Introduction: National Grid is required under the Pipeline Safety Regulations to manage the risks associated with the high pressure transmission pipeline network to a level which is “As Low As Reasonably Practicable” (ALARP). The AGI Safe (previously developed as “CompCab” under the IFI project “ Risk Methodologies) package is used by National Grid to perform quantitative risk assessments (QRAs) of a wide range of existing or proposed above-ground high pressure gas installations, including compressor sites, pressure reduction stations, offtakes, in order to prioritise safety expenditure and demonstrate compliance. A number of improvements and extensions to the functionality of the package has been identified and will be developed as part of this scope:

1. Modelling of pipework in pits which gives improved functionality and a more realistic model.

2. Creation of a module to model on site above ground pipework. This will allow site Emergency Shut Down to be taken into account using generic assumptions.

3. Provision for modelling ‘L’ shaped pipework areas.

4. Allowing for a greater aspect ratio to model long, thin sections of pipework, currently limited to an aspect ratio of 10 (length can be a maximum of 10 times the width of the block).

5. Automatic generation of escalation matrices for thermal radiation to allow modelling of the most cost effective means of fire protection.

6. Provision for User defined wind rose so that assessments can take into account local wind patterns across the UK

Also included will be various automation aspects to allow for greater efficiency including automation of the ‘Internal Leaks QRA module’ with the ‘Main Site QRA module’ so that the internal leaks do not have to be run as separate scenarios and then be manually added to the risk results database by the user, and provision of a ‘copy site’ function whereby a current site in the database can be duplicated so that the User can edit the duplicated site without changing database information for the current site.

Objectives:

To develop an enhanced risk assessment model for above ground installations.

Expected Benefits: The delivery of a fully functional tool “AGI safe”.