r-Lake. Louis

From:Sent:To:Cc:Attachments:

Ali;

Lake, LouisTuesday, November 24, 2009 8:23 AMRezai, AliChan, Terence; Franke, MarkResponse to NDT Question from NRR.pdf; 059169NDT Qualification Letter_1 1-11-09.pdf;Request 10.docx; Request 11 .docx; Request 16.docxI ,' / 7 ).J

/)D fJu~-I understand that you have been assigned to review the NDT activities at Crystal River.

To facilitate your re~iew, attached are the responses provided by Crystal River staff to your questions on theNDT techniques used for identification of the de-lamination in the CR containment. I included responses Ireceived to some of the related questions asked by the SIT team and on the personnel qualification issue. Ihave resumes/individual qualification information (not attached) for each NDT technician that was on site. Letme know if you need this info.

Note that there is no industry standard on how to qualify these NDT techniques. The NDT results weresubsequently confirmed by core bores in the containment surface.

If needed, we can set up a conference call next week to resolve any questions you may have. I will out of theoffice beginning today at 11:00am and will return on Monday, Nov. 30.

Louis LakeSIT leadLouis.Lake@nrc.gový404-562-4683

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Reply to NRC Questions provided from Lou Lake on 11/13/09 to Condition Assessment

Team Lead.

1. Technical Justification:

General

Impulse Response (IR) technique was developed from the vibration method for pileintegrity testing and has been known variably as the transient dynamic response (TDR),mobility or impedance method for many years. The method has been extended to theinspection of concrete structures other than piles, particularly plate-like elements such asfloor slab, walls and large cylindrical structure. Theoretical researches and applicationcase studies about Impulse Response method have been well published. A list of recentpublication references about IR method for concrete structural evaluation is attached. Arecent research in theoretical interpretation of IR method is presented by Ottosen, N.S.,M. Ristinmaa and A.G. Davis in 2004 (Ref 1)

Average Mobility is a principal parameter that IR test produces. The Average Mobility isdefined as the structural surface velocity responding to the impact divided by the forceinput [a measure of flexibility]. The mean mobility value over the 0.1-1 kHz range isdirectly related to the modulus, density and most importantly the thickness of a plate-likeelement. In general, presence of significant voiding or an internally delaminated orunbonded layer will result in an increased average mobility value. On the other hand, asound concrete element without distress will produce a relatively low average mobilityvalue. The test results can be analyzed and presented in the form of contour plots. Thesuspect areas can be identified through a scaled color scheme. In practice, the IRmethod is utilized on a comparative basis, which allows the engineer to compare thedifference in dynamic responses between test areas within the same structure orbetween similar structures. The different responses are correlated to the condition viaintrusive sampling such as core bore or chipping at the beginning stage of the testprogram for the specific structure.

The IR test method for concrete structure evaluation is in the process of beingstandardized by ASTM Committee C09 (Concrete & Concrete Aggregate) and its sub-committee C09.64 (Nondestructive In-place Testing). In addition, ACI Committee 228(Nondestructive Testing) is revising the committee report 228.2R "Nondestructive TestMethods for Evaluation of Concrete in Structures" which will include IR testing forconcrete structure evaluation in addition to pile integrity evaluation.

Impact-Echo (IE) testing is well known NDT method in concrete industry. Besideshundreds of published papers in 1980s and 1990s, its theory and application arecollectively summarized in a book by Prof. Sansalone, M. and W.B. Streett of ConnellUniversity in 1997, "Impact-Echo: nondestructive evaluation of concrete and masonry,"published by Bullbrier Press, Ithaca, NY. The IE test method is included in ACI report228.2R-98, and also ASTM ASTM C1383 - 04 "Standard Test Method for Measuring theP-Wave Speed and the Thickness of Concrete Plates Using the Impact-Echo Method".

When evaluating presence of delamination in a plate-like structure, the stress wavegenerated by the impact will be reflected by the boundary such as a delamination orback wall of the structure and the echo signal received by the transducer. The typical

speed of stress wave transmission in modern concrete is approximately 4,000 m/s.Therefore by obtaining the resonant frequency of the effective thickness under the testpoint, the depth of the thickness can be calculated. If no delamination is present, the fullwall thickness is obtained.

a. Detection of delamination in a plate-like concrete element is one principal applicationof IR and IE methods. The application of these methods to detect delaminations isdirectly analogous to thickness evaluation. When a plate like structure contains asignificant delamination it behaves like two independent plates. The effective thicknessis defined as distance from the test surface to a crack parallel to the surface ifdelaminated, or the full structural thickness if no internal separations exist. The averagemobility value of a structure is somewhat proportional (inversely) to the cube of thethickness (moment of inertia 1/12bh 3), making the response from an area with adelamination at 10 inches several times higher than the response from a 42 inch thickstructure. The presence of delamination will effectively reduce the thickness of wallor slab responding to the impact, which results in a drastically increased averagemobility value. This is in consistence with the test results obtained on the containmentwall structure in Crystal River. The typical mobility value in areas where delaminationswere noted typically exceeded 1.0 (up to about 15 or so depending on the depth ofdelamination) while in solid concrete areas the value is typically below 0.4. There is largedifference in structural response to the hammer impact when comparing a 42 inches wallin solid concrete area to an approximately 6 to 12 inches thick delaminated layer. Thedifference in effective thickness resulted in an approximately 5 to 10 times difference inaverage mobility values.

Limitations:The potential limitations about IR testing in detecting delamination in plate-like structureinclude: 1) the absolute size or width of the crack could not be evaluated, other methodsuch as core hole examination using boroscope shall be used; 2) the absolute depth ofthe delamination from surface can not be readily determined, the depth can only beascertained by coring or other NDT method; 3) The depth of influence is typically around20 inches.

b. The submitted method description was an outdated document and shall be replaced.Use of IR testing to evaluate concrete structure has been constantly used in the industryin the past 15 years. A list of more recent publications related to its application(evaluating presence of delamination or other internal defects) is located in Enclosure 1.

c. Use of IE testing to evaluate delamination is analogousto thickness measurement.When delamination is present, instead of measuring the full wall thickness, the testmeasures the thickness of the delaminated layer which is separated from the substrateconcrete.

Since its inception, the IE test theory has not changed, the book by Sansalone andStreett is still the most complete reference to this technique. The potential limitations ofIE testing in evaluating the delamination in containment wall structure include: 1) relativeslow process which requires laying out the PT ducts and reinforcement prior to testing; 2)the test data is affected by the surrounding tendons in the vicinity of test points whichfrequently cause false-positive indications of delamination. Due to this limitation, corebore sampling, instead of IE testing, to verify / confirm the IR test results are constantlyused in this testing program.

2. Qualifications:a. Separate files provided with qualifications for individuals from CTL.b. Honggang Cao, PE, possesses certificate of ASNT Level III in Ultrasonic Testing (No.148008, expires Sep, 2012).c. Honggang Cao, PE, has more than 12 years experience using IE and 8 yearsexperience using IR techniques. (Sample of previous report will be made available toNRC once the client approves the release.)d. See enclosure 2

3, Currently there is no agency in industry responsible for approving concrete NDTequipment.

4. The IR test method for concrete structure evaluation is in the process of beingstandardized by ASTM Committee C09 (Concrete & Concrete Aggregate) and its sub-committee C09.64 (Nondestructive In-place Testing). In addition, ACI Committee 228(Nondestructive Testing) is revising the committee report 228.2R "Nondestructive TestMethods for Evaluation of Concrete in Structures" which will include IR testing forconcrete structure evaluation in addition to pile integrity evaluation. The IE test methodis included in ACI report 228.2R-98, and also ASTM ASTM C1 383 - 04 "Standard TestMethod for Measuring the P-Wave Speed and the Thickness of Concrete Plates Usingthe Impact-Echo Method". Application of both methods include detection of delamination.

5. a Interaction of propagating stress wave with reinforcing steels and / or tendons arenot significant factors to IR testing on this containment wall structure, comparing to theinfluence from a delamination at 6 to 14 inches depth. Trial testing along known tendonlines or between a pair of two circumferential tendons using IR indicated marginallyhigher mobility values (0.2 to 0.6 or so). The influence of reinforcement and tendons inthe structure has generally less impact for IR than it would for IE test. The signalresponse in IR testing will be dominated by presence of delamination, if any. It makes itideal to evaluate the presence of delamination without having to layout locations oftendon and reinforcing bars prior to the testing in a time critical project. As statedpreviously, the IE testing will be affected by presence of tendons in the vicinity of testpoint. It may be difficult to analyze a complex signal obtained near unbonded tendons orfalse positive may result. Therefore, it is important to layout locations of bothcircumferential tendons and vertical tendons prior to the IR testing. This is also one ofthe main reasons that IR was chosen as a primary method to evaluate delamination inthe containment wall structure. A large number of core samples removed from thestructure based on the IR test results have strongly supported the accuracy of thetechnique in this application.

b. No stress wave methods are effective to detect multiple layers of delamination inconcrete. Essentially all energy is reflected back at the first delamination, makingdetection of lower delaminations unlikely.

c. The IR test is particularly sensitive to delaminations because it does not rely on thepresence of an air gap to cause a reflection. The flexural response of the delaminatedlayer will change significantly even if the structural sections are in intimate contact.

According to Sansalone and Streett, the minimum delamination size which will interruptthe stress propagation in IE testing is approximately 0.08 mm.

d. The useful frequency range for IR testing is approximately 0.1 kHz to 1 kHz. Theimportant frequency range for IE testing is typically between 2 kHz and 40 kHz.

6. b. type of impactor: IR - 1 kg hammer with load cell from PCB (model # 086D20 or086M91); IE - ball bearing size range from, 5mm to 12 mm.

" Distance range: not critical. Typically from 18 to 24 inches.Geophone: SM-6

o Power sources: power from laptop computer through USB connectiono Max depth: IR - approximately 20 inches.

IE - by changing the size of impactor, the delamination isdetectable within 42 inches wall

o Environmental conditions will not significantly affect the IR or IE results.

Ref: 1: Ottosen, N.S., M. Ristinmaa and A.G. Davis. "Theoretical Interpretation ofImpulse Response Tests of Embedded Concrete Structures". Journal of EngineeringMechanics, ASCE September 2004.

Enclosure 1

IMPULSE RESPONSE REFERENCES

Significant and more recent references:

1. Paquet, J. 1968. "btude vibratoire des pieux en b~ton: r~ponse harmonique. (Vibrationstudy of concrete piles: harmonic response)." Annls. Inst. Tech. Bdtim., (France), 2 1styear, 245, 789-803. English translation by Xiang Yee in Master of Eng. Report,University of Utah, 1991, 33-77.

2. Briard, M., 1970. "Contr6le des pieux par la mithode des vibrations (Pile Control by theVibration Method)," Annls. Inst. Tech. Bdtim., (France), 23rd Year, 270, June, 105-107.

3. Gardner, R.P.M. and G.W. Moses, 1973. "Testing Bored Piles formed in LaminatedClays", Civ. Engrg. And Public Works Rev., 68 (Jan.), London, England, 60-83.

4. Davis, A.G. and C.S. Dunn, 1974. "From Theory to Experience with the NondestructiveVibration Testing of Piles". Proc. Inst. Civ. Engnrs. Part 2, Vol. 57, paper 7764, 571-593.

5. Discussion published in Proc. Inst. Civ. Engnrs. 1975, Part 2, Vol. 59, 867-875.6. "Esso's Giant Oil Tanks - a question of more haste, less speed', New Civ. Engr., 1974,

Inst. Of Civ. Engrs., London, England, 81(Feb.), 28-38.7. Davis, A.G. and S.A. Robertson, 1975. "Economic Pile Testing". Ground Engng Vol. 8,

No. 3, 40-43.8. Robertson, S.A., 1976. "Vibration Testing", The Consulting Engineer (UK), Jan. 1976,

36-37.9. Davis, A.G. and S.A. Robertson, 1976. "Vibration Testing of Piles". Struct. Engnr. Vol.

54, No. 6, A7.10. Paquet, J. and M. Briard, 1976. "Contr6le non destructif des pieux en baton

(Nondestructive Control of Concrete Piles)", Annls. Inst.Tech. Bdtim., (France), 2 9 th year,337, 50-79.

11. Weltman A.J., 1977. "Integrity Testing of Piles: A Review", Construction IndustryResearch and Information (UK), Report PG4, Technical Guide No. 18, Sept. 1977, 36 pp.

12. Document Technique Unifid (D.T.U.), 1978. "Travaux de Fondations Profondes pour leBdtiment (Deep Foundation Works for Buildings)", French Building Code D.T.U. 13.2,Centre Scientifique et Technique du Batiment, Paris, France.

13. Higgs, J.S. and S.A. Robertson, 1979. Integrity Testing of Concrete Piles by ShockMethod", Concrete (UK), 13, No. 10, Oct., 31-33.

14. Guillermain, P. 1979. Contribution 6 l'interprbtation g~otechnique de 1'essaid'imp~dance mdcanique d'un pieu (Contribution to the Geotechnical Interpretation of theMechanical Impedance Test on a Pile)", Ph. D. Thesis, Universitd Pierre et Marie Curie,Paris, France.

15. Davis, A.G. and P. Guillermain, 1979. "Interpretation g~otechnique des courbes deresponse d'une excitation harmonique d'un pieu" (The Geotechnical Interpretation ofthe Response of a Pile to Harmonic Excitation). La R6vue Frangaise de Gdotechnique(France) No. 8, 15-2 1.

16. Davis, A.G. and P. Guillermain, 1980. "La vibration des pieux: interpretationsg~otechniques" (Pile Vibration: Geotechnical Interpretation.) Annales de 1'ITBTP(France) No. 380, 71-96.

17. Davis, A.G., 1981. "The Nondestructive Testing of Piles by Mechanical Impedance",Proc. 10th Int. Conf. Soil Mech. & Found. Engng., Stockholm, July 1981, Session 8 Vol.2.

18. Robertson, S.A., 1982. "Nondestructive Control of Deep Foundations - New Techniquesand Recent Experiences", Regional Symposium on Underground Works and SpecialFoundations, Singapore, March 1982, 7 pp.

19. Stain, R.T., 1982. "Integrity Testing", Parts I and II, Civil Engineering (UK), Apr., 55-59& May, 77-87.

20. S.A. Robertson, 1982. "Integrity and Dynamic Testing of Deep Foundations in S.E.Asia", Proc 7th Southeast Asian Geotechnical Conf., Hong Kong, Nov. 1982, 403-421.

21. Stain, R.T. and A.G. Davis, 1983. "Nondestructive Testing of Bored Concrete Piles -Some Case Histories", Proc. Int. Conf. on Nondestructive Testing, London, Nov. 1983,77-87.

22. Swann, L.H., 1983. "The Use of Vibration Testing for the Quality Control of Driven CastIn-situ Piles ", Proc. Int. Conf. on Nondestructive Testing, London, Nov. 1983, 113-123.

23. Davis, A.G., 1985. "Nondestructive Testing of Piles Founded in Glacial Till - Analysis ofover 30 Case Histories ", Proc. Int. Conf. Construction in Glacial Tills & Boulder Clays,Edinburgh, March 1985, Vol. 1, 193-212.

24. Forde, M.C., H.F.C. Chan & A.J. Batchelor, 1985. "Acoustic and Vibration NDT Testingof Piles in Glacial Tills and Boulder Clay", Proc. int. Conf. Construction in Glacial Tills& Boulder Clays, Edinburgh, March 1985, Vol. 1.

25. Pederson, C.M. and L.J. Senkowski, 1986. "Slab Stabilization of PCC Pavements",Paper presented at TRB Annual Conference, Washington, D.C. Jan. 1986.

26. Davis, A.G., 1987. "Application of Dynamic Test Methods to the Evaluation of BridgeStructures", 1st NATO USA-European Workshop on Bridge Evaluation, Repair &Rehabilitation, St. Rdmy-les-Chevreuses, France, July 1987, 11 pp.

27. Davis, A.G. and B.H. Hertlein, 1987. "Nondestructive Testing of Concrete PavementSlabs and Floors with the Transient Dynamic Response Method" Proc. Int. Conf.Structural Faults & Repair, London, July 1987, Vol. 2, 429-433.

28. Lilley, D.M., W.M. Kilkenny & R.F. Akroyd, 1987. "Investigation of Pile Integrity ofPile Foundations using a Vibration Method", Proc. Int. Conf. Found. and Tunnels,Engrg. Tech. Press, Edinburgh, Scotland, Vol. 1, 177-183.

29. Williams, H. and R.T. Stain, 1987. "Pile Integrity Testing - Horses for Courses", Proc.Int. Conf. Found. and Tunnels, Engrg. Tech. Press, Edinburgh, Scotland, Vol. 1, 184-191.

30. Ellway, K., 1987. "Practical Guidance on the use of Integrity Tests for the QualityControl of Cast In-situ Piles ", Conf. Found. and Tunnels, Engrg. Tech. Press, Edinburgh,Scotland, Vol. 1, 228-234.

31. Chan, H.F.C., C. Heywood & M.C. Forde, 1987. "Developments in Transient Shock PileTesting", Conf. Found. and Tunnels, Engrg. Tech. Press, Edinburgh, Scotland, Vol. 1,245-261.

32. Olson, L.D. and C.C. Wright, 1989. "Nondestructive Testing of Deep Foundations withSonic Methods ", Foundation Engineering: Current Principles and Practices, ASCE, Vol.2,1173-1183.

33. Davis, A.G., "CEBTP and the English Channel Tunnel" TRB Annual Conf.,Washington, D.C., Jan. 1990, 11 pp.

34. Davis, A.G. and B.H. Hertlein, "Assessment of Bridge Deck Repairs by a NondestructiveTechnique", 2 nd NATO USA-European Workshop on Bridge Evaluation, Repair &Rehabilitation, ASCE Struct. Conf., Baltimore, Apr. 1990, 229-233.

35. Scull, T.P. and A.G. Davis, 1990. "Experiences in Nondestructive Testing by ImpulseRadar and Impedance Methods in the Evaluation of Concrete Highways ", 6 th Int Symp.on Concrete Roads, Madrid, Oct. 1990, 103-112.

36. Hertlein, B.H. and A.G. Davis, 1991. "Pavement Performance Data: an attempt torelieve the Log Jam ", Paper presented at TRB Annual Conf., Washington, DC, Jan. 1991,26 pp.

37. Davis, A.G. and B.H. Hertlein, 1991. "The Development of Nondestructive Small StrainMethods for Testing Deep Foundations ", Paper No. 910243 presented at TRB AnnualConf., Washington, D.C., Jan. 1991, 23 pp.

38. Paquet, J., 1991, "A New Method for Testing Integrity of Piles by Dynamic Impulse: TheImpedance Log" (in French), Int. Colloquium on Deep Foundations, Ecole des Ponts etChaussres. Paris, France, March, 1-10.

39. Nazarian, S., M. Baker and R. Smith, 1991. "Measurement Concepts and TechnicalSpecifications of Seismic Pavement Analyzer". Strategic Highway Research Program,Washington, D.C.

40. Reddy, S. 1992, "Improved Impulse Response Testing: Theoretical and PracticalValidations", Master of Science Thesis, University of Texas at El Paso (Director, S.Nazarian), 219 pp.

41. Nazarian, S and M. Baker, 1992 "A New Nondestructive Testing Device forComprehensive Pavement Evaluation". Proc. Conf. Nondestructive Evaluation of CivilStructures and Materials, University of Colorado at Boulder, May 1992 (Ed. Suprenant,Noland & Schuller), 437-452.

42. Rix, G.J., L.J. Jacobs & C.D. Reichert, 1993. Evaluation of Nondestructive Test Methodsfor Length, Diameter and Stiffness Measurements on Drilled Shafts ", Paper No. 930620presented at Transportation Research Board Annual Meeting, Washington, D.C., Jan., 19pp.

43. Davis, A.G., 1993. "Evaluation of the Integrity of Some Large Concrete Structures usingNDT", A.C.I. Spring Convention, Vancouver B.C., Committee 228 Session on Locationof Flaws in Concrete using NDT, March 1993, 17 pp. published in: Innovations inNondestructive Testing of Concrete, ACI SP-168, Ed. S. Pessiki & L.Olson, 1997, 333-356.

44. Baker, C.N. Jr., Drumwright, E.E., Briaud, J-L., Mensah-Dumwah, F. and Parikh, G.,1993. "Drilled Shafts for Bridge Foundations." FhwA Pub. No. FHWA-RD-92-004.Federal Hwy. Administration (FhwA), Washington, D.C.

45. Nazarian, S, M.R. Baker and K. Crain, 1993. "Development and Testing of a SeismicPavement Analyzer". Research Report H-375, Strategic Highway Research Program,Washington, D.C., 165 pp.

46. Davis, A.G., 1994. "Novel Nondestructive Techniques for the Evaluation of LargeConcrete Structures ", Struct. Mat. & Tech.: an NDT Conf., Atlantic City, February 1994,99-103.

47. Davis, A.G., 1994. "Nondestructive Testing of Wood Piles", Int. Conf. Wood Poles &Piles, EDM and Colorado State University, Fort Collins, March 1994, 94-101.

48. Davis, A.G., 1994. "The Integration of Nondestructive Evaluation in the Maintenance ofour Concrete Infrastructure ", XXIII Pan-American Engineering Convention - Theme:Modernization of Engineering in the Conservation of Facilities. Pan-American Union ofEngineers Association, Acapulco, Mexico, July 1994.

49. Davis, A.G., 1995. "Nondestructive Evaluation of Existing Deep Foundations". J. Perf.Constr. Fac., ASCE, Feb. 1995, 9(1), 57-74.

50. Davis, A.G., 1995. "Evaluation of Deep Foundations Beneath Buildings Damagedduring the 1994 Northridge Earthquake ", Proc. 31st Symp. Eng. Geol. & Geotech.Engng., Logan, UT, March 1995, 171-179

51. Davis, A.G. and B.H. Hertlein, 1995. "Nondestructive Testing of Concrete Chimneys andOther Structures ", Proc. Conf. Nondestructive Evaluation of Aging Structures and Dams,S. Nazarian & L. Olson, Ed., Proc SPIE 2457, 129-136, Oakland, CA, June 1995.

52. Davis, A.G., B.H. Hertlein, M.K. Lim and K. Michols, 1996. "Impact-Echo and ImpulseResponse Stress Wave Methods: Advantages and Limitations for the Evaluation ofHighway Pavement Concrete Overlays ". Conf. Nondestructive Evaluation of Bridges andHighways, S.B. Chase, Ed., Proc SPIE 2946, 88-96, Scottsdale, AZ, December 1996.

53. Hertlein, B.H. and A.G. Davis, 1996. "Performance-based and Condition-based NDTforPredicting Maintenance Needs of Concrete Highways and Airport Pavements". Conf.Nondestructive Evaluation of Aging Aircraft, Airports and Aerospace HardWare, R.D.Rempt and A.L. Broz, Ed., Proc SPIE 2945, 273-28 1, Scottsdale, AZ, December 1996.

54. S. Nazarian, S. Reddy, "Study of parameters affecting Impulse Response method",Journey of Transportation Engineering, July/August, 1996.

55. Davis, A.G., 1997. "How NDE can help Adjusters in Property Loss and ConstructionDefects Cases ". Colorado State Loss Adjusters Journal, February 1997.

56. Davis, A.G., 1997. "Evaluation of Deep Foundations beneath Buildings damaged duringthe 1994 Northridge Earthquake". Innovations in Nondestructive Testing of Concrete,ACI SP-168, Ed. S. Pessiki & L. Olson, May 1997, 319-332.

57. Davis, A.G. and B.H. Hertlein, 1997. "Evaluation of the Integrity of some LargeConcrete Structures using NDT". Innovations in Nondestructive Testing of Concrete,ACI SP-168, Ed. S. Pessiki & L. Olson, May 1997, 333-356.

58. Davis, A.G., J.G. Evans and B.H. Hertlein, 1997. "Nondestructive Evaluation ofRadioactive Concrete Waste Tanks ". J. Perf. Constr. Facilities, ASCE, Vol. 11, No. 4,November 1997, pp. 161-167.

59. Davis, A.G., 1997. "A Place for Nondestructive Evaluation in the Maintenance of ourConcrete Infrastructure". Materials Evaluation, Vol. 55 No. 11, 1234-1239, November1997.

60. Davis, A.G. and J. Kennedy, 1998. "Impulse Response Testing to Evaluate the Degree ofAlkali-Aggregate Reaction in Concrete Drilled Shaft Foundations under ElectricityTransmission Towers ". Conf. Nondestructive Evaluation of Utilities and Pipelines, ProcSPIE 3398, Paper 21, San Antonio, TX, April 1998.

61. Hertlein, B.H. and A.G. Davis, 1998. "Locating Concrete Consolidation Problems usingthe Nondestructive Impulse Response Test ", American Concrete Institute Fall Convention,Los Angeles, CA, October 25, 1998.

62. American Concrete Institute Report ACI 228.2R-98, "Nondestructive Test Methods forEvaluation of Concrete in Structures ". ACI, Farmington Hills, Michigan, 1998, 62 pp.

63. Davis, A.G., 1999. "Assessing the Reliability of Drilled Shaft Integrity Testing",Transportation Research Board Record, February 1999.

64. Davis, A.G., "The Nondestructive Impulse Response Test in North America: 1985-2001 ".

NDT&E International, 36 (2003), 185-193.65. Michols, K.A., A.G. Davis and C.A. Olson, "Evaluating Historic Concrete Bridges".

Concrete Repair Bulletin, Vol. 14, No.4, July/August 2001, 5-9.66. Corley, W.G. and A.G. Davis, "Forensic Engineering Moves Forward". Civil

Engineering, June 2001, Vol. 71 No. 6, 64-65.67. Ottosen, N.S., M. Ristinmaa and A.G. Davis. "Theoretical Interpretation of Impulse

Response Tests of Embedded Concrete Structures ". Journal of Engineering Mechanics,ASCE, September, 2004.

68. Davis, A.G., and C. G. Petersen, "Nondestructive Evaluation of Prestressed ConcreteBridges using Impulse Response". International Symposium (NDT-CE 2003), Non-Destructive Testing in Civil Engineering 2003.

69. Davis, A.G., M.K. Lim and C. Germann Petersen, "Rapid and Economical Evaluation ofConcrete Tunnel Linings with Nondestructive Impulse Response and Impulse Radar".

Keynote Address, Conference on Structural Faults and Repair 2001, London U.K., July2001.

70. Gentry, T.A. and A.G. Davis, "Integrating Advanced Evaluation Techniques with TerraCotta Examinations ". ASTM Symposium, STP 1444 Building Facade Maintenance,Repair and Inspection, October 12-13, 2002, Norfolk Virginia, 13 pp.

71. Farahmandpour, K., V.A. Jennings, T.J. Willems and A.G. Davis, "EvaluationTechniques for Concrete Building Envelope Components ". RCI Interface, Vol. XX, No. 3,March 2002, 3-15.

72. Davis, A.G., "NDE of Existing Transmission Tower Foundations". Conference onStructural Faults and Repair 2001, London U.K., July 2001.

73. A.G. Davis, "Rapid non-destructive test method at the Taiwan High-Speed Rail project",Concrete Technology Today, Volume 3, 2004.

74. A. Davis, G. Seegebrecht, and H. Cao, "Concrete Bridge Deck Overlays Evaluated byNDT", Proceeding of ASNT Structural Materials Technology (SMT) Conference -NDT/NDE for Highways and Bridges, Buffalo, New York, September, 2004.

75. Sansalone, M. and W.B. Streett, 1997, "Impact-Echo: nondestructive evaluation ofconcrete and masonry," Bullbrier Press, Ithaca, NY.

76. H. Cao, "Implementation of NDT techniques in an underground tunnel investigation",Proceeding of 6 th International Symposium on NDE in Civil Engineering, St. Louis,Missouri, 2006.

77. E. Dodge, M. Sherman, "Structure evaluation and repair of internally damaged concrete",Proceedings of Fourth Forensic Congress, Cleveland, Ohio, 2006.

Enclosure 2

CTLGroup: Nuclear Facility & Nuclear Safety RelatedConsulting QualificationsThe recent Crystal River post-tensioned secondary containment structure incident is asignificant concern to the owner-utility, and to the US NRC. The damaged concretecontainment wall is 42 inches thick, contains mild reinforcement and un-bonded posttensioning tendons. It is lined with a mechanically-anchored steel liner plate.During steam generator replacement construction, workers found a planarcrack/delamination in the wall, about nine inches from the outer surface. Based onsuccessful experience with services furnished at other Progress Energy plants, CTLGroupwas asked to extend its assistance, related to demonstrating nondestructive testmethodology-based definition of the extent of the delamination anomaly, as well assupplementary inspection services and testing and characterization of the concretematerials.

RELEVANT PROJECTS AND ACCOMPLISHMENTSCTL has successfully furnished a wide scope of assistance to the nuclear industry,encompassing projects at more than 20 nuclear generating stations nationwide, since1978.

Additionally, CTLGroup has provided technical services and applied research solutionsto EPRI and the US NRC, helping improve the safety, facility management and quality ofcommercial nuclear facilities. Historic accomplishments related to structural engineering,condition inspection and analysis, facility management consulting, and materialstechnology in the nuclear power & nuclear safety-related programs are illustrated basedon a select project chronology below:

- 1978 - Grand Gulf Nuclear Generating Station's 520-ft tall cooling tower'scrane is toppled by high winds while construction nears completion inMississippi, leaving 100-ft-deep notch; CTL engineers use nondestructivediagnosis and structural analysis to advise contractors how to salvage tower.

* 1979 - Marble Hill Nuclear Generating Station safety and non-safety relatedstructure construction was nearing completion in Indiana. Although the facilitynever is placed on line since management failures causes the utility, State andFederal regulators to terminate the project, US NRC requires that acomprehensive review of deficient reinforced concrete construction beaddressed with a plant-wide concrete NDT and lab testing program,performed at the expense of the construction contractor, by CTL.

- 1979 to 1986 - EPRI Concrete Containment Wall Leakage Research wasconducted nationally by several research firms and national laboratories,

including CTL following the TMI accident. It refined the structural design basisfor containment wall element design. On the basis of this national engineeringresearch effort, failure criteria and an analysis methodology for predictingconcrete containment leakage was developed. CTL's Structural EngineeringLaboratory and structural engineering experts conduct a series of complex fullscale experiment under ultra high loading, exploring the inelastic behavior underover pressurization and seismic events, of containment walls and largepenetrations.

- 1983 - Condition Assessment and Repair of Reactor Bldg Floor Slab,Monticello Nuclear Generation Station in Minnesota is needed when torus ringsupplementary support installation reveals presence of severe voids anddelaminating in the reinforced concrete base mat. Concrete NDT methods areadopted by CTL to define the complete extent of base mat planar defects, a repairprocedure adopting pressure adhesive injection is designed and repairs areconducted. NDT methods are used to verify quality and comprehensiveness ofrepairs.

- 1991 - Databasing of Long Term Concrete Materials Property Data forNuclear Generating Stations is performed by CTL to support the US NRCStructural Aging Program, under DOE contract. These data serve as the basis forfuture plant relicensing decisions.

* 1991 - In-Service Inspection and Structural Integrity Assessment Methodsfor NPP's - CTL reviewed and assessed nondestructive evaluation, sampling, andstructural integrity testing techniques which have application to the evaluation ofsafety-related concrete components in nuclear power plants, as a component ofthe US NRC Structural Aging Program.

* 1995 - SELF-MONITORING SURVEILLANCE SYSTEM FOR PRESTRESSINGTENDONS - CTL structural engineers/experts in behavior of post tensioningmaterials demonstrate feasibility of an autonomous prestressing tendon wire breakdetection system for continuous monitoring of post-tensioned concretecomponents of nuclear power plants. A one-tenth scale ring model of the PaloVerde nuclear containment structure is used. Strong and recognizable signatureswere detected by the accelerometers used. It was concluded that the unbondedprestressing tendons provide an excellent path for transmission of stress wavesresulting from wire breaks. Work is conducted under the US NRC SBIR program.

* 1996- Evaluation of Makeup and Blowdown Pipeline Ruptures, Illinois -Multiple ruptures of the piping system experienced since 1980 resulted inunanticipated, costly emergency-basis repairs at the LaSalle Station. Thedisruptive nature of these failures prompted a CTL review of feasibility and costof rehabilitation/replacement options. The objectives of CTL's work were (1) toevaluate theoretical strength and serviceability of the pipeline in its potentiallydeteriorated state, (2) to identify alternative remedial strategies, (3) to assess

technical feasibility and compare economic factors for available alternatives, and(4) to analyze and present effective rehabilitation methodologies.

* 2000 - Nondestructive Testing, Cook Nuclear Power Plant, Michigan - CTLperformed nondestructive impulse radar testing in selected areas to locatehorizontal and vertical embedded wall reinforcement.

* 2003 - Onsite Condition Assessment of Concrete, Davis Besse Nuclear PowerStation, Ohio - CTL nondestructive inspection experts and concrete technologistsevaluated the presence and extent of poor concrete consolidation and internalconcrete cracking in concrete walls of the rod refueling area.

- 2004 - Nondestructive Evaluation of Reinforced Concrete Pump Pedestals -CTL performed nondestructive testing on ten (reinforced concrete pedestalfoundations to pumps in the Screen Building at Three Mile Island Nuclear PowerStation. Excessive vibrations had been noted. CTL proposed a nondestructive testprogram comprising a combination of Ultrasonic Pulse Velocity (UPV), Pulseechoultrasound (UT) and vibrationmeasurements to a) measure the integrity andquality of the concrete in the pedestals, b) evaluate the quality of the sole plategrout and its bond with the concrete substrate, and c) evaluate the mating of thesteel top plate with the sole plate.

* 2005 - Nondestructive and Materials Evaluation of Cracking and LeakageThrough Reactor Spent Fuel Pool Walls - The spent fuel pool walls are 5-ftthick, stainless steel-lined reinforced concrete. The plant owner has noticed waterleakage associated with concrete cracking near the middle of this area. During thesite visit, CTL visually and nondestructively examined spent fuel pool wallsurfaces to evaluate its current condition for any signs of distress, such ascracking or poor consolidation. Conceptual repair recommendations were made.

- 2007 - Evaluation of 2 Natural Draft Cooling Towers at Byron NuclearStation, Illinois - Evidence of concrete deterioration and aging in 22 and 24-yearold, 495-ft tall cooling towers prompted durability evaluation. Byron incorporatesthe use of two reinforced concrete hyperbolic natural draft cooling towers forcondenser cooling. Exelon retained CTLGroup to assist its staff in evaluating theexisting condition of the structure and to provide recommendations for futureevaluation and repair needs for the structures.

CONTINUITY OF TECHNICAL EXPERTISE & ADDITIONALRESOURCESTo augment project teams such as the one that is presently active at the Crystal River site,CTLGroup's key senior staff and management have historically sustained continuity oftechnical and project management expertise and innovation, contact with the powerindustry decision makers, and led professional development efforts needed to providetimely solutions associated with nuclear safety and facility management issues.

For example, CTLGroup Senior Principal Structural Engineer R.G. Oesterle, S.E.who led the EPRI containment wall integrity research referenced in this document, isChairman of the ASME/ACI Reactor Vessel Committee's Subgroup on Design TaskGroup on Shear, and a nationally recognized structural engineer expert in diagnosis andrepair of structural failures.

Additionally, CTLGroup Senior Principal Engineer Adrian Ciolko, P.E. served thenuclear power utilities and regulatory agency at the Marble Hill, Monticello, Byron, USNRC Tendon Surveillance System and LaSalle projects referenced above, and ispresently project manager for an EPRI project entitled, Concrete Aging ReferenceManual for Long Term Operation. In this project, a review of degradation mechanismshas been conducted. Likely locations in plants have been identified. Individual structuresand subcomponents will be prioritized based on degradation mechanisms andconsequence and probability of failure. The scope of this analysis will include safetyrelated structures, such as containments, spent fuel storage, auxiliary buildings andradwaste buildings, as well as balance of plant structures such as cooling towers, intakestructures, intake canals, circulating cooling water lines, turbine pedestals and other keyexterior structures, looking ahead the next plant relicensing interval.

When CTL is using IR and IE, can they determine relative concrete quality of locations tested as part of

CTL NDE procedure?

In general, the Impulse Response (IR) test results is influenced by concrete quality and existence ofdefects at the test point. The aspects in concrete influencing IR results include presence of delamination,cracking, significant void or honeycomb and change in concrete properties. The most significant factor isthe presence of delamination which effectively reduces the thickness of wall or slab responding to theimpact. Considerable difference in quality of concrete is typically reflected in the test results. For example,a core removed from panel RBCN-0014-N (Core #13) where a higher mobility value was obtained byNDT, had less coarse aggregate in the concrete, which changed density and modulus in that localizedarea, no delamination was noted in these areas with subsequent boroscope examinations.

Discuss the planned NDE method, its reliability, industry experience and other pertinentinformation, B) discuss supplementary verification plans to ensure results are reliable.

A) Impulse Response (IR) test was chosen as the primary NDT technique to evaluate the extentof delamination. The IR method uses a low strain impact from a hammer equipped with a loadcell to send a stress wave through the element under test. The response to the input stress ismeasured using a velocity transducer (geophone). Both the hammer and the geophone arelinked to a portable field computer for data acquisition and storage. Time records for both thehammer force and the geophone velocity response are transformed into the frequency domainusing the Fast Fourier Transform (FFT) algorithm.Average Mobility is the key parameter that the dynamic IR test produces. It is defined as thestructural surface velocity responding to the impact divided by the force input [(m/s)/N]. Themean mobility value over the 0.1-1 kHz range is directly related to the modulus, density andthe effective thickness of the element. In general, presence of significant voiding or an internallydelaminated or un-bonded layer will result in an increased average mobility value. On the otherhand, a sound concrete element without distress will produce a relatively low average mobilityvalue. The test results can be analyzed and presented in the form of contour plots. The suspectareas can be identified through a scaled color scheme.

Comparing to another well-known NDT method Impact-Echo (IE) test, the IR test uses acompressive stress impact approximately 100 times that of the IE test. This greater stress inputmeans that the plate responds to the IR hammer impact in a bending mode over a very muchlower frequency range (0-1 kHz for plate structures), as opposed to the reflective mode of the IEtest which normally requires a frequency range of approximately 5 to 30 kHz, The influence ofreinforcement and tendons in the structure has generally less impact than it would for IE test,while delamination at relatively shallow depth, if any, will dominate the signal response in IRtesting. It makes it ideal to evaluate the presence of delamination without having to layoutlocations of tendon and reinforcing bars prior to the testing in a time critical project. However,the IR test cannot detect with high certainty the absolute depth of delamination; rather it's on acomparative basis. The width or size of crack cannot be determined in the IR testing.

The IR test method has been used to evaluate concrete structure condition in the past 20 years.The test method is in the process of being standardized by ASTM. CTLGroup has extensiveexperiences in utilizing this method to characterize defects in concrete. IR test has been used inevaluating concrete structures in both nuclear and fossil power plants. CTL Group experiencefor nuclear related structures has been compiled (see attached).

B) According to the Progress Energy procedure PT-407T, Rev. 2, concrete core samples areremoved in areas with high mobility values (greater than 1.0) to confirm the presence ofdelamination. Core samples are also removed in areas where mobility value is in the "Gray"(between 0.4 and 1.0) range to verify the condition, unless the slightly elevated values can bedispositioned through evaluation. Many cores have been removed based on the IR test resultsalong the boundary of delamination in the section where steam generator opening is located. Atthis time, the approximate 20 cores so far removed indicated the IR results have been accuratein characterizing the extent of delamination in the steam generator opening area. Also accordingto the test procedure, a population of core samples is also removed from areas where lowmobility values (less than 0.4) are obtained to confirm the sound concrete condition. Based onthe core samples removed, the IR results have been accurate to detect a delamination in theconcrete.

- .~ \.

C&TGROUPBuilding K ege. Deloverg Resultsm . www.CTLGroup.com

November 13, 2009

Via e-mail: paul.e.fa-qan(,pqnmail.comMr. Paul FaganTech Services SupportProgress Energy Corp.15760 West Powerline Rd.Crystal River, FL 34428-6708

Crystal River Nuclear Plant: Engineering Consulting Related to Delaminations in thePrimary Containment Concrete Wall, CR3 - Qualifications StatementCTLGroup Project No. 059169

Dear Mr. Fagan:

As you requested, CTLGroup has prepared nondestructive testing (NDT) qualificationinformation for each member of our NDT team involved in the testing at the Crystal RiverNuclear Power Plant, Florida.

Honggang Cao, CTLGroup Senior Engineer, is the NDT expert and a team leader for groundpenetrating radar (GPR), impulse response (IR), and impact echo (IE). He has extensiveknowledge and experience in various NDT methods for testing and evaluation of civilengineering structures. He is a voting member of the American Concrete Institute (ACI)Committee 228, Nondestructive Testing of Concrete in Structures. He published 13 technicalarticles on nondestructive testing and evaluation.

Additional members of the CTLGroup NDT team are as follows:

* Team Leaders for GPR, IR, and IE:

o Salvador (Sal) Villalobos-Chapa, Associate II in Structural Evaluation Group

o Jerry Harano, Senior Technical Specialist in Structural Evaluation Group

o Muamer (Mike) Klaric, Technician in Structural Evaluation Group

o Dean Adams, Technician in Structural Evaluation Group (GPR only)

* Team Support:

o Dean Adams, Technician in Structural Evaluation Group (also GPR TeamLeader)

o Michael Bonner, Associate I in Structural Evaluation Group

" Julia Johnson, Associate I in Materials Testing Group

All NDT team members have undergone training in applications of different NDT techniques.The training was lead by personnel experienced in NDT evaluation. The training took placeeither at the CTLGroup laboratory or in the field on specific projects. In addition, some of theteam members received training from the NDT equipment manufacturers and some took

Corporate Office: 5400 Old Orchard Road Skokie, Illinois 60077-1030 Phone: 847-965-7500 Fax: 847-965-6541

Washington D.C. Office: 9030 Red Branch Road, Suite 110 Columbia. Maryland 21045-2003 Phone: 410-997-0400 Fax: 410-997-8480

CTLGroup is a registered d/b/a of Construction Technology Laboratories, Inc.

Mr. Paul Fagan, Progress Energy Corp.Crystal River Nuclear PlantCTLGroup Project No. 059169

Page 2 of 2November 13, 2009

academic level courses related to NDT. Information on the types of NDT training of our staff isprovided in the attached CTLGroup Performance Based Training Records. These records wereprepared specifically for the Crystal River Power Plant project. In addition to the trainingrecords, updated resumes for all NDT team members are also provided.

We appreciate the opportunity to work with you on this project. Should you have any questionsconcerning qualifications of our NDT team or this project please contact us at (847) 972-3150.

Very truly yours,

Jerzy Z. Zemajtis, Ph.D.

4Senior Engineer1 and Project Managerizemaitis(@ctlqroup.comTel. (847) 972-3150

Attachments

1 Registered Professional Engineer in Washington, British Columbia, Manitoba and Ontario

k." ,gK, ds v.fl.... ..... .. www.CTLGroup.comr

Does the PGN Testing Procedure identify how CTL calibrates their equipment, qualification ofpersonnel, and equipment set-up (i.e., frequencies)?

This question pertains to PGN procedure PT-407T, Reactor Building Concrete Examination andTesting, Revision 2.

The question is split into three areas with specific procedure steps stated to address each area.

Area 1 - Calibration

Step 3.2 Responsibilities

Step 3.2.1

The Condition Assessment Consultant is responsible for:

Provide equipment list and associated calibration documentation

Step 3.3 Limits & Precautions

Step 3.3.2

The equipment utilized to perform the NDT was calibrated in the field during trial use byCTLGroup. This method of validating the test process and equipment for a specificapplication is standard practice for concrete condition assessments utilizing NDT.

Step 5.3 Reports

Step 5.3.1

An equipment list with calibration documentation will be provided for the NDT used. TheNDT process calibration/validation document will be included in the report.

Enclosure 7

For a critical structure of this scale, more correlation data is desired in order to finalize amore comprehensive calibration.

Enclosure 8

Individual equipment packages have been established to track specific calibratedequipment in order to link individual NDT locations with a calibrated equipment package.The Exterior Containment Inspection Log requires an Equipment Package Number to berecorded for each NDT location. The Equipment Package Number is traceable to apermanent plant record documenting the calibration records for the equipment.

Area 2 - Qualification

Step 3.2 Responsibilities

Step 3.2.1

Page 1 of 2

The Condition Assessment Consultant, CTLGroup, shall be responsible for assuring that

all individuals under his supervision are properly trained in the use of this procedure andassociated equipment.

Step 3.2.1

The Condition Assessment Consultant is responsible for:

Provide personnel qualification records for lead Engineer

Step 3.5.2 Initial Conditions

ENSURE that all personnel are familiar with the operating manuals of the equipment to

be used during the inspection.

Step 5.3 Reports

Step 5.3.1

The report will include personnel qualification records of lead engineers who performed

the NDT.

Area 3 - Equipment set-up

Step 3.2 Responsibilities

Step 3.2.1

The Condition Assessment Consultant is responsible for:

Provide calibration/validation documentation to substantiate the NDT methods to beused and to support the dedication of the software (SMASH) being used to evaluate theNDT data.

Step 3.3 Limits & Precautions

Step 3.3.2

The equipment utilized to perform the NDT was calibrated in the field during trial use byCTLGroup. This method of validating the test process and equipment for a specificapplication is standard practice for concrete condition assessments utilizing NDT.

Enclosure 5, page 1

TURN ON the computer to start setup process.

Enclosure 6, page 1

TURN ON the computer to start setup process.

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