CONTROLLING NDT TO MINIMIZE DOWNTIME AND RISK AND TO COMPLY WITH REGULATORY REQUIREMENTS ON 500-MW PLANT

National Power the largest of the CEGB successor companies, has a cons iderable amount of mid-merit generating plant, the majority of which i s coal-fired A large number of the existing power stations are based o n 500 MW boilers of several different designs. The Pressure Systems an d Transportable Gas Containers Regulations, 1989, allow users of such systems to extend the periods between thorough examinations by develop ing written schemes of examination which include references to the tec hnical information and records generated by non-destructive testing an d inspection surveys. A substantial amount of NDT is carried out durin g each thorough examination, mostly by contract staff. Quality control of these activities is an essential element of the justification for extending the period between thorough examinations, which results in c onsiderable cost reduction.