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in creator/contributor: "Ludewig, H"

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Steam generator and circulator model for the HELAP code

An outline is presented of the work carried out in the 1974 fiscal year on the GCFBR safety research project consisting of the development of improved steam generator and circulator (steam turbine driven helium compressor) models which will eventually be inserted in the HELAP (1) code. Furthermore, a code was developed which will be used to generate steady state input for the primary and secondary sides of the steam generator. The following conclusions and suggestions for further work are made:… more

Date: July 1, 1975

Creator: Ludewig, H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Modifications to the HELAP code. [GCFR steam generator model]

The improvements made to the steam generator model originally developed for the HELAP code and improvements made to the HELAP code itself are described. In the first case, the numerical algorithm which solves the controlling equations of the steam generator was re-cast into a purely implicit scheme. This change was motivated by excessive running time and numerical instabilities brought about by rapidly varying heat transfer coefficients when the fluid changes phase. The second of the above ment… more

Date: February 1, 1976

Creator: Ludewig, H

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Analysis of GCFBR transients without scram

The analyses of four transients imposed on a Gas Cooled Fast Breeder Reactor (GCFBR) plant are presented. These calculations were carried out using the HELAP code, which is based on RELAP 3B. The transient imposed on the system is a design basis depressurization accident (DBDA) with no scram. Furthermore, the rupture size causing the depressurization was varied over a range from .6 ft/sup 2/ to zero. In the limit of no rupture the transient imposed on the system is due only to the transient beh… more

Date: February 1, 1976

Creator: Ludewig, H

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Survey and evaluation of FFTF instrumentation for systems code validation

FFTF instrumentation and preoperational tests are examined here to determine whether the proposed tests and associated instrumentation can provide relevant information needed for verification of systems codes such as SSC. Details of both the in-core and out-of-core instrumentations are studied and their accuracy examined. From a series of multichannel core calculations, the temperatures in instrumented subassemblies were correlated with temperatures in uninstrumented subassemblies. It is found … more

Date: January 1, 1979

Creator: Majumdar, D.; Ludewig, H. & Cerbone, R.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Use of nuclear energy for bimodal applications in space

The versatile bimodal nuclear reactor is proposed for producing space station-keeping power of 100's kW and also capable of bursts of power by ramping to 100's MW for short times to operate high power magnetic systems. The particle bed reactor, using half-millimeter diameter fuel particles immersed in coolant, provides the heat transfer capability needed for this power level. The coolant is a gas when directly coupled to a Brayton Cycle and is particularly responsive. The reactor design uses 37… more

Date: January 1, 1986

Creator: Horn, F. L.; Powell, J. R. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Linear accelerator fission product transmuter (LAFPT)

The use of a Linear Accelerator Fission Product Transmuter (LAFPT) for the purpose of reducing the quantity of long-lived fission products (LLFP's) waste including transuranic waste (TU's) by means of spallation and neutron reactions, converting the LLFP's to shorter-lived isotopes or to stable type material, is considered. The linear accelerator offers proton energies in the range of 0.5 to 1.5 GeV which are capable of producing spallation reactions in heavy metal targets, thus yielding large … more

Date: January 1, 1977

Creator: Steinberg, M.; Takahashi, H.; Ludewig, H. & Powell, J.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Fast-Mixed Spectrum Reactor progress report. Results of the FMSR Benchmark calculations and an assessment of current fission product libraries

As part of the Initial Feasibility Study of the Fast Mixed Spectrum Reactor, a series of benchmark calculations were made to determine the sensitivity of the physics analysis to differences in methods and data. Argonne National Laboratory (ANL), the Massachusetts Institute of Technology (MIT), and Oak Ridge National Laboratory (ORNL) were invited to participate with Brookhaven National Laboratory in the analysis of a FMSR model prescribed by BNL. Detailed comparisons are made including a compre… more

Date: June 1, 1980

Creator: Ludewig, H.; Durston, C.; Atefi, B. & Cerbone, R.J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Mechanistic determination of fission product releases for a Mark III BWR plant

During the review of the GESSAR-II PRA by the Nuclear Regulatory Commission (NRC) and their contractors at Brookhaven National Laboratory (BNL) it was necessary to reanalyze potential fission product releases to the environment for several core meltdown accident sequences. The reanalysis was performed at BNL in two stages. The first stage was carried out prior to detailed mechanistic models were available at BNL and consisted of a sensitivity analysis using the MARCH and CORRAL computer codes. … more

Date: January 1, 1986

Creator: Ludewig, H.; Yu, W. S.; Jaung, R. & Pratt, W.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Containment performance evaluation for the GESSAR-II plant for seismic initiating events

As a part of the overall effort undertaken by Brookhaven National Laboratory (BNL) to review the GESSAR-II probabilistic risk assessment, an independent containment performance evaluation was performed using the containment event tree approach. This evaluation focused principally on those accident sequences which are initiated by seismic events. This paper reports the findings of this study. 1 ref.

Date: January 1, 1986

Creator: Shiu, K.K.; Chu, T.; Ludewig, H. & Pratt, W.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of containment failure modes and fission product releases during core meltdown accidents in a BWR with a Mark III containment

An assessment is described of potential failure modes and fission product releases for a large number of postulated core meltdown accidents in a BWR with a Mark III containment. For this containment design, the most important failure mode was found to be due to hydrogen related phenomena. A one-dimensional lumped parameter computer code has been developed and used to determine the probability of various hydrogen phenomena for a range of postulated core meltdown sequences. Potential containment … more

Date: January 1, 1985

Creator: Ludewig, H.; Yu, W. S.; Jaung, R. & Pratt, W. T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ultra-high temperature direct propulsion

Potential advantages of ultra-high exhaust temperature (3000 K - 4000 K) direct propulsion nuclear rockets are explored. Modifications to the Particle Bed Reactor (PBR) to achieve these temperatures are described. Benefits of ultra-high temperature propulsion are discussed for two missions - orbit transfer (..delta..V = 5546 m/s) and interplanetary exploration (..delta..V = 20000 m/s). For such missions ultra-high temperatures appear to be worth the additional complexity. Thrust levels are redu… more

Date: January 1, 1987

Creator: Araj, K. J.; Slovik, G.; Powell, J. R. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

KINETIC -- a system code for analyzing Nuclear Thermal Propulsion rocket engine transients

A system code suitable for analyzing Nuclear Thermal Propulsion (NTP) rocket engines is described in this paper. The code consists of a point reactor model and nodes to describe the fluid dynamics and heat transfer mechanism. Feedback from the fuel coolant, moderator and reflector are allowed for, and the control of the reactor is by motion of control elements (drums or rods). The worth of the control clement and feedback coefficients are predetermined. Separate models for the turbo-pump assemb… more

Date: July 1, 1993

Creator: Schmidt, E.; Lazareth, O. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Study of a multi-beam accelerator driven thorium reactor

The primary advantages that accelerator driven systems have over critical reactors are: (1) Greater flexibility regarding the composition and placement of fissile, fertile, or fission product waste within the blanket surrounding the target, and (2) Potentially enhanced safety brought about by operating at a sufficiently low value of the multiplication factor to preclude reactivity induced events. The control of the power production can be achieved by vary the accelerator beam current. Furthermo… more

Date: March 1, 2011

Creator: Ludewig, H. & Aronson, A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Generation of neutronic thermal data in support of space nuclear propulsion

The scattering kernel data for {sup 7}LiH have been generated for the first time in the temperature range 50--1000 K. This is based on a phonon distribution function derived from both experimental data and theoretical calculations. A detailed study of the variation of the moderator temperature coefficient {alpha}{sub m}(T) with temperature, T, is carried out for a typical space nuclear reactor of the particle bed type. It is established that the moderator temperature coefficient due to chemical… more

Date: May 1, 1993

Creator: Mughabghab, S.; Schmidt, E. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Generation of neutronic thermal data in support of space nuclear propulsion

The scattering kernel data for [sup 7]LiH have been generated for the first time in the temperature range 50--1000 K. This is based on a phonon distribution function derived from both experimental data and theoretical calculations. A detailed study of the variation of the moderator temperature coefficient [alpha][sub m](T) with temperature, T, is carried out for a typical space nuclear reactor of the particle bed type. It is established that the moderator temperature coefficient due to chemical… more

Date: January 1, 1993

Creator: Mughabghab, S.; Schmidt, E. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Small propulsion reactor design based on particle bed reactor concept

In this paper Particle Bed Reactor (PBR) designs are discussed which use /sup 233/U and /sup 242m/Am as fissile materials. A constant total power of 100MW is assumed for all reactors in this study. Three broad aspects of these reactors is discussed. First, possible reactor designs are developed, second physics calculations are outlined and discussed and third mass estimates of the various candidates reactors are made. It is concluded that reactors with a specific mass of 1 kg/MW can be envision… more

Date: January 1, 1989

Creator: Ludewig, H.; Lazareth, O.; Mughabghab, S.; Perkins, K. & Powell, J.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Particle Bed Reactor scaling relationships

Scaling relationships for Particle Bed Reactors (PBRs) are discussed. The particular applications are short duration systems, i.e., for propulsion or burst power. Particle Bed Reactors can use a wide selection of different moderators and reflectors and be designed for such a wide range of power and bed power densities. Additional design considerations include the effect of varying the number of fuel elements, outlet Mach number in hot gas channel, etc. All of these variables and options result … more

Date: January 1, 1987

Creator: Slovik, G.; Araj, K.; Horn, F. L.; Ludewig, H. & Benenati, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nuclear Thermal Propulsion engine based on Particle Bed Reactor using light water steam as a propellant

In this paper the possibility of configuring a water cooled Nuclear Thermal Propulsion (NTP) rocket, based on a Particle Bed Reactor (PBR) is investigated. This rocket will be used to operate on water obtained from near earth objects. The conclusions reached in this paper indicate that it is possible to configure a PBR based NTP rocket to operate on water and meet the mission requirements envisioned for it. No insurmountable technology issues have been identified.

Date: June 1, 1993

Creator: Powell, J. R.; Ludewig, H. & Maise, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Safety aspects of Particle Bed Reactor plutonium burner system

An assessment is made of the safety aspects peculiar to using the Particle Bed Reactor (PBR) as the burner in a plutonium disposal system. It is found that a combination of the graphitic fuel, high power density possible with the PBR and engineered design features results in an attractive concept. The high power density potentially makes it possible to complete the plutonium burning without requiring reprocessing and remanufacturing fuel. This possibility removes two hazardous steps from a plut… more

Date: August 1, 1993

Creator: Powell, J. R.; Ludewig, H. & Todosow, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

2400mwt Gas-Cooled Fast Reactor Dhr Studies Status Update.

A topical report on demonstrating the efficacy of a proposed hybrid active/passive combination approach to the decay heat removal for an advanced 2400MWt GEN-IV gas-cooled fast reactor was published in March 2006. The analysis was performed with the system code RELAP5-3D (version 2.4.1.1a) and the model included the full complement of the power conversion unit (PCU): heat exchange components (recuperator, precooler, intercooler) and rotating machines (turbine, compressor). A re-analysis of the … more

Date: June 1, 2007

Creator: Cheng, L. Y. & Ludewig, H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Assessment of Uncertainties in Core Melt Phenomenology and Their Impact on Risk at the Z/Ip Facilities

An evaluation of core meltdown accidents in the Z/IP facilities has been performed. Containment event trees have been developed to relate the progression of a given accident to various potential containment building failure modes. An extensive uncertainty analysis related to core melt phenomenology has been performed. A major conclusion of the study is that large variations in parameters associated with major phenomenological uncertainties have a relatively minor impact on risk when external in… more

Date: January 1, 1983

Creator: Pratt, W. T.; Ludewig, H.; Bari, R. A. & Meyer, J. F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Advanced Neutron Source enrichment study. Volume 2: Appendices -- Final report, Revision 12/94

A study has been performed of the impact on performance of using low enriched uranium (20% {sup 235}U) or medium enriched uranium (35% {sup 235}U) as an alternative fuel for the Advanced Neutron Source, which is currently designed to use uranium enriched to 93% {sup 235}U. Higher fuel densities and larger volume cores were evaluated at the lower enrichments in terms of impact on neutron flux, safety, safeguards, technical feasibility, and cost. The feasibility of fabricating uranium silicide fu… more

Date: December 31, 1994

Creator: Bari, R. A.; Ludewig, H. & Weeks, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Neutron Source enrichment study -- Volume 1: Main report. Final report, Revision 12/94

Date: December 31, 1994

Creator: Bari, R. A.; Ludewig, H. & Weeks, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Small low mass advanced PBR`s for propulsion

The advanced Particle Bed Reactor (PBR) to be described in this paper is characterized by relatively low power, and low cost, while still maintaining competition values for thrust/weight, specific impulse and operating times. In order to retain competitive values for the thrust/weight ratio while reducing the reactor size, it is necessary to change the basic reactor layout, by incorporating new concepts. The new reactor design concept is termed SIRIUS (Small Lightweight Reactor Integral Propuls… more

Date: October 1, 1993

Creator: Powell, J. R.; Todosow, M. & Ludewig, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department