(Press-News.org) In a Policy Forum, R. Scott Kemp and colleagues argue that promoting new nuclear reactor technologies using high-assay low-enriched uranium (HALEU) threatens the international system of controls that has prevented nuclear weapons proliferation for over 30 years. “Governments and others promoting the use of HALEU have not carefully considered the potential proliferation and terrorism risks that the wide adoption of this fuel creates,” write Kemp et al. The authors warn that if HALEU becomes a standard reactor fuel without strict regulations, nations could obtain and process weapons-usable HALEU, driving nuclear proliferation with little deterrence. Commercial reactor fuels typically have 3 to 5% 235U, which is insufficient for explosive chain reactions, thereby preventing weaponization. While enrichments above 6% can sustain fast chain reactions, the required mass for a weapon is impractical without advanced enrichment capabilities, limiting this to a few countries. HALEU, containing 10 to 20% 235U, is necessary for many modern reactors, including microsized designs, which use 19.75% HALEU to avoid the security restrictions of highly enriched uranium (HEU). However, HALEU’s high enrichment levels pose significant security risks, as a single HALEU-fueled reactor could contain enough material for a nuclear weapon. Kemp and colleagues highlight that the U.S. and other countries are subsidizing HALEU reactor development and fuel production without adequately considering the risks. They urge U.S. lawmakers to commission a new review of HALEU’s proliferation and security risks through the Department of Energy’s Nuclear Security Administration, emphasizing the need for a new and lower enrichment limit for weapons-usable uranium. “A key outcome of this study should be to set a new, technically justified, and lower enrichment limit for weapons-usable uranium,” write the authors. “An unfettered HALEU policy leaves no margin of safety.”
END
Widespread use of high-assay low-enriched uranium raises significant nuclear security concerns
2024-06-06
ELSE PRESS RELEASES FROM THIS DATE:
JWST uncovers features of very-low-mass star’s protoplanetary disk that influence planet composition
2024-06-06
James Webb Space Telescope (JWST) observations have revealed abundant hydrocarbons in the protoplanetary disk surrounding a young, very-low-mass star – findings that provide novel insights into the chemical environment from which many terrestrial planets, in particular, are born. Planets form in disks of gas and dust that orbit young stars. Observations show that terrestrial planets form more efficiently than gas giant planets around very-low-mass stars (VLMSs) – those with less than 0.3 solar masses. Although the chemical compositions of the inner disk regions around higher mass stars ...
Mammalian adipose tissue thermogenesis evolved in eutherian mammals
2024-06-06
Heat production in fat tissue, a trait also known as adipose tissue thermogenesis, evolved over two stages in mammals, fully developing in eutherian mammals after the group’s evolutionary divergence from marsupials, according to a new study. The results could provide insights that inform future therapies related to metabolism and obesity. Many organisms produce heat internally to regulate body temperature. It is thought that the evolution of the ability to maintain high body temperatures provided ...
The first example of cellular origami
2024-06-06
“There are some things in life you can watch and then never unwatch,” said Manu Prakash, associate professor of bioengineering at Stanford University, calling up a video of his latest fascination, the single-cell organism Lacrymaria olor, a free-living protist he stumbled upon playing with his paper Foldscope. “It’s … just … it’s mesmerizing.”
“From the minute Manu showed it to me, I have just been transfixed by this cell,” said Eliott Flaum, a graduate student ...
Planet-forming disks around very low-mass stars are different
2024-06-06
Planets form in disks of gas and dust, orbiting young stars. The MIRI Mid-INfrared Disk Survey (MINDS), led by Thomas Henning from the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany, aims to establish a representative disk sample. By exploring their chemistry and physical properties with MIRI (Mid-Infrared Instrument) on board the James Webb Space Telescope (JWST), the collaboration links those disks to the properties of planets potentially forming there. In a new study, a team of researchers ...
Researchers identify key differences in inner workings of immune cells
2024-06-06
From the outside, most T cells look the same: small and spherical. Now, a team of researchers led by Berend Snijder from the Institute of Molecular Systems Biology at ETH Zurich has taken a closer look inside these cells using advanced techniques. Their findings show that the subcellular spatial organisation of cytotoxic T cells – which Snijder refers to as their cellular architecture – has a major influence on their fate.
Characteristics that determine a cell’s fate
When cells with nuclear invaginations encounter a pathogen, they turn into powerful effector cells that rapidly proliferate and kill the pathogen. Their fellow ...
Molecular pathway that impacts pancreatic cancer progression and response to treatment detailed
2024-06-06
CHAPEL HILL, North Carolina – Researchers at UNC Lineberger Comprehensive Cancer Center and colleagues have established the most comprehensive molecular portrait of the workings of KRAS, a key cancer-causing gene or "oncogene," and how its activities impact pancreatic cancer outcomes. Their findings could help to better inform treatment options for pancreatic cancer, which is the third leading cause of all cancer deaths in the United States.
The research was published as two separate articles in Science.
“Because ...
Ferroelectric material is now fatigue-free
2024-06-06
Researchers at the Ningbo Institute of Materials Technology and Engineering (NIMTE) of the Chinese Academy of Sciences, in collaboration with research groups from the University of Electronic Science and Technology of China and Fudan University, have developed a fatigue-free ferroelectric material based on sliding ferroelectricity.
The study was published in Science.
Ferroelectric materials have switchable spontaneous polarization that can be reversed by an external electric field, which have been widely applied to non-volatile memory, sensing, and ...
Marsupials key to discovering the origin of heater organs in mammals
2024-06-06
Around 100 million years ago, a remarkable evolutionary shift allowed placental mammals to diversify and conquer many cold regions of our planet. New research from Stockholm University shows that the typical mammalian heater organ, brown fat, evolved exclusively in modern placental mammals.
In collaboration with the Helmholtz Munich and the Natural History Museum Berlin in Germany, and the University of East Anglia in the U.K., the Stockholm research team demonstrated that marsupials, our distant relatives, possess a not fully evolved form of brown fat. They discovered that the pivotal heat-producing protein called ...
Epstein-Barr Virus and brain cross-reactivity: possible mechanism for Multiple Sclerosis
2024-06-06
The role that Epstein-Barr Virus (EBV) plays in the development of multiple sclerosis (MS) may be caused a higher level of cross-reactivity, where the body’s immune system binds to the wrong target, than previously thought.
In a new study published in PLOS Pathogens, researchers looked at blood samples from people with multiple sclerosis, as well as healthy people infected with EBV and people recovering from glandular fever caused by recent EBV infection. The study investigated how the immune system deals with EBV infection as part of worldwide efforts to understand how this common virus can lead to the development of multiple ...
Fish out of water: How killifish embryos adapted their development
2024-06-06
The annual killifish lives in regions with extreme drought. A research group at the University of Basel now reports in “Science” that the early embryogenesis of killifish diverges from that of other species. Unlike other fish, their body structure is not predetermined from the outset. This could enable the species to survive dry periods unscathed.
The turquoise killifish inhabits areas characterized by extreme conditions. The species, native to Africa, can survive prolonged periods of drought ...