IEC 61468 pdf – Nuclear power plants – Instrumentation systems important to safety – In-core instrumentation: Characteristics and test methods of self-powered neutron detectors This document applies to in-core neutron detectors，viz. self-powered neutron detectors(SPNDs),which are intended for application in systems important for nuclear reactor safety:protection，instrumentation and control. This document contains SPND characteristics andtest methods. ln this document, the main sources...