WI: Less Focus on Reprocessing and Breeder Reactors in the 1960s/1970s

Apart from Canada, were there any other countries looking into natural uranium reactors in the 1960s and 1970s? Was anyone looking into using them alongside enriched uranium reactors?

Britain with Magnox. IIRC it's successor, the AGR, ended up using LEU, but they initially wanted to go with natural uranium. Since Magnox used natural uranium, they ended up with both LEU-fueled and natural-fueled.
 
Why are there no breeder reactors used today? They could be used to get rid of all that nuclear waste.
 
Why are there no breeder reactors used today? They could be used to get rid of all that nuclear waste.

They're expensive to build, and the designs that were tested have some safety issues. (For example, they used sodium coolant, which is flammable. In principle, it's possible to build breeders with other, safer coolants, but it's harder, and nobody's done it yet.)
 

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Britain with Magnox. IIRC it's successor, the AGR, ended up using LEU, but they initially wanted to go with natural uranium. Since Magnox used natural uranium, they ended up with both LEU-fueled and natural-fueled.

Magnox is able to use natural uranium because the magnesium cladding doesn't reduce neutron capture too much. However, the AGR had to use steel so it could operate at higher temperatures with more efficiency, which requires the fuel to be enriched to compensate for the higher neutron capture of steel. The fuel types are thus incompatible with each other going either direction. Is there a type of fuel that could have been used for both Magnox and the AGR? What about zirconium alloy?

Why are there no breeder reactors used today? They could be used to get rid of all that nuclear waste.

They are not commercially viable right now for any role. It is less expensive to mine new uranium than to use a breeder reactor or even reprocess existing fuel. Breeder reactors are also not as reliable as fossil fuel powered generation or more conventional nuclear reactors. While conventional reactors are the most reliable form of power generation and operate 90% of the time, the most reliable breeder reactor has achieved a capacity factor of around 70%. Many have been quite lower.

However, in a few decades they may be economically viable selling both electricity and fuel.
 
Magnox is able to use natural uranium because the magnesium cladding doesn't reduce neutron capture too much. However, the AGR had to use steel so it could operate at higher temperatures with more efficiency, which requires the fuel to be enriched to compensate for the higher neutron capture of steel. The fuel types are thus incompatible with each other going either direction. Is there a type of fuel that could have been used for both Magnox and the AGR? What about zirconium alloy?

I think CO2 corrodes zirconium.

I can't seem to find the reference at the moment, but IIRC the British considered using helium in the AGR, but decided against it because US helium was too expensive. Shortly after that they found helium in the North Sea fields, which might have made it practical to use helium in the AGR, which would be a better coolant anyway. Another option might be to use carbide cannings like in the pebble-bed reactors, but I don't think the tech was available at the time.

Yet a third option might be to do something with the British heavy water reactor designs, which seem to have been a rather interesting hybrid between LWRs and the CANDU.
 

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I think CO2 corrodes zirconium.

I can't seem to find the reference at the moment, but IIRC the British considered using helium in the AGR, but decided against it because US helium was too expensive. Shortly after that they found helium in the North Sea fields, which might have made it practical to use helium in the AGR, which would be a better coolant anyway. Another option might be to use carbide cannings like in the pebble-bed reactors, but I don't think the tech was available at the time.

Yet a third option might be to do something with the British heavy water reactor designs, which seem to have been a rather interesting hybrid between LWRs and the CANDU.

I've been told that the British nuclear program ran on ten year cycles. The end of the second cycle was 1974, which would imply that it began in 1964. That would have been a year before petroleum and natural gas started being discovered in the North Sea.

I'm not sure why having to purchase helium from the United States would be an issue though. The government has a monopoly on it, and it doesn't cost that much. The British also didn't have a nuclear autarky when it came to other dealings with Canada and the United States. If they really wanted to, they could have made a contract with British Petroleum. Once the coolant/moderator is purchased, it can last quite a while without the need for replacement if properly managed.
 
I've been told that the British nuclear program ran on ten year cycles. The end of the second cycle was 1974, which would imply that it began in 1964. That would have been a year before petroleum and natural gas started being discovered in the North Sea.

I'm not sure why having to purchase helium from the United States would be an issue though. The government has a monopoly on it, and it doesn't cost that much. The British also didn't have a nuclear autarky when it came to other dealings with Canada and the United States. If they really wanted to, they could have made a contract with British Petroleum. Once the coolant/moderator is purchased, it can last quite a while without the need for replacement if properly managed.

You should really read Atomic Empire, which I just finished and is all about this. You'd like it.

My impression, for what it's worth, is that the British civilian nuclear energy program was very poorly organized. They had three separate entities involved: the CEGB, who were the nationalized electrical utility; the various groups of engineering firms that built the reactors; and the AEA, who designed the reactors. Since the AEA only did "broad overview" level work for the reactors outside of the actual core, and the engineering firms had little internal nuclear physics competence, British designs were even less standardized then American. At least in the US, the different reactor vendors were much more in control of their own designs. I think the Brits might have done a lot better if they had taken the French approach - but then, I say that about every national nuclear program. :p
 

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You should really read Atomic Empire, which I just finished and is all about this. You'd like it.

My impression, for what it's worth, is that the British civilian nuclear energy program was very poorly organized. They had three separate entities involved: the CEGB, who were the nationalized electrical utility; the various groups of engineering firms that built the reactors; and the AEA, who designed the reactors. Since the AEA only did "broad overview" level work for the reactors outside of the actual core, and the engineering firms had little internal nuclear physics competence, British designs were even less standardized then American. At least in the US, the different reactor vendors were much more in control of their own designs. I think the Brits might have done a lot better if they had taken the French approach - but then, I say that about every national nuclear program. :p

So that's why every Magnox reactor was essentially a totally unique design? I thought it was due to experimentation and/or funding constraints. That probably explains why everything took so long to build, especially since they weren't large. Even in the United States the major vendors had standard reference designs, although they would allow some components to be altered. I'm not familiar with there being a lot of construction errors with the British reactors though, so it seems they were built well.

If the core was the only standard part though, why didn't someone try to make an advanced Magnox by hooking it up to a closed cycle gas turbine? Apparently it isn't that recent a proposal either for nuclear energy or fossil fuel plants (more here).
 
So that's why every Magnox reactor was essentially a totally unique design? I thought it was due to experimentation and/or funding constraints. That probably explains why everything took so long to build, especially since they weren't large. Even in the United States the major vendors had standard reference designs, although they would allow some components to be altered. I'm not familiar with there being a lot of construction errors with the British reactors though, so it seems they were built well.

Even the cores weren't completely standardized. It seems to have been a bit of a mess.

If the core was the only standard part though, why didn't someone try to make an advanced Magnox by hooking it up to a closed cycle gas turbine? Apparently it isn't that recent a proposal either for nuclear energy or fossil fuel plants (more here).

I'm not really clear on that, but I think gas turbine technology only became cost-competitive relatively recently. Gas turbines only became a common feature of proposed gas-cooled reactors some time after the '70s.
 

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Even the cores weren't completely standardized. It seems to have been a bit of a mess.

So then what did the Italians and Japanese order and who did they work with when they purchased the Latina and Tokai Mura Magnox reactors?

I'm not really clear on that, but I think gas turbine technology only became cost-competitive relatively recently. Gas turbines only became a common feature of proposed gas-cooled reactors some time after the '70s.
To my understanding that is the case, although apparently there were seven fossil fuel powered closed cycle turbines ordered in Germany and Switzerland before 1978. The closed cycle turbines actually ran mostly on coal and became obsolete when more open cycle and combined cycle turbine plants started being built to operate on natural gas. Perhaps the issue was more the fact that steam turbines are a natural means of harnessing coal, and large scale gas turbines didn't really start to be considered until natural gas prices decreased and environmental pressures made coal gasification an interesting option.

The British had a lot of coal production even in the 1960s, and they were leaders in turbine technology, so perhaps a demonstration closed cycle turbine plant could be built to use coal?
 
So then what did the Italians and Japanese order and who did they work with when they purchased the Latina and Tokai Mura Magnox reactors?

IIRC, they worked with one of the British engineering coalitions and the AEA, just like how the Brits built their own reactors.

At one point there were five of these engineering coalitions running around.

To my understanding that is the case, although apparently there were seven fossil fuel powered closed cycle turbines ordered in Germany and Switzerland before 1978. The closed cycle turbines actually ran mostly on coal and became obsolete when more open cycle and combined cycle turbine plants started being built to operate on natural gas. Perhaps the issue was more the fact that steam turbines are a natural means of harnessing coal, and large scale gas turbines didn't really start to be considered until natural gas prices decreased and environmental pressures made coal gasification an interesting option.

The British had a lot of coal production even in the 1960s, and they were leaders in turbine technology, so perhaps a demonstration closed cycle turbine plant could be built to use coal?

Maybe? This is not something I know anything about.
 

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So, what led the British to choose the AGR over the heavy water designs?

Also, I've read that utilities placed orders for ten HTGR-Steam Cycle reactors ranging from 770 to 1,160 megawatts with General Atomics sometime in the early 1970s. Do you know anything about those? Information on page 26/PDF page 31 of this PDF.
 
So, what led the British to choose the AGR over the heavy water designs?

The AGR was a lot closer to deployment, and the heavy water design doesn't seem to have had much of a constituency within either the AEA or the CEGB outside of its own staff. The CEGB, in particular, was dead-set against it.

Also, I've read that utilities placed orders for ten HTGR-Steam Cycle reactors ranging from 770 to 1,160 megawatts with General Atomics sometime in the early 1970s. Do you know anything about those? Information on page 26/PDF page 31 of this PDF.

Sorry, I do not.
 
The AGR was a lot closer to deployment, and the heavy water design doesn't seem to have had much of a constituency within either the AEA or the CEGB outside of its own staff. The CEGB, in particular, was dead-set against it.
The SGHWR, possibly the least-pronounceable reactor design of all time, was actually fairly similar in concept to the Advanced CANDU Reactor currently being promoted. I don't see the attraction myself, the combination of heavy and light water seems overcomplicated, but then I'm not a nuclear engineer.

Deployment of the SGHWR was planned for several sites in the late 1970s, but by the time new reactors were being ordered new British designs were out of favour and AGRs were ordered. Subsequent reactors would have been PWRs - the CEGB liked the reliability and standardisation the American designs could provide. The UKAEA made a big deal about PWRs being unsafe and (especially early on) unproven by comparison to 'their' gas-cooled reactors.

I'm rather curious as to what the British Phase III HTGRs based on the DRAGON reactor would have been. I've found hints that a demonstration plant was planned for Bradwell, or maybe Oldbury, and probably would have been a 625/660 MW(e) plant, but very little besides. I think this might have used closed-cycle gas turbines, but that's little more than speculation.

No argument from me that British nuclear engineering would have done a lot better without the five (!) consortia trying to outdo one another in the engineering stakes.
 

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The SGHWR, possibly the least-pronounceable reactor design of all time, was actually fairly similar in concept to the Advanced CANDU Reactor currently being promoted. I don't see the attraction myself, the combination of heavy and light water seems overcomplicated, but then I'm not a nuclear engineer.

Some of these designs are really just difficult to wrap your heads around without a diagram of what is going on. I found one for CANDU that shows the light and heavy water circuits.

In this diagram, the heavy water/moderator circuit is yellow. The light water/coolant circuit is blue and red.

591px-CANDU_Reactor_Schematic.svg.png


I'm not aware of there being any advantage to using heavy water as the coolant instead of light water, so using light water in the coolant circuit seems like an expedient way to save money.

Deployment of the SGHWR was planned for several sites in the late 1970s, but by the time new reactors were being ordered new British designs were out of favour and AGRs were ordered. Subsequent reactors would have been PWRs - the CEGB liked the reliability and standardisation the American designs could provide. The UKAEA made a big deal about PWRs being unsafe and (especially early on) unproven by comparison to 'their' gas-cooled reactors.
I talked to my professor some more about this (he's a British nuclear policy expert), and there are some interesting insights regarding this.

In the legislation for the second cycle of the British nuclear power program (1964 to 1974) it was required for liquid cooled reactors to be developed and deployed. The Advanced Gas Cooled Reactor actually is liquid cooled, because it uses liquid carbon dioxide as a coolant.

Gas cooling also has some inherent safety relative to liquid cooling under certain circumstances. In a gas cooled reactor, you can heat the gas all you want and it remains stable. In a water cooled design, you must maintain a safe operating temperature or the water will convert into steam, which has reduced cooling capabilities as it is a gas. If the temperature gets too high you run the risk of it undergoing spontaneous electrolysis, producing helium and oxygen. Apparently there isn't much of an explosive risk from that (most explosions are due to steam, the same as any boiler), but it does create a fire risk that can lead to other issues. Three Mile Island and Fukushima suffered from spontaneous electrolysis.

Gas cooled reactors have the issue of Wigner radiation from the graphite moderator they must use. Wigner radiation is energy that gets trapped in the graphite, and it can result in power surges when the control rods are inserted into the reactor. Windscale suffered from Wigner radiation.

Now, the worst type of reactor you can have for safety is a water cooled graphite moderated reactor, as with the RBMK of Chernobyl infamy. That combines the worst attributes of both types, because you can get spontaneous electrolysis and have to worry about Wigner radiation induced instability. When Chernobyl suffered cooling problems, the water began turning into steam, leading to a temperature increase. This led to the fatal mistakes that happened next, and arguably best practice would have been to do nothing. Instead the operators put the control rods back in to the reactor, but that caused a power surge and panicked the operators even more. They decided to try to put more water into the reactor to cool it, but that just ended up turning into steam and eventually undergoing spontaneous electrolysis, leading to the fires and explosions.

The reason why Windscale was able to be recovered partially through the use of water is because it was a gas cooled design, so it was under low pressure to begin with. There was still a risk of spontaneous electrolysis though, which is why that was only resorted to when the fire began to approach the temperature rating for the concrete and the structure was at risk of failing. I'm not sure if the water actually stopped the fire or if finally shutting off the air intake did, but the water injection and closing the air intakes stopped the incident.

One final consideration for gas vs. water cooling is that gas, or at least carbon dioxide, tends to corrode metal. This is an issue since irradiation already causes strange effects such as crystallization. Fort St. Vrain in the United States was helium cooled and had corrosion issues as well, but that was due to water leaking into the helium circulators.

I'm rather curious as to what the British Phase III HTGRs based on the DRAGON reactor would have been. I've found hints that a demonstration plant was planned for Bradwell, or maybe Oldbury, and probably would have been a 625/660 MW(e) plant, but very little besides. I think this might have used closed-cycle gas turbines, but that's little more than speculation.

No argument from me that British nuclear engineering would have done a lot better without the five (!) consortia trying to outdo one another in the engineering stakes.
Perhaps it would have been similar to Fort St. Vrain. With a Brayton cycle closed cycle gas turbine it could have even higher efficiency.
 
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