> I don't think that's a serious concern from a radioactive meltdown of a small core.

Was that the only issue over the years at this site though?

Others have cited four 'incidents' reported (I have no idea what these were), various experiments and tests, and I imagine there's the implication of a legacy of less than rigorous material handling and storage being possible.

From the wikipedia page: > At least four of the ten nuclear reactors had accidents during their operation.

> The reactors located on the grounds of SSFL were considered experimental, and therefore had no containment structures.

Given all that I'd say the possibilities are wide open.

> Got any publications describing this concern in more detail?

Your best bet might be to drop Alex Wellerstein a line and ask if he knows of (or knows anyone who knows of) what documents the DOE | NASA have released into the public domain and whether there are whispers of further releases in the wind.

I tend to track things of this nature not in central north america.

[1] https://en.wikipedia.org/wiki/Santa_Susana_Field_Laboratory

[2] https://alexwellerstein.com/writing/books/restricted-data/

Surely if you have an "experimental reactor" you build BIGGER containment structures?

IIRC the first (or one of the first) US experimental fission reactor piles was 'contained' within a university basketball court . . .

These were rugged days when onions were worn on belts and rocketship reactors were fashion in garages from materials scavanged froom smoke detectors.

Nice you reveal your bias.

Measurable radioactive dose is easy to measure, so of course it is what you would like us to pay attention to. But radionuclides invading tissue is what causes cancers. Those risks are harder to measure. Which radionuclides? What grain size? A nanogram of the wrong stuff in the wrong place is all it takes.

Do to know how many nanograms of radioactive natural Potassium-40 and natural radon are in your body right now?

For potassium 40 it's about 10,000,000 nanograms. It is a strong beta and gamma emitter. It has been in all creatures that have ever lived.

It's difficult to postulate that levels 7 orders of magnitude less than that are major threats.

Half life is 1.25 billion years and rate is the inverse of lifetime, so I don't understand why you classify potassium-40 as a "strong" emitter?

Radon-222 has a half life of 3.8 days, so that at least is a strong emitter. Less of it in the environment, but IIRC still the biggest source of background radiation for us.

Yeah, radon doesn't concentrate.

People get cancer when a microscopic grain of Pu lodges in an alveola and just blasts and blasts that one spot for years.

Radon may not concentrate within the body but it does concentrate within unventilated basements and within valleys in granite heavy areas.

It blows away and expresses fresh from the ground on a daily basis such that prolonged exposure is equivilant to a two|three pack a day smoking habit wrt cancer risk.

Radon is much heavier than air (7.5x), so pools in basements. You should be able to keep it cleared out with the gaseous equivalent of a sump pump.

Yep, that's what happens - it pools.

Modern standards in many G20 countries require new (and rennovating) houses in radon prone areas to provide appropriate ventilation.

Geographically in also pools in still valleys, often during the night and morning with radon 'clouds' clearing from the floor by afternoon (as can be seen when processing airborne radiometric survey data and applying radon removal filtering to normalise U-Y-Th maps).

Details seem to matter.

The common (in a nuclear accident) short half live isotopes of Iodine, Stronium, Cesium, Plutonium, and other highly bioabsorptive alpha emitters would like a word?

Not to mention the chemical toxicity of many of them is non trivial.

Radioactive isotopes cause damage by imparting energy in the form of energetic emissions that can be measured quantitatively in units of mSv. You get 6 mSv/yr from natural and normal man-made sources. 100 mSv acutely causes a small increase in lifetime cancer risk from a baseline of 40%. 300 mSv over a year does the same. Above that, cancer risk increases with dose. Arount 2000 mSv acute you start getting acute radiation syndrome (which is what the ~40 first responders at Chernobyl died from). Human LD 50/30 with medical intervention is about 8000 mSv.

So unless someone is getting more than 300 mSv a year, it's highly unlikely that they are being harmed by the radiation.

That’s an overly reductive analysis based on generalized whole body doses from (external generally) ionizing radiation, and not relevant to absorbed isotopes and internal radiation.

Which is what we were discussing.

There is a reason one of the first things handed out during a nuclear accident is potassium iodide pills, and it’s not to protect against gamma radiation.

What is your point exactly?