Science news: perchlorate groundwater studies, energy projects, Handbook of Modern Ion Beam Analysis

New studies, money fuel science programs

Big push for energy projects supporting the Lab’s Energy Security Capability

Chlorine isotopic signature distinguishes natural and anthropogenic perchlorate in groundwater
Perchlorate (ClO₄) from natural atmospheric reactions, synthetic products; and the worldwide use of Chilean nitrate fertilizer containing high concentrations of natural ClO contaminates many municipal water supplies and can cause human health risk.

Jeff Heikoop (EES-14/LANL Water Stewardship Project) and collaborators investigated chlorine isotopic signatures as a tracer of ClO₄ sources and found that groundwater and desert soil samples from the southwestern U.S. (including uncontaminated sites in the Jemez Mountains and Pajarito Plateau) contain ClO₄ with a high abundance of the radioactive isotope chlorine-36, compared with those from Chile and synthetic ClO₄ products. The results have application to determine the sources of ClO₄ in water supplies and foodstuffs.  At LANL, these findings will assist scientists to determine if ClO₄ in groundwater at concentrations similar to accepted background levels is natural, anthropogenic, or a mixture.  Such information could help determine the nature and extent of ClO₄ contamination in groundwater.  The DOE Environmental Management Program supported the LANL work, which was published in Environmental Science and Technology.

New energy projects support the Lab’s Energy Security Capability

• The Solar Energy Technologies Program, which is part of the DOE Energy Efficiency and Renewable Energy Program, focuses on developing cost-effective solar energy technologies that have the greatest potential to benefit the nation and the world.  LANL leads two of the 15 new projects. Tom Picraux (MPA-CINT) will lead “Assessment of Silicon Nanowire Architecture for Photovoltaic Application”. The goal is to develop silicon nanowire solar cells that would require about 1/10 the amount of silicon as conventional crystalline silicon solar cells. This would cut the cost of solar-generated electricity in half.

• Steve Obrey (C-IIAC) will lead the “Hybrid Organic Silicone Heat Transfer Fluids Utilizing  Endothermic Chemical Reactions for Latent Heat Storage” project to develop silicone-based heat transfer fluids for concentrated solar power (CSP) systems. In CSP, solar energy is concentrated using mirrors to produce a high-density heat source. This heat is collected in a heat transfer fluid, which is then used to produce steam that is subsequently used to produce electricity using a steam turbine.  The goal of the project is to fabricate a new class of heat transfer fluid that maximizes both the thermal stability and the thermal storage capacity compared to conventional fluids and is stable at temperatures approaching 600°C. If successful, a 20% to 33% cost reduction over currently used CSP systems could be realized.
• LANL is collaborating with the University of Utah on one of 12 new DOE Fossil Energy projects to capture carbon dioxide (CO2) from industrial sources for storage or beneficial use. In the LANL project, more than one million tons of CO2 per year from various industrial sources will be transported via intra-state pipelines for CO2 enhanced oil recovery and deep saline sequestration research in Kansas. Beneath each enhanced oil recovery target, a major saline aquifer spanning most of the State of Kansas will be used for CO2 injection.  LANL Principal Investigator Rajesh Pawar (EES-16) will lead activities focusing on risk assessment associated with CO2 injection and storage in the proposed project.  LANL will utilize its CO2 PENS (Predicting Engineered Natural Systems) risk assessment model and the numerical simulators, FEHM (Finite Element Heat and Mass) and P-FLOTRAN.

Also, publication of the second edition of the Handbook of Modern Ion Beam Analysis by the Materials Research Society continues to bring worldwide recognition to LANL work in ion beam analysis and ion-solid interactions.