Upgrade of C.N. Jose Cabrera, Zorita

The 160 MWe, pressurised water reactor C.N. Jose Cabrera (CNJC), located at Zorita, approx. 95 km east of Madrid began commercial operation in 1968 and had consistently operated since then with an availability factor in excess of 80%. Over the period mid-1979 to October 1985 an extensive programme was implemented by the plant owners, Union Electrica Fenosa S.A. (UEFSA), to upgrade CNJC, taking cognizance of regulatory requirements and clarifications which had begun to appear in 1974, and which had not been specific elements in the formulation of the original CNJC design and construction criteria. This programme comprised three phases: survey and assessment, conceptual design and detailed design/implementation. The implementation was completed over two periods of approximately nine months, during extended refuelling/maintenance shutdowns in 1982/83 and 1985. The author addresses the electrical changes and additions that were essential aspects in supporting the overall plant upgrade