This Section contains Division 1 and 3, in one volume and provides rules for the examination, inservice testing and inspection, and repair and replacement of components and systems in light water cooled and liquid metal cooled nuclear power plants. The Division 2 rules for inspection and testing of components of gas cooled nuclear power plants have been deleted in the 1995 Edition. With the decommissioning of the only gas cooled reactor to which these rules apply, there is no apparent need to continue publication of Division 2. Application of this Section of the Code begins when the requirements of the Construction Code have been satisfied. The rules of this Section constitute requirements to maintain the nuclear power plant while in operation and to return the plant to service, following plant outages, and repair or replacement activities. The rules require a mandatory program of scheduled examinations, testing, and inspections to evidence adequate safety. The method of nondestructive examination to be used and flaw size characterization are also contained within this Section. Careful application of this Section will help users to comply with applicable regulations within their jurisdictions, while achieving the operational, cost and safety benefits to be gained from the many industry best-practices detailed within these volumes.