1. StocExpo 2012 Ross Coulman
15th March 2012

20. History has told us multiple events occur

21. Multiple Tanks and Bund / Dykes=
Natural escalation

22. Worse case is the Bund/Dyke
Not your largest tank

36. not enough foam

37. 430k for 65 minute application
not enough foam
430k for 65 minute application

38. 559k for 85 minute application
not enough foam
559k for 85 minute application

39. INSERT Dyke Volume Calculation BUND Holds XXXXX litres
not enough capacity
INSERT Dyke Volume Calculation
BUND Holds XXXXX litres

40. INSERT Dyke Volume Calculation Fire water alone is 11,272,300 litres
not enough capacity
INSERT Dyke Volume Calculation
Fire water alone is 11,272,300 litres

41. INSERT Dyke Volume Calculation
not enough capacity
INSERT Dyke Volume Calculation
Fire water plus xx% = XX,XXX,XXX litres

42. INSERT Dyke Volume Calculation
not enough capacity
INSERT Dyke Volume Calculation
Fire water plus xx% = XX,XXX,XXX litres
PLUS Product 100% largest tank, 10% of all others = XX,XXX,XXX litres

43. designed to standards BS 2654,3 BS EN 14015,4 API 620,5 API 6506
IP 19
HSG 176
CIRA 598
EN 1992
BS EN 14015
vertical, cylindrical, non-refrigerated, above-ground storage tanks typically
designed to standards BS 2654,3 BS EN 14015,4 API 620,5 API 6506

44. Single case pre-plan methodology
Boilover potential provides escalation – potential to create lots of multiple events

45. Single case pre-plan methodology
Pessimism is good – saying singles case is acceptable due to frequency level is naïve

46. Single case pre-plan methodology
Have you taken the shared learning and applied it post buncefield?

47. Single case pre-plan methodology
Negatives
History has told us multiple events occur (Buncefield) – Multiple Tanks natural escalation
Worse case is the Dyke not your largest tank – shortcomings;
- not enough foam
- not enough water
- not enough manpower
- not enough …..
Boilover potential provides escalation – potential to create lots of multiple events
Pessimism is good – saying singles case is acceptable due to frequency level is naïve
Have you taken the shared learning and applied it post buncefield?

48. Single case pre-plan methodology
The factors to be taken into account when sizing bunds to deal with multi-tank failure scenarios and fire water management, plus the capacity for remote [tertiary] containment systems, are:
Primary capacity - 100% of primary capacity. Consider the possible failure modes and where appropriate, include the capacity of all primary tanks in multi-tank installations, incidence of multiple tanks in one bund and where tanks are hydraulically linked in which case they should be treated as if they were a single tank.
Rainfall - subject to operational procedures, in order to calculate the volume to be contained, allow for a 10 year return, 8 days rainfall prior to the incident, and a 10 year return, 24 hour rainfall, plus an allowance for rain falling directly on to remote containment and areas of the site draining into it, immediately after the incident. The post-incident component and the allowance for dynamic effects (see e) are not additive.
Fire fighting and cooling water - Allow for the volume of extinguishing and cooling water delivered through fixed and non-fixed installations based on BS5306, VCI, CEA, ICI and Institute of Petroleum methodologies, with appropriate adjustments in the light of the particular circumstances.
Consultation with the regulators and the fire service is essential.
Foam - Allow a freeboard of not less than 100 mm.
Dynamic effects - this is to allow for the initial surge of liquid and for wind-blown waves.
In the absence of detailed analysis, allow 250mm (750 mm for earth walled bunds).

49. Tailored to risk, not Prescriptive Swiss Cheese Model
Health and Safety Executive (UK) recommendations on multi tank and bund/dyke modelling post Buncefield disaster
Tailored to risk, not Prescriptive
Swiss Cheese Model
People – Process – Plant
People are the weakest link
Identify Vulnerability

50. Compare and contrast single source and multi-source incident scenarios

51. No excuses – it’s easy to model multi-source

52. Q&A