I'm a Radiological and Nuclear Subject Matter Expert Ask Me Anything

[u/HazMatsMan]

Hello r/preppers,

Welcome to my Ask Me almost Anything. I’m a Radiological Operations Support Specialist. I’ve been privileged to receive advanced training from institutions such as the Centers for Disease Control and Prevention (CDC), Texas A&M Engineering Extension (TEEX), the Center for Radiological/Nuclear Training (CTOS), the Defense Threat Reduction Agency, the Department of Energy, FEMA’s Center for Domestic Preparedness, and others. As a subject matter expert, I provide guidance to responders, decision-makers, stakeholders, and the public.

Things I probably won't answer:

• Anything that involves controlled information (classified or not).
• Specifics of incidents I've responded to.
• Anything that may reveal personally identifiable information about me, or enable doxxing.

Examples of things I am more than happy to answer:

• Questions about radiation, how it harms you, and how you can protect yourself from it.
• Questions about nuclear weapon effects, fallout, and public protection.
• Questions about different classes of radiological emergencies. i.e. "Dirty Bombs", Nuclear Detonations, and Nuclear Power Plant accidents.
• Questions about how responders and public officials are likely to respond to the above, and how you can prepare for or protective actions you can take.
• Questions about careers and how to "get into" this line of work.

Thank you in advance for participating. Ignore the "Just Finished" message, the AMA will go all week. Feel free to ask me anything about radiological emergencies, response, public protection, equipment, PPE, or anything else related to radiological emergencies.

[u/Soff10]

If I build or use an underground shelter. What’s the minimum depth I need to be to be safe from all radiation?

[u/HazMatsMan → u/Soff10]

Approximately 3 feet of soil, assuming fallout only. IIRC, that's what's needed to reduce the radiation by a factor of 1000. If you're concerned about prompt radiation and/or neutron radiation from a detonation within 1 mile... you need more than that, but that's beyond the scope of this AMA... in short, there are books you need to consult about it.

[u/Soff10 → u/HazMatsMan]

Thanks. Does it matter if it’s dirt, water, concrete or all three?

[u/HazMatsMan → u/Soff10]

Doesn't matter, though all three of those have different shielding factors or half-value layers. For example, it may be 3 feet of packed soil, but 2 feet of concrete. I have a spreadsheet somewhere that does those calculations... but is something like every 3.5" of packed soil or 2 to 2.5" of concrete cuts the intensity of the radiation in half (and you're shooting for 10 half-value layers, which reduces the intensity 2¹⁰ or 1024 times. There are some other caveats in that the higher the energy of the radiation, for example, the gamma radiation emitted by Co-60 is stronger and more penetrating than the radiation emitted by Cs-137. But, for nuclear weapon fallout it's common to use Cs-137's numbers as an approximation or shorthand.