G. L. Silver

Rearrangement equations for plutonium

The percents of all oxidation states produced by Pu disproportionation, including unreacted starting material, can be obtained by new equations that are easy to apply. The equations are useful for quantifying the extent and the stoichiometry of disproportionation, the consequences of complexation, and the effects of temperature changes on the composition of the oxidation-state mixture.

Triple-point analysis for estimating a plutonium hydrolysis constant

Six discrete formulas are used to estimate the equilibrium constant of the first hydrolysis reaction of tetravalent plutonium. They apply the pH, the oxidation number, one equilibrium constant, and fractions of two of the plutonium oxidation states. The new formulas are not restricted to the equilibrium condition.

Plutonium oxidation states in seawater

Studies of the oxidation-state distribution of plutonium in the ocean illustrate the need to characterize seawater by means of the pH, the E(H), and quanititative complexation parameters. The parameters are combined in an easy-to-use equation that determines the fractions of the four oxidation states. Similar analyses have been applied to plutonium in other solutions, and the same methods can be applied to seawater. An appendix shows how to estimate and interpret the alpha coefficient for tetravalent plutonium using published information for tetravalent thorium.

The Method of Roots and New Latin Square Equations

* - Work was performed under the auspices of the Los Alamos National Laboratory, operated by the University of California for the U.S. Department of Energy under contract W-7405-ENG-36.A new method for interpolating the four-point rectangle is illustrat..

Work and disproportionation for aqueous plutonium.

The relation of two plutonium work integrals has recently been illustrated. One of the integrals applies to the work of disproportionation of tetravalent plutonium in 1 M acid and the other to the work of oxidation of plutonium from the trivalent to a higher oxidation state. This paper generalizes the disproportionation work integral so that it can be applied to tetravalent plutonium at any acid concentration. An equation is provided that can be used to verify work estimations obtained by integration. It applies to oxidation and disproportionation processes and it is easy to use.

Environmental plutonium: The curious case of seawater

A method for quantitatively estimating the fractions of plutonium oxidation states that derive from disproportionation, or other oxidation-reduction reactions, is illustrated with data for seawater. The results agree with experiment and can be checked numerically. Attention is drawn to a discrepancy in what we think is known about seawater.

Plutonium: verification of comprehensive disproportionation equations

Equations representing disproportionation reactions should be numerically verifiable. Comprehensive, balanced equations for plutonium disproportionation reactions can be verified in several ways. Overall equations for Pu disproportionation reactions do not meet all the requirements.

Bayesian Estimation of Reliability for Batches of High Reliability Single-Use Parts

ABSTRACT When batches of critical, very high-reliability single-use parts are being produced, rigorous testing is often required to qualify the parts and allow them to be used by the customer. Frequentist and Bayesian approaches are described for predicting the reliability of the remaining subset of the batch, conditional on all of the other tested parts working correctly. Answers from different methods are compared, their strengths and weaknesses are considered, and their robustness to initial assumptions are examined. Some related questions are explored to consider the impact on reliability from different choices of the relative number of the tested and sale units, and the condition for passing the batch from both the manufacturers and customers’ points of view. We describe the approach in the context of automotive air bag inflation devices on most vehicles, but the approach is relevant to batches of single-use parts that have a very high requirement for reliability and must be destructively tested.

Least-squares estimations of the first hydrolysis constant of Pu(IV)

The numerical value of the first hydrolysis constant of tetravalent plutonium is uncertain by a factor of about ten. This article illustrates the estimation of that constant by a least squares method applied to simultaneous equations involving all of the Pu oxidation states.

Ambiguous and forbidden parameter combinations for aqueous plutonium

The concepts of forbidden and ambiguous oxidation-state distributions for plutonium are easier to understand when presented graphically. This note describes two diagrams that illustrate the phenomena.