1. Federal department of environment, transport, energy and communications ETEC Federal Office for the Environment FOEN Risk Assessment on Pipelines: the Swiss Approach 8 March 2006 Risk Prevention Division

2. 2 Risk Assessment on Pipelines, the Swiss Approach Layout of the presentation (focus is on new pipelines) The legal context The stakeholders Step 1 of assessment: max. possible damage Step 2 of assessment: FN-curves calculation Risk criteria Experience so far A look at the future

3. 3 Risk Assessment on Pipelines, the Swiss Approach The legal context: Ordinance relating to Pipelines, LPE OrP applies to hydrocarbon pipelines (pressure > 5 bar) OrP requires state-of-the-art safety technology (“safety in the pipe”) Control entrusted to the Federal Pipeline Inspectorate For new pipelines: procedure in two steps for the risk assessment Protection against catastrophes is a requirement of the Law on the Protection of the Environment (LPE)

4. 4 Risk Assessment on Pipelines, the Swiss Approach The stakeholders „ Owner“ of the gas pipeline, who bears the responsibility for the safety of the pipeline Federal Office for Energy (SFOE) lead authority, decides after consultation, concerning risk and other aspects, with: Federal Office for the Environment (FOEN) Federal Pipeline Inspectorate Cantonal authorities Third Parties Public

5. 5 Risk Assessment on Pipelines, the Swiss Approach First step of the risk assessment Owner has to carry out in a summary report an assessment of the maximum damage that may be caused to the public or the environment Assessment rough, conservative Carried out according to a standardised methodology, jointly developed by the main stakeholders Summary report is part of the environmental impact assessment and as such available to third parties and the public

6. 6 Risk Assessment on Pipelines, the Swiss Approach Estimation of the maximum possible damage to the public (worst case) Scenario assumed: Full bore rupture of a pipeline, followed by a "fireball" Number of fatalities is considered Parameters: pressure, pipeline diameter → maximum lethality distance (MLD), number of persons usually within MLD Sheltering effects of houses, etc., usually neglected

7. 7 Risk Assessment on Pipelines, the Swiss Approach Profile: fatalities (worst case) Drawn up over the entire length of the project Simplifications lead to conservative results On this basis, the authority evaluates whether a serious damage to the public (10 fatalities or more) is possible

8. 8 Risk Assessment on Pipelines, the Swiss Approach Second step of the procedure For those sections of the pipeline for which the maximum damage exceeds a given level, the authorities require a risk study Requires a quantification of the risk to the public, to be displayed as a cumulative frequency distribution Quantification carried out according to a standardised methodology, jointly developed by the main stakeholders Risk criteria are used for final decision

9. 9 Risk Assessment on Pipelines, the Swiss Approach Scenarios considered

10. 10 Risk Assessment on Pipelines, the Swiss Approach Parameters used in the risk study Pipeline operating pressure and diameter Wall thickness Steel grade Depth of cover Presence or not of concrete slab covering Number of persons outdoors or in buildings that do not provide adequate protection from heat radiation Number of persons in buildings that do provide adequate protection from heat radiation

11. 11 Risk Assessment on Pipelines, the Swiss Approach Calculation of the FN-curve A pipeline length of 300 m is used as a reference length for the risk study The consequences and the probability of the different scenarios are calculated every 10 m. The results of these calculations are then summed up in the FN-curve

12. 12 Risk Assessment on Pipelines, the Swiss Approach FN-Curves compared to risk criteria

13. 13 Risk Assessment on Pipelines, the Swiss Approach Main additional safety measures Optimisation of pipeline route Greater wall thickness Better steel grade Greater depth of cover Addition of concrete slab covering All these measures are subject to a number of constraints

14. 14 Risk Assessment on Pipelines, the Swiss Approach Experience so far The procedure described in this presentation has been applied on several hundred kilometres of new gas pipelines in Switzerland over the last years The use of a common basis for risk assessment has led in most cases to a fair approval process and to a comparatively high acceptance of new natural gas pipeline projects Risk is only one aspect among others

15. 15 Risk Assessment on Pipelines, the Swiss Approach A question for the future Population density along existing, and possibly old, pipelines significantly increased in the past and will increase also in the future The risk is increasing accordingly Safety measures for existing pipelines are particularly costly Question for the future: How are we going to handle fairly these cases Land Use Planning ? Safety measures on the pipe ? Safety measures for development along he existing pipelines ?

16. 16 Risk Assessment on Pipelines, the Swiss Approach Principles to be taken into account The safety of the public cannot be compromised A solution can be arrived at only by involving all stakeholders in an adequate manner All the possibilities mentioned in the previous slide should play a role There is no need to rush for an all- encompassing solution now Adequate priorities and deadlines will have to be set