Source: US ‘disappointed’ that Rolls-Royce will build UK’s first small modular reactors | Nuclear power | The Guardian Keir Starmer has announced that the UK’s first small modular nuclear reactors will be built in north Wales ... Wylfa on the island of Anglesey, or Ynys Môn, will be home to three small modular reactors (SMRs) to be built by British manufacturer Rolls-RoyceSMR. The government said it will invest £2.5bn. SMRs are a new . . . technology aiming to produce nuclear power stations in factories to drive down costs and speed up installation. Rolls-Royce plans to build reactors, each capable of generating 470 megawatts of power, mainly in Derby. This works for me as I have two EVs and A/C in warm weather. Bob Wilson
I remember there was an incident, typhoon or tsunami, where a nuclear powered boat or ship connected to local grid at a port after a natural disaster. Somewhere on the Western Pacific. My understanding is the early ship and boat nuclear power plants were boiling water reactors. Still the case today? Same architecture as Rickover pushed through? Reading the Wiki: United States naval reactors - Wikipedia Bob Wilson
Small nuke reactors are not small at all when you do true cost accounting on low level and high level nuke waste management for its entire lifespan. Most of these hairbrained schemes are about pocketing the money up front and then having an easy out when cost over runs cause the project to fail before it even gets started.
470 MWe (electric) isn't really "small". Other sources describe SMRs as 300 MWe or less. ... unless they mean MW-thermal.
Excellent point! MW-thermal - 100% of the total energy from the fission reactions ~30-35% thermal efficiency - the actual, usable power generated best if coupled with a battery farm to handle peaks and valleys in actual usage you still have find a second use for 65-70% of the waste heat without making rivers into fish soup The big advantage is paying the "engineering" cost once and using manufacturing to clamp the building and operational costs. USA reactors have been "one of" designs which significantly increases the cost as each one is a custom build. They are like "disposable" rockets, way too expensive until SpaceX and the recent Blue Origin booster landings changed the game. Bob Wilson
Compared to coal ash and CO{2} heating, it is a more manageable problem. However, I'm interested in proposed liquid salt reactors. The theory is in-plant processing of the molten salt allows chemical extraction and reprocessing of the still usable fuel while significantly reducing the volume of radioactive waste. Waste that can be further reduced by cycling around the nuclear fission close enough to transmute them into faster decaying, soon to be low level waste. A second advantage is higher heat temperature which improves efficiency of the generator system. More power with less waste heat. But the engineering faces significant materials challenges. Bob Wilson
The thermal output is 1358MW. https://www.rolls-royce-smr.com/ I've seen the 300mW figure, but guessing it isn't a hard limit. The important tribute of being a SMR is in the physical size. Small enough to make the reactor in a factory, and then ship to the power plant. Granted, the transport for bigger ones will be more extreme, but the costs just have to not exceed the central production savings. By virtue of the smaller core size, these might make more waste through the higher neutrino leakage. [UPDATED] Researchers Say SMRs Will Produce More Waste Than Large Nuclear Reactors, NuScale Disputes Claim https://www.pnas.org/doi/full/10.1073/pnas.2111833119 Haven't read the paper, but it may not be considering how the running of a SMR will differ from a typical nuclear plant. They are like batteries; some can't be refueled. The SMR is installed in an underground vault and coolant lines connected to the power plant. 30 years goes by and plant no longer is producing enough heat. Then the vault is sealed, and you dig a hole for a new SMR, or convert the plant to hydrogen or other renewable fuel that has become available. The important thing is that the nuclear waste disposal was already factored in with the installation. There is more nuclear waste, but it doesn't need to be hauled away to another site with those concerns.
That's entirely absurd to say... Coal ash doesn't turn everything it touches into low level nuclear waste that is very, very difficult to dispose of, with the actual nuclear waste being way harder.
I had long thought that an important element was being small enough to allow passive cooling in emergencies. I hope you mean neutrons, which are input elements of the chain reactions. Neutrinos are nearly entirely lost even in reactors the size of the sun. They are not meaningful inputs to anything except neutrino detectors, which capture only an exceedingly minuscule fraction of the neutrinos passing through them.
In terms of the nasty stuff, spent fuel and high level waste, the US produces about 2000 metric tons a year. That is 3% of the total annual amount. 95% is low level waste, which includes non energy industry generation. We could reduce spent fuel waste through recycling. Coal ash doesn't turn stuff it touches into coal ash, but we do produce much, much, much more of it at 130 million tons per year. It is laced with heavy metals and radioisotopes. Shorter half lives, but again, 130 million tons per year. A person receives a higher radiation dose living next to a coal plant than next to a nuclear one. On a related note, used fracking brine is radio active and unregulated on that front. Some was being sold as ice melt. People were putting radium laced salt water on their side walks. That too, but I believe passive cooling is being built into even the MW reactors these days. Some SMR designs are just scaled down versions of those. I did. Sounds like it is a surface area to volume issue. More neutrons can 'leak' out of a smaller core.
We will all soon agree on nuke waste and radioactive fracking fluids having no place in our future when fusion replaces fission.
Cheap fusion power has been "20 years away" for what, 60 years now? 70? It is still far too early to hold my breath for it. Fusion reactors will also make nuclear waste, albeit less. The containment vessels will experience neutron irradiation, turning them radioactive.
The neutron irradiation is what "turn everything it touches into low level nuclear waste that is very, very difficult to dispose of" and makes most of the waste from a fission plant.
We're far closer than you think with current record of human made fusion at WEST tokamak (formerly Tore Supra in France) sustained for 22 minutes 17 seconds. As for the radiation many fusion designs use deuterium-tritium (D–T) fuel. Tritium is radioactive (beta emitter), with a half-life of only about 12.3 years https://www.iaea.org/sites/default/files/19/09/harnessing-energy-from-nuclear-fusion.pdf And to your point, when high-energy neutrons from fusion hit the reactor’s structural materials (walls, support structures, shielding, etc.), they can convert stable isotopes in those materials into radioactive ones — a process called neutron activation. The resulting waste is expected to be low to intermediate, not like the high-level, long-lived waste from fission: Safety and the environment
That type has not yet reached breakeven on a scientific basis, let alone engineering or economic basis.
The long lived, high energy waste from a nuclear reactor is spent fuel. That is only a tiny bit of the waste generated. The rest is low to intermediate created by...neutron activation. In terms annual waste produced, from all sources, high level makes up just 3%. Low level is 95%. A switch to fusion will only make a tiny change in the waste produced.
