"Maybe my hand shook"

Leningrad NPP became a record holder for emergency shutdowns

Power units at domestic nuclear power plants shut down five times in October 2006. The corresponding data was published by Rostekhnadzor specialists on November 13. Deviations from operating standards were recorded at the Kalinin and Leningrad nuclear power plants. Moreover, in four out of five cases, power units stopped at the Leningrad NPP. “In all cases, the automatic protection system worked on time, now analysts will check all cases and determine the corrective measures,” Oleg Lapshev, head of the nuclear power plant inspection department of Rostechnadzor, told Vremya Novostey.

On two occasions, on October 28 and 31, 2006, power unit No. 2 of the Leningrad NPP was shut down due to stormy weather. On the 28th, the protection was triggered due to damage to the arrester of the 4T block transformer during a storm wind of 24-25 m/sec. On the 31st, the power unit was shut down due to a volley of flooded mud entering the cooling water treatment grids of turbogenerators TG-5 and TG-6. “Steam does not flow to the turbine first, you need to create an environment in the condenser, i.e. vacuum, as soon as the effect is achieved, the turbine immediately starts working,” explained the acting director. Head of the LNPP information center Mikhail Milekhin. “In our case, the turbines were stopped due to lack of vacuum, there was not enough water.”

But two other cases caused particular concern among specialists. On October 13 and 20, the shutdown of the 2nd power unit of the Leningrad NPP was due to the human factor. The protection was triggered when new power parameters were set. “It was planned to increase the energy generation capacity by 1%, but people set 2%, maybe the hand trembled, maybe something else, an imbalance led to the reaction of the protection system,” said Oleg Lapshev. In Russian, due to personnel errors, an imbalance occurred in the two systems that control the operation of the units. The first team got in, but the second didn’t. Due to the lack of synchronization in the operation of the systems, work was suspended.

On October 24, the human factor led to a deviation in the operation of the Kalinin NPP. “The reason for this was an increase in the coolant level in the 3PG-1 steam generator, caused by a transient process due to incorrect actions of personnel when switching in the electrical circuit for auxiliary needs,” stated Oleg Lapshev. As Rostekhnadzor emphasized, there are no violations of the limits and conditions for the safe operation of power units. The radiation situation in the areas where the Leningrad and Kalinin NPP facilities are located is normal and amounts to 14 microroentgens per hour.

Everything that happened at the nuclear power plant was not news to the employees of both the plants themselves and the controlling structures. Since the beginning of the year, according to the head of Rostekhnadzor, Konstantin Pulikovsky, deviations from operating standards have been recorded at Russian nuclear power plants 120 times. “People are getting used to the new equipment, it is necessary to reduce personnel errors to zero - this is a nuclear power plant,” Mr. Pulikovsky said at a recent meeting of Rostechnadzor.

The Leningrad Nuclear Power Plant “distinguished itself.” “We have commissioned the 2nd power unit after a long modernization, and we are now gaining experience, we are in a pilot-technical operation mode, so errors may occur,” Mikhail Mikhelin emphasized. Experts emphasize that emergency situations are prevented by automation in every case. If a miracle happens and the multi-level protection fails, in this case a person can manually shut down the reactor. We just need to do better training.

Maxim GLADKY