Microstructural characteristics of HIP-bonded monolithic nuclear fuels with a diffusion barrier

Jue, Jan‐Fong; Keiser, Dennis D.; Breckenridge, Cynthia R.; Moore, George A.; Meyer, M. K.

doi:10.1016/j.jnucmat.2014.02.004

Cited by 55 publications

(29 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the presence of -U (possibly -U with anneal at lower temperature of 520~580°C during subsequent HIP may adversely affect the irradiation behavior of the bonding between the U10Mo fuel and Zr diffusion barrier. Previous works [28][29][30] has noted several changes in the phase constituents including the presence of UZr 2 , after secondary anneal at lower temperature, with or without pressure, relevant to HIP (520~580°C), after the initial anneal at higher temperature (e.g., 650°C).…”

Section: Phase Constituents and Microstructurementioning

confidence: 93%

“…Park et al [29] further examined phase constituents and microstructure changes as function of temperature (520, 540, 560 and 580 °C for 90 minutes) and duration (45~345 minutes at 560 °C) of hot-isostatic pressing (HIP) during fabrication. Jue et al [30] also evaluated the HIP-bonded monolithic fuels with Zr diffusion barrier with emphasis on decomposition of U-Mo region, formation of Mo 2 Zr precipitates and geometry-restricted processing defects associated with hot-rolling process.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Interdiffusion and reactions between U–Mo and Zr at 650 °C as a function of time

Park

Keiser

Sohn

2015

Journal of Nuclear Materials

View full text Add to dashboard Cite

Development of monolithic U-Mo alloy fuel (typically U-10wt.%Mo) for the Reduced Enrichment for Research and Test Reactors (RERTR) program entails a use of Zr diffusion barrier to eliminate the interdiffusion-reactions between the fuel alloy and Al-alloy cladding. The application of Zr barrier to the U-Mo fuel system requires a co-rolling process that utilizes a soaking temperature of 650°C, which represents the highest temperature the fuel system is exposed to during both fuel manufacturing and reactor application. Therefore, in this study, development of phase constituents, microstructure and diffusion kinetics of U-10wt.%Mo and Zr was examined using solid-to-solid diffusion couples annealed at 650°C for 240, 480 and 720 hours. Phase constituents and microstructural development were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Concentration profiles were mapped as diffusion paths on the isothermal ternary phase diagram. Within the diffusion zone, single-phase layers of -Zr and -U were observed along with a discontinuous layer of Mo 2 Zr between the -Zr and -U layers. In the vicinity of Mo 2 Zr phase, islands of -Zr phases were also found. In addition, acicular -Zr and U 6 Zr 3 Mo phases were observed within the -U(Mo) terminal alloy. Growth rate of the interdiffusion-reaction zone was determined to be 1.81 x 10 -15 m 2 /sec at 650°C, however with an assumption of a certain incubation period.

show abstract

Section: Phase Constituents and Microstructurementioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Interdiffusion and reactions between U–Mo and Zr at 650 °C as a function of time

Park

Keiser

Sohn

2015

Journal of Nuclear Materials

View full text Add to dashboard Cite

show abstract

“…Between the U10Mo and Zr barrier, the interaction zone mainly consists of α-U, Mo 2 Zr and UZr 2 phases, which did not grow significantly during the HIP. Jue et al [22] also evaluated the HIP-bonded monolithic fuels with Zr diffusion barriers. Microstructure of decomposed U-Mo region (e.g., γ-U → α-U + U 2 Mo eutectoid) depended on the rolling direction.…”

Section: Introductionmentioning

confidence: 99%

“…Microstructure of decomposed U-Mo region (e.g., γ-U → α-U + U 2 Mo eutectoid) depended on the rolling direction. Jue et al [22] also postulated that the Mo 2 Zr precipitates formed by the reaction between UZr 2 and the U10Mo matrix. Jue et al [22] furthermore reported complex (i.e., distorted and smeared) microstructure near the edge of the fuel within the cladding and none-Zr-coated fuel region.…”

Section: Introductionmentioning

confidence: 99%

“…Jue et al [22] also postulated that the Mo 2 Zr precipitates formed by the reaction between UZr 2 and the U10Mo matrix. Jue et al [22] furthermore reported complex (i.e., distorted and smeared) microstructure near the edge of the fuel within the cladding and none-Zr-coated fuel region. Huang et al [23] examined the diffusion couples between U10Mo alloy and pure Zr, but were unable to document any significant interaction at temperature below 700°C.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microstructural anomalies in hot-isostatic pressed U–10 wt.% Mo fuel plates with Zr diffusion barrier

Park

Eriksson

Keiser

et al. 2015

Materials Characterization

View full text Add to dashboard Cite

Microstructural anomalies in the co-rolled-and-HIP'ed U-10 wt.% Mo (U10Mo) metallic fuel plate with Zr diffusion barrier assembly were examined as a function of HIP temperature (from 520 to 580°C) and duration (45, 60, 90, 180 and 345 min) by scanning and transmission electron microscopy. The anomalies observed in this study are carbide/oxide inclusions within the U10Mo fuel alloy, and regions of limited interaction between the U10Mo alloy and Zr barrier, frequently associated with carbide/oxide inclusions. In the U10Mo alloy, the cF8, Fm3m (225) UC phase (a = 4.955 Å) and cF12, Fm3m (225) UO 2 phase (a = 5.467 Å) were observed throughout the U10Mo alloy with an approximate volume percent of 0.5 to 1.8. The volume percent of the UC-UO 2 inclusions within the U10Mo alloy did not change as functions of HIP temperature and time. These inclusion phases, located near the surface of the U10Mo alloy, were frequently observed to impede the development of interdiffusion and reaction between the U10Mo alloy and Zr diffusion barrier. The regions of limited interaction between the U10Mo and Zr barrier decreased with an increase in HIP temperature, however no noticeable trend was observed with an increase in HIP duration at constant temperature of 560°C.

show abstract

Residual Stress Measurements in Extreme Environments for Hazardous, Layered Specimens

et al. 2022

View full text Add to dashboard Cite

Background In nuclear fuel plates of low-enriched U-10Mo (LEU) clad with aluminum by hot isostatic pressing (HIP), post-irradiation stresses arising during reactor shutdown are a major concern for safe reactor operations. Measurement of those residual stresses has not previously been possible because the high radioactivity of the plates requires handling only by remote manipulation in a hot cell. Objective The incremental slitting method for measuring through-thickness stress profiles was modified, and a system for automated, remote operation was built and tested. Methods Experimental modifications consisted of replacing electric-discharge machining (EDM) with a small end mill and strain-gauge measurements with cantilever displacement measurements. The inverse method used to calculate stresses was the pulse-regularization method modified to allow discontinuities across material interfaces. The new system was validated by comparing with conventional slitting on a depleted U-10Mo (DU) fuel plate. Results The new system was applied to two measurements each on six as-fabricated (pre-irradiation) LEU miniature fuel plates. Variations between the measurements at two locations in the same plate were strongly correlated with measured geometrical heterogeneity in the plate—a tilt in the fuel foil. Compressive stresses in the U-10Mo were shown to increase from 20 to 250 MPa as the ratio of aluminum thickness to U-10Mo thickness increased causing increased constraint during cooling. Faster cooling rates during processing also increased stress magnitudes. Conclusions The measurements trends agreed with data in the literature from similar plates made with DU, which further validates the method. Because other methods are impractical in a hot cell, the modified slitting method is now poised for the first measurements of post-irradiation stresses.

show abstract

Microstructural characteristics of HIP-bonded monolithic nuclear fuels with a diffusion barrier

Cited by 55 publications

References 25 publications

Interdiffusion and reactions between U–Mo and Zr at 650 °C as a function of time

Interdiffusion and reactions between U–Mo and Zr at 650 °C as a function of time

Microstructural anomalies in hot-isostatic pressed U–10 wt.% Mo fuel plates with Zr diffusion barrier

Residual Stress Measurements in Extreme Environments for Hazardous, Layered Specimens

Contact Info

Product

Resources

About