Transport of radon in flowing boreholes at Stripa, Sweden

Journal Article · Thu Mar 10 04:00:00 EST 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB088iB03p02395· OSTI ID:6270624

Nelson, P H; Rachiele, R; Smith, A

Granitic rock in an underground experimental waste storage site at Stripa, Sweden, is unusually high in natural radioelements (approx.40 ppm unranium), with higher concentrations occurring locally in thin chloritic zones and fractures. Consequently, groundwater seeping through fractures into open boreholes is highly anomalous in its radon content, with activity as high as 1 ..mu..Ci/l. When total count gamma-ray logs are run in boreholes where groundwater inflow is appreciable, the result is quite unusual: the radon daughter activity in the water adds considerably to the gamma contribution from the rock, and in fact often dominates the log. The total gamma activity increases where radon-charged groundwater enters a borehole and decays as the water flows along the hole in response to the hydraulic gradient. As a consequence the gamma log serves as a flow profile, locating zones of water entry (or loss) by an increase (or decrease) in the total gamma activity. If mixing within the borehole does not occur, the activity decreases exponentially along the hole away from the entry point because of the steady decay of radon and its daughter products as they migrate with the flow in the water column. This spatial decay rate can be converted to a linear flow rate since the 3.8-day half-life of radon governs the response time. Independent measurements of emanation and concentration produce reasonable estimates of fracture aperture. Although uranium concentration values at Stripa are unusually high, neither the emanation coefficients nor the fracture properties appear to be unusual for granitic rock. It therefore seems likely that many granitic sites must exist where the radon content in groundwater is higher than in other geological terranes, although perhaps not as high as the microcurie per liter concentrations found at the Stripa site.

• Research Organization: Earth Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720
• OSTI ID: 6270624
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 88:B3; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

052002 -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
BOREHOLES
CAVITIES
ELECTROMAGNETIC RADIATION
ELEMENTS
ENVIRONMENTAL TRANSPORT
FLOW RATE
FLUIDS
GAMMA RADIATION
GASES
GRANITES
GROUND WATER
HYDROGEN COMPOUNDS
IGNEOUS ROCKS
IONIZING RADIATIONS
MANAGEMENT
MASS TRANSFER
NONMETALS
OXYGEN COMPOUNDS
PLUTONIC ROCKS
RADIATIONS
RADIOACTIVE WASTE DISPOSAL
RADIONUCLIDE MIGRATION
RADON
RARE GASES
ROCKS
WASTE DISPOSAL
WASTE MANAGEMENT
WATER