 Nadia Lima (Civil Engineering) About DOE Fellow Study of Aged Concrete Structures at Savannah River Site Nadia is currently working on researching the deterioration of facilities at Savannah River Site by studying the degradation mechanisms in aged concrete cores. Analysis of the concrete cores focuses mainly on the condition of the concrete’s current state, the degradation mechanisms present, and the extent of degradation. |
105-R Reactor Disassembly Basin D&E Canal – Heat Of Hydration Experimental Mock Up And Heat Transfer Analysis
This past summer, Nadia also worked alongside the “Savannah River Site Team” of DOE Fellows (Cristian Acevedo, Denisse Aranda, Jose Rivera, Alessandra Monetti, Givens Cherilus and Elicek Delgado-Cepero) in studying the heat of hydration of a special cementitious fill for its use in the in-situ decommissioning of the 105-R Reactor Disassembly Basin D & E Canal. This experiment focuses on the temperature range of grout both vertically and horizontally. The experiment also verifies that the grout is curing correctly by measuring the compressive strength with time.
Cured Properties of Cellular Grout for Its Use in In-Situ Decommissioning of the 105-P Reactor Disassembly Basin D & E Canal
Nadia interned at Savannah River National Laboratory (SRNL) the summer of 2010. Her main task involved studying the cured properties of cellular grout for its use in in-situ decommissioning of the 105-P Reactor Disassembly Basin D & E Canal. The Department of Energy has set a goal to reduce its footprint at SRS, therefore identifying the 105-P Reactor for decommissioning. Part of the decommissioning process involves filling all below grade areas with cementitious materials; this is referred to as in-situ decommissioning. The 105-P Reactor Disassembly Basin D & E Canal is one of these below grade areas that are being filled with cementitious materials
The section that is to be filled is on top of an underlying chase; therefore, it is imperative to use a proper filling material to avoid collapsing into the cavity. Cellular grout is the lead candidate for filling this space because of its light weight. Cellular grout, otherwise known as foam grout, is a lightweight material containing gas cells. The selection of cellular grout was based upon its low density, thermal conductivity, and excellent flow properties. These characteristics were ideal for filling the area.
Precipitation of Polyphosphate with Calcium in the Aqueous Environment at the Hanford Site
Previously, Nadia worked with Dr. Prabhakar Pant on uranium remediation of the 300 Area at the Hanford site in Washington State. Nadia studied the reaction kinetics of calcium and phosphate in order to be able to apply findings to the reaction studies between uranium and polyphosphates. The project’s purpose is to prevent uranium from moving any further into the groundwater, which is in danger of contaminating the Columbia River. One way to prevent the movement of uranium is through polyphosphate technology. Polyphosphate technology uses polyphosphate injection, allowing phosphate to bind to aqueous uranium which produces an insoluble precipitate, in turn reducing the uranium concentrations.