UK Rolls-Royce SMRs at Wylfa, Space Moss Survival, Phage Therapy, and Iran Cloud Seeding

The Naked Scientists discuss the UK’s first foray into small modular reactors with a three-unit Rolls-Royce design at Wylfa on Anglesey, including cost and scaling considerations. The episode also covers a US study that evolves bacteriophages to combat Klebsiella pneumoniae, potentially broadening antibiotic alternatives. In Iran, cloud seeding is evaluated as a method to mitigate severe drought, while a Japanese-led experiment reveals moss spores surviving nine months in space before germinating on return to Earth. Together, these segments illustrate how innovation in energy, microbiology, climate intervention, and space biology is shaping future technology and policy decisions.

UK SMR Plans at Wylfa: A Modular Path to Nuclear Power

The program opens with the UK selecting Anglesey's Wylfa as the home for Rolls-Royce small modular reactors (SMRs). Malcolm Grimston, honorary senior research fellow at Imperial College, explains SMRs as nuclear plants in the 200–400 megawatt range, manufactured in factories and assembled on-site to reduce costs through standardization. He clarifies that SMRs aim to deliver a large installed capacity through multiple modules rather than a single massive reactor, potentially enabling quicker construction and staged income as modules come online. The debate centers on whether the economies of scale from factory manufacturing can outperform traditional large reactors, given the still-early stage of UK SMR deployment. He notes that while fossil or renewable options compete for cost, nuclear waste management and grid reliability remain considerations. “the real benefit of this comes from manufacturing them at a huge scale in factories” - Malcolm Grimston

Phage Therapy: Broadening the Battle Against Antibiotics

David Pride (UCSD) discusses a novel approach to bacteriophage therapy for Klebsiella pneumoniae. By evolving phages against clinical bacterial samples in the lab for 30 days, researchers create a “superphage” with broader activity and reduced resistance potential, offering a possible antibiotic substitute. Pride emphasizes that the resulting phages are more like antibiotics in breadth and kill efficiency, and importantly, fewer pathogens acquire resistance quickly. The method translates environmental phages into clinically useful agents, with potential applicability to other resistant bacteria, such as MRSA or E. coli, though the degree of improvement varies by organism. Pride highlights that resistance remains a central concern for any antimicrobial strategy and argues this evolution-based approach could provide a robust off-the-shelf therapy option. “resistance can develop very, very quickly” - David Pride

Cloud Seeding in Iran: Weather Modification and Ethical Bounds

The conversation shifts to Iran’s drought response via cloud seeding. Peter Gibbs outlines the science and limitations: seeding aims to increase condensation nuclei to encourage rainfall, using silver iodide or charged particles to influence droplet formation. He notes the effectiveness is debated and challenging to prove, given the lack of controlled experiments with identical clouds. The discussion also touches on ethical considerations, including cross-border water implications and the sovereignty issues of weather modification. The likelihood of meaningful relief depends on favorable weather patterns; seeding alone cannot create rain when conditions are unfavorable. “increase the number of cloud nuclei, condensation nuclei within a cloud” - Peter Gibbs

Moss in Space: Implications for Space Habitats and Terraforming

The final segment reports a space biology study showing moss spores that were exposed outside the International Space Station germinated at ~80% after nine months in space, with dark and UV-filtered controls showing high germination when shielded from UV. The researchers conclude moss demonstrates notable UV resistance and suggest implications for terraforming strategies and off-world biology. The study also highlights potential genetic and pigment changes that warrant further investigation. The broader context considers whether hardy terrestrial organisms could be stationed on future spacecraft or surfaces to support long-duration missions or planetary colonization. “80% of moss spores can survive for 9 months outside the International Space Station” - Jen Bromley

Conclusion: Innovation Across Energy, Medicine, Climate and Space

The program ties together cutting-edge energy engineering with advances in microbiology, climate intervention ethics, and space biology. It frames a future where modular energy production, evolving phage therapies, tested climate techniques, and resilient organisms could interact with regulatory, economic, and ethical frameworks to shape policy and industry directions in the coming decade.