Wang Dazhong, nuclear expert. (PHOTO PROVIDED TO CHINA DAILY)

Wang Dazhong, a renowned nuclear energy scientist, was awarded the State Preeminent Science and Technology Award for 60 years dedicated to the development of nuclear energy, and for helping advance China's scientific, economic and national defense strengths.

Wang, who is an academician at the Chinese Academy of Sciences, led the research, design and operation of China's first 5MW Low Temperature Nuclear Heating Reactor (NHR-5) and later of its 10MW High Temperature Gas-cooled Reactor (HTR-10). Both bolstered the inherent safety of nuclear energy, as well as the application of clean energy.

All SciTech workers should dedicate themselves to selfreliance and innovation in science and technology, which is an important way to show love for our motherland.

Wang Dazhong, nuclear expert

Wang said that his award belongs to all hardworking science and technology workers and that "scientific research is a noble cause, worthy of a lifetime of pursuit".

"Our nation is in its best period of development. Scientific self-reliance is a strategic support for national development. All SciTech workers should dedicate themselves to self-reliance and innovation in science and technology, which is an important way to show love for our motherland," he added.

Wang's engagement in nuclear energy began in the 1950s. In 1955, the Chinese government outlined a strategic plan to develop nuclear energy. Consequently, Tsinghua University set up its Department of Engineering Physics in 1956. Wang was one of the first batch of students to specialize in nuclear reactor studies.

Following accidents in Three Mile Island in the United States in 1979 and Chernobyl in the Soviet Union in 1986, scientists all over the world have worked hard to ensure that reactors are made "inherently safe", meaning that they do not rely on countermeasures powered by external (and hence potentially fallible) resources to remain stable.

Despite theoretical research on the subject, achieving inherent safety was a major engineering difficulty. Wang had his team focus on the subject, as he believed safety was the key to the future development of nuclear energy.

In 1982, Wang and his colleagues began to research Low Temperature NHRs. It was his wish that any reactor they developed should not only be safe, but also able to generate district heating to help solve China's energy problems. The team spent a year discussing proposals, visiting and investigating different types of heating reactors in Europe, before finalizing their own design.

Wang Dazhong (first from left) announces the successful start of the 5MW Nuclear Heating Reactor in November 1989. (PHOTO PROVIDED TO CHINA DAILY)

Their 5MW Nuclear Heating Reactor (NHR-5) went into operation in 1989. Low temperature, low pressure and low power density, it featured a natural circulation mechanism to remove residual heat, as well as the hydraulic-driven design of control rods. Many key technological breakthroughs were made.

The NHR-5 is considered to be forward-looking, as using natural circulation in a water-cooled nuclear energy system later became one of the main technological trends of the 21st century. The project also won first prize of China's State Scientific and Technological Progress Award in 1992.

In 1981, Wang was working at Germany's Juelich Nuclear Research Centre as a visiting scholar, when he came across the modular High Temperature Gas-Cooled Reactor (HTGR), a newly developed concept proposed primarily in Germany, which was based on the lessons learned from the Three Mile Island accident. It was designed to eliminate the possibility of a core meltdown.

In 1982, he returned to China and was appointed deputy director of the Institute of Nuclear Energy Technology at Tsinghua University. While developing the Low Temperature NHR, he also began to plan development of an HTGR.

Wang decided to focus on a modular reactor based on "pebble bed technology", which uses spherical fuel elements known as "pebbles". The pebbles are piled up to form a bed, which serves as the reactor core.

Between 1987 and 1990, Wang and his team made important breakthroughs in key technologies related to helium coolants and fuel elements. In 1992, the State Council approved the building of an experimental 10MW HTGR at Tsinghua University. The reactor reached criticality in 2000 and full power operation in 2003. Its completion ushered in a new generation of nuclear energy systems that effectively eliminate the possibility of reactor core meltdown.

At the first session of the 10th National People's Congress, the HTGR was introduced in the 2003 Government Work Report as one of the four major scientific and technological achievements influencing the world. It also won Wang first prize in the State Scientific and Technological Progress Award again in 2006.

He Jiankun, former Tsinghua executive vice-president, said Wang's scientific achievements have paved the way for clean energy as China strives to become carbon neutral.

He said that nuclear power emits zero carbon and can ensure the safe and stable operation of the power grid. Being inherently safe, Modular HTGR can also generate hydrogen while producing electricity, which can be used to replace fossil fuels as a heat source.