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Eulerian method for large-displacement fluid-structure interaction in reactor containments

Description: An Eulerian method for analyzing large-displacement fluid-structure interaction in reactor containments is presented. The emphasis is on the development of a generalized hydrodynamic scheme to treat the irregular cells created by the movement of the structure with respect to the fixed Eulerian coordinates. A relaxation equation is derived from the boundary condition at the fluid-structure interface for the solution of the pressure at the interface. By combining this with the Poisson equation a … more
Date: January 1, 1977
Creator: Chang, Y. W. & Wang, C. Y.
Partner: UNT Libraries Government Documents Department
open access

Preliminary analysis of fission gas behavior and fuel response during an LMFBR operational transient

Description: This summary presents results obtained from a preliminary analysis of gas behavior and oxide fuel response during an LMFBR operational transient. The DiMelfi and Deitrich model is extrapolated to operational transient regimes to delineate brittle versus ductile fuel response modes. All pertinent parameters necessary for application of the DiMelfi and Deitrich model were obtained from the LIFE-3 code.
Date: January 1, 1983
Creator: Liu, Y. Y.
Partner: UNT Libraries Government Documents Department
open access

Eulerian algorithm for analyzing fluid-structure interaction in the fast reactor containment

Description: The Eulerian algorithm described is capable of analyzing two-dimensionally the fluid-structure interaction in a typical LMFBR containment consisting of various structure components. The algorithm has several special features. First, it employs the Eulerian coordinates in the formulation and enables the technique to be applicable to excursions involving large material distortions. Second, it provides rigorous hydrodynamic analyses at the fluid-structure interface and at the geometrical discontin… more
Date: January 1, 1977
Creator: Wang, C. Y.; Chang, Y. W. & Fistedis, S. H.
Partner: UNT Libraries Government Documents Department
open access

Attenuation mechanisms in the transport of in-vessel radiological source term fission products in an LMFBR

Description: Quantifying the release of radiological source term fission products from an LMFBR reactor vessel (RV) is a necessary input to the containment analysis. To estimate this initial source term value, the distribution of the fission products and actinides inside the RV, prior to release, must be known. The in-vessel source term fission product distribution and transport behavior is also essential in assessing and mitigating the plant contamination and cleanup problems which occur from any significa… more
Date: December 1, 1983
Creator: Woodley, R. E.; Nguyen, D. H. & Hunter, C. W.
Partner: UNT Libraries Government Documents Department
open access

Response of subassembly model with internals

Description: Analytical tools have been developed and validated by controlled sets of experiments to understand the response of an accident and/or single subassembly in an LMFBR reasonably well. They have been subjected to a variety of loadings and boundary environments. Some large subassembly cluster experiments have been performed, however little analytical work has accompanied them because of the lack of suitable analytical tools. Reported are analytical approaches to: (1) development of more sophisitica… more
Date: January 1, 1977
Creator: Kennedy, J. M. & Belytschko, T.
Partner: UNT Libraries Government Documents Department
open access

Simulation of LMFBR excursion models by means of ICECO

Description: Test data from experiments dealing with LMFBR containment studies are compared with containment code solutions. The features of fluid spillage, which is a subject of some concern in experiments, is modeled in the ICECO code and is stressed. Several variations of spillage solution were arrived at gaining more insight to this problem and thus serve in reducing some of the uncertainties connected with fluid spillage. Other features of the analytical models are utilized and described.
Date: January 1, 1977
Creator: Marchertas, A. H.; Wang, Y. C. & Fistedis, S. H.
Partner: UNT Libraries Government Documents Department
open access

Fission product release into the primary coolant. [HTGR]

Description: The analytic evaluation of steady state primary coolant activity is discussed. The reported calculations account for temperature dependent fuel failure in two particle types and arbitrary radioactive decay chains. A matrix operator technique implemented in the SUVIUS code is used to solve the simultaneous equations. Results are compared with General Atomic Company's published results.
Date: January 1, 1977
Creator: Apperson, C.E.
Partner: UNT Libraries Government Documents Department
open access

Hypothetical air ingress scenarios in advanced modular high temperature gas cooled reactors

Description: Considering an extremely hypothetical scenario of complete cross duct failure and unlimited air supply into the reactor vessel of a modular high temperature gas cooled ractor, it is found that the potential air inflow remains limited due to the high friction pressure drop through the active core. All incoming air will be oxidized to CO and some local external burning would be temporarily possible in such a scenario. The accident would have to continue with unlimited air supply for hundreds of h… more
Date: January 1, 1988
Creator: Kroeger, P. G.
Partner: UNT Libraries Government Documents Department
open access

Analysis of LMFBR containment response to an HCDA using a multifield Eulerian code. [MICE code]

Description: During a hypothetical core disruptive accident (HCDA), a core meltdown may cause the fuel cladding to rupture and the fuel fragments to penetrate into the sodium coolant. The heat in the molten fuel may cause the liquid sodium to boil, changing its phase. The interactions between materials are so complicated that a single-material model with homogenized material properties is not adequate. In order to analyze the above phenomena more realistically, a Multifield Implicit Continuous-Fluid Euleria… more
Date: January 1, 1977
Creator: Chu, H.Y. & Chang, Y.W.
Partner: UNT Libraries Government Documents Department
open access

Scoping systems analysis of a 350 MWt modular liquid metal cooled reactor

Description: The systems analysis code SASSYS was used to explore the sensitivity of the system response to various inherent reactivity feedback mechanisms and design features for a small, liquid-metal-cooled reactor during the first 1000 s following the initiation of an unprotected loss-of-flow and/or loss-of-primary-heat-removal transient. The results show that to maximize the inherent safety of small, liquid-metal-cooled reactors, inherent feedback mechanisms should be accounted for in establishing desig… more
Date: January 1, 1985
Creator: Morris, E. E.; Rhow, S. K. & Switick, D. M.
Partner: UNT Libraries Government Documents Department
open access

Analysis of reactor material experiments investigating corium crust stability and heat transfer in jet impingement flow

Description: Presented is an analysis of the results of the CSTI-1, CSTI-3, and CWTI-11 reactor material experiments in which a jet of molten corium initially at 3080/sup 0/K was directed downward upon a stainless steel plate. The experiments are a continuation of a program of reactor material tests investigating LWR severe accident phenomena. Objective of the present analysis is to determine the existence or nonexistence of a corium crust during impingement from comparison of the measured heatup of the pla… more
Date: January 1, 1985
Creator: Sienicki, J. J. & Spencer, B. W.
Partner: UNT Libraries Government Documents Department
open access

Structural response of large LMFBR head closures to hypothetical core disruptive accidents

Description: A preliminary study of the dynamic response of a large (1200 MWe) pool-type deck structure to an energetic core disassembly accident was performed. The analysis proceeded as two independent, decoupled calculations: containment calculations and deck response calculations. The containment calculations were performed mainly to derive a loading pressure history for the deck structure. In part of the study, the deck was considered rigid so the derived loading pressures were conservative. In the seco… more
Date: January 1, 1977
Creator: Kulak, R.F.; Marciniak, T.J. & Belytschko, T.B.
Partner: UNT Libraries Government Documents Department
open access

Hydrogen mixing study (HMS) in LWR type containments

Description: A numerical technique has been developed for calculating the full three-dimensional time-dependent Navier-Stokes equations with multiple speies transport. The method is a modified form of the Implicit Continuous-fluid Eulerian (ICE) technique to solve the governing equations for low Mach number flows where pressure waves and local variations in compression and expansion are not significant. Large density variations, due to thermal and species concentration gradients, are accounted for without t… more
Date: January 1, 1983
Creator: Travis, J.R.
Partner: UNT Libraries Government Documents Department
open access

Analyses of hypothetical FCI's in a fast reactor

Description: Parametric analyses using the SIMMER code were performed to evaluate the potential for a severe recriticality from a pressure-driven recompaction caused by an energetic FCI during the transition phase of a hypothetical accident in a fast reactor. For realistic and reasonable estimates for the assumed accident conditions, a severe recriticality was not predicted. The conditions under which a severe recriticality would be obtained or averted were identified. 10 figures, 2 tables.
Date: January 1, 1981
Creator: Padilla Jr., A.; Martin, F. J. & Niccoli, L. G.
Partner: UNT Libraries Government Documents Department
open access

Special consideration for the fire protection of liquid metal fast breeder reactors

Description: In addition to the possible radiation hazard in LMFBRs, there exists the hazard of reactive metals. The principal-fire hazard associated with sodium is its rapid reaction with water, producing hydrogen. The oxygen atmosphere can be inerted or reduced, metal sinks used, combustible materials avoided, and automatic sprinklers excluded in areas where a hazard of metal coolant fires exist. Automatic fire suppression systems are discussed. Passive fire protection features are described. Liners and c… more
Date: November 1, 1983
Creator: Sansone, F.M.
Partner: UNT Libraries Government Documents Department
open access

Experimental investigations of two-phase mixture level swell and axial void fraction distribution under high pressure, low heat flux conditions in rod bundle geometry

Description: Experimental data is reported from a series of quasi-steady-state two-phase mixture level swell and void fraction distribution tests. Testing was performed at ORNL in the Thermal Hydraulic Test Facility - a large electrically heated test loop configured to produce conditions similar to those expected in a small break loss of coolant accident. Pressure was varied from 2.7 to 8.2 MPa and linear power ranged from 0.33 to 1.95 kW/m. Mixture swell was observed to vary linearly with the total volumet… more
Date: January 1, 1981
Creator: Anklam, T. M. & White, M. D.
Partner: UNT Libraries Government Documents Department
open access

Prediction of thermal consequences of plenum fission gas release in an LMFBR fuel assembly

Description: One of the types of hypothetical accidents important in the safety analysis of Liquid Metal Fast Breeder Reactors is that in which fission gas release is postulated to occur from the plena of fuel pins at such a rate that significant perturbation to coolant flow occurs. Past consideration of such events has employed highly conservative calculations in the interest of simplicity and expediency. This paper describes a method developed to predict more accurately the thermal consequences of such fi… more
Date: January 1, 1978
Creator: Kadambi, N.P.
Partner: UNT Libraries Government Documents Department
open access

Three-dimensional computer code for the nonlinear dynamic response of an HTGR core. [OSC3D code]

Description: A three-dimensional dynamic code has been developed to determine the nonlinear response of an HTGR core. The HTGR core consists of several thousands of hexagonal core blocks. These are arranged inlayers stacked together. Each layer contains many core blocks surrounded on their outer periphery by reflector blocks. The entire assembly is contained within a prestressed concrete reactor vessel. Gaps exist between adjacent blocks in any horizontal plane. Each core block in a given layer is connected… more
Date: January 1, 1979
Creator: Subudhi, M.; Lasker, L.; Koplik, B.; Curreri, J. & Goradia, H.
Partner: UNT Libraries Government Documents Department
open access

Transient quenching of superheated debris beds during bottom reflood

Description: The experimental data suggest that for small liquid supply rate and low initial particle temperature, the bed quench process is a one-dimensional frontal phenomenon. The bed heat flux is constant during most of the duration of the quench period. The range of conditions which display one-dimensional frontal cooling characteristics is identified as the deep bed regime of bed quenching, and a limiting mathematical model was developed to describe the observed behavior. For large liquid supply rate … more
Date: January 1, 1984
Creator: Tutu, N. K.; Ginsberg, T.; Klein, J.; Schwarz, C. E. & Klages, J.
Partner: UNT Libraries Government Documents Department
open access

Boilup threshold for the bottled-up transition phase pool. [LMFBR]

Description: Since the inception of the hypothesized transition phase, for the late stages of a postulated LMFBR accident, there has been a continual effort to characterize the anticipated conditions of such a hypothetical state. To date, several techniques and methods have been employed to analyze the potential for energetic criticality. As part of this effort, an arbitrary criterian of monotonical dispersiveness has been employed as the measure of diminished recriticality potential. The various attempts t… more
Date: October 1, 1978
Creator: Martin, F. J.
Partner: UNT Libraries Government Documents Department
open access

FRAP-GCFR: a code for the transient analysis of gas-cooled fast reactors

Description: The fuel rod analysis computer program (FRAP-T) has been modified to analyze transient fuel rod behavior in the gas cooled fast reactor (GCFR). Major features modeled include the effects of helium coolant, ribbed cladding, pressure equalization system, and 316 stainless-steel material properties. The code capabilities include models of elastic-plastic-creep deformation behavior, two-dimensional heat conduction, rod ballooning, and transient axial gas flow. The models are particularly relevant t… more
Date: January 1, 1979
Creator: Peck, S O; Hagrman, D L & Bohn, M P
Partner: UNT Libraries Government Documents Department
open access

Role of similitude in the design of LMFBR safety-related simulation experiments

Description: In this paper we examine the implications of scaling in the design of simulation experiments for two major areas of fast reactor safety research - the transition phase and postdisassembly energetics. Specific scaling requirements and compatible experimental designs are formulated and compared with ongoing programs having similar objectives. Suggestions are also outlined for future out-of-pile experimental research.
Date: January 1, 1979
Creator: Chapyak, E.J. & Starkovich, V.S.
Partner: UNT Libraries Government Documents Department
open access

SAS3A analysis of natural convection boiling behavior in the Sodium Boiling Test Facility

Description: An analysis of natural convection boiling behavior in the Sodium Boiling Test (SBT) Facility has been performed using the SAS3A computer code. The predictions from this analysis indicate that stable boiling can be achieved for extensive periods of time for channel powers less than 1.4 kW and indicate intermittent dryout at higher powers up to at least 1.7 kW. The results of this anaysis are in reasonable agreement with the SBT Facility test results.
Date: January 1, 1979
Creator: Klein, G A
Partner: UNT Libraries Government Documents Department
open access

Three-dimensional finite-element computations of the transient response of components typical of a reactor structure. [SADCAT code]

Description: A structural analysis, finite-element code SADCAT has been developed to compute the elastoplastic response of thin-walled structural members undergoing rapid, large displacements in three-dimensional space. A convected-coordinate technique permits a simplified description of large displacements and rotations. The computational procedure consists of a lumped-mass, explicit numerical scheme suited to the nonlinear path-dependent material behavior. Code predictions have been compared with analytic… more
Date: January 1, 1979
Creator: Ash, J.E.; Kulak, R.F. & Marchertas, A.H.
Partner: UNT Libraries Government Documents Department
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