RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS Calculations in the Netherlands By: ir. Piet Timmers Ing. Gea Stam RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Contents History and project outline Calculating Safety Distances for HRS Results Conclusions RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

History and project outline 2006: ‘Safety distances for hydrogen filling stations’ Matthijsen, Kooi, J. of Loss Prevention in the Process Ind. 2010: ‘Dutch practical guideline’ (NPR 8099) 2015: PGS35: ‘Hydrogen; installations for delivery of hydrogen to road vehicles’. 2014: European Directive for deployment of alternative fuel infrastructure (2014/94/EU) appropriate number of hydrogen refueling points. 2014: “Dutch vision on a Sustainable Fuel Mix” Intention Dutch Government: >20 public HRS in 2020 RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

History and project outline RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Calculating safety distances for HRS 3rd Party Risk: Risk Based approach. Rules: “Reference Manual Bevi Risk Assessments” Location specific risk limit = 10-6 per year Societal risk: indicative limit: 𝐹 𝑖𝑛𝑑 = 10 −3 𝑁 2 RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Calculating safety distances for HRS (assumptions) Calculations based on 1000 kg hydrogen per day For composite hoses a factor 10 lower failure rate is assumed for scenario ‘breaking of the hose’ (compared to Reference Manual) 2 buffer storages for delivery are present: one 440 bar (40 kg) one 950 bar (20 kg) Probability of direct ignition is 1 for release of gaseous hydrogen Probability of direct ignition is 0.9 for release of liquid hydrogen Weather conditions: mean value for the Netherlands Discussion: Failure probability of automatic ESD: Reference Manual: probability 0.001 per use, reaction time 120s Advisory Board: probability 0.01 per use, reaction time 5s All calculations done with SAFETI-NL 6.7 RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Calculating safety distances for HRS (steps) Define all scenario’s that are relevant Reference Manual defines the ‘General failure frequency’ Define relevant factors like fraction per year available or length of pipelines Calculate the actual failure frequency per year Calculate the Risk Safety Distances RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Calculating safety distances for HRS (steps) RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Results Type of station Distance to PR 10-6 (m) Supply of gaseous hydrogen by piping or local production 30 35 Supply of gaseous hydrogen by tube- or cylinder trailer 55 Supply of liquid hydrogen by a tank car. 95 130 RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Results Type of station Distance to PR 10‑6 Risk determining scenarios (% that scenario contributes to IR 10-6) Effect distance (1% lethality) Supply of gaseous hydrogen by piping or local production 30 m Intermediate storage (20 kg) at 950 bar – leak (83%) 35 m Intermediate storage (40 kg) 440 bar – inst release (17%) Supply of gaseous hydrogen by tube- or cylinder trailer Tube trailer – fireball as a result of fire in the surrounding (96%) Supply of liquid hydrogen by a tank car. Tank car – instantaneous release as a result of external interference (33%) 1200 m Delivery hose breaks – ESD working (17%) 90 m Intermediate storage (20 kg) at 950 bar – leak (17%) Tank car – BLEVE as result of fire in surrounding (13%) 130 m Results RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Results Type of station Scenario Effect distan ce (m) Supply of gaseous hydrogen by piping or local production Intermediate storage (20 kg) at 950 bar – leak 35 Intermediate storage (40 kg) at 440 bar – inst. release 30 Intermediate storage (40 kg) at 440 bar – leak 25 Supply of gaseous hydrogen by tube- or cylinder trailer Storage (400 kg) at 80 bar – instantaneous release 55 Tube trailer - Fireball Tube trailer – inst. release Supply of liquid hydrogen by a tank car. Tank car – Instantaneous release (weather type F1.5) 1200 Tank car – Instantaneous release (weather type D1.5) 490 Tank car – Instantaneous release (weather type E5) 370 Results RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017

Conclusions safety distances, based on PR 10-6 contour, for a HRS (1000 kg per day), is around 35 m. However, large effect distance (1200m) for inst. release of tank car liquid hydrogen. Scenario with large effect distance has low frequency (3.5·10-8 per year) so doesn’t contribute significant to safety distance. Results are used by Dutch Government for prescription of a fixed set of safety distances for HRS. For supply of liquid hydrogen further research is anticipated. RISK BASED SAFETYDISTANCES FOR HYDROGEN REFUELING STATIONS | 11 september 2017