Resolution of Generic Safety Issues: Item B-27: Implementation and Use of Subsection NF (Rev. 1) ( NUREG-0933, Main Report with Supplements 1–34 )
Since the adoption by the ASME Code, Section III, of Subsection NF on component supports, technical review has been limited to conformance of the information provided in the application and commitment by the applicants to component support design in accordance with the provisions in Subsection NF.
Certain deficiencies in the use of Subsection NF, however, have been identified primarily by NRC Code Committee members on the Working Group on Component Supports and its Task Forces. Examples of these deficiencies are:
|(1)||The absence of definitive criteria to be used in defining the jurisdictional boundary between a load carrying building structure designed by AISC rules which do not contain inservice inspection requirements and an attached NF component support having NF inservice inspection requirements.|
|(2)||As the design limits for Class 1 liner type component supports presently appear in the Code, the allowable stresses exceed those permitted for other Code-designed components. If these limits are approached repeatedly in the component support, the support could fail by fatigue.|
When this issue was added to NUREG-0933 in 1983, it was anticipated that some of the identified deficiencies would be addressed and corrected by revisions to the Code. This NUREG-04713 task would develop a BTP that would assess the remaining deficiencies for use by the staff in case reviews of component supports.
This item is a Licensing Issue. As a part of the improvements to NUREG-0933, the NRC staff clarified in SECY-11-0101, “Summary of Activities Related to Generic Issues Program,” dated July 26, 2011,1967 that the Generic Issues Program will not pursue any further actions toward resolution of licensing and regulatory impact issues. Because licensing and regulatory impact issues are not safety issues by the classification guidance in the legacy Generic Issues Program, these issues do not meet at least one of the Generic Issues Program screening criteria and do not warrant further processing in accordance with Management Directive 6.4, “Generic Issues Program,” dated November 17, 2009.1858 Therefore, this issue will not be pursued any further in the Generic Issues Program.
- NUREG-0471, “Generic Task Problem Descriptions (Categories B, C, and D),” U.S. Nuclear Regulatory Commission, June 1978.
- Management Directive 6.4, “Generic Issues Program,” U.S. Nuclear Regulatory Commission, November 17, 2009.
- SECY-11-0101, “Summary of Activities Related to Generic Issues Program,” July 26, 2011. [ML111590814]