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Comment by JoeAltmaier | Hacker News Reader

Curious. I would expect something that seems so threatening, has such a tiny effect on the environment that it can't even be detected. Something not adding up.

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Cs-137 is dangerous to animals (including humans) in close proximity, precisely because of the gamma radiation it emits. But, like any radiative emission, the power density drops off with the inverse square of distance from the source, which makes it detectable well beyond any range at which it poses a hazard. Think of stadium lights: if you stand five feet in front of one, it will blind you, while from a mile away, it's harmless but you still can see it. With gamma radiation you need a detector (ie a Geiger counter), and with an at the moment presumably unshielded Cs-137 source, a reasonably sensitive detector will indeed pick it up at some distance. So, at worst, if you put enough people in trucks with Geiger counters along the same route the original truck followed, sooner or later you will find the lost source.

That said, this method while effective may take some time, and the major concern here may not be so much the direct radiation emission from the intact source, as the possibility of damage leading to dispersal of its contents. In the Goiânia incident of 1987 [1], scrappers removed a Cs-137 source from an improperly decommissioned radiotherapy machine and broke it open, dispersing the loose isotope material it contained in ignorance of the danger it posed. Several people died, others were badly injured, and at least one house and a lot of soil had to be removed for disposal. If this lost Australian source is similar in design to that one, warning people about it while looking for it is an eminently sensible public safety measure.

[1] https://en.m.wikipedia.org/wiki/Goiânia_accident

This also happened in Ukraine. The capsule was lost in a gravel pit and ended up being built into the wall of an apartment and several people died as a result.

https://en.wikipedia.org/wiki/Kramatorsk_radiological_accide...

Not really a regionally significant nuclear accident then. About the same as a gas leak?

A gas leak will either blow you up or kills you quicker and can be identified and fixed quickly but radiation kills you slowly, making identification of the cause very tricky for authorities.

Or you end up raising a family of mutants.

/goes to eat a Rio Red grapefruit.

Remember this? 8 deaths. https://en.wikipedia.org/wiki/San_Bruno_pipeline_explosion

“A few people here may die” is a relatively serious nuclear accident. Worse than three-mile island at least.

I don’t disagree. But I wonder if the cost to recovering this pellet would save more lives spent in another way.

A few grand to dig it out of a wall? A few hundo to slap some lead shielding over it (it is an X-ray source after all)?

In any case the primary expense is going to be one of paying off all the people to get the right approvals. Crunching the numbers on how to safely rectify it and actually going through those actions will be dirt cheap compared to getting someone with the "right credentials" to tell the government, the insurers and whoever else that your obvious solution any highschooler can crunch the numbers on is in fact acceptable

I think finding it is the expensive part.

It pretty much broadcasts its location if you wave the right instrumentation around.

You "just" need to wave that instrument over 1400km of highway, potentially with a 100m+ width if the capsule has been kicked some distance away by a truck tyre.

I’m trying to imagine the scale of this. I guess it depends on how close you have to be to pick up the signal. And how many false signals there might be.

I was talking about the "gets concreted into a wall" case.

Did you work at Ford as an executive during the Pinto era?

I insist they are safe at any speed so long as you keep their gas tanks empty!

It seems the pinto narrative was framed in way to make it look worse but compared to other cars of similar type it wasn’t all that bad[1]. This exaggerated narrative despite vindicating data is perpetuated in biz ethics.

[1] https://www.hemmings.com/stories/2017/10/17/misunderstood-ca...

Yup. The lesson to be learned once you dig into it is "if you're doing some industry standard thing that someone could ever potentially portray as seedy definitely don't document it".

Not to rehash my other comment, but depending on the nature of the source it might become regionally significant if somebody screws up bad enough.

If you dropped a Cs-137 source of this scale way out in the middle of nowhere, far away from any road or crops, it might not be a big deal. The half life is only 30 years, and it could get buried under soil or in silt. However, losing it near civilization isn't good. (Even sparsely settled areas.) It's a shiny metal object, and if it's in a gas station, hotel, or restaurant parking lot, some kid could easily find it. Plus, gamma sources are relatively easy to detect, which should help the search.

If the military lost a hand grenade on a similar road trip, I'm sure people would want to find it, and this source is at least as dangerous.

This is the nature of highly radioactive materials. Walk past it? No problem. Walk on the crushed capsule, brush your hand against the bottom of your shoe, eat a sandwich? Die horribly.

Hyperbole.

   "the equivalent of 10 X-rays in an hour"

So no, walk on it and you would never know. Nobody dies, not without carrying it around for days. Then they get burns.

It's important to understand the numbers - and the magnitude of this radiation source is concerning but not dire.

> crushed capsule

is key here -- leading to ingestion, which is much more dangerous than brief proximity: https://en.wikipedia.org/wiki/Committed_dose#Physical_factor...

"An hour of exposure at about a meter away is the equivalent of having 10 X-rays, and prolonged contact can cause skin burns, acute radiation sickness and cancer, they said."

Ingesting is of course a completely different story and will indeed kill you horribly.

“Walk on the crushed capsule [and then] brush your hand against the bottom of your shoe [and then] eat a sandwich? Die horribly.” is the intended reading.

That's one meter away.

Inside your body? Another story.

The point is that the danger depends on how people interact with it. That's why they're doing this PSA (and trying to recover it). It would be very easy for that little canister to get ruptured, and loose radioactive material is a very different game from nicely-packaged-in-a-capsule material.

Because it’s enormously dangerous to stand a meter from, and people near it won’t even know (eg it could have been picked up in a tyre tread so someone is carrying it around), but radiation and therefore ability detect drops according to the inverse square law so it will be hard to find from much further away. And Australia is big.

Again, hyperbole.

   "the equivalent of 10 X-rays in an hour"

People routinely get exposed to that during their normal job. An x-ray is a fraction of a year's natural exposure from the sun. Airline pilots experience this radiation in a few months at work.

The numbers matter. This instance, the device hardly matters. Not as much as a national news report anyway. We'd be better off reading about pay disparity or access to health care.

> People routinely get exposed to that during their normal job.

What jobs you're referring to? Your examples cite years and months but the quoted sentence states "in an hour."

It's all sort-of fine until someone brings it home and sticks it on a shelf and thereby kills their entire family. Walking around with this in your pocket will kill you eventually.

This sort of thing has happened before with loose radioactive sources.

To back up your point: If "X-ray" is a chest x-ray, then per https://xkcd.com/radiation/ this would be equivalent to one-tenth of a head CT scan, which are routinely done without consideration to any increased risk of cancer.

If the goal is to minimize loss of life, I think there are far better things that time could be spent on than looking for this thing. People are bad at thinking about opportunity cost.

You're bad at arithmetic, that's 100 boxes on the XKCD chart, so it's one-hundredth of a head CT scan, and the medics might not tell you they considered increased risk, but if they actually didn't consider it they're incompetent, that's a non-trivial effect.

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