Document: NUREG-0800
Document ID: 9756acc3-3645-4542-87b2-dba98ae1d5d5
Document Type: srp
Title: TURBINE ROTOR INTEGRITY
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190015.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.2.3
CFR Part: 
CFR Title: 

Content:
identified above are as follows for the review described in this SRP section. The SRP is not a substitute for the NRC’s regulations, and compliance with it is not required. However, an applicant is required to identify differences between the design features, analytical techniques, and procedural measures proposed for its facility and the SRP acceptance criteria and evaluate how the proposed alternatives to the SRP acceptance criteria provide acceptable methods of compliance with the NRC regulations. 1. Materials Selection. The turbine forged or welded rotor 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 performed for each forging. Elements that have a deleterious effect on toughness, such as sulfur and phosphorus, should be controlled to low levels. B. The 50% fracture appearance transition temperature (FATT) as obtained from Charpy tests performed in accordance with specification ASTM A-370 should be no higher than -18EC (OEF) for low-pressure turbine rotors. The nil-ductility transition (NDT) temperature obtained in accordance with specification ASTM E-208 may be used in lieu of FATT. NDT temperatures should be no higher than -35EC (-30EF). C. The Charpy V-notch (Cv) energy at the minimum operating temperature of each low-pressure rotor in the tangential direction should be at least 8.3 kg-m (60 ft-lbs). A minimum of three Cv specimens should be tested in accordance with specification ASTM A-370. 2. Fracture Toughness. The low-pressure turbine disk forged or welded rotor fracture toughness properties are acceptable if the following criteria are met. The ratio of the fracture toughness (KIc ) of the rotor material to the maximum tangential stress at speeds from normal to design overspeed should be at