AlphaGUARD and AlphaPM used for radon and radon progeny risk assessment on an oil platform. Molycorp Mountain Pass Minerals Mine, USA, have begun enhancing and modernizing their facilities. AlphaGUARD and AlphaPM have been used for a study to compare passive radon thoron detectors (track etch detectors) and real-time detectors (AlphaGUARD). In the case of passive monitoring, once a high exposure event has been recorded, it affects the average for that timeframe irrespective of the lows for that period. Real-time monitoring measures actual lows and highs of exposures and weighted averages are determined. Real-time measurements and the use of the DataExpert software package allowed results for all areas to be displayed and reported prior to leaving the platform.