Streamlined Approach for Environmental Restoration Closure Report for Corrective Action Unit 198: Test Cell C Filter Tank Closure Nevada Test Site, Nevada

This closure report (CR) provides documentation for the closure of Corrective Action Unit (CAU) 198 identified in the Federal Facility Agreement and Consent Order (FFACO). The site is located at the Nevada Test Site (NTS) Area 25 Test Cell C Complex (Figure 1). The CAU consists of one Corrective Action Site (CAS) 25-23-12 which includes two aboveground radioactive wastewater filter tanks used during the Nuclear Furnace Testing at Test Cell C. The Test Cell C complex was one of several facilities dedicated to the development of nuclear rocket technology. Test Cell C was designed to test nuclear rocket reactors. Part of the testing program included Nuclear Furnace Tests. The Nuclear Furnace was a water-moderated, hydrogen-cooled, 44-megawatt reactor used to test fuel elements for the nuclear rocket engine. The Nuclear Furnace in itself was not a nuclear rocket engine. During testing, hydrogen exited the reactor at a temperature of 2,440 degrees Kelvin. Water was injected into the gas stream to cool the hydrogen and capture the various radiological isotopes. Hydrogen gas effluent was decontaminated through a multistage process before being burned at the Test Cell C flare stack. A by-product of the decontamination process produced water contaminated with mixed fission products. Prior to discharge to a tile drain system (CAU 267) the water was filtered through the two 2271-liters (600-gallon) filter tanks (Department of Energy [DOE], 1998). Reactor development, engine testing, and rocket development activities were ended in the early 1970s. The filter tanks have remained inactive since that time. The site is currently roped off and posted with ''Caution Radiation Area'' signs. The filter tanks were located on the east side of Test Cell C, approximately 15.2 meters (50 feet) from the facility fence line (Figure 2)