Security: Nuclear Forensics Reference Material (RM) Program

Summary

The Countering Weapons of Mass Destruction Office CWMD, within U.S. Department of Homeland Security (DHS), is mandated to enhance the U.S. Government's knowledge and capabilities regarding the forensic examination of pre-detonation radiological and nuclear materials. This materials forensics program supports Homeland Security through the development and maintenance of an enduring national capability to conduct comprehensive, accurate, and timely forensic analysis of those materials. One mission area of the Pre-detonation Materials Capability Development is the creation of necessary reference standards.

Whether it is interdicted nuclear material or material collected after detonation of an improvised nuclear device (IND), the goal of a nuclear forensics investigation is to determine “who is responsible”. Any analyses performed to help constrain possible sources of material or responsible parties need to be highly reliable—especially as prosecution, policy, or even retaliation decisions depend upon the right answer. In general, any measurement is only as good as the reference material (RM) used to calibrate the measurement. In other words, a primary component in highly reliable analytical work is the existence of well-constrained RMs for the purposes of instrument calibration, measurement evaluation, and method development. Many of the measurements associated with nuclear forensics, however, are relatively new and non-routine. Therefore, new nuclear forensic reference materials (NFRMs) are needed to provide the traceability, precision, and accuracy that will assure the scientific and legal integrity of existing analytical capabilities and allow for development of improved capabilities.

Description

NIST coordinates the production and characterization of nuclear forensics reference materials (NFRMs), which are vital for making precise and accurate measurements of nuclear materials. These materials will help ensure that measurements of nuclear material evidence are highly reliable, are traceable, and will withstand legal scrutiny. 

Completed Projects:

• Peruvian Soil II spiked with various radionuclides
• ²⁴⁴Pu, ²³³U, ²⁴³Am, ²⁴¹Pa, and ²²⁹Th high purity isotopic tracers and calibration materials
• Cs-Ba radiochronometer NFRM
• Trace elements in bulk U oxide NFRM
• Trace actinides in bulk Pu oxide NFRM

Current projects:

• ¹³⁴Ba isotopic tracer for improved radiochronometric measurements
• Surrogate Post-Detonation Urban Debris (SPUD) SRM 4600 with natural U and SRM 4601 with enriched ²³⁸U
• Trace elements in bulk Pu oxide

Future Aims:

• Expand measurement capability for both atom-counting (isotopic ratio mass spectrometry) and decay counting
  • State of the art multi-collector mass spectrometry
  • Calorimetric spectrometry (could become new radioactivity standard)
• Expand reference material capabilities, including
  • Particle NFRMs—composition, shape, and size
  • Neptunium NFRMs
  • Isotopic RMs ²⁴³Am/²⁴¹Am and ²³⁰Th/²³²Th
• Improve fundamental decay data relevant to nuclear forensics