Lin Teng, Peidong Ling, Chunbo Zhao, Zengqiang Zhang, Bin Liu, J. Li, Pengbo Yin, Zhenchao Li, Lilong Jiang
Ammonia pipelines are gaining renewed attention as key enablers of hydrogen energy systems, offering a practical solution to hydrogen transport and storage. However, current safety standards remain insufficient, as they often rely on risk models developed for natural gas or petroleum pipelines. This paper presents a novel, data-driven risk assessment methodology tailored specifically developed to establish scientifically justified safety distances for ammonia pipelines. A comprehensive dataset of 232 ammonia pipeline accidents spanning 1970 to 2023 was systematically collected and analyzed, revealing that material and welding defects account for 36.21% of failures. By applying Bayesian updating to failure data, individual and societal risk assessment models tailored explicitly for ammonia pipelines were developed. Risk assessment simulations indicate that Pipeline-1 (250 mm / 25 bar) reaches an individual risk level of 10 -6 at 300 m, while Pipeline-3(150 mm / 20 bar) shows similar risk grade at 190 m. In comparison, Pipeline-2(200 mm / 25 bar) and Pipeline-4(100 mm / 15 bar) reach 10 -7 at 325 m and 145 m, respectively. The proposed methodology delivers a scientifically grounded basis for determining safety distances, and offers actionable insights for improving ammonia pipeline design, permitting, and safety regulation.