Lesson Learned Statement:Prior characterization of beryllium contamination is not sufficient to predict the generation of airborne beryllium contamination when the work involved may uncover or disturb hidden contamination. Therefore respiratory protection must be used if there is any question.
Discussion:The single remaining lab bench in Room 108 of Building 865 was removed and managed as Low Level Waste. The lab bench represented the only established radiologically controlled area outside of Room 145. Two weeks later the result of the single breathing zone air sample was received by Industrial Hygiene. The 8-hour time weighted average for the filter was 1.1029 ug/m3, based on a sample size of 0.22 cubic meter and a runtime of 115 minutes—the duration of the activity.
Prior to beginning the job a temporary CA was established to control the area. Additionally, the beryllium characterization (for horizontal surfaces below 8 feet), for the room had been reviewed. The characterization review indicated that there was minimal radiological contamination associated with the bench. The beryllium results for the room indicated that four horizontal-surface samples had been taken, three of which were below the detection limit (0.1 ug/100 square centimeters) and one that was at 3.76 ug/100 square centimeters. The contaminated “spot” was cleaned in the fall of 1999 and resampled. The results of the sampling indicated that the entire room was below 0.1 ug/100 square centimeters.
Additional beryllium characterization data for areas above eight feet were available in the room. Thirty-two samples were taken above the eight-foot level. Only nine of these samples detected reportable quantities of beryllium. These nine averaged 0.26 ug/100 square centimeters. The 32 samples averaged 0.07 ug/100 square centimeters.
These data established the boundaries for the job and the laboratory bench removal process began. The workers donned PPE, which consisted of modesty clothing, tyvek coveralls, two pairs of gloves, two pairs of booties, hard hat, safety glasses, and safety shoes. No respiratory protection was used. The initial step was to HEPA vacuum the area. Following this misting sprayers were utilized to wet the work area and the laboratory bench. The laboratory bench was moved away from the wall to allow radiological sampling of the area. Support braces under the laboratory bench were removed, as were the faucet and drain lines. These items were placed into plastic bags and sent to Room 145 for packaging. The remaining portions of the cabinet were also removed and sent to Room 145 for packaging. The removal process took 115 minutes, according to the run time for the air-sampling pump. It was concluded that the source of the beryllium was not positively known, but could have come from the polishing wheels that were in the counter top of the laboratory bench, from the area behind the floor molding, and the wall, and/or from the areas under loose floor tiles.
Following receipt of breathing zone air sampling results from a cabinet removal evolution, which had been conducted on two weeks earlier, Room 108 of Building 865 was posted as a beryllium regulated area and access was restricted to the room due to an elevated personal breathing zone sample. Industrial Hygiene personnel sampled areas in Room 108. Of the 30 samples that were collected, 10 were found to have beryllium concentrations above the laboratory detection limit of 0.1 ug/100 square centimeters. The average of the samples was 0.17 ug/100 square centimeters. The highest beryllium value was 0.89 ug/100 square centimeters and was outside of the area that the cabinet had occupied.
Analysis:Beryllium is a toxic metal. High level, acute exposures result in a pneumonitis, which can be fatal. For those who develop a sensitization to beryllium, chronic beryllium disease (CBD) may result in a systemic disease that evidences itself primarily in reduced lung function, but is rarely fatal. The migration of fine particles of beryllium, those that pose a hazard if inhaled, is not readily detectable due to lack of technology for real time detection and measurement. Similarly, the “suspension factor” associated with potential for surface beryllium contamination to become airborne is not correlated with a resulting likely airborne concentration. Considering these factors, conservative controls need to be implemented to prevent contamination spread and subsequent potential for worker exposures in areas with beryllium contamination.
The amount of surface contamination beryllium particulate that can be raised into the air depends on so many variables (such as, relative humidity, particle size, wind velocity, wind direction, electrostatic charge, etc.) that it is not practical (though theoretically possible) to predict airborne levels from surface contamination levels. This is especially the case when machinery, cabinets and other items that have been stationary for many years are removed and reveal beryllium contamination under or behind these objects. Possible additional surface sampling and thorough planning and envisioning of the planned work and its ability to reveal and raise settled particulate matter is recommended if the room configuration is to be changed. Where there is a potential to cause Be contamination to become airborne, respiratory equipment must be used.
Recommended Actions:Conservative controls need to be implemented to prevent contamination spread and subsequent potential for worker exposures in areas with beryllium contamination.
Possible additional surface sampling and thorough planning and envisioning of the planned work and its ability to reveal and raise settled particulate matter is recommended if the room configuration is to be changed. Where there is a potential to cause Be contamination to become airborne, respiratory equipment must be used.
Originator:Richard Schassburger, (303)966-4888
Validator:M. Bullock, (303)966-5866
Contact:B. Clausen, (303)966-7781
Name Of Authorized Derivative Classifier:R. Hoffman, (303)966-4598
Name Of Reviewing Official:R. Hoffman, (303)966-4598
Priority Descriptor:Yellow / Caution
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DOE Function / Work Categories:Decontamination & Decommissioning
ISM Category:Analyze Hazards
Develop / Implement Controls
Hazard:Personal Injury / Exposure - Beryllium
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