ANSI N42.54-2018 pdf free download – American National Standard Instrumentation and Systems for Monitoring Airborne Radioactivity.
4.General requirements
The contents of this clause apply to all monitors. Specific monitor types have additional requirements listedin Clause 6 through Clause 10. It is only in Clause 6 through Clause 10 that any of these requirements maybe modified for specific technologies.
The monitoring of airborne radioactivity requires obtaining a sample of the air, evaluating the radioactivecontent of the sample,and returning the sample to the environment. The general requirements forequipment used to evaluate the sample are discussed in this clause.
This standard is applicable to equipment for collecting and measuring radioactivity in the workplace duringnormal operations and during anticipated abnormal operations，in effluent,and in the environment. Thisstandard does not apply to cquipment specifically for use in accident or post-accident conditions. Suchequipment may require additional capabilities as described in ANSI N320.
This standard is restricted to equipment for collecting and/or measuring airborne radioactivity includinggasses and acrosols. It does not deal with sample extraction (i.e.,ANSLHPS N13.1) or radiochemistry. Theobject of this standard is to establish mandatory general requirements and give examples of acceptablemethods to collect and measure airborne radioactivity.
The general performance criteria, test procedures, calibration procedures, radiological, electrical, safety andenvironmental characteristics, the identification and certification for the airborne monitoring equipment arespecified in this clause. If this equipment is part of a centralized system for continuous radiation monitoringin a nuclear facility, there may be additional requirements from other standards.
This standard addresses the requirements for commercial grade instrumentation.For safety-relatedmonitors used in nuclear power plants，the applicable plant environmental and seismic qualificationrequirements cstablished by the U.S. Nuclear Regulatory Commission (NRC), the Institute of Electrical andElectronics Engineers (IEEE), the American Society of Mechanical Engineers(ASME) and other industrystandards shall be consulted.
4.1 Software operability
Where the instrumentation is controlled by software, the software and any underlying algorithms used shallbe shown to operate correctly by the manufacturer under operational conditions. This should includereviewing all assumptions utilized in algorithms for dissemination in a technical basis document.Thisrequirement equally applies to software after any changes have occurred to the software that could affect itsperformance.
4.2 Test criteria
All tests done in accordance with this standard must be fully reproducible and documented.
4.3 System reliability
Monitors and/or samplers shall be able to perform their intended function and be capable of providing reliable measurements in environments and process conditions to which the monitor may be subjected.
4.4 Human factors
The design should take into account human factors for the monitor users. This includes all of the following to provide reliable monitor performance:
Functional testing
Maintenance (including collection media replacement)
Calibration
Decontamination activities
4.5 Air circuit
Air path integrity shall be sufficient to allow quantitative measurement of radioactivity concentrations in air.
4.5.1 Out-leakage Out-leakage is a facility issue that should be addressed when a monitoring system is being installed and before becoming operational. The testing should include the entire sampling line and the detector. This testing should be performed using sulfur hexafluoride (SF 6 ), an inert and harmless gas, at all system joints, valves, and any piping connections. The SF 6 can be detected at parts per billion levels and can pinpoint leaks. Any detected leak shall be sealed and the testing repeated to verify sealing.ANSI N42.54 pdf download.