Conventional wisdom among Greens these days is that our power needs can be provided primarily by wind and solar aided by efficiency gains, along with some biomass and geothermal. Unfortunately these arguments are based more on hopes and dreams than engineering reality. Nuclear power is the only realistic technology that can displace coal and meet our needs for baseload electric power and today’s nuclear waste can power next generation power plants. Renewables all face ceilings on their potential contributions and many proposed technologies have not been proven to work at all. The demand for power is growing and we are going to need every solution we can find including wind, solar, biomass, geothermal and nuclear to squeeze out the use of dirty fossil fuels.
The biggest fears of nuclear power are nuclear waste and nuclear weapons and the irony is that best solution to both of these problems is to move ahead with next generation nuclear power plants and even more importantly a next generation nuclear fuel cycle that consumes existing nuclear waste and avoids production of plutonium which is the critical element for weapons. The history of nuclear power is that it was first a military exercise to produce weapons and power ships and civilian uses were secondary. Long-‐term environmental hazards were not a concern in the early days. The light water reactor, which is the dominant design for most nuclear power plants today was developed to power nuclear submarines and when it proved mechanically reliable and safe enough to work around inside an enclosed sub it was adopted for civilian power plants. Though critics hate to admit it, the safety record of our nuclear navy is quite good. The nuclear fuel cycle of processing uranium into high grade uranium and plutonium was put into place to serve military needs for bombs and ships and civilian power needs were an amendment.
There are hundreds of potential designs for nuclear reactors, some better and some worse. It is a critical mistake to limit the discussion of nuclear power to the status quo of our current designs. One of the most promising designs is the molten salt reactor, of which prototypes were operated successfully for a decade in the 1960s-‐ 70s at Oak Ridge National Labs in Tennessee. The molten salt reactor, which comes in various technical flavors, has tremendous advantages over light water reactors in terms of waste, safety and proliferation because it can consume todays waste as fuel, has a much more efficient fuel cycle that produces only a fraction of the waste of light water reactor with dramatically reduced half-‐lifes. MSR’s can utilize thorium in addition to uranium as fuel which is important because thorium is four times as abundant than uranium and is impractical to be upgraded into weapons grade plutonium (one the reasons it was never used in the first place).
The advantages of molten salt reactors in terms of safety lie in the fact that it operates at atmospheric pressure and the fission takes place inside of a bath of molten salt (typically fluoride) that is self cooling. In the case of a catastrophic failure, such as an earthquake where are all of the workers flee, the system shuts down passively and the radiation is contained in the salts. This is in contrast to a conventional pressurized system where the workers constantly seek to keep the pressure from building up too high or allowing the plant to blow up due to the loss of cooling, such as what occurred at Fukushima.
There are many other proposed designs for safer nuclear power, some little more than updates to today’s light water reactors, while others are radical new concepts such as the traveling wave reactor. Another concept is the breeder reactor that produces its own fuel and would essentially never run out. Breeder reactors were the cutting edge in the 1970’s and were considered to be the future of nuclear power, but operational difficulties, legitimate fears of plutonium proliferation and spiraling costs ended those efforts with only one being built in the US and one commercial reactor in France that was eventually shut down. With more research in the future perhaps breeder reactors may be resurrected and with it the possibility of unlimited fuel supplies.
Today’s aging fleet of light water reactors with their spent fuel pools are accidents waiting to happen. They are built on 1950’s technology and based on requirements to satisfy the needs of the US Navy not public safety. They are pressurized, often times poorly sited, with incredibly complex cooling systems that have been subject to internal corrosion and at risk of failure. All 104 existing plants in the USA should be dismantled, but this does not mean that we should dismiss nuclear power as a critical component of our energy mix. Nuclear power is the only existing technology that can replace coal to produce the majority of our baseload power. I favor an all of the above solution set to our energy needs. I favor the use of wind and solar, biomass and waste to energy. But I am also a realistic practitioner who bases my expectations on how technologies actually work and not on how I wish they would work.
Regarding wind and solar, not to be rude to their proponents, but it will simply never work to produce the majority our energy needs from them. The limitation on wind is that there are only a limited number of locations that are suitable for large wind turbines and once those sites have all been built we will be maxed out, similar to the situation with hydro power. Wind works great where it works, and so does hydro, but there are also serious environmental liabilities to wind power just as there is with hydroelectric dams. Wind turbines produce serious noise pollution in the form of vacillating low frequency vibrations that travel for miles and have been causing significant health issues for people who live near wind farms. These vibrations have not even been studied (to my knowledge) for their effects on wildlife on land or in the sea. People who find themselves living near wind farms have found their quality of life severely impacted, particularly if they valued a quiet, idyllic life in the country, and the worst-‐case scenario is to be living in the shadows of a wind turbine such that you get an oscillating strobe effect that can make a house unlivable. The environmental movement should not underestimate the impact of industrial wind turbines and the implication is that large wind turbines should not be placed within a mile of any residence. Unless the wind industry can do something technical to reduce the noise and low frequency vibrations then the NIMBY issues around siting wind turbines will not go away and the number of potential locations for wind farms will be reduced to a fraction of what the industry is promoting now.
The limitation on PV is that the panels only produce trivial amounts of power and only do that for a few hours a day. If you cover the roof of a house or building with PV panels they will not produce enough electricity to power that building and certainly could not power a factory or produce any heat. PV farms take up tremendous space at ~5 acres per 1 MW of capacity, but that only produces a few MW hours per day. Large solar farms require thousands of acres and there is a limited amount of land that can be put to such use, once that land is maxed out capacity will be capped. I would like to see PV so cheap that it can be used indiscriminately as a building material. Then PV can be installed widely enough that it can have a meaningful impact on our energy grid, but it will never be baseload power. Another critique of PV is that it requires substantial manufacturing overhead to produce (with attendant carbon emissions) and PV panels have a seven year energy deficit before they have even produced the power that went into manufacturing them.
Another common argument made is that efficiency will be a substantial part of the energy mix, this is a very seductive notion because it seems so logical that if we use less fuel we can make the fuel supplies go farther. This myth of energy efficiency is dangerously inaccurate because it has never proven to be true. The reality and history of energy efficiency is that it makes devices (or buildings or factories or autos) cheaper to operate and therefore they get used more and the net energy consumption remains constant or growing. Industry has always strived to make machines more efficient; it is a core tenet of engineering, fewer parts, less fuel and less waste makes for a more cost effective and productive widget. The cheaper the widget is to operate the more people use them. The demand for power is only growing worldwide and while efficiency is very desirable for individual devices it has zero impact on net energy consumption and should be dismissed from any discussions of macro energy policy.
I am a Green who is pro wind and solar, and also pro nuclear. Greens need to get realistic about the actual technical capabilities of the solutions they are dreaming of and the sooner they get a firm grasp of the engineering realities the sooner we can arrive at practical solutions to our global problems. We need all of the above and none of these technologies are mutually exclusive. Greens need to be honest about the environmental impacts of manufacturing and placing wind and solar installations because they are not eco-‐cost free. At the same time we need to be educated and realistic about the health and safety issues of nuclear power. What is the actual number of worker deaths in nuclear power plants? Not many. What are the realities of nuclear radiation and cancer? Lets not react hysterically about things we do not completely understand. How can we implement the lessons learned from past nuclear accidents and achieve a peaceful nuclear power industry? The reality is that nuclear fission provides millions of times more power than any other resource and we have only begun to scratch the surface of its potential. Capturing fission is like capturing fire, it is an epic historic moment from which there is no looking back. Just as fire burns and carries risk so does fission, but we should not let fear conquer us. We must be brave as we move forward in uncertain times and conquer our fears through honesty, intelligence and acquired wisdom.