The use of low grade uranium enrichment for a more near term version is the one that is often described. However, if weapons grade uranium (90% enrichment) is used then he exhaust would be at 1.575% of the speed of light. A 30,000 ton ice asteroid and 7500 tons of uranium could propel a 300 ton payload including a crew to 7.62% of light speed.

One of key parts of the engineering is to use water to protect the nozzle from the intense heat of the system. A combination of the coatings and space between the pipes would prevent the solution from reaching critical mass until it was pumped into a reaction chamber. It would reach critical mass and it being expelled through a nozzle to generate thrust. The nozzle would be protected by running water.

Scott Manley calls it a constant Chernobyl rocket. It is a nuclear reactor constantly at meltdown temperatures. The rocket was designed so that the liquid flow rate or velocity was what mattered most in the process, not what it was made out of. Robert Zubrin argued that if the proper velocity was chosen for the liquid traveling through the reaction chamber, the site of maximum fission release could then be located at the end of the chamber, thus allowing the system to remain intact and safe to operate.

The NSWR is a vehicle with ISP at the best ion drive levels or beyond and operating with hundreds of gigawatts of power.

The weaker NSWR engine analysis assumed a very low yield of 0.1% and a modest enrichment of 20%. The potential ultimate performance of a NSWR if more optimistic values are assumed.

An NSWR utilizing a 2% uranium bromide solution with 90% enriched U233, and obtaining a 90% fission yield. Assuming a nozzle efficiency of 0.9, the exhaust velocity of this system will be 4725 km/s, or about 1.575% of the speed of light (a specific impulse of 482,140 seconds). If the 300 tonne Titan mission spacecraft is endowed with 2700
tonnes of propellant (for a mass ratio of 10) a maximum velocity of 3.63% of speed of light could be obtained, allowing the ship to reach Alpha Centauri in about 120 years.

Deceleration could be accomplished without the use of substantial amounts of rocket propellant by using a magnetic sail (or "magsail") to create drag against the interstellar
medium.