Soap Solution test with air in the annular gap and by smearing soap solution. Bubbling of the soap layer was noticed only in the defective spot.

Permascope measurement to check for uniformity of the annular gap by eddy current method and found more or less uniform.

Helium Sensitive Leak Test by MFL and India Gandhi Centre for Atomic Research's Handy leak detector was carried out. No indication other than the defect spot.

Ammonia Vapour Leak test conducted by fixing the Ammonia Print paper on the shell with Ammonia vapour in the annular gap after attending the leaky spot. No colour change noticed which confirmed absence of liner defects.

By using the above Non-Destructive methods the liner leak was detected efficiently while, the widely used NDT techniques like Ultrasonic and Radiography were found to have its own limitations.