Paul Abramson

Pbalaw · Project development and finance

A general discussion of the major physical phenomena and analysis techniques associated with evaluating the consequences of a small break LOCA in PWRs is presented. Some examples of the use of the RELAP5 computer code to analyze the transient behavior of a nuclear system under small break LOCA are presented. Results of a series of steam generator t...

An analysis of transients in pressurized water reactor (PWR) systems is presented, involving the assessment of the response of the total plant, including primary and secondary coolant systems, steam piping and turbine (including the complete feedwater train), and various control and safety systems. Transient analysis is performed as part of the pla...

Abstracts are provided under citations for Chapter 3.1 and Chapter 7.

Operational transients occur with relative frequency in nuclear power plants. However, only a very small number of these are such that they might lead to endangering the public health and safety, and an even smaller number have actually followed a course of events which went far enough to be clearly problematic. This article examines the spectrum o...

The recent Semiscale test S-UT-8 indicates the possibility for primary liquid to hang up in the steam generators during a SBLOCA, permitting core uncovery prior to loop-seal clearance. In analysis of Small Break Loss of Coolant Accidents with RELAP5, it is found that resultant transient behavior is quite sensitive to the selection of nodalization f...

Engineering transient analysis codes, which are in general more accurate than the present generation of simulator software, can be expected to yield reasonably accurate results (+-20% or so on system pressure) if carefully utilized and if the two-phase and transient flow conditions are not severe. As the severity of the transient increases, the con...

This report documents the status of a computer code developed by Argonne National Laboratory (ANL) and the Nuclear Safety Analysis Center (NSAC) for predicting temperatures and oxidation of a pressurized-water reactor (open lattice) core during an undercooling transient. The initial use of this code has been for analyzing the TMI-2 core initial unc...

The computer code EPIC models fuel and coolant motion which results from internal fuel pin pressure (from fission gas or fuel vapor) and possibly from the generation of sodium vapor pressure in the coolant channel subsequent to pin failure in a liquid-metal fast breeder reactor. The EPIC model is restricted to conditions where fuel pin geometry is...

Deterministic calculations simulating a hypothetical accident in a liquid-metal fast breeder reactor that leads to a hydrodynamic disassembly of the core have been carried out to estimate the system's damage potential due to the vapor-pressure-driven expansion of molten core material and its dependency on the heat transfer to the remaining structur...

Most recent numerical modeling of two-phase flow involves an implicit determination of a pressure field upon which computational efficiency is strongly dependent. While cell by cell schemes (which treat the pressures in adjacent cells as known source terms) offer fast running times, permit the use of large time steps limited by a Courant condition...

Eulerian computer codes for the combined thermodynamic and hydrodynamic analysis of accident progression in nuclear reactors have a major drawback: they do not conserve thermodynamic potential energy. Eulerian schemes allow mass and energy to flow through calculational cells which are fixed in space. Pressures that drive the hydrodynamics are calcu...

A great effort has been devoted recently to the development of multifield, multicomponent thermohydrodynamic computer codes whose main objective is the detailed study of hypothetical core disruptive accidents (HCDAs) in liquid-metal fast breeder reactors. The main contributions such as codes are expected to make are the inclusion of detailed modeli...

In the use of large computers to analyze severe accidents in liquid-metal fast breeder reactors (LMFBRs), it has long been recognized that many of the fundamental phenomena cannot be precisely predicted because of uncertainty in the parameters that govern them. As a direct result, mechanistic analysis of such accidents has proceeded along a paramet...

The computer code EPIC models fuel and coolant motion that results from internal fuel pin pressure (from fission gas or fuel vapor) and/or from the generation of sodium vapor pressures in the coolant channel subsequent to pin failure in a liquid-metal fast breeder reactor. The modeling includes the ejection of molten fuel from the pin into a coolan...

In the very unlikely event of a loss-of-flow accident in a liquid-metal fast breeder reactor being accompanied by complete failure to scram, the reactor could go prompt critical, generating a large amount of neutronic heat on a millisecond time scale. We find that fuel-to-steel heat transfer has a minimal influence upon the neutronic energy deposit...

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Subroutine POOL was developed for the study of hypothetical core disruptive accidents in nuclear reactors and, as such, is set up for use as a subroutine in the FX-2 Dynamic Neutronics Code. This combination permits scoping studies of the total neutronic/hydrodynamic interactions and is capable of performing phenomenological investigations of hypot...

An energy balance, similar to the Hicks-Menzies concept but including a simple examination of the pressure versus temperature path to equilibrium, has been performed for mixtures of steel and mixed-oxide reactor fuel with ratios of mass of fuel to mass of steel ranging from 0.5 to 5.0 and with initial fuel temperatures from 3500 to 7500/sup 0/K. Th...

The model described was developed as a substitute for VENUS II and has been coupled to FX2 to yield a completely interactive thermohydraulic-neutronic computer program which describes the interactions in a boiling cylindrical pool of fuel and steel. The model treats the Eulerian Hydrodynamics and Thermodynamics of the interactions in the pool and f...

An alternative rigorous derivation is given of the operator equation on which the effective-mass theory for electrons in periodic potentials and applied fields is based. The relationship of this work to previous derivations is briefly discussed.

The EPIC computer code has been used to analyze the post-fuel-pin-failure behavior in the PBE-5S experiment performed at Sandia Laboratories. The effects of modeling uncertainties on the calculation are examined. The calculations indicate that the majority of the piston motion observed in the test is due to the initial pressurization of the coolant...

In the simulation of transient events in large PWR reactor systems for reactor safety studies, the plant model is quite detailed and must include most of the plant components and control systems to adequately analyze the range of transients. The results discussed were calculated with the RELAP4/MOD6 code and reveal the need for the analysis to care...

This paper presents a series of modeling experiences and problems in simulating the thermal-hydraulic behavior of large PWR steam generators using the RELAP4 and RELAP5 computer codes. Sensitivity studies investigating the heat transfer characteristics of both once-through and U-tube steam generators are discussed. Suggestions and recommendations a...

This text provides reconsideration of all safety-related design, analysis, emergency procedures, and operator training of nuclear reactors. Recent accidents necessitate a reappraisal of nuclear plant safety. Research work and experience obtained through the analysis of reactor behavior under different conditions has enabled higher confidence in est...

Thesis (Ph. D.)--University of Colorado, 1968. Includes bibliographical references (leaves [57]-[59]). Typescript.