The low level of the Danube puts pressure on the cooling system of the Kozloduy NPP, but there is no need to shut down the units at the moment. The river level has risen slightly to 20.6 meters, and the shore pumping station continues to supply the necessary amount of water.
The power plant needs nearly 9 million cubic meters of water per day to operate at maximum capacity. The shore pumps pump an amount equal to the flow of two rivers like Iskar in an hour.
“There is a problem with the levels, but from now on the system is working normally“, said the chairman of the Nuclear Regulatory Agency, Tsanko Bachiiski. According to him, the pumps provide water for the turbine condensers.
The power of the fifth unit has been reduced preventively
The shore pumping station has 34 pumps that supply water to the seven-kilometer cold channel. It cools the condensers of the fifth and sixth units, located outside the nuclear part of the facility.
A procedure for action at different levels of the Danube has been activated. Below an elevation of 21 meters, the accumulation of maximum water reserves begins. At a level below 20.30 meters, the power of the units must be reduced to a minimum, and below 19.70 meters, the shore pumping station stops working.
The power of the fifth unit has already been reduced preventively. The director of the NRA Directorate, Orlin Velichkov, specified that the measured level was above the value at which limitation is required, but the power has not been restored due to monitoring the long-term trend.
Measures have also been prepared in case of a new decline
In the event of a continued decrease in the river, pumps from the fire department have been provided that can assist in the safe shutdown of the two units. NRA inspectors are conducting inspections and collecting information about the condition and safety of the facilities.
The cooled water returns to the Danube via a warm channel. Its temperature must not exceed 33 degrees in order to prevent thermal pollution.
The “Kozloduy“ NPP provides about a third of the country's electricity. Therefore, a possible shutdown before the planned annual maintenance and refueling of the sixth unit would create an additional load on the energy system in the winter. The plant expects to continue working until the planned repair.
According to Tsanko Bachiiski, the facilities are on a flood-proof site and are not threatened by high waters. In the event of a sharp rise in the Danube, brought branches, tree trunks and other pollution could pose a risk, but there are grates in front of the machine rooms to contain them.
Sources: BNT