66

In addition to accidental releases of uranium, a

number of accidental releases of HF occurred. For

example, an analysis was performed in 1975 to explain

high gaseous fluoride readings in the ambient air

samples. In this occurrence, system failures in the feed

plant were attributed to the high readings. Other

accidental or unplanned releases have also occurred.

For example, several former and current workers

interviewed reported blue flames 10 inches high in the

classified landfill after a heavy rain.

Diffuse and Fugitive Emissions

Diffuse and fugitive emissions were generally not

calculated for the site from 1952 through 1990. A limited

set of data exists for releases during the mid-1950s from

some processes, such as uranium metal pickling,

smoking ash receivers, and drum dryer exhaust.

Workplace air samplers and contamination on roofs and

ground in the site area point to the occurrence of

unmonitored releases. One example is the C-404

Holding Pond. Uranium-contaminated water was

originally piped to the pond, and in 1957 the pond was

turned into a solid waste burial area. A ramp was later

constructed to reduce dust emissions from the area.

After the mid-1960s, the ambient air samplers could

have reflected some air concentration contributions to

diffuse and fugitive emissions. However, no modeling

studies were performed to evaluate how those samples

might represent these emissions. Also, only low volume

samples were taken. This Oversight investigation found

no evidence that the performance of the low volume

ambient air sampler network was ever evaluated under

a variety of wind and weather conditions. There was

no evidence that diffuse and fugitive emissions were

substantively included in release inventories and

subsequent public dose calculations. Also, even though

diffuse emissions of transuranics would have occurred

during pulverizing of the feed plant receiver ash, no

estimates of these emissions were found.

Diffuse and fugitive emissions of fluorides were

not calculated for the site from 1952 through 1990. In

addition, the investigation team did not have sufficient

information to estimate releases of fluorides using the

limited set of data for uranium releases during the mid1950s. However, as discussed under UF4

 and metal

production (see Section 3.2.3), the release of fluoride

from the production of UF4

 was the probable cause of

ecological damage in the areas around C-340.

Planned Releases

Four planned atmospheric releases of UF6 occurred

at PGDP: two 4.4 kg releases in 1955 and two 0.68 kg

releases in 1974. These releases were designed to model

plume behavior from a surface release and were

followed by an additional series of tests where

approximately 160 grams of UF6 was released at ground

level directly into the atmosphere. Finally, six releases

occurred in the 1975-1976 timeframe, involving a total

of approximately 1 kg of UF6.

As described in Section 3.2.2, there is some evidence

that planned releases occurred when preparing the

cascade cells for maintenance. Jetting of the cells,

possibly to decrease the concentration of uranium in

the cells, was accomplished by releasing UF6 from vents

on the roofs of the process building. The frequency

and amounts of the releases are unknown. Because a

large quantity of uranium could have been involved,

jetting of the cascades could be a major contributor to

the annual releases. Interviews with the former health

physics manager revealed that contaminants jetted to

the atmosphere in cascade buildings were not factored

into release estimates.

4.5 Environmental Management

Summary

The waste management program at the Plant

reacted to external requirements. The waste

management program that was implemented during the

1980s eventually was able to correct waste activities

that had been inadequately managed for years.

However, large volumes of waste materials accumulated

on site with inadequate characterization for waste

classification and disposal. Controls on waste disposal

practices were not stringent or fully implemented in the

early years of Plant operations, resulting in the creation

of numerous disposal sites at the Plant. Additionally,

based on employee interviews and a review of

procedures and correspondence, it is clear that

radiological waste materials were inappropriately

disposed of in old and sanitary landfills used at the Plant

before the sanitary landfill was permitted by the

Commonwealth of Kentucky. Interviews with current

and former workers identified locations where waste

was discarded around the site from the very early days

of operations. With few exceptions, these locations

correspond to past landfills, scrap yards, lagoons, and

spill sites that have been identified as SWMUs as part
67

of the current cleanup program under the Federal Facility

Agreement.

The Health Physics and Hygiene Department has

recognized the need to ensure the proper segregation of

clean from contaminated materials prior to their release

from the site. However, there were documented

problems associated with proper implementation of scrap

handling procedures and only a very small number of

health physics personnel available to perform radiological

surveys. Therefore, it is likely that materials exceeding

appropriate radiological release guidelines were sent off

site on a routine basis until the late 1980s.

Past liquid effluents have had a significant adverse

impact on environmental quality with respect to onsite

ditches and streams and groundwater resources in the

vicinity of the site. Operations at C-400 produced the

most significant radiological effluent, releasing uranium,

thorium, and small quantities of fission products and

transuranic isotopes in process effluents. Additionally,

C-400 operations also released significant amounts of

TCE from cleaning operations into the environment,

resulting in significant environmental liabilities for the

Department. Interviews and documents indicate that

from the beginning of Plant operations, Plant personnel

made deliberate decisions regarding radioactive effluent

releases, with the objective of ensuring acceptable impact

on the quality of the Ohio River. Significant efforts

were undertaken to improve the quality of area surface

waters during the 1970s, consistent with increasing

regulatory requirements and an increased sensitivity to

environmental protection.

There is evidence that air emissions from 1952 to

1990 exceeded previous estimates. Stack monitoring

was not conducted until the mid-1970s; before then,

process knowledge was used to estimate potential

releases from this pathway. Personnel who performed

these estimates acknowledged that these calculations

are highly uncertain. It was also acknowledged that

other isotopes, such as plutonium and neptunium, could

have been released, but based upon the limited quantity,

these isotopes were considered to be insignificant

contributors to dose. Therefore, these isotopes were

not included in published estimates. Process gas

releases were common throughout 1952 to 1990, and

the potential for these to be vented to the atmosphere

was high. The magnitude of these unmonitored releases

is unknown. Additionally, unauthorized purging of

cascade cell gases through the process of jetting appears

likely to have been another significant pathway for

unmonitored releases, which have never been estimated

or factored into known uncertainties. Given all this, it

is apparent that past estimates of public dose have a

questionable level of accuracy and conservatism.