NDAA Section 3116 Waste Incidental to Reprocessing (WIR) at the Savannah River Site (SRS) in South Carolina – Tank Farms (TFs)

SRS F-Tank Farm (FTF) in Aiken, South Carolina

Operator: U.S. Department of Energy Docket Number: PROJ0734 Site Description: 22 underground carbon steel tanks approximately 24.4 – 30.5 meters (80 – 100 feet) in diameter and approximately 7 meters (23 feet) high Waste Volume: approximately 2.84x106 – 4.92x106 Litres (750,000 – 1,300,000 gallons) capacity per tank

SRS H-Tank Farm (FTF) in Aiken, South Carolina

Operator: U.S. Department of Energy Docket Number: PROJ0734 Site Description:29 carbon steel tanks Waste Volume: TBD

Under Section 3116(b) of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA), the U.S. Nuclear Regulatory Commission (NRC), in coordination with the NDAA-Covered State monitors the U.S. Department of Energy (DOE) disposal actions to assess compliance with the NRC regulations in Title 10 of the Code of Federal Regulations (10 CFR) Part 61, "Licensing Requirements for Land Disposal of Radioactive Waste," Subpart C, "Performance Objectives." The NDAA-Covered States are currently Idaho (ID) and South Carolina (SC).

The Savannah River Site (SRS) is a 802 square kilometer (km²) (310 square mile (mi²)) facility located in south-central SC that was developed in the 1950's as part of the United States’ growing weapons program. Many activities took place at SRS, including the reprocessing of spent nuclear fuel in reinforced concrete buildings (i.e., canyons). The SRS TFs consists of the F-Tank Farm (FTF) and the H-Tank Farm (HTF). Liquid waste managed from the reprocessing process involves 51 underground storage tanks contained in either the FTF or the HTF.

The FTF is a 0.089 km² (22 acre) site that is in the F-Area of the SRS General Separations Area. The FTF is located approximately 10 km (6.2 mi) from the nearest SRS site boundary. The FTF contains 22 of the 51 tanks in the SRS TFs. The HTF is a 0.182 km² (45 acre) site that is in the H-Area of the SRS General Separations Area. The HTF is located near the center of the SRS site. The HTF contains 29 of the 51 tanks in the SRS TFs.

The FTF contains 22 below grade, carbon steel and reinforced concrete tanks that store or previously stored liquid radioactive waste generated from the chemical separations facility in the F-Canyon. The waste tanks consist of three basic types. Type-I tanks are the original tanks from the 1950's (i.e., 23 meters (m) (75 feet (ft.)) in diameter, 7.5 m (24.5 ft.) in height, capacity of 2,850 cubic meters (m³) (750,000 gallons)). Type-IV tanks are from the late 1950's (i.e., 26 m (85 ft.) in diameter, 11 m (34.5 ft.) in height, capacity of 4,940 m³ (1,300,000 gallons)). Type-III tanks are from 1969 to 1980 (i.e., 26 m (85 ft.) in diameter, 11 m (34.5 ft.) in height, capacity of 4,940 m³ (1,300,000 gallons).

The HTF contains 29 below-grade, carbon steel and reinforced concrete tanks that store or previously stored liquid radioactive waste generated primarily from the chemical separations facility in the H-Canyon. The waste tanks consist of four basic types (i.e., Type-II and same three types as in the FTF). Type-I tanks are the original tanks from the 1950's. Type-II tanks are from 1955-1956 (i.e., 26 m (85 ft.) in diameter, 8.3 m (27 ft.) in height, capacity of 3,914 m³ (1,030,000 gallons). Type-III tanks are from 1966-1981. Type-IV tanks are from 1958-1962.

HTF has many similarities to the FTF. Tank types, sizes, and supporting infrastructure are largely the same. However, HTF contains four Type-II tanks while there are no Type-II tanks in FTF. In addition, HTF includes tanks that are either fully- or partially-submerged in the groundwater. While bottoms of several FTF tanks (i.e., Type-IV) are in the zone of water table fluctuation, no tanks have historically been fully submerged.

In the 1990's, prior to implementation of the NDAA, the DOE closed two FTF tanks with approval of South Carolina Department of Health and Environmental Control (SCDHEC). The DOE is engaged in an expansive campaign to clean, stabilize, and close the other underground waste storage tanks under the NDAA. The DOE cleanup activities also include cleaning out the supporting ancillary structures (i.e., evaporators, pump pits, pump tanks, diversion boxes, transfer valve boxes, piping) used to process and transfer generated waste. The waste tanks and ancillary structures are several decades old. The Type-I, Type-II, and Type-IV tanks without a full secondary containment are out of compliance and are targeted closure. The DOE plans to clean, grout, and close the waste tanks and ancillary structures in place to reduce the risks to the workers, the public, and the environment. The DOE intends to close geographic sections of the SRS TFs in stages. Following closure of a geographic section, the area will be left in an interim closure state in preparation for final closure of an entire tank farm (i.e., FTF and HTF).

The tank waste is a mixture of relatively insoluble metal hydroxide solids, referred to as sludge, and soluble salt supernate. In the tank closing process, the supernate volume is reduced by evaporation, which also concentrates the soluble salts to their solubility limits. The resultant solution crystallizes as salts and the resulting solid is referred to as saltcake. The saltcake and supernate combined are referred to as salt waste. The DOE removes the salt waste, treats it to remove Highly Radioactive Radionuclides to the maximum extent practical, and disposes of the low activity fraction in the SRS SDF.

Eight tanks have been closed: Tanks 17 and 20 in the 1990’s before the NRC monitoring activities under NDAA Section 3116(b) began; Tanks 18 and 19 in 2012; Tanks 5 and 6 in 2013; Tank 16 in 2015; and Tank 12 in 2016. In the future, after FTF is closed, the DOE will cover it; and, after HTF is closed, the DOE will cover it.

Major NDAA WIR Consultation & Monitoring Documents For The SRS TFs:

Current Status Of NDAA Section 3116(b) Monitoring For The SRS TFs:

NRC Project Manager: Mathews George, 301-415-3648, Mathews.George@nrc.gov