Facility Effluent Monitoring

Liquid and airborne effluents that may contain radioactive or hazardous constituents are continually monitored when released to the environment at the Hanford Site. Facility operators perform the monitoring mainly through analyzing samples collected near points of release into the environment. Effluent monitoring data are evaluated to determine the degree of regulatory compliance for each facility or the entire Site, as appropriate. The evaluations are also useful in assessing the effectiveness of effluent treatment and control systems and management practices. Major facilities have their own individual effluent monitoring plans, which are part of Environmental Monitoring Plan United States Department of Energy Richland Operations Office (DOE 1994c), the comprehensive Site environmental monitoring plan required by DOE.

Measuring devices quantify most facility effluent flows, but some flows are calculated using process information. Effluent sampling methods include continuous sampling for most radioactive air emissions and proportional or "grab" sampling for most liquid effluents. Liquid and airborne effluents with a potential to contain radioactive materials at prescribed threshold levels are measured for total alpha and total beta activity and, as warranted, specific radionuclides. Nonradioactive constituents are also either monitored or sampled, as applicable.

Small quantities of the radionuclides americium-241, antimony-125, cesium-134, cesium-137, cobalt-60, europium-154, europium-155, iodine-129, krypton-85, plutonium-238, plutonium-239,240, ruthenium-106, strontium-90, tin-113, tritium, uranium, zinc-65, and zirconium-95 continue to be released to the environment. However, most radionuclides in effluents at the Site are approaching levels indistinguishable from background concentrations. A new Site mission of environmental restoration, replacing nuclear materials production, is largely responsible for the improved trend in radioactive emissions. This decreasing trend results in significantly smaller offsite radiation doses to the maximally exposed individual that are attributable to Site activities. Figures 3.1.1

and 3.1.2

depict quantities of several long-lived prominent dose-contributing radionuclides released from the Site over the past 7 years. In 1994, releases of radioactive and nonradioactive constituents in effluents were less than applicable standards.

Effluent release data are also documented in several other publicly available reports. For instance, the Richland Operations Office annually submits to EPA a report of radioactive airborne emissions from the Site, in compliance with National Emission Standards for Hazardous Air Pollutants (DOE 1994g). Data quantifying radioactive liquid and airborne effluents discharged from WHC facilities and activities are reported to DOE annually in the Environmental Releases Report (WHC 1995b). Monitoring results for liquid streams regulated by the National Pollutant Discharge Elimination System permit are reported monthly to EPA. Yearly data on nonradioactive emissions from fossil-fuel boilers are reported to Ecology.

Airborne Emissions

Radioactive Airborne Emissions

The continuous monitoring of radioactive emissions involves analyzing samples collected at points of discharge to the environment, usually from a stack or vent. Samples are analyzed for total alpha and total beta activity and selected radionuclides. The selection of the specific radionuclides that are sampled, analyzed, and reported is based on 1) an evaluation of maximum potential unmitigated emissions expected from known radionuclide inventories in a facility or activity area, 2) sampling criteria given in contractor environmental compliance manuals, and 3) the potential each radionuclide has to contribute to the offsite public dose. Continuous air monitoring systems with alarms are also used at selected discharge points when a potential exists for radioactive emissions to exceed normal operating ranges by levels requiring immediate personnel alert.

Radioactive emission discharge points are located in the 100, 200, 300, 400, and 600 Areas. The sources for these emissions are summarized below:

• In the 100 Areas, emissions originate from the shutdown N Reactor, the two 100-K Area water-filled storage basins containing irradiated fuel, a recirculation facility that filters radioactive water from the N Reactor basin, which was used for storage of irradiated fuel, a room used for cleaning contaminated tools and equipment, and a radiochemistry laboratory. Seven radioactive emission points were active in the 100 Areas during 1994.
• The 200 Areas contain facilities for nuclear-fuel chemical separations and reprocessing, waste-handling and disposal, and steam generation using fossil fuels. Primary sources of radionuclide emissions are the PUREX Plant, the Uranium-TriOxide Plant, the Plutonium Finishing Plant, T Plant, the 222-S Analytical Laboratory, underground tanks for storage of high-level radioactive waste, and waste evaporators. During 1994, 57 radioactive emission discharge points were active in the 200 Areas.
• The 300 Area primarily contains laboratories, research facilities, and a fossil-fuel-powered steam plant. Primary sources of radionuclide emissions are the 324 Waste Technology Engineering Laboratory, the 325 Applied Chemistry Laboratory, the 327 Post-Irradiation Laboratory, and the 340 Vault and Tanks. Radioactive emissions arise from research and development and waste-handling activities. During 1994, 37 radioactive emission discharge points were active in the 300 Area.
• The 400 Area contains the FFTF, the Maintenance and Storage Facility, and the Fuels and Materials Examination Facility. Operations and support activities at FFTF and the Maintenance and Storage Facility released small quantities of radioactive material to the environment, even though the reactor did not operate in 1994. The 400 Area had four active radioactive emission discharge points during 1994.
• The 600 Area encompasses the remaining portions of the Hanford Site not assigned to other areas. One minor radioactive emission point was active during 1994 (the 6652-H Ecology Laboratory on the ALE Reserve).

Nonradioactive Airborne Emissions

In past years, gaseous ammonia has been emitted from the PUREX Plant, 242-A Evaporator, 241-AP Tank Farm, and 241-AW Tank Farms. Ammonia emissions are monitored only when activities at these facilities are capable of generating them. In 1994, the 242-A Evaporator operated during April, May, June, September, October, and November producing reportable ammonia emissions. The 241-AP and 241-AW Tank Farms also produced reportable ammonia emissions in 1994. The ammonia releases from the 242-A Evaporator, 241-AP and 241-AW Tank Farms are summarized in Table 3.1.2.

The Uranium-TriOxide Plant operated during May 1994 and for the final time in June 1994. Emissions from the Uranium-TriOxide Plant were continuously monitored for nitrogen oxides, as required by the Prevention of Significant Deterioration permit (No. PSD-X80-14).

Operating powerhouses on the Site emit particulate matter, sulfur oxides, nitrogen oxides, volatile organic compounds, carbon monoxide, and lead. The total annual releases of these constituents is reported in accordance with the air quality standards established by Ecology. Powerhouse emissions are calculated from the quantities of fossil fuel consumed, using EPA-approved formulas.

Should activities lead to chemical emissions that exceed quantities reportable under CERCLA, the release totals are reported immediately to EPA. If the emissions remain stable at predicted levels, they may be reported annually with EPA's permission. Table 3.1.2 summarizes 1994 emissions of nonradioactive constituents (the 100, 400, and 600 Areas have no nonradioactive emission sources of concern).

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