Russia’s 9M730 Burevestnik Missile Reactor 1000 Times Smaller than Submarine Reactor

Russia’s 9M730 Burevestnik, the long-endurance nuclear-powered cruise missile, continues to generate both fascination and controversy. Central to its mystery is its power source — a miniaturized nuclear reactor that Russia claims is 1,000 times smaller than the one used in a nuclear submarine, yet capable of delivering comparable endurance. This extraordinary claim, if taken literally, allows for an approximate calculation of its output and helps us understand what such a power system could mean for missile propulsion.

Estimating the Power of Burevestnik’s Reactor

A typical Russian submarine reactor, such as the OK-650 used on several nuclear attack submarines, produces about 190 megawatts (MW) of thermal power. If Burevestnik’s nuclear power unit is 1,000 times smaller, the arithmetic is straightforward:

190 MW ÷ 1,000 = 0.19 MW, or 190 kilowatts (kW) of thermal power.

This 190 kW figure refers to the thermal energy generated by the reactor core — the total heat output, not the mechanical power available for propulsion. To understand how much of this heat could translate into thrust, we need to account for energy conversion efficiency.

Converting Heat into Propulsion

In a compact nuclear engine, much of the reactor’s heat is lost during conversion into mechanical energy. Assuming an efficiency between 25% and 35% — realistic for a small thermal-to-jet system — Burevestnik’s useful propulsion power would range between 47.5 kW and 66.5 kW, or roughly 64 to 89 horsepower.

That power range is modest when compared to conventional jet engines, yet it offers one critical advantage: endurance. A reactor generating continuous power in this range could, in theory, allow the missile to stay airborne for extremely long durations, limited only by airframe fatigue or guidance constraints.

The Practical Meaning of “Miniature Power”

A 0.19 MW thermal reactor may seem small by nuclear standards, but in the context of a missile, it represents a remarkable engineering feat. Such power could sustain long-duration subsonic flight over vast distances — potentially global reach. This is why Burevestnik has often been portrayed as a “missile with unlimited range”, though practical limitations like airframe drag, shielding, and thermal management complicate that claim.

However, the small reactor size imposes design trade-offs. Effective radiation shielding to protect the onboard electronics (and possibly launch crews during handling) adds mass, while heat exchange systems must be compact yet robust enough to manage continuous reactor heat at high altitude and speed. The combination of high energy density and limited cooling capacity pushes the limits of materials science and system integration.

Safety and Environmental Risks

Compact nuclear propulsion introduces unavoidable radiological hazards. If the reactor directly heats air (as a nuclear ramjet might), radioactive particles could be released during operation. In the event of a crash or failed test, fragments of the reactor core could contaminate a wide area.

Russia’s previous accident at Nyonoksa (2019), which reportedly involved a test of a nuclear-powered missile prototype, highlighted these risks. That incident caused radiation spikes and multiple fatalities, reinforcing the inherent danger of testing compact nuclear propulsion systems.

Recent Developments and Official Claims

In October 2025, President Vladimir Putin stated that Russia had successfully tested the Burevestnik missile, suggesting that the nuclear propulsion system is now operational. Russian media claimed the missile flew for over 14,000 kilometers during a 15-hour test, though no independent verification has been provided. Western defense analysts remain skeptical, noting that the engineering and safety challenges remain formidable.

Burevestnik’s design philosophy appears rooted in Cold War-era concepts like Project Pluto, the U.S. effort to develop a nuclear-powered ramjet in the 1960s. While that project achieved ground test success, it was ultimately canceled due to environmental and political concerns — the same issues that would likely limit large-scale deployment of Burevestnik.

Uncertainties and Technical Limitations

It is important to emphasize that much of what is known about Burevestnik remains speculative. The phrase “1,000 times smaller” could refer to volume, mass, or power output, and Russia has not clarified the metric. Even assuming a 0.19 MW thermal core, it is uncertain how that energy is transferred into thrust — whether through direct air heating, a turbine-driven fan, or a hybrid cycle.

Moreover, the efficiency of conversion, reactor lifetime, and control mechanisms under missile flight conditions remain undisclosed. Until credible technical evidence or international monitoring confirms these capabilities, the system’s operational status should be treated cautiously.

If the claim of being “1,000 times smaller than a submarine reactor” refers to power, Burevestnik’s nuclear unit likely produces around 0.19 megawatts (190 kW) of thermal energy. With conversion efficiency taken into account, its usable propulsion power would be in the 50–70 kW range — enough to sustain low-speed flight over intercontinental distances, but not to achieve high-speed performance.

Whether this translates into a reliable weapon or remains a symbol of technological experimentation depends on how Russia resolves the immense challenges of miniaturization, shielding, and safe testing. For now, Burevestnik stands as both a scientific curiosity and a strategic statement — a reminder that nuclear propulsion, while theoretically boundless, comes with costs that extend far beyond engineering.