Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Radiological Traceability Program (RTP)

Summary

Quality Assurance (QA) is a mission critical tool for quantitatively assessing the performance of laboratories. The performance of individual labs for specific measurements is determined by the use of a proficiency test. Results reported by labs are compared to a reference value for the given sample (measurand) and the laboratory’s performance is evaluated to aid in performance improvement. NIST coordinates three PT programs (NRIP, RTP, and BSAP) that target laboratories that perform measurements in support of the Nuclear Defense Spectrum.

Description

The Radiological Traceability Program (RTP) is a Proficiency Testing (PT) program that establishes traceability for the Radiological and Environmental Sciences Laboratory (RESL) to the National Institute of Standards and Technology (NIST).

RESL is the designated reference laboratory for DOE and the Nuclear Regulatory Commission (NRC) Radiological Measurement Assurance Program (RMAP).  As defined in ANSI N42.23-1996, RESL serves as a secondary reference laboratory to NIST and maintains direct traceability to NIST through this RTP.  In this role, DOE has authorized RESL to prepare and distribute PT materials in a variety of sample matrices to laboratories that perform radiochemical analyses of environmental, bioassay, and other samples.  

The RTP provides an annual exchange of PT materials between NIST and RESL.  It is designed to provide a mechanism for evaluating the ability of RESL scientists to prepare PT materials containing known activities of various radionuclides (Table 1), and to analyze materials of unknown activities.  

The objective of the Program is to conduct measurement traceability evaluations of the DOE RESL Reference Laboratory consistent with ANSI N13.30, N42.22 and N42.23. The RTP consists of two performance parts:

  1. NIST prepares PT materials to be analyzed by RESL, evaluates RESL’s analytical results, and issues a Report of Traceability of Characterization of Materials Containing Radionuclides for the following matrices:
    1. synthetic urine,
    2. vegetation,
    3. water samples.
    4. synthetic feces,
    5. air filters, 
    6. soil samples.
  2. NIST performs verification measurements on PT samples prepared by RESL and compares RESL’s values with the experimental results generated by NIST, and issues a Report of Traceability for Preparation of Performance Evaluation Material

The natural background activity contained in the sample matrix is subtracted from all analytical measurements.  The result reported to NIST represents the activity added by NIST, not the total activity contained in the sample.  

NIST certifies the radionuclide activities by propagating the uncertainties of the Standard Reference Material (SRM) and sample preparation. The uncertainty of the activity of the SRM and subsequent dilutions is required to be <1.5% (k=1).  The natural background activity contained in the sample matrix will be subtracted from all analytical measurements.  The result reported to NIST will represent the activity added by NIST, not the total activity contained in the sample.  

Table 1. Matrix, Radionuclides, Activity Ranges and Sample Size for RTP (NIST Samples Sent to RESL)

Matrix

Radionuclides

Activity Range

Synthetic Fecal

 

Mixture of Alpha Emitting Radionuclides (230Th, 238U, 234U, 237Np, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0 Bq/sample

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10 Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn,57Co, 65Zn)

10-100 Bq/sample

Glass Fiber Filters

Mixture of Alpha Emitting Radionuclides (238U, 234U, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0  Bq/sample

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10  Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn, 57Co, 65Zn)

10 – 100  Bq/sample

Soil

 

Mixture of Alpha Emitting Radionuclides (238U, 234U, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0 Bq/sample

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10 Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn,57Co, 65Zn)

0.1 – 1.0 Bq/g

Synthetic Urine

 

Mixture of Alpha Emitting Radionuclides (230Th, 238U, 234U, 237Np, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0  Bq/sample

Pure Beta Emitting Radionuclide  3H

1 –10 Bq/g

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10  Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn, 57Co, 65Zn)

10-100 Bq/sample

Vegetation

 

Mixture of Alpha Emitting Radionuclides (238U, 234U, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0  Bq/sample

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10  Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn,57Co, 65Zn)

10-100 Bq/sample

Water

 

Mixture of Alpha Emitting Radionuclides (238U, 234U, 238Pu, 239/240Pu, 241Am)

0.1 – 1.0 Bq/sample

Pure Beta Emitting Radionuclide  3H

1 – 10 Bq/g

Pure Beta Emitting Radionuclides  90Sr/90Y

1 – 10 Bq/sample

Isotopically Pure Radionuclide 125I or 131I

100-2000 Bq/sample

Mixture of Gamma Emitting Radionuclides (137Cs, 134Cs, 60Co, 54Mn, 57Co, 65Zn)

10-100 Bq/sample

nuclear defense spectrum
This chart shows the NIST Homeland Security programs that support the Nuclear Defense Spectrum. Those programs are: Nuclear Forensics Reference Materials, Proficiency Testing programs (RTP, NRIP, BSAP), Natural Matrix Standard Reference Materials, and Radiation Detection Documentary Standards.

Created September 19, 2016, Updated July 18, 2017