Facilities

The Pacific Northwest National Laboratory (PNNL) maintains a Radiological Calibration and Standards Laboratory on the Hanford Site at Richland Washington. Laboratory staff provides expertise and experience in Health Physics, Radiation Measurements, Dosimetry and Calibrations. Tangential groups also provide expertise in Monte Carlo modeling/simulations, detector development, sample counting and radiochemical analysis, which have benefitted the calibration laboratory in the characterization of its facilities. These groups are available for client benefit as well, although they are not affiliated with the accredited processes, per se.

The Calibration Research and Accreditation Group (CR&A), which is in the PNNL Energy and Environment Directorate, offers technical expertise for the configuration and protocol planning for calibration or testing of radiation-measuring devices as well as irradiation of other artifacts for radiation induced effects, response, resiliency (i.e., radiation “hardness”), etc. Organic and inorganic samples can be irradiated for research purposes.

Beta Standards Laboratory

The Beta laboratory contains Buchler GmbH calibration apparatus for use with PTB, Amersham, or other ISO-6980 Series I compliant sources. The original PTB (German National Standards Laboratory) supplied sources and irradiation apparatus compose an international secondary standard for beta irradiations.

A second beta system utilizing a modified Beta Secondary Standard BSS2 system adds the 85Kr exposure capability to the Calibration Laboratory.

X-Ray Facility

The x-ray facility consists of a shielded control room and a 4.7 m x 12.6 m x 4 m irradiation room. Two identical Philips Model 324 x-ray machines are currently in use for dosimeter irradiations and instrument calibrations. One of the machines produces bremsstrahlung (broad) spectra NIST and ISO techniques while the other is configured to produce K-fluorescence (narrow) techniques.

¹³⁷Cs, ⁶⁰Co and ²⁴¹Am Gamma Facilities

JL Shepherd Model 81 Irradiator - The gamma field produced in this facility is generated by a ¹³⁷Cs source (nominal activity of 100 Ci) used within a collimated geometry (30 collimation angle). The source is calibrated specifically at 1- and 3-meters and the beam is unobstructed until it encounters a concrete wall at a distance of approximately 5.5-meters.

High Exposure Facility - The gamma fields produced in this facility are generated by two ¹³⁷Cs sources (nominal activities of 10 and 100 Ci) and two ⁶⁰Co sources (nominal activities of 660 and 5890 Ci) used within a collimated geometry (30 collimation angle). The calibration range extends to approximately six meters, with the beam unobstructed until it encounters a concrete wall at a distance of approximately 8.2 meters.

²⁴¹Am Irradiator - This source, with a primary photon energy of 60 keV, produces a nominal exposure rate of 119 mr/hr.

Low Scatter Room

The low scatter room is a large irradiation area housing neutron and gamma irradiation stations with an extremely low room scatter component. The room has concrete walls and is approximately 10 m x 9 m x 15 m. The neutron irradiation station is mounted on a raised aluminum platform in the approximate geometric center of the room. A pneumatically driven "rabbit" system is used to move sources from their storage location to the irradiation station.

Source Well Room

This room contains four calibration source wells, each 0.3 m in diameter by 10 m deep, with trolley-mounted radionuclide sources. Trolley movement is controlled by a dedicated personal computer programmed to position the source to achieve the desired exposure or dose rate at the top of the well. These wells provide automatic compensation for temperature, pressure, and source decay as well as the ability to automate positioning for specific instruments. Three 137Cs gamma sources and one 252Cf neutron source are available in a well geometry. The neutron well is calibrated against the low-scatter facility to provide a free-field equivalent result.

Dosimetry Proficiency Testing

Scope

PNNL provides proficiency testing in accordance with ANSI/HPS N13.11 for whole body dosimetry and ANSI/HPS N13.32 for extremity dosimetry.  This testing supports laboratory accreditation requirements (such as for the National Voluntary Laboratory Accreditation Program), administered by the National Institute of Standards and Technology (NIST).

Four test sessions are conducted each year to address the testing of passive dosimetry (whole body and extremity) as well as electronic and hybrid dosimetry.

Proficiency Testing Schedule

How to get started with Proficiency Testing

To get your proficiency testing process started, visit the NIST website to obtain instructions for applying for accreditation. The National Voluntary Laboratory Accreditation Program page provides links to instructions, application forms, registration documents, NIST Handbooks, and much more.

For shipping, please be sure to identify No PO in the address below to assure expedited delivery.

Dosimeters-for NVLAP Proficiency Testing

ATTN: Andy Maine, NVLAP
Battelle for the US DOE
No PO
790 6th Street
Richland, WA 99354

For electronic dosimeter shipping instructions, visit our “Doing Business” page.

*We request that you provide PNNL with a copy of your registration 3 months in advance of the start of your testing. This allows us time to receive the information from you that we need and provide you with the information that you need from us, make sure there is a contract in place to conduct the work, etc. Once you have provided us with a copy of your registration documents, you will be in the queue to receive the quarter’s information and testing packet approximately 1 month prior to the start of your testing. The information and testing packet contains the schedule of due dates for the testing quarter, shipping instructions, data reporting instructions, and the barcode stickers required for submittal. Please contact us if you have any questions about scheduling or registration.

Calibration of Transfer Standards and Other Specializes Measurements

PNNL provides radiological calibration and measurement resources for various types of photon, neutron, and beta-sensitive radiation measurement equipment. Such calibrations/measurements may satisfy a variety of purposes for clients. Most often, they enable the:

• Establishment of measurement traceability
• Provide a system for evaluating measurement traceability
• Evaluate a provider's service or vendor's product
• Enable the evaluation of unique radiological conditions

Typical examples include the following:

• Reference Class Air-Ionization Chambers
• Condenser Chambers
• Extrapolation Chamber Beta Standards
• Beta/Gamma Survey Instruments
• Neutron Survey Instruments
• Dosimeters (electronic and passive)

Establishment of measurement traceability:

PNNL provides NVLAP-accredited calibration (lab code 105020-0) of the client’s suitable transfer standards to establish traceability of in-house photon, beta, and neutron "reference fields." The suitability of transfer standards depends upon the particular application but can range from a precision (reference class) cavity air ionization chamber to a passive, solid-state dosimeter (e.g., TLD). The transfer standard and appropriate reference field are determined via interaction with the client. It is possible that for some efforts in this category, work outside of PNNL's NVLAP-accredited (lab code 105020-0) scope may be necessary. It is therefore, highly important for the client to clearly state and have knowledge of their need for "accredited" service. Once the calibration and/or measurement effort is clearly determined, the client submits the standard to PNNL for calibration. The calibration is performed, and a "report of calibration (or test)" is prepared for submission to the client.

Provide a system for evaluating in-house measurement traceability:

PNNL can provide an intercomparison capability for radiological calibration facilities. Such intercomparisons provide a mechanism to improve calibration and characterization capabilities and to confirm consistency on a periodic basis. This capability can be tailored to the client's specific needs. PNNL offers the provision of several reference instruments and beta source sets to laboratories wishing to confirm their internal measurement capabilities. As an alternative, a "verification" format may also be implemented in which the client submits a "calibrated" artifact (electronic dosimeter, survey instrument, etc.) that would then be verified (as-found calibration) in PNNL's reference field of the client's choosing.

For this interaction, PNNL provides a "report of calibration" for the measurement. The client may wish to treat this interaction as a proficiency evaluation; however, it is left to the client to verify the "constancy" of the artifact prior to departure for and upon its return from PNNL to assure its stability throughout the process of transportation and measurement at PNNL.

Evaluate a provider's service or vendor's product:

Analogous to our provision of the client's in-house confirmation capability, PNNL provides a means for independent testing of vendor-provided instrument calibration and/or personnel dosimetry services. The most common implementation of this activity is via the provision of irradiated "blind spike" passive dosimeters; however, this may also be applied to the attainment of offsite instrument calibrations in which a periodic independent check is desired.

NOTE: Vendors may implement comprehensive, independent verification protocols. To avoid duplication of effort and cost, the potential client should consult with their provider(s) of services to identify such efforts.

Enable the evaluation of unique radiological conditions:

Occasionally, the energy or geometry characteristics of radiological fields are outside of the normal design parameters or previously evaluated range of an instrument or dosimeter device. With the various radiological sources, X-ray reference fields, characterization/calibration standards, and modeling capabilities available at PNNL, investigation of detector performance in a variety of situations is possible.

Survey Instruments

PNNL provides radiological calibrations of various radiation detection instruments, including neutron and gamma-sensitive dose rate instruments and contamination survey instruments. Instruments may be calibrated for use as survey instruments or as transfer standards. Transfer standard calibrations fall within the scope of the NVLAP-accredited laboratory (lab code 105020-0).

Survey instrument calibrations do not include a full uncertainty analysis and are typically calibrated to within ±10% of the conventionally true value. Survey instrument calibrations are traceable to the National Institute of Standards and Technology (NIST) and are compliant with ANSI N323.

Transfer standard instrument calibrations include a full uncertainty analysis, are calibrated to a tighter tolerance (typically ± 2% of the conventionally true value), and are traceable to NIST.

Survey instrument calibrations are available through the Radiological Calibration Laboratory, which can be contacted at (509)375-7300. Transfer standard calibrations are available through Calibration Research and Accreditation, which can be contacted at (509)375-7330.