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

Title: Solvent Hold Tank Sample Results for MCU-18-123- 125 (April 2018), MCU-18-135-137 (May 2018), and MCU-18-192-197(June 2018): Quarterly Report

Technical Report ·
DOI:https://doi.org/10.2172/1480837· OSTI ID:1480837
 [1];  [1]
  1. Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

A trend summary of three Solvent Hold Tank (SHT) monthly samples MCU-18-123-125, MCU-18-135- 137, and MCU-18-192-197 are reported. Most of the conclusions are based on the June SHT sample (MCU- 18-192-197). Analyses of the June SHT sample (MCU-18-192-197) indicated that the Modifier (CS-7SB) and the extractant (MaxCalix) concentrations were at the nominal recommended concentrations (169,000 mg/L and 46,400 mg/L respectively). The suppressor (N,N’,N”–tris(3,7-dimethyloctyl)guanidine or TiDG) concentration has decreased since the April 2018 measurement (Modular Caustic-Side Solvent Extraction Unit or MCU resumed processing radioactive salt solution from May through August 2018) to 1,116 mg/L, well above the minimum recommended concentration (479 mg/L), but below the nominal concentration. The apparent “downwards” trends observed in the TiDG, MaxCalix, Modifier, and gamma measurement are consistent with the start up (and/or proficiency runs) of MCU on May 22, 2018 since these new concentrations are consistent with the concentrations observed when MCU was fully operational in 2016.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC09-08SR22470
OSTI ID:
1480837
Report Number(s):
SRNL-STI-2018-00068
Country of Publication:
United States
Language:
English