Part 1 of 2 Parts (Please read Part 1 first)
Severe cold weather is many parts of the U.S. last week caused power outages affecting millions of electricity customers across Texas, Louisiana and Oklahoma. The resources of power plants were strained because cold weather tripped units, natural gas supplies were curtailed and there were outages of wind power generation. Independent systems operators the Electric Reliability Council of Texas (ERCOT), Southwest Power Pool and the Midcontinent Independent System Operator were all forced to implement controlled power outages across parts of their systems in order to manage the increased load caused by the extreme cold weather.
Excursions of the Polar Vortex into the U.S. resulted in Texas experiencing its heaviest snowfall in seventy two years. Three of the four nuclear reactors in Texas continued to operate at full power during the extreme weather. The two-unit South Texas Project plant is located ninety miles south-west of Houston. Unit One at the plant automatically tripped on the 15th of February following a cold weather-induced failure of a feedwater pressure sensing line in the non-nuclear area of the plant. Unit One was subsequently restarted and was reconnected to the Texas grid on the 17th of February.
U.S. nuclear reactors have previously demonstrated heir reliability during extreme weather such as the polar vortex events that occurred during 2014 and 2019. Exelon Generation said that all six of its Illinois nuclear power plants were able to continue to maintain almost one hundred percent output during the latest cold snap. Exelon said, “Winter resiliency and reliability requires year-long planning and maintenance. Exelon Generation workers spend months ensuring that backup generators and supplemental equipment are ready for inclement weather.”
FERC and the North American Electric Reliability Corporation announced last week that they would conduct a joint inquiry into the operation of the U.S. bulk-power system during extreme winter weather conditions. Yesterday, the regulator said that it’s Office of Enforcement is reviewing wholesale natural gas and electricity market activity during the extreme weather last week to determine whether any market participants engaged in market manipulation or other violations. FERC said, “If the Office of Enforcement finds any potential wrongdoing that can be addressed under FERC's statutory authority, it will pursue those matters as non-public investigations.”
The examination will take place as part of an ongoing surveillance of the behavior of market participants in the wholesale natural gas and electricity markets. The investigation will be carried out by FERC’s Division of Analytics and Surveillance. Market participant-lvel trading data and data from the financial markets is used to screen daily and monthly trading at U.S. physical and financial natural gas trading hubs and wholesale electricity markets. The FERC Division works to identify and scrutinize any potentially anticompetitive or manipulative behavior to determine if further investigation is warranted.
I have already posted articles about the affect of high temperatures, water supplies and hurricanes on the operation of nuclear power plants. With predictions of more extreme weather events in the U.S., the review of resilience and reliability of U.S. nuclear power plants is welcome.