f Safe Venting and Recompression of Hydrogen - Final Technical Report

This document summarises The Safe Venting and Recompression of Hydrogen project (NIA_NGGT0205) project carried out by Wood PLC for National Gas Transmission from Feb 2023 to Feb 2024. The project explored the possible impacts of transition from natural gas fuel to hydrogen (or to hydrogen/natural gas mixtures) on the requirement to depressurise transmission pipelines and associated equipment for maintenance or other purposes. NGT currently employ gas recompression or venting to atmosphere as a means of achieving safe conditions for intrusive work. The project investigated the impact of the presence of hydrogen on these and other potential technologies for providing safe conditions of work. Details of the work carried out is recorded in Technical Notes TN01 to TN04. High level summaries of each technical note are included at the end of this Executive summary.
This report was submitted to HSE for their assessment of the safety evidence for 100% hydrogen heating, which can be found at Hydrogen heating: HSE assessment of the safety evidence - GOV.UK.
Queries should be directed to DESNZ: https://www.gov.uk/guidance/contact-desnz.