Monday, February 14, 2005

Multiple choice test

My friend Triticale alerted me to this piece on pebble bed reactors a few days ago and now I see Instapundit has it up as "the answer" to America's energy problems. As a former Naval Reactor Operator I might have a thing or two to say about the radiation and safety questions. As a student of energy systems I might ask how much net energy can be gotten out of such a device net manufacturing and mining energy. Which includes the cost of enriching the uranium. But I'm not going to deal with any of those questions.

Which brings me to my multiple choice test.

Is there enough plutonium in the world?

a. just enough
b. too much
c. more is needed


Joe Katzman said...

In some places, there's too much. North Korea comes to mind.

In other places, I suspect too little for massive nuclear power investments. It would have to be created, as it isn't something you mine; and repurposing plutonium from decomissioned nuclear weapons would not be enough.

The question then shifts to the cost and energy efficiency of creation, which seems to happen as a byproduct in power-producing breeder reactors.

Not sure what you're getting at here.

back40 said...

The post you point to is about the Toshiba 4S micro-nuke rather than a pebble bed reactor. See this page for design features.

see this post which does discuss pebble-bed reactors

M. Simon said...


Thanks for the update. I ought to read more carefully. I still have my doubts about sodium cooling.

And if the diagram is correct it is actually cooled by a lead bismuth solution.

The best solution to the plutonium proliferation problem is to not make any more.

BTW nuclear is a short term solution to our energy problems. Wind is a better immediate bet. Longer term solar cell costs are still falling and efficiencies are still rising. The rate is slow but improvements are continuous.

And then we have possible biotech solutions.

Did I mention the hydrogen car of the future? At least 20 years in the future and possibly 50 to 100 years if ever? As an economic transportation vehicle. Plenty of "cost no object" demos running on the road to fool the public into asking for something not yet and possibly not ever possible.

M. Simon said...

The reactor boys want to have a prototype by the end of the decade. By then wind will have declined another 20% to 30% in cost.

They will be too late.

back40 said...

I think nuclear has way more legs than wind because it works everywhere, all the time; even on the moon where there is no air, much less wind; and on the ships that ply interplentary space. Even on Titan where the sun is too weak to melt methane ice.

Solar is attractive because it is possible to extrapolate currrent kludgey tech as we gain materials science nano-skills and imagine far more efficient absorbers that gather a greater percentage and a wider spectrum, becoming interesting indeed for special applications.

Wind is hopeless. It's ugly, immobile, and dangerous to things that live in the air. It alters micro-climates by causing atmospheric mixing, is at its best when it is needed least, and altogether absent far too often. Tidal and wave power are similar but far better ways to tap currents and flows. Wind will never provide above a tiny percentage of energy needs, a boutique technology.

M. Simon said...


I'm all for nuclear in interplanetary space. Far from any gravitational well. i.e. for interplanetary transportation.

I even like it for military ships on earth.

As to wind being ugly - in the eye of the beholder. On the way from my father's funeral in Oct of 2001 I saw a really pretty windmill on Highway 80 in Iowa. Stopped and turned around to get a better view and watch it for a while. Poetry in motion.

The really big jobs >1 MW(peak) like the Iowa mill I saw are not significant bird killers. Tall buildings are worse.

Right now wind is cheaper than gas turbine electricity and helps to keep the cost of natural gas down. Storage is not a problem until wind represents >20% of grid power. We are no where near that. Plus I have some storage ideas.

I don't see why wind being immobile is a problem for grid use. Every technology has its place.

Solar will alter microclimates. In fact a honkin nukeplant will alter microclimates. In fact breathing alters micro climates. A camp fire alters microclimates. I suppose we could all live in space. If you have a rocket I'm ready to travel.

America could go 100% wind with energy left over if there was a suitable storage mechanism. And a lot of transmission from ND and SD to the other states.

Contact me if you have $$$$. I have ideas. Did I mention I'm a former Naval Nuke and currently an aerospace electrical generation engineer?

I have the extreme good fortune to have had in my hot little had in 1962 one of the first commercial (such as it was) solar cells. I have been interested in power and control my whole life. Well at least 50+ years of it.

I have the good fortune to be well versed in all types of energy generation from an engineering stand point. Nukes, jet engines, boilers for steam, wind, biomass, fuel cells, etc. etc. etc.

BTW I'm against nuclear power because the total amount of fuel is limited and then there is the problem of plutonium in the hands of crazies.

back40 said...

The idea that nuclear fuel is limited is true in the absolute sense, but not relevant for human use. The same is true for fossil fuels. There is plenty of both but there is a confusion about the difference between proven reserves and probable reserves, as well as a confusion about costs, which is related.

There are only small proven reserves of nuclear fuel because there is a market glut. Stockpiles amassed in past decades in anticipation of a boom that didn't happen depress the price and eliminate incentive for exploration. Those who are aware of this issue and how it affects discovery prefer to speak of probable reserves and guess a ten fold increase, though that is only a guess, it may be a hundred or thousand fold increase. More importantly the world is awash in nuclear fuel in low concentrations. The seas brim with U235 but the cost to extract it from seawater is above current market price.

Newer designs for reactors require less fuel because they burn it more completely, exhausting all fissionable material. And we have always had the technology to produce U235 from the much more abundant U238 using breeder reactors.

The notion of limited nuclear fuel isn't valid, anymore than the notion of limited fossil fuels is valid. Both arguments are bait and switch obfuscation that conceal relevant facts.

Plutonium in the hands of crazies is not a nuclear power issue, it's a crazies issue. It's the same for biotechnology and nanotechnology. There is absolutely no way that any nation or collection of nations can control either the amount or distribution of Pu in the world. China alone proves that point but there are several other players, and if there weren't that would merely be incentive for others to enter the market. It's worrisome, but it is a fantasy to think that we can make any difference by inhibiting ourselves. This is a head-in-the-sand approach.

It isn't that there are any sure answers to crazies that we could implement if we only had the will. It is that there are no answers, no way to eliminate risks. Like gunpowder, there is simply no way to stifle the spread of this technology so we must focus on managing it, engage with the issue rather than seeking to hide from it.