The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments.

The Monitored Geologic Repository Waste Package Operations of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Navy (Refs. 1 and , 2). The Navy SNF has been considered for disposal at the potential Yucca Mountain site. For some waste packages, the containment may breach (Ref. 3), allowing the influx of water. Water in the waste package may moderate neutrons, increasing the likelihood of a criticality event within the waste package.

The effective termination of the Yucca Mountain program by the U.S. Administration in 2009
has left the U.S. program for management of used fuel and high level radioactive waste (HLW)
in a state of uncertainty. In concert with this major policy reset and in response to the resulting
policy vacuum, the President directed the Energy Secretary to establish the Blue Ribbon
Commission on America’s Nuclear Future (BRC) “…to conduct a comprehensive review of
policies for managing the back end of the nuclear fuel cycle and to provide recommendations for

The Monitored Geologic Repository (MGR) Waste Package Operations (WPO) of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Emico Fermi Atomic Power Plant (Ref. 1). The Fermi fuel has been considered for disposal at the potential Yucca Mountain site.

Fuel from the Fast Flux Test Facility ' (FFTF) has been considered for disposal at the proposed

Dear Members of the South Carolina Congressional Delegation:
Thank you all for your letter of October 27th. We appreciate hearing your views on the
Yucca Mountain project, the safety benefits of deep geologic disposal, and the
importance of the retaining the H Canyon facility at the Department of Energy’s
Savannah River Site.
In our draft report, the Commission finds that deep geologic disposal is an essential
component of a comprehensive nuclear waste management system. Your comments

This paper draws on my experience as a reviewer of the scientific programs and performance assessments of the geological repository for transuranic waste at the Waste Isolation Pilot Plant in New Mexico and the proposed repository for spent nuclear fuel and high-level waste at Yucca Mountain in Nevada. In addition, I have served on numerous committees of the National Research Council that have addressed many aspects of nuclear waste management.

The Monitored Geologic Repository Waste Package Operations of the Civilian Radioactive Waste Management System Management & Operating Contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Training, Research, Isotopes, General Atomics (TRIGA) reactor (Ref. 1). The TRIGA SNF has been considered for disposal at the potential Yucca Mountain site.

The Monitored Geologic Repository (MGR) Waste Package Department of the Civilian Radioactive Waste Management System Management & Operating contractor (CRWMS M&O) performed calculations to provide input for disposal of spent nuclear fuel (SNF) from the Shippingport Light Water Breeder Reactor (LWBR) (Ref. 1). The Shippingport LWBR SNF has been considered for disposal at the potential Yucca Mountain site.

This report presents a two-phased approach to develop and analyze a “thermal envelope” to represent the postclosure response of the repository to the anticipated range of repository design thermal loadings. In Phase 1 an estimated limiting waste stream (ELWS) is identified and analyzed to determine the extremes of average and local thermal loading conditions. The coldest thermal loading condition is represented by an emplacement drift loaded exclusively with high-level radioactive waste (HLW) and/or defense spent nuclear fuel (DSNF).

This report is developed from Technical Work Plan for: Thermodynamic Databases for Chemical Modeling (BSC 2006 [DIRS 177885]). The purpose of this analysis report is to update the thermochemical database data0.ymp.R4 (Output DTN: SN0410T0510404.002). Various data have been added, corrected, or corroborated, partly in response to four Condition Reports (CRs): CR 6489, CR 6731, CR 7542, and CR 7756. The most notable changes are a general revision of phosphate data to achieve consistency with the recommendations from the Committee on Data for Science and Technology (CODATA) (Cox. et al.

This report documents the development and validation of the in-drift precipitates/salts (IDPS) process model. The IDPS process model is a geochemical model designed to predict the postclosure effects of evaporation and deliquescence on the chemical composition of water within the Engineered Barrier System (EBS) in support of the total system performance assessment (TSPA). Application of the model in support of TSPA is documented in Engineered Barrier System: Physical and Chemical Environment (BSC 2005 [DIRS 175083]).

The purpose of this model report is to describe the evolution of the physical and chemical environmental conditions within the waste emplacement drifts of the repository, including the drip shield and waste package surfaces. This report documents the development of a new process-level model, the near-field chemistry (NFC) model, and develops two abstraction models.