Field application test. A small-scale column test performed in the Salem Nuclear Station count room by EnergySolutions, evaluating Fluid Tech media. The summary below is for reference; figures are in the underlying test report.
01 The problem
During refueling outages, commercial nuclear plants' liquid radwaste systems often struggle to remove activated corrosion products — notably cobalt-58 and cobalt-60 — down to the administrative limits required for environmental discharge. At Salem, the existing liquid waste processing system (ALPS) was leaving cobalt above the administrative discharge limit, releasing nickel, and providing no organic reduction. The station needed a media that could polish cobalt to below its discharge limit.
02 The test
EnergySolutions ran a small-scale ion-exchange column test in the plant's count room, comparing two Fluid Tech media:
- FHA — Fluid Tech Hydroxyapatite
- WTZ 100 — Fluid Tech Anhydrous Sodium Aluminosilicate (zeolite)
A 400 ml ion-exchange column and peristaltic pump were used; the plant provided TOC, pH, conductivity, iron/nickel (AA spectroscopy), boron, total suspended solids, and gamma-spectrum analysis on the influent and effluent.
03 Results
- Both media removed cobalt well — FHA best. WTZ 100 showed good initial cobalt removal but lost its affinity after processing less than 2 liters through 200 ml of media.
- FHA drove cobalt below the discharge limit. Running ALPS effluent through 200 ml of FHA at 20 ml/min (a 10-minute contact time) brought cobalt below the administrative limit for environmental discharge.
- Robust to water chemistry. FHA was also tested on higher-conductivity influent and still removed cobalt below the limit — indicating higher conductivity does not interfere with cobalt removal.
04 Why it matters
- Solves a recurring outage problem: activated cobalt is a persistent challenge for outage liquid-radwaste discharge.
- Outperformed the installed system: FHA met the discharge limit where the plant's existing process could not.
- Selective and durable: hydroxyapatite's affinity for cobalt held up across water chemistries.