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ZPR-3 Assembly 11 : A cylindrical sssembly of highly enriched uranium and depleted uranium with an average {sup 235}U enrichment of 12 atom % and a depleted uranium reflector.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 11 (ZPR-3/11) was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 12 at.% and a depleted uranium reflector. Approximately 79.7% of the total fissions in this assembly occur above 100 keV, approximately 20.3% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor ...
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Security, National & Engineering, Inst. of Physics and Power

ZPR-3 Assembly 12 : A cylindrical assembly of highly enriched uranium, depleted uranium and graphite with an average {sup 235}U enrichment of 21 atom %.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 12 (ZPR-3/12) was designed as a fast reactor physics benchmark experiment with an average core {sup 235}U enrichment of approximately 21 at.%. Approximately 68.9% of the total fissions in this assembly occur above 100 keV, approximately 31.1% occur below 100 keV, and essentially none below 0.625 eV - thus the classification as a 'fast' assembly. This assembly is Fast Reactor Benchmark No. 9 in the ...
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D.; Perel, R. L.; Wagschal, J. J.; Division, Nuclear Engineering & Physics, Racah Inst. of

ZPR-3 Assembly 6F : A spherical assembly of highly enriched uranium, depleted uranium, aluminum and steel with an average {sup 235}U enrichment of 47 atom %.

Description: Over a period of 30 years, more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited for nuclear data validation and to form the basis for criticality safety benchmarks. A number of the Argonne ZPR/ZPPR critical assemblies have been evaluated as ICSBEP and IRPhEP benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. ZPR-3 Assembly 6 consisted of six phases, A through F. In each phase a critical configuration was constructed to simulate a very simple shape such as a slab, cylinder or sphere that could be analyzed with the limited analytical tools available in the 1950s. In each case the configuration consisted of a core region of metal plates surrounded by a thick depleted uranium metal reflector. The average ...
Date: September 30, 2010
Creator: Lell, R. M.; McKnight, R. D; Schaefer, R. W. & Division, Nuclear Engineering

ZPR-6 assembly 7 high {sup 240} PU core : a cylindrical assemby with mixed (PU, U)-oxide fuel and a central high {sup 240} PU zone.

Description: Over a period of 30 years more than a hundred Zero Power Reactor (ZPR) critical assemblies were constructed at Argonne National Laboratory. The ZPR facilities, ZPR-3, ZPR-6, ZPR-9 and ZPPR, were all fast critical assembly facilities. The ZPR critical assemblies were constructed to support fast reactor development, but data from some of these assemblies are also well suited to form the basis for criticality safety benchmarks. Of the three classes of ZPR assemblies, engineering mockups, engineering benchmarks and physics benchmarks, the last group tends to be most useful for criticality safety. Because physics benchmarks were designed to test fast reactor physics data and methods, they were as simple as possible in geometry and composition. The principal fissile species was {sup 235}U or {sup 239}Pu. Fuel enrichments ranged from 9% to 95%. Often there were only one or two main core diluent materials, such as aluminum, graphite, iron, sodium or stainless steel. The cores were reflected (and insulated from room return effects) by one or two layers of materials such as depleted uranium, lead or stainless steel. Despite their more complex nature, a small number of assemblies from the other two classes would make useful criticality safety benchmarks because they have features related to criticality safety issues, such as reflection by soil-like material. The term 'benchmark' in a ZPR program connotes a particularly simple loading aimed at gaining basic reactor physics insight, as opposed to studying a reactor design. In fact, the ZPR-6/7 Benchmark Assembly (Reference 1) had a very simple core unit cell assembled from plates of depleted uranium, sodium, iron oxide, U3O8, and plutonium. The ZPR-6/7 core cell-average composition is typical of the interior region of liquid-metal fast breeder reactors (LMFBRs) of the era. It was one part of the Demonstration Reactor Benchmark Program,a which provided integral experiments characterizing ...
Date: October 1, 2007
Creator: Lell, R. M.; Schaefer, R. W.; McKnight, R. D.; Tsiboulia, A.; Rozhikhin, Y.; Division, Nuclear Engineering et al.

ZPR-6 assembly 7 high {sup 240}Pu core experiments : a fast reactor core with mixed (Pu,U)-oxide fuel and a centeral high{sup 240}Pu zone.

Description: ZPR-6 Assembly 7 (ZPR-6/7) encompasses a series of experiments performed at the ZPR-6 facility at Argonne National Laboratory in 1970 and 1971 as part of the Demonstration Reactor Benchmark Program (Reference 1). Assembly 7 simulated a large sodium-cooled LMFBR with mixed oxide fuel, depleted uranium radial and axial blankets, and a core H/D near unity. ZPR-6/7 was designed to test fast reactor physics data and methods, so configurations in the Assembly 7 program were as simple as possible in terms of geometry and composition. ZPR-6/7 had a very uniform core assembled from small plates of depleted uranium, sodium, iron oxide, U{sub 3}O{sub 8} and Pu-U-Mo alloy loaded into stainless steel drawers. The steel drawers were placed in square stainless steel tubes in the two halves of a split table machine. ZPR-6/7 had a simple, symmetric core unit cell whose neutronic characteristics were dominated by plutonium and {sup 238}U. The core was surrounded by thick radial and axial regions of depleted uranium to simulate radial and axial blankets and to isolate the core from the surrounding room. The ZPR-6/7 program encompassed 139 separate core loadings which include the initial approach to critical and all subsequent core loading changes required to perform specific experiments and measurements. In this context a loading refers to a particular configuration of fueled drawers, radial blanket drawers and experimental equipment (if present) in the matrix of steel tubes. Two principal core configurations were established. The uniform core (Loadings 1-84) had a relatively uniform core composition. The high {sup 240}Pu core (Loadings 85-139) was a variant on the uniform core. The plutonium in the Pu-U-Mo fuel plates in the uniform core contains 11% {sup 240}Pu. In the high {sup 240}Pu core, all Pu-U-Mo plates in the inner core region (central 61 matrix locations per half of the split ...
Date: February 23, 2009
Creator: Lell, R. M.; Morman, J. A.; Schaefer, R.W. & McKnight, R.D.

ZPR-9 airborne plutonium monitoring system

Description: An airborne plutonium monitoring system which is installed in the ZPR-9 (Zero Power Reactor No. 9) facility at Argonne National Laboratory is described. The design and operational experience are discussed. This monitoring system utilizes particle size and density discrimination, alpha particle energy discrimination, and a background-subtraction techique operating in cascade to separate airborne-plutonium activity from other, naturally occurring, airborne activity. Relatively high sensitivity and reliability are achieved. (auth)
Date: January 1, 1975
Creator: Rusch, G.K.; McDowell, W.P. & Knapp, W.G.

Zr and Mo isotopes in single presolar graphite grains : a record of stellar nucleosynthesis.

Description: Thirty-two individual graphite grains from the Murchison meteorite were analyzed for their Mo and/or Zr isotopic compositions by laser ablation resonant ionization mass spectrometry. {sup 96}Zr/{sup 94}Zr ratios range from 0.074 times to 10 times the solar value. Five grains have depletions in {sup 96}Zr, suggestive of the s-process, and two grains have extraordinary enrichments in {sup 96}Zr, suggestive of the r-process. Most graphite grains have close-to-terrestrial Mo isotopic imposition, but five have s-process Mo nucleosynthesis signatures.
Date: February 10, 1998
Creator: Nicolussi, G. K.

Zr and Mo isotopic constraints on the origins of unusual types of presolar SiC grains.

Description: Although most presolar silicon carbide grains form in asymptotic giant branch red giant stars (the so-called mainstream grains) or supernovae (the X-grains), there are a number of other minor types of grains whose origin is less clear. The dominant mechanisms of heavy element nucleosynthesis, the s-process and r-process, are thought to occur mainly in AGB stars and supernovae, respectively [1], and the isotopic patterns in heavy elements in presolar grains can be used to constrain their origins. We have previously reported that mainstream SiC grains have strong enrichments in the s-process isotopes of Sr, Zr and Mo [2-5] and that X-grains have an unusual Mo isotopic composition that differs from s- and r-process expectations [6,7]. We report here the first measurements of Zr and Mo isotopes in several grains of other rare types that were found in the same mount as the mainstream and X-grains reported previously.
Date: March 1, 2000
Creator: Pellin, M. J.; Davis, A. M.; Calaway, W. F.; Lewis, R. S.; Clayton, R. N. & Amari, S.

ZrH-reactor-technology program. Progress report, April-June 1974

Description: The report on the 2 kW(e) reactor-organic Rankine system was drafted. This report details the design parameters of a minimum weight, 2 kW(e) reactor-organic Rankine system. The system is designed for 5 years unattended life in space. The reactor produces 16.2 kW of thermal power with a NaK outlet temperature of 800/sup 0/F and a 200/sup 0/F ..delta..T. The reactor contains 19 fuel elements, 1.25'' in diameter by 10'' long, hydrided to an N/sub H/ of 6.35. The terrestrial applications effort was oriented towards the establishment of the feasibility of utilizing the zirconium hydride reactor technology in a subsea application for supplying electrical power to deep water, and other environmentally severe, oil well installations. The overall system concept is shown. The power system is composed of three basic modules (i.e., a reactor module, a generator module, and a heat rejection system) mounted on a barge. The barge is then towed to the installation site and submerged to mate with a previously installed seafloor foundation. An assembly/disassembly sequence was drafted detailing the steps required to assemble the reactor module and to disassemble it after 4 years of operations.
Date: July 12, 1974

ZrO sub 2 and ZrO sub 2 /SiC particle reinforced-MoSi sub 2 matrix composites

Description: ZrO{sub 2}-MoSi{sub 2} and ZrO{sub 2}/SiC-MoSi{sub 2} composites were fabricated by hot pressing and hot pressing/HIP at 1700{degrees}C. No reactions between ZrO{sub 2}, SiC, and MoSi{sub 2} were observed. An amorphous silica glassy phase was present in all composites. Composites with unstabilized ZrO{sub 2} particles exhibited the highest room temperature fracture toughness, reaching a level three times that of pure MoSi{sub 2}. Both the room temperature toughness and 1200{degrees}C strength of ZrO/{sub 2}SiC-MoSi{sub 2} composites were higher than ZrO{sub 2}-MoSi{sub 2} composites, indicating beneficial effects of combined reinforcement phases. Low strength levels were observed at 1400{degrees}C due to the presence of the silica glassy phase. Elimination of glassy phases and refinements in microstructural homogeneity are processing routes important to the optimization of the mechanical properties of these types of composites. 18 refs., 7 figs.
Date: January 1, 1991
Creator: Petrovic, J.J.; Bhattacharya, A.K.; Honnell, R.E.; Mitchell, T.E. (Los Alamos National Lab., NM (United States)); Wade, R.K. (Arizona Materials Lab., Tucson, AZ (United States)) & McCellan, K.J. (Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering)

THE ZrO$sub 2$-CaO-UO$sub 2$ CERAMIC FUEL FABRICATION FOR THE EBWR SPIKED CORE ELEMENTS. Final Report-Metallurgy Program 7.9.5

Description: A series of experiments was proposed in which the thermal output of the EBWR is increased to 100 Mw. The increase in thermal enengy will be accomplished by inserting 32 spike elements in the initial fuel core. The fuel selected for the spike elements was a cubic solid solution in the system ZrO/sub 2/- CaO- UO/ sub 2/. The ceramic fuel was fabricated in the form of pellets by compacting a mixture of U/sub 3/O/sub 8/, CaCO/sub 3/, and ZrO/sub 2/. The pressed pellets were sintered in air at 1675 deg C plus or minus 25 deg C to form a cubic solid solution having a composition of 9.01 wt.% UO/sub 2/ (93% enriched), 9.07 wt.% CaO, and 81.92 wt.% ZrO/sub 2/. The procedures used in forming the fuel pellets are described. Following fabrication, the pellets were loosely inserted into Zircaloy-2 tubes for subsequent assembly into fuel elements. (auth)
Date: May 1961
Creator: Lied, R. C.; Lynch, E. D. & Handwerk, J. H.

ZrO sub 2 reinforced-MoSi sub 2 matrix composites

Description: ZrO{sub 2} particle-MoSi{sub 2} matrix composites were fabricated by wet processing/hot pressing, using high quality unstabilized, partially stabilized, and fully stabilized ZrO{sub 2} powders. Composite room temperature indentation fracture toughness increased with increasing volume fraction of ZrO{sub 2} reinforcement. Unstabilized ZrO{sub 2} produced the highest composite fracture toughness, 7.8 MPa m{sup {1/2}} as compared to 2.6 MPa m{sup {1/2}} for pure MoSi{sub 2}. Unstabilized ZrO{sub 2} composites exhibited matrix microcracking, and the spontaneous tetragonal-to-monoclinic ZrO{sub 2} phase transformation induced significant plastic deformation in the MoSi{sub 2} matrix. Partially stabilized ZrO{sub 2} produced a lesser extent of composite fracture toughening, possibly as a result of an inhomogeneous ZrO{sub 2} particle distribution and presence of a glassy phase. 13 refs., 6 figs., 1 tab.
Date: January 1, 1991
Creator: Petrovic, J.J.; Honnell, R.E.; Mitchell, T.E. (Los Alamos National Lab., NM (USA)); Wade, R.K. (Arizona Materials Lab., Tucson, AZ (USA)) & McClellan, K.J. (Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Materials Science and Engineering)

ZT-40 administrative plan

Description: An administrative plan for the ZT-40 project has been developed. It describes baselines and procedures that will be used for the remainder of the construction phase of the project.
Date: August 1, 1978
Creator: Thomas, K.S. (comp.)

ZT-40M system design, modification, and installation

Description: ZT-40 is a reversed field pinch experiment which had been operated as originally designed, with a ceramic discharge tube until November 1980. At that time, the experiment was shut down for major modifications. This paper will describe these modifications in general and discuss in detail the design of the energy system.
Date: January 1, 1981
Creator: Hammer, C.F.

ZT-P: an advanced air core reversed field pinch prototype

Description: The ZT-P experiment, with a major radius of 0.45 m and a minor radius of 0.07 m, was designed to prototype the next generation of reversed field pinch (RFP) machines at Los Alamos. ZT-P utilizes an air-core poloidal field system, with precisely wound and positioned rigid copper coils, to drive the plasma current and provide plasma equilibrium with intrinsically low magnetic field errors. ZT-P's compact configuration is adaptable to test various first wall and limiter designs at reactor-relevant current densities in the range of 5 to 20 MA/m/sup 2/. In addition, the load assembly design allows for the installation of toroidal field divertors. Design of ZT-P began in October 1983, and assembly was completed in October 1984. This report describes the magnetic, electrical, mechanical, vacuum, diagnostic, data acquisition, and control aspects of the machine design. In addition, preliminary data from initial ZT-P operation are presented. Because of ZT-P's prototypical function, many of its design aspects and experimental results are directly applicable to the design of a next generation RFP. 17 refs., 47 figs.
Date: January 1, 1986
Creator: Schoenberg, K.F.; Buchenauer, C.J.; Burkhardt, L.C.; Caudill, L.D.; Dike, R.S.; Dominguez, T. et al.

ZTI: An ignition class reversed-field pinch

Description: A cost-optimized conceptual design of an intermediate-step, ignition-class RFP device (ZTI)for the study of alpha-particle physics and burn control in a DT plasma is reported. With major and minor plasma radii R{sub T} = 2.4m and {tau}{sub p} = 0.4m, respectively, and for conservative extrapolations of experimental energy-confinement times, ion-density profiles, and impurity levels, the ZTI operating conditions during a 5-s period of constant fusion power are: toroidal plasma current I{sub {phi}} {approx equal} 9 MA, plasma temperature T {approx equal} 11 keV, plasma density n{sub i} {approx equal} 3 {times} 10{sup 20} m{sup {minus}3}, fusion power P{sub F} {approx equal} 100 MW, and physics Q-value Q{sub p} {approx equal} 5 for a total machine size that corresponds to P{sub F}/M{sub FPC} {approx equal} 590 kW/tonne. This physics design point was adopted as a strawman'' with which to examine the requirements of ohmic heating to DT ignition and to perform a cost-optimized magnetics design. The ZTl design reflects potentially significant cost savings relative to similar ignition-class tokamaks for device parameters that reside on the path to a viable commercial RFP reactor. The methodology and results of coupling realistic physics, engineering, and cost models through a multi-dimensional optimizer are reported for this device that would follow the 2-4 MA ZTH presently under construction.
Date: January 1, 1990
Creator: Bathke, C.G.; Krakowski, R.A.; Miller, R.L. & Werley, K.A.

ZTI: Preliminary characterization of an ignition class reversed-field pinch

Description: A preliminary cost-optimized conceptual design of an intermediate-step, ignition-class RFP device (ZTI) for the study of alpha-particle physics in a DT plasma is reported. The ZTI design reflects potentially significant cost savings relative to similar ignition-class tokamaks for device parameters that reside on the path to a viable commercial RFP reactor. Reductions in both device costs and number of steps to commercialization portend a significantly reduced development cost for fusion. The methodology and result and coupling realistic physics, engineering, and cost models through a multi-dimensional optimizer are reported for ZTI, which is a device that would follow the 2--4 MA ZTH on a {approx gt} 1996--98 timescale. 15 refs., 7 figs., 2 tabs.
Date: January 1, 1990
Creator: Bathke, C. G.; Krakowski, R. A.; Miller, R. L. & Werley, K. A.

ZX Pulsed-Power Design

Description: ZX is a new z-pinch accelerator planned as the next generation z-pinch driver at SNL, and as an intermediate step towards X-1. It is planned to drive either a single 50 MA z-pinch load, or two 25 to 30 MA z pinches. Three designs for the ZX accelerator are presented. All require 7 to 8 MV at the insulator stack to drive the z-pinch load to implosion in 100 to 120 ns. Two of the designs are based on the Z accelerator, and use water-line technology; a transit-time-isolated water adder, and a water transformer. The third design uses inductive-voltage adders in water. They also describe a low-inductance insulator stack design that helps minimize voltage requirements. This design is evaluated for water and vacuum break-down using JCM, THM, and magnetic-flashover-inhibition criteria.
Date: August 2, 1999
Creator: Corley, J.P.; Johnson, D.L.; McDaniel, D.H.; Spielman, R.B.; Struve, K.W. & Stygar, W.A.