The Fracture and Aerosol Release of Impacted HLW Glasses and HLW Canisters

1988 ◽  
Vol 127 ◽  
Author(s):  
Hans G. Scheibel ◽  
V. Friehmelt ◽  
H. Froehlich

ABSTRACTThe fracture and release mechanism of radioactive aerosols of HLW glass and HLW canisters are studied experimentally by laboratory scale and full scale drop tests. The experimental conditions model the conditions of accidental drops in a deep salt repository. The laboratory scale drop tests have a scaling factor of 1:10. Accelerated probes of simulated HLW glass impact on a ground plate and the size distributions of broken fines and released aerosols are measured by sieving and scanning electron microscopy (SEM) of aerosol samples.The impact velocity is determined as the dominating impact parameter. Further parameters tested, such as waste glass composition, cooling time (residual thermal stresses), probe temperature at impact, and ground characteristics, show no measurable influence. Source terms of released respirable aerosols are evaluated for two reference cases, borehole drop (impact velocity v = 80 m/s) and reloading hall drop (v = 14 m/s), the values being 0.1 % and to 2.10-4 % respectively of the glass probe mass. The full scale drop tests are performed with European Standard HLW canisters. The canisters keep their integrity in all tests up to drop heights of 14 m. On opening the canisters, the broken fines are analyzed by sieving. The results are in good agreement with the small scale tests and confirm their acceptability for use in a safety analysis.

Author(s):  
Chris Timms ◽  
Doug Swanek ◽  
Duane DeGeer ◽  
Arjen Meijer ◽  
Ping Liu ◽  
...  

The TurkStream pipeline project is designed to transport approximately 32 billion cubic meters of natural gas annually from Russia to Turkey under the Black Sea, with more than 85% of the deep-water route being deeper than 2000 m. The offshore section is intended to consist of two parallel lines, each approximately 900 km long. The preliminary stages of the front end engineering design (pre-FEED) phase was managed by INTECSEA. To support the analyses and design of the deepest portions, a full scale collapse test program was performed by C-FER Technologies (C-FER). This collapse test program, which included 62 full-scale collapse and pressure+bend tests, 54 medium-scale ring collapse tests, and hundreds of small-scale tests, was primarily aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance resulting from the thermal induction heat treatment effect (thermal ageing) that arises during the pipe coating process. Two grades of 32-inch (813 mm) outside diameter (OD) line-pipe, SAWL450 and SAWL485 with wall thicknesses of 39.0 mm or 37.4 mm, respectively, were supplied from various mills for testing. The collapse test program objectives were as follows: • Determine the collapse resistance of line pipes originating from various pipe mills; • Determine the pressure+bend performance of line pipes originating from various pipe mills; • Measure the effect of thermal ageing on material and collapse testing results, including the impact of multiple thermal cycles; and • Evaluate the results of medium-scale ring collapse tests as compared to full-scale tests. This paper presents selected results of this work, along with some comparisons to predictive equations.


Author(s):  
Richard Villavicencio ◽  
Young-Hun Kim ◽  
Sang-Rai Cho ◽  
C. Guedes Soares

Numerical simulations are presented, on the dynamic response of a one-tenth scaled tanker double hull structure struck laterally by a knife edge indenter. The small stiffeners of the full-scale prototype are smeared in the small-scale model by increasing the thicknesses of the corresponding plates. The dynamic response is evaluated at an impact velocity of 7.22 m/s and the impact point is chosen between two frames to assure damage to the outer shell plating and stringers. The simulations are performed by LS-DYNA finite element solver. They aim at evaluating the influence of strain hardening and strain rate hardening on the global impact response of the structure, following different models proposed in the literature. Moreover, the numerical model is scaled to its full-scale prototype, summarizing the governing scaling laws for collision analysis and evaluating the effect of the material strain rate on the plastic response of large scaled numerical models.


2020 ◽  
Vol 20 (3) ◽  
pp. 975-983 ◽  
Author(s):  
B. Teychene ◽  
F. Chi ◽  
J. Chokki ◽  
G. Darracq ◽  
J. Baron ◽  
...  

Abstract Polar mobile organic compounds (PMOC) are highly polar chemicals and tend to accumulate in short water cycles. Due to their properties, PMOC might be partially eliminated by advanced water treatment technologies. The goal of this study is to investigate the rejection of 22 PMOC (highly mobile and persistent) by reverse osmosis (RO) and nanofiltration (NF) membranes. The impact of transmembrane pressure was evaluated through laboratory-scale cross-flow constant pressure filtration tests. Among the investigated experimental conditions, PMOC rejection with NF at eight bars is comparable to values obtained on RO at 15 bars. Negatively charged PMOC are highly rejected by both RO and NF membranes while guanidine-like compounds exhibit higher passage values and are strongly impacted by transmembrane pressure. In order to model the rejection mechanism, decision tree methodology was employed to link PMOC physicochemical properties to rejection values. Based on laboratory-scale results, decision trees were computed and emphasized that the NF rejection mechanism is governed by electrostatic interaction and sieving effects. In contrast, PMOC rejection on the RO membrane strongly depends on the topological polar surface area (TPSA) of the PMOC. This study suggests that micropollutant TPSA should be more investigated in order to describe RO removal efficiency. Moreover, it is shown that the decision tree is a powerful numerical tool in order to reveal the specific sequence leading to micropollutant removal by RO and NF membranes.


2013 ◽  
Vol 683 ◽  
pp. 353-356 ◽  
Author(s):  
Yi Hua Dou ◽  
Yang Li ◽  
Zhi Guo Wang ◽  
Zhen Li

With the development of hydraulic fracturing technology, the failure of the equipments during production test and completion well becomes more and more severe due to the behaviors of erosion-corrosion. In this paper, the erosion-corrosion behaviors of N80, P110 and VM140 materials were investigated with the jet impingement experimental device. The corrosive rate of these materials by the weight loss method was carried out under different flow velocities and jet angles. It was observed that the weight loss of the three materials is increased by the rising of the impact velocity. The relation of erosion-corrosion weight loss to impact velocity is well described as the equation E=KVn (E is the speed, V is fluid velocity, k and n are the fitting parameters). As a results, the resistance ability for corrosion-erosion under experimental conditions is P110>N80>VM140.


Author(s):  
Gang Wang ◽  
Gregory Hiemenz ◽  
Wei Hu ◽  
Norman M. Wereley

The goal of this study is to provide shock mitigation in an active (or semi-active) shock absorption system, typically comprising of a spring, and an adjustable stroking load element, such as an adaptive energy absorber (EA) or semiactive damper element, in which the stroking load can be electronically adjusted in real-time. Typically, there is a maximum limiting stroking load that can be accommodated by a payload. Thus, a Constant Stroking Load Regulator (CSLR) is developed that accepts sensor feedback, and then selects control gains that result in the energy absorber (EA) providing the required controllable stroking load. A key benefit of this regulator is that it is capable of adapting to a varying range of payload mass, impulse types, and impulse excitation levels. The payload mass is measured and used as a control input parameter. The measured impact velocity is used to determine the impulse acceleration level by assuming an impulse profile, which tends to be application-specific. Finally, the required constant stroking load is determined using a physics-based model. The CSLR is designed to achieve a “soft landing” such the payload comes to rest when the available stroke is used completely, in order to minimize the stroking load and thereby minimize the potential for payload damage. The CSLR methodology was then experimentally validated for a representative occupant protection system consisting of a seat suspension with an adaptive stroking element, which in this case was a magnetorheological energy absorber (MREA). A MREA was used as the stroking element because its stroking load can be adjusted electronically. To validate the CSLR strategy, experimental drop tests were conducted for two different payloads. The impact velocity was 10.3 ft/s (3.15 m/s) and the acceleration profile was a 50 ms duration half-sine pulse. The constant stroking load was pre-calculated as a function of payload mass and initial velocity. During each drop test, the required stroking load was supplied to the MREA in order to achieve a “soft landing.” The CSLR was successfully demonstrated under laboratory conditions. These tests demonstrated feasibility of using the CSLR, in conjunction with a MREA as the stroking element.


1999 ◽  
Vol 556 ◽  
Author(s):  
T. S. Rudisill ◽  
J. C. Marra ◽  
D. K. Peeler

AbstractThe Savannah River Technology Center (SRTC) is developing an immobilization process for graphite fines residues generated during nuclear materials production activities at the Rocky Flats Environmental Technology Site (Rocky Flats). The continued storage of this material has been identified as an item of concern. The residue was generated during the cleaning of graphite casting molds and potentially contains reactive plutonium metal. The average residue composition is 73 wt% graphite, 15 wt% calcium fluoride (CaF2), and 12 wt% plutonium oxide (PuO2 ). Approximately 950 kg of this material are currently stored at Rocky Flats.The strategy of the immobilization process is to microencapsulate the residue by mixing with a sodium borosilicate (NBS) glass frit and heating at nominally 700°C. The resulting waste form would be sent to the Waste Isolation Pilot Plant (WIPP) for disposal. Since the PuO2 concentration in the residue averages 12 wt%, the immobilization process was required to meet the intent of safeguards termination criteria by limiting plutonium recoverability based on a test developed by Rocky Flats. The test required a plutonium recovery of less than 4 g/kg of waste form when a sample was leached using a nitric acid/CaF2 dissolution flowsheet.Immobilization experiments were performed using simulated graphite fines with cerium oxide (CeO2) as a surrogate for PuO2 and with actual graphite fines residues. Small-scale surrogate experiments demonstrated that a 4:1 frit to residue ratio was adequate to prevent recovery of greater than 4 g/kg of cerium from simulated waste forms. Additional experiments investigated the impact of varying concentrations of CaF2 and the temperature/heating time cycle on the cerium recovery. Optimal processing conditions developed during these experiments were subsequently demonstrated at full-scale with surrogate materials and on a smaller scale using actual graphite fines.In general, the recovery of cerium from the full-scale waste forms was higher than for smaller scale experiments. The presence of CaF2 also caused a dramatic increase in cerium recovery not seen in the small-scale experiments. However, the results from experiments with actual graphite fines were encouraging. A 4:1 frit to residue ratio, a temperature of 700°C, and a 2 hr heating time produced waste forms with plutonium recoveries of 4±1 g/kg. With an increase in the frit to residue ratio, waste forms fabricated at this scale should meet the Rocky Flats product specification. The scale-up of the waste form fabrication process to nominally 3 kg is expected to require a 5:1 to 6:1 frit to residue ratio and maintaining the waste form centerline temperature at 700°C for 2 hr.


1997 ◽  
Vol 78 (6) ◽  
pp. 3222-3233 ◽  
Author(s):  
G.E.C. Slager ◽  
E. Otten ◽  
T.M.G.J. van Eijden ◽  
J. D. van Willigen

Slager, G.E.C., E. Otten, T.M.G.J. van Eijden, and J. D. van Willigen. Mathematical model of the human jaw system simulating static biting and movements after unloading. J. Neurophysiol. 78: 3222–3233, 1997. When the resistance to a forceful isometric bite is suddenly removed in unloading experiments, the bite force drops to zero and the mandible reaches a constant velocity. This occurs at an initial bite force of 100 N after ∼12 ms when the incisors have moved 4.5 mm. Reflex activity is far too slow to limit the velocity at impact. To explore the influence of other factors (cocontraction, force-length properties, and force-velocity properties of the muscles) on the velocity at impact, a numerical forward dynamic model of the jaw system is formulated. Unloading experiments in different experimental conditions were simulated with the model. Most parameter values of the model are based on physiological data, both from literature and a data basis from a human cadaver study. Other parameter values were found by optimally fitting the model results to data from the unloading experiments. The model analysis shows that the limitation of the jaw velocity mainly may be due to the force-velocity properties of the jaw-closing muscles. Force-length properties of the jaw muscles hardly contribute to the impact velocity. The compliance of tendinous sheets in the jaw muscles is unfavorable for the reduction in impact velocity, whereas cocontraction of jaw-opening and -closing muscles helps to limit impact velocity. The force-velocity propertiesof the muscles provide a quick mechanism for dealing withunexpected closing movements and so avoid damage to the dental elements.


2011 ◽  
Vol 1 (32) ◽  
pp. 44
Author(s):  
Jun Mitsui ◽  
Masato Yamamoto ◽  
Satoshi Noboru ◽  
Ichiro Nishiwaki

Breakage of wave dissipating concrete blocks occasionally occurs due to collision with other blocks during rocking motion under wave action. Therefore, an understanding of the impact forces induced by rocking blocks is important to solve this problem. The authors formulated impact forces using impact velocity, properties of materials, and dimensionless parameters depending on the shape of blocks to propose a theory to predict the magnitude of impact force. Fundamental drop tests using tetrapods were also conducted to confirm the proposed formula. Various sizes of blocks were used in the drop tests to reveal the scale effects. It is shown that predicted impact forces agree well with measured ones and that no scale effects concerning impact force seem to exist in the range of this study.


2015 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Rohani Mohd ◽  
Badrul Hisham Kamaruddin ◽  
Khulida Kirana Yahya ◽  
Elias Sanidas

The purpose of the present study is twofold: first, to investigate the true values of Muslim owner managers; second, to examine the impact of these values on entrepreneurial orientations of Muslim small-scale entrepreneurs. 850 Muslim owner managers were selected randomly using the sampling frame provided by MajlisAmanah Rakyat Malaysia (MARA). 162 completed questionnaires were collected and analyzed. For this paper only two dimensions of entrepreneurial orientations were analyzed: proactive orientation and innovative orientation. Interestingly, the findings revealed that Muslim businessmen/women are honest, loyal, disciplined and hard working. Loyalty and honesty are positively related to proactive orientation, while discipline and hard-work are positively related to innovative orientation. The findings provide implications for existing relevant theories, policy makers, practitioners and learning institutions. 


2017 ◽  
pp. 527-533
Author(s):  
Paul Jensen ◽  
Steve Davis

The term ‘Direct Clear Juice’ (DCJ) refers to the production of clear juice (CJ) within a modified sugarcane diffuser, thus negating the need for further juice purification in a settling clarifier. The feasibility of producing CJ by filtering treated diffuser juice through a shredded cane bed was demonstrated on a laboratory scale at the Sugar Milling Research Institute NPC (SMRI) and reported at the 2013 ISSCT congress. Factory trials were subsequently conducted at Tongaat Hulett’s Maidstone factory where the promising laboratory results were replicated in a full-scale diffuser. The production of DCJ requires consideration of the juice flow path in the diffuser, the method of lime and flocculant addition, and the screening of the juice after the diffuser. This paper summarises the results and learnings from the DCJ trials between 2011 and 2015. The development of the DCJ technology has been a collaborative project between the SMRI and Tongaat Hulett Sugar.


Sign in / Sign up

Export Citation Format

Share Document