The Effect of Fuel Burnup and Dispersed Water Intrusion on the Criticality of Spent High-Level Nuclear Fuel in a Geologic Repository

1993 ◽  
Vol 333 ◽  
Author(s):  
William G. Culbreth ◽  
Paige R. Zielinski
Keyword(s):  
Fuel Burnup ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Chain Reaction ◽  
Worst Case ◽  
Mixture Ratio ◽  
Waste Package ◽  
Radiological Data ◽  
A Chain ◽  
High Level

ABSTRACTStudies of the spent fuel waste package have been conducted through the use of a Monte-Carlo neutron simulation program to determine the ability of the fuel to sustain a chain reaction. These studies have included fuel burnup and the effect of water mists on criticality. Results were compared with previous studies.In many criticality studies of spent fuel waste packages, fresh fuel with an enrichment as high as 4.5% is used as the conservative (worst) case. The actual spent fuel has a certain amount of “burnup” that decreases the concentration of fissile uranium and increases the amount of radionuclides present. The LWR Radiological Data Base from OCRWM has been used to determine the relative radionuclide ratios and KENO 5.a was used to calculate values of the effective multiplication factor, keff.1Spent fuel is not capable of sustaining a chain reaction unless a suitable moderator, such as water, is present. A completely flooded container has been treated as the worst case for criticality. Results of a previous report that demonstrated that keff actually peaked at a water-to-mixture ratio of 13% were analyzed for validity. In the present study, these results did not occur in the SCP waste package container.

Centralization of Canada’s Spent Nuclear Fuel

2013 ◽  
Author(s):  
Krista Nicholson ◽  
John McDonald ◽  
Shona Draper ◽  
Brian M. Ikeda ◽  
Igor Pioro
Keyword(s):  
Nuclear Fuel ◽  
Site Selection ◽  
Nuclear Power ◽  
Power Plants ◽  
Spent Nuclear Fuel ◽  
Selection Process ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Candu Reactors ◽  
High Level

Currently in Canada, spent fuel produced from Nuclear Power Plants (NPPs) is in the interim storage all across the country. It is Canada’s long-term strategy to have a national geologic repository for the disposal of spent nuclear fuel for CANada Deuterium Uranium (CANDU) reactors. The initial problem is to identify a means to centralize Canada’s spent nuclear fuel. The objective of this paper is to present a solution for the transportation issues that surround centralizing the waste. This paper reviews three major components of managing and the transporting of high-level nuclear waste: 1) site selection, 2) containment and 3) the proposed transportation method. The site has been selected based upon several factors including proximity to railways and highways. These factors play an important role in the site-selection process since the location must be accessible and ideally to be far from communities. For the containment of the spent fuel during transportation, a copper-shell container with a steel structural infrastructure was selected based on good thermal, structural, and corrosion resistance properties has been designed. Rail has been selected as the method of transporting the container due to both the potential to accommodate several containers at once and the extensive railway system in Canada.

A Comparison of the Performance of Nuclear Waste Glasses by Modeling

1987 ◽  
Vol 112 ◽  
Author(s):  
B. Grambow ◽  
D. M. Strachan
Keyword(s):  
Nuclear Waste ◽  
Nuclear Reactors ◽  
Liquid Waste ◽  
Spent Fuel ◽  
High Level Liquid Waste ◽  
Geologic Repository ◽  
Waste Forms ◽  
The Earth ◽  
Soluble Solid ◽  
High Level

The reprocessing of spent fuel from nuclear reactors and processing of fuels for defense purposes have generated large volumes of high-level liquid waste that need to be immobilized prior to final storage. For immobilization, the wastes must be converted to a less soluble solid, and, although other waste forms exist, glass currently appears to be the choice for the transuranic-containing portion of the reprocessed waste. Once produced, this glass will be sent in canisters to a geologic repository located some 200 to 500 m below the surface of the earth.

The Importance of Criticality in the Safety Analysis of the Spent-Fuel Waste Container

1992 ◽  
Vol 294 ◽  
Author(s):  
William G. Culbreth ◽  
Paige Zielinski
Keyword(s):  
Thermal Effects ◽  
Federal Regulations ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Waste Container ◽  
Neutron Multiplication ◽  
Accident Conditions ◽  
High Level ◽  
Internal Configuration ◽  
Selection Of

ABSTRACTThe storage of high-level spent reactor fuel in a proposed national geologic repository will require the construction of containers to be placed in boreholes drilled into the host rock. Federal regulations require that the fuel be maintained subcritical under normal or accident conditions. This is determined through the calculation of a neutron multiplication factor, keff, that must remain below 0.95. Criticality will play an important role in the container design, the internal configuration of the fuel, and the selection of neutron poisons. An analysis of keff should be a normal step in the conceptualization of new waste container designs. Unlike thermal effects in a proposed repository, criticality will remain a problem long after the 10,000 year lifetime of the facility.

Spent Fuel Storage in the Post-Yucca Mountain Paradigm

2012 ◽  
Author(s):  
Earl Easton ◽  
Christopher Bajwa ◽  
Zhian Li ◽  
Matthew Gordon
Keyword(s):  
Spent Nuclear Fuel ◽  
Data Availability ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Safety Standards ◽  
Dose Rates ◽  
Fuel Storage ◽  
High Burnup ◽  
High Level ◽  
Time Frames

The current uncertainty surrounding the licensing and eventual opening of a long term geologic repository for the nation’s civilian and defense spent nuclear fuel (SNF) and high level radioactive waste (HLW) has shifted the window for the length of time spent fuel could be stored to periods of time significantly longer than the current licensing period of 40 years for dry storage. An alternative approach may be needed to the licensing of high-burnup fuel for storage and transportation based on the assumption that spent fuel cladding may not always remain intact. The approach would permit spent fuel to be retrieved on a canister basis and could lessen the need for repackaging of spent fuel. This approach is being presented as a possible engineering solution to address the uncertainties and lack of data availability for cladding properties for high burnup fuel and extended storage time frames. The proposed approach does not involve relaxing current safety standards for criticality safety, containment, or permissible external dose rates.

Estimating the Alteration Kinetics of the French Vitrified High-Level Waste Package in a Geologic Repository

1998 ◽  
Vol 123 (1) ◽  
pp. 67-81 ◽  
Author(s):  
Patrick Jollivet ◽  
Michèle Nicolas ◽  
Etienne Vernaz
Keyword(s):  
High Level Waste ◽  
Geologic Repository ◽  
Waste Package ◽  
High Level ◽  
Kinetics Of

High-Level Waste Package Licensing Considerations for Extrapolating test Data

1986 ◽  
Vol 84 ◽  
Author(s):  
T.C. Johnson ◽  
K.C. Chang ◽  
T.L. Jungling ◽  
L.S. Person ◽  
C.H. Peterson ◽  
...  
Keyword(s):  
Test Data ◽  
Nuclear Regulatory Commission ◽  
High Level Waste ◽  
Geologic Repository ◽  
Waste Package ◽  
Performance Predictions ◽  
Technical Issues ◽  
Regulatory Commission ◽  
High Level ◽  
General Standard

AbstractPrograms intended to provide supporting information for the high-level radioactive waste (HLW) repository program must consider the licensing requirements and the technical issues involved with extrapolation of short-term test data to periods of up to 10,000 years. The licensing requirements of the Nuclear Regulatory Commission (NRC), and the issues the NRC staff considers important for the development of predictive methods, are described. Because performance predictions of the geologic repository and particular components of the waste package must largely be based upon inference, a reasonable assurance, on the basis of the record before the Commission, is the general standard that will be required.

Performance Analysis of Conceptual Waste Package Designs in Salt Repositories

1983 ◽  
Vol 26 ◽  
Author(s):  
George Jansen ◽  
Gilbert E. Raines ◽  
John F. Kircher
Keyword(s):  
Performance Analysis ◽  
Flow Rate ◽  
High Level Waste ◽  
Spent Fuel ◽  
Radiation Level ◽  
Waste Package ◽  
Corrosion Rates ◽  
Salt Dissolution ◽  
Bedded Salt Formations ◽  
High Level

ABSTRACTA performance analysis of commercial high-level waste and spent fuel conceptual package designs in reference repositories in three salt formations was conducted with the WAPPA waste package code. Expected conditions for temperature, stress, brine composition, radiation level, and brine flow rate were used as boundary conditions to compute expected corrosion of a thick-walled overpack of 1025 wrought steel. In all salt formations corrosion by low Mg salt-dissolution brines typical of intrusion scenarios was too slow to cause the package to fail for thousands of years after burial. In high Mg brines judged typical of thermally migrating brines in bedded salt formations, corrosion rates which would otherwise have caused the packages to fail within a few hundred years were limited by brine availability. All of the brine reaching the package was consumed by reaction with the iron in the overpack, thus preventing further corrosion. Uniform brine distribution over the package surface was an important factor in predicting long package lifetimes for the high Mg brines.

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