Chinese containment model completes structural testing

The Xuanwu experimental platform, the world's largest containment test model, is a 1:3.2 scale replica of a Chinese-designed Hualong One prestressed concrete containment shell. It is located at CNPE's research and development facility in Langfang City.

On 20 June, the team completed the world's first high-temperature and high-pressure coupling test, "providing scientific reference as well as technological support for the assessment of the structural performance of containment vessels in serious incidents", CNNC announced.

"Making several technological breakthroughs, the test provides support for the research and development of next-generation nuclear power technology following Hualong One and the safe operation of in-service nuclear power plants," it added.

"This test is the structural performance test of the world's largest containment model under high temperature-high pressure coupled loading conditions, filling the gap in the international test of containment structures under the complex environment of high temperature-high pressure-high humidity caused by severe accidents," the Harbin Institute of Technology noted.

"The test was successfully loaded according to the preset temperature-pressure loading curve, which verified the structural performance of the containment under high-temperature and high-pressure for a long time."

"At present, the number of nuclear power units under construction in China ranks first in the world, and the safe use of nuclear energy is a prerequisite for the development of nuclear power," Fan Feng, vice president of Harbin Institute of Technology and director of its Spatial Structure Research Centre was quoted as saying by the Guangming Daily.

"Nuclear containment, as the last barrier to protect the safety of nuclear power plants, faces various tests during its service period."

The containment structure is a major component for protecting nuclear power reactors and preventing the release of radioactive materials into the environment in the event of a serious accident.

France's EDF has also constructed a scaled-down reactor containment facility to be used to verify construction methods and to study ageing of the materials used in the structure. Construction of the one-third scale, double-walled containment building - referred to as Vercors (from Verification Réaliste du Confinement des Réacteurs) - began in August 2013 at EDF's research and development laboratory at Renardières in Seine-et-Marne, near Paris. It was completed in 2016.

The structure is 30 metres in height and has a diameter of 16 metres. Some 5000 tonnes of concrete were used in its construction. It features 700 sensors and 2 kilometres of optical fibre positioned in the concrete and on both the rebar and prestressing cables for measuring temperature, deformation and water content of the concrete.