Resolution of Generic Safety Issues: Item B-49: Inservice Inspection Criteria and Corrosion Prevention Criteria for Containments (Rev. 1) ( NUREG-0933, Main Report with Supplements 1–35 )

DESCRIPTION

GDC-53, "Provisions for Containment Testing and Inspection," requires in part that the reactor containment be designed to permit: (1) periodic inspection of all important areas, and (2) an appropriate surveillance program. 10 CFR 50, Appendix J, "Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors," requires a general inspection of the surfaces of the containment prior to any Type A test to uncover any evidence of structural deterioration.

Containment designs typically utilize any one of the following structural materials: steel, steel-lined reinforced concrete, and steel-lined prestressed concrete. At the time this issue was added to NUREG-0933 in 1983, the only detailed criteria that were developed for ISI of containments related to tendon surveillance for prestressed concrete containments. These criteria were contained in Regulatory Guides 1.35⁴⁸¹ and 1.90⁴⁸² which addressed ungrouted and grouted tendons, respectively. These Regulatory Guides dealt primarily with the prestressing hardware; no detailed ISI criteria existed for the steel liner or other portions of the containment. Similarly, there were no criteria for ISI of steel containments or steel-lined reinforced concrete containments. In view of this, detailed and comprehensive criteria needed to be developed for performing ISI of all types of containments.

In addition, the long-term corrosion problems of reinforcements and of the steel liner in contact with concrete in concrete containments, or the corrosion of the steel surface in contact with the water in BWR suppression chambers, had yet to be adequately analyzed. Long-term studies of these corrosion phenomena needed to be undertaken to develop criteria and requirements to prevent corrosion in all types of containments. This issue is documented in NUREG-0471.³

CONCLUSION

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.

REFERENCES

0003. NUREG-0471, "Generic Task Problem Descriptions (Categories B, C, and D)," U.S. Nuclear Regulatory Commission, June 1978. 0481. Regulatory Guide 1.35, "Inservice Inspection of Ungrouted Tendons in Prestressed Concrete Containments," U.S. Nuclear Regulatory Commission, February 1973, (Rev. 1) June 1974, (Rev. 2) January 1976 [7907100149], (Rev. 3) July 1990 [7809180004]. 0482. Regulatory Guide 1.90, "Inservice Inspection of Prestressed Concrete Containment Structures with Grouted Tendons," U.S. Nuclear Regulatory Commission, August 1977. [7907100329] 1858. Management Directive 6.4, "Generic Issues Program," U.S. Nuclear Regulatory Commission, November 17, 2009. 1967. SECY-11-0101, "Summary of Activities Related to Generic Issues Program," July 26, 2011. [ML111590814]