Section 2 Types of Risk

201. General

1. It is changed the characteristics of the risk that is to be considered by major interest of the safety assessment, i.e. the target object of the safety assessment and correspondent risk assessment criteria accordingly is changed. Therefore various types of risk can be applied in accordance with the pur- pose of approval and the contents of the subjected design.

2. Generally the type of risk is as followings. In addition to the followings, new type of risk can be defined and applied if necessary.

(1) Risk to human

(2) Risk to environment

(3) Risk to asset

3. This section prescribes risk to human and environmental risk that are considered as important risk.

However, if necessary, it may also be considered risk to asset in approval process by the consensus

of the approval team and design team.

202. Risk to human

1. Risk to human includes fatality risk and health risk for direct workers, indirect workers, passengers or other related people.

2. Usually risk to human is taken to be the risk of death and health risk are ignored or can be con- sidered in terms of the risk of death in accordance with the appropriate criteria. The equivalent fa- tality concept is applied in order to convert the health risk to the risk of death, For example, one(1) fatality and ten(10) severe injuries may be considered equal.

3. Risk to human can be divided into individual risk and social risk depending on the number of tar- get persons as following. Calculation and evaluation of the individual risk will be sufficient if con- tents of subjected design are simple and a small amount of people are associated. However, if the subjected design is complicated and a large number of people are associated, both of the individual risk and the social risk are to be calculated and evaluated.

(1) Individual risk

(A) Individual risk is respective risk when specific individual(one or several people) is exposed to the risk of danger in the particular place(work place or residence place).

(B) The purpose of estimating the Individual Risk is to ensure that individuals, who may be af-

fected by a possible accident, are not exposed to excessive risks.

(C) Individual Individual hours and

risk is to be calculated differently for each work location and work time. risk considers the individuals fractional exposure to that risk such as working operating distance. For example if an explosion is occurred in the particular place

in the ship, the individual risk for a crew in the vicinity of the explosion position will be higher than for a crew in the distance.

(D) Individual risk can be calculated quantitatively using the following formula.

ĄĎ Q Ä ∙ Ç ∙ Â

IR = Individual Risk

F = Frequency

P = Resulting casualty probability)

E = Fractional exposure to that risk)

(2) Social risk

(A) Social risk is the group risk for all individuals when entire persons(all workers and all pas- sengers, etc.), who are directly and indirectly related to the target vessel, are exposed to risk.

(B) The purpose of calculating the social risk is to understand comprehensively safety of the target design by identifying a large-scale accidents and the resulting number of deaths that

may occur.

(C) Social risk is not limited to a particular individual or a particular place and is the in- tegration of life-risk for all persons(crew, passenger, port workers and third party, etc.) ex- posed to all possible accidents that may occur at any place. That is to say that social risk is the integration result of individual risk according to a specific method.

(D) Social risk may be calculated with respect to each incident type and also be represented for the entire target design with a combination of social risk for all types of accident.

(E) Social risk is mainly indicated as the risk of death, i.e., fatality risk and can be quantita- tively represented by the following method.

(a) FN curve(frequency-fatality curve)

(i) FN curve is a diagram continuously indicated the

accident deaths of more than N that has occurred. relationship between the fatality N and cumulative

excess cumulative probability of

In other words, it is shown the probability F of the accident in

which the number of fatalities can be N or more. For example, F at N=1 is probability of entire fatality accident.

(ii) FN curve is made by calculating the number of deaths taking into account all hazards and accident scenarios in a sequence. It can be effectively represented

social risk.

(b) Potential loss of life(PLL)

the

the the

(i) The potential loss of life is defined as the estimated number of annual deaths(fatal-

ity per ship-year), which is simply summed all human risk(risk of death) of the ac- cidents that may occur.

(ii) The potential loss of life has the benefit of being able to indicate the social risk simply and clearly than FN curve but it is not able to figure out the relative im-

portance of individual accidents. For example, the single accident that kills 1,000 people and 1,000 accidents that kill a single person has a same risk level in accord- ance with potential loss of life. Attention is to be paid in this regard when using

PPL.

4. In order to ensure sufficient life safety for the design, not only required reduction of the average integrated risk to human but also necessary to reduce the maximum individual risk is necessary. Therefore, all risks can be fully understood and controled when usually considering the individual risk and social risk simultaneously.

203. Risk to environment

1. Risk to environment is the factors that may affect the ecosystem, i.e., it is mainly the risk to the safety of environmental protection against pollution.

2. Since the results of the accident regarding the atmosphere and ocean pollution is very broad and complex, it is difficult to estimate the exact damage scale. Therefore, precautionary principle is most effective to reduce the risk to environment by removing the hazards that may cause environ- mental pollution.

3. The main sources of material that is to be ship is as follows.

(1) Discharge during ship operation

considered when dealing with the environmental risk of

(A) Exhaust gas (CO2, NOx, SOx,

(B) Sewage and wastewater

(2) Cargo

(A) Grain

(B) Coal and Minerals

(C) Oil

(D) Refinery petroleum products

(E) Toxic liquids and chemicals

(F) Radioactive material

etc)