Friday, January 22, 2010

Tritium and Health


The tritiated water was discovered in the test well around the time the walkers were headed to Montpelier. I went to Montpelier for their press conference and their cookies, and I had a sign "Yes Vermont Yankee." One woman jokingly offered me a portion of her orange juice, saying: "Here's some tritiated water, drink it." I shot back: "Yeah, give me that water, but YOU are going to have to eat a banana!"

Indeed, both bananas and tritium are beta-emitters, which means they emit an electron and some energy. It turns out that the beta emissions from the potassium in the banana are more energetic than those from tritium, and also potassium stays in the body longer than water does. I asked a friend who is a health physicist to do a calculation: 2 liters of test well water (20,000 pCi from tritium) equaled how many bananas? The answer: two liters of test-well water is the biological equivalent dose of eating part of a banana. One-twentieth of a banana, to be precise. In other words, to encounter the equivalent dose as you would receive from eating a banana, you would have to drink forty liters of test-well water. That's a lot of water.

The State of California has tritium limits which are lower than the EPA limits. For consistency, these limits should be matched with limits on banana consumption (two a year).

Idaho State University suggests that, if you get more tritium than you prefer (let's say you ate a tritium-containing rifle sight device) you could flush it out by drinking a lot of non-tritiated water. It's probably better to avoid eating the rifle sight.

Another take on the test well is described in the medicine and research blog, Big Medicine. Their calculations show that drinking water with this level of tritium for a year would yield an exposure of four millirems per year. For comparison, background radiation is about 300 millirems per year, and a cross-country plane trip increases exposure by three millirems, due to cosmic radiation.

In other words, if the test well tritium were found in drinking water it would not be a public health risk. And of course, this level isn't even in drinking water. It's in a test well. Test wells have been monitored for years around the plant, and this is the first time tritium has appeared.

If the anti-Vermont Yankee woman in Montpelier really had tritiated water available from the test well, I would have enjoyed a glass or two, quite cheerfully. We were standing near the cafeteria, so I could have bought a banana for her. Luckily for her peace of mind, I didn't.

I decided not to tell the woman in Montpelier what my doctor told me. My doctor said that since I am getting older, I need to think about protecting my bones. I should take calcium pills and vitamin D pills, and eat bananas several times a week. I'm supposed to eat the bananas for the potassium.

12 comments:

Robert Hargraves said...

It's reassuring to know that if someone broke through the security at Vermont Yankee, drilled a well, and drank the water, the EPA says it's not harmful.

Jason Ribeiro said...

Meredith, I noticed your comment about 5 democratic candidates running for governor of Vermont on Atomic Insights. Of the 5 that I looked up - Susan Bartlett, Matt Dunne, Deborah Markowitz, Doug Racine, and Peter Shumlin - who do you think has the best chances? Which of any of them might be the most reasonable about Vermont Yankee?
I'm thinking I ought to do a blog post about these candidates and wanted to hear your opinion.

Meredith Angwin said...

Thanks for the note, Jason. I have forwarded your question to others who are better connected with the Democratic party.

My own feeling is that Shumlin is the front-runner. He is president pro tem of the Senate and gets a lot of press. De facto, he has been running for governor for a long time.

The other candidate I consider worth watching is Matt Dunne. He has served as a Vermont Senator, so he is not a political newbie. He is also very tech-savvy, young, and has roots in Vermont. As a matter of fact, he lives in the house in which he grew up. (That sort of thing matters a lot in Vermont.) He is smart, articulate and personable. I like his wife, Sarah Stewart Taylor, and can heartily recommend that people read her books. But alas, Matt has also jumped on the anti-VY bandwagon.

http://www.mattdunne.com/news/48-clear-action-needed-matt-responds-to-vt-yankee-leaks

GRLCowan said...

Candidates should be pressed on the matter of whether they consider natural gas, typically with as much radioactivity (due to radon) per unit volume as the groundwater in the test wells reportedly has due to T, is an acceptable interim substitute for Vermont Yankee's output.

Is radioactivity in the air everyone breathes preferable, from their point of view, to the same in water no-one drinks? Does the fact that natural gas costs several million dollars per tonne-uranium-equivalent, much of it government royalties, have any bearing on their preference? (A tonne of the real thing costs less than $200K.)

Anonymous said...

Meredith, I don't understand your answer. Are you saying that Shumlin & Dunne are the most friendly to nuclear power, or that you think they have the best chance to win? From what I can see, Bartlett is the only candidate who has not said, "Absolutely not."

Meredith Angwin said...

I think Shumlin and Dunne have the best chance to win. Shumlin is a dyed in the wool anti. He comes from the same county as the plant, but he is constantly "concerned." The town of Vernon is for the plant, and has even hired its own lobbyist. But the county (including Brattleboro) is anti. I see this division as a class divide. Just my opinion, and I don't want to say more about it.

harvey wasserman said...

Let's hope, for all our sakes, that Vermont Yankee & all other nuclear plants are shut as quickly as possible.

It's time to move into the 21st century, with technology that actually works.

No Nukes/4 Solartopia...Harvey Wasserman

Jason Ribeiro said...

You don't really mean that Harvey. If all the nukes were gone, you'd be out of business.

Peter said...

The frustrating thing as an observer of the VY situation is how the anti-nuclear crowd take advantage of the ignorance of the general public.

One only has to mention the word 'radiation' and 'leak' to the average person on the street to provoke fear and alarm. The anti-nuclear argument is based on this principle of ignorance and fear.

Sadly there are legions of politicians and so called "environmentalists" that are all too happy to exploit this for votes, financial gain and/or a feeling of righteousness.

Meredith Angwin said...

Peter

Thank you. It's very hard to know how to get the truth out there. If we are too scientific, people fall asleep. If we are more emotional, it becomes he-said-she-said without any strength in our argument. I have decided that there is no secret sauce. We just have to keep repeating the truth, to the best of our abilities, and showing a willingness to speak out.

At least, I hope so.

Meredith

Carol said...

Interesting post. Were they able to clarify the truth to this? It would have been great if we knew.

Meredith Angwin said...

Carol. Thank you for your comment.

Drinking water which contains tritium at the EPA limit gives less internal beta irradiation than eating part of a banana or drinking a glass of milk. Bananas and milk contain potassium, which is naturally radioactive.

There are many sources for this information in the literature and on the web. I have several links in the post itself.