Determination of radon-222 in ground water using liquid scintillation counting-survey of carefree cave-creek water basin in Arizona

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:45172

Barnett, J M; McKlveen, J W ^[1]; Hood, III, W K ^[2]

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1. Arizona State Univ., Tempe, AZ (United States)
2. Arizona Department of Environmental Quality, Phoenix, AR (United States)

Well water used in homes may contribute additional {sup 222}Rn to the indoor radon concentration. Our research objectives are to establish a method to measure radon in ground water using liquid scintillation (LS) spectrometry, and to determine the lung dose from the radon released into the air. The method involves collecting a nonaerated, slow, steady flow of water from a pumping well into a 437-mi (16-oz) glass bottle. A high meniscus assures no head space, and the sample is capped. In the laboratory, standard 22-ml LS glass vials are filled with 10 ml of a toluene-based, mineral oil, LS cocktail and two 5-ml sample aliquots. The vial is capped tightly, shaken vigorously, and placed in the LS counter. Equilibrium was established in about 3.5 h, after which samples were counted for 100 min each. Only radon and daughters were measured. According to NUREG/CR-4007, the lower limit of detection is 1.9 Bq L{sup -1} (51 pCi L{sup -1}) in the window of interest. The radon progeny detection efficiency was between 320 and 330% per unit radon activity (accounting for the detection efficiency of each alpha particle and the beta continuum), and the average background was approximately 6 counts per minute. We expect that wells containing radon concentrations between 100 and 1000 Bq L{sup -1} would produce an effective dose equivalent to the lungs of 0.4 to 0.7 mSv y{sup -1} (40-70 mrem y{sup -1}). Our study of 28 wells in Carefree-Cave Creek indicates that in 25% of the wells, radon levels were over 100 Bq L{sup -1} (2700 pCi L{sup -1}). Twelve wells were chosen for monthly monitoring to ensure the efficiency of the methodology. This simple method allows us to count a large number of samples over a short time period.

• OSTI ID: 45172
• Report Number(s): CONF-901010--Pt.1
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
GROUND WATER
HOUSES
INDOOR AIR CONTAMINATION
RADIATION HAZARDS
RADIATION MONITORING
RADIOECOLOGICAL CONCENTRATION
RADON
RADON 222
SCINTILLATION COUNTING
WATER WELLS