Contact Information

James D. Prikryl
(210) 522-5667

Peña Blanca Natural Analog Project

Nuclear industries generate toxic waste products that will persist for time periods exceeding the known duration of human civilization. A growing, worldwide technical consensus supports permanent disposal of high-level nuclear wastes (HLW) in geologic repositories. Assessment of the ultimate safety of geologic repositories for long-lived nuclear wastes will require predictions or estimations of the behavior of these geologic systems for thousands or tens of thousands of years into the future. One approach to identify and characterize processes that operate on this time scale and to judge the validity of predictive assessments is by studying analogous systems.

The Peña Blanca Natural Analog Project

The Nopal I uranium deposit in the Sierra Peña Blanca of northern Mexico provides an exceptional natural analog to the U.S. Nuclear Regulatory Commission's proposed high-level nuclear waste repository at Yucca Mountain, Nevada. Uraninite, analogous chemically to spent nuclear fuel, has been oxidized at Nopal I, where present geological, geochemical, and hydrological conditions closely resemble those at Yucca Mountain. Issues of contaminant source and transport over periods of time and under conditions relevant to geologic isolation of nuclear waste at Yucca Mountain can be addressed at Peña Blanca.

image: View of the excavated exposure of the Nopal I deposit. Excavation has been cleared of loose rock, soil, and debris.

View of the excavated exposure of the Nopal I deposit. Excavation has been cleared of loose rock, soil, and debris.

CNWRA-conducted research at the Nopal I uranium deposit includes:

  • Evaluating the mechanisms of uraninite alteration, controls on groundwater and mineral compositions, and processes affecting elemental migration
  • Performance assessment modeling of nuclear waste geologic repositories through solid phase evolution and rates and mechanisms of radionuclide transport
  • Mapping, sampling, and analyzing U-rich opal and caliche deposits at Nopal I to evaluate the most recent radionuclide release and transport

A detailed report on the relevance of natural analog studies to nuclear waste disposal is available in a PDF.

CNWRA maintains this web site to distribute information and promote natural analog studies related to nuclear waste management in the Sierra Peña Blanca. Information in this website documents work performed by the CNWRA for the US Nuclear Regulatory Commission (NRC) under contract NRC-02-97-009. It is an independent product of the CNWRA and does not necessarily reflect the views or regulatory position of the NRC.

Related Terminology

Nuclear Regulatory Commission (NRC)  •  Yucca Mountain Project (YMP)  •  Office of Civilian Radioactive Waste Management (OCRWM)  •  Sierra Peña Blanca  •  Nopal I uranium deposit  •  uraninite alteration  •  Yucca Mountain  •  performance assessment modeling of nuclear waste geologic repositories

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Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 9 technical divisions.