There’s no denying that names have power. There are lots of names which, if dropped into a conversation, inspire strong emotional reactions. Many of those names inspire fear. Hitler, Stalin, Voldemort, the Death Star are only a random top-of-the-head selection. Fear is a very powerful and primal emotion. It’s also very destructive of rational analysis.
“Fear of the name increases fear of the thing itself.” as Hermione Granger put it. In this post, I’m going to take a look at the problems fear of the name plutonium causes.
Another quote, this one from the novel “The Martian”, by Andy Weir. “Plutonium-238 is an incredibly unstable isotope. It’s so radioactive that it will get red hot all by itself.” There are other remarks on just how dangerous tampering with it is, both in the book and the movie.
“The Martian” is very hard science fiction indeed. Weir did a metric buttload of research, and ran the first drafts past a community of beta readers I can only envy and dream of. This one got past him, and them.
Plutonium has a number of isotopes. If you want to hit pause and refresh yourself on the details, I’ll wait.
Back? Okay, onward. Plutonium 238 is indeed an unstable isotope in the sense that it decays with a pretty short half-life, 87.7 years to be precise.
It Glows!
While this looks impressive, there is a hard fact here. Pu-238 is not fissile. It can’t support a chain reaction. It won’t do anything but sit there and be hot.
But, it’s radioactive! I can practically hear the chorus now. So it is. There’s radiation and there’s radiation. Some of it is penetrating and very hard to shield against. Gamma and X-rays are two of the serious players in this regard. What Pu-238 emits is alpha radiation.
To be technically precise, it emits alpha particles at an energy of 5.593 MeV. These are heavy charged particles that don’t penetrate worth beans. Whatever they hit will stop them cold, giving up their energy as heat. That’s why that chunk of Pu-238 in the picture is glowing. The majority of the atoms are inside (obviously) and when they decay they hit the next atom over and give up their energy as heat. Zero chance of a chain reaction, because they’re alpha particles, not neutrons, and Pu-238 isn’t fissile.
Shielding against the alpha particles is trivial. They can’t even penetrate human skin. A glove will do nicely, or a sheet of aluminum. Pick it up, and your real problem is a plain old thermal burn, just like a hot dish from the oven.
Pu-238 will do some damage if it is ingested. The record is held by a man named Albert Stevens, a volunteer test subject during the Manhattan Project. He was injected with a mix of isotopes, mostly Pu-238. He died twenty years later, of a heart attack.
That’s the actual hazard from Pu-238. As serious death goes, it’s pretty low on the spectrum.
The precautions built in to the design of RTG’s are formidable. The fuel elements aren’t pure Pu-238. They’re the oxide, which is very tough and heat resistant. The shielding around them is designed to withstand reentry from orbit, and it has. There are RTGs on the the ocean bottom which have been there for fifty years without causing a problem.
The launch of the Cassini probe in 1997 is a good example. Cassini had plutonium on board. The safety precautions surrounding the RTGs in the probe would have been overkill of the most excessive in any other context. When the Name is invoked, no precaution is too extreme, no expense is too great.
All it took for activists to gather the rioters was to invoke the Name, whereat rational thought stopped and the demonstrators swallowed whole the blatant lie that the rocket would blow up, resulting in a world-wide calamity.
The protesters who were energetically climbing high fences to get into the launch area were putting themselves at a risk many times greater than any risk from the plutonium in the probe. A fall from ten feet on to concrete can easily result in serious injury or death.
It’s also rather odd that these people were expending so much effort to get closer to what they were loudly proclaiming was going to be a disaster of planetary proportions.
The power of the Name can be overcome rather easily, especially now, in the age of the Internet.
In the words of the great Chris Hadfield, “If something scares you, get into it and learn about it.”
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