Document: NUREG-0800
Document ID: 93695235-ba5b-4bfb-be93-d9aec2460bd0
Document Type: srp
Title: STEAM AND FEEDWATER SYSTEM MATERIALS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0631/ML063190016.pdf
Revision Date: 2023-06
Chapter: 10
Section ID: 10.3.6
CFR Part: 
CFR Title: 

Content:
ater reactors (PWRs) and boiling water reactors (BWRs). If cast austenitic stainless steel material is proposed for use, the adequacy of the material fracture toughness properties to withstand thermal aging over the design life of the component is reviewed. 3. Flow-Accelerated Corrosion (FAC) (previously referred to as Erosion-Corrosion). To address operating experience insights presented in NRC generic correspondence, including Generic Letter (GL) 89-08, “Erosion-Corrosion-Induced Pipe Wall Thinning,” the following aspects of FAC mitigation for the steam and feedwater systems are reviewed: A. Utilization of materials resistant to FAC. B. Specification of an adequate corrosion allowance. C. Piping design measures to minimize the effects of FAC. The terms FAC and erosion-corrosion (EC) have often been used interchangeably because early cases of FAC (high-energy carbon steel piping failures) were initially attributed to EC. GL 89-08 and the associated NUREG-1344 were written to address those piping failures, which are now recognized as FAC. FAC and EC are two distinct thinning mechanisms related to flow. FAC results from mass transfer and corrosion effects; EC results from mechanical and corrosion effects. Since FAC and EC are both related to flow effects, some licensees manage FAC as a subset of a comprehensive EC program. Computer programs designed for FAC management (e.g., CHECWORKS) are unlikely to accurately model corrosion rates for other forms of flow- related thinning such as EC. The subject of this review area is FAC. 4. Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC). For design certification (DC) and combined license (COL) reviews, the staff reviews the applicant's proposed ITAAC associated with the structures, systems, and components (SSCs) related to this SRP section in accordance with SRP Section 14.3, "Inspections, Tests, Analyses, and Acceptance Criteria." The staff recognizes that the review of ITAAC cannot be completed until after