Analytical NDA Techniques at Laboratories

Some of the NDA verification techniques on samples of nuclear material taken during a safeguards inspection are carried out at specialized analytical laboratories, for example, the Safeguards Analytical Laboratory (SAL) at Seibersdorf in Austria or the On-Site Laboratory (OSL) at the Rokkasho Reprocessing Plant in Japan. Commercially available and customer-specific equipment is used to determine amounts and isotopic compositions of plutonium and uranium in inspection samples, having various chemical and physical forms, to supplement or replace destructive analysis. A parallel analysis of one and the same sample by NDA and DA serves the quality assurance of the analytical methods and control of the results. 

The hybrid K-edge densitometry (HKED) at OSL is the main instrument to analyze solutions samples firom the input accountability tank (lAT) and output accountability tank (OAT) containing U and/or Pu over a concentration range from 0.5 to 400 g/1. The KEDG-mode is applied down to 40 g/1 and the XRF-mode down to 0.5 g/1 U or Pu. Thus, the evaluation of KEDG and XRF spectra of a sample from the lAT yields the concentration of U (KEDG alone), the U/Pu ratio (XRF alone), and the Pu concentration (KEDG and XRF combined). 

The OSL Alpha Spectrometer (OSAS) estimates plutonium in diluted solutions containing less than 10 mg/1 of plutonium. An a-source can be made from the sample through a simplified 

The OSL-curium neutron analyzer (OSCA) is a neutron coincidence counter that measures in solutions. At OSL, the system is integrated within a Hybrid-K-Edge (HKED) enclosure. The OSCA associated with HKED or isotope dilution mass spectrometry (IDMS) will provide analytical data to establish the Cm/Pu and Cm/U ratios in lATsolutions or in high active liquid waste solutions. 

The OSL-density meter (OSDM) measures the density of solutions to estimate accurately the mass of a solution contained in a sampled vessel/container. OSDM measures the frequency of an oscillating tube filled with the solution sample. The instrument is calibrated by measuring the frequency of oscillation using air, water, or liquid density standards. A sample solution is injected, or drawn, into the temperature-stabilized tube and a built-in computer automatically converts the frequency measurement into a density reading. 

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