Physical Insights

An independent scientist’s observations on society, technology, energy, science and the environment. “Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.” – Carl Sagan

Archive for the ‘bad science’ Category

Helen Caldicott and the fine art of making up nonsense.

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Here’s a particularly egregious and scientifically vapid (as you’d expect, of course) interview with Helen Caldicott… recorded recently on some kind of “environmentalist” podcast.

Now… I could write a comprehensive technical deconstruction and debunking of essentially the whole lot… but I’m only one person, with a finite amount of time.

I’ll get started, just for now, by taking a look at just one particular sentence of nonsense from Caldicott.

Ask questions. Seek the evidence. Ask everybody questions, and never take anybody’s word for it. Are factual statements backed up by evidence? Are quantitative statements backed up by measurements, calculations, or derivations? Can those measurements or derivations be described and reproduced? Read everything you possibly can, and you decide.

Do people like Caldicott have the right idea? Or do people like George Monbiot have the right idea – that beneath the FUD, rhetoric and hysteria, these people have absolutely no real evidence, facts, knowledge or technical literacy at all?

HC: “Well it won’t recover. These accidents go on forever because plutonium’s half-life is 24,400 years. It lasts for half a million years. Thirty tons of plutonium got out at Chernobyl.”

Thirty tons of plutonium “got out” at Chernobyl!?

Personally, that reads many thousands of counts per minute on my baloney detector.

Let’s follow Dr. Caldicott’s favourite piece of advice… let’s read her book. Surely, just like all of Caldicott’s other “references” usually are, it’s got to be “in my book”, right?

“Plutonium is so carcinogenic that the half-ton of plutonium released from the Chernobyl meltdown is theoretically enough to kill everyone on Earth with lung cancer 1100 times, if it were to be uniformly distributed into the lungs of every human being.”

(From Nuclear Power is Not The Answer).

Hmmmm. Curious. It looks like we’ve gone from “a half-ton” in the book to “thirty tons” in this recent interview. Well, so much for “you should read my book… it’s all in the book!”

(By the way… that “kill everyone on Earth with lung cancer 1100 times…” bit is complete baloney. But that’s a story for another day.)

Reactor-grade plutonium typically consists of approximately 1.3% 238Pu, which has a half-life of 87.7 years and a specific activity of 634 GBq/g, 56.7% 239Pu, which has a half-life of 24,110 years and a commensurately far smaller specific activity of 2.3 GBq/g, 23.2% of 240Pu, with a half-life of
6564 years and a specific activity of 8.40 GBq/g, 13.9 % of 241Pu, with a half-life of 14.35 years and a specific activity of 3.84 TBq/g, and 4.9% of 242Pu, with a half-life of 373,300 years and a specific activity of 145 MBq/g.

Taking the weighted sum of all the above, we find that the overall specific activity of reactor-grade plutonium is 545.3 GBq/g, predominantly due to the 241Pu and the 238Pu content.

(Reactor-grade plutonium is considerably more radioactive than weapons-grade plutonium, due to the presence of substantial concentrations of these relatively unstable, high-activity plutonium nuclides. Weapons-grade plutonium is almost entirely 239Pu, which despite being a good fissile fuel, is more stable and less radioactive. The radiological heat output of 238Pu, gamma-radiation (from the 241Am daughter of 241Pu) and the high rate of neutron emission from the spontaneous fission of 240Pu all make these nuclides extremely deleterious and undesirable in nuclear weapon design and engineering.)

The best value determined based on the available data for the quantity of plutonium (a reactor-grade cocktail of different plutonium nuclides) released at Chernobyl is, as published in the reports of the Chernobyl Forum, 3 PBq (3×1015 Bq).

The approximate total mass, based on the best available data, of plutonium released into the environment at Chernobyl is 3 PBq divided by 545.3 GBq/g.

As the British physicist David Mackay put it, I’m not trying to be pro-nuclear. I’m just pro-arithmetic.

It’s 5.5 kilograms.

Incidentally, that’s a very small amount of plutonium compared to the amount of plutonium that has been dispersed around the environment from half a century of nuclear weapons testing. 5.5 kilograms of plutonium is, approximately, the amount of plutonium in the pit of a single nuclear weapon. A single zero-yield “fizzle” of a nuclear weapon with no fission, or a zero-yield one-point-implosion safety test, or the accidental HE explosion (without proper implosion of the primary, as in the Palomares and Thule accidents) of a single nuclear weapon will disperse a roughly comparable mass of plutonium into the environment. (But less radioactivity, since weapons-grade Pu is less radioactive than reactor-grade Pu.)

So, Caldicott has gone from exaggerating the true number by a factor of approximately 100 to exaggerating the true number by a factor of approximately 6000.

Anyway… let’s just step back a minute. 30 tons of plutonium released at Chernobyl? Let’s apply what scientists, engineers and technologists sometimes refer to as the “reasonableness test” or the “smell test”. Can you quickly “smell” the data and determine if it is roughly plausible or not?

The total mass of uranium dioxide fuel in the fuel assemblies of a fully fueled RBMK reactor is about 180 tonnes. That’s about 159 tonnes of uranium, if you take off the mass of the oxygen in the uranium dioxide. When LEU fuel is irradiated at a typical burnup in a nuclear power reactor, about one percent of the mass of the original uranium ends up as transuranic actinides, mostly plutonium, by the time the fuel is removed. So, that’s a total plutonium inventory in the Chernobyl reactor of approximately 1.6 tonnes.

So, if we make a conservative, pessimistic and entirely unrealistic assumption that 100% of the plutonium inventory in the nuclear fuel was entirely vaporised and released into the environment during the Chernobyl accident, that would be 1.6 tonnes of plutonium released to the environment. (In reality, that fraction was something more like 0.34% of the total inventory of plutonium within the irradiated uranium dioxide fuel.)

So, does “thirty tons” pass the smell test? Not by a long shot.

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Written by Luke Weston

April 23, 2011 at 6:47 am

The Bomb That Fell On Niagara: The Sphere

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Feel like reading something really, really stupid? This seems appropriate.

It’s pretty obvious that if it looks like an ammonia gas tank, quacks like a gas tank, and they say it’s a gas tank, then it’s probably a gas tank.

It certainly doesn’t look like any early prototype of any nuclear reactor design I’ve ever heard of.

Almost 4,000 tons of radioactive radium-226, the largest repository in the western hemisphere, representing a staggering quantity of radiation.

4000 tons of radium!? In 1937, radium cost $25,000 per gram. That’s, uh, 91 trillion dollars, in 1937 US dollars, anyway.

There is also polonium-210 on site. According to Bob Nichols, a San Francisco-based researcher and writer who reviewed the same documents as Weyman, polonium was used as a trigger in nuclear weapons. Its presence in quantities sufficient to detect all these years and half-lives later is not easily explained by the KAPL wastes.

It ought to be obvious where any Po-210 comes from – it’s a daughter product of radium, and it’s present in secular equilibrium where ever there is radium present. In fact, given the quite short 138-day half-life of Po-210, the decay of radium is indeed the only possible source of any Po-210 detectable on the site today.

Written by Luke Weston

October 12, 2008 at 2:52 pm

Anti-nuclear quote of the week.

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“The reuse of spent fuel is catastrophically dangerous. It means separating plutonium from the radioactive waste, fabricating it into fuel rods and fueling a reactor with 5 to 15 tons of plutonium, which is cooled by liquid sodium, a highly reactive explosive material.

As 10 pounds of plutonium is critical mass, and as less than one millionth of a gram is carcinogenic, a loss of the volatile coolant could induce a massive nuclear explosion which could be seen from the moon, scattering deadly plutonium to the four winds.”

There are no prizes for guessing who this is from. You can stop over on that page and post comments, if you feel so inclined.

We seem to just keep hearing claims that move further and further from reality, and further into the realm of just Making Stuff Up.

There was one simple sentence delivered by Carl Sagan in The Demon-Haunted World that Caldicott, and her followers, might do well to take heed of: Try science.

Please just try the scientific method, just for once.

Written by Luke Weston

October 9, 2008 at 4:12 pm

Genepax “Water Energy System”: Redux

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An update on the latest “breakthrough car that runs on water!”:

http://techon.nikkeibp.co.jp/english/NEWS_EN/20080616/153301/

Kiyoshi Hirasawa, president of Genepax Co Ltd, unveiled part of the reaction mechanism of the company’s new fuel cell system called “Water Energy System” in an interview with Nikkei Electronics.

The system, which is capable of generating power with water and air, was first presented June 12, 2008. As reported in our previous article, the system produces hydrogen through a chemical reaction between water and a metal (or a metal compound) on the fuel electrode side (See related article).

Genepax uses a metal or a metal compound that can cause an oxidation reaction with water at room temperature, the company said. Metals that react with water include lithium, sodium, magnesium, potassium and calcium. The main feature of the Water Energy System is that it can be operated for a longer period of time by controlling the reaction of the metal or the metal compound, the company said.

According to Genepax, the metal or the metal compound is supported by a porous body such as zeolite inside the fuel electrode of the membrane electrode assembly (MEA). The products of the hydrogen generation reaction dissolves in water, and the water containing them will be discharged with water inside the system. Upon the completion of the reaction, the generation of hydrogen and power stops.

There is nothing revolutionary here – nothing that violates the laws of physics. Rather than “running on water” the device if fuelled with chemical potential energy in the form of a reactive chemical – such as lithium metal – that will spontaneously reduce water to hydrogen gas on contact, consuming the lithium. Energy is “stored” in such a material, which requires considerable energy input to create, and does not occur in the free metallic form in nature.

This is essentially nothing more than a non-rechargeable chemical battery. When its chemical “fuel” is depleted, it doesn’t work, and the chemical material must be replenished.

Written by Luke Weston

July 14, 2008 at 5:21 am

Depleted uranium… for dinner!

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 This isn’t about nuclear energy, strictly speaking – but I still think it’s worth spreading.

“Dr. Buzzo”, the blogger behind the “Bad Science” blog Depleted Cranium – has recently published a great little video on YouTube:

“Not long ago I noticed that during some flaming and name-calling on the the anti-depleted uranium crowed stated that “If you love depleted uranium so much why don’t you have it for dinner.”

http://www.youtube.com/watch?v=qk9vHQrKMdk

The YouTube video is pretty self explanatory – go check it out!

Written by Luke Weston

March 8, 2008 at 7:29 am