8,976 Matching Results

Search Results

Advanced search parameters have been applied.

Stress relaxation analysis and irradiation creep and swelling in pressure tubes

Description: An analysis is presented of slit width test information on two pressure tubes that had been irradiated in test reactors. The analysis showed that differential swelling stresses and thermal stresses undergo relaxation. The mechanism responsible for the stress relaxation at temperatures less than 700 K was irradiation creep. Irradiation creep in thermal test reactor pressure tubes is evidently greater than it would be at equivalent conditions in fast reactors. The residual stresses observed in the slit width tests varied between 30 and 257 MPa and would act to reduce the operating stresses, thus allowing for increased service life of the tubes as compared with no stress relaxation.
Date: January 1, 1979
Creator: Beeston, J.M. & Burr, T.K.
Partner: UNT Libraries Government Documents Department

Shielding materials. [LMFBR]

Description: The higher neutron flux levels associated with fast reactors, when compared to thermal reactors of the same power, dictate the use of structural steels in the primary reactor shields and the need to design replaceable shield components. The loop-type reactor design being developed in the United States eliminates the need for graphite or other moderating material within the reactor vessel. Sufficient reactor shielding is employed to assure that permanent structural members retain mechanical characteristics comparable to unirradiated material. Removable or replaceable components are designed to retain specific required physical characteristics until replaced. The concretes and compensatory shields used throughout the fast reactor plant are quite similar to those employed in thermal reactor systems. High density concretes containing metallic ores and iron are used where space limitations dictate. Selection of compensatory shield materials is complicated by the diversity of the problems that exist and by the limited knowledge of the long-term behavior of some materials.
Date: November 1, 1978
Creator: Bunch, W. L. & Blackburn, L. D.
Partner: UNT Libraries Government Documents Department

Seismic design and development for fast reactors: a design-application perspective with directions for improvement

Description: Applications of seismic design criteria and qualification methods to the US breeder reactor projects have developed new findings, improvements in design methods, and identified areas for further development. Discussions are presented regarding site free field motion, soil-structure interaction, equipment response spectra, piping, snubbers and support design analyses, dynamic decoupling, seismic qualification testing, and protection of Seismic Category I components from Non-Category I equipment failures.
Date: July 19, 1979
Creator: Severud, L. K.
Partner: UNT Libraries Government Documents Department

Qualification of tribological materials and coatings for use in sodium. [LMFBR]

Description: This paper describes some of the essential performance measures used to qualify materials for tribological applications in liquid sodium environments and summarizes relative properties of some of the newer tribological materials now qualified for use in sodium systems.
Date: April 21, 1980
Creator: Johnson, R.N. & Farwick, D.G.
Partner: UNT Libraries Government Documents Department

LMFBR fuel component costs

Description: A significant portion of the cost of fabricating LMFBR fuels is in the non-fuel components such as fuel pin cladding, fuel assembly ducts and end fittings. The contribution of these to fuel fabrication costs, based on FFTF experience and extrapolated to large LMFBR fuel loadings, is discussed. The extrapolation considers the expected effects of LMFBR development programs in progress on non-fuel component costs.
Date: October 29, 1981
Creator: Epperson, E.M.; Borisch, R.R. & Rice, L.H.
Partner: UNT Libraries Government Documents Department

Summary description of the Fast Flux Test Facility

Description: This document has been compiled and issued to provide an illustrated engineering summary description of the FFTF. The document is limited to a description of the plant and its functions, and does not cover the extensive associated programs that have been carried out in the fields of design, design analysis, safety analysis, fuels development, equipment development and testing, quality assurance, equipment fabrication, plant construction, acceptance testing, operations planning and training, and the like.
Date: December 1, 1980
Creator: Cabell, C.P. (comp.)
Partner: UNT Libraries Government Documents Department

FFTF utilization for irradiation testing

Description: FFTF utilization for irradiation testing is beginning. Two Fuels Open Test Assemblies and one Vibration Open Test Assembly, both containing in-core contact instrumentation, are installed in the reactor. These assemblies will be used to confirm plant design performance predictions. Some 100 additional experiments are currently planned to follow these three. This will result in an average core loading of about 50 test assemblies throughout the early FFTF operating cycles.
Date: January 1, 1980
Creator: Corrigan, D.C.; Julyk, L.J.; Hoth, C.W.; McGuire, J.C. & Sloan, W.R.
Partner: UNT Libraries Government Documents Department

Surveillance and in-service inspection (SISI) program at FFTF

Description: Assurance of the integrity of the sodium coolant pressure boundaries of the Fast Flux Test Facility systems and components is essential for safe operation. A program has been developed to monitor the integrity of the coolant boundaries and certain plant conditions. Specific equipment and features have been designed into the plant for monitoring. The purpose of SISI is to prevent failures or minimize their consequences through early detection. The program which administers the requirements for monitoring applicable plant conditions whose integrity is necessary to protect public health and safety is known as the Surveillance and In-service Inspection (SISI) Program. The SISI program utilizes a wide range of monitoring techniques to ensure that material degradation or structural deficiencies will not result in the loss of the ability to shut down the reactor, cool the reactor core, or cause the release of radioactive material to the environment.
Date: January 1, 1980
Creator: Conrads, T.J.
Partner: UNT Libraries Government Documents Department

Thermal bowing of wire-wrapped fuel pins in fast reactors

Description: The mechanism of thermal bowing of fuel pins is discussed. Finite element models for thermal bowing analysis using MARC-CDC and BEAMCREEP programs are presented. Analytical results are in reasonably close agreement with each other. Thermal bowings of edge fuel pins in various FTR core positions are predicted. Conservative predictions indicate that the reference edge pins with 30.48 cm (12 in.) axial pitch may touch the duct wall in as little as 1000 h or irradiation. The results further indicate that the axial stress induced in the cladding by thermal bowing is 4 times as much as that due to fission gas release. However, the combined axial stress level is still below that to cause stress rupture in the design life of the pin.
Date: January 1, 1979
Creator: Chan, D. P. & Jackson, R. J.
Partner: UNT Libraries Government Documents Department

Selection of power plant elements for future space electric power systems

Description: A study on the type of nuclear reactor power plants that should be developed for future space missions is described. After careful consideration of power plant configuration weights, sizes, reliabilities, safety, development cost and time, the configuration selected to be pursued was a heat-pipe reactor design with thermoelectric converters and heat-pipe radiator.
Date: January 1, 1979
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department

Rossi Alpha Method

Description: The Rossi Alpha Method has proved to be valuable for the determination of prompt neutron lifetimes in fissile assemblies having known reproduction numbers at or near delayed critical. This workshop report emphasizes the pioneering applications of the method by Dr. John D. Orndoff to fast-neutron critical assemblies at Los Alamos. The value of the method appears to disappear for subcritical systems where the Rossi-..alpha.. is no longer an ..alpha..-eigenvalue.
Date: January 1, 1985
Creator: Hansen, G.E.
Partner: UNT Libraries Government Documents Department

Bond graph modeling of nuclear reactor dynamics. [PWR]

Description: A tenth-order linear model of a pressurized water reactor (PWR) is developed using bond graph techniques. The model describes the nuclear heat generation process and the transfer of this heat to the reactor coolant. Comparisons between the calculated model response and test data from a small-scale PWR show the model to be an adequate representation of the actual plant dynamics. Possible application of the model in an advanced plant diagnostic system is discussed.
Date: January 1, 1981
Creator: Tylee, J.L.
Partner: UNT Libraries Government Documents Department

100-kW/sub e/ Nuclear space electric power source

Description: The current 100-kW/sub e/ space nuclear power technology program could provide an electric power source for nuclear electric propulsion. The power plant is relatively compact, light weight, and has the advantages of long life and immunity to degradation while passing through the Van Allen belts. The reactor is a unique design using heat pipes to transfer heat from the reactor core to the thermoelectric converters. The converters are an improved design over those used in the radioisotope space program. The radiator, used to eliminate waste heat to space, also makes use of heat pipes. All single failure points have been eliminated from the power plant design and redundancies are provided to ensure high reliability. The power plant configuration and some key results of the current component experimental program are discussed.
Date: January 1, 1979
Creator: Buden, D.
Partner: UNT Libraries Government Documents Department

Heat pipe thermal control of slender optics probes

Description: The thermal design for a stereographic viewing system is presented. The design incorporates an annular heat pipe and thermal isolation techniques. Test results are compared with design predictions for a prototype configuration. Test data obtained during heat pipe startup showing temperature gradients along the evaporator wall are presented. Correlations relating maximum wall temperature differences to a liquid Reynolds number were obtained at low power levels. These results are compared with Nusselt's Falling Film theory.
Date: January 1, 1979
Creator: Prenger, F.C.
Partner: UNT Libraries Government Documents Department

Performance characteristics of gravity-assisted, potassium heat pipes

Description: Experiments with potassium-stainless steel gravity-assisted heat pipes were performed. Performance limitations due to entrainment or flooding of the liquid return flow are compared with analytical model predictions. The effect of heated pool height was investigated and problems with surface wetting are discussed. A comparison between entrainment limits for smooth-walled and textured-walled heat pipes was made and a minimum internal surface texturing depth is suggested.
Date: January 1, 1985
Creator: Prenger, F.C.; Keddy, E.S. & Sena, J.T.
Partner: UNT Libraries Government Documents Department

New instrument for the confirmation of declared power histories of central station nuclear power plants

Description: An operationally simple, portable, microprocessor-based, unattended reactor power monitor was developed for International Atomic Energy Agency inspector use in confirming operator records of the power history of nuclear power plants. The monitor is based on the principle that the leakage neutron flux outside the biological shield is proportional to the thermal power level. The leakage flux is detected and compared with the leakage flux from the same reactor for a confirmed calibration period. Several output options are available, and a record of more than three months of hourly measurements of the themal power of the plant can be obtained. The monitor has battery backup power for interruptions of host power of duration up to 18 hours.
Date: January 1, 1979
Creator: Dowdy, E.J.; Robba, A.A.; Hastings, R.D. & France, S.W.
Partner: UNT Libraries Government Documents Department

Missions and planning for nuclear space power

Description: Requirements for electrical and propulsion power for space are expected to increase dramatically in the 1980s. Nuclear power is probably the only source for some deep space missions and a major competitor for many orbital missions, especially those at geosynchronous orbit. Because of the potential requirements, a technology program on reactor components has been initiated by the Department of Energy. The missions that are foreseen, the current reactor concept, and the technology program plan are described.
Date: January 1, 1979
Creator: Buden, D.
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

Sodium

Description: The physical properties of sodium are described and the use of sodium as the coolant in liquid metal fast breeder reactors is discussed. Sodium technology facilities at HEDL for research and testing support of the Fast Flux Test Facility are described.
Date: unknown
Partner: UNT Libraries Government Documents Department

Decommissioning handbook. First quarterly progress report, May 1--August 27, 1978

Description: The objectives for this reporting period were to develop data on facilities and equipment at typical DOE owned/operated sites, and to contact individuals and organizations with decommissioning experience to explore state-of-the-art equipment and methods for decontamination and dismantling. Nuclear Energy Services has scheduled meetings in September at the DOE Richland office to meet with other contractors and discuss D and D methods and equipment available. Also, NES will tour the Hanford facilities to review unique characteristics which may require special treatment or handling. A tour of the West Valley, NY Reprocessing Plant has also been scheduled. During this report period, NES prepared drafts of handbook chapters which will be submitted to DOE. Results of the discussions mentioned above will be factored into the draft handbook chapters on metal cutting equipment, concrete demolition methods, and decontamination processes. Four handbook chapters are ready for submission to DOE. These include: estimation of radioactive inventory; removal of radioactive metals; removal of radioactive concrete; and cost estimating procedure.
Date: January 1, 1978
Partner: UNT Libraries Government Documents Department