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

The purpose of this report is to document and validate the external accumulation model that predicts accumulation of fissile materials in the invert, fractures and lithophysae in the rock beneath a degrading waste package containing spent nuclear fuel (SNF) in the monitored geologic repository at Yucca Mountain. (Lithophysae are hollow, bubblelike structures in the rock composed of concentric shells of finely crystalline alkali feldspar, quartz, and other materials (Bates and Jackson 1984 [DIRS 128109], p.

Dear Tim:
As we work to complete our final recommendations to the Secretary by January 29, 2012,
we have determined that our efforts would be aided by the formation of an ad hoc
subcommittee to investigate the issue of co‐mingling of defense and commercial wastes.
Specifically, the ad hoc subcommittee would review and make a recommendation to the
Commission on the issue of whether the 1985 Presidential decision to co‐mingle defense
and commercial wastes for disposal should be revisited in light of changes that have

The Blue Ribbon Commission on America’s Nuclear Future (BRC) asked us to study whether
occupational safety and health conditions in today's U.S. nuclear industry are reasonably safe,
and if those conditions have improved since the Three Mile Island event in 1979. The BRC also
asked us to look to the future, to try to anticipate worker safety and health risks that should be
addressed by the industry, its government regulators and private watchdogs.
Over the eight weeks allotted, we performed a limited review of the literature and spoke with

Dear Mr. Frazier:
At our request, the Commission staff is in the process of assembling information on the costs and financing of the US program to manage used fuel and high-level nuclear wastes. To assist in the completion of this effort, it would be most helpful if the Department could provide the information listed int the attachment.
...

This paper presents an assessment of the benefits for extended burnup credit in transporting
pressurized-water-reactor (PWR) spent nuclear fuel (SNF) in the United States. A prototypic 32-
assembly cask and the current regulatory guidance were used as bases for this assessment. By
comparing recently released PWR discharge data with actinide-only-based loading curves, this
evaluation shows that additional negative reactivity (through either increased credit for fuel burnup or

Approximately 54,000 tons of spent nuclear fuel are stored at operating nuclear power plants and several decommissioned power plants throughout the country. Spent fuel storage at these sites was never intended to be permanent. The current Federal plan is to place the fuel in a repository for permanent disposal in Nevada at Yucca Mountain.

The purpose of this calculation is to document the Three Mile Island Unit 1 pressurized water reactor {PWR) reactivity calculations performed as part o f the commercial reactor critical (CRC) evaluation program. CRC evaluation reactivity calculations are performed at a number of statepoints, representing reactor start-up critical conditions at either beginning of life (BOL), beginning of cycle (BOC), or mid- cycle when the reactor resumed operation after a shutdown.

The purpose of this calculation is to document the McGuire Unit 1 pressurized water reactor (PWR) fuel depletion calculations performed as part of the commercial reactor critical (CRC) evaluation program. The CRC evaluations support the development and validation of the neutronics models used for criticality analyses involving commercial spent nuclear fuel in a geologic repository.

At the request of the staff to the Blue Ribbon Commission on America’s Nuclear Future (“BRC”), we have reviewed whether certain recommendations in the BRC’s July 29, 2011 Draft Report respecting near-term actions by the Department of Energy (“DOE”) or other officers or agencies in the Executive Branch can be implemented under existing law. These recommendations relate to:
(1) Initial steps to site, license and construct consolidated interim storage facilities for spent nuclear fuel (“spent fuel”);

An Account of the Programs of Federal Agencies and Events That Have Led to the Selection of a Potential Site for a Geologic Repository for High-Level Radioactive Waste

The benefits of burnup credit and the technical issues associated with utilizing burnup credit in spent
nuclear fuel (SNF) casks have been studied in the United States for almost two decades. The issuance of the
U.S. Nuclear Regulatory Commission (NRC) staff guidance for actinide-only burnup credit in 2002 was a
significant step toward providing a regulatory framework for using burnup credit in transport casks. However,
adherence to the current regulatory guidance (e.g., limit credit to actinides) enables only about 30% of the existing

Gentlemen,
In accordance with the charter of the Blue Ribbon Commission on America's Nuclear Future and as the Secretary's designee, I approve your request to establish an ad hoc subcommittee to review and make a recommendation to the Commission regarding the co-mingling of defense and commercial waste.
This letter also serves to appoint Dr. Allison Macfarlane as the chair of the subcommittee and the membership of the subcommittee as identified in your letter to me dated October 31, 2011.

The purpose of this scientific analysis report, Commercial Spent Nuclear Fuel Igneous Scenario Criticality Evaluation, is to investigate the effects of an igneous intrusion event occurring in the repository on commercial spent nuclear fuel (CSNF) stored in waste packages. This activity supports the Postclosure Criticality Department's development of bounding (design-basis) configurations for loading specifications and the evaluation of features, events, and processes (FEPs) that could lead to waste package criticality.

Thep purpose of this calculation is to perform degraded mode criticality evaluations of plutonium disposed in a ceramic waste form and emplaced in a Monitored geologic Repository (MGR). A 5 Defense High-Level Waste (DHLW) Canister Waste Package (WP) design, incorporating the can-in-canister concept for plutonium immobilization is considered in this calculation. Each HLW glass pour canister contains 7 tubes. Each tube contains 4 cans, with 20 ceramic disks (immobilized plutonium) in each.

Construction workers were and are considered temporary workers at many construction sites. Since WWII, large numbers of construction workers were employed at US DOE nuclear weapons sites for periods ranging from a few days to over 30 years. These workers performed tasks during new construction and maintenance, repair, renovation, and demolition of existing facilities.

US policy for management of used nuclear fuel (UNF) and high level radioactive wastes (HLRW) is at a crossroads, and the success of new policy directions will depend in part on broad public acceptance and support. In this paper I provide an overview of the evidence concerning the beliefs and concerns of members of the American public regarding UNF and HLNW. I also characterize the evidence on American’s policy preferences for management of these materials.

Uncertainties in the predicted isotopic concentrations in spent nuclear fuel represent one of the largest
sources of overall uncertainty in criticality calculations that use burnup credit. The methods used to
propagate the uncertainties in the calculated nuclide concentrations to the uncertainty in the predicted
neutron multiplication factor (keff) of the system can have a significant effect on the uncertainty in the
safety margin in criticality calculations and ultimately affect the potential capacity of spent fuel transport

How to dispose of highly radioactive wastes from commercial nuclear power plants is a question that has remained unresolved in the face rapidly changing technological, economic, and political requirements. In the three decades following WWII, two federal agencies -- the Atomic Energy Commission and the Energy Research and Development Administration -- tried unsuccessfully to develop a satisfactory plan for managing high level wastes.

The purpose of this calculation is to document the Quad Cities Unit 2 boiling water reactor (BWR) fuel depletion calculations performed as part of the commercial reactor critical (CRC) evaluation program. The CRC evaluations constitute benchmark calculations that support the development and validation of the neutronics models used for criticality analyses involving commercial spent nuclear fuel in a geologic repository. The revision of this calculation incorporates control blade effects and minor variations in the SAS2H assembly modeling.