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PubMed1993

Radioactive waste management at a large university and medical research complex.

A radioactive waste management program was developed for a large university and medical research complex to contain costs and to reduce the impact of the Low-Level Radioactive Waste Policy Act. The program takes advantage of decay-in-storage, incineration, special packaging techniques, and increased training and awareness. A series of metrics are presented to evaluate the effectiveness of the radioactive waste management program. Through the use of this program the amount of waste disposed of at commercial burial sites decreased from 98% to 1.61% of the waste generated. At the same time the volume of waste generated per laboratory declined by almost 45%, from 0.35 m3 (12.31 ft3) to 0.19 m3 (6.80 ft3).

Academic Medical Centers↗

PubMed1994

Potential for radioactive patient excreta in hospital trash and medical waste.

Radioactive excreta from nuclear medicine patients can enter solid waste as common trash and medical biohazardous waste. Many landfills and transfer stations now survey these waste streams with scintillation detectors which may result in rejection of a hospital's waste. Our survey indicated that on the average either or both of Boston University Medical Center Hospital's waste streams can contain detectable radioactive excreta on a weekly basis. To avoid potential problems, radiation detectors were installed in areas where housekeepers carting trash and medical waste must pass through to ensure no radioactivity leaves the institution.

Housekeeping, Hospital↗

PubMed1996

Radioactivity: conception to birth. The Health Physics Society 1995 Radiology Centennial Hartman Oration.

Röntgen's description of his discovery of x rays was convincing and comprehensive. The response of the scientific community and public was immediate and intense. In contrast, the discovery of radioactivity was a muddled affair that excited little interest. While it would prove far more revolutionary than that of x rays, the discovery of radioactivity began, in the words of Alfred Romer, as something of a dead horse. There it lay, too big to ignore, but what did you do with it? Even the discoverer, Henri Becquerel, left it to decay and went on to pursue other interests. For various reasons, others chose to investigate: Marie and Pierre Curie in France, William Crookes in England, and Ernest Rutherford in Canada. But it was Frederick Soddy, a young chemist with a fascination for alchemy, who, together with Rutherford, revealed the true nature of radioactivity: transmutation.

Fluorescence↗

PubMed1997

Calibration of a portable tritium-in-air monitor for various radioactive gases.

A commercially available portable tritium-in-air monitor was calibrated for detecting the concentration of tritium-in-air, 14C-in-air, and various radioactive noble gases. Calibrations were performed both experimentally, using assayed quantities of the calibration gases, and theoretically, by simulating the monitor's response using Monte Carlo code. The experimental and theoretical calibrations agreed within +/- 10% for all gases tested with the exception of 41Ar-in-air where the agreement was approximately 20%. The results show that, although the monitor can be used to measure a wide range of radioactive gases, if more than one gas is present the monitor can not be used to accurately determine the concentration of, and hazard posed by, these gases. It is also shown that the monitor's ability to accurately assess tritium-in-air hazards would be seriously compromised by the presence of other radioactive gases.

Air Pollutants, Radioactive↗

PubMed1997

Radioactivity in sediments of the Karnaphuli river estuary and the Bay of Bengal.

Sediment samples from the Karnaphuli river estuary, nearshore, and off-shore regions off the coast of Chittagong in the Bay of Bengal were analyzed for the natural radioactivity contents of 232Th, 238U and 40K and anthropogenic radioactivity contents of 137Cs and 134Cs using HPGe gamma spectrometry, together with the measurement of sediment pH and grain size analyses of the collected samples. The activity of 232Th found in sediment ranged from 10.44 +/- 2.31 to 64.02 +/- 8.13 Bq kg(-1), 238U activity ranged from 5.87 +/- 1.21 to 27.85 +/- 1.71 Bq kg(-1), 40K activity from 118.28 +/- 19.70 to 608.21 +/- 75.70 Bq kg(-1), and the activity 137Cs ranged from 0.09 +/- 0.06 to 4.64 +/- 0.19 Bq kg(-1), no 134Cs radioactivity was detected at any of the sampling stations.

Geologic Sediments↗

PubMed1999

Stirring system for radioactive waste water storage tank.

A stirring system for 100-m(3) radioactive liquid waste tanks was constructed to unify radioactive concentrations in the tank. The stirring system is effective in certifying that the radioactive concentrations in the tanks are less than the legal limits before they are drained away as waste liquid. This system is composed of discharge units, pipe lines, and a controller. The performance of the system was assessed by comparing the calculated red ink and 32P concentrations with those monitored at six locations in the tanks. The concentration reached equilibrium after stirring 60 to 120 min with discharge units equipped with six fixed openings configured in differing directions. Residual chlorine in city water used for dilution occasionally bleached the red ink and reduced its concentration. The adsorption of 32P by slime on the walls of the tanks storing actual waste water lowered the equilibrium concentration.

Radioactive Waste↗

PubMed2000

Implementation of the MARSSIM philosophy to evaluate the remedial status of a radioactive waste disposal site at the Idaho National Engineering and Environmental Laboratory. Multi-Agency Radiation Survey and Site Investigation Manual.

Implementation of the MARSSIM remedial-verification protocol at a radioactive waste disposal site is described in some detail to provide a record of the utility of this process. The selected site was the Stationary Low-Power Reactor No. 1 burial ground at the Idaho National Engineering and Environmental Laboratory. Evaluation was restricted to 137Cs in the uppermost 10 cm of potentially contaminated soils. According to the MARSSIM, this site warranted a "Class 1" designation based on previous remedial activities within the burial ground, its status as a radioactive disposal facility, and the anticipated presence of discrete radioactive particles. Nine survey units within the confines of the burial ground were selected, based primarily on the presence of physical boundaries and disparate histories. Surface scans with 100% coverage were performed using a hand-held plastic scintillator and rate meter with audible output. In situ gamma-ray spectrometry was not used for the individual stationary measurements due to the limited area and proximity of engineered barriers. Instead, individual soil samples were obtained using a standard hand-held coring device. The number of soil samples taken from the background reference area and each survey unit were determined with the MARSSIM protocol, which resulted in a total of 160 (including quality-control samples). Two of the nine regions exhibited elevated radiation levels and the null hypothesis could not be rejected in one survey unit, thereby indicating the need for additional remediation. The MARSSIM process proved to be flexible, scientifically rigorous, and cost effective in this field application. Several modifications to the procedure are discussed and offered as recommendations for enhancement of the MARSSIM.

Humans↗

PubMed2001

Determining the solubility of aqueous radioactive waste from a pharmaceutical research and development lab.

The management of radioactive waste disposal at pharmaceutical research facilities is often the responsibility of the Radiation Safety Office. Aqueous waste containing a variety of radionuclides may be generated by numerous research procedures. Disposal of this waste at commercial facilities is costly and each dollar spent in disposal costs is money not spent on research. An alternative to commercial disposal is release of radioactive aqueous waste into the sanitary sewer as provided by the Code of Federal Regulations (10CFR20.2003). This method of disposal must meet certain criteria regarding the amount and concentration of radioactivity released to the sewer. In addition, the material must be "readily soluble (or readily dispersible biological material) in water." This paper describes the process used at our R&D facility to determine the solubility of aqueous waste.

Drug Industry↗

PubMed2002

The development of field-based measurement methods for radioactive fallout assessment.

An overview is provided on the development of field equipment, instrument systems, and methods of analyses that were used to assess the impact of radioactive fallout from atmospheric weapons tests. Included in this review are developments in fallout collection, aerosols measurements in surface air, and high-altitude sampling with aircraft and balloons. In addition, developments in radiation measurements are covered in such areas as survey and monitoring instruments, in situ gamma-ray spectrometry, and aerial measurement systems. The history of these developments and the interplay with the general advances in the field of radiation and radioactivity metrology are highlighted. An emphasis is given as to how the modifications and improvements in the instruments and methods over time led to their adaptation to present-day applications to radiation and radioactivity measurements.

History, 20th Century↗

PubMed2006

National survey on the natural radioactivity and 222Rn exhalation rate of building materials in The Netherlands.

The present study reports on results of a nation-wide survey on the natural radioactivity concentrations and Rn exhalation rates of the prevailing building materials in the Netherlands. In total 100 samples were taken and analyzed for the activity concentrations of Ra, Ra, Th, and K and for their Rn exhalation rate. The sampled materials consisted of gypsum products, aerated concrete, sand-lime and clay bricks, mortars and concrete, representing about 95% of the stony building materials used in the construction of Dutch homes. The laboratory analyses were performed according to two well-documented standard procedures, the interlaboratory reproducibility of which is found to be within 5% on average. The highest radionuclide concentrations were found in a porous inner wall brick to which fly ash was added. The second highest were clay bricks with average Ra and Ra levels around 40 Bq kg. Concrete and mortar show the highest exhalation rates with a fairly broad range of 1 to 13 microBq (kg s). Low natural radioactivity levels are associated with either natural gypsum (products) or gypsum from flue gas desulphurization units, and low exhalation rates with clay bricks. To evaluate the radiological impact the radioactivity concentrations in each sample were combined into a so-called dose factor, representing the absorbed dose rate in a room with a floor, walls and ceiling of 20 cm of the material in question. For that purpose, calculations with the computer codes MCNP, Marmer and MicroShield on the specific absorbed dose rates were incorporated in the paper. The results of these codes corresponded within 6% and average values were calculated at 0.90, 1.10, and 0.080 nGy h per Bq kg for the U series, the Th series, and K, respectively. Model calculations on the external dose rate, based on the incidence of the various building materials in 1,336 living rooms, are in accordance with measured data.

Air Pollutants, Radioactive↗

PubMed2006

A security vulnerabilities assessment tool for interim storage facilities of low-level radioactive wastes.

Limited permanent low-level radioactive waste (LLRW) disposal capacity and correspondingly high disposal costs have resulted in the creation of numerous interim storage facilities for either decay-in-storage operations or longer term accumulation efforts. These facilities, which may be near the site of waste generation or in distal locations, often were not originally designed for the purpose of LLRW storage, particularly with regard to security. Facility security has become particularly important in light of the domestic terrorist acts of 2001, wherein LLRW, along with many other sources of radioactivity, became recognized commodities to those wishing to create disruption through the purposeful dissemination of radioactive materials. Since some LLRW materials may be in facilities that may exhibit varying degrees of security control sophistication, a security vulnerabilities assessment tool grounded in accepted criminal justice theory and security practice has been developed. The tool, which includes dedicated sections on general security, target hardening, criminalization benefits, and the presence of guardians, can be used by those not formally schooled in the security profession to assess the level of protection afforded to their respective facilities. The tool equips radiation safety practitioners with the ability to methodically and systematically assess the presence or relative status of various facility security aspects, many of which may not be considered by individuals from outside the security profession. For example, radiation safety professionals might not ordinarily consider facility lighting aspects, which is a staple for the security profession since it is widely known that crime disproportionately occurs more frequently at night or in poorly lit circumstances. Likewise, the means and associated time dimensions for detecting inventory discrepancies may not be commonly considered. The tool provides a simple means for radiation safety professionals to assess, and perhaps enhance in a reasonable fashion, the security of their interim storage operations. Aspects of the assessment tool can also be applied to other activities involving the protection of sources of radiation as well.

Criminal Law↗

PubMed2006

Scrap metals industry perspective on radioactive materials.

With more than 80 reported/confirmed accidental melts worldwide since 1983 and still counting, potential contamination by radioactive materials remains as a major concern among recycled scrap and steel companies. Some of these events were catastrophic and have cost the industry millions of dollars in business and, at the same time, resulted in declining consumer confidence. It is also known that more events with confirmed radioactive contamination have occurred that involve mining of old steel slag and skull dumps. Consequently, the steel industry has since undergone massive changes that incurred unprecedented expenses through the installation of radiation monitoring systems in hopes of preventing another accidental melt. Despite such extraordinary efforts, accidental melts continue to occur and plague the industry. One recent reported/confirmed event occurred in the Republic of China in 2004, causing the usual lengthy shutdown for expensive decontamination efforts before the steel mill could resume operations. With this perspective in mind, the metal industry has a long-standing opposition to the release of radioactive materials of any kind to commerce for fear of contamination and the potential consequences.

Decision Making↗

PubMed2001

Options in radioactive waste management revisited: a proposed framework for robust decision making.

Deregulation, with concurrent pressure on electricity utilities, has fundamentally changed the once-"closed" radioactive waste management system controlled by the so-called "nuclear establishment." Advocacy coalitions may change-who knows in which direction-but policy learning may also take place. This article presents a framework to evaluate the management options for a specified concept of "sustainability." When weighing the different objectives in view of the long-lasting potential danger of radiotoxic substances, the overall goal of a sound waste management system is to demonstrate safety. The first-priority objective of a disposal system, therefore, is its stability so that it can comply with the protection goal, that is, the long-term protection of humans and the environment from ionizing radiation. The complementary objective is flexibility, defined here as intervention potential. Because trade-offs within the "sustainability triangle" of ecology, economy, and society are unavoidable, the concept of "integral robustness"-both technical and societal-is introduced into radioactive waste management. A system is robust if it is not sensitive to significant parameter changes. In the present case, it has to have a conservative, passively stable design with built-in control and intervention mechanisms. With regard to technical implementation, a concept called "monitored long-term geological disposal" is presented. Such an "extended" final disposal concept emphasizes technical robustness, recognizes evaluation demands (for a potential break-off of a project), and enhances process-based transparency. This open approach admittedly sets high challenges with regard to technicalities as well as the institutional setting and the management process. It requires "mutual learning" by and from all stakeholders to achieve a truly sustainable radioactive waste management system.

Decision Making↗

PubMed1997

DRINK: a biogeochemical source term model for low level radioactive waste disposal sites.

Interactions between element chemistry and the ambient geochemistry play a significant role in the control of radionuclide migration in the geosphere. These same interactions influence radionuclide release from near surface, low level radioactive waste, disposal sites once physical containment has degraded. In situations where LLW contains significant amounts of metal and organic materials such as cellulose, microbial degradation in conjunction with corrosion can significantly perturb the ambient geochemistry. These processes typically produce a transition from oxidising to reducing conditions and can influence radionuclide migration through changes in both the dominant radionuclide species and mineral phases. The DRINK (DRIgg Near field Kinetic) code is a biogeochemical transport code designed to simulate the long term evolution of the UK low level radioactive waste disposal site at Drigg. Drigg is the UK's principal solid low level radioactive waste disposal site and has been receiving waste since 1959. The interaction between microbial activity, the ambient geochemistry and radionuclide chemistry is central to the DRINK approach with the development of the ambient pH, redox potential and bulk geochemistry being directly influenced by microbial activity. This paper describes the microbial aspects of the code, site data underpinning the microbial model, the microbiology/chemistry interface and provides an example of the code in action.

Environmental Microbiology↗

PubMed1964

DISTRIBUTION OF RADIOACTIVITY IN AUTOLYZED CELL WALL OF BACILLUS CEREUS DURING SPHEROPLAST FORMATION.

Kronish, Donald P. (Warner-Lambert Research Institute, Morris Plains, N.J.), Raam R. Mohan, and Benjamin S. Schwartz. Distribution of radioactivity in autolyzed cell wall of Bacillus cereus during spheroplast formation. J. Bacteriol. 87:581-587. 1964.-Spheroplasts of Bacillus cereus strain T were produced from cells grown in the presence of uniformly labeled C(14)-glucose. At regular intervals during spheroplast formation, enzymatically degraded cell wall was isolated by a new procedure. Radioactivity of solubilized cell wall in cell-free material increased from 2.5 to 42% of the total incorporated label during spheroplast formation. The rate of cell-wall degradation as measured by increase in radioactivity was biphasic with relative slopes of 2.0 and 5.0. During autolytic depolymerization of B. cereus cell wall, two major components were solubilized at different rates. Chemical fractionation revealed these to be a peptide and a mucopeptide. The possibility of two enzymes being involved in spheroplast formation and cell-wall degradation is discussed.

Amino Acids↗

PubMed1961

The urinary excretion of assayable vitamin B12 and radioactivity after parenteral 58Co B12 in man.

Evidence is presented that after injection of radioactive vitamin B(12) in man, there is a close correlation between the amount of radioactivity excreted and the amount of assayable vitamin B(12) excreted, and thus that the amount of radioactivity excreted is a true measure of the vitamin B(12) excreted. The possible reasons for this occurrence are discussed and it is suggested that in the body vitamin B(12) does not exist as such but as an analogue or active derivative.

Cobalt↗

PubMedDate not supplied

High performance liquid chromatography coupled with radioactivity detection: a powerful tool for determining drug metabolite profiles in biological fluids.

High performance liquid chromatography coupled with continuous radioactivity detection represents an advancement in drug metabolism research. Using radioactive substances labelled in biologically stable positions, all metabolites can be specifically detected by radioactivity measurement. Thus no clean-up of biological fluids is required prior to HPLC. This can prevent artefact formation from unstable metabolites, reduces recovery problems and facilitates quantitation. Separation of highly polar and unpolar metabolites is possible in a single chromatographic run using gradient elution and reversed phase materials. This technique is also well-suited for preparative isolation and purification of metabolites for subsequent structure elucidation. Various metabolite profiles of drugs labelled with carbon-14 or tritium are shown. Metabolites of the following drugs are presented: norfenefrine, etozolin, thymoxamine, naloxone, and levobunolol. We review the general methodology and report our experience with this technique. In principle, this technique may be useful for all biological systems in which tracer techniques are applied.

2-Hydroxyphenethylamine↗

PubMed1999

Measurement of airborne radon concentrations at several sites in a radioactivity research laboratory.

Radon-222 is a natural, gaseous, radioactive nuclide released from the ground and building materials into the air. Radon and its daughter nuclides can be an important disturbance factor for the measurement of environmental radioactivity. Radon concentrations in air in a radiation laboratory were measured with PICO-RAD detectors, which directly adsorb radon gas on activated charcoal. Generally, radon concentration increased in the absence of ventilation; a high concentration was observed in a radioisotope storage room without ventilation. Concentrations were low in other rooms used for experiments and measurement, which suggests that the radiation control practice in this laboratory is satisfactory and that the influence of natural radon gas on the measurement of radioactivity is negligible.

Air Pollutants, Radioactive↗