China Makes Breakthrough in Fourth Generation Nuclear Power System

The sodium-supercritical carbon dioxide heat exchanger, the core technology of the sodium-cooled fast reactor (SFR) of China's fourth generation nuclear power system, recently passed expert inspection.

It is the first of its kind in the country and a milestone of liquid metal-cooled fast dynamic conversion technology.

China has mastered the design, manufacturing and testing technology of the sodium-supercritical carbon dioxide heat exchanger and has reached an internationally leading level, which lays a solid foundation for future industrial application of the reactor.

The research of the sodium-cooled fast technology based on the supercritical carbon dioxide dynamic cycle technology was scheduled by the China Institute of Atomic Energy, a subsidiary of China National Nuclear Corporation (CNNC), in 2016 to meet the high requirement of the advanced fourth generation nuclear power system.

As one of the most advanced engine cycle fluids in the world, supercritical carbon dioxide has high cycle efficiency and requires smaller and fewer facilities, which lowers construction and maintenance costs.

What's more, as there is no drastic reaction between carbon dioxide and liquid sodium, security of the sodium-cooled fast process is greatly improved.

As a key device of the supercritical carbon dioxide dynamic cycle, the SFR is asked to realize highly-efficient heat exchange in conditions like high temperatures and pressures and strong corrosion.

Jointly developed by CNNC and China State Shipbuilding Corporation Limited, the newly developed reactor is a compact heat exchanger with advantages of both tubular and plate heat exchanger designs.

The prototype of the SFR was completed in December 2019 and the heat transfer performance was tested this May. The test showed that the machine has good main indices including heat transfer power and temperature distribution to add to its excellent design.

In addition to the sodium-cooled fast reactor, the exchanger can also be used in power conversion systems of other liquid metal-cooled reactors, which promotes its application potential.

A part of the sodium-supercritical carbon dioxide heat exchanger jointly developed by CNNC and China State Shipbuilding Corporation Limited [Photo/sasac.gov.cn]

(Executive editor: Wang Ruoting)