Skip to main content

NOAA Looks at the Waters Near Fukushima Daiichi

noaa_ship_450The American National Oceanic and Atmospheric Agency sent a research vessel boat to Japan last April to study the waters near the Fukushima Daiichi facility and assess the impact of radioactive isotopes released into the water by the plant. The international team of researchers found isotopes of cesium, which was expected, and silver, which was not expected. (Radioactive silver has a half-life of 250 days).

The conclusion in the abstract: “Radiation risks due to these radionuclides are below those generally considered harmful to marine animals and human consumers, and even below those from naturally occurring radionuclides.”

And that’s striking. Especially interesting was this:

To be comparable just to doses from 210Po, 137Cs levels in fish would need to range from 300 to 12,000 Bq·kg−1 dry weight, some 1–3 orders of magnitude higher than what we observed ≥30 km off Japan. Thus, radiation risks of these isotopes to marine organisms and human consumers of seafood are well below those from natural radionuclides.

And this:

Further, we can calculate an external dose to humans if immersed/swimming in these waters of <0.01 μSv·d−1 at 134Cs and 137Cs levels of 1,000 Bq·m−3, which is <0.3% of the average Japanese dose of about 4 μSv·d−1 from all radioactivity sources.

And the conclusion:

Finally, these levels are several orders of magnitude lower than those used in one study that assumed exposure to the most heavily impacted water discharged from the Fukushima NPPs [nuclear power plants] to predict marked reproductive effects and possible mortality in marine biota.

Biota is the flora and fauna of a region.

These are very heartening findings. Still, the authors are careful not to overstate the case:

Ultimately, though the radionuclide levels of 137Cs and 134Cs offshore are currently low with respect to human health effects, any assessment of radiation dose should also consider long-term exposure if the NPP remains a continued source of radionuclides (5) and if, as has been reported, coastal sediments are contaminated with multiple radionuclides.

Those “if”s require a different study.

As the samples above show, the paper can be appropriately dense, but still readable by non-experts. Do take  a look at the whole thing.

The NOAA ship Ka'imimoana (Hawaiian for “ocean seeker”) was used for the research described in the paper.


jimwg said…
Wonder how fast and prominently the media is going to lap these official findings up...

James Greenidge
Queens NY
jimwg said…
What's curiously overlooked in media reviews of Mark Lynas' mentions of (supposedly) Fukushima radioactivity found in kelp is that the man very deftly only states that radioactivity was DETECTED in kelp, NOT whether it was actually harmful or even just background. Just because you can detect agents or poisons in tiny amounts doesn't mean the whole barn is condemned. You can can detect arsenic in apple seeds; does that mean bar apples? What other baddies in tiny amounts around us aren't being reported?

James Greenidge
Queens NY

Popular posts from this blog

How Nanomaterials Can Make Nuclear Reactors Safer and More Efficient

The following is a guest post from Matt Wald, senior communications advisor at NEI. Follow Matt on Twitter at @MattLWald.

From the batteries in our cell phones to the clothes on our backs, "nanomaterials" that are designed molecule by molecule are working their way into our economy and our lives. Now there’s some promising work on new materials for nuclear reactors.

Reactors are a tough environment. The sub atomic particles that sustain the chain reaction, neutrons, are great for splitting additional uranium atoms, but not all of them hit a uranium atom; some of them end up in various metal components of the reactor. The metal is usually a crystalline structure, meaning it is as orderly as a ladder or a sheet of graph paper, but the neutrons rearrange the atoms, leaving some infinitesimal voids in the structure and some areas of extra density. The components literally grow, getting longer and thicker. The phenomenon is well understood and designers compensate for it with a …

Missing the Point about Pennsylvania’s Nuclear Plants

A group that includes oil and gas companies in Pennsylvania released a study on Monday that argues that twenty years ago, planners underestimated the value of nuclear plants in the electricity market. According to the group, that means the state should now let the plants close.


The question confronting the state now isn’t what the companies that owned the reactors at the time of de-regulation got or didn’t get. It’s not a question of whether they were profitable in the '80s, '90s and '00s. It’s about now. Business works by looking at the present and making projections about the future.

Is losing the nuclear plants what’s best for the state going forward?

Pennsylvania needs clean air. It needs jobs. And it needs protection against over-reliance on a single fuel source.

What the reactors need is recognition of all the value they provide. The electricity market is depressed, and if electricity is treated as a simple commodity, with no regard for its benefit to clean air o…

Why Nuclear Plant Closures Are a Crisis for Small Town USA

Nuclear plants occupy an unusual spot in the towns where they operate: integral but so much in the background that they may seem almost invisible. But when they close, it can be like the earth shifting underfoot., the Gannett newspaper that covers the Lower Hudson Valley in New York, took a look around at the experience of towns where reactors have closed, because the Indian Point reactors in Buchanan are scheduled to be shut down under an agreement with Gov. Mario Cuomo.

From sea to shining sea, it was dismal. It wasn’t just the plant employees who were hurt. The losses of hundreds of jobs, tens of millions of dollars in payrolls and millions in property taxes depressed whole towns and surrounding areas. For example:

Vernon, Vermont, home to Vermont Yankee for more than 40 years, had to cut its municipal budget in half. The town closed its police department and let the county take over; the youth sports teams lost their volunteer coaches, and Vernon Elementary School lost th…