Method and apparatus for measuring reactivity of fissile material

Patent · Tue Sep 07 00:00:00 EDT 1982

OSTI ID:5840469

Lee, D M; Lindquist, L O

Given are a method and apparatus for measuring nondestructively and noninvasively (i.e., using no internal probing) the burnup, reactivity, or fissile content of any material which emits neutrons and which has fissionable components. The assay is accomplished by altering the return flux of neutrons into the fuel assembly by means of changing the reflecting material. The existing passive neutron emissions in the material being assayed are used as the source of interrogating neutrons. Two measurements of either emitted neutron or emitted gamma-ray count rates are made and are then correlated to either reactivity, burnup, or fissionable content of the material being assayed, thus providing a measurement of either reactivity, burnup, or fissionable content of the material being assayed. Spent fuel which has been freshly discharged from a reactor can be assayed using this method and apparatus. Precisions of 1000 MWd/tU appear to be feasible.

• DOE Contract Number: W-7405-ENG-36
• Assignee: ERA-08-053722; EDB-83-175504
• Application Number: ON: DE83018101
• OSTI ID: 5840469
• Country of Publication: United States
• Language: English

Related Subjects

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL PROTECTION
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FISSILE MATERIALS
NONDESTRUCTIVE ANALYSIS
SPENT FUEL ELEMENTS
BURNUP
FISSIONABLE MATERIALS
FUEL ASSEMBLIES
NEUTRON DETECTION
REACTIVITY
CHEMICAL ANALYSIS
DETECTION
FUEL ELEMENTS
MATERIALS
RADIATION DETECTION
REACTOR COMPONENTS
055001* - Nuclear Fuels- Safeguards
Inspection
& Accountability- Technical Aspects
400103 - Radiometric & Radiochemical Procedures- (-1987)