Nicolay Sorokin about operation experience of Rosatom's NPPs in 2007

A series of works for increasing neutron-physic characteristics was implemented at nuclear power plants with RBMK reactors of "Rosenergoatom" company - declared a technical director of the company Nicolay Sorokin in his speech in Moscow at the International Scientific-Technical Conference - 2008 "Safety, effectiveness and economy of nuclear energy".

"These works give us a chance to revise earlier limitations maintaining all the current safety standarts", - said Sorokin.

The nuclear operative also noted that in 2007 works for increasing fuel effectiveness were continued. "New types of fuel with increased stability and burnout coefficient have been introduced" - commented Sorokin on the activities undertaken at VVER reactors.

"Fuel for RMBK reactors is also being modernized, though there are no plans of building new channel-type reactors" - stated Sorokin. He also stressed, that at all RMBK units uranium-erbium fuel with 2% enrichment is used now.

In his speech Nicolay Sorokin touched upon such a problem as operating units lifetime prolonging. According to his words, prolonging of the lifetime of Russian reactors for 15 years "gives a supplementary output of more then 2 000 billion kWh". Units with a prolonged lifetime have already worked out 111.6 billion kWh for today.

"Rosenergoatom" representative mentioned the following factors that favor lifetime prolonging works:

• Conservatism of the earlier (sixties) adopted estimation base;
• Significant volume of modernizations, implemented within the designed lifetime period;
• Economic advantages in comparison with building of new units.

At the same time Sorokin stressed that "one thing (building of new units), certainly, shouldn't be substituted for another one (lifetime prolonging)."

Among principal problems, that face Russian nuclear operatives nowadays, Sorokin named corrosive-erosive damages, electro-technical equipment failures and natural impacts.

"As for corrosive-erosive damages… we have problems with welding connection at steam-generators (connecting water feeding pipelines with collector). We had faced this problem at VVER-1000 steam generators. Nowadays we have detected it at VVER-440, using new control methods. It doesn't threaten the facility safety, as the problems were detected beforehand after their possible evaluation and were removed", - said Sorokin.

Speaking about electro-technical equipment failures, Sorokin reminded of electricity transformers damages: "This problem is not a new one. Program for replacing all the electricity transformers of this type with transformers without oil - it means not explosive ones has been adopted. Cost of this work is about 1.5 billion rubles. According to the program it should be finished in 2009".

As examples of natural impacts technical director of the company reminded of such impacts as birds (April 2007, storks' nestling on the switching device that coursed electricity generator failure) and slime hurling at Leningradsaya NPP filters.

"Here measures are elaborated, that will either solve these problems or minimize them" - added Sorokin.

"We are speaking frankly about our problems. We have programs for their solution, they will be either solved or compensated. It demands time and funds. Publicity - is one of the main principles of the safety culture that we are guided by in our practice. " - stressed the company representative.

"We conduct external examinations and checks. Especially such form showed its efficiency as attracting of specialists from traditional energy sector to the inspections of electro-technical and heat-mechanical non-nuclear equipment." - noted Sorokin.

"And as an appreciation, as a result of our activities (NPP safety maintaining) during the three years period was presentation of the Russian Federation national report at the fourth conference of contracting parties according to the nuclear safety convention. This conference took place in Vienna in April 2008. The report of Russian Federation was heard out and discussed by all the participants. Conclusion of the conference - Russian Federation implements the safety convention", - said Nicolay Sorokin in conclusion.

SOURCE: AtomInfo.Ru

DATE: June 02, 2008

Topics: NPP, Russia