A major focus of DOE's environmental management mission at Hanford is cleanup of the site's waste from more than 45 years of nuclear weapons production. Managing this legacy waste—as well as other waste from past and current operations--involves safe storage, treatment, and final disposal of a large amount and variety of radioactive and chemical materials. It also involves remediating several hundred inactive waste disposal sites and stabilizing inactive facilities and the material inside them to prevent leaks or avoidable radiation exposures. Environmental restoration and pollution prevention are key parts of the environmental management mission.
An agreement between DOE, the Washington State Department of Ecology, and the U.S. Environmental Protection Agency (EPA), known as the Tri-Party Agreement, provides the legal and procedural basis for cleanup of waste sites at Hanford. The Tri-Party Agreement contains a schedule, using numerous enforceable major and interim milestones and unenforceable target dates, which reflects a concerted goal of achieving full regulatory compliance and remediation.
Waste management at Hanford includes designing, building, and operating a variety of facilities to store, treat, and prepare the waste for disposal. At Hanford, a large part of this process involves safely managing 177 underground storage tanks (149 single-shell tanks and 28 double-shell tanks) that contain millions of liters of high-level liquid waste.
Cleanup activities on the Hanford Site generate radioactive, hazardous, and mixed waste. This waste is handled and prepared for safe storage on the site or shipped to offsite facilities for treatment and disposal. In 2001, cleanup activities generated 328,500 kilograms (724,300 pounds) of solid mixed waste and 1.7 million kilograms (3.7 million pounds) of radioactive waste on the Hanford Site. There were also 127,000 kilograms (280,000 pounds) of mixed waste and 4.7 million kilograms (10.4 million pounds) of radioactive waste received at Hanford from offsite sources.
In addition to newly generated waste, significant quantities of legacy waste remain from years of nuclear material production and waste management activities. Most legacy waste from past operations at the Hanford Site resides in waste sites that comply with the Resource Conservation and Recovery Act (RCRA) or is stored awaiting cleanup and ultimate safe storage or disposal. Examples include high-level radioactive waste stored in single- and double-shell tanks and transuranic waste stored in vaults and on storage pads.
Underground waste storage tanks were built in groups (called tank farms) in the 200-East and 200-West Areas. The farms contain underground pipes so waste can be pumped between tanks, between farms, and between the 200-East and 200-West Areas.
Sixty percent of the nation's nuclear waste is stored in tanks at the Hanford Site. The DOE's goal is to safely remove the liquid waste from the tanks, separate the radioactive elements from non-radioactive chemicals, and create a solid form of waste that can be disposed. The approach selected to solidify the waste is called vitrification, a process that turns the liquid into a rock-like glass.
Since the 1950s, waste leaks from 67 single-shell tanks have been detected, and some of this waste has reached the groundwater underlying the 200 Areas. To date, scientists estimate that 2.8 to 3.9 million liters (750,000 to 1 million gallons) of radioactive waste have leaked from single-shell tanks. All single-shell tanks have exceeded their design life by about 30 years.
In 1998, Congress established the DOE Office of River Protection to manage storage, retrieval, treatment, and disposal of the high-level liquid waste stored in the underground tanks and close the tank farm facilities at the Hanford Site.
The status of the waste tanks as of December 2001 is as follows:
To date, 129 of 149 (87%) single-shell tanks have been stabilized, and the tank stabilization program is ahead of schedule.
During 2001, four tanks were declared stable. Liquid waste from 13 single-shell tanks was pumped into the double-shell tank system, removing 1.9 million liters (500,000 gallons) of waste from the single-shell tanks.
Approximately 204 million liters (54 million gallons) of radioactive and hazardous waste are stored in 149 underground single-shell tanks and 28 underground double-shell tanks. This waste is an accumulation of more than 40 years of plutonium production operations. The DOE River Protection Project currently is upgrading tank farm facilities to deliver waste from underground storage tanks to a new waste treatment facility.
The Waste Treatment Plant will be built on 26 hectares (65 acres) located on the Central Plateau outside of the Hanford 200-East Area. Currently, three major facilities are planned: a pretreatment facility, a high-level waste vitrification facility, and a low-activity waste vitrification facility. Supporting facilities also will be constructed. The River Protection Project is currently upgrading tank farm facilities to deliver waste to the planned Waste Treatment Plant.
During 2001, infrastructure construction for the Waste Treatment Plant was completed. This included installation of an electrical substation, potable water services, effluent piping systems, and roads. Additionally, excavation for the Waste Treatment Plant footprint was begun. Construction, as defined by the Tri-Party Agreement, began in 2002.
Treatment will separate the waste into a low-radioactivity fraction and a high radioactivity and transuranic fraction. Both fractions will be vitrified in a process that will destroy or extract organic constituents, neutralize or deactivate dangerous waste, and immobilize toxic metals.
The immobilized low-radioactivity portion will be disposed of in a facility on the Hanford Site. The immobilized high-radioactivity fraction will be stored onsite until a geologic repository is available offsite for permanent disposal.
Liquid waste is managed in treatment, storage, and disposal facilities to comply with RCRA and state regulations, as briefly described below.
The 242-A Evaporator processes double-shell tank waste into a concentrate and a process condensate stream. In 2001, the evaporator treated 3.2 million liters (840,000 gallons) of tank waste and produced 3.1 million liters (820,000 gallons) of process condensate that were sent to the Liquid Effluent Retention Facility.
This facility consists of three RCRA-compliant surface basins that temporarily store liquid waste, including condensate from the 242-A Evaporator. Approximately 32.7 million liters (8.6 million gallons) of liquid waste were stored in the facility's basins at the end of 2001.
Liquid effluents are treated in the Effluent Treatment Facility (200-East Area) to remove toxic metals, radionuclides, and ammonia and destroy organic compounds. The treated effluent is stored in verification tanks, sampled and analyzed, and discharged to the State-Approved Land Disposal Site. Approximately 95.0 million liters (25.1 million gallons) of aqueous waste were treated in 2001.
This facility collects and disposes of non-RCRA-permitted waste that has been treated using best available technology/all known and reasonable treatment. In 2001, ~484 million liters (~128 million gallons) of effluent were discharged to two 2-hectare (5-acre) disposal ponds located east of the 200-East Area.
Treatment, storage, and disposal of solid waste takes place at a number of locations on the Hanford Site, such as those described in the following paragraphs. Solid waste may originate from work on the Hanford Site or from sources offsite that are authorized by DOE to ship waste to the site.
Ongoing cleanup and research and development activities, as well as remediation activities, generate the waste received at the Central Waste Complex from onsite sources. The waste includes low-level, transuranic, and mixed waste as well as radioactively contaminated polychlorinated biphenyls.
The Waste Receiving and Processing Facility analyzes, characterizes, and prepares drums and boxes of waste for disposal. Waste destined for the facility includes Hanford's legacy waste as well as newly generated waste from current site cleanup activities. The waste consists primarily of cloth, paper, rubber, metal, and plastic.
Eight disposal packages containing defueled U.S. Navy reactor compartments were received in the 200-East Area during 2001. Four were submarine reactor compartments, and four were cruiser reactor compartments. This brings the total number of reactor compartments received to 102. All Navy reactor compartments shipped to the Hanford Site for disposal have originated from decommissioned nuclear-powered submarines or cruisers.
The Washington State Department of Ecology regulates the disposal of reactor compartments as dangerous waste because lead is used as shielding. The reactor compartments also are managed as mixed waste because of their radioactivity.
Environmental restoration at Hanford involves characterizing and remediating contaminated soil and groundwater; stabilizing contaminated soil; remediating disposal sites; decontaminating, decommissioning, and demolishing former plutonium production process buildings, nuclear reactors, and separation plants; maintaining inactive waste sites; transitioning facilities into the surveillance and maintenance program; and mitigating effects to biological and cultural resources from site development and environmental cleanup and restoration activities.
This disposal facility is located near the 200-West Area and began operations in July 1996. Constructed with double liners and a leachate collection system, the facility was designed to serve as the central disposal site for contaminated waste removed during cleanup operations conducted under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) on the Hanford Site.
Cleanup materials may include soil, rubble, or other solid waste materials contaminated with hazardous, low-level radioactive, or mixed (combined hazardous chemical and radioactive) waste. As of early 2002, the facility had received 3.1 million metric tons (3.43 million tons) of contaminated soil and other waste.
Remediation continued through 2001 at several liquid waste disposal sites in the 100-B/C, 100-H, 100-F, and 100-N Areas. In 2001, over 540,000 million metric tons (over 594,000 tons) of contaminated soil were removed from the remediation sites. This soil has been transported to the Environmental Restoration Disposal Facility since the beginning of waste site remediation operations in 1996.
Decontamination and decommissioning activities continued in 2001 in the 100-D/DR, 100-H, and 100-F Areas. These activities are conducted to support the interim safe storage of the four reactor buildings (D, DR, F, and H) for up to 75 years. Interim safe storage minimizes potential risks to the environment, employees, and the public and reduces surveillance and maintenance costs. These activities are conducted as non-time-critical removal actions under CERCLA. Demolition of D Reactor also was initiated in 2001 and progressed through three areas (the lunchroom, the valve pit and shops, and the fan room and ventilation system tunnels). Demolition work at F Reactor Fuel Storage Basin continues.
|Status of Waste Site Remediation|
|Location of Waste Site||Amount of Contaminated Soils Removed, metric tons (tons)|
|100-B/C Area||110,000 (121,000) in 2001; 732,000 (807,000) since startup|
|100-H Area||136,000 (150,000) in 2001; 413,000 (455,00) since startup|
|100-F Area||321.000 (353,000) in 2001; 470,000 (517,000) since startup|
|100-N Area||112,000 (123,000) since startup|
The wetland habitat by the 100-B/C Area created in early 2000 near the Columbia River was enhanced with the planting of an additional 1.6 hectares (4 acres) along the slopes of Borrow Pit 24. This planting effort will provide the borrow area with a much needed seed source to promote continual restoration of the pit.
In January 2001, 50 bitterbrush seedlings were planted as additional mitigation for shrubs lost during the initial stages of the 618-4 Burial Ground remediation.
A new electrical transmission line with tower pads was installed to provide electrical power to the planned vitrification plant near the 200-East Area. The areas surrounding the tower pads that were disturbed during pad installations were revegetated during February 2001.
Monitoring of survival and growth continued for ~90,000 sagebrush seedlings that were planted on about 90 hectares (222 acres) at nine locations on the Fitzner/Eberhardt Arid Lands Ecology Reserve Unit during December 2000. This effort was the last phase of sagebrush transplanting as compensatory mitigation for the disturbance of sagebrush habitat resulting from development of the site and infrastructure for the planned waste vitrification facility. Monitoring of these plants will continue through fiscal year 2004.
The Groundwater/Vadose Zone Integration Project brings together all activities that affect Hanford's subsurface. Restoring the condition of the groundwater under the Hanford Site is a major focus of the project. The goal of groundwater restoration is to prevent contaminants from entering the Columbia River, reduce the contamination in areas of high concentration, prevent the movement of contamination, and protect human health and the environment.
During 2001, the Integration Project team compiled an array of accomplishments that span its key focus areas — Site-Wide Fieldwork Integration Focus Area, the System Assessment Capability Focus Area, Science and Technology Focus Area, Integration of Information Focus Area, Technical Review Focus Area, and Public Involvement Focus Area. The efforts within these task areas directly support the DOE's plan for the Hanford Site.
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Document Number: PNNL-13910-SUM
Document Date: September 2002
Posted: October 2002