Restart of Doel 4 brought forward
16 December 2014
Repairs to the turbine of unit 4 at Belgium's Doel nuclear power plant are almost complete and the reactor could be restarted ten days earlier than previously planned.
Doel 4 shut down automatically on 5 August following the loss of oil in its steam turbine. Initial inspections found that the lubricant had been discharged through a valve which had probably been left open by a worker. This led to significant damage to the turbine.
Plant owner and operator Electrabel said on 15 December that repairs to the unit's steam turbine are "nearly finished." It said that following the repair of various components in Germany and the turbine's reassembly, "in the final phase, the shaft is being aligned as this is critical to the correct operation of the turbine."
Electrabel said, with good progress having been made, it has brought forward the expected restart date for Doel 4 from 31 December to 21 December.
Additional security measures
In consultation with and under the supervision of the Federal Agency for Nuclear Control (FANC), additional security and safety measures will be introduced to make the unit's restart possible, Electrabel said.
Referring to the turbine damage, FANC said, "Since there are strong indications that the evacuation pipe was deliberately turned without the instruction having been given, soon the suspicion arose that it was malice."
Following the incident, FANC immediately put in place additional security measures in order to prevent a similar incident happening again. One of these measures was the so-called "four eyes principle," which states that plant operators in certain areas can only work in pairs.
FANC has now called for further measures to be taken, which will be introduced at all of Belgium's nuclear power plants. These include the placement of a large number of additional cameras and changes to the badging system.
In addition, FANC has also demanded further safety measures, such as additional checks on the correct configuration of safety equipment and emergency systems.
"A judicial inquiry into the person or persons responsible for this incident is still ongoing," FANC noted.
Researched and written
by World Nuclear News