165 Matching Results

Search Results

Advanced search parameters have been applied.

Gas Reactor International Cooperative Program. Interim report. Safety and licensing evaluaion of German Pebble Bed Reactor concepts

Description: The Pebble Bed Gas Cooled Reactor, as developed in the Federal Republic of Germany, was reviewed from a United States Safety and Licensing perspective. The primary concepts considered were the steam cycle electric generating pebble bed (HTR-K) and the process heat pebble bed (PNP), although generic consideration of the direct cycle gas turbine pebble bed (HHT) was included. The study examines potential U.S. licensing issues and offers some suggestions as to required development areas.
Date: September 1, 1978
Partner: UNT Libraries Government Documents Department

US/FRG joint report on the pebble bed high temperature reactor resource conservation potential and associated fuel cycle costs

Description: Independent analyses at ORNL and KFA have led to the general conclusion that the flexibility in design and operation of a high-temperature gas-cooled pebble-bed reactor (PBR) can result in favorable ore utilization and fuel costs in comparison with other reactor types, in particular, with light-water reactors (LWRs). Fuel reprocessign and recycle show considerable promise for reducing ore consumption, and even the PBR throwaway cycle is competitive with fuel recycle in an LWR. The best performance results from the use of highly enriched fuel. Proliferation-resistant measures can be taken using medium-enriched fuel at a modest ore penalty, while use of low-enriched fuel would incur further ore penalty. Breeding is possible but net generation of fuel at a significant rate would be expensive, becoming more feasible as ore costs increase substantially. The /sup 233/U inventory for a breeder could be produced by prebreeders using /sup 235/U fuel.
Date: November 1, 1979
Creator: Teuchert, E.; Ruetten, H.J.; Worley, B.A. & Vondy, D.R.
Partner: UNT Libraries Government Documents Department

Pebble Bed Reactor: core physics and fuel cycle analysis

Description: The Pebble Bed Reactor is a gas-cooled, graphite-moderated high-temperature reactor that is continuously fueled with small spherical fuel elements. The projected performance was studied over a broad range of reactor applicability. Calculations were done for a burner on a throwaway cycle, a converter with recycle, a prebreeder and breeder. The thorium fuel cycle was considered using low, medium (denatured), and highly enriched uranium. The base calculations were carried out for electrical energy generation in a 1200 MW/sub e/ plant. A steady-state, continuous-fueling model was developed and one- and two-dimensional calculations were used to characterize performance. Treating a single point in time effects considerable savings in computer time as opposed to following a long reactor history, permitting evaluation of reactor performance over a broad range of design parameters and operating modes.
Date: October 1, 1979
Creator: Vondy, D.R. & Worley, B.A.
Partner: UNT Libraries Government Documents Department

PEBBLE: a two-dimensional steady-state pebble bed reactor thermal hydraulics code

Description: This report documents the local implementation of the PEBBLE code to treat the two-dimensional steady-state pebble bed reactor thermal hydraulics problem. This code is implemented as a module of a computation system used for reactor core history calculations. Given power density data, the geometric description in (RZ), and basic heat removal conditions and thermal properties, the coolant properties, flow conditions, and temperature distributions in the pebble fuel elements are predicted. The calculation is oriented to the continuous fueling, steady state condition with consideration of the effect of the high energy neutron flux exposure and temperature history on the thermal conductivity. The coolant flow conditions are calculated for the same geometry as used in the neutronics calculation, power density and fluence data being used directly, and temperature results are made available for subsequent use.
Date: September 1, 1981
Creator: Vondy, D.R.
Partner: UNT Libraries Government Documents Department

Interface-currents integral transport model for treating doubly-heterogeneous, multisystem geometries

Description: An analytical model for calculating neutron spectra in the doubly-heterogeneous fuel-moderator geometries of the pebble bed reactor concept is presented. The model is capable of simultaneously treating more than one type of fuel grain in the fuel matrix and more than one type of pebble in the reactor core. The model was developed to assess the need for treating various levels of material heterogeneity in processing neutron multigroup cross sections in the resolved resonance energy range. The slowing-down calculation is performed over a pointwise energy mesh tailored to the cross section structure for the nuclides present in the problem. Isotropic, elastic scattering theory is applied in an explicit calculation of down-scattered sources due to neutron interaction with all materials in all zones. At each energy point, neutron transport between zones is calculated with the interface-currents integral transport technique. Here, this technique is extended to include the simultaneous treatment of coupled, one-dimensional, multiregion systems. The coupling between the two levels of heterogeneity (grain systems and pebble systems) is accomplished by a sequence of source normalization and cross section averaging treatments. The equations applied in the slowing-down and spatial transport models are presented. Results from the analyses of single pebble and double pebble systems indicate the importance of resonance shielding as a function of fuel kernel diameter, fuel loading in each pebble, and the presence of more than one type of pebble in the system.
Date: January 1, 1979
Creator: Westfall, R.M. & Bjerke, M.A.
Partner: UNT Libraries Government Documents Department

Gas Reactor International Cooperative program. Pebble bed reactor plant: screening evaluation. Volume 3. Appendix A. Equipment list

Description: This report consists of three volumes which describe the design concepts and screening evaluation for a 3000 MW(t) Pebble Bed Reactor Multiplex Plant (PBR-MX). The Multiplex plant produces both electricity and transportable chemical energy via the thermochemical pipeline (TCP). The evaluation was limited to a direct cycle plant which has the steam generators and steam reformers in the primary circuit. Volume 1 reports the overall plant and reactor system and was prepared by the General Electric Company. Core scoping studies were performed which evaluated the effects of annular and cylindrical core configurations, radial blanket zones, burnup, and ball heavy metal loadings. The reactor system, including the PCRV, was investigated for both the annular and cylindrical core configurations. Volume 3 is an Appendix containing the equipment list for the plant and was also prepared by United Engineers and Constructors, Inc. It tabulates the major components of the plant and describes each in terms of quantity, type, orientation, etc., to provide a basis for cost estimation.
Date: November 1, 1979
Partner: UNT Libraries Government Documents Department

Gas reactor international cooperative program interim report: German Pebble Bed Reactor design and technology review

Description: This report describes and evaluates several gas-cooled reactor plant concepts under development within the Federal Republic of Germany (FRG). The concepts, based upon the use of a proven Pebble Bed Reactor (PBR) fuel element design, include nuclear heat generation for chemical processes and electrical power generation. Processes under consideration for the nuclear process heat plant (PNP) include hydrogasification of coal, steam gasification of coal, combined process, and long-distance chemical heat transportation. The electric plant emphasized in the report is the steam turbine cycle (HTR-K), although the gas turbine cycle (HHT) is also discussed. The study is a detailed description and evaluation of the nuclear portion of the various plants. The general conclusions are that the PBR technology is sound and that the HTR-K and PNP plant concepts appear to be achievable through appropriate continuing development programs, most of which are either under way or planned.
Date: September 1, 1978
Partner: UNT Libraries Government Documents Department

Gas Reactor International Cooperative program. Pebble bed reactor plant: screening evaluation. Volume 2. Conceptual balance of plant design

Description: This report consists of three volumes which describe the design concepts and screening evaluation for a 3000 MW(t) Pebble Bed Reactor Multiplex Plant (PBR-MX). The Multiplex plant produces both electricity and transportable chemical energy via the thermochemical pipeline (TCP). The evaluation was limited to a direct cycle plant which has the steam generators and steam reformers in the primary circuit. This volume describes the conceptual balance-of-plant (BOP) design and was prepared by United Engineers and Constructors, Inc. of Philadelphia, Pennsylvania. The major emphasis of the BOP study was a preliminary design of an overall plant to provide a basis for future studies.
Date: November 1, 1979
Partner: UNT Libraries Government Documents Department

Gas reactor international cooperative program interim report. Pebble bed reactor fuel cycle evaluation

Description: Nuclear fuel cycles were evaluated for the Pebble Bed Gas Cooled Reactor under development in the Federal Republic of Germany. The basic fuel cycle specified for the HTR-K and PNP is well qualified and will meet the requirements of these reactors. Twenty alternate fuel cycles are described, including high-conversion cycles, net-breeding cycles, and proliferation-resistant cycles. High-conversion cycles, which have a high probability of being successfully developed, promise a significant improvement in resource utilization. Proliferation-resistant cycles, also with a high probability of successful development, compare very favorably with those for other types of reactors. Most of the advanced cycles could be adapted to first-generation pebble bed reactors with no significant modifications.
Date: September 1, 1978
Partner: UNT Libraries Government Documents Department

Interim report on core physics and fuel cycle analysis of the pebble bed reactor power plant concept

Description: Calculations were made to predict the performance of a pebble bed reactor operated in a mode to produce fissile fuel (high conversion or breeding). Both a one pebble design and a design involving large primary feed pebbles and small fertile pebbles were considered. A relatively short residence time of the primary pebbles loaded with /sup 233/U fuel was found to be necessary to achieve a high breeding ratio, but this leads to relatively high fuel costs. A high fissile inventory is associated with a low C/Th ratio and a high thorium loading, causing the doubling time to be long, even though the breeding ratio is high, and the fuel cost of electrical product to be high. Production of /sup 233/U fuel from /sup 235/U feed was studied and performances of the converter and breeder reactor concepts were examined varying the key parameters.
Date: December 1, 1977
Creator: Vondy, D.R.
Partner: UNT Libraries Government Documents Department

Exploiting the steady state, continuous fueling reactor model

Description: A continuously fueled reactor presents an analysis challenge, especially so when the neutron accounting is sensitive to the core design and the fuel handling. A scheme was implemented to solve the steady state, continuous fueling problem. This problem is an accurate model of the reactor for assessing performance at a point in its operating history. Available capability in a modular code system developed to treat fixed fuel reactors was extended in this effort. Parametric studies have been made with this capability to assess the performance of a pebble bed power plant reactor over a wide range of fueling possibilities. The model and the calculational methods are discussed. A global iteration scheme is used to effect a solution for the critical reactor state. The schemes used to accelerate the rate of convergence of one- and two-dimensional problems are described and the interactive behavior is shown for representative problems.
Date: January 1, 1979
Creator: Vondy, D.R.; Cunningham, G.W. & Fowler, T.B.
Partner: UNT Libraries Government Documents Department

Hot Fuel Examination Facility's neutron radiography reactor

Description: Argonne National Laboratory-West is located near Idaho Falls, Idaho, and is operated by the University of Chicago for the United States Department of Energy in support of the Liquid Metal Fast Breeder Reactor Program, LMFBR. The Hot Fuel Examination Facility, HFEF, is one of several facilities located at the Argonne Site. HFEF comprises a large hot cell where both nondestructive and destructive examination of highly-irradiated reactor fuels are conducted in support of the LMFBR program. One of the nondestructive examination techniques utilized at HFEF is neutron radiography, which is provided by the NRAD reactor facility (a TRIGA type reactor) below the HFEF hot cell.
Date: January 1, 1983
Creator: Pruett, D.P.; Richards, W.J. & Heidel, C.C.
Partner: UNT Libraries Government Documents Department

Neutronics analysis of the proposed 25-MW leu TRIGA Multipurpose Research Reactor

Description: More than two years ago the government of Indonesia announced plans to purchase a research reactor for the Puspiptek Research Center in Serpong Indonesia to be used for isotope production, materials testing, neutron physics measurements, and reactor operator training. Reactors using low-enriched uranium (LEU) plate-type and rod-type fuel elements were considered. This paper deals with the neutronic evaluation of the rod-type 25-MW LEU TRIGA Multipurpose Research Reactor (MPRR) proposed by the General Atomic Company of the United States of America.
Date: 1982-23~
Creator: Nurdin, M.; Bretscher, M. M. & Snelgrove, J. L.
Partner: UNT Libraries Government Documents Department

New neutron simulation capabilities provided by the Sandia Pulse Reactor (SPR-III) and the Upgraded Annular Core Pulse Reactor (ACPR)

Description: The paper briefly describes the nuclear reactor facilities at Sandia Laboratories which are used for simulating nuclear weapon produced neutron environments. These reactor facilities are used principally in support of continuing R and D programs for the Department of Energy/Office of Military Application (DOE/OMA) in studying the effects of radiation on nuclear weapon systems and components. As such, the reactors are available to DOE and DOD agencies and their contractors responsible for the radiation hardening of advanced nuclear weapon systems. Emphasis is placed upon two new reactor simulation sources; the Sandia Pulse Reactor-III (SPR-III) Facility which enhances the neutron exposure volume capabilities over those presently available with the existing SPR-II Facility, and the Upgraded Annular Core Pulse Reactor (ACPR) Facility which enhances the neutron exposure capabilities over those of the former ACPR Facility.
Date: July 1, 1978
Creator: Choate, L.M. & Schmidt, T.R.
Partner: UNT Libraries Government Documents Department

Gas Reactor International Cooperative Program. Interim report: assessment of gas-cooled reactor economics

Description: The merits of introducing Pebble Bed Gas Reactors (PBRs) into the existing US electric generating sector are discussed. Information is presented concerning an economic model; nuclear fuel costs; capital cost targets; time comparison of nuclear power costs; introduction scenarios; domestic economic incentives; the selection of a discount rate for national energy supply studies; nuclear fuel cycle cost calculation code RAMMER; and PBR and HTGR fabrication and reprocessing costs.
Date: August 1, 1979
Partner: UNT Libraries Government Documents Department

Hypothetical accident scenario analyses for a 250-MW(t) modular high temperature gas-cooled reactor

Description: This paper describes calculations performed to characterize the inherent safety of a 250-MW(t), 100-MW(e), pebble bed modular high temperature gas-cooled reactor (HTGR) design with vertical in-line arrangement (i.e., upflow core with steam generators directly above the core). A variety of postulated accident sequences involving combinations of loss of forced primary coolant (helium) circulation, loss of primary coolant pressurization, and loss of heat sink were studied and were discussed.
Date: November 1, 1985
Creator: Harrington, R.M.; Ball, S.J. & Cleveland, J.C.
Partner: UNT Libraries Government Documents Department

Thermal-hydraulic analysis techniques for axisymmetric pebble bed nuclear reactor cores. [PEBBLE code]

Description: The pebble bed reactor's cylindrical core volume contains a random bed of small, spherical fuel-moderator elements. These graphite spheres, containing a central region of dispersed coated-particle fissile and fertile material, are cooled by high pressure helium flowing through the connected interstitial voids. A mathematical model and numerical solution technique have been developed which allow calculation of macroscopic values of thermal-hydraulic variables in an axisymmetric pebble bed nuclear reactor core. The computer program PEBBLE is based on a mathematical model which treats the bed macroscopically as a generating, conducting porous medium. The steady-state model uses a nonlinear Forchheimer-type relation between the coolant pressure gradient and mass flux, with newly derived coefficients for the linear and quadratic resistance terms. The remaining equations in the model make use of mass continuity, and thermal energy balances for the solid and fluid phases.
Date: March 1, 1979
Creator: Stroh, K.R.
Partner: UNT Libraries Government Documents Department

PINEX-2: pinhole-TV imaging of fuel ejection from an internally vented capsule

Description: The LASL pinhole-intensified TV system was used at the TREAT reactor to image an internally vented, fuel-ejection capsule designed and built by HEDL. Several improvements in the imaging system over PINEX-1 were incorporated. A sequence of 16-ms TV frames shows axial expansion, expulsion of fuel from the pin, and retention of clad integrity during the time of coverage.
Date: January 1, 1979
Creator: Berzins, G.J. & Lumpkin, A.H.
Partner: UNT Libraries Government Documents Department

Engineering studies to support a liquid sodium cooled pebble bed target/blanket for an accelerator breeder

Description: Preliminary calculations on using a liquid sodium cooled pebble bed of thorium metal for the target and blanket of a particle accelerator to convert fertile material to fissile have indicated the concept has considerable merit. Fuel management is simple and continuous on-line feed is effected. Additional features include excellent heat transfer, low pressure drop, minimization of structures and enhanced safety. Promising features strongly suggest that the work be continued to further refine the studies. Although specific to the target and blanket of the accelerator breeder concept, the work is readily extended to a high efficiency liquid metal cooled nuclear reactor employing a pebble bed as the fuel. 10 refs., 4 figs., 1 tab.
Date: January 1, 1977
Creator: Cooper, K.C. & Malenfant, R.E.
Partner: UNT Libraries Government Documents Department

Extended-capacity high-speed-disk recording system for TREAT hodoscope

Description: New requirements for time resolution, test duration, field of view, and recording redundancy in dynamic digital radiographic imaging of fuel motion in TREAT and TREAT-Upgrade (TU) in-pile experiments have been formulated. This has necessitated the design and fabrication of a new hodoscope high-speed data acquisition system. Recently an array of proportional counters was installed to operate in tandem with the Hornyak-button array. The full implementation of this new array, together with the increased field-of-view needed for future TU 37-pin experiments, required a separate recording system operting in parallel with that for the Hornyak buttons. The new recording system was required to have substantially higher capacity than the earlier recording system in use, in order to record sufficient data channels and samples with adequately small collection intervals, for some new types of experiments.
Date: January 1, 1983
Creator: Rhodes, E.A.; Travis, D.; DeVolpi, A.; Burrows, D.; Ray, D. & Stanford, G.
Partner: UNT Libraries Government Documents Department

Neutron flux enhancement in the NRAD reactor

Description: In 1987 a series of experiments were conducted at the NRAD reactor facility at Argonne National Laboratory - West (ANL-W) to investigate the possibility of increasing the thermal neutron content at the end of the reactor's east beam tube through the use of hydrogenous flux traps. It was desired to increase the thermal flux for a series of experiments to be performed in the east radiography cell, in which the enhanced flux was required in a relatively small volume. Hence, it was feasible to attempt to focus the cross section of the beam to a smaller area. Two flux traps were constructed from unborated polypropylene and tested to determine their effectiveness. Both traps were open to the entire cross-sectional area of the neutron beam (as it emerges from the wall and enters the beam room). The sides then converged such that at the end of the trap the beam would be 'focused' to a greater intensity. The differences in the two flux traps were primarily in length, and hence angle to the beam as the inlet and outlet cross-sectional areas were held constant. It should be noted that merely placing a slab of polypropylene in the beam will not yield significant multiplication as neutrons are primarily scattered away.
Date: January 1, 1988
Creator: Weeks, A.A.; Heidel, C.C. & Imel, G.R.
Partner: UNT Libraries Government Documents Department

Neutron radiography at the NRAD facility

Description: The NRAD facility uses a 150 kW TRIGA reactor as a source of neutrons and is integrated with a hot cell such that highly radioactive specimens can be radiographed without removing them from the hot cell environment. A second beam tube is located in a separate shielded addition to HFEF and permits neutron radiography of irradiated or unirradiated specimens without subjecting them to the alpha-contaminated hot cell environment. Both beams are optimized for neutron radiography of highly radioactive nuclear fuels. Techniques for using these facilities are described. Advantages include: the ability to perform thermal and epithermal neutron radiography on specimens either inside or outside the hot cell, lack of competition for the use of the reactor, versatility of facility design, and the addition of neutron tomography. (LEW)
Date: January 1, 1984
Creator: McClellan, G.C. & Richards, W.J.
Partner: UNT Libraries Government Documents Department

Reconfiguration of the NRAD delay loop for proposed 1 MW operations

Description: The Hot Fuel Examination Facility, HFEF, is one of several facilities located at the Argonne Site. HFEF comprises a large hot cell where both nondestructive and destructive examination of highly-irradiated reactor fuels are conducted in support of the LMFBR program. One of the nondestructive examination technqiues utilized at HFEF is neutron radiography. Neutron radiography is provided by the NRAD reactor facility, which is located beneath the HFEF hot cell. The NRAD reactor is a TRIGA reactor and is operated at a steady-state power level of 250 kw solely for neutron radiography and the development of radiography techniques. Modifications of the NRAD delay loop for 1 MW operations are described.
Date: January 1, 1984
Creator: Heidel, C.C.; Richards, W.J. & Pruett, D.P.
Partner: UNT Libraries Government Documents Department

Proposed power upgrade of the Hot Fuel Examination Facility's neutron radiography reactor. [NRAD reactor]

Description: The Hot Fuel Examination Facility, HFEF, is one of several facilities located at the Argonne Site. HFEF comprises a large hot cell where both non-destructive and destructive examination of highly-irradiated reactor fuels are conducted in support of the LMFBR program. One of the non-destructive examination techniques utilized at HFEF is neutron radiography. Neutron radiography is provided by the NRAD reactor facility, which is located beneath the HFEF hot cell. The NRAD reactor is a TRIGA reactor and is operated at a steady state power level of 250 kW solely for neutron radiography and the development of radiography techniques. When the NRAD facility was designed and constructed, an operating power level of 250 kW was considered to be adequate for obtaining radiographs of the type of specimens envisaged at that time. A typical radiograph required approximately a twenty-minute exposure time. Specimens were typically single fuel rods placed in an aluminum tray. Since that time, however, several things have occurred that have tended to increase radiography exposure times to as much as 90 minutes each. In order to decrease exposure times, the reactor power level is to be increased from 250 kw to 1 MW. This increase in power will necessitate several engineering and design changes. These changes are described.
Date: January 1, 1984
Creator: Pruett, D.P.; Richards, W.J. & Heidel, C.C.
Partner: UNT Libraries Government Documents Department