The classical statistics approach used in health physics for the interpretation of measurements is deficient in that it does not allow for the consideration of needle in a haystack effects, where events that are rare in a population are being detected. In fact, this is often the case in health physics measurements, and the false positive fraction is often very large using the prescriptions of classical statistics. Bayesian statistics provides an objective methodology to ensure acceptably small false positive fractions. The authors present the basic methodology and a heuristic discussion. Examples are given using numerically generated and real bioassay data (Tritium). Various analytical models are used to fit the prior probability distribution, in order to test the sensitivity to choice of model. Parametric studies show that the normalized Bayesian decision level k{sub {alpha}}-L{sub c}/{sigma}{sub 0}, where {sigma}{sub 0} is the measurement uncertainty for zero true amount, is usually in the range from 3 to 5 depending on the true positive rate. Four times {sigma}{sub 0} rather than approximately two times {sigma}{sub 0}, as in classical statistics, would often seem a better choice for the decision level.

The US is developing a strategy for the disposition of surplus weapons-usable uranium-233 ({sup 233}U). The strategy (1) identifies the requirements for the disposition of surplus {sup 233}U; (2) identifies potential disposition options, including key issues to be resolved with each option; and (3) defines a road map that identifies future key decisions and actions. The disposition of weapons-usable fissile materials is part of a US international arms-control program for reduction of the number of nuclear weapons and the quantities of nuclear-weapons-usable materials worldwide. The disposition options ultimately lead to waste forms requiring some type of geological disposal. Major options are described herein.

A laser drive plate, that is a dense solid plate drive by a laser heated, lower density plasma, is inherently Raleigh-Taylor (R-T) unstable, We have previously indicated that observed surface perturbation on the plate are probably R-T instabilities, initiated by the mode structure of the driving laser beam. Using a semi- transparent impact target viewed with a polarized Epi-Illuminated Confocal Streak Microscope, has allowed us to measure the amplitude and growth of the instability.

A concern has been identified regarding the viability of redesigning and requalifying existing glovebox lines for use as glovebox lines integral to future mission activities in the 773-A laboratory building at the Savannah River Site (SRS). The Bechtel Savannah River Inc. (BSRI) design engineering team has been requested to perform an evaluation which would investigate the reuse of these existing gloveboxes versus the procurement of completely new glovebox systems. The existing glovebox lines were manufactured for the Plutonium (Pu) Metallograph Facility, Project 3253, located in building 235-F at SRS. These gloveboxes were designed as independent, fully functional Pu `metal` and Pu `oxide` processing glovebox systems for this facility. These gloveboxes, although fully installed, have never processed radioactive material. The proposed use for these gloveboxes are: (1) to utilize the Pu `metal` glovebox system for the primary containment associated with the Pre-Processing/Re-Processing Laboratory for obtaining radioactive glass compound viscometer analysis and (2) to utilize the Pu `oxide` glovebox system for primary containment associated with the Pu `Can in Can` Demonstration for proof of principle testing specific to long term Pu immobilization and storage technology. This report presents objective evidence that supports the engineering judgment indicating the existing gloveboxes can be requalified …