Tennessee nuclear plant affected by low water levels

The operator of a nuclear power plant in east Tennessee was forced to bring in an unscheduled supply of water from upstream in early June to keep the plant's efficiency within acceptable levels.

The Sequoyah nuclear power plant is located on the Tennessee river and run by the Tennessee Valley Authority (TVA), the US’s largest electricity generator. Following an unusually dry spring, TVA found it necessary to increase the amount of river water flowing into the plant in order to maintain cooling efficiency. The river water is used to convert steam back into water by cooling it.

A Sequoyah plant spokesperson acknowledged the intake of extra water over a four-hour period in early June, but emphasised that the east Tennessee region has had adequate rainfall since mid-June and such action has been unnecessary since then.

“We’ve seen this several times with the TVA plants where the cooling efficiency is related to the river water temperature,” says Paul Gunter, director of the Reactor Watchdog project at the Nuclear Information & Resource Service (NIRS) in Washington, DC. The NIRS is an organization that lobbies against nuclear power generation. “It is an on-going issue. The higher the river water temperature, the higher the loss of cooling efficiency. There are technical specifications about river water temperatures that are part of the overall safety standards for the plants.”

“Situations like this would apply to any of the plants in the [American] south that are using river water for the services water for the cooling of water in the condenser before it is returned to the river,” says Gunter. “The safe operation of these plants depends on adequate supply of cold water.”

Drought conditions in east Tennessee until mid-June reduced flow on the Tennessee river and increased the temperature of its water.

TVA is a US federal government corporation. It operates other nuclear power plants in Tennessee and is the environmental steward of the Tennessee River basin.

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