Nuclear Clay

<div class="htmlview paragraph">One of the most important aims of the automotive industry is to provide the best possible protection for drivers, passengers and pedestrians. Through their CAPS (Combined Active and Passive Safety) program (see <span class="xref">Figure 1</span>), Bosch is developing new functions which help to achieve these goals and contribute to accident mitigation and/or reduction of accident severity. By linking existing active and passive automobile safety systems and extending these by adding systems for monitoring and evaluating the vehicle's environment, the foundation for new safety functions is created.</div> <div class="htmlview paragraph">The growing number of airbags in vehicles provides more and better protection against injury for the occupants. In addition, active safety systems such as the ESP® Electronic Stability Program help to prevent an accident occurring in the first place. If these systems are linked together, they can share information and provide even better safety for drivers and passengers through new functions. For example, if ESP® recognizes a threat to the driving stability of the vehicle, it can activate passive safety systems such as reversible seatbelt tensioners. If radar or video sensors indicate that an accident is unavoidable, the airbag system performance can be improved, resulting in better occupant protection. Improved operation of the airbags offers especially good potential for better protection in rollovers or side crashes.</div> <div class="htmlview paragraph">The following article presents one important element of the overall CAPS approach. The improvement of the occupant protection, through the use of Vehicle Dynamic Data and Surround Sensing Systems.</div>

<div class="section abstract"><div class="htmlview paragraph">Traffic injuries are an important public health issue. To prevent these injuries, safety systems in a vehicle are recognized as valuable tools. These safety systems are active before and during a crash event. Passive safety is one such safety tool which comprises of occupant restraint systems to prevent fatal injuries during an event of a crash. To improve the real life safety further, active safety systems plays an important role in mitigating the real world accidents. Moreover, effective integration of active and passive safety systems has a potential to further reduce car occupant fatalities. However, in the recent developments in India towards road safety, vehicle safety standards are oriented more towards passive safety. In the present work, road accidents data from India between 2005 and 2014 are studied, to estimate the major mode of accidents and factors influencing the fatal injuries. Technological and human factor interventions are derived from these accidents statistics. The data collected can be an important input in developing the active safety systems representing the real world scenario. The human errors and injury severities associated with above accidents, emphasize the need of both active and passive safety systems in a vehicle to avoid accidents and mitigate injuries. This paper signifies the need of a robust regulatory system combining both active and passive safety systems to reduce the proportion of road accidents and the fatalities.</div></div>

Due to urbanization and the significantly increasing number of vehicles, urban roads are becoming more congested day by day, with the result that the rear-end collision has become the third most common type of collision. By developing and integrating active and passive safety systems, car manufacturers are working to prevent accidents and reduce the consequences of an accident. The present study examines a braking procedure and its applicability based on the integration of a passive and active safety system and provides development guidelines for the reduction of personal injuries and property damage in the event of a rear-end accident.

The SPES-2 is a full height, full pressure experimental test facility reproducing the Westinghouse AP600 reactor with a scaling factor of 1/395. The experimental plant, designed and operated by SIET in Piacenza, consists of a full simulation of the AP600 primary core cooling system including all the passive and active safety systems. In 1992, Westinghouse, in cooperation with ENEL (Ente Nazionale per l` Energia Elettrica), ENEA (Enter per le numove Technlogie, l` Energia e l` Ambient), Siet (Societa Informazioni Esperienze Termoidraulich) and ANSALDO developed an experimental program to test the integrated behaviour of the AP600 passive safety systems. The SPES-2 test matrix, concluded in November 1994, has examined the AP600 passive safety system response for a range of small break LOCAs at different locations on the primary system and on the passive system lines; single steam generator tube ruptures with passive and active safety systems and a main steam line break transient to demonstrate the boration capability of passive safety systems for rapid cooldown. Each of the tests has provided detailed experimental results for verification of the capability of the analysis methods to predict the integrated passive safety system behaviour. Cold and hot shakedown tests have been performed on the facility to check the characteristics of the plant before starting the experimental campaign. The paper first presents a description of the SPES-2 test facility then the main results of S01007 test {open_quotes}2{close_quotes} Cold Leg (CL) to Core Make-up Tank (CMT) pressure balance line break{close_quotes} are reported and compared with predictions performed using RELAP5/mod3/80 obtained by ANSALDO through agreement with U.S.N.R.C. (U.S. Nuclear Regulatory Commission). The SPES-2 nodalization and all the calculations here presented were performed by ANSALDO and sponsored by ENEL as a part of pre-test predictions for SPES-2.

Different variations of a passive safety containment for a BWR with active and passive safety systems

Canadian Nuclear Laboratories (CNL) is planning to decommission the Waste Management Area (WMA) standpipe and bunker structures at the Whiteshell Laboratories (WL) site located in Pinawa, Manitoba. The decommissioning activities will include retrieving historical radioactive waste from standpipes and bunkers. The waste stored in standpipes and bunkers ranges in activity from Low-Level Waste (LLW) to Intermediate-Level Waste (ILW). The standpipes and bunkers include radioactive solid waste stored in containers of unknown integrity and radioactive liquid waste, a byproduct of water ingress into the waste storage structures. The unknown integrity of waste containers presents a high risk of worker exposure to radiological hazards. In recent years, CNL has conducted extensive research developing automated systems for handling radioactive waste during decommissioning activities. Adopting modern technologies and tooling to reduce human interaction with radiological material minimizes worker exposure. The design concept of these systems is based on the operational experiences and lessons learned (internal and external) from the WL Hot Cell Facility. When implementing modern technologies and tooling to handle radioactive materials remotely, it is important to implement defence-in-depth in the system design (multiple layers of protection) to ensure the safety of workers, the public, and the environment. These layers of protection act as barriers to prevent a Postulated Initiating Event (PIE) from progressing into a severe accident. The more independent the layers are, the more robust the defence. Layers of protection in the design of a system include inherently safe design, control and monitoring of the system, alarms requiring operator intervention or critical alarms with safety interlock to prevent an accident, passive or active protection to mitigate the consequence of the hazardous event, and emergency response. The system designs were conservative, with safety margins between normal operations and abnormal conditions. This paper outlines some of the recent efforts of CNL in radioactive waste management, particularly in designing systems for radioactive waste handling activities involving historic solid waste. These activities include retrieving, characterization, sorting, segregation, and repackaging of radioactive waste. A high-level hazard identification methodology is used to identify hazards and PIEs associated with the design and operation of these remotely operated waste retrieval and handling systems. These hazards and PIEs are assessed and compared with the non-automated retrieval method to demonstrate that remotely operated waste retrieval and handling systems reduce the risk of radiological exposure to workers and protect the environment.

The difficulty occurred in nuclear power plants that the accumulated radioactive solid waste is beyond the design capacity and unable to be sent to disposal is focused on in this paper. The deep reasons for the difficulty occurred are concluded to be the unclear responsibility for disposal of radioactive waste and the divided national function of nuclear power development and radioactive waste management, by analyzing the disposal demand of radioactive solid waste caused by continuous development of nuclear power and the current situation and existing problems for the disposal of low-intermediate level radioactive solid waste in China. The policy suggestions of issuing the disposal siting plan of radioactive solid waste, forming independent firms of radioactive waste storage and disposal and improving radioactive waste management fund system are proposed based on above analysis and investigation.

Controls that support safe driving and help to alleviate damage in the event of a collision can be categorized in accordance with the driving scenario and degree of risk. These categories include driver assistance, active safety, precrash safety (PCS), and passive safety systems, as well as technologies for enhancing safety after the collision has occurred. Various driver assistance systems for providing information and alleviating driver burden in normal driving have been developed. These include adaptive front‐lighting systems (AFS), night vision, and back guide monitors that support the driver's field of view, corner sonar, and tire pressure monitoring systems for notifying the driver of potential danger, as well as adaptive cruise control ( ACC ) and lane keeping assistance systems ( LKAS ) for alleviating driver burden. Active safety systems have been developed to assist driver operation when a potentially dangerous situation can be avoided. These include brake controls such as anti‐lock brake systems ( ABS ), traction control systems ( TCS ), and electronic stability control ( ESC ), in addition to other active safety technologies. Some PCS systems also help to alleviate damage in more dangerous situations when the collision is unavoidable. Passive safety technologies are deployed in the event that an accident occurs. These include airbags for protecting the occupants of the vehicle, and fuel cut and emergency notification systems that aim to facilitate rescue after the accident. Developers are continuing to optimize driver assistance technologies in accordance with the situation by creating seamless combinations between safety systems with the ultimate goal of reducing traffic accident fatalities and injuries to zero. This chapter describes active safety systems and PCS , and the millimeter‐wave radar and image recognition sensors used in these systems.

Effect evaluation on performance issues of passive safety system – Part Ⅰ. Passive heat removal system

Heavy Goods Vehicles (HGVs) are involved in a large share of all serious and fatal collisions. Among these, about 30% are collisions involving Vulnerable Road Users (VRUs). The aim of the present study was to evaluate the potential of Heavy Goods Vehicle countermeasures to prevent fatalities with vulnerable road users in Sweden. Both the General Safety Regulation (GSR) and coming Euro NCAP test program were taken into account. Furthermore, elaboration on existing passive HGV safety systems were used to investigate any additive benefit. The Swedish Transport Administration carry out in-depth studies of all road fatalities. All in-depth studies for the period 2015–2020 were analysed retrospectively by a consensus group of three analysts, to assess the effectiveness of 22 active and passive safety systems. For each technology, target populations and boundary conditions were defined in order to facilitate the assessment. In total, 63 fatal crashes were found, compiled of 28 pedestrians, 13 bicyclists and 22 Powered Two Wheelers (PTWs, i.e. motorcyclists and moped riders). Overall, it was found that active and passive safety technologies could prevent up to 59% (37/63) of the included fatalities. For pedestrians, the potential of improved HGV driver vision, both with a surround view system and an improved direct vision, would have the larger potential to save lives. For bicyclists where the turn-right scenario is overrepresented, the implementation of Advanced Emergency Braking in junctions and Blind Spot Information Systems had the highest potential to save lives. For passive safety systems, HGV wheel protection had a potential to save many bicyclists by preventing them from being run over. Crash scenarios involving a PTW are the most challenging to address with HGV safety systems, mostly due to high PTW speed. Nevertheless, wheel protection on the HGV could save the lives of PTW drivers, by preventing them from being overrun. The present study showed that the included active and passive safety technologies for Heavy Goods Vehicles could prevent 59% of fatalities among vulnerable road users in Sweden. The fatalities not targeted by the HGV safety technologies included in the study would need other countermeasures such as connected safety technology (e.g. V2V or V2I), infrastructure, or education.

The objective of this study is to develop a method that uses a combination of field data analysis, naturalistic driving data analysis, and computational simulations to explore the potential injury reduction capabilities of integrating passive and active safety systems in frontal impact conditions. For the purposes of this study, the active safety system is actually a driver assist (DA) feature that has the potential to reduce delta-V prior to a crash, in frontal or other crash scenarios. A field data analysis was first conducted to estimate the delta-V distribution change based on an assumption of 20% crash avoidance resulting from a pre-crash braking DA feature. Analysis of changes in driver head location during 470 hard braking events in a naturalistic driving study found that drivers' head positions were mostly in the center position before the braking onset, while the percentage of time drivers leaning forward or backward increased significantly after the braking onset. Parametric studies with a total of 4800 MADYMO simulations showed that both delta-V and occupant pre-crash posture had pronounced effects on occupant injury risks and on the optimal restraint designs. By combining the results for the delta-V and head position distribution changes, a weighted average of injury risk reduction of 17% and 48% was predicted by the 50th percentile Anthropomorphic Test Device (ATD) model and human body model, respectively, with the assumption that the restraint system can adapt to the specific delta-V and pre-crash posture. This study demonstrated the potential for further reducing occupant injury risk in frontal crashes by the integration of a passive safety system with a DA feature. Future analyses considering more vehicle models, various crash conditions, and variations of occupant characteristics, such as age, gender, weight, and height, are necessary to further investigate the potential capability of integrating passive and DA or active safety systems.

Disposal of radioactive liquid wastes through deep wells may be categorized as containment or confinement. Containment means the placement of wastes under conditions that preclude their movement out of a definable zone. Confinement means the placement of wastes in a zone where movement may take place under restricted conditions that can be controlled or monitored. Disposal of liquid wastes on a continuing basis by containment probably is not practical except for small quantities and may be possible in only a few areas. It is probable, therefore, that any deep disposal of radioactive liquid wastes will be by confinement of wastes in certain geologic zones through which they will move at measured rates. Hydrologic principles applied to the available data indicate that there is circulation of fluids in almost all sediments. Movement of fluids tends to be restricted in the basal parts of sedimentary basins, but any assumption that wastes introduced into a basin would not eventually move out of the basin or to the near-surface formations should be carefully scrutinized. Introduction of wastes into an anomalously low-pressure zone should not be considered safe unless the reasons for the low pressure can be explained. Data necessary to define the hydrodynamics of fluids injected through deep wells will be expensive to obtain, and many of them will have to be collected for each particular disposal site. Geochemical factors may influence greatly the movement of radioactive material in deep formations. A system of monitoring, and possibly removal, is a prime requisite of deep-well disposal of radioactive wastes. Initial disposal activities necessarily will be on an experimental basis pending the results of such monitoring. End_of_Article - Last_Page 2073------------

Disposal of radioactive liquid wastes through deep wells may be categorized as containment or confinement. Containment means the placement of wastes under conditions that preclude their movement out of a definable zone. Confinement means the placement of wastes in a zone where movement may take place under restricted conditions that can be controlled or monitored. Disposal of liquid wastes on a continuing basis by containment probably is not practical except for small quantities and may be possible in only a few areas. It is probable, therefore, that any deep disposal of radioactive liquid wastes will be by confinement of wastes in certain geologic horizons through which they will move at measured rates. Hydrologic principles applied to the data presently available indicate that there is circulation of fluids in almost all sediments. Movement of fluids tend to be restricted in the basal parts of sedimentary basins, but any assumption that wastes introduced into a basin would not eventually move out of the basin or to the near-surface formations should be carefully scrutinized. Introduction of wastes into an anomalously low-pressure zone should not be considered safe until or unless the reason for the low pressure can be explained. Data necessary to define the hydrodynamics of fluids injected through deep wells will be expensive to obtain, and many of them will have to be collected for each particular disposal site. Geochemical factors may influence greatly the movement of radioactive material in deep formations. A system of monitoring, and possibly removal, is a prime requisite of deep-well disposal of radioactive wastes. Initial disposal activities necessarily will be on an experimental basis pending the results of such monitoring.

<div class="section abstract"><div class="htmlview paragraph">‘Active safety systems’ are actively being developed to prevent collisions. The integration of ‘active safety systems’ and traditional ‘passive safety systems’ such as seatbelt and airbags is an important issue. The ‘Integrated safety’ performance is that comprehensively controls the performance of ‘active’ and ‘passive’ safety systems to reduce occupant injuries. To develop ‘integrated safety’ performance, it is important to develop crash scenarios for autonomous vehicles. This study is about the development of ‘Estimation Tool of Occupant Injury Risk’ for deriving risk integrated safety scenarios focused on occupant injury. The results of random traffic simulation using ‘Virtual Prototype’ were used to select parameters, and ‘MADYMO Equivalent Simplified Vehicle Crash Analysis Model’ was used to derive F-D characteristics for each vehicle collision condition. The ‘Estimation Tool of Occupant Injury Risk’ was developed through the analysis of occupant injuries using the Hyundai Active Human Model for Safety (HAHMS).</div></div>

Two types of a passive safety containment for a near future BWR with active and passive safety systems