## 1 Introduction
[PERSON] [15] gives overpressure values from 14 to 20 kPa as estimation for rupture of oil storage tanks. The TNO Green Book [16] assumes the roof of a storage tank will collapse at 7 kPa, while cracking in empty oil tanks occurs at around 20 to 30 kPa. Furthermore, in Chapter 2, Section 7.2.2, of [16], a positive load duration equal to 100 ms is adopted for blast studies in industrial facilities. Based on these data, steel tanks can be accepted as a reliable containment system against a blast load of 10 kPa overpressure with a positive load duration of 100 ms. However, tank designers should consider site- and project-specific requirements for verification of the blast resistance of the tank structure. In future planning processes, the design of ammonia storage tanks for significantly higher peak overpressures will become important. There are two main reasons for this: firstly, the design of tanks for high blast overpressure is intended to establish a higher safety standard. This is particularly important because tank structures are components of critical infrastructure. A failure not only affects the tank and its immediate production environment but also often has far-reaching consequences. A higher safety standard in the design, especially against accidental loads such as explosion pressure, can lead to lower failure probabilities. Secondly, the design of a tank for today's requirements should not result in any limitations for future projects with requirements that are not yet foreseeable. In the ever-faster changing world, it is also necessary to design industrial sites and in particular receiving terminals for future changing utilization concepts. To date, prestressed concrete external tanks have usually been used when a risk of high explosion pressure loads exists. Nevertheless, the construction of concrete tanks, especially as an outer shell with an internal steel tank, is more elaborate than the installation of steel tanks. The authors of [17] estimate that utilizing a double steel full containment tank instead of a full containment tank with a pre-stressed concrete secondary liquid container may result in a potential reduction in overall tank system cost ranging from 20% to 40%. However, it is important to note that the actual cost savings will vary depending on factors such as the tank size and geographical location. In addition to considering construction costs, it is also important to assess the long-term maintenance costs associated with different types of tank systems. Maintaining pre-stressed concrete structures is more complex compared to steel structures. Regular inspections, specialized repair techniques, and environmental considerations are necessary for concrete structures. The expertise and training required for pre-stressed concrete maintenance are higher compared to steel structures. While steel structures also require maintenance, it is generally less intricate and maintenance costs are therefore lower. It is generally known that cement production constitutes a significant share of the total CO2 emissions worldwide. From this perspective, steel tanks may be interesting as well looking at the latest developments in climate-neutral steel production. The aim of this publication is to address the following two issues in the context of steel tanks: (i) the feasibility of utilizing steel tanks in scenarios involving long-duration and high-pressure blast loads and (ii) introduction of an appropriate methodology for the analysis of blast-loaded steel tanks. Therefore, this paper presents the results of a study that investigates the potential for effectively adapting existing steel tank designs suitable for ammonia storage to withstand high explosion pressure loads over a prolonged duration. A representative steel tank geometry of an ammonia tank was numerically investigated for a peak overpressure of 30 kPa and 300 ms positive phase load duration. The load scenario was selected based on its inclusion as a requirement for safe tank design in both the Belgian and Dutch guidelines [13; 14].