Russia’s NTP Accident
The mysterious Russian nuclear rocket engine accident on August 8, 2019 has left behind clues which fit the scenario of a runaway reactor followed by a powerful liquid hydrogen explosion. This missile and rocket technology, called Nuclear Thermal Propulsion (NTP), use a micro reactor to rapidly heat and ignite liquid hydrogen to produce thrust through a rocket nozzle.
Something went wrong with the test firing of the rocket engine – causing it to explode with terrific force and disperse nuclear isotopes. Five scientists were killed, supporting the conclusion that the accident occurred on the ground in what is known as a static engine test.
People have been warned not to visit the area around the test range, including the coastal waters where some debris has washed ashore. Russian authorities insist that the accident took place in the White Sea. The NTP engine had defacto become a dirty bomb causing plumes of radioactivity over huge parts of the former Soviet Union. However, the radioactivity of the extended plumes is not very serious for now. Radioactive particles which settle in cities and towns could be strong enough that people exposed to the energetic particles over a long period of time could develop cancers.
The Russians have been developing a rocket engine designed to circumvent a nation’s missile defenses by flying a path which they claim is “too unpredictable” to be intercepted. This cruise missile called “Skyfall” by western intelligence, will fly a zig-zag or a curvy path. To that end, the rocket engine must be able to provide thrust for a long time. Using the thermal properties of a reactor, the flight would only be limited by the amount of liquid hydrogen the missile can carry.
U.S. Historical Pursuit of NTP For “Rocket Vehicles”
The United States successfully pursued this technology from 1955 to 1972 in what was called the NERVA program. NERVA was short for “Nuclear Engine for Rocket Vehicle Application.”
More than twenty nuclear reactor rocket engines were built and tested. Recent scientific developments indicate that advanced nations are experimenting with new fuel compositions which supposedly are safer and release smaller amount of radiation than the original designs. Yes, these deliverers of death via military applications spew radiation in their exhaust plumes as they fly over territories of the innocent or uninvolved.
What Are “Fast Reactors”
In an NTP rocket engine, heat from a small “fast reactor” ignites the hydrogen resulting in more than two times the thrust (actually “specific impulse”) of a normal rocket engine. A fast reactor operates at about 4000 degrees Fahrenheit and the uranium fuel lifetime is extended by 200 times. That means a smaller amount of uranium, with the advantage of reduced weight, can be employed in a more efficient rocket design. Nuclear power plants in the United States use slow reactors which are much more reliable and safer than fast reactors.
The problem is, things can go wrong very quickly in a fast reactor. An unstable fast reactor can go supercritical in seconds or even just one second. The resulting explosion would then ignite the liquid hydrogen stored in the propellant tanks of the rocket and launch the nuclear components, isotopes and gases into the atmosphere. Anyone nearby would be killed by the explosion. The health effects from the dispersal of the radioactivity would vary but would likely require decontamination efforts or evacuations of some areas.
Radioactive cesium-137 was found in the muscle tissue of one of the doctors who treated some of the victims of the explosion. Russian authorities made the doctors sign a non-disclosure agreement. The doctors have revealed that they were taken to Moscow. The gowns worn by the doctors were found to be radioactive.
U.S. Renewed Interest In NTP For Space Missions
While many people are concerned about the Russian accident, the United States is planning to revive the NERVA program. However, it might take another ten years before we start turning out newly designed nuclear reactor rocket engines in Nevada. NASA and the Department of Defense are the chief customers.
NASA would like this technology to take men to Mars and back. Between those two entities, I don’t think our NTP program will be abandoned. Just this week NASA began campaigning for NTP as a “game changer.”
NTP Rocket Vehicle Safety Concerns
Let’s hope the Russian’s let everyone know what went wrong. After all, we agreed to end atmospheric nuclear testing so I can see motivation to share data to prevent a repeat of the problem of the accidental explosion.
One of the principal objections to this technology, as listed by the Idaho National Laboratory (INL), is the fact that radioactivity is released in the exhaust stream of these missiles. The public reacts strongly to that little quirk. (I once gave a presentation on nuclear madness called “The Quacks, Quirks and Quarks of the Nuclear Scientists.)
The last point listed by the INL is the possibility of the reactor going “sub-critical on launch abort.” Maybe the laboratory should add the concern “super-criticality during flight.” Let’s hope all nations abort these nuclear power rocket engine programs.