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How to find a tiny radioactive source while doing 70 kph

ansto.gov.au

21–30 of 83 posts

Re: How to find a tiny radioactive source while doing 70 kph

#21
post #17
post #4

Earlier quoted context omitted.

I was rather baffled by so many sources claiming that this would be super difficult to find. It seemed like such a simple task to drive up and down roads with some radiation detection equipment, log the data and investigate any hotspots. Well, I guess it was? Or maybe I'm severely underestimating the complexity of this?

Depends if the wind blows it away.

Or a radioactive magpie.

Re: How to find a tiny radioactive source while doing 70 kph

#22
post #14

Do gamma rays bounce back on a rock or do you need line of sight to capture the source? If it is the latter they were very lucky, effectively one small stone away from never being able to find it.

Most rock is semi-transparent to gamma rays, which is how the lost source is intended to be used, to determine density of rock.

Re: How to find a tiny radioactive source while doing 70 kph

#23
post #12

Earlier quoted context omitted.

In some other thread I believe someone said with his known equipment, even if not occluded, a scan would take some seconds... so with that wouldn't have been to be that easy? So now not sure if normal.or amazing that they can do this with a 70km/h drive by?! ( Edit: https://news.ycombinator.com/item?id=34623782 sounds like not too amazing :) )

It's not too amazing. Perth has a few companies that do this work for a living - as a grind job, flying contracts for an actuall million line kilometres of 256 channel radiometric mapping at anything from $7 to $15 AU per line kilometre for mineral exploration. This has been ongoing for 50 years (see: Radiometric Map of Australia) and I'm slighlty baffled why a plane wasn't flown along the road on day one. Realistic…

I want to know this other story, I haven't found it by cursory search - what should I be searching for?

Re: How to find a tiny radioactive source while doing 70 kph

#24
post #14

Do gamma rays bounce back on a rock or do you need line of sight to capture the source? If it is the latter they were very lucky, effectively one small stone away from never being able to find it.

If the gamma rays are at 662 keV [1], you'd need about 8cm of rock [2] to block 50%. For comparison, sunglasses typically block 70%-80% of visible light.

[1] https://en.wikipedia.org/wiki/Caesium-137

[2] https://pdfs.semanticscholar.org/7248/4e8995c811d31837199d7c...

Re: How to find a tiny radioactive source while doing 70 kph

#25
post #12

Earlier quoted context omitted.

In some other thread I believe someone said with his known equipment, even if not occluded, a scan would take some seconds... so with that wouldn't have been to be that easy? So now not sure if normal.or amazing that they can do this with a 70km/h drive by?! ( Edit: https://news.ycombinator.com/item?id=34623782 sounds like not too amazing :) )

It's not too amazing. Perth has a few companies that do this work for a living - as a grind job, flying contracts for an actuall million line kilometres of 256 channel radiometric mapping at anything from $7 to $15 AU per line kilometre for mineral exploration. This has been ongoing for 50 years (see: Radiometric Map of Australia) and I'm slighlty baffled why a plane wasn't flown along the road on day one. Realistic…

> the national agencies wanted to shine and test their new gadget

Exactly. After reading the press release and how they promote their device, I'm not so sure this wasn't deliberate.

Re: How to find a tiny radioactive source while doing 70 kph

#26
post #12

Earlier quoted context omitted.

In some other thread I believe someone said with his known equipment, even if not occluded, a scan would take some seconds... so with that wouldn't have been to be that easy? So now not sure if normal.or amazing that they can do this with a 70km/h drive by?! ( Edit: https://news.ycombinator.com/item?id=34623782 sounds like not too amazing :) )

It's not too amazing. Perth has a few companies that do this work for a living - as a grind job, flying contracts for an actuall million line kilometres of 256 channel radiometric mapping at anything from $7 to $15 AU per line kilometre for mineral exploration. This has been ongoing for 50 years (see: Radiometric Map of Australia) and I'm slighlty baffled why a plane wasn't flown along the road on day one. Realistic…

What I don't understand is, what kind of technology is it? It is obviously great. The technical explanation is not there

Re: How to find a tiny radioactive source while doing 70 kph

#27
post #12

Earlier quoted context omitted.

It's not too amazing. Perth has a few companies that do this work for a living - as a grind job, flying contracts for an actuall million line kilometres of 256 channel radiometric mapping at anything from $7 to $15 AU per line kilometre for mineral exploration. This has been ongoing for 50 years (see: Radiometric Map of Australia) and I'm slighlty baffled why a plane wasn't flown along the road on day one. Realistic…

> the national agencies wanted to shine and test their new gadget Exactly. After reading the press release and how they promote their device, I'm not so sure this wasn't deliberate.

My thought exactly

Re: How to find a tiny radioactive source while doing 70 kph

#28
post #3

Good job, but a lot of the reports really exaggerate the size of the search area. > in the formidable conditions of the outback... > It’s fair to say finding a piece of equipment the size of a button in a vast desert was no easy task Let's not go too far here. It was two metres from the road and they knew exactly which 1400km of roads to check.

Also:

“... we’re a sophisticated nuclear nation and in many ways, we’re world leaders that punch above our weight when it comes to nuclear expertise and stewardship."

The stewardship claim bit seems maybe a bit overstated considering they weren't able to secure an object the size of a button leading to it "falling off the back of a truck"

My minds eye is seeing a crocodile Dundee type holding a beer in one hand and carefully balancing the capsule next to a sleeping kangaroo on a truck bed and securing it one handed with twine.

Re: How to find a tiny radioactive source while doing 70 kph

#29
post #2

Back story: Rio Tinto apologises for losing radioactive capsule in Australia https://www.bbc.com/news/business-64448879

private company fucks up and government cleans up the mess :)

Still better than private company fucks up and hides their mess, continues polluting environment for decades.

The funds for this kind of search and similar emergency cleanups really need to be collected ahead of time (e.g. via taxes or required insurance) as making the company pay for it on the spot only encourages coverups.

Re: How to find a tiny radioactive source while doing 70 kph

#30

Earlier quoted context omitted.

private company fucks up and government cleans up the mess :)

Still better than private company fucks up and hides their mess, continues polluting environment for decades. The funds for this kind of search and similar emergency cleanups really need to be collected ahead of time (e.g. via taxes or required insurance) as making the company pay for it on the spot only encourages coverups.

In one of the articles yesterday, Rio Tinto said they'll pay the full cost of the recovery if the government sends them a bill.
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