An Update on Two Competing Models of Radiation: Linear No-Threshold vs Hormesis

The author of one of my favorite nuclear blogs, Rod Adams, found a new and compelling document explaining the beneficial health effects of low doses of radiation. The document has generated quite the number of comments at his site and I could see why. Here are some good quotes and background info from the paper (pdf):

In the early stages of nuclear development, more than 60 years ago, the world regulatory agencies (e.g. ICRP) had little understanding of the mechanisms by which nuclear radiation interacts with living things. They observed an excess incidence of cancer death following high dose exposures and measured a linear relationship between dose and cancer mortality in the high dose range. They were unable to observe excess cancers in the low dose range, so they assumed that excess cancer is proportional to dose in that range, all the way down to zero dose. That is, they made a linear extrapolation from evidence in the high range down through the low range, where there is no evidence of harmful effects. This is called the Linear No-Threshold (LNT) model. (p.4)

...

So what levels of radiation are harmful and what levels are not? Based upon human data, a single whole body dose of 150 mSv (15 rem) is safe. The high background of 700 mSv/year (70 rem/year) in the city of Ramsar, Iran, is also a safe dose limit for continuous chronic exposure. Both dose limits are also beneficial. However, our regulations limit exposure to human-made radiation to only 20 mSv/year (2 rem/year) for workers- and 1 mSv/year (0.1 rem/year) for the public. Why have these limits been set so low? (p. 6)

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There is considerable evidence that exposure to a low dose or a low dose rate of radiation has a stimulatory effect on all living organisms. The immune system is stimulated by a short-term radiation dose. The body has built-in adaptive defences against higher levels of exposure after having been exposed to low-dose or low dose rates of radiation. This is called radiation hormesis. The extensive scientific evidence of the beneficial effects following low dose or low dose rate exposure (e.g. 192 studies in UNSCEAR 1994) and the scientific explanations for the effects appear to have been ignored by the government regulatory authorities (ICRP, NCRP). (p. 7)

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The doses or dose rates of radiation received in the nuclear industry and by the public living near nuclear plants are within the range of natural background radiation levels and far below the levels where harmful effects have been observed. Radiobiological evidence supports the radiation hormesis model: beneficial health effects for low-dose or low dose rate radiation exposures and harmful effects for high-dose or high dose rate exposures. (p. 9) ...

It'll be interesting to watch how the regulators and public react as more and more evidence like this comes out explaining that radiation maybe isn't as bad as they think. Like I said before, radiation saves lives.

Fluor Invests in NuScale

You know, it’s kind of sad that no one is willing to invest in nuclear energy anymore. Wait, what? NuScale Power celebrated the news of its company-saving $30 million investment from Fluor Corp. Thursday morning with a press conference in Washington, D.C. Fluor is a design, engineering and construction company involved with some 20 plants in the 70s and 80s, but it has not held interest in a nuclear energy company until now. Fluor, which has deep roots in the nuclear industry, is betting big on small-scale nuclear energy with its NuScale investment. "It's become a serious contender in the last decade or so," John Hopkins, [Fluor’s group president in charge of new ventures], said. And that brings us to NuScale, which had run into some dark days – maybe not as dark as, say, Solyndra, but dire enough : Earlier this year, the Securities Exchange Commission filed an action against NuScale's lead investor, The Michael Kenwood Group. The firm "misap...

Wednesday Update

From NEI’s Japan micro-site: NRC, Industry Concur on Many Post-Fukushima Actions Industry/Regulatory/Political Issues • There is a “great deal of alignment” between the U.S. Nuclear Regulatory Commission and the industry on initial steps to take at America’s nuclear energy facilities in response to the nuclear accident in Japan, Charles Pardee, the chief operating officer of Exelon Generation Co., said at an agency briefing today. The briefing gave stakeholders an opportunity to discuss staff recommendations for near-term actions the agency may take at U.S. facilities. PowerPoint slides from the meeting are on the NRC website. • The International Atomic Energy Agency board has approved a plan that calls for inspectors to evaluate reactor safety at nuclear energy facilities every three years. Governments may opt out of having their country’s facilities inspected. Also approved were plans to maintain a rapid response team of experts ready to assist facility operators recoverin...

Nuclear Utility Moves Up in Credit Ratings, Bank is "Comfortable with Nuclear Strategy"

Some positive signs that nuclear utilities can continue to receive positive ratings even while they finance new nuclear plants for the first time in decades: Wells Fargo upgrades SCANA to Outperform from Market Perform Wells analyst says, "YTD, SCG shares have underperformed the Regulated Electrics (total return +2% vs. +9%). Shares trade at 11.3X our 10E EPS, a modest discount to the peer group median of 11.8X. We view the valuation as attractive given a comparatively constructive regulatory environment and potential for above-average long-term EPS growth prospects ... Comfortable with Nuclear Strategy. SCG plans to participate in the development of two regulated nuclear units at a cost of $6.3B, raising legitimate concerns regarding financing and construction. We have carefully considered the risks and are comfortable with SCG’s strategy based on a highly constructive political & regulatory environment, manageable financing needs stretched out over 10 years, strong partners...

NEI Nuclear Notes

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