IEC 61468:2021 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 and test methods. In this document, the main sources of errors, and the possibilities for their minimization are also considered. This document contains requirements, recommendations and instructions concerning selection of SPND type and characteristics for various possible applications.

This document about SPNDs uses the basic requirements of IEC 61513 and IEC 60568 and complements them with more specific provisions in compliance with IAEA Safety Guides.

This second edition cancels and replaces the first edition, published in 2000, and its Amendment 1, published in 2003.

This edition includes the following significant technical changes with respect to the previous edition:

a. Title modified.

b. Justify the requirements for SPND characteristics in terms of influencing factors.

c. Align the terminology with the current state of the regulatory framework.