One of the EPR reactors of the Taishan nuclear power plant in southern China recorded "an increase in the concentration of some noble gases in the primary circuit", the French group EDF said.
EDF, one of the groups that participated in the construction of the plant, "was informed of the increase in the concentration of some noble gases in the primary circuit of reactor no.1 of the Taishan nuclear power plant, managed by TNPJVC, a joint-venture of CGN (70%) and EDF (30%) ", reads a statement.
The primary circuit is a sealed circuit that contains pressurized water, which heats up in the reactor tank in contact with combustible elements. Among the so-called "noble" or rare gases, there are argon, helium, krypton, argon or neon.
"The presence of some noble gases in the primary circuit - specifies EDF - is a known phenomenon, studied and foreseen by the reactor management procedures".
The American TV CNN, on the basis of a letter sent by Framatome to the US Department of Energy, spoke of a possible "leak" in the plant, where there are two EPR reactors with French technology. According to CNN, Chinese security authorities have detected "acceptable" limits of radiation outside the site to avoid suspending the plant.