SAFETY REQUIREMENTS FOR CARRIAGE OF LIQUEFIED HYDROGEN IN BULK. Risk assessment of liquefied hydrogen carriers. Submitted by Japan SUMMARY

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1 E SUBCOMMITTEE ON CARRIAGE OF CARGOES AND CONTAINERS rd session Agenda item 4 CCC /INF.0 July 06 ENGLISH ONLY SAFETY REQUIREMENTS FOR CARRIAGE OF LIQUEFIED HYDROGEN IN BULK Risk assessment of liquefied hydrogen carriers Submitted by Japan SUMMARY Executive summary: This document introduces the outline of the risk assessment of liquefied hydrogen carriers conducted by Japan Strategic direction: 5. Highlevel action: 5.. Output: Action to be taken: Paragraph 7 Related documents: CCC /4; CCC /4 and CCC /4/ Background In the Correspondence Group on Development of Safety Requirements for Carriage of Liquefied Hydrogen in Bulk, it was recommended by some participants to conduct a risk assessment of liquefied hydrogen carriers prior to the development of the safety requirements for such ships. Japan considers that the risk assessment should be conducted in the design spiral. Hazard Identification studies As part of the safety risk assessment, Hazard Identification (HAZ) studies were carried out using a preliminary design of liquefied hydrogen carrier based on the existing LNG carrier technologies, practices and the revised IGC Code requirements, to identify additional hazards for liquefied hydrogen carriers in the Front End Engineering Design (FEED) stage. For the purpose of the studies, it was assumed that Gas Combustion Units (GCUs) would be permitted by the Administration.

2 Page The HAZ studies were performed using two different approaches and with participants from different areas of expertise to cover all the potential hazards. As a result of the risk assessment (i.e. HAZ) several hazards were identified, some of which were found to require additional risk reducing measures. The outline of the HAZ is set out in the annex to this document. 4 A detailed analysis of these additional measures was conducted at a later stage separate from the HAZ studies. The outline of the analysis is set out in the annex. Findings 5 This analysis revealed that, while most of the additional measures were properly covered by the special requirements proposed in the annex to CCC /4, an additional risk reducing measure to minimize the number of bolted flange connections of hydrogen piping could be incorporated into the draft interim recommendations for carriage of liquefied hydrogen in bulk. 6 Furthermore, through the analysis, it was found that the following issues can be incorporated into the draft interim recommendations as the items to be considered in the risk assessment at the design stage:. venting release scenarios which might catch fire by lightning to be identified;. fire suppression system (e.g. snuffing system) of vent mast for fire by lightning to be investigated;. LNG numerical models for liquefied hydrogen release scenarios to be verified for elimination of sources of ignitions;.4 Human Factor Engineering for designing access route to critical equipment;.5 theoretical assessment on Boiling Liquid Expanding Vapour Explosion and Rapid Phase Transitions to be investigated;.6 congestions of piping (turbulence which may cause detonation) Compressor house/pipe racks/pressurized Gas Combustion Unit to be studied; and.7 implication of small volume spill on Emergency Shut Down disconnection to be considered. Actions requested of the SubCommittee 7 The SubCommittee is invited to note the outline of the risk assessment set out in the annex. ***

3 Annex, page ANNEX OUTLINE OF THE HAZARD ENTIFICATION STUDIES OF LIQUEFIED HYDROGEN CARRIERS AND ANALYSIS Introduction Kawasaki Heavy Industries, Ltd. has been in charge of research and development of a,500 m liquefied hydrogen carrier, which is expected to be the first vessel to carry bulk liquefied hydrogen in the world. As part of the safety risk assessment, Hazard Identification (HAZ) studies were carried out using a Front End Engineering Design of liquefied hydrogen carrier based on the existing LNG carrier technologies, practices and the IGC Code requirements, to identify additional hazards for liquefied hydrogen carriers in the Front End Engineering Design stage. The HAZ studies were performed by two different approaches with participants from different areas of expertise to cover all the potential hazards. The primary purpose of the first HAZ study was to identify and classify potential hazards. For this purpose, brainstorming was conducted to identify cause, location and consequence related to the cargo handling system and cargo containment system in each operational stage with a particular focus put on the differences in the physical features of cargoesrelated systems of conventional LNG carriers and the project liquefied hydrogen carrier. This HAZ study was performed under the premise that the requirements in the revised IGC Code and the draft requirements proposed in the annex to document CCC /4 were satisfied. The purpose of the second HAZ study * was to enumerate wider hazards based on the knowledge of experts to the fullest extent possible. For this purpose, another brainstorming was conducted to identify hazards associated with onshore facilities, e.g. mooring system, loading arm system, and natural hazards, e.g. earthquake, lightning, more extensively by a small number of experts, without considering the above mentioned requirements in the Code and the annex to document CCC /4. After the second HAZ study, the safety measures identified in the study were compared with the above mentioned requirements. Then additional safety measures which may be incorporated into the draft interim recommendations were identified. First HAZ study. Participants The first HAZ study was held from 5 to 7 of October 05, attended by the following experts from various fields related to seaborne carriage of liquefied gas in Japan: From ClassNK Consulting Service Co., Ltd.: Facilitator (expert in risk assessment); and A secretary; From Nippon Kaiji Kyokai (ClassNK): An expert in ship hull design; An expert in cargo containment system; and An expert in cargo handling systems; * This HAZ study was conducted as part of Shell's riskbased approach associated with liquefied hydrogen project (ship & terminal)

4 Annex, page From Japan Marine Science Inc.: Three experts in the deck operation of gas carriers (including a captain); From National Maritime Research Institute: Three experts in risk analysis; From Kawasaki Heavy Industries, Ltd.: Eight experts in ship design; Two experts in risk assessment; and An expert in cryogenic engineering. Some more members from Kawasaki Heavy Industries, Ltd. attended the study for the explanation on the Front End Engineering Design and its operation.. Scope of study A,500 m liquefied hydrogen carrier, as illustrated in Figure, was utilized as a baseline specification for hazard identification and risk evaluation. The main particulars of the vessel were as follows; Ship principal particulars Dimensions: Gross tonnage: Maximum continuous output: Speed: Persons on board Endurance L PP : m x B: 9.00 m x D: 0.60 m abt. 8,000 tons,650 kw x 40 rpm abt..0 knots (including 50% sea margin) 5 persons abt. 0,000 nautical miles Cargo containment system Total capacity:,500 m (No. & No. :,50 m each) Tank type: IMO independent cylindrical type C Max. design pressure: 0.4 MPaG Min. design temperature: 5 C (0 K) Tank material: Austenitic stainless steel Insulation system: Vacuum insulation + panel pnsulation Press. & temp. control system: Pressure accumulation. Procedures of study In the study, so called "SWIFT", i.e. Structured What If Technique, which is commonly utilized for this kind of study in various industries, was applied. The procedures utilized in the HAZ were; Step Define area of assessment Step Brief the design/operation of the area Step Identify possible hazards by brainstorming for each operational stage Step 4 Consider possible consequences based on existing safeguards Step 5 Assign frequency and severity of each hazard Step 6 Evaluate whether or not additional safeguards are needed Step 7 Record the discussion

5 Annex, page Relevant hazards were discussed by considering various hazardous scenarios in the following operational stages one by one during the study:. Loading;. Seagoing;. Unloading;.4 Dock in; and.5 Dock out; These operational stages were further classified into 'Study nodes' (i.e. substages) based on the sequence of each cargo operation to promote the efficiency of the study as shown in figure. Guidewords shown in table were used to aid the identification of hazards. The frequency and severity of each hazard scenario identified were evaluated, and indices of frequency (FI) and severity (, and risk ranking matrix were determined based on the scale given in table, table and figure respectively. To evaluate frequency of each scenario, statistical incident data of maritime and oil and gas industries were used. The risk of each scenario was evaluated to determine the necessity of additional risk reducing measures..4 Results Table 4 shows the hazards identified in the study. Figure 4 shows the risk category of each of these hazards. Second HAZ study. Participants The second HAZ study was held from to 4 December 05, attended by the following 7 experts of liquefied natural gas carriers: From Shell International Trading and Shipping Company Limited: Facilitator (expert in risk assessment); An expert in cryogenic engineering; An expert in instrumentation and control engineering; and Two experts on the deck operation of gas carriers (including a captain); From Nippon Kaiji Kyokai (ClassNK): An expert in ship hull design; An expert in cargo containment system; and An expert in cargo handling systems; From Kawasaki Heavy Industries, Ltd.: Six experts in ship design; Two experts in risk assessment; and An expert in cryogenic engineering; IHS Maritime World Casualty Statistics; Offshore reliability data.

6 Annex, page 4. Procedures of study In this study, 'SWIFT' was applied as described in section. considering various scenarios in the operational stages in figure. The following guidewords in addition to those in table were used: Natural and environmental hazards Extreme weather conditions (e.g. wave, wind, temperature, snow, blizzards, fog) Lightning Earthquake Manmade hazards (terrorism, security threat) Environmental impact of facilities to the environment The definitions of Frequency Index (FI), Severity Index ( and risk ranking matrix, which are Shell engineering standard, are shown in table 5, table 6 and figure 5, respectively. According to Shell engineering standard, those identified as "S: SERIOUS" and "H: HIGH" in figure 5 are recommended to reduce the risk to "M: MEDIUM" or lower.. Results In the study, 89 hazards were identified as listed in table 7. Figure 6 shows the hazard risk rankings determined after the HAZ study based on the above mentioned definitions without taking into account any safety measures in the revised IGC Code and the annex to document CCC /4. 4 Analysis of results of HAZ studies 4. Result of Correspondence Group Special requirements Nos. to were proposed in the annex to document CCC /4, prior to the establishment of the Correspondence Group on Development of Safety Requirements for Carriage of Liquefied Hydrogen in Bulk (CG). Then, draft special requirements Nos. to 7 were proposed in the CG as set out in the annex to document CCC /4. 4. First HAZ study The risk reducing measures identified in the first HAZ study were compared with the draft special requirements proposed in the CG. Table 8 shows the result of comparison. In this table SR No. means the number of the draft special requirements proposed in the CG. As shown in the table, no additional requirements were identified. 4. Second HAZ study The risk reducing measures identified in the second HAZ study were analysed in relation to the safety requirements in the revised IGC Code and in the annex to document CCC /4, for the reason that the safety requirements had not been considered in the second HAZ study. Through the analysis, risk reducing measures additional to the safety requirements were identified. The additional risk reducing measures were compared with the draft special requirements proposed in the CG. Table 9 shows the result of comparison.

7 Annex, page 5 As shown in the table, the following risk reducing measure is not covered in the result of the CG: Reducing number of flange connections (preferable for more welded pipe systems) to be considered for hydrogen leakage. Therefore, the following new special requirement can be incorporated into the draft interim recommendations: Minimize number of bolted flange connections of hydrogen piping. The following are deemed as the issues to be considered in the risk assessment at the design stage required by SR No.5: Venting release scenarios which might catch fire by lightning to be identified. Fire suppression system (e.g. snuffing system) of vent mast for fire by lightning to be investigated. LNG numerical models for liquefied hydrogen release scenarios to be verified for elimination of sources of ignitions. Human factor engineering for designing access route to critical equipment. Theoretical assessment on boiling liquid expanding vapour explosion and rapid phase transitions to be investigated. Congestions of piping (turbulence which may cause detonation) compressor house/pipe racks/ pressurized gas combustion unit to be studied. Implication of small volume spill on Emergency Shut Down disconnection to be considered. Therefore, the above mentioned issues can be incorporated into the draft interim recommendations as the items to be considered in the risk assessment at the design stage required by SR No.5 Figure : General arrangement

8 Annex, page 6. Unloading 4. Dock in Unloading Warm Up Piping Cool Down Drain off / Purge Inerting (GH > GN) Tank Pressure Drop off Aeration (GN > Air). Seagoing Laden Voyage Ballast Voyage Dry Dock*. Loading 5. Dock out Tank Pressure Drop off Inerting (Air > GN) Piping Cool Down Ballast Voyage* Drain off / Purge Tank Cool down Gassing Up (GN > GH) Loading Initial Cool Down * not considered in these studies Figure : Operational stages and study nodes (common to the first and the second HAZ studies)

9 Frequency Index (FI) CCC /INF.0 Annex, page 7 6 H H H H 5 M H H H 4 M M H H M M M H L M M M L L M M 4 Severity index ( Notes: H: High Risk shall be reduced M: Medium Risk should be reduced as reasonably practicable L: Low No risk reduction measures are required. Figure : Risk ranking matrix (first HAZ study) Frequency Index (FI) , 8, 6, 6,,, 4,,, 54, 55 7, 0, 6, 9, 0,,, 9, 40, 48, 50,, 0, 5, 6, 4 5, 4, 56 8, 9, 4, 7, 5, 8, 6 4, 6, 7 4 Severity Index ( Figure 4: Risk category of each hazard (first HAZ study) Frequency Index (FI) E L M H S S S D L M H H S S C L M M H H S B L L M M H H A L L L M M H Severity Index ( Notes: S: SERIOUS Identify and implement controls and recovery measures to reduce risk to ALARP and provide a document demonstration of ALARP by a bowtie or equivalent methodology. H: HIGH Identify and implement controls and recovery measures to reduce risk to ALARP. M: MEDIUM Manage for continuous improvement through the effective implementation of the HSSE management system. L: LOW Manage for continuous improvement, although businesses may set lower priority for further risk reduction. HSSE Health, Safety, Security and Environment Figure 5: Risk ranking matrix (second HAZ study)

10 Annex, page 8 Frequency Index E D 48 C B,,,, 87 5, 40, 67, 68 90, A 57, 80, 8, 5, 75 84, 85 9, 4, 45, 7, 7, 74, 77 0, 46, 47, 49, 70, 7, 78 4, 7, 8, 9 6, 8, 5, 9, 6 50, 5, 54, 55, 58, 59, 60, 6, 6, 64, 76 4, 7, 8, 9,, 6, 7, 8,, 6, 4, 5, 6, 4, 5, 56, 65, 79, 8, 86, 9 66, 69, 8 88, 89 0, 7, 0,,,, 4, Severity Index Figure 6: Risk ranking matrix without safety measures (second HAZ study) Table : Guidewords used for identification of hazards (first HAZ study) LH CH FGH DH EFH HE Guidewords Layout hazards Gas dangerous zone Ignition source Access/maintenance Escape/evacuation/rescue Cryogenic hazards Low temperature property changes Low temperature embrittlement Thermal contraction Cold burn Flammable gas/liquid hazards Flammable limit Dispersion Fire (flash, jet and pool fire) Explosion Asphyxiation Deterioration hazards Vacuum Erosion and corrosion Equipment failure hazards Leakage (e.g. piping/valve/flange/diaphragm/gasket/seal) Instrumentation air/hydraulic Sensors Control System Human errors Operational error Lack of maintenance

11 Annex, page 9 Table : Definition of Frequency Index (first HAZ study) FI Frequency Definition (per ship year) 6 Occurs several times per year per ship 0 < P 5 Occurs several times per year per operator 0 < P < 0 4 Has been experienced by most operators 0 < P < 0 Some accidents have occurred in the industry 0 4 < P < 0 Never heard of in the industry 0 5 < P < 0 4 Failure is not expected P < 0 6 Table : Definition of Severity Index (first HAZ study) SI Severity 4 Catastrophic Severe Significant Minor Definition Effect on humans (conversion to death toll) Effect on the vessel (required repair) Multiple fatalities Total lost (0 ) (in dock) Single fatality or multiple Severe damage severe injuries (0 0 ) (in dock) Multiple or severe injuries Nonsevere ship damage (0 ) (at berthing) Single or minor injuries Local equipment damage (0 ) (on board)

12 Annex, page 0 Table 4: List of identified hazards (first HAZ) Hazard Guide Possible Cause (FI/ word consequences Measures (Prevention) Operational stage: Loading Loading (Ship / Shore interface procedure after berthing) Manifold of HE Gas sampling during cargo line FGH manifold purging Residual GH Observation of (FI:,SI:) Operation Manual Insufficient manifold purging by GN due to misoperation when disconnecting the cargo piping after unloading GH leakage from shore connection around loading station when a blind flange is disconnected Formation of flammable atmosphere due to GH leakage Risk of gas ignition if ignition source is within flammable atmosphere Measures (Mitigation) Hazardous area to be designed around manifold including provision of safety apparatus to prevent thermal or mechanical explosion Dry chemical powder fireextinguishing system to be installed Water spray system to be installed Portable gas detector to be provided Personal protection equipment to be provided according to ISO/TR 596 requirements Risk Reducing Measures In accordance with ISO/TR 596, the Operation Manual shall state that generally a hydrogen fire is not extinguished until the hydrogen source has been eliminated, because of the danger of ignition of a large combustible cloud that could form from the unburned hydrogen Operation manual shall state that cleaning and purging of the manifold should be carried out periodically during voyage

13 Annex, page Hazard Guide Possible Cause (FI/ word consequences Measures (Prevention) Manifold of hot HE Same as GH leakage from shore Observation of GH line FGH connection around Operation Manual Residual GH loading station when a (FI:,SI:) blind flange is disconnected Formation of flammable atmosphere due to GH leakage Risk of gas ignition if ignition source is within the flammable atmosphere Operational stage: Loading Manifold Purging (Air to N Gas) No specific hazards are identified, for the reason that the operation is the same as the operation of LNG. Operational stage: Loading Manifold Purging (N Gas to Hot H Gas) No specific hazards are identified, for the reason that the operation is similar to the operation of LNG. Operational stage: Loading Inner shell Pressure Drop Off No specific hazards are identified, for the reason that the operation is similar to the operation of LNG. Risk Reducing Measures (Mitigation) Measures Same as Same as

14 Annex, page Hazard Guide (FI/ word Cause Operational stage: Loading Cool Down (Cargo Piping) 6 Cargo liquid line HE Malfunction of Significant EFH shore LH facilities thermal stress CH Flow rate from the due to a shore supply is too thermal high gradient Low temperature outside of the from shore supply allowable Nonobservance of range Operation Manual (FI:,SI:) Insufficient monitoring of temperature Possible consequences Damage to cargo liquid line due to significant thermal stress on cargo liquid line between shore connection and cargo Loss of vacuum in cargo piping vacuum insulation system Formation of LO/LN around out side of double wall piping Cryogenic damage to ship structure due to exposure through dripping/contact with LO/LN Measures (Prevention) Stress calculations for cargo piping including thermal stress to be carried out and approved by class Monitoring devices to be provided (temperature sensors on cargo lines, flow meters on shore facilities) SUS to be applied for external side of double wall piping Observation of Operation Manual GH and LH to be controlled on shore to avoid thermal gradient exceeding allowable range Measures (Mitigation) Early detection of ice on outer side of double wall piping to avoid formation of LO/LH Detection of vacuum loss in double wall piping due to rupture of a seal off valve Risk Reducing Measures

15 Annex, page Hazard (FI/ 7 Cargo liquid line Significant thermal stress due to a thermal gradient outside of the allowable range (FI:,SI:) Guide word HE EFH CH Cause Same as 6 Operational stage: Loading Cool Down (Cargo Tank) 8 Cargo Significant thermal stress due to a thermal gradient outside of the allowable range (FI:,SI:) HE EFH CH Misscommunication between ship and shore Malfunction of shore LH facilities Nonobservance of Operation Manual Insufficient monitoring of temperature Possible consequences Damage to cargo liquid line due to significant thermal stress on cargo liquid line between shore connection and cargo Cargo leakage from outer side to inner side in double wall piping Overpressure in outer side of double wall piping due to vaporization of leaked cargo Risk of fire on deck due to damage in outer side of double wall piping Damage to inner shell of cargo LH/GH leakage to outer shell from inner shell of cargo at the damaged part Loss of vacuum in cargo vacuum insulation system Overpressure in cargo due to large BOG Measures (Prevention) Measures (Mitigation) Dry chemical powder fireextinguishing system to be installed Water spray system to be installed Personal protection equipment to be provided according to ISO/TR 596 requirements Monitoring devices to be provided (temperature sensor in cargo ) Allowable thermal gradient to be stated in Operation Manual Observation of Operation Manual Cargo to be designed in consideration of shrinkage Insulation panel on outer shell of cargo to be provided to avoid loss of vacuum PRV to be installed considering volume of BOG during loss of vacuum Vent to be safety positioned Risk Reducing Measures Same as Alarm system to be provided to detect problematic thermal gradients in inner shell of cargo s

16 Annex, page 4 Hazard Guide (FI/ word Cause Operational stage: Loading Loading 9 Manifold for CH Malfunction of cargo liquid line mooring device LH leakage Drastic change in (FI:,SI:) sea and weather conditions Unexpected external force and/or damage to shore connections Small gap due to thermal differences 0 Manifold for cargo liquid line LH leakage (FI:,SI:) Possible consequences Equivalent LH leakage volume from shore connection until ESD valve is closed Cryogenic damage of ship structure due to dripping of/contact with LO/LN at flanges FGH Same as 9 Equivalent LH leakage volume from shore connection until ESD valve is closed Generation of GH due to evaporation of LH Risk of fire/explosion if flammable atmosphere forms around the manifold Measures (Prevention) ESD valve to be automatically activated when deviation from normal conditions is detected ERS to be activated Measures (Mitigation) Drip tray and water curtain to be installed on manifold ESD valve to be closed within 0 sec according to class rules SUS to be applied Hazardous area to be designed around manifold including provision of safety apparatus to prevent thermal or mechanical explosion Dry chemical powder fireextinguishing system to be installed Water spray system to be installed ESD valve to be closed within 0 sec according to class rules Portable gas detector to be provided Personal protection equipment to be provided according to ISO/TR 596 requirements Risk Reducing Measures

17 Annex, page 5 Hazard (FI/ Manifold for Gas line GH leakage (FI:,SI:) Outer side of double wall piping Formation of LO/LH (FI:,SI:) Guide Cause word FGH Malfunction of mooring device Drastic change in sea and weather conditions Unexpected external force and damage to shore connections Small gap due to thermal differences at flanges CH Insufficient insulation procedures Loss of vacuum in double wall piping Possible consequences Equivalent GH leakage volume from shore connection taking into consideration all piping lines Risk of fire/explosion if flammable atmosphere forms around the manifold Cryogenic damage of ship structure due to dripping/contact with LO/LN Risk of ignition due to rich supply of LO Measures (Prevention) ESD system to be automatically activated when deviation from normal condition is detected ERS to be activated Leak test to be carried out using He gas Measures (Mitigation) Same as 0 Portable gas detector to be provided Personal protection equipment to be provided according to ISO/TR 596 requirements Dry chemical powder fireextinguishing system to be installed Water spray system to be installed Detection of vacuum loss in double wall piping due to rupture of a seal off valve Early detection of ice on outer side of double wall piping to avoid formation of LO/LH Risk Reducing Measures ESD valve to be provided for seal gas supply line ERS to be provided for seal gas supply line also or a procedure to manually isolate ship/shore interface for seal gas supply line to be detailed in Operation Manual

18 Annex, page 6 Hazard (FI/ Cargo Overfilling (FI:,SI:) 4 Instruments Loss of power (FI:,SI:) Guide word HE EFH EFH FGH HE Cause Malfunction of overflow system Override of overflow system High supply rate Low return rate Fire in Engine Room/ Cargo Control Room Black out due to misoperation Black out due to failure Possible consequences Flow of LH to vapour line from cargo vapour lines Damage of cargo compressor due to suction of LH Cryogenic damage of ship structure due to dripping/contact with LH in cargo machinery room Risk of fire/explosion due to formation of flammable atmosphere in cargo machinery room No monitoring of pressure, temperature, liquid level, or vacuum in cargo Possibility of overfilling in cargo Possibility of overpressure in cargo Measures (Prevention) Sensors for high level alarm and overflow system to be installed independently Level gauge to be type approved for LH Observation of Operation Manual Interlock system to be provided for override system Fire detector/alarm system Fire extinguishing system Observation of Operation Manual Measures (Mitigation) Fixed gas detector to be provided in cargo machinery room Hazardous area to be designed in cargo machinery room including provision of safety apparatus to prevent thermal or mechanical explosion Dry chemical powder fireextinguishing system to be installed Water spray system to be installed CO gas fireextinguishing system to be installed in cargo machinery room Ventilation system to be installed in cargo machinery room Personal protection equipment to be provided according to ISO/TR 596 requirements Loading to be stopped due to ESD system Electric power to be supplied by battery and Uninterruptible Power Supply Electric power to be recovered by standby generator or emergency generator Risk Reducing Measures Adequate fire detector to be provided to detect initial H fire outbreak in cargo machinery room

19 Annex, page 7 Hazard (FI/ 5 Instruments Loss of power (FI:,SI:) Guide word EFH FGH HE Cause Same as 4 Possible consequences Discontinued supply of seal GN to cargo compressor Seal GH leakage from cargo compressor Risk of fire/explosion due to formation of flammable atmosphere in cargo machinery room Measures (Prevention) Measures (Mitigation) Fixed gas detector to be provided in cargo machinery room Hazardous area to be designed in cargo machinery room including provision of safety apparatus to prevent thermal or mechanical explosion Personal protection equipment to be provided according to ISO/TR 596 requirements Dry chemical powder fireextinguishing system to be installed Water spray system to be installed CO gas fireextinguishing system to be installed in cargo machinery room Ventilation system to be installed in cargo machinery room Risk Reducing Measures ESD valve to be provided for seal gas supply line Adequate fire detector to be provided to detect initial H fire outbreak in cargo machinery room

20 Annex, page 8 Hazard Guide (FI/ word Operational stage: Loading Drain Off 6 Cargo liquid line Overpressure (FI:,SI:) 7 Cargo liquid line Overpressure (FI:,SI:) 8 Cargo liquid line Significant thermal stress due to thermal gradient outside of the allowable range (FI:,SI:) HE LH EFH CH HE LH EFH FGH HE LH EFH Cause Drain residue due to improper piping installation LH in cargo liquid line due to misoperation of valves Vaporization of LH in cargo liquid line Same as 6 Nonobservance of Operation Manual No temperature monitoring Hot GH supplied at cryogenic conditions Possible consequences Damage to cargo liquid line Loss of vacuum in cargo line vacuum insulation system Formation of LO/LN around outside of double wall piping Cryogenic damage of ship structure due to dripping of/contact of LO/LN Damage to cargo liquid line Cargo leakage from inner side to outer side of double wall piping Overpressure in outer side on double wall piping due to vaporization of leaked cargo Possibility of fire on deck due to damage to outer side on double wall piping Damage of cargo liquid line due to significant thermal stress on cargo liquid line Measures (Prevention) Pressure indicator to be fitted on cargo liquid line Drain valve to be provided Observation of Operation Manual Measures (Mitigation) PRV to be fitted on cargo liquid lines Early detection of ice on outer side of double wall piping to avoid formation of LO/LH Detection of loss of vacuum in double wall piping Dry chemical powder fireextinguishing system to be installed Water spray system to be installed Portable gas detector to be provided Personal protection equipment to be provided according to ISO/TR 596 requirements Stress calculations of cargo piping including thermal stress to be approved by class Observation of Operation Manual PRV to be fitted on cargo liquid lines Risk Reducing Measures

21 Annex, page 9 Hazard (FI/ 9 Cargo liquid line Significant thermal stress due to thermal gradient outside of the allowable range (FI:,SI:) Guide word HE LH EFH Cause Same as 8 Possible consequences Cargo leakage from inner side to outer side of double wall piping Overpressure in outer side on double wall piping due to vaporization of leaked cargo Risk of fire on deck due to damage of outer side of double wall piping Operational stage: Loading Manifold Purging (Hot H Gas to N Gas) 0 Manifold for cargo lines Solidified/ liquefied N gas (FI:,SI:) HE CH No temperature monitoring GN supplied in cryogenic conditions in cargo lines Solidified N fitted with valve seat Insufficient GH purging due to a blockage of solidified N Operational stage: Loading Ship / Shore interface procedure before berthing Manifold for cargo lines Residual H gas (FI:,SI:) HE FGH Nonobservance of Operation Manual Insufficient purging Same as Manifold for gas lines Residual H gas (FI:,SI:) HE FGH Nonobservance of Operation Manual Insufficient purging Same as Measures (Prevention) Measures (Mitigation) Detection of vacuum loss in double wall piping Dry chemical powder fireextinguishing system to be installed Water spray system to be installed Portable gas detector to be provided Personal protection equipment to be provided according to ISO/TR 596 requirements Observance of Operation Manual Proper inspections Risk Reducing Measures

22 Annex, page 0 Hazard Guide (FI/ word Cause Operational stage: Seagoing BOG management Cargo EFH Loss of vacuum in Increase in FGH cargo vacuum heat input insulation system (FI:,SI:) due to leakage from pipe joints 4 Cargo Increase in heat input (FI:,SI:) 5 Cargo Inability to operate GCU (FI:,SI:) 6 Cargo Accumulated days exceed the design maximum (FI:,SI:) EFH FGH EFH FGH HE EFH Possible consequences Increase in BOG Overpressure in cargo Fire on deck Increase in a large volume of BOG Overpressure in cargo Discontinued supply of steam to cargo heater Malfunction of temperature control valve in cargo heater Collision/grounding Changes to original voyage plan due to severe weather etc. Operational stage: Seagoing Cargo Safety Storage Small leakage of EFH Damage of ballast ballast water from ballast to cargo hold due to cracks in welded parts Inability to treat BOG Overpressure in cargo Overpressure in cargo Measures (Prevention) Welded joints for piping to be applied in cargo vacuum system Vacuum insulation systems of dome to be separated from those if cargo s Use certified safe type equipment in Hazardous area Measures (Mitigation) Cargo to be a pressure accumulation design BOG to be treated using GCU PRV to be fitted on cargo Vent to be safety positioned Same as Cargo to be a pressure accumulation design PRV to be fitted on cargo Vent to be safety positioned BOG to be treated using GCU Cargo mixing system to be installed in cargo PRV to be fitted on cargo Vent to be safety positioned Exclude from study for the reason that the operation is the same as the operation of LNG. Risk Reducing Measures Flange joints to be considered to mitigate leakage in vacuum exhaust line

23 Annex, page Hazard (FI/ Large leakage of ballast water from ballast to cargo hold 0 Very small leakage of GN in cargo hold to cargo vacuum system (FI:,SI:) Small leakage of GN in cargo hold of cargo vacuum system (FI:,SI:) Guide Cause word EFH Collision with other vessels (damage of side shell and inner hull) EFH DH EFH DH Damage of cargo outer shell due to welding cracks Crack in bellows in dome Collision with other vessels (damage to side shell and inner hull, cargo outer shell) Possible consequences Measures (Prevention) Measures (Mitigation) Risk Reducing Measures Exclude from study for the reason that the operation is the same as the operation of LNG. Decrease in performance of insulation systems due to LN/Solidified N Decrease in performance of insulation systems due to loss of vacuum Overpressure in cargo s due to formation of BOG Decrease in performance of insulation systems due to LN/Solidified N Decrease in performance of insulation systems due to loss of vacuum Overpressure in cargo s due to formation of BOG Welding Procedure Specification to be observed, including inspection Use reliable bellows and take into consideration materials, method of fitting and inspection Cargo to be a pressure accumulation design PRV to be fitted on cargo assuming loss of vacuum in insulation system BOG to be treated using GCU Vent to be safety positioned Monitoring of vacuum in cargo vacuum system Cargo to be a pressure accumulation design PRV to be fitted on cargo considering loss of vacuum in insulation system BOG to be treated using GCU Vent to be safety positioned Monitoring of vacuum in cargo vacuum system

24 Annex, page Hazard (FI/ Large leakage of GN in cargo hold to cargo vacuum system (FI:,SI:4) Very small leakage of LH from cargo inner shell (FI:,SI:) Guide word EFH DH EFH DH CH Cause Same as High permeability of welding, seal parts Fatigue cracks on welding parts due to sloshing loads, cycle loads Possible consequences Decrease in performance of insulation systems due to rapid loss of vacuum Rapid overpressure in cargo Partial blockage of vent line due to two phase flow Decrease in performance of insulation systems due to loss of vacuum Overpressure in cargo due to increase in BOG Significant thermal stress due to shrinkage, and embrittlement on cargo outer shell Measures (Prevention) Measures (Mitigation) Cargo to be a pressure accumulation PRV to be fitted on cargo considering loss of vacuum insulation system BOG to be treated by GCU Vent mast to be safety located Monitoring of vacuum for cargo vacuum system Double gasket to be Leak test to be carried applied out using He gas Cargo to be Cargo to be a designed as a Type C pressure accumulation based on IGC Code design PRV to be fitted on cargo considering loss of vacuum insulation system BOG to be treated using GCU Vent to be safety positioned SUS to be applied for cargo outer shell Cargo to be designed considering thermal stress Monitoring of vacuum for cargo vacuum system Risk Reducing Measures

25 Annex, page Hazard (FI/ 4 Small leakage of LH from cargo inner shell (FI:,SI:4) 5 Small leakage of LH from cargo inner shell (FI:,SI:) Guide word EFH DH CH EFH DH CH Cause Collision with other vessels (damage to side shell and inner hull cargo outer shell) Grounding (Damage of double bottom, cargo outer shell) Possible consequences GH flow to cargo hold, residual GN, air changed to solidified N Decrease in performance of insulation system due to rapid loss of vacuum Rapid increase in BOG and overpressure in cargo Partial blockage of vent due to two phase flow Rise in temperature due to sea water flow to cargo hold and vacuum space in cargo vacuum insulation system Decrease in performance of cargo vacuum insulation system due to rapid loss of vacuum Overpressure in cargo due to rapid increase in BOG Partial blockage of vent due to two phase flow Measures (Prevention) Measures (Mitigation) Leak test to be carried out using He gas Cargo to be a pressure accumulation design PRV to be fitted on cargo considering loss of vacuum in insulation system BOG to be treated using GCU Vent to be safety positioned SUS to be applied in cargo outer shell Cargo designed considering thermal stress Monitoring of vacuum in cargo vacuum system Cargo PRV Cargo hold PRV Risk Reducing Measures

26 Annex, page 4 Hazard (FI/ 6 Moderate leakage of LH from cargo inner shell (FI:,SI:4) 7 Large leakage of LH from cargo inner shell (FI:,SI:4) Guide word EFH DH CH EFH DH CH Cause Collision with other vessels (damage to side shell and inner hull, cargo outer shell) Collision with other vessels (damage of side shell and inner hull, cargo outer shell) Possible consequences Decrease in performance of cargo vacuum insulation system due to rapid loss of vacuum Overpressure in cargo due to rapid increase in BOG Partial blockage of vent line due to two phase flow Diffusion of GH to cargo hold and deck Possibility of jet fire Decrease in performance of cargo vacuum insulation system due to rapid loss of vacuum Rapid overpressure in cargo due to rapid increase in BOG Partial blockage of vent due to two phase flow Diffusion of GH to cargo hold and deck Possibility of pool fire Spread of pool fire to other vessels Measures (Prevention) Measures (Mitigation) Heat radiation to be reduced by cargo cover Tank dome to be cooled by water spray systems PRV (50% x ) to be fitted Risk Reducing Measures

27 Annex, page 5 Hazard (FI/ 8 Leakage of GN to cargo vacuum insulation space at piping connections in the space (FI:,SI:) 9 Leakage of LH to cargo vacuum insulation space at pipe connections in the space (FI:,SI:) Guide word EFH DH CH EFH DH CH Cause Damage of inner FRP support Excessive displacement of pipes in vacuum insulation space (Damage of connection part to cargo outer shell) Excessive deformation of pipes in vacuum insulation space due to damage of FRP support for cargo inner shell (Damage to connection part to cargo inner shell) Possible consequences Increase in BOG Overpressure in cargo Increase in BOG Overpressure in cargo Significant thermal stress due to shrinkage, embrittlement on cargo outer shell Measures (Prevention) Redundancy of FRP cargo inner shell support Redundancy of FRP cargo inner shell support Measures (Mitigation) Segregation of vacuum space between cargo and dome Monitoring of vacuum for dome vacuum insulation space Cargo to be a pressure accumulation design PRV to be fitted on cargo considering loss of vacuum in insulation system BOG to be treated using GCU Vent to be safety positioned Segregation of vacuum space between cargo and dome Monitoring of vacuum for dome vacuum insulation space SUS to be applied for cargo outer shell Cargo to be a pressure accumulation design Cargo to be designed considering thermal stress Risk Reducing Measures

28 Annex, page 6 Hazard (FI/ 40 Instruments (Laden voyage) Loss of power (FI:,SI:) 4 Cargo BOG release from vent (FI:,SI:) 4 Cargo (Ballast voyage) Excessive residual drain in cargo (FI:,SI:) Guide word EFH FGH HE EFH FGH HE HE EFH FGH Cause Fire in Engine Room/ Cargo Control Room Black out due to misoperation Black out due to failure GH leakage from seat of PRV Misoperation Level gauge malfunction Possible consequences No monitoring of pressure, temperature, level, vacuum in cargo Possibility of overpressure in cargo Formation of flammable atmosphere around the vent outlet Risk of fire due to lightening Vaporization of cargo heel Vaporization of residual drain in cargo liquid line Formation of BOG Overpressure in cargo Operational stage: Unloading Ship / Shore interface procedure after berthing Same as Operational stage: Loading Ship / Shore interface procedure after berthing Operational stage: Unloading Manifold Purging (Air to N gas) Same as Operational stage: Loading Ship / Shore interface procedure after berthing Operational stage: Unloading Manifold Purging (N Gas to Hot H gas) Same as Operational stage: Loading Manifold Purging (N Gas to Hot H gas) Operational stage: Unloading Inner shell Pressure Drop Off Same as Operational stage: Loading Inner shell Pressure Drop Off Measures (Prevention) Measures (Mitigation) Fire detector/alarm Electric power to be system supplied by battery and Fire extinguishing Uninterruptible Power system Supply Observation of Electric power to be Operation Manual recovered by standby generator or emergency generator Vent to be safety positioned N gas fire extinguishing system in vent Emergency isolation valve to be fitted between PRV and cargo Observation of Operation Manual Cargo to be a pressure accumulation design BOG to be treated using GCU PRV to be fitted on cargo Vent to be safety positioned Redundancy of level gauge Risk Reducing Measures PRV to be designed considering characteristics of GH Fixed gas detector to be fitted in vent

29 Annex, page 7 Hazard Guide (FI/ word Cause Operational stage: Unloading Cool Down (Cargo Piping) Same as Operational stage: Loading Cool Down (Cargo Piping) 48 Cargo HE Failure of EFH cargo spray pump (FI:,SI:) Solidified N is drawn into the spray pump due to residual N during the manifold purge solidifying and accumulating in the cargo Operational stage: Unloading Unloading Same as Node Operational stage: Loading Loading 50 Cargo HE Failure of EFH cargo pump (FI:,SI:) Solidified N drawn into spray pump due to residual N during manifold purge solidifying and accumulating in the cargo Possible consequences Impossible to conduct cool down procedure using cargo spray pump Unloading stopped by cargo pump Inability to conduct normal unloading Operational stage: Unloading Drain Off Same as Operational stage: Loading Drain Off Operational stage: Unloading Manifold Purging (Hot H Gas to N gas) Same as Operational stage: Loading Manifold Purging (Hot H Gas to N gas) Operational stage: Unloading Ship / Shore interface procedure before berthing Same as Operational stage: Loading Ship / Shore interface procedure before berthing Measures (Prevention) Strainer to be fitted on cargo spray pump suction Strainer to be fitted on cargo spray pump suction inlet Measures (Mitigation) Two cargo spray pumps per ship to be installed Two cargo pumps per to be installed Unloading by gas pressurization Risk Reducing Measures

30 Annex, page 8 Hazard Guide (FI/ word Cause Operational stage: Dock in Warm Up 54 Cargo HE Malfunction of Significant EFH temperature control thermal stress valve for cargo due to a heater thermal Temperature of gradient GH supplied too outside of the high allowable Insufficient range monitoring of (FI:,SI:) temperature 55 Inability to operate cargo compressor (FI:,SI:) HE EFH No supply of GH Seal function failure Operational stage: Dock in Inerting (H Gas to N Gas) 56 Cargo line Solidified/ liquefied N (FI:,SI:) HE CH EFH Insufficient warming up due to misoperation Temperature of cargo line/cargo Possible consequences Damage to inner shell of cargo due to excessive thermal stress LH/GH leakage from inner shell to outer shell of cargo at damaged part Loss of vacuum in the cargo vacuum insulation system Inability to perform warming up operations using the cargo compressor onboard Blockage in cargo line due to Solidified N Measures (Prevention) Monitoring devices to be provided (temperature sensor in cargo ) Observation of Operation Manual Cargo to be designed considering thermal stress Observation of Operation Manual Observation of Operation Manual Monitoring devices to be provided (temperature sensor in cargo ) too low Operational stage: Dock in Aeration(N Gas to Air) No specific hazards are identified, for the reason that the operation is the same as the operation of LNG. Operational stage: Dock out Inerting (Air to N Gas) No specific hazards are identified, for the reason that the operation is the same as the operation of LNG. Operational stage: Dock out Hydrogen Gas Filling (N Gas to Hot H Gas) No specific hazards are identified, for the reason that the operation is similar to the operation of LNG. Measures (Mitigation) Seal GH supplied by GH bottles on ship Hot GH supplied by shore without using the cargo compressor onboard Risk Reducing Measures

31 Annex, page 9 Hazard Guide Possible Cause (FI/ word consequences Operational stage: Dock out Cool Down (Cargo Piping) Cargo liquid line Same as Operational stage: Loading Cool Down (Cargo Piping) Significant thermal stress due to a thermal gradient outside of the allowable range 6 Cargo line HE Solidified/ EFH liquefied N CH (FI:,SI:) Improper piping installation that causes air pockets to develop Insufficient hydrogen gas filling Residual GN Damage to cargo valves, cargo compressor, cargo heater Blockage in the cargo line Malfunction of instruments (pressure gauges, temperatures) Operational stage: Dock out Cool Down (Cargo Tank) 6 Cargo Same as Operational stage: Loading Cool Down (Cargo Tank) Significant thermal stress due to a thermal gradient outside of the allowable range (FI:,SI:) Measures (Prevention) Purge valve to be fitted at air pockets Gas sampling during hydrogen gas filling Observance of Operation Manual Measures (Mitigation) Risk Reducing Measures

32 Annex, page 0 Hazard (FI/ 6 Cargo Solidified/ liquefied N (FI:,SI:) Guide word HE EFH CH Cause Insufficient hydrogen gas filling Residual GN Possible consequences Damage to cargo valves, cargo pump Malfunction of instruments (cargo liquid temperature gauge, wall temperature gauge, gas sampling line Measures (Prevention) Gas sampling during hydrogen gas filling Operation manual to be observed Measures (Mitigation) Risk Reducing Measures

33 Table 5: Frequency Index and Definitions (Second HAZ study) FI Frequency A Never heard of in the industry B Heard of in the industry C Has happened in the organization or more than once per year in the industry D Has happened at the location or more than once per year in the organization E Has happened more than once per year at the location FI: Frequency Index CCC /INF.0 Annex, page Table 6: Severity Index and Definitions (Second HAZ study) SI Effect on Peoples Assets Environment Reputation 5 More than fatalities No damage No effect No impact 4 Permanent total disability or up to Slight damage Slight effect Slight impact fatalities Major injury or health effect Minor damage Minor effect Minor impact Minor injury or health effect Moderate damage Moderate effect Moderate impact Slight injury or health effect Major damage Major effect Major impact 0 No injury or health effect Massive damage Massive effect Massive impact SI: Severity Index

34 Annex, page (FI:C, SI:) (FI:C, SI:) Natural, environmental and man created hazards Extreme weather conditions (e.g. wave, wind, temperature, snow, blizzards, fog ) Passing ship effects Table 7: List of Identified Hazards (Second HAZ study) 4 5 Weather conditions deteriorate resulting in exceedance of mooring capacity Passing ship effect on vessel loading/unloading. Weather conditions deteriorate resulting in exceedance of mooring capacity breakout/ Loss of containment Significant vessel movement or breakout Overstress or fracture of loading arm/ Loss of containment / Fatalities ) Design based on appropriate (location/route specific) metocean data ) Weather forecast ) Weather monitoring onboard 4) Adverse Weather Guidelines 5) LH Transfer Operations Checklist to include weather requirements. 6) Stop work policy 7) Emergency release system and linked ESD systems 8) Operations and Maintenance ) Design based on metocean data ) Weather forecast ) Weather monitoring onboard 4) Adverse Weather Guidelines 5) LH Transfer Operations Checklist to include weather requirements. 6) Stop Work Policy 7) Emergency Release System and linked ESD systems 8) SIL(Safety Integrity level) Assessment for transfer arm system and ESD functions Sheltered location being assessed ) Appropriate site selection ) Operations Philosophy to be developed

35 Annex, page (FI:B, SI:4) 4 SI:4) 5 (FI:B, SI:) 6 (FI:B, SI:) Lightning 4 5 Earthquake/ tsunami Manmade hazards (Terrorism, security threat) Environmental Impact of facilities to the environment Lightning strike during shore to ship transfer/ sea going/ dock in/dock out Due to the seismic nature of Japan, site location may be affected by earthquakes and/or Tsunamis Security breaches Leakage, discharges Injury/ fatality/ Asset damage Asset damage/ Loss of containment/ Injury / fatality Asset damage/ Loss of containment/ Injury/ fatality Asset damage/ Loss of containment/ injury/ fatality ) Design based on metocean data ) Weather forecast ) Weather monitoring onboard 4) Adverse Weather Guidelines 5) LH Transfer Operations Checklist to include weather requirements. 6) Approved procedures and stop work policy (e.g. no venting policy, ensure correct earthing) Site SelectionPossible occurrence of Seismic Activity to be factored into the site selection process so as to eliminate high activity areas. ) ISPS terminals and vessel ) Access control at terminal ) Crew and visitor declaration at terminal ) Detailed Site selection ) Environmental Impact Assessment Onshore facilities ) Emergency Response Plan ) Consider vapour return ) To conduct vent dispersion analysis. ) Vent stack design (e.g. location, height, heater) 4) Identify release scenarios which might catch fire. 5) To investigate fire suppression system (e.g. snuffing system) 6) Operations Philosophy to be developed ) Consider seismic effects on terminal, jetty and connections (arms). Terminal design considerations. Japanese codes for structural design ) Emergency separation ) Earthquake warning system to allow time to disconnect (refer to LNG terminals) ) Any additional security barriers to be considered as step out of LNG terminal ) Consider Local opposition ) Regular drills and training of crew Consider closed loading system.