28 research outputs found
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Assessment groundwater monitoring plan for single shell tank waste management area B-BX-BY
Single Shell Tank Waste Management Area B-BX-BY has been placed into groundwater quality assessment monitoring under interim-status regulations. This document presents background and an assessment groundwater monitoring plan to evaluate any impacts of risks/spills from these Single Shell Tanks in WMA B-BX-BY on groundwater quality
Identification of new states in 26Si using the29Si(3He,6He)26Si reaction and consequences for the 25Al(p,y)26Si reaction rate in explosive hydrogen burning environments
We have studied the [Formula Presented] reaction and have identified new states in [Formula Presented] at [Formula Presented] and [Formula Presented] Based on these measurements and other recent evidence, we suggest spin-parity assignments of [Formula Presented] for the 5.678 MeV state and [Formula Presented] for the 5.945 MeV state, which would account for all the “missing” unnatural parity states in [Formula Presented] in the excitation energy region important to hydrogen burning in novae. New reaction rates are presented for the [Formula Presented] reaction based on this possible assignment of states
Unexpected Behavior of Heavy-Ion Fusion Cross Sections at Extreme Sub-Barrier Energies
The excitation function for fusion evaporation in the system was measured over a range in cross section covering 6 orders of magnitude. The cross section exhibits an abrupt decrease at extreme sub-barrier energies. This behavior, which is also present in a few other systems found in the literature, cannot be reproduced with present models, including those based on a coupled-channels approach. Possible causes are discussed, including a dependence on the intrinsic structure of the participants
Rotational bands in the proton emitter 141Ho
The rotational bands feeding the ground state and the isomeric state in the proton emitter 141Ho are presented using the recoil-decay tagging method. A quadrupole deformation of β2 = 0.25(4) was deduced for the ground state band. The observed band crossings and signature splittings agreed with the configurational assignments for the ground state and the isomer analyzed from the proton-decay rates
Alignments in the odd-proton actinides 237Np and 241Am
High spin states in 237Np and 241Am have been studied with the "unsafe" Coulomb excitation technique. In each nucleus, signature partner rotational bands built on the [523]5/2- and [642]5/2+ orbitals of respective h9/2 and i13/2 parentage have been delineated. An additional pair of bands based on the [521]3/2- (f7/2) state was also observed in 241Am. New information on the even-even 236Pu and 242Cm transfer products is also presented. From the present data, the role of i13/2 protons in generating angular momentum in the even-even nuclei of the region is documented. A satisfactory description of the evolution of the rotational sequences with spin is achieved within the framework of the cranked shell model. Nevertheless, when combined with information on odd-neutron nuclei available from elsewhere, the data highlight significant shortcomings of the available theoretical predictions
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Fate and transport of constituents leaked from Tank 241-A-105
Following a January 28, 1965 sudden steam release in Tank 241-A-105, the carbon steel liner of the tank was noted to have bulged to a maximum height of about 8.5 feet (2.6 meters). Most of this bulging likely resulted from the January 28, 1965 incident. But available data indicate that some bulging during an earlier leak in 1963 when waste was being added to the tank may have contributed. By March 8, 1965, increases in radiation in the 14-05-03 leak detection lateral indicted that fluids had escaped the tank and that the liner was ruptured. Waste was subsequently transferred from Tank 241-A-105 to other tanks, and liquid levels in Tank 241-A-105 were maintained at about 18 inches to control temperature to prevent deterioration of the concrete. Spray cooling water was added weekly to the tank from February 1971 to December 1978 to maintain liquid levels and temperatures, and some of this fluid is assumed to have leaked from the tank. This study examined available data to determine, to the extent possible, the distribution of the leaked constituents in surrounding soils and whether they migrated to groundwater. In this assessment, available data from gross gamma logging of dry wells and leak detection laterals as well as data from analyses of groundwater samples were examined throughout the period of interest. Logs of wells and photographs taken during construction of the 241-A-105 Tank Farm were also examined
A Testpart for Interdisciplinary Analyses in Micro Production Engineering
In 2011, a round robin test was initiated within the group of CIRP Research Affiliates. The aim was to establish a platform for linking interdisciplinary research in order to share the expertise and experiences of participants all over the world. This paper introduces a testpart which has been designed to allow an analysis of different manufacturing technologies, simulation methods, machinery and metrology as well as process and production planning aspects. Current investigations are presented focusing on the machining and additive processes to produce the geometry, simulation approaches, machine analysis, and a comparison of measuring technologies. Challenges and limitations regarding the manufacturing and evaluation of the testpart features by the applied methods are discussed