Cesium in the Biosphere: Guest Post by Stewart Farber

Stewart Farber
MSPH

Air Pollution and Dosimetry

Starting in 1972, for about 3 years, as a Public Health scientist and air pollution control specialist, I was responsible for upgrading and reviewing the Radiological Environmental Monitoring Program data from VY (and other Yankee plants) and generating periodic summary reports to the NRC.

In 1975, I was responsible for getting approval for a multi-million dollar centrally located state-of-the-art, greatly enhanced environmental lab. This lab was far more advanced than the labs of any of the then-current commercial contractors.  The lab was established as the Yankee Atomic Electric Co. Environmental Lab in Westboro, MA. Vermont Yankee management were willing to share in the substantial expense of setting up this advanced facility. This lab analyzed radiological environmental samples from VY, as well as Maine Yankee, Yankee-Rowe, and Seabrook (and misc. other plant samples) and performed personnel dosimetry services for these nuclear plants for over 25 years.

Meteorological Monitoring

I proposed upgrading the meteorological monitoring program at all Yankee plants in 1974, including VY. To its credit, VY willingly, despite the cost, supported installation of a 300' meteorological tower (vs. 120'). This met tower had  more advanced met instrumentation, and a computerized data acquisition system to digitize wind speed, wind direction, and temperature at 3 elevations so it could be reviewed from a central facility on a routine basis. This made met parameters available remotely in the event of an emergency, in order to assist in emergency planning. VY recognized the value of having good met and environmental radiological data and willingly shared in the costs this required. The sponsor companies and staff at VY deserve substantial credit.

A comment follows on the variability of environmental radioactivity of nuclear fission isotopes as a cautionary note on jumping to conclusions about environmental radioactivity based on limited sampling, something which VT politicians with an agenda often used against VY to negatively influence public opinion and advance their short-sighted agenda.

Wood Ash and Cs

Wood burning fireplace

In 1990 I took a sample of wood ash from burning hardwoods in my fireplace at a vacation home I had in Warren, VT (which is 130 miles distant from VY in Vernon, VT) and had it analyzed for radioactivity level by sensitive gamma spectroscopy at the Yankee lab. Wood ash is the end product of burning roughly 100 to 300 pounds of wood to yield 1 pound of ash, so ash concentrates what minerals are in the wood to yield a sample that can serve as a very sensitive indicator of natural environmental radioactivity and potential contamination from man-made isotopes . This sample from Warren, VT as would be expected, contained very high levels of the natural isotope K-40 (half life= 1.2 billion years), multiple isotopes of the U-238 (half life 4.5 billion years) decay chain, and multiple isotopes of the Th-232 (half life= 14 billion years) decay series. These are primordial isotopes present in the environment; they are residual from the Big Bang. In addition, this sample contained very high, and quite surprising, levels of the nuclear fission product Cs-137 residual from atmospheric nuclear bomb testing by the US and USSR which ended in 1963.

This initial sample of wood ash from Warren, VT contained 15,000 pCi/kg ash of Cs-137 --the highest level of Cs-137 the Yankee Lab had ever seen in any background environmental sample analysis. I asked VY staff (and other nuclear facilities across the US) to submit a wood ash sample gamma spec analysis after the initial measurement in Warren was so surprisingly high. The wood ash sample from trees grown near VY was analyzed showing a Cs-137 level of about 1,500 pCi/kg ash --10% of the level of fallout Cs-137 seen 130 miles distant!!!! This demonstrated how variable man-made nuclear isotope fallout can be in the environment. This has NOTHING to do with a nuclear plant: a nuclear plant releases essentially zero levels of Cs-137 and Sr-90 in airborne releases.

Cs lower near Vermont Yankee

Many years later after 2011, anti-nuclear politicians like Governor Shumlin in VT, set out with their agenda to make VY look bad because slight differences in Sr-90 (present throughout the environment residual from open air bomb testing) were seen in a few fish near the plant and upriver from VY. A few isolated environmental measurements mean very little. As was seen with the wood ash measurements mentioned above, the Cs-137 level in wood ash near VY in 1990 was 1/10th the level measured 130 miles away in Warren.

This difference was not likely due to major differences in fallout from past bomb testing in Central vs. Southern VT but due to soil chemistry factors between the two locations. Can you imagine what some environmental activist charlatans might do and demand if Cs-137 levels in trees was 10 times higher near VY vs. 130 miles away, rather than the other way around as is actually the case?

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Steward Farber holds a degree in chemistry from Brown University, and an MS Public Health from UMass Amherst.  Farber originally submitted this post as a two-comment set on my blog post Cinco de Bye-O at Vermont Yankee. However, I felt this knowledgeable and extensive comment deserved its own post.  You might also want to look back at the original post, where Farber's writing gathered two more comments. One was about the different uptake of Cs by different tree species, and and the second comment was about pulses of radionuclides that are released in forest fires.

Sunny News about Fish and Vermont Yankee

All fish are radioactive. South Vermont fish, North Vermont fish, all fish.

The Vermont Department of Health (DOH) periodically tests radiation levels of fish in the Connecticut River. They always find background levels of radioactive strontium and cesium in the fish. Meanwhile, the opponents always say that Vermont Yankee contaminated the fish.

In the past two days, the DOH has announced test results of fish from the far north of Vermont, far from Vermont Yankee. The fish had the same level of radioactivity as the fish near the plant. Background levels.

The Northern Fish

Both the Brattleboro Reformer and the Burlington Free Press posted stories about the measurements of the northern fish.

Here's a quote from the Reformer: "The results are that cesium-137 and strontium-90 in Lake Carmi fish is in the same range as Connecticut River fish," said Irwin. "We take this as some evidence that all fish in Vermont are likely to have radioactive cesium and strontium at these levels and that, as we've hypothesized, it is from nuclear weapons fallout and the releases of Chernobyl. All of us are glad to have proof and not just conjecture."

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"There's no danger in eating the fish," said Irwin. "Should we ever find that there are reasons to restrict diet from any sampling for any kind of radioactive or toxicological events, we would keep in mind different cultures have different diets."

(Bill Irwin is the radiological safety officer of the Vermont Department of Health)

In the Burlington Free Press, David Deen, a long-time foe of the plant acknowledged, however, that if future samples remain consistent, then Vermont Yankee officials were right that the plant was not the source of the strontium 90.

A Partial History of Fish Scares

Claiming radioactivity in the fish is due to the power plant is a well-worn tactic. In 2010, when strontium was detected in a fish from the Connecticut River, the nuclear opponents made this a centerpiece of their marches. Maggie Gundersen said that people should "throw the fish back" and not eat Connecticut River fish. Her husband, Arnie Gundersen, said they were finding radioactive fish near the plant but "blaming the bomb." In other words, he implied that Vermont Yankee was saying the fish had merely background radiation, but that was just a way to avoid acknowledging that it was Vermont Yankee's fault. My blog post It's the Nukes What Gets the Blame describes these events.

In 2011, there was another fish with strontium. Governor Shumlin said he wouldn't eat fish from the Connecticut River because of the strontium in this fish. Meanwhile the head of the Vermont Department of Health contradicted him, saying the fish was safe and the levels were low. I have a video of this press conference in the post That Strontium Fish in the Connecticut River. Later, Lochbaum and Markey weighed in on the side of the governor. I blogged about their assertions, also. They exaggerate.

Potassium and Strontium

In a wonderful guest post, Richard Schmidt compared the relative dangers of strontium, mercury, and naturally-radioactive potassium in the fish. In his post What is the Real Impact? Richard Schmidt on Strontium, Mercury and Potassium in Fish, Schmidt points out that 2 % of the radioactivity in the fish comes from strontium, and the rest comes from natural potassium.

Yesterday, the Brattleboro Reformer said pretty much the same thing. In the Reformer: In the same analyses, the fish had almost 500 times more potassium-40 in them than they do cesium-137, [Irwin] said. Potassium-40 is a naturally occurring radioactive material that is in nearly everything and was created when the planet was formed billions of years ago, said Irwin.

In other words, the natural radioactivity in the fish swamps any man-made sources of radioactivity.

It is safe to eat the fish. The fish in the north of Vermont. The fish near the plant. All the fish.

The Bomb: Not Banned Soon Enough

Where did all that strontium come from? It came from atmospheric testing of nuclear weapons. Fallout is real. Fallout measurements are not something a power plant "hides behind." Though the atmospheric test ban treaty in 1963 stopped most of bomb testing, there have been 2000 bomb tests.

On this video, you can see the accelerated rate of testing through the early 60s.

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Picture at the head of the post shows me approaching Blinky the fish outside a Public Service Board meeting in July 2010. I have the light-green top and black purse: Blinky has three eyes. Picture by Howard Shaffer, published in earlier blog post.