UPower (YC S14) Is Building Nuclear Batteries

http://large.stanford.edu/courses/2013/ph241/waisberg1/

"However, the project was hampered in 1994 after a series of controversies involving safety issues and nuclear non-proliferation policies."

Concerning the carbon free issue: That is false advertising and needs to be put in an extremely negative light because it suggests something to the consumer which is not true. How much carbon or emissions a power plant generates under some specific conditions (like in its main operation time) is completely irrelevant to how environmently friendly it is. The complete balance needs to be taken into account, otherwise you end up cheating yourself (or others) into believing you have reduced emissions when overall you haven't.

It's true that standing next to a kg of U238 for a limited amount of time will likely not hurt you much. The same is true for lead for example. That does not mean it is not hazardous! It still needs to be taken care of. Also, it is interesting that you ignored the Pu. I'm not trying to fear-monger. The statement from the article is simply wrong. Nuclear waste has to be taken care of for tens of thousands of years, not hundreds.

    Frac Remain In 1 Day = 0.5 ^ ((1/365)/4,500,000,000 years)
    Frac Remain In 1 Day = 0.999999999999578
    
    Frac Decay In 1 Day = 1 - Frac Remain In 1 Day
    Frac Decay In 1 Day = 4.22 * 10^-13
    
    Have 4 Decays In 1 Day = Total U238 * Frac Decay In 1 Day
    4 = Total U238 * 4.22 * 10^-13
    4 / (4.22 * 10^-13) = Total U238
    Total U238 = 9.48 * 10 ^ 12 atoms

I'm glad you brought up the dirty bomb factor again.

The perpetuation of the myth of the dangers of the dirty bomb is truly sad. We all intuitively realize that the dangers of chemical warfare, biological dispersion (especially because it is transmissible long after the incident), and the dangers of bombs themselves are so much greater than some amount of radiation that decays rapidly and, by the nature of a bomb, is highly dispersed.

As an example of the worst possible radiological contamination (which would not practically be achieved by a dirty bomb to scale), read about the story of the "Atomic Man". In an instant, he received 500 times the "lethal lifetime dose." He died at 75 of unrelated causes. The atopsy showed zero cancer. The chemicals were terrible. the explosion was terrible. Ultimately the radiation itself was not as bad as expected.

In another example, studies showed mice fed plutonium dust had their lives expanded by 120%. See here for an overview of these types of studies and natural effects of hormesis. http://www.radpro.com/641luckey.pdf

It's my belief this disproportionate fear is really a tragedy, a play on the fears of uneducated people (again, fed by media since anything nuclear is like sex or plane crashes) that may ultimately cheat them from peace of mind and clean, reliable energy sooner. What if people refused transportation:vehicles, trucks, and planes because gasoline is highly combustible and kills so many per year? Our economy exploded with oil at the turn of the last century.

But that's a side point, sorry for digression.

Could this be blown up? 1) it's underground 2) it's surrounded by concrete that has been tested to be safe to drop from hundreds of feet in the air 3) it's a solid metal block. It doesn't have dispersion capabilities like other forms.

Unrelated fact since we aren't reprocessing: It's a common misconception that reprocessing is not legal in the US. It is. Also for instance, France does it and has been doing it for a while.

that means roughly 2 million times less transportation, less land use and less waste. (Land use comparisons: http://newenergyandfuel.com/wp-content/uploads/2010/06/LandU...)

How can we factor in the amount of CO2 removal lost by removal of millions of trees for wind farms? (http://www.telegraph.co.uk/news/politics/10546071/Millions-o...) Or millions less train use in transport of coal?

It's a good point though. We should count not just that the reactor itself saves 200,000 tons of CO2 during operation, but also the frequently 10x that of fuel burnt to transport that diesel in conventional generators. So each reactor deployment may save 2 million tons of CO2.

Nuclear facilities are also much longer lived than many. Eg solar panel life degrades significantly after a decade. Wind turbines generally have a life of 15 years of so. So that's less concrete, construction, etc.

You're right it's tough or impossible to quanitfy. Intuitively, it all comes back to the energy density number. 2 million times more energy dense, no emissions or pollution in operation, and the "waste" is actually useful fuel which produces energy.