Replies

I am talking about electricity for home and work in the following.

Nuclear IS the best non-polluting “green” source of electrical energy, but we need to use the best nuclear technology. Not the ones generally used to date.

A combination of thorium/uranium-cycle breeder and burner reactors could supply energy “forever”, based on extraction of uranium from seawater, as well as the conventional mined sources of nuclear fuel.

Current light-water reactors usefully extract less than 1% of the available energy in the nuclear fuel. Breeder reactors can extract almost all of the energy contained in uranium and thorium. We are talking about up to two orders of magnitude greater efficiency.

Between breeding and burning nuclear cycles, these processes can consume or destroy virtually every bit of the most dangerous, long-lived and thus very hazardous waste. No need for the Yucca Flat storage areas, we just use the fuel over and over again until it is used up.

Finally, using molten-salt cycles, we are no longer dealing with massively-large highly pressurized systems, eliminating a key complexity in nuclear reactors.

This is something that should be seriously re-evaluated.

Jimmah Carter issued an executive order in 1977 banning the reprocessing of nuclear fuel in the US. The concern was that plutonium generated in the process could be stolen by terrorists and used to make A-bombs.

But it is virtually impossible to separate the key plutonium isotope (239) from the other Pu isotopes to the degree necessary to use it for fissile bombs.

Instead, we should just engineer it into the mix and burn it for fuel.

Other issues actually do favor these breeder/burner processes over coal, such as the volume and mass of waste generated by them - pounds for nuclear versus tons for coal, and emissions. Coal plants emit radioactive elements, albeit at a very low level, as a normal part of the operation in the fly ash.

And consider that radiation is a normal part of the environment. We evolved with normal background radiation in the natural world. Low-level radiation does Not produce biologic damage in a linear fashion. There is a threshold effect, and at very low levels the body self-repairs itself. This is one of the systematic errors made in extrapolating from high-dose data to low-dose predictions in epidemiological and and toxicity studies.

And renewables? Wind can never be significantly useful, because you have to have base-demand generation capability at all times to back it up. The UK grid almost collapsed a couple of years ago when an extremely long cold spell with no wind spiked demand and zeroed out the wind-farms.

Even as a technologists, there are still huge increases in solar-cell efficiency vs costs plus energy storage technology for direct photoelectric conversion to really matter. And there are those pesky solar-cell manufacturing wastes to deal with.

I am a little intrigued by the molten-salt solar thermal process. But these only work in the desert southwest, for example. You cannot put a thermal-solar plant in Canada and Alaska and expect much for half the year, for example.

SO - as an important point - all of these really need to be supported by and combined with the US building a new national long-distance DC electric grid (hardened to resist X50+? class solar flares and direct impact by huge coronal mass ejections, like the 1859 Carrington solar event).

(Note - if one of these solar events were to happen next week, then all bets are off. The US - let alone the rest of the industrialized world - is not prepared. In the Carrington flare, the CME hit the earth 17 hours after the flare occured. This is not enough time to prepare. There will be no computers, no cars with chips, no cell phones, no electricity, pretty much no anything that you cannot walk to or carry yourself for the following several years. We are all basically camping out for a long, long time. Depending on how old you are, maybe for the rest of your life. Oh well...)

As far as oil is concerned, we do have a multiple-century supply (at higher prices over time), but the best uses for liquid hydrocarbons are not electric generation, but as fuel for transportation, and feedstocks in the chemical industry. This also applies to liquids from any biomass technology, even if enhanced with genetic engineering.

So when it comes to electricity, a little hydro, a little wind and a little solar will help some, but cannot come even close to meeting demand.

We only have three choices - from worst to best - coal, natural gas, or nuclear.

The first two we can do now basically.

One last but important point to consider. There is enough nuclear fuel in the earth and its oceans to last literally millions of years, with the technology discussed above. I know that seems like a long time, but it is something to think about.

Coal, oil and natural gas may last for hundreds of years, maybe thousands. But what if we last longer than this?

China has a continuous history stretching back 5000 years. Just 8000 years ago the Sumerians were doing their thing. So the long view is worth looking at.

Nuclear and renewables can basically last forever...

... or until the Yellowstone caldera explodes,
... or the next huge comet/asteroid impact,
... or the next ice-age,
... or the sun burns out - whichever comes first.

:-)