Subcritical physics testing (SPT) is an NRC approved alternative to traditional low power physics testing (LPPT) to confirm that the as-built core is consistent with core design predictions with the added benefits of less critical path time and less burden on station personnel to conduct the test.

Creates additional value by eliminating many ancillary aspects of LPPT such as elimination of temporary test equipment and plant connections. Design constants can be generated on premises at the actual plant conditions.
Can be utilized anytime following refueling through reactor startup, thus offering unique shutdown monitoring & analysis capabilities to improve reactivity management and outage execution prior to criticality.