Lifecycle management tools in the development of SNS credited safety systems

A new FPGA/PLC credited Beam Power Limit System (BPLS) ensures beam power to the SNS First Target Station does not exceed a safety envelope of 2MW + 10%. A new SNS beamline, VENUS, uses a single safety PLC to perform safety interlock logic. In order to link and track the extensive documentation required to manage a safety credited system, the commercial tool Reqtracer® was used to develop and link dozens of documents from the system requirements, specifications, code, down to specific test results. This level of linkage helps to ensure the pedigree of the SNS safety systems remains intact over the life of the system. This paper will discuss the experience, advantages, and disadvantages of using such a tool in the lifecycle of a safety credited system.