Last Energy obtained site control at the Llynfi site in South Wales in October 2024 and plans four PWR-20 microreactor power plants (4 × 20 MWe = 80 MWe total) at the site. The UK's nuclear regulators (ONR, Environment Agency, and Natural Resources Wales) completed a Preliminary Design Review (PDR) of the PWR-20 in June 2025 — the first nuclear developer to complete a PDR in the UK. Last Energy is on track for a site licence decision by December 2027. The company is the only known developer with a regulator-confirmed pathway toward a potential 2027 UK site licence. The PWR-20 is a 20 MWe (60 MWt) single-loop pressurised water reactor using standard full-length PWR fuel enriched to 4.95%, fabricated, transported, and assembled within 24 months. The plan is for four 20 MWe PWR-20 reactors at the former Llynfi Coal Power Station site, potentially the first new commercial nuclear site to enter UK licensing since Torness in 1978; Last Energy is targeting a site-licensing decision by December 2027. The Llynfi site adds to Last Energy's UK pipeline alongside the separate English site that entered ONR licensing in February 2025 (recorded separately).