Crazy idea of a way to heat homes. Would it work? Would it be practical?

Question

Despite the stigma radioactivity holds upon us since Hiroshima and Nagasaki, I have this crazy idea of a way to heat a home. That would be to have thick aluminum canisters tightly and safely containing a certain amount of the radioisotope strontium 90. The thick aluminum surrounding the strontium 90 would be able to easily block beta radiation from leaving the container yet at the same time easily conduct heat from the radioactive decay outside of the container safely heating surrounding water or air placed near the drums without any fossil fuel consumption and a constant supply of warm water. Unlike most radioactive isotopes strontium 90 has a half life of 29.1 years and then decays to an even shorter living isotope of yttrium 90 lasting only 2.67 days and then finally decays into the harmless stable isotope of zirconium 90 finally leaving it safe for disposal. Would this actually work to generate enough heat for a home? How much strontium 90 would it require?Intelligent answer please

Answer 1

I'll ignore the fear people have at the mere mention of radiation and consider the practical aspects of the idea.

One problem I see is there is no way to turn off the heat. I guess you could have the heater outside and only pipe the hot water into the house when you wanted it.

But I see a safety problem. What if you don't remove the heat from the strontium 90? What if the heat exchanger fails. Especially if it fails on a summer day when you are not piping the heat into your house and are not paying any attention to it. It would overheat and melt the container and cause a radioactive spill.

Answer 2

They actually use this idea (radioisotopes making heat) to power some satellites that are going on long missions, especially far from the sun.  So your science is good.

But it takes energy to make Sr-90.  That energy to heat the home has to come from somewhere.

You' d basically be using energy to make Sr-90 to make heat.  I can't imagine that's not way less efficient than using the energy more directly in the home.  And you'd need a lot of Sr-90, though how much, I don't know.  

And people here are right, using it to heat homes is too risky.  Imagine the factory that would build the units.  Imagine what a terrorist could do with that huge amount of Sr-90.

Your science is good, but your engineering on this one is questionable.  Keep thinking, though.

Answer 3

You are right. That is a crazy idea, way outside the box thinking! Let's consider this idea carefully. The first issue is where do you get the Sr 90. The pretty much only source is reprocessing of spent nuclear fuel. Since there is already substantial amounts of spent nuclear, many tons, that may not be a bad thing because we need to get rid of all that nuclear waste some how so why not store it in our houses?

I would be concerned though about using Sr 90 for a couple of other reasons. One is that it is a calcium analogue in the body and so is readily absorbed into bones and the like where it causes bone cancer. Secondly although Sr90 does not give off gamma radiation directly. Beta radiation does give off gamma radiation when it hits other matter and so an Sr90 Radioisotope heater would need a fair amount of lead shielding. There are other isotopes that might be more suitable preferably alpha emitters rather than beta emitters. Plutonium 238 with a half life of 87.7 years seems to be the preferred thermo-generator fuel for this reason. The clear downside to Pu 238 is that it is fissionable and thus a nifty bomb fuel. Pu 238 is also substantially poisonous and somewhat less available that Sr90 and has less attractive decay products.

The idea might be improved by making a thermoelectric generator rather than just a thermal generator. That way you would generate both heat and electricity making the unit more valuable. Which brings me to the next concern. This will probably be a pretty expensive item. Reprocessing costs for the nuclear component will likely be the really big ticket cost. Due to safety concerns it cannot be done just any old which way and so the basic fuel is likely to be very pricey.

My final concern has to do with terrorism. In order to generate a useful amount of heat and or electricity these units will contain substantial quantity's of radio isomers. I was unable to locate energy density information on Pu 238 but Po 210 was quoted as having a phenomenal energy density at 140 W/g. That implies many grams of the isotope will be required to produce the amount of energy the typical house consumes. That means a terrorist would only need to steal just one of these devices to make a very effective dirty bomb or possibly even a thermonuclear bomb if the fuel were Pu 238.

To summarize, the device is likely to be too expensive and should it fall into the wrong hands too dangerous to be practical.

Answer 4

scary

Answer 5

I'm sorry, what was that? My eyes and ears are bleeding from radiation poisoning, I missed that last sentence after "strontium 90".....

Answer 6

Yea great idea Wile E.  That is of course until the first house fire which boils the liquid causing it to explode creating a vapor cloud which will wipe out hundreds of thousands of people!  Back to the drawing board Einstein.