Counting system for field determination of radium-226 in soils

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:5292311

Minnema, D M; Rarrick, H L; Brewer, L W

A counting system has been developed to determine the Radium-226 content of soils in core barrel samplers either on or near uranium mill tailings piles. More than 3000 samples have been counted to determine the Ra-226 activity of tailings and of soils beneath the tailings. Minimum detectable activity is about two pCi Ra-226/gm of soil in a 0.5 mr/hr background with a three minute count. The counting system consists of a 136 kg lead shield, a 5 cm x 2.5 cm NaI crystal coupled to a photomultiplier tube, a preamplifier and amplifier, and two single channel analyzers (SCAs). The window on one SCA is set to pass gamma energies between 150 KeV and 380 KeV. To determine contribution of Th-232 daughters the second SCA is set to pass gamma rays between 225 and 260 KeV. The counts from the two SCAs, a standard source and background are entered into a programmable printing calculator to perform the necessary calculations. The system is mounted in a delivery van. Power is supplied by a 500 W gasoline-powered generator. This system operated reliably under field conditions for over nine months in temperatures from below freezing to over 40/sup 0/C. Approximate cost of the system excluding vehicle is $8000. Problems concerning sampling, calibration, radiation standards, statistical analysis and operational difficulties and the solutions to these problems will be discussed.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 5292311
• Report Number(s): SAND-82-0287C; CONF-820655-2; ON: DE82016809
• Country of Publication: United States
• Language: English

Related Subjects

053000* -- Nuclear Fuels-- Environmental Aspects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
440101 -- Radiation Instrumentation-- General Detectors or Monitors & Radiometric Instruments
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
510301 -- Environment
Terrestrial-- Radioactive Materials Monitoring & Transport-- Soil-- (-1987)
54 ENVIRONMENTAL SCIENCES
ABANDONED SITES
ALKALINE EARTH ISOTOPES
ALPHA DECAY RADIOISOTOPES
CALIBRATION
COST
COUNTING CIRCUITS
COUNTING TECHNIQUES
DATA
DESIGN
DETECTION
DISCRIMINATORS
ELECTROMAGNETIC RADIATION
ELECTRONIC CIRCUITS
ELEMENTS
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FEED MATERIALS PLANTS
GAMMA DETECTION
GAMMA RADIATION
HEAVY NUCLEI
INDUSTRIAL PLANTS
INFORMATION
IONIZING RADIATIONS
ISOTOPES
LEAD
MEASURING INSTRUMENTS
METALS
MILL TAILINGS
MONITORING
NAI DETECTORS
NUCLEAR FACILITIES
NUCLEI
NUMERICAL DATA
PULSE CIRCUITS
PULSE DISCRIMINATORS
RADIATION DETECTION
RADIATION DETECTORS
RADIATION MONITORING
RADIATIONS
RADIOISOTOPES
RADIUM 226
RADIUM ISOTOPES
SAMPLING
SCINTILLATION COUNTERS
SHIELDING
SOILS
SOLID SCINTILLATION DETECTORS
SOLID WASTES
TAILINGS
WASTES
YEARS LIVING RADIOISOTOPES