Regulatory Guide 1.80

Preoperational Testing of Instrument Air Systems

ML13064A110
Person / Time
Issue date:	06/30/1974
From:	US Atomic Energy Commission (AEC)
To:
References
RG-1.080
Download: ML13064A110 (2)

June 1974 U.S. ATOMIC ENERGY COMMISSION

R E G U LAT.0

DIRECTORATE OF REGULATORY STANDARDS

Y GUI DE

REGULATORY GUIDE 1.80

PREOPERATIONAL TESTING OF INSTRUMENT AIR SYSTEMS

A. INTRODUCTION

The applicant is responsible for the development of a suitable preoperational test program for the instrument General Design Criterion -1, "Quality Standards and air system, the preparation of adequate procedures for Records," of Appendix A, "General Design Criteria for carrying out the program, the proper conduct of the Nuclear Power Plants," to 10 CFR Part 50, "Licensing preoperational tests, and the validity of the test results.

of Production and Utilization Facilities," requires that structures, systems, and components important to safety A significant consideration related to the be tested to quality standards commensurate with the performance of the instrument air system is how the importance of the safety functions to be performed. valves controlled by the system will respond to the loss Criterion XI, "Test Control," of Appendix B, "Quality of instrument air supply. Valves are designed to respond Assurance Criteria for Nuclear Power Plants and Fuel in a given manner, i.e., fail open, fail closed, or fail as is, Reprocessing Plants," to 10 CFR Part 50 requires that a if the instrument air supply is lost. Verification of design test program be established to assure that all testing, response to a loss-of-instrument-air accident is an including preoperational testing required to demonstrate essential part of testing at the preoperational stage, at that structures, systems, and components will perform which time it can be accomplished with a minimum risk satisfactorily in service is identified and performed. This to power plant equipment and personnel. The test will guide describes a method acceptable to the Regulatory also provide a means for determining the adequacy of staff for complying with the Commission's regulations operating and emergency procedures for coping with a with respect to verifying the operability of safety-related loss of instrument air supply.

instrument air systems 1 before placing these systems into servic

B. DISCUSSION

As part of the initial preoperational testing program, and also after major modifications or repairs to a Operation experience has shown that there is a need facility, the instrument air system should be tested as.

for guidance in conducting an adequate preoperational described below to verify that all components function test on the instrument air systems. There have been valve properly and that the systems respond as designed to a operator failures due to foreign matter in the instrument loss-of-instrument-air-supply accident.

air, which would indicate .either inadequate cleaning of the system after installation or inadequate filtering of 1. The test program for the instrument air system and the supply air taken into the system during operation. its associated equipment should include applicable There have been several incidents in which the air supply checks, verifications, tests, and reports outlined in to vital instruments was cut off due to the freezing of Regulatory Guide 1.68, "Preoperational and Initial excessive moisture in the instrument air line. In one case, Startup Test Programs for Water-Cooled Power the freezing was the result of an improperly set dryer Reactors" as a prerequisite to or in conjunction with the refrigerant expansion valve. In other cases, the freezing tests of this regulatory guide.

was caused by unusually cold weather.

2. Compressors, aftercoolers, oil separator units, and air receivers should be tested to verify proper operation This guide should also be considered applicable to according to system design. Check operation of instrument systems utilizing other gases such as nitrogen. compressor unloaders, automatic and manual start and USAEC REGULATORY GUIDES Copies of published guides may be obtained by request indicating the divisions desired to the US. Atomic Energy Commission, Washington, D.C. 20545, Regulatory Guides are issued to describe and make available to the public Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of improvements in these guides are encouraged and should be sent to the Secretary the Commission's regulations, to delineate techniques used by the staff in of the Commission, U.S. Atomic Energy Commission, Washington. D.C. 20545, evaluating specific problems or postulated accidents, or to provide guidance to Attention: Chief, Public Proceedings Staff.

applicants. Regulatory Guides are not substitutes for regulations and compliance with them is not required. Methods and solutions different from those set out in The guides are issued in the following ten broad divisions:

the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of a permit or license by the Commission. 1. Power Reactors

6. Products

2. Research and Test Reactors

7. Transportation

3. Fuels and Materials Facilities 8. Occupational Health Published guides will be revised periodically, as appropriate, to accommodate 4. Environmentalland Siting 9. Antitrust Review comments and to reflect new information or experience. 5. Materials and Plant Protection 1

0. General

stop circuits of standby compressors, high and low on the largest number of branches of the system that can pressure alarms, pressure indicators, and temperature be adequately managed as follows:

indicators. Verify validity of relief valve settings.

a. Prior to the test, place the valves to be tested, except for those valves which fail as is, in a position

3. Test air dryer units for proper functioning and other than the failed position. Maintain the rest of the operate units through at least one regeneration cycle.

Verify operation at maximum flow rates. Verify plant in as close to normal operating condition as is possible. (It should be noted that not all valves can be appropriate differential pressures and proper operation placed in the required positions because of operating of pressure switches, high and low pressure alarms, procedure requirements or personnel or equipment safety and/or relief valves, bypass valves and alarms, and safety factors.)

resets.

b. Shut off instrument air supply in a manner that

4. Verify by test that the instrument air system will would simulate an instrument air pipe break and verify meet specifications relating to flow, pressure, and the movements of the affected components. Also verify temperature of the product air. the adequacy of the various feeders or branches to sustain an adequate share of the decaying air supply as

5. Verify by test that the system will meet cleanliness required by the operational mode; i.e., verify that requirements with respectto oil, water, and particulate branches of smaller pipe sizes are not starved by flow to matter contained in the product air by analyzing the air branches of larger capacity.

at the end of each main feeder line using continuous flow techniques or by the analysis of a discrete sample. 9. Rerun the test outlined in Regulatory Position C.8 with the exception that, during this test, shut off instrument air supply very slowly to simulate the loss of

6. When redundant components of the instrument air instrument air by moisture freezing and plugging the system are required, verify by test that the failure or loss of function of one component will not prevent the main supply line.

proper operation of the others.

10. Rerun the tests outlined in Regulatory Positions C.8'

and C.9 with the exception that, during these tests, place

7. Test and check for proper operation all the valves in their normal operating position.

safety-related instruments, controls, and valves served by the instrument air system. Verify that all safety-related 11. The results of each test performed in accordance instruments, controls, and valves served by each branch with Regulatory Positions C.A through C.10 above of the system are properly labeled and that their remote should be included in the startup report2 which should controls, indicators, and alarms are correctly identified. present a description of the test, a comparison of test Verify by test that the failure of any non-safety-related results predicted by the test procedures, identification of instruments, controls, and valves served by the conditions encountered which were not anticipated, instrument air system or the lines leading thereto will corrective actions, if any, and an evaluation of test not jeopardize the safety-related parts of the system. results.

8. Conduct a loss-of-instrument-air-supply test on all See Regulatory Guide 1.16, "Reporting of Operating branches of the system simultaneously, if practicable, or Information," Revision 1, October 1973., Section C.l.a.(1). K

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