Imagine low-cost nuclear-powered torpedoes that can travel largely undetected in a swarm across the Pacific Ocean and strike U.S. targets in about a week.
To a group of researchers in Beijing, that’s not just a fever dream, it’s a concept they believe they can turn into reality. And an ambition U.S. State Department officials have been warning about.
Chinese researchers say they completed a conceptual design for such a weapons system in a paper published this month by the peer-reviewed Journal of Unmanned Undersea Systems, a publication run by China’s biggest naval contractor, the South China Morning Post (SCMP) reported Tuesday.
The torpedo system would use a disposable nuclear reactor to reach and maintain a cruising speed of over 30 knots (35 mph) for 200 hours before dumping the reactor. It would then fall to the seabed. The torpedo would continue to draw power from a battery to launch its conventional (non-nuclear) attack.
It is unclear what kind of targets Guo's team is considering for this weapon. The SCMP article did not offer any specifics.
While SCMP likened the system to the Russian Poseidon undersea nuclear-powered, nuclear-tipped torpedo-drone, there are major differences, which scientist Guo Jian from the China Institute of Atomic Energy reportedly noted in the Journal of Unmanned Undersea Systems paper.
The Poseidon is one of Vladimir Putin's six so-called 'super weapons' highlighted in a fiery address in 2019. Its main job is to strike at coastal installations with little to no warning. It reportedly has an especially dirty nuclear warhead, which means it would not only cause immediate damage, but also contaminate the area with radiation and impede any continued operations or repairs. Some believe Poseidon would detonate off the coast near large naval installations and/or major population centers and send a wall of irradiated water inland, swamping and contaminating large areas with radioactivity. Its nuclear propulsion and other design elements would allow it to be launched from thousands of miles away and potentially loiter for long periods on standby before prosecuting an attack or being recalled.
The special missions submarine Belgorod, which was turned over to the Russian Navy earlier this month, carries that torpedo.
By contrast, the Chinese weapon proposed by Guo and his team has a conventional warhead (there is no reason why a nuclear warhead wouldn't be possible), is small enough to fit in a conventional torpedo tube, and can be produced in far great quantities.
“Thanks to its high flexibility and low cost, this unmanned underwater vehicle equipped with the nuclear power system can be used as a conventional force like an attack nuclear submarine, rather than as a nuclear missile,” he said, according to SCMP.
It would in part meet growing demand in China for “small, high-speed, long-range unmanned underwater vehicles that can be used in reconnaissance, tracking, attack and strategic strike."
The key to Guo’s system is a low-cost, disposable nuclear reactor that gives off just enough power to propel the torpedo great distances before detaching ahead of the system's final attack.
To build a new nuclear power system with “mature and simple technology that is easy to use and maintain, inexpensive and suitable for mass production, we need to think out of the box,” Guo said.
Guo’s team “stripped most shielding materials from their reactor, protecting only some critical components from radiation,” SCMP reported.
They also replaced “expensive coatings made with rare earth elements inside the reactor core with cheap materials such as graphite.”
The resulting reactor would generate “more than 1.4 megawatts of heat with less than 8.8lbs of low-concentration uranium fuel.”
The reactor would be so cheaply designed that only about 6% of the generated heat would be converted to electricity to power the torpedo, but that would be more than enough for a one-way trip.
“When the manufacturing cost is low enough, even if the nuclear-powered device can only be used once, the overall cost will be low,” the researchers said, according to SCMP. “This in turn stimulates us to make the system simpler and smaller.”
Under the Guo design, a chain reaction would not start until about a half-hour after the torpedo left the launching platform. That makes it safe to handle, because it would not be radioactive until it reached a safe distance from whatever platform launched it.
That chain reaction would happen about 20 times faster than a typical reactor on a nuclear submarine to be able to reach a working temperature of nearly 600 degrees Fahrenheit. That would accelerate the torpedo to a cruising speed of around 37 mph.
The researchers estimate the reactor would “be able to operate for up to 400 hours, cruising over 6,200 miles – about the distance from Shanghai to San Francisco.”
It would then separate from the torpedo and fall to the bottom of the deep sea, activating a safety mechanism to kill the remaining chain reaction, they said, according to SCMP. "Even if the hull is broken, the interior is filled with water, and the whole body falls into the wet sand on the seabed, the reactor will not have a critical accident. The safety is ensured.”
The weapons would be designed to be fired from any number of platforms, but especially from China's growing fleet of submarines.
Many questions remain about such a concept.
SCMP did not publish a link to the Guo paper and efforts to find it have proven unsuccessful. SCMP has, in the past, published stories of extraordinary-sounding Chinese military technology that has not actually materialized, including weather-modifying radar and a laser assault rifle among examples of this phenomenon that we've previously addressed.
Then there are questions about some of the details. The SCMP article, for instance, says the torpedo can travel 200 hours before dropping its reactor and having the torpedo powered by a battery to its target. It also mentions it can travel for 400 hours. Whether that means it can travel for 200 hours on battery power alone is unclear.
Beyond that is an even bigger question. Though the Journal of Unmanned Undersea Systems is run by the China Shipbuilding Industry Corporation, and Guo works for the China Institute of Atomic Energy - the China National Nuclear Corporation's (CNNC) main research institute - it's unclear just how feasible this concept really is. We've reached out to several nuclear reactor experts for analysis and will update this story with any response.
It is possible that Guo's team is talking about a radioisotope thermoelectric generator (RTG), a sort of nuclear battery that converts the heat from radioactive decay into electric power. An RTG was initially considered to have been involved three years ago in a still very mysterious explosion during the test of Russia's Burevestnik nuclear-powered missile. Whether than can fit into a conventional torpedo tube and be safely handled by a crew remains to be seen.
But regardless of what kind of nuclear power source is used, the concept of it being dumped on a seabed, no matter how safe Guo and his team claim that might be, is sure to raise alarms from well beyond the halls of the Pentagon.
The SCMP article also mentions that China is interested in swarming technology for its undersea weapons programs.
“Smart torpedoes” acting in packs would play an important role in future sea battles, Ma Liang, a researcher studying submarine launch technology with the Navy Submarine Academy in Qingdao, Shandong province, SCMP quoted her as saying.
AI technology would enable the torpedoes to select and attack targets with little or no human intervention, she said in a separate paper published in the same journal on July 13. China is certainly deeply engaged in developing such capabilities.
Smart torpedoes would be able to set up an ambush on the other side of the ocean and “strike submarines as they leave a port in home waters that is difficult to reach by manned platforms.” Ma said.
The torpedo swarm could take orders from humans or from an unmanned underwater vehicle that is able to carry out a wide range of missions, such as reconnaissance and following a high-value target, she added.
“This is the most dynamic research technology field at present.”
All of this sounds easy when loosely discussed, but actually pulling it off, especially when it comes to finding and successfully attacking dynamic targets over very long ranges — while still being in the loop of any command and control architecture at all — is much easier said than done.
Still, there is a great deal of concern about China's development of these types of weapons. Last year, Ambassador Robert Wood, the U.S. envoy to the Conference on Disarmament in Geneva, suggested that China was looking at the kinds of nuclear-powered underwater drones and nuclear-powered cruise missiles being developed by Russia, according to The Associated Press.
Wood said China hasn’t developed or been able to weaponize the technology yet, “if they were to develop ... these kinds of weapons and aerial systems, this has the potential to change the strategic stability environment in a dynamic way.”
Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists, told the AP that he hadn’t heard any U.S. government official make a similar assertion.
But “it’s not surprising that China would be developing and exploring technologies they see others working on,” Kristensen, an experienced analyst of Chinese, Russian and American nuclear arsenals, said.
He added that developing weapons technology, but leaving it on the shelf, rather than deploying it, “is an old trademark of the Chinese.”
Last September, Undersecretary of State for Arms Control and International Security Bonnie Jenkins hinted at U.S. concerns about China's "novel nuclear-powered capabilities."
"Beijing is planning to substantially expand its nuclear arsenal," she said during a speech at the 17th Annual NATO Conference on WMD Arms Control, Disarmament, and Nonproliferation. "The [People's Republic of China’s] nuclear build-up, which has accelerated in the last year, now looks to include novel nuclear-powered capabilities and a massive increase of its silo-based ICBM forces. The destabilizing dynamic originating from the PRC’s rapid and opaque nuclear build-up cannot be ignored."
The U.S. is clearly not ignoring the threat of a wide range of new nuclear-powered Chinese and Russian weapons.
Tuesday, we told you about the Space Defense Agency awarding $1.3 billion in contracts to launch 28 satellites that will become part of a massive constellation used to detect and track hypersonic weapons, for instance.
Unlike the massive Russian Belgorod submarine armed with the Poseidon city-killer torpedo, the Guo concept is still merely notional — or at least it appears to be. But there can be little doubt that very long-range autonomous weaponry concealed below the waves is a rapidly growing concern for the U.S. and its allies.
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