This report provides the results of the semiannual post-closure inspections conducted at the closed Corrective Action Unit (CAU) sites located on the Tonopah Test Range (TTR), Nevada. This report covers calendar year 2006 and includes inspection and repair activities completed at the following nine CAUs: CAU 400: Bomblet Pit and Five Points Landfill (TTR); CAU 404: Roller Coaster Lagoons and Trench (TTR); CAU 407: Roller Coaster RadSafe Area (TTR); CAU 423: Area 3 Underground Discharge Point, Building 0360 (TTR); CAU 424: Area 3 Landfill Complexes (TTR); CAU 426: Cactus Spring Waste Trenches (TTR); CAU 427: Area 3 Septic Waste Systems 2, 6 (TTR); CAU 453: Area 9 UXO Landfill (TTR); and CAU 487: Thunderwell Site (TTR). Post-closure inspections were conducted on May 9, 2006, May 31, 2006, and November 15, 2006. All inspections were conducted according to the post-closure plans in the approved Closure Reports. The post-closure inspection plan for each CAU is included in Attachment B, with the exception of CAU 400. CAU 400 does not require post-closure inspections, but inspections of the vegetation and fencing are conducted as a best management practice. The inspection checklists for each site inspection are included in Attachment C, the field notes are …

Corrective Action Sites (CASs) and Corrective Action Units (CAUs) at the Tonopah Test Range (TTR) may be placed into three categories: Clean Closure/No Further Action, Closure in Place, or Closure in Progress.

Measurements were performed with a single annular, stainless-steel-canned casting of uranium (93.17 wt% 235U) metal ( ~18 kg) to provide data to verify calculational methods for criticality safety. The measurements used a small portable DT generator with an embedded alpha detector to time and directionally tag the neutrons from the generator. The center of the time and directional tagged neutron beam was perpendicular to the axis of the casting. The radiation detectors were 1x1x6 in plastic scintillators encased in 0.635-cm-thick lead shields that were sensitive to neutrons above 1 MeV in energy. The detector lead shields were adjacent to the casting and the target spot of the generator was about 3.8 cm from the casting at the vertical center. The time distribution of the fission induced radiation was measured with respect to the source event by a fast (1GHz) processor. The measurements described in this paper also include time correlation measurements with a time tagged spontaneously fissioning 252Cf neutron source, both on the axis and on the surface of the casting. Measurements with both types of sources are compared. Measurements with the DT generator closely coupled with the HEU provide no more additional information than those with the Cf source …

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The key to being able to operate the MICE superconducting solenoids on small coolers is the use of high temperature superconducting (HTS) leads between the first stage of the cooler and the magnet, which operates at around 4.2 K. Because MICE magnets are not shielded, all of the MICE magnets have a stray magnetic field in the region where the coolers and the HTS leads are located. The behavior of the HTS leads in a magnetic field depends strongly on the HTS material used for the leads and the temperature of the cooler first stage temperature. The HTS leads can be specified to operate at the maximum current for the magnet. This report shows how the HTS leads can be specified for use the MICE magnets. MICE magnets take from 1.3 hours (the tracker solenoids) to 3.7 hours (the coupling magnet) to charge to the highest projected operating currents. If the power fails, the cooler and the upper ends of the HTS leads warm up. The question is how one can discharge the magnet to protect the HTS leads without quenching the MICE magnets. This report describes a method that one can use to protect the HTS leads in the …

These carefully performed and documented measurements with unreflected and unmoderated highly enriched uranium (HEU) castings can be used to benchmark calculational methods for the time decay of the fission chain multiplication process as measured with small (1 x 1 x 6 in. thick plastic scintillators with 1/4-in.-thick lead on all detector surfaces) detectors adjacent to the tightly fitting stainless steel cans that contained the HEU ({approx}93 wt%) metal. Prompt time decay measurements were performed stimulating the fission chain multiplication process with a timed, tagged Cf spontaneous fission source that emitted fission-spectrum neutrons and a time and directionally tagged 14.1-MeV neutrons from the DT reaction in a steady state generator with an embedded alpha detector. Time decay measurements were performed with HEU masses varying from 18 to 90 kg for a wide variety of source-detector-casting configurations. The use of a DT generator provided no addition information about the fission chain behavior beyond that provided by a time-tagged Cf spontaneous fission source. The main quantities obtained in the measurements were (1) the time distribution of the counts in a detector after a neutron fission in the Cf source or after the alpha detection coincident with the emission of a neutron from the …

The Nevada Test Site Environmental Report 2006 (NTSER) was prepared to meet the information needs of the public and the requirements and guidelines of the U.S. Department of Energy (DOE) for annual site environmental reports. It was prepared by National Security Technologies, LLC (NSTec). This Executive Summary presents the purpose of the document, the major programs conducted at the Nevada Test Site (NTS), NTS key environmental initiatives, radiological releases and potential doses to the public resulting from site operations, a summary of nonradiological releases, implementation status of the NTS Environmental Management System, a summary of compliance with environmental regulations, pollution prevention and waste minimization accomplishments, and significant environmental accomplishments. Much of the content of this Executive Summary is also presented in a separate stand-alone pamphlet titled Nevada Test Site Environmental Report Summary 2006 produced to be a more cost-effective means of distributing information contained in the NTSER to interested DOE stakeholders.

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File Part 2 of 10 (Comprises Appendices C through O, Library Distribution List, and Geophysics Data Images