Putting Picos In Perspective
Feb12

Putting Picos In Perspective

Fast Fission Podcast #23 – Download mp3 Here Ever thought about how many zeros there are there in a “pico” something? Remember back in grade school when we learned the metric system of measures?  We started out with units that are easy to visualize: meters get 1000 times bigger and become kilometers; meters get 1000 times smaller and become millimeters.  We understand these intuitively because we have a frame of reference and can visualize each of those unites of length and distance.  Units of mass are the same way; we know a gram is a small unit of mass – we can hold a gram of almost any material in the palm of our hand.  For example, a penny weighs 2.5 grams. Stack up 400 pennies and you have a kilogram, or 1000 grams.  Cut a thin copper shaving off a penny and you have a milligram, or one 1,000th of a gram.  Again, these are things we can see, and that makes it easier to understand. As our schooling progressed we learned about very large and very small numbers, exponents, and scientific notation.  We put these principles to use in science and learned there are other units of measure larger than a “kilo” and smaller than a “milli”.  These are harder to visualize because we have to think in terms we can’t see.  For example, the mass of Mount Everest,  is 3E18 grams, or 3 “exa-grams” and the mass of the planet earth is 6×10^24 kg, or 6E27 grams (6,000 “yotta-grams”) (see note below). On the opposite end of the scale is the prefix “nano” or 1E-9 of a unit. A nanometer is 1E-9 meters, and a nanosecond is 0.000000001 seconds.  I had a hard time visualizing a nano second of time until I learned that it takes about 1 nanosecond for a beam of light to travel one foot.  That kind of puts a nano into perspective, doesn’t it?  The newest computer chips, for example have transistors with a thickness of 45 nanometers!  We can only see things that small with powerful electron microscopes. A “pico” is even smaller than a “nano” , 1000 times smaller!  “Pico” means there are 12 places behind the decimal point.  Even for a person like me who deals with engineering and science all the time, it can be difficult to visualize a “pico” of something.  A pico is so small that even a million picos is still very small amount. It takes a million, million pico grams to make one gram.  If you have a million pico-curies in a liter of water, it would take one million liters to provide a...

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“What nuclear waste problem?” (TWiN Podcast 77)

Get the MP3 Here Download printable version here I have a family member that I love dearly and have an infinite amount of respect for.  She is a fantastic mother, a caring person, respected in her chosen profession, and a good friend.  She would do anything she could to help someone in need.  When we first met she was strongly opposed to nuclear energy.  Over the years we have discussed it from time to time and I’ve had some influence on her perspective.  She’s not totally won over yet, but we’re making progress.  Not too long ago she asked me, “But what about the waste?  That really worries me!”  She really didn’t believe me when I said “There’s no such thing as a nuclear waste problem.  That’s nothing but a myth.” Let me explain. Used nuclear fuel is very safely stored in earthquake proof storage pools and dry storage casks at nuclear plants around the USA.  It can stay there until we’re ready to recycle it, and we WILL recycle it eventually because it would be a waste not to do so.  When we remove used fuel from a reactor more than 90% of the potential energy is still in the fuel.  It would be wasteful to even consider putting it in a hole a mile underground!  Also, when we do recycle it, the left over material is much smaller and is much easier to handle, but we’ll talk about that in a few minutes. First we need to look at the components of used power reactor fuel, and recognize that with recycling each of the components can be separated from one another.  A typical batch of used nuclear reactor fuel is made up of the following materials (not counting the structural materials): % Composition (approx) Uranium 93% Plutonium 1.5% Minor Actinides 0.2% Fission Products 5.3% When the fuel is new the concentration of the isotope U-235 is about 4% and U-238 is the rest.  After the fuel is burned in a reactor the uranium is mostly U-238 (very close to the isotopic mix of natural uranium) because most of the U-235 gets burned out by absorbing neutrons and fissioning.  There is also a small but important amount of plutonium that is formed when uranium atoms capture neutrons but do not fission.  This is called “breeding” and in fact at the end of life of a reactor fuel load more than 20% of the heat generated is from the fission of plutonium atoms formed by breeding.  All of this plutonium and uranium can be mixed back together to make new nuclear fuel.  This is what is commonly referred to as mixed oxide fuel,...

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Episode 74 – The Renewable Question and Germany’s Nuclear Reversal (audio podcast)

Download the Audio File Here In this podcast I discuss the question “Is Nuclear Energy Renewable?” that I first posed in a recent blog post. In addition, I added the following discussion of recent news and events: Indian Point License Extension Proceeds Despite Anti-Nuclear Hurdles Despite barriers erected by anti-nuclear groups to block the license renewal for the Indian Point nuclear reactors, the two unit nuclear plant in NY has passed two major hurdles in the life extension process. On August 12 NRC issued their final safety evaluation report and concluded there are no safety issues that would preclude running the plants for another 20 years. On Sept 23 the independent Advisory Committee on Reactor Safeguards, and independent team of experts that advice the NRC, recommended that the license extension be granted. Unless renewed, the current licenses expire in 2013 and 2015. In 2007 the anti-nuclear group Riverkeeper filed five contentions opposing the 20 year license extensions.  The NRC granted Riverkeeper a hearing to review arguments on three of their five contentions.  In those hearings Riverkeeper was unable to provide sufficient evidence to support their claims and the NRC ruled the contentions had no merit. On the NRC’s web site they have a schedule showing a tentative final decision on Indian Point’s relicensing in February of 2010. Riverkeeper’s opposition of the plant is backed by several elected officials including Andrew Cuomo, the State Attorney General with a long family tradition of anti-nuclear politics.  Twenty years ago his father, then Governor Mario Cuomo successfully closed the brand new Shoreham nuclear plant.  In Super Mario’s deal the state purchased the plant for $1, and passed on $5 Billion in construction costs to taxpayers who received nothing in return except some of the highest electricity rates in the country.  That case was a perfect example of the flawed two-step licensing process in which utilities were first issued a permit to construct the plant, and then after the plant was built they applied for a license to operate the reactor.  The new reactor licensing process is a combined construction and operating license (called a COL) that should be more predictable for utilities and investors. The NRC has received 17 COL applications from utilities interested in building 26 new reactors, but has suspended the review of four applications at the request of the applicants. Pro-Nuclear Victory in Germany This week there was a huge win in Germany for supporters of nuclear energy.  Angela Merkel was reelected Chancellor and vowed to reverse that nation’s plans to prematurely shut down their 17 nuclear reactors.  Nuclear energy currently provides 31% of Germany’s electricity and closing the reactors...

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Is Nuclear Energy Renewable? How about “Inexhaustible”?

For quite some time I’ve been debating the argument that nuclear energy is equally “renewable” as energy derived from hydro, wind, and biomass. My thought process goes like this… Rivers go dry with over use and periods of drought, and winds shift with changing weather patterns such as those that will occur with global climate change.  The availability of biomass is dependent on favorable weather and must be replenished using agricultural processes that are reliant on fossil fuels.  The ultimate energy source of all these “renewables” is the sun, and while the sun is not “infinite,” it is unlikely to extinguish during the course of human existence.  The ability of the sun to replenish hydro, wind, and biomass make these energy sources renewable. In contrast, the source of nuclear energy is fuel contained entirely on planet Earth.  And while there are a finite number of uranium and thorium atoms on the planet, the supply will last for as long as human beings need it.  The myth propagated by the anti-nuclear crowd that we will run out of fuel for nuclear reactors is simply untrue.  They grossly underestimate the amount of uranium that exists, they discount already proven technologies like breeder reactors, and they ignore the existence of thorium, a fuel even more plentiful than uranium.  We have sufficient nuclear fuel to last for more than 1,000 years, even if we expand the number of nuclear plants by more than a factor of ten.  This makes nuclear energy inexhaustible. I’ve often discussed the how Renewable Portfolio Standards (RPS) will encourage investment in wind and solar energy, but alone will NOT result in the desired reductions in CO2 emissions.  If the goal is CO2 reduction, why not promote the expansion of nuclear energy, the greatest source of low-carbon energy in existence? Keith Johnson of the Wall Street Journal Blog discusses the “renewable” question, and issues surrounding the logic of a national RPS in his recent post titled “Is Nuclear Power Renewable Energy?“.  In particular, Keith points out the inconsistencies in the Waxman-Markey approach to fighting climate change. Nuclear-power proponents are puzzled by what seems a logical inconsistency on part of Democrats who consistently shoot down the [nuclear energy] proposals.   If the goal is to promote low-emissions power sources, then nuclear power should be part of the mix.   If the goal is to promote new power sources, then existing wind and solar power facilities shouldn’t be showered with federal goodies.  That is, states that already have loads of wind power would be half-way to meeting new renewable-energy targets without building any new clean energy. And later… But if the whole game in...

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