148g,mPm: Evaluation of the decay schemes for two important reactor poisons

•New evaluation of 148gPm and 148mPm following DDEP methodology.•Recommended γ ray energies and emission intensities.•Recommended β energies and emission intensities.•Complete decay scheme.•Reactor poison nuclides: 148gPm and 148mPm.

During reactor operation 148gPm and 148mPm are formed in large quantities from thermal neutron capture on the fission product 147Pm. Subsequent neutron capture reactions, on the 148Pm ground state and isomer, have cross sections differing by a factor of 5 and so precise knowledge of their decay properties is vitally important. New decay scheme evaluations using the DDEP methodology for 148gPm and 148mPm are presented. The complete data tables and detailed evaluator comments are available through the DDEP website.