Development of water extraction system for liquid scintillatorpurification of JUNO

TL;DR

This paper presents the development and testing of a water extraction system for purifying liquid scintillator in JUNO, focusing on optimizing parameters to effectively reduce radioactive contaminants.

Contribution

It introduces a counter current water extraction system for liquid scintillator purification and analyzes key factors affecting extraction efficiency, supported by laboratory and pilot plant experiments.

Findings

Optimized flow rate ratio and droplet size improve extraction efficiency.

Counter current extraction effectively reduces radioactive metal ions in LS.

Engineering insights from prototype and pilot plant implementations.

Abstract

The Jiangmen Underground Neutrino Observatory (JUNO) uses 20k tons of liquid scintillator (LS)to detect neutrinos. The content of radioactive substances in the liquid scintillator will affect theexperimental results. JUNO will use counter current water extraction to reduce the radioactive metalions inside the LS. In this article, The factors that affect the final water extraction like the partitioncoefficient and the factors that affect it, the optimal mass transfer droplet size, the flow rate ratio,theoretical stage and different working mode (LS as continuous phase or dispersed phase) have beenstudied. We built counter current extraction prototype in the laboratory and a pilot plant in Daya Bay.We not only study the factors above, but also get a lot of engineering experience that worth sharing.