On December 23, 2010, a system spillage onto the open reactor was held at power unit No.4 of Kalinin NPP. During this technological operation an after-mounting clearance (flushing) of pipelines of safety systems and normal operation systems, connected to the reactor, was held.

It had been preceded by numerous run-ups of engines and mechanisms, which helped to pass water to the emergency cooling system hydraulic reservoirs. The spillage of the first two reservoirs – Nos. 3 and 4 was held at the initial stage. After that the open reactor spillage of the safety systems and normal operation systems will be held.

According to the comments of Deputy General Director of Rosenergoatom Concern OJSC – Capital Construction Director Vladimir Suchkov, the operation, preceded by a good preparation, was held in a normal operation conditions in accordance with the nominal schedule, originally determined by the project. “This is a great work of NPP personnel, department directors, adjusters and constructors – all who was engaged into preparation for this event. It is notable that the spillage was held a bit ahead of the schedule. Ofcourse , I am pleased with it .”

According to Kalinin NPP Director – Head of power unit No.4 commissioning Leonid Martynovchenko, this operation is the beginning of real pre-commissioning works. “It was held a bit ahead of the schedule and this is a guarantee that the nuclear fuel load into of the reactor will be performed in a strict compliance with the schedule,” Leonid Martynovchenko said.