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At least 37 records · Page 2

Proceedings of Meeting on Problems and Techniques Associated with the Decontamination and Sterilization of Spacecraft

The United States is about to embark on an ambitious program of Lunar and Space Exploration. This program will not only serve the needs of the national and international scientific community but will also enhance the prestige of the United States in the eyes of the peoples of the world.There are many problems associated with such pioneering investigations, among which is included the effecting of adequate safe- guards against biological contamination of celestial bodies with ter- restrial microorganisms. In the not too distant future, the reverse problem of preventing contamination of our terrestrial body with extraterrestrial microorganisms must be considered. In order to determine the current status of decontamination and sterilization procedures and to arrive at areas of research required in order to increase the knowledge in this field, the NASA sponsored a meeting at which time this problem was discussed. Invitations to attend this meeting were extended to agencies actively concerned with the development of spacecraft and launch vehicles as well as those groups involved in the investigation and development of decontamination and sterilization techniques. The meeting was held in Washington, D, C. on June 29, 1960. The recorded minutes of this meeting, which have been edited, are included in this paper, as well as a listing of recommendations resulting from the deliberations.

Posner, Jack↗

Method of decontaminating a contaminated fluid by using photocatalytic particles

A system for decontaminating the contaminated fluid by using photocatalytic particles. The system includes a reactor tank for holding the contaminated fluid and the photocatalytic particles suspended in the contaminated fluid to form a slurry. Light irradiates the surface of the slurry, thereby activating the photocatalytic properties of the particles. The system also includes stirring blades for continuously agitating the irradiated fluid surface and for maintaining the particles in a suspended state within the fluid. The system also includes a cross flow filter for segregating the fluid (after decomposition) from the semiconductor powder. The cross flow filter is occasionally back flushed to remove any semiconductor powder that might have caked on the filter. The semiconductor powder may be recirculated back to the tank for reuse, or may be stored for future use. A series of such systems may be used to gradually decompose a chemical in the fluid. Preferably, the fluid is pretreated to remove certain metal ions which interfere with the photocatalytic process. Such pretreatment may be accomplished by dispersing semiconductor particles within the fluid, which adsorb ions or photodeposit the metal as the free metal or its insoluble oxide or hydroxide, and then removing the semiconductor particles together with the adsorbed metal ions/oxides/hydroxide/free metal from the fluid. A method of decontaminating a contaminated fluid is also disclosed.

Cooper, Gerald↗

Integrated electrochemical nuclear decontamination system

An electrochemical cell that oxidizes a solution provides a continuous and stable supply of an oxidizing ion solution to a fixture or vessel used for the purposes of decontaminating metal and metal alloys. The electrochemical cell includes an anode compartment that oxidizes the solution in nitric acid or methane sulfonic acid at a rate equal to or greater than a rate of reduction, or generates the oxidizing ions prior to use in a batch. The electrochemical cell is part of a larger system that facilitates online measurement system which measures the oxidizing ion solution and the dissolved PuO 2 , UO 2 , AmO 2 , other radionuclides, or other contaminates in real-time. Solution decontamination system removes the dissolved PuO 2 /UO 2 /AmO 2 , other radionuclides, or other contaminates from the oxidizing ion solution, real time acoustic monitoring of the thickness of the surface being contaminated, and automation of a delivery system facilitates flow between surface and electrochemical cell.

Karmiol, Benjamin↗

The distribution and selective decontamination of carbon-14 from nuclear graphite

This work investigates 14 C release behaviour from UK Magnox reactor sourced irradiated graphite under relatively low temperature oxidation conditions: a 1% oxygen in argon atmosphere at temperatures ranging from 600°C to 700°C, and durations from 4 to 120 hours. A method is used for construction of a detailed 14 C release profile with mass loss. The 14 C release profile is predictable between samples, and an empirical release profile is derived to predict releases to higher mass losses than in this work. An accelerated 14 C release rate at small mass losses is observed, indicative of a 14 C-enriched surface region with a depleting concentration gradient into the material, and the source terms and complexities associated with predicting where the 14 C arose from are discussed. Selective decontamination of a fraction of the 14 C is possible, with the limitation of a reducing efficiency with mass loss and time. This work demonstrates a method for determining the distribution of 14 C between near-surface regions and the bulk material in differing sources of irradiated graphite, and provides data in support of making an informed assessment for the adoption of low temperature thermal treatment and isotopic reduction of irradiated graphite wastes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Evaluation of sustainable waste management: An analysis of techno-economic and life cycle assessments of municipal solid waste sorting and decontamination

This study evaluates the economic and environmental feasibility of Municipal Solid Waste (MSW) sorting and decontamination technologies across urban, suburban, and rural areas. Using Techno-Economic Analysis (TEA) and Life Cycle Assessment (LCA), the research assesses cost-effectiveness and environmental impacts, with a focus on cost variability analyzed through Monte Carlo simulations. Findings indicate significant cost differences based on population density: rural areas incur high costs up to $$764/ton due to low waste volumes and limited infrastructure, whereas suburban and urban areas have more feasible costs ranging from $36.3 to $142.5/ton. Environmental impacts also vary, with greenhouse gas emissions at 171 kg CO 2 eq/ton for copy paper and 118.6 kg CO 2 eq/ton for plastics. PM2.5 levels are 9.1 g/ton for copy paper and 6.3 g/ton for plastics, with sorting lines being the main contributors. Monte Carlo simulations reveal a 50% probability of costs being below $$102.26/ton for copy paper and $115.8/ton for plastics in suburban settings. Further, the study underscores the importance of customized waste management strategies to improve economic viability and sustainability based on local conditions.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

NASA Announces Spacecraft Decontamination Procedures

The National Aeronautics and Space Administration has announced procedures for the sterilization of planetary spacecraft and revised the procedures for the decontamination of unmanned lunar landers.

DECONTAMINATION↗

Municipal Solid Waste Decontamination

The project goals are to understand the current types of contamination and their impact on conversion yields, to develop decontamination strategies, and to understand the TEA/LCA tradeoffs for these proposed strategies.

09 BIOMASS FUELS↗