Method and apparatus for monitoring contamination
AssigneeWestinghouse Electric Corp.
InventorsJeffrey W. Dickinson, Charles G. Hudson, Daniel S. Johnson, Richard McGinley, Richard J. Sexton
Life of this patent
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Abstract
A method for measuring the fixed contamination level in a confined area such as small diameter pipe. The method measures the accumulated detection response over a given area and prescribed time period. To obtain the measurement a plurality of sensors are connected in tandem to form a flexible detector string and remotely positioned within the area to be monitored. The measurement is correlated to a standard obtained by using a known source in a simulated mockup environment. In one embodiment a passive monitor such as a Thermo-Luminescence Dosimeter is employed as the sensor.
Claims34
A method for measuring the level of contamination in a given inaccessible monitored area to approximately background levels, per unit of time, comprising the steps of:
- sizing a plurality of detectors, which are responsive to measure the contamination to be monitored to background levels, to fit within and readily move through the monitored area;
- coupling the plurality of detectors in tandem, a fixed distance from each other, sized to enable the detectors to traverse approximately 90.degree. bends inside a tubular conduit, with a flexible coupling to form a detector string that enables the detector assemblies to rock with respect to each other as they traverse the bends;
- inserting the detector string within the monitored area;
- leaving the detector string within the area for a specified period of time;
- and
- reading the accumulated measurement monitored from the detectors.
Apparatus for measuring contamination at approximately background levels in a given inaccessible monitored area, per unit of time, comprising:
- a plurality of detectors, which are individually responsive to measure the contamination to be monitored;
- and
- flexible connectors for connecting the detectors together in tandem a fixed given distance from each other to form a flexible detector string that enables the detector assemblies to rock with respect to each other.
A method for measuring the contamination in a given monitored area to approximately background levels, per unit of time, comprising the steps of:
- inserting a first passive detector, sized to fit within the monitored area;
- leaving the first detector within the area for a specified period of time;
- withdrawing the first detector from the area after the specified period of time;
- reading the accumulated measurement monitored from the first detector;
- creating a simulation of the given area by placing a known calibrated contamination source within a corresponding uncontaminated environment in a manner that, aside from the level of contamination, substantially simulates the environment being monitored and accommodates a second detector;
- inserting the second detector within the simulated environment for a set period of time;
- reading the accumulated measurement monitored from the second detector;
- correlating the measurement of the first and second detectors to establish a calibrated contamination measurement per unit of area per unit of time.
Dependencies are inferred from the claim text.