ML102720335

Regulatory Analysis to DG-1196, Qualification for Cement Grouting for Prestressing Tendons in Containment Structures

ML102720335
Person / Time
Issue date:	10/04/2010
From:	Office of Nuclear Regulatory Research
To:
Bayssie Mekonen/RES 251-7489
References
DG-1196 RG-1.107, Rev 2
Download: ML102720335 (2)

Text

REGULATORY ANALYSIS QUALIFICATION FOR CEMENT GROUTING FOR PRESTRESSING TENDONS IN CONTAINMENT STRUCTURES (Proposed Revision 2 of Regulatory Guide 1.107, dated February 1977)

Statement of the Problem The NRC issued Regulatory Guide 1.107, Revision 1, in February 1977, to describe quality standards that the NRC staff considered acceptable for the use of portland cement grout as the corrosion inhibitor for prestressing tendons in prestressed concrete containment. The staff is revising the existing regulatory guide (1) to ensure consistency with other similar regulatory guides, (2) to update the references that form the technical bases for staff regulatory positions, and (3) to update the guidance to reflect recent revisions of the relevant ASME Code, updating some of the exceptions that the staff had previously taken from the prior version of the ASME Code, because the revised and newer ASME Code has included those exceptions. Therefore, a revision to this regulatory guidance is necessary to include the updated information.

Objective The objective of this regulatory action is to update the NRCs guidance on the use of portland cement grout as the corrosion inhibitor for prestressing tendons in prestressed concrete containment to give applicants and licensees the opportunity to take advantage of the revised ASME Code requirements and the current staff positions. Updating the NRCs guidance in this area should lead to increased regulatory effectiveness.

Alternative Approaches The NRC staff considered the following alternative approaches:

Do not revise Regulatory Guide 1.107.

Update Regulatory Guide 1.107.

Alternative 1: Do Not Revise Regulatory Guide 1.107 Under this alternative, the NRC would not revise this guidance, and the current guidance would be retained. If the NRC does not take action, there would not be any changes in costs or benefit to the public, licensees, or the NRC. However, the no-action alternative would not address identified concerns with the current version of the regulatory guide. The NRC would continue to review each application on a case-by-case basis. This alternative provides a baseline condition from which any other alternatives will be assessed.

Alternative 2: Update Regulatory Guide 1.107 Under this alternative, the NRC would revise Regulatory Guide 1.107 to reflect the revised ASME Code requirements and current staff positions.

One benefit of this action would be that the licensees and the staff would use the latest ASME Code requirements and current staff positions in evaluations. Therefore, the revised Regulatory Guide 1.107 could improve regulatory effectiveness while maintaining or enhancing safety.

The impact to the NRC would be the costs associated with preparing and issuing the regulatory guide revision. The impact to the public would be the voluntary costs associated with reviewing and providing comments to the NRC during the public comment period. The value to the NRC staff and its applicants would be the benefits associated with enhanced efficiency and effectiveness in using a common guidance document as the technical basis for license applications and other interactions between the NRC and its regulated entities.

Conclusion Based on this regulatory analysis, the NRC staff recommends a revision of Regulatory Guide 1.107. The staff concludes that the proposed action would improve regulatory effectiveness, increase efficiency, and maintain or enhance safety.

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