control problems at French nuclear cladding plant
FT.com, December 13, 2000
By Matthew Jones in London
A French nuclear fuel cladding manufacturer
failed to reveal quality control problems at its assembly plant for
nine months while British Nuclear Fuels was facing international criticism
for similar problems at its Sellafield plant in Northern England.
Cezus, a subsidiary of Framatome,
the French atomic fuel group, produced up to 900,000 zirconium alloy
cladding tubes without proper quality checks during an 18 month period.
Cezus discovered the problem at its
Paimboeuf plant in France in February this year but only told Framatome
management, who then informed the French nuclear safety regulator, in
November. Most of the cladding tubes had by then been installed in reactors
in Europe, North America, Africa and Asia.
The revelation is likely to embarrass
the French nuclear industry as the quality control problems occured
at the same time as problems at British Nuclear Fuels' mixed-oxide (Mox)
production plant in Sellafield.
BNFL admitted in September 1999 that
some of its workers had falsified quality checks on fuel sent to Japan,
leading to widespread international condemnation and a moratorium on
BNFL Mox fuel contracts.
Mycle Schneider, executive director
of WISE-Paris, a French energy consultancy that has investigated the
affair, said that although there was no evidence of Cezus deliberately
falsifying quality checks, as in the case of BNFL, parallels between
the two cases could be drawn.
"The length of time before this was
revealed and the scale of the cladding tubes produced without proper
quality checks means this is in some senses more serious than the BNFL
affair," he said.
The problem occured when an automatic
ultrasonic inspection unit, used for detecting blemishes and cracks
in the metal cladding tubes, failed to work properly. Framatome said
statistical checks had shown that only 11 defective tubes would have
slipped through the checking process out of the 900,000 manufactured
during the period.
"This would not have any safety consequences
and is very different to BNFL's problems. We are, however, conducting
an investigation into the procedures at Cezus to make sure this doesn't
happen again," said an official.
The French nuclear regulator has
classified the incident at "level 1" on the International Nuclear Event
Scale, which has seven levels, because of the delay in disclosing the
problem. The BNFL incident was not considered by the UK regulator to
be serious enough to register on the scale at all.
Cladding tubes are used to house
nuclear fuel pellets which are then inserted into a nuclear reactor.
Mr Schneider said he would now like to see more thorough investigations
carried out by Framatome's customers to ensure there was no danger of
non-complying tubes preventing the insertion of control rods required
to regulate atomic reactors.