D1c.1 Safety framework for industrial 8 to 16 bar hydrogen networks

The energy transition is leading to an increasing need for industrial hydrogen distribution networks operated on medium-high pressure (from 8 to 16 bar). This is a new domain for regional grid operators (DSOs) and there is no clearly formulated safety framework available yet. This report outlines a safety framework for the industrial hydrogen distribution networks operated on medium-high pressure.

Two representative cases have been explored: the H2avennet in the port of Amsterdam and the East Groningen Industrial Cluster (Industriecluster Oost‑Groningen, IC-OG). A safety framework has been developed based on analysis of laws and regulations, quantitative risk analysis (QRA), and research of incident approach and practical guidelines.

The (safety) requirements from the granting of permits for industrial hydrogen networks with a medium pressure of 8 to less than 16 bar were investigated. It follows from the analysis of the Environment and Planning Act (*Omgevingswet, ow) and associated decrees (Bal, Bkl, Bbl and Or) that hydrogen pipelines with an operating pressure below 16 bar are not formally regarded as environmentally harmful activities (milieubelastende activiteit), which means that no direct notification or permit requirement applies. It is recommended that this interpretation is legally reviewed, as competent authorities can still impose additional requirements through customization or planning rules.

For the time being, normative and technical alignment will be made with existing natural gas regulations and standards, such as relevant NEN standards and the Environmental Safety Manual, with the premise that these will be adapted to the specific properties of hydrogen where necessary. The aim is to achieve an equivalent safety level compared to natural gas, whereby odorization is not always appropriate due to industrial quality requirements.

Due to the provisional nature of legislation and regulations, the State Supervision of Mines (Staatstoezicht op de Mijnen, SodM) works with temporary guidelines and a supervisory arrangement for hydrogen pilots, based on self-regulation by network operators. These temporary frameworks are the starting point until permanent regulations and supervisory structures are established.

For both cases, a QRA was carried out in accordance with the Environmental Safety Calculation Regulations (Rekenvoorschrift Omgevingsveiligheid), with modelling in Safeti-NL. For both the Amsterdam and Groningen clusters, it is possible to define a hydrogen pipeline with the right set of measures where the safety distance of 10-6 per year is less than 5 metres. Because the risk is dominated by early effects of a flare fire, rapid emergency shutdown interventions have a limited effect on the calculated risk distances

The report elaborates guidelines for detection, alerting and approach of incidents for distribution networks in an industrial context. Reliable detection systems, use of thermal imaging, conservative safety distances and clear cooperation between grid operators, company fire brigades and public emergency services are of great importance in this respect.
Based on the results described above, a safety framework has been drawn up that provides practical tools for:
-Compliance with- and supervision of relevant laws and regulations,
-the prevention of incidents through system design, operational procedures and incident response procedures.