scope:

PURPOSE AND SCOPE

Oil leaks have historically been a problem for oil-filled cables, as oil is a pollutant it is important to minimise the amount lost to the environment. National Grid is committed to the prevention of pollution and continual improvement in our environmental performance. As such undertake measures, where necessary, to improve the efficiency of leak location and to try and contain any lost oil. At present there is no industry-wide standard to define what measures should be adopted.

To help reduce the impact of oil leaks National Grid continues to support a range of initiatives such as:

(a) The installation of Dralim, a transducer based oil pressure monitoring system

(b) The use of Perflurocarbon Tracing (PFT) to detect leaks without the need to dig

(c) Research into the movement and remediation of cable oils in backfill and soils

(d) Improved oil containment systems

This Technical Guidance Note (TGN) describes suitable installation techniques of systems to detect and contain leaking oil from power cables.