See
BTP 3-3 Protection Against Postulated Piping Failures in Fluid Systems Outside Containment (Former Section 3.6.1 BTP has been separated into an individual section.)
APPENDIX A
DEFINITIONS
What are the pressure/temperature boundary conditons of High Energy Piping Systems and where are they defined by NRC or ASME specifically?
I found this description in a document with no references:
"...high energy (pressure > 275 psi or temperature > 200 F) pipe ruptures..."