Nondestructive measurement of neutron exposure in the BR-3 pressure vessel by continuous gamma-ray spectrometry

Conference · Sun Jul 01 04:00:00 EDT 1984

OSTI ID:6311913

McNeece, J P; Gold, R; Fabry, A; DeLeeuw, S; Gubel, P

Continuous gamma-ray spectrometry was used in the instrument tube of the BR-3 reactor water shield tank in an attempt to quantify the neutron exposure of the pressure vessel. A hybrid lead-natural uranium collimator-shield was used to surround the Si(Li) detectors of the Janus gamma-ray spectrometry probe. This hybrid collimator provided sufficient attenuation of the gamma field to reduce count rates to tolerable levels. Measurements were carried out at different elevations near midplane, from approximately 20 cm above to 10 cm below midplane. The dominant structure observed in these gamma-ray spectra was that of WCo, whereas the search for the VUMn gamma-ray (0.835 MeV) did not reveal any intensity above statistical fluctuations in the data. The absolute flux of WCo gamma-rays observed with the Janus probe is in good agreement with the calculated WCo flux. These calculations are based on the well-defined neutronic exposure of the BR-3 pressure vessel environment, which has been characterized on the basis of surveillance capsule dosimetry, dedicated thermal shield dosimetry sampling, and transport theory calculations. In light of this good agreement, the general applicability of continuous gamma-ray spectrometry for non-destructive neutron exposure measurements of light water reactor pressure vessels is discussed.

• Research Organization: Hanford Engineering Development Lab., Richland, WA (USA); Centre d'Etude de l'Energie Nucleaire, Mol (Belgium)
• DOE Contract Number: AC06-76FF02170
• OSTI ID: 6311913
• Report Number(s): HEDL-SA-3124-FP; CONF-840902-23; ON: DE86005480
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
BR-3 REACTOR
CONTAINERS
ENRICHED URANIUM REACTORS
GAMMA SPECTROMETERS
MATERIALS TESTING
MEASURING INSTRUMENTS
NEUTRON FLUX
NONDESTRUCTIVE TESTING
POWER REACTORS
PRESSURE VESSELS
PWR TYPE REACTORS
RADIATION FLUX
REACTOR SAFETY EXPERIMENTS
REACTORS
RESEARCH PROGRAMS
SPECTROMETERS
TESTING
THERMAL REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS