Section 3 Risk based analysis

3.1 Purpose

3.1.1 The purpose of the risk based analysis is to:

evaluate safety considerations that are specific to the regasification and send-out equipment, see Pt 11, Ch 20, 3.2 System safety risk assessment;
evaluate dependability of the regasification plant, see Pt 11, Ch 20, 3.3 System dependability;
specially consider arrangements which deviate from the requirements of these Rules, see Pt 11, Ch 20, 3.2 System safety risk assessment.

3.2 System safety risk assessment

3.2.1 The objectives of the assessment are to:

Evaluate safety risks associated with the use of the regasification system where the requirements within the Rules are not satisfied;
Evaluate safety risks associated with the use of the regasification system where specifically required by the Rules;
for Pt 11, Ch 20, 3.2 System safety risk assessment 3.2.1 and Pt 11, Ch 20, 3.2 System safety risk assessment 3.2.1, demonstrate that an appropriate level of safety is achieved, which is commensurate with that generally accepted for the containment of LNG cargoes through compliance with these Rules.

3.2.2 Where the risks cannot be eliminated, an inherently safer design shall be sought in preference to operational/procedural controls. This shall focus on engineered prevention of failure (e.g. minimised number of connections, increased reliability, and redundancy).

3.2.3 The risk assessment may identify the requirement for safety measures in addition to those specifically stated in these Rules.

3.2.4 The scope of the risk assessment may include but not be limited to:

normal operation, start-up, normal shutdown, non-use, and emergency shutdown of the system, during:
- pressurised gas discharge to shore; high pressure gas venting;
- storage and handling of flammable or toxic secondary heat transfer fluids (as applicable);
- continuous presence of liquid and vapour cargo outside the cargo containment system;
- Barge or offshore unit-LNG transfer.
physical layout of machinery and equipment including extension of hazardous areas and evacuation arrangements;
fire and explosion, process upset conditions, over-pressure and under-pressure, mechanical and electrical failures and human error. Consideration being given to the effects of pool and jet fires;
the effect of cryogenic spills and pressurised leaks.

3.2.5 The risk assessment shall be undertaken by suitably qualified and experienced individuals to a recognised Standard (e.g. as outlined in ISO/IEC 31010-2009: Risk management – Risk assessment techniques) in accordance with LR’s ShipRight Procedure Assessment of Risk Based Designs and the associated Appendix on LNG.

3.2.6 The risk assessment shall be assessed in accordance with Pt 11, Ch 5, 8.5 Liquefied gas transfer system 8.5.2, and:

analysis of risk associated with the barge or offshore unit-to-ship LNG transfer in accordance with ISO 28460:2010 Petroleum and natural gas industries – Installation and equipment for liquefied natural gas – Ship-to-shore interface and port operations and the relevant parts of EN 1474 as applicable, and SIGTTO LNG Ship-to-Ship Transfer Guide for Petroleum, Chemicals and Liquefied Gases.
process upsets associated with the land-based receiving systems;

3.3 System dependability

3.3.1 Where Class Notation ✠Lloyd’s RGP+ is to be assigned, an assessment shall be carried out to demonstrate that a fault in any active component or system will not result in reduced availability of the plant to send-out gas.

3.3.2 The level of availability of the regasification system shall be specified by the Owner or operator, see Pt 11, Ch 20, 2.2 Systems and arrangements 2.2.2.

3.3.3 The assessment shall be undertaken by suitably qualified and experienced individuals using approaches acceptable to LR.