Interminable innumeracy: "renewables" versus nuclear

Interestingly, Doc Brown's modified Delorean was also the
equivalent output of a modern nuclear plant. Heavy.

A confession - I listen to and read a fair amount of science stories. (Yes, self-outing as a nerd right out the gate). And whenever the topic of renewable energy sources comes up, invariably a spurious comparison to the generating capacity to nuclear plants will come up. For example, identified resources for say, offshore wind will be identified somewhere in the realm of tens of gigawatts, to which the guest will inevitably state, "That's the equivalent of dozens of nuclear plants!" (i.e., about 1 GW each). Naturally, no clarification is given to the important factors here - as in, just how many wind turbines / solar cells / magical crystal arrays (okay, so maybe I'm exagerating with the last one) are required to accomplish this task, much less the inherent capacity factor in such a generating system. (In other words, the sun doesn't shine and the wind doesn't blow all the time, meaning these generators sit idle for more time than they actually generate power).

A basic unfamiliarity with these concepts (i.e., the scale of individual energy generators and their respective availability factors) tends to produce a pervasive level of innumeracy, which in turn leads to genuinely terrible energy policy positions, such attempting to displace some or all of baseload capacity (including nuclear) with intermittent sources. In an effort to combat this epidemic (and inspired by the old Total cereal commercials which used to air back when I was growing up) I've put together an infographic to demonstrate just how many of these types of generators one needs to replace just one baseload unit.

I've made high-resolution versions available for download and reuse as well (svg and pdf).

The next time someone claims that renewable energy sources can somehow "displace" nuclear sources for baseload (such as say, Germany is attempting to do), I invite you to ask just how many units (and at what assumed capacity) will be required to accomplish the task. Chances are very good the advocate either doesn't know or simply isn't being honest with the numbers.

An aside: Does this mean I don't think we should use renewable sources at at all? Not really - if sources which coincide with peak demand (such as solar) can shave off demand for "peak unit" power (typically provided by fast-response units like natural gas turbines) and do so at an economically competitive price, more power to them. But don't count on inherently diffuse sources of energy providing baseload power needs anytime soon.

Cultural bias and nuclear

I was recently perusing the comments on an NPR article on nuclear waste disposal, ("How to find a nuclear waste site? Woo a town."). In perfectly foolish measure, I perused the comments - a bad idea for anyone with an IQ north of room temperature and a level of patience south of Mahatma Gandhi. I found myself taken aback with, to put it bluntly, the level of gross ignorance of nuclear opponents. A couple of examples:

[...]The truth of the matter is that, to prevent dangerous overheating of nuclear waste, the rail cars used to ship the waste would allow air to move freely which also meant radiation could move freely. While it would just be small amounts of radiation, this could add up for families living next to railways and cause a multitude of health problems.[...]

So, we don't UNDERSTAND nuclear and our little waste problem. This condescending, ridiculous bantor from the industry nver ceases to amaze me. The industry's problem is that more people are beginning to understand the dangers of nuclear. The lifespan and inability to rid ourselves of it was reason enough to have never began this horrid mess. Indeed, I DO understand and, therefore,I want this needless perpetuation of nuclear to end! 

 My reaction to the first of the above was almost to say aloud in Morbo fashion (from Futurama, to the uninitiated), "Windmills do not work that way!" In other words, it conveys a serious lack of understanding about just how radiation works.

Image credit: NRC

To explain it briefly - ionizing radiation (i.e., the kind that can cause health problems) doesn't just blow around like dust in the wind - it comes from a source: like the atoms decaying inside nuclear fuel, or the sun for instance. (Yes, the sun - ever wonder why you get a sunburn from staying out in the sun too long? You just got a very mild radiation burn.) For gamma radiation, (i.e., energy emitted from nuclear transitions, ranging from ultraviolet rays to x-rays to gamma rays), this travels in a straight line, just like visible light - because it is light; it doesn't simply scatter to the wind. Further, it attenuates strongly as a function of both distance and shielding; fuel transport casks are designed such that a person standing directly next to the cask would have to stand there for any awfully long time to get anything approaching a dangerous level of radiation exposure, but further, gamma radiation attenuates as the square of the distance. In other words, for every factor of 10 one moves away from a radiation source, the exposure drops by a factor of 100.

A standard rail shipping cask (courtesy Wikipedia)

But getting back to the issue at hand - yes, casks are air-cooled, but so what? For radiation to "move freely" as the commenter describes, this would require radioactive material to move freely. Yet the transportation casks are clearly designed such that heat from the fuel is conducted to the outside of the cask, where it is carried away by convection. In no way does the fuel get exposed to air, the only plausible way in which this event could happen (i.e., particles of the fuel itself allowed to be picked up into the air and carried away). To further put this myth to rest, these same casks have to be tested against all kinds of conceivable accident scenarios - drops, fires, punctures, crushes - anything that the fuel container could possibly experience in an accident condition.

Below is a video released by Sandia National Laboratories demonstrating the types of tests performed on an older design of the transportation casks:

Basically, any cask which is certified to transport used nuclear fuel must go through a battery of punishing tests before it is ever licensed to transport fuel.

Getting back to the main point here - namely, that the information on safety is out there and widely available, how is it that such gross misinformation still manages to persist? The second comment seems to point to a a particular phenomenon - cultural bias which ultimately leads to mistrust of the (accurate) information being given by experts. If you will forgive the (slight) hyperbole:

1. Nuclear energy is an industry run by giant, evil corporations with no regard for human life
2. Information conveyed by nuclear experts and supporters is chiefly in service to the above
3. Therefore, technical experts in nuclear are untrustworthy.

Hence we get have people resorting to "folk science" (in other words, lies) peddled by hucksters with their own agendas - be they political or economic in nature. (One can already begin to see the irony forming here.) Or you get the "proud ignorance" - "I don't need to know anything to know this is dangerous and you're lying to me!"

How do we get around this? I confess that I'm not an expert in this realm (I mean, after all, my first thought reading the above comments was to simply apply palm to face and mutter, "Windmills do not work that way!") But it does seem like there is a strong need to present a human element to this, conveying above all else that we, too share their (valid) concerns over the health and safety of our respective loved ones, and as such we have the utmost interest in obtaining and conveying accurate information.

Of course, a lot of us do this already - sometimes on a daily basis. A large part of the problem seems like an inability to penetrate "hardened" ideological structures where such ideas are formed and reinforced. And certainly, this applies far more broadly than just nuclear technology - think global warming, for example - a near-mirror image of this same phenomenon can be observed (accusations of science being manipulated for economic and political interests, etc.) If anything then, this seems to speak of a larger societal problem in conveying scientific and technical information about risk to the public.

What to Expect from Japan's Nuclear Fleet and 2011 in Context

A late Happy New Years to all our readers! And the new year, of course, means we have new exciting full sets of data for 2011!

The EIA hosts a useful online data browser for international energy statistics. However, if one was interested in the nuclear electric generation in Japan, for instance, they would find the data only goes through the year 2009. Although that is still decent, it certainly won't give up-to-date information about how the 3/11/2011 earthquake-tsunami event off Japan's Tohoku coast affected the energy market. For that, I have turned to statistics from the Federation of Electric Power Companies of Japan (FEPC). It was just last week, 1/17, that they released the data for December 2011, wrapping up the year. As pdf files, it wasn't the most convenient format to work with, but it's the only place I know to find this. I couldn't resist plotting this data to compare what the nuclear generation in 2011 versus 2010 (as a reference) was. Here is what I found:



What is this graph showing? The Earthquake automatically tripped a number of reactors, so there was a instantaneous decrease in generation at that second, so for the month of March 2011 the time before the earthquake averages with the time after the earthquake to give a number in-between what you would have if the fleet was running normally versus when crippled by the earthquake. One would expect the number for April would be a better representation of the generating capability of the post-earthquake fleet.

A funny thing happens after April 2011. The generation from nuclear in Japan continues to decline almost every month. This is the political and regulatory backlash from the event. Reactors that were not immediately affected were shut down due to safety concerns. Others had trouble getting approval to restart after scheduled outages. By December, the total generation is at a disturbingly low level. Just for a sanity check, the reported capacity factor for Dec 2011 is just 15.2%, and this is excluding the Fukushima plants.

How does this compare to past troubles Japan's nuclear industry has faced? And what are reasonable expectations for the future? Glad you asked. Firstly, I'm going to explain how I made up a guesstimate for future generation. I made up 3 different values.

• For 2012, I multiplied the average of Oct, Nov, and Dec 2011 by 12 (months per year). This is how much energy the fleet with produce in 2012 if they continue at the same performance as the end of 2011.
• For 2014 and beyond I took the generation in April 2011 (see my prior arguments) and multiplied that by 12 (mo/year).
• For 2013 I just made up a number.
  

I believe that these give the most reasonable baseline to use for comparison purposes right now. The ex-Fukushima capacity factor of the total fleet in April 2011 was about 70%. Is it reasonable to expect that they will perform better than that in 2015? That's certainly a loaded question, but I don't think so. I also don't think it's reasonable to give much credit for new builds. We could see significant new capacity addition, but we could also see the number go to a flat 0.0 starting in 2013.


For this graph, keep in mind that my number for 2011 includes the first 2 months and 10 days when everything was working normally. Because of that, I didn't find it representative to stop with that year. Let me address each of the historical dips in this graph so we can look at the current state of affairs in context.

• Chernobyl - This event obviously did not happen in Japan but it obviously affected their safety regulations and the nuclear plants (even though in the middle of a growth period) saw reduced availability as a result.
• TEPCO Scandals - Around 2003 there were numerous data fabrication scandals by TEPCO coming to light. Before 2011, this was one of the most costly events in the worldwide nuclear industry. You can see that the event was more gradual than abrupt, contrary to the natural disasters. It takes time for investigations to proceed and the regulator starts with incomplete information.
• Kashiwazaki-Kariwa earthquake - This was a major event impacting the largest nuclear plant in the world owned by TEPCO. Record breaking shaking occurred in many of the buildings on site, up to 20 m/s^2 in one turbine hall. The severity of the earthquake exceeded design specs by a large margin, although the reactors safely shut down. Because this kicked up new concerns about seismic safety, the plants were completely out of commission in 2008 and slowly began starting back up in 2009.
  
• 2011 Tohoku Earthquake-Tsunami event - Obviously the greatest nuclear disaster since Chernobyl, this was domestic to Japan. Similar to the K-K earthquake, it was found that a natural disaster far exceeding the design specifications not only posed a risk, but actually caused a full scale nuclear disaster. Similar to the anatomy of prior scandals and regulatory revisions, however, plants all over the nation were gradually shut down over safety concerns. This event, no doubt, caused more loss of capacity than all other events combined and today even threatens to bring Japan's entire nuclear fleet to a halt if the recent months are any indication.

What has made up for this shut down of nuclear plants? Fossil fuels exclusively. Hydroelectric or any renewables don't have the ability to adjust. Well, we need to mention that demand reduction was also a large factor.

Japan's Generation (TW-h) by all Fuel Type
(only large utilities) for 2010 and 2011

One would imagine that this could have an impact on Japan's economy. I am very interested to know myself. The fact that fossil fuel imports to Japan have increased and will stay high is obvious. The impact on the Uranium market also can't be understated.

Topic for my Next Post

Also with the year of the Dragon, we have a new EIA Annual Energy Outlook (AEO) draft for 2012! What are the predictions? Increasing nuclear production, explosive growth in shale natural gas production, and after decades of failed promises we finally start decreasing our dependence on foreign oil. Starting now. How is this possible? I don't know myself.

I'll take a shot at what's predicted and set my own reasonable expectations for nuclear generation in the United States, somewhat like I've done for Japan here.

Extra Links

Here are some thing I ran across after the fact:

• New Data: Nuclear Down, Carbon Intensity Up in Japan
• Japanese annual trade deficit reflects industrial strategy reversal
  

Summary of these two: Japan is now importing much more fossil fuels. Again, not surprising.

Why the Vermont Yankee case matters

Beyond the obvious implications for nuclear and the state of Vermont itself, the outcome of the Vermont Yankee case has several key implications for energy projects writ large. Among them:

• Nailing down who regulates radiological safety: Per the Atomic Energy Act of 1954, the federal government is the sole regulator of radiological safety issues. While confined mostly to the nuclear fleet, it goes without saying that such issues (be they currently regulated or not) also implicitly come into play with other energy sources such as coal, which emits far more radiation from the flue than any nuclear plant (due to trace uranium daughter products found naturally in the ground with coal, in turn concentrated and lofted into the air as coal is burned). The Vermont Yankee case was particularly egregious in the regard that it pitted decisions of radiological safety (clumsily couched in terms of "reliability" to avoid legal objection) between a decidedly non-expert (and frankly arbitrary) state legislature versus the professional expertise of regulatory staff at the NRC, working from established regulatory guidelines and specific scientific principles. Given the significant investment at stake with nuclear units, it is eminently reasonable to expect an objective and consistent review process performed by experts across the nuclear fleet - especially compared to the alternative of decidedly arbitrary decisions by state lawmakers whose background in radiological safety issues to be (in rather generous terms), decidedly limited.
  
• Highlighting the problems of ex post facto rulemaking with multi-billion dollar assets: An issue which has burned both the nuclear industry as well as others before it has been the issue of after-the-fact rule changes which adversely impact multi-billion dollar investments. The most infamous of these cases in U.S. history may have been the fate of commercial spent fuel reprocessing facilities, which represented billions of dollars of private investment by companies such as Nuclear Fuel Services, General Electric and others. With a stroke of a pen, President Jimmy Carter wiped out the value of each of these investments through his famous executive order indefinitely suspending spent fuel reprocessing. While this order was later revoked by President Reagan, the damage had been done - companies became acutely aware of the political volatility associated with such investments, and thus were unwilling to risk further political reversals - thus precipitating the stalemate in spent fuel management which persist until today.
  
  Vermont Yankee represents a similar point along this trend - after Entergy signed an MOU with the State of Vermont agreeing to the conditions for the purchase of the plant, the state legislature decided to retroactively change the conditions of the arrangement, granting the state a legislative veto over future operation of the plant not included in the arrangement Entergy originally agreed to (and arguably an arrangement which would have lowered Entergy's offering price had it been included in the original deal). While the case itself did not turn on this matter of ex post facto rule-making by the state of Vermont, the case establishes an important precedent against such adverse rule-making by states. Such a matter has implications for energy investments ranging far beyond nuclear.
  
• Establishing that states cannot predicate approval of energy projects on below-market energy sales agreements: This may be perhaps the most important and yet understated consequence of the federal court decision. One tactic Vermont had attempted to employ against Vermont Yankee was to attempt to force Entergy to enter into favorable, long-term, below-market sales agreements for power from the plant to the state as a condition of renewing its Certificate of Public Good (i.e., its authorization from the state to continue operations). If such a tactic sounds like brazen extortion, that's because it is. Fortunately, this was explicitly identified by the federal court judge as violating the dormant Commerce Clause (and thus unconstitutional). Again, such a finding has implications well beyond nuclear projects - it clearly repudiates the corrupt practice of states extorting electric utilities into favorable energy sales arrangements as a condition of operation.

A brief summary of the Vermont Yankee decision

A disclaimer: I am not a lawyer (although I play one on TV the internet); I do hold a Ph.D. in Nuclear Engineering however and have at least some basic ability to read indecipherable tomes. End disclaimer


Reading through the court decision rejecting the Vermont legislature's attempt to shut down Vermont Yankee through a pocket veto, several key points come up:

• The NRC retains sole regulatory authority for nuclear plants on matters of safety: One of the findings of the case was that the Vermont legislature's law requiring legislative approval for a Certificate of Public Good (CPG) on nuclear reactors in the state (i.e., Vermont Yankee) was substantially motivated over concerns of radiological safety. Under the doctrine of federal preemption, it was held that this was an unconstitutional infringement upon the federal government's regulatory powers under the 1954 Atomic Energy Act.
• The legislature cannot simply declare per-se rulemaking to be "not about safety" to get around pre-emption: This one may seem obvious, but it undergirded the state's rationale for the legislative CPG requirement. In essence, legislators openly admitted their concerns being driven chiefly by radiological safety concerns, although upon receiving semi-competent legal advice, decided to simply use different wording. That being said, the court found significant evidence that despite the stated goals of the legislation, the intent of the legislature was to govern the re-licensing and operation of the Vermont Yankee plant on the basis of safety concerns - the sole domain of the NRC, which granted Entergy a license renewal.
• Vermont cannot predicate approval of a CPG on favorable electricity sales agreements: Requiring Entergy to sell the state electricity at below-wholesale market prices was found to be an unconstitutional infringement of Entergy's rights under the Commerce Clause. To quote the decision, "The New England Power decision makes clear that a state’s requirement that a wholesale plant satisfy local demands and provide its residents an “economic benefit” not available to customers in other states runs afoul of the Commerce Clause, because it impermissibly burdens interstate commerce."

So what is the end result? Arguably (based upon my limited, non-lawyerly understanding of the decision), the Vermont Legislature may not pre-empt the Vermont Public Service Board on the matter of deciding whether or not to issue a Certificate of Public Good. Further, the VPSG is narrowly constrained in that it may not make considerations of radiological safety in its decision on whether to issue a new CPG to Entergy for Vermont Yankee (i.e., to operate for another 20 years); in general, the allowed space for its decision include economics, impact on the electrical grid, environmental considerations, specifically with comparison to the relevant alternatives.

In this regard, while the continued operation of Vermont Yankee past March is far from certain, it is difficult to make the case that shutting down an operating, licensed nuclear facility (whose capital costs have already been paid) would prove less economically or environmentally viable than the next most plausible alternatives (such as new natural gas plants), particularly given the extremely low operating cost of a fully paid-for nuclear plant.

Note: George Angwin at Yes Vermont Yankee has his own layman's interpretation, which appears to (comfortingly!) agree with my own.

Vermont Yankee lives to power another day

The Vermont Yankee nuclear plant, supplier of 73% of Vermont's emission-free electricity (and approximately one-third of the state's total electricity), won its day in federal court today, thus granting it the right to keep the doors open and the lights on (for the rest of the state). Vermont resident Meredith Angwin has been tirelessly championing Vermont Yankee's cause, both in person and through her blog, "Yes Vermont Yankee."

Entergy's Vermont Yankee plant had been under siege by a nuclear-hostile governor (Pete Shumlin) and in particular targeted by anti-nuclear groups hoping to seize upon a legislative window to shut down the plant for good. To give some background: when the plant changed ownership to Entergy in 2002, a condition of the deal  (signed in a memorandum of understanding with the legislature) was that Entergy agreed to submit an application with the Vermont Public Service Board (VPSB) for a "Certificate of Public Good" - in essence, a license required of all power operators. Vermont Yankee's current CPG expires on March 12, 2012.

Pray that Vermont does not alter

the deal any further.

Fast foward to the present. Entergy recently received an approval with its application to the NRC to re-license Vermont Yankee for another 20 years of operation (ending in 2032). (Side note: It cannot be over-emphasized that the original licensing period for reactors - 40 years - is one governed historically by anti-trust and economic considerations, rather than any scientific basis. Relicensing appliations are handled by the NRC on a case-by-case basis, wherein operators must prove the plant is physically capable of safely operating to NRC specifications over the extended time period.)

Then, in perfect keeping with Darth Vader's preferred negotiating style, the Vermont Senate passed a law blocking the VPSB from issuing such a certificate, thus attempting to circumvent the NRC and block the plant from operating. Again, this all is in spite of the fact that the NRC (staffed by trained engineering professionals) evaluated Vermont Yankee and determined it safe to operate; instead, this judgement was over-ruled by the governor and legislature of Vermont, distinctly lacking in such engineering credentials.

The full ruling turned essentially on how binding the MOU Entergy signed with the Vermont legislature was; in essence, the court's ruling was that this agreement bound Entergy to the jurisdiction and decision of the VPSB (i.e., obligating them to seek a certificate of public good), however such an agreement did not grant the legislature the right to pre-empt the decision process from the board. Thus, the legislature's move to circumvent the VPSB's process amounted to a change in the implicit contract with Entergy after the fact. (Such shenanigans were not limited to altering the deal after the fact - as has been covered in depth by Angwin, the legislature attempted in mafioso style to impose other conditions for receiving the certificate, such as requiring Entergy to sell electricity to the state at below-market rates.)

So what does this mean in the end for Vermont Yankee? Ultimately, the fate of the plant still rests in the hands of the VPSB, where Entergy must make the case to the board that Vermont Yankee provides an adequate balance of safety, environmental, and economic concerns relative to other sources in its continued operation.  However, today's ruling now grants Entergy that opportunity, the same one afforded to all other energy producers in the state. Finally, unlike the Legislature, such a case in one judged by findings of fact rather than political arm-twisting.

Why does Rep. Markey oppose natural gas exports?

It is often stated that politics makes for strange bedfellows. And energy politics makes for perhaps the strangest.

The Research Triangle Energy Consortium blog recently reported on a letter Representative Ed Markey (D-MA) sent to Energy Secretary Steven Chu urging him to reconsider licensing natural gas export terminals. Markey, a ranking member of the House Natural Resources Committee, is known to be a notorious (and notoriously opportunistic) nuclear opponent.

Markey states in his letter than his concerns are twofold - first, the oft-declared view of natural gas as a "bridge fuel" to solar, wind, and other alternatives (so long as those "alternatives" leave the atom unfissioned as God and nature intended...) as well as a matter of keeping energy prices affordable. Given Markey's track record of outright hostility to one of the cheapest forms of zero-carbon baseload energy around, his sudden concern for energy affordability - particularly in light of the high production cost of wind and solar - is almost laughable.

Opponents of exporting LNG cite a panoply of arguments against allowing U.S. companies to allow exports, the impact on energy prices notwithstanding. One is the possibility of producing higher-value products than the raw gas exported (e.g., ammonia-based products such as fertilizer, of which natural gas is a chief component). The second, cited by Markey and others, is the impact of rising natural gas prices on its direct competitiveness with coal (again, nevermind nuclear...).

Yet both of these arguments are equally specious. For one, given that the asset in question (i.e., LNG) is privately-owned, one should be asking where the government has the right or authority to assert that private producers can no longer sell their products to those who bid at the highest price (i.e., LNG importers), but rather must sell it to businesses deemed "suitable" to the current political agenda. Without going full Galt, it has all the creepy vibes of a stock villain from an Ayn Rand novel.

Second, with regard to concerns over the potential "bid-up" of natural gas prices, it beggars belief that such a similar phenomenon would not also occur as demand rose with increased consumption of natural gas for manufacturing, energy production, and as a transportation fuel. In other words, LNG boosters simply can't have it both ways: cheap natural gas will inspire demand across multiple sectors (energy, manufacturing, and export), and thus the price will not forever remain "cheap." Further, in a market economy, producers will sell their product at the highest margin - be it direct export, manufacturers, or energy companies.

And now, a plot twist

One interesting snag in all of this is something Rod Adams at Atomic Insights pointed out awhile ago as a speculation as to Markey's anti-nuclear fervor: Markey's district represents Everett Marine Terminal, the only operating LNG terminal in the U.S. (note this is a major source of LNG import activity). While I don't share Rod's enthusiasm for pinning down financial interest in the fossil industry as the sole and principle reason for organized opposition to nuclear energy (I find that there is far greater room for ideology in energy politics), it certainly does raise eyebrows. In Rod's thesis, opposition to nuclear naturally drives up demand for natural gas imports - good for Markey's constituency, which makes it good for him.

Yet the shale gas boom throws a wrench into all of this - petroleum companies like ConocoPhillips are already putting in applications to become natural gas exporters. At first glance, one has to wonder then why Markey remains in strident opposition to what would appear to work just as well for his district.

And so we go back to Markey's letter, in which I am forced to wonder perhaps if his intent is to push natural gas prices down, namely by shutting out alternative markets for natural gas consumption. In as much, by keeping the prices low, Markey hopes to outflank competition to alternatives (again, where I part ways with Adams - I truly believe that Markey does want to see an all-solar/wind future, and to hell with the consequences) by undercutting the competition through natural gas. Thus, the "bridge" - natural gas as a vehicle to drive out all future competition to renewables. This line of logic is readily apparent in his letter, where he describes natural gas being used to displace coal (although the term "nuclear" is not present at all in his multi-page letter to Dr. Chu). In as much, Markey's strategy becomes quite clear.

Ultimately, a new abundance of shale natural gas is a boon for energy consumers. While I am a feverent believer that safe and affordable nuclear energy offers the best path toward long-term reductions in carbon emissions and a better environment, the other thing I recognize is the need for affordable energy all-around, of which natural gas clearly does have a role to play. However, Markey's ham-fisted attempts to shunt supply solely to energy production under the guise of "affordability" (and ultimately as a means of manipulating sources of energy production over the long-term) could not be more readily transparent.

When the cure proves more harmful than the disease

Recently, the Boston Globe published a series of haunting images taken from the evacuation zone surrounding the stricken Fukushima plants. Perhaps what is most striking is the unearthly nature of the abandoned towns, now turned feral, their only inhabitants being abandoned pets and livestock. These are more snapshots from a post-apocalyptic wasteland; it is difficult to imagine these as bustling, populated places less than a year ago.

Several news agencies have taken up the issue of the evacuation zone, referring to it as "poisoned" and "uninhabitable for decades to come." And of course, taking a look at maps such as that put out by the Washington Post, indeed the situation does look quite grim. (For an excellent, authoritative view of the data, the NNSA has continued to publish updated radiation measurements).

The evacuation zone - and the surrounding dire rhetoric - is founded on the idea of maintain a "safe" level of annual radiation exposure, set as 20 milliSieverts (mSv) per year, or 2 rads/year. (Note that the NRC limits for the general public are 1 mSv/year for the general public, and 50 mSv/year for radiation workers). By contrast, an average member of the public would receive on average 4 mSv/year simply from natural and synthetic sources of radiation each year (including x-rays, CT scans, and the like).

Yet without getting into the issue of radiation hormesis (i.e., the theory that low doses of radiation may show an overall benefit), the epidemiological understanding of radiation risk from protracted exposures at levels under 50-100 mSv is extremely murky. (This is not to assert no long-term risk of excess cancers exists for this level, but simply that our currently understanding of this risk is extremely limited). Conversely, long-term doses above 100 mSv have been shown to contribute to an excess risk of cancers.

Two critical questions should arise at this point. First, what risk exactly is the 20 mSv/year limit based upon? For reference, estimates of radiation doses from smokers put their annual doses around 150 mSv/year (due to polonium-210 deposited into smokers' lungs). While clearly no one should endorse smoking as a healthy life choice, it is regardless a risk that individuals freely make each day at that we as a society (reluctantly) accept. In this sense then, why is the government of Japan making a choices of risk for thousands of displaced individuals at thresholds far lower than individuals themselves accept?

Taking the linear-no-threshold model (LNT) at its face, a common value for excess fatal cancers is assumed to be 0.005 fatal cancers / Sv (i.e., 0.00005 fatal cancers / mSv; the value established by NCRP 115). Assuming a dose of 20 mSv/year, this leads to an overall increase in risk of fatal cancer of 0.03 over 30 years - in other words, 1 in 33 individuals can be expected to develop an excess fatal cancer over a period of 30 years. That comes down to 1 fatal cancer per year per 1,000 individuals exposed - a rate approaching statistical noise.

Still sound scary? Let's put this into the context of other common everyday risks:

Risk	Order (death/year)
Meteorite impacts	~0.000000001
Radiation risk to U.S. population from nuclear power plant	~0.00000001
Radiation from high-altitude flight	~0.0000001
Lightning	~0.0000001
Radiation death from consumer products	~0.0000001
Flood, tornadoes, or earthquakes	~0.000001
Death from cholera or whooping cough	~0.000001
Train passenger death	~0.000001
Natural background radiation	~0.00001
Passenger deaths in aircraft accidents	~0.00001
Death from leukemia or tuberculosis	~0.00001
Brain damage from whooping cough vaccination	~0.0001
Overall road accident deaths	~0.0001
Death from bronchitis or influenza	~0.0001
Death from childbirth	0.00024
Lung cancer risk from smoking (20 cigarettes/day)	~0.001
Death from all causes at age 55	~0.001
Death from cancer, stroke, or heath disease	~0.001
Deaths from 20 mSv exposure (Fukushima exposure limit)	~0.001

In other words, the absolute limit on exposure established by the Japanese government corresponds to roughly equal that of the mortality risk of an average smoker (assuming conservative projections of low-dose risk). Beyond this, residents are to be permanently exiled from their homes.

Now conceive of a relatively conservative limit of even 50 mSv/year - a little over double the current exposure limit. From the above exposure maps, this would roughly halve the area requiring permanent evacuation ("permanent" in the sense of on the order of 30 years given the half-life of Cs-137, assuming no further decontamination). This would lead to a risk of about 0.0025 cancer deaths per year - 1 in 400. 

While such a certainly not trivial (although based in conservative projections), the question which should be asked is, "Compared to what?" Those evacuated have been deprived entirely of their livehoods - homes, farms, businesses, and ancestral lands. Clearly, they should be made whole by TEPCO, and failing this, the Japanese government. Yet the additional risk of death from cancer should be balanced against the very real physical and emotional costs of a mass involuntary exodus (not even taking into account the economic consequences for both those impacted and the country as a whole). What is the toll in terms of premature death from stress and associated mental health disorders (including alcoholism, depression, etc.) In essence, what is the cost in terms of human life from a forced exile? 

Nor are forced evacuations without cost - recently, Japan's blanket 20 km evacuation order recently came under fire due to its generic nature (ignoring real-time radiation exposure data, showing that contamination was spreading in a northwestern direction due to seasonal winds). As a result, many individuals received a higher dose than that if they'd simply stayed in place (due to evacuating to the northwest). Likewise, these evacuations themselves necessitated leaving homes (areas where radiation exposure is lower) and taking up residence in less sanitary conditions with greater exposure to the outdoors (increasing overall exposure). Thus, evacuation itself is not without risk. Each alternative must be evaluated for its own inherent risks - there is no free lunch.

I am not about to assert that there is zero risk from allowing residents to return - namely because the data regarding prolonged low-dose exposures is too poor to make a definitive assessment of risk. However, what should happen is that residents themselves should be allowed to make this choice from themselves - rather than the government. Perhaps one of the most disturbing images of the Fukushima evacuation zone is the constant vigil of police forces enforcing the no-entry zone; an act done ostensibly for residents' "own good," despite the legions of family pets and livestock abandoned to starvation or a return to ferity.

Within reason, these are risks residents should be allowed to evaluate on their own in an informed manner, rather than having them imposed upon them.

Coming out of hibernation

Much like the Nuclear Renaissance, we're not quite dead yet here - merely hibernating. Apologies for the general lack of activity on this blog; apparently, starting a new job at Oak Ridge and conducting a massive relocation tends to put a pinch on blogging activities. (Especially when one is drowning in boxes).

We'll be back to posting here soon, so stay tuned...