Document: NUREG-0800
Document ID: 967102fd-cb63-4897-b488-1358be1b2640
Document Type: srp
Title: TURBINE DISK INTEGRITY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350072.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.2.3
CFR Part: 
CFR Title: 

Content:
ablish that the turbine disk materials exhibit adequate fracture toughness at normal operating temperature and during startup. 3. Preservice Inspection The preservice inspection program information is reviewed to verify that the disk forgings are first machined with minimum excess stock prior to heat treatment, that visual and surface inspections are performed on all finished machined surfaces, and that a 100% volumetric (ultrasonic) examina- tion is performed. 4. Turbine Disk Design The low-pressure turbine rotor design information, including allowable stresses, temperature distributions, and design overspeed considerations, is reviewed. 5. Inservice Inspection Descriptions of the baseline and inservice phases of the inservice inspec- tion program, including types of inspections, areas to be inspected, frequencies of inspection, and acceptance criteria, are reviewed. II. ACCEPTANCE CRITERIA MTEB acceptance requirement is based on meeting the relevant requirements of General Design Criterion 4, "Environmental and Missile Design Bases," as it relates to structures, systems, and components important to safety being appro- priately 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 disk are as follows: 10.2.3-2 Rev. 1 - July 1981 1. Materials Selection The turbine disk should be made from a material and by a 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%