Effect of Storage Temperature on Self-Irradiation Damage of 238PU-Substituted Zirconolite

1982 ◽  
Vol 15 ◽  
Author(s):  
F. W. Clinard ◽  
D. E. Peterson ◽  
D. L. Rohr ◽  
R. B. Roof ◽  
L. W. Hobbs
Keyword(s):  
Ambient Temperature ◽  
Crystalline Structure ◽  
Amorphous Matrix ◽  
Storage Temperature ◽  
Alpha Decay ◽  
Irradiation Damage ◽  
Partial Recovery ◽  
Defect Clusters

ABSTRACT238Pu-substituted cubic zirconolite (CaPuTi2 O7) was stored at ambient temperature, 575 K and 875 K until alpha decay doses of 2.4 to 3.6 × 1025/m3 had been accumulated. The ambient temperature material swelled to a saturation value of 5.5 vol%, and the originally crystalline structure was transformed to one with an amorphous matrix and small domains that had retained their crystallinity. At 575 K lesser amounts of swelling (4.1 vol%) and transformation were observed, reflecting concurrent partial recovery. The material held at 875 K remained crystalline, swelled only 0.4 vol%, and exhibited formation of isolated defect clusters.

scholarly journals Density Changes in Plutonium Observed from Accelerated Aging using Pu-238 Enrichment

2003 ◽  
Vol 802 ◽  
Author(s):  
B. W. Chung ◽  
S. R. Thompson ◽  
C. H. Woods ◽  
D. J. Hopkins ◽  
W. H. Gourdin ◽  
...  
Keyword(s):  
Accelerated Aging ◽  
Physical Property ◽  
Recoil Nucleus ◽  
Irradiation Damage ◽  
Volume Changes ◽  
Defect Clusters ◽  
Particle Decay ◽  
Lattice Damage ◽  
Property Changes ◽  
Inside Out

Plutonium, because of its radioactive nature, ages from the “inside out” by means of self-irradiation damage and thus produces Frankel-type defects (vacancies and self-interstitial atoms) and defect clusters. The self-irradiation damage in Plutonium-239 occurs mainly by α-particle decay, where most of the damage comes from the U-235 recoil nucleus. The defects resulting from the residual lattice damage and helium in-growth could result in microstructural and physical property changes. Because these self-irradiation effects would normally require decades to measure, with a fraction (7.5 wt%) of Pu-238 is added to the reference plutonium alloy thus accelerating the aging process by approximately 18 times the normal rate. By monitoring the properties of the Pu-238 spiked alloy over a period of about 3.5 years, the properties of plutonium in storage can be projected for periods up to about 60 years. This paper presents density and volume changes observed from the immersion density and dilatometry measurements equivalent to aging the reference plutonium alloys to nine years.

DEVELOPMENT OF DAMAGE IN THE BUDS DURING STORAGE OF IRRADIATED ONIONS

1972 ◽  
Vol 52 (5) ◽  
pp. 817-826 ◽  
Author(s):  
NAOMI TEMKIN-GORODEISKI ◽  
R. S. KAHAN ◽  
R. PADOVA
Keyword(s):  
Radiation Dose ◽  
Ambient Temperature ◽  
Shelf Life ◽  
Storage Temperature ◽  
Low Doses ◽  
Ambient Temperatures ◽  
Dormancy Period ◽  
Growth Differences ◽  
Effects Of Radiation ◽  
And Storage

Darkening of onion buds due to irradiation was investigated during three seasons on three cultivars of onion, Riverside, Egyptian, and Grano. The effects of radiation dose (0.7–80 krads), delay in irradiation after harvest, and storage temperature were studied. No darkening occurred during storage of up to 8 months at 0 C, though slight darkening sometimes appeared during subsequent shelf life. At ambient temperatures (10–30 C) three types of radiation damage were found. The onset of darkening occurred not earlier than 2 months after irradiation. With all doses above 1.0 krad there was 100% incidence of darkening after about 5 months storage at ambient temperature. The intensity of darkening increased with length of storage. Very low doses (0.7–1.0 krad) did not prevent sprouting but caused slight darkening. Doses between 2 and 80 krads completely inhibited external sprouting; however, if delayed till 3 months postharvest, these doses failed to prevent sprouting, but did cause severe darkening, which was not dependent on the dose. There was no correlation between the delay in irradiation after harvest and the intensity or incidence of darkening. The length of the dormancy period varied in different years, apparently as a result of different conditions prevailing during crop growth. Differences in the intensity of darkening in different years seem to be connected with this phenomenon.

Physiology of Oil Seeds. X. Seed Quality of Peanut Genotypes as Affected by Ambient Storage Temperature1

1992 ◽  
Vol 19 (2) ◽  
pp. 72-77 ◽  
Author(s):  
Darold L. Ketring
Keyword(s):  
Ambient Temperature ◽  
Seedling Growth ◽  
Seed Quality ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Ambient Conditions ◽  
Ambient Storage ◽  
Wide Range ◽  
Genotype Diversity ◽  
Field Emergence

Abstract Proper storage of peanut (Arachis hypogaea L.) pods following drying is a critical step in maintenance of seed quality for the next planting season. The objective of this study was to examine the effect of ambient storage temperature (similar to farmers stock peanuts stored in warehouses) on seed germination and seedling vigor of selected peanut genotypes. Peanuts were grown in the field for three successive seasons. Pods were harvested, dried, and shelled. Seed samples were taken for storage under ambient conditions, humidity effects were eliminated by storing the seeds in plastic freezer bags in sealed containers. Seasons were: (1) 1986, 19 months storage at ambient temperature, (2) 1987, 7 months storage at ambient temperature, and (3) 1988, seeds without storage. When comparisons were made among genotypes within seasons, exposure to Season 1 conditions resulted in the least germination and seedling growth, but a wide range of genotype diversity occurred. Germination of seeds from Seasons 2 and 3 ranged from 81 to 98%, and significant differences in seedling growth occurred among genotypes. When comparisons were made across Seasons, the data indicated a significant storage effect, which resulted in different seed quality for individual genotypes. Usually field emergence was significantly different among genotypes and was highly correlated with germination for all seasons. Generally, emergence was negatively correlated with slow seedling growth and positively correlated with rapid seedling growth. Thus, for seeds of lower vigor (Seasons 1 and 2), rapid seedling growth was particularly critical for early, uniform emergence (10 DAP) in the field. Genotypes were significantly different in extent of seed quality reduction and field emergence both within and across storage periods. Genotype diversity to ambient storage conditions suggests there is genetic potential to improve longevity of seed quality during storage and enhance stability of field emergence.

scholarly journals Evaluation of coatings for application in raffia big bags in conditioned storage of soybean cultivars in seed processing units

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242522
Author(s):  
Paulo Carteri Coradi ◽  
Roney Eloy Lima ◽  
Charline Zaratin Alves ◽  
Paulo Eduardo Teodoro ◽  
Ana Carina da Silva Cândido
Keyword(s):  
Ambient Temperature ◽  
Storage Temperature ◽  
Cumulative Effect ◽  
Soybean Seeds ◽  
Storage Duration ◽  
Soybean Cultivars ◽  
Temperature Conditions ◽  
Seed Processing ◽  
Physiological Quality

Different regions have different environmental conditions, which may be unfavorable for the preservation of the quality of stored soybean seeds over time. Thus, it is necessary to adopt specific technologies to control the storage environment conditions. Big raffia bags are widely used for the storage of soybean seeds, however these consist of a porous, permeable material that allows the exchange of gases between the packaging and the storage environment. In an effort to find a solution to this problem, in this study we evaluated low cost big bag coating alternatives, in order to minimize the effects of temperature and intergranular humidity on stored seeds. Thus, the aim of this work was to evaluate the quality of soybean cultivars subjected to different temperature and storage duration conditions and stored in raffia bags with or without internal coating. We used a completely randomized, three-factor (10 × 6 × 5) experimental design. We assessed 10 soybean cultivars, six storage environments, and five evaluation periods. Our results showed that seeds of the M-SOY 8866, M7110 IPRO, CD 2737 RR, and BMX DESAFIO 8473 RSF soybean cultivars preserved their physiological quality better in different storage environments. The storage duration had a cumulative effect on the negative factors that favor the deterioration of the quality of the stored seeds. The storage temperature was the main factor that affected the physiological quality of the stored seeds. The use of coated packaging was beneficial in preserving the physiological quality of stored soybean seeds; however, its effect was greater at ambient temperature than in a cold environment. The best storage environment for the preservation of the quality of the seeds was characterized by 10°C temperature conditions and the use of coated packaging, while the worst storage environment was characterized by ambient temperature conditions without the use of coated packaging. Thus, it was concluded that the use of coatings in raffia big bags can be an alternative for maintaining the quality of seeds of different soybean cultivars during storage in seed processing units.

scholarly journals Influence of hygromechanical history on the longitudinal mechanosorptive creep of wood

Holzforschung ◽  
2012 ◽  
Vol 66 (6) ◽  
pp. 757-764 ◽  
Author(s):  
Cédric Montero ◽  
Joseph Gril ◽  
Clémentine Legeas ◽  
David G. Hunt ◽  
Bruno Clair
Keyword(s):  
Ambient Temperature ◽  
Norway Spruce ◽  
The Other ◽  
Single Type ◽  
Partial Recovery ◽  
Four Point Bending ◽  
Strain Dependent ◽  
Usual Pattern

Abstract An experiment was performed on Norway spruce to simplify our understanding of mechanosorptive creep. Two well-matched sets of specimens were subjected to the same humidity history but loaded in four-point bending at different times. One set was loaded dry, and thus experienced a considerable creep at first adsorption (the so-called ++ effect). The other set was then loaded wet and only exhibited, together with the dry-loaded set, the usual pattern of creep increase during drying (- effect) followed by a partial recovery during remoistening (+ effect). Both sets converged to the same response after a few cycles. The results confirm that a single type of mechanosorption, combined with strain-dependent hygroexpansion and humidity-dependent viscoelascity, is sufficient to account for all observed features of longitudinal creep of wood at ambient temperature.

scholarly journals Alpha Decay Self-Damage in Cubic and Monoclinic Zirconolite

1981 ◽  
Vol 6 ◽  
Author(s):  
F. W. Clinard ◽  
C. C. Land ◽  
D. E. Peterson ◽  
D. L. Rohr ◽  
R. B. Roof
Keyword(s):  
Ambient Temperature ◽  
Alpha Decay ◽  
Natural Mineral ◽  
X Ray ◽  
Cell Dimensions ◽  
Damage Response ◽  
The Matrix

ABSTRACTSamples of primarily-monoclinic 238 Pu-doped zirconolite were stored at ambient temperature to allow accumulation of alpha decay self-damage to a dose of 6 × 1024 α/m3 (equivalent to a SYNROC age of ֮103 y). Bulk swelling reached 2.3 vol% with no tendency toward saturation, a damage response similar to that observed for cubic Pu-doped zirconolite. X-ray volumetric swelling at 4 × 1024 ֮/m3 was 1 vol%, considerably less than that for the cubic material. Changes in cell dimensions differed significantly from those reported by others for a monoclinic natural mineral. Extensive microcracking was observed, and is attributed at least partially to swelling differences between the matrix and minor phases.

scholarly journals Krypton and Helium Irradiation Damage in Yttria-stabilised Zirconia

2011 ◽  
Vol 1298 ◽  
Author(s):  
M. Gilbert ◽  
C. Davoisne ◽  
M. C. Stennett ◽  
N. C. Hyatt ◽  
N. Peng ◽  
...  
Keyword(s):  
Ion Beam ◽  
Cluster Formation ◽  
Matrix Material ◽  
Alpha Decay ◽  
Irradiation Damage ◽  
Thin Sections ◽  
Inert Matrix ◽  
Atomic Displacements ◽  
Transmission Electron ◽  
Focussed Ion Beam

ABSTRACTA candidate matrix material for inert matrix fuel (IMF), yttria-stabilised zirconia (YSZ) has been doped with Nd3+ as a surrogate for Pu3+. To simulate and assess the effects of fission gas accommodation and alpha decay on the microstructure, samples of (Y0.1425,Nd0.05,Zr0.8075)O1.904 have been irradiated with 2 MeV 36Kr+ ions, at fluences of 1×1014 and 5×1015 cm−2, and 200 keV 4He+ ions at fluences of 1×1014, 5×1015 and 1×1017 cm-2. Analysis by transmission electron microscopy (TEM) of thin sections prepared by focussed ion beam (FIB) milling revealed damage was only observed at the highest 36Kr+ and 4He+ fluences. Monte Carlo simulations using the TRIM code showed that it is only at these fluences that the level of atomic displacements was sufficient to result in observable defect cluster formation within the material.

scholarly journals The Influence of Storage Temperature on the Bread Quality

2012 ◽  
Vol 69 (2) ◽  
Author(s):  
Adriana Paula DAVID ◽  
Giorgiana Mihaela CÄ‚TUNESCU ◽  
Oana Maria DAVID ◽  
Daiana OLAR
Keyword(s):  
Ambient Temperature ◽  
Analytical Methods ◽  
Storage Temperature ◽  
Quality Standards ◽  
Quality Parameters ◽  
Sensory Characteristics ◽  
Bread Quality ◽  
Physicochemical Changes

The main purpose of this paper is the study of sensory and physicochemical changes occurring in bread, preserved at ambient temperature and refrigeration temperature for 7 days. The study has been achieved using bread commercialized in a supermarket, sliced and packaged in polyethylene foil. Monitoring the quality parameters has been achieved daily so be as visible changes. The quality parameters monitored was elasticity, porosity, acidity, humidity and sensory characteristics, indicators which reflect the freshness of bread. The analytical methods used are those of standards and values are within the limits of quality standards.

scholarly journals Actinides induced irradiation damage and swelling effect in irradiated Zircaloy-4 after 30 years of storage

2021 ◽  
Vol 1 ◽  
pp. 7-8
Author(s):  
Mara Marchetti ◽  
Michel Herm ◽  
Tobias König ◽  
Simone Manenti ◽  
Volker Metz
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Reactor Core ◽  
Fission Products ◽  
Alpha Decay ◽  
Irradiation Damage ◽  
Monte Carlo Code ◽  
Pressurized Water ◽  
Dry Storage ◽  
Inner Surface

Abstract. After several years in the reactor core, irradiated nuclear fuel is handled and subsequently stored for a few years under water next to the core, to achieve thermal cooling and decay of very short-lived radionuclides. Thereafter, it might be sent to dry-cask interim storage before final disposal in a deep geological repository. Here, the spent nuclear fuel (SNF) is subject to a series of physicochemical phenomena which are of concern for the integrity of the nuclear fuel cladding. After moving the SNF from wet to dry storage, the temperature increases, then slowly decreases, leading the hydrogen in solid solution in the cladding to precipitate radially with consequent hydride growth and cladding embrittlement (Kim, 2020). Another phenomenon affecting the physical properties of the cladding during interim dry storage is the irradiation damage produced in the inner surface of the cladding by the alpha decay of the actinides present at the periphery of the pellet, particularly when the burnup at discharge is high. SNF pellets with high average burnup present larger fuel volumes at the end of their useful life due to accumulation of insoluble solid fission products and noble gases, which leads to disappearance of the as-fabricated pellet–clad gap. Further swelling is expected as a consequence of actinide decay and the accumulation of helium. This leads to larger cladding hoop stress and larger alpha decay damage. The present work first investigates the variation in diameter caused by pellet swelling in an irradiated Zircaloy-4 cladding after chemical digestion of the uranium oxide (UOx) pellet. Second, the irradiation damage produced during the 30 years elapsed since the end of irradiation in terms of displacements per atom (dpa) is studied by means of the FLUKA Monte Carlo code. The irradiation damage produced by the decay of actinides in the inner surface of the cladding extends for less than 3 % in depth. The considered cladded UOx pellet was extracted from a pressurized water reactor (PWR) fuel rod consisting of five segments, with an average burnup at discharge of 50.4 GWd (tHM)−1.

scholarly journals SAFETY OF STORING THE LIGHT HYDROCARBONS BROAD FRACTION

2015 ◽  
pp. 89-92
Author(s):  
V. N. Permyakov ◽  
M. V. Omelchuk
Keyword(s):  
Ambient Temperature ◽  
Vapor Phase ◽  
Evaporation Rate ◽  
Storage Temperature ◽  
Light Hydrocarbons ◽  
Broad Fraction ◽  
Geometrical Dimensions ◽  
A Share

A share of the flashed mass of the light hydrocarbons broad fraction and the evaporation rate of the remaining fluid portion at different material storage temperature and ambient temperature is estimated in the paper. It was found out that a drop of the storage temperature and ambient temperature impedes the vapor phase generation and thereby reduces the geometrical dimensions of dangerous zones by all factors of impact.

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