The flaws of the Chinese nuclear engine

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Under Mao Zedong, China focused entirely on nuclear weapons. Building on the success of nuclear weapons production, Zhou Enlai proposed in 1970 to turn to nuclear power generation. This led to preliminary work soon after. Serious attempts to design a large pressurized reactor (PWR) requiring enriched uranium began after the adoption of the “reform and open” policy in 1978. In parallel, for rapid results, the China has simultaneously entered into negotiations with France to build two large REPs. These became operational in 1986. China then ordered further reactors from Canada, Russia and the United States (US). Today, out of a total of about 60 reactors, China alone has built 40 reactors.

Chinese experts estimate that China will need 300 to 500 reactors by 2050 to meet the government’s goal of net zero carbon emissions. That’s a five to eight times jump from the present. Despite the progress made so far, the way forward is not easy. This is due to various factors.

Availability of uranium: China’s domestic uranium reserves are insufficient even to sustain the current fleet for its entire lifespan. Ongoing uranium storage through market purchases and acquisitions of uranium mines in many countries since 2006 would still prove insufficient for the planned large PWR fleet.

Use of plutonium as fuel: A practical solution to the uranium issue is what is known as “closing the fuel cycle”. It provides for the recovery of residual uranium and plutonium from spent fuel discharged by PWRs and the use of their mixture (MOX for Mixed Oxides) in the same reactors. This can only reduce uranium requirements by 25%. Recycling the plutonium produced in fast breeder reactors (FBR) would allow the full use of uranium. China adopted this approach in 1983. China’s progress in building PWRs is impressive, but the success of plutonium recovery and reuse in PWRs and RBFs is elusive.

China produced about two tons of plutonium for nuclear weapons from small military reactors until the mid-1980s, when it ceased. A pilot plant was commissioned in 2006 for the production of plutonium for civil purposes from the much hotter spent fuel from large PWRs. Designed to produce 500 kg per year, it encountered operational problems. China’s statement to the International Atomic Energy Agency (IAEA), last filed in December 2016, indicates that only 41 kg constitute its civilian inventory of plutonium. No subsequent report appears to have been submitted. About 3,000 kg of plutonium are needed to load a reactor with MOX fuel.

Negotiations sustained at the highest level for many years to induce France to build a large plutonium recovery plant in China have not succeeded. More recently, a memorandum of understanding was signed in the presence of the presidents of both countries in 2018. There has been no progress since.

Nevertheless, the indigenous construction of a plant which could produce two tons of plutonium per year, began in 2015 and should be commissioned in 2025. At the same time, the construction of a second plant of this type has also started without waiting for the commissioning of the first. This suggests the urgent need to produce plutonium for recycling in PWRs.

Introduction of fast reactors: In parallel, construction began in 2000 of the China Experimental Fast Reactor (CEFR), with a nominal power of 20 MWe. It was built by a Russian consortium and started operating in 2010, not with MOX fuel, but highly enriched uranium (HEU) supplied by Russia. The reactor underwent commissioning tests for ten years. It was restarted in June 2018. China has not provided information on its status to the IAEA database since then.

In an effort to rapidly transition to rapid breeding, efforts have continued since 2009 to import a large Russian-designed FBR. It didn’t bear fruit. Thus, China alone started the construction of a large sodium-cooled fast reactor (China Fast Reactor -1) in 2017. The reactor has a capacity of 600 MWe, similar to the Indian PFBR. Three years later, work on a second reactor also began on the same site.

Seeking to establish MOX fuel fabrication capability for these reactors, China built a small-scale plant in 2008. However, due to lack of plutonium, all of the above fast reactors will initially be fueled with HEU that Russia has agreed to provide.

It is not uncommon to fail early in attempts to establish a new technology. In the case of China, the lack of success so far in recovering plutonium and operating fast reactors comes as a surprise. Especially considering its track record of producing plutonium for nuclear weapons in the past alone, and its proven industrial capability in building PWRs. The lack of an imported plant to begin with could well be a reason.

An article published seven years ago in the Bulletin of the Chinese Academy of Sciences pointed out that China is a latecomer in nuclear fuel cycle technology and is 25 years behind India in key areas such as fabrication of MOX fuel and reprocessing of spent nuclear fuel.

Use of thorium: Like India, China is also counting on its modest thorium resource to eventually avoid dependence on uranium. China has started R&D on reactors fueled with a mixture of plutonium and thorium. With molten salt as the coolant, this reactor can operate at temperatures high enough to facilitate the production of hydrogen from water. To begin with, a two MW reactor has just been commissioned with enriched uranium fuel. The shortage of plutonium is clearly a serious impediment to progress in the near future. China hopes to benefit from the US experience of six decades ago in building a molten salt reactor that was later shut down due to problems with the structural material.

Management of high level waste: Recovering plutonium from spent fuel results in the production of high-level liquid radioactive waste. The conversion of liquids into non-leachable glass blocks, a process known as vitrification, is an established safe solution adopted by many countries. China has been working with teams in Germany since 2009 to learn the technology. In September 2021, the first glass block was produced, probably from military waste, in a small demonstration plant built with German help.

Expansion of nuclear energy: Adopting an Import, Digestion, Absorption and Reengineering (IDAR) policy, China has established an impressive capacity for enriched uranium production and manufacturing of all major PWR equipment in the country. Five companies have been created, each of which can supply the equipment needed to build two large REPs each year.

The approximately 60 reactors currently in operation and under construction in China are spread over 18 sites. All of these are located on the seashore as this facilitates the use of seawater to condense the steam before it can be pumped into the reactor. Since the possibilities of identifying more recent coastal sites are limited, future reactors should be located on inland sites. Dozens of such sites would be needed even though each site can house eight reactors. Gaining public acceptance for indoor venues is becoming a key requirement.

Despite the authoritarian nature of the regime, the decade from 2007 saw successful street protests in China against proposed dams, chemical plants producing paraxylene, GM crops, the incineration of municipal waste and rail lines to high speed in addition to nuclear facilities. Some of them have to be dropped. This included two planned nuclear power projects, one on the coast and one inland on the Yangtze River bordering two provinces. Protesters at the latter site included a respected scientist who wrote to then-Prime Minister Wen Jiabao and secured the decision to postpone not only this project, but also general plans to house future nuclear reactors at the inland. In two other cases (1) a large plutonium recovery and MOX fuel fabrication plant and (2) enriched uranium fuel production plants for several nearby PWRs were also closed following protests. The real test of winning public acceptance would be when more indoor sites are seen as part of nuclear power expansion.

Reactor Exports: Meanwhile, China is keen for nuclear industry circles to build PWRs in other countries in addition to domestic expansion. Six reactors have been built in Pakistan. A deal for four more was signed late last year. A report by the China National Nuclear Corporation claimed that 30 reactors could be built by 2030 outside China under the Belt Road initiative. China has signed nuclear cooperation agreements with 27 countries offering to build reactors large and small for them. Seventeen of them were signed between 2015 and 2017. Several countries do not yet have the capacity to manage the reactors or even the means to pay for them. The objective is clearly to establish lasting relations with the beneficiary countries most dependent on China.

China has a five-year REP construction record, now the shortest in the world. It has the capacity in principle to add 200 PWRs as well as some RBFs by 2060, the year of the projected carbon emission peak. This, however, depends on success on many fronts.

India has built a strong base of indigenous expertise for adding more heavy water reactors and is considered to be well ahead of China in FBR technology. He is able to add more reactors of both types than on the anvil now. The nation’s announcement at COP26 last November of a goal to peak emissions by 2050 can be brought within reach with rapid funding support and site selection. Placing all new installations under international safeguards would also allow for productive interaction with other countries.

(The article was written by LV Krishnan, Former Director of Safety Research Group, Indira Gandhi Center for Atomic Research, Tamil Nadu. )


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