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Repair of Reinforced Concrete of Existing Nuclear Power Plants (RCTG). Chiara Ferraris, NIST Nathan Sauer, SIMCO Technologies. Schedule. July 2011 : TG was approved by NESCC December 2012: Final report to ballot Nov. 28, 2012 – January 4,2013: Ballot January-March 2013: address comments
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Repair of Reinforced Concrete of Existing Nuclear Power Plants (RCTG) Chiara Ferraris, NIST Nathan Sauer, SIMCO Technologies
Schedule • July 2011: TG was approved by NESCC • December 2012: Final report to ballot • Nov. 28, 2012 – January 4,2013: Ballot • January-March 2013: address comments • March 28, 2013: to NESCC for comments • April – July 2013: address comments and publication
Ballot December- January • 119 comments on content (no editorial allowed) • All were on missing documents and missing references. Some details were added • Did not change the conclusions as presented in November
Table of content • Introduction • Objectives overview • Inventory of NRC documents • Evaluation of the concrete structure • Concrete repair strategy and design • Repair implementation • Monitoring quality control • Conclusions • Index of Standards documents
Objectives • Categorize codes and standards related to concrete repair in NRC documents • Identify relevant repair concrete codes and standards missing from the NRC documents • Identify technologies and new research that could translated in to new standards and codes to be adopted by an SDO • Identify new technology and research needs to fill knowledge gaps in existing concrete repair codes and standards
Overall recommendations • NRC should have a mechanism to evaluate any new version of an SDO document and determine its adoption or clearly state the reason for rejection • Develop a repair code specific for nuclear structures • Increase/sponsor research on the effects of radiation on concrete, combined with the effect of temperature exposure over a long period of time.
Overall recommendations (2) • Standardized process from NRC should be implemented to pre-approve new technology and materials (database from SAG) • Develop models for prediction of service life of repairs, especially taking into account the interaction with the concrete substrate • Develop models for evaluation of remaining service life of a damaged structure.
Overall recommendations (3) • Develop standard test methods to evaluate a structure for repair, quality control and quality assurance.