Calogena is developing a 30 MWt light water reactor designed specifically for integration into existing district heating networks. Selected as part of the EU SMR Alliance CityHeat project alongside Steady Energy. The design targets urban heat decarbonisation — replacing gas boilers in European district heating systems with low-carbon nuclear heat. France's dense district heating networks make it an ideal initial market. An earlier record described the project as focused on industrial heat applications (decarbonising industrial processes that need high-temperature heat) and gave its capacity as 20 MW; the regulator's list (August 2026) shows the CAL30 industrial prototype at 30 MWth. Regulatory status (ASNR, August 2026): Calogena is at Step 3 (pre-licensing): it submitted a request for an opinion on the safety options of the CAL30 on October 31, 2024 (amended June 20, 2025) and further requests on December 23, 2025, January 6, 2026 and May 11, 2026. An earlier note placing it at Step 2 alongside Naarea and Thorizon is out of date. Calogena is part of the French SMR startup ecosystem catalysed by the France 2030 programme.