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Finite element method for neutron diffusion problems in hexagonal geometry

Description: The use of the finite element method for solving two-dimensional static neutron diffusion problems in hexagonal reactor configurations is considered. It is investigated as a possible alternative to the low-order finite difference method. Various piecewise polynomial spaces are examined for their use in hexagonal problems. The central questions which arise in the design of these spaces are the degree of incompleteness permissible and the advantages of using a low-order space fine-mesh approach over that of a high-order space coarse-mesh one. There is also the question of the degree of smoothness required. Two schemes for the construction of spaces are described and a number of specific spaces, constructed with the questions outlined above in mind, are presented. They range from a complete non-Lagrangian, non-Hermite quadratic space to an incomplete ninth order space. Results are presented for two-dimensional problems typical of a small high temperature gas-cooled reactor. From the results it is concluded that the space used should at least include the complete linear one. Complete spaces are to be preferred to totally incomplete ones. Once function continuity is imposed any additional degree of smoothness is of secondary importance. For flux shapes typical of the small high temperature gas-cooled reactor the linear space fine-mesh alternative is to be preferred to the perturbation quadratic space coarse-mesh one and the low-order finite difference method is to be preferred over both finite element schemes. (auth)
Date: June 1, 1975
Creator: Wei, T.Y.C. & Hansen, K.F.
Partner: UNT Libraries Government Documents Department

Using SA508/533 for the HTGR Vessel Material

Description: This paper examines the influence of High Temperature Gas-cooled Reactor (HTGR) module power rating and normal operating temperatures on the use of SA508/533 material for the HTGR vessel system with emphasis on the calculated times at elevated temperatures approaching or exceeding ASME Code Service Limits (Levels B&C) to which the reactor pressure vessel could be exposed during postulated pressurized and depressurized conduction cooldown events over its design lifetime.
Date: June 1, 2012
Creator: Demick, Larry
Partner: UNT Libraries Government Documents Department

New method for coating microspheres with zirconium carbide and zirconium carbide--carbon graded coats

Description: A new method for the chemical vapor deposition of ZrC and C--ZrC alloys has been developed. This process has been applied to the fabrication of coated particle nuclear fuels of the type used in the large High-Temperature Gas-Cooled Reactor. A powder feeder is used to supply ZrCl$sub 4$ to the fluidized bed coating furnace where it undergoes reaction with a hydrocarbon to form ZrC. Quantitative metering of the ZrCl$sub 4$ makes it possible to control the deposition of the ZrC and the codeposition of the C--ZrC alloys on the fuel particles. Examples of both types of coats made using the described technique are discussed and illustrated. (auth)
Date: June 1, 1975
Creator: Hollabaugh, C.M.; Reiswig, R.D.; Wagner, P.; Wahman, L.A. & White, R.W.
Partner: UNT Libraries Government Documents Department

Modularization and nuclear power. Report by the Technology Transfer Modularization Task Team

Description: This report describes the results of the work performed by the Technology Transfer Task Team on Modularization. This work was performed as part of the Technology Transfer work being performed under Department of Energy Contract 54-7WM-335406, between December, 1984 and February, 1985. The purpose of this task team effort was to briefly survey the current use of modularization in the nuclear and non-nuclear industries and to assess and evaluate the techniques available for potential application to nuclear power. A key conclusion of the evaluation was that there was a need for a study to establish guidelines for the future development of Light Water Reactor, High Temperature Gas Reactor and Liquid Metal Reactor plants. The guidelines should identify how modularization can improve construction, maintenance, life extension and decommissioning.
Date: June 1, 1985
Partner: UNT Libraries Government Documents Department

Nuclear proliferation and civilian nuclear power. Report of the Nonproliferation Alternative Systems Assessment Program. Volume IX. Reactor and fuel cycle description

Description: The Nonproliferation Alterntive Systems Assessment Program (NASAP) has characterized and assessed various reactor/fuel-cycle systems. Volume IX provides, in summary form, the technical descriptions of the reactor/fuel-cycle systems studied. This includes the status of the system technology, as well as a discussion of the safety, environmental, and licensing needs from a technical perspective. This information was then used in developing the research, development, and demonstration (RD and D) program, including its cost and time frame, to advance the existing technology to the level needed for commercial use. Wherever possible, the cost data are given as ranges to reflect the uncertainties in the estimates.
Date: June 1, 1980
Partner: UNT Libraries Government Documents Department

Process heat reactor design and analaysis. Quarterly progress report, April 1-June 30, 1978

Description: This report summarizes the third quarter FY-1978 results of concept design studies at General Atomic Company (GA) for an 842-MW(t) VHTR utilizing an intermediate helium heat transfer loop to provide thermal energy for the production of reducing gas (H/sub 2/ + CO) by steam-reforming a light hydrocarbon. Basic carbon sources may be coal, residual, or oil shale. The report summarizes the various plant configurations selected for the study and presents the conceptual plant layout drawings. Results of design studies on the intermediate heat exchanger are also presented. The status of the performance/optimization code development is discussed, and completion of the core auxiliary cooling system study is summarized.
Date: June 30, 1978
Partner: UNT Libraries Government Documents Department

Gas-cooled reactor programs: high-temperature gas-cooled reactor technology development program. Annual progress report for period ending December 31, 1981

Description: Information is presented concerning HTGR chemistry; fueled graphite development; irradiation services for General Atomic Company; prestressed concrete pressure vessel development; HTGR structural materials; graphite development; high-temperature reactor physics studies; shielding studies; component flow test loop studies; core support performance test; and application and project assessments.
Date: June 1, 1982
Partner: UNT Libraries Government Documents Department

Irradiation performance of HTGR fuel rods in HFIR experiments HRB-11 and -12

Description: Capsules HRB-11 and -12 were irradiated in support of development of weak-acid-resin-derived recycle fuel for the high-enriched uranium (HEU) fuel cycle for the HTGR. Fissil fuel particles with initial oxygen-to-metal ratios between 1.0 and 1.7 performed acceptably to full burnup for HEU fuel. Particles with ratios below 1.0 showed excessive chemical interaction between rare earth fission products and the SiC layer.
Date: June 1, 1980
Creator: Homan, F.J.; Tiegs, T.N.; Kania, M.J.; Long, E.L. Jr.; Thoms, K.R.; Robbins, J.M. et al.
Partner: UNT Libraries Government Documents Department

Fort St. Vrain experience report

Description: This report describes the core region constraint devices (RCDs) which will be installed in Fort St. Vrain to remedy core temperature fluctuations at high power-to-flow thresholds, summarizes the engineering analyses supporting the design, and evaluates effects on fuel handling operations. (DLC)
Date: June 1, 1980
Creator: Available, Not
Partner: UNT Libraries Government Documents Department

HTGR Generic Technology Program. Semiannual report for the period ending March 31, 1979

Description: This document reports the technical accomplishments on the HTGR Generic Technology Program at General Atomic during the first half of FY-79. It covers a period when the major design direction of the National HTGR Program is in the process of changing from the HTGR-SC emphasis to an HTGR-GT emphasis in the near term. The HTGR Generic Technology Program activities have been redirected to ensure that the tasks covered are supportive of this changing emphasis in HTGR applications. The activities include the need to develop a medium enriched uranium (MEU) fuel, and the need to qualify materials and components for the higher temperatures of the gas turbine plant.
Date: June 1, 1979
Creator: Available, Not
Partner: UNT Libraries Government Documents Department

HTGR fuel particle crusher: Mark 2 design

Description: The double-roll crusher for fracturing the silicon carbide coatings of high-temperature gas-cooled reactor (HTGR) fuel particles has been redesigned to improve the equipment. The housing was simplified and reduced to a two-piece assembly; the bearings were changed to accommodate thermal effects; the bearing protection seals were improved with triple redundancy; the bearing preload arrangement was simplified and improved; and localized wear areas were reinforced with better materials or special treatment. In addition, the crusher drive was changed for impoved characteristics and an increase in power.
Date: June 1, 1979
Creator: Baer, J.W.
Partner: UNT Libraries Government Documents Department

Consolidated reprocessing program. Quarterly progress report for the period ending May 31, 1979

Description: This publication continues the quarterly series presenting results of work performed under the Consolidated Reprocessing Program at General Atomic Company. Results of work on this program prior to June 1974 were included in a quarterly series on the HTGR Base Program. The work reported includes the development of unit processes and equipment for reprocessing of High-Temperature Gas-Cooled Reactor (HTGR) fuel, the design and development of an integrated pilot line to demonstrate the head end of HTGR reprocessing using unirradiated fuel materials, and design work in support of Hot Engineering Tests (HET). Work is also described on trade-off studies concerning the required design of facilities and equipment for the large-scale recycle of HTGR fuels in order to guide the development activities for HTGR fuel recycle.
Date: June 1, 1979
Creator: Available, Not
Partner: UNT Libraries Government Documents Department

Circulating water subsystem design description: 4 x 350 MW(t) Modular HTGR [High-Temperature Gas-Cooled Reactor] Plant

Description: The Circulating Water System is a subsystem within the Heat Rejection Group (HRG). The Circulating Water System consists of two independent loops to remove waste heat from the turbine building closed cooling water system and from the condensers associated with each turbine generator set. In normal plant operation circulating water is pumped from the cooling tower basin through the condensers and heat exchangers and back to the cooling tower where the waste heat is released to the atmosphere via mechanical draft cooling towers. The system consists of two flow paths with two half-size, vertical pumps associated with each path.
Date: June 1, 1986
Partner: UNT Libraries Government Documents Department

Makeup water treatment and auxiliary boiler building structural design description: 4 x 350 MW(t) Modular HTGR [High-Temperature Gas-Cooled Reactor] Plant

Description: The Makeup Water Treatment and Auxiliary Boiler Building (MWABB) is a grade-founded, single-story, steel-framed structure with insulated sheet metal exterior walls and roof decking. It houses the electrically-heated auxiliary boiler and related equipment, and the Raw Water Treatment System. The Makeup Water Treatment and Auxiliary Boiler building is located adjacent to the Maintenance Building in the Energy Conversion Area of the plant.
Date: June 1, 1986
Partner: UNT Libraries Government Documents Department

Liquid radioactive waste subsystem design description

Description: The Liquid Radioactive Waste Subsystem provides a reliable system to safely control liquid waste radiation and to collect, process, and dispose of all radioactive liquid waste without impairing plant operation. Liquid waste is stored in radwaste receiver tanks and is processed through demineralizers and temporarily stored in test tanks prior to sampling and discharge. Radwastes unsuitable for discharge are transferred to the Solid Radwaste System.
Date: June 1, 1986
Partner: UNT Libraries Government Documents Department

Class 1E dc power subsystem design description: 4 x 350 MW(t) Modular HTGR [High-Temperature Gas-Cooled Reactor] Plant

Description: The Class 1E DC Power System of the Electrical Group provides reliable and regulated 125 V dc electric power to the plant safety-related dc loads connected to the Four redundant and independent 125 V dc Class 1E buses to ensure plant safe shutdown or mitigate the effects of a design basis event. These four dc buses comprise the plant four Class 1E dc control and instrument channels (A, B, C and D).
Date: June 1, 1986
Partner: UNT Libraries Government Documents Department

Predicted discharge plutonium isotopics for LEU [low-enriched uranium] test pebble irradiated in the AVR [Arbeitsgemeinschaft Versuchsreaktor]

Description: A Subprogram Plan related to the Arbeitsgemeinschaft Versuchsreaktor (AVR) Test Program is in place and describes cooperative work being carried out under the United States/Federal Republic of Germany (US/FRG) Implementing Agreement for Cooperation in Gas-Cooled Reactor Development. The AVR information to be provided as described in the plan will provide a basis for examining the accuracy of computational methods used for performance and safety analysis. The purpose of the cooperation is to obtain experimental information from the AVR relevant to the performance and safety of modular gas-cooled reactors, and to compare measured results with predictions of analytical tools. This report provides a progress report on the prediction of plutonium buildup in LEU fuel in a high-enriched uranium (HEU) core and also describes the method for calculating the U-238 resonance integral (cross section). 4 refs., 5 figs., 11 tabs.
Date: June 1, 1988
Creator: Lane, R.K. & Lefler, W.L.
Partner: UNT Libraries Government Documents Department