Examining

Well, we had a too high hydrogen consumption at the generator of unit EC 4.
A stop was planned and a lot of other activities were planned in this weekend too.
Hydrogen is a very good coolant for generators (alternators) but together with air it's highly explosive.
So a generator has to be very tight and a special seal oil system is used to keep the hydrogen inside.
Here is a view at that system.
We have some software tools to check the consumption of hydrogen per 24 hours and when the values exceeded certain limits we checked all the suspected places with a special hydrogen leak detection tool.
After all the spots were marked a stop was planned.
We first have to force out the hydrogen with carbondioxyde (CO2) and subsequently replace the CO2 with air. There has to be an inert gas to avoid the contact between hydrogen and air in the generator.
The displaced gas is lead to the roof of the building.

It all takes about 6 to 8 hours to complete that operation.

So here the hatches and the rubber seals are inspected.

Here is a look at the inspection holes. In the back the low pressure turbine can be seen.

After the repair we have to do all the work in reverse order.

Here inLARGE....