Evaluation of the Low-Level Waste Treatment Plant at Oak Ridge National Laboratory, and suggested changes in the design and operation

Technical Report · Sat Mar 01 04:00:00 EST 1980

DOI:https://doi.org/10.2172/5649959· OSTI ID:5649959

Chilton, J M

The operation of the Low-Level Waste Treatment (LLWT) Plant was monitored for one month to determine why the precipitation-filtration step failed to remove the normal amount of hardness. Each of the three resin beds loaded with Duolite CS-100 resin was taken through one loading-elution cycle. The primary radioactivity in this waste is /sup 90/Sr and /sup 137/Cs, and, under optimum conditions, the plant discharges about 0.015 dpm/ml of /sup 90/Sr and 0.06 dpm/ml of /sup 137/Cs. Although no strontium breakthrough was noted, the results showed that cesium broke through each of the beds after the passage of about 550 bed volumes. Development work for this process had indicated a useful capacity of about 2000 bed volumes, however, and the plant has routinely operated using this value. Resin samples showed that the static volumetric distribution coefficient (DC) for cesium had dropped from 3900 for new resin to about 475 for used resin. Also, the DC for strontium dropped from 20,000 to about 5500. The optimum loading of cesium was found at pH 11.9. No clear-cut cause could be established for the occasional incomplete calcium precipitation. Even using exhausted resin, however, the exit stream is below the permissible concentration for all radionuclides in public streams. Recommendations from this study are immediate replacement of all three resin columns, relocation of the pH-sensing electrode in the precipitation step, use of a more dilute caustic solution for regeneration, institution of a sampling routine to determine more promptly the breakthrough of cesium from the resin, and relocation and possible modification of the gamma detector in the exit stream.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 5649959
• Report Number(s): ORNL-5618
• Country of Publication: United States
• Language: English

Related Subjects

052001* -- Nuclear Fuels-- Waste Processing
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALKALI METAL ISOTOPES
ALKALINE EARTH ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CESIUM 137
CESIUM ISOTOPES
CLEANING
DECONTAMINATION
EFFICIENCY
EVEN-EVEN NUCLEI
FILTRATION
INTERMEDIATE MASS NUCLEI
ION EXCHANGE
ISOTOPES
LOW-LEVEL RADIOACTIVE WASTES
MANAGEMENT
NUCLEAR FACILITIES
NUCLEI
ODD-EVEN NUCLEI
OPERATION
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLYMERS
PRECIPITATION
PROCESSING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE FACILITIES
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTES
RADIOISOTOPES
RECOMMENDATIONS
RESINS
SEPARATION PROCESSES
STRONTIUM 90
STRONTIUM ISOTOPES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
YEARS LIVING RADIOISOTOPES