China's Experimental Fast Reactor (CEFR) operated by the China Atomic Energy Institute (CAIE) has started what was described as "high-power operations," as quoted in a World Nuclear News Report.
The reactor, which is designed to operate with "65MW thermal power and 20MW experimental generation power", first reached criticality in July 2010 and it was connected to the grid in July 2011. In 2014, it operated at full power for 144 hours (72 hours according to a different source). It appears that CEFR was shut down after that to be restarted and connected to the grid for the second time in October 2015, at 20% nominal power.
According to a CNNC report, the reactor was shut down at some point after completing the low-power test phase. It was restarted on 19 June 2020 "for high-power operations." About 40 days of tests appear to have concluded with a "100 percent power manual emergency shutdown test," conducted on 31 July 2021. After that the reactor entered shutdown for its first refueling and maintenance.
The reactor was restarted again on 19 January 2021 and re-connected to the grid on 15 February 2021. It appears that this time CEFR entered the "power test phase" of the tests.
CEFR operates with HEU fuel (64.4% HEU) supplied by Russia. The most recent shipment of fuel took place in July 2019.