HPS ANSI/HPS N13.37

This standard is applicable to passive environmental dosimetrysystems used to monitor areas surrounding radiological facilitiesto assess potential facility-related radiation doses and to verifycompliance with public dose limits. Such environmental dosimetrysystems include dosimeters which accumulate radiation dose and anyreadout device required to process the dosimeters. Passivedosimeters include thermoluminescence dosimeters (TLDs), opticallystimulated luminescence (OSL) dosimeters, and direct ion-storagedosimeters, which are deployed at field locations around a facilityand exchanged periodically (e.g., quarterly). Dosimeters could beprocessed at the facility or off-site.

Sections 1 through 4 of this standard cover the overview,definitions, general considerations and a summary of requirementsand recommendations. Sections 5 and 6 describe laboratory typetests to determine the fundamental performance characteristics of aspecified dosimetry system design and establish criteria that willenable a level of bias and precision in field measurements suitablefor quantifying the radiological impact of facility operations onmembers of the public and the surrounding environment. Section 7 ofthis standard provides implementation performance objectives,requirements, and recommendations for field measurements using adosimetry system that has satisfied the performance criteria inSection 5 and 6.

Establishing conformance with this standard requires fullydocumenting the system design. The system design is defined toinclude the dosimeters, readout equipment and other processinghardware as well as the equipment configuration,operating/processing procedures, and dose calculation methods usedfor type testing. All of these play a significant role indetermining system performance.¹ If a specificdocumented system design has been tested and shown to meet theperformance criteria in Sections 5 and 6, then the test results areapplicable to any processor implementing the same systemdesign.

It is important to note that the type tests in Sections 5 and 6are not intended as tests of a particular processor but rather astests of a specific system design. Some manufacturers may offerturn-key systems (hardware and software) and recommended operatingprocedures that have been optimized for environmental monitoring.Others offer systems with flexibility in configuration andoperation that allow the processor to design a system tailored totheir needs. It is ultimately the processor who determines thefinal system design that is implemented and which is the subject ofthe type tests in this standard. ² It is recognized thatthe end user must sometimes take certain actions that alter thesystem design that has been tested (e.g., additional dosimeterpackaging or field mounting hardware). When this is the case, theend user shall document that those changes have not altered thebasic performance characteristics that were determined in the typetests.

Purpose

This standard provides performance test methods and criteria forsystem design and implementation of environmental radiationdosimetry systems used to measure external photon radiation.

¹ For example, with TLD and OSL systems, depending onthe particular detector material used, the preirradiation annealtreatment and readout protocols (e.g., time-temperature profile forTLD, or optical stimulation wavelength, power, and duration forOSL) can significantly impact the sensitivity, reproducibility, andminimum quantifiable dose for a system, as well as the fadingcharacteristics of the system. The dose calculation algorithms usedcan significantly influence the angular and energy dependence ofdose results. Because routine dose calculation methods are calledfor in many of the type tests, details of those methods shall beincluded in the documentation of the system design that istested.

² The distinctions between manufacturer and processorand processor and end user are not always clear. In some cases, themanufacturer and processor may be one and the same, or have a closeworking relationship. In other cases (e.g., “in-house” dosimetryprograms) the processor and end user may be one and the same, orhave a close working relationship. The term “processor” is usedgenerically here to refer to the laboratory in which dosimeters areprepared and processed (i.e., readout and results reported to enduser).

Edition:

14

Published:

01/01/2014

ANSI:

ANSI Approved

Number of Pages:

45