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:
°F) as constant (T* = 1). The NRC’s updated research only includes data up to 325 °C (615 °F), and the updated Fen expression for wrought and cast austenitic stainless steels does not plateau at temperatures above 325 °C. Therefore, the Code Case may provide nonconservative estimates of Fen for temperatures above 325 °C. g. -2424 defines the transformed temperature for Ni-Cr-Fe steels for temperatures above 325 °C (615 °F) as constant (T* = 1). The NRC’s updated research only includes data up to 325 °C (615 °F), and the updated Fen expression for Ni-Cr-Fe steels does not plateau at temperatures above 325 °C. Therefore, the Code Case may provide nonconservative estimates of Fen for temperatures above 325 °C. The NRC recommends that Code Case N-792-1 be revised to reflect NUREG/CR-6909 Rev. 1 after it is published. The NRC staff abstained from voting on this item at Standards Committee and commented that the staff does not support the Code Case based on NRC sponsored research that is ongoing. N-804 Alternative Preheat Temperature for Austenitic Welds in P-No. 1 Material without PWHT, Section III, Division 1 The NRC believes that the test data provided are insufficient to support a reduction in the Code-required preheat of 200 °F. Data for the welds in the production valve bodies tested indicate the presence of martensite, which results in unacceptably high hardness values. Hydrogen cracking of the welds could result in the absence of proper preheat. 10/14/11 N-812-1 Alternate Creep-Fatigue Damage Envelope for 9Cr-1Mo-V Steel, Section III, Division 5 Code Case N-812 utilizes Section III, Division, Subsection NH, “Class 1 Components in Elevated Temperature Service.” The NRC has not approved Subsection NH for use. 1/10/13 DG-1408, Page 11 CODE CASE NUMBER TABLE 1 UNACCEPTABLE SECTION III CODE CASES SUMMARY DATE OR SUPPLEMENT/ EDITION N-818-1 Use of NDE and Fracture Mechanics for Acceptance of Full Penetration Butt Welds in Lieu of Weld Repair, Class