Concept Design of Nuclear-Powered FPSO Achieves Sustainable Offshore Energy

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 37089, “Sustainable Offshore Energy: Concept Design of a Nuclear-Powered FPSO,” by Mayir Mamtimin, SPE, Jorge Segovia, and Jin Wang, American Bureau of Shipping, et al. The paper has not been peer-reviewed. Copyright 2026 Offshore Technology Conference. _ Floating production, storage, and offloading (FPSO) units are a standard solution for offshore oil and gas developments where export pipelines are impractical or uneconomic. Power typically is provided by gas turbines burning associated gas, which is attractive economically but results in significant CO2 and methane. This paper explores the application of a modular, high-temperature gas-cooled reactor (HTGR) to a Very Large Crude Carrier (VLCC)-class FPSO. The emphasis of the complete paper is on a coherent case study framework rather than detailed design optimization. Regulatory, Safety, and Commercial Framework Overall Governance and Assumptions. For this study, the FPSO is assumed to be permanently moored within a shelf state’s Exclusive Economic Zone, with a single outbound transit to the field and a single return transit for decommissioning. Operationally, the unit is treated as a fixed offshore installation subject to a field-specific safety case while retaining its status as a ship-shaped unit. The reactor is supplied by an original equipment manufacturer (OEM) operating under a national nuclear license in the licensing state. The FPSO operator is responsible for overall unit operation and integration into the offshore safety regime, while the OEM retains custodianship of the nuclear core and specialized nuclear functions. Regulatory Architecture and Safety Case. In broad terms, the licensing state approves the reactor design and controls fuel movement; the flag state authorizes installation and operation of the reactor on the vessel under Safety of Life at Sea, IMO Resolution A.491(XII), and national maritime law; and the shelf state approves the installation through an offshore regulatory regime. To avoid the regulatory complexity associated with frequent transit through multiple coastal and port states, the concept is limited to a permanently moored FPSO within a single host jurisdiction. Liability, Emergency Response, and Operational Envelope. Nuclear liability is assumed to follow a regime in which operator liability is capped by national or international instruments, supported by mandatory insurance and industry risk-pooling mechanisms. A dedicated nuclear service organization is envisaged to provide specialized transport, installation, maintenance, and emergency-response capabilities for marine reactors. The FPSO and reactor are designed and assessed against a defined metocean and station-keeping envelope appropriate to the field location. Within this envelope, the reactor must demonstrate safe shutdown and decay heat removal for design-basis and beyond-design-basis events, including combined hydrocarbon and nuclear incidents. Nuclear and conventional emergency preparedness are integrated into a single field-level plan.