Expanding interest in nuclear power and advanced fuel cycles indicate that use of mixed-oxide (MOX) fuel in the current and new U.S. reactor fleet could become an option for utilities in the coming decades. In light of this renewed interest, EPRI has reviewed the substantial knowledge base on MOX fuel irradiation in light water reactors (LWRs). The goal was to evaluate the technical feasibility of MOX fuel use in the U.S. reactor fleet for both existing and advanced LWR designs (Generation III/III+).

The objective of this analysis is to evaluate accumulations within the thermally altered tuff surrounding a drift. The evaluation examines accumulation of uranium minerals (soddyite), plutonium oxide (Pu01), and combinations of these materials. A hypothetical model of the tuff is used to provide insight into the factors that affect criticality for this near-field scenario. The factors examined include: the size of the accumulation, the fissile composition of the accumulation, the water or clayey material fraction in the accumulation and the water fraction in the tuff

The American Nuclear Society (ANS) appreciates the opportunity to comment on the draft Nuclear Waste Administration Act (NWAA). The ANS is a not-for-profit, international, scientific, and educational organization with nearly 12,000 members worldwide. The core purpose of ANS is to promote awareness and understanding of the application of nuclear science and technology. As an organization, it has published a number of position statements regarding the issue of spent fuel and radioactive waste.

The American Nuclear Society (ANS) supports the safe, controlled, licensed, and regulated interim
storage of used nuclear fuel (UNF) (irradiated, spent fuel from a nuclear power reactor) until disposition
can be determined and completed. ANS supports the U.S. Nuclear Regulatory Commission’s (NRC’s)
determination that “spent fuel generated in any reactor can be stored safely and without significant
environmental impacts for at least 30 years beyond the licensed life for operation.

It is increasingly apparent that the United States will require a large expansion of nuclear power
generation capacity to meet its future baseload electricity needs while reducing greenhouse gas
emissions. As a result, Congress and the Administration must act to update U.S. nuclear fuel
cycle policy to address these realities. This will likely require a multifaceted approach involving
some combination of on-site/centralized dry cask interim storage, nuclear fuel recycling, and
emplacement of high-level wastes in long-term geological storage.

More than 45 million shipments of radioactive materials have taken place in the United States
over the last three decades, with a current rate of about three million per year. The majority of
these radioactive shipments consist of radiopharmaceuticals, luminous dials and indicators,
smoke detectors, contaminated clothing and equipment, and research and industrial sources.
Fewer than 3,500, or 0.01%, have been involved in any sort of accident, incident, or anything

The American Nuclear Society (ANS) supports (1) the development and use of geological
repositories for disposal of high-level radioactive wastes and (2) expeditious processing of the
Yucca Mountain license application in an open, technically sound manner. Geological disposal
means placing the wastes hundreds of feet underground and far from the biosphere. The U.S.
Nuclear Regulatory Commission (NRC) is following a legislatively well-defined regulatory
process to evaluate the safety of the proposed Yucca Mountain Site to meet both the scientific