Radiological monitoring and assessment of the radiation situation in the Kungur Ice Cave

This article presents the results of comprehensive radiological studies conducted in 2021 in order to assess the radiation situation in the Kungur Ice Cave (hereinafter referred to as the KIC). Since the cave is a fairly popular sightseeing object, therefore, the safety of both tourists and workers is a key task for scientific study. The radiation safety assessment was carried out taking into account the parameters of the radiation (gamma) background, measurements of radon and thoron concentrations, microclimatic indicators (air temperature, humidity), airflow rate, illumination and calculation of the indicator of a special assessment of working conditions (SAWC). Such comprehensive and detailed studies were conducted in the KIC for the first time, allowing some patterns to be identified and confirmed. For the indicators of gamma-activity and radon concentration, there is a clear dependence on the season of the year, which is directly related to microclimatic indicators, as well as to compliance with the ventilation regulations that have been established in the cave. The applied ventilation modes provide safe values of the radiation background and toron. In the summer months, the average radon content in the cave exceeds the maximum permissible concentrations by a factor of 7, which required calculation of the time of work in the cave. For the first time, special assessment of working conditions has been calculated for Kungur Ice Cave, but only for the winter period. The SAWC is defined for a working group consisting of engineers, workers and guides, taking into account such parameters as temperature, illumination, humidity, severity and intensity of labor and ionizing radiation (radiation background). According to preliminary data, the overall assessment of labor based on all parameters falls under the “harmful” class of conditions.