Pressurized powder release through micro-openings in faulted containers
Estimates of the quantity of a powder potentially released from a faulted shipping container can be highly conservative under the practices currently in use. The integrity of accident-resistant shipping containers is often determined by measuring the leak rate of a gas that can be measured with great sensitivity (such as helium) after a series of rigorous tests. The gas is assumed to contain some mass concentration of powder and the quantity released to the air is the volume released times the mass per volume. A method of more accurately estimating releases of powder through micro-openings has been developed. Under the sponsorship of the Systems Performance Branch of the US Nuclear Regulatory Commission, the Pacific Northwest Laboratory conducted a series of experiments to determine the transmission of a stable powder, such as plutonium dioxide, through micropathways. Dimensions of these pathways were consistent with theoretical openings and measured leak rates determined while testing the inner container of the Plutonium Air Transportable (PAT) package (NRC 1978). The driving force required to obtain a positive leak outward is supplied by heat (radioactive decay and potential fires). In a real situation, the number, size, and shape of the pathways and their orientation with respect to the powder contained (above or below) can vary greatly. To make the problem more tractable, the study was limited to a single, round opening (orifice or capillary). The assumption is still conservative since it results in the largest cross-sectional area for any given gas flow. The study was divided into three phases: the prediction of gas flows through micro-orifices and -capillaries; the transmissions of powder through these pathways; and a methodology to apply the finding to assess the potential airborne release of contained powders from faulted containers.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 5189778
- Report Number(s):
- PNL-SA-8510; CONF-801115-44; ON: DE82007066; TRN: 82-013627
- Resource Relation:
- Conference: 6. international symposium on packaging and transporting radioactive material, Berlin, F.R. Germany, 10 Nov 1980; Other Information: Portions of document are illegible
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
CAPILLARIES
GAS FLOW
CONTAINERS
LEAKS
PLUTONIUM DIOXIDE
FORECASTING
POWDERS
ACTINIDE COMPOUNDS
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
CHALCOGENIDES
FLUID FLOW
ORGANS
OXIDES
OXYGEN COMPOUNDS
PLUTONIUM COMPOUNDS
PLUTONIUM OXIDES
TRANSURANIUM COMPOUNDS
420204* - Engineering- Shipping Containers
050900 - Nuclear Fuels- Transport
Handling
& Storage