RESULTS OF THE 2H EVAPORATOR ACID CLEANING AND IN-POT NEUTRALIZATION

Wilmarth, B ; Phillip Norris, P ; Terry Allen, T

Savannah River Site (S.C.)

关键词: Evaporators;    Aluminium Silicates;    Flowsheets;    Descaling;    Nitric Acid;   

DOI  :  10.2172/921968
RP-ID  :  WSRC-STI-2007-00286
RP-ID  :  DE-AC09-96SR18500
RP-ID  :  921968

美国|英语

来源: UNT Digital Library

【 摘 要 】

The estimated 200 gallons of sodium aluminosilicate scale (NAS) present in the 242-16H Evaporator pot prior to chemical cleaning was subjected to four batches of 1.5 M (9 wt%) nitric acid. Each batch was neutralized with 19 M (50 wt %) sodium hydroxide (caustic) before transfer to Tank 38. The chemical cleaning process began on November 20, 2006, and was terminated on December 10, 2006. An inspection of the pot's interior was performed and based on data gathered during that inspection; the current volume of scale in the pot is conservatively estimated to be 36.3 gallons, which is well below the 200 gallon limit specified in the Technical Safety Requirements. In addition, the performance during all aspects of cleaning agreed well with the flowsheet developed at the bench and pilot scale. There were some lessons learned during the cleaning outage and are detailed in appendices of this report.