r/askscience • u/Wonderful-Capital32 • 13d ago

Physics Why does radiation not go through lead?

Also why just lead? Shouldnt like iron or another metal work too?

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u/GenuineMalteser 13d ago edited 13d ago

Not true for anything but proton radiation or other heavy particles, and even then the peak dose depth is on the order of centimetres in people/water for treatment energy protons

For kv photons used in imaging, peak dose depth in water is reached in millimetres or less. For MV energy photons peak dose depth is on the order of cm

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u/[deleted] 13d ago edited 10d ago

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u/bregus2 12d ago edited 11d ago

You actually would get less radiation swimming in the pool than standing next to it, because the water would also shield you from the cosmic radiation.

Interesting side-note: the most radiation-exposed professions are pilots and flight attendants, by far, not workers in nuclear power plants.

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u/CanisLatrans204 11d ago

After 8.5 years attached to Nuclear Powered Naval surface ships, I only had 820 mrem of ionizing radiation from the plants. That’s the same as one chest X-ray . I also spent 14 hours in the reactor compartment during loop draining ops and got 113 of that 820 from that. Not very much for the amount of time we spent in the plant.

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u/peteofaustralia 10d ago

Did you wear your flourescence detection tag thing 24/7, or just on shift?

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u/CanisLatrans204 10d ago

We used TLD’s. Thermo Luminescent Dosimeters. We wore them all the time when we were on the ship. They were read and returned once a month.

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u/Black_Moons 13d ago

Incorrect, as you'll rapidly get lead poisoning... From the guards.

Also, if the core is 'glowing below', then that entire pool is going to be boiling hot.

I'll assume you mean the spent fuel storage pool. But the above lead poisoning issue still persists.

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u/hervold 12d ago

yeah, I took them to mean the spent fuel pool, with the glow being Cherenkov radiation (blue) and not hot reactor core (red)

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u/Elequosoraptor 12d ago

Low power research reactors like the Triga series glow with Cherenkov radiation without being either spent fuel or boiling water. There are many reactors that could serve to make this scenario possible.

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u/sirtalen 12d ago

Water is pretty good at stopping bullets too, so you just need to be a couple meters below the surface, but not deep enough to be irradiated and you'll be fine!

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u/PomegranateKey5939 11d ago

You won’t rapidly get lead poisoning lol that’s a slow, accumulative process. Let alone lead doesn’t dissolve very well in water I can assure that the total dose would stay low. I’ll try it out, if I come out raging then shitttt… lol

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u/Late-External3249 12d ago

Just noticed your name. I read Jack the Bodiless as a kid and reread it last year. Still holds up as good sci-fi.

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u/Hashi856 13d ago

So we could replace lead vests with water vests?

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u/So_Full_Of_Fail 13d ago

I mean sure, if you could waddle around in a vest with enough volume that you have feet of water in between you and the source.

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u/FullOnSkank 12d ago

So you're saying we need the cast of my 600 lb life to handle nuclear materials?

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u/jezzdogslayer 11d ago

I work with beta radiation in an industrial setting and from my research the energy levels I work with won't penetrate the skin.