Design basis documentation program-a critical overview

It is noted that many nuclear power plant owners have undertaken a massive effort of reviewing and reconstituting the design basis documentation (DBD) for the safety-related systems, components, and structures of their plants. In spite of the Nuclear Management and Resource Council´s (NUMARC´s) guideline on this issue, a significant amount of confusion exists in the industry about the need, requirements, extent, and the depth of the review and reconstitution efforts. A well-developed DBD program, developed on the basis of a plant´s unique design, licensing, and operation history, can be very cost-effective and can pay back the investment within a short time. Ingredients necessary for developing such a program are discussed. A critical overview of the various parameters, both technical and programmatic, affecting the DBD issue is also presented. The author addresses two documents that he considers to be the keys to an effective DBD program: (i) a road-map-type plant-level DBD that will establish the plant design bases through tables and matrices uncluttered by lengthy design change and licensing histories, and (ii) a comprehensive document establishing the design margin of individual components.<>