Saturday, September 7, 2013

Why I Believe that Nuclear Power is the Safest Form of Energy

One of the advantages of having a father who was a nuclear safety researcher is that I had a chance to look at nuclear safety from the inside rather than from the outside. Most of my father's work during his twenty-nine year Oak Ridge career was either directly or indirectly related to nuclear safety. My father made significant contributions to the safety of reactors in several respects. He also made contributions to the study of the release of radioisotopes in the environment through a number of sources including natural gas. He concluded that radioisotopes from natural gas could be far more dangerous to customers than radioisotopes from nuclear power plants because some radioisotopes are delivered to homes through natural gas pipes. Needless to say, people who are frightened about radiation from nuclear power plants steadily ignore the far more dangerous problem of radio active materials traveling into the home through natural gas pipes. My father estimated that there were as many as ten thousand causalities in the US every year due to breathing radioisotopes transmitted to the home by natural gas. Critics of nuclear power do not worry about the radiation safety problems of natural gas even though they may be far more serious.

The first commercial reactors were far less safe than the current generation of reactor design. Reactor scientists expressed their concern during the 1960s and early 1970, although the nuclear establishment in Washington D.C. steadfastly refused to acknowledge the problem. Eventually, this refusal led to the Three-Mile Island accident, but subsequently great strides were made in improving nuclear safety. The accident at Fukushima was the result of human error as well as huge and unexpected natural events. The human error was not anticipating a natural event; a forty-five foot tsunami that overwhelmed the backup generation system of the Fukushima reactors. This deprived the reactors of coolant water and eventually led to partial core meltdowns.  Despite these catastrophic accidents, no one was killed by core meltdowns or the radiation released as a consequence. The truth is, that no one has ever been killed as a result of a commercial reactor core meltdown.

In contrast, construction and maintenance workers have fallen to their death from wind generator towers making wind far more dangerous than a nuclear power plant. There have also been causalities in relationship to both solar voltaic installations and concentrated solar energy facilities. Despite this evidence, some claim that nuclear power is more dangerous. When asked to explain this claim, they say that accidents will happen because we are human and human beings always make mistakes, however there is one way to avoid human mistakes leading to serious nuclear accidents. That is to take human judgment out of the equation. Reactors can be designed so that they will be safe by nature.

Nuclear accidents in the past have been the consequence of human errors, but if you take the safety out of the hands of human operators and place it in the hands of Mother Nature you can avoid accidents. How do you put nuclear safety in the hands of Mother Nature? In a West African nation called Gabon in a place called Okla there is a Uranium mine. Scientist exploring the Uranium mine discovered evidence that ore in the Uranium deposit had gone critical spontaneously some two billion years ago and continued to go critical at times over a period of several million years. The criticality came about as underground water seeped into the ore and, as in Light Water Reactors, it moderated neutron speed thus stimulating a chain reaction.

There were as many as twenty separate natural reactors uncovered in the mine none of which had what could be called a nuclear accident. As the temperature of water in the ore went up, it boiled away and as it boiled away the chain reaction slowed and then stopped. The heat was not great enough to melt the ore and most of the nuclear byproducts did not leave the locality. Eventually, as the natural reactor cooled, water seeped back into it and the chain reaction commenced again. Finally, the amount of U-235 in the ore became too low to sustain further chain reactions and the natural reactors died. The Okla events tell us that by following the laws of nature nuclear safety is possible. Furthermore, if we are only following the laws of nature, it is not possible for mistakes in human judgment to produce major accidents. We need only trust the laws of nature to establish safe nuclear power. Unfortunately, safety of Light Water Reactors is not based on the laws of nature.  Their safety is based on multi layered defense systems.

The latest generation of reactors is designed to partially use natural safety, but still has to go on the multi layered defense system in order to make them safe enough. The next generation of reactors called generation IV includes a number of designs that are even safer than the most recent water cooled reactor designs. These include both the Integral Fast Reactor and all forms of Molten Salt Reactors including LFTRs. Critics of nuclear safety often fail to recognize the evolution of reactor safety design and further fail to recognize the potential for developing even safer reactors. Given that nuclear power is now the safest form of energy and that very great improvements in nuclear safety are possible, the arguments against nuclear power for safety reason are absurd. The critics of nuclear power have been informed of the actual situation of nuclear safety. The source of information is science, thus the attacks on the safety of nuclear power are attacks on science.


Engineer-Poet said...

FYI:  The site of the natural reactors is Oklo, not Okla.

-- The copy editor and sometime fact checker

John in the Lot said...

Hi Charles,
As usual, I agree with everything you say in this piece. The fundamental problems that arise when discussing the safety of nuclear power with green activists are, the irrational fear of any radiation exposure, and the complete lack of any appreciation of numbers. This is particularly true concerning risk evaluation. In general, the public, whether green or not, are incapable of comparing risks and drawing consequences. They resort to emotional reflexes and beliefs. “All radiation is bad for health. Nuclear power uses radiation and so it must be bad”. The conversation then usually turns to Tchernobyl (a reactor which didn’t even have a containment vessel), which they are convinced has caused thousands of deaths even though the WHO report doesn’t support that assertion. It’s difficult to get past that and try to point out that there are dozens of ways of designing reactors, some of which, as you say, can be made fail safe by the application of fundamental design parameters and not by relying on multiply redundant active mechanisms, including backup generators (which in my experience have a good chance of failing to start even without a tsunami).
The chain of logic which has taken me through the technicalities of; the need for base load generation independent of wind and sunshine; the absence of any viable energy storage technology on the scale necessary to make these forms of renewable power generation feasible; the details of nuclear power plant design; leading on to the advantages of molten salt reactors powered by thorium, is just too long to embark upon with people who are not technically qualified.
There’s an enormous public education job to do here and it won’t be done by politicians, who don’t understand the issues and don’t want to say anything unpopular anyway. There’s also a problem of lack of trust. We’re so used to politicians putting a spin on the truth that we don’t believe most of what they say.
I consider myself an environmentalist. I burn wood for heating, which in our part of France is a managed renewable resource. We also use wood for cooking for half the year. We have properly insulated the house and we would love to install solar hot water heating, if there was a south facing location that we would be allowed to use. But I believe that whatever we in the West do to conserve energy, it’s only going to give the planet a short breathing space. In my opinion the only viable way of reducing CO2 emissions globally is by building new nuclear plants as fast as possible, particularly in rapidly developing countries like China. Even then we would still have the problem of transport to solve.

John in the Lot said...
This comment has been removed by the author.
Anonymous said...

The problem of transport can also be solved by nuclear energy. Carbon can be taken from ocean water and combined with hydrogen from electrolysis to produce gasoline, diesel or jet fuel via Fischer Tropsch. All this can be powered by nuclear power to provide liquid fuels cheaper than $100 per barrel of oil equivalent. The US Navy has a report on the feasibility of this.

Even while much of (communter) transport could be electrified, a large amount of synthetic liquid fuel will be needed to make crude oil obsolete. However, competing with oil from the best wells (in the Middle East) is probably not possible, unless nuclear technology evolves to become REALLY cheap (i.e. < 2 ct/kWh). Another way to make synthetic liquid fuels really cheap would be if high temperature nuclear technology in combination with thermolysis of water was perfected.

Joris van Dorp


Blog Archive

Some neat videos

Nuclear Advocacy Webring
Ring Owner: Nuclear is Our Future Site: Nuclear is Our Future
Free Site Ring from Bravenet Free Site Ring from Bravenet Free Site Ring from Bravenet Free Site Ring from Bravenet Free Site Ring from Bravenet
Get Your Free Web Ring
Dr. Joe Bonometti speaking on thorium/LFTR technology at Georgia Tech David LeBlanc on LFTR/MSR technology Robert Hargraves on AIM High