United States Nuclear Regulatory Commission - Protecting People and the Environment

Operability Guidance

10 CFR Section 50.36 requires that each applicant for a license authorizing operation of a production or utilization facility include in his application proposed technical specifications (TS).  This regulation also requires the TS to include limiting conditions for operation (LCO) and defines LCO as the lowest functional capability or performance levels of equipment required for safe operation of the facility.  The regulation requires that when an LCO of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial actions permitted by the TS until the condition can be met.

The operability determination process is used to assess TS required structures, systems or components (SSCs) and their support functions for compliance with TS when a degraded or nonconforming condition is identified for a specific SSC for an associated necessary and related support function.

IMC 0326, "OPERABILITY DETERMINATIONS & FUNCTIONALITY ASSESSMENTS FOR CONDITIONS ADVERSE TO QUALITY OR SAFETY"

On September 26, 2005, the NRC issued Regulatory Issue Summary (RIS) 2005-20 to inform licensees that it had revised the guidance contained in two sections of NRC Inspection Manual Part 9900, Technical Guidance, "Operable/Operability: Ensuring the Functional Capability of a System or Component" and "Resolution of Degraded and Nonconforming Conditions," and had combined these two documents into a single document. The revised inspection guidance reflected relevant changes that have been made to NRC regulations, policies, and practices, and clarified selected issues based on operating experience. This guidance superseded the guidance previously provided in GL 91-18 and Revision 1 to GL 91-18.

On June 15, 2015, the NRC issued Regulatory Issue Summary (RIS) 2005-20, Revision 2, to inform licensees that NRC Inspection Manual Part 9900, Technical Guidance (TG 9900), "Operability Determinations & Functionality Assessments for Resolution of Degraded and Nonconforming Conditions Adverse to Quality or Safety" had been reissued as Inspection Manual Chapter (IMC) 0326 (ML13274A578), "Operability Determinations and Functionality Assessments for Conditions Adverse to Quality or Safety" dated January 31, 2014.  The revised inspection guidance reflects relevant changes that have been made to NRC policies and practices, and clarifies selected issues based on operating experience.  This guidance supersedes the guidance previously provided in Revision 1 to RIS 2005-20 and GL 91-18.

To top of page

Page Last Reviewed/Updated Friday, November 20, 2015