"Dangerous" (quote unquote) radiation levels detected in San Francisco

[DEFCON Warning System]

Article by SFGate greatly exaggerates how much radiation was found in a shipyard last year.

However, the article is frustratingly vague.

Philip said the city health department only found out this month that a type of plutonium called Pu-239 was detected in an air filter at the site when workers were grinding asphalt during field work operations last year. The plutonium levels were more than double the Environmental Protection Agency’s “action level,” when further steps must be taken to ensure public safety, according to the letter.

According to the EPA, 10 mrems/year is the standard. So if this is the scale the article was using, that means 20 mrems/year. Hardly "dangerous."

Though if anyone can dig up what exactly the article is referring to, that would help. I looked over the EPA and couldn't find a reference for "action levels" for radiological issues, but I may have missed it.

 

[teekay99]

Article by SFGate greatly exaggerates how much radiation was found in a shipyard last year.

However, the article is frustratingly vague.



According to the EPA, 10 mrems/year is the standard. So if this is the scale the article was using, that means 20 mrems/year. Hardly "dangerous."

Though if anyone can dig up what exactly the article is referring to, that would help. I looked over the EPA and couldn't find a reference for "action levels" for radiological issues, but I may have missed it.

I found an article on this with the following quote.
"Kai Vetter, a University of California, Berkeley, nuclear physics professor who specializes in radiation detection, said that a plutonium level at two times the action level should not be a “cause for concern.

It would take 1,000 times the action level to see detrimental health impacts from radiation such as cancer and radiation poisoning, Vetter said."

Source: U.S. Navy found elevated plutonium in Bayview. S.F. says it was kept in the dark.

It's San Francisco. I have a feeling that that free-range smoke detectors with Americium unnecessarily ramps up concern there...

 

[DEFCON Warning System]

I'd like to put out some kind of statement about this, but because I don't know what exactly the article is referring to, I don't know how much they exaggerated.

 

[Irag8er]

The U.S. Navy did decommission nuclear-powered vessels at the Hunters Point Naval Shipyard (HPNS) in San Francisco, primarily during two periods: 1966–1973 and 1985–1989. During these times, HPNS served as a berthing, maintenance, and repair facility for nuclear-powered ships, functioning as a short-term annex to the primary decommissioning site at Mare Island Naval Shipyard in Vallejo, California. This work involved handling radioactive materials associated with nuclear propulsion systems, contributing to the site's radiological contamination history under the Naval Nuclear Propulsion Program.

Additionally, HPNS was a major decontamination facility for 79 Navy vessels (including submarines and support ships) that became radioactively contaminated during nuclear weapons tests like Operation Crossroads (1946) and Operation Redwing (1950s) at Bikini Atoll. While these vessels were not nuclear-powered (as nuclear propulsion technology emerged later in the 1950s), the decontamination processes—such as sandblasting and acid treatments—effectively decommissioned them by rendering them safe for further use or scrapping, and this work spread radioactive residues across the shipyard. The site's Naval Radiological Defense Laboratory (NRDL, 1946–1969) oversaw much of this activity, including experiments on irradiated ships like the USS Independence.

 

[teekay99]

Here is the letter from the SF department of Health to the Navy.

https://newspack-missionlocal.s3.amazonaws.com/mission/wp-content/uploads/2025/10/10.30.25-SF-Health-Officcer-Navy-Letter-re-Shipyard_final.pdf

Here is a document referenced in the letter with respect to "Action Level," with graphs.

https://media.defense.gov/2025/Oct/16/2003815761/-1/-1/0/PARCEL%20C%20AIR%20MONITORING%20FACT%20SHEET_APR_JUNE%202025.PDF

 

[DEFCON Warning System]

Here is the letter from the SF department of Health to the Navy.

https://newspack-missionlocal.s3.amazonaws.com/mission/wp-content/uploads/2025/10/10.30.25-SF-Health-Officcer-Navy-Letter-re-Shipyard_final.pdf

Here is a document referenced in the letter with respect to "Action Level," with graphs.

https://media.defense.gov/2025/Oct/16/2003815761/-1/-1/0/PARCEL%20C%20AIR%20MONITORING%20FACT%20SHEET_APR_JUNE%202025.PDF

Wow, how did you find all that?!

So it seems SFGate sent me on a wild goose chase, as it was not the EPA that had action levels but the Navy.

 

[teekay99]

Wow, how did you find all that?!

So it seems SFGate sent me on a wild goose chase, as it was not the EPA that had action levels but the Navy.

Dumb luck. I found the links in the article I referenced earlier from Mission Local. I think the Mission Local article is marginally better than the SF Gate article.