Towards environmental risk acceptance criteria. Pierre C. Sames and Rainer Hamann Germanischer Lloyd AG

Transcription

1 Towards environmental risk acceptance criteria Pierre C. Sames and Rainer Hamann Germanischer Lloyd AG

2 Introduction to risk evaluation criteria 1 Risk assessment requires criteria! Such criteria must be accepted by society. Example: risk evaluation criteria related to human life individual risk and societal risk MSC 83/INF.2 FSA guidelines (MSC 83/INF.2) provides such criteria for the maritime regulatory framework. Basic philosophy of risk assessment: Risks between negligible and intolerable should be made As Low As Reasonably Practicable (ALARP). Risk should be made ALARP by adopting cost-effective risk control measures. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 2

3 Introduction to risk evaluation criteria 1 Risk assessment requires criteria! Such criteria must be accepted by society. Example: risk evaluation criteria related to human life individual risk and societal risk Max. negligible tolerable To crew member To passenger To third parties FSA guidelines (MSC 83/INF.2) provides such criteria for the maritime regulatory framework. Basic philosophy of risk assessment: Risks between negligible and intolerable should be made As Low As Reasonably Practicable (ALARP). Risk should be made ALARP by adopting cost-effective risk control measures. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 3

4 Introduction to risk evaluation criteria 2 But how to evaluate environmental risk? Transfer of the safety philosophy requires: Definition of risk categories ( intolerable intolerable, tolerable, negligible) Criterion for CEA SAFEDOR suggested a new cost effectiveness criterion related to accidental oil spills of tankers in 2005: Cost of Averting a Tonne of oil Spilt (CATS) CATS is a cost-effectiveness criterion for ALARP process. The ALARP area for environmental risk not yet defined. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 4

5 Introduction to risk evaluation criteria 3 CATS (Thr) (> C/R) Is a criterion independent of the oil type and the spill size. For application in FSA investigation Considers cleaning costs (USD 16,000/tonne), environmental costs (USD 24,000/tonne) and an assurance factor (> 1, present proposal 1.5) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 5

6 Brief review of tanker operation 1 Data for major oil tanker segments (fleet at risk) and accidents was compiled using the LRFP-database: PANAMAX 200 No. of ships Panamax SH Aframax SH Suezmax SH VLCC SH Panamax DH Aframax DH Suezmax DH VLCC DH AFRAMAX SUEZMAX Year VLCC & ULCC Data from the period was used resulting in ship years Presently about 2000 tankers (> 60,000 DWT) are operating Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 6

7 Brief review of maritime oil spills accidents with oil spills ranging from 1kg to 260,000 t were analysed. (total: ~1 million tonnes) The number of accidents from double hull (DH) tankers is significantly smaller than for single hull (SH) tankers. 70 Accidents between 1990 and 2007 broken down to categories No. of accidents = 10 >10 to 100 >100 to 1000 >1000 to Spill size (tonnes) >10000 to > No. of accidents Collision 1 SH DH Contact Fire/Explosion Foundered Grounding Hull and machinery Misc Wrecked/Stranded 1 Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 7

8 Brief review of maritime oil spills 2 Frequency of N or more tonnes spilt per ship year 1 E+00 1 E-01 1 E-02 1 E-03 1 E-04 1 E-05 F-T-diagram: cumulative oil spill size frequency for maritime transport by oil tankers for the period 1990 to E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 8

9 Brief review of maritime oil spills 3 1 E-02 Accumulated frequency of oil spill quantity Frequency of N or more tons spilt per ship year 1 E-03 1 E-04 1 E E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Factor 3 Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 9

10 Introduction to ALARP It defines that risks should be reduced to as low as reasonable practical and costeffectiveness is used to assess risk control options. An ALARP area can be defined by two lines in the double-logarithmic F-N diagram. A slope of -1 is typically used to express risk aversion. In FSA the anchor point is set using economic considerations. Frequency of N or mor re tonnes spilt per ship ye ear 1 E+00 1 E-01 1 E-02 1 E-03 1 E-04 1 E-05 1 E-06 Anchor point negligible Distance intolerable tolerable Slope Upper bound Low er bound 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 10

11 Setting an ALARP area Approach 1: It is accepted as means of transport, and associated risks are also considered acceptable. Approach 2: Societal acceptance of oil spills is based on the same economic value considerations as the societal acceptance of loss of life. Approach 2b: Approach 2 + non constant CATS Approach 3: Transfer from oil transport by pipeline. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 11

12 Setting an ALARP area approach 1 It is accepted as means of transport, and associated risks are also considered acceptable. Therefore, current maritime oil transport by tankers defined by data - is JUST acceptable and cost-effective risk control options should be implemented. SH and DH tankers are considered. Boundary to intolerable risk defined by tangent of F-T diagram. Slope of -1 The width of the ALARP area is taken as two orders of magnitude. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 12

13 Setting an ALARP area approach 1 1.E+00 or more tonnes spilt r shipyear Frequency of N per 1.E-01 intolerable 1.E-02 1.E-03 1.E-04 tolerable tolerable 1.E-05 1.E-06 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Note: presently, all spills smaller than 20 tons are rendered negligible. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 13

14 Setting an ALARP area approach 2 It is assumed that the societal acceptance of oil spills is based on the same economic value considerations as the societal acceptance of loss of life. This implies that a translation of the value of life to the value of environment is possible. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 14

15 Setting an ALARP area approach 2 The ratio of cost-effectiveness criteria CAF and CATS is used to scale existing ALARP boundaries. CATS Thr = 60,000 USD CAF = 3 million USD Anchor point for tolerable - intolerable boundary for tanker crew safety: N = 1; F = 2J10-2. The anchor (T= 50; F1= 0.02) Slope of -1 The width of the ALARP area is taken as two orders of magnitude. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 15

16 Setting an ALARP area approach 2 1 E+00 Frequency of N or more tonnes spilt per sh hip year 1 E-01 intolerable 1 E-02 1 E-03 1 E-04 Upper bound Lower bound DH+SH (90-06) tolerable 1 E-05 negligible 1 E-06 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Note: presently, all spills larger than 700 tons are rendered intolerable. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 16

17 Setting an ALARP area approach 2 Frequency of N or more tonnes spilt per ship year 1 E+00 1 E+00 Frequency of N or more tonnes spilt per ship year 1 E-011 E-01 1 E-021 E-02 1 E-031 E-03 1 E-041 E-04 1 E-051 E-05 negligible negligible intolerable rable tolerable tole rable Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 17 Effect of one accident with a spill of tonnes? SH+DH (97-06) DH DH SH SH Upper bound Upper Lower bound Low DH+SH er bound (90-06) A ssumption Effect of one accident 1 E-06 1 E-06 1 E+00 1 E+01 1 E+00 1 E+01 1 E+02 Category 1 E+03Av. Tank 1 E+04 Size 1 E+02 1 E+03 E+04 1 Stdv. E+05 1 E % E+06 Quantile 1 E+06 PANAMAX Spill size (tonnes) 5600 t 1500 t 3600 t Spill size (tonnes) AFRAMAX 8000 t 1800 t 5900 t SUEZMAX t 2300 t 8300 t VLCC t 2800 t t ULCC t 3000 t t

18 Cost of oil spills Cost of oil spills vary with spill location, spill size, oil type, etc. Larger oil spills typically cost less per unit oil spilt. Examples: OSIR data: Grey data: 10,000 USD/tonne 1,000 USD/tonne 100,000 USD/tonne 1,000 USD/tonne A spill-size dependent CATS was created and tested to define the ALARP area using CAF/CATS. Open sea For last ten years Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 18

19 Cost of oil spills Cost of oil spills vary with spill location, spill size, oil type, etc. Larger oil spills typically cost less per unit oil spilt. Examples: OSIR data: Grey data: 10,000 USD/tonne 1,000 USD/tonne 100,000 USD/tonne 1,000 USD/tonne A spill-size dependent CATS was created and tested to define the ALARP area using CAF/CATS. USD spill-siz e dependent CATS E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tons) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 19

20 Cost of oil spills Glacier Bay Exxon Valdez Iliad Honan Sapphire Arco Ancorage Costs per tonne Katja American Trader Ondina ToyotakaMaru Agip Abruzo Antonio Gramsci Diamant grace Antonio Gramsci Baltic Carrier Jeong Yang Nissos Amorgos Erika Prestige Sea Empress Aegean Sea Alambra 1000 Haven Pontoon300 Braer Av. of 25 spills: 42,000 USD/tonne Source: Grey, IOPC, US Spill size (tonnes) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 20

21 Setting an ALARP area approach 2b Frequency of N or more tonnes spilt per ship year 1 E+00 SH+DH (97-06) DH 1 E-01 intolerable SH Lower bound 1 E-02 Upper bound Upper bound (cost) 1 E-03 Lower bound (cost) 1 E-04 neglegible tolerable 1 E-05 1 E-06 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Note: spill-size dependent CATS shifted boundaries to higher frequencies. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 21

22 Setting an ALARP area approach 3 Pipeline as reference? Crude oil is transported also by pipeline. About miles of pipelines span the US. The contribution to GDP from the pipeline industry averages to 10.5 billion USD per year ( ). At the same time, the volume of oil spilt in pipeline accidents averages to t per year ( ). This results in 1.41 t oil spilt per million USD contribution to GDP. Source: The four major oil tanker classes were considered separately and their current charter rate (per day for 1-year time charter) was used to determine annual revenues. The average annual revenue from oil transport by tanker is 16 million USD. Combining the pipeline data with the shipping data yields a target value for PLO of 22.6 t oil spilt / per ship year. This can be used to construct the acceptance criteria in the FTdiagram. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 22

23 Setting an ALARP area approach 3 Frequency of N or more tonnes spilt per sh hip year 1 E+00 1 E-01 intolerable 1 E-02 ALARP 1 E-03 1 E-04 negligible 1 E-05 1 E-06 1 E+00 1 E+01 1 E+02 1 E+03 1 E+04 1 E+05 1 E+06 Spill size (tonnes) Note: using pipeline data shifted boundaries to higher frequencies. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 23

24 Conclusions and outlook 1 Risk assessment requires criteria! Risk acceptance criteria are not based on natural law. Safety and environmental criteria must be accepted by society. ALARP principle p in combination o with cost-effectiveness analysis to determine acceptable risk. Presupposition: definition of intolerable and negligible risk. Different approaches for a definition of tolerable area are presented. Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 24

25 Conclusions and outlook 2 Cost-benefit analysis within FSA process requires a threshold. Such a threshold may either be constant of spill size dependent. The definition of such a threshold should consider The societal need of environmental protection. The application in IMO process (improvement of regulations) That most of the tanker operate worldwide and transport different oil grades. CATS was proposed by SAFEDOR (CATS Thr = 60,000 USD) Workshop Environmental Risk Evaluation Criteria Athens Feb Last modified: No. 25

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