High {sup 222}Rn levels, enhanced plateout, increased diffusion coefficient
In a previous study of plateout and resuspension effects for {sup 222}Rn progeny, an unexpected suppression of the airborne {sup 218}Po and {sup 214}Po levels, which is total unrelated and not predicted by theory or other works, was observed when high {sup 222}Rn concentrations were utilized in a 0.283-m{sup 3} test chamber. Two separate time-dependent methods were used and are reported here to measure this airborne progeny suppression effect to attempt to possibly determine the magnitude and cause of the effect and possible consequences on prior and current ongoing radon research by others. The earlier buildup method was used to observe the buildup phase of {sup 222} Rn and its daughters from a constant emanation source, a constant air change rate (ACH), and initially zero concentrations Rn and progeny. The data were compared with theory using Leonard`s solutions to the Bateman equations to determine the magnitude of the suppression. The second method, referred to as the {open_quotes}down{close_quotes} method, was to measure the decrease in {sup 222}Rn and progeny concentrations from an initially injected high {sup 222}Rn activity concentration in the test chamber, the decrease resulting from a constant ACH of {approximately}0.1 h{sup -1} imposed by the gradual removal of air from the chamber at a constant rate of {approximately}0.5 l/min. No {sup 222}Rn emanation source was present during the second method after the initial injection so that the level of the {sup 222}Rn underwent a monotonic decrease in concentration.
- OSTI ID:
- 89249
- Report Number(s):
- CONF-941102--
- Journal Information:
- Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN 0003-018X; ISSN TANSAO
- Country of Publication:
- United States
- Language:
- English
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