6 ms·

"Nothing like this will be built again": a tour of a working nuclear reactor

160 points by gjm11 16y ago

gjm11 16y ago
This has been posted here before, about two years ago -- http://news.ycombinator.com/item?id=569564 http://news.ycombinator.com/item?id=569564 -- but (1) it's very good and (2) the old URL no longer works. It's by Charlie Stross, a science fiction author and former hacker. It describes a lengthy tour of the nuclear reactor complex at Torness in Scotland.
- ScotterC 16y ago
  Not to mention that it's an AGR (Advanced Gas cooled Reactor) something that doesn't exist in the U.S. or most of the world. Very cool.
  - lkiujhygjk 16y ago
    Very clever design, much more efficent, much safer - negative temp coeff and no chance of a steam explosion. But they never reached the critical mass (sorry) to make them standard and so cheap to build and operate.
- burgerbrain 16y ago
  He also posts on HN as 'cstross'.
arethuza 16y ago
When I worked in academia I did one project with Scottish Nuclear and one of their team had worked on the project to build Torness. He had a story about one of the failure modes they had to consider during the design. AGRs can be refueled while they are operational by a huge machine that moves across the top of the reactor and allows the fuel rods to be extracted from the extremely high pressure environment of the reactor core. The refueling machine is basically a long thing container that fuel rods can be raised into or lowered from. They had to consider the case of what would happen if the refueling machine wasn't properly pressurized before the connection to the reactor core was opened (which can't really happen for a variety of reasons). However, if it did happen they realized that the refueling machine would basically act like a very large gun shooting hot fuel rods through the roof of the reactor building powered by the high pressure CO2 from the reactor core. Every time I pass Torness on the train I can't help looking to see if there are any fuel rods flying into the air. So far, so good....
jedsmith 16y ago
> For starters, some embedded controllers in racks in the auxilliary deisel generator control rooms have EPROMs which have been known to be erased by camera flashes in the past Not being in EE, I didn't know that this was possible; and, with the knowledge that a bright flash erases EPROMs, that they'd be left in a position where this could occur. More interestingly, the NRO has a notice about it: http://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1997/in97082.html http://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-... The government verbiage for the hack here (tape over the window) is amusing in itself: > They also confirmed that the light from the Canon flash and the Polaroid flashbulb could be effectively blocked by "black bagging" the flash, or by blocking the EPROM window with "tin foil" held in place by clear cellulose tape, or by blocking the EPROM window with "standard electrical tape."
- nitrogen 16y ago
  I remember seeing a motherboard or video card BIOS stored on EPROMs as a kid, and wondering what it would happen if I took the light-blocking sticker off and shined a black light in the computer while it was running. It is interesting, though not too surprising, that the EPROMs are exposed in the racks. If nobody's ever going to be in the room, why bother putting walls on the racks? Also, it's probably a good thing that flash memory was invented before the ultraviolet LED, otherwise we might be stuck with LED-based EPROMs with painfully slow erase cycles ;).
  - spitfire 16y ago
    Trident 8800CS! Had hi/lo eeproms with a reflective hologram sticker over the eeprom window. Now we upload microcode/firmware on bootup. We have things so good.
    - nitrogen 16y ago
      I loved my Trident. It was the first video card I owned that could do 1024x768. It's been so many years that I don't remember all the other steps I went through between Hercules and CGA to a modern nVidia, but almost every one of them was special in some way.
ScotterC 16y ago
"Energy to cheap to meter". It pains me. I'm so glad to see a good writer give some strength to how massive and impressive these reactors are. But it pains me as he describes system after thoroughly redundant system adding to the costs of these reactors. I'm much more familiar with PWRs (Pressurized Water Reactors) which yes, are a bit smaller and less efficient, but the plans and schematics are like a first time run through of a problem. Nothing re-factored, nothing elegant, just plain and simple brute force design to make it work. There's no reason for four diesel generators when two would do. There's no reason for multiple chemical volume and control systems. There's no reason for 6 foot thick, steel re-barred concrete containment in a negative void coefficient reactor! My take-away from working in the industry is regulation severely impedes innovation. I fear that our greatest discovery since fire is languishing. Nuclear energy will be used to great extent in the future, but I can't stand the current delays. Energy is conceivably too cheap to meter in it's current form. You could conceivably pay, not by your kilowatt-hour, but a fixed monthly subscription to unlimited energy. Just think about what you could do with that! Edit: -- Misread the article. PWR's are less efficient than AGRs
- moe 16y ago
  There's no reason for four diesel generators when two would do. There's no reason for multiple chemical volume and control systems. So you are saying this reactor type is still safe even when both diesels fail or when the chemical volume/control systems fail? I'm honestly curious (my knowledge about nuclear reactors is fairly minimal).
- Retric 16y ago
  Sorry, they are less efficient not more. Getting 43% from a nuclear power plant is incredibly difficult.
  - ScotterC 16y ago
    Noted and edited. However, not the point of my post. AGR's, PWR's, and all current reactors for that matter are grossly over designed. 43% of energy is incredible but the redundant systems of the plant have nothing to do with the efficiency of the plant.
uvdiv 16y ago
Here's a large (35 inches) cutaway drawing of a Magnox reactor, which gives some visual scale to the monster that is a gas-cooled reactor: (PDF) http://econtent.unm.edu/cgi-bin/showfile.exe?CISOROOT=/nuceng&CISOPTR=47&filename=42.pdf http://econtent.unm.edu/cgi-bin/showfile.exe?CISOROOT=/nucen... (Note this isn't the AGR that Stross depicts, but its predecessor the Magnox). For size reference, the six boilers are 118 feet tall by 18 feet diameter (36m * 5.5m); the building is 170 feet high (52 m).
Maro 16y ago
When I was getting my degree is Physics we had a lab in the "student reactor", which was still in a large building of its own. As part of the lab we got to sit down to the control console of the reactor and control it, on our own. I remember I was turning one knob increasing the power output when suddenly there was a loud noise, everything shook, and the power output went to zero. Turned out it was the failsafe (I think cadmium rods dropped into the core) as I was too agressive with the controls --- it was a normal occurence for students. (All modern reactors are designed in a way that you can't overdrive them, they'll automatically shut down.) It was great fun and a story I'll be telling for the rest of my life.

160 points by gjm11 16y ago

gjm11 16y ago

This has been posted here before, about two years ago -- http://news.ycombinator.com/item?id=569564 http://news.ycombinator.com/item?id=569564 -- but (1) it's very good and (2) the old URL no longer works. It's by Charlie Stross, a science fiction author and former hacker. It describes a lengthy tour of the nuclear reactor complex at Torness in Scotland.

ScotterC 16y ago
Not to mention that it's an AGR (Advanced Gas cooled Reactor) something that doesn't exist in the U.S. or most of the world. Very cool.
- lkiujhygjk 16y ago
  Very clever design, much more efficent, much safer - negative temp coeff and no chance of a steam explosion. But they never reached the critical mass (sorry) to make them standard and so cheap to build and operate.
burgerbrain 16y ago
He also posts on HN as 'cstross'.

arethuza 16y ago

When I worked in academia I did one project with Scottish Nuclear and one of their team had worked on the project to build Torness. He had a story about one of the failure modes they had to consider during the design. AGRs can be refueled while they are operational by a huge machine that moves across the top of the reactor and allows the fuel rods to be extracted from the extremely high pressure environment of the reactor core. The refueling machine is basically a long thing container that fuel rods can be raised into or lowered from. They had to consider the case of what would happen if the refueling machine wasn't properly pressurized before the connection to the reactor core was opened (which can't really happen for a variety of reasons). However, if it did happen they realized that the refueling machine would basically act like a very large gun shooting hot fuel rods through the roof of the reactor building powered by the high pressure CO2 from the reactor core. Every time I pass Torness on the train I can't help looking to see if there are any fuel rods flying into the air. So far, so good....

jedsmith 16y ago

> For starters, some embedded controllers in racks in the auxilliary deisel generator control rooms have EPROMs which have been known to be erased by camera flashes in the past Not being in EE, I didn't know that this was possible; and, with the knowledge that a bright flash erases EPROMs, that they'd be left in a position where this could occur. More interestingly, the NRO has a notice about it: http://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-notices/1997/in97082.html http://www.nrc.gov/reading-rm/doc-collections/gen-comm/info-... The government verbiage for the hack here (tape over the window) is amusing in itself: > They also confirmed that the light from the Canon flash and the Polaroid flashbulb could be effectively blocked by "black bagging" the flash, or by blocking the EPROM window with "tin foil" held in place by clear cellulose tape, or by blocking the EPROM window with "standard electrical tape."

nitrogen 16y ago
I remember seeing a motherboard or video card BIOS stored on EPROMs as a kid, and wondering what it would happen if I took the light-blocking sticker off and shined a black light in the computer while it was running. It is interesting, though not too surprising, that the EPROMs are exposed in the racks. If nobody's ever going to be in the room, why bother putting walls on the racks? Also, it's probably a good thing that flash memory was invented before the ultraviolet LED, otherwise we might be stuck with LED-based EPROMs with painfully slow erase cycles ;).
- spitfire 16y ago
  Trident 8800CS! Had hi/lo eeproms with a reflective hologram sticker over the eeprom window. Now we upload microcode/firmware on bootup. We have things so good.
  - nitrogen 16y ago
    I loved my Trident. It was the first video card I owned that could do 1024x768. It's been so many years that I don't remember all the other steps I went through between Hercules and CGA to a modern nVidia, but almost every one of them was special in some way.

ScotterC 16y ago

"Energy to cheap to meter". It pains me. I'm so glad to see a good writer give some strength to how massive and impressive these reactors are. But it pains me as he describes system after thoroughly redundant system adding to the costs of these reactors. I'm much more familiar with PWRs (Pressurized Water Reactors) which yes, are a bit smaller and less efficient, but the plans and schematics are like a first time run through of a problem. Nothing re-factored, nothing elegant, just plain and simple brute force design to make it work. There's no reason for four diesel generators when two would do. There's no reason for multiple chemical volume and control systems. There's no reason for 6 foot thick, steel re-barred concrete containment in a negative void coefficient reactor! My take-away from working in the industry is regulation severely impedes innovation. I fear that our greatest discovery since fire is languishing. Nuclear energy will be used to great extent in the future, but I can't stand the current delays. Energy is conceivably too cheap to meter in it's current form. You could conceivably pay, not by your kilowatt-hour, but a fixed monthly subscription to unlimited energy. Just think about what you could do with that! Edit: -- Misread the article. PWR's are less efficient than AGRs

moe 16y ago
There's no reason for four diesel generators when two would do. There's no reason for multiple chemical volume and control systems. So you are saying this reactor type is still safe even when both diesels fail or when the chemical volume/control systems fail? I'm honestly curious (my knowledge about nuclear reactors is fairly minimal).
Retric 16y ago
Sorry, they are less efficient not more. Getting 43% from a nuclear power plant is incredibly difficult.
- ScotterC 16y ago
  Noted and edited. However, not the point of my post. AGR's, PWR's, and all current reactors for that matter are grossly over designed. 43% of energy is incredible but the redundant systems of the plant have nothing to do with the efficiency of the plant.

uvdiv 16y ago

Here's a large (35 inches) cutaway drawing of a Magnox reactor, which gives some visual scale to the monster that is a gas-cooled reactor: (PDF) http://econtent.unm.edu/cgi-bin/showfile.exe?CISOROOT=/nuceng&CISOPTR=47&filename=42.pdf http://econtent.unm.edu/cgi-bin/showfile.exe?CISOROOT=/nucen... (Note this isn't the AGR that Stross depicts, but its predecessor the Magnox). For size reference, the six boilers are 118 feet tall by 18 feet diameter (36m * 5.5m); the building is 170 feet high (52 m).

Maro 16y ago

When I was getting my degree is Physics we had a lab in the "student reactor", which was still in a large building of its own. As part of the lab we got to sit down to the control console of the reactor and control it, on our own. I remember I was turning one knob increasing the power output when suddenly there was a loud noise, everything shook, and the power output went to zero. Turned out it was the failsafe (I think cadmium rods dropped into the core) as I was too agressive with the controls --- it was a normal occurence for students. (All modern reactors are designed in a way that you can't overdrive them, they'll automatically shut down.) It was great fun and a story I'll be telling for the rest of my life.