Use of natural gas for power generation should increase somewhat during the next couple of months as many commercial nuclear units hold maintenance and refueling outages, according to the Energy Information Administration (EIA).
With 8.6 GW, or 9%, of nuclear power capacity offline on Sept. 16, the 2015 fall nuclear refueling season is underway. As of early Sept. 18, seven of the nation’s 99 nuclear reactor units were listed at zero power generation, according to data from the Nuclear Regulatory Commission (NRC).
EIA said that the firm Bentek Energy estimates that currently as much as 1.4 billion cubic feet (Bcf) of natural gas consumed in the electric power sector (power burn) can be attributed to the nuclear outages.
Of the 99 nuclear power reactors operating in the United States, 30 reactors in 20 states, with a combined capacity of 30 GW, are scheduled to refuel between September and December, according to the EIA posting.
While not all of the 30 nuclear power reactors will be shut down at the same time, 16 are expected to be offline in the first week of October, causing the loss of 18.2 GW that typically operates at 90.7% of capacity, EIA said.
If all of this lost nuclear generation is replaced by natural gas generation, it will require, on average, 1.9 Bcf/d of natural gas to meet the increase in demand. In comparison, power sector consumption averaged 28 Bcf/d during the first week of September, when nuclear outages were relatively low.
Nuclear power plant operators typically refuel during the low-demand seasons of spring and fall in order to limit the effect of these outages and to minimize the cost of replacement power.
Most nuclear power reactors refuel every 18 to 24 months, during which time one-third to one-half of the plant's fuel rods are replaced. Although the refueling process can be completed in as few as 10 days, outage periods are typically longer because of maintenance and infrastructure work that is completed concurrently with refueling to minimize downtime over the course of the year.
Outages are coordinated to ensure that replacement power sources are available.