The Truth About Tritium: A Guest Post By Thomas Curphey

This letter appeared in the Valley News (my local newspaper) on January 19 2011. I have never met Thomas Curphey, but I phoned him when I read the letter. He graciously allowed me to use his letter as a guest post in my blog.

The Truth About Tritium

To the Editor:

A Valley News editorial some time ago decried the rise of "truthiness," the attitude that facts matter not at all and that perception is everything. The editorial closed by saying, "History is full of frightening examples of what can happen when individuals and political factions come to believe they are entitled to their own facts. Let's not go there."

In light of these noble sentiments, it is unfortunate that the Valley News continues to publish articles misrepresenting the risk of exposure to the radioactive element tritium. For example, on Jan. 12, the Valley News published an Associated Press article ("Hearing on Vt. Yankee Leaks") stating that tritium "is a carcinogen when ingested in high amounts." This statement is a particularly slippery example of "truthiness," one designed to play on our fears of radioactivity and cancer.

How has tritium been linked to cancer? In none of the ways that the reader is likely (and perhaps intended) to assume. As pointed out in previous letters to the editor, there is no documented case where a human has ingested large amounts of tritium and has subsequently developed cancer. Results of animal studies have been ambiguous. There are no statistical studies linking tritium exposure to cancer. In fact, the so-called link between tritium and cancer is purely hypothetical: because tritium is radioactive and exposure to radiation can lead to cancer, therefore, exposure to tritium leads to cancer.

Perhaps to cover up a paucity of actual facts and to lend credibility, the qualifiers "ingested in high amounts" are added. Why? Because the radiation emitted by tritium is of such low energy that it cannot penetrate human skin or even a piece of paper. Therefore, to have any chance of causing cancer, tritium, would have to be ingested in large amounts.

A balanced assessment by the California EPA of the health risks from tritium may be found on the Web at

http://oehha.ca.gov/water/phg/pdf/phgtritium030306.pdf.

I urge readers interested in learning the facts about this issue to read this document.

Apparently, for the Valley News, some people, in this case environmentalists opposed to Vermont Yankee, are entitled to their own facts.

Thomas J. Curphey

Hanover

The writer is a retired research professor of pathology at Dartmouth Medical School and a retired adjunct professor of chemistry at Dartmouth College.

Tritium Summary

I have done several posts on tritium in the past few days. Some are quite long. So here's an executive summary

In Tritium Is Three, I pointed out the three important questions about the tritium leak at Vermont Yankee
1) Is the tritium a danger to public health?
2) Does the existence of a tritium leak prove that the plant is badly managed?
3) Did Entergy lie about its underground piping?

The next two posts, Tritium and Health and Tritium, Oil and Kale answer the first question about health. Tritium is not dangerous at the levels found in the test wells. These posts compare the radiation levels to bananas and kale, and compare the spill levels to recent oil spills.

The next post, Tritium and Plant Management, answers the second question. The existence of a tritiium leak proves nothing about plant management. Tritium leaks have been found at many plants, and Vermont Yankee has taken all appropriate steps (test well, inspections, informing regulators and NRC) to handle the leak.

The next two posts answer the third question: Did Entergy lie about its underground piping? These are long posts containing many quotes.

In Miscommunication? I point out that the different groups have different definitions of underground and buried, the terms were used interchangeably in many cases, and there was plenty of room for honest misunderstandings.

In the final post, Piping and Misinformation, I ask a simple question: in all this testimony, why did nobody refer to a piping diagram? The regulators may have had such diagrams, but not looked at them. Or the regulators didn't request such diagrams. In either case, the regulators, as well as Entergy, has serious egg on its face. Referral to such diagrams could have put a complete end to any misunderstanding or miscommunication.

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.