#edwinlyman — Public Fediverse posts

Not to mention all the #WaterConsumption! There are plans to restart aging nuclear reactor as well as untested SMR reactors! Will #AI’s huge energy demands spur a #nuclear renaissance?

By Davide Castelvecchi
25 October 2024

Do small modular reactors carry extra risks?

"In some cases, small modular reactors 'could actually push nuclear power in a more dangerous direction', says #EdwinLyman. 'Advanced isn’t always better.'

"In particular, Lyman points out that the pebble-bed designs drawn up by #XEnergy and #Kairos would rely on high-assay low-enriched #uranium (#HALEU), which comprises 10–20% uranium-235 — compared with the 5% enrichment level required by most existing reactors (and by #NuScale’s reactor). HALEU is still classified as low-enrichment fuel (as opposed to the highly enriched uranium used to make nuclear bombs), but that distinction is misleading, Lyman says. In June, he and his collaborators — including physicist Richard Garwin, who led the design of the first hydrogen bomb — warned in a Science article that a bomb could be built with a few hundred kilograms of HALEU, with no need for further enrichment.

"Smaller reactors are also likely to produce more nuclear waste and to use fuel less efficiently, according to work reported in 2022 by Macfarlane and her collaborators. In a full-size reactor, most of the neutrons produced by the splitting of uranium travel through a large volume of fuel, meaning that they have a high probability of hitting another nucleus, rather than colliding with the walls of the reactor vessel or escaping into the surrounding building. 'When you shrink the reactor, there’s less material in there, so you will have more neutron leakage,' Macfarlane says. These rogue neutrons can be absorbed by other atomic nuclei — which would then themselves become radioactive."

Original article:
https://www.nature.com/articles/d41586-024-03490-3

Archived version:
https://archive.ph/mODpF#selection-952.0-991.164

#AI #ArtificialIntelligence #Cryptocurrency #DataCenters #RethinkNotRestart #NoNukesForAI #NoNukes #NuclearHype #NeutronEmbrittlement #NuclearWaste #NotCarbonFree

Report Finds That ‘Advanced’ #Nuclear Reactor Designs Are No Better Than Current Reactors—and Some Are Worse

Proposed Non-Light-Water Reactors Not Clearly Safer and Will Likely Take Decades to Achieve Reliable Commercial Operation

Published Mar 18, 2021
Union of Concerned Scientists

"One of the proposed sodium-cooled fast reactors, #TerraPower’s 345 megawatt #Natrium, has received considerable media attention recently because TerraPower founder #BillGates has been citing it during interviews about his new book, How to Avoid a Climate Disaster. In mid-February, Gates told 60 Minutes correspondent Anderson Cooper that the #Natrium reactor will produce less waste and be safer than a conventional light-water reactor.

"In fact, according to the #UCS report, sodium-cooled fast reactors such as the Natrium would likely be less '#uranium-efficient.' They would not reduce the amount of #NuclearWaste that requires long-term isolation in a geologic repository. They also could experience safety problems that are not an issue for light-water reactors.

"Sodium coolant, for example, can burn when exposed to air or water, and a sodium-cooled fast reactor could experience uncontrollable power increases that result in rapid core melting.

“'When it comes to safety and security, sodium-cooled fast reactors and molten salt-fueled reactors are significantly worse than conventional light-water reactors,' says Dr. #EdwinLyman.
'High-temperature, gas-cooled reactors may have the potential to be safer, but that remains unproven, and problems have come up during recent fuel safety tests.'"

Read more:
https://www.ucsusa.org/about/news/report-advanced-nuclear-reactors-no-better-current-fleet

#MSRHype
#NoNukes
#NoNewNukes #SmallModularNuclearReactors #BigEnergy #SMR