Workshop on Radiological Surveys in Support of the Edgemont Clean-up Action Program

The Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards, has given Pacific Northwest Laboratory (PNL) the responsibility for the development of procedures for the identification of offsite structures and properties in the vicinity of Edgemont, South Dakota, that require remedial action because of elevated radiation levels caused by residual radioactivity as defined in the Uranium Mill Tailings Radiation Control Act of 1978. In order to acquaint interested investigators with the procedures PNL has developed and the measurements that have been performed at Edgemont using these procedures, and also to obtain suggestions for the improvement of these procedures, PNL organized a "Workshop on Radiological Surveys in Support of the Edgemont Clean-up Action Program" on behalf of the Nuclear Regulatory Commission. This workshop was held in Denver on January 21 and 22, 1981. On the first day of the workshop an in-depth discussion of the procedures employed in the entire radiological survey program at Edgemont was held. It included a description of the equipment, techniques and procedures employed in radon daughter measurements within structures, indoor and outdoor gamma radiation surveys, and 226Ra measurements in surface and sub-surface soil samples. On the second day, the results of the measurements that have been conducted at Edgemont were presented. During the afternoon an open discussion of the radiological survey procedures used at Edgemont was held for the purpose of obtaining suggestions for the possible improvement of these procedures. Many useful suggestions were made and a few modifications in the survey procedures at Edgemont have been made in response to these suggestions

Study of Plutonium Oxide Powder Emissions from Simulated Shipping Container Leaks

To provide data to facilitate the predictions of PuO{sub 2} emissions through leaks in PuO{sub 2} shipping containers under accident conditions, a series of experiments was conducted using PuO{sub 2} powder and an experimental system designed to simulate a shipping container leak. Over two hundred experiments were completed. The experimental parameters investigated were the leak size/type, internal system pressure, agitation of the apparatus, leak orientation with respect to the powder location and the run time. No single parameter appeared to have any observable effect on the quantities of PuO{sub 2} emitted. However, there was an apparent dependency on the interaction between the orifice area and the internal pressure. The dependency took the form of a function of A{radical}P. Although this functional form was suggested by the data, the data were not sufficient to allow a more detailed function to be determined. The results of experiments in which the run time was variable produced the observation that changes in the run time did not result in changes in the quantities of PuO{sub 2} emitted. This observation led to the conclusion that the majority of PuO{sub 2} observed is emitted during the initial pressurization of the leak tube

Real-Time Remediation Utilizing The Backpack Sodium Iodide System And The U.S. EPA Triad Approach

Real-time characterization during remediation activities is being accomplished at the Idaho National Laboratory (INL) with the use of the backpack sodium iodide system (BaSIS). The BaSIS is comprised of a 3-in. by 5-in. sodium iodide (NaI) detector, differential corrected global positioning system (GPS), and portable computer, integrated into a lightweight backpack deployment platform. The system is operated with specialized software that allows the operator and/or remediation field manager to view data as they are collected. Upon completion of planned excavation stages, the area is surveyed for residual radiological contamination. After data collection is complete, data is available to the remediation field manager as a contour map showing the area(s) that require further excavation. The use of real-time measurement systems, rapid turn-around time of data, and dynamic work strategy support the U.S. Environmental Protection Agency’s (EPA) Triad approach. Decisions are made in real-time as to the need for further remediation. This paper describes the BaSIS system calibration, testing and use, and outlines negotiations with the appropriate CERCLA regulatory agencies (U.S. Environmental Protection Agency, Idaho Department of Environmental Quality, and U.S. Department of Energy Idaho Operations Office) to allow the use of real-time instrumentation during the remediation process, and for confirmation surveys. By using the BaSIS in such a manner, the INL seeks to demonstrate compliance with remediation objectives

QTL detection by multi-parent linkage mapping in oil palm (Elaeis guineensis Jacq.)

A quantitative trait locus (QTL) analysis designed for a multi-parent population was carried out and tested in oil palm (Elaeis guineensis Jacq.), which is a diploid cross-fertilising perennial species. A new extension of the MCQTL package was especially designed for crosses between heterozygous parents. The algorithm, which is now available for any allogamous species, was used to perform and compare two types of QTL search for small size families, within-family analysis and across-family analysis, using data from a 2 × 2 complete factorial mating experiment involving four parents from three selected gene pools. A consensus genetic map of the factorial design was produced using 251 microsatellite loci, the locus of the Sh major gene controlling fruit shell presence, and an AFLP marker of that gene. A set of 76 QTLs involved in 24 quantitative phenotypic traits was identified. A comparison of the QTL detection results showed that the across-family analysis proved to be efficient due to the interconnected families, but the family size issue is just partially solved. The identification of QTL markers for small progeny numbers and for marker-assisted selection strategies is discussed

Characteristics of Acacia mangium shoot apical meristems in natural and in vitro conditions in relation to heteroblasty

PDF version of the authors can be published in January 2013International audienceMorphological and histocytological characteristics of Acacia mangium shoot apical meristems (SAMs) were assessed in natural and in vitro conditions in relation to heteroblasty. In the natural environment, SAMs with a mature-phyllode morphology were much bigger, contained more cells with larger vacuolated area, or vacuome, and lower nucleoplasmic ratios than those from the juvenile type (Juv). In these latter, nuclei appeared more voluminous, evenly and lightly stained, with clearly distinguishable nucleolei and less abundant chromocenters. In vitro, where reversions from mature to juvenile morphological traits do occur unpredictably, heteroblasty was less obvious in the SAM characteristics examined. In vitro SAMs corresponding to the juvenile and mature types showed similarities with outdoor Juv SAMs, but could be distinguished from these latter by a much larger vacuome that might be induced by the culture conditions. These findings encourage pursuing the investigations at the chromatin and nucleolus level in SAM zones where heteroblasty-related differences have been detected

Particulates Generated During the Air Oxidation of Uranium

The effect of temperature on the nature of oxide formed from uranium oxidizing in air is pronounced, there being an increase in particle size wtth increasing temperatare over the range 400 to 800 deg C. At 1000 deg C and above the oxide formed remains largely intact, giving rise to few-micron size particles during the heating period. In relating these facts to fission product release, it would be anticipated that the effect of air velocity on the release of fission products would be more pronounced at lower temperatures. Only a fraction of those oxide particles of apparert entrainable size become airborne, emphasizing the possible effects of fuel elemert geometry and orientation. This stability of a mass of fine particles is an importart factor to consider in a system where localized high air velocities or explosions might occur. This material once dispersed by a sudden rise in air stream velocity could remain suspended for extended periods of time. Deposition of uranium oxide and fission products on experimental apparatus points out the importance of the location of the fuel element during an overheating incident. In conclusion, particulate entrainment and deposition, fuel element geometry, oriensations and location are variables which may have an important effect on fission product release. These variables along with effects of temperature, fuel elemert composition, cladding, air velocities, and irradiation level compose a very complex system. Since little research to date has dealt with deposition parameters, this area merits added consideration. (auth

Atomic Energy Commission Reports

From objective: "The objective of this work was to design, develop, assemble, and test and automatic analyzing monitor for recording the prominent isotopes in reactor effluent cooling water.