skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Radiolytic and Thermal Processes Relevant to Dry Storage of Spent Nuclear Fuels

Abstract

The scientific and engineering demands of the Department of Energy (DOE) Environmental Restoration and Waste Management tasks are enormous. For example, several thousand metric tons of metallic uranium spent nuclear fuel (SNF) remain in water storage awaiting disposition. Of this inventory, 2300 metric tons are N-Reactor fuel that have been stored for up to 24 years in the Hanford, Washington KBasins. No significant precautions were taken to prevent the fuel from corroding since the fuel rods were intended to be reprocessed. Termination of reprocessing has left these fuels stranded in prolonged water storage and an appreciable quantity of the fuel has corroded. In addition, other defense fuels including the aluminum-clad fuels at the Savannah River Site and Idaho National Engineering Laboratory have corroded during interim storage in water. In 1994, the DOE began to implement a strategy for moving water-stored Hanford fuels into dry interim storage and a Record of Decision 1 ( ROD) documenting this action was put forth by the Department of Energy on March 4, 1996. Several documents 1-4 including this ROD and the final environmental impact statement (FEIS)1, evaluated and documented concerns regarding the potential for releases of radionuclides to the environment. The DOE plans tomore » remove metallic uranium SNF from water storage and seal it in overpack canisters for ''dry'' interim storage, for up to 75 years. Much of the SNF that will be stored will have been severely corroded during water storage. Chemically bound water not removed during proposed drying operations may lead to long-term corrosion and generation of combustible H2 and O2 gas-mixture via radiolysis. No thoroughly tested model is currently available to predict fuel behavior during ''dry'' storage. The PNNL collaborating with the Rutgers University studied the thermo-chemical and radiolytic reactions of actual and prototype SNF materials. The purpose of this project is to deliver pertinent information which can be used to make decisions concerning the safety and treatment issues associated with dry storage of spent nuclear fuel materials. In particular, we set out to establish an understanding of: (1) water interactions with failed-fuel rods and metal-oxide materials; (2) the role of thermal processes and radiolysis (solid-state and interfacial) in the generation of potentially explosive mixtures of gaseous H2 and O2, and (3) the potential role of radiation assisted corrosion during fuel rod storage. The project meets several major DOE/EMSP science needs for the Spent Nuclear Fuel Focus Area: (1) Stabilization of spent nuclear fuel, including mechanism of pyrophoricity and combustion parameters for various fuel types; (2) Characterization of spent nuclear fuel; (3) Development of methods to remove moisture without damage to fuel elements; and (4) Characterization of corrosion, degradation, and radionuclide release mechanisms, kinetics, and rates for fuel matrices.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab., Richland, WA; Rutgers University, Piscataway, NJ; Georgia Institute of Technology, Atlanta Georgia (US)
Sponsoring Org.:
USDOE Office of Environmental Management (EM) (US)
OSTI Identifier:
831160
Report Number(s):
EMSP-60392
R&D Project: EMSP 60392; TRN: US0405749
DOE Contract Number:
FG07-97ER14833
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 8 Sep 2000
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 29 ENERGY PLANNING, POLICY AND ECONOMY; 54 ENVIRONMENTAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CONTAINERS; DRY STORAGE; ENVIRONMENTAL IMPACT STATEMENTS; FUEL ELEMENTS; FUEL RODS; KINETICS; MATRICES; NUCLEAR FUELS; RADIOISOTOPES; RADIOLYSIS; STABILIZATION; STORAGE; URANIUM; WASTE MANAGEMENT; WASTE STORAGE

Citation Formats

Marschman, Steven C., Madey, Theodore E., Orlando, Thomas M., Cowin, James P., and Petrik, Nikolay G.. Radiolytic and Thermal Processes Relevant to Dry Storage of Spent Nuclear Fuels. United States: N. p., 2000. Web. doi:10.2172/831160.
Marschman, Steven C., Madey, Theodore E., Orlando, Thomas M., Cowin, James P., & Petrik, Nikolay G.. Radiolytic and Thermal Processes Relevant to Dry Storage of Spent Nuclear Fuels. United States. doi:10.2172/831160.
Marschman, Steven C., Madey, Theodore E., Orlando, Thomas M., Cowin, James P., and Petrik, Nikolay G.. Fri . "Radiolytic and Thermal Processes Relevant to Dry Storage of Spent Nuclear Fuels". United States. doi:10.2172/831160. https://www.osti.gov/servlets/purl/831160.
@article{osti_831160,
title = {Radiolytic and Thermal Processes Relevant to Dry Storage of Spent Nuclear Fuels},
author = {Marschman, Steven C. and Madey, Theodore E. and Orlando, Thomas M. and Cowin, James P. and Petrik, Nikolay G.},
abstractNote = {The scientific and engineering demands of the Department of Energy (DOE) Environmental Restoration and Waste Management tasks are enormous. For example, several thousand metric tons of metallic uranium spent nuclear fuel (SNF) remain in water storage awaiting disposition. Of this inventory, 2300 metric tons are N-Reactor fuel that have been stored for up to 24 years in the Hanford, Washington KBasins. No significant precautions were taken to prevent the fuel from corroding since the fuel rods were intended to be reprocessed. Termination of reprocessing has left these fuels stranded in prolonged water storage and an appreciable quantity of the fuel has corroded. In addition, other defense fuels including the aluminum-clad fuels at the Savannah River Site and Idaho National Engineering Laboratory have corroded during interim storage in water. In 1994, the DOE began to implement a strategy for moving water-stored Hanford fuels into dry interim storage and a Record of Decision 1 ( ROD) documenting this action was put forth by the Department of Energy on March 4, 1996. Several documents 1-4 including this ROD and the final environmental impact statement (FEIS)1, evaluated and documented concerns regarding the potential for releases of radionuclides to the environment. The DOE plans to remove metallic uranium SNF from water storage and seal it in overpack canisters for ''dry'' interim storage, for up to 75 years. Much of the SNF that will be stored will have been severely corroded during water storage. Chemically bound water not removed during proposed drying operations may lead to long-term corrosion and generation of combustible H2 and O2 gas-mixture via radiolysis. No thoroughly tested model is currently available to predict fuel behavior during ''dry'' storage. The PNNL collaborating with the Rutgers University studied the thermo-chemical and radiolytic reactions of actual and prototype SNF materials. The purpose of this project is to deliver pertinent information which can be used to make decisions concerning the safety and treatment issues associated with dry storage of spent nuclear fuel materials. In particular, we set out to establish an understanding of: (1) water interactions with failed-fuel rods and metal-oxide materials; (2) the role of thermal processes and radiolysis (solid-state and interfacial) in the generation of potentially explosive mixtures of gaseous H2 and O2, and (3) the potential role of radiation assisted corrosion during fuel rod storage. The project meets several major DOE/EMSP science needs for the Spent Nuclear Fuel Focus Area: (1) Stabilization of spent nuclear fuel, including mechanism of pyrophoricity and combustion parameters for various fuel types; (2) Characterization of spent nuclear fuel; (3) Development of methods to remove moisture without damage to fuel elements; and (4) Characterization of corrosion, degradation, and radionuclide release mechanisms, kinetics, and rates for fuel matrices.},
doi = {10.2172/831160},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Sep 08 00:00:00 EDT 2000},
month = {Fri Sep 08 00:00:00 EDT 2000}
}

Technical Report:

Save / Share:
  • The purpose of this project is to deliver pertinent information that can be used to make rational decisions about the safety and treatment issues associated with dry storage of spent nuclear fuel materials. In particular, we will establish an understanding of: (1) water interactions with failed-fuel rods and metal-oxide materials; (2) the role of thermal processes and radiolysis (solid-state and interfacial) in the generation of potentially explosive mixtures of gaseous H2 and O2; and (3) the potential role of radiation-assisted corrosion during fuel rod storage.
  • 'This project involves basic research in chemistry and physics aimed at providing information pertinent to the safe long-term dry storage of spent nuclear fuel (SNF), thousands of tons of which remain in water storage across the DOE complex. The Hanford Site K-Basins alone hold 2,300 tons of spent fuel, much of it severely corroded, and similar situations exist at Savannah River and Idaho National Engineering and Environmental Laboratory. The DOE plans to remove this fuel and seal it in overpack canisters for dry interim storage for up to 75 years while awaiting permanent disposition. Chemically-bound water will remain in thismore » fuel even following proposed drying steps, leading to possible long-term corrosion of the containers and/or fuel rods themselves, generation of H{sub 2} and O{sub 2} gas via radiolysis (which could lead to deflagration or detonation), and reactions of pyrophoric uranium hydrides. No thoroughly tested model is currently available to predict fuel behavior during pre-processing, processing, or storage. In a collaboration between Rutgers University, Pacific Northwest National Laboratory, and Brookhaven National Laboratory, the authors are studying the radiolytic reaction, drying processes, and corrosion behavior of actual SNF materials, and of pure and mixed-phase samples. The authors propose to determine what is omitted from current models: radiolysis of water adsorbed on or in hydrates or hydroxides, thermodynamics of interfacial phases, and kinetics of drying. A model will be developed and tested against actual fuel rod behavior to insure validity and applicability to the problems associated with developing dry storage strategies for DOE-owned SNF. This report summarizes work after eight months of a three-year project.'« less
  • This project involves basic research in chemistry and physics aimed at providing information pertinent to the safe long-term dry storage of spent nuclear fuel (SNF), thousands of tons of which remain in water storage across the DOE complex. The Hanford Site K-Basins alone hold 2300 tons of spent fuel, much of it severely corroded, and similar situations exist at Savannah River and Idaho National Engineering and Environmental Laboratory. DOE plans to remove this fuel and seal it in overpack canisters for ''dry'' interim storage for up to 75 years while awaiting permanent disposition. Chemically bound water will remain in thismore » fuel even after the proposed drying steps, leading to possible long-term corrosion of the containers and/or fuel rods themselves, generation of H2 and O2 gas via radiolysis (which could lead to deflagration or detonation), and reactions of pyrophoric uranium hydrides. No thoroughly tested model is now available to predict fuel behavior during preprocessing, processing, or storage. In a collaborative effort among Rutgers University, Pacific Northwest National Laboratory, and Brookhaven National Laboratory, we are studying the radiolytic reaction, drying processes, and corrosion behavior of actual SNF materials and of pure and mixed-phase samples. We propose to determine what is omitted from current models: radiolysis of water adsorbed on or in hydrates or hydroxides, thermodynamics of interfacial phases, and kinetics of drying. A model will be developed and tested against actual fuel rod behavior to ensure validity and applicability to the problems associated with developing dry storage strategies for DOE-owned SNF.« less
  • Characterize the effects of temperature and radiation processes on the interactions of H20 with oxide surfaces. Our experiments focused on the fundamental interaction of H20 molecules with surfaces of U02. We characterized the surface chemistry of adsorbed H2O using thermal desorption methods and radiotracer methods, as well as x-ray photoelectron spectroscopy (XPS) and low energy ion scattering (LEIS). In parallel with these measurements of thermal effects, we examined the effects of secondary electrons and high-energy photons on hydrogen and oxygen generation and, and how this related to corrosion of spent nuclear fuel. These studies concentrated on neutral and ionic (cationmore » and anion) desorption products of low-energy electron irradiation of water-covered UO2.« less
  • The Pacific Northwest Laboratory has evaluated the basis for moving selected spent nuclear fuels in the CPP-603 and CPP-666 storage pools at the Idaho Chemical Processing Plant from wet to dry interim storage. This work is being conducted for the Lockheed Idaho Technologies Company as part of the effort to determine appropriate conditioning and dry storage requirements for these fuels. These spent fuels are from 22 test reactors and include elements clad with aluminum or stainless steel and a wide variety of fuel materials: UAl{sub x}, UAl{sub x}-Al and U{sub 3}O{sub 8}-Al cermets, U-5% fissium, UMo, UZrH{sub x}, UErZrH, UO{submore » 2}-stainless steel cermet, and U{sub 3}O{sub 8}-stainless steel cermet. The study also included declad uranium-zirconium hydride spent fuel stored in the CPP-603 storage pools. The current condition and potential failure mechanisms for these spent fuels were evaluated to determine the impact on conditioning and dry storage requirements. Initial recommendations for conditioning and dry storage requirements are made based on the potential degradation mechanisms and their impacts on moving the spent fuel from wet to dry storage. Areas needing further evaluation are identified.« less