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Waste Management Radioactive Shipments4.2 TECHNIQUES AND TRAINING . As the need for production of special nuclear materials for defense purposes diminished and long-time Hanford workers began to retire, the decision was made to document Hanford's experience with portable health physics instruments while the resources to do so were still available. In 1989, only a few health physics instrument specialists, radiation technicians and health physicists who worked at Hanford in the late 1940s still live in the vicinity. Of these, even fewer were available to assist in developing and reviewing this document. From those few, a team was selected and the document was developed. Most of the information about the instruments and their use and maintenance was obtained from the files of people who participated in the instrument program, and from the team of authors, who have a combined Hanford experience of over 200 man-years. To the degree possible, this review is presented chronologically to relate the changes in development and in practices for use in routine Hanford operations. Initial Techniques Technique Changes and Bases Records Generation Applications to Radiation Control SCOPE OF DOCUMENTSection 2.0 of this document summarizes the conclusions made concerning Hanford's portable health physics instruments and the users over a period of 45 years. Section 3.0 describes most of the instruments used during the past 45 years and provides some insight on how they work and how changes evolved. Section 4.0 discusses 1) typical instrument operation and maintenance in various types of facilities and 2) training and requirements for control of radioactive materials. Section 5.0 focuses on calibration and maintenance of health physics instruments over the past 45 years. It also provides some comparative instrument calibration data between older and newer instruments. Section 6.0 discusses the records that are generated for portable health physics instruments. Section 7.0 provides the conclusions reached by the authors of this document, and Section 8.0 provides the references. The remainder of this section discusses the types of radiations measured, the units that quantify them and the media needed to detect or measure them with electronic instruments, and summarizes the history of portable instruments and the evolution of instrument usage.1.1 RADIATIONS TYPES, UNITS, AND DETECTION MEDIATo understand how instruments detect radiation, it is necessary to generally understand the penetrating capabilities of nuclear radiations, the units that quantify them, and the media needed to detect or measure them with electronic instruments. This section provides simplified explanations of these factors. Types of Nuclear RadiationThere are four common types of nuclear radiation: alpha and beta particles, gamma rays, and neutrons.Alpha particles, composed of two protons and two neutrons, are released from an atom's nucleus during radioactive decay. Because no electrons are associated with them, they have a positive electrical charge. The heavies...

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Measurements of the decomposition pressure for the reaction ThN(s) = Th(l) + VsNsCg) in the temperature range 2416 to 2790°are described. ThN melts congruently at 2790 ± 30°under a nitrogen pressure somewhat less than 1 atm. The presence of Th02 as an impurity in the ThN was found to have a large effect on the melting point and decomposition pressure. The decomposition pressure -temperature relation for pure ThN is described by the equation log p (atm.