Document: NRC Regulatory Guide
Document ID: a4944d20-ef6e-480b-a45d-14425bedd2e5
Document Type: regulatory_guide
Title: ASME Code Cases Not Approved for Use (Rev. 8)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2219/ML22196A065.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.193
CFR Part: 
CFR Title: 

Content:
UMMARY DATE OR SUPPLEMENT/ EDITION N-519-1 Use of 6061-T6 and 6061-T651 Aluminum for Class 1 Nuclear Components Code Case N-519 only applies to one U.S. Department of Energy aluminum vessel. N-519 was reinstated as Code Case N-519-1 on 11/26/18 with no change in the code case. Reinstated 11/26/18 N-530 Provisions for Establishing Allowable Axial Compressive Membrane Stresses in the Cylindrical Walls of 0-15 psi Storage Tanks, Classes 2 and 3, Section III, Division 1 There are numerous errors in the equations. The errors must be corrected before the Code Case can be approved for use. 2/3/03 N-565 Alternative Methods of Nozzle Attachment for Class 1 Vessels, Section III, Division 1 Code Case N-565 essentially requires a design that uses a seal to protect the threads from the contained fluid, and seals are not a Code item. The seal, which plays a very important part in the integrity of the joint, imposes too great a vulnerability in the design. The supporting information for Code Case N-565 does not demonstrate that the resulting threaded nozzle configuration is equivalent in integrity to that of a welded connection. 12/3/99 N-659-3 Use of Ultrasonic Examination in Lieu of Radiology for Weld Examination, Section III, Divisions 1 and 3 Code Case N-659-3 is not be allowed for new fabrication/construction because the interchangeability of UT vs. RT has not been adequately proven and defined. Section III requires examination on full thicknesses of the examination volumes. RT has been demonstrated to be capable of meeting this requirement, while UT capability has not been demonstrated. Also, UT is adapted to detecting cracklike flaws, while most construction flaws are not crack-like, thus radiography is more appropriate for characterizing and determining the acceptability of construction flaws. Additional performance demonstrations are needed to address acceptance criteria for procedures, personnel, and the UT equipment to be used for new fabrication/construction