Domino Effects and Storage Sites of Propane in the Netherlands

Transcription

1 Domino Effects and Storage Sites of Propane in the Netherlands Soedesh Mahesh Workshop Domino Effects in the Process Industry Bologna, Italy April 16-17, 2014

2 Content 1. Introduction 2. Guidelines to prevent Domino Effects 3. Propane Storage Sites 4. Safety distances 5. Physical safety measures 6. Conclusions Netherlands Workshop Domino Effects in the Process Industry, April 16-17, 2014

3 Introduction (1) RIVM (recognized leading centre of expertise) Fields: health, nutrition and environmental protection Client: the Dutch government Collaborate: governments and supranational bodies around the world Process: research, monitoring, modelling and risk assessment Results: are used to underpin policy on public health, food, safety and the environment Employees: 1500 employees (working in multidisciplinary fields) Centre for Environmental Safety and Security Focus: response during and recovery after incidents (physical basis, reducing risks, mitigating consequences) Operational support: public authorities during and after incidents (response and recovery). Knowledge support: enforcement, protection and policy development, scenario and risk analyses (pro-action, prevention and preparation) 3 Netherlands - Workshop Domino Effects in the Process Industry, April 16-17, 2014

4 Introduction (2) Centre for Environmental Safety and Security Management role for the government Software programs for risk assessment Safeti-NL (e.g. storage sites, warehouses) RBMII (transport) CAROLA (high pressure natural gas in transportation pipelines) GEVERS (civil aviation) Drafting of uniform documents (quantitative risk or effect assessments) Guidelines (e.g. LPG, LNG and warehouse) Protocols (e.g. modifying failure frequencies) Instruments (e.g. Instrument Domino Effects) 4

5 Outline guidelines to prevent Domino Effects in NL Outside the establishment Instrument Domino Effects (IDE) Identification of establishments (exposed to or caused domino effects) The control of major-accident hazards involving dangerous substances European Seveso Directives 96/82/EG and 2012/18/EU At the establishment (assessment is based on) Fireworks Act (consumer and professional fireworks) Guideline AASTP-1 of the NATO (explosives, ammunitions) Guidelines PGS (Publication series for hazardous substances) -> BAT Documents (legal basis) 5

6 National guidelines and Domino Effects For Propane Storages Sites 4 PGS Guidelines (storages, loading, users) Big users/producers: depots, terminals, refineries Small users: private users, construction sites, farms How to prevent domino effects at propane storage sites? Spatial separation (safety distances) Physical safety measures (architectural, technical requirements) What is the most likely scenario for Domino Effects? Maximum Credible Event (MCA) potential hazard Propane pressure vessel propane pressure vessel ->leak -> jet fire Flammable liquids in vessels propane pressure vessel -> pool -> pool fire Fire from buildings propane pressure vessel -> pool -> flat heat radiator (wall opnenings) What are the hazard criteria to prevent Domino Effects? Heat radiation level 10 kw/m 2 (standard value) and 35 kw/m 2 (prove that the exposed object is resistent to this value) 6

7 Most likely scenario for Domino Effects for pressure vessels Leak (small leaks at joints of pressure vessel, most likely, once in hundred thousand pressure vessel years) Rupture (at joint of pressure vessel, not likely, once in 1 million pressure vessel years ) Instantaneous failure and release of entire content of pressure vessel very small probability of failure -> once in 2 million pressure vessel years (very unlikely) Release of the entire content of the pressure vessel in 10 minutes very small probability of failure -> once in 2 million pressure vessel years (very unlikely) 7

8 Most likely DE-scenario for Propane sites Incident analysis (for Europe, last 30 years) NL (no data available) ARIA database MARS database Results incident analysis: ARIA: 2 incidents (2002 and 2004) Leaks at the joint (gas) Diameter leak: 1 mm (1) and 12.7 mm (2) Cause of the leaks: Corrosion / Fatigue MARS: 552 incidents (35 with LPG, Butane and Propane) Most common event -> leak 8

9 MARS Database 9

10 Leak analysis from MARS database Event (%) Leak from loading/unloading 12 hose Leak from pipe/pipeline 24 Leak form valve (drain, 27 safety) Leak from flange 9 Catastrophic rapture 6 Other / unknown 22 10

11 Summary for most likely DE-scenario for pressure vessels Most likely are the small leaks at joints of pressure vessel Relevant: the biggest connection at pressure vessel -> outflow leak Hole size of the leak: 10% of diameter of the biggest connection (mostly pipelines) from the pressure vessel HAZARD CRITERIA Major potential hazard from leak -> jet fire Main consequence -> heat radiation Heat radiation level 10 kw/m 2 (standard value) 35 kw/m 2 (prove that the exposed object (vessel) is resistant to this value) 11

12 Modelling safety distances for jet fire Software program: SAFETI-NL (v6.54) Model: Vessel or pipe source Discharge material: Propane Vessel: 20 m 3 Saturated liquid Temp: 9 C Pressure: 5.15 barg Scenario: leak Diameter: variable Release Elevation: 1 m Release direction: horizontal Weather parameters: D 5 (m/s) Results: heat radiation levels for 10 and 35 kw/m 2 12

13 Effect distances for jet fires (liquid) for propane 60 Afstand gemeten vanaf de bron van de fakkel in m bij weertype: D Diameter van het lek in mm 3kW/m2 (SAFETI-NL 6.54) 10kW/m2 (SAFETI-NL 6.54) 35kW/m2 (SAFETI-NL 6.54) Explanation: horizontal axis -> leak diameter in mm Vertical axis -> effect distance in m 13

14 Domino Effect distance for propane storage sites Propane pressure vessel (volume V) Jet -> liquid Safety distance (m) Jet -> gas Safety distance (m) 0,15 m 3 < V 1,0 m 3 5 (4) 3 (2.5) 1,0 m 3 < V 5 m 3 6 (4.5) 3 (2.5) 5 m 3 < V 13 m (6.5) 3 (3) 13 m 3 < V 100 m 3 11 (9) 6 (4) 100 m 3 < V 150 m (11) 6 (5) V > 150 m 3 15 (12.5) 6 (5) Values within the brackets refer to the 35 kw/m 2 distance 14

15 Effect distances for propane loading For hose and pipe(line) with different diameter Horizontal axis -> nominal diameter hose / pipe(line) in mm Vertical axis -> effect distance (10 and 35 kw/m 2 ) in m Afstand van de aansluiting tot een warmtestralingsintensiteit van 10 en 35 kw/m 2 40 Afstand tot 10 en 35 kw/m 2 [m] Nominale diameter van de aansluiting [mm] 10 kw-contour 35 kw-contour 15

16 Pool fires and Domino Effects Storage flammable liquids (in vessel) Software program SAFETI-NL Scenario: pool fire (in bund or without bund) Heat radiation effect distance 30 Warmtestralingsintensiteit van 10 en 35 kw/m 2 van een plasbrand Horizontal-axis: surface of pool or bund (m 2 ) Vertical-axis: effect distance heat radiation level 10 and 35 kw/m 2 from the edge of the bund or pool Afstand v/d rand van plas tot 10 en 35 kw/m 2 contour [m] Oppervlakte waarover de brandbare vloeistof zich kan verspreiden [m 2 ] 10 kw-contour 35 kw-contour 16

17 Fire in buildings and Domino Effects Storage of flammable liquids (e.g. hydrocarbons) in building Building is not sufficiently fire resistant (< 30 min) or openings in de walls Scenario: fire from wall openings Q: safety distance to prevent domino effect from building to the propane pressure vessel Modelling: Yellow Book (PGS 2) Methods for calculating of physical effects Model: vertical flat radiator q receiver = τ F max Q source [kw/m 2 ] τ : atmospheric transmissivity [-] F max : viewfactor [-] Q source : actual power of flat radiator Q source = ε σ (T vl4 -T a4 ) [kw/m 2 ] ε = emissiefactor [-] = 1 σ = onstant of Stefan-Boltzmann (5, kw/m 2 K 4 ) T vl = temperature of radiator surface of the flame (K) T a = ambient temperature (K) Hydrocarbon fires: T vl 1200 K -> Q source = 120 kw/m 2 17

18 Results for fire from buildings: Safety distance versus opening area in the wall Distance from the opening in the wall to a heat level of 10 kw/m 2 [m] Surface area of the opening in the wall [m 2 ] Hoogte opening 2,5 m Hoogte opening 5 m Hoogte opening 7,5 m Hoogte opening 10 m 18

19 Results for fire from buildings: safety distance versus opening area in the wall 10 Distance from the opening in the wall to a heat level of 35 kw/m 2 [m] Surface area of the opening in the wall [m 2 ] Hoogte opening 2,5 m Hoogte opening 5 m Hoogte opening 7,5 m Hoogte opening 10 m 19

20 Physical safety measures and conditions Important conditions for consideration technical integrity during operating time is guaranteed manufactured with non-combustible material resistant to the action of propane Fire resistance: 1 h -> vessel, 2 -> bearing structures must withstand fire-fighting criteria for sustainability weather conditions and ambient conditions (frost, rain, temperature changes, UV light) resistance to external impact (collision) resistance to corrosion always be easily accessible (for inspection) 20

21 General Safety Measures for propane vessels Fire protective coating (+) Fire protective paint (+) Covering with soil (+) Firewall (+) Water sprinkler installation Sprinklers (+) Water screens (-) Fire curtain (-) Retaining wall / retaining mound (-) 21

22 Specific Safety Measures for propane vessels (PGS) Water sprinkler installation Fire protective coating materials based on epoxy and cement Covering with soil (underground or mounding) Firewall Fire protective paint paint with intumescent effect vulnerable to scratches limited protection against pool fires and no protection against jet fire -> only effective: no contact with pool fires and jet fires solitary vessel Reduction in safety distance: nearly 70% ( 2/3) 22

23 Conclusions (1) There are national guidelines in the Netherlands to assess domino effects for propane storage sites For propane pressure vessels the major potential hazards from leak are jet fires and the main consequence is heat radiation To prevent domino effects between propane vessels we use as a standard value for the heat radiation level 10 kw/m 2 Higher heat radiation level up to 35 kw/m 2 is only allowed if the owner of the vessel can prove that the exposed object (vessel) is resistant to this higher value It is preferred to use safety distances in order to prevent domino effects Safety distances between stationary storage vessels vary from 5 to 15 m (and depend on the content of the storage vessel) Safety distances for loading vary from 5 to 40 m and (depend on the diameter of the hoses or pipe(line)s) 23

24 Conclusions (2) Domino effects between vessels with flammable liquids and propane vessels can be prevented by maintaining safety distances of 7.5 to 25 m between these vessels. These safety distances depend on the size of the bund or the pool Domino effects between buildings with flammable liquids and propane vessels can also be prevented by maintaining safety distances from this building to the propane vessels. This safety distances depend on the type of fire in the building and the size of the opening in the wall. Safety distances can vary from 3 m to 20 m for an hydrocarbon fire and openings from 1 to 100 m 2 in the walls Domino effect can be prevented by using safety measures for propane vessels: water sprinkler installation, fire protective coating or painting, covering with soil and firewall. The reduction in safety distance is nearly 70% 24

25 Thank you for your attention? Soedesh Mahesh RIVM-National Institute for Public Health and the Environment T