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Debugging Fortran on a shared memory machine

Description: Debugging on a parallel processor is more difficult than debugging on a serial machine because errors in a parallel program may introduce nondeterminism. The approach to parallel debugging presented here attempts to reduce the problem of debugging on a parallel machine to that of debugging on a serial machine by automatically detecting nondeterminism. 20 refs., 6 figs.
Date: January 1, 1987
Creator: Allen, T.R. & Padua, D.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effect of low dose rate irradiation on the swelling of 12% cold-worked 316 stainless steel.

Description: In pressurized water reactors (PWRs), stainless steel components are irradiated at temperatures that may reach 400 C due to gamma heating. If large amounts of swelling (>10%) occur in these reactor internals, significant swelling related embrittlement may occur. Although fast reactor studies indicate that swelling should be insignificant at PWR temperatures, the low dose rate conditions experienced by PWR components may possibly lead to significant swelling. To address these issues, JNC and … more
Date: March 2, 1999
Creator: Allen, T. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The sodium-cooled fast reactor (SFR).

Description: The primary mission for the SFR is the management of high-level wastes, and in particular, management of plutonium and other actinides. The Generation IV Roadmap Fuel Cycle Crosscut Group (FCCG) found that the limiting factor facing an essential role for nuclear energy with the once-through cycle is the availability of repository space worldwide [FCCG Report]. This becomes an important issue, requiring new repository development in only a few decades. Systems that employ a fully closed fuel cyc… more
Date: October 25, 2002
Creator: Lineberry, M. J. & Allen, T. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radiation damage of a glass-bonded zeolite waste form using ion irradiation.

Description: Glass-bonded zeolite is being considered as a candidate ceramic waste form for storing radioactive isotopes separated from spent nuclear fuel in the electrorefining process. To determine the stability of glass-bonded zeolite under irradiation, transmission electron microscope samples were irradiated using high energy helium, lead, and krypton. The major crystalline phase of the waste form, which retains alkaline and alkaline earth fission products, loses its long range order under both helium a… more
Date: December 5, 1997
Creator: Allen, T. R. & Storey, B. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The correlation between swelling and radiation-induced segregation in iron-chromium-nickel alloys.

Description: The magnitudes of both void swelling and radiation-induced segregation (RIS) in iron-chromium-nickel alloys are dependent on bulk alloy composition. Because the diffusivity of nickel via the vacancy flux is slow relative to chromium, nickel enriches and chromium depletes at void surfaces during irradiation. This local composition change reduces the subsequent vacancy flux to the void, thereby reducing void swelling. In this work, the resistance to swelling from major element segregation is esti… more
Date: March 5, 1998
Creator: Allen, T. R.; Busby, J. T.; Kenik, E. A. & Was, G. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radiation-induced segregation and the relationship to physical properties in irradiated austenitic alloys.

Description: Radiation-induced changes in composition are studied because these changes can degrade failure of materials irradiated in nuclear reactors. In this work, the effect of alloy composition on radiation-induced segregation, hardening, and void swelling is presented. Five alloys, Fe-18Cr-8Ni, Fe-16Cr-13Ni, Fe-18Cr-40Ni, Fe-16Cr-13Ni+Mo, and Fe-16Cr-13Ni+Mo+P (all compositions in wt. %), were irradiated with 3.2 MeV protons at 400 C to a dose of 0.5 displacements per atom. The change in grain boundar… more
Date: June 5, 2002
Creator: Allen, T. R.; Cole, J. I.; Was, G. S. & Kenik, E. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Developing improved structural materials using proton irradiation as a rapid analysis tool.

Description: The overall goal of the project is to develop austenitic stainless steel structural materials with enhanced radiation resistance. For this project, the term radiation resistance is being used to describe resistance to dimensional changes caused by void swelling and resistance to material failures caused by irradiation assisted stress corrosion cracking (IASCC). IASCC has been linked to both hardening and changes in grain boundary composition during irradiation. To achieve such enhanced radiatio… more
Date: October 7, 2003
Creator: Allen, T. R.; Cole, J. I.; Dropek, R.; Gan, J. & Was, G. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Mechanical properties of 20% cold-worked 316 stainless steel irradiated at low dose rate.

Description: To assess the effects of long-term, low-dose-rate neutron exposure on mechanical strength and ductility, tensile properties were measured on irradiated 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-47 dpa at temperatures from 371-385 C and dose rates from 0.8-2.8 x 10{sup -7} dpa/s. These dose rates are about one order of magnitude lo… more
Date: December 11, 2001
Creator: Allen, T. R.; Tsai, H.; Cole, J. I.; Ohta, J.; Dohi, K. & Kusanagi, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Properties of 20% cold-worked 316 stainless steel irradiated at low dose rate.

Description: To assess the effects of long-term, low-dose-rate neutron exposure, tensile, hardness, and fracture properties were measured and microstructural characterization performed on irradiated 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-390 C and dose rates from 0.8-3.3 x 10{sup -7} dpa/s. Irradiation caused… more
Date: June 5, 2002
Creator: Allen, T. R.; Tsai, H.; Cole, J. I.; Ohta, J.; Dohi, K. & Kusanagi, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

National Scientific User Facility Purpose and Capabilities

Description: The U.S. Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF) in April 2007. This designation allows the ATR to become a cornerstone of nuclear energy research and development (R&D) within the U.S. by making it easier for universities, the commercial power industry, other national laboratories, and international organizations to conduct nuclear energy R&D. The mission of the ATR NSUF is to provide nuclear energy researchers access t… more
Date: September 1, 2010
Creator: Rosenberg, K. E.; Allen, T. R.; Haley, J. C. & Meyer, M. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The influence of pre-irradiation heat treatments on thermal non-equilibrium and radiation-induced segregation behavior in model austenitic stainless steel alloys.

Description: The effect of pre-irradiation heat treatments on thermal non-equilibrium grain boundary segregation (TNES) and subsequent radiation-induced grain boundary segregation (RIS) is studied in a series of model austenitic stainless steels. The alloys used for this study are based on AISI 316 stainless steel and have the following nominal compositions: Fe-16Cr-13Ni-1.25Mn (base 316), Fe-16Cr-13Ni-1.25Mn-2.0Mo (316 + Mo) and Fe-16Cr-13Ni-1.25Mn-2.0Mo-0.07P (316 + Mo + P). Samples were heat treated at t… more
Date: July 29, 2002
Creator: Cole, J. I.; Allen, T. R.; Was, G. S.; Dropek, R. B. & Kenik, E. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The EBR-II materials-surveillance program. 5: Results of SURV-5.

Description: In March of 1965, a set of surveillance (SURV) samples was placed in the EBR-II reactor to determine the effect of irradiation, thermal aging, and sodium corrosion on reactor materials. Eight subassemblies were placed into row 12 positions of EBR-II to determine the effect of irradiation at 370 C. Two subassemblies were placed into the primary sodium basket to determine the effect of thermal aging at 370 C. One half of all samples were exposed to primary system sodium while one half were sealed… more
Date: January 1, 1998
Creator: Ruther, W. E.; Staffon, J. D.; Carlson, B. G. & Allen, T. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Design of Radiation-Tolerant Structural Alloys for Generation IV Nuclear Energy Systems

Description: The objective of this program is to improve the radiation tolerance of both austenitic and ferritic-martensitic (F-M) alloys projected for use in Generation IV systems. The expected materials limitations of Generation IV components include: creep strength, dimensional stability, and corrosion/stress corrosion compatibility. The material design strategies to be tested fall into three main categories: (1) engineering grain boundaries; (2) alloying, by adding oversized elements to the matrix; and … more
Date: December 28, 2005
Creator: Allen, T. R.; Was, G. S.; Bruemmer, S. M.; Gan, J. & Ukai, S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Microstructure Characterization of RERTR Fuel

Description: A variety of phases have the potential to develop in the irradiated fuels for the reduced enrichment research test reactor (RERTR) program. To study the radiation stability of these potential phases, three depleted uranium alloys were cast. The phases of interest were identified including U(Si,Al)3, (U,Mo)(Si,Al)3, UMo2Al20, UAl4, and U6Mo4Al43. These alloys were irradiated with 2.6 MeV protons at 200ºC up to 3.0 dpa. The microstructure is characterized using SEM and TEM. Microstructural charac… more
Date: September 1, 2008
Creator: Gan, J.; Miller, B. D.; Keiser, D. D.; Allen, T. R. & Wachs, D. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Nuclear energy plant optimization (NEPO) final scientific/technical report

Description: The overall objective of this 3 year research program has been to support the aging management programs for LWR reactors through the extended 60-year lifetimes by adding to the knowledge base of irradiation-induced effects on the mechanical properties and cracking resistance of stainless steel (SS) core components. Over the course of this project, efforts have focused on enhancing the understanding of the link between deformation and fracture behavior in work-hardened and irradiated stainless s… more
Date: February 2, 2004
Creator: Cole, J. I.; Daum, R. S.; Tsai, H.; Porter, D. L.; Allen, T. R. & Wirth, B. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Radiation Effect on Microstructural Stability of RERTR Fuel

Description: Three depleted uranium alloys are successfully cast for the radiation stability studies of the fuel-cladding interaction product using proton irradiation. SEM analysis indicates the presence of the phases of interest: U(Si,Al)3, (U,Mo)(Si,Al)3 and a mixture of UMo2Al20, U6Mo4Al43, and UAl4. Irradiation with 2.6 MeV protons at 200ºC to the doses of 0.1, 1.0 and 3.0 dpa are carried out.
Date: March 1, 2008
Creator: Gan, J.; Keiser, D. D. Jr.; Miller, B. D.; Allen, T. R. & Wachs, D. M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Beam-broadening effects in STEM/EDS measurement of radiation-induced segregation in high-purity 304L stainless steel

Description: Radiation-induced segregation (RIS) is the spatial redistribution of elements at defect sinks such as grain boundaries and free surfaces during irradiation. This phenomenon has been studied in a wide variety of alloys and has been linked to irradiation-assisted stress corrosion cracking (IASCC) of nuclear reactor core components. Therefore, accurate determination of the grain boundary composition is important in understanding its effects on environmental cracking. Radiation-induced segregation … more
Date: October 1997
Creator: Busby, J. T.; Was, G. S.; Allen, T. R.; Kenik, E. A. & Zaluzec, N. J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The EBR-II materials-surveillance program. 4: Results of SURV-4 and SURV-6

Description: In March of 1965, a set of surveillance (SURV) samples was placed in the EBR-II reactor to determine the effect of irradiation, thermal aging, and sodium corrosion on reactor materials. Eight subassemblies were placed into row 12 positions of EBR-II to determine the effect of irradiation at 370 C. Two subassemblies were placed into the primary sodium basket to determine the effect of thermal aging at 370 C. For both the irradiated and thermally aged samples, one half of all samples were exposed… more
Date: January 1, 1998
Creator: Ruther, W. E.; Hayner, G. O.; Carlson, B. G.; Ebersole, E. R. & Allen, T. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Cracking Behavior and Microstructure of Austenitic Stainless Steels and Alloy 690 Irradiated in BOR-60 Reactor, Phase I.

Description: Cracking behavior of stainless steels specimens irradiated in the BOR-60 at about 320 C is studied. The primary objective of this research is to improve the mechanistic understanding of irradiation-assisted stress corrosion cracking (IASCC) of core internal components under conditions relevant to pressurized water reactors. The current report covers several baseline tests in air, a comparison study in high-dissolved-oxygen environment, and TEM characterization of irradiation defect structure. S… more
Date: February 16, 2010
Creator: Chen, Y.; Chopra, O. K.; Soppet, W. K.; Shack, W. J.; Yang, Y.; Allen, T. R. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Advanced Test Reactor National Scientific User Facility Advancing Nuclear Technology

Description: To help ensure the long-term viability of nuclear energy through a robust and sustained research and development effort, the U.S. Department of Energy (DOE) designated the Advanced Test Reactor and associated post-irradiation examination facilities a National Scientific User Facility (ATR NSUF), allowing broader access to nuclear energy researchers. The mission of the ATR NSUF is to provide access to world-class nuclear research facilities, thereby facilitating the advancement of nuclear scienc… more
Date: May 1, 2009
Creator: Allen, T. R.; Benson, J. B.; Foster, J. A.; Marshall, F. M.; Meyer, M. K. & Thelen, M. C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

The effect of low dose rate irradiation on the tensile properties and microstructure of austenitic stainless steel.

Description: To assess the effects of long-term, low-dose-rate neutron exposure on mechanical strength and ductility, tensile properties were measured on 12% and 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-440 C and dose rates from 0.5-5.8 x10{sup -7} dpa/s. These dose rates are approximately an order of magnitude… more
Date: September 17, 2002
Creator: Allen, T. R.; Tsai, H.; Cole, J. I.; Yoshitake, T.; Akasaka, N.; Donomae, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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