Graduate Thesis Or Dissertation
 

Investigation of special RETRAN modeling options with regard to BWR stability under natural circulation conditons

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/g445cg70b

Descriptions

Attribute NameValues
Creator
Abstract
  • The limiting conditions of operation with regard to system stability for BWRs are presently set using computer models which employ conservative assumptions regarding the mechanisms which affect stability. Development of BWR models using "best estimate" codes, such as RETRAN, may allow more exact stability limits to be determined and precise stability margins to be set. In this study, options regarding the specification of a time-dependent thermodynamic boundary condition as a method of introducing a perturbation function are examined, along with the effects of several RETRAN modeling options and systems parameters on the stability characteristics of the system being modeled. These parametric studies were performed modeling the system under natural circulation cooling conditions. The desired pressure, and a default value of zero for the quality, were found to produce meaningful results when used to specify the time dependent conditions in the steam dome. The results were independent of the size of the time-dependent steam dome volume , so long as the flow length in the volume remained the same. The results of the parametric studies showed that changes in the suction flow area used in the jet pump model have no effect on the stability of the system so long as the total core flow is unchanged. The homologous pump head curves were found to have a small effect on the system stability through their role in determining the total core flow. Comparison of the two-phase-flow models revealed that the homogeneous equilibrium mixture model produced less system stability than the algebraic slip model. The manner in which the RETRAN code calculates the reactivity feedback for the core volume in which the boiling boundary is located was found to produce a "nodal" effect which prevented any valid assessment of the effect of the axial power profile on the stability characteristics of the system. It was determined, however, that system stability is reduced when the reactor power level is increased.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using ScandAll PRO 1.8.1 on a Fi-6670 in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details HershbergerDarylE1983.pdf 2017-08-07 Public Download