Measurements of 60Co in spoons activated by neutrons during the JCO criticality accident at Tokai-mura in 1999

Neutron activated items from the vicinity of the place where the JCO criticality accident occurred have been used to determine the fluence of neutrons around the facility and in nearby residential areas. By using underground laboratories for measuring the activation products, it is possible to extend the study to also cover radionuclides with very low activities from long-lived radionuclides. The present study describes gamma-ray spectrometry measurements undertaken in a range of underground laboratories for the purpose of measuring (60)Co more than 2 years after the criticality event. The measurements show that neutron fluence determined from (60)Co activity is in agreement with previous measurements using the short-lived radionuclides (51)Cr and (59)Fe. Limits on contamination of the samples with (60)Co are evaluated and shown to not greatly affect the utility of neutron fluence determinations using (60)Co activation.     

Larval development in the Tasmanian mysids Anisomysis mixta australis, Tenagomysis tasmaniae and Paramesopodopsis rufa (Crustacea: Mysidacea)

We describe the brood duration and marsupial development of three temperate coastal mysid species, Anisomysis mixta australis (Zimmer), Tenagomysis tasmaniae Fenton and Paramesopodopsis rufa Fenton, found commonly in Tasmanian waters. Larvae cultured in vitro had brood durations at 13 °C (17 °C) of 22 (15), 23 (15), and 28 (20) d, respectively. Development through seven larval stages, and brood durations for these three species are similar to those reported for coastal mysids from other temperate areas throughout the world. Received: 10 June 1997 / Accepted: 1 July 1997     

Some effects of prolonged starvation on the metabolism of the red and white myotomal muscles of the plaice Pleuronectes platessa

The effect of starvation on glycogen, lipid, water content and muscle proteins of red and white muscles in the plaice Pleuronectes platessa L. has been investigated. The two muscle systems behave differently in their response to food shortage, glycogen and protein depletion being more marked in the white muscle. Little change occurred in the constituents of the red muscle, except lipid. Starvation resulted in an increase in water content in the white, but not in the red muscle. The differential response of these two musole systems to starvation is discussed. It is suggested that the small amount of red muscle in the body is spared from the effects of starvation because it is needed for continuous activity during swimming at all speeds.     

Overview of proposed air emission standards and guidelines for municipal waste combustors

The EPA proposed regulations for municipal waste combustors (MWCs) on December 20, 1989. The regulations include (1) performance standards under Section 111(b) of the Clean Air Act (CAA) for new, modified, or reconstructed MWCs and (2) draft emission guidelines and compliance schedules for the states to use to develop control requirements from existing MWCs under Section 111(d). This paper will outline the proposed air emission standards and guidelines, as well as the basis for the prescribed emission limits. The schedule for the remainder of the regulations development will also be discussed.     

In vitro dissolution studies of uranium bearing material in simulated lung fluid

Inhaled uranium (U) bearing material will partially dissolve in the fluid lining of the lung, followed by a combination of retention, re-distribution, and excretion of the U. The rate of dissolution influences the retention time at the site of deposition, and the extent to which the material is available for re-distribution to other tissues. The consequential radiation dose is dependent upon the material distribution in the body and the exposure time to various tissues. The International Commission on Radiological Protection, ICRP 66 [International Commission on Radiological Protection (ICRP), 1994. Human Respiratory Tract Model for Radiological Protection. ICRP Publication 66] recommends the use of experimentally determined solubility coefficients in dose modelling. Material specific absorption parameters allow for better dose estimation than using ICRP default values for F (fast), M (moderate) and S (slow) classifications of U compounds. In vitro dissolution tests were carried out on U material collected from two U mines located in Australia. A static technique was designed in which particle samples were sandwiched between two 0.1-mum pore size membrane filters. The filter sandwich was exposed to a solvent (simulated lung fluid) for selected time intervals, at controlled test conditions for temperature and pH. The collected solution was analysed for U concentration using ICP-MS. The resulting dissolution curves were fitted with a double or triple exponential equation to determine the dissolution coefficients.     

Hydrothermal oxidation of waste lipids, protein, and starch from New Zealand meat- and vegetable-processing plants.

Disposal of organic waste materials from the meat- and vegetable-processing industries historically has been undertaken by dumping, drying followed by combustion, or biological oxidation. As a result of higher intensity processing rates and increasingly stringent legislation, these are no longer economical. Hydrothermal oxidation, also referred to as "wet" oxidation, has been used to lower the chemical and biological oxygen demand of waste samples from the above two industries. The starch-based wastes were readily oxidized without a catalyst. For the lipid and protein-based wastes, the use of copper calcium silicate and nitrate catalysts provided a significant reduction in oxygen demand at 230 degrees C.