Epidemiologic Studies

Y-12 Mercury Task Force Files

This introduction briefly describes the Epidemiologic Records Inventory Project and HAI's role in the project. Specific attention will be given to the history of the DOE-Oak Ridge Reservation, the development of the Y-12 Plant, and the use of mercury in the production of nuclear weapons during the 1950s and early 1960s. This introduction provides background information on the Y-12 Mercury Task Force Files, an assembly of documents resulting from the 1983 investigation of the Mercury Task Force into the effects of mercury toxicity upon workplace hygiene and worker health, the unaccountable loss of mercury, and the impact of those losses upon the environment. This introduction also explains the methodology used in the selection and inventory of these record series. Other topics include the methodology used to produce this guide, the arrangement of the detailed record series descriptions, and information concerning access to the collection.

The Epidemiologic Records Inventory Project
The Epidemiologic Records Inventory Project reflects DOE Secretary Hazel R. O'Leary's efforts to support openness initiatives in the areas of environment, safety, and health. In view of the importance of various administrative, organizational, and operational records to epidemiologic and health-related studies, a moratorium on the destruction of such records has been in effect since 1989.

In May 1992, the DOE Office of Epidemiology and Health Surveillance (EH-42), responsible for coordinating all epidemiologic activities throughout the Energy complex, directed each DOE site and DOE contractor to prepare an inventory of all records pertinent to worker or community health-related studies. EH-42 prepared and furnished each site with guidelines that defined epidemiologic records, provided instruction for describing record series, outlined the site's role in inventorying epidemiologic records, and discussed the relationship of the epidemiologic inventory to DOE's comprehensive records inventory. These inventories should be completed in 1995.

In August 1993, DOE selected History Associates as its support services contractor for the Epidemiologic Records Inventory Project. HAI, a professional records management, archives, and historical research services firm incorporated in 1981, has provided records management, historical research, and technical support for a number of DOE projects. HAI's role in this project includes verifying the accuracy, comprehensiveness, and quality of existing inventories, providing guidance to site records management teams, and, in some cases, conducting additional inventories.

As part of its task to verify and conduct inventories of epidemiologic and health related records at DOE and DOE contractor sites, HAI conducted a pilot study at the DOE-Oak Ridge Reservation. The primary purpose of this pilot project was to assist DOE in responding to the information needs identified in a March 1994 meeting with DOE, the Tennessee Department of Health (TDH), and other stakeholders. These groups expressed interest in the records relating to radioactive lanthanum (RaLa), iodine-131 and iodine-133, cesium-137, and the Mercury Task Force files. HAI began this task by inventorying and describing the record series contained in the Mercury Task Force files related to operations using large quantities of mercury. HAI is currently identifying and inventorying records relating to RaLa, iodine, and cesium, as well as resolving protocol and access issues. Although the identification and inventory of record series relating to other topics are still in progress, this process when completed, will allow DOE to provide the best possible assistance to health researchers interested in using the records relating to these hazardous substances.

HISTORY OF OAK RIDGE

The Oak Ridge plants produced significant amounts of hazardous waste by-products, and the Environmental Protection Agency (EPA) included Oak Ridge on its National Priorities List of Superfund hazardous waste sites in November 1989. In 1991 DOE signed the Oak Ridge Health Agreement that provides funds to the state of Tennessee for independent health assessment studies of the Oak Ridge operations and the surrounding population.

The Y-12 Plant
Since its inception in 1943, the official mission of Y-12 has changed over the decades. Originally, Y-12 separated the fissionable uranium isotope, uranium-235, from the more plentiful, but stable uranium-238 isotope, using the electromagnetic process. After the war, when this process was discontinued, Y-12's mission changed to manufacturing and developmental engineering. The plant produced nuclear weapon components, developed and fabricated test hardware for weapons, processed source and special nuclear materials, provided fabrication support for other Oak Ridge Reservation Plants, and supported other federal agencies. Y-12 recovered enriched uranium from obsolete weapons and scrap materials, processed enriched uranium from other DOE sites, and produced lithium compounds. Currently, the plant's mission is to serve as a key technology center for the development and demonstration of unique materials, components, and services of importance to DOE and the nation. Y-12 accomplishes its mission through the manufacture, reclamation, and storage of nuclear materials, construction of components for the nation's defense capabilities, and support of national security programs.

Since 1943, three contractors have operated the Y-12 Plant for the Manhattan Engineer District (MED) and its successor agencies. Tennessee Eastman, a subsidiary of Eastman Kodak Company, was the original contractor with the US Army Corps of Engineers. The Atomic Energy Act of 1946 assigned all atomic energy activities to the US Atomic Energy Commission (USAEC), effective January 1, 1947, and, later that year, the MED disbanded. In 1947, the Carbide and Carbon Chemical Corporation (CCCC), which later became known as Union Carbide Corporation (UCC)-Nuclear Division, replaced Tennessee Eastman and remained the Y-12 site contractor until 1984. In that year, Martin Marietta Energy Systems (MMES) assumed the Y-12 contract.

Lithium Isotope Separation and Enrichment at Y-12
In the early 1950s, the United States started to develop thermonuclear weapons. Unlike previous nuclear weapons, which derived their explosive force from the fission of uranium atoms, these new weapons obtained their energy from the fusion, or combination, of heavy hydrogen atoms. For this reason, these weapons became known as hydrogen bombs.

The primary material used in thermonuclear weapons was a form of hydrogen fuel known as lithium deuteride, produced from the lithium-6 isotope. Naturally occurring lithium contains about 7 percent of the lithium-6 isotope, while the rest of it is the lithium-7 isotope. In the 1950s, the Y-12 Plant developed, designed, constructed, and operated an industrial scale production process to separate and enrich the lithium-6 isotopes from lithium-7 isotopes for the production of lithium deuteride.
The separation process that produced most of the lithium deuteride was called Colex, a column-exchange process, in which the lithium isotopes were separated as the lithium was transferred between two chemical phases. One of the phases was an aqueous solution of lithium hydroxide and the other a lithium amalgam, a solution of lithium in mercury. The lithium-6 isotope dissolved more thoroughly in mercury than lithium-7. Lithium amalgam remained in a stable state while in contact with an aqueous solution. In other words, the lithium-6 atoms migrated to the amalgam and the lithium-7 atoms adhered to the lithium hydroxide in the aqueous fluid. Cold War production schedules of lithium deuteride required millions of pounds of mercury, and President Eisenhower authorized Y-12 to use a significant portion of the mercury from the National Stockpile for the Colex process from 1955 to 1963.

Colex operations were located in Buildings 9201-4 (Alpha 4) and 9201-5 (Alpha 5), and these became the mainstay of Y-12's lithium separation and enrichment process. Active from 1955 to 1963, Colex operations produced enough enriched lithium to fulfill anticipated future needs in the weapons program. In 1963, the Y-12 lithium separation and enrichment program was shut down, and over the next several years, the plant was engaged in dismantling production equipment and recovering mercury from the production facilities and equipment. Most of the equipment still remains in Building 9201-4.

Oak Ridge developed and used other methods to separate lithium isotopes. In the early 1950s, ORNL experimented with substituting water with an organic solvent. This process, known as Orex, an organic exchange process, was not pursued beyond the pilot stage because of technical difficulties. Buildings 9733-1 and 9202 housed the Orex pilot plants from 1951 to 1953. Another method used in the separation of lithium isotopes was Elex, an electro-chemical separation process. Elex was conducted in Buildings 9733-2 and 9201-2 between 1950 and 1951. A production scale Elex process was started up in Building 9204-4 (Beta 4) and operated from 1953 to 1956. By 1956, Y-12 found Elex to be an inefficient process, abandoned it entirely, and operated the Colex process only.

The Establishment of the Y-12 Mercury Task Force Files

On May 20, 1983, Y-12 managers selected a Task Force to investigate the apparent mercury problem at Y-12. The Task Force's investigation took eight weeks, during which time the group collected pertinent documents concerning the lithium separation and enrichment processes, mercury material accountability, monitoring of the workplace for mercury contamination, worker exposure, and environmental releases. Following the investigation, the Mercury Task Force summarized its findings in a classified report entitled Mercury at Y-12: A Study of Mercury Use at the Y-12 Plant, Accountability, and Impacts on Y-12 Workers and the Environment-1950 to 1983 (Y/EX-21). A declassified version (Y/EX-24) is available, as is Mercury at the Y-12 Plant: A Summary of the 1983 UCC-ND Task Force Study (Y/EX-23).

Workplace Hygiene and Worker Health

An area of interest of the Mercury Task Force was the impact of mercury toxicity on workplace hygiene and worker health. From the beginning of the lithium isotope separation and enrichment process at Oak Ridge, AEC officials and Y-12 Plant managers and industrial hygienists recognized the need to safeguard and monitor the health of the workforce. From 1950 to 1954, industrial hygiene programs were instituted in the Orex, Elex, and Colex pilot plants. With the industrial scale use of mercury in the Colex operations after 1954, these officials became especially concerned about the medically recognized hazards of inhaling toxic mercury vapor. Since greater quantities of mercury would be used in full-scale Colex operations than previously, the plant expanded existing industrial hygiene programs and implemented new ones to protect worker health.

The Colex process was a pioneering technology that required specialized pumps, valves, and other equipment not used previously for such applications. Plant engineers anticipated frequent maintenance and operational problems during the initial months of operation. In 1955, the first full-scale year of the Colex process, the pumps and valves required much service and repair. Often the processing system was full of mercury and large quantities of it leaked and spilled on the floor. Drainage systems were modified so that the floor drains would direct the mercury into special tanks that separated the mercury from wastewater, mainly mopwater, collected in sumps that emptied into the creek.

From the outset of the Colex operations in 1953, Y-12 conducted both routine air sampling to monitor the mercury concentrations within the workplace and a urinalysis program to monitor individual worker exposure. During the start-up of Colex operations in 1955, air sampling indicated that mercury concentrations in Buildings 9201-4 and 9201-5 were higher than the then recommended standard of 0.1 milligram/cubic meter (now 0.5 mg/m3). Urinalysis also indicated that workers had been exposed to higher concentrations of mercury than normal in 1955. In general, the risk of mercury exposure was greatest in 1955 and 1956, the ramp-up years of Colex operations. After 1956, the risk declined as air sampling data indicated mercury concentrations below the threshold limit value of 0.1 mg/m3.

In addition to the air sampling and urinalysis programs, Y-12 conducted a special medical surveillance program of the Colex workforce. Workers were medically examined every six months and workers with a history of albuminuria, kidney problems, or hypertension were screened out and not assigned to work in mercury exposed areas.

In late 1955, AEC and Y-12 managers instituted various mechanisms to reduce mercury concentrations in the workplace and safeguard worker health. The plant studied paints and other substances that could reduce vapor pressure and dissolve mercury droplets. Large fans were installed at the ends of the process buildings to remove contaminated air and circulate fresh air throughout the production areas. A special vacuum system was installed for mercury removal. In early 1956, the plant emphasized the use of respirators and, after a close examination of the commercially available respirator filter cartridges, selected the Mersorb cartridge for use by Colex workers. The effectiveness of these and other measures is documented in the historical record of air concentrations, which shows significant reduction of mercury concentrations in the air by March 1956 and successful control of mercury release during the subsequent operating years.

Worker Medical and Mortality Studies, 1974-1983

The Mercury Task Force reviewed existing medical and mortality studies of mercury workers and suggested an additional one. In 1974, the National Institute for Occupational Safety and Health (NIOSH), under the direction of Dr. Z. Bell, conducted a medical check-up of 23 former Colex workers still employed at Y-12. Bell's examination revealed no cases of mercury poisoning and only one case of mercurialentis, a harmless discoloration of the eye, in a worker for whom there was no record of exposure.

In 1983, Oak Ridge Associated Universities conducted a preliminary mortality study of the Y-12 mercury workforce (1,477) and other Y-12 workers (4,920), comparing these groups to the U.S. population as a whole, to see if the death rates were higher for workers exposed to mercury than those not exposed to mercury. No differences were found between either cohort of Y-12 workers and the U.S. population, and no difference was found between Y-12 mercury workers and other Y-12 workers in death rates due to cancer, neurological disease, respiratory disease, and kidney failure.

As a result of the investigation by the Mercury Task Force, Y-12 initiated a special medical examination of the Y-12 mercury workforce, a study that offered the opportunity to evaluate a large group of people (2,450) 20 years after well documented exposure to mercury (27,000 urinalyses). Whereas studies conducted elsewhere of human populations with similar degrees of mercury exposure indicated no organic effects, this one could offer different results since the Y-12 population was larger and had a longer term after exposure. The investigators were looking for the most common symptoms of chronic metallic mercury poisoning--tremors, memory loss, and gingivitis. These symptoms are also signs of the natural aging process, another characteristic of the extant Y-12 mercury workforce. In August 1983, Y-12 selected eight experts in mercury toxicity and chronic mercurialism diagnosis and requested their recommendations on what

Mercury Material Balance
According to the 1977 Mercury Inventory Report, 2.4 million pounds of mercury were "lost" or "spilled" during the lithium separation process. Although the report correctly referred to this figure as the amount "lost" or "spilled" plus an "unaccounted for" amount, the subsequent public debate over the Y-12 mercury problem obscured the distinctions between those terms. The Task Force attempted to clear up the confusion over the amount of mercury "lost" and the amount "unaccounted for" by reviewing the extant records dealing with shipping, receiving, flasking, storage, accounting, and budget.

After reviewing the records, the Mercury Task Force determined that 2.0 million pounds of mercury were "lost" or "unaccounted for." The Task Force reported a lower figure than the 1977 Inventory Report because it found increases in several areas in which mercury was unaccounted for originally. The Task Force arrived at a lower amount of losses because in its in-depth review of the records, it was able to account for mercury previously believed to be lost. Of the 2.0 million pounds of "lost" mercury, the Task Force determined that 0.7 million pounds could be traced to losses to the environment.

The Task Force concluded that 1.3 million pounds of mercury still remained "unaccounted for," estimating that 60,000 pounds might be located within the structure of the buildings-- inside the walls, ceilings, floors, and insulation. These are areas where the mercury would have been hardest to recover, as vapors and droplets were absorbed into these fixtures throughout the period of greatest mercury use. The Task Force based this estimate on an EPA study of the chlor-alkali industry, which showed substantial losses of mercury each year by absorption into building structure.

After its investigation, the Task Force remained uncertain about how much mercury was actually received at Y-12 during the 1950s and early 1960s. Rust Engineering conducted the mercury receiving operation for the AEC at Y-12. All records concerning such receipt had been transferred to the Federal Records Center in East Point, Georgia, and subsequently destroyed. The Task Force failed to uncover any data concerning the amount of mercury received at Y-12, but, based on interviews with former AEC officials, speculated that the facility had received somewhere between 500,000 and 900,000 pounds. From interviews, the Task Force also learned that much of the mercury was never weighed by the GSA, the AEC, Y-12, or Rust Engineering. These interviews revealed that the mercury flasks, which held up to 76 pounds of the substance, often leaked and many were not full when emptied into the Colex cascade.

INFORMATION FOR ACCESSING RECORDS

In a March 1994 meeting with DOE, the Tennessee Department of Health and other stakeholders, HAI agreed to identify, inventory, and describe the record series which comprise the Y-12 Mercury Task Force Files. Since the records were already gathered as part of the investigation of the 1983 Mercury Task Force, there was no need for HAI to formulate criteria for the identification and selection of these records. Instead the HAI team familiarized themselves with the history of Oak Ridge, the Y-12 Plant, the use of mercury there, and the lithium isotope separation and enrichment processes. HAI accomplished background research through a thorough review of Mercury at the Y-12 Plant: A Summary of the 1983 UCC-ND Task Force Study (Y/EX-23) and Mercury at Y-12 (Y/EX-24) reports and the Oak Ridge Health Studies: Phase 1 Report, produced by ChemRisk in September 1993. HAI also conducted a preliminary examination of the Y-12 Mercury Task Force Files in March 1994.

In June 1994, HAI identified, inventoried, and described the record series of the Y-12 Mercury Task Force Files. Because of the sensitivity of this collection (a majority of the documents are classified as being Confidential, or Secret Restricted Data for national security reasons) classification officers at Y-12 reviewed HAI's completed inventory forms. For quality control, a member of HAI senior management reviewed the inventory that was completed by a different HAI employee against the actual records.

Data Elements
In accordance with the guidelines in Information Required by the Department of Energy for Epidemiologic and Health Studies, DOE developed a list of 123 (later revised to 85) data elements to assign to record series descriptions. In general, the data elements consist of terms pertaining to contractor organizations, individual employees, industrial hygiene activities, and facilities characteristics that help categorize and describe the major information contained in each of the record series. The data elements assigned to each record series are listed as numbers that correspond to the data elements found in Appendix A.

PRODUCTION AND USE OF THE GUIDE

SCOPE OF THE GUIDE

ARRANGEMENT OF THE GUIDE

I. FINDING AIDS & REFERENCE REPORTS

II. PROGRESS REPORTS

III. MERCURY ACCOUNTABILITY RECORDS

IV. HEALTH AND ENVIRONMENTAL RECORDS

Data Items in Record Series
Each record series description contain fifteen major pieces of information. Each of the fifteen is listed and further explained below.

Title and Inclusive Dates
Each record series description begins with a title that reflects the broad content of the record series and the inclusive dates of the records.

Location
Information on the physical location of the record series and an indication of its status, active or inactive, is provided here. Active records are necessary to conduct current business and are generally maintained in an office. Inactive records are those no longer needed for current business and are generally transferred to records storage areas for disposition. The Y-12 Mercury Task Force Files are located in the Y-12 Records Center vault.

Access Restrictions
Since most of the documents contained in the Y-12 Mercury Task Force Files are classified for national security reasons, access to the collection requires an individual to possess a DOE "Q" clearance and a demonstrated need to know. These requirements also hold for entrance to the Y-12 Records Center vault, where the collection is housed. For information on access to the Y-12 Mercury Task Force Files, researchers must first contact the custodian of the collection, Lowell L. McCauley, 615-574-7593.

The Y-12 Mercury Task Force Files were reviewed by the Y-12 Office of Classification to determine which documents could be released to the public based on current DOE guidelines. These documents were identified, recommended for public release, and sent to the DOE-OR Public Reading Room by Y-12 Information Management Services. The DOE-OR Public Reading Room is located at 55 Jefferson Circle. Copies of these unclassified materials are also located on the Y-12 Plant in Building 9106, Room 41. For information on viewing these collections at the DOE-OR Public Reading Room, contact Pam Buchanan, 615-576-1216. For information on viewing these documents onsite, contact Steve Wiley, Y-12 Health Studies Agreement Coordinator and Tennessee Oversight Agreement Coordinator, 615-576-0263.

For information regarding access to the Y-12 Records Center, contact Jack Lewis, Y-12 Records Manager, 615-576-8834.

Classified Information
To assist researchers and others in understanding the types of classified information, and the restrictions that govern access to it, the following excerpts from the DOE's Understanding Classification (June 1987) are provided: Categories of Classified Information
There are three categories of classified information: Restricted Data; Formerly Restricted Data; and National Security Information.

1. RESTRICTED DATA (RD) is a special category of classified information with which the Department of Energy is principally concerned. The Restricted Data category is defined in the Atomic Energy Act as follows:

"The term RESTRICTED DATA means all data concerning (1) design, manufacture, or utilization of atomic weapons; (2) the production of special nuclear material; or (3) the use of special nuclear material in the production of energy, but shall not include data declassified or removed from the Restricted Data category pursuant to section 142."

2. FORMERLY RESTRICTED DATA (FRD) is information which has been removed from the Restricted Data category after the Department of Energy and the Department of Defense (DOD) have jointly determined that the information relates primarily to the military utilization of atomic weapons and can be adequately safeguarded in the same manner as National Security Information in the United States. This is known as transclassification. Such data may not be given to any other nation except under specially approved agreements.

3. NATIONAL SECURITY INFORMATION (NSI) is information which requires protection against unauthorized disclosure in the interest of the national defense or foreign relations of the United States and has been determined to be classified in accordance with the provisions of Executive Order 12356 or a prior Executive order.

Levels of Classified Information
There are three levels of classified information: Top Secret; Secret; and Confidential.

1. TOP SECRET is the level assigned to information of utmost importance to the national defense and security. Its unauthorized disclosure could reasonably be expected to cause exceptionally grave damage to national security.

2. SECRET is the level for information which, in the event of an unauthorized disclosure, could reasonably be expected to cause serious damage to national security.

3. CONFIDENTIAL is the level for information which, in the event of unauthorized disclosure, could reasonably be expected to cause damage to national security.

For further information, see also DOE Office of Safeguards and Security Headquarters, Security Education Overview Handbook (DOE/SA-0004).

Volume
An estimated volume of the records is given in linear feet and the exact number of file folders is provided as part of the record series description. One cubic foot is, on the average, equal to 24 file folders.

Accession/Other Identification Number
The Y-12 Mercury Task Force Files are organized according to a numerical filing system. Each file is numbered (1-853) and the number is preceded by an "M" for mercury. The number of each file for each record series is provided in sequential order as part of the record series description.

Condition
HAI judged the physical condition of the record series, categorizing them as either good, fair, or poor. If the records were judged to be in poor condition, an explanation is provided.

Container Number
Most records are stored in standard containers that hold one cubic foot of documents. In the case of the Y-12 Mercury Task Force Files, the container numbers represent file cabinet drawers. The Y-12 Mercury Task Force Files are contained in four legal-size filing cabinets secured by combination locks in the vault of the Y-12 Records Center. Drawer numbers are listed sequentially as part of the record series. Drawer 1: M1-M55; Drawer 2: M56-M109; Drawer 3: M110-M164; Drawer 4: M165-M230; Drawer 5: M231-M303; Drawer 6: M304-M349; Drawer 7: M350-M402; Drawer 8: M403-M462; Drawer 9: no M-numbered files; Drawer 10: M463-M498; Drawer 11: M499-M598; Drawer 12: M599-M699; Drawer 13: M700-M853; Drawer 14: Y-12 Mercury Task Force Database Printouts.

Medium
The physical nature of the records, such as paper, microfilm, electronic, or audiovisual, is noted.

Scanning Suitability
HAI has provided a statement concerning the suitability of records for electronic scanning purposes. Factors which may effect scanning suitability, including paper size, weight, ink and paper colors, type font, and the presence of handwritten data, graphics, diagrams, and photographs are noted under this heading. Depending on the state-of-the-art in scanning technology, this statement may not be accurate in the future.

Duplication
As part of a classification review of the records in the Y-12 Mercury Task Force Files, all originally unclassified records were copied and placed in the DOE-OR Public Document Reading Room, 55 Jefferson Circle, 615-576-1216. Copies of these originally unclassified documents are also located on the Y-12 Plant in Building 9106, Room 41.

Arrangement
The arrangement of the record series, for example, numerical, chronological or alphabetical, is described when possible. The Y-12 Mercury Task Force Files are arranged by a numerical filing system. Each file is numbered (1-853) and the number is preceded by an "M" for mercury.

Originating Office
The originating office of the organization (e.g., Health Physics Department, Radiation Safety Division, or Union Carbide Company) which produced the records is provided here. In some cases, as in Technical Reports, Technical Memoranda, and Quarterly Reports, for example, several organizational departments and divisions contributed documents to the record series, and the term "various departments and divisions" is used.

Finding Aids
If finding aids exist, they are described.

Disposition Authority
Disposition authorities cited refer to the NARA General Records Schedules and DOE Records Schedules. Since this is a permanent collection, disposition authority is not applicable.

Data Elements
The data elements, which are similar to key words, that HAI considered pertinent to the record series are listed in numerical order. The numbers correspond to the revised data elements list (see Appendix A).