Document: NUREG-0800
Document ID: 60504484-b86d-4048-bba0-59d150675db4
Document Type: srp
Title: TURBINE DISKROTOR  INTEGRITY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070578.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.2.3
CFR Part: 
CFR Title: 

Content:
xamined, giving particular attention to stress risers and welds; and that welds will be ultrasonically examined in the radial and radial-tangential sound beam directions.10 4. Turbine DiskRotor Design The low-pressure turbine rotor design information, including allowable stresses, temperature distributions, and design overspeed considerations, is reviewed. 5. Inservice Inspection 10.2.3-3 DRAFT Rev. 2 - April 1996 Descriptions of the baseline and inservice phases of the inservice inspection program, including types of inspections, areas to be inspected, frequencies of inspection, and acceptance criteria, are reviewed. II. ACCEPTANCE CRITERIA MTEB The NRC acceptance requirement is based on meeting the relevant requirements of 11 General Design Criterion 4 GDC 4, "Environmental and Missile Dynamic Effects Design 12 Bases," as it relates to structures, systems, and components important to safety being appropriately protected against environmental and dynamic effects, including the effects of missiles, that may result from equipment failure. The specific criteria necessary to meet the relevant requirements of GDC 4 to reduce the probability of failure of the turbine diskrotor are as follows: 1. Materials Selection The turbine disk forged or welded rotor should be made from a material and by a 13 process that tends to minimize flaw occurrence and maximize fracture toughness properties, such as a NiCrMoV alloy processed by vacuum melting or vacuum degassing. The material should be examined and tested to meet the following criteria: a. Chemical analysis should be made for each forging. Elements that have a deleterious effect on toughness, such as sulfur and phosphorus, should be controlled to low levels. b. The fracture appearance transition temperature (50% FATT) as obtained from Charpy tests performed in accordance with specification ASTM A-370 should 14 be no higher than -18 C (O F) for low-pressure turbine diskrotors. 15 Nil-ductility transition (NDT) temperature