4 ms·

I consider these passively-stable waste disposal solutions that are supposed to last 10,000-1,000,000 years without maintenance over-engineered and founded on d

I consider these passively-stable waste disposal solutions that are supposed to last 10,000-1,000,000 years without maintenance over-engineered and founded on dubious assumptions. I think that something like surface dry cask storage in a dry, geologically stable area is a lot better. The facility should have ongoing monitoring and the capability to re-cask units every few decades or centuries. If there's some weird failure mode that can't be discovered in artificial accelerated aging tests, future caretakers will be much better poised to cope with the problem if they actually have access to the waste. You don't need to try to invent a language that will survive into deep time, you don't have to use gargantuan safety margins to in an attempt to offset the unknowns of deep time, and so on. What if the maintainer-civilization collapses? And what if nobody a thousand years from now knows how to build steel and concrete vessels or detect ionizing radiation? The somewhat cold but IMO correct answer is then those future low-tech humans will not suffer much risk from our spent fuel, relatively speaking. Making steel and concrete, making radiosensitive photographic emulsions -- these are 19th century technologies. If humans of the distant future don't have even 19th-century-equivalent technology, they probably have such high ambient morbidity and mortality from infectious disease that leaking nuclear waste will not much diminish their quality nor quantity of life. Not to mention that the most dangerous components of spent fuel -- short- and medium-lived fission products -- will be diminished a billion-fold or more after 1,000 years pass. Spent light water reactor fuel fresh from the reactor is orders of magnitude more hazardous per unit mass than any stable element. But after 1,000 years or so the hazard is greatly diminished. At that point it's more akin to a mundanely-hazardous waste like cadmium. Nobody plans how to communicate the hazards of cadmium exposure into geological time even though it endures forever.

cmsmith 10y ago
There is also a lot of more dangerous nuclear material scattered all over the country in bombs and power plants - none of which are designed to last more than a few decades. If society does collapse, and that collapse is not precipitated by total nuclear war, then it seems like the spent fuel won't even be the worst of the nuclear worries out there.
- xvilka 10y ago
  I think nuclear submarines are even more dangerous, since marine environment is much more aggressive than terrestrial one. Thus it will lead to very fast corrosion and reactor's shell corruption. But nobody cares about that.
redwood 10y ago
How do you quantify and then accept the risk of said casks being hit and made to catch fire by a kinetic object?
- philipkglass 10y ago
  The casks are too thick to be penetrated by civilian firearms. They could be further protected from man-portable weapons (e.g. anti-tank guided missiles) by locating them shallowly underground, where monitoring/maintenance is still easy. Military attack on the storage site with heavy weapons? That's approximately equal to the case of a military attack on a live power reactor, with the same dire consequences and responses. (If a shooting war has escalated to war crimes against nuclear powers, I expect that MAD is just around the corner.)
- edblarney 10y ago
  It's not flammable. And properly processed, even a leakage in the containment wouldn't necessarily be disastrous, i.e. requires cleanup, but no like chernobyl problems. I wish we would put more research into this. Imagine if we could make nuclear waste relatively benign? It would revolutionize the entire world.
pdkl95 10y ago
> over-engineered and founded on dubious assumptions Not only is it over-engineered, it's incredibly wasteful. Eventually we will move to other reactor designs that utilize more than just a few percent of the useful isotopes in the fuel. With several types of breeder rectors and/or reprocessing a lot of that "waste" is potential fuel. I suspect most people don't understand just how little fuel is required for nuclear power. We are used to the scale of chemical fuels and don't have an experience with the massive difference in energy density. The chemical. mining, and other industries associated with the Superfund have already caused an incredible amount of damage that we will be cleaning up for the foreseeable future. I'd much rather live near nuclear waste stored in easily manage dry casks over any of the sites with e.g. PCB or heavy metal contamination.
- inetknght 10y ago
  Yeah I'm not a chemist but it always strikes me as odd that "hazardous nuclear waste" cannot be recycled. Even now there are ways to capture carbon waste (eg, genetically-engineered carbon-eating bacteria et al). I find it hard to believe that we won't have a way to capture radiation in the future, or (even better) utilize the radiation-producing materials in subsequent reactions.
  - bsder 10y ago
    > I find it hard to believe that we won't have a way to capture radiation in the future The problem is the energy density. Nuclear reactions are soooo much more energetic than chemical that it's ridiculous. "Capturing" a gamma ray is really hard. Beta particles are "easier", but you still have to handle a LOT of them. And cracking the nucleus apart is what you were doing in the first place generating energy from it. The best bet is to use reactor technology that actually burns up the waste almost completely rather than leaving 95% of it intact. The problem is that the superpowers like their reactors that can give Plutonium. Until the a country decides it wants power rather than weapons and designs a reactor for that, we're going to continue all this political dancing.
  - gh02t 10y ago
    It can be, quite effectively. Nuclear waste is more or less a solved issue from a technical standpoint, with the caveat that there are a lot of gotchas but the general concept is well understood and several other countries do it to some degree. With regard to the USA, we don't do it for two reasons. First is political, which that the recycling process is highly susceptible to weapons proliferation. While that's not a problem in the US per se (since we're a treaty nuclear weapons state), there was a ban put on reprocessing in the US because we didn't want it to become widespread due to the proliferation risk. Remember that pretty much all policy regarding nuclear energy was totally subservient to policy regarding nuclear weapons up until like the 1990's. Second is economic. Uranium is cheap as chips and it'd require a big investment to move to reprocessing. We will probably do it some day though, the general sentiment in the nuclear community is that reprocessing is a much better route than ultra long-term geological repositories.
danpat 10y ago
As a practical example, the aboriginal people of Australia (particularly in the north) refer to a thing called "sickness country": http://www.artistwd.com/joyzine/australia/abr_culture/sickness_country.php These have generally been found to be regions with a lot of near surface uranium ore. Given enough time, people will figure out that certain areas are dangerous and should be avoided. As long as it's not everywhere, it probably won't threaten the whole of humanity.
mikeash 10y ago
It's weird that we have chemical waste that lasts forever and nobody's trying to leave messages for future civilizations about it. Something about having a definite timeline makes people worry more. Saying that X will be dangerous for ten thousand years motivates people more than saying Y will be dangerous until the end of time.
- DrScump 10y ago
  Not to mention the legacy of waste dumped into the atmosphere, including airborne radioactive waste from coal burning.
  - mikeash 10y ago
    The one that really blows my mind is the recommendation that children and pregnant women limit their intake of seafood due to mercury contamination. That's an entire category of food, covering two thirds of the planet, made noticeably dangerous by chemical waste.
wycx 10y ago
Particularly if those casks contain HLW stabilised as Synroc[1]. Synroc, unlike glass wasteforms, consists of mineral phases, the bulk composition is carefully chosen such that the mineral assemblage provides each nuclide with an energetically favorable crystallographic site. [1] https://en.wikipedia.org/wiki/Synroc https://en.wikipedia.org/wiki/Synroc

cmsmith 10y ago

There is also a lot of more dangerous nuclear material scattered all over the country in bombs and power plants - none of which are designed to last more than a few decades. If society does collapse, and that collapse is not precipitated by total nuclear war, then it seems like the spent fuel won't even be the worst of the nuclear worries out there.

xvilka 10y ago
I think nuclear submarines are even more dangerous, since marine environment is much more aggressive than terrestrial one. Thus it will lead to very fast corrosion and reactor's shell corruption. But nobody cares about that.

redwood 10y ago

How do you quantify and then accept the risk of said casks being hit and made to catch fire by a kinetic object?

philipkglass 10y ago
The casks are too thick to be penetrated by civilian firearms. They could be further protected from man-portable weapons (e.g. anti-tank guided missiles) by locating them shallowly underground, where monitoring/maintenance is still easy. Military attack on the storage site with heavy weapons? That's approximately equal to the case of a military attack on a live power reactor, with the same dire consequences and responses. (If a shooting war has escalated to war crimes against nuclear powers, I expect that MAD is just around the corner.)
edblarney 10y ago
It's not flammable. And properly processed, even a leakage in the containment wouldn't necessarily be disastrous, i.e. requires cleanup, but no like chernobyl problems. I wish we would put more research into this. Imagine if we could make nuclear waste relatively benign? It would revolutionize the entire world.

pdkl95 10y ago

> over-engineered and founded on dubious assumptions Not only is it over-engineered, it's incredibly wasteful. Eventually we will move to other reactor designs that utilize more than just a few percent of the useful isotopes in the fuel. With several types of breeder rectors and/or reprocessing a lot of that "waste" is potential fuel. I suspect most people don't understand just how little fuel is required for nuclear power. We are used to the scale of chemical fuels and don't have an experience with the massive difference in energy density. The chemical. mining, and other industries associated with the Superfund have already caused an incredible amount of damage that we will be cleaning up for the foreseeable future. I'd much rather live near nuclear waste stored in easily manage dry casks over any of the sites with e.g. PCB or heavy metal contamination.

inetknght 10y ago
Yeah I'm not a chemist but it always strikes me as odd that "hazardous nuclear waste" cannot be recycled. Even now there are ways to capture carbon waste (eg, genetically-engineered carbon-eating bacteria et al). I find it hard to believe that we won't have a way to capture radiation in the future, or (even better) utilize the radiation-producing materials in subsequent reactions.
- bsder 10y ago
  > I find it hard to believe that we won't have a way to capture radiation in the future The problem is the energy density. Nuclear reactions are soooo much more energetic than chemical that it's ridiculous. "Capturing" a gamma ray is really hard. Beta particles are "easier", but you still have to handle a LOT of them. And cracking the nucleus apart is what you were doing in the first place generating energy from it. The best bet is to use reactor technology that actually burns up the waste almost completely rather than leaving 95% of it intact. The problem is that the superpowers like their reactors that can give Plutonium. Until the a country decides it wants power rather than weapons and designs a reactor for that, we're going to continue all this political dancing.
- gh02t 10y ago
  It can be, quite effectively. Nuclear waste is more or less a solved issue from a technical standpoint, with the caveat that there are a lot of gotchas but the general concept is well understood and several other countries do it to some degree. With regard to the USA, we don't do it for two reasons. First is political, which that the recycling process is highly susceptible to weapons proliferation. While that's not a problem in the US per se (since we're a treaty nuclear weapons state), there was a ban put on reprocessing in the US because we didn't want it to become widespread due to the proliferation risk. Remember that pretty much all policy regarding nuclear energy was totally subservient to policy regarding nuclear weapons up until like the 1990's. Second is economic. Uranium is cheap as chips and it'd require a big investment to move to reprocessing. We will probably do it some day though, the general sentiment in the nuclear community is that reprocessing is a much better route than ultra long-term geological repositories.

danpat 10y ago

As a practical example, the aboriginal people of Australia (particularly in the north) refer to a thing called "sickness country": http://www.artistwd.com/joyzine/australia/abr_culture/sickness_country.php These have generally been found to be regions with a lot of near surface uranium ore. Given enough time, people will figure out that certain areas are dangerous and should be avoided. As long as it's not everywhere, it probably won't threaten the whole of humanity.

mikeash 10y ago

It's weird that we have chemical waste that lasts forever and nobody's trying to leave messages for future civilizations about it. Something about having a definite timeline makes people worry more. Saying that X will be dangerous for ten thousand years motivates people more than saying Y will be dangerous until the end of time.

DrScump 10y ago
Not to mention the legacy of waste dumped into the atmosphere, including airborne radioactive waste from coal burning.
- mikeash 10y ago
  The one that really blows my mind is the recommendation that children and pregnant women limit their intake of seafood due to mercury contamination. That's an entire category of food, covering two thirds of the planet, made noticeably dangerous by chemical waste.

wycx 10y ago

Particularly if those casks contain HLW stabilised as Synroc[1]. Synroc, unlike glass wasteforms, consists of mineral phases, the bulk composition is carefully chosen such that the mineral assemblage provides each nuclide with an energetically favorable crystallographic site. [1] https://en.wikipedia.org/wiki/Synroc https://en.wikipedia.org/wiki/Synroc