on Nuclear Safety and Radiation Protection - Energie EDF

THE INSPECTOR GENERAL’S REPORT
ON NUCLEAR SAFETY AND RADIATION PROTECTION
I also confirmed the continued good results achieved in
2012 in the field of fire hazards (fighting, organisation
and training), with few outbreaks and no major firerelated
events. An event that occurred on 5 April 2012
relating to a Penly 2 reactor coolant pump warranted my
attention. It was not considered as a major outbreak of
fire according to the definitions in force, but it did occur in
the reactor building near equipment important for nuclear
safety, which constitutes a noteworthy event. Firstly, I note
the responsiveness and efficiency of the plant response
team, which was rapidly backed up by the Civil Accident
Response Services (French acronym SDIS). Secondly,
analysis of the event revealed sub-standard maintenance
followed by sub-standard operation. I observe increasing
care in observing the fire rules with players that are
motivated and respected: plant response staff, Risk
Management Department technicians, and fire brigade
officers. Once again this year, I would like to emphasise
the care needed in replacing the first generation of fire
brigade officers, and I encourage the plant managers to
focus on fire prevention as a priority matter.
I also note the forced loss rate (during reactor
operation) which confirms the progress made in 2011.
With an average rate of 2.8%, the French plants are now
at a good international level. I see this as the combined
effect of the very substantial investments begun some
years ago to address the aging of some main components
(alternators and transformers) and the progress with
rationalisation of the activities performed with the reactor
in operation, together with far stricter management of
the technical hazards. These results, recorded over the
last two years (was above 5% in 2010) are contributing
to nuclear safety by reducing the number of unplanned
reactor transients. Nonetheless, I regret that we are not
yet seeing comparable progress with the extension of unit
outages, which is also highly prejudicial to nuclear safety.
Finally, I would like to emphasise the high availability of
the engineered safety systems such as the safety injection
system, the steam generator auxiliary feedwater system, and
emergency diesels with the very low unavailability factors of
0.13%, 0.01% and 0.04% respectively (WANO indicators).
The operating organisation must be constantly vigilant to
minimise the outage time for maintenance and testing of
this indispensable equipment to minimise accident risks
and mitigate their consequences. The results for the French
plants are also among the best in the world.
Subjects for attention
The nuclear safety significant events detected during unit
outage activities and during activities conducted with the
reactor in service are similarly numerous in both cases, but
12
NUCLEAR OPERATING SAFETY: CONTRASTING RESULTS
their impact on nuclear safety is substantially greater during
unit outages (events classified as nuclear safety significant
and violations of the technical specifications for operation).
More generally, I am still concerned about the degradation
of some of the lines of defence essential for the proper
execution of our operating activities, despite the actions
taken. In 2011, I already drew attention to this issue
affecting our core activities, at a time of staff generation
turnover. As regards maintenance work, pre-job risk
analysis, technical checking and requalification of
equipment after maintenance have not been up to
standard. As regards operations-related activities, I still
observe weakness in the configuration and alignment of
systems, as well as in conducting surveillance tests to test
the operability of our nuclear safety equipment. Control
room surveillance remains, to a lesser degree, a subject of
concern, especially during unit outages.
It is noteworthy that the results for surveillance tests and
violations of the technical specifications for operations,
our highway code, which had been improving for a
number of years, slipped back perceptibly in 2012. I
would like to emphasise that, for the latter in particular,
excursions outside the authorised operating envelope are
in themselves serious, and undermine the credibility of the
operating organisation in the eyes of the nuclear safety
authority. In particular, there has been a significant increase
in cases of failure to comply with the actions laid down in
waivers that needs to be resolved.
Again this year, I note that equipment modifications
have been the cause of an excessively large number of
nuclear safety significant events, and that the trend is a
worrying one. During my visits to the plants, I have found
the motivation of the joint Nuclear Engineering Division and
Nuclear Operations Division teams to be good. However,
all too many matters are still being sent to the plants at
a late stage, preventing proper planning, particularly
during unit outages. The quality of the case files for
certain modifications is not up to standard and can result
in severe constraints on operations, if not discrepancies,
mainly during unit outages. I believe this issue needs to be
analysed in depth by the Nuclear Engineering Division and
the Nuclear Operations Division so as to reverse the trend.
In the plants in the UK
In EDF Energy, the number of nuclear safety significant
events declared in 2012 dropped slightly (to 4.6 per
reactor from 4.7 per reactor), with different declaration
rules in France and the United Kingdom reflecting the
requirements of their respective nuclear safety authorities.
A better yardstick is the number of events ranked level 1