Detecting and characterizing special nuclear material for nuclear nonproliferation applications.

Area of Science:

• Nuclear Engineering
• Nuclear Security
• Applied Physics

Background:

• There is a critical need for advanced instrumentation and techniques for the detection and characterization of special nuclear material (SNM), such as highly enriched uranium and plutonium.
• Developing and validating these technologies requires experimental data from SNM itself, which is often scarce and highly controlled.

Purpose of the Study:

• To evaluate novel instruments and methodologies for detecting, characterizing, and localizing SNM.
• To demonstrate the efficacy of prototype detection systems using unclassified, kilogram-quantity SNM objects.

Main Methods:

• Experiments were conducted at the National Criticality Experiments Research Center using prototype detectors and techniques.
• Passive detection and imaging of plutonium and uranium were performed using gamma-ray and dual particle (fast neutron and gamma-ray) imaging.
• Active interrogation of uranium was analyzed through delayed neutron emissions using a neutron generator.

Main Results:

• Successful detection and characterization of SNM samples with masses ranging from 3.3 to 13.8 kg were achieved.
• New results in passive imaging of plutonium and uranium objects were presented.
• A novel analysis of delayed neutron emissions during active interrogation of uranium was demonstrated.

Conclusions:

• The developed prototype detection systems show promise for SNM detection and characterization.
• The experimental findings support the advancement of technologies for nuclear material monitoring and verification.
• Further research and development are warranted to enhance SNM detection capabilities.