One of the significant issues yet to be resolved for using
burnup credit ~BUC! for spent nuclear fuel ~SNF! is establishing
a set of depletion parameters that produce an adequately conservative
representation of the fuel’s isotopic inventory. Depletion
parameters ~such as local power, fuel temperature, moderator temperature,
burnable poison rod history, and soluble boron concentration!
affect the isotopic inventory of fuel that is depleted in a
pressurized water reactor ~PWR!. However, obtaining the detailed
Criticality safety analysis devoted to spent-fuel storage and transportation has to be conservative in order to be sure no accident will ever happen. In the spent-fuel storage field, the assumption of freshness has been used to achieve the conservative aspect of criticality safety procedures. Nevertheless, after being irradiated in a reactor core, the fuel elements have obviously lost part of their original reactivity. The concept of taking into account this reactivity loss in criticality safety analysis is known as burnup credit.
The effect of fixed absorbers on the reactivity of pressurized water reactor (PWR) spent nuclear fuel (SNF) in support of burnup-credit criticality safety analyses is examined. A fuel assembly burned in conjunction with fixed absorbers may have a higher reactivity for a given burnup than an assembly that has not used fixed absorbers. As a result, guidance on burnup credit, issued by the U.S. Nuclear Regulatory Commission's Spent Fuel Project Office, recommends restricting the use of burnup credit to assemblies that have not used burnable absorbers.
The purpose of this directory is to make available a convenient source of information on package designs approved by the U.S. Nuclear Regulatory Commission. To assist in identifying packages, an index by Model Number and corresponding Certificate of Compliance Number is included at the front of Volume 2. The report includes all package designs approved prior to the publication date of the directory as of September 2013.
The Federal Government will continue to meet Germany’s existing international obligations, par- ticularly with regard to fulfilment of the Joint Convention. In submitting this report, the Federal Re- public of Germany is demonstrating its compliance with the Joint Convention and ensuring the safe operation of facilities for the management of spent fuel and radioactive waste, including the de- commissioning of nuclear installations. At the same time, there is still a need for future action in order to maintain the required high standards of safety and ensure disposal.
The issue of interim storage of used (spent)1 fuel is dependent on a number of key factors, some
of which are not known at this time but are the subject of this study. The first is whether or not
the Yucca Mountain Project continues or is cancelled such that it may be able to receive spent
fuel from existing and decommissioned nuclear power stations. The second is whether the United
States will pursue a policy of reprocessing and recycling nuclear fuel. The reprocessing and
Preliminary system-level analyses of the interfaces between at-reactor used fuel management, consolidated storage facilities, and disposal facilities, along with the development of supporting logistics simulation tools, have been initiated to provide the U.S. Department of Energy (DOE) and other stakeholders with information regarding the various alternatives for managing used nuclear fuel (UNF) generated by the current fleet of light water reactors operating in the United States.
A technical assessment of the current inventory [~70,150 metric tons of heavy metal (MTHM) as of
2011] of U.S.-discharged used nuclear fuel (UNF) has been performed to support decisions regarding fuel
cycle strategies and research, development and demonstration (RD&D) needs. The assessment considered
discharged UNF from commercial nuclear electricity generation and defense and research programs and
determined that the current UNF inventory can be divided into the following three categories:
The U.S. Nuclear Regulatory Commission (NRC) is responsible for issuing regulations for the
packaging of spent fuel (and other large quantities of radioactive material) for transport that
provide for public health and safety during transport (Title 10 of the Code of Federal Regulations
(10 CFR) Part 71, “Packaging and Transportation of Radioactive Waste,” dated
January 26, 2004). In September 1977, the NRC published NUREG-0170, “Final Environmental
Statement on the Transportation of Radioactive Material by Air and Other Modes,” which
Reference concepts for geologic disposal of used nuclear fuel and high-level radioactive waste in
the U.S. are developed, including geologic settings and engineered barriers. Repository thermal
analysis is demonstrated for a range of waste types from projected future, advanced nuclear fuel
cycles. The results show significant differences among geologic media considered (clay/shale,
crystalline rock, salt), and also that waste package size and waste loading must be limited to meet
targeted maximum temperature values.
The responsibility for the governance of Australia is shared by the Australian government and the governments of the six states and two self governing territories. Responsibility for radiation health and safety in each State and Territory rests with the respective State/Territory government, unless the activity is carried out by an Australian government agency or a contractor to a Australian government agency; in those cases the activity is regulated by the Australian government.
Use of an on-site dry transfer system (DTS) allows utilities with limited crane capacities or other plant restrictions to take advantage of large efficient storage systems. By using this system, utilities can also transfer fuel from loaded storage casks to transport casks without returning to their fuel storage pool.
Due to the delayed opening of a final geological repository for spent nuclear fuel, the lifespan of dry cask storage systems may be increased to 120 years or longer. To ensure safety over this extended period of interim storage, degradation mechanisms that have the potential to cause penetration of the canister confinement boundary must be evaluated and understood.
Stress corrosion cracking (SCC) of welded stainless steel dry storage canisters may potentially impact systems exposed to corrosive atmospheric elements, such as those occurring near salt water bodies. Conditions important for atmospheric-related SCC include concentration and chemical species of the contaminants, temperature, and humidity. Calvert Cliffs Nuclear Power Plant conducted this historically important first inspection of spent fuel canisters to collect data for an SCC evaluation as part of the EPRI-led Extended Storage Collaboration Program (ESCP).
This Interim Staff Guidance (ISG) provides guidance to the staff for determining if
storage systems to be licensed under 10 CFR Part 72 allow ready retrieval of spent fuel.
This guidance is not a regulation or a requirement.
This Interim Staff Guidance (ISG) provides guidance to the staff on classifying spent nuclear
fuel as either (1) damaged, (2) undamaged, or (3) intact, before interim storage or
transportation. This is not a regulation or requirement and can be modified or superseded by
an applicant with supportable technical arguments.
Revision 2
Compliance with 10 CFR 72.122(l) has been interpreted to mean that a licensee, during any
point in the storage cycle, must have a means of retrieving and repackaging individual fuel
assemblies even after an accident. The staff has reevaluated this interpretation.
The closure weld for the outer cover plate for austenitic stainless steel designs may be
inspected using either volumetric or multiple pass dye penetrant techniques subject to the
following conditions:
• Dye penetrant (PT) examination may only be used in lieu of volumetric
examination only on austenitic stainless steels. PT examination should be done
in accordance with ASME Section V, Article 6, “Liquid Penetrant Examination.”
• For either ultrasonic examination (UT) or PT examination, the minimum
In June 2008, the U.S. Department of Energy (DOE) submitted a license application to the U.S. Nuclear Regulatory Commission (NRC) for the construction of a geologic repository at Yucca Mountain, Nevada, for the disposal of spent nuclear fuel and high-level radioactive waste. The license application was accepted for formal NRC review in September 2008. Throughout the more than 20-year history of the Yucca Mountain project, EPRI has performed independent assessments of key technical and scientific issues to facilitate an understanding of overall repository performance.
This report presents a best-estimate probabilistic risk assessment (PRA) to quantify the frequency of criticality accidents during railroad transportation of spent nuclear fuel casks. The assessment is of sufficient detail to enable full scrutiny of the model logic and the basis for each quantitative parameter contributing to criticality accident scenario frequencies. The report takes into account the results of a 2007 peer review of the initial version of this probabilistic risk assessment, which was published as EPRI Technical Report 1013449 in December 2006.
There has been a resurgence of interest in the possibility of processing the US spent nuclear fuel, instead of burying it in a geologic repository. Accordingly, key topical findings from three relevant EPRI evaluations made in the 1990-1995 timeframe are recapped and updated to accommodate a few developments over the subsequent ten years. Views recently expressed by other US entities are discussed.
Spent Nuclear Fuel Management: Outreach Needed to Help Gain Public Acceptance for Federal Activities That Address Liability
GAO-15-141: Published: Oct 9, 2014. Publicly Released: Nov 12, 2014.
