Controlled-potential coulometric determination of plutonium

Corrections for systematic errors from analog integration in controlled-potential coulometry

“…final voltage output signal and Lit) is the signal loss due to leakage which depends upon the time, t, for a given Vf. Equations for determining the loss in the voltage output signal due to leakage for an analog integrator used in controlledpotential coulometry may be derived from a form of the capacitor discharge equation, eq 5, where V(t) is the voltage on dV dt (5) the integrating capacitor as a function of time. The correction for the leakage error requires the use of the appropriate V(t), which specifically describes the integrator charging curves in controlled-potential coulometry.…”

“…The integrator voltage output signal corrected for both leakage and offset, VL', is calculated by using eq 12. Substitution of eq Vi/ = VL -V0(f8et (12) 4 and 10 into eq 12 gives the leakage and offset correction for electrical calibration.…”

“…In application, the use of controlled-potential coulometry based on the Faraday is not simple. Many of the special considerations required for this application have been well researched: accurate corrections for background current (3,4), correction for the fraction of the sample electrolyzed within the selected potential span (5), the uncertainty in the value of the Faraday (6), and the general requirements of an integrator for controlled-potential coulometry (7,8). Although analog integrators have been designed which, in practice, are close to meeting the integration requirements, no corrections for the significant deviations from ideal integrator response in controlled-potential coulometry have been proposed.…”

The production and certification of a plutonium equal-atom reference material: NBL CRM 128

“…The observed mass spectrometer data were corrected for mass discrimination effects using data trom the analysis of uranium isotopic SRM's that had been analyzed under similar conditions, S R M 947 contains uranium and americium isotopeS, including growing-in daughters of plutonium that are isobaric with the plutonium isotopes. In addition, there may be radiation damage to the glass bottle and the teflon cap liner resulting in small glass slivers, Therefore, in it's use, a chemical separation that provides a purified plutonium fraction isessentialt9 the attainment oi high accuracy, The plutonium assays were performed by the Los Alamos National Laboratory with collaborative analysis performed at the Department of Energy, New Brunswick Laboratory, The Los Alamos National Laboratory used two titfimetry methods utilizing both photometric and potentiometric end points [I,2,3,4], The New Brunswick Laboratory used a , controlled-potential coulometric method [5,6].…”

Mass measurement uncertainty for plutonium aliquots assayed by controlled-potential coulometry

“…ISO standard 12183 ''Controlled-potential coulometric assay of plutonium,' ' [8] is based upon the measurement methodology [9] and control-potential coulometer measurement systems [10] used at the Savannah River Site's Analytical Laboratory, Aiken, SC (a contractor operated facility of U.S. Department of Energy), the U.S. Department of Energy's New Brunswick Laboratory, Argonne, IL, and the International Atomic Energy Agency's Safeguards Analytical Laboratory, Seibersdorf, Austria. This methodology and instrumentation is being implemented by the Japan Atomic Energy Agency's laboratory at the Tokai Reprocessing Plant in Tokai-mura, Japan.…”