Abstract
Due to cryogenic and flammable nature of LNG, the LNG-fueled ships require the risk assessment for the safety designs against the release of LNG during operation. Fire is a major accident resulting from LNG leak and the rational fire protection can be achieved by considering the probability and consequence of fire, i.e., the risk of fire. However, the current fire protection of the LNG-fueled ship depends on the prescriptive approach and this may lead to an unreasonable design of the ship. The validity of the fire protection requirement has been questioned and this paper proposes the need for the risk-based design approach. An LNG-fueled product carrier is developed and uncertainty on the interpretation of a part of the fire protection requirement in the design standard is discussed. Using a quantitative assessment technique, a fire risk is estimated and the results are presented through a risk contour which is expressed as a combination of a specific fire intensity and frequencies of fire occurrence. As the result of the risk assessment study, an affordable fire protection design is adopted and the findings of this paper are summarized in relation to the needs for the risk -based fire safety design of the LNG-fueled ship.
