A continuous real time monitor (referred to as the CAM 10) for airborne depleted uranium particles in the respiratory range of less than about 10 microns
A protype of a continuous real time monitor (referred to as the CAM 10) for airborne depleted uranium particles in the respiratory range of less than about 10 microns that meet the design and operational requirements of patent numbers US 2018/0017477 A1; January 18, 2018 and US 10,031,060 B2; July 24, 2018. We believe that the prototype can be assembled using commercially available components.
Description of Prototype
The prototype CAM 10 is designed to provide continuous real time measurements and readout of the concentration of depleted uranium aerosols at any location and as a function of particle size, ranging from less than 1 micron to at least 10 micron activity median aerodynamic diameter (AMAD). The continuous readout will be expressed in in units of Bq/m3 or mg/m3 or any other unit that is convenient to the user. The prototype will be designed to have a detection limit that corresponds to the instantaneous concentration of 5-micron AMAD DU particles that can result in 100 mrem effective dose commitment if an adult is exposed to that concentration for 2000 working hours per year from the chronic inhalation of insoluble particles in the presence of an overall chronic dust loading of 1 mg/m3 within which the DU particles are suspended. Once the prototype is demonstrated to meet these basic requirements, the CAM 10 will then be enhanced in a stepwise manner to achieve expanded functional capabilities, including:
* A detection limit that corresponds to the instantaneous concentration of 1-micron AMAD DU particles that can result in 50 mrem effective dose commitment to any age group chronically exposed for 1 year to DU from all those pathways described in RESRAD 7.2 and where the chronic total airborne dust loading within which the DU is contained corresponds to 200 µg/m3.
* A monitor that is operated by genetic software that continuously controls the air flow intake rate, air sampling duration, and the count time of each sample to achieve incremental measurements of the respirable airborne DU concentrations that achieve a prespecified lower limit of detection in the shortest possible time.
* A monitor that includes the ability to continuously monitor the airborne concentration (mg/m3) of DU aerosols up to 50 microns mass median aerodynamic diameter in order to assess the potential for the DU aerosols to cause not only radiogenic cancers from inhalation but also non-radiogenic adverse health effects, such as kidney damage.
The above design objectives would appear to indicate that the monitor is not a continuous airborne monitor, but presents output representing the average concentration of airborne DU over some incremental period of time. However, as described below in the detailed description of the prototype, the monitor is designed to continuously measure the particle size distribution (mass median aerodynamic diameter (mmad)) and airborne mass concentration distribution (µg/m3) in the respirable range that will allow interpolation and presentation of the instantaneous DU concentrations between the incremental counting time periods.
Given the instantaneous continuous readout of the DU aerosol concentration and particle size distribution, the unit will be able to derive and present the effect dose commitment and organ equivalent dose commitment for any age group and exposure pathway in SI or conventional units using ICRP approved inhalation and ingestion dose coefficients. It will also provide the concentration of airborne DU that might pose other adverse health effects, including kidney damage and other adverse effects only recently identified in the peer reviewed literature.
The device is anticipated to be small (size of shoebox and no larger than a breadbox) and easily portable. It will operate using a battery pack for an estimated 8 hours before a battery changeout is required and also operate continuously if a plug-in power supply is available. The device can be used both indoors and outdoors at legacy and remediation sites that contain DU, at combat sites where DU is used in penetrators and armor, and at DOD contractor facilities where weaponry is being designed and tested that employ DU as a penetrator, armor, or in any other capacity where such testing can generate DU aerosols of any size and chemical form and which can represent a potential radiological or heavy metal health hazard to radiation workers, non-radiation workers, and members of the nearby public.
Locations with relatively high soil concentrations of DU can be disturbed by wind, weather, overland transportation, and remediation efforts putting workers and the public at risk. Grab and air sampling sent to a laboratory can take days. The advent of a portable continuous detection of suspended or resuspended DU particulates in air is not only ALARA protective but can save significant costs with more efficient DU cleanup operations.
Exposures and radiation doses can be derived for inhalation and inadvertent ingestion of DU by remediation workers and military personnel. In addition, exposure and radiation doses can be derived for nearby members of the public from any of a myriad of potential pathways and age groups, including direct inhalation of DU aerosols, inhalation of resuspended DU aerosols, and the ingestion of DU in food at any location and for any duration.
I recognize that these exposure and dose calculations are not unique and will employ current widely used and accepted methods adopted and accepted by the Nuclear Regulatory Commission, the Environmental Protection Agency, the National Council on Radiation Protection and Measurement, the International Commission on Radiation Protection, the International Atomic Energy Agency, and other rule-making and standard setting bodies concerned with the protection of workers and members of the public from the potential adverse radiological and toxic chemical effects associated with exposure to DU. What is unique about this prototype is the ability to perform real time continuous measurements of the airborne concentrations and particle size distributions of DU aerosols under virtually any set of operational or environmental condition or circumstances.
In 2015, I attended a symposium on sustainability, where I ran into an old friend, who, at that time, was a remediation contractor. He and I were acquainted from the time we both worked at Ebasco Services in New Your City. Ebasco was a large architectural engineering firm, whose clients were primarily nuclear utilities who were licensing and building commercial nuclear power plants. At that time, I was the manager of the Health Physics and Radiation Protection Department and prepared sections of the Environmental Reports and Safety Analysis Reports for the facilities. I also defended these reports before the Nuclear Regulatory Commission (NRC) and hearings held by the Atomic Safety and Licensing Board (ASLB) and the Advisory Committee on Reactor Safeguards (ACRS). These documents and hearings were required, in part, for utilities to be granted a construction permit and operating license for their facilities.
During the sustainability symposium, I was asked if there were any continuous airborne monitors for respirable aerosols of depleted uranium (DU). Apparently DU is a recurring problem at many of the remediation sites because workers and the nearby public were required to be protected from the inhalation and inadvertent ingestion of DU. In addition, the nearby public was often quite outspoken over their concern with DU.
Most health physics personnel simply take air grab samples over the course of a given day of cleanup and send them to a lab for analysis of DU; the results of which are often returned days later. Air samples are typically taken upwind and downwind of excavation operations and also at the locations of the workers. In addition, breathing zone samples are often collected and, at times, urine samples are taken from workers. These sampling and analysis protocols meet all regulatory requirements for protection of workers and the public, but it would be highly desirable to be able to also collect continuous real time data on the airborne concentration of respirable DU at a number of locations. Such monitors would alarm if some preset level was exceeded, but, more importantly, the data would provide continuous plots of the airborne concentration of DU in Bq/m3 and µg/m3 as a function of particle size (i.e., mass median aerodynamic diameter) at any desired location and display these plots at any location onsite or offsite. Such data would provide useful information during remediation, as the workers performed their work, where the concentrations of DU in the soil and debris might change and the characteristics of the soil and the micrometeorological condition might change. Such information would help to better manage the cleanup operation, protect the workers, and ensure the public that everything was being done to protect them.
I did a little homework and found that such monitors do not appear to be available from any of the major instrument vendors. It was at this time that I began to think about building and obtaining a patent for such a monitor. However, before embarking on such a project, I did some investigations of the possible market for such a monitor. I called an individual who was previously in charge of DU penetrator and armor testing operations at Aberdeen Proving Ground (APG) in Aberdeen Maryland.
It was explained to me that at APG, which included testing of penetrators and armor outdoors, testing generated huge amounts of very fine aerosols of DU and also large chunks of DU that required cleanup. Also, the trajectory and performance of the DU projectiles were studied by firing them into mounds of soil. A degree of cleanup was then performed but residual DU often remained, which became oxidized and represented a potential resuspension hazard. In addition, it was explained to me that members of the nearby public expressed concern over the possibility that DU aerosols were being transported to their communities.
Because of these concerns, APG moved this type of testing indoors, where the DU was contained. However, continuous monitor for airborne particles of DU would still be very useful indoors. Apparently, the technical staff have to wait until the airborne DU levels declined to acceptable levels before personnel could enter the testing chamber, or, alternatively, enter the testing chamber using respiratory protection, which workers did not like at all. Hence, a real time DU monitor would be very useful in managing the indoor tests.
I then contacted a senior military consultant, including who held contracts with Aberdeen Proving Grounds and other military installations. He put me in touch with the lead instrumentation researcher and project manager for BMI stationed at APG, who indicated that, at such time when I have a prototype for such a monitor, I should call him and he would accompany me on a visit to a number of military bases where DU is a concern.
I next contacted a lead health physicist for the Commonwealth of Pennsylvania regarding this matter. His response to my inquiries regarding DU was quite enthusiastic. He told me that he currently was overseeing cleanup of a site in PA where DU was an issue, and it was a real burden collecting air and bioassay samples, sending them to a lab, and waiting on the results as cleanup work progressed. He indicated that, if I had such a monitor, I should bring it to him immediately.
Needless to say, the above correspondence encouraged me to build a prototype of the monitor and begin the process of obtaining a patent for the device. Working with my patent attorney, I obtained two patents for my device.
I would like to obtain funding to build a protype DU monitor that meets the description provided in two patents awarded to me, as follows:
Design, construction and testing of a prototype of a continuous real time monitor for airborne depleted uranium particulates in the respiratory range of less than 10 microns and also airborne depleted uranium particles above the respiratory range that meet the design and operational requirements of patent numbers US 2018/0017477 A1; January 18, 2018 and US 10,031,060 B2; July 24, 2018 .
ATSDR 2013. Toxicological Profile for Uranium, U.S. Department of Health and Human Services, Agency for Toxic Substances and Disease Registry, February 2013.
Besic, L., I. Muhovic, A. Adna, A. Kurtovic-Kozaric 2017, Meta-analysis of depleted uranium levels in the Nalkan region, Journal of Environmental Radioactivity 172 (2017) 207-217.
EPA 2006, Depleted Uranium-Technical Brief. Radiation Protection Division of the Office of Radiation and Indoor Air of the Environmental Protection Agency.
Cheng, Y.S., J. L. Kenoyer, R.A. Guilmette, Yung Sung Cheng and, M.A. Parkhurst, 2009. Physiochemical Characterization of Capstone Depleted Uranium Aerosols II: Particle Size Distribution as a Function of Time, Health Physics, Volume 96, Number 4, pp 266-275. March 2009.
Choy, C.C., G.P. Korfatis, and X. Meng, 2006. Removal of Depleted Uranium from Contaminated Soil. J. Hazard Mater. 2006Aug 10; 136(1): 53-60. Epub 2005 Dec 28.
Crean, D.E., F.R. Livens, M. Sajih, M.C. Stennett, D. Goleman, C.N. Broca, and N.C. Hyatt, “Remediation of soils contaminated with particulate depleted uranium by multi-stage chemical extraction,” Journal of Hazardous Materials 263 (2013 (382-390, August 2, 2013.
Eckerman, K.F. and R. W. Leggett USER GUIDE TO DCFPAK 3.0. Environmental Sciences Division Oak Ridge National Laboratory Oak Ridge, Tennessee 37831, USA Miller, G., Y.S. Cheng, R.J. Traub, T.T. Little, and R. Guilmette, 2009. Methods Used to Calculate Doses Resulting from Inhalation of Capstone Depleted Uranium Aerosols, Health Physics, Vol. 96, No. 3, p. 306-327, March 2009.
Mohammes, A.A., A Sh. Hussien, and N.F. Tawfiw, 2008. “Assessment of depleted uranium concentration in selected Iraqi soils”, Journal of Al-Nahrain University, Volume 11(1), pp 74-81, April 2008.
NCRP 1987. Exposure of the Population in the United States and Canada from Natural Background Radiation, National Council on Radiation Protection and Measurements, NCRP Report No. 94, December 30, 1987.
Parkhurst, M.A., E.G. Daxon. G.M. Lodde, F. Szron, R.A. Guilmette, L.E. Roszell, G.A. Falco, and C.B. McKee, “Depleted Uranium Aerosol Doses and Risks: Summary of U.S. Assessments,“ prepared for the US Army by Battelle under the Chemical and Biological Defense Information Analysis Center, Task 241, DO 0189, Aberdeen Maryland, PNWD-3476. October 2004 Rostker, 2000. Environmental Exposure Report, Depleted Uranium in the Gulf (II). Special Assistant to Gulf War Illness, Department of Defense, 200179-0000002, Ver 2.0; http://wwwgilflink.osd.mil/du_ii/<https://gcc02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwwwgilflink.osd.mil%2Fdu_ii%2F&data=04%7C01%7Cjmauro%40scainc.com%7C10a818bf76724386315e08d997ebbf22%7C0db7fb1c4adf484389cdb09bbcaa77b9%7C1%7C0%7C637707861061016173%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=BwNJ5DScnl%2BTS47H%2FwCXc2w6zBP0m9mvUAtSiSGBMlQ%3D&reserved=0>.
Sarap, N.B. et al. 2014, “Environmental radioactivity in southern Serbia at locations where depleted uranium was used,” Arh Hig Rad Toksikol 2014: 65: 189-197. DOI: 10.2478/10004-1254-65-2014-2427.
Seiler, F.A., G.J. Newton, and R.A. Guilmette, Continuous Monitoring for Airborne α Emitters in a Dusty Environment, in Health Physics, Vol 54. No. 5 (May) pp 503-515, 1988.
This email may contain privileged and confidential information intended only for the use of the specific entity named herein.