Dalhart post shot investigation

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:6399536

Mathews, M A; Thompson, J L; Hahn, K R ^[1]; Madigan, W P; Gadeken, L L ^[2]

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1. Los Alamos National Lab., NM (United States)
2. Halliburton Logging Services, Inc., Houston, TX (United States)

The nuclear test Dalhart, U4u, was executed at a depth of 2100 ft on October 13, 1988. This test has multiple radioactive isotopes or fission products associated with it and knowledge of the distribution of these isotopes is desirable for the Nuclear Test Program. A slant post shot hole was drilled in late August 1990 to sample the geologic material from the collapsed zone or chimney above Dalhart. This 9 7/8 inch borehole was drilled at approximately 19 degrees from the vertical toward the Dalhart executive depth. This borehole started at approximately 734 ft due south of the Dalhart event. Drilling circulation was lost at a slant depth of 1030 ft (980 ft True Vertical Depth, TVD). Drilling was completed to 2280 ft (2156 ft TVD). The water level was encountered at a depth of 1063 ft (1513 ft TVD). A Halliburton 1 11/16 in diameter TracerScan gamma-ray-spectroscopy log was run inside the drill string at a speed of 10 ft/min. Spectra were obtained from TD to the surface. Radioactive material produced by the test was present from TD to 1850 ft (1746 ft TVD). Spectra were acquired at .025 ft depth intervals and averages recorded digitally every ten ft and thirty ft were displayed on the blue line log together with the total observed gamma ray and casing collar locater signal. Also a DOE high intensity gamma log was run by Atlas Wireline Services from TD to the surface. This log did not detect any radioactive activity in the hole. The gamma-ray photo peaks on the spectroscopy log were used to determine the depths for sampling with the Hunt sidewall sampling tool. Eleven samples were acquired from the depth interval 2212 ft to 1823 ft (2089 to 1721 ft TVD). None of these samples contained enough activity to be measured with normal drillback survey instruments. 7 refs., 8 figs., 3 tabs.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 6399536
• Report Number(s): LA-UR-91-2681; CONF-9108135--3; ON: DE91018023
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
450200 -- Military Technology
Weaponry
& National Defense-- Nuclear Explosions & Explosives
54 ENVIRONMENTAL SCIENCES
540230* -- Environment
Terrestrial-- Radioactive Materials Monitoring & Transport-- (1990-)
540330 -- Environment
Aquatic-- Radioactive Materials Monitoring & Transport-- (1990-)
ALKALI METAL ISOTOPES
ANTIMONY 125
ANTIMONY ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BOREHOLES
CAVITIES
CESIUM 137
CESIUM ISOTOPES
DRILL CORES
DRILLING
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
EXPLOSIONS
FISSION PRODUCTS
GAMMA LOGGING
GROUND WATER
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MASS TRANSFER
MATERIALS
NUCLEAR EXPLOSIONS
NUCLEI
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
RADIOACTIVE MATERIALS
RADIOACTIVITY
RADIOACTIVITY LOGGING
RADIOISOTOPES
RADIONUCLIDE MIGRATION
RUTHENIUM 106
RUTHENIUM ISOTOPES
SPECTRA
SUBSURFACE ENVIRONMENTS
WATER
WELL LOGGING
YEARS LIVING RADIOISOTOPES