Upcoming Events and Recent Monthly Activities

Recent Activities, 2003

January 1 - March 31, 2003

Oil and Gas Project

Sample preparation of brine samples from 18 batteries, representing 86 wells in the vicinity of WIPP, was completed in March. Preliminary results from Gamma Spectrometry Analysis indicate non-detects for ¹³⁷Cs in all 18 samples. The finalized results for Gamma Analysis should be completed shortly. Verification and validation of a newly developed method for ²²⁶Ra analysis has been completed. Verification and validation of methods for the chemical analysis of actinides is in progress.

Gnome Project

A sample of soil collected from the vicinity of the Gnome site was prepared for analysis by accelerator mass spectrometry (AMS) and shipped to the Lawrence Livermore National Laboratory to determine the isotopic ratios of plutonium. Several dilutions of this sample were prepared in order to evaluate the detection level of the AMS methodology. Samples have also been prepared for analysis at CEMRC for the concentrations of the actinides and gamma-emitting radionuclides for nine soils collected near the Gnome site. These measurements are currently in progress.

In addition to the analyses of the Gnome-contaminated soils, a draft report analyzing the vertical distribution of ¹³⁷Cs in the soil has been prepared by Mark Walthall, Tom Kirchner, Carl Schloesslin, David Ganaway, Joel Webb and Scott Webb. A comparison of soil profiles collected at four locations within the CEMRC sampling areas indicate that peak ¹³⁷Cs concentrations can be found both near the surface and much deeper in the soil. Soil column studies of the vertical transport of ¹³⁷Cs in WIPP soils, simulating about 30 years of precipitation, showed negligible movement of cesium beyond a few millimeters. These results suggest that surface erosion and deposition are likely to be the primary mechanisms determining the vertical distribution of ¹³⁷Cs and similar contaminants in the soil.

Sandia Performance Assessment

The code for the pre-processor for the CCDFGF performance assessment code was prepared and delivered to Sandia for installation under configuration management. The pre-processor extracts results from over 150 files of model results and integrates them into a single file for processing by CCDFGF. The model results are produced by an assortment of transport models dealing with the results of intrusions into the waste repository, intrusions into pressurized brine below the repository, subsequent transport between waste panels in the repository, and transport to the surface and ground water. The CCDFGF code applies stochastic sampling of parameters using a Latin Hypercube design to select and interpolate among the model results to yield statistical distributions (as complementary cumulative frequency distribution functions, or CCDFs) for the potential releases from the repository. The CCDFGF is currently being revised to eliminate options that are no longer needed, to upgrade the code from Fortran 77 to Fortran 90, and to allow greater flexibility in the design of assessment scenarios.

Seminars

CEMRC hosted two seminars as part of the ongoing LANL-CEMRC Actinide Chemistry and Repository Science Seminar Series. Dr. Marian Borkowski, Deputy Head of the Radiochemistry Department at the Institute of Nuclear Chemistry and Technology in Warsaw, Poland and Visiting Scientist, Chemistry Division from Argonne National Laboratory presented "New Insight in Third Phase Formation in the TBP-Alkane System." Dr. Dien Li, Los Alamos National Laboratory, presented "Sorption of aqueous U⁶⁺ onto nano-size silica-water interfaces: a route to the immobilization of radioactive nuclides." CEMRC also hosted a colloquium by Dr. Larry R. Foulke, a Consultant in Reactor Physics at Bechtel Bettis, Inc. and Vice-President/President Elect of the American Nuclear Society, entitled "A Perspective: The Status and Future of Nuclear Power in the United States."

Papers published

1) Savoie, D. L., R. Arimoto, W. C. Keene, J. M. Prospero, R. A. Duce, and J. N. Galloway, Marine biogenic and anthropogenic contributions to nonsea-salt sulfate in the marine boundary layer over the North Atlantic Ocean, Journal of Geophysical Research 107, NO. D18, 4356, doi:10.1029/2001JD000970, 2002. 2) Arimoto, R., Sources and composition of aerosol particles, In: Handbook of Weather, Climate, and Water, T. D. Potter and B. R. Colman, editors, John Wiley and Sons, Inc., Hoboken, NJ, pp. 193-214, 2003. 3) Prospero, J., D. L. Savoie, and R. Arimoto, Long term record of nss-sulfate and nitrate in aerosols on Midway Island, 1981-2000: Evidence of increased (now decreasing?) anthropogenic emissions from Asia, Journal of Geophysical Research 10.1029/2001JD001524, 2003. 4) Arimoto, R., R. A. Duce B. J. Ray, and U. Tomza, Dry deposition of trace elements to the Western North Atlantic, Global Biogeochemical Cycles, Vol. 17 No. 110.1029/2001GB001406, 2003.

April 1 - June 30, 2003

Paper Published

Zhang, X. Y., S. L. Gong, R. Arimoto, Z. X. Shen, F. M. Mei, D. Wang and Y. Cheng, Characterization and temporal variation of Asian dust aerosol from a site in the northern Chinese deserts, Journal of Atmospheric Chemistry, 44, 241-257, 2003.

July 1 - September 30, 2003

Scientific Seminar

Dr. James Conca, Los Alamos National Laboratory - Carlsbad Operations, presented a scientific seminar, "Differential Weathering Studies in the Dry Valleys of the Antarctic."

Presentation

R. Arimoto presented the following: Arimoto, R., T. Kirchner, J. Webb, B. Stewart, D. Moir and D. Schoep, Relationships between dust and transuranics in aerosol particles from the Carlsbad/WIPP area, Book of Abstracts 2003 Radiochemistry Conference, Radiochemistry Society, 2003.

Publication

Sander, R., W.C. Keene, A.A.P. Pszenny, R. Arimoto, G.P. Ayers, E. Baboukas, J.M. Cainey, P.J. Cruzen, R.A. Duce, G. Honninger, B.J. Huebert, W. Maenhaut, N. Mihalopoulos, V.C. Turekian, and R. Van Dingenen, 2003, Inorganic bromine in the marine boundary layer: a critical review, Atmospheric Chemistry and Physics Discussions, 3:2963-3050.

Poster Presented

R. Arimoto presented a poster at the 2nd Workshop on Mineral Dust held September 2003 in Paris, France. The poster was part of Session 2: Measurements of atmospheric dust concentration, vertical distribution and deposition, chaired by R. Arimoto (USA) and P. Formenti (Italy). The poster was titled "The dirt on dust."