Document: NRC Regulatory Guide
Document ID: 25a5daff-c390-423e-a736-7744b82624bb
Document Type: regulatory_guide
Title: Preoperational Testing of Instrument Air Systems
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1306/ML13064A110.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.80
CFR Part: 
CFR Title: 

Content:
June 1974 U.S. ATOMIC ENERGY COMMISSION R E G U LAT. 0 Y DIRECTORATE OF REGULATORY STANDARDS GUI DE REGULATORY GUIDE 1.80 PREOPERATIONAL TESTING OF INSTRUMENT AIR SYSTEMS A. INTRODUCTION General Design Criterion -1, "Quality Standards and Records," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50, "Licensing of Production and Utilization Facilities," requires that structures, systems, and components important to safety be tested to quality standards commensurate with the importance of the safety functions to be performed. Criterion XI, "Test Control," of Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50 requires that a test program be established to assure that all testing, including preoperational testing required to demonstrate that structures, systems, and components will perform satisfactorily in service is identified and performed. This guide describes a method acceptable to the Regulatory staff for complying with the Commission's regulations with respect to verifying the operability of safety-related instrument air systems 1 before placing these systems into service. B. DISCUSSION Operation experience has shown that there is a need for guidance in conducting an adequate preoperational test on the instrument air systems. There have been valve operator failures due to foreign matter in the instrument air, which would indicate .either inadequate cleaning of the system after installation or inadequate filtering of the supply air taken into the system during operation. There have been several incidents in which the air supply to vital instruments was cut off due to the freezing of excessive moisture in the instrument air line. In one case, the freezing was the result of an improperly set dryer refrigerant expansion valve. In other cases, the freezing was caused by unusually cold weather. This guide should also be considered applicable to instrument systems utilizing