Collaborations between the US and West Germany began in the 1970′s when both countries were investigating salt for the option of radioactive waste disposal. However, technical evaluations for disposal of heat-generating waste in salt experienced a rather long hiatus in the United States subsequent to certification of the Waste Isolation Pilot Plant and issuance of the Nuclear Waste Policy Act Amendment, which ended salt disposal research for the civilian program. Similar salt repository research in Germany was held up by a ten-year moratorium, which ended in 2010. At that time, developments in Germany and the United States led to renewed efforts in salt repository investigations. Representatives of institutions in both countries wished to renew collaborations and cooperation on overall salt repository science, to coordinate a potential research agenda of mutual interest, and to leverage collective efforts for the benefit of their respective programs. Thus, these workshops were re-initiated with the first workshop held in Mississippi. The purpose of that workshop was to assemble invited key investigators in salt repository science and engineering and to identify a coordinated research agenda that participants could agree in principle to pursue (individually or in concert with others), with the intent of maximizing individual resources for mutual benefit. The objectives of ongoing workshops are to build collaborative research activities, to create a potential research agenda, and to renew working relationships at the institutional and individual levels.


2010 Canton Mississippi. Recent developments in Germany and the United States have renewed efforts in salt repository investigations. Representatives of institutions in both countries reinitiated collaborations and cooperation on overall salt repository science by conducting a workshop in Canton Mississippi USA. The workshop was hosted by Mississippi State University and Sandia National Laboratories. The purposes of the workshop were to coordinate a potential research agenda of mutual interest and to leverage collective efforts for the benefit of their respective programs.

Workshop #1 Proceedings


Kneeling:  Andrew Orrell, Rose Mary Dill, Mark Horstemeyer, Tilmann Rothfuchs, Frank Hansen, Leo Van Sambeek, Roger Nelson

Standing from left to right:  Till Popp, Greg Roselle, Sean McKenna, Teresa Gammill, Marion Borkowski, Otto Schulze, Jeff Williams, Karl-Heinz Lux, Uwe Düsterloh, Norbert Rempe, Lutz Schneider, Kirby Mellegard, Mark Tschopp, Peter Kamlot, Jörg Hammer, Enrique Biurrun, Cliff Hansen, Zach Rowland, Jack Moody, Wilhelm Bollingerfehr, Tom Pfiefle, John VandeKraats, Eric Knox, Rick Beauheim, Jörg Mönig, Nina Müller-Hoeppe, Walter Steininger, Joe Carter, Klaus-Jürgen Röhlig, Gabriel Wittum, Michael Bograd, Larry Brush, Horst Geckeis, Leif Ericsson.

2011 Peine Germany. The objectives of the 2nd US/German workshop were to continue collaborative research activities, to build upon the research agenda, and to renew working relationships at the institutional and individual levels. This workshop focused on mechanical, thermal and to a lesser extent hydrological aspects of HLW disposal in salt. The crucial elements of sealing the repository were covered in some detail. There remains a strong technical basis for salt disposal, including compelling evidence that the waste disposed in salt will be entombed. Thermal, hydrologic, and geochemical considerations suggest that radionuclides in a salt repository for HLW would not migrate from the disposal horizon. Therefore, topics of this workshop examined how well we can seal shafts and drifts and how well we understand thermal effects on mechanical deformation.

Workshop #2 Proceedings

 2nd salt workshop

From left to right front row: Frank Hansen, Gary Callahan, Lupe Argüello, Enrique Biurrun, Roger Nelson, Christi Leigh, Norbert Rempe, Volkmar Bräuer, Andreas Hampel, Karl-Heinz Lux. Second Row: Tim Gunter, Joachim Stahlmann, Ralf Mauke, Klaus-Jürgen Röhlig, Andrew Orrell, Nina Müller-Hoeppe, Dieter Stührenberg, Abe Van Luik.  Third row: Jörg Mönig, Christian Lerch, Otto Schultze, Klaus Wieczorek, Ulrich Noseck, Michael Bühler, Jacque Grupa, Peter Kamlot, Tilmann Rotfuchs, Wolfgang Minkley, Walter Steininger, Gernot Eilers

2012 Albuquerque New Mexico. The main workshop topics included readiness for the safety case for high-level waste disposal in salt, results of the Joint Project on the Comparison of Constitutive Models for Rock Salt, which involves benchmark modeling of thermomechanical field-scale tests, and reconsolidation of granular salt. Effort also focused on building new collaborations and researcher-to-researcher relationships. Both the German rock salt repository program and the US waste management program grapple with challenges in terms of maintaining and honing their respective current state-of-the-art core capabilities in rock salt repository science and technology. Areas where collaborations have made significant progress included development of an international catalogue for features, events and processes for generic heat-generating waste salt repository, salt knowledge archive, natural analogues, use of a salt underground research laboratory, and quantifying uncertainty.

Workshop #3 Proceedings

large 3-us german workshop photo

2013 Berlin Germany.  The 4th US/German Workshop on Salt Repository Research, Design, and Operation was held in Berlin, Germany September 17 and 18, 2013. The workshop was preceded on September 16 by two related meetings: 1. Organisation for Economic Co-operation and Development/Nuclear Energy Agency (OECD/NEA) “Salt Club” held in Berlin, Germany, and 2. BMWi-funded US/German Joint Project on the “Comparison of Current Constitutive Models and Simulation Procedures on the Basis of Model Calculations of the Thermo-Mechanical Behavior and Healing of Rock Salt” held in Leipzig, Germany. The main workshop topics focused on collaborative efforts between technical peers in the US and Germany. These include 1) selected aspects of the safety case for salt disposal of high-level waste; 2) plugging and sealing of a salt repository; 3) salt mechanics modeling; and 4) repository design including potential uses of an underground research laboratory. Ancillary discussions included geochemistry, microbiology, and hydrogeology modeling.

Workshop #4 Proceedings


From left to right. Seated: Nina Müller-Hoeppe, Jane Perrone, Bärbel Kleinefeld, Nancy Buschman, Christi Leigh, Julie Swanson. Sandra Fahland, Gloria Kwong. From left to right first row standing: Frank Hansen, Kris Kuhlman, Abe Van Luik, Enrique Biurrun, Wilhelm Bollingerfehr, Jörg Mönig, Ulrich Noseck, Dieter Stührenberg, Michael Hofmann, Michael Bühler, Norbert Rempe, Ralf Mauke, Joachim Stahlmann, Klaus Wieczorek, Geoff Freeze, Lance Roberts, Kirby Mellegard, Hiroomi Aoki. From left to right second row standing: Walter Steininger, Max Wippich, Ernie Hardin, Wolfgang Minkley, Bernhard Kienzler, Maximilian Pusch, Till Popp, Benno Haverkate, Jörg Hammer, Ralf Eickemeier, Stephan Bödecker, Tim Gunter, Werner Gräsle, Thilo von Berlepsch, Andreas Hampel, Jens Wolf, Erika Neeft, Marcus Altmaier.

 Tour Group at the Asse Facility (2013)
Tour Group at the Morseleban Facility (2013)