If TAE Technologies Succeeds With Commercial Fusion Then a Fusion Rocket Will Follow

TAE Technologies has also looked at building a nuclear fusion rocket. Nextbigfuture had covered TAE Technologies recent announcement that they will have a commercial nuclear fusion rocket by 2023.

The design is from an older 2004 paper. Any new system that is built after TAE Technologies actually achieves commercial power generation with fusion would be vastly better than what is in the 2004 paper.

Nuclear fusion rockets are simpler and less challenging than creating commercial energy that is nearly as cheap as coal. A commercial nuclear reactor needs to be generating power for an average of 70-90% of a year. A nuclear fusion rocket just has to be better than ion drive or more useful than chemical rockets in some situations.

UPDATE – TAE Technologies emailed about how they are not working on the fusion rocket. I knew they were not working on a nuclear fusion rocket but wanted to publish the 2004 paper. I expect and agree that the handful of companies that are funded and focused on nuclear fusion rockets are ahead. I will cover those other nuclear fusion and advanced propulsion projects again.

Still my point is that if a company can make a commercial nuclear fusion reactor on land then creating a nuclear fusion rocket would not be that difficult. Although, General Fusions design approach does not lend itself to conversion other than as a power source for a high-efficiency drive. TAE also said 2023 is only the start of commercialization. Starting 2023 on commercialization is still aggressive. Going from no net power to net power in about 2 years and then to P-B11 are all huge leaps.

The 2004 Fusion Rocket Paper

The AIP Conference Proceedings 2004 – Colliding Beam Fusion Reactor Space Propulsion System

The Colliding Beam Fusion Reactor (CBFR( requires approximately 50 MW of injected power for steady-state operation. The H-B11 CBFR would generate approximately 77 MW of nuclear (particle) power, half of which is recovered in the direct-energy converter with 90% efficiency. An additional 11.5 MW are needed to sustain the reactor which is provided by the thermo-electric converter and Brayton-heat engine. The principal source of heat in the CBFR-SPS is due to Bremstrahlung radiation. The thermo-electric converter recovers approximately 20% of the radiation, or 4.6 MW, transferring approximately 18.2 MW to the closed-cycle, Brayton-heat engine.

CBFR‐SPS, is an aneutronic, magnetic‐field‐reversed configuration, fueled by an energetic‐ion mixture of hydrogen and boron11 (H‐B11). Particle confinement and transport in the CBFR‐SPS are classical, hence the system is scalable. Fusion products are helium ions, α‐particles, expelled axially out of the system. α‐particles flowing in one direction are decelerated and their energy recovered to “power” the system; particles expelled in the opposite direction provide thrust. Since the fusion products are charged particles, the system does not require the use of a massive‐radiation shield. This paper describes a 100 MW CBFR‐SPS design, including estimates for the propulsion‐system parameters and masses. Specific emphasis is placed on the design of a closed‐cycle, Brayton‐heat engine, consisting of heat‐exchangers, turbo‐alternator, compressor, and finned radiators.

The reactor is fueled by an energetic-ion mixture of hydrogen and boron (p-11B). Fusion products are helium ions (α-particles) expelled axially out of the system. α-particles flowing in one direction are decelerated and their energy directly converted to power the system. Particles expelled in the opposite direction provide thrust. Since the fusion products are charged particles and does not release neutrons, the system does not require the use of a massive radiation shield.

The CBFR-SPS promises many benefits for advanced-space propulsion. Many of the technologies needed to realize a CBFR-SPS either exist, or could be developed readily in a several-year timeframe. Continued evolution and refinements in these technologies would favorably impact the definition of the CBFR-SPS concept reported here, for example: high-temperature superconductors, high energy density fuel cell technology, and advanced composite materials, etc. The scaleable nature of this system provides a cost-effective scenario for developing a flight system: development and testing could be done on a small, low-power device and then scaled up to a larger flight s ystem. The use of H-B11fuel would minimize the need for a large, massive, radiation shield. The high-beta, magnetic configuration and the use of energetic ions would facilitate the use of indigenous fuels, and perhaps enable system re-fueling at planetary destinations. Alternate design implementations of the CBFR-SPS could be used to provide prime power for existing,electric-propulsion concepts, for example: Hall thrusters, ion-propulsion systems, VASIMIR (Chang-Diaz,1999), etc. The modular design of the CBFR-SPS could provide base-station power at a missions finaldestination, or to provide a staged approach to exploration, involving outpost-base stations.

A fusion rocket system that worked for a few weeks at 100 MW would still be far better than any ion drive we have now and better than chemical rockets for deep space missions. Even if the fusion rocket did not generate energy but required more energy that it put out the system could still be useful.

Updating for New Post 2023 Power System

The 2004 paper would need to be updated for the potential 400 MW long duration power reactor that TAE Technologies plans to build.

The capital cost for energy the TAE Technologies commercial fusion reactor will be at $4300/kW.
Natural gas plant cost $2000 per kW
Current nuclear in the USA costs $9000 per kW

U.S. has uniquely cheap gas but TAE will be competitive globally from the start of commercialization. They will have 350 MWe to 400 MWe plant size for the commercial reactor.

A 350 MWe nuclear fusion drive that could run with net energy and operate for years would likely mean propulsion that could achieve 1-5% of the speed of light.