Regulatory document REGDOC-3.1.1, Reporting Requirements for Nuclear Power Plants, sets out the timing and information that nuclear power plant licensees are required to report to the CNSC to support the conditions of applicable power reactor operating licences. This document presents the types of reports, their frequency and the applicable timeframe for reporting. This document also contains guidance, explanatory information and templates to assist users in meeting reporting requirements. Additional forms and data sheets can be found on the CNSC website. Version 1 of this document replaced S-99, Reporting Requirements for Operating Nuclear Power Plants, published in March 2003. Version 2 of this document includes the following revisions: removal of the performance indicator data sheets from appendix B (these are now available on the CNSC’s website); inclusion of references to the Packaging and Transport of Nuclear Substances Regulations, 2015, for requirements for packaging and transport of nuclear substances.