Kursk Nuclear Power Plant

Kursk Nuclear Power Plant: Safe and Efficient Power Generation with a Reliable Partner


"We are extremely pleased to mark our fifteenth successful year of placing our trust in Kopitan-Dem's talented engineers and Eaton's high-performance equipment."

Alexander Vladimirovich Uvakin
Chief Engineer at the Kursk Nuclear Power Plant


Background
Kopitan-Dem is one of Eaton's longest-standing partners in using medium- and high-capacity UPS units at enterprises in Russia. For over 15 years, Kopitan-Dem's engineering division has specialised in implementing continuous and uninterruptible power supply (UPS) projects for equipment of critical importance.

Kopitan-Dem plays an important part in Russia's atomic-energy sector: the company has been granted a license by the Federal Environmental, Industrial and Nuclear Supervision Service to manufacture and supervise the installation of electrical equipment for us in nuclear power-plant. Since 2001, Kopitan-Dem's regular customer has been the Kursk Nuclear Power Plant, a subsidiary of Rosenergoatom, whose primary task is to generate electricity and heat at Russia's nuclear power plants in a safe and cost-effective way. It currently has ten nuclear power plants across Russia, including the one located in Kursk, which is the site of what has become an extremely significant project jointly implemented by Kopitan-Dem and Eaton.

Challenges
Instead of a traditional, centralised uninterruptible power supply system, Kopitan-Dem was tasked with developing a distributed system based on Eaton’s UPS units to supply electricity to the most important computerised safety systems for nuclear power plant generating units.

One challenging aspect was that the UPS system was to power the integrated reactor control-and-protection system. This is the most important system at any nuclear power plant as it relates to both reactor operation and safety, and one that must ensure safety functions continue for 30 minutes in case of a loss of power to ensure the balance-of-plant services. Moreover, the sheer size of the project had to be taken into account: as each power-generating unit has a capacity of up to 1 GW, one going idle would led to enormous economic losses. The UPS unit reliability specifications were therefore very stringent.

Although Eaton’s 9315 UPS units met power demand needs and were thus authorised for use as the basis for the UPS system design, equipment deployed at the nuclear power plant needs to meet specific requirements. A decision was therefore made to have Kopitan-Dem modify the Eaton UPS units. Kopitan-Dem ensured the 9315 complied with requirements regarding sinusoidal vibration resistance, seismic resistance, electromagnetic compatibility, and the degree of protection against environmental exposure.

Solution
After completing the necessary modifications and subsequent testing, Kopitan-Dem proposed a three-channel double UPS system with N+1 redundancy that can withstand failures in every uninterruptible power supply system. The 9315 UPS served as the basis for the N+1 redundancy. The UPS were the ones that would power the integrated reactor control-and-protection system. The uninterruptible power supply system consisted of eight 65-160 kVA Eaton UPS units and was first installed in block one of the Kursk Nuclear Power Plant. Above all else, this system ensured a consistent and uninterrupted supply of electricity. UPS units of this type were also employed in the emergency core cooling system and normal operating systems which are vital to plant safety.

The Kursk Nuclear Power Plant UPS equipment modernisation was so successful that it served as a model for modernisations at other nuclear power plants with high power channel-type reactors. Thus, by the end of 2012 in order to power the most critical components at the Kursk Nuclear plant, 46 Eaton UPS units were installed. The overall total of 92 60-250kVA 9315 and 9390 UPS units for a total capacity of 10 MVA were installed together with more than 100 6 kVA UPS units at all nuclear power plants of the similar type, including the Kursk Nuclear Power Plant.

In keeping with its energy-efficient architecture concept, Eaton developed unique, cutting-edge technologies to improve system efficiency without compromising on reliability. The double-conversion design of the 9390 provides maximum protection from any possible electrical problems through the mains. Thanks to a transformer-free design and high-precision measurement and control technologies, the Eaton 9390 UPS unit delivers up to 94 percent efficiency, and up to 99 percent efficiency in energy-saving mode, with a power factor of 0.9. The high efficiency of the 9390 means lower energy costs, longer service lives for internal components of the UPS unit, and decreased cooling load.

With Hot Sync® technology, two or more UPS units work in parallel to provide distributed load-sharing. Meanwhile, unlike with traditional parallel systems, the technology enables load sharing without any communication line. Since such a system lacks a potential single point of failure, the possibility of it failing is virtually zero. It is also worth mentioning the three-stage ABM® charging technique, whereby the UPS constantly monitors the battery charge state, optimises charging time, and prolongs service life by up to 50 percent.

In addition to the important product features mentioned above, chief engineer Alexander Uvakin added, "We shoulder an enormous responsibility - and not only for reliable and uninterrupted power supply, but also for ensuring nuclear and radiation safety at nuclear power plants, and so we cannot afford anything but the highest performance and most dependable equipment. We are also very pleased to mark our fifteenth successful year of placing our trust in Kopitan-Dem's talented engineers and Eaton's high-performance equipment."

Results
After ten years of uninterrupted operation, a more extensive study was carried out in June 2012 on all eight Eaton UPS units of the UPS system of block one of the Kursk Nuclear Power Plant. The study revealed that the mean time between failures without bypass was 173,994 hours, and 347,988 hours with bypass for the entire period of operation. The former figure exceeds the time between failures declared by Eaton by a factor of three, and the latter by a factor of two.

Kopitan-Dem Technical Director Victor Ashurkov explained: "Together with Kursk Nuclear Power Plant representatives, we analysed the results of ten years' of operation, and can confidently state our main conclusion: the outcome of our work together significantly exceeded expectations, and demonstrated the superior reliability and exceptionality of Eaton equipment. A system architecture in which three failures lead to no downtime in powered equipment, high-quality output current, remote monitoring of all system-component UPS units, and system maintenance without full blackouts or supplied load outages - these are all indisputable advantages that make our nuclear power plant both efficient and safe."