The Leningrad NPP will become the first one in Russia to implement an automated gas loop chemical control system at the 3rd power block’s reactor.

This new system has been delivered to the NPP as a part of the international cooperation between the Rosenergoatom Concern and the Swedish radiation safety agency – SSM (the Swedish national supervisory body in the realm of atomic power). The equipment was manufactured by a US-based company named GOW MAC Instrument Co.

Pursuant to the standard operating procedure, the concentrations of nitrogen, helium, oxygen, methane, hydrogen, carbon monoxide and carbon dioxide (?? and ??2), as well as the percentage of moisture in a gas mixture, are to be controlled. The new system will help automatically define the composition of the basic components and the impurity contents in the gas mixture cooling the core graphite stack (a mixture of nitrogen and helium).

The system possesses automated gas chromatographs and humidity sensors installed at the sample lines. Those help to avoid manual sampling and makes the analysis more frequent and precise.

According to Sergey Ushakov, the head of the Leningrad NPP chemical workshop, the composition of the gas mixture circulating through the reactor department is strictly formalized and controlled. “For example, if the oxygen concentration within the core gas environment is too high, it can result in graphite blocks corrosion and destruction, which is unacceptable”, he explained. “We are constantly managing the gas environment in the Leningrad NPP reactor, and the technicians at the chemical workshop do sampling and analysis at every shift”.

Mr. Ushakov said that early identification of any deviances in the gas environment helps to take emergency actions, thus making the reactor operations more reliable and safe. The Rosenergoatom Concern and the Swedish counterparts have approved the Leningrad NPP specialists’ suggestion on organizing automated monitoring of the reactor’s core gas environment.

The test results will be logged into a database, analyzed, and displayed as tables, graphs, and chromatogram at the computers installed at the chemical workshop laboratory and the gas loop operational shield.

The implementation of such system is a pilot project for RBMK power blocks which can then be scaled up to include other blocks.

At the moment, the system is ready for a trial run and is going to be launched in 2017.

The Leningrad NPP is an affiliate company for Rosenergoatom Concern OJSC. The plant is based in the city of Sosnovy Bor, 40 km to the west from Saint Petersburg at the Gulf of Finland shore. The Leningrad NPP is the first Russian nuclear power plant having RBMK-1000 reactors (uranium-graphite channel-type thermal neutron reactors). The NPP exploits 4 power blocks with the electric capacity of 1000 megawatt each. Also, pursuant to the NPP-2006 project, 1,2 VVER-1200 power blocks included into The State Atomic Energy Corporation ROSATOM long-term plan are being constructed. Rosenergoatom Concern OJSC is the owner and developer of the project. Holding TITAN-2 is the primary contractor. ATOMPROEKT is the general designer.


Leningrad  NPP Information and Public Relations Administration.