Four STEP-12 fuel units and four CZ zirconium alloy tube units developed by the China National Nuclear Co (CNNC) were assembled for a project at the Ling'ao Nuclear Power Plant recently, for testing with the reactor, marking a breakthrough for CNNC after a successful test of the CF3 fuel unit for HPR1000 nuclear power technology, for a pressurized water reactor fuel unit for wide use.

The CNNC has seen many technological breakthroughs since 2011, in components such as tube socket, grills, and framework and has done verification checks for CZ zirconium alloy, providing a solid foundation for the units.

With the successful qualification of the last unit of STEP-12, on Jan 14, 2016, CNNC completed its R&D task of all of the eight units in internal irradiation.