Nondestructive Quantitative Analysis of Difficult-to-Measure Radionuclides ¹⁰⁷Pd and ⁹⁹Tc

Area of Science:

• Nuclear Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Nuclear waste management requires accurate analysis of challenging nuclides like palladium-107 (¹⁰⁷Pd).
• ¹⁰⁷Pd is difficult to measure due to its lack of decay gamma rays and extremely long half-life.
• Spent nuclear fuel reprocessing generates complex mixtures, including Technetium-Platinum Group Metals (Tc-PGMs).

Purpose of the Study:

• To design and evaluate a nondestructive analytical scheme for measuring difficult-to-detect nuclides in nuclear waste.
• To specifically address the challenge of quantifying ¹⁰⁷Pd in simulated Tc-PGM samples.
• To assess the capabilities of prompt gamma-ray analysis (PGA), neutron resonance capture analysis (NRCA), and TOF-PGA for nuclear waste analysis.

Main Methods:

• Development of a sophisticated instrument combining Ge detectors, time-of-flight (TOF) measurement of neutrons, and a high-intensity pulsed neutron beam.
• Simultaneous application of TOF-coupled PGA (TOF-PGA), PGA, and NRCA.
• Analysis of simulated Tc-PGM samples derived from spent nuclear fuel partitioning.

Main Results:

• PGA and NRCA can accurately analyze individual nuclides but struggle with complex mixtures.
• Time-of-flight-coupled prompt gamma-ray analysis (TOF-PGA) successfully quantified both ¹⁰⁷Pd and ⁹⁹Tc in simulated Tc-PGM samples.
• TOF-PGA demonstrated superior capability for analyzing difficult-to-measure nuclides in mixed waste streams.

Conclusions:

• The developed TOF-PGA technique is highly effective for the nondestructive analysis of ¹⁰⁷Pd and ⁹⁹Tc.
• This method offers a significant advancement for nuclear waste characterization and management.
• TOF-PGA provides a reliable solution for analyzing challenging fission products in spent nuclear fuel.