The US Nuclear Regulatory Commission (NRC) has approved a power uprate for Exelon Generation's Peach Bottom 2&3 in Delta, Pennsylvania, which will increase the reactors' capacity by an estimated 1.66%.

The uprate should be implemented within 90 days, NRC said 17 November.

Each 1355MWe boiling water reactor unit is authorised to increase its maximum power level from 3951MWt to 4016MWt, which represents an increase of about 20MWe over the current gross output.

NRC’s safety evaluation focused on several areas, including the nuclear steam supply systems, instrumentation and control systems, electrical systems, accident evaluations, radiological consequences, operations and training, testing, and technical specification changes.
 
NRC "determined that Exelon could safely increase the reactors' output primarily through more accurate means of measuring feedwater flow, after reviewing Exelon's evaluations showing the plant's design can handle the increased power level”. 

Measurement uncertainty recapture (MUR) uprates depend on more precise instrumentation to measure the feedwater flow used to calculate reactor power. UP to 2011, MUR uprates added about 500MWe in nuclear capacity in the US at the cost of about $63m million, according to the International Atomic Energy Agency.  Peach Bottom 2&3 began commercial operation in 1974.


Photo: Peach Bottom (credit: Exelon)