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Media Nuclear Power Plant news

27. 9. 2006

Others

Bath of a future IAEA inspector fell out well

Over the last week a training of a group of fifteen future IAEA inspectors proceeded at Dukovany NPP. On Friday, 22nd September, 8:00 to 11:00 p.m., there was a practical exam under way in which the students were supposed to perform what they learned in practical inspection skills.

One of these tasks was a practical check of completeness of spent fuel assemblies stored into a spent fuel storage pond. This task took place in the reactor hall of the Unit 1 and it demanded to remove covers from both the spent fuel storage pond and related refuelling service pond which was empty but filled with clean boron water. The control of completeness of spent fuel assemblies is carried on from the sidewalk of the refuelling machine that moves on the rails between both opened ponds. The sidewalk is narrow, it is sufficiently equipped with handrail and only one man can pass through the way. The check was carried on based on an IAEA inspectors request with half of the lights in the reactor hall switched off for better visibility of the assemblies origin using the Tcherenkov glow effect.

The fact that the lights in one half of the reactor hall were switched off and the shine coming from the spent fuel storage pond was dominant at that moment was essential for the forthcoming event.

A group of three students and one instructor was on the sidewalk of the refuelling machine. The first of the trainees had finished his tasks and decided to go to the instructor for other instructions. Two other students were still working between him and his instructor and so he decided not to disturb them and step down from the refuelling machine and go around the service pond. When passing the service pond he tripped up and slipped down into the service pond. As he was a good swimmer it was not a couple of seconds when he climbed up using the side stairs and it was not necessary to use the life belt placed nearby the ponds.

The training of instructors was immediately terminated and the bathed student was provided with a proper shower and with dry clothing (TYVEK). The following health and radio diagnosis check excluded any external and internal contamination. The water in the service pond was sampled immediately after the event and the analyzed activity was on the level of 500 Bq/l which activity is similar to a standard of table water (360 Bq/l) and is bellow permitted activity of milk (1000 Bq/l). The personal electronic dose-meter of the student indicated a normal value of 1 microSievert and verified that there was no irradiation of the person during his venture in the service pond.

The event was immediately investigated by the Industrial Safety and Radiation Protection experts and all necessary statements were recorded. Prior start of the training the participants of the training course were very well instructed about rules of safe behavior at the NPP. The affected trainee stated that he was aware of the mistake he did and he should not break the rule of leaving the training group, particularly in such less familiar environment. It is a principle that should be kept during real inspections because IAEA inspectors come nearly always into unknown environment or at least they are not fully familiar with a strange power plant and they should rely on their counterparts from whom they should not separate.

The incident has no health and radiation consequences, the vicinity and environment of nuclear power plant was not endangered at all. This event with happy end, however, will serve as operating experience for other training of not only IAEA inspectors but also NPP workers worldwide.

Petr Spilka – spokesman of Dukovany NPP

Zbynek Grunda – manager for technical international relations