Gamma densitometer for measuring Pu density in fuel tubes
A fuel-gamma-densitometer (FGD) has been developed to examine nondestructively the uniformity of plutonium in aluminum-clad fuel tubes at the Savannah River Plant (SRP). The monitoring technique is ..gamma..-ray spectroscopy with a lead-collimated Ge(Li) detector. Plutonium density is correlated with the measured intensity of the 208 keV ..gamma..-ray from /sup 237/U (7d) of the /sup 241/Pu (15y) decay chain. The FGD measures the plutonium density within 0.125- or 0.25-inch-diameter areas of the 0.133- to 0.183-inch-thick tube walls. Each measurement yields a density ratio that relates the plutonium density of the measured area to the plutonium density in normal regions of the tube. The technique was used to appraise a series of fuel tubes to be irradated in an SRP reactor. High-density plutonium areas were initially identified by x-ray methods and then examined quantitatively with the FGD. The FGD reliably tested fuel tubes and yielded density ratios over a range of 0.0 to 2.5. FGD measurements examined (1) nonuniform plutonium densities or hot spots, (2) uniform high-density patches, and (3) plutonium density distribution in thin cladding regions. Measurements for tubes with known plutonium density agreed with predictions to within 2%. Attenuation measurements of the 208-keV ..gamma..-ray passage through the tube walls agreed to within 2 to 3% of calculated predictions. Collimator leakage measurements agreed with model calculations that predicted less than a 1.5% effect on plutonium density ratios. Finally, FGD measurements correlated well with x-ray transmission and fluoroscopic measurements. The data analysis for density ratios involved a small correction of about 10% for ..gamma..-shielding within the fuel tube. For hot spot examinations, limited information for this correction dictated a density ratio uncertainty of 3 to 5%.
- Research Organization:
- Du Pont de Nemours (E.I.) and Co., Aiken, SC (United States). Savannah River Lab.
- DOE Contract Number:
- AC09-76SR00001
- OSTI ID:
- 5184141
- Report Number(s):
- DP-1599; ON: DE82014894; TRN: 82-013841
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
DENSITOMETERS
GAMMA SPECTROMETERS
FUEL RODS
HOT SPOTS
NONDESTRUCTIVE TESTING
SPECIAL PRODUCTION REACTORS
ACCURACY
ATTENUATION
COLLIMATORS
FLUOROSCOPY
LEAKS
LI-DRIFTED GE DETECTORS
PERFORMANCE TESTING
PHOTON TRANSMISSION SCANNING
PLUTONIUM 241
PLUTONIUM DIOXIDE
SAVANNAH RIVER PLANT
URANIUM 237
ACTINIDE COMPOUNDS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOMEDICAL RADIOGRAPHY
CHALCOGENIDES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
EVEN-ODD NUCLEI
FUEL ELEMENTS
GE SEMICONDUCTOR DETECTORS
HEAVY NUCLEI
ISOTOPES
LI-DRIFTED DETECTORS
MATERIALS TESTING
MEASURING INSTRUMENTS
MEDICINE
NATIONAL ORGANIZATIONS
NUCLEAR MEDICINE
NUCLEI
OXIDES
OXYGEN COMPOUNDS
PHOTOMETERS
PLUTONIUM COMPOUNDS
PLUTONIUM ISOTOPES
PLUTONIUM OXIDES
PRODUCTION REACTORS
RADIATION DETECTORS
RADIOISOTOPES
RADIOLOGY
REACTOR COMPONENTS
REACTORS
SEMICONDUCTOR DETECTORS
SPECTROMETERS
TESTING
TRANSURANIUM COMPOUNDS
URANIUM ISOTOPES
US AEC
US DOE
US ERDA
US ORGANIZATIONS
YEARS LIVING RADIOISOTOPES
440103* - Radiation Instrumentation- Nuclear Spectroscopic Instrumentation
220700 - Nuclear Reactor Technology- Plutonium & Isotope Production Reactors