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Title: Steady-State Thermal-Hydraulics Analyses for the Conversion of the BR2 Reactor to LEU

BR2 is a research reactor used for radioisotope production and materials testing. It’s a tank-in-pool type reactor cooled by light water and moderated by beryllium and light water. The reactor core consists of a beryllium moderator forming a matrix of 79 hexagonal prisms in a hyperboloid configuration; each having a central bore that can contain a variety of different components such as a fuel assembly, a control or regulating rod, an experimental device, or a beryllium or aluminum plug. Based on a series of tests, the BR2 operation is currently limited to a maximum allowable heat flux of 470 W/cm2 to ensure fuel plate integrity during steady-state operation and after a loss-of-flow/loss-of-pressure accident. A feasibility study for the conversion of the BR2 reactor from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel was previously performed to verify it can operate safely at the same maximum nominal steady-state heat flux. An assessment was also performed to quantify the heat fluxes at which the onset of flow instability and critical heat flux occur for each fuel type. This document updates and expands these results for the current representative core configuration (assuming a fresh beryllium matrix) by evaluating the onset of nucleate boilingmore » (ONB), onset of fully developed nucleate boiling (FDNB), onset of flow instability (OFI) and critical heat flux (CHF).« less
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [2]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium)
Publication Date:
OSTI Identifier:
1330567
Report Number(s):
ANL/GTRI/TM--14/8 Rev. 1
130671; TRN: US1700450
DOE Contract Number:
AC02-06CH11357
Resource Type:
Technical Report
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation (NA-20)
Country of Publication:
United States
Language:
English
Subject:
22 GENERAL STUDIES OF NUCLEAR REACTORS; SLIGHTLY ENRICHED URANIUM; BERYLLIUM; CRITICAL HEAT FLUX; BR-2 REACTOR; THERMAL HYDRAULICS; NUCLEATE BOILING; STEADY-STATE CONDITIONS; REACTOR CORES; INSTABILITY