Characterization and Decontamination of Contaminated Structures Using a Profiling Technology

2003 ◽  
Author(s):  
S. Aggarwal ◽  
G. Charters ◽  
D. Thacker
Keyword(s):  
Hot Spot ◽  
Cross Contamination ◽  
Chemical Contamination ◽  
Considerable Time ◽  
Activity Profile ◽  
Concrete Core ◽  
Porous Concrete ◽  
The Core ◽  
Waste Segregation ◽  
Contamination Problem

Certain radioisotopes (tritium, radium, cobalt, plutonium, and cesium) can penetrate porous concrete and contaminate the concrete well below the easily measured surface. Certain radioisotopes can penetrate concrete and contaminate the concrete well below the surface. The challenge is to determine the extent of the contamination problem and the magnitude of the problem in a real-time. Currently, concrete core bores are shipped to certified laboratories where the concrete residue is run through a battery of tests to determine the contaminants. The existing core boring operation volatilizes some of the contaminants (like tritium) and oftentimes cross-contaminates the area around the core bore site. The volatilization of the contaminants can lead to airborne problems in the immediate vicinity of the core bore. Cross-contamination can increase the contamination area and thereby increase the amount of waste generated. The goal is to avoid those field activities that could cause this type of release. The concrete profiling technology, TRUPROSM in conjunction with portable radiometric instrumentation produces a profile of radiological or chemical contamination through the material being studied. The data quality, quantity, and representativeness may be used to produce an activity profile from the hot spot surface into the material being sampled. This activity profile may then be expanded to ultimately characterize the facility and expedite waste segregation and facility closure at a reduced cost and risk. Performing a volumetric concrete or metal characterization safer and faster (without lab intervention) is the objective of this characterization technology. This way of determining contamination can save considerable time and money.

scholarly journals EDUCATION ON THE RISKS OF USING HAZARDOUS ADDITIVES IN SNACKS FOR STUDENTS AT MARGAHAYU II ELEMENTARY SCHOOL IN BEKASI CITY

2021 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Annisa Amalia ◽  
Sari Defi Okzelia ◽  
Fajar Amirullah ◽  
Ristiana Kusumawinahyu ◽  
Dina Wahyu Pratiwi ◽  
...  
Keyword(s):  
Elementary School ◽  
Community Service ◽  
Rhodamine B ◽  
Elementary School Children ◽  
Community Education ◽  
Hazardous Substances ◽  
Chemical Contamination ◽  
The Core ◽  
Food Safety And Quality ◽  
Health Objective

Background: Food safety and quality studied by BPOM Indonesia in 2008-2011 showed that around 48% of hazardous substances are found in snacks of elementary school children. Throughout 2012, this percentage increased to 66.7%. Cases of chemical contamination that are still frequently found are the use of additives such as formaldehyde, borax and rhodamine B. Lack of supervision and education to children causes the possibility of consuming dangerous foods to be large thus increasing the risk to health. Objective: This activity was conducted to improve understanding, knowledge and awareness of the community, especially students about the risk of using hazardous additives in snacks. Method: Stages of community service activities include: (1) Pre-activity; (2) Implementation; and (3) Evaluation. The method used was a combination of community education and demonstration. In the core of the activity, there were three sub-activities implemented. Results: An increase in understanding hazardous additives in snacks for students was achieved. It was known that the sample circulating around school did not contain rhodamine B and borax. Futhermore, students can practice one simple way to implement clean and healthy living. Conclusion: The program provided an increase in understanding and awareness of hazardous additives in snacks for students.

scholarly journals Uranium(VI) and neptunium(V) transport through fractured, hydrothermally altered concrete

2000 ◽  
Vol 88 (9-11) ◽  
Author(s):  
S.L. Matzen ◽  
J.M. Beiriger ◽  
P.C. Torretto ◽  
P. Zhao ◽  
B.E. Viani
Keyword(s):  
Chemical Properties ◽  
High Level Waste ◽  
Physical And Chemical Properties ◽  
Hydrothermal Conditions ◽  
Concrete Core ◽  
The Core ◽  
Waste Repository ◽  
High Level ◽  
Physical And Chemical ◽  
And Chemical Properties

In a high level waste repository in which temperatures are elevated due to waste decay, concrete structures will be subjected to hydrothermal conditions that will alter their physical and chemical properties. Virtually no studies have examined the interaction of hydrothermally altered concrete with radionuclides. We present the results of experiments in which soluble and colloid-associated U and Np, were eluted into a fractured, hydrothermally altered concrete core. Although the fluid residence time in the fracture was estimated to be on the order of 1 minute, U and Np in the effluent from the core were below detection (10

VHTR Core Preliminary Analysis Using NEPHTIS3 / CAST3M Coupled Modelling

2008 ◽  
Author(s):  
Fre´de´ric Damian
Keyword(s):  
Fuel Element ◽  
System Analysis ◽  
Hot Spot ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Design Parameters ◽  
Block Type ◽  
Fuel Temperature ◽  
Coupled Modelling ◽  
The Core

Along with the GFR another gas-cooled reactor identified in the Gen IV technology roadmap, the VHTR is studied in France. Some models have been developed at CEA relying on existing computational tools essentially dedicated to the prismatic block type reactor. These models simulate normal operating conditions and accidental reactor transients by using neutronic [1], thermal-hydraulic, system analysis codes [2], and their coupling [3, 4]. In the framework of the European RAPHAEL project, this paper presents the results of the preliminary investigations carried out on the VHTR design. These studies aimed at understanding the physical aspects of the annular core and to identify the limits of a standard block type VHTR with regard to a degradation of its passive safety features. Analysis was performed considering various geometrical scales: fuel cell and fuel column located at the core hot spot, 2D and 3D core configurations including the coupling between neutronic and thermal-hydraulic. From the thermal analysis performed at the core hot spot, the capability to reduce the maximum fuel temperature by modifying the design parameters such as the fuel compact and the fuel block geometry was assessed. The best performances are obtained for an annular fuel compact geometry with coolant flowing inside and outside the fuel compact (ΔT > 50°C). The reliability of such design option should however be addressed with respect to its performance during the LOFC transient (the residual decay heat will be evacuated by radiation during the transient instead of conduction through graphite). As far as the fuel element geometry is concerned, a gain of approximately 50°C can be achieved by making limited changes on the fuel compact distribution in the prismatic block: reduction of the number of fuel compact in the outer ring of the fuel element where the average ratio between coolant channels and fuel compact is smaller. On the other hand, the adopted modifications should also be evaluated with respect to the maximum temperature gradient achieved in the fuel (amoeba effect). In the end, calculations performed on the full core configuration taking into account the thermal feedback showed that the radial positioning of the fuel elements allows to reduce significantly the power peaking factor and the maximum fuel temperature. The gain on the fuel temperature, which varies during the core irradiation, is in the range 100 – 150°C. Several modifications such as the increase of the bypass fraction and the replacement of a part of the graphite reflector by material with better thermal properties were also addressed in this paper.

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injector: Part 14—Cooling Characteristics of the Particulate Core Material Debris Accumulated in Horizontal Narrow Gap

2006 ◽  
Author(s):  
Y. Hirao ◽  
G. Su ◽  
K. Sugiyama ◽  
T. Narabayashi ◽  
M. Mori ◽  
...  
Keyword(s):  
Heat Supply ◽  
Nuclear Power ◽  
High Efficiency ◽  
Hot Spot ◽  
Research Work ◽  
Lower Surface ◽  
Injection System ◽  
Core Material ◽  
Metal Debris ◽  
The Core

When LOCA occurs in proposed nuclear reactor systems, the coolability of the core would be kept by the SI core injection system and therefore the probability of the core meltdown is negligible small. In this research work, we make it clear that the coolability of the RPV bottom is secured even if a part of the core should melt and a substantial amount of debris should be deposited on the lower plenum. In this report, we examined experimentally the coolability of the RPV bottom that a Zircaloy-based loose debris layer is deposited on. We set up a heat supply section made by SUS304 on the loose debris layer and measured the heat flux released into the loose debris bed and the temperature at the lower surface of the heat supply section. In addition, we measured the temperature distribution at the bottom of the loose debris bed. It became clear in this study that the coolability depends on the amount of coolant supplied, and the hot spot would not occur when coolant is supplied. Even if a hotspot should occur in the oxidization of loose metal debris accompanied with rapid heat generation. It is found that when a small amount of coolant can be supplied, it disappears because of a high capillary force of oxidized loose debris. So it is confirmed that the soundness of RPV is basically maintained.

Rapid Detection Techniques for Biological and Chemical Contamination in Food: A Review

2009 ◽  
Vol 5 (5) ◽  
Author(s):  
Yali Tang ◽  
Lixin Lu ◽  
Wei Zhao ◽  
Jun Wang
Keyword(s):  
Developing Countries ◽  
Food Safety ◽  
Rapid Detection ◽  
Detection Methods ◽  
Chemical Contamination ◽  
Detection Techniques ◽  
Examination Technique ◽  
Production Improvement ◽  
Long Time ◽  
Contamination Problem

The contamination problem in food safety is still a major concern not only for developing countries but also for the industrialized world. To guarantee the food safety, the advanced examination technique is needed urgently. However, the traditional methods have some typical drawbacks which include: high costs of implementation, long time of analysis and low samples throughput, and the need for high qualified manpower. The availability of fast, reliable and simple to use detecting tools for food products is therefore a target both for the safeguard of customer's health and production improvement. This article overviews the progress of the rapid detection methods for biological and chemical contamination in food.

Dynamic Trust Model of Internet-Ware Based on Task Classification

2012 ◽  
Vol 155-156 ◽  
pp. 221-225 ◽  
Author(s):  
Gui Sheng Yin ◽  
Shu Yin Wang
Keyword(s):  
Information Security ◽  
Trusted Computing ◽  
Hot Spot ◽  
Trust Model ◽  
Information Storage ◽  
Security Design ◽  
The Core ◽  
Task Classification ◽  
Present Information ◽  
Dynamic Trust

with the Internet popularity and the widely application of information storage technology, people pay more and more attention on the information security. Trust model is the hot spot of present information security field. It is connected with the safety interaction and operation of the entire system. Internet has the characteristic of openness, anonymity, and autonomy. All these extrude the security problems. How to build the safety and reliable trust model is the most reliable approach to solve the network security problems. Trusted computing is the core center of trust model. Through the trusted computing, we will get the perfect security design.

scholarly journals RESEARCH OF STRENGTH OF CONTACT OF THE PLASTIC PIPE ANDCONCRETE WHEN CALCULATING PLASTIC PIPE CONCRETE STRUCTURES

2019 ◽  
pp. 38-45
Author(s):  
А. Долженко ◽  
Aleksandr Dolzhenko ◽  
А. Наумов ◽  
A. Naumov ◽  
А. Шевченко ◽  
...  
Keyword(s):  
Strain State ◽  
Plastic Shell ◽  
Stress Strain ◽  
Concrete Core ◽  
Friction Forces ◽  
The Core ◽  
Stress Strain State ◽  
Numerical Studies ◽  
Plastic Pipe ◽  
Tangential Friction

This article presents numerical studies of the stress-strain state of centrally compressed short plastic-tube-concrete (PTC) cylindrical cores, having experimentally obtained and analyzed the influence of the tangential friction forces at the boundary of the concrete core and plastic shell layers on the stress-strain state of the PTC core under the assumption of elastic work of the core materials and shell. The need for these studies is associated with a lack of theoretical and numerical studies of the influence of tangential friction forces on the stress-strain state of this type of structural elements, including the classical solution with a steel shell. In this regard, mathematical modeling and the creation of engineering methods for calculating the PTC based on the study of the actual joint work of the concrete core and the cylindrical plastic shell has significant scientific potential. The performed calculations demonstrated the relevance with engineering accuracy of using the mathematical model of a short PTC rack for engineering calculations and structural analysis of the structure. It has been established that the use of an analytical model allows us to study the effect of variations in the physical and mechanical characteristics of the materials of the core and shell of the PTC on the parameters of the stress-strain state of the structure and to rationally design the PTC elements in the construction of civil and industrial buildings with reference to the widely used materials market.

Manhattan West: Converting Site Challenges into Design Opportunities

2019 ◽  
Author(s):  
Preetam Biswas ◽  
Georgi I. Petrov ◽  
Yunlu Shen ◽  
Samuel Wilson ◽  
Charles Besjak
Keyword(s):  
New York ◽  
Structural System ◽  
Moment Frame ◽  
Steel Moment Frame ◽  
Concrete Core ◽  
The Core ◽  
Steel Core ◽  
Train Tracks ◽  
Penn Station ◽  
Structural Solutions

<p>As cities worldwide are increasing in density, building departments and municipalities are allowing construction using the air‐rights above transportation infrastructure to maximize use of valuable real estate. One Manhattan West (1MW) and Two Manhattan West (2MW) are supertall office towers recently designed and engineered by Skidmore, Owings &amp; Merrill (SOM) that rise above the underground train approach to New York City’s Penn Station. Although the towers are neighbors and have a similar program, they are undercut by the train tracks in different ways. The disparate below ground conditions result in two distinct structural solutions.</p><p>The structural system of 1MW is a concrete core and a perimeter steel moment frame. The site conditions prevent the perimeter of the 304‐meter‐tall tower from reaching the foundation. This challenge is addressed by transferring the perimeter to the core above the ground, thus making 1MW one of the slenderest structures in New York City. The structural system of 2MW consists of a central braced steel core with outrigger and belt trusses and a perimeter steel moment frame. Here the perimeter reaches the foundation with a few lateral transfers however only half of the core reaches terra firma. This paper presents a side‐by‐side comparison of the structural solutions for the two towers.</p>

Sign in / Sign up

Export Citation Format

Share Document