The Disposal Criticality Analysis Methodology Topical Report (Reference 1) states that the accuracy of the criticality analysis methodology (MCNP Monte Carlo code and cross-section data) designated to assess the potential for criticality of various configurations in the Yucca Mountain proposed repository is established by evaluating appropriately selected benchmark critical experiments.

This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development Department (WPDD) in response to a request received via a QAP-3-12 Design Input Data Request (Reference 5.1) from Waste Acceptance, Storage, & Transportation (WAST) Design (formerly MRSMPC Design). This design analysis is an answer to the Design Input Data Request to provide: Specific requirements for long-term criticality control.

The main question before the Transportation and Storage Subcommittee was whether the United States
should change its approach to storing and transporting spent nuclear fuel (SNF) and high-level
radioactive waste (HLW) while one or more permanent disposal facilities are established.
To answer this question and to develop specific recommendations and options for consideration by the
full Commission, the Subcommittee held multiple meetings and deliberative sessions, visited several

Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013

he U.S. Nuclear Regulatory Commission (NRC) regulates storage of spent nuclear fuel (SNF) from commercial nuclear power plants. An increasing amount of the SNF in storage is in dry storage systems, mostly at current and decommissioned plants. As directed by the Commission (in SRM-COMSECY-10-0007; December 6, 2010), in expectation of continued use of dry storage for extended periods of time, the NRC staff is examining the technical needs and potential changes to the regulatory framework that may be needed to continue licensing of SNF storage over periods beyond 120 years.

Guidance concerning regulatory requirements for criticality analysis of new and spent fuel storage at light-water reactor power plants used by the Reactor Systems Branch.

As part of the Mined Geologic Disposal System Waste Package Development design activities, it has been determined that it may be beneficial to add material to fill the otherwise free spaces remaining in waste package after loading high-level nuclear waste. The use of filler material will benefit criticality control in spent nuclear fuel waste packages, by the moderator displacement method.

An Act to provide for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel, to establish a program of research, de- velopment, and demonstration regarding the disposal of high-level radioactive waste and spent nuclear fuel, and for other purposes.

The purpose of this analysis is to evaluate the types of defects or imperfections that could occur in a waste package or a drip shield and potentially lead to its early failure, and to estimate a probability of undetected occurrence for each type. An early failure is defined as the through-wall penetration of a waste package or drip shield due to manufacturing or handling-induced defects, at a time earlier than would be predicted by mechanistic degradation models for a defect-free waste package or drip shield.

About 20,000 metric tons of spent, or used, nuclear
fuel have accumulated since the beginning of commercial
nuclear power prbduction in the United States. At the end
of the currently licensed period of all existing nuclear power
plants and those under construction, the amount of spent
nuclear fuel is expected to total 87,000 metric tons.
Thus far, practically all of the spent nuclear fuel is
stored in water-filled pools at reactor sites. However, space
does not exist in the pools to store all the spent fuel expected

The main question before the Transportation and Storage Subcommittee was whether the United States should change its approach to storing and transporting spent nuclear fuel (SNF) and high-level radioactive waste (HLW) while one or more disposal facilities are established.

The objective of this siting study work is to support DOE in evaluating integrated advanced nuclear plant and ISFSI deployment options in the future. This study looks at several nuclear power plant growth scenarios that consider the locations of existing and planned commercial nuclear power plants integrated with the establishment of consolidated interim spent fuel storage installations (ISFSIs).

Understanding the changing nuclear and mechanical characteristics of used nuclear fuel (UNF) over time and how these changing characteristics affect storage, transportation, and disposal options can require many tools and types of data. To streamline analysis capabilities for the waste management system, a comprehensive, integrated data and analysis tool has been assembled—UNF-Storage, Transportation & Disposal Analysis Resource and Data System (UNF-ST&DARDS).

This report provides information on the inventory of commercial spent nuclear fuel, referred to herein as used nuclear fuel (UNF), as well as Government-owned UNF and high-level radioactive waste (HLW). Actual or estimated quantitative values for current inventories are provided along with inventory forecasts derived from examining a different future commercial nuclear power generation scenarios. The report also includes select information on the characteristics associated with the wastes examined (e.g. type, packaging, heat generation rate, decay curves).

The “Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste” report was issued by the Department of Energy (DOE) in January 2013. The strategy includes a phased, adaptive, and consent based approach to siting and implementing a comprehensive management and disposal system. It also endorses a waste management system containing a pilot interim storage facility and a full-scale interim storage facility, which prioritizes the acceptance of fuel from shut-down reactors. Required features of the system and facilities are:

1.0 INTRODUCTION

Under a contract with the Department of Energy (DOE), the AREVA Team has evaluated the alternatives for developing a used nuclear fuel (UNF) Consolidated Storage Facility (CSF) for UNF from US reactor plants. The study, based upon specific criteria and requirements for the US, considered numerous credible storage options and selected the one that met the needs of the country. For this task, the AREVA Team comprises AREVA, URS, Duke Energy, Dominion, and Coghill Communications, Inc.

1.1 Purpose