Delayed neutron method for measurement of fissile/fertile content of samples ranging from environmental to irradiated fuel
A delayed-neutron assay method is described which is capable of accurately determining the /sup 235/U and /sup 238/U contents of a wide range of materials. The method consists of irradiation in the Coupled Fast Reactivity Measurement Facility (CFRMF) at the Idaho National Engineering Laboratory (INEL), one position in the thermal driver area for /sup 235/U assay, and a fast neutron flux position for /sup 238/U. After irradiation, delayed neutron counting is used to measure the uranium content of the sample. By utilizing fast and thermal neutron irradiation and counting cycles, the samples /sup 238/U and /sup 235/U contents are determined. Minimal sample preparation and handling is required to obtain accurate results. The method has been used successfully on a wide range of samples, including environmental (soil) samples, irradiated and unirradiated fuel, and debris from the Three Mile Island Unit II Reactor core. Measurement precision of up to 0.5% can be achieved; sensitivity for low level samples is 9 counts min/sup -1/ nanogram/sup -1/ for /sup 235/U and 0.02 counts min/sup -1/ nanogram/sup -1/ for /sup 238/U. The fissile and/or fertile contents of samples containing /sup 233/U, /sup 239/Pu, /sup 240/Pu, /sup 237/Np, or /sup 232/Th could be determined by the same method. Data from representative samples are presented to illustrate the usefulness of these techniques.
- Research Organization:
- EG and G Idaho, Inc., Idaho Falls, Idaho
- OSTI ID:
- 6318149
- Report Number(s):
- CONF-840734-
- Journal Information:
- Nucl. Mater. Manage.; (United States), Vol. 13; Conference: 25. annual meeting of the Institute of Nuclear Materials Management, Columbus, OH, USA, 15 Jul 1984
- Country of Publication:
- United States
- Language:
- English
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37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FERTILE MATERIALS
ISOTOPE RATIO
FISSILE MATERIALS
NEPTUNIUM 237
DELAYED NEUTRON ANALYSIS
PLUTONIUM 239
PLUTONIUM 240
THORIUM 232
URANIUM 233
URANIUM 235
URANIUM 238
ACCURACY
CFRMF REACTOR
COUNTING TECHNIQUES
NUCLEAR FUELS
NUCLEAR MATERIALS MANAGEMENT
QUANTITATIVE CHEMICAL ANALYSIS
RADIOACTIVE WASTE MANAGEMENT
SAMPLE PREPARATION
SENSITIVITY
SOILS
SPENT FUELS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
CHEMICAL ANALYSIS
ENERGY SOURCES
EPITHERMAL REACTORS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXPERIMENTAL REACTORS
FAST REACTORS
FISSIONABLE MATERIALS
FUELS
HEAVY NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MANAGEMENT
MATERIALS
MINUTES LIVING RADIOISOTOPES
NEPTUNIUM ISOTOPES
NONDESTRUCTIVE ANALYSIS
NUCLEAR REACTION ANALYSIS
NUCLEI
ODD-EVEN NUCLEI
PLUTONIUM ISOTOPES
RADIOISOTOPES
REACTOR MATERIALS
REACTORS
RESEARCH AND TEST REACTORS
THORIUM ISOTOPES
URANIUM ISOTOPES
WASTE MANAGEMENT
YEARS LIVING RADIOISOTOPES
ZERO POWER REACTORS
055001* - Nuclear Fuels- Safeguards
Inspection
& Accountability- Technical Aspects
400101 - Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures