Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

npr.org

Post reply on HN
Print view View original

61–70 of 108 posts

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#61

Post by Daniel_sk »

kevin_b_er wrote: post #10
ams6110 wrote: post #2

Pretty lacking on specifics. What was the actual radiation level measured? I would assume these were not buckets of pure uranium, but of uranium ore that is naturally all over the place in the West, and not terribly radioactive in its natural state.

* 800 mR/hr if you physically touched the rocks * 280-320 mR/hr if you physically touched the bucket(s) * 13.9 mR/hr if you were within 5 ft * 1.85 mR/hr inside the building more than 5 feet away. Also can be thought of as "0 mR/hr above background" * 2.02 mR/hr outside, in the park, on a bright sunny day. 2.02 is "background". i.e. the levels everyone is getting from natural sources outside. 13.9 mR/hr is 139 micros…

The milliroentgen values are probably wrong - 800 mR/hr would be way too much, something I wouldn't recommend touching :-). The average background radiation is around 0.010 mR/hr - or 0.1µSv/hr.

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#62

Post by eveningcoffee »

saul_goodman wrote: post #58

Jeezus Cripes, way over reaction. I have Fiestaware plates that put out over 30uSv/h / 3mR/h / 9200cpm. Unrefined uranium ore puts out waaaay less that. As long as you're not sleeping with the junk under your bed or working with it next to your desk all day long you're fine. Even then, it's still less exposure than air crews that fly every day receive. No one was harmed by this.

For the reference, I measured the levels with my basic dosimeter on one flight. Measurements topped at 72 uSv/h. Common reading during the flight was in the 50-60 uSv/h range.

What I found very interesting was that the levels were slightly lower in the air near the ground than on the ground where I landed.

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#63

Post by AnaniasAnanas »

gotocake wrote: post #12
trimbo wrote: post #11

Earlier quoted context omitted.

From a screenshot at [1] * 800 mR/hr if you touched the ore * 280 mR/hr on the surface of the bucket (sealed) * "0 above background" if you were 5 ft away from the bucket * 2.5 mR/hr if you were touching the cabinet it was in [1] - https://www.azcentral.com/story/news/local/arizona/2019/02/1...

Basically unless you were having a very prolonged and loving relationship with the bucket, you were exposed to nothing of consequence. That doesn’t excuse the morons who kept this stuff, and if a kid took a souvenir home or there had been a fire it could have been a lot worse. They may have also had unacceptable levels of radon. If I worked there I’d want to know more, but just as a visitor I’d shrug and get on with…

> and if a kid took a souvenir home

A great way to teach them to not steal along with punishing the parents.

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#64

Post by jacobolus »

saul_goodman wrote: post #58

Jeezus Cripes, way over reaction. I have Fiestaware plates that put out over 30uSv/h / 3mR/h / 9200cpm. Unrefined uranium ore puts out waaaay less that. As long as you're not sleeping with the junk under your bed or working with it next to your desk all day long you're fine. Even then, it's still less exposure than air crews that fly every day receive. No one was harmed by this.

It’s entirely plausible that in practice nobody received a dangerous amount of radiation in this case, but...

> The report indicated radiation levels at "13.9 mR/hr" where the buckets were stored, and "800 mR/hr" on contact with the ore.

> [...] The commission lists a maximum safe dosage for the public, beyond natural radiation, is no more than 2 millirems per hour, or 100 per year.

https://www.azcentral.com/story/news/local/arizona/2019/02/1...

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#65

Post by lostlogin »

mehrdadn wrote: post #28
soy_comptroller wrote: post #22

Earlier quoted context omitted.

Time to whip out the XKCD radiation chart[1], which gives us measures around: * One chest CT per hour for touching the ore (or about 9 hours touching the ore to reach your annual max dosge) * One head CT per hour for touching the bucket * nothing for 5ft away * One chest XRay per hour touching the cabinet (less than a cross-country flight LA NYC) [1] https://xkcd.com/radiation/

I've seen this chart and yet it's always fascinating. A dental X-ray is like eating 50 bananas, and half of what you would get over the course of a normal day.

The physcists we have had come in to check x-ray gear can generally do a conversion to banana equivalent dose in their head when asked. Seem to check out as accurate too.

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#66

Post by lostlogin »

userbinator wrote: post #19
gumby wrote: post #18

I remember visiting the Toronto science centre in the 1970s and just pickingup a block of uranium for comparison with a block of aluminium and perhaps other ones. They wanted to teach kids about density. Glad they didn't use plutonium, which is toxic!

Uranium is toxic too, but I bet that was depleted uranium, which isn't all that radioactive and the bigger danger is its regular toxicity: https://en.wikipedia.org/wiki/Depleted_uranium

Can any of the down voters add a comment? Is this inaccurate?

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#67

Post by lostlogin »

darkpuma wrote: post #53
supermw wrote: post #50

My mother still has old uranium glassware in her home. Not really sure if it's dangerous or not but it's pretty cool to see in person.

Radiologically, Uranium glass is virtually harmless. However I believe Uranium glass often contains a lot of lead as well, similar to the lead crystal glassware a lot of people own. Lead crystal glass is mostly harmless but not totally harmless, if you leave anything alcoholic or acidic in it long enough, it will leach a significant amount of lead. Used briefly on occasion it's not really a big deal.

It’s important to down the drink fast to reduce the risk of poisoning?

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#68

Post by darkpuma »

lostlogin wrote: post #67
darkpuma wrote: post #53

Earlier quoted context omitted.

Radiologically, Uranium glass is virtually harmless. However I believe Uranium glass often contains a lot of lead as well, similar to the lead crystal glassware a lot of people own. Lead crystal glass is mostly harmless but not totally harmless, if you leave anything alcoholic or acidic in it long enough, it will leach a significant amount of lead. Used briefly on occasion it's not really a big deal.

It’s important to down the drink fast to reduce the risk of poisoning?

It's not quite that serious. It's fine to serve yourself with a lead crystal but you shouldn't be storing wine in a lead crystal decanter or something like that.

https://en.wikipedia.org/wiki/Lead_glass#Safety

Re: Grand Canyon Museum Had Buckets of Uranium Sitting Around for 18 Years

#69

Post by austincheney »

tco03 wrote: post #49
austincheney wrote: post #48

Earlier quoted context omitted.

How so?

https://en.m.wikipedia.org/wiki/Metal_toxicity It appears as there if is little correlation between metal density and toxicity

Weird, your source says the opposite.

> Toxic metals sometimes imitate the action of an essential element in the body, interfering with the metabolic process resulting in illness. Many metals, particularly heavy metals are toxic

Metal toxicity is the correlation between density and reactivity.

Iron and manganese are limited exceptions where iron is about 84% of hemoglobin, which is about 80% of red blood cells, but its toxic (though in larger doses) matches almost exactly the implications of other metal toxicity.

Post reply on HN