France’s Choice for Naval Nuclear Propulsion: Why Low-Enriched Uranium Was Chosen

This special report is a result of an FAS task force on French naval nuclear propulsion and explores France’s decision to switch from highly-enriched uranium (HEU) to low-enriched uranium (LEU). By detailing the French Navy’s choice to switch to LEU fuel, author Alain Tournyol du Clos — a lead architect of France’s nuclear propulsion program — explores whether France’s choice is fit for other nations. Read or download now.

Suggestions about Japan’s Nuclear Fuel Recycling Policy Based on U.S. Concerns

Image courtesy of Shutterstock

To date, Japan’s peaceful nuclear energy use has taken the form of a nuclear fuel recycling policy that reprocesses spent fuel and effectively utilizes the plutonium retrieved in light water reactors (LWRs) and fast reactors (FRs). With the aim to complete recycling domestically, Japan has introduced key technology from abroad and has further developed its own technology and industry. However, Japan presently seems to have issues regarding its recycling policy and plutonium management.

Because of recent increasing risks of terrorism and nuclear proliferation in the world, the international community seeks much more secure use of nuclear energy. All of the countries that store plutonium (which can be used for making nuclear weapons) must make the best efforts possible to decrease it. Taking this into account, concerns about Japan’s problem of plutonium management have been growing in the international community and Japan’s accountability for its recycling policy is essential.

In this paper, Yusei Nagata, an FAS Research Fellow from MEXT, Japan, analyzes U.S. experts’ opinions and concerns about Japan’s problem and considers what Japan can (and should) do to solve it.


Read the full report here.

Look to Texas Rather Than Nevada for a Site Selection Process on Nuclear Waste Disposal

Republican gains in the 2014 midterm elections have refocused attention on a number of policy areas–including nuclear waste storage. Although President Obama has consistently championed nuclear power by providing federal loan guarantees for new reactors and placing nuclear power among the “clean energy” sources targeted for an 80 percent share of the nation’s electricity production by 2035, he has also placed the viability of nuclear power in doubt by thwarting efforts to build a high level radioactive waste repository at Yucca Mountain, Nevada. Several newspapers around the country have run editorials arguing that the Yucca Mountain ought to be revived or even, as the Chicago Tribune suggested, “fast-tracked.” Arguments like these emphasize the risks associated with our current interim storage of spent fuel at more than one hundred power plants in close proximity to population centers throughout the country, commitments for disposal capacity the federal government owes utilities and contaminated legacy sites like those in South Carolina and Washington State, and the amount of research and spending that has already been devoted to investigating the suitability of the Yucca Mountain site.

However, it is unlikely that Yucca Mountain will ever receive shipments of nuclear waste. Nevada’s persistent and successful efforts to thwart the Yucca Mountain project and the Nuclear Waste Policy Act of 1982 are likely to continue as they demonstrate the futility of a policy that forces disposal on an unwilling host state. Three years ago the Blue Ribbon Commission on America’s Nuclear Future said as much, recommending instead a “consent-based” approach to siting nuclear waste storage and disposal facilities. How would such an approach work?

For the past three years, Texas has been accepting what so many other states and localities have rejected in past decades- radioactive waste from the nation’s nuclear power plants. A newly opened private facility operated by Waste Control Specialists in Andrews County, Texas has been receiving shipments of low-level radioactive waste from multiple states. This year, the Texas Commission on Environmental Quality has amended the license for the Andrews County site to more than triple its capacity and it can begin accepting “Greater Than Class C Waste”- the most highly radioactive materials in the low-level radioactive waste stream, as well as depleted uranium. Residents and elected officials in Andrews County are now considering whether or not to support a proposal for a high-level radioactive waste disposal facility.

We should take a closer look at past developments in Nevada and more recent decisions in Texas to guide our future nuclear waste policy. These two states are engaging with different aspects of the nuclear waste stream, governed by very different policy approaches. Nevada’s efforts to thwart the Yucca Mountain project are rooted in the coercive approach codified in the Nuclear Waste Policy Act of 1982. In contrast, the willingness of Texas to establish new disposal capacity stems from the Low-level Radioactive Waste Policy Act of 1980—a law that expanded the authority of states hosting disposal sites in an effort to overcome state opposition to waste sites in the midst of an urgent shortage of disposal capacity.

First, let’s consider the troublesome politics that has infused the Nevada case. The Nuclear Waste Policy Act of 1982 established a scientific site selection process for an eastern and western waste repository. However, President Reagan abandoned this process in 1986 by halting the search for an eastern site amid fears of midterm election losses in potential host states of Wisconsin, Georgia and North Carolina. In 1987, Congress abandoned the search for a western site when House Speaker Jim Wright (D-TX), and House Majority Leader Tom Foley (D-WA), amended the law to remove Texas and Washington from consideration. The amended law became known as the “Screw Nevada” plan because it designated Yucca Mountain as the sole site for the waste repository.

While politics effectively trumped science in the selection of Yucca Mountain, opponents- led by Senator Harry Reid of Nevada- have employed politics to effectively thwart the project. In 2005, Reid placed 175 holds on President Bush’s nominations for various executive appointments until Bush finally nominated Reid’s own science advisor, Gregory Jaczko, to the Nuclear Regulatory Commission (NRC).  In 2006 Reid persuaded the Democratic National Committee to move the Nevada caucuses to the front of the 2008 presidential primary calendar, prompting each candidate to oppose Yucca Mountain.  President Obama fulfilled his campaign promise by tapping Jaczko to chair the NRC and dismantling Yucca Mountain. Each year the President’s budget proposals zeroed out funding for the facility, the NRC defunded the license review process and the Department of Energy has continued to mothball the project.  Although court decisions have forced the administration to begin reviewing the project, progress has been slow and in the meantime the Yucca facility offices have been shuttered, workforce eliminated, and computers, equipment and vehicles have been surplused.  Jaczko was forced to resign amidst concern from other NRC members that his management style thwarted decision making processes. However, Jaczko’s chief counsel, Stephen Burns was sworn in as the commissioner of the NRC on November 5, 2014.

We should expect, accept, and plan for such political maneuvering. Our system of locally accountable representatives empowers individual office holders with a wealth of substantive and procedural tools that make all nuclear politics local. Any decision making on this issue will be a political contest to locate or avoid the waste. Consequently, if there is to be a politically feasible nuclear waste repository, it will require a willing host. Money and the promise of jobs alone have not proven alluring enough for acceptance of such a project. We would do better to embrace our decentralized politics and offer the host significant authority over the waste stream.

This is the current situation that Texas enjoys: Congress gave states responsibility for establishing low-level radioactive waste sites and, as an incentive, enabled states to join interstate compacts.  Once approved by Congress, a compact has the authority to accept or decline waste imports from other states, which is a power that is normally not extended to states because it violates the interstate commerce clause of the U.S. Constitution. Texas is in a compact with Vermont, and as host state, Texas shapes the waste market by determining disposal availability for other states. Texas also has authority to set fees, taxes, and regulations for disposal in collaboration with federal agencies. Compacts can dissolve and host states can cease accepting waste altogether at a future date. While even under these provisions most states will refuse to host radioactive waste, the extension of state authority at least courts the possibility (as in Texas) of the rare case that combines an enthusiastic local host community in a relatively suitable location, a supportive state government, and a lack of opposition from neighboring communities and states. This approach better meets our democratic expectations because it confronts the local, state and national politics openly and directly, courting agreement at each level and extending authority over the waste stream to the unit of government bearing responsibility for long term disposal within its borders.

What if we adopt this approach and there is no willing host for spent fuel at a technically suitable site? What if a site is established, but at some future date the host state and compact exercise authority refuse importation or dissolve altogether? We would be left with interim onsite storage- the same result our current predictably failed policy approach has left us in. If there is no willing host, or if long term disposal is less certain due to the host’s authority over the waste stream, we also gain authentic and valuable feedback on societal support for nuclear energy. That is, our willingness to provide for waste disposal in a process compatible with our democratic norms and decentralized political system should influence our decisions on nuclear energy production and waste generation.

Nuclear Power and Nanomaterials: Big Potential for Small Particles

Nuclear power plants are large, complex, and expensive facilities. They provide approximately 19 percent of U.S. electricity power supply,[ref]DOE U.S. Energy Information Administration, Annual Energy Review, 2011.[/ref] and in the process consume enormous quantities of water. However, a class of very small particles may be gearing up to lend a helping hand in making power plants more efficient and less costly to operate. This article will briefly introduce nanomaterials and discuss ways in which some of these particles may make nuclear power plants more efficient.

The race to synthesize, engineer, test, and apply new nanoscale materials for solving difficult problems in energy and defense is in full swing. The past twenty five years have ushered in an era of nanomaterials and nanoparticles – objects with at least one dimension between 1 and 100 nanometers[ref]G.L. Hornyak, Fundamentals of Nanotechnology, 2009.[/ref] – and researchers are now implementing these materials in areas as disparate as neuroscience and environmental remediation. To provide a sense of scale, most viruses are a few hundred nanometers in size, most bacteria are a few thousand nanometers in size, and a period at the end of a sentence is about a million nanometers. This new category of materials has ignited the imaginations of scientists and engineers who envision nanomaterials capable of tackling difficult problems in energy, healthcare, and electronics.

Nanomaterials are not new, and indeed occur naturally all over Earth. This includes viruses, the coatings of a lotus leaf, the bottom of a gecko’s foot, and some finely powdered clays. These objects represent natural materials with significant, and often highly functional, nanoscale features. Some researchers have even discovered signs of nanoscale materials in space.[ref]D.A. Garcia-Hernandez, S. Iglesias-Groth, J.A. Acosta-Pulido, A. Manchado, P. Garcia-Lario, L. Stanghellini, E. Villaver, R.A. Shaw, and F. Cataldo, Astrophys. J. 737, L30, 2011.[/ref] One of the oldest documented applications of nanomaterials dates back to the Lycurgus Cup, a 4th century Roman glass which was made out of a glass containing gold and silver particles. The result is a glass that appears green when lit from the outside, but red when lit from the inside.[ref]I. Freestone, N. Meeks, M. Sax, and C. Higgitt, Gold Bulletin 40, 270-277, 2007.[/ref] The effect results from the glass filtering various wavelengths of light differently depending on the various lighting conditions. Of course, the Romans did not know they were using nanoparticles in the process of making this glass.

But what makes nanoparticles interesting or unique? The answer to this question depends on the specific material and application, but a few themes persist. Because of their small size, the physical principles governing how particles behave and interact with their environments change. Some of these changes are due to how basic properties such as volume and surface area change as an object becomes smaller. As a sphere shrinks, the ratio of the surface area to the volume grows. This has far reaching implications for how particles interact with light, heat, and other particles. Visionary researchers are now looking into ways in which these interesting properties may make nuclear power plants more efficient.

One important implication for our discussion is the flow of thermal energy. Consider the process of transferring the thermal energy of your body from your hands to an ice cube. Clearly, you are (hopefully!) warmer than the ice cube. If you place the ice cube on a chilled dish and touch the ice cube with one finger, the cube will melt, but probably fairly slowly. Placing your entire hand over the top half of the ice cube increases the melting rate, and placing the ice cube in your hand and closing your fist further increases the melting rate. This is an example of thermal energy transfer via conduction. Conductive heat transfer from one object to another depends on the area over which the thermal transfer takes place. A larger contact surface area leads to faster conduction. But how does this relate to nanoparticles? As a particle becomes very small, the ratio of the particle’s surface area to its volume increases very rapidly. Since thermal conduction through volume is a function of surface area, particles with large ratios of surface area to volume are able to change temperature very quickly. If you place a large quantity of small cold particles in a warm body of water, the particles will heat quickly. If you take the same volume of particles, but instead compress it into one large particle, then that large particle will warm slowly. As this surface area to volume ratio increases with decreasing size, a general trend is for smaller particles to transfer heat more effectively than larger particles.



So how does this relate to nuclear power plants? Nuclear power plants are water-intense operations and rely on conductive heat transfer to convert nuclear energy to grid-ready electricity. The most common Western reactors are pressurized water reactors (PWRs) in which water is heated by pumping it through the reactor core, then pumping the hot water to a steam generator. This water flows through piping called the primary system and is kept in the liquid state by applying very high pressure through a device called a pressurizer. In the steam generator this primary system water transfers much of its heat to water in a secondary system. High-strength piping, which is a very effective heat conductor, keeps the water in the two systems from directly contacting each other. The secondary system’s water turns to steam when it absorbs the heat from the primary system. The steam is then directed via piping to drive a turbine, which turns an electric generator, thus completing the cycle of converting nuclear energy to readily usable electricity for the grid. After passing through the turbines, the steam is captured and condensed for recycling. This reclaimed water can then be sent back through the steam generator. However, a significant amount of the energy of this steam is lost to the atmosphere via a third system of cooling water that is used to condense the steam. Large amounts of water (in the form of water vapor) are released to the environment in this process. Think of the water vapor plume at the top of the iconic cooling towers seen in the cartoon TV show The Simpsons. (Not all nuclear power plants use these types of cooling towers, but all must emit heat to the environment through some means of cooling.)

A new class of nanomaterials called core-shell phase change nanoparticles may help in reducing the water loss. First, let’s parse the name of the nanoparticle. The core-shell nomenclature refers to the fact that the particle has a center made out of one material, and an outer skin made out of another material. The phase change component of the name refers to the fact that the particle center changes from a liquid to a solid under certain conditions. These particles may be mixed into the water used for transporting the thermal energy generated within the reactor. Once mixed into the reactor water, the particle cores melt as the water picks up thermal energy from the reactor. The melted material in the particle core is contained by a shell, which remains solid at reactor temperatures. Thus, as the water leaves the reactor it carries with it tiny particles containing bundles of liquid thermal energy wrapped in a solid core. The notion is that as these particles travel to the cooling tower, they solidify and dissipate their heat into the surrounding water, thus decreasing the amount of water needed to convert the thermal energy created by the reactor to steam for turning turbines. Additionally, since these particles do not vaporize, they are much more easily retained for recycling. The Electric Power Research Institute is currently working with scientists at Argonne National Laboratory to commercialize these particles and has suggested that this technology could decrease power plant water requirements by as much as 20 percent.[ref]“Multifunctional Particles for Reducing Cooling Tower Water Consumption,” Electric Power Research Institute, 2012.[/ref]

Another nanoparticle-based approach for increasing reactor efficiency seeks to tackle a different problem. Pressurized water reactors place the water in direct contact with the fuel rods of the nuclear reactor. However, bubbles that form on the surfaces of the fuel rods can significantly decrease efficiency by insulating the rods from the water. When this happens, heat transfer efficiency suffers. One lab at the Massachusetts Institute of Technology (MIT) has implemented alumina nanoparticles that coat the fuel rods and prevent the buildup of bubbles on the heating elements. Alumina, a compound of aluminum and oxygen, is stable and has a high melting temperature. Testing these particles in the MIT reactor, the group found that the alumina nanoparticles coated the fuel rods. The result was an increase in the efficacy of the reactor. The engineers explain the findings by suggesting that the alumina nanoparticles allow for quick removal of the bubbles forming on fuel rod surfaces, thus minimizing the insulating layer of bubbles and maximizing heat transfer efficiency.[ref]S.J. Kim, I.C. Bang, J. Buongiorno, and L.W. Hu, Int. J. Heat Mass Transf., 50, 2007.[/ref] To validate this, the researchers heated identical thin, steel wires a fraction of a millimeter in diameter. One wire was submerged in water, the other in a nanofluid containing alumina particles. The wires were heated to the point of boiling the surrounding fluid. After boiling the wires were examined using a powerful electron microscope. The experimenters observed that the wire heated in the nanofluid was indeed coated with nanoparticles, while the other wire maintained its original smooth surface.

Most importantly, there are also potential safety applications of having nanofluids capable of quickly transporting large quantities of thermal energy. One proposal calls for the use of nanofluids in standby coolant stored in Emergency Core Cooling Systems (ECCS). The ECCS are independent, standby systems designed to safely shut down a reactor in the case of an accident or malfunction. One ECCS component is a set of pumps and backup coolant to be sprayed directly onto reactor rods. Such systems are critical in preventing a loss of coolant accident (LOCA) from spiraling out of control. Because ECCS have backup reservoirs of coolant, technologies that make this backup coolant more effective at removing heat from the reactor could improve the safety of reactors. Because nanofluids can increase the heat transfer efficacy of water by 50 percent or more, some researchers have suggested that they may also be useful in emergency scenarios.[ref]R. Taylor, S. Coulomb, T. Otanicar, P. Phelan, A. Gunawan, W. Lv, G. Rosengarten, R. Prasher, and H. Tyagi, J. Appl. Phys. 113, 011301, 2013.[/ref]

Steam generators at both nuclear and coal power plants accounts for approximately 3 percent of overall freshwater consumption in the United States. Generally speaking, nuclear power plants consume about 400 gallons of water per megawatt-hour (MWh). Their coal and natural gas counterparts consume approximately 300 and 100 gallons per MWh, respectively.[ref]“Water Use and Nuclear Power Plants,” Nuclear Energy Institute, 2013.[/ref] Thus, nuclear power plants stand to gain considerably by becoming more water-efficient.

However, there are many hurdles to tackle before nanoparticles can be safely and effectively used in operating power plants. Scaling up particle production to the large volumes of particles necessary for implementation in a power plant is expensive and labor intensive. New synthesis infrastructures may be necessary for large-scale production of these tiny particles. Additionally, broad adoption of this technology will not occur until significant cost savings are proven effective at a functioning plant. As a result, particles must be made available at a cost reasonable for adoption by power plant operators. A rough cost estimate can be made using commercially available alumina nanoparticles, as these particles have been tested extensively in the heat transfer literature. A typical nuclear power plant in the United States supplies enough electricity to power 740,000 homes. To do this, the plant requires between 13 and 23 gallons of water per home per day.8 Thus, water usages for the plant may range from 10 to 17 million gallons per day. Current vendors of aluminum oxide nanoparticles sell 1kg of nanopowder for around $200. With an expectation that economies of scale would bring that price down to $100/kg and that the particles could be easily recovered and recycled, loading a nuclear power plant with a 0.1% volume fraction of alumina nanoparticles would cost about $14.7 to $25 million per power plant. This is a substantial initial investment. Naturally, if nanoparticles were to cost $10/kg, then particle outfitting costs of $1.5 to $2.5 million per nuclear plant could be achieved. If 100 percent recovery of the particles could be achieved, then this initial cost would be recovered over time by the expected 2 to 4 percent increase in plant efficiency.

In addition to cost-benefit analysis, extensive testing must be performed to ensure long-term application of these particles does not threaten the operational safety of the plant. To accomplish this, smaller scale reactors (like those housed at research facilities and universities) may test these particles over the course of years to track the impacts of long-term use. Potential pitfalls include increased corrosion, system clogging, and nanoparticle leakage into wastewater. Corrosion engineers will be needed to validate the degree to which nanoparticles contribute to the overall aging of reactors in which they are used. Nanoparticle designers and hydrodynamicists will be needed to ensure that system clogging is manageable. Additionally, filtration experts and the Environmental Protection Agency will be needed to establish best practices for minimizing the amount of nanomaterial that exits the facility, as well as understanding and quantifying the environmental impacts of that emitted material. None of these potential roadblocks are trivial. However, while the challenges seem large, it is encouraging to see potential applications of nanotechnology in power plants.


A Looming Crisis of Confidence in Japan’s Nuclear Intentions

Nearly two years into Prime Minister Shinzo Abe’s second stint at governing Japan, his tenure has been characterized by three primary themes. The first two themes include his major legislative priorities: enabling Japan’s economic revival and bringing Japan closer to the status of a “normal” country that takes on a greater share of its own security needs. Both of these priorities are largely celebrated in the United States, which longs to see Japan become a more able and active partner in the region.  A third theme has not been well received in Washington: the prime minister’s apparent efforts to whitewash Japan’s wartime past.  Through personal expressions of admiration for convicted war-criminals, an official reinvestigation of past apologies for war-time atrocities, and appointments of hardline nationalists to prominent posts (such as the NHK board of governors), the prime minister’s actions have raised the spectre among wary neighbors of a Japanese return to militarism and begun raising eyebrows even among friends in Washington.

It is against this backdrop that Japan is now attempting to reinstate its nuclear energy program.  Japan, which, not long ago, had planned to generate half of its electricity from nuclear power by 2030, has watched its nuclear reactors sit largely idle since the Fukushima disaster in 2011. Abe’s government views nuclear restarts as a critical pillar of his first legislative priority—Japan’s economic recovery.  However, observers both outside and inside Japan note that, in addition to providing Japan the baseload electricity that its economy craves, the country’s sophisticated nuclear energy program effectively serves a dual purpose, providing Japan a latent nuclear weapons capability as well.

Citing Abe’s particular treatment of historical issues, some have begun to question whether reinstatement of Japan’s nuclear program is really more about the prime minister’s security goals than his economic agenda. China, for one, has hinted at allegations of a Japanese nuclear weapons program—after a recent incident in which Japan negotiated to repatriate an aging store of highly enriched uranium (HEU) to the United States, Chinese media propagated a narrative that twisted the event into evidence of Japan’s militaristic intentions.[ref]See for example: Chong Liu, “Japan’s Plutonium Problem.” China Internet Information Center, 21 March 2014. Web. 23 September 2014.[/ref] Koreans have begun expressing similar concerns.[ref]See for example: “Is Japan Going Nuclear?: The international Community Ought to Strongly Say ‘No.’” The Korea Times. Hankook Ilbo, 14 March 2014. Web 23 September 2014.[/ref]

In fact, Japan’s current movement towards a more normal military posture is not entirely unrelated to the push to restart the country’s nuclear energy program—it was the Fukushima nuclear disaster that both idled Japan’s nuclear fleet and helped enable the return of the more hawkish LDP government. But the relationship likely ends there.  As a legacy of World War II, Japanese society’s discomfort with the idea of a “normal” Japan has restricted Abe’s normalization efforts to steps that are only modest by any comparable measure.[ref]Green, Michael and Jeffrey W. Hornung, “Ten Myths about Japan’s Collective Self-Defense Change.” The Diplomat. 10 July 2014. Web 27 October 2014.[/ref] Events that have conspired to suggest the possibility of Japanese nuclear weapons are reflective of awkward timing and, perhaps, less than acute politics, but not likely of some new militant spirit in Japanese society. Unfortunately, as Japan pushes to restart its nuclear energy program in the months and years ahead, circumstances are aligning that will amplify—not mitigate—alarm over Japan’s nuclear intentions.


Japan’s Plutonium Economy

For a tangle of social and legal reasons, the restart of Japanese reactors is tied together with operation of Japan’s nuclear fuel reprocessing plant at Rokkasho Village in Aomori Prefecture.  Under agreements with reactor host communities, utilities cannot operate reactors unless there is somewhere for nuclear fuel to go once it has been used.  Because Japan lacks a geological repository and nearly all plant sites lack dry cask storage facilities,[ref]Fukushima Daiichi, coincidentally, is one of two exceptions.  There is some evidence that, post-Fukushima, momentum may be building for acceptance of on-site interim storage.  In 2013, the Governor of Shizuoka Prefecture, which hosts the Hamaoka Nuclear Power Plant, broke with precedent in suggesting that the plant should develop interim storage as an enhanced safety measure.[/ref] Rokkasho is currently the only viable destination for spent fuel from Japan’s reactors. Unless this situation changes, Japan is effectively unable to operate reactors without Rokkasho.

Rokkasho itself is, in turn, effectively dependent on Japan’s operating reactors.  According to a sort of public-private arrangement that has been in place since before Fukushima, Japanese utilities send spent nuclear fuel to Rokkasho, where it is separated into waste and fissionable MOX (mixed uranium and plutonium oxides) powder.  MOX is processed into fresh reactor fuel and sent back to Japan’s reactors.  High-level waste is ultimately sent to a geological repository that is to be built in a different prefecture (one of Aomori Prefecture’s conditions for originally agreeing to host the reprocessing plant). Of Japan’s reactors, 16 to 18 of the 54 that were operating prior to the Fukushima accident would, after receiving local government consent, consume MOX in an effort to maximize use of Japan’s limited energy resources.  That was the plan—prior to the Fukushima disaster, anyway.

As a legacy of the Fukushima disaster, Japan’s nuclear reactors currently sit idle.  The six at Fukushima Daiichi will never operate again, nor will a number of others that are older, particularly vulnerable to earthquakes and tsunamis, or for other reasons not worth the trouble and expense of restarting.  While impossible to predict for certain, a consensus seems to be emerging among experts and industry watchers that post-Fukushima, somewhere in the order of half of Japan’s original 54 reactors will return to service under Japan’s new regulatory regime. Currently, two reactors (Sendai 1 and 2 in southwestern Japan) have cleared safety reviews from Japan’s new regulator, the Japan Nuclear Regulatory Authority (JNRA), and now appear headed towards restart this winter.  Eighteen more reactors await review from the JNRA. Of those 20 reactors, only five[ref]Three further Japanese reactors had received approvals for MOX but have not applied for restart authorization.[/ref] have received consent to use MOX, but that was prior to Fukushima.  All 20 reactor restarts depend on the promise of a functioning Rokkasho. But if Rokkasho were to restart on a similar timeframe as the reactors, one thing is certain—there will be far fewer than the originally envisioned 16 to 18 reactors available to consume the MOX when the plant starts up.[ref]Furthermore, the plant that will fabricate the MOX powder into reactor fuel is not planned to be operational until October 2017, meaning that any MOX powder produced by Rokkasho will have to wait until after that date to be consumed, the status of Japanese MOX-burning reactors notwithstanding.[/ref]


Reactor Restart X-Factors

As with Rokkasho, the question of when the JNRA will conclude its reviews of the next eighteen reactors remains quite murky.  However, it stands to reason that ultimately most, if not all, of the reactors that have applied for restart will ultimately pass safety inspections.  Japan’s electric power companies are unlikely to have invested the time and resources in plant upgrades and regulatory application had they less than a high degree of confidence that they would qualify under Japan’s new regime.  Likewise, there is little question that Japan’s LDP government (assuming an LDP government at the time of restart) would stand in the way of restarts.  But the JNRA and national government are only two of the three main factors in restarting Japan’s reactors—leaders of the towns and prefectures that host nuclear power plants have a de facto say in the matter as well.

The conventional wisdom is that local leaders have strong financial incentives to restart the nuclear power plants that they host: government and industry have historically lavished incentives on host communities and prefectures in order to overcome any inclination toward local resistance. In one sense, local governments have over time become dependent on plants and can ill afford to forego not only the government and utility incentives, but also the base of jobs and tax revenues they represent.  On the other hand, communities need now only look to the example of the towns that have been rendered uninhabitable by the Fukushima disaster to see a terrifyingly clear picture of their tradeoff.

In some cases, apparently including the Sendai reactors, it is unlikely that local government would stand in the way of restarts.  Earthquakes are less common in Kyushu,[ref]Kyushu, the island on which the Sendai Nuclear Power Plant is located, is one of four main islands that comprise the Japanese archipelago.  Kyushu sits to the southwest of Japan’s main island, Honshu, where Fukushima Daiichi is located roughly in the center, on the Pacific coast.  The Sendai reactors are located approximately 700 miles southwest of Fukushima Daiichi.[/ref] the geography on the west coast is less prone to large tsunamis, and local residents may take comfort in the fact that Sendai reactors are pressurized water reactors—not the boiling water rector type used at Fukushima Daiichi.  But in other cases, local approvals may not be as certain. Take for example TEPCO’s Kashiwazaki-Kariwa plant in Nagano prefecture, where Governor Izumida has very publicly challenged TEPCO.  He has insisted that, irrespective of the findings of the JNRA, with the Fukushima Daiichi reactor cores still too highly radioactive to investigate and verify the true nature of the accident, he will be unwilling to allow the Kashiwazaki-Kariwa reactors to restart.

In addition to the local government factor, an X-factor may be emerging—preemptive lawsuits against reactor restarts. Earlier this year, in Fukui prefecture where political leadership otherwise favors nuclear power, a citizens group brought a lawsuit alleging an inadequate basis for confidence in the restart of the Oi plant.[ref]Ota Ko. “Fukui court deals setback to Kansai Electric bid to restart Oi reactors.” The Asahi Shimbun AJW. The Asahi Shimbun. 21 May 2014. Web. 23 September 2014.[/ref] More recently, a second lawsuit has been brought by the city of Hakodate (Hokkaido prefecture) against the yet-to-be completed Ohma plant in nearby Aomori prefecture.[ref]Isozaki Kozue. “Court hears first arguments in Oma nuclear plant lawsuit.” The Asahi Shimbun AJW. The Asahi Shimbun. 4 July 2014. Web. 23 September 2014.[/ref] In the case of Oi, a local judge sided with the plaintiffs, but the decision has been appealed by Kansai Electric Power Company, and the case is all but certain to drag out until long past the serviceable lifetime of the Oi reactors.  The Hakodate case is ongoing.

It is possible that Governor Izumida is an outlier and that the Fukui and Hakodate challenges will prove to be ineffective and isolated. However, it is equally possible that there are more Governor Izumidas and lawsuits yet to come. Furthermore, what is undeniable is that these cases have set a precedent and raised public pressure on local officials to seriously consider opposing restart of local reactors even if they do pass JNRA safety inspections. In any case, it is premature to presume that once the JNRA has rendered a safety verdict, reactor restart is imminent.


The MOX Question

Within the concurrent push to open Rokkasho and restart reactors, the availability of MOX-burning reactors seems to be assumed. But, notwithstanding all of the other hurdles facing nuclear reactor restarts in Japan, MOX fuel itself has been a subject of controversy and public discomfort since even before the Fukushima disaster.  As utilities received approvals to burn MOX fuel and subsequently began receiving shipments of MOX from Europe (where it had been processed on behalf of Japan’s utilities), they were met with consistent and passionate public protests.  These protests were typically confined to a cohort of smaller national-level interest groups that argue that using MOX elevates risk in transportation and regular reactor operation.[ref]By coincidence, Fukushima Daiichi Unit 3 was one of only four reactors in Japan that were using MOX fuel at the time of the accident, and, as the American Nuclear Society argues, MOX has not yet been shown to have contributed to the disaster any differently than the conventional fuel in Units 1 and 2. See: Brady Raap, Michaele. The Impact of Mixed Oxide Fuel Use on Accident Consequences at Fukushima Daiichi. Chicago, Il: American Nuclear Society. American Nuclear Society Technical Brief, March 2011. Available at[/ref]  On a national scale, prior to Fukushima the fuel cycle has been a relatively fringe issue—MOX had been a largely unfamiliar acronym to the public.  Post-Fukushima, as utilities push for restarts amidst an atmosphere of heightened public scrutiny, there will be no free pass for MOX.  For nuclear energy opponents, the prospect of MOX usage would provide one more narrative with which to hammer against proposed reactor restarts.

At the macro level, utilities share in the incentive to burn MOX fuel as they depend on Rokkasho, and Rokkasho is hard to rationalize in the absence of a functioning MOX program. However, in a much more tangible and immediate sense, utilities desperately need their reactors up and running again.  Most of Japan’s utilities have posted consistent losses since their reactors were relegated to nonperforming assets on their balance sheets and they were forced to substitute expensive fossil fuels for relatively cheaper nuclear power.  For Japan’s utilities, restarting nuclear reactors could be a life or death proposition.  That being the case, can it be taken for granted that utilities will risk complicating their restart efforts by forging ahead with plans to burn MOX?  Will the government create explicit incentive for utilities to do so?  Given enhanced public scrutiny, it cannot be assumed that the pre-Fukushima local approvals for MOX usage will be honored anyway.

The Japanese government’s 2014 energy policy (despite reaffirming Japan’s commitment to its beleaguered ‘no surplus plutonium’ policy), gives blessing to proceeding with Rokkasho (recognizing that, among other things, if it didn’t, Aomori threatens to send the spent nuclear fuel right back to the plants of origin). But even assuming that the five MOX reactors under regulatory review do receive restart approval and recommence MOX burning, the original goal of 16 to 18 Japanese reactors burning MOX fuel seems far off.[ref]It is worth noting that one of these sixteen to eighteen reactors was to include the under-construction Ohma plant in Aomori prefecture, but as previously noted, Ohma is subject of an ongoing lawsuit.[/ref] There has been some suggestion that Rokkasho could restart slowly, at a throughput commensurate with the ability to consume MOX.  However, as Meiji University Professor Tadahiro Katsuta points out, reducing throughput of Rokkasho effectively raises the per-unit cost of MOX, necessitating a reexamination of the cost basis on which the MOX program was justified to Japanese ratepayers.[ref]Katsuta Tadahiro, “The Influence of the Fukushima Accident on Japan’s Reprocessing Policy and the Challenges Ahead” (working paper, Graduate School of Humanities, Meiji University, 2014).[/ref]


Rokkasho Controversy

Even outside of the MOX capacity question, Rokkasho is not without controversy.  Officially, Rokkasho is justified as an investment in energy security for Japan. However, from the standpoint of global nonproliferation concerns, Japan sets an uncomfortable precedent with Rokkasho.  While otherwise a leading global champion for peace and nuclear disarmament, Japan is the only non-nuclear weapons country to possess a commercial nuclear fuel recycling program. Whereas global nonproliferation efforts prioritize limiting the spread of reprocessing capabilities, Rokkasho has enabled Iran, for one, to point to Japan in defending the legitimacy of its own fuel cycle activities.  South Korea, seeking American consent for a Korean recycling program, also cites Japan’s example in negotiating a replacement for the U.S.-ROK nuclear cooperation agreement that expires in 2016.

Controversial or not, Japan’s leaders feel compelled to push forward with Rokkasho and through an agreement under section 123 of the Atomic Energy Act,[ref]Section 123 of the United States Atomic Energy Act requires so-called “123 agreements” determining the conditions for nuclear cooperation with a given foreign state.  For further details, see: “The U.S. Atomic Energy Act Section 123 At a Glance.” Arms Control Association, 2013. Web 27 October 2014.[/ref] they enjoy the support of the United States government. American consent to Rokkasho is only guaranteed through 2018, but the United States, which granted consent in 1988 largely out of deference to diplomatic concerns, for the same reason is highly unlikely to withdraw consent in 2018. Given the effective concurrence of the 2018 date with U.S.-ROK negotiations and the looming startup of Rokkasho in the face of low (or no) capacity to consume MOX, timing has become extremely awkward.

As Rokkasho proceeds towards restart, public reaction from Washington has been surprisingly muted.  Perhaps this reflects appreciation for the energy conundrum in which Japan finds itself, or tacit consent that bringing Japan’s nuclear industry back onto solid footing after the Fukushima disaster was always going to be awkward—Japan has an inherent chicken or egg dilemma in restarting Rokkasho and its reactors. But the reality is that Japan’s situation puts Washington in a very tough spot.  Washington is effectively complicit in what might appear to be Japanese disregard for its own commitments to global nonproliferation.  This poses a risk to the global nonproliferation regime and American credibility on the subject.



Global nonproliferation principles undoubtedly remain a high priority for Japan.  But it is likely that in the short term, the eyes of Japan’s leaders are focused more intently on bringing nuclear reactors back on line. Particularly in the context of Prime Minister Abe’s provocative views on history, the perception outside of Japan is certain to be one of alarm if Japan is seen to be separating plutonium without a credible pathway for its disposition.  While the coincidence of the 2016/2018 Korea and Japan 123 agreements and Japan’s reentry into nuclear energy will shine a spotlight on the American role in Japan’s nuclear fuel cycle scheme, it is seen as highly unlikely that the United States will attempt to withdraw from or renegotiate the 123 agreement with Japan irrespective of Japan’s plutonium balance concerns.  This will effectively make the United States appear complicit in Japan’s growing inventory of plutonium.

For the United States, this situation has consequences on three fronts.  Firstly, Japan’s apparent failure to abide by its plutonium commitments undercuts American interests in limiting fuel cycle capabilities through treaty agreements. Nowhere is this more obvious than in the ongoing U.S.-ROK 123 agreement negotiations. Secondly, Japan is a leader, if not the symbolic face of the global nonproliferation regime. For Japan to be separating plutonium for no demonstrable purpose dramatically undercuts its own leadership on nonproliferation and aggravates the already controversial precedent it sets with its fuel cycle program, elevating the risk of proliferation in the region. Thirdly, at just the time when the United States is working to underscore its alliance with Japan as the bedrock of its security presence in East Asia, Japan’s growing plutonium surplus will only exacerbate concerns of Japan’s return to militarism, eroding its legitimacy and efficacy as a partner in regional security.

In the aftermath of the Fukushima disaster, the United States has appeared somewhat ambivalent in its response to Japan’s efforts to restart its nuclear energy system.  However, the American stake in Japan’s road ahead is profound. While it is not the case in all foreign capitals, in Tokyo, opinions and preferences from Washington are meaningful. Washington, particularly the Department of State and Department of Energy, has an opportunity to protect American interests by formulating and articulating an unambiguous American position on Japan’s path forward on nuclear energy to Japan’s leadership.

The critical interest of the United States would be for Japan to demonstrate clear commitment to the no-surplus plutonium policy and to the global nonproliferation regime.  As elements of a policy that might be necessary to make that happen, the United States should urge Japan’s leadership and utilities to:

  • Articulate a plan for plutonium disposition that provides quantifiable and publicly demonstrable benchmarks for reducing Japan’s plutonium inventory.
  • Call for official, temporary suspension of operations at Rokkasho until MOX burners or another credible disposition pathway for Japan’s separated fissile materials, is available.
  • Advocate operating Rokkasho (if and when started), at an output rate that is no more than commensurate with plutonium disposition goals and available means for plutonium disposition.
  • Encourage utilization of temporary dry-cask storage of spent nuclear fuel in order to enhance safety at reactor sites while expanding nuclear fuel cycle policy options. One of the rare positive stories to emerge from the Fukushima Daiichi disaster was the robustness of dry cask storage. Utilities and the government should capitalize on this success story and prioritize arrangements with local communities to allow for expeditious transfer of spent nuclear fuel from wet-storage to on-site dry casks.

There is no nuclear weapons program in Japan’s foreseeable future. However, there is a significant risk of an outward appearance that suggests otherwise to South Korea, China, North Korea, Iran, and the rest of the world.  Whether or not appearance differs from reality, the real world consequences would likely be the same. While Japan has serious and immediate energy concerns, it also has a very deep and fundamental commitment to global nonproliferation. With support from friends in Washington, Japan must face its looming nuclear energy challenges head on with eyes fully open. The stakes are too high to allow current circumstances to dictate their own outcomes.

Next year is the 70th anniversary of the atomic bombings of Hiroshima and Nagasaki.  The event would provide a fitting platform for Prime Minister Abe to recognize opportunities in Japan’s current crisis and make bold decisions on Japan’s nuclear energy program.  The right decisions can help regain global confidence in Japan’s intentions, while reminding the world of Japan’s unwavering commitment to nuclear safety and nonproliferation. The anniversary would make an equally unfortunate occasion to demonstrate otherwise.


Ryan Shaffer is an Associate Director of Programs at the Maureen and Mike Mansfield Foundation in Washington, D.C., where he manages Japan and Northeast Asia policy programs including the Mansfield-FAS U.S.-Japan Nuclear Working Group. Prior to joining the Mansfield Foundation, Mr. Shaffer served as a research analyst for the Federation of Electric Power Companies of Japan.


Advancing U.S. Leadership in Nonproliferation and Nuclear Energy through Effective Partnerships

Although the United States still has the largest number of nuclear power plants in the world, it does not dominate global nuclear power. While the United States was the leading nuclear power supplying nation more than thirty years ago—at least for states outside of the Soviet sphere of influence—the reality today is clearly that the U.S. nuclear industry is only one of several major suppliers. The United States can no longer build a large nuclear power plant on its own. Foreign nuclear companies own major U.S. nuclear power companies.

In addition, the United States no longer supplies the majority of the world’s enriched uranium for nuclear fuel; instead, the United States Enrichment Corporation has shut down its enrichment plants based on gaseous diffusion and has been struggling to commercialize the American Centrifuge Project partly due to reduced global demand for enriched uranium and also due to competition from established enrichment companies.

Nonetheless, the United States continues to have great influence on the nuclear market because many of the major supplying nations have built their nuclear power programs on the basis of U.S. technology. In a new issue brief, FAS President Dr. Charles Ferguson takes a look at options for the United States to gain back leadership via a cooperative approach. The brief analyzes what nations could be effective partners for the United States in furthering nonproliferation while providing for the continued use of peaceful nuclear energy. The nuclear industry is increasingly globalized and the United States needs to partner with allies and other nations to advance nonproliferation objectives.

View Full Brief


Luncheon Briefing on Advanced Nuclear Reactors

Luncheon Briefing: Making the Next Step Forward with Advanced Nuclear Reactors: Assessing Progress and Overcoming Roadblocks on Safety, Technology and Policy


Thursday, July 24, 2014

11:30 a.m. – 1:30 p.m.

Rayburn House Office Building, Room B-318

Washington, DC


The Federation of American Scientists (FAS) and the American Nuclear Society (ANS) hosted a workshop that addressed the state of the safety, science, and technology for advanced nuclear reactors and discussed policy considerations to overcome roadblocks to their development and adoption.

Briefing Materials for the event can be found below.


Presentation Slides: Past, Present and Future of Nuclear Power in U.S., Dr. Peter B. Lyons, Assistant Secretary for Nuclear Energy, Department of Energy

Fast Reactor Technology: A Path to Long-Term Energy Sustainability, American Nuclear Society

Enabling a Sustainable Nuclear Energy Future, Argonne National Laboratory

PROTEUS: Simulation Toolset for Reactor Physics and Fuel Cycle Analysis, Argonne National Laboratory

SHARP: Reactor Performance and Safety Simulation Suite, Argonne National Laboratory

Consortium for Advanced Simulation of Light Water Reactors (CASL), U.S. Department of Energy

A Look Inside America’s Source of Energy and Security Solutions, Idaho National Laboratory

Solving Big Problems: Science and Technology at Oak Ridge, Oak Ridge National Laboratory



11:20 a.m. – Luncheon and Registration

11:30 a.m. – Opening Address by Dr. Charles D. Ferguson, President, Federation of American Scientists

  • Keynote Speaker: Dr. Peter B. Lyons, Assistant Secretary for Nuclear Energy, Department of Energy

11:45 a.m. – Panel Session One: What is the current state of U.S. science and technology for advanced nuclear reactors?

Moderator: Dr. Mark Peters, Argonne National Laboratory


  • Dr. Leslie Dewan, Transatomic Power
  • Dr. Dan Ingersoll, NuScale
  • Dr. Hussein Khalil, Argonne National Laboratory
  • Dr. Doug Kothe, Oak Ridge National Laboratory
  • Dr. John Parmentola, General Atomics

12:30 p.m. – Panel Session Two: What policies and partnerships might increase the NRC’s consideration of and funding for new nuclear technologies?

Moderator: Dr. Kennette Benedict, Executive Director and Publisher of the Bulletin of the Atomic Scientists


  • Dr. George Apostolakis, former NRC Commissioner
  • Mr. David Blee, Nuclear Infrastructure Council
  • Mr. Phil Hildebrandt, Idaho National Laboratory
  • Mr. Craig Piercy, American Nuclear Society
  • Mr. Daniel Stout, Tennessee Valley Authority


Japan’s Role in Asia’s Nuclear Security

In a new article published by the Wilson Center, Japan Fellow Hideshi Futori examines Japan’s role in the development of nuclear energy. Japan has the potential to serve as a role model for the safe and peaceful use of nuclear energy with close ties to the U.S. nuclear sector and the recent growth of nuclear power in Asia.

Japan needs efficient, reliable and safe reactors in a region where the demand for nuclear power is growing. Post- Fukushima, there is strong public opposition to nuclear power and Japanese political leaders have yet to make a clear decision on global nuclear energy development. Other factors that play a factor in Japan’s decision are China’s nuclear energy needs and security and Japan’s cooperation with the United States on the development of new nuclear products for civilian use.

Read the article here. 

Event: Pandora’s Promise Screening

On Thursday, January 16, 2014, FAS President Dr. Charles Ferguson will participate in a screening and panel discussion regarding the film Pandora’s Promise and the future use of nuclear energy held at Middlebury College in Middlebury, Vermont.

The screening and discussion is free and open to the public and begins at 3pm.

For more information, visit the event page. 

A foolish consistency

EmersonConsistency is good – there’s a sense of security in knowing that some things will generally remain constant over time. We can always count on gravity, for example, to hold us firmly to the ground; politicians are typically pandering and self-serving; I can count on radioactivity to consistently decay away; and so forth. Of course, not all consistency is good – as Emerson noted, “A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines.” We can also count on the American public to consistently question whether or not evolution actually occurs; many of us know that our perfectionist boss will always insist on yet another round of reviews and edits before letting a document go out the door; we will always find people who are apparently proud of their lack of knowledge; and we can expect that a certain category of blogger will continue to see the end of the world on the near horizon. It is this latter category I’d like to talk about this time – particularly the batch that continues to insist that the reactor accident at the Fukushima Dai’ichi site is going to kill millions.

Before launching into this piece I’d like to point you to a wonderful counter-example of what I just said – a blog posting by oceanographer and University of Washington professor Kim Martini. I have been accused of being part of the pro-nuclear and/or pro-radiation lobby because of my long years of experience as a radiation safety professional – Dr. Martini told me that she became interested in this topic, researched it herself, and came to her conclusions independently of the nuclear energy and radiation safety professionals. In short, she is scientifically competent, intelligent, and has no reason to be biased either pro- or anti-nuclear.

The latest round of Fukushima silliness is the contention that Americans need to evacuate the West Coast because of an apparently imminent release from one or more of the affected reactors and/or the Reactor 4 spent fuel pool. There are also those who blame the Fukushima accident for massive starfish die-offs, for sick animals along the Alaskan coast, and more – all of which (according to the good Dr. Martini) are far from accurate. And anti-nuclear activist Helen Caldicott has gone as far as to state that the entire Northern Hemisphere might need to be evacuated if things get as bad as she fears and the Unit 4 spent fuel pool collapses. So let’s see what the facts are, what the science can tell us, and what the real story might be.

Can the melted reactors go critical?

There have been predictions that the ruined reactor cores will somehow achieve criticality, producing more fission products and spreading more contamination into the water. While this is not strictly speaking impossible it is highly unlikely – sort of like saying that it is remotely possible that Bill Gates will leave me his fortune, but I’m still contributing to my 401(k) account. To achieve criticality (to a nuclear engineer or a reactor operator, “criticality” simply means that the reactor is operating at a constant power) requires reactor fuel that’s enriched to the right percentage of U-235, a critical mass of the uranium (enough to sustain a chain reaction), and it has to be in a configuration (the critical geometry) that will permit fission to occur. Also important in most reactors is a moderator – a substance such as water that will slow neutrons down to the point where they can be absorbed and cause the U-235 atoms to fission. In reactors such as the ones destroyed in Fukushima require all of these components to achieve criticality – take away any one of them and there will be no fission chain reaction.

The ruined reactor cores meet some of these requirements – since they’d been operating at the time of the accident we know that they had a critical mass of sufficiently enriched uranium present. Surrounded by water (either seawater or groundwater), they are likely also immersed in a moderator. But absent a critical geometry the cores cannot sustain a fission chain reaction. So the question is whether or not these cores can, by chance, end up in a critical geometry. And the answer to this is that it is highly improbable.

Consider, for example, the engineering and design that goes into making a nuclear reactor core. Granted, much of this design goes into making the reactors as efficient and as cost-effective to operate as possible, but the fact is that we can’t just slap some uranium together in any configuration and expect it to operate at all, let alone in a sustained fashion. In addition, reactors keep their fuel in an array of fuel rods that are immersed in water – the water helps slow the neutrons down as they travel from one fuel element to the next. A solid lump of low-enriched uranium has no moderator to slow down these neutrons; the only moderated neutrons are those that escape into the surrounding water and bounce back into the uranium; the lumps in a widely dispersed field of uranium will be too far apart to sustain a chain reaction. Only a relatively compact mass of uranium that is riddled with holes and channels is likely to achieve criticality – the likelihood that a melted core falling to the bottom of the reactor vessel (or the floor of the containment) would come together in a configuration that could sustain criticality is vanishingly low.

How much radioactivity is there?

First, let’s start off with the amount of radioactivity that might be available to release into the ocean. Where it comes from is the uranium fission that was taking place in the core until the reactors were shut down – the uranium itself is slightly radioactive, but each uranium atom that’s split produces two radioactive atoms (fission fragments). The materials of the reactor itself become radioactive when they’re bombarded with neutrons but these metals are very corrosion-resistant and aren’t likely to dissolve into the seawater. And then there are transuranic elements such as plutonium and americium formed in the reactor core when the non-fissioning U-238 captures neutrons. Some of these transuranics have long half-lives, but a long half-life means that a nuclide is only weakly radioactive – it takes 15 grams of Pu-239 to hold as much radioactivity as a single gram of radium-226 (about 1 Ci or 37 GBq in a gram of Ra-226), and the one gram of Cs-137 has about as much radioactivity as over a kilogram of Pu-239. So the majority of radioactivity available to be released comes from the fission products with activation and neutron capture products contributing in a more minor fashion.

This part is basic physics and simply isn’t open to much interpretation – decades of careful measurements have shown us how many of which fission products are formed during sustained uranium fission. From there, the basic physics of radioactive decay can tell us what’s left after any period of decay. So if we assume the worst case – that somehow all of the fission products are going to leak into the ocean – the logical starting place is to figure out how much radioactivity is even present at this point in time.

In January 2012 the Department of Energy’s Pacific Northwest National Laboratory (PNNL) used a sophisticated computer program to calculate the fission product inventory of the #1 and #3 reactors at the Fukushima Dai’ichi site – they calculated that each reactor held about 6.2 million curies (about 230 billion mega-becquerels) of radioactivity 100 days after shut-down. The amount of radioactivity present today can be calculated (albeit not easily due to the number of radionuclides present) – the amount of radioactivity present today reflects what there was nearly three years ago minus what has decayed away since the reactors shut down. After 1000 days (nearly 3 years) the amount of radioactivity is about 1% of what was present at shutdown (give or take a little) and about a tenth what was present after 100 days. Put all of this together and accounting for what was present in the spent fuel pools (the reactor in Unit 4 was empty but the spent fuel pool still contains decaying fuel rods) and it seems that the total amount of radioactivity present in all of the affected reactors and their spent fuel pools is in the vicinity of 20-30 million curies at this time.

By comparison, the National Academies of Science calculated in 1971 (in a report titled Radioactivity in the Marine Environment) that the Pacific Ocean holds over 200 billion curies of natural potassium (about 0.01% of all potassium is radioactive K-40), 19 billion curies of rubidium-87, 600 million curies of dissolved uranium, 80 million curies of carbon-14, and 10 million curies of tritium (both C-14 and H-3 are formed by cosmic ray interactions in the atmosphere).

How much radioactivity might be in the water?

A fair amount of radioactivity has already escaped from Units 1, 2, and 3 – many of the volatile and soluble radionuclides have been released to the environment. The remaining radionuclides are in the fuel precisely because they are either not very mobile in the environment or because they are locked inside the remaining fuel. Thus, it’s unlikely that a high fraction of this radioactivity will be released. But let’s assume for the sake of argument that 30 million curies of radioactivity are released into the Pacific Ocean to make their way to the West Coast – how much radioactivity will be in the water?

The Pacific Ocean has a volume of about 7×1023 ml or about 7×1020 liters and the North Pacific has about half that volume (it’s likely that not much water has crossed the equator in the last few years). If we ignore circulation from the Pacific into other oceans and across the equator the math is simple – 30 million curies dissolved into 3×1020 liters comes out to about 10-13 curies per liter of water, or about 0.1 picocuries (pCi) per liter (1 curie is a million million pCi). Natural radioactivity (according to the National Academy of Sciences) from uranium and potassium in seawater is about 300 pCi/liter, so this is a small fraction of the natural radioactivity in the water. If we make a simplifying assumption that all of this dissolved radioactivity is Cs-137 (the worst case) then we can use dose conversion factors published by the US EPA in Federal Guidance Report #12 to calculate that spending an entire year immersed in this water would give you a radiation dose of much less than 1 mrem – a fraction of the dose you’d get from natural background radiation in a single day (natural radiation exposure from all sources – cosmic radiation, radon, internal radionuclides, and radioactivity in the rocks and soils – is slightly less than 1 mrem daily). This is as close as we can come to zero risk.

This is the worst case – assuming that all of the radioactivity in all of the reactors and spent fuel pools dissolves into the sea. Any realistic case is going to be far lower. The bottom line is that, barring an unrealistic scenario that would concentrate all of the radioactivity into a narrow stream, there simply is too little radioactivity and too much water for there to be a high dose to anyone in the US. Or to put it another way – we don’t have to evacuate California, Alaska, or Hawaii; and Caldicott’s suggestion to evacuate the entire Northern Hemisphere is without any credible scientific basis. And this also makes it very clear that – barring some bizarre oceanographic conditions – radioactivity from Fukushima is incapable of causing any impact at all on the sea life around Hawaii or Alaska let alone along California.

Closing thoughts

There’s no doubt that enough radiation can be harmful, but the World Health Organization has concluded that Fukushima will not produce any widespread health effects in Japan (or anywhere else) – just as Chernobyl failed to do nearly three decades ago. And it seems that as more time goes by without the predicted massive environmental and health effects they’ve predicted, the doom-sayers become increasingly strident as though shouting ever-more dire predictions at increasing volume will somehow compensate for the fact that their predictions have come to naught.

In spite of all of the rhetoric, the facts remain the same as they were in March 2011 when this whole saga began – the tsunami and earthquake killed over 20,000 people to date while radiation has killed none and (according to the World Health Organization) is likely to kill none in coming years. The science is consistent on this point as is the judgment of the world’s scientific community (those who specialize in radiation and its health effects). Sadly, the anti-nuclear movement also remains consistent in trying to use the tragedy of 2011 to stir up baseless fears. I’m not sure which of Emerson’s categories they would fall into, but I have to acknowledge their consistency, even when the facts continue to oppose them.

The post A foolish consistency appears on ScienceWonk, FAS’s blog for opinions from guest experts and leaders.