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:
y gap more than 1/32-inch between transducer and weld. 5. Paragraph (g) of the code case seems to be the discussion of a calibration block, not a qualification block. 6. Paragraph I-3.2(d) states that “…Examination procedures, equipment, and personnel are qualified for depth-sizing when the RMS [root-mean- square] error of the flaw depth measurements, as compared to the true flaw depths, does not exceed 0.125 in. (3 mm)…” The RMS error was meat for depth sizing of service-induced surface connected flaws. The NRC staff does not find using this RMS error is appropriate for measurements of fabrication defects. 7. The location of the fabrication defect is important in that if the fabrication defect is located closer to the inside surface vs outside surface of the pipe. 8. The depth of the maximum flaw permitted by the code case for the preservice examination is 20 percent through wall. The concept of such fabrication defect permitted to remain in the component prior to service is contrary to the fundamental design philosophy of ASME Code, Section III which is that a component is not designed to have flaws. In addition, the allowable limits for primary and secondary stresses and cumulative fatigue usage factors in NB-3000 and NC-3000 are based on a component without flaws. 8/20/14 DG-1408, Page 12 CODE CASE NUMBER TABLE 1 UNACCEPTABLE SECTION III CODE CASES SUMMARY DATE OR SUPPLEMENT/ EDITION 9. Permitting a 20 percent depth flaw to remain in a component prior to service reflects a tacit approval of a lower quality of the product and subpar workmanship. N-837 Alternative to the Registered Professional Engineer Requirements, Section III, Divisions 1, 2, 3, and 5 This Code Case is only for non-U.S. nuclear facilities; therefore, it does not apply to U.S. nuclear facilities regulated by the NRC. 10/22/13 N-846 Certificate Holder Ability to Supply Polyethylene Material, Section III, Division 1 Code Case N-846 is not consistent with NRC position documented in NRC