Using PARET and CONVEC to perform accident analysis of the University of Missouri-Rolla Nuclear Reactor

Author

Christopher M. Carroll

Abstract

"The Safety Analysis Report, SAR, is very important to commercial and research nuclear reactors alike and should be considered a living document. The Nuclear Regulatory Commission has instituted changes over the past few years to rely more on the SAR for the processes of licensing, relicensing, and uprating in power. As result of these changes the NRC has streamlined the licensing processes such that the length of time expended for application approval is shorter and in addition, easier for facilities.

The University of Missouri-Rolla Reactor, UMRR, is up for relicensing January 2005 and has begun to review and revise its SAR to update to current NRC standards. A preliminary investigation into the possibility of a power uprate has also begun. As a part of this investigation, PARET-ANL and CONVEC were used to analyze accident scenarios at the currently licensed power of 200 kW_t and at possible uprate powers of 400 kW_tand 500 kW_t . CONVEC is a natural convection modeling code and PARET is a code used to investigate reactor reactivity transients. Due to the NRC permitting credit to be taken for a reactor SCRAM function, the hypothetical severe accident scenarios have been evaluated with the use of the UMRR safety channel SCRAM set-point of 150% of licensed power.

Several improbable, but significant accident scenarios are expected in the SAR. The first accident is an insertion of excess reactivity that assumes a fuel element being placed accidentally next to the UMRR core. For the second accident, a loss of coolant accident (LOCA) in which all coolant is assumed to drain was evaluated. As a final accident, a startup accident was analyzed in which the UMRR's control elements were assumed to uncontrollably withdraw from the core. Each of these accidents is important to analyze due to the risk of fuel cladding failure that could potentially result in the release of fission products. The analysis described in this thesis proves that the UMRR would maintain fuel integrity during the aforementioned accident scenarios and thus avert the release or fission products "--Abstract, page iii.

Advisor(s)

Tokuhiro, Akira

Committee Member(s)

Mueller, Gary Edward, 1954-
Bertino, Massimo

Department(s)

Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering

Comments

Appendices D, E, P, Q, R and S are available for download as supplemental files. The pdfs are from the accompanying CD-ROM and are the best quality available.

Publisher

University of Missouri--Rolla

Publication Date

Spring 2004

Pagination

x, 131 pages

Note about bibliography

Includes bibliographical references (pages 129-130).

Geographic Coverage

United States

Rights

© 2004 Christopher Michael Carroll, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Nuclear reactors -- Safety measures -- EvaluationNuclear reactor accidents -- AnalysisRisk assessment -- United States

Thesis Number

T 8469

Print OCLC #

56435255

Electronic OCLC #

905609186

Recommended Citation

Carroll, Christopher M., "Using PARET and CONVEC to perform accident analysis of the University of Missouri-Rolla Nuclear Reactor" (2004). Masters Theses. 2488.
https://scholarsmine.mst.edu/masters_theses/2488