China will activate an experimental nuclear molten salt reactor, hoping to obtain full intellectual rights

In China’s northwest Gansu Province, Chinese scientists have successfully constructed and designed an experimental thorium powered molten sodium reactor. They’re now ready to turn it on.

Initially, 2024 was the projected completion date for the prototype; but a healthy research and design budget, plus a push from Beijing, thrust completion of the reactor ahead of schedule.

The technology behind the molten salt reactor isn’t new–Alvin Weinberg at the Oak Ridge National Laboratory operated a similar prototype in the 1960s; but conventional water-cooled reactors were put in use instead.

The Chinese hope that if they successfully convert from uranium into thorium, and demonstrate commercial viability for their nuclear reactors, then they will be able to obtain full intellectual property rights.

‘First of Its Kind ‘

In January 2011, the Shanghai Institute of Applied Physics (SINAP) launched a $444 million research and design program for a thorium-breeding molten salt reactor (TMSR). The R&D was successful, and in Sep. 2018, construction on the TMSR began, with an estimated completion time of 2024.

However, 2024 was too far out for some. After successfully expediting construction, the Ministry of Ecology and Environment approved SINAP’s request to start its 2 megawatts thermal (MWt) reactor on Aug. 2, according to the World Nuclear Association.

” Our bureau reviewed your application materials and determined that the 2MWt liquid fuel-thorium-based, molten salt reactor experimental reactor commissioning plans is acceptable. .”

The Ministry stated that any major abnormality occurring during commissioning must be reported to Northwest Nuclear and Radiation Safety Supervision Station in time .”

Local woman paving straw before planting trees in the desert at Mingqin county in Wuwei, Gansu Province, China, on March 28, 2019. (Wang He/Getty Images)

Concerning energy generation, 2 MWt can power approximately 1,000 homes, meaning the prototype won’t generate a significant amount of energy compared to traditional nuclear reactors. But if the prototype is successful, China hopes to build a 373 MWt by 2030.

Initially, thorium will only account for 20 percent of TMSR’s fuel source. The plan is to work up from 20 percent thorium fission to 80 percent.

China closely guards its TMSR design. However, the World Nuclear Association reports that the new design builds on Oak Ridge National Laboratory’s 1965 molten salt reactor experiment (MSRE).

As in China, Oak Ridge started its MSRE with an enriched and depleted uranium fuel mix. Then in 1968, uranium-233 was added to the mix–thorium doesn’t split and release energy; instead, thorium transmutes to the isotope uranium-233 when it absorbs a neutron.

Importantly, the core in a molten-salt reactor is made up of converted thorium and liquefied sodium. This allows the liquid to be used as both a coolant and a fuel. As an added benefit, molten salt reactors operate at lower pressure reducing the risk of explosive meltdowns, experts claim.

After including U-233, Oak Ridge’s MSRE operated successfully until Dec. 1968. It was closed due to advances in nuclear technology, as well as a lackluster political support. Oak Ridge Lab’s MSRE was never commercially viable.

Thorium Versus Uranium

Current nuclear technology uses uranium as a fuel. It is relatively common, but not renewable.

Moreover, while total world resources of uranium aren’t known, current known sources are enough to supply conventional reactors for approximately 90 years. While that may sound concerning, it’s a “higher level of assured resources than is normal for most minerals,” according to the World Nuclear Association.

However, uranium nuclear power plants have many drawbacks. Not the least is the radioactivity of uranium waste for thousands of years.

Conversely, thorium is also abundant, possibly three times more than uranium, and produces less radioactive waste with a hazardous life of about 300 years. Thorium is also chemically more stable than uranium and relatively inert which makes storage and disposal easier.

Uranium rod elements of a nuclear reactor. (Parilov/Adobe Stock)

Molten salt reactors do not require cooling water, so they are able to operate in dry areas. China plans to take full advantage of this factor by building TMSRs across its western desert regions, Nuclear Engineering International reports.

Thorium reactors have their drawbacks.

For example, components used in molten salt reactors must maintain their integrity even when exposed to radioactive and corrosive environments.

In 1995, the Defense Nuclear Facilities Safety Board reviewed the MSRE at the Oak Ridge National Laboratory. “The Fuel Drain Tanks are believed to be corroding and the potential exists for stress corrosion cracking in the off-gas system piping and charcoal bed vessel,” the report (pdf) found.

Another problem is radioactive fission product. Fission products, as well as actinides, are radioactive and can cause the confinement to be eroded and allow for the migration of chemicals to other locations. This is what happened with the Oak Ridge MSRE.

“Since the Molten Salt Reactor Experiment shut down 25 years ago, several kilograms of fissile uranium (mostly 233U) have migrated from the Fuel Drain Tanks through the piping of the off-gas system and deposited in a short section of a charcoal bed,” the Defense Nuclear Board report states.

Despite the drawbacks of its nuclear power, China still believes that thorium-molten salt reactors are the way forward. And if China successfully proves commercial viability of its TMSR, the Chinese Academy of Sciences plans to pursue full intellectual property rights on the technology, according to the World Nuclear Association.

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