Dear Tench:
a) Nuclear power has its own problems, namely with security. In this age of terrorism where the free world is unwilling to fix the problem at its source, nuclear power plants will have to be guarded more fiercely than other types of power plants.
Wrong! You can make a self contained GCFBR that is buried below ground. It will not go into meltdown on loss of coolant as the coolant is what allows it to become critical. If it gets too hot, the coolant density drops below the amount necessary for critically and the reaction shuts down. To keep it running, you need to actively extract the heat from the coolant. To fix it, you have to shut it down, let it cool off, remove the coolant, pull it up out of the ground, make repairs, lower back down, add the coolant back in, power it back up, wait for it to reach operating temperature and then put it back on line. Refueling is also done this way. When it becomes time to decommission it, you can do it via one of two ways. Either pull it up out of the ground and dismantle it, reprocessing any high level radioactive materials or simply remove the fuel and flood it with concrete, permanently entombing the rest of it. And you can have that as an emergency solution. Something like an explosion and the concrete flows over the core preventing any large releases.
Terrorists would have a difficult time of blowing it up because the radioactive parts are deep underground. They aren't very good at blowing up bunkers, just easy to reach places.
b) What's cheaper than directly burning natural gas for heating?
Many things. In the lower half of the country, where winter temps rarely go below freezing (0C) over extended periods, pumping heat from the ground into the home during winter and reversing the process during the summer. You can pump 10 times the heat as in the electricity used. NG fired power plants have about a 35-40% efficiency. So a NG power plant powering heat pumps provide 4 times the heat that simply burning NG does. Nuclear, hydropower and even coal is cheaper at making electricity than NG fired power plant. And most heating is done during the night when power demand is at it lowest. If you have enough heat capacity in the building mass, you can heat during the night hours when off peak power costs 1/2 to 1/3 as much and have it stay warm all day. Now you are beyond 10 times as much heat in the lower half of the US. In the upper half portions where temperatures rarely go below zero (F), its about half that. But even if you just use electric resistance heat during off peak hours during the coldest times, below zero (F), it is still cheaper than directly burning NG.
Around here off peak power goes for $0.03 a KWH. One therm is about 30KWH and electric resistance heat is 100% efficient thus, one therm costs under $1. Less than what one therm of NG goes for during the winter. 10-20 years ago, it was the other way around before the NG power and heat craze. The thing is that you can target the electric resistance heat to just the critical things, water pipes, both supply and drain, blankets over the kids and you while you sleep allowing the home to be kept at around 10C (50F). This is uses half the requirement of keeping the entire home at 22C (72F) when its -8C (18F) outside.
Also even though you burn one therm of NG, some of it goes up the chimney and you have to use some electric power to move the medium around (air, water or steam). So thats about 1.25 therms of NG ($1.50 at $1.20 a therm) plus $0.05 of electric power, assuming furnace at 100% duty cycle (at 12.5% or a therm every 8 hours which is more typical, $0.25 (fan always on)), for a total of $1.55 using NG. Now with electric being able to need half the heat to keep everyone just as warm, thats $0.50 during off peak and $1.50 on peak average $1.00, versus $1.55 using NG.
GCFBR power is below $0.01 a KWH, if the onerous building codes could be reduced to what either coal fired or NG fired plants use. Even with them, nuclear plants generate at about $0.02 a KWH. Now we have $0.50 a therm, all of the time ($0.25 during off peak and $0.75 on peak) for electric resistance heat, $0.10 a therm for heat pumped from minimum -18C (0F) air and $0.05 a therm for heat pumped from minimum 0C (32F) air. Ground here in Milwaukee is about 7C (45F) average which using that gets us to $0.05 a therm even here where the temperature sometimes stays below 0F for many days at a time like earlier this month.
c) The production of hydrogen has to be powered by existing power plants, since hydrogen itself isn't the source of energy, but merely a medium to transport and store the energy.
True only for the next 20-30 years. Hydrogen is the fuel used by the Sun to give us light and heat. After 30 years, we will have terrestrial fusion (likely DT or DD at first (Deuterium and Tritium are isotopes of hydrogen at 0.7% and 0.001% by mass respectively) and normal H much later). Then 1g of hydrogen containing 7mg of deuterium will be more energetic than 7 gallons of gasoline. 1g of hydrogen is contained in 9g of water. A 2 liter bottle of tap water in Milwaukee contains 222g of hydrogen and 1.55g of deuterium which is about the energy contained in 40 barrels of oil. The world uses about 80 million barrels of oil a day so the deuterium contained in 2 million 2 liter bottles would produce the same amount of energy. 4 million liters is about the quantity contained in a pool about the size of a NFL football field, not including the end zones, 3 feet deep. Or 0.1" of rain on 2 square miles of ground, about what we get here in Milwaukee on an average day.
Pretty energetic for plain water wouldn't you say?
Hence the folly of trying to replace fossil fuels with the existing alternatives simply because of global warming.
Nuclear power has more energy and can be distributed using various means other than electric power. HTGCFBRs can thermally split water into hydrogen and oxygen at efficiencies approaching 60%. A lower temperature process can make hydrogen peroxide and hydrogen at 67% efficiencies. The hydrogen can be used to replace NG and the 2(HO) can be used for micro turbine powered vehicles (it exothermically decomposes into H2O and O2). We have 800 years, if used for all US energy needs, of uranium within the United States alone using GCFBRs.
Pete |
