[en] Diffractive deep-inelastic scattering events observed at the HERA electron-proton collider are interpreted as an interaction involving a virtual photon scattering off a colour-singlet state within the proton. Models which attempt to describe the colour-singlet exchanged in diffractive interactions range from the purely phenomenological Donnachie-Landshoff form factor approach to the QCD-motivated gluon-exchange models and the scalar-pomeron model. It is important to find ways to test these models. In this thesis colour-singlet exchange models of diffractive DIS are compared with cross section and structure function data from the H1 detector. H1 select diffractive data by requiring there to be a large angle between the forward proton direction and any other significant detector activity. This pseudo-rapidity gap cut extracts colour-singlet exchange events from the standard DIS data sample. For a wide range of the parameter space covered by the HERA experiments, however, the pseudo-rapidity gap cuts restrict the final-state phase space available for diffractive scattering. One consequence is that pseudo-rapidity gap cuts can be used to select diffractive events in which the colour-singlet only couples to off-shell partons. To leading order in the strong coupling constant, the diffractive final state consists of a quark-antiquark pair. Higher-order events include diffractive production of quark-antiquark-gluon states. In the region where pseudo-rapidity gap cuts restrict the accessible phase space, the cuts reject low transverse momentum quark-antiquark diffractive events. Pseudo-rapidity gap data selection cuts also allow selection of an enhanced 3-jet data sample. The structure function and transverse momentum distribution data can be described by either a two-gluon model or by the Donnachie-Landshoff model, both models requiring a significant contribution from quark-antiquark-gluon diffractive final states to fit the full kinematic range of the diffractive data. Further experiments and analyses are suggested to refine the studies of diffractive DIS and colour-singlet exchange models. (author)

[en] This technical basis document was developed to support the Tank Farms Documented Safety Analysis (DSA) and describes the risk binning process and the technical basis for assigning risk bins for the tank bump representative accident and associated hazardous conditions. The purpose of the risk binning process is to determine the need for safety-significant structures, systems, and components (SSC) and/or technical safety requirement (TSR)-level controls for a given representative accident or represented hazardous conditions based on an evaluation of the frequency and consequence. Note that the risk binning process is not applied to facility workers, because all facility worker hazardous conditions are considered for safety-significant SSCs and/or TSR-level controls. Determination of the need for safety-class SSCs was performed in accordance with DOE-STD-3009-94, ''Preparation Guide for US Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports'', as described in this report

[en] This report documents the accident analyses and nuclear safety control options for use in Revision 7 of HNF-SD-WM-SAR-062, ''K Basins Safety Analysis Report'' and Revision 4 of HNF-SD-SNF-TSR-001, ''Technical Safety Requirements - 100 KE and 100 KW Fuel Storage Basins''. These documents will define the authorization basis for Sludge Water System (SWS) operations. This report follows the guidance of DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Safety Analysis Reports'', for calculating onsite and offsite consequences. The accident analysis summary is shown in Table ES-1 below. While this document describes and discusses potential control options to either mitigate or prevent the accidents discussed herein, it should be made clear that the final control selection for any accident is determined and presented in HNF-SD-WM-SAR-062

[en] Radiological and toxicological consequences are calculated for 4 postulated accidents involving the Waste Feed Delivery (WFD) diluent addition systems. Consequences for the onsite and offsite receptor are calculated. This analysis contains technical information used to determine the accident consequences for the River Protection Project (RPP) Final Safety Analysis Report (FSAR)

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[en] The purpose of this analysis is to compare the consequences of an 8 molar NaNO2 spray leak to the Tank Farm Final Safety Analysis Report (FSAR) evaluation of sprays of up to 19 molar (50%) NaOH. Four conditions were evaluated. These are: a spray during transfers from a one-inch pipe, a spray resulting from a truck tank Crack, a spray resulting from a truck tank rupture, and a spray in the 204-AR Waste Unloading Facility

[en] A large volume of aluminum contaminated with uranium of varying percentages of ²³⁵U is being generated from scrap as a result of the uranium enrichment Cascade Improvement and Uprating programs. A rapid analytical method for determining uranium isotopic content in the ingots is necessary to insure compliance with existing and proposed Federal regulations. Gamma spectroscopy has been shown to be reliable in determining the ²³⁸U, ²³⁵U, and ²³⁷Np contents in the aluminum scrap. The lower limits of detection for a 1024 second count interval are 15 ppM of natural uranium and 5 ppB of ²³⁷Np

[en] A large volume of radioactively contaminated nickel is being generated from scrap as a result of the Cascade Improvement and Uprating programs of the ERDA gaseous diffusion plants. With appropriate conditions, melting of the scrap reduces the contaminating radioactive isotopes of uranium, ²³⁷Np and ²³⁹Pu below 3 ppM, 1 x 10^-3 ppM and 1 x 10^-5 ppM, respectively. The fission product nuclide, ⁹⁹Tc, is not removed in the melting process. It has been shown that bremsstrahlung produced from beta emissions is a reliable measure of the concentration of ⁹⁹Tc. The lower limit of detection is estimated to be 100 ppb +- 50 ppb with a Ge(Li) detector. A count time of five minutes is sufficient to determine a concentration of 5 ppM +- 1 ppM. It has also been shown that ²³⁵U and ²³⁷Np can be determined to be less than 3.5 ppM and 1 x 10^-3, respectively by gamma spectroscopy techniques in samples containing traces of ⁹⁹Tc

[en] The phenomenology of hydride formation has been summarized for Group IVa, Va, Y and several hexagonal rare earth metals. The large volume change which accompanies hydride formation has an effect on the habit plane and kinetics of formation as is discussed. A rationale for the influence of alloying elements on hydride habit plane is also presented. This rationale is related to the requirement for plastic punching to accommodate the volume change. The influence of hydride formation on ductility loss during fracture is examined and the mechanism of embrittlement is discussed. Lastly, the occurrence of sustained load cracking is briefly described and the possible role of hydrogen in this process is discussed