ML14230A909
| ML14230A909 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/18/2014 |
| From: | Ricardo Torres NRC/NMSS/SFST |
| To: | |
| Goshen J | |
| Shared Package | |
| ML14230A903 | List: |
| References | |
| TAC L24475 | |
| Download: ML14230A909 (17) | |
Text
Generic Concrete Aging Management Program Ricardo D. Torres,, Ph.D.
Division of Spent Fuel Storage and Transportation Office of Nuclear Material Safety and Safeguards U S Nuclear Regulatory Commission U.S.
Calvert Cliffs ISFSI Renewal Meeting July 17, 2014 1
Basis for Development Valid basis include applicable consensus codes/standards and/or NUREG guidance, e.g.:
ACI 349.3R, Evaluation of Existing Nuclear Safety-Related Concrete Structures ASME C Code d S Section ti XIXI, S Subsection b ti IWL IWL, R Requirements i t ffor Cl Class CC Concrete Components of Light-Water-Cooled Plants NUREG-1801, Generic Aging Lessons Learned (GALL) Report Applicant may propose AMPs based on alternate criteria:
Exclusion of aging effects/mechanisms in the above codes/standards should be justified with a site-specific technical basis (e.g., engineering analysis, l i operational ti l experience i d data).
t )
Justification should demonstrate that the excluded aging mechanisms will not adversely affect the ability of the in-scope structure to perform its intended function during g the license pperiod of extended operation.
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Aging Effects/Mechanisms Mechanism Effect Freeze-thaw Cracking, loss of material (spalling, scaling)
Chemical attack [Cl, SO4] Cracking, loss of material (spalling, scaling)
Aggregate reactions/expansion Cracking and loss of strength Corrosion of embedded steel Cracking, loss of material (spalling, scaling) and loss of bond Leaching of Ca(OH)2 CaCO3 Increase in porosity/permeability porosity/permeability, loss of strength Long-term settlement Cracking, distortion Gamma/neutron irradiation Cracking, reduction in strength (change in Cracking mechanical properties)
High temperature dehydration Cracking, reduction in strength (change in mechanical properties)
Not necessarily all-inclusive 3
Aging Effects/Mechanisms Irradiation/ Thermal Dehydration Reductions in strength and elastic modulus not managed by this AMP - visual examination not sufficient TLAA may be used to demonstrate that no part of the concrete exceeds:
Critical cummulative fluences per ACI 349.3R: 1017 neutrons/m2; 1010 rad (gamma dose)
Temperature limits per ACI 349: 150°C (general), 200°C (localized)
Change in Materials Properties Definition per either ASTM C1562 or EPRI 1002950* not implicit, i.e.:
increases in permeability and porosity reduction in pH value, tensile strength, compressive strength, modulus of elasticity, and bond strength Reference to this aging aging effect effect should include proper definition in the LRA EPRI 1002950 not endorsed by SFST 4
AMP Element 1:
Scope of the Program NUREG-1927: The scope of the program should include the specific structures and components subject to an AMR
- 1. Visual inspection of all above-grade (accessible, inaccessible) and below-grade (underground) concrete areas ACI 349 349.3R:
3R: All All safety safety-related related structures should be visually inspected at intervals not to exceed 10 years
- 2. Groundwater chemistry program to manage below-grade (underground) effects Corrosion of embedded steel Chemical attack (chloride, sulfate induced degradation) 3
- 3. Periodic radiation surveys Controlled Area: Compliance with 10 CFR 72.104.
Near cask (e.g. 1m): Monitor effectiveness as neutron shield (i.e. dose uptrends);
FSAR validation at specific locations 5
AMP Element 2:
Preventive Actions NUREG-1927: Preventive actions should mitigate or prevent the applicable aging effects Program is for Condition Monitoring Design in accordance to ACI 318 or ACI 349 349, as applicable applicable.
Otherwise, For locations in moderate (100-500 day-inch/yr) and severe (>500 day-inch/yr) weathering conditions, concrete mix design should meet air content & water-to-cement ratio requirements of ASTM C260 or ASME Sect. III, Div. 2.
Petrographic examination (ASTM C295 or equivalent) should demonstrate reactive aggregates do not lead to loss of function.
Site-specific AMP required if:
Dewatering system used to prevent long-term settlement Embedded aluminum components without protective insulating coating 6
AMP Element 3:
Parameters Monitored/ Inspected NUREG-1927: Parameters monitored or inspected should be linked to the effects of aging on the intended functions of the particular structure and component
- Quantify effects including cracking, material loss (spalling, scaling), loss of bond, increased porosity/permeability.
- ACI 201 201.1R 1R and d SEI ASCE 11 11-99:
99 exemplary l visuals i l off effects.
ff t
- Evaluation should identify, e.g:
affected surface area popouts, voids geometry/depth of defect exposure of embedded steel cracking, crazing, curling staining/ evidence of corrosion delaminations, deflections dusting, efflorescence of any color h
honeycombing, bi b bug hholes l
- Contributing factors should be evaluated/documented, e.g.:
surface ggeometry y supportingg ponding, g lack of air entrainment widening due to abrasion/ other weather effects 7
AMP Element 4:
Detection of Aging Effects NUREG-1927: Define method or technique, frequency, sample size, data collection, and timing to ensure timely detection of aging effects
- Method/technique (meet criteria in ACI 349.3R/ IWL-2512)
AMP should include justification that the technique can achieve the acceptance criteria; reference valid calibration methods and frequency.
q y ABOVE-GRADE (accessible): visual (e.g., feeler gauges, crack comparators)
ABOVE-GRADE (inaccessible)/ BELOW-GRADE (underground)
Visual: site-qualified system with valid sensitivity/resolution (e.g., video/ fiber optic camera)
Ground water monitoring program: qualified chemical analysis method Radiation surveys: calibrated detector, valid energy range
- F Frequency off Inspection I ti (
(commensurate t with ith ACI 349 349.3R) 3R)
ABOVE-GRADE (accessible and inaccessible): 5 years BELOW-GRADE (underground): 10 years, and when excavated for any reason Use of opportunistic inspections in lieu of planned inspections should include valid technical basis (engineering justification, operational experience data).
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AMP Element 4:
Detection of Aging Effects (cont (cont.))
NUREG-1927: Define method or technique, frequency, sample size, data collection and timing to ensure timely detection of aging effects collection, Frequency of Inspection (cont.)
Water chemistry program/ radiation survey measurements: justified Daily D il iinspections ti off iinlet/outlet l t/ tl t vents t tto ensure ACI 349 ttemperature t lilimits it ((or technical specifications) are not exceeded.
Sample size:
All surface areas as stated in scope, p , or justified j size Clearly identify and justify specific locations (specify accessible or inaccessible)
Data collection Commensurate with applicable standards: e.g. ACI 224.1R for quantitative analysis (width, depth, extent), ACI 562, ACI 364.1R.
Reference adequate clearinghouse for Operating Experience Timing Lead canister inspection / frequency specified by AMP Inspection frequencies may be accelerated per site CAP 9
AMP Element 5:
Monitoring & Trending NUREG-1927: Should provide for prediction of the extent of the effects of aging and timely corrective or mitigative actions Commensurate with:
Defect evaluation standards (e.g. ACI 201.1R, ACI 207.3R, ACI 364.1R, ACI 562 ACI 224 562, 224.1R 1R - crack evaluation)
Acceptance criteria and inspector qualifications (e.g., ACI 349.3R, ASME Code Section XI)
AMP should reference plans/procedures used to:
Establish a baseline prior to or at the beginning of the renewal period Track trending of parameter, or effect not corrected in a previous inspection, e.g.:
Crack growth rates Corrosion rates Pore density/ affected areas Dose D rates t
10
AMP Element 6:
Acceptance Criteria NUREG-1927: Acceptance criteria, against which the need for corrective action will be evaluated; should ensure that SSC functions are maintained Visual: Commensurate with ACI 349.3R (3-Tier Quantitative Criteria):
Acceptance without further evaluation Acceptance after review Acceptance requiring further evaluation Groundwater Chemistry Program: ASME Code Section XI, NUREG-1801 Aggressive below-grade environment: pH < 5.5, chlorides > 500 ppm, or sulfates > 1500 ppm Radiation Surveys Controlled area: 10 CFR 72.104 (bounding limit)
Near cask (e.g., 1 m): A statistically significant uptrend in neutron dose rate, justified criteria
((e.g.
g moving g average) g )
Alternative acceptance criteria may be provided, but should:
Include a quantitative basis (justifiable by OE, engineering analysis/standards)
Avoid use of non quantifiable phrases (e.g. significant, moderate, minor, little, slight, f
few, etc.)
t )
Be achievable and clearly actionable - Method/technique should be qualified to meet the stated quantitative criteria (i.e. sufficient resolution/sensitivity) 11
AMP Element 7:
Corrective Actions NUREG-1927: Corrective actions, including root cause determination and prevention of recurrence, recurrence should be timely CAP commensurate with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B.
Justification for non-repairs (e.g., engineering analysis)
AMP should reference applicable concrete rehabilitation standards.
Cracking: ACI 224.1R, ACI 562, ACI 364.1R, and ACI RAP Bulletins Spalling/scaling: ACI 562, ACI 364.1R, ACI 506R, and ACI RAP Bulletins AMP should reference criteria used to determine which inspection results will require either:
An Action Request (e.g, Tier 2 Acceptance per ACI 349.3R)
Modification to the existing AMP (e.g. increased frequency)
Notification to the NRC (e.g., Tier 3 Acceptance per ACI 349.3R)
AMP should reference how industry-wide y OE will lead to any y of the above action items 12
AMP Elements 8/9:
Confirmation Process/Admin Controls NUREG-1927:
The confirmation process should ensure that preventive actions are adequate and appropriate corrective actions have been completed and are effective Administrative controls should provide a formal review and approval process Elements should reference:
Quality Assurance Program consistent with 10 CFR 72 Subpart G, or 10 CFR 50 Appendix B.
Methods M h d to confirmfi adequate d actions i are taken, k andd are verified ifi d as effective ff i Inspector qualifications Commensurate with ACI 349.3R Record retention requirements Review process of inspection results Frequency/methods for:
reporting inspection results to NRC evaluating suitability of AMP based on industry-wide OE 13
AMP Element 10:
Operating Experience NUREG-1927: Include past corrective actions; provide objective evidence to support a determination that the effects of aging g g will be adequately q y managed g so that the SSC intended functions will be maintained during the period of extended operation Reference and evaluate applicable OE:
Internal and industry industry-wide wide CRs Identify age-related degradation Include justification for CRs not identified as age-related degradation Consider CARs when proposing:
Method/technique, acceptance criteria, frequency of inspection NRC Information Notices Applicable industry initiatives (e.g. DOE cask demo, EPRI-sponsored inspections)
OE presentedt d iin LRA should h ld supportt th the proposed d AMP Reference OE clearinghouse INPO or other adequate system Methods for capturing and evaluating operating experience from other ISFSIs with similar in-scope SSCs.
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Additional Slides 15
Radiation Bounding Criteria NUREG-1536 (SRP Spent Fuel Dry Storage Systems/ General License)
Section 6.5.4.3 - Dose Rates Guidance for the selection of points at which the dose rates should be calculated.
For normal and off-normal conditions, applicant should indicate the dose rate at all locations accessible to occupational personnel during cask loading loading, transport to the ISFSI, and maintenance and surveillance operations.
Locations include points at or near various cask components and in the immediate vicinity of the cask and the bottom of the transfer cask.
e.g.: ventt areas, trunnion t i areas, peakk side id off th the cask, k peak k ttop off the th cask, k
the canister-gap region Calculate dose rates at 1m from these locations.
NUREG 1567 (SRP Spent Fuel Dry Storage Facilities)
Section 11.4.3 - Dose Assessment Estimated dose rates should be provided for representative points within the restricted areas as well as on and beyond the perimeter of the controlled area.
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Acronyms ACI: American Concrete Institute AMP: Aging Management Program ASCE: American Society of Civil Engineers ASME: American Society of Mechanical Engineers ASTM: American Society for Testing and Materials CAP: Corrective Action Program CAR: Corrective Action Report CFR: Code of Federal Regulations CR: Condition Report DOE: Department of Energy EPRI: Electric Power Research Institute FSAR: Final Safety Analysis Report ISFSI: Independent Spent Fuel Storage Installation INPO: Institute of Nuclear Power Operations ITS: Important to Safety LRA: License Renewal Application OE: Operating Experience RAP: Repair Application Procedure SEI: Structural Engineering Institute SRP: Standard Review Plan SSC Structure, SSC: Str ct re System, S stem or Component TLAA: Time-Limited Aging Analysis 17