Based on published data, this report identifies potential fate and transport mechanisms for the ammonium hydroxide condensate that was discharged to 216-A-37-1 Crib from Hanford fuel rod decladding before PUREX dissolution and separation operations. Crib 216-A-37-1 received 377 million liters of alkaline condensate discharged from March 1977 through April 1989. The following major processes were identified as controlling the ammonia (NH3) fate and transport:
1. Liquid migration rates through the vadose zone
2. NH3 microbial oxidation to nitrite and nitrate
3. Ammonia species [NH4+, NH3(aq)] sorption to sediments
4. NH3 precipitation reactions after pH buffering occurs in sediments
The travel time through the vadose zone was estimated to be 2.5 to 9 months during periods of high subsurface discharge rates. These travel times are based on tritium migration through the vadose zone, a co-contaminant also discharged to the 216-A-37-1 crib.
Revised: December 15, 2020 |
Published: May 31, 2020