Relaxation of rod misalignment technical specification requirements: An increased operational flexibility

The pressurized water reactor technical specification (T/S) limiting condition for operation (LCO) for rod misalignment and rod position indication (RPI) typically requires all rod cluster control assemblies to be positioned with ±12 steps of the group demand position. The LCO is approved by the U.S. Nuclear Regulatory Commission (NRC) for use by all Westinghouse plants, and the core design incorporates a peaking factor uncertainty to accommodate potential rod misalignments within this approved LCO. Also, the LCO requires all RPI channels and the demand position indicator system to be operable and capable of determining the control rod position within ±12 steps