The Teledyne Wah Chang facility is a manufacturer of the rare metal
zirconium. The facility has been in constant production since 1956. In 1973
an attempt to utilize different sand ore sources from Nigeria and India in a
new carbiding process, prior to chlorination, failed. The resulting
byproducts of the carbiding process and approximately 2000 kg of zircon
sand ore were lost in what is now called the Former Sand Unloading Area.
In 1982, Teledyne Wah Chang facility was listed as a Superfund site. The
Former Sand Unloading Area was contaminated with naturally-occurring
radioactive material. After being listed, Teledyne Wah Change began the
Remedial Investigation / Feasibility Study process in an attempt to cleanup
the Former Sand Unloading Area and other contaminated sites.
Afterwards, it was discovered that the remediation goals for the Former
Sand Unloading Area only addressed exposure pathways to current workers
on site. No consideration had been given to possible future occupants under
long term exposure scenarios. In this study, three scenarios were modeled
to illustrate the most plausible occupancy uses of the Former Sand
Unloading Area. The scenarios were: current industrial worker,
commercial worker, and a residential occupant. The pathways that were
used to model the exposure scenarios were, direct external radiation,
inhaled and ingested soil, and plant consumption. The RESRAD computer
code was used to estimate the dose rates to current and future occupants
working or living on the Former Sand Unloading Facility. The maximum
resulting radiation dose received was 16.7 mrem y����� for the industrial
worker scenario. The lowest maximum radiation dose received was 13.6
mrem y����� for the commercial worker scenario. The most conservative
assumptions and efforts were used to ensure the maximum dose rate was
modeled. The maximum radiation dose rate received at the Former Sand
Unloading Area was below the regulatory maximum allowable exposure
limit of 25 mrem y�����. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32452 |
| Date | 16 November 2001 |
| Creators | Miller, Robert E. |
| Contributors | Higley, Kathryn A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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