skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: 241-C-106 ACID DISSOLUTION MATERIAL COMPATIBILITY ASSESSMENT

Technical Report ·
DOI:https://doi.org/10.2172/812319· OSTI ID:812319

Tank 241-C-106 is one of twelve 100-series single-shell tanks (SSTs) located in the 241-C Tank Farm. The tank was constructed during 1943 and 1944 with a nominal capacity of 530,000 gal (approximately 2 million liters). The tank is underground, and is constructed as a cylindrical, reinforced concrete shell with a domed roof and a ''dished'' bottom. The interior of the tank contains a 75 ft (23 m) diameter liner constructed of mild steel, extending up the tank wall to a height of 18 ft (5.5 m). The concrete shell of tank 241-C-106 maintains the structural integrity of the steel liner by protecting it from soil loads. Tank 241-C-106 was placed in service in 1947 and received waste from various sources during its operation. The tank was declared inactive in 1979. In 1999, approximately 186,000 gal of liquid sludge were removed from the tank by past-practice sluicing to resolve a high-heat safety issue, leaving some free liquid, sludge, and a ''hard heel'' in the tank. Equipment installed for the recent sluicing retrieval or prior operations remains in the tank as well. The tank is considered sound (i.e., non-leaking) and ''partial interim isolated''. Tank 241-C-106 contains approximately 9 kgal of residual sludge waste in the form of hardpan and broken solids. Based on successful retrievals completed at Savannah River and laboratory tests, oxalic acid has been chosen to mobilize this type of waste for retrieval. Oxalic acid will be added to the tank in 30,000 gallon increments. The soak time of the first acid addition is anticipated to be approximately two days. Subsequent acid additions will remain in the tank for up to one week. During the soak time, the acid will be gently agitated recirculated within the tank. All spent acid additions will be transferred to tank 241-AN-106 prior to each fresh acid addition. Several material compatibility assessments have been performed. The purpose of these evaluations were to ensure that appropriate materials are included within the design of the acid dissolution waste retrieval system to preclude premature equipment failure (new and existing) due to the acid solutions utilized in the waste retrieval process. These assessments focused on two transfer system safety-related components, the leak detectors, and the back flow pressure transmitters. Additionally, the assessment considered the new transfer pumps, the tank ventilation system, the flush system, and miscellaneous equipment down stream of the HEPA filters.

Research Organization:
CH2M Hill Hanford Group, Inc., Richland, WA (United States)
Sponsoring Organization:
USDOE Office of Environmental Management (EM) (US)
DOE Contract Number:
AC27-99RL14047
OSTI ID:
812319
Report Number(s):
RPP-16256, Rev.1; ECN-720708; TRN: US0303360
Resource Relation:
Other Information: PBD: 25 Jun 2003
Country of Publication:
United States
Language:
English