Possible use for PET

as the gas is transported through pipes to storage the pipes can get damaged, and the insides eroded and cracked.

magnetic particle inspection uses small magnetic particles to stick to and show faults in welding and metalwork due to a changing magnetic field over he surface of the metal and is widely used due to its non-intrusive nature.

http://me.aut.ac.ir/staff/solidmechanics/alizadeh/Magnetic%20Particle%20Inspection.htm

the non-radioactive kind is limited by the fact that contact must be made with the damaged surface, this may not always be positive however.

magnetic particles with inserted beta emitters will form the same structure on the faults but will be on the inside of the pipe and detectable using PET and if part is too damaged it can be removed.

A scanner able to do this job has been developed in Birmingham.

References
Nde-ed.org, (2015). Intro to MPI. [online] Available at: https://www.nde-ed.org/EducationResources/CommunityCollege/MagParticle/Introduction/introduction.htm [Accessed 12 Nov. 2015].
Np.ph.bham.ac.uk, (2015). Positron Imaging Centre. [online] Available at: http://www.np.ph.bham.ac.uk/pic/uses_mob_detector [Accessed 13 Nov. 2015].