China's first small modular reactor ACP100 passes cold tests

Construction of China's modular reactor at the Changjiang power plant has reached an important milestone on the way to commissioning. The first unit of its kind, featuring an ACP100 reactor with an electrical output of 125 MW, has successfully completed cold tests. During the tests, technicians checked in particular the integrity of the primary circuit and other components. Before its expected start-up sometime next year, the unit still has a series of tests to complete, including hot functional tests.

China National Nuclear Corporation (CNNC) announced that its first ACP100 small modular reactor (SMR) has successfully completed cold tests. The modular reactor, also known as Linglong One, has an installed capacity of 125 MW and is located at the Changjiang power plant in Hainan province.

“The successful cold functional testing of the primary circuit at the Linglong One small reactor demonstration project demonstrates the integrity and leak-tightness of the primary circuit. It also verified the quality of the installation of the relevant equipment and piping, ensuring subsequent safe and stable operation,” CNNC said.

In addition to checking the integrity of the primary circuit, cold tests are also being used to test the operation of auxiliary systems for the first time. Testing is taking place at the power plant as well as on two other new large conventional Hualong One units, which are due to start generating electricity at the site sometime next year.

Path to commissioning

China began construction of the ACP100 pressurised water reactor as the fifth unit at the Changjiang power plant in July 2021. CNNC expects construction to take a total of 58 months (just under 5 years). Before entering commercial operation in 2026, the unit still needs to undergo hot functional tests, nuclear fuel loading and tests at various power levels.

The country has been developing the reactor design since 2010, and in 2016 Linglong One became the first SMR to pass a safety review by the International Atomic Energy Agency. In addition to generating electricity, the reactor can be used to produce heat and steam or to desalinate seawater. Its estimated annual electricity generation is 1 TWh.