Compare readiness levels

The graphs below provide information on nuclear fuels and their readiness levels. You can view the combined fuels and readiness levels or select them individually by clicking on the coloured labels and filters.

Exploring the advantages of nuclear as a marine fuel

  1. Straightforward onboard requirements: Nuclear reactors take up significantly less space than is required for alternative fuels, and no regular maintenance and operational crew input is needed. Additionally, there is safety by design (in the structure)

  2. Infrequent bunkering: Regular bunkering is not required, saving time and costs associated with bunkering stops.

  3. Zero emissions: No GHG emissions or particulate matter are produced during operation.

  4. Depleted fuel management: Much of the waste can be used for power using new-generation nuclear technologies. 

Risks and disadvantages 

  1. Public perception and understanding: Nuclear power's perceived safety risks and potential environmental impact have led to opposition from communities and environmental organisations.

  2. Disposal of radioactive waste: This requires secure and sustainable solutions to prevent environmental contamination.

  3. Safety considerations: Nuclear power systems require stringent safety measures to ensure any incidents have low consequences. 

Differences between nuclear fuels

Pressurised Water Reactor (PWR)

PWRs have been developed into small modular reactors that could be used onboard. They use uranium as fuel to generate heat through a controlled nuclear fission chain reaction. The heat is transferred to the coolant, which in a PWR is typically ordinary water. The heated coolant remains in a liquid state at the high temperatures due to the high pressure maintained within the reactor vessel. This heat can then be used for conversion to electrical power or direct thermal energy for heating purposes.

  • Resources: uranium, water
  • Production: manufacturing processes
  • Bunkering and ports: flasks for transport, infrastructure for nuclear
  • Handling and storage: N/A (protected by structure)
  • Propulsion: turbine, electrical power
Heat pipe

A nuclear heat pipe (low pressure microreactor) is a passive heat transfer device. Uranium is used as fuel to generate heat through a controlled nuclear fission chain reaction in the reactor core. The heat is transferred to a working fluid in the heat pipe. This heat can then be used for conversion to electrical power or direct thermal energy for heating purposes.

  • Resources: uranium 
  • Production: manufacturing processes
  • Bunkering and ports: transport, infrastructure for nuclear
  • Handling and storage: N/A
  • Propulsion: turbine, electrical power
Molten salt

A molten salt (low-pressure) reactor uses uranium dissolved in a molten fluoride salt liquid mixture to generate heat through a controlled nuclear fission chain reaction in the core. The molten salt acts as a coolant and a moderator, sustaining the chain reaction. The heat is transferred to a working fluid. This heat can then be used for conversion to electrical power or direct thermal energy for heating purposes. Molten salt reactors are fuelled for life; therefore, no bunkering is required.

  • Resources: uranium, salt 
  • Production: manufacturing processes 
  • Bunkering and ports: transport, infrastructure for nuclear
  • Handling and storage: N/A
  • Propulsion: turbine, electrical power

 

Nuclear readiness insights

Review data on Pressurised Water Reactor (PWR), Heat pipe and Molten salt
Technology Readiness Levels (TRL)

 

Resources
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 9 Production and product fully operational A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Scaled-up uranium mining is required to meet current demand and increased demand from other sectors, such as shipping, adopting nuclear technologies.
Nuclear (heat pipe) 9 Production and product fully operational A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Scaled-up uranium mining is required to meet current demand and increased demand from other sectors, such as shipping, adopting nuclear technologies.
Nuclear (molten salt) 9 Production and product fully operational A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Scaled-up uranium mining is required to meet current demand and increased demand from other sectors, such as shipping, adopting nuclear technologies.

 

Production (of the energy system - nuclear)
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 4 Validation of integrated prototype in test environment The technology exists but is not proven in commercial shipping Standards in commercial shipping need to be defined 
Nuclear (heat pipe) 4 Validation of integrated prototype in test environment The technology exists but is not proven in commercial shipping Standards in commercial shipping need to be defined 
Nuclear (molten salt) 4 Validation of integrated prototype in test environment The technology exists but is not proven in commercial shipping Standards in commercial shipping need to be defined 

 

Reactor refuelling and ports
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 3 First assessment feasibility concept and technologies Technology concept and procedures are being formulated. Refuelling of PWRs is already well-established for use in other sectors, and is not specific to shipping. However, the infrastructure to do this is not yet available in civillian ports. Experience from naval nuclear vessels and ports will be leveraged to develop  infrastructure and procedures for docking and repair shipyards that will handle nuclear ships. Nominated ports need to demonstrate refuelling capabilities, including spent fuel removal and transportation. 
Nuclear (heat pipe) 1 Basic principle observed Technology concept and procedures are being formulated. The heat pipe is returned to manufacturers facilities for refuelling, and is not an in-port activity.  Experience from naval nuclear vessels and ports will be leveraged to develop  infrastructure and procedures for docking and repair shipyards that will handle nuclear ships.  However, nominated ports need designated areas for the withdrawal, transportation and replacement activity. 
Nuclear (molten salt) 1 Basic principle observed Technology concept and procedures are being formulated Experience from naval nuclear vessels and ports will be leveraged to develop  infrastructure and procedures for docking and repair shipyards that will handle nuclear ships. Nominated ports  need to develop infrastructure and develop capabilities and procedures for maintenance of nuclear ships.

 

Ship - Onboard handling and storage (operation - nuclear)
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 2 Technology concept formulated Technology concept formulated, leveraging defence sector experience, however this has not been proven in commercial shipping Regulation needs to be defined so that appropriate procedures and technology can be developed and tested onboard. 
Nuclear (heat pipe) 2 Technology concept formulated Technology concept formulated, however this has not been proven in commercial shipping Note: this does not require any onboard operations (remote monitoring) Regulation needs to be defined so that appropriate procedures and technology can be developed and tested onboard. 
Nuclear (molten salt) 2 Technology concept formulated Technology concept formulated, leveraging defence sector experience, however this has not been proven in commercial shipping Regulation needs to be defined so that appropriate procedures and technology can be developed and tested onboard. 

 

Ship - Propulsion (reactor and turbine)
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 4 Validation of integrated prototype in test environment The technology is proven in a test environment, but testing on board has not been completed Regulation needs to be defined so that appropriate procedures and technology can be developed and tested onboard. 
Nuclear (heat pipe) 4 Validation of integrated prototype in test environment The technology is proven in a test environment, but testing on board has not been completed Regulation needs to be defined so that appropriate procedures and technology can be developed and tested onboard. 
Nuclear (molten salt) 3 First assessment feasibility concept and technologies The technology is undergoing validation The technology needs to be validated

 

Investment Readiness Levels (IRL)

 

Resources
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 4 Multiple commercial applications A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Signals need to be provided to investors that show a stable, attractive market, in order for investment for scale-up supply
Nuclear (heat pipe) 4 Multiple commercial applications A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Signals need to be provided to investors that show a stable, attractive market, in order for investment for scale-up supply
Nuclear (molten salt) 4 Multiple commercial applications A uranium supply chain already exists to serve other sectors. More uranium needs to be mined to satisfy current demand, and technology providers will be competing to serve several sectors. Signals need to be provided to investors that show a stable, attractive market, in order for investment for scale-up supply

 

Production (of the energy system - nuclear)
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 1 Hypothetical commercial proposition Multiple supply chains exist, but none have been proven for use in commercial shipping. Performance and revenue projections exist. Solutions need to be proven for shipping, and strong market demand is needed to scale 
Nuclear (heat pipe) 1 Hypothetical commercial proposition Multiple supply chains exist, but none have been proven for use in commercial shipping. Performance and revenue projections exist. Solutions need to be proven for shipping, and strong market demand is needed to scale 
Nuclear (molten salt) 1 Hypothetical commercial proposition Multiple supply chains exist, but none have been proven for use in commercial shipping. Performance and revenue projections exist. Solutions need to be proven for shipping, and strong market demand is needed to scale 

 

Reactor refuelling and ports
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 1 Hypothetical commercial proposition No commercial trials have started yet, however, there are minimal technological risks to investing based on technology demonstration for naval application Regulations and sites need to be developed to reduce risks in investment (will happen concurrently)
Nuclear (heat pipe) 1 Hypothetical commercial proposition No commercial trials have started yet, however minimal investment required in facilities is anticipated Regulations and sites need to be developed to reduce risks in investment (will happen concurrently)
Nuclear (molten salt) 1 Hypothetical commercial proposition No commercial trials have started yet, however minimal investment required in facilities is anticipated Regulations and sites need to be developed to reduce risks in investment (will happen concurrently)

 

Ship
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 1 Hypothetical commercial proposition Cost projections for use of the technology in commercial shipping exist, however no commercial trials have begun yet Trials are needed to validate assumptions, cost projections and data used in the initial economic case
Nuclear (heat pipe) 1 Hypothetical commercial proposition Cost projections for use of the technology in commercial shipping exist, however no commercial trials have begun yet Trials are needed to validate assumptions, cost projections and data used in the initial economic case
Nuclear (molten salt) 1 Hypothetical commercial proposition Cost projections for use of the technology in commercial shipping exist, however no commercial trials have begun yet Trials are needed to validate assumptions, cost projections and data used in the initial economic case

 

Community Readiness Levels (IRL)

 

Resources
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 4 Evidence becoming wide-spread resulting in initial stakeholder acceptance Lifecycle impacts are understood and existing mining practices are in place Communities need to be educated and engaged on the lifecycle impacts of using uranium in nuclear technologies
Nuclear (heat pipe) 4 Evidence becoming wide-spread resulting in initial stakeholder acceptance Lifecycle impacts are understood and existing mining practices are in place Communities need to be educated and engaged on the lifecycle impacts of using uranium in nuclear technologies
Nuclear (molten salt) 4 Evidence becoming wide-spread resulting in initial stakeholder acceptance Lifecycle impacts are understood and existing mining practices are in place Communities need to be educated and engaged on the lifecycle impacts of using uranium in nuclear technologies

 

Production (of the energy system - nuclear)
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 1 Stakeholder support or opposition is hypothetical Rules and regulations exist for using nuclear technology for commmercial shipping, however they have been outpaced by current technology Safety and environmental regulations need to be updated, and communities need to be engaged and educated on the lifecycle impacts
Nuclear (heat pipe) 1 Stakeholder support or opposition is hypothetical Rules and regulations exist for using nuclear technology for commmercial shipping, however they have been outpaced by current technology Safety and environmental regulations need to be updated, and communities need to be engaged and educated on the lifecycle impacts
Nuclear (molten salt) 1 Stakeholder support or opposition is hypothetical Rules and regulations exist for using nuclear technology for commmercial shipping, however they have been outpaced by current technology Safety and environmental regulations need to be updated, and communities need to be engaged and educated on the lifecycle impacts

 

Reactor refuelling and ports
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 1 Stakeholder support or opposition is hypothetical Environmental and safety regulation to enable nuclear ships to visit ports is not defined Safety and environmental regulations need to be defined, and community perceptions need to be understood. 
Nuclear (heat pipe) 1 Stakeholder support or opposition is hypothetical Environmental and safety regulation to enable nuclear ships to visit ports is not defined Safety and environmental regulations need to be defined, and community perceptions need to be understood. 
Nuclear (molten salt) 1 Stakeholder support or opposition is hypothetical Environmental and safety regulation to enable nuclear ships to visit ports is not defined Safety and environmental regulations need to be defined, and community perceptions need to be understood. 

 

Ship
Fuel Type Rating Description Justification Challenge
Nuclear (PWR) 2 Stakeholder support or opposition is becoming understood as a result of pilots Pilots in other sectors providing an indication of stakeholder response. Safety and environmental regulations in shipping have been outpaced by current technology. Pilots in shipping are needed to provide evidence to address stakeholder issues, and regulations need to be updated.
Nuclear (heat pipe) 2 Stakeholder support or opposition is becoming understood as a result of pilots Pilots in other sectors providing an indication of stakeholder response. Safety and environmental regulations in shipping have been outpaced by current technology. Pilots in shipping are needed to provide evidence to address stakeholder issues, and regulations need to be updated.
Nuclear (molten salt) 2 Stakeholder support or opposition is becoming understood as a result of pilots Pilots in other sectors providing an indication of stakeholder response. Safety and environmental regulations in shipping have been outpaced by current technology. Pilots in shipping are needed to provide evidence to address stakeholder issues, and regulations need to be updated.