French regulator warns of risks from frequent nuclear power plant load-following

Increasingly frequent load-following by French nuclear reactors is raising concerns about adding to the workload of control room operators, the French nuclear safety authority (ASNR) said on Thursday. EDF also announced an initiative to examine the impact of more frequent load-following on the ageing of reactor components.

Load-following by nuclear reactors in response to demand or market signals is becoming more common as France’s and Europe’s energy systems undergo a transition. The growing need for load-following, linked to the rising share of renewables in electricity generation, is changing day-to-day operations.

“During these load changes, staff are fully occupied managing operations, which can prevent them from carrying out other tasks,” ASNR head Pierre-Marie Abadie said during a hearing of the parliamentary office for the assessment of scientific and technological choices.

Abadie added that operational feedback would be needed to assess any potential impact on safety.

“The main change we are seeing today concerns the atmosphere in the control room... with daily, and sometimes multiple, power changes in a single day,” Abadie said.

“We are still managing for now, but it is putting staff under considerable stress,” a union representative told Montel. Unions also voiced concerns about the pressure on employees.

EDF, which operates all 57 reactors at 18 nuclear power plants in France, announced an initiative on Wednesday to assess the impact of more frequent reactor load-following on component ageing. The secondary circuit was identified as a particular focus, as it is more exposed to pressure and temperature changes during power adjustments.