Nuclear CHP as a solution

GreatApe

For a country like the UK 6 nuclear power stations with 3.5 EPRs in CHP mode plus an additional 5GW thermal heat only reactor to be used in the winter.

Therefore 33.6GW nuclear electricity capacity, 60.9GW of waste heat capacity, 30GW of top up heat capacity from heat only reactors.

Upto 272 TWh electricity
Upto 490 TWh heat from CHP and 100TWh from heat only reactors

100% of electricity and 100% of heating solved
( Assuming Electricity demand falls to 270TWh as currently electricity heated homes are converted to district heat via the nuclear CHP)

The heat output is oversized but that's ok since it's mostly waste heat and the heat only reactors are cheap

3GW pumped plus soon 2.8GW to Norway will allow the buffering of 6GW plus refueling in the summer when demand is lower will allow operating the nukes with very little curtailment of max possible output

Heating and electricity solved with nuclear capacity much less than the French system.
No imaginary mass hydrogen to buffer wind and solar. No mass grid upgrades. No huge amount of wind and solar and biomass to fill in gaps.

I don't think the above should be done it's too late for the UK but it shows you how nuclear is a full solution that can work and this is only a small amount of nuclear capacity it's about half that of the French built decades ago to solve both electricity and heating.

Could have been a solution to the EU
If we had started in 2010 could have been finished in 2025
If BEV happen to take over land transport you'd just need to build 1-2 more of these nuclear power stations

GreatApe

Even at £21B for HPC the above would cost £220 billion perhaps half of that cost if financed by gilts and even less if there is some learning curve. Would of course need to build a distributed heat or stem grid which would be another £50 billion or so.

A capital cost of £7,700 per household to provide all the heat and electricity needed by a country (not just for their homes but also the office they work at the shops they shop at the entertainment venues they use and the schools and hospitals they take their kids to. And in time the BEVs they drive)

With the nuclear fuel assembly costing about 1/10th of what natural gas costs

There would also be no waste because once you use the fuel rods, which last aboout 5 years in a reactor, you store them in the district heating pools where they will be free fuel for decades and decades so as long as humans need heat for their homes it's not waste it's fuel.

And this infrastructure will likely last 100 years unlike wind farms batteries and PV systems which are said to be 20-30 years

A full solution without imaginary hydrogen chemical plants to do seasonal storage, without dirty biomass and output the need for huge internal and external grid upgrades and not dependent on other nations trading electricity with you.

GreatApe

I'd give the heat away for free since it's almost all a byproduct of waste heat that would be thrown away into the ocean. A free national heating service or NHS for short

Help the poor and the old, no worrying about heating or buying and replacing costly boilers or heat pumps or having to deal with doggy plumbers who might not even be qualified but can still call themselves plumbers. Maybe limit it to 12,000 units free which will be fine for the majority of households and would be an incentive to conserve and insulate to get to below this figure

unforeseen

It may be free heat but you will still have ongoing maintenance costs of the distribution system.

GreatApe

unforeseen wrote: »

It may be free heat but you will still have ongoing maintenance costs of the distribution system.

Yes of course but that would be true for all and any system you can think of

Nuclear heat, free from CHP...... But Cost of maintenance and upkeep of hot water grids

Hydrogen gas (not free has to be produced in very large quantities from wind power) and hydrogen boilers.... Cost of maintenance and upkeep of hydrogen grids and boilers

Electricity (mix of heat pumps and resistance heaters) powered by wind which isn't free. This wind power then needs to be transported over a much beefed up electricity grid which needs upkeep


My argument is to say nuclear can do electricity and heating and achieve 100% of both with very little curtailment and no need for mass storage (via batteries or hydrogen or ammonia or syn fuels none of which is proven on a large scale to be cost effective for seasonal storage) that would be need for a wind heavy system

ABrass

So, build thousands of ponds (you can't pump superheated steam that far and lower temperature would cool too much) into which you would put radioactive waste spread over the entirety of the UK, or predominantly in built up areas. Rip up huge tracts of the roads to install massive steam pipes and then rebuild all the housing stock to make use of it.

I am not a nuclear scientist, nor an engineer working in that industry but that's clearly a non starter.

Security costs would be epic, cost to build bigger and maintenance costs legendary.

Martyn1981

ABrass wrote: »

So, build thousands of ponds (you can't pump superheated steam that far and lower temperature would cool too much) into which you would put radioactive waste spread over the entirety of the UK, or predominantly in built up areas. Rip up huge tracts of the roads to install massive steam pipes and then rebuild all the housing stock to make use of it.

I am not a nuclear scientist, nor an engineer working in that industry but that's clearly a non starter.

Security costs would be epic, cost to build bigger and maintenance costs legendary.

Yep, it's just more silliness from the NAACB (nuclear-at-any-cost-brigade) trying to find some way to justify a far more expensive way of generating leccy.

So generate leccy at a high cost, then try to find a market for some of the waste energy (heat), in order to compete against far cheaper, cleaner, safer, and quicker RE generation.

Why not just use the cheap RE leccy to run heat pumps via the existing electricity network, or use cheap RE excess to produce bio-gas to run GCH boilers via the existing gas network.

But, but, but SMR'ssssssssssssss is a very similar argument to but, but, but clean coallllllllllllllllllll*, used as a delaying and diversionary tactic to prolong the status quo and the continued use of FF's whilst we wait for 'the next best thing in coal, nuclear etc' to arrive, as it's always just round the corner ....... apparently?

*Personal gripe at that term, as it's a deliberate misrepresentation, being a shortened version of the term 'cleaner coal', and in reality still being horrifically dirty.

zeupater

ABrass wrote: »

So, build thousands of ponds (you can't pump superheated steam that far and lower temperature would cool too much) into which you would put radioactive waste spread over the entirety of the UK, or predominantly in built up areas. Rip up huge tracts of the roads to install massive steam pipes and then rebuild all the housing stock to make use of it.

I am not a nuclear scientist, nor an engineer working in that industry but that's clearly a non starter.

Security costs would be epic, cost to build bigger and maintenance costs legendary.

Hi

So the latest harebrained variant on this idea is to turn the distribution temperature up significantly? ...

Great, so what sort of pressures are we talking about in the distribution network now? ... Currently the gas infrastructure runs at around 0.015bar and water at around 0.7bar, however when something ruptures underground due to material failure or maintenance issues we're all aware of the damage & disruption this may cause .....

Just imagine a heatmain distribution system running at mains water pressure running at temperatures of ~70C .... If there were to be a mains rupture you're looking at a 7m head fountain of technically scalding hot water potentially appearing in the middle of populated areas! ... no H&S issues here then ... :whistle:

So, if the belief is that underground water mains rupture very rarely because they are designed & engineered using modern materials with pressure safety margins well above what the infrastructure is ever likely to achieve ... maybe, but add the variable of temperature and everything changes ...

As an example, pipeline manufactured to maintain 12bar pressure at standard operating temperatures would likely be derated to around/below 2bar when operating at ~70C which seriously increases the likelihood of material failure, this being one of the major reasons why district heating systems have their heat sources close to centres of population ...

So, heat sources in area of high population density in context of this thread means resources containing nuclear material being located in the middle of cities .... London could build them in all of the green parks, that may work with metal pipes carrying the heat over relatively short distances, and I'm pretty sure that the population wouldn't mind years of disruption as every mile of road is ripped up, pipes are buried and everything reinstated, but above this the idea of everyone living their lives with a healthy 'readybreak' glow would be more than appealing to the majority, thus minimising any potential opposition .... :rotfl:

Okay, so what about maintaing a lower temperature and increasing pressure? .... well, this is where laminar flow becomes an issue. The idea of increasing pressure would be to increase flow rate, but as flow rate increases the likelihood of laminar flow breakdown increases which results in turbulence & cavitation, the major cause of in service high pressure pipeline component degradation .... this is why water flow rates (m/s) are minimised through varying pipe diameter as opposed to maintaining diameter and increasing pressure ...

It's all basic material science really with appropriate material being needed to be specified. On another thread the same issue has been raised to quantify the scale of investment needed to provide a national heat-grid to deliver energy to the majority of UK households on a Co-gen or heat only basis from whatever heat source could plug into the system .... it's £trillions, so even if the heat sources were free, it makes little sense to address on a national basis as opposed to individual, communal & district based solutions, the answer therefore is to maintain a more decentralised/distributed approach to heating, as is current global practice ....

HTH
Z

GreatApe

ABrass wrote: »

So, build thousands of ponds (you can't pump superheated steam that far and lower temperature would cool too much) into which you would put radioactive waste spread over the entirety of the UK, or predominantly in built up areas. Rip up huge tracts of the roads to install massive steam pipes and then rebuild all the housing stock to make use of it.

I am not a nuclear scientist, nor an engineer working in that industry but that's clearly a non starter.

Security costs would be epic, cost to build bigger and maintenance costs legendary.

Well I am a scientist (degree in physics) and an engineer (worked as a process engineer before starting my own business) and I see no obvious reason why 1 district heating cannot work and 2 why nuclear heat can not work. Both in fact exist. There are over 400 commercial nuclear reactors that do generate heat and convert it to electricity. and there are district heating grids in existence which seem to be affordable

With regards to nuclear waste you don't know what you are talking about
A light water reactor is typically 3 or 4 loops that means the water you pump to homes hasn't been in contact with a reactor. Even the water that heats that water hasn't been in contact with a reactor. Plus sensors to monitor everything

Regarding heat loss this would not be a huge problem especially for the bulk pipes.
Their surface area to mass is low so there would be no large heat loss and with insulation the heat loss would be very acceptable.

For a 75cm pipe with 10cm mineral wool insulation carrying hot water it would have a heat loss of about 80 watts per meter in the open (less in the ground)

That is a pipe carrying 500 MW of heat
So for 10 miles it would have a loss of 1.3 MW out of 500MW it is which is less than 0.3% heat loss

Even if your nuclear heat station is 40 miles away you have a loss of just 1.04%

As I've said previously and proven now, the heat loss in the bulk pipes would be negligible only about 1%. There is also a return pipe but the loss there is less due to the return water being cooler but whatever let's pretend it's the same loss so we are at 2% if you pipe it from a nuke 40 miles away

The heat loss in the second and third legs of moving this hot water around would be more but still most of your heat is not lost it is used. I'd hazard a guess of less than 10% possibly as low as 6% overall that beats transmission losses on electricity and perhaps even methane losses in the natural gas wells/grids

GreatApe

Martyn1981 wrote: »

Yep, it's just more silliness from the NAACB (nuclear-at-any-cost-brigade) trying to find some way to justify a far more expensive way of generating leccy.

So generate leccy at a high cost, then try to find a market for some of the waste energy (heat), in order to compete against far cheaper, cleaner, safer, and quicker RE generation.

Why not just use the cheap RE leccy to run heat pumps via the existing electricity network, or use cheap RE excess to produce bio-gas to run GCH boilers via the existing gas network.

But, but, but SMR'ssssssssssssss is a very similar argument to but, but, but clean coallllllllllllllllllll*, used as a delaying and diversionary tactic to prolong the status quo and the continued use of FF's whilst we wait for 'the next best thing in coal, nuclear etc' to arrive, as it's always just round the corner ....... apparently?

*Personal gripe at that term, as it's a deliberate misrepresentation, being a shortened version of the term 'cleaner coal', and in reality still being horrifically dirty.

You can electrify heating which is probably the path we will try to take but you will soon find that you need massive grid upgrades probably turning the UK grid from 50GW peak to 200+ GW peak. You would also find you need thermal capacity equal to this 200GW so what's your poison 200GW of new CCGTs or 200GW or dirty Biomass? Batteries can't do seasonal storage

A UK in 2050 will be about 40 million boilers you would need a truly massive grid to handle that

GreatApe

zeupater wrote: »

Hi

So the latest harebrained variant on this idea is to turn the distribution temperature up significantly? ...

Great, so what sort of pressures are we talking about in the distribution network now? ... Currently the gas infrastructure runs at around 0.015bar and water at around 0.7bar, however when something ruptures underground due to material failure or maintenance issues we're all aware of the damage & disruption this may cause .....

Just imagine a heatmain distribution system running at mains water pressure running at temperatures of ~70C .... If there were to be a mains rupture you're looking at a 7m head fountain of technically scalding hot water potentially appearing in the middle of populated areas! ... no H&S here then ... :whistle:

So, if the belief is that underground water mains rupture very rarely because they are designed & engineered using modern materials with pressure safety margins well above what the infrastructure is ever likely to achieve ... maybe, but add the variable of temperature and everything changes ...

As an example, pipeline manufactured to maintain 12bar pressure at standard operating temperatures would likely be derated to around/below 2bar when operating at ~70C which seriously increases the likelihood of material failure, this being one of the major reasons why district heating systems have their heat sources close to centres of population ...

So, heat sources in area of high population density in context of this thread means resources containing nuclear material being located n the middle of cities .... London could build them in all of the green parks, that may work with metal pipes carrying the heat over relatively short distances, and I'm pretty sure that the population wouldn't mind years of disruption as every mile of road is ripped up, pipes are buried and everything restated, but above this the idea of everyone living their lives with a healthy 'readybreak' glow would be more than appealingly to the majority, thus minimising any potential opposition .... :rotfl:

Okay, so what about maintaing a lower temperature and increasing pressure? .... well, this is where laminar flow becomes an issue. The idea of increasing pressure would be to increase flow rate, but as flow rate increases the likelihood of laminar flow breakdown increases which results in turbulence & cavitation, the major cause of in service high pressure pipeline component degradation .... this is why water flow rates (m/s) are minimised through varying pipe diameter as opposed to maintaining diameter and increasing pressure ...

It's all basic material science really with appropriate material being needed to be specified. On another thread the same issue has been raised to quantify the scale of investment needed to provide a national heat-grid to deliver energy to the majority of UK households on a Co-gen or heat only basis from whatever heat source could plug into the system .... it's £trillions, so even if the heat sources were free, it makes little sense to address on a national basis as opposed to individual, communal & district based solutions, the answer therefore is to maintain a more decentralised/distributed approach to heating, as is current global practice ....

HTH
Z

You do realise there are valves and computers?

In the event of a rupture, and pipes don't do that very often, the valve is closed in something like half a second and there is your fix to that problem

Regarding the radioactive water, the water never comes in contact with radioactive material there is no loss of radioactive materials it sits inside zirconium rods plus there would be 3 loops the water you get wouldn't have been in contact with any radioactive materials. The water that heats that water wouldn't even have been in contact with any materials

Regarding pressure I would imagine it would be done around 5-10 bar
Water doesn't boil until around 150 centigrade at 10 bar
There would be no cavitation (not that that is that big a deal) because the pipes would mostly be going in straight lines there wouldn't be 90 degree turns as you might have in your home.


You keep trying to suggest the distributed grid would be impossible

But how is the cold water grid possible?
How is the gas grid possible
How are oil pipelines possible?
How is the electricity grid possible?

Also what is the alternative? Heat pumps need an electricity gird that can handle 200GW+ how are you going to expand the UK grid 4x ?

And regarding lots of digging
No I would imagine something closer to drilling
Directional drilling as they do for shale oil and gas
There is also tech to do that with much smaller pipes and distances
And it doesn't even necessarily have to be front of property you might lay them in the gardens. Or even a street of terrace homes might be fed with a pipe running clipped to the walls on the rear of the property. There would be lots of innovation to do this in a more and more automated way. There are machines which dig holes and lay cables semi autonomously. Lots of possibilities
Perhaps even lots of smaller plastic pipes bundled together and insulates rather than one big pipe. This way if there is a leak it's one pipe in a bundle of a couple of hundred and that one pipe can be turned off fixed or replaced and then turned back on.


Regarding smaller reactors closer to demand. I don't think that would be a good idea. Better for one big 10GW dual reactor feeding an area about the population of inside the M25 (about 10 million people).