only be concocted in the fevered imagination of a German “atomic expert.”