The Savannah River Site (SRS) has been operating a nuclear fuel cycle since the 19S0''s to produce nuclear materials in support of the national defense effort. The department of Energy authorized the construction of the Defense Waste Processing Facility (DWPF) to immobi1ize the high level radioactive waste resulting from these processes as a durable borosilicate glass. The DWPF, after having undergone extensive testing, has been approved for operations and is currently immobilizing radioactive waste.
To ensure reliability of the DWPF remote canyon processing equipment, a materials evaluation program was performed prior to radioactive operations to determine to what extent erosion/corrosion would impact design life of equipment. The program consisted of performing pre-service baseline inspections on critical equipment and follow-up inspections after completion of DWPF cold chemical demonstration runs. Non-destructive examination (NOE) techniques were used to assess erosion/corrosion as well as evaluation of corrosion coupon racks. These results were used to arrive at predicted equipment life for selected feed preparation equipment. It was concluded with the exception of the coil and agitator for the slurry mix evaporator (SME), which are exposed to erosive glass frit particles, all of the equipment should meet its design life.
The Department of Energy''s Savannah River Site (SRS) has operated a nuclear fuel cycle in the manufacture of defense nuclear materials since the early 1950''s. The processing of irradiated fuels and targets to recover the desired isotopes has resulted in a mixed high level nuclear waste stream containing a variety of radioisotopes. During this time, approximately 83 million gallons of high level waste has been produced and, to conserve storage space, the waste solutions have been concentrated to approximately 33 million gallons by evaporation. The waste is stored in alkaline form in 1.3 million gallon carbon steel tanks located at the SRS Separations Areas. Most metal ions in the waste are precipitated as hydroxides while the alkali metals stay in solution. Waste processing has resulted in three discrete forms in the waste tanks: sludge, salt cake, and saturated salt solution. Most of the radioactive components are in the sludge except Cs137 and small amounts of plutonium and strontium which are found in the salt cake and supernate.
The Department of Energy authorized construction of the Defense Waste Processing Facility (DWPF) to immobilize the high level liquid waste as a durable borosilicate glass contained in stainless steel canisters, prior to emplacement in a fec1cral repository. To ensure the reliability of the DWPF process before radioactive operation, a series of start-up tests and qualification runs were performed during "cold chemical runs" (i.e. non-radioactive) testing. One of the start-up tests that was to be performed required an assessment of plant equipment in regard to erosion/corrosion. This materials evaluation will be the focus of this paper. However, given the broad scope of the DWPF process, this paper will concentrate only on the feed preparation systems in the process.
