THE WORTH OF SINGLE CONTROL RODS IN HYDROGENOUS REACTORS

Technical Report · Mon Jul 28 04:00:00 EDT 1958

OSTI ID:4278348

Bach, D R; Way, M E

Reactivity measurements of the worth of single slabtype control rods fabricated from a variety of materials were made in five flexible Plastic Reactor assemblies. These assemblies cover what is believed to be a reasonable spectral range for hydrogen-moderatod reactors ( beta gamma = 0.08 to 0.71). An analysis of these experiments shows that the relative worths, which are sensitive functions of the spectrum, can be described by a two-group absorption area scheme. The measured ratio of the worth of an absorber having complicatod resonances io that of a simple material with a slowly varying cross section is used to evaluate the epithermal transmission probability of the former. It is shown that when this parameter is used to calculate the relative worth in a different spectrum, good agreement with experiment is obtained. That is, in view of the agreement with the measurements, the epithermal transmission probability is a constant and can be used over the entire range or spectra examined. Measurements were also made of the dependence of control rod worth on radial position. A comparison of these measurements with statistical weight calculations shows good agreement. A penturbation theory approach which employs the absorption area was then used to evaluate the absolute worth of a single cadmium slab rod in each of the five reactors. Comparison with experimental worths indicates a maximum discrepancy of 8% in DELTA k/k. (auth)

• Research Organization: Knolls Atomic Power Lab., Schenectady, N.Y.
• DOE Contract Number: W-31-109-ENG-52
• NSA Number: NSA-13-009100
• OSTI ID: 4278348
• Report Number(s): KAPL-1961
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
CADMIUM
CONFIGURATION
CONTROL ELEMENTS
CROSS SECTIONS
EPITHERMAL NEUTRONS
ERRORS
HYDROGEN
MEASURED VALUES
MODERATORS
PERTURBATION THEORY
PHYSICS AND MATHEMATICS
REACTIVITY
REACTORS
RESONANCE
RODS
SPECTRA
STATISTICS
VARIATIONS