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Chronology of Activities at Paducah

Gaseous Diffusion Plant

Past activities (1952 to 1990) at PGDP are

presented in chronological fashion within a series

of functional areas summarizing key Plant

operations and activities and relating to the safety

and health of workers, the public, and the

environment.

2.1 Site Background

In August 1950, the U.S. government

determined that it would need to double the

capacity of domestic fissionable materials

production that existed at the Oak Ridge K-25

Plant. The Atomic Energy Commission (AEC)

selected a Plant option consisting of 400 stages

modeled after the K-31 facility at Oak Ridge

(which would become C-331 at the Paducah

Plant) and 480 stages twice the size of the Oak

Ridge K-31 stages (which would become C-333

at the Paducah Plant). Based on a decision to

disperse the major portions of the new production

capacity, eight areas were identified as candidate

locations for the Plant, all in the southeastern U.S.

From the application of additional criteria, three

sites were identified: the Kentucky Ordnance

Works (KOW) at Paducah, the Louisiana

Ordnance Plant at Shreveport, and the Longhorn

Ordnance Works at Marshall, Texas. From these,

the AEC approved, on October 18, 1950, the

KOW site as the location for the new gaseous

diffusion plant.

PGDP construction spanned 1951 through

1956 and was conducted in two phases.

Construction of the first phase began January 2,

1951, and included erection of the following

process and production facilities: C-331 and C333, the gaseous diffusion process buildings; C410/420, UF6

 Feed Plant; C-310, Purge and

Product Withdrawal Building; C-315, Surge and

Waste Building; and C-300, Central Control

Building. On January 6, 1951, the Tennessee

Valley Authority began construction of the fourunit Shawnee Steam Plant near the Paducah Plant

on the Ohio River to provide a portion of the

needed electricity. On February 15, 1951, Electric

Energy, Incorporated began construction of the

Joppa Steam Plant, in Joppa, Illinois, to also provide

electricity to PGDP. Authorization to proceed with

the second phase of Plant construction was received

on July 15, 1952. Two additional enrichment

facilities, C-335 and C-337, were added, and

construction was completed in 1956. Carbide and

Chemicals Company (which became Union Carbide

Corporation Nuclear Division) was named as the

original site contractor based on the companyís

experience with gaseous diffusion operations at Oak

Ridge. Carbide operated PGDP for the AEC, and

its successor agencies the Energy Research and

Development Administration (ERDA) and DOE,

until 1984, when they were replaced through a

competitive procurement by Martin Marietta Energy

Systems, Inc.

In the early 1950s, the Plant provided some

of the better paying jobs in the area, if not the

region. Workers believed that the mission of the

Plant was important to national security, and they

worked hard to meet expectations. Accordingly,

being an employee of the Plant engendered respect

and there was civic pride in the fact that Paducah

was the location of a facility that played a role

that was important to the nation. Many of the

Plantís original operators and workers were military

veterans and viewed the opportunity to work at

PGDP as a way to continue their service to the

country. This notion of service is reflected in the

fact that a significant proportion of workers would

Construction at PGDP

2.0
12

become long-term Plant employees, transcending

changes in Federal oversight organizations and transitions

in contractors.

Demands on the Plant and the workers were high,

given the requirements of the Cold War. Work was

difficult, production schedules were challenging, and

the work environment was often hot, loud, dirty, and

laden with noxious fumes. The security demands of

the Cold War also affected worker awareness of hazards

in that, prior to 1989, documents discussing many

aspects of operations were classified and, at the direction

of line management and AEC security, detailed

knowledge of work activities was based on a ìstrict

need to know.î The workersí sense of loyalty and

service would also translate into acceptance of these

security policies and the expectation that they would be

told everything that they needed to know.

From the 1950s to the 1990s, government oversight

of ES&H elements of PGDP contractor activities

evolved. The primary offices of the Federal regulatory

organizations for the diffusion plants ó the AEC,

ERDA, and DOE ó have always been located in Oak

Ridge, although there was a Federal presence at PGDP

for most of the period 1952 to 1990. Records indicate

AEC involvement in collaborative research activities

related to radiation and health physics in the 1950s

through the 1970s, but there is little evidence of direct

observation of, or direction to, the PGDP contractor

regarding ES&H, which was not an uncommon practice

for a regulatory agency during that period. Carbide

provided quarterly progress reports to the AEC

summarizing operational, maintenance, construction,

industrial hygiene, health physics, and accident data and

analysis and responded to information requests on health

physics issues. However, the interactions between the

contractor and AEC clearly emphasized maintaining or

increasing production. In the 1970s, as new

environmental regulations were enacted, there is

evidence of growing involvement by the Commonwealth

of Kentucky and OR in site activities and in the effects

of site activities on the environment and the public. In

the 1980s, increased DOE oversight was evidenced by

additional ES&H inspections by the local site office

and OR. On September 18, 1985, then-Secretary of

Energy John Herrington announced that DOE-wide

environmental surveys would be conducted; the PGDP

survey occurred in November and December 1987.

These surveys led to changes in DOE and contractor

ES&H programs. However, the 1990 DOE Tiger Team

identified ineffective DOE oversight and unclear

oversight roles and responsibilities as key management

findings.

2.2 Operations

Although major construction activities would

continue through 1956, Union Carbide began hiring

approximately 1,700 permanent Plant workers in 1951.

The first process buildings, C-331, C-333, C-310, and

C-315, were completed and started operation in

September 1952, and the first product was withdrawn

in November. The purpose of the gaseous diffusion

plant has been and continues to be the enrichment of

uranium, initially for military applications and

subsequently for commercial reactor fuel. PGDP

enriches feed material in the form of UF6 gas with

approximately 0.7 percent uranium-235 to UF6 with

one to three percent uranium-235. The enriched product

from PGDP was sent to other DOE sites at Portsmouth

or Oak Ridge for further enrichment. Most UF6 feed

material came from the depleted tails produced during

normal diffusion operations at PGDP and from Oak

Ridge and Portsmouth. From 1952 through 1977, UF6

feed material was also produced from uranium trioxide

or UO3

 (called ìyellowcakeî) at PGDP in Buildings C410 and C-420; this feed material was supplied by

sources such as El Dorado Mining and Refining,

Mallinkrodt Chemical Works, and General Chemicals

(now Allied Chemical) and comprised less than 10

percent of the UF6 fed to the cascade. From 1953

through 1964 and intermittently from 1968 through

1977, the feed plant also produced UF6

 from UO3 from

spent reactor fuel processed at the Hanford and

Savannah River sites. After 1977, all feed came in the

form of UF6

 from outside sources such as Oak Ridge,

Portsmouth, and Allied Chemical.

Although natural uranium is not a highly radioactive

material, it is toxic, both chemically and radiologically,

when inside the body. The uranium exposure pathway

of greatest hazard at PGDP was inhalation of uranium

dust. Feed material was made from production reactor

tails from 1953 until 1964, and intermittently from 1968

to 1977. The percentage of PGDP cascade feed

material from reactor tails averaged 19 percent during

the 19 years this material was used, ranging from 3

percent in 1975 to 65 percent in 1973. Processing of

UO3

 into UF6 was accomplished in three steps:

reduction, hydro-fluorination, and fluorination (see

Figure 3).

Reduction involved transforming UO3

 into UO2

(commonly referred to as ìblack oxideî) using hydrogen

gas. Hydro-fluorination of UO2

 into UF4 (commonly

referred to as ìgreen saltî) was accomplished by adding

anhydrous hydrofluoric acid (HF). Fluorination was