MULTILAYER SHIELD EXPERIMENT II

Technical Report · Mon Jun 30 04:00:00 EDT 1958

OSTI ID:4071140

Luce, G A; Burton, B S; Wheeler, D M

The first tests of multilayer shield mock-ups in the Outside Tank Facility have been completed. The tests were designed to provide information for design of the shield for the XMA-1 power plant. In the experiment, slabs of various shielding materials were assembled in different arrangements into shield- sector mock-ups. These assemblies were then placed in the Outside Tank Facility and subjected to radiation from the Ground Test Reactor. Three types of measurements were taken: 1.) external measurements, with dosimeters and BF/sub 3/ counters; 2.) internal measurements, with activation foils and chemical dosimeters placed between shield layers; and 3.) external measurements of the gamma spectra emitted. Results of the internal measurements indicate that Hevimet is quite opaque to thermaI neutrons, and that gamma rays from thermal and resonance neutron capture in Hevimet may contribute significantiy to the external gamma dose rate. Hevimet capture gamma rays were found, in some cases, to cause a significant number of photoneutrons in mock-ups containlng beryllium as well as those containing beryllium oxide. The effect of hydrogenous backing of non- hydrogenous neutron-shielding materials was found to be relatively small. For fast neutrons and gamma rays, the external dose rates were found to be independent of the location of the hydrogenous material within the non- hydrogenous column. The external thermal neutron flux wag reduced most when the non-hydrogenous material was placed at the outer end of the mock-up. Many of the dose measurements indicate that gamma rays from capture in the OTF structural materials contribute significantiy to the external dose. This conclusion is substantiated by the observed gamma-ray spectra. Typical gamma spectra are shown. (auth)

• Research Organization: Convair, Fort Worth, Tex.
• NSA Number: NSA-18-015594
• OSTI ID: 4071140
• Report Number(s): NARF-58-29R; MR-N-213
• Country of Publication: United States
• Language: English

Related Subjects

ABSORPTION
ACTIVATION ANALYSIS
BAKING
BERYLLIUM
BERYLLIUM OXIDES
BORON FLUORIDES
CAPTURE
CHEMICAL REACTIONS
COUNTERS
DIAGRAMS
DOSEMETERS
FAST NEUTRONS
FOILS
GAMMA RADIATION
GTR
HYDROGEN
LAYERS
MATERIALS TESTING
MEASURED VALUES
MOCKUP
NEUTRON DETECTION
NEUTRON FLUX
PHOTONEUTRONS
PLANNING
PLATES
POWER PLANTS
PRODUCTION
QUANTITY RATIO
RADIATION DOSES
RADIATIONS
REACTOR TECHNOLOGY
REACTORS
RESEARCH REACTORS
RESONANCE NEUTRONS
SHIELDING
SPECTRA
THERMAL NEUTRONS
VARIATIONS
ZONES