FUEL BEARING FIBERGLAS IN ALUMINUM-BASE FUEL ELEMENTS. Final Report

Technical Report · Fri Jun 01 00:00:00 EDT 1962

OSTI ID:4748113

Baskey, R H

Al-coated fiberglas containing 50 wt% U/sub 3/O/sub 8/ in solid solution was consolidated into 99+% dense core material by hot pressing. These core materials were fabricated into Al-clad MTR fuel plates. MTR fuel plates (19) containing Al-coated enriched (93+%) U-bearing fiberglas core sections (10.53 plus or minus 0.2 grams U/sup 235/ per plate) and clad with alclad 5154 were scanned for core homogeneity, formed to correct radius, and mechanically assembled into a prototype MTR fuel element. This element will be tested in the MTR and then examined to determine the effects of irradiation. One capsule with 9 unclad and clad composite specimens containing core material of glass fibers dispersed in an 1100 Al matrix was irradiated. The fibers contained 50 wt% U/sub 3/O/sub 8/. The materials were irradiated at 100 deg C to depletion burnups of 17 to 24% of the U/sup 235/ and to a fastneutron (>1 Mev) exposure of 1.8 x 10/ sup 20/ to 2.6 x 10 nvt. The surface appearance of the specimens was unchanged. Dimension and density measurements indicated that the materials swelled to the same order of magnitude as alloy fuels which experienced similar irradiation exposures. Fission-gas release could be accounted for by recoil mechanism. The ultimate tensile strengths and elastic moduli were increased while ductility did not change appreciably. Metallographic examination at magnifications up to 1000X did not reveal any evidence of change in the microstructure, and evidence of fission recoil in the matrix was not observed. The fiberglas reinforced the Al core matrix by increasing its strength retention at elevated temperatures. The fiber length and orientation influenced the physical properties. The hot pressed material had tensile strengths up to 19,000 psi at 1000 deg F when the fibers were aligned parallel to the applied stress. However, the same material with fibers aligned perpendicular to the applied stress had strengths of 7000 psi at 600 deg F and 5500 psi at 800 deg F. Stress rupture tests at 400, 600, 800, and 1000 deg F, to at least 764 hours in some instances, confirmed the excellent strength retention of hot pressed materials. The unclad fiberglas-reinforced Al had strengths of 10,200 and 6,500 psi at 600 and 800 deg F, respectively. Fuel plates clad with alclad 6061 were 50% stronger at 600 deg F than the cladding material (alclad 6061). Fuel plates clad with alclad 5154 exhibited, in general, about the same tensile strength as commercial grade 5154 Al. The stress rupture properties of alclad 5154 fuel plates at 400 and 600 deg F up to 185 hours were less than commercial grade 5154. The elongations and reduction in area of unclad material were normilly less than 1%. It usually bent only 7 to 9 degrees around a 1/4 in. radius at room temperature without breaking. The clad materials exhibited reductions in area up to 38% and elongations up to 11% at 800 deg F. Cladding the fiberglas-reinforced Al core with Al alloys increased the formability to the extent that it could be bent up to 90 degrees around a 1/4 in. radius at room temperature without breaking. Elevated temperature bend tests at 450 to 550 deg F indicated that the plates clad with 5154 Al were bent 180 degrees around a 1/8 in. radius without cracking. Plates clad with alclad fiberglasreinforced Al cracked after bending 30 and 45 degrees around a 1/8-in. radius. (auth)

• Research Organization: Clevite Corp. Mechanical Research Div., Cleveland
• DOE Contract Number: AT(40-1)-2557
• NSA Number: NSA-17-006530
• OSTI ID: 4748113
• Report Number(s): TID-16847
• Resource Relation: Other Information: Orig. Receipt Date: 31-DEC-63
• Country of Publication: United States
• Language: English

Related Subjects

METALS, CERAMICS, AND OTHER MATERIALS
ALUMINUM
COATING
ENRICHMENT
EXPANSION
FABRICATION
FAST NEUTRONS
FIBERS
FISSION PRODUCTS
FUEL CANS
FUEL ELEMENTS
GLASS
IRRADIATION
MATERIALS TESTING
MECHANICAL PROPERTIES
METALLOGRAPHY
MTR
PLATES
RADIATION DOSES
REACTORS
RESEARCH REACTORS
SOLID SOLUTIONS
TEMPERATURE
U3O8
URANIUM 235