Regular readers of Nuclear Reaction will by now be all too familiar with the ever-lengthening list of problems with Areva’s supposedly state-of-the-art, third-generation European Pressurized Reactor.
To recap, currently just two EPRs are being built in the world right now – one at Olkiluoto in Finland and one in Flamanville in France. Both have been beset by long-running construction problems, schedule and cost overruns, and all-round hilarious ineptitude and controversy.
The predecessor of the EPR, its parent if you like, was the Framatome N4 of which France has four. The N4 had problems of its own which sound all too familiar…
The early life of the N4 units was marked by a series of design-related problems. The reactors suffered delays in commissioning (from three to six years) and numerous shutdowns because of the novelty of their overall design, electronic control and components. The first of the N4 reactors, Chooz-B1 was connected to the grid in August 1996, Chooz-B2 in April 1997, Civaux-1 in December 1997 and Civaux-2 in December 1999.
The first problems appeared with Civaux 1 before the plant was even taken into commercial operation. On May the 12th 1998 three hundred square meters of radioactive water leaked from the primary circuit into the reactor building because the heat removal system (RHS) failed. It happened because of a mistake in the technical design of N4's heat removal system. Because of this design flaw the operator had to unload the reactor's fuel. The fuel had to be removed in the other N4 reactors, Chooz B2 and Chooz B1 as well. The cracked section of the RHR was eventually redesigned and replaced in each N4 reactor.
In the following year, 1999, a cracked welding was discovered in the residual heat removal pump bypass line at Civaux 1. Again the problem was caused by thermal fatigue. In each N4 reactor this section of piping was replaced but not first redesigned.
The problems with Civaux 1 didn't stop there. Eventually it wasn't until the 17th of August 1999 before the plant was restarted. The reactor had been offline since 12 May 1998. Chooz B1 and B2 were put back on line in March 1999.
In 1996, EDF officials estimated the two Chooz B units had cost already 23-billion French francs (3.5-billion euros) and the two Civaux units FF 21-billion.
Design-related problems? Delays in commissioning? Cracked welding? N4 and EPR could be identical twin brothers, not father and son. Has nothing been learned? Nothing at all? We’ve heard this story before. Areva are remaking their own disaster movie.