For your convenience, a quick overview of the main conclusions of the Safety Program
This LNG Safety Program has been set up to address a range of LNG Safety related matters which were a concern to the Dutch Authorities at the start of the introduction of LNG as a fuel for trucks, barges and ships. Open questions existed in the area of best available technology, external safety risks in relation to LNG facilities in the built environment, impact distances and response to any incident if ever happening. The Program has been designed to generate answers to these questions not only in a scientific way but also by translating the obtained information to the work floor of the administrative worker in the town hall, the fireman exposed to an incident, the safety advisors involved in granting LNG related permits, etc.
The Program has been split over 6 main activities, each divided in a range of sub-activities again. Summaries of each of these sub-activities and their main conclusions plus the full final reports can be downloaded from the website www.SafeLNG.nl.
The purpose of this summary is to provide a few relevant general conclusions from the complete program:
- A series of Hazard Identification (HAZID) Sessions for the small scale LNG chain have been conducted delivering the credible incident scenarios. A list of 158 recommendations came out of the HAZID with potential owners for the follow up suggested. The knowledge obtained and recorded throughout the HAZID sessions are the basis (and provide input) for the LNG transfer (composite) hose test program and the ‘heat transfer from an external fire subjected to an LNG tank’ test. A separate, dedicated taskforce is making sure all 158 recommendations are being accepted and executed by proposed possible owners or when needed, relevant new owners.
- The ‘Tank Research Activity’ resulted in a bon fire test where a double wall vacuum insulated LNG storage tank of 3m3 was loaded with 2m3 liquid nitrogen (safe equivalent of LNG) and exposed for 2 hours to an external heat load of 75 kW/m2. The tank did not fail during this period, safety valves acted as designed and temperature of the inner tank did not exceed 50°C at any point, far away from the critical 300°C where the steel would start to lose integrity.
- The ‘Transfer Systems Research Activity’ focused on experiments with mainly composite LNG hoses. From this work it can be concluded that these type of hoses will likely leak before they fully break if exposed i) to the wheels of a loaded trailer driving across the cold hose in full operation or ii) the hose is degraded over time due to fatigue until it leaks such that it will be noticed by an operator.
- Under main activity ‘Codes and Regulations’, a ‘no regret’ Interim Policy for LNG permit procedures has been developed based on conservative assumptions for a range of relevant risk parameters. The earlier described conclusions from the research activities have validated these assumptions and for now, no new release of the Interim Policy Document is needed. It is expected to be incorporated as is in the new environmental legislation (Omgevingswet) or with still some small improvements, now based on solid proven knowledge.
- The ‘Emergency Response Activity‘ has created relevant Protocols for the fire brigades to instruct their commanders prior to arrival how to act once at the scene. Several field tests with real LNG pool fires have created a much better understanding about how to approach such fire. It is concluded that a water screen of very fine droplets (water fog) effectively can protect the direct vicinity, leaving the pool fire to continue till all LNG has been burnt.
- The ‘Local Authorities Activity‘ has resulted next to some advisory documents, in a permanent LNG Meeting Table (LNG Kennistafel) where representatives of emergency response, safety advisory teams for local authorities, Knowledge Institutes and LNG industry are meeting on a regular basis to discuss the lessons learned from incidents of any nature with LNG , not only in the Netherlands but also abroad.