Ruben Muradyan, Expert of National Adaptation Program in Armenia UNDP-GCF Program, Leading Researcher at Scientific Research Institute of Energy CJSC, presented the assessment of climate change risks and impact on the energy sector in Armenia in the course of “National Programme on Renewable Energy and Energy Saving for 2022-2030 workshop held on December 21, 2021.
Ruben Muradyan said, "Disruptions often occur with the combination of dangerous events. Safety limits are no longer sufficient and cannot be reliable in the whole operational life of the infrastructure system. Every asset of the system requires long-term planning," he said.
Armenian Nuclear Power Plant
Changes in air temperature, decreases in water volume, landslides, changes in wind speed are stressors of energy facilities, including the ANPP, which is operated by a second-generation single water pressure reactor JJER-440/V-270.
"The Armenian Nuclear Power Plant (ANPP) is a sensitive object in terms of climate change. The re-equipment carried out at the ANPP in 2021 has created an opportunity to increase the plant's capacity by 15%. At the same time, the problems related to the impact of climate change are complicated by 15%," Ruben Muradyan said.
According to him, in case of using water cooling system in the nuclear power plant, the increase of air temperature by 5ºC, in case of air cooling system by 1ºC, may lead to a decrease of 1 and 0.1% in the output of the nuclear power plant, respectively.
The heat dissipation area of a nuclear reactor is extremely limited. Six powerful primary cooling pumps perform heat abstraction. Deviations in the water balance of the primary circuit can lead to critical thermal deformation of the reactor body.
The other is typical of the ANPP, as well as other nuclear power plants of the same type. Nuclear technology can produce low vapor pressure and under the conditions of room temperature. The turbine system is equipped with low pressure turbines. The steam pressure before the turbine is only 44.0 Bar. Condensation of water droplets occurs at low pressure at the end of the heat paddles. The droplets can hit the low-pressure turbine blades. Care must be taken not to cause this event to occur so that the paddles and the turbine operate under normal conditions.
The radioactive waste accumulated at the station needs constant refrigeration. This is especially true for cooling ponds and dry fuel storage warehouses. "Different levels of waste are generated as a result of the plant operation. When the fuel temperature drops enough, they are sent to dry storage a few years later. "If the air temperature changes, problems can arise here," he explained. A dry storage of used nuclear fuel is located in the territory of the ANPP.
According to Ruben Muradyan, 30 tons of water per hour must be provided for the sustainable operation of the cooling towers of one block. "In case of violation of the water regime of the pumps, cracks in the body of the nuclear power plant may appear, which can be detected by using special technologies," he said.
Extreme weather conditions and lack of precipitation can disrupt the operation of equipment and processes necessary for the safe operation of the nuclear power plant.
The other problem, according to Ruben Muradyan, is that in case of violation of the temperature norm, the sensors and measuring devices can cause a false response to the technological-electrical automatic operation of the ANPP. "Violation of the ventilation system may lead to a change in the background radiation at the ANPP. The operation of backup diesel generators can be disrupted in case of problems with its own cooling system," he explained.
Yerevan Thermal Power Plant
Touching upon the impact of climate change on the operation of Yerevan Thermal Power Plant, Ruben Muradyan said that the plant equipment has vulnerabilities. "First of all, it is the height of the station. The thermal power plant is 900 m above sea level. Every 1000 m reduces the efficiency of such stations by 10%. Another vulnerability is rising temperatures. With every increase by 3ºC, the efficiency decreases by 1%," he said.
HPPs and SHPPs
With each 3ºC increase in ambient air temperature, a 1% decrease in efficiency can also be observed in the operation of HPPs and SHPPs.
Solar Energy
Increasing the air temperature by 1ºC can change the conversion efficiency of a crystalline silicon photovoltaic cell by 0.08%, can increase the load of transformers by 1%, change the load capacity of a transmission line by 0.5-1%, increase the resistance by 0.4%.
January 03, 2022 at 11:08