5 ms·

New cracks in Hunterston reactor

39 points by reirob 12y ago

lucaspiller 12y ago
TL;DR; The cracks were expected and are well within the safety margin. > The tubular graphite bricks, each about a metre high, moderate nuclear reactions and are essential to safe operation. However, they cannot be replaced. Can anyone comment on why they can't be replaced?
- asuidyasiud 12y ago
  Re "well within the safety margin": > EDF was granted permission by the regulator in the summer to relax its graphite weight-loss limit at the Dungeness reactor in Kent from 6.2% to 8% after it came close to breaching the original safety margin. > Hinkley-B and Hunterston-B are also getting close to their higher 15% limits, too.
- deleted 12y ago
  [deleted]
- jackgavigan 12y ago
  You'd have to disassemble the entire core and rebuild it with new bricks. Kind of like replacing the bricks in a brick house. More information: http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport/7810.pdf http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport...
  - wastedhours 12y ago
    Except you can replace bricks in a brick house individually...
- 7952 12y ago
  Not every discussion about nuclear power has to be just about safety. I don't think anyone is seriously sugesting that these stations are dangerous. And most of us lack the expertise to have an opinion on the technicalities of the particular issue anyway. This does demonstrate an interesting aspect of large nuclear stations. Technical issues can remove large amounts of capacity from a grid. And as stations age the long term wear and tear make outages less predictable.
- ninjaoxygen 12y ago
  I think it is because the rods are inside the sealed reactor core, it's all radioactive. There's no way of opening them up in a way that would allow replacement of the rods.
sspiff 12y ago
Sounds similar to what caused the shutdown of some nuclear reactors in Belgium earlier this year and late last year. As a result we're facing power shortages in the coming winter.
- Luc 12y ago
  Only very superficially similar. The microscopic cracks in the Belgian reactors are in the steel pressure vessel, and are probably a manufacturing defect. What's puzzling is that the manufacturer in the Netherlands supplied pressure vessels of the same model to other countries (including 10 to the U.S.), and that the different testing procedures in those countries haven't turned up any problems.
brc 12y ago
This type of problem with extending lifetime shows the problems that are coming from a two- decade plus halt in construction of new plants due to fearmongering by pressure groups. Even though plant construction has recommenced, it's not possible to catch up. So the pressure groups have actually engendered a situation where a safety problem is more likely. Eliminating the plants was never going to be possible, accelerated replacement with better designs would have been a better outcome.
- spacefight 12y ago
  "pressure groups"? Care to explain the term?
  - brc 12y ago
    Any group that has spread non-factual anti-nuclear hysteria in order to oppose nuclear power generation and specifically the construction of new plants. The list is pretty extensive, really.
    - pjc50 12y ago
      There are plenty of farmers in the UK who had their livelihoods destroyed by Chernobyl (also a graphite-moderated design). Advocates of new nuclear cannot just dismiss concerns of catastrophic accidents as scaremongering, because the worst cases of accidents are extremely bad, even compared to chemical plants and coal related disasters. They also need to address the cost argument.
      - themartorana 12y ago
        Not that I have an answer to offer, but this is interesting to me. Coal and other fossil fuel power plants have caused slow, irreparable harm to the environment and human lives, but because of its slow and plodding nature, many consider it superior to nuclear. Nuclear disasters are much more furious in short periods of time, but I'm not sure that compressed in to a single number, that nuclear has been more harmful per-power-produced as fossil fuels. Maybe someone can properly refute or corroborate that statement. But it feels like an airliner going down. The size of the tragedy is great which puts irrational fear of flying in to people's heads, when it's about the safest mode of travel that exists.
dmm 12y ago
Everyone seems to talk about the safety of nuclear power but to me the costs are as big a problem. If it was affordable to build new plants these long term problems would be less important. I mean, has a nuclear power plant ever been built on budget? In my state the only nuclear plant was finished years late and 2 billion over the original 1 billion budget. Now they are trying to build another with a 6 billion budget. How much over will that one go? The prediction is that it will be producing power in 15-20 years. That's so long from now and meanwhile power users will be charged interest on the loans to build this thing. They are predicting a 30% increase in power demand in the next 20 years, so maybe it is the best option...
- reirob 12y ago
  Another cost that you don't mention is the cost of waste disposal. As far as I am informed no single country has yet found a safe, clean and cost-effective solution for nuclear waste disposal (correct me if I'm wrong here). If that is true this means that the cost estimation of all the reactors that we have until now are false and until now we do not even know what it will cost us in the future to "clean up the mess".
  - anon1385 12y ago
    No single country has yet found a safe, clean and cost-effective solution for coal waste disposal either. If you are going to get into the externalities of nuclear power, then you have to do the same for other technologies.
  - juliangamble 12y ago
    I'm interested to hear the critiques of Synrock as one method of addressing this problem. http://en.wikipedia.org/wiki/Synroc http://en.wikipedia.org/wiki/Synroc
  - gambiting 12y ago
    Because it's not really a pressing problem. Spent nuclear waste can sit in a swimming pool of water for any amount of time without endangering anyone. And water is so good at shielding radiation that you can even swim in such a pool. After few years the waste is moved to outside casks which are also not a danger to anyone. The only real problem is protecting those places from terrorists and such. But then again we have burnt coal ash sitting in huge piles outside under clear sky, and I would argue they pollute a lot more than a spent nuclear fuel cask does.

39 points by reirob 12y ago

TL;DR; The cracks were expected and are well within the safety margin. > The tubular graphite bricks, each about a metre high, moderate nuclear reactions and are essential to safe operation. However, they cannot be replaced. Can anyone comment on why they can't be replaced?

asuidyasiud 12y ago
Re "well within the safety margin": > EDF was granted permission by the regulator in the summer to relax its graphite weight-loss limit at the Dungeness reactor in Kent from 6.2% to 8% after it came close to breaching the original safety margin. > Hinkley-B and Hunterston-B are also getting close to their higher 15% limits, too.
deleted 12y ago
[deleted]
jackgavigan 12y ago
You'd have to disassemble the entire core and rebuild it with new bricks. Kind of like replacing the bricks in a brick house. More information: http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport/7810.pdf http://www.greenpeace.org.uk/MultimediaFiles/Live/FullReport...
- wastedhours 12y ago
  Except you can replace bricks in a brick house individually...
7952 12y ago
Not every discussion about nuclear power has to be just about safety. I don't think anyone is seriously sugesting that these stations are dangerous. And most of us lack the expertise to have an opinion on the technicalities of the particular issue anyway. This does demonstrate an interesting aspect of large nuclear stations. Technical issues can remove large amounts of capacity from a grid. And as stations age the long term wear and tear make outages less predictable.
ninjaoxygen 12y ago
I think it is because the rods are inside the sealed reactor core, it's all radioactive. There's no way of opening them up in a way that would allow replacement of the rods.

sspiff 12y ago

Sounds similar to what caused the shutdown of some nuclear reactors in Belgium earlier this year and late last year. As a result we're facing power shortages in the coming winter.

Luc 12y ago
Only very superficially similar. The microscopic cracks in the Belgian reactors are in the steel pressure vessel, and are probably a manufacturing defect. What's puzzling is that the manufacturer in the Netherlands supplied pressure vessels of the same model to other countries (including 10 to the U.S.), and that the different testing procedures in those countries haven't turned up any problems.

brc 12y ago

This type of problem with extending lifetime shows the problems that are coming from a two- decade plus halt in construction of new plants due to fearmongering by pressure groups. Even though plant construction has recommenced, it's not possible to catch up. So the pressure groups have actually engendered a situation where a safety problem is more likely. Eliminating the plants was never going to be possible, accelerated replacement with better designs would have been a better outcome.

spacefight 12y ago
"pressure groups"? Care to explain the term?
- brc 12y ago
  Any group that has spread non-factual anti-nuclear hysteria in order to oppose nuclear power generation and specifically the construction of new plants. The list is pretty extensive, really.
  - pjc50 12y ago
    There are plenty of farmers in the UK who had their livelihoods destroyed by Chernobyl (also a graphite-moderated design). Advocates of new nuclear cannot just dismiss concerns of catastrophic accidents as scaremongering, because the worst cases of accidents are extremely bad, even compared to chemical plants and coal related disasters. They also need to address the cost argument.
    - themartorana 12y ago
      Not that I have an answer to offer, but this is interesting to me. Coal and other fossil fuel power plants have caused slow, irreparable harm to the environment and human lives, but because of its slow and plodding nature, many consider it superior to nuclear. Nuclear disasters are much more furious in short periods of time, but I'm not sure that compressed in to a single number, that nuclear has been more harmful per-power-produced as fossil fuels. Maybe someone can properly refute or corroborate that statement. But it feels like an airliner going down. The size of the tragedy is great which puts irrational fear of flying in to people's heads, when it's about the safest mode of travel that exists.

dmm 12y ago

Everyone seems to talk about the safety of nuclear power but to me the costs are as big a problem. If it was affordable to build new plants these long term problems would be less important. I mean, has a nuclear power plant ever been built on budget? In my state the only nuclear plant was finished years late and 2 billion over the original 1 billion budget. Now they are trying to build another with a 6 billion budget. How much over will that one go? The prediction is that it will be producing power in 15-20 years. That's so long from now and meanwhile power users will be charged interest on the loans to build this thing. They are predicting a 30% increase in power demand in the next 20 years, so maybe it is the best option...

reirob 12y ago
Another cost that you don't mention is the cost of waste disposal. As far as I am informed no single country has yet found a safe, clean and cost-effective solution for nuclear waste disposal (correct me if I'm wrong here). If that is true this means that the cost estimation of all the reactors that we have until now are false and until now we do not even know what it will cost us in the future to "clean up the mess".
- anon1385 12y ago
  No single country has yet found a safe, clean and cost-effective solution for coal waste disposal either. If you are going to get into the externalities of nuclear power, then you have to do the same for other technologies.
- juliangamble 12y ago
  I'm interested to hear the critiques of Synrock as one method of addressing this problem. http://en.wikipedia.org/wiki/Synroc http://en.wikipedia.org/wiki/Synroc
- gambiting 12y ago
  Because it's not really a pressing problem. Spent nuclear waste can sit in a swimming pool of water for any amount of time without endangering anyone. And water is so good at shielding radiation that you can even swim in such a pool. After few years the waste is moved to outside casks which are also not a danger to anyone. The only real problem is protecting those places from terrorists and such. But then again we have burnt coal ash sitting in huge piles outside under clear sky, and I would argue they pollute a lot more than a spent nuclear fuel cask does.