18/7 Tass 334
ST. PETERSBURG, July 18 (Itar-Tass) —— Leningrad Nuclear Power Plant-2 will be commissioned several weeks later than was initially planned because of mistakes made during the placement of concrete in the outer protective shell of unit No. 1.
It will take several weeks to replace the deformed section of the shell, Rosenergoatom told Itar-Tass on Monday, July 18.
On July 17, one hour and twenty minutes after the placement of concrete in the outer protective shell, the reinforcement cage appeared to be deformed more than eight metres above ground. According to preliminary information, the deformation was caused by a breach of construction technology by the subcontractor.
“No machine or mechanism was damaged,” Rosenergoatom said.
The project general contractor said earlier that design, construction and assembly works at the site of Leningrad Nuclear Power Plant-2 were proceeding as scheduled.
Alexei Kaidalov, director of the SPbAEP engineering company, which is the general contractor, said, “the LAES-2 project is part of Rosatom’s long-term programme.”
The public contract for the construction of the first two units at LAES-2 was signed with SPbAEP on March 14, 2008. The company builds modern nuclear power plants on a turnkey basis. This is termed engineering procurement construction management and includes justification of investments, surveying, design, equipment supply, construction and assembly works, start-up works, and commissioning.
Each power unit with a VVER reactor can generate 1,198.8 megawatts of electricity and 250 gigacalories/hour of thermal power. The estimated service life of LAES-2 is 50 years, and that of its main equipment is 60 years, Kaidalov said.
Water-cooled water-moderated reactors to be used at NPP-2 are considered to be the safest, Rosenergoatom Deputy Director-General Sergei Boyarkin said earlier.
“Reactors of this type have four independent safety systems. They will be complemented with another two in this project. The probability of an accident is estimated as one per 10 million years,” he said.
In order to exclude a radiation release, two 1.5-metre-thick concrete containment vessels will be built around the reactor. “Such vessel can withstand even a plane crash. Therefore a release of radiation into the environment will be ruled out,” Boyarkin said.
A cone-shaped metal construction was earlier installed under the future power unit at the NPP-2, the so-called molten-core catcher, which is designed to keep irradiated metal inside the reactor and curb the chain reaction in case of emergency.
The catcher for LAES-2 was designed by Russian specialists to have a double-wall casing, with the space between the walls filled with black iron and aluminium oxide granules. This makes it possible to embed molten mass in glass and then cool it.
Specialists say that local residents fears that they will get increased level of radiation after the commissioning of the power plant are groundless. Rosatom (State Atomic Energy Corporation) assessments indicate that 88 percent of radiation received by the local population every year comes from natural sources, 10 percent from medical procedures involving radiation, and the remaining 2 percent from other technogenic sources, of which the nuclear power plant will account for a mere 0.3 percent.
Speaking of the cost of construction, Boayrkin said the construction of two power units, to be commissioned in late 2013 and in late 2016 respectively, would cost 180 billion roubles. The power units will break even in 15-17 years.
Boyarkin admitted that this is longer than in Europe because Russian electricity producers sell it at lower prices on the domestic market than their colleagues do in Europe where 1 kWh of electricity costs 50-60 eurocents.
The Director-General of the St. Petersburg-based Atomenergoproyekt company, Leonid Reznikov, said four power units would be built under the LAES-2 project. All power units will generate almost 18 billion kWh of electricity a year. The power units are designed to operate for 50-60 years with a possible extension of their life cycle after modernisation.
“The Leningrad nuclear power plant currently generates 30 percent of electricity in the North-West of Russia and 50 percent in St. Petersburg. LAES-2 will open up tremendous prospects for the development of the region,” Reznikov said.
The Leningrad nuclear power plant is located 80 kilometres west of St. Petersburg on the southern shore of the Gulf of Finland.
Public hearings on the construction of units No. 3 and No. 4 were held in June. Lebedev said earlier that budget financing of the construction of LAES-2 would be reduced by 16 percent due to the economic crisis.
Leningrad region Deputy Governor Nikolai Pasyada stressed that the construction of the nuclear power plant should be accompanied by the construction of a power network under an investment programme of the Federal Network Company.
Electricity transmission will require the construction of 330 kilovolt power lines.
The construction of the Leningrad NPP-2 in Sosnovy Bor, Leningrad region, has entered an active stage.
The concreting of the foundation for the reactor of unit No. 1 was carried out in October 2008. The future four reactors will generate enough electricity to provide the whole North-West of the country with electricity and heat till the end of the century, Sosnovy Bor city administration head Dmitry Pulyaevsky said.
Anatoly Molchanov, designing director of Atomenergoproekt (general designer and contractor of NPP-2 phase one), said this was an innovative project.
“Experience was gained when building standard VVER-1000 nuclear power plants that have been operating in Russia for about thirty years,” he said.
“The plant will remain up-to-date for years and will meet both Russian and international standards and requirements,” Molchanov said.