ML120440284
| ML120440284 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse, Seabrook, Crystal River  |
| Issue date: | 02/16/2012 |
| From: | Jardaneh M, Alfred Issa NRC/NRO/DCIP/CITB, NRC/NRO/DCIP/CAEB |
| To: | |
| Jardaneh M., NRO/DCIP/CCIB/CIT, 415-2753 | |
| References | |
| Download: ML120440284 (14) | |
Text
Issue Generic Communications Domestic Events
- Collect for Collect Screen Evaluate Apply Assess impacts on International Events Screen for applicability to New Reactors Collect for Trending
- Communicate to impacted NRC staff
- Evaluate Lessons Learned p
Licensing Programs Assess impact on Inspection Programs Rule Making/ Long Term Research 2
Construction of nuclear installations include significant concrete activities.
Review of domestic and international experience suggests that concrete quality is still an issue.
suggests that concrete quality is still an issue.
3
Include:
Pressure retaining / containment / shielding; Housing of structures, systems and components (SSCs);
Structural support for SSCs; Protection of SSCs from natural disasters such as earthquakes, tornadoes and hurricanes; Protection of SSCs from internally and externally generated missiles; Separation and protection of redundant SSCs from the effects of single failures.
4
Varies based on several factors such as:
The functions of the impacted structure and the associated SSCs; The type of defect; The time of discovery : more significant for catastrophic self revealing failures; less significant for catastrophic self revealing failures; less significant for slow and progressive failures detected as part of normal monitoring; The design margin; The corrective actions planned or taken.
5
Include:
Latent design defects due to inadequate structural design, improper waterproofing, inattention to details and improper design changes; Latent construction defects caused by poor practices and negligence; g g Improper or inadequate maintenance; Environmental stressors; Beyond design bases accidents.
6
NUREG-1055 covers among other things, historical concrete issues; NUREG/CR-6927 focuses on concrete degradation mechanisms and includes a comprehensive list of previous concrete problems at various operating nuclear plants; p
IN 2008-17 lists recent concrete issues at nuclear facilities both domestic and international; IN 2011-20 discusses concrete degradation by Alkali-silica Reaction.
7
Alkali-Silica Reaction (ASR) at Seabrook.
Containment Delamination at Crystal River Shield Building Cracking at Davis-Besse 8
Seabrook identified ASR in Control Building/Electrical Building (and below-grade structures) in summer of 2009 during license renewal walkdowns; Standards used for testing during original construction may not accurately predict ASR. Additional tests (ASTM 1260 and 1293) are now recommended; ASR was also discovered in nuclear plants in Japan and Canada.
9
On October 6, 2009 and again on March 15, 2011, the concrete containment at Crystal River 3 delaminated.
On October 10, 2011, Davis-Besse discovered cracks in the Shield Building wall.
10
The NRC has issued many publications that address the prevention or minimization of concrete issues; Combined License (COL) applicants/holders should evaluate the available operating and construction experience to prevent similar problems; experience to prevent similar problems; The staff continues to monitor and evaluate new developments for additional lessons learned.
11
Use ConE insights to inform concrete inspections using Inspection Procedures IP-65001.01, Inspection of ITAAC-Related Foundations & Buildings, IP-65001.02, Inspection of ITAAC-Related Installation of Structural Concrete and IP-35007, Quality Assurance Program Implementation During Construction and Program Implementation During Construction and Pre-Construction Activities; Update NRC guidance documents to incorporate lessons learned as needed; Communicate lessons learned publically via issuing generic communications.
12
NUREG-1055, Improving Quality and the Assurance of Quality in the Design and Construction of Nuclear Power Plants covers among other things, historical concrete issues. See ML063000293; NUREG/CR-6927, Primer on Durability of Nuclear Power Plant Reinforced Concrete Structures - A Power Plant Reinforced Concrete Structures A Review of Pertinent Factors. See ML070850183; IN 2008-17, Construction Experience with Concrete Placement. See ML081850581; IN 2011-20; Concrete Degradation By Alkali-silica Reaction. See ML112241029; 13
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