Half a curie is an extremely dangerous source! An acquaintance of mine who ran a research reactor for something like ten years was surprised they made a 0.5 Ci Cs-137 at that gauge. He had expected a mining source to be in the tens of mCi range when the news first broke (though he also admitted he's less knowledgeable about mining industry uses than other ones).
Here and in the several prior HN threads on this topic, people often seem to insist on trying to make a movie plot out of it, as if it somehow fails to satisfy by being "merely" a serious industrial accident which was promptly and successfully resolved with at least as yet no evident casualties.
I don't understand what narrative so many seem driven to look for here and then complain about not finding, and I certainly don't see what benefit accrues to them or anyone else from the attempt.
Maybe I was bored, and my mind wandered into something fanciful. No harm no foul, except it seems to have perturbed you. So I like to shoot short films and fun things with friends, and we're always chatting about random things from life that could be spun into a short story. It's habit. Never seemed to have bother anyone till now.
Are you the type that gets irritated when people call out "great name for a band" during normal conversations. Some people just catch onto things in conversation and the mind takes its own spin on it. It can make for great conversations. Unless you're just against having fun.
Edit: never mind the plot of China Syndrome was an industrial accident, yet a very compelling plot. Or "Sully", or the one where Denzel inverts the plane to avoid tragedy, or any of the other numerous plots involving industrial accidents like CHUD!!!
I wasn't really talking about what you said, but I guess this deserves a response, even if "do you hate fun?" is frankly pretty weak.
I also write, but I don't talk about it very often, because it turns out most people aren't super excited to see an involved and wholly unrelated conversation interrupted with a more or less totally off topic plot idea someone happened to have. Unless you're actually at a workshop, that's what notebooks are for. If you don't have one, get one.
In response to some comments from someone else who seemed really anxious to be able to argue, on no sound or sensible basis whatsoever, that the whole thing's absurdly overblown and no one should be taking it seriously as the danger to life and health that it was, which is something I've seen a frankly bewildering number of people on HN this week put effort into doing.
I wasn't really replying to your comment at the head of the subthread I was replying to. But, fair: if I'd considered the context a bit more thoroughly, I'd have picked some other metaphor than a movie plot for the unrelated kind of confabulation I was complaining about.
> 50 millisieverts: Maximum yearly dose permitted for US radiation workers
> 100 millisieverts: Lowest one-year dose clearly linked to increase of cancer risk.
> 400 millisieverts: Dose causing symptoms of radiation poisoning if received in a short time.
So if you keep the source for a day in your pocket, you reach the limit of radiation of a radiation worker. It's not wise, but that number is still quite conservative. I guess it's not lethal, but I definitively would not try to do that.
A few days or a week? It looks like a very very very bad idea.
If I were in charge, I'd also try to recover it as soon as possible. The idea is to minimize the health risk and the radiation received by people. And if some moron decides to open it, the health risk and cleanup would be much worse.
From the same article:
> “It emits both beta and gamma rays, so if you have contact or close to you, you could either end up with skin damage, including skin burns … and if you have it long near you it could cause acute radiation sickness,” Dr Robertson said.
It sounds definitively dangerous, but not all dangerous things are lethal (in a short time).
>So if you keep the source for a day in your pocket, you reach the limit of radiation of a radiation worker
You're missing the part where 2 millisieverts / hour is the dose at a distance of 1 meter. If you put in your pocket, you would rapidly sustain radiation burns.
You're also missing that a dose sustained over a short period is much more deadly than a dose dragged out over a year. In the latter case, the body will be repairing the damage as it happens, mitigating the effect.
Where did you get the distancie of 1 meter? It's very hard to get any data from the press.
I think you are right. Let's make some back of the envelope calculations.
The frontal surface of a person is 1m^2 approximately. The surface of a sphere of 1m is 4/3*pi*(1m)^2 ~= 4m^2. The silly proportion is 2msV/1m^2*4m^2 = 8mSv, but 1m is not far enough to assume the sphere is almost flat. Let's duplicate it to 16mSv (8 idiots can form a round at 1m, shoulder to shoulder and absorb almost all the radiation). May I round it to 20 mSv?
If someone put it in the pocket, s/he will get half of the radiation, that is 10mSv/hour. [Before you find more errors in my comment, I agree that it's more complicated. The front pockets of the pants are probably the worst area. Holding it in a closed hand would double the radiation. Anyway, if you have a more accurate calculation, it is welcome.]
A Chest CT scan is 7mSv and it takes like half an hour, but it's more evenly distributed.
My guess is that you can get some nasty radioactive burns as warned in the press article, but in a short time it's not lethal as clamed by the GP.
The risk with radiation sources dramatically increases within 1 m – we can calculate the dose rate using the ‘inverse square law’:
At 1 cm, the dose rate will be 10,000 time higher …. 16,650 mSv/h (or 16.65 Sv/h)
At 1mm (ie, if you were to pick the source up with your fingers), the dose rate would be 1,665 Sv/h – this will cause some serious damage to your fingers and surrounding tissues.
>>>
I'm a little suspicious of their inverse-square calculation, though, as by their logic the dose rate would be infinite at a distance of 0m (skin contact). That's clearly not the case.
Thanks for the link. It looks like the get the official data at 1m and decided to extrapolate, but those calculations don't make any sense. The inverse square law is only a good approximation when the source and the target are small (or other special configurations, for example when one of them is a sphere).
Right. If a "weak" thing like this ends up in a place where somebody is near it constantly - like a workplace desk, or in somebody's home? It may take months but they will accumulate a lethal dose.
