What is used to calculate the threshold for evaluating the cost benefit ratio of a given countermeasure?

Repair techniques

Countermeasures are implemented to satisfy performance requirements, based on the results of evaluation and judgment. Countermeasures include stricter inspections, service restrictions, repair of the FRP system, additional upgrading, improvement of appearance, and dismantling and disposal. For minor deterioration, countermeasures should consist primarily of stricter inspections and repair of the FRP system. The method selected should depend on the deterioration mechanism and the extent of changes observed. However, JSCE suggests the following for consideration. For swelling, peeling, and lifting, resin fill can be used, while for cracking, wearing, and erosion, patching can be used. When serious deterioration or deterioration over a wide area is observed, additional FRP upgrading should be performed. In such cases, the existing FRP should be removed and the upgrading plan reexamined.

To implement suitable maintenance, the results of design, construction, inspection, evaluations and judgments, repairs, additional upgrading, and so on, are to be recorded and the records maintained. The ease of maintenance is affected by the upgrading plan and by design and construction. More specifically, the placement of access paths to the structure that allow inspection and monitoring equipment affects ease of maintenance. For this reason, it is recommended to give thorough consideration to maintenance considerations in the upgrading plan, as well as in design and construction.

4.2.2.1 Hints for countermeasures

Countermeasures to avoid bellows vibrations due to fluid flow are described next. When the mean flow velocity through the bellows is roughly higher than 0.75 times the critical velocity, vibrations can be expected. Countermeasures include the following:

Changing the flow rate so that the mean flow velocity through the bellows falls below the critical velocity.

Addition of a straight length section between an elbow and the bellows, when the bellows are installed downstream of an elbow and the straight length is not long enough.

Shifting the mechanical natural frequency of the bellows so that the critical velocity may be higher than 1.33 times the mean velocity of the bellows.

Eliminating the creation of free shear layers from the bellows convolutions by installation of sleeves within the bellows. The sleeve thickness should be determined carefully considering flow conditions. Corrosion should also be considered because stagnation regions are created between sleeves and bellows.

4.1.2.2.1 Countermeasure

Countermeasure to prevent the bypass flow was considered and taken as shown in Fig. 4.3. The concept of the countermeasure is to minimize the pressure drop between A and B in Fig. 4.2. For this purpose, square holes were bored on the side of the guide pipe for the control rod support cable and new holes for coolant paths were bored in the top plate of the control rod guide tubes as designated new openings. For controlling the flow rate of the primary coolant in the control rod guide block column, the multistage orifice was installed along the path for the control rod support cable instead of the orifice in Fig. 4.2. It was considered that the bypass flow could be prevented.

At the same time, the gaps of the components for the control rod drive mechanism were sealed by synthetic rubber gaskets so that paths for leakage flow of helium gas are reduced and that most purge gas flows downward between the standpipe and the control rod guide sleeve as shown in Fig. 4.3. The purge gas works not only for cooling the control rod drive mechanism but also for preventing the bypass flow and cooling the standpipe.

3.07.4 Hazards and Disasters

Natural disasters have a long historical record. Plato in his dialogue Timaeus and Critias (360 BC) described that Atlantis (the island of Atlas) sank into the ocean in ∼9000 BC “in a single day and night of misfortune.” This information was confirmed by reading the Egyptian hieroglyphs and was disseminated by the lawmaker Solon.

Although the terms hazard and disaster have an overlapping meaning in everyday life, they are assumed to have different meanings here.

Hazard is a probability of a natural event that might cause harm and should be estimated by experts, whereas disaster is the output of a hazard and might be estimated by a multidisciplinary team of experts.

The risk exposure is a function of the population and assets in a given area.

Countermeasures to reduce vulnerability can be classified according to World Bank:

Mitigation (to minimize GHG emissions so as to minimize extreme weather events)

Prevention (to build a plinth-wall for floods)

Preparedness (to plan building evacuations)

Relief (to help people after a disaster)

Finally, disaster risk is a multiplication of hazard, exposure, and vulnerability.

Total disaster impact is the sum of direct and indirect effects. Direct disaster impacts can be estimated in terms of human and capital loss. Indirect disaster impact in an economy is more complicated to estimate because it deals with the changed structure of the economy (e.g., production, consumption, employment) after the disaster.

Other socioeconomic factors are extremely important to gauge total disaster impact. The level of development of a nation is critical for the absorption of disasters. For example, Haiti’s last earthquake was less on the Richter scale than Chile’s last earthquake, but damage absorption was much better in Chile than in Haiti.

The development of the theory of economics on natural disasters since the seminal work of Dacy and Kunhreuther (1969) has been modified and directed to the economics of climate (Nordhaus 2006; Stern 2007).

The insight of this research-evolution is that global warming might be the cause of most natural disasters. The empirical work for the effect of natural disasters on national economies in terms of capital and human losses has been increased in the last 20 years (Alexander 1997; Cavalo and Noy 2009).

Although there is no widely accepted definition of natural disaster, the CRED definition from Belgium is used here:

Situation or event which overwhelms local capacity, necessitating a request to national or international level for external assistance; an unforeseen and often sudden event that causes great damage, destruction and human suffering.

Preventing disasters means using policies that minimize exposure and vulnerability to human suffering and destruction. Exposure relates to the people and property subject to hazard. It is a function of population density and location indicators.

These three factors determine how some communities can absorb disasters and recover more easily than others.

Natural disasters can be classified into three categories:

Hydro-meteorological: floods, droughts, landslides

Geophysical: earthquakes, volcanic eruptions

Biological: epidemics

The severity and frequency of disasters in the last several decades have generated an increased interest in data and methodologies to better understand disaster complexity. Disaster impact on the development and growth of nations became an important issue for investigation.

The prediction of disasters has been one of the main themes for many research works in social and natural sciences. Ongoing improvement in data quality may lead to increased disaster prediction accuracy.

Disaster issues have been investigated by both natural and social scientists (mainly economists, sociologists, and political scientists) in an interdisciplinary way. A more holistic disaster approach has been conducted by scientists lately, which is very promising.

Finally, a ‘before the disaster’ policy can be exemplified by the reallocation of the Tokyo metropolitan area. A review of this is given in Section 3.07.6.

Public policy makers need more quantitative data so as to assess disaster risks and generate preparedness and mitigation planning.

Establishing the Budget

The security budget has three dimensions: countermeasure determination, prioritization, and phasing.

Countermeasures Determination

Appropriate countermeasure selection is a process that involves the following steps, which are from the NIST 780 American Petroleum Institute (API) risk analysis methodology. This methodology is one of the most complete and straightforward to use, and it allows for a financial and risk calculation that is most thorough as well as allowing for stakeholder input into the process1:

•

Define the assets to be protected and characterize the facility where they are located. Facility characterization includes a complete description of the environment, including the physical environment, security environment, and operational environment. Determine the criticality of each major asset and the consequences of the loss of the asset. Consequences can be measured in loss of life or injury, loss of monetary value, environmental damage, and loss of business or business continuity.

•

Perform a threat analysis. Define both the potential threat actors and the threat vectors (methods and tactics that the threat actors may use to gain entry or stage an attack). Threat actors may include terrorists, activists, and criminals. Criminals may be either economic criminals or violent criminals, such as those who cause workplace violence. Rank the threat actors’ motivation, history, and capabilities. Rank the threats by their ability to harm the assets using the previous criteria.

•

Review the basic vulnerabilities of all the protected assets to the types of attacks common to the declared threat actors.

•

Evaluate the existing and natural countermeasures that are already in place or in the existing design of the building or its site. For example, does a storm levy make vehicle entry more difficult? Is existing lighting a deterrent? The difference is the remaining vulnerabilities to protect.

•

Determine the likelihood of attack:

○

Determine the probable value of each of the assets to the probable threat actors (asset target value calculation).

○

Likelihood = threat ranking × asset attractiveness × remaining vulnerabilities.

•

Calculate the risk of attack: Risk = consequences × likelihood.

•

Determine additional countermeasures needed to fill the remaining gap in vulnerabilities prioritized by the risk calculation previously (Fig. 8.1).

Figure 8.1. API/NPRA risk calculation.

•

Determine from what resources the additional countermeasures can be sourced.

11.7.5 Construction of deep foundations

The time taken for construction of deep foundations for both conventional and ABC methods is not likely to change. For example, drilling of piles cannot start unless demolition of the existing foundations has been completed. The alternative is to use staged construction and perform demolition in stages. Provision of shielding by riprap or using structural countermeasures is desirable, even for deep foundations that may become exposed during peak floods (Figure 11.7).

In the case of long piles, countermeasures will not be required unless the bridge is located close to a sea front or on a highly scourable river.

Minimum countermeasure requirements in lieu of deep foundations: If the projected (computed) scour is small or negligible, theoretically design of a formal countermeasure will not be required. Such cases are:

When a spread footing is located or placed on bedrock or when a spread footing is located or placed below the total scour depth

When an additional pile length equal to the projected scour depth is provided

When pile stiffness exceeds the minimum required and the exposed length of pile due to erosion can safely act as a long column

Although minor surface erosion of soil will not cause a danger to footings, a soil cover or protection to the concrete footing or piles is still required. An adequate soil cover needs to be maintained for:

Frost resistance (minimum frost depth requirement)

As-built cosmetic appearance

Unforeseen error in the scour analysis data or computations

There are several countermeasures used for protection of bridge abutments by different state Departments of Transportation and federal agencies. Two typical approaches for protecting bridge abutments from scour are:

Mechanically stabilizing the abutment slopes with riprap, gabions, cable-tied blocks, or grout-filled bags

Aligning the upstream flow by using guide banks, dikes, or spurs, or in-channel devices such as vanes and bendway weirs

3.3 Evaluation of the effects of measures taken against the thermal environment on space utilization [33]

If countermeasures against heat are taken as an adaptation measure and a comfortable environment can be created in a thermal environment, people can actively use outdoor spaces even in a thermal environment.

Therefore, we investigated the relationship between the thermal environment and space utilization by people. The survey was conducted in a thermal environment with residents on four benches in an outdoor plaza. Two of the four benches were used as measures against the thermal environment (Fig. 2.22), and the remaining two were each located under the sun and the shade.

Fig. 2.23 shows the changes in the SET∗ indicating the measurement results of the thermal environment. Compared to the sun, the location of the benches as countermeasures and the one in the shade had a lower SET∗, confirming the effect of thermal countermeasures.

As the numbers of bench users vary depending on the time of the day, it was difficult to capture trends common to all time zones. Therefore, a standardization was performed, and the number of standardized users was calculated. The standardized number of users is the ratio of the average number of users in a certain place/time zone. Furthermore, the probability density distribution and the probability function were approximated from the relationship between the obtained SET∗ and the number of standardized users. The calculation results are shown in Fig. 2.24. It can be seen that this space was easy for humans to use when the SET∗ fell below 30°C. According to the results at 12:00 on the survey day, the SET∗ was reduced by about 5°C from 35.0°C in the sun by implementing measures against the heat, increasing the number of standardized users by 0.76. Considering the average number of users at 12:00, an increase of 1.40 users per minute could be expected.

From the results, the relationship between the thermal environment and the number of users indicates the possibility of promoting the study and implementation of heat countermeasures for the purpose of promoting the use of space.

Mine Countermeasures Vessels

Mine countermeasure ships may be either sweepers or hunters of mines, or combine the two functions in one hull. Modern mines can lie on the bottom and only become active when they sense a target with quite specific signature characteristics. They may then explode under the target or release a homing weapon. They may only react after a selected number of ships have passed nearby or only at selected times. All these features make them difficult to render harmless.

Sweeping mines depend upon either cutting their securing wires or setting them off by simulated signatures to which they will react. The latest mines have been developed to the point where they are virtually unsweepable. They need to be hunted, detection being usually by a high-resolution sonar. They can then be destroyed by placing a small charge alongside the mine, usually laid by a remotely operated underwater vehicle, and setting it off. Because mine countermeasure vessels themselves are a target for the mines they are trying to destroy, the ship signatures must be extremely low and the hulls very robust. Nowadays hulls are often made from glass reinforced plastic and much of the equipment is specially made from materials with low magnetic properties.

3.2 The efforts by Osaka HITEC

Osaka Heat Island Countermeasure Technology Consortium (HITEC) was established in January 2006, for the purpose of the development and spread of heat island countermeasure technologies, implementation of measures and verification of their effects, and the collaboration between industry, academia, government, and the private sectors [15]. The consortium called on local governments, private companies, universities, research institutes, environmental NGOs, and NPOs to participate. The consortium has five working groups (WGs); WG related to the materials, WG on heat utilization and reduction of anthropogenic heat release, WG on cool spot creation technologies, WG on thermal load evaluation method, and WG on urban design.

Osaka HITEC started the certification system of heat island measures technology in October 2011. In 2019, the category of certification technology increased to nine; high solar reflectance paint for roof, high solar reflectance pavement (excluding for roadways), high solar reflectance waterproof sheet (membrane), high solar reflectance roofing materials (tile, slate, metal, etc.), water-retaining pavement block, external insulation specification for roof, external insulation specification for outer wall, retroreflective high solar reflectance outer wall material, and retroreflective high solar reflectance window film. Three high solar reflectance paints for roof, five high solar reflectance pavements (excluding for roadways), three high solar reflectance roofing materials, one external insulation specification for outer wall, and one retroreflective high solar reflectance window film were certified [15].

Osaka HITEC has also held town planning ideas competition in consideration of the heat islands measures, recruitment and selection of cool spots and cool roads, and technology seminars.

Osaka HITEC is currently working on evaluation and implementation of adaptation measures against extreme heat. Several adaptation technologies have been developed by various companies and their evaluation methods were discussed so that they may be properly implemented in society. Adaptation measures for urban heat islands and their effects and associated evaluation indices are organized. A simple method to evaluate the adaptation measures is examined focusing on their appropriate introduction in urban space. Osaka HITEC is promoting the following three activities; organization of adaptation measures, examination of specific image of adaptive city, and examination of evaluation method of adaptive city. In this book, the results of above activities are organized. The table of contents and the outline of this book are as follows.

Background and purpose (by Prof. Takebayashi and Prof. Moriyama): Various approaches related to adaptation measures, for example, adaptation city in Karlsruhe and countermeasure guideline for heat in the urban area by Ministry of Environment of Japan are reviewed.

Adaptation measures and their performance (by Prof. Takebayashi, Prof. Misaka and Dr. Akagawa): Adaptation measure technologies listed in the guideline of Ministry of Environment are reviewed. These technologies are evaluated using indicators such as solar transmittance and solar reflectance.

Priority introduction place “hot spot” of adaptation measures (by Prof. Takebayashi): The relationship between urban morphology and solar shielding and urban ventilation is described. The appearance of hot spots in various urban blocks is presented.

Case study of adaptation city (by Prof. Masuda, Prof. Nishimura, Prof. Nabeshima, Mr. Shiba and Dr. Akagawa): Case studies of adaptation cities are introduced for various urban blocks.

Evaluation method of adaptation city (by Prof. S. Yoshida, Prof. A. Yoshida and Prof. Kinoshita): The method of human thermal environment assessment is explained. A method for simulating the thermal environment of an adaptive city is explained.

The role of local government (by Dr. Masumoto): In discussing adaptation cities, the role of local government is described.

Summary (by Prof. Takebayashi and Prof. Moriyama): Strategies for introducing adaptation measures are stated.

23.28.3 Some hazard assessments

As already described, there have been a considerable number of hazard assessments for marine transport, covering shipping, ports and terminals.

An early generic study was that given in the vulnerability model by Eisenberg, Lynch and Breeding (1975), as described in Chapters 16–18Chapter 16Chapter 17Chapter 18.

A hazard assessment of marine transport at an oil terminal at the Deep Water Port, Galveston, Texas, has been described by Bergmann and Riegel (1983). The scenarios considered were collisions and groundings, giving rise to a fire or explosion.

The authors’ estimates of the frequencies and probabilities of these events are as follows. The frequencies of collision and grounding are estimated, respectively, as 1.5 × 10−4/movement and 3.5 × 10−4/movement, and the probabilities, given collision, of spill, fire and explosion as 0.25, 0.33 and 0.1. They give the following figures: They take as negligible the probability that, given a soft bottom with no hard underwater object, a grounding would result in a spill or fire.

The authors found that for collisions only one in 23 spills resulting in fire propagated into an explosion, but that all explosions had resulted in spill and fire. Records indicate that where an explosion occurs, between 29% and 94% of the cargo tanks become involved, but that where a fire occurs some 10–13% of the cargo is spilled and burned. They take the proportion of cargo involved as 36% for an explosion and 12% for a fire.

Bergmann and Riegel have developed event trees for the three scenarios of collision, grounding and dockside fire/explosion. They assess the effects of explosion using the methods of W.E. Baker et al. (1978), including correlations of overpressure vs scaled distance for a fuel-air explosive and of damage in terms of the pressure–impulse diagram. For fire, the treatment is largely concerned with firefighting and mitigatory measures, and appears essentially qualitative.

The two Canvey Reports, described in Appendix 7, cover marine risks, including collision, grounding and loading/unloading, and give a full assessment of individual and societal risks.

A further hazard assessment of marine transport at the British Gas LNG terminal at Canvey is described by Lucas, Rowe and Waterlow (1983). This study details the various hazard scenarios, as described in Section 23.28.1, and gives an engineering assessment of each one. As a result of this assessment, some postulated scenarios are rejected, whilst others are accepted and countermeasures are described. For example, it is concluded that failure of the bellows expansion units in the ship–shore transfer line would be manifested by a small crack rather than sudden rupture, and that the latter is not a credible failure mechanism. Likewise, major failure due to low temperature brittle fracture following LNG spillage on the ship's deck is discounted. Further, a fire on deck or on the sea is not expected to cause failure or overpressure of the inner hull. On the other hand, the authors do consider to be credible explosions in the ballast space or, with ingress of flammable vapour, in the engine room. They describe various measures taken to counter these hazards such as improved emergency shut-down, deck protection and engine room explosion relief.

One countermeasure described is to arrange that in operation the man-way hatches to each ballast tank are closed, though not secured. This, it was calculated, would allow sufficient pressure to build up as the first LNG entering the tank vaporizes that further entry of LNG through cracks would be inhibited. This is an example of the exploitation of the characteristics of the initial event to prevent escalation.

The authors comment that whilst a full quantitative risk assessment (QRA) has its place, in many instances, most of the benefits may be obtained from the detailed engineering analysis which should in any case be part of a good QRA. It is often more fruitful to put effort into discovering unidentified problems rather than into quantifying those already identified. This should be done in cooperation with the engineers involved in the design and operation of the system.

The ACDS Transport Hazard Report gives a set of hazard assessments for specific ports and utilizes this to obtain an assessment of national societal risks.