Future of transportation on Earth - Electric airplanes or Vactrains?

[K^2]

As far as I understand it, modern concepts for nuclear isomer batteries work by "turning on" radioactive decay of an otherwise stable or metastable isomer. Once you stimulate decay, you're still constrained by the half life of the isomer, so it's next to impossible to release all of the energy at once (unless you can build a trigger based on completely different physics from the one you use for the controlled release of energy).

Essentially. However, the metastable half-life is on the order of decades, while the triggered half-life can be on the order of fraction of a second. So while there is, technically, a half-life limit, in practice, it's short enough that you can get as much power as you need for your application.

That said, from my layman's understanding, such batteries might not be "rechargeable", and therefore would be extremely expensive for civilian use.

Some of them are rechargeable, but the only known, practical way to recharge these is with synchrotron radiation. So currently, it's absurdly expensive either way.

That said, it's already much more manageable now than it was a decade ago. So we might see practical rechargeable nuclear isomer batteries within our life time.

[Idobox]

Seriously, nuclear isomer batteries cannot be used on airplanes, not because of safety issues, but because of cost issues.

Nuclear isomers are produced in small quantities by certain nuclear reaction. They are basically extracted for spent fuel. They make sense for space probes or other applications where RTG are relevant, but can't be used as a energy storage solution on any meaningful scale (Unless somebody found a way to charge them up). And the stimulated decay is predicted, and although some observations have been made, confirmation is still needed to make sure it can actually happen.

Making nuclear bombs is not so much a physics problem as it is an engineering one, a very expensive one, and then you need a delivery mechanism. The French nuclear arsenal (quite small compared to other countries) is estimated to cost between 3 and 15 billion euros a year (people are arguing right now about whether we should keep it or not). A single University doesn't have the resources to build a useful nuclear bomb.

[Jouni]

Making nuclear bombs is not so much a physics problem as it is an engineering one, a very expensive one, and then you need a delivery mechanism. The French nuclear arsenal (quite small compared to other countries) is estimated to cost between 3 and 15 billion euros a year (people are arguing right now about whether we should keep it or not).

Nuclear weapons themselves are actually quite cheap. According to one estimate, the biggest expenses in the US nuclear weapons program were the following:

• 57% for delivery systems
  
• 16.1% for defending against nuclear weapons
  
• 14.3% for targeting and control systems
  
• 7% for the nuclear warheads themselves
  
• 6.3% for handling nuclear waste and environmental damage
  

The biggest expense is maintaining a major military force. Adding nukes to the mix only increases the costs by 10-20%.

A single University doesn't have the resources to build a useful nuclear bomb.

A few of them might actually have. Harvard, Yale, and King Abdullah have endowments comparable to the cost of the Manhattan Project. Several others also have over $10 billion.

[cpast]

A few of them might actually have. Harvard, Yale, and King Abdullah have endowments comparable to the cost of the Manhattan Project. Several others also have over $10 billion.

King Abdullah meaning KAUST, or something else?

[WestAir]

I wonder how NATO and the UN would react if Yale began a Manhattan Project as a senior class project, with the final exam being an above ground test at sea.

"Next week, class, we're going to combine a Tsar Bomba with some of NATO's cease and desist orders. Please review all of your thermonuclear ICBM homework assignments."

Edited August 26, 2014 by WestAir

[Kryten]

A few of them might actually have. Harvard, Yale, and King Abdullah have endowments comparable to the cost of the Manhattan Project. Several others also have over $10 billion.

That's not what was meant by resources. You can't build a nuke out of dollar bills, no matter how many you have.

[K^2]

Seriously, nuclear isomer batteries cannot be used on airplanes, not because of safety issues, but because of cost issues.

Nuclear isomers are produced in small quantities by certain nuclear reaction. They are basically extracted for spent fuel. They make sense for space probes or other applications where RTG are relevant, but can't be used as a energy storage solution on any meaningful scale (Unless somebody found a way to charge them up). And the stimulated decay is predicted, and although some observations have been made, confirmation is still needed to make sure it can actually happen.

They can be recharged and they can be triggered. The experiments on both are still partially classified, but the conclusions have been released on at least some of them.

Granted, current method of recharge involves a particle accelerator. So the cost of using rechargeable nuclear isomer batteries is still quite high. In fact, higher than these produced as byproduct of nuclear reactor. But there have been a lot of interesting results in just past few years on reducing energy requirements, bringing it closer to possibility of eventually having cost-efficient charge stations some time in the future.

I wouldn't hold my breath for it, but we will more likely than not have practical nuclear isomer batteries eventually.

[Idobox]

They can be recharged and they can be triggered. The experiments on both are still partially classified, but the conclusions have been released on at least some of them.

Granted, current method of recharge involves a particle accelerator. So the cost of using rechargeable nuclear isomer batteries is still quite high. In fact, higher than these produced as byproduct of nuclear reactor. But there have been a lot of interesting results in just past few years on reducing energy requirements, bringing it closer to possibility of eventually having cost-efficient charge stations some time in the future.

I wouldn't hold my breath for it, but we will more likely than not have practical nuclear isomer batteries eventually.

Do you have references on the triggering?

Nuclear isomer will be used if they manage to make them work, for sure, but for applications where you don't care about the cost, and neither chemical batteries nor liquid fuel can do the job. That means space, and maybe some military applications. If we're very lucky, we might see them applied to medical exoskeletons, but air-metal batteries seem to make much more sense there.

Even if they figure out an efficient way to recharge them with synchrotron radiation, remember that synchrotron radiation is terribly expensive.

For reference, the ESRF, the European Synchrotron Facility, has 41 beamlines of 10kW, and it has cost 2.6 billion FF (400M€) to build , and 340 million FF (50M€) yearly to run (in 1998, couldn't find more recent numbers). This gives us a running cost of 14€/kWh (actually a bit more, I assumed continuous operation all year long). For comparison, electricity costs around .1 €/kWh. Even by imagining very cost efficient synchrotron sources, nuclear isomers batteries will be significantly more expensive to run than chemical ones.

[NGTOne]

I wonder how NATO and the UN would react if Yale began a Manhattan Project as a senior class project, with the final exam being an above ground test at sea.

*hurriedly goes to write a proposal*

[YNM]

My opinion goes to anything akin of a train. Infrastructure might be more expensive but you get a slightly faster return, not to mention that you need less space (it can be all underground or so, unlike airplanes).

Planes are just for remote areas (like, those oceanian countries. Or small, remote islands...)