3 ms·

Question about SMRs generally: does the fact that random private companies can apply to buy one of these, mean that nuclear reactors are now basically "state-se

by derefr 4y ago

Question about SMRs generally: does the fact that random private companies can apply to buy one of these, mean that nuclear reactors are now basically "state-secret free" as a technology? Or are there still state secrets, but they're all in the e.g. uranium enrichment part of the pipeline — that buying one of these gets you no closer to seeing — rather than in the reactor design?

scythe 4y ago
Building a nuclear warhead requires assembling a large sphere (ish) of material well above critical mass faster than it can explode. Only then does the chain reaction efficiently consume a lot of fuel before it breaks up (inertial confinement). Usually, you need to use explosives to blast the different pieces of fuel into each other. This requires very accurate control of the explosions that ignite the warhead, and is where the secrets are. A nuclear reactor uses fuel juuuust barely above critical mass so the reaction is slow. It's a very different thing. Producing the fuel is just basic centrifuge isotope separation, which has many non-fission applications.
- febusravenga 4y ago
  > juuuust barely above critical mass Interesting. Everyone says that nuclear reactors are safe and material can't be used to build bomb, how are we ensuring that were always only tiny bit above CM... And this bit doesn't grow unexpectedly. As laic, i see many failure modes, starting with simple accidents in handling of rods or bad storage
  - Wildgoose 4y ago
    It's actually just below Critical Mass. (For obvious reasons). You need sufficient fissile material to provide the increased neutron flow generating heat which you can use to power generators, but you have to then extract that heat efficiently to prevent your nuclear core from literally melting.
- YakBizzarro 4y ago
  well, not really. the fuel in typical reactor is lowly enriched uranium (LEU), meaning that only a small percentage of the fuel is actually fissile (ie. it breaks when interacting with one neutron and release energy). So no, it can't get sustain an exponentially growing reaction chain in any condition, since neutrons are absorbed by the non-fissile part of the fuel
le-mark 4y ago
Unintuitively, the principles nuclear reactors operate on are really very simple. Put enriched uranium rods close together and they get hot, hot enough to create steam and hence electricity. The complexity comes from designing and engineering for the reliability and safety scenarios. So no, no state secrets.
acidburnNSA 4y ago
All power reactors are free of state secrets and owned by private institutions. Some information is required by law to remain secret, such as locations of security hardening features, cameras, guns, etc. Good old Eisenhower and Atoms for Peace, 1953.
- derefr 4y ago
  > Some information is required by law to remain secret, such as locations of security hardening features, cameras, guns, etc. This was more what I was trying to motion toward — if you sell a power reactor to the private market, aren't you basically guaranteeing that "locations of security hardening features" and so forth will be able to be scrutinized at leisure by foreign state actors who can then use that information to attack other power infrastructure made to the same template?
  - geraldhh 4y ago
    true, this information will also be available to everyone in short time, but i don't think it's a big problem. secrecy is a sliding scale, and delaying and thinning out access to this information makes it "more secure" but surely some cleaning person will tell their buddies over a pint.
antonvs 4y ago
The security of nuclear power stations themselves is overseen in the US by the federal government - there’s a good description here: https://www.nei.org/resources/fact-sheets/nuclear-plant-security-and-access-control https://www.nei.org/resources/fact-sheets/nuclear-plant-secu... I worked on automated conversion of a large collection of documents for nuclear power stations some years back, and there was a lot of bureaucracy around who could access the documents, and how. I wasn’t supposed to take any files home, for example, which meant I couldn’t copy them onto a laptop. Management claimed that this was due to federal laws, but I didn’t ever investigate the legal basis.

by derefr 4y ago

scythe 4y ago

Building a nuclear warhead requires assembling a large sphere (ish) of material well above critical mass faster than it can explode. Only then does the chain reaction efficiently consume a lot of fuel before it breaks up (inertial confinement). Usually, you need to use explosives to blast the different pieces of fuel into each other. This requires very accurate control of the explosions that ignite the warhead, and is where the secrets are. A nuclear reactor uses fuel juuuust barely above critical mass so the reaction is slow. It's a very different thing. Producing the fuel is just basic centrifuge isotope separation, which has many non-fission applications.

febusravenga 4y ago
> juuuust barely above critical mass Interesting. Everyone says that nuclear reactors are safe and material can't be used to build bomb, how are we ensuring that were always only tiny bit above CM... And this bit doesn't grow unexpectedly. As laic, i see many failure modes, starting with simple accidents in handling of rods or bad storage
- Wildgoose 4y ago
  It's actually just below Critical Mass. (For obvious reasons). You need sufficient fissile material to provide the increased neutron flow generating heat which you can use to power generators, but you have to then extract that heat efficiently to prevent your nuclear core from literally melting.
YakBizzarro 4y ago
well, not really. the fuel in typical reactor is lowly enriched uranium (LEU), meaning that only a small percentage of the fuel is actually fissile (ie. it breaks when interacting with one neutron and release energy). So no, it can't get sustain an exponentially growing reaction chain in any condition, since neutrons are absorbed by the non-fissile part of the fuel

le-mark 4y ago

Unintuitively, the principles nuclear reactors operate on are really very simple. Put enriched uranium rods close together and they get hot, hot enough to create steam and hence electricity. The complexity comes from designing and engineering for the reliability and safety scenarios. So no, no state secrets.

acidburnNSA 4y ago

All power reactors are free of state secrets and owned by private institutions. Some information is required by law to remain secret, such as locations of security hardening features, cameras, guns, etc. Good old Eisenhower and Atoms for Peace, 1953.

derefr 4y ago
> Some information is required by law to remain secret, such as locations of security hardening features, cameras, guns, etc. This was more what I was trying to motion toward — if you sell a power reactor to the private market, aren't you basically guaranteeing that "locations of security hardening features" and so forth will be able to be scrutinized at leisure by foreign state actors who can then use that information to attack other power infrastructure made to the same template?
- geraldhh 4y ago
  true, this information will also be available to everyone in short time, but i don't think it's a big problem. secrecy is a sliding scale, and delaying and thinning out access to this information makes it "more secure" but surely some cleaning person will tell their buddies over a pint.

antonvs 4y ago

The security of nuclear power stations themselves is overseen in the US by the federal government - there’s a good description here: https://www.nei.org/resources/fact-sheets/nuclear-plant-security-and-access-control https://www.nei.org/resources/fact-sheets/nuclear-plant-secu... I worked on automated conversion of a large collection of documents for nuclear power stations some years back, and there was a lot of bureaucracy around who could access the documents, and how. I wasn’t supposed to take any files home, for example, which meant I couldn’t copy them onto a laptop. Management claimed that this was due to federal laws, but I didn’t ever investigate the legal basis.