Cook nuclear plant on 6 January

Nuclear power plants in the United States have so far been "unfazed" by the huge mass of Arctic air that has seen temperatures drop below freezing at locations in all 50 states. Temperatures are expected to rise over the coming days.

No nuclear energy facility had reported unusual issues during the cold snap as of 7 January, and according to the US Nuclear Energy Institute plants have been running at near 100 percent capacity, helping to meet near-record electricity demand.

The US nuclear regulator said its resident inspectors typically check a plant for cold-weather vulnerabilities at the start of the season.

All but two of the USA’s 100 reactors (Arkansas Nuclear 2, which has been offline since a transformer fire in December 2013, and Beaver Valley 1) were producing power on 9 January, according to the US Nuclear Regulatory Commission’s power reactor status report. Most units were operating at close to 100% power, with Indian Point 3 at 45% power and Prairie Island 2 at 64% power.

Sub-zero temperatures and 33F cooling water in Lake Michigan, improved efficiency of American Electric Power’s Cook Nuclear Plant. Its two units were operating at 100% power on 6 January, pushing 2230 MW of electricity to the grid, it said.

Minor issues at two reactors

Unit 3 at Entergy’s Indian Point nuclear power plant in New York was shut down for short unplanned outage during the cold snap. The 1041 MW Westinghouse pressurized water reactor (PWR) automatically shut down at 9:15PM on Monday 6 January, after water levels lowered inside one of the plant’s four steam generators. It returned to the grid in the afternoon on Wednesday 8 January, after replacement of a controller that regulates the flow of water in that SG.

Also on 6 January, Unit 1 at First Energy’s Beaver Valley Power Station in Shippingport, Pennsylvania, suffered a main transformer trip. FENOC said in a report to the NRC that the cause of the trip was being investigated.

Electricity prices soar amid record demand

The intense cold snap has increased electricity demand considerably throughout the United States.

"Nuclear power plants supplied over a fifth of TVA’s 32,460 MW peak load on Tuesday"

The Tennessee Valley Authority (TVA) revealed, 9 January, that homes and business across its seven-state region used a record 703 GWh of electricity on Tuesday 7 January, the most ever over a 24-hour period. Nuclear power plants supplied over a fifth (21%) of TVA’s 32,460 MW peak load on Tuesday, with 28% coming from coal-fired plants, 24% from gas plants, 11% from hydroelectric dams, 2% from wind farms and 13% from power market purchases.

The Nuclear Energy Institute said that the high demand led to a surge in wholesale electricity prices, as some non-nuclear plants had to drop off the grid due to low gas pipeline supplies and cold-related mechanical failures.

Power prices reached a price cap of $5000/MWh in Texas and above $1500/MWh at PJM, the grid operator that covers the mid-Atlantic region and parts of the Midwest. More typical wholesale prices for these segments of the grid are between $30 and $50 per MWh, the NEI said.

According to the US Energy Information Administration, peak electricity prices on 9 January are expected to remain above $200/MWh in both New York and New England.

Temperatures, which averaged 12°F in New York on Tuesday (7 January), are expected to increase to 29°F today, with continued rises expected through the weekend.

Photo: The Cook Nuclear Plant