slides - Cook Nuclear Plant, Dry Cask Loading & Storage
slides - Cook Nuclear Plant, Dry Cask Loading & Storage
Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013
Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013
The purpose of this calculation report, Range of Applicability and Bias Determination for Postclosure
Criticality of Commercial Spent Nuclear Fuel, is to validate the computational method used to perform
postclosure criticality calculations. The validation process applies the criticality analysis methodology
approach documented in Section 3.5 of the Disposal Criticality Analysis Methodology Topical Report.1
The application systems for this validation consist of waste packages containing transport, aging, and
The purpose of this study is to provide insights into the neutronic similarities that may exist between a
generic cask containing typical spent nuclear fuel assemblies and commercial reactor critical (CRC) state-
points. Forty CRC state-points from five pressurized-water reactors were selected for the study and the
type of CRC state-points that may be applicable for validation of burnup credit criticality safety
calculations for spent fuel transport/storage/disposal systems are identified. The study employed cross-
Because there is currently no designated disposal site for used nuclear fuel in the United States, the nation faces the prospect of extended long‐term storage (i.e., >60 years) and deferred transportation of used fuel at operating and decommissioned nuclear power plant sites. Under U.S. federal regulations contained in Title 10 of the Code of Federal Regulations (CFR) 72.42, the initial license term for an Independent Spent Fuel Storage Installation (ISFSI) must not exceed 40 years from the date of issuance. Licenses may be renewed by the U.S.
In the 1980s, a series of critical experiments referred to as the Haut Taux de Combustion (HTC)
experiments was conducted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) at the
experimental criticality facility in Valduc, France. The plutonium-to- uranium ratio and the isotopic
compositions of both the uranium and plutonium used in the simulated fuel rods were designed to be
similar to what would be found in a typical pressurized-water reactor fuel assembly that initially had an
At the request of the U.S. Congress, the National Academies assessed the safety and
security of spent nuclear fuel stored in pools and dry casks at commercial nuclear power
plants in the United States. The public report can be viewed on the National Academies
Press website at http://books.nap.edu/catalog/11263.html.
This report was prepared in accordance with Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package (BSC 2004 [DIRS 171583]). This report provides information on the phase stability of Alloy 221, the current waste package outer barrier material. The goal of this model is to determine whether the single-phase solid solution is stable under repository conditions and, if not, how fast other phases may precipitate.
This report provides details of dry storage cask systems and contents in U.S. for commercial light water
reactor fuel. Section 2 contains details on the canisters used to store approximately 86% of assemblies in
dry storage in the U.S. Transport cask details for bare fuels, dual purpose casks and canister transport
casks are included in Section 3. Section 4 details the inventory of those shutdown sites without any
operating reactors. Information includes the cask type deployed, transport license and status as well as
Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013
Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013
Presented at the NEI Used Fuel Management Conference, St. Petersburg, FL, May 7-9, 2013
Taking credit for the reduced reactivity of spent nuclear fuel (SNF) in criticality analyses is referred to as burnup credit (BUC). Criticality safety evaluations require validation of the computational methods with critical experiments that are as similar as possible to the safety analysis models, and for which the keff values are known. This poses a challenge for validation of BUC criticality analyses, as critical experiments with actinide and fission product (FP)
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
This report provides details of dry storage cask systems and contents in U.S. for commercial light water
reactor fuel. Section 2 contains details on the canisters used to store approximately 86% of assemblies in
dry storage in the U.S. Transport cask details for bare fuels, dual purpose casks and canister transport
casks are included in Section 3. Section 4 details the inventory of those shutdown sites without any
operating reactors. Information includes the cask type deployed, transport license and status as well as
Dry cask storage systems are deployed at nuclear power plants for used nuclear fuel (UNF)
Presentation made at International Conference on The Management of Spent Nuclear Fuel from Nuclear Power Reactors, An Integrated approach to the Back-End of the Fuel Cycle (IAEA-CN-226). The purpose of the conference was to highlight the importance of an integrated long-term approach to the management of spent fuel from nuclear power reactors.
In 1999, the United States Nuclear Regulatory Commission (U.S. NRC) initiated a research program
to support the development of technical bases and guidance that would facilitate the implementation of burnup
credit into licensing activities for transport and dry cask storage. This paper reviews the following major areas of
investigation: (1) specification of axial burnup profiles, (2) assumption on cooling time, (3) allowance for
assemblies with fixed and removable neutron absorbers, (4) the need for a burnup margin for fuel with initial
In the 1980s a series of the Haut Taux de Combustion (HTC) critical experiments with fuel pins in a water-moderated lattice was conducted at the Apparatus B experimental facility in Valduc (Commissariat à l'Energie Atomique, France) with the support of the Institut de Radioprotection et de Sûreté Nucléaire and AREVA NC. Four series of experiments were designed to assess profit associated with actinide-only burnup credit in the criticality safety evaluation for fuel handling, pool storage, and spent-fuel cask conditions.
In the United States, burnup credit has been used in the criticality safety evaluation for storage pools at
pressurized water reactors (PWRs) and considerable work has been performed to lay the foundation for use of
burnup credit in dry storage and transport cask applications and permanent disposal applications. Many of the
technical issues related to the basic physics phenomena and parameters of importance are similar in each of these
applications. However, the nuclear fuel cycle in the United States has never been fully integrated and the
Analytical methods, described in this report, are used to
systematically determine experimental fuel sub-batch
reactivities as a function of burnup. Fuel sub-batch reactivities
are inferred using more than 600 in-core pressurized water
reactor (PWR) flux maps taken during 44 cycles of operation
at the Catawba and McGuire nuclear power plants. The
analytical methods systematically search for fuel sub-batch
reactivities that minimize differences between measured and
computed reaction rates, using Studsvik Scandpower’s
Pressurized water reactor (PWR) burnup credit validation is
demonstrated using the benchmarks for quantifying fuel reactivity
decrements, published as Benchmarks for Quantifying Fuel Reactivity
Depletion Uncertainty, Electric Power Research Institute (EPRI)
report 1022909. This demonstration uses the depletion module
TRITON (Transport Rigor Implemented with Time-Dependent
Operation for Neutronic Depletion) available in the SCALE 6.1
(Standardized Computer Analyses for Licensing Evaluations) code
This paper provides insights into the neutronic similarities between a representative high-capacity rail-transport cask containing typical pressurized water reactor (PWR) spent nuclear fuel assemblies and critical reactor state-points, referred to as commercial reactor critical (CRC) state-points. Forty CRC state-points from five PWRs were analyzed, and the characteristics of CRC state-points that may be applicable for validation of burnup-credit criticality safety calculations for spent fuel transport/storage/disposal systems were identified.