D. G. Black
Onsite and offsite environmental releases of radioactive and regulated materials during 1994 were reported to
DOE and to federal and state agencies as required by law. The specific agencies notified depended on the
type, amount, and location of the individual occurrences. In some cases an occurrence may be under
continuing observation and evaluation. During 1994, all unusual and off-normal occurrences at the Hanford
Site were reported to the Hanford Site Occurrence Notification Center. This Center is responsible for
maintaining both a computer database and a hard copy file of event descriptions and corrective actions.
Copies of occurrence reports are made available for public review in the DOE Public Reading Room located
on the Washington State University Tri-Cities campus in Richland, Washington.
As defined in DOE Order 5000.3B, emergency occurrences "are the most serious occurrences and require an
increased alert status for onsite personnel and, in some specified cases, for offsite authorities." There were no
emergency occurrence reports filed in 1994.
Unusual occurrences are defined as nonemergency occurrences that may have a "significant impact or
potential for impact on safety, environment, and health." There were 33 unusual occurrence reports filed
during 1994 for Site contractors. The only unusual occurrences of environmental significance are
summarized below.
Off-normal environmental occurrences are referred to as "abnormal or unplanned events or conditions that
adversely affect, potentially affect, or are indicative of degradation in, the safety, environmental or health
protection performance or operation of a facility." There were 16 off-normal environmental release-related
occurrence reports filed at the Hanford Site during the year most of which involved releases of various types
of oil. DOE contractors submitted these reports to the DOE reporting database, Occurrence Reporting and
Processing System during calendar year 1994. The "Nature of Occurrence" for these occurrences was
determined to be either "Hazardous Substances/Regulated Pollutants/Oils" or "Hazardous Material
Contamination". The more significant of these off-normal occurrences are summarized below.
Unusual Occurrences
Diesel Tank Leak at the 6652-L Building
After an underground diesel oil storage tank was removed, soil sample results indicated the soil under the tank
was contaminated with oil. Soil samples were collected and tested and the analyses were submitted to
Ecology. Based on Ecology's decisions, the site was cleaned up.
Disturbance of Native American Burial Ground
During excavation of an area south of the 300 Area for construction of the EMSL, an apparent Native
American burial site was uncovered. The Hanford Cultural Resources Laboratory representative who was
monitoring the excavation made the discovery and halted the work. Representatives of the tribes were
notified immediately, and meetings were held with DOE to discuss stabilization and restoration needs. The
tribes assumed responsibility for directing the restoration with funding provided by DOE. The planned
building and facilities were relocated to avoid further disturbance.
Tank 241-C-110 Saltwell Diluted Waste Spill
In December 1994, while flushing a transfer line at the C-110 Saltwell in the 200-East Area, an operator
noticed a quick disconnect that was leaking diluted waste onto a concrete pad and adjacent soil. Samples of
the waste were taken to determine the what radiological contaminants were present. In addition to
radiological contaminants in the diluted waste, hexavalent chromium was found at a concentration of 27.6
ppm, which exceeded the regulatory limit of 5.0 mg/l (5 ppm). The spilled liquid was therefore determined to
be a dangerous waste exhibiting the toxicity characteristic for chromium. The total quantity spilled was
calculated to be 4.540 kg (10.008 lb) containing 0.102 g (
) of chromium. This spill was
upgraded to an unusual occurrence upon detection of the presence of the dangerous waste and the
determination of the reportable quantity. The spill was cleaned up.
Off-Normal Occurrences
Oil Leaks in the 183-KW Transformer Yard
In March 1994, during maintenance surveillance of the 183-KW transformer yard, maintenance personnel
noticed one transformer (Number D42719F) had leaked approximately 38 L (10 gal) of oil onto the ground.
Substation maintenance was contacted for a spill assessment. During inspection of the transformer yard with
substation maintenance, another transformer (Number D42718F) was discovered that had also leaked at least
38 L (10 gal) of oil to the ground. Both transformers were clearly labeled "Non-PCB-Contaminated Oil."
Substation maintenance notified the spill office, electrical utilities, and the K Basins maintenance manager.
Further investigation with electrical utilities produced documentation that each transformer had been
retrofilled and contained PCB concentrations of between 5 ppm and 6 ppm, which meets EPA qualifications
for non-PCB contaminated oils (less than 50 ppm). The spills were cleaned up.
384 Powerhouse Tank Removal Discovery of Contaminated Soil
In May 1994, while removing one empty diesel and one empty unleaded fuel tank, an offsite contractor
discovered fuel-contaminated soil under the tanks. Approximately 
(
) of contaminated soil
were excavated. The leaks appeared to be around the fuel line fittings and not from the tanks themselves.
Maximum soil concentrations were 4300 ppm and 660 ppm for diesel and gasoline, respectively.
384 Powerhouse Release of Number 6 Fuel Oil
In May 1994, during ongoing efforts to locate and repair an existing leak in the Number 6 fuel oil transfer
line, employees performing excavation work were unable to prevent accumulated oil from leaking to the
ground. Approximately 38 L (10 gal) of the oil leaked from a containment tray inside a heat retention
encasement that also holds the transfer line. The oil was cleaned up.
224-U Building Instrument Air Compressor Oil Leak
In June 1994, water was noticed coming from the Number 2 Joy air compressor cabinet, a backup instrument
air compressor located on the third floor of the 224-U Building. When the unit's doors were opened, water
was observed exiting the air inlet of the unit. Plant maintenance was called to shut-off electrical power to the
unit. The Number 2 Joy air compressor was not in operation but in stand-by mode. According to a work
package procedure, the plant millwright removed the lid from the oil sump and noticed that water was
present, indicating that the unit's oil had been displaced. Further troubleshooting determined that
approximately 94.6 L (25 gal) of lubricating oil had been displaced from the unit. Investigations determined
that the oil/water had drained into the nearby floor drain that leads to the 207-U Diversion Basin situated
approximately 0.4 km (0.25 mi) west of the Uranium-TriOxide Plant. (The Material Safety Data Sheet for the
lubricating oil notes that the product is not regulated.)
Vehicle Accident - Overturned Water Truck
In September 1994, a contractor for ICF Kaiser Hanford Company overturned a water truck at the intersection
of Route 4S and the entrance road to the 400 Area, Route 40, while attempting to make a left turn. The
Hanford Fire Department, Benton County Sheriff, and Hanford Hazardous Materials Group responded to the
accident. The driver was transported to Kadlec Hospital for observation and was released. The water truck
released 38 to 57 L (10 to 15 gal) of gasoline and approximately 11,000 L (2,900 gal) of water to the soil.
Environmental remediation activities to clean up the gasoline spill were completed according to procedure.
1171 Building Oil Release to Environment
In November 1994, during excavation of an in-ground vehicle floor hoist, work crews discovered
oil-saturated soil beneath the leaking hoist. Initial evaluation determined the accumulation of oil over time to
be in excess of 38 L (10 gal) of hydraulic oil. The release was cleaned up.
CERCLA and WAC Reportable Releases
There were 33 releases reported under the CERCLA-reportable quantity and WAC requirements by Hanford
Site contractors in 1994. Twenty two of these were ethylene glycol released from motor vehicles or
equipment, none of which were of any notable concern. The EPA Administrator has proposed an upward
adjustment in the threshold level reportable quantity by regulation for ethylene glycol. The final rule should
be published sometime in early 1995. An upward adjustment would have a major effect on the number of
reportable ethylene glycol releases by eliminating the 0.454 kg (1 lb) threshold reportable quantity criteria.
There were nine release reports filed in accordance with the requirements of Underground Storage Tank
Regulations, WAC 173-360. Eight releases were from underground storage tanks undergoing remediation
under the Hanford Infrastructure Underground Storage Tank L-044 Project. One release was from an
underground storage tank that was unearthed during excavation at the EMSL construction project. All
releases were remediated with Ecology concurrence, per regulatory cleanup standards.
Other Releases:
- On May 18, 1994, 38 L (10 gal) of Number 6 fuel oil was discovered to have leaked to the soil from the
bulk storage tank piping system at the 300 Area 384 Powerhouse. The release was remediated
and the piping system was repaired and put back into operation.
- On December 12, 1994, 27.6 mg (
) of hexavalent chromium were released to the top of a
concrete pad and a small amount was released to the soil during a flushing operation at the tank
farm area, Tank C-110 Saltwell Pump Pit. A detailed description of this release can be found
under "Unusual Occurrences" in this section.
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