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{{#Wiki_filter:Topical Report No. 213 Revision 0 Page 1 of 49 Topical Report 213 40th Year Reactor Building Tendon Surveillance (Period 10)(Rev 0)Responsible Engineer DateýA;Reviewer Design Verification Required?Section Manager Dote EJYes DgNo Date 4W-# | |||
Topical Report No. 213 Revision 0 Page 2 of 49 Table of Contents 1. PURPOSE AND INTRODUCTION p4 2. | |||
==SUMMARY== | |||
OF WORK PERFORMED AND INSPECTION RESULTS p6 2.1. Work Performed p6 2.1.1. Sample Selection p6 2.1.2. Post-Tensioning System Testing and Examination p7 2.1.3. Containment Surface Examination p8 2.2. Inspection Results p9 2.2.1. Post-Tensioning System p9 2.2.2. Containment Surface p11 3. POST-TENSIONING SYSTEM TESTS AND EXAMINATION p12 3.1. Examination Sample Selection p12 3.2. Tendon Forces p14 3.2.1. Individual Tendon Forces p14 3.2.2. Group Mean Forces p17 3.2.3. Projected Group Mean Forces p18 3.2.4. Control Tendon Force Trends p27 3.3. Tendon Elongations and Re-Tensioning p29 3.3. | |||
==Subject:== | ==Subject:== | ||
i 40TH YEAR SURVEILLANCE TENDON TENSIONED FROM SINGLE | i 40TH YEAR SURVEILLANCE TENDON TENSIONED FROM SINGLE END | ||
== Description:== | == Description:== | ||
Random sample selection was performed to establish RB tendon | |||
: 2. Walkdown the 14 single end tensioned tendons to determine | Originator: | ||
* 14 / 330 -0.3%.The 0.3% overall reduction would be relatively insignificant if the 14 tendons were | MICHAEL GRIMM Supv Contacted: | ||
* 0.9 = 0.84 of the predicted force, additional | John Piazza/Mark Torborg Condition | ||
: 1. The seal injection room is inaccessible as the rams can't fit around the | |||
: 1. Last Tendon above roof line - | == | ||
: i. Buttress 2 -Turbine Building 365' | Description:== | ||
: 1. | |||
: 1. | Random sample selection was performed to establish RB tendon population for the 40th year tendon surveillance scheduled in TIR20. Hoop tendons, H24-15 and H13-03, were selected for examination and lift-off testing.Stressing cards indicate that these tendons are two of 14 hoop tendons that were single end tensioned during construction. | ||
: 1. Inaccissible due to pipe interference and contaminated | It is industry practice to tension horizontal hoop tendons from both ends and the perform lift-off testing from both ends. With single end tensioning the potentiaI exists that lower pre-stressing forces were achieved and subsequ nt lift-off testing may yield stressing forces below the ASME Section XI Subsection IWL-3220 Code Acceptance Criteria.If results of lift-off testing do not meet acceptance criteria, the condition must be evaluated for continued operation and additional testing will need to be performed on adjacent tendons. In the case of H24-15 the next adjacent accessible tendons are H24-18 and 19. These tendons were also single end tensioned. | ||
: 1. | The adjacent tendons for H13-03 were tensioned from both ends.An additional concern is that the contracted MPRjanalysis for the acceptability of reduced force tendons assumes a11 TMI hoop tendons are dual end tensioned. | ||
: 1. | Immediate actions taken: Conducted phone call with Responsible Engineer (Howard Hill), Corporate ISI Program Engineer (Gene Navratil), TMI Design Manager (John Piazza), TMI Programs Manager (Mark Torborg) and TMI ISI Program Engineer (Michael Grimm) to discuss options for inspection of tendon H24-15 and path going forward for the MPR analysis.Reviewed single end tensioned tendons to determine if any were previously surveilled (ex. H24-19).Recommended Actions: 1. Work with Howard Hill to develop flow chart for decision making when inspecting single end tensioned tendons. (Sean Taylor -9/30/2013) | ||
: 1. | Topical Report 213 Attachment 1 Page 2 of 110 | ||
: 2. Walkdown the 14 single end tensioned tendons to determine accessiblity of both ends. (Michael Grimm -8/30/2013) | |||
: 3. Revise procedure 1301-9.1 to incorporate single end tensioned tendon inspection methodolgy. (Sean Taylor -9/30/2013) | |||
: 4. Work with Howard Hill to provide calculations of reduced force estimates for the 14 single end tensioned tendons for the MPR analysis.(Sean Taylor -9/30/2013) | |||
: 6. Determine if calculation C-1101-153-E410-046 required revision, and initiate revision accordingly. (Sean Taylor -9/30/2013) | |||
: 7. Rev~iew original design basis/calculations for single end tensioning justification. (Dave Yerkes -9/30/2013) | |||
What activities, processes, or procedures were involved?Tendon Surveillance planning activities including review of tendon data and force curves.Why did the condition happen?During construction Inryco single end tensioned 14 hoop tendons because of accessibility issues. Gilbert Associates reviewed/approved single end tensioning. | |||
What are the consequences? | |||
The potential exists that the 14 single end tensioned tendons will have a reduced pre-stress force below predicted values in calculation C-1101-153-E410-046 and below the ASME Section XI Subsection IWL-3220 code acceptance criteria of 95% of predicted force. This will result in additional tendons requiring lift off testing. Additionally the MPR analysis being performed for the acc ptance of reduced forces in adjacent tendons may be affected by the redu1ed pre-stress tendons.Review of H24-19 (originally single end tensioned) surveillance in year 3, indicates that though the pre-stress after the Structural Integrity Test was lower than similar hoop tendons (double end tensioned), the difference was minimal and has no consequence with respect to containment structural integrity. | |||
This IR is to identify potential additional scope. It does not imply a deficient condition with the containment building.Were any procedural requirements impacted? | |||
I Site procedure 1301-9.1 and corporate procedure ER-AA-330-P6 do not address the condition where a hoop tendon was only single enltensioned. | |||
Were there any adverse physical conditions? | |||
There is the possibility of reduced pre-stressing forces in the 14 single end tensioned hoop tendons. However, review of H24-19 (single end tensioned tendon) in subsequent surveillance indicates that the reduction was minimal and did not impact containment structural integrity. | |||
List of knowledgeable individuals: | |||
John Piazza Mark Torborg Gene Navratil Michael Grimm Howard Hill Repeat or similar condition? | |||
Topical Report 213 Attachment 1 Page 3 of 110 No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: CRAIG W SMITH 07/30/2013 14:23:06 CDT Reviewer Comments: There are no operability, reportability, or functionality concerns.Additional lift off testing may be neeyed to evaluate as found condition. | |||
If not stisfactory, additional IR will bý requied to document condition. | |||
SOC Reviewed by: MELISSA L MORLEY 08/01/2013 09:40:11 CDT SOC Comments: Close to actions created (MGF 8/1/13) (SOC 8/1/13)0 Topical Report 213 Attachment 1 Page 4 of 110 Assign #: 01 AR #: 01541172 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 08/04/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details I/Subject/Description: | |||
40TH YEAR SURVEILLANCE TENDON TENSIONED FROM SINGLE END Assignment Completion I I In Progress Notes: Completion Notes:-1 Topical Report 213 Attachment 1 Page 5 of 110 Single End Tensioned Hoop Tendon Discussion Page 1 of 3 9/5/2013 TMI-1 4 0 th Year Containment (RB) In-Service Inspection (ISl)Measurement | |||
& Evaluation of Force in Single End Tensioned Hoop Tendons The following discussion and flow chart address issues unique to the treatment of the single-end tensioned hoop tendons randomly selected for examination during the 4 0 th year Reactor Building (RB) Inservice Inspection (ISI). Single-end tensioned tendons are not addressed in ISI program documents or ASME Section XI Subsection IWL and, with one exception, have not been previously included in the random examination samples. Single end tensioned hoop tendon H24-19, the exception, was included in the 3 rd year (after the 1976 Structural Integrity Test (SIT)) ISI surveillance Oample. During that examination, lift-off forces were measured at both ends of H24-19. The average of the measured end anchorage forces was reported to have met the acceptance criterion (at or above 95% of the predicted value determined for a double end tensioned tendon).II The tendon sample randomly selected for examination during the 4 0 th year RB in-service inspection includes 2 hoop tendons, H13-03 and H24-15, tensioned at only one end during construction. | |||
It has been determined that both ends of H13-03 are currently accessible for lift-off measurement. | |||
Subsequent to selection, H24-15 has been determined inaccessible due to access restrictions to the Seal Injection Room. H24-22, double end tensioned, has replaced H24-15 for this surveillance. | |||
H24-15 shall be examined per the requirements of this document and the attached flow chart.During construction, 14 hoop tendons were single end tensioned. | |||
The mean force in a single end tensioned hoop tendon is calculated to be about 6.5% less than that in a hoop tendon tensioned at both ends. The RB design calculations do not account for the associated reduction in mean hoop pre-stressing force. The RB is pre-stre sed by 330 hoop tendons and if 14 of these are 6.5% below the level specified in the design, the overall reduction in mean hoop pre-stressing force is 6.5 | |||
* 14 / 330 -0.3%.The 0.3% overall reduction would be relatively insignificant if the 14 tendons were well distributed around the circumference and height of the RB wall. However, 5 of the 14 single end tensioned hoops are in the Hxx-03 group, one is in the adjacent Hxx-04 group and 3 are closely spaced in the H24-xx group. As a consequence, there is a -3' high band low on the RB wall that has a possible significant shortfall in pre-stressing force.The reduced pre-str ssing force in these localized regions may have struc ural significance when the reduction iý evaluated against the design criteria. | |||
For this reason, 'lit is important to measure, where possible, the force at both anchorages of each single end tensioned random sample tendon. Having data for both ends of said tendons will greatly facilitate any required evaluation of structural conditions in the localized regions.If a single end tensioned hoop tendon is only accessible at one end, lift-off at the accessible end should be measured for confirmatory information, this is not a code required examination. | |||
The lift-off force will be evaluated but, if it is below 0.95 of the forecast value, subsequent actions will be as specified by the Responsible Engineer (RE). In addition, the originally designated sample tendon will be replaced with the nearest tendon in the same buttress grouping that is accessible at both ends. TMI site procedure (1301-9.1) requirements will apply to the replacement tendon whether it is single or double end tensioned (a requirement for additional evaluation is discussed in the subsequent paragraph). | |||
Topical Report 213 Attachment 1 Page 6 of 110 Single End Tensioned Hoop Tendon Discussion Page 2 of 3 9/5/2013 The following flow chart identifies actions to take depending both on the accessibility of single-end tensioned random sample hoop tendons and on the results of the lift-off measurements. | |||
The flow chart includes an action to evaluate the condition if the average (both ends) lift-off force determined for a single end tensioned hoop tendon is below 84% of the predicted force (which is based on double end tensioning). | |||
As noted above, the mean force in a single end tensioned tendon is expected to be about 93.5% of that in a double end tensioned tendon. If the average lift-off force determined for a single end tensioned tendon is below 90% of this expected value or, below 0.935 | |||
* 0.9 = 0.84 of the predicted force, additional engineering evaluation is deemed necessary. | |||
If the lift-off is above 0.84 the acceptance and evaluation criteria of 1301-9.1 shall apply.Topical Report 213 Attachment 1 Page 7 of 110 Single End Tensioned Hoop Tendon Discussion Page 3 of 3 9/5/2013 Tendon Lift-Off Measurement Flow Chart Is random sample, replacement No or adjacent hoop tendon single o Proceed per end tensioned? | |||
1301-9.1 Select as replacement the nearest tendon accessible at both ends.Yes A F Is tendon accessible for lift-off measurements at both ends?4 Yes Measure single end lift-off.V Is average (both ends)lift-off force below 0.84 times predicted force?Yes RE to evaluate.Topical Report 213 Attachment 1 Page 8 of 110 A walkdown was performed on the single end tensioned tendons. Several tendons could not be accessed due to current plant conditions, i.e. scaffold builds, temporary RCAs, etc. A follow-up assignment will be issued to verify accessibility of these tendons prior to annotation in procedure 1301-9.1.A follow-up assignment will be issued to document the following walkdown as an attachment to 1301-9.1. While the single end tensioned tendons determined to be inaccessible during this walkdown will remain in population, they can be diagnosed from the pictures, or those taken during the follow-up walkdown, as inaccessible or accessible based on the rams available for the surveillance. | |||
If the ram technology is the same as it was for the 4 0 th year surveillance, then these inaccessible tepdons will remain inaccessible and an adjacent tendon will be selected.The seal injection room, will be annotated in the procedure as inaccessible, as current equipment can't access the room because of space restrictions around the motor control centers.Disposition of Single End Tensioned Tendons 1. Summary a. Accessible Tendons i. H24-18 ii. H24-19 iii. H62-44 iv. H 13-03 b. Inaccessible Tendons i. H24-15 ii. H13-12 iii. H51-20 iv. H46-03 v. H24-03 c. Indeterminate due to current access restrictions | |||
-Conduct additional walkdown i. H62-24 -Turbine Building RCA Restriction ii. H3p2 Turbine Building RCA Restriction ii. H 5-03 -Access to part of alligator pit iv. H35-04 -Access to part of alligator pit v. H62-03 -Access to part of alligator pit II. H24-15 a. Scheduled in T1R20 b. End Locations i. Buttress 2-Turbine Building 322' Elevation Topical Report 213 Attachment 1 Page 9 of 110 ii. Buttress 4-Auxiliary Building 305' Elevation -Seal Injection Room Topical Report 213 Attachment 1 Page 10 of 110 | |||
: 1. The seal injection room is inaccessible as the rams can't fit around the MCCs 2. Additional clearance issues exist with safety related conduit in front of the tendon end cap 111. H-24-18 a. Not Scheduled b. End Locations i. Buttress 2 -Turbine Building 322' Elevation 1. Inaccessible due to piping obstruction ii. Buttress 4 -Above Auxiliary Building Roof Topical Report 213 Attachment 1 Page 11 of 110 | |||
: 1. Last Tendon above roof line -accessible IV. H24-19 a. This tendon was inspected during 3 d Year Surveillance | |||
: i. Lift-Off was conducted from both ends.ii. Tendon passed surveillance | |||
-no issues identified V. H62-24 a. Not Scheduled b. End Locations i. Buttress 2 -Turbine Building 346' Elevation 1. Indeterminate accessibility | |||
-Roped off RCA area due to scaffold construction | |||
: a. Appears to be inaccessible due to Fire Service Piping 2. Will need to re-assess when access is available ii. Buttress 6- RB Exterior Above Equipment Hatch 1. Accessible with Work Platform VI. H62-34 a. Not Scheduled b. End Locations Topical Report 213 Attachment 1 Page 12 of 110 | |||
: i. Buttress 2 -Turbine Building 365' Elevation 1. Indeterminate accessibility | |||
-roped off RCA due to scaffold construction | |||
: 2. Will need to re-assess when access is available ii. Buttress 6 -RB Exterior above Equipment Hatch 1. Accessible with work platform VII. H62-44 a. Not Scheduled b. End Locations i. Buttress 2 -Below Roof line of Turbine Building.Tendon is accessible ii. uttress 6- RB Exterior 1. Accessible from Work Platform VIII. H 13-012 a. Not Scheduled b. End Locations i. Buttress 3 -Turbine building 302' Elevation outside of Personnel Hatch Topical Report 213 Attachment 1 Page 13 of 110 | |||
: 1. Accessible ii. Buttress 1 -Intermediate Building 295' Elevation 1. Inaccessible due to piping interference | |||
: c. Note: This tendon deforms around the personnel hatch.IX. H51-20 a. Not Scheduled b. End Locations i. Buttress 1- Intermediate Building 322' Elevation 1. Inaccessible due to pipe interference ii. Buttress 5- RB exterior above Auxiliary Building 1. Accessible with Work Platform X. H46-03 a. Not Scheduled b. End Locations i. Buttress 6- Alligator Pit Topical Report 213 Attachment 1 Page 14 of 110 | |||
: 1. Accessible ii. Buttress 4- Auxiliary Building 281' Elevation 1. Inaccessible due to pipe interference XI. H24-03 a. Not Scheduled b. End Loca ions i. Buttress 4 -Auxiliary Building 281' Elevation I Topical Report 213 Attachment 1 Page 15 of 110 | |||
: 1. Inaccissible due to pipe interference and contaminated area ii. Buttress 2 -Alligator Pit 1. Indeterminate | |||
-will need to identify in an additional walkdown XII. H35-04 a. Not Scheduled b. End Locations i. Buttress 3 -Alligator Pit 1. Indeterminate -will need to id ntify in an additional walkdown ii. Buttress 5- Alligator Pit Topical Report 213 Attachment 1 Page 16 of 110 | |||
: 1. Accessible XIII. H35-03 a. Not Scheduled b. End Locations i. Buttress 3 -Alligator Pit 1. Indeterminate | |||
-will need to identify in an additional walkdown ii. Buttress 5 -Alligator Pit 1. Accessible XIV. H 62-03 a. Not Scheduled b. End Locations i. Buttress 6 -Alligator Pit Topical Report 213 Attachment 1 Page 17 of 110 | |||
: 1. Accessible ii. Buttress 2 -Alligator Pit 1. Indeterminate-will need to identify in an additional walkdown XV. H 13-03 a. Scheduled T1R20 b. End Locations i. Buttress 3 -Alligator Pit 1. Accessible ii. Buttress 1 -Alligator Pit Topical Report 213 Attachment 1 Page 18 of 110 | |||
: 1. Accessible Topical Report 213 Attachment 1 Page 19 of 110 0Go Back Print I New search I Home AR Number: 01567897 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/31/2013 Aff System: 153 Event Date: 10/03/2013 CR 4/D Disc Date: 10/03/2013 Level/Class: | |||
How H02 Orig Date: 10/04/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
SHIM GAP IDENTIFIED ON H24-22 BUTTRESS | SHIM GAP IDENTIFIED ON H24-22 BUTTRESS 4 | ||
== Description:== | == Description:== | ||
During tendon surveillance activities on Hoop Tendon H24-22 at Buttress | |||
* 3 1 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate | Originator: | ||
MICHAEL GRIMM Supv Contacted: | |||
John Piazza/Mark Torborg Condition | |||
== | |||
Description:== | |||
During tendon surveillance activities on Hoop Tendon H24-22 at Buttress 4 a shim gap measuring linch was identified, with the opposite side of the shims measuring zero. This shim gap is in excess of the 0.25 inch average allowed per procedure ER-AA-330-006. | |||
Immediate actions taken: IR initiated e The shim gap was reset to meet de 1 ign requirements after lift-off.Briefed Responsible Engineer on the condition Recommended Actions: Evaluate the pre-existing condition. | |||
What activities, processes, or procedures were involved?Conduct of tendon surveillance activities. | |||
Why did the condition happen?During original construction the shim gap was not set properly.What are the consequences? | |||
The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components. | |||
The shim gap has since been reset. The anchorage components exhibited no evidence of degradation. | |||
Tendon H24-22 Buttress 4 has been fully restored to the design requirements. | |||
Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of ER-AA-330-006. | |||
Were there any adverse physical conditions? | |||
The AISC allowable design bearing stress of 90% of yield was exceeded at the time of original construction, the yield stress was not exceeded.Relaxation of the tendon and the corresponding loss of prestress during Topical Report 213 Attachment 1 Page 20 of 110 the first year of service, resulted in a reduction in the bearing stress, and thereafter, 90% yield criteria was met.The shim gap has been reset to an acceptable average width of 0.25 inches or less, and the lift off test was performed satisfactory, restoring H24-22 Buttress 4 to teh as-designed condition. | |||
List of knowledgeable individuals: | |||
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition? | |||
Yes IR 1014485 written on 1/10/2010. | |||
Non conforming shim gaps on three tendons during the final stressing inspections of the steam generator replacement tendons.Operable Basis: Reportable Basis: Functional Basis: Reviewed by: CRAIG W SMITH 10/05/2013 12:10:45 CDT Reviewer Comments: There are no operability, reportability, or fj nctionality concerns.The shim gap has since been reset. The arýchorage components exhibited no evidence of degradation. | |||
Tendon H24-22 Buttress 4 has been fully restored to the design requirements. | |||
Initial engineering evaluation has determined tendon continued to maintain design function in as found condition. | |||
Action to Engineering to document formal evaluation when complete. | |||
If evaluation does not reach satisfactory conclusion, a separate IR should be generated. | |||
SO( Reviewed by: DIANE M SCHNEIDER 10/08/2013 09:40:56 CDT SO Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/07/13). | |||
10/07/2013 | |||
-Per S/M Comments: | |||
The shim gap has since been reset. The anchorage components exhibited no evidence of degradation. | |||
Tendon H24-22 Buttress 4 has been fully restored to the design requirements. | |||
Initial engineering evaluation has determined tendon continued to maintain design function in as found condition. | |||
Action to Engineering to document formal evaluation when complete. | |||
If evaluation does not reach satisfactory conclusion, a separate IR should be generated. | |||
D. Hockley Close to comments and action taken and created. (benson 10/8/13) (SOC 10/08/13)Topical Report 213 Attachment 1 Page 21 of 110 1 0 Topical Report 213 Attachment 1 Page 22 of 110 Assign #: 01 AR #: 01567897 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/09/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/l!escription: | |||
SHIM GAP IDENTIFIED ON H24-22 BUTTRESS 4 Assignment Completion In Progress Notes: Completion Notes: t 4 Topical Report 213 Attachment 1 Page 23 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 1 of 5 1.0 Reason for Evaluation/Scope This is evaluation is being performed to document the acceptability of a non-conforming condition that was identified during the TMI-1 4 0 th year In-service Inspection of the Reactor Building post-tensioning system (tendons). | |||
During the as-found examination of surveillance hoop tendon H24-22 (a non Steam Generator Replacement Project affected tendon) end anchorage at buttress 4, the top side shim gap was found to be 1 linch. The shim halves were in sensible contact at the bottom. tAfter the lift-off measurement was completed, the shims were realigned to restore the gaps between shim halves to 0.25 inches, which is compliant with the requirements specified in Par. 4.4.1.5.A of Exelon Corporate Procedure ER-AA-330-006, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section XI 2004 Edition Subsection IWL, to evaluate and document the acceptability of the as-found condition for tendon H24-22, as well as to establish criteria for the maximum allowable shim gap for hoop tendons to be used in future inspections. | |||
This evaluation was screened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, SuIsection IWL.2.0 Detailed Evaluation As documented in IR 1567897, the shim stack on hoop tendon H24-22 was found with a 1 inch gap on one side and no gap on the other side. During lift-off testing of the tendon, technicians restored the shim gap to the acceptable 0.25 inches average gap in accordance with ER-AA-330-006. | |||
This evaluation provides the maximum allowable shim gap assuming the highest as-found hoop tendon lift-off force. This evaluation may be used for the acceptance of additional hoop tendon shim gaps assuming the maximum issumed lift-off force is not exceeded.2.1. As-Found Condition The post-tensioning system vendor (INRYCO) manual, VM-TM-2485, provides relatively detailed instructions for tendon installation and stressing. | |||
However, these instructions do not address shim gap, suggesting that the implied warranty of good workmanship would result in shim halves being pushed into contact either with each other or with the tendon wire bundle.The manual includes a drawing (identified only by title as 170 Wire Split Shim / Part No.101006), also present in TMI Electronic Document Management System (EDMS) as PS-01. This drawing shows a maximum material removal of 0.25 inches along the line where the 10 inch square shim blank is flame cut in half. Drawings are available for all shims sizes. The smallest Topical Report 213 Attachment 1 Page 24 of 110 Exelon Generation, Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 2 of 5 shim, 10 gauge, shows dimensions for the cut gap as a maximum of 0.125 inches. Although manufacturing tolerances allow for the flame cut to remove up to 0.25 inches along the centerline, a conservative assumption of 0.125 inches is used for the purposes of this evaluation as it provides the greatest reduction in bearing surface area making it a bounding condition. | |||
A 5.625 inch diameter center hole is cut through the shim blank before the blank is cut in half.This is sufficient to clear the wire bundle maximum diameter (diameter varies with angular position due to the anchor head hole pattern) at the anchor head exit. If 0.125 inches are removed along the cut line when the shim blank is split, the shim halves may not necessarily close against each other when placed around the wire bundle. Depending on the orientation of the anchor head relative to the shim parting line, shim halves may be separated by up to 0.125 inches when pushed into contact with the wires.American Institute of Steel Construction (AISC) specifications (which covers TMI's post-tensioning system components) limit steel bearing stress to 90% fv, where fy is the minimum tensile yield stress specified for the material. | |||
Shims 0.25 inches and larger are cut from ASTM A 36 plate (per the previously cited shim drawing) which has a minimum required tensile yield of 36 ksij Therefore, the AISC bearing limit for this material is 0.90 | |||
* 3 1 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate Tensile Strength (GUTS), or 1,394 kips, per TMI Updated Final Safety Analysis Report, Chapter 5 Appendix 5B. This seating force requires an area of 1,394 / 32.4 = 43.02 in 2 between the anchor head and the shim in contact with the anchor head. To ensure a bearing area of at least 43.02 in 2 , the average shim gap, computed using the expression discussed in Section 2.2 of this evaluation, cannot exceed a value of 0.21 inches, which is 0.085 inches greater than the cut gap of 0.125 inches.The 1 inch gap observed at the top of the H24-22 buttress 4 shim stack results in a net bearing area of about 42 in 2.At the design tendon seating force of 1,394 kip (0.70 GUTS), the resulting bearing stress would be close to 1,394 / 42 = 33.2 ksi or about 92% f,.While it is conservative to limit bearing to 90% fv, this conservatism is provided by AISC to account for unknown variations in loads and material properties. | |||
Construction records show that H24-22 was seated at an average (of both ends) force of 1,458 kips and not 70% GUTS (1,394 kips). If both ends of the tendon are treated as having equal seating forces, the initial anchor head to shim bearing stress at the buttress 4 end would have been about 34.8 ksi, or 97% f,. While this stress exceeds the AISC limit of 90% fv, it is still below the minimum specified Topical Report 213 Attachment 1 Page 25 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 3 of 5 material yield and well below the actual material yield. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load, which was verified by visual inspection of the shim stack.Tendon forces are currently well below the initial seating levels (lift-oft at the shop end of H24-22 was 1,186 kips) due to the effects of elastic shortening and time dependent losses. At this time, bearing stress at all hoop tendon anchor head to shim interfaces should be under 32.4 ksi (90% fy for A 36 material), assuming that bearing areas are not significantly less than 42 in'.The bearing stress at the buttress 4 end of H24-22 with the as-found 1 inch shim gap was 1,186 kips / 42 in 2 = 28.2 ksi, which is well below the 90% fy level of 32.4 ksi. Still, there is no current design basis for reducing the required bearing area to anything less than that needed at initial tensioning. | |||
For this reason, it is important to show with confidence that shim gaps are acceptable based on the initial design requirements. | |||
This is done below.2.2. Maximum Evaluated Acceptable Shim Gap The subsequent evaluation applies only to hoop tendons. Vertical and Dome (Evaluation 1569980-02) | |||
Tendons will require a separate evaluation. | |||
At the present time, hoop tendon forle levels are well below initial lock-off values. The expected current mean hoop tendon force level, determined by the trend of surveillance measurements is 1,150 kips. The greatest mean anchorage force observed in hoop tendons examined during surveillances 4 through 9 (surveillance years 10 through 35) is 1,218 kips. This value was computed as the average of the 1,201 kips and 1,235 kips forces measured at the anchorages of hoop tendon H13-11 during Surveillance 8 (3 0 th year) in 2004. On the basis of these trended and measured tendon force levels, it is reasonable to conclude that any easured dome tendon anchorage force from this time forwa 1d will not exceed 1,235 kips. If a im gap is found in a dome tendon with a lift-off exceeding this 1,235 kips criteria, a separate evaluation shall be conducted to determine its acceptability. | |||
The minimum required shim bearing area required to support a tendon anchorage force of 1,235 kips is 1 k10 =M ng .The anchor head to shim bearing area, Ab, is effectively equal to the value computed using the following expression: | |||
Where; -6 Id c) i Where;Topical Report 213 Attachment 1 Page 26 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 4 of 5-ý m %,S75 Inc.,, which is the Anchor Head Diameter dz -5,I25 .'-,, which is the Shim Hole Diameter d, = 0.25 i.P.,, which is the assumed width of the shim cut line G, is the sum of the top and bottom shim gap widths Substituting the above values, rounded to the nearest 0.01 inches, into the expression for Ab gives:--%.15D ---01z) % -C 44'For a required bearing area of 38.12 in 2 , the sum (G) of the top and bottom gaps may not exceed = ,,, .9, this value is reduced to 1.4 inches for conservatism. | |||
Using the conservative value of 1.4 inches for G, mean gap width (G / 2) cannot exceed 0.70 inches.3.0 Conclusion/Findings Based on the above computation, the conclusion of this evaluation is that a mean shim gap width _0.70 inches is acceptable for hoop tendons. This conclusion is considered to be valid unless a current or future measurement of a dome tendon anchorage force exceeds 1,235 kips.There is no evidence that hoop tendon average shim galls in excess of 0.70 inches have been observed during prior examinations. | |||
In addition, during the present surveillance a total of 35 hoop, vertical, and dome end anchorages will be examined. | |||
Of these, 28 ends are randomly selected sample tendons (including 4 Steam Generator Replacement (SGR) tendons) that have not been previously examined since initial installation. | |||
The remaining seven have been previously examined.It is expected that the results of the examinations performed during the present surveillance will show that the 0.7 ihch mean gap between the H24-22 shim stack halves is an ano naly and that mean gaps found aý the anchorages of the remaining surveillance sample dome t ndons will be smaller.As is shown above, a mean gap of 0.70 inches is acceptable for hoop tendons. If the remaining hoop tendon end anchorage examinations do not uncover a larger gap and if no hoop tendon end anchorage lift-off force is found to exceed 1,235 kips, conditions with respect to shim gap will be considered acceptable and no further evaluation will be required.In summary, based on the computation presented in this evaluation, it is concluded that a mean dome tendon shim gap < 0.70 inches is acceptable for an end anchorage force < 1,235 kips. As the Topical Report 213 Attachment 1 Page 27 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 5 of 5 lift-off measured on H24-22 was 1,186 kips, which is less than 1,235 kips, the as-found shim gap is acceptable. | |||
==4.0 References== | |||
: 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection ond Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structurol Integrity Tendon Surveillance | |||
: 4. AISC Handbook 5. IR 1569980 6. TMI-1 UFSAR Chapter 5, Appendix 5B 5.0 Attachments None Approvals Responsible Engineer: | |||
Howard Hill Date: See EDMS Preparer: | |||
Michael Grimm Date: See EDMS V Independent Reviewtr: | |||
Sean Taylor Date: Sle EDMS Manager: MarkTorborg Date: See EDMS 0 Topical Report 213 Attachment 1 Page 28 of 110 0 Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01579266 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/06/2013 Aff System: 153 Event Date: 10/31/2013 CR 4/D Disc Date: 10/31/2013 Level/Class: | |||
How H02 Orig Date: 10/31/2013 Discovered:I Action Request Details | |||
==Subject:== | ==Subject:== | ||
SHIM GAP IDENTIFIED ON DOME TENDON H13- | SHIM GAP IDENTIFIED ON DOME TENDON H13-08 | ||
== Description:== | == Description:== | ||
During tendon surveillance activities on Hoop Tendon H13-08 a shim | |||
Originator: | |||
MICHAEL GRIMM Supv Contacted: | |||
Mark Torborg Condition | |||
== | |||
Description:== | |||
During tendon surveillance activities on Hoop Tendon H13-08 a shim gap measuring 1 inch was identified, with the opposite side of the shims measuring 0.125 inches. This shim gap is in excess of the 0.25 inch average allowed per PSC procedure SQ 8.0 Revision 1 and corporate procedure ER-AA-330-006. | |||
This condition was previously evaluated for Hoop Tendon H24-22 Buttress 4 (IR 1567897) and Dome Tendon D-134 (IR 1569980); | |||
both tendons were determined to be acceptalle. | |||
Tendon H13-08 is undergding visual examination only as it was determined to be inaccessible during pre-outage walk downs. There are no plans to restore this shim gap to the 0.25 inch acceptable gap.The evaluation of shim gaps for hoop tendons was completed previously for Hoop Tendon H24-22 Buttress 4 under IR 1567897. At construction the design lock-off force was 1394 Kips which results in a bearing force 92%of yield. The allowable design bearing force per the AISC manual is 90%of yield.Lift-off data from past tendon surveillances shows tljat pre-stressing force decreases rapidly over the first couple years oflservice and then more slowly during the remaining lifetime. | |||
During thl 40 year life of the TMI Unit 1 containment building the highest as-found lift-off force for a hoop tendon was 1218 Kips. It was determined in the evaluation of H24-22 in IR 1567897 that a maximum shim gap average of 0.7 inches was acceptable for service at an as-found force of 1218 Kips.As H13-08 has not had a lift-off performed, the maximum observed lift-off force for the life of the plant is assumed. The as-found shim gap average was 0.6 inches. Therefore the shim gap average is below the allowable shim gap and acceptable for continued service.Immediate actions taken: IR initiated Briefed Responsible Engineer on the condition Topical Report 213 Attachment 1 Page 29 of 110 PSC issued NCR-N1091-005 Recommended Actions: Create action to close to evaluation in IR 1567897 once completed (Michael Grimm)What activities, processes, or procedures were involved?Conduct of tendon surveillance activities. | |||
Why did the condition happen?During original construction the shim gap was not set properly What are the consequencWs? | |||
The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components. | |||
The anchorage components exhibited no evidence of degradation. | |||
Tendon H13-08 could not be restored to the as-designed condition as the tendon will not undergo a lift-off test and will remain' under tension.Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of PSC procedure SQ 8.0 Revision 1 or corporate procedure ER-AA-330-006. | |||
Were there any adverse physical conditions? | |||
The AISC allowable design bearing stress of 90% of yield was exceeded at the time of original construction; however the yield stress was not exceeded. | |||
Relaxation of the tendon and the corresponding loss of pre-stress during the first year of service, resulted in a reduction of the bearing stress, and thereafter, the 90% yield criterion was met.The shim gap could not be reset to the as-designed cond tion as no lift-off test was performed and the bearing assembly renjained under tension.List of knowledgeable individuals: | |||
Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar Yes IR 1569980 for shim gap on Dome Tendon D-143 IR 1567897 for shim gap on Hoop Tendon H24-22.IR 1014485 written on 1/10/2010. | |||
Non conforming shim gaps on three tendons during the final stressing inspections of the steam generator replacement tendons.Operable Basis: Reviewed TS 3.19 and 4.4.2. This 'as found' shim gap was in excess of the 0.25 inch average allowed per ER-AA-330-006. | |||
As documented in the IR, It was determined in the evaluation of H24-22 in IR 1567897 that a maximum shim gap average of 0.7 inches was acceptable for service at an as-found force of 1218 Kips. The as-found shim gap average was 0.6 inches.Topical Report 213 Attachment 1 Page 30 of 110 Therefore the shim gap average is below the allowable shim gap and acceptable for continued service.1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability? | |||
TS 3.19, 4.4.2, 1301-9.1, ER-AA-330-006 | |||
: 3. Describe the function of the SSC and basis for operability/availability determination. | |||
See below 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103. | |||
: 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO I The following functions are maintained even with the deviation in shim gaps: 153-ROl : Contain fission products to prevent radioactive release (153).153-R02 : Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural integrity (153).Reportable Basis: This is not reportable IAW the Exelon Reportability Manual.Functional Basis: See operability basis SOC Jeviewed by: CRYSTAL A WARLOW 11/04/2013 09:47:40 CST SOC Comments: REACTOR BUILDING Close to action created. (benson 11/1/13)11/03/2013 | |||
-Unchecked Shift Review Complete Radio Button because the shift needs to address the TS=Yes Required Modes. D. Hockley Not a CCF. Close to action created. (SOC 11/04/13)Reviewed by: BRADLEY A PARFI-T 11/01/2013 16:19:17 CDT Reviewer Comments: | |||
I See operability and reportability basis.Reviewed by: EDWARD M CARRERAS 11/03/2013 13:44:45 CST Reviewer Comments: Added required modes. EMC 11/3/13 Topical Report 213 Attachment 1 Page 31 of 110 Assign #: 01 AR #: 01579266 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 11/05/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
ISHIM GAP IDENTIFIED ON DOME TENDON H13-08 Assignment Completion In Progress Notes: Completion Notes: 4 Topical Report 213 Attachment 1 Page 32 of 110 Assign #: 02 AR #: 01579266 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: GRIMMX Due Date: 12/06/2013 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 12/06/2013 Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
Ensure that evaluation under IR 1567897 satisfactorily co vers this issue. Create additional actions as needed.Assignment Completion In Progress Notes: The condition observed on this tendon is addressed under technical evaluation 1567897-02 as the condition is bounded by the evaluation. | |||
No further actions are required.-Michael Grimm 11/27/2013 Completion Notes: Topical Report 213 Attachment 1 Page 33 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01569980 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 11/15/2013 Aff System: 153 Event Date: 10/09/2013 CR 4/D Disc Date: 10/09/2013 Level/Class: | |||
How H02 Orig Date: 10/09/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
SHIM GAP IDENTIFIED ON DOME TENDON D- | SHIM GAP IDENTIFIED ON DOME TENDON D-143 | ||
== Description:== | == Description:== | ||
During tendon surveillance activities on Dome Tendon D-143 a shim | |||
: 4. Is the SSC available (Paragon)? (Y/N) | Originator: | ||
* 36 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate | MICHAEL GRIMM Supv Contacted: | ||
Mark Torborg Condition | |||
== | |||
Description:== | |||
During tendon surveillance activities on Dome Tendon D-143 a shim gap measuring 1 inch was identified, with the opposite side of the shims measuring zero. This shim gap is in excess of the 0.25 inch average allowed per PSC procedure SQ 8.0 Revision 1 and corporate procedure ER-AA-330-006. | |||
The as-found condition corresponds to a bearing stress of 81% of yield., which is less than the 90% of yield strength design criteria.This condition wos previously evaluated for Hoop Tendon H24-22 Buttress 4 (IR 1567897) a Id determined to be acceptable. | |||
After lift-off the shim gap was adjusted, but was unable to be restored to the required 0.25 inch average gap required by procedure due to interference from the wire bundle. The as-left condition of the shim stack is 0.5 inch gap on top and 0.25 inch gap on the bottom. This condition is acceptable as the bearing stress is 78% of yield.Immediate actions taken: IR initiated The shim gap was reset to the smallest ga 3 achievable with the wire bundle interference (the shims are in contact withl the wire bundle).Briefed Responsible Engineer on the condition PSC issued NCR-N1091-004 Recommended Actions: Document evaluation of the pre-existing and as-left condition What activities, processes, or procedures were involved?Conduct of tendon surveillance activities. | |||
Why did the condition happen?During original construction the shim gap was not set properly.What are the consequences? | |||
Topical Report 213 Attachment 1 Page 34 of 110 The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components. | |||
Per AISC the design criteria for the bearing stress should be 90% of yield. With the as-found shim gap, the bearing stress at time of construction was 9 2% of yield and 81% of yield with the as-found lift-off. | |||
The bearing stress of the anchorage assembly never exceeded the yield strength of the material.The anchorage components exhibited no evidence of degradation. | |||
Tendon D-143 could not be restored to the as-designed condition, the as-left shim gap is 0.5 inch on top and 0.25 inch on the bottom. The as-left condition corresponds to bearing stress of 78% of yield.Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of PSC procedure SQ 8.0 Revision 1 or corporate procedure ER-AA-330-006. | |||
Were there any adverse physical conditions? | |||
The AISC allowable design bearing stress of 9 0% of yield was exceeded at the time of original construction; however the yield stress was not exceeded. | |||
Relaxation of the tendon and the corresponding loss of pre-stress during the first year of service, resulted in a reduction of the bearing stress, and thereafter, the 90% yield criterion was met.The shim gap could not be reset to the as-designed condition due to interference with the wire bundle. The as-left condition of the shim stack has a 0.5 inch gap on top and 0.25 inch gap on the bottom, an average of 0.375 inches. This condition is below the 90% yield criteria (actual is 7 8% of yield) with the current pre-stress in the tendon (1218.68 kips), and is therefore acceptable for continued service.List of knowledgeable individuals: | |||
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition? | |||
Yes IR 1567897 for shim gap on Hoop Tendon H24-22.IR 1014485 written on 1/10/2010. | |||
Non conforming shim gaps on three tendons during the final stressing inspections of the stearn generator replacement tendons. /Operable Basis: Reviewed TS 3.19 and 4.4.2. This 'as found' shim gap was in excess of the 0.25 inch average allowed per ER-AA-330-006. | |||
As docuimented in the IR, this corresponds to a bearing stress of 81% of yield., which is less than the 90% of yield strength design criteria. | |||
The shim gap has been adjusted but cannot attain the desired final average gap. The as-left condition results in an acceptable bearing stress of 78% of yield.1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability? | |||
TS 3.19, 4.4.2, 1301-9.1, ER-AA-330-006 | |||
: 3. Describe the function of the SSC and basis for operability/availability determination. | |||
See below Topical Report 213 Attachment 1 Page 35 of 110 | |||
: 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103. | |||
: 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO The following functions are maintained even with the deviation in shim gaps: 153-ROl : Contain fission products to prevent radioactive release (153).153-R02 : Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural lintegrity (153).Reportable Basis: This does not meet any reporting thresholds. | |||
Functional Basis: Reviewed by: EDWARD M CARRERAS 10/09/2013 19:29:22 CDT Reviewer Comments: Engineering to document an evaluation of the pre-existing and as-left condition for this tendon. Generate an IR, as needed, if results require additional actions.SOC Reviewed by: DIANE M SCHNEIDER 10/11/2013 09:30:25 CDT SOC Comments: | |||
S REACTOR BUILDING This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/10/13). | |||
Close to action created. (benson 10/10/13) (SOC 10/11/13)0 Topical Report 213 Attachment 1 Page 36 of 110 S Assign #: 01 AR #: 01569980 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/14/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
SHIM GAP IDENTIFIED ON DOME TENDON D-143 Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 37 of 110 Exeton Generation. | |||
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY J SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 1 of 6 1.0 Reason for Evaluation/Scope This evaluation is being performed to document and evaluate for acceptability a non-conforming condition that was identified during the TMI-1 4 0 th year In-service Inspection of the Reactor Building post-tensioning system (tendons). | |||
During the as-found examination at the buttress 4 end of surveillance dome tendon D-143, the top side shim gap was found to be 1 inch. The shim halves were in sensible contact at the bottom. After the lift-off measurement was completed, the shims were realigned to restore the gaps between halves to 0.5 inches on the top and 0.25 inches on the bottom. It was not possible to reduce the gaps further. Both the as-found mean gap of 0.5 inches and the resulting as-left mean gap of 0.375 inches exceed the 0.25 inches limit specified in Par.4.4.1.5.A of Exelon Corporate Procedure ER-AA-330-006, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section Xl, 2004 Edition, Subsection IWL, to evaluate and document the acceptability of both the as found and as left conditions of tendon D-143, as well as establish criteria for the maximum allowable shim gap for dome tendons to be used in future inspections. | |||
This evaluation was screened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section XI, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation As documented in IR 1569980, the shim stack on dome tendon D-143 was found with a 1 inch gap on top and no gap on the bottom. During lift-off testing of the tendon, technicians attempted to restore the shim gap to the acceptable 0.25 inches average gap as provided in ER-AA-330-006. | |||
Due to interferences with the wire bundle, the as-left shim gap was 0.5 inches on top and 0.25 inches on the bottom, for an average of 0.375 inches gap. This evaluation provides the maximum acceptable shim gap assuming the highest as-found dome tendon lift-off force. This evaluation may be used for the acceptance of additional dome tendon shim gaps assuming the maximum assumed lift-off force is not exceeded.2.1. As-Found Condition The post-tensioning system vendor (INRYCO) manual, VM-TM-2485, provides detailed instructions for tendon installation and stressing. | |||
However, these instructions do not address the presence of shim gaps, suggesting that the implied warranty of good workmanship of the shims would result in shim halves being pushed into contact either with each other or with the tendon wire bundle, resulting in a gap consistent with manufacturing tolerances. | |||
Topical Report 213 Attachment 1 Page 38 of 110 ExeLon Generation. | |||
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 2 of 6 The manual includes a drawing (identified only by title as 170 Wire Split Shim / Part No.101006). This drawing shows a maximum material removal of 0.25 inches along the line where the 10 inch square shim blank is cut in half (flame cut). Drawings are available for all shims sizes. The smallest shim, 10 gauge steel, shows dimensions for the cut gap as a maximum of 0.125 inches. Although manufacturing tolerances allow for the flame cut to remove up to 0.25 inches along the centerline, a conservative assumption of 0.125 inches is used for the purposes of this evaluation as it provides the greatest reduction in bearing surface area making it a bounding condition. | |||
A 5.625 inch diameter center hole is cut through the shim blank before the blank is cut in half.This is sufficient to clear the wire bundle maximum diameter (diameter varies with angular position due to the anchor head hole pattern) at the anchor head exit. If 0.125 inches is removed along the cut line when the shim blank is split, the shim halves may not necessarily close against each other when placed around the wire bundle. Depending on the orientation of the anchor head relative to the shim parting line, shim halves may be separated by up to 0.125 inches when pushed into contact with the wires.American Institute of Steel Construction (AISC) specifications (which covers TMI's post-tensioning system components) limit steel bearing stress to 90% fy, where fy is the minimum tensile yield stress specified for the material. | |||
Shims 0.25 inches and larger are cut from ASTM A 36 plate (per the previously cited shim drawing) which has a minimum required tensile yield of 36 ksi. Therefore, the AISC bearing limit for this material is 0.90 | |||
* 36 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate Tensile Strength (GUTS), or 1,394 kips, per TMI Updated Final Safety Analysis Report, Chapter 5 Appendix 5B. This seating force requires an area of 1,394 / 32.4 = 43.02 in 2 between the anchor head and the shim in contact with the anchor head. To ensure a bearing area of at least 43.02 in 2 , the average shim gap, computed using the expression discussed in Section 2.2 of this evaluation, cannot exceed a value of 0.21 inches, which is 0.085 inches greater than the cut gap of 0.125 inches.The 1 inch gap observed at the top of the H24-02 Buttress 4 end shim stack results in a net bearing area of approximately 42 in 2.At the design tendon seating force of 1,394 kip (70%GUTS), the resulting bearing stress would be approximately 1,394 / 42 = 33.2 ksi or about 92%fy.While it is conservative to limit bearing to 90% fy, this conservatism is provided by AISC to account for unknown variations in loads and material properties. | |||
Construction records show that D-143 was seated at an average (of both ends) force of 1,394 kips = 70% GUTS. If both Topical Report 213 Attachment 1 Page 39 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT I PAGE Michael Grimm Evaluation of D-143 Shim Gap 3 of 6 ends of the tendon are treated as having equal seating forces, the initial anchor head to shim bearing stress at the shop end would have been approximately 33.2 ksi, or 92% fy, as stated in the previous paragraph. | |||
While this stress exceeds the AISC limit of 90% fy, it is still below minimum specified material yield and well below the actual material yield. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load, which was verified by visual inspection of the shim stack.Tendon forces are currently well below the initial seating levels (lift-off at the shop end of D143 is 1,219 kip) due to the effects of elastic shortening and time dependent losses. At this time, bearing stress at all dome tendon anchor head to shim interfaces should be under 32.4 ksi (90%fy for A 36 material), assuming that bearing areas are not significantly less than 42 in 2.The bearing stress at the shop end of D143 with the as-found I inch shim gap was about 1,218 / 42= 29 ksi which is well below the 90% fy level of 32.4 ksi. Still, there is no current design basis for reducing the required bearing area to anything less than that needed at initial tensioning. | |||
For this reason, it is important to show with confidence that shim gaps are acceptable based on the initial design requirements. | |||
This is done below.2.2. Maximum Evaluated Acceptable Shim Gap The subsequent evaluation applies only to dome tendons. Vertical and Hoop Tendons will require a separate evaluation. | |||
At the present time, dome tendon force levels are well below initial lock-off values. The expected current mean dome tendon force level, determined by the trend of surveillance measurements is 1,121 kips. The greatest mean anchorage force observed in dome tendons examined during surveillances 4 through 9 (surveillance years 10 through 35) is 1,290 kips. This value was computed as the average of the 1,286 kip and 1,294 kip forces measured at the anchorages of dome tendon D-314 during Surveillance 4 (l 0 th year) in 1984. On the basis of these trended and measured tendon force levels, it is reasonable to conclude that any measured dome tendon anchorage force from this time forward will not exceed 1,294 kips. If a shim gap is found in a dome tendon with a lift-off exceeding this 1,294 kips criteria, a separate evaluation shall be conducted to determine its acceptability. | |||
The minimum required shim bearing area required to support a tendon anchorage force of 1,294 kip is 1294kips -39.94 in 2.The anchor head to shim bearing area, Ab, is effectively (90%*36 ksi)equal to the value computed using the following expression: | |||
7r (d,2 -d 2)G Ab -dc(d- dh) -(2_dcd. in 2 Where;Topical Report 213 Attachment 1 Page 40 of 110 Exeton Generation, Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 4 of 6 da = 9.375 inches, which is the Anchor Head Diameter dj, = 5.625 inches, which is the Shim Hole Diameter d, = 0.125 inches, which is the assumed width of the shim cut line G, is the sum of the top and bottom shim gap widths Substituting the above values, rounded to the nearest 0.01 inches, into the expression for Ab gives: Ab 7 (9.382 -5.622) _ 0.12(9.38 | |||
-5.62) -(-0.12) 9.38 =44.97 -4.69G i71 2 For a required minimum bearing area of 39.94 in 2 , the sum (G) of the top and bottom gaps may not exceed (44973994) | |||
= 1.07 inches, this value is reduced to 1.0 inches for conservatism. | |||
4.69 Using the conservative value of 1.0 inches for G, mean gap width (G / 2) cannot exceed 0.50 inches.3.0 Conclusion/Findings Based on the computation performed in section 2.2, the conclusion of this evaluation is that a mean shim gap width < 0.50 inches is acceptable for dome tendons. This conclusion is considered to be valid unless a current or future measurement of a dome tendon anchorage force exceeds 1,294 kip.There is no evidence that dome tendon average shim gaps in excess of 0.50 inches have been observed during prior examinations. | |||
In addition, during the present surveillance a total of 35 hoop, vertical and dome end anchorages will be examined. | |||
Of these, 28 ends are randomly selected sample tendons (including 4 Steam Generator Replacement (SGR) tendons) that have not been previously examined since initial installation. | |||
The remaining seven have been previously examined.It is expected that the results of the examinations performed during the present surveillance will show that the 0.5 inch mean gap between the D-143 shim stack halves is an anomaly and that mean gaps found at the anchorages of the remaining surveillance sample dome tendons will be smaller.As is shown above, a mean gap of 0.50 inches is acceptable for dome tendons. If the remaining dome tendon end anchorage examinations do not uncover a larger gap and if no dome tendon end anchorage lift-off force is found to exceed 1,294 kips, conditions with respect to shim gap will be considered acceptable and no further evaluation will be required.In summary, based on the computation presented in this evaluation, it is concluded that a mean dome tendon shim gap < 0.50 inches is acceptable for an end anchorage force < 1,294 kip. As the lift-off measured on D-143 was 1,219 kips, which is less than 1,294 kips, the as-found shim gap is Topical Report 213 Attachment 1 Page 41 of 110 Exelon Generation. | |||
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 5 of 6 acceptable. | |||
Based on this same analysis and reasoning, the as-left shim gap of 0.375 inches is acceptable for continued service of tendon D-143.4.0 References | |||
: 1. ASME Section X1, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance | |||
: 4. AISC Handbook 5. IR 1569980 6. TMI-1 UFSAR Chapter 5, Appendix 5B 5.0 Attachments None Topical Report 213 Attachment 1 Page 42 of 110 Exelon Generation. | |||
Evaluation of Shim Gap at D-143 Anchorage PREPARED BY SUBJECT Michael Grimm Evaluation of D-143 Shim Gap Approvals Responsible Engineer: | |||
Howard Hill (See EDMS)Preparer: | |||
Michael Grimm (See EDMS)Independent Reviewer: | |||
Sean Taylor (See EDMS)I Manager: Pat Bennett (See EDMS)1569980-02 PAGE 6 of 6 Date: Date: Date: Date: l Topical Report 213 Attachment 1 Page 43 of 110 0Go Back Print I New Search I Home 0 Go Back Print j New Search Home AR Number: 01565440 Linked ARs Aft Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5552CAP Due Date: 12/20/2013 Aff System: 153 Event Date: 09/30/2013 CR 4/D Disc Date: 09/30/2013 Level/Class: | |||
How H02 Orig Date: 09/30/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
TENDON H24-15 HAD 2 WIRES PROTRUDING FROM ANCHOR | TENDON H24-15 HAD 2 WIRES PROTRUDING FROM ANCHOR HEAD | ||
== Description:== | == Description:== | ||
While performing a visual inspection on tendon H24-15 it was discovered | |||
Originator: | |||
MARVIN H ESPENSHADE Supv Contacted: | |||
Howard Stein Condition | |||
== | |||
Description:== | |||
While performing a visual inspection on tendon H24-15 it was discovered by QV personnel that there was 2 wires protruding about 0.25" above the anchor head. Per the vendors procedure an NCR-N1091-001 was written for engineering to evaluate and comment on a corrective action if required.Immediate actions taken: Generated this IR to capture that engineering reviews the NCR-N1091-001 for resolution on protruding 2 wires.Recommended Actions: Assignment to engineering (Mike Grinm and Howard Hill) to reviews the NCR-N1091-001 for any resolutions that may be required.Operable Basis: Discussed issue with Engineering. | |||
The 2 protruding wires represent a potential issue where the cables are not tensioned. | |||
Numerous wires exist in the anchor head and per engineeing up to 12 cables can be detensioned before the structural integrity of the tendon is challenged. | |||
Reasonable assurance exists that tendon H24 remains capable of performing its design function.Reportable Basis: This is not reportable IAW the Exelon Reportability manual.Functional Basis: Reviewed by: JOSEPH W KULASINSKY 09/30/2013 12:39:26 CDT Reviewer Comments: JWK SOC Reviewed by: LINDA C WITTER 10/01/2013 09:42:22 CDT SOC Comments: REACTOR BUILDING(#1) | |||
This condition does not meet definition for CCF. Close to action created (MGF 10/01/13) (SOC 10/01/13)0 Topical Report 213 Attachment 1 Page 44 of 110 Assign #: 01 AR #: 01565440 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/05/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
TENDON H24-145 HAD 2 WIRES PROTRUDING FROM ANCHOR HEAD Assignment Completion In Progress Notes: Completion Notes: t Topical Report 213 Attachment 1 Page 45 of 110 Exelon Generation. | |||
Evaluation of Unseated Buttonheads 1565440-02 at H24-15 Buttress 2 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-15 Unseated Buttonheads 1 of 2 1.0 Reason for Evaluation/Scope This evaluation is performed to document the acceptability of the condition observed at the Buttress 2 end of the hoop tendon H24-15 during the 40th Year Tendon Surveillance. | |||
IR 1565440 was issued to document that 2 buttonheads were protruding on H24-15 during the as-found visual examination of the tendon. The buttonheads were protruding | |||
===0.1 inches=== | |||
beyond the seating surface. Hoop tendon H24-15 was single-end stressed durin, construction from the Buttress 4 end.This evaluation was screened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During the as-found visual examination of hoop tendon H24-15 two protruding buttonheads were found. The buttonheads were protruding | |||
===0.1 inches=== | |||
from the seating surfaces and IR 1565440 was written to document the non-conforming condition. | |||
During examination it was noted that the buttonheads did not move when pushed or pulled, which indicates that the wires are not broken close to the anchorhead. | |||
The observed condition is nct unexpected for the non-tensioned end of a curved single enc tensioned tendon. Due to tendon twist (nominally one turn per 40 feet of length) and the effect of the curved duct, contact friction results in a gradual transfer of force between wires. In extreme cases, the load in one or more wires is completely transferred to other wires along the tendon length. In these cases, the affected wires are essentially load-free at the non-tensioned end. Thusly buttonheads on theses wires may remain unseated after tensioning at the far end is completed. | |||
This frictional force transfer phenomenon does not affect the total force in the tendon, only its distribution among wires. Therefore, the observed ccnndition, which is occasionally found at the anchorages of single-end tensioned, curved tendons, nd more rarely at the anchorages of tendons tensioned from both ends, does not degrade the performance of the post-tensioning system.3.0 Conclusion/Findings In light of the above discussion, it is concluded that the unseated button heads at the H24-15 Buttress 2 end are acceptable as-is. No corrective action, further evaluation or additional examination is required.4.0 References | |||
: 1. ASME Section Xl, Subsection IWL, 2004 Edition Topical Report 213 Attachment 1 Page 46 of 110 ExelonGeneration. | |||
Evaluation of Unseated Buttonheads 1565440-02 at H24-15 Buttress 2 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-15 Unseated Buttonheads 2 of 2 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance | |||
: 4. IR 1565440, Tendon H24-15 had 2 Wires Protruding from Anchor Head 5.0 Attachments None Approvals Responsible Engineer: | |||
Howard Hill Date: EDMS Preparer: | |||
Michael Grimm Date: EDMS Independent Reviewer: | |||
Sean Taylor Date: EDMS Manager: MarkTorborg Date: EDMS t Topical Report 213 Attachment 1 Page 47 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01567224 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/13/2013 Aff System: 153 Event Date: 10/03/2010 CR 4/D Disc Date: 10/03/2010 Level/Class: | |||
How H02 Orig Date: 10/03/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
TENDON V136 MISSING 1 WIRE.Description: Originator: MARVIN H ESPENSHADE Supv Contacted: Butch | TENDON V136 MISSING 1 WIRE.Description: | ||
Originator: | |||
MARVIN H ESPENSHADE Supv Contacted: | |||
Butch Espenshade Condition | |||
== Description:== | == | ||
While performing the 40 year tendon surveillance V136 had a missing | Description:== | ||
While performing the 40 year tendon surveillance V136 had a missing wire identified on the bottom end. The top had no protruding wires visible.NCR-N1091-002 was generated for engineering to evaluate the as found condition. | |||
Immediate actions taken: Generated this IR to track that engineering(Mike Grimm & Howard Hill)perform an evaluation of NCR-N1091-002 Recommended Actions: Engineering to perform NCR-N1091-002 evaluation on missind wire.Operable Basis: Discussed issue with Engineering. | |||
The missing wire does not impact the operability of the tendon. 169 wires exist in each tendon and per engineering up to 12 wires can be missing, or detensioned, before the structural integrity of the tendon is challenged. | |||
Reasonable assurance exists that tendon V136 remains capable of performing its design function with one wire missing.Reportable Basis: This is not reportable I W the Exelon Reportability manual.Functional Basis: SOC Reviewed by: CRYSTAL A WARLOW 10/04/2013 09:26:03 CDT SOC Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/03/13). | |||
Close to action created. (benson 10/4/13) (SOC 10/04/13)Reviewed by: CRAIG W SMITH 10/03/2013 14:07:35 CDT Reviewer Comments: There are no operability, reportability, or functionality concerns.Topical Report 213 Attachment 1 Page 48 of 110 Assign #: 01 AR #: 01567224 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/08/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
TENDON V136 MISSING 1 WIRE.Assignment Completion In Progress Notes: Completion Notes: t Topical Report 213 Attachment 1 Page 49 of 110 V136 Evaluation and Recommendation 1567224-02 Page 1 of 4 131004 Vertical Tendon V136 Discontinuous Wire Evaluation and Recommendation 11 October 2013 During the as-found visual examination of the V136 bottom end anchor head, one wire button head was observed to be missing. The V136 stressing card completed by SGT at the end of the steam generator replacement outage identifies 169 effective wires; i.e., no missing button heads. The button head was not found in the CPM removed from the V136 hardware. | |||
HovIever, the search for the button head did not includý heating and sieving the CPM. Passing the CPM through a % inch mesh is required by Par. 11.4 of PSC Procedure SQ 8.0, Anchorage Inspection. | |||
During the late 2010 augmented surveillance of Steam Generator Replacement (SGR)tendons, two wires were observed to be protruding above the top anchor head of one vertical. | |||
Subsequent examination determined that both wires had broken at a point close to the bottom face of the top anchor head. As this condition was not documented on the SGT stressing cards, it was concluded that these wires fractured after the as-left examination of the anchor head, i.e., after the application of the Original Stressing Force (OSF) load and final seating of the anchor head on the shim stack and, probably, after re-installation of the end cap.As noted in the above paragraphs, three SGR tendon wires have been found to be discontinuous (two fractured and one for a reason yet to be determined). | |||
The metallurgical report on the evaluation of the br ken wires found in 2010 concluded that these were somehow bent and significantly ov rstressed to the point of eventual failure during installation and / or stressing. | |||
It is important to establish the reason for the apparent failure of the discontinuous wire in V136 and, in particular, to show that there is not a generic issue associated with the SGR tendons; i.e., to show that the breaks found in 2010 and the current discontinuity represent unique, isolated and unrelated events. As the initial search of the removed CPM did not uncover a broken wire segment, it is tentatively concluded that one of the following condillions exists.(1) The button head was incompletely formed and, over time, pulled through the anchor head.(2) The button head detached (a not uncommon phenomenon that generally results from a problem with button header adjustment or operation) and, due to its small size, was missed during the search through the CPM removed from the tendon hardware (some was drained directly into a drum and not searched). | |||
(3) The wire was not button headed at the bottom end, an unlikely but not impossible QC oversight. | |||
Topical Report 213 Attachment 1 Page 50 of 110 V1 36 Evaluation and Recommendation 1567224-02 Page 2 of 4 131004 Condition (2) is considered to be the most likely. Therefore, it is recommended that all of the CPM removed from V136, including the CPM drained directly into the drum, be thoroughly searched by heating and: (1) Trying to retrieve the button head with a magnet and/or;(2) Pumping all heated CPM through a sieve If a detached button head is recovered, this should be sent off for metallurgical examination. | |||
I I If a button head is not recovered, it will be necessary to remove the discontinuous wire for visual and, probably, metallurgical examination to establish cause (continuity test).While at this point it could be postulated that the cause is either a defective button head or no button head, the cause remains indeterminate until the button head or wire is retrieved. | |||
The cause of the break is required to determine if there is a generic issue applicable to the SGR tendons and if corrective actions are required.The discontinuous wire can be identified through the continuity test procedure described in PSC Procedure SQ 10.5 (the tendon must be de-tensioned first). Once it is identified, it can be removed from the tendon by the procedure employed for test wire removal.The current condition of V-136 with 167 effective wires (removal of test wire and loss of an ad litional load carrying wire) does not represent an op rability concern. The tendon is co npletely capable of performing its design function an carrying a pre-stressing load in excess of the required 1033 kips, the current pre-stress on V-136 is 1414 kips.Topical Report 213 Attachment 1 Page 51 of 110 V136 Evaluation and Recommendation 1567224-02 Page 3 of 4 131004 N1091 PSC PROCEDURE SQ 8.0 ANCHORAGE INSPECTION Data Sheet 8.OA 09103/13 Page 1 of I Revision 0 Project: TMI 2013 TENDON SURVEILLANCE Ig UNIT 1 (7.13)Tendon No.: V -, Tendon End: | |||
' Field ANCHORAGE INSPECTION CRITERIA IR As-Found 0 Post De-Tensioning I Pre-Wire Removal [3 Post Re-Tensioning Q.C. Signoff 9.0 & 10,0 CORROSION | |||
& CRACK INSPECTION (9.2) Buttonheads Level: (10.1) Cracks [] Yes 1 7 , No MI N/A (9.2) Anchorhead Level- (10.1) Cracks r'0 Yes 12) RNo Q N/A (9.2) Shims Level: (10.1) Cracks E] Yes 12) No [O N/A (9.2) Bearing Plate Level: (10.1) Cracks [3 Yes [] No 0 N/A ,o-- I)llLCoisroon Leye of C rquims a NCR. {1CoSe a sketch of the cracks on Sketch Sheet 8,0 and Inate a NCR.11.0- PUTTONHEAD IN.PECTION D Offsize (Malformed) | |||
ProtrudIngfunseated | |||
' wire/butlonheads 0 Broken/missing wire/buttonheads | |||
* Pevlousty idenriied as missing 00000000 00000000000 Dlsconllnuous-removed this 000000000000 | |||
,,, surveillance. | |||
O2 O0000000000 vira(s) removed during this I 0000000000000C0 suverllance for testing 0000000000000 00000000000000 0000000000000 q 00000000000000 (11.2)Anchorieaddl.D. | |||
Iq oooo00o oooooooo/Located on Sketch [&,Yes [INo 000000000000 (11.4) Missing Buttonheads Found; 00000000000 OO OO 00000000-Yes W No Quantity:. | |||
1 0000000 Additional Information: | |||
(12.2) Number of Protruding Buttonheads (w):(18.31 Illumiaion a 4 2e -2 U (12.3) Number of Missing Buttonheads (0, g _): (12.4) Total of Protruding | |||
+ Missing Buttonheads: | |||
-(12.6) Continuity Test Requested? | |||
0 Yes EJ No (12.5) Total # of Effective Buttonheads Seated: Wtres Identified? | |||
E] Yes E) No (12.7) Overall Results [l Acceptable I. Un-Acceptable Customer Notified NCR#* rJ .CO. -/..QC Reviewed: | |||
Level: Date: 18 SQ 8.O.TMl.13 1Sl Topical Report 213 Attachment 1 Page 52 of 110 V136 Evaluation and Recommendation 1567224-02 Page 4 of 4 131004 NONCONPORMANCE/ | |||
CORRECTIVE ACTION REPORT FORMV HOLD TAG NO.: #/A NC ICA NO.: ,Vee- At/01( -a t ?NONCONFORMANCE.,1: | |||
AdA -4ki,4 I n~N f~4 44o heAd-%4 /A Alt%# /p/evst1ily repodAed. | |||
ier Psc proceeck4re SO t -o sec, t3.' wle-u I e~o ne0re n,,.S5,?j wjt5 or &NoV-HWhCA d~ 5 1f die-4C(e 8~go. CKXO-A% 10, 6#8j0. 'Aq 6ý j / A (AfillelY | |||
~ Jjg /fic vo .2-J'I'S S 4 w /f., 0 ,,, 0- -,F-Aitl!E,n | |||
-4 V I i';Cl APPARENT CAUSE KNOWN: Uj YES MMO IF YES, DESCR~IBE: | |||
RECOMMENDED CORRECTIVE ACTION: Cl;w4 4,> .ANY NONCONFORMING ITEM TO BE REPAIRED SHALL HAVE AN APPROVED REPAIR PROCEDURE. | |||
CORRECTIVE ACTION TO PREVENT RECURRENCE: | |||
j #_ INITIATOR: | |||
TITLE DATE: SIGNIFICANT CONDITION: | |||
El YES 9 NO IF YES. REFER TO OAM SECTION 15, APPROVAL COMMENTS: SIGN & DArE: /- 2-Za __/EXELON AP ROVAL REQUIRED 0 YES N- NO ENGINEER D All IQA DATE COMMENTS: DISTRIBUTION DISPOSITION COMPLETED El QASECT'ION 0 VICE PRESIDENT E VENDOR SIGNED: Cl CE SECTION Fj CONTR. MGMT. 0_ _ TITLE: l ENGINEERING | |||
[3 EXELON El _ DATE: 43 OA o'rMI. 3 ISI Topical Report 213 Attachment 1 Page 53 of 110 Assign #: 03 AR #: 01567224 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: GRIMMX Due Date: 12/13/2013 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 12/13/2013 Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
Track completion of follow-uplactivites for V-136 Track follow up activities as follows: 1.Retrieve button head from grease using strainer or magnet or; 2. Retrieve broken wire from tendon using a continuity test Assignment Completion In Progress Notes: Grease was heated and run through a strainer. | |||
The buttonhead was not found. This assignment is closed to 1567224-04, technical evaluation that accepts the tendon condition as is.-Michael Grimm 11/27/2013 Completion Notes: Topical Report 213 Attachment 1 Page 54 of 110 Exelon Generation. | |||
Evaluation of Missing Buttonhead 1567224-04 at V-136 Lower Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of V-136 Missing Buttonhead 1 of 3 1.0 Reason for Evaluation/Scope This evaluation is being performed to evaluate the acceptability of a condition in which a buttonhead was found missing on the lower anchorage of vertical tendon V-136 during the 40th Year Tendon Surveillance. | |||
Previously, under assignment 1567224-02, it was identified that while this condition does not represent a failure of the tendon, efforts should be taken to retrieve either the missing buttonhead or the broken wire for evaluation. | |||
Assignment 1567224-03 tracked the completion of activities to locate the missing buttonhead. | |||
This included heating the grease removed from V-136 and draining it through a Y4" strainer/filter in accordance with PSC procedure SQ8.0. The buttonhead was not recovered during this activity. | |||
This evaluation will demonstrate that while the buttonhead was not recovered the condition is acceptable and no further actions are required to retrieve the broken wire.This evaluation was screened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section XI, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During visual examination of the bottom anchorage of vertical tendon V-136 one buttonhead was observed to be missing. The top anchorage was found with 169 buttonheads, which alig rs with the SGT stressing cards from 2J09, indicating 169 buttonheads for both the top and bottom dlnchorages. | |||
This indicates the 168 observed buttonheads on the bottom anchorage is a post-construction condition. | |||
The corrosion protection medium (CPM) removed from the bottom end of V136 was searched for the broken wire stub and/or buttonhead. | |||
Since nothing was found, it can be concluded that the wire itself did not break, as any length of wire attached to the buttonhead would have made the missing piece larger and easier to find. Additionally, since the as-left examination records from 2009 show 169 acceptable button heads following tensio ing, it can be concluded that the missing wire did not have a significantly undersized button head ýhat may have pulled through the drilled hole in the anchor head.This leads to the conclusion that the button head detached from the wire. Per the Responsible Engineer this is a rare, but not an unheard of condition, which usually results from an imperfection in the forming process inducing an area of weakness due to excessive cold working. Since the button head itself is quite small, it could have easily been missed in the search for a stub wire or, possibly, caught on one of the rags used to wipe CPM from the anchor head.As stated above, detached button heads are rare, isolated events, that are not indicative of a generic condition; either at an individual anchor head or across a set of anchorages regardless of crew and Topical Report 213 Attachment 1 Page 55 of 110 Exelon Generation. | |||
Evaluation of Missing Buttonhead 1567224-04 at V-136 Lower Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of V-136 Missing Buttonhead 2 of 3 hydraulic dies. For this reason, there is no concern that additional instances of detached buttonheads at the anchorages of other SGR replacement tendons exist in sufficient numbers to degrade containment integrity. | |||
To date, eight anchorages at the ends of SGR replacement tendons have been examined with no evidence of other detached buttonheads. | |||
The current condition of V-136 with 167 effective wires (removal of test wire and loss of an additional load carrying wire due to a missing buttonhead) does not represent an operability concern. The tendon is completely capable of performing its design function and carryinL a pre-stressing load in excess of the required 1033 kips as each tendon wire is capable of carrying a load of 11.77 kips or 1966 kips total with 167 wires. The current pre-stressing force on V-136 in the as-left condition is 1414 kips.3.0 Conclusion/Findings For the above reasons, it is concluded that the missing buttonhead at the bottom anchorage of V136 is an isolated finding and does not represent current or potential future degradation of the TMI-1 pre-stressing system. The loss of a single effective vertical tendon wire is an insignificant condition with respect to the structural integrity of the Reactor Building and the ability of the tendon to perform its design function. | |||
Therefore, the condition is deemed acceptable as-is and no further examinations or evaluations are required. | |||
However, as the broken wire was not retrieved during the 4 0 th Year Tendon Surveillance, it is recommended that an additional visual examination be performed on the bottom anchorage of vertical tendon during the 4 5 th year Tendon Surveillance (scheduled for 2018). This is to provide ye rfication that the missing wire found at the V136 bottom anchorage was the result of a unique and isolated event.4.0 References | |||
: 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revi ion 23A, RB Structural Integrity Tendon Surveillance | |||
: 4. IR 1567224, T"ndon V-136 Missing 1 Wire T 5.0 Attachments None S Topical Report 213 Attachment 1 Page 56 of 110 Exelon Generation. | |||
Evaluation of Missing Buttonhead at V-136 Lower Anchorage PREPARED BY SUBJECT Michael Grimm Evaluation of V-136 Missing Buttonhead 1567224-04 PAGE 3 of 3 Approvals Responsible Engineer: | |||
Howard Hill Preparer: | |||
Michael Grimm Independent Reviewer: | |||
Sean Taylor Manager: MarkTorborg Date: EDMS Date: EDMS Date: EDMS Date: EDMS Topical Report 213 Attachment 1 Page 57 of 110 0Go Back Print I New Search I Home AR Number: 01569458 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 11/07/2013 Aff System: 153 Event Date: 10/07/2013 CR 4/D Disc Date: 10/07/2013 Level/Class: | |||
How H02 Orig Date: 10/08/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
, LOCK-OFF FORCE IN TENDON V-136 EXCEEDED ACCEPTANCE | , LOCK-OFF FORCE IN TENDON V-136 EXCEEDED ACCEPTANCE CRITERIA | ||
== Description:== | == Description:== | ||
During tendon surveillance activities, selected tendons are de-tensioned(pre-stressing force is removed) and a wire sample is taken from | |||
Originator: | |||
MICHAEL GRIMM Supv Contacted: | |||
John Piazza/Mark Torborg Condition | |||
== | |||
Description:== | |||
During tendon surveillance activities, selected tendons are de-tensioned (pre-stressing force is removed) and a wire sample is taken from the tendon. The tendons are then re-stressed to within plus 6%/minus 0% of the as-found lift off force or 7 0% of the Guaranteed Ultimate Tensile Strength (GUTS), whichever is less, by procedure 1301-9.1 and PSC Vendor Procedures. | |||
During re-stressing activities vertical tendon V-136 was locked-off at 1414 kips. This value exc eds the 7 0% GUTS value allowed by procedure as determined by the effecti e number of wires. This condition was identified during the data sheet review by the Responsible Engineer.V-136 has 167 effective wires (one broken, one removed for testing), 70%GUTS corresponds to 8.24 kip per effective wire or 1376 kips. The lock-off value of 1414 kips corresponds to 72% GUTS.This condition has no impact on the ability of the tendon to perform its function and does not compromise the tendon integrity as it does not exceed the Guaranteed Ultimate Tensile Strength of the tendon wire material. | |||
The lock-off force of 1414 kips restores the tendon pre-stress to the as-left condition during the Steam Generator lReplacement Project, 71% GUTS, which was performed by a different procedure with different acceptance criteria.Immediate actions taken: IR initiated NCR issued by PSC Recommended Actions: Revision to PSC procedure SQ 11.0 to clarify requirement to not exceed 7 0%GUTS during re-tensioning. | |||
What activities, processes, or procedures were involved?Review of Tendon Surveillance data sheets by the Responsible Engineer.Why did the condition happen?Topical Report 213 Attachment 1 Page 58 of 110 During re-tensioning activities PSC restored the tendon to the as-found condition instead of the 70% GUTS condition as required by the procedure. | |||
What are the consequences? | |||
There are no adverse consequences on the containment or the tendon. The tendon is capable of performing its intended design function and is within the guaranteed strength of the material.Were any procedural requirements impacted?The lock-off force exceeded the acceptance criteria of both the approved PSC Vendor Procedures and the TMI Surveillance Procedure 1301-9.1.Were there any adverse physical conditions? | |||
There arý no adverse physical conditions. | |||
The tendon stress is higher than the acceptable value; however it is well within the guaranteed strength of the tendon material. | |||
The containment and the tendon are capable of performing their design functions in this condition. | |||
List of knowledgeable individuals: | |||
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition? | |||
No Operable Basis: Reviewed TS 3.19 and 4.4.2. Tendon V-136 is tensioned slightly greater than desired. However, this does not compromise its ability to perform its intended function. | |||
Applied forces are greater than the minimum required by procedure (1033 Kips) and lust slightly greater than the upper target of 1376 Kips. The as left corresponds to 72% GUTS which is well below the ultimate yield strength of the tendon.As noted in the IR, this condition has no impact on the ability of the tendon to perform its function and does not compromise the tendon integrity as it does not exceed the Guaranteed Ultimate Tensile Strength of the tendon wire material. | |||
The lock-off force of 1414 kips restores the tendon pre-stress to the as-left condition during the Steam Generator Replacement Project, 71% GUTS, which was performed by a different procedure with different cceptance criteria..Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability? | |||
TS 3.19, 4.4.2, 1301-9.1 3. Describe the function of the SSC and basis for operability/availability determination. | |||
See below 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103. | |||
: 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO The following functions are maintained even with the slightly greater applied force on this tendon.Topical Report 213 Attachment 1 Page 59 of 110 153-ROl Contain fission products to prevent radioactive release (153).153-R02 Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural integrity (153).Reportable Basis: This does not meet any reporting thresholds. | |||
Functional Basis: Reviewed by: EDWARD M CARRERAS 1/08/2013 23:39:35 CDT Reviewer Comments: Added Reactor Building as the component ID. Engineering review is required.SOC Reviewed by: DIANE M SCHNEIDER 10/10/2013 09:52:14 CDT SOC Comments: REACTOR BUILDING(#1) | |||
This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/09/13). | |||
HU has been adressed with the PSC crew (Kaplan,BD 10/10/13). | |||
Close to actions taken/created. (benson 10/10/13) (SOC 10/10/13)Topical Report 213 Attachment 1 Page 60 of 110 Assign #: 01 AR #: 01569458 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/13/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details SubjectlDescription: | |||
LOCK-OFF FORCE IN TENDON V-136 EXCEEDED ACCEPTANCE CRITERIA Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 61 of 110 Assign #: 02 AR #: 01569458 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: STEIHX Due Date: 10/18/2013 Schedule Ref: Prim Grp: A5520MS Orig Due Date: 10/18/2013 Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: (Steinj Verify (PSC) has revised PSC procedure SQ 11.0 to clarify requirement to not exceed 70% GUTS during re-tensioning. | |||
Create additional action as needed.Assignment Completion, In Progress Notes: Completion Notes: 9.8.3 Lock-off Force (LOF) -That force at which the tendon load is transferred to the shim stack from the ram. If the detensioned tendon had an accepted lift-off force greater than its Predicted Force obtained in PSC Procedure SQ 9.0 the Lock-Off Force shall be the as found lift-off force within a tolerance of minus 0% and plus 6%. If the detensioned tendon had a lift-off force less than its Predicted Force obtained in PSC Procedure SQ 9.0 the Lock-Off Force shall be the Predicted Force from PSC Procedure SQ 9.1 within a tolerance of minus 0% and plus 6%. Lock-off Force is not to exceed 70% of G.U.T.S. (1394 kips for a 169 wire tendon, or 8.25 kips per wire).Topical Report 213 Attachment 1 Page 62 of 110 0 Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01572452 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5520CAP Due Date: 11/14/2013 Aff System: 153 Event Date: 10/15/2013 CR 4/D Disc Date: 10/15/2013 Level/Class: | |||
How H02 Orig Date: 10/15/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
DOME TENDON D-143 IDENTIFIED TO BE | DOME TENDON D-143 IDENTIFIED TO BE INACCESSIBLE | ||
== | |||
Description:== | |||
Originator: | |||
MICHAEL GRIMM Supv Contacted: | |||
Mark Torborg Condition | |||
== Description:== | == | ||
The tendons selected for examination during the 40th Year | Description:== | ||
The tendons selected for examination during the 40th Year Tendon Surveillance were walked down prior to the start of the surveillance to identify any tendons that were inaccessible. | |||
During the walk down dome tendon D-143 was not identified as inaccessible. | |||
During the performance of surveillance activities, it wa-s identified that an installed Seismic Box, with Accelerometer, created an interference with the hydraulic ram, making the tendon inaccessible for surveillance. | |||
Per the requirements of ASME Section XI Subsection IWL-2541.1 the closest tendon, not previously inspected, shall be selected as a s bstitute. | |||
The inaccessible tendon shall have a visual examination and a grease sample taken for analysis.The nearest accessible tendon for surveillance is D-146.Immediate actions taken: Verified condition in field Wrote this IR Recommended Actions: 1. Add replacemerlt tendon D-146 to the scope of the surveillance for examination (lift-off, visual, and grease sample).2. Perform visual examination and take a grease sample from D-143.3. Identify why the condition was not identified during pre-surveillance walk downs.What activities, processes, or procedures were involved?Tendon surveillance activities on Dome Tendons.Why did the condition happen?Pre-surveillance walk down of tendon did not identify the interference. | |||
What are the consequences? | |||
Tendon is inaccessible, and additional adjacent tendon is required to be selected and examined. | |||
The inaccessible tendon is examined to the extent possible.Were any procedural requirements impacted?Topical Report 213 Attachment 1 Page 63 of 110 No Were there any adverse physical conditions? | |||
No List of knowledgeable individuals: | |||
Mark Torborg Butch Espenshade Howard Stein Mike Grimm Repeat or similar condition? | |||
Yes Pre surveillance tendons H24-15 and H13-08 were identified to be inaccessible and alternate tendons were selected for exa mination.Operable Basis: Reportable Basis: Functional Basis: Reviewed by: ROBERT R BRADY 10/16/2013 04:01:45 CDT Reviewer Comments: Reviewed by Operations for operability and reportability. | |||
This issue has no impact on the ability to safely operate the plant, to achieve or maintain the plant in a safe shutdown condition, or to mitigate the effect of any accident condition. | |||
This is a process issue that does not identify an equipment deficiency that affects operability of any SSC. There are no operability or reportability concerns.SOC Reviewed by: CR4STAL A WARLOW 10/18/2013 09:46:55 CDT SOC Comments: REACTOR BUILDING This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/16/13). | |||
Recommended Actions 1 &2 should go to Maintenance Support (Howard Stein)for scheduling. | |||
and Recommended action 3 should go to Maintenance Support (Butch Espenshade) for review of how it was missed.Followup to Maint CR to address actions. (SOC 1 /17/13)RA#1 -Completed 10/17/2013. | |||
RA#2 -Scheduled under existing work order for 10/18/2013. | |||
RA#3 -Walkdowns were done prior to ability to be at the tendon with use of inspection platform. | |||
Interference was not seen during walkdown due to the inaccessiblity Close to comments and actions taken. (Smokowicz 10/17/13) (SOC 10/18/13)10/16/2013 | |||
-Per the IR Originator's request, corrected Tendon Nos.throughout the IR. D. Hockley Reviewed by: JONATHAN J SMOKOWICZ 10/17/2013 16:12:06 CDT Reviewer Comments: Topical Report 213 Attachment 1 Page 64 of 110 Assign #: 01 AR #: 01572452 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 10/20/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
DOME TENDON D-143 IDENTIFIED TO BE INACCESSIBLE Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 65 of 110 0 Go Back Print New Search I Home AR Number: 01585403 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/30/2013 Aff System: 153 Event Date: 11/14/2013 CR 4/D Disc Date: 11/14/2013 Level/Class: | |||
How H02 Orig Date: 11/14/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
TENDON REGREASING EXCEEDED ACCEPTANCE | TENDON REGREASING EXCEEDED ACCEPTANCE LIMITS | ||
== Description:== | == Description:== | ||
The tendon population selected for inspection during the 40th year | |||
: 1. Evaluate cause of the condition and acceptability for | Originator: | ||
MICHAEL GRIMM Supv Contacted: | |||
John Piazza Condition | |||
== | |||
Description:== | |||
The tendon population selected for inspection during the 40th year tendon surveillance included four dome tendons. Of the four dome tendons, one was found to be inaccessible during the conduct of surveillance activities (IR 1572452), and a replacement was selected. | |||
All five dome tendons had end caps removed and inspection activities performed: | |||
D-143 D-146 D-237 D-22 During the conduct of the surveillance activities, the bulk filler grease that protects the tendons from corrosion drains from the tendon conduit.The grease is collected in drums and the amount removed is measured. | |||
The tendon duct is then refilled with grease after inspection activities are completed. | |||
Per procedure 1301-9.1, the regreasing is required to be with-0/+10% of the total tendon duct volume. Reference AR Evals A2238266-02 and 04 for the computed tendon duct volumes.During refill activities, three dome tendons took more the +10% duct volume to fill.D-143 .+59.94% grease fill D-146 .+58.84% grease fill D-237 .+48.08% grease fill It is noted that no grease leakage was noted from the dome area of the containment building prior to the conduct of inspection activities. | |||
Additionally no water was found in the grease removed from the dome tendons. A wire sample was taken from D-237 and no corrosion was noted on the wire surface.Immediate actions taken: Contacted Responsible Engineer Wrote IR Recommended Actions: Topical Report 213 Attachment 1 Page 66 of 110 | |||
: 1. Evaluate cause of the condition and acceptability for continued service.What activities, processes, or procedures were involved?Tendon Surveillance Activities | |||
/ regreasing Why did the condition happen?The condition is a result of original construction greasing. | |||
The grease was pumped into the tendon duct using the opposite end cap as the vent point. As the dome is spherical, the high point of the tendon duct is at a higher elevation than the vent location. | |||
Dome tendons that run along the outer edges of dome have less of an elevation difference and as a result will have a smaller grease void.What are the consequences? | |||
The consequences of the grease void is that a section of the dome tendons is not covered by bulk filler grease. There are no adverse consequences on the containment as these three dome tendons were tested satisfactorily. | |||
The lift-off and grease visuals were acceptable and as expected. | |||
A wire sample was pulled from D-237 and did not show signs of corrosion. | |||
Were any procedural requirements impacted?The grease refill did not meet the acceptance criteria of 1301-9.1.Were there any adverse physical conditions? | |||
There are no adverse physical conditions in the containment. | |||
The dome tendons are performing their functions as demonstrated by the acceptable lift-off tests. Additinally there is no noted grease leakage from the dome tendons and there was no water found in the tendon grease or end caps.Additionally there was no corrosion found on the wire sample taken from D-237 which stands as a representative sample. The tendon wires were coated in Viscon rust 1601 Amber, that per UFSAR section 5.2.2.3.7 provides protectifon from corrosion prior to bulk grease filling.List of knowledgeable individuals: | |||
Michael Grimm Sean Taylor Howard Hill Repeat or similar condition? | |||
No Operable Basis: As stated in ht body of the IR there are nooperability issues with the containment. | |||
Reportable Basis: There are o reportability concerns Functional Basis: Reviewed by: MARKO MALINEN 11/14/2013 21:02:26 CST Reviewer Comments: MPM SOC Reviewed by: CRYSTAL A WARLOW 11/16/2013 10:47:32 CST SOC Comments: Close to action created (BBalliet 11/15/13) (SOC 11/16/13)Topical Report 213 Attachment 1 Page 67 of 110 I I Topical Report 213 Attachment 1 Page 68 of 110 Assign #: 01 AR #: 01585403 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 11/19/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
TENDON REGREASING EXCEEDED ACCEPTANCE LIMITS Assignment Completion In Progress Notes: Completion Notes:.t Topical Report 213 Attachment 1 Page 69 of 110 Exeton Generation. | |||
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 1 of 5 1.0 Reason for Evaluation/Scope During tendon bulk filler grease (Corrosion Protection Medium (CPM)) refill activities in the dome tendons during the TMI Unit 1 40th Year Tendon Surveillance, the quantity of refill tendon grease was found to exceed the acceptance criteria specified in Exelon Procedure ER-AA-330-006 Revision 7, section 4.4.4.1, states: I I"The absolute difference between quantity of corrosion protection medium (sheathing filler grease)removed and amount replaced shall not EXCEED 10% of net duct volume." I I The purpose of this evaluation is to evaluate this condition for its affect on containment integrity and to determine its acceptability for continued service. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section XI 2004 Edition, Subsection IWL.This evaluation wasscreened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors; however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation As IR 1585403 documents, dome tendon regreasing activities conducted during the TMI Unit 1 4 0 th Year Tendon Surveillance resulted in grease fill exceeding the acceptance criteria of PSC procedure SQ 12.1 and Exelon procedure ER-AA-330-006 of 10% of the total net duct volume. The actual quantities of grease replaced are shown below in table 1.Table 1: Grease Replacement Volumes% Difference Net Duct Grease Added' tal Grease Total Duct Volume Te don Volume 1 (Gallons) | |||
Replaced (Gallons) (Gallons)D143 59.94% 51.2 70.69 85.4 D146 58.84% 47.7 63.16 81.0 D237 48.08% 44.6 65.37 92.8 Notel: Net duct volume is gross volume of duct, trumpets and end caps less the volume of tendon wire, anchor heads and shims.Note 2: Grease added is the difference between the grease removed during surveillance activities and that pumped back into the tendon a Topical Report 213 Attachment 1 Page 70 of 110 Exelon Generation. | |||
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 2 of 5 As there has been no evidence of significant leakage at the tendon end caps as evidenced from Topical Report 150, it can be concluded that the tendon ducts did not drain during their 40 year service life. Thusly this implies that the tendon ducts were not completely filled at the time of construction. | |||
TMI does not have high point vents for the dome tendons; as such the observed condition is not unexpected. | |||
I I During construction, dome tendon ducts were generally filled with CPM in pairs. The supply hose from the pump was connected at the end of one tendon and the return (to the hot CPM reservoir) hose at the nearby end of an adjacent tendon. A third hose was connected to the far ends of the two tendons. CPM was pumped through the two tendons until the CPM exiting the end cap at the return end reached a specified temperature. | |||
At that point, the supply and return hoses were isolated by valves and the end caps sealed by threaded plugs inserted through the fittings used to attach the hoses.This procedure ensured that the duct on the inlet side of both tendons was filled to the high point and that the end caps on the outlet ends were filled. But, since the hot, fluid CMP flowed freely from the high points to the outlet end caps, the air voids on the outlet sides of the ducts were not necessarily purged. As a consequence, it is expected that dome tendon ducts have significant air voids trapped between the duct high points and the end caps on the return ends.It should be noted that while this condition is not 4 uexpected, past tendon surveillances at TMI have not reported grease voids in excess of the acceptance criteria. | |||
This may be due to limitations within the procedure used for grease refill, or these three tendons could be an anomaly from original plant construction. | |||
As the number of confirmed dome tendons affected by this condition is small, and the lack of high point vents to allow for the filling of the duct, it is desired to show by evaluation that the dome tendons will continue to perform acceptably for the remainder of plant life.Unlike typical Bechtel containments, the TMI Unit 1 containment uses schedule 40 pipe for the tendon duct than rolled spiral seam sheet metal. As such the pipe du ts are impervious to water penetration and are well protected from exterior corrosion by the suriounding alkaline concrete environment. | |||
Since water penetration is not an issue with the TMI design, it is not necessary to fill tendon duct with bulk filler grease (CPM) as the entry point for water into the tendon duct is at the low points (tendon end caps). During initial tendon greasing, grease was pumped through the tendon duct from one end until a constant stream of grease exited the opposite side, ensuring that the tendon end caps are filled with CPM. This is sufficient for preventing water intrusion into the tendon end cap and lower portions of the tendon duct, and thusly into the upper portions.Additionally, during construction, the TMI tendons were coated with a hard wax-like corrosion preventive material, Visconorust 1601 Amber, as referenced in the TMI Updated Final Safety Analysis Report section 5.2.2.3.7. | |||
Further during CPM pump through, the tendon wires would Topical Report 213 Attachment 1 Page 71 of 110 Exelon Generation. | |||
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 3 of 5 experience some CPM coating. Therefore, the tendon wire maintains some corrosion protection against the initial environment within the tendon duct.The dome area above the ring girder is well drained with no areas in which rain water or snow melt can collect in significant quantity, percolate into the concrete, and accumulate around the tendon ducts. To date 72 TMI-1 dome tendon anchorages (both ends of 36 dome tendons) have been examined under the containment ISI program. Forithe life of the plant (40 years), no significant water intrusion has been noted, and all grease samples taken from the dome tendons have met the acceptance criteria in procedure ER-AA-330-006. | |||
Test wires have been removed from 10 tendons and examined. | |||
No significant corrosion has been found and all wire samples have had satisfactory tensile tests. This provides convincing evidence that water intrusion and wire corrosion are not areas of concern for the TMI Unit 1 dome tendons.Additional industry Operating Experience (OPEX) on tendon grease voids was reviewed for applicability to TMI. Both Crystal River Unit 3 (OE 169794 and 178114) and South Texas (CE 121945)have identified grease replacements that exceeded the acceptance criteria on their vertical tendons.Both plants reported that the conditions did not pose a containment integrity issue, and no tendon degradation was observed.3.0 Conclusion/Findings The above discussion supports the conclusion that the observed shortfall of CPI does not have an adverse impact on the dome tendon integrity. | |||
The geometry of the dome and the rigid pipe duct ensure that tendons are fully protected from water intrusion. | |||
The shop coating of Visconorust 1601 Amber on the tendon wires and further coating during CPM installation ensures that the bare tendon wire is not exposed to a possibly moist atmosphere in those segments of duct that are not completely filled with CPM. Extensive examinations conducted to date provide conclusive evidence that there has been no degradation of the TMI Unit 1 dome tendon wires, and scheduled future examinations are expected to yield similar results. Therefore it is concluded that the as-found grease void condition in the dome tendons is acceptable for continued operation and no further inspection or repair activities are required It this time.4.0 References | |||
: 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance | |||
: 4. TMI-1 UFSAR Chapter 5 5. IR 1585403, Tendon Regreasing Exceeded Acceptance Limits 6. Tendon Surveillance Topical Reports 7. InRyco Drawings PS-xx series Topical Report 213 Attachment 1 Page 72 of 110 ExeLon Generation. | |||
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 4 of 5 5.0 Attachments None Topical Report 213 Attachment 1 Page 73 of 110 INEMW Exeton Generation. | |||
Evaluation of Dome Grease Voids that Exceed Acceptance Criteria 1585403-02 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 5 of 5 Approvals Responsible Engineer: | |||
Howard Hill Preparer: | |||
Michael Grimm Independent Reviewer: | |||
Sealn Taylor Manager: Mark Torborg Date: EDMS Date: EDMS Date: EDMS I Date: EDMS Topical Report 213 Attachment 1 Page 74 of 110 Full Action Request Report Page I of 5 O Go Back Print I New Search Home AR Number: 01587456 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5520CAP Due Date: 12/20/2013 Aff System: 153 Event Date: 11/18/2013 CR 4/D Disc Date: 11/19/2013 Level/Class: | |||
How H02 Orig Date: 11/19/2013 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
SURVEILLANCE TENDON DE-TENSIONED BEFORE LIFT-OFF | SURVEILLANCE TENDON DE-TENSIONED BEFORE LIFT-OFF COMPLETED | ||
== Description:== | == Description:== | ||
The random tendon selection for the TMI Unit 1 40th Year | |||
Originator: | |||
MICHAEL GRIMM Supv Contacted: | |||
Mark Torborg Condition | |||
== | |||
Description:== | |||
The random tendon selection for the TMI Unit 1 40th Year Tendon Surveillance included Hoop Tendon H13-03. H13-03 was originally tensioned from a single-end (Buttress | |||
: 1) during construction due to interferences and as such it is expected that the opposite end (Buttress | |||
: 3) will have a lower lift-off force.IR 1541172 was put in previously for another single-end tensioned tendon (H24-15) to declare the tendon inaccessible as it was not possible to ccess both ends of the tendon. Per ASME Section XI, 2004 Editioln, ubsection IWL-3000 the average lift-off value from both ends shiall be used for comparison to the acceptance criteria. | |||
This implies that All tendons should have the lift-off test performed from both ends. TMI has proceduralized that all dome and hoop tendons shall have lift-off tests performed from both ends, only vertical tendons are exempt from this requirement. | |||
Per Exelon procedure and ASME Section XI, it was determined that any hoop tendon not accessible from both ends, regardless of how the tendon was originally stressed, would be declared inaccessible. | |||
TMI has taken a further stance that information only lift-offs will be performed on single-end tensioned tendons inaccessible from the opposite end to comply with the intent of ASME Section XI, Subsection IWL-2521 which states that the tendon anc orage shall be examined to the extent practical. | |||
Due to questions raised around this issue during the planning phase of the tendon project, a decision tree flow diagram was issued to PSC under assignment 1541172-02. | |||
This decision tree was intended to provide a visual representation to aide PSC and Exelon personnel with determining the best course of action for various conditions (such as this one) during the surveillance. | |||
During the pre-surveillance walkdowns it was identified that both ends of H13-03 were accessible for lift-off testing. As a result, this tendon was not declared inaccessible and PSC was instructed to test the tendon, de-tension, and re-tension the tendon from both buttresses. | |||
Once in the field for performance of the surveillance on H13-03, PSC identified that they could not in fact couple their ram to the tendon to perform the lift-off measurement. | |||
PSC did not stop work, and continued to de-tension the tendon from one end, after lift-off was performed from the Topical Report 213 Attachment 1 Page 75 of 110 http://eamgenco.ceco.com/cap/serv let/ReportFu I IA RServ let 4/10/2014 Full Action Request Report Page 2 of 5 accessible end. This course of action was not proscribed by the decision tree and is counter to PSC procedure SQ9.0 which states: "The tendon will have been monitored for tendon force as required of PSC Procedure SQ9.0. The De-tensioning shall continue from that point where the final or third liftoff was taken. The tendon shall not be de-tensioned until the liftoffs are documented. | |||
The ram will still be coupled to the anchorage that all Hoop tendons are to have lift-off tests performed from both ends." In addition, the measurement of the lift-off on H13-03 was counter to PSC procedure SQ9.0 which states the following: "Monitoring of Tendon Force can be performed on both ends of a tendon in a nimultaneous and controlled manner or on one tendon end at a titne, independent of the opposite end of the tendon. These procedures have been developed so that they apply to one end of the tendon. Every effort should be made to measure lift-off at opposite ends of a tendon at the same time.If this is prohibited by plant conditions (i.e., one end is accessible only with the plant operating and the other only when the plant is shut down), then measurements must be made as close together in time as possible and under similar temperature regimes. Adequate communication shall be maintained between both ends of the tendon during the taking of lift-off readings for simultaneous stressing operations. | |||
Vertical tendon monitoring of force is to be performed from one end, top end, only unless the tendon was double end stressed during original installation." As H13-03 is not a vertical tendon the lift-off testing of a single-end is not acceptable. | |||
Further PSC procedure SQ10.0 specifies that both ends of a tendon be de-tensioned in unison except single-end stressed vertical tendons. Thus the de-tensioning of H13-03 from one end violated the procedure SQ10.0.Finally PSC and TMI do not havr a procedure that allows for or addresses the re-tensioning of hoop tend d ns from a single-end. | |||
PSC procedure SQ12.0 states that "Retensioning of te' dons shall be performed on both ends of a hoop and dome tendon, or, single end of a vertical tendon which are only retensioned from the top end. Where it is not possible to perform simultaneous stressing of a tendon, Exelon Engineering shall be notified in writing to provide resolution for such conditions." Immediate actions taken: IR initiated PSC personnel modified the ram jib arm to allow access tp the Buttress 3 end of H13-03.Recommended Actions: 1. Maintenance Support to address Human Performance issue 2. Engineering to perform technical evaluation to determine the average as-found tendon pre-stressing force.3. Maintenance to submit vendor FMS What activities, processes, or procedures were involved?Conduct of tendon surveillance activities. | |||
Why did the condition happen?Failure to comply with procedure Topical Report 213 Attachment 1 Page 76 of 110 http://eaiigenco.ceco.com/cap/servlet/ReportFuIlARServ let 4/10/2014 Full Action Request Report Page 3 of 5 What are the consequences? | |||
Per the intent of ASME Section XI, subsection IWL and TMI engineering position the lift-off of H13-03 does not constitute a code exam as it was not taken from both ends of the tendon. However, the as-found average pre-stressing force in the tendon can be determined through a computation using the tendon elongation during re-tensioning activities. | |||
Were any procedural requirements impacted?PSC procedures SQ9.0, SQ10.0, and SQ12.0 were violated during the performance of surveillance activities on H13-03. Further engineering was not notified of the non-conforming condition. | |||
Were there any adverse physical conditions? | |||
None. The plant is currently in Cold Shutdown, however, it is acceptable to have one h~op tendon de-tensioned while the plant is in operation. | |||
List of knowledgeable individuals: | |||
Mark Torborg Michael Grimm, Sean Taylor Howard Hill Repeat or similar condition? | |||
No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: BRADLEY A PARFITT 11/20/2013 11:39:55 CST Reviewer Comments: Reviewed by Operations for operability and reportability. | |||
This issue has no impact on the ability to safely operate the plant, to achieve or maintain the plant in a safe shutdown condition, or to mitigate the effect of any accident condition. | |||
This issue does not identify an equipment deficiency that affects operability or functionality of any SSC. the as-found average pre-stressing force in the tendon can be determined through a computation using the tendon elongation during re-tensioning activities. | |||
The tendon will be retensioned prior to heat up, however, it is acciptable to have one hoop tendon de-tensioned while the plant is i h opera ion. This issue is not reportable because this condition doesn't meet 6r exceed any reportability criteria of the Exelon Reportability Reference Manual.SOC Reviewed by: CRYSTAL A WARLOW 11/21/2013 09:56:12 CST SOC Comments: Tendon surveillances are complete. | |||
HU addressed with contractor. | |||
Action created to submit FMS for contractor. | |||
Close to actions created/taken (Smokowicz 11/21/2013) | |||
Action created for RA#2. (Lytle 11/21/13)Close to actions taken/created. (SOC 11/21/13)Topical Report 213 Attachment 1 Page 77 of 110 http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet 4/10/2014 Full Action Request Report Page 4 of 5 Assign #: 01 AR #: 01587456 0 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 11/24/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
SURVEILLANCE TENDON DE-TENSIONdD BEFORE LIFT-OFF COMPLETED Assignment Completion In Progress Notes: Completion Notes: 0 Topical Report 213 Attachment 1 Page 78 of 110 http://eam-genco.ceco.comn/cap/servlet/ReportFulIARServlet 4/10/2014 Full Action Request Report Page 5 of 5' Assign #: 02 AR #: 01587456 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: STEIHX Due Date: 12/20/2013 Schedule Ref: Prim Grp: A5520MAINT Orig Due Date: 12/20/2013 Unit Condition: | |||
Sec Grp: Assignment Details I Subject/Description: | |||
Submit FMS for vendor PSC Assignment Completion In Progress Notes: Surveillance Tendon H 13-03 De-tensioned before Liftoff of other Tendon End Contract & Procedure The 40th Year Tendon Surveillance was performed by Precision Surveillance Corp. The surveillance process followed an approved Procedure that incorporated both Station and Corporate requirements. | |||
N1091 PSC Procedure SQ 10.0, Section 8.0 Detensioning the Tendon, provides direction for this activity.Procedure SQ 10.0, Section 8.0 Detensioning the Tendon"Both ends of a tendon shall be de-tensioned in unison unless otherwise directed by the PSC Superintendent." The H13-03 hoop tendon was only tensioned from one (1) end during Station construction as confirmed by the shim on the side that PSC initially detensioned being a proximately 14 inches thick whereas the opposite end shim thickness was he minimal 2 inches thickness for a non-tensioned end.Based on this finding, PSC elected only to detension from one end (following the Procedure). | |||
Per direction from the Station via Howard Hill (consulting engineer), PSC retensioned H13-03 from both ends.Recommendations | |||
: 1) Insure that Station requirements are made clear in the Procedure (which was updated, reviewed and approved by the Station).2) Clearly define during the walkdown as well as confirm via the Schedule Description for each tendon when a tendon is to be retensioned from both ends. Secondly, a Summary Scope 9 f Work should be developed that clearly describes what is to be performed for elch tendon to be surveyed.As-Built Tendon Card Shows one end was stressed.Completion Notes: 0 Topical Report 213 Attachment 1 Page 79 of 110 http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet 4/10/2 014 Full Action Request Report Page I of 3 0 Go Back Print I New Search Home AR Number: 01645620 Linked ARs Aff Fac: Three Mile AR Type: CR Status: APPROVED Island Aff Unit: 01 Owed To: A5551CAP Due Date: 05/10/2014 Aff System: 153 Event Date: 04/09/2014 CR / Disc Date: 04/09/2014 Level/Class: | |||
How H02 Orig Date: 04/10/2014 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
REVISION REQUIRED FOR TECHNICAL EVALUATION 1587456- | REVISION REQUIRED FOR TECHNICAL EVALUATION 1587456-03 | ||
== Description:== | == | ||
During the preparation of the 40th Year Tendon Surveillance Topical | Description:== | ||
Originator: | |||
MICHAEL GRIMM Supv Contacted: | |||
Mark Torborg Condition | |||
== | |||
Description:== | |||
During the preparation of the 40th Year Tendon Surveillance Topical Report 213 it was identified that an alternate method for computing the average tendon pre-stressing force would provide a more conservative result for trending purposes. | |||
The average pre-stressing force in the tendons is used to demonstrate that the expected tendon pre-stressing force will be greater than the minimum required pre-stressing force at the time of the next tendon surveillance. | |||
This IR is written to supersede the original technical ev luation.Immediate actions taken: Revised the technical evaluation Issued IR Recommended Actions: Close to actions taken.What activities, processes, or procedures were involved?Preparation of the 40th Year Tendon Surveillance Topical Report 213.Why did the con lition happen?A different methodology was used in the preparation of the original evaluation under IR 1587456-03 that was not as conservative. | |||
A more conservative approach was utilized in the revision of the technical evaluation. | |||
What are the consequences? | |||
None, the force computed in the technical evaluation is not used for acceptance of the tendon's as-found condition, but is utilized in the hoop tendon force trend to predict the expected pre-stressing force at the time of the next surveillance. | |||
Were any procedural requirements impacted?No Were there any adverse physical conditions? | |||
None List of knowledgeable individuals: | |||
Topical Report 213 Attachment 1 Page 80 of 110 http://eamngenco.ceco.com/cap/servlet/ReportFullARServ let 4/14/20 14 Full Action Request Report Page 21 of 3 Mike Grimm Sean Taylor Mark Torborg Repeat or similar condition? | |||
No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: JOSEPH W KULASINSKY 04/10/2014 13:28:54 CDT Reviewer Comments: The information in the Tech Eval is not used to determine surveillance testing acceptance criteria. | |||
Reasonable assurance exists that the RB tendons remain operable. | |||
There are no reportability or functionality concerns.SOC Reviewed by: RANDY E HESS 04/11/2014 10:53:43 CDT SOC Comments: Close to action created. (benson 4/11/14)Topical Report 213 Attachment 1 Page 81 of 110 http://earngenco.ceco.comn/cap/servlet/ReportFullARServlet 4/14/2014 Full Action Request Report Page 3 of 3 Assign #: 01 AR #: 01645620 Aff Fac: Three Mile Island Assign Type: TRKG Status: AWAIT/C Priority: | |||
Assigned To: Due Date: 04/15/2014 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
REVISION REQUIRED FOR TECHNICAL EVALUATION 158ý456-03 Assignment Completion I I In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 82 of 110 http://eai-genco.ceco.co-n/cap/servlet/ReportFullARServlet 4/14/2 014 Exelon Generation. | |||
Evaluation of As-Found Force 1645620-02 for H 13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 1 of 6 1.0 Reason for Evaluation/Scope The purpose of this evaluation is to determine the as-found average pre-stress force in hoop tendon H13-03. H13-03 was single-end stressed during plant construction due to access restrictions during the construction process. Prior to the 4 0 th Year Tendon Surveillance it was determined that both ends of H13-03 were accessible for testing and the tendon was not declared inaccessible. | |||
During surveillance activities, safety related conduit was found to be in the way of the ram jib arm and as a result the Buttress 3 end was not tested. Further H13-03 was de-tensioned without informing engineering, reference IR 1587456 for complete description. | |||
ASME Section XI 2004 Edition No Addenda Subsection IWL, Subsection IWL-2522(a) requires that"The pre-stressing force in all inspection sample tendons shall be measured by lift-off or an equivalent test." The force in a curved tendon is normally documented as the average of the lift-off values measured at the individual ends. However, this is not mandated in IWL. A technically acceptable alternative, i.e., "equivalent test", for tendons that are de-tensioned/re-tensioned is to compute tendon mean force using the as-found shim stack height, the re-tensioning force/elongation data, tendon length, tendon area and elastic modulus of the wire.This evaluation will analytically determine the as-found average pre-stressing force on tendon H13-03. The computed mean force will be used in the hoop tendon normalized group mean force and mean force trend projections. | |||
The H13-03 predicte force (C-1101-153-E410-046) is based on the single end (Buttress | |||
: 1) lock-off force as documentedIon the stressing cards. Therefore, force measured at the tensioned end of H13-03 (Buttress 1), and not the computed mean, is compared to the predicted value for the purpose of determining the acceptability of time dependent losses (which are normally assumed to be relatively proportional at all points along the tendon length)experienced by this tendon. Therefore, special considerations are required to compare the "as-found" and predicted forces. These considerations are discussed the following evaluation. | |||
This evaluatio was screened per HU-AA-1212. | |||
Review of attachment 2 of H -AA-1212 identified no risk f hoever, as this evaluation pertains to a safety related componeft, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During the 40th Year Tendon Surveillance hoop tendon H13-03 was lift-off tested from one end and then detensioned. | |||
This single end lift-off provides the data needed to establish time dependent losses and the acceptability of these as determined by comparing this lift-off force to the predicted value. The predicted value, taken from Calculation C-1101-153-E410-046, is based on the "as-installed" lock-off force, which was performed from one end (Buttress 1). For this reason it is reasonable to use the single-end lift-off measurement from Buttress 1 for direct comparison with Topical Report 213 Attachment 1 Page 83 of 110 ExeLon Generation. | |||
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 2 of 6 the predicted force to determine time dependant losses. However, it is prudent to compare the average "as-found" force computed in the following evaluation with a modified version of the predicted force.2.1. Development of single-end tensioned acceptance criteria During construction of the TMI Unit 1 Containment Building 14 hoop tendons were found to be inaccessible from one end, and were thusly single-end tensioned. | |||
Correspondance between Inland-Ryerson (Inryco), Gilbert Associates (GAI), and GPU Nuclear shows acceptance the acceptance of this condition with the acknowledgement of reduced pre-stressing forces in the affected tendons.However, during the original tendons selection for surveillance (TMI selected all 40 years of surveillance tendons at the same time shortly after original construction), the single-end tensioned tendons were not included in the surveillance population due to their accessibility. | |||
As a result the original pre-stressing force calculation, DC-5390-225.01-SE, did not address the difference in the predicted tendon force.During the revision of the predicted force calculation to include the steam generator replacement (SGR) tendons and a complete listing of all TMI tendons as a result of the incorporation of the IWL requirements into the surveillance, no consideration was given to single-end tensioned tendons outside of identifying which tendons were single-end stressed. | |||
At the start of the 40th Year Tendon Surveillance in 201 it was identified that two tendons selected for examination vere originally single-end tension4d. | |||
While one of these tendons was eventually ruled to be ia ccessible, it was deemed prudent to develop guidance to help in the disposition of these tendons. This guidance included a flow-chart for determining accessibility, lift-off measurements, and methodology for evaluating the results.The main conclusion from the guidance was that the predicted force values developed for the single-end tensioned tendons were not representative of the expected average pre-stressing force in the single-end tensioned tendons. It was expected that single-end tensioned tendons would have a predicted pre-stress force approximately 5% less than that in double-end tensioned tendons.This led to a modified predicted force of 93. % of the originally calculated predicted force (1,013.5 kips), with the 95% of predicted force acceptance criteria being equal to 88% of the original predicted force (954 kips).Further evaluation of the single-end tensioned tendons and their effect on the pre-stressed containment structure for the period of extended operation will be evaluated in an MPR analysis.The forces developed in this analysis will be utilized for future surveillances as applicable, and additional guidance will be incorporated into the TMI Surveillance Procedure, 1301-9.1, to address single-end tensioned tendons.Topical Report 213 Attachment 1 Page 84 of 110 Exelon Generation. | |||
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 3 of 6 2.2. Computation of the "As-Found" Average Pre-Stressing Force While the actual surveillance test results are acceptable for determining time dependent losses, the"as-found" average pre-stressing force is required to compute the normalized group mean pre-stressing force, the group mean trend to demonstrate acceptability until the next surveillance, and to compare to the modified predicted force developed in section 2.1. The mean force in an individual hoop tendon can be represented as the average of lift-off forces measured at the individual ends approach) or computed directly as outlined below The method of computing the as-found average tendon pre-stress force is as follows: 1. Using the force (F,) and elongation (Xi) data recorded at Buttresses 1 and 3 during re-tensioning, where i represents the buttress number, plot the average end force (Favg) against the total tendon elongation (Xtotal).avg F + F 3 XtotaI= X 1 + X 3 The plot is represented by a linear trend line; represented as follows: F = mX + b 2. Extrapolate the plot back to zero force to determine the zero-stress clearance (X 0) between the bearing plate and anchor head for both tendon ends.X =--3. Subtract X 0 from the total "as-found" shim stack height (hs)to get the "as-found" tendon elongation (Xf). The "as-found" shim stack height will be the same as the "as-installed" shim stack height. Then divide by tendon length (L) to get the mean "as-found" tendon strain (Ema).hs = h 1 + h3 Xf = h, -Xo xr 4. Computý mean as-found tendon force (Fm) using the tendon modulus oý elasticity (E) and the cross sectional area of the tendon (A).F.= ()(E)(A)E = 29x103ksi T/r 2 A = (Nvires) 2 In accordance with PSC procedure SQl.0, Retension Tendons, the pre-stress force in the tendons is taken at four separate elongations as the tendon is taken to 80% of the Guaranteed Ultimate Tensile Strength (GUTS), referred to as the overstress condition. | |||
This is done from both ends simultaneously and the tendon elongation and force are recorded on data sheet SQl1.1. Table 1 Topical Report 213 Attachment 1 Page 85 of 110 ExeLon Generation. | |||
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 4 of 6 shows the pre-stressing forces and corresponding elongations recorded during re-tensioning of H13-03. The total elongation and the average pre-stress force are computed in table 1.Table 1: Tendon Pre-Stressing Force for Recorded Tendon Elongations Buttress 1 Buttress 3 H13-03 Elongation Force Elongation Force Total Elogation Average Force (inches) (kips) (inches) (kilýs) (inches) (kips)4.4 206.04 4.1 207.2 8.5 206.62 6.8 800.28 6.2 797.59 13 798.935 8.2 1199.18 7.65 1201.15 15.85 1200.165 9.3 1462.37 8.7 1462.72 18 1462.545 The total elongation is then plotted in figure 1 versus the average pre-stressing force. A linear trend line is fitted to the data to show the as-found tendon condition. | |||
Tendon Elongation vs. Pre-Stressing Force 2000:1500 100 4 500 y = 133.12x -924.92 0 I I I I I I I I 0 2 4 6 8 10 12 14 Tendon Elongation (inches)I I I 16 18 20 Figure 1: Plot of the total tendon elongation versus the average pre-stressing force.Using the linear trend equation X 0 is found to be 6.95 inches. Tendon H13-03 had 169 wires in the"as-found" condition and the corresponding tendon area (A) is 8.30 in 2.The total shim height (hj)from measurements taken by PSC and recorded on data sheets 8.OA and 8.0B is 15.3 in. The tendon length (L), as recorded on test wire examination data sheet 10.2, is 155 ft and 6 in, or 1,866 in.Using this data, the "as-found" mean strain (Em) is found to be 4.47x10-3 , and the respective "as-found" mean pre-stressing force (Fm,) is 1,076 kips.The measured lift-off at Buttress 1 was recorded on PSC data sheet 9.0 as 1,230 kips. The T = 39.5 (years after the March 1974 RB SIT) prediction for force at the Buttress 1 end of H13-03 is 1,141 kip.S Topical Report 213 Attachment 1 Page 86 of 110 Exelon Generation. | |||
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 5 of 6 The measured force exceeds that predicted and, therefore, meets the acceptance criterion (measured force at least 95% of predicted (1,084 kips)), and is used to show the time-dependant pre-stessing losses are acceptable. | |||
Additionally, the computed average tendon force (1,076 kips) is equivalent to 94.3% of the predicted pre-stressing force, which exceeds the modified predicted force (1,013.5 kips) discussed in section 2.1. Therefore, both the Buttress 1 measured lift-off force and the computed average pre-stressing ftrce are acceptable in the "as-found" condition. | |||
The comparison of the computed average pre-stressing force to the modified predicted force is included for reference only.The computed average pre-stressing force will be further utilized in the 4 0 th Year Tendon Surveillance Topical Report for computation of the Hoop Tendon Group Mean Pre-Stressing Force and the Group Mean Pre-Stressing Trend.3.0 Conclusion/Findings As the above computation shows, the as-found mean pre-stressing force in hoop tendon H13-03 is 1,076 kips, or 94.3% of the predicted tendon pre-stress force, which is greater than the modified predicted force developed in section 2.1. Additionally, as the "as-found" lift-off force measured at Buttress 1 was 1,141 kips, which is greater than 95% of the predicted tendon pre-stress force the tendon's "as-found" condition is acceptable. | |||
The average pre-stressing force, computed in the above evaluation, will be used in the 4 0 th Year Tendon Surveillance Topical Report for computling the mean hoop tendon force as w~ll as determining the hoop tendon force trend until the next surveillance. | |||
No additional actions are required.4.0 References | |||
: 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance | |||
: 4. IR 1587456, Surveillance Tendon Detensioned Befor Lift-Off Completed 5. PSC Inspection Manual N1091 6. C-1101-153-E410-046, TMI-1 RB Post Tensioning System ISI Program Tendon Force Prediction | |||
: 7. DC-5390-225.01-SE, Surveillance Tendon Selection Reactor Bldg. Post Tensioning System Tendon Selection and Force vs. Time Curves Surveillances 6 through 10 5.0 Attachments | |||
: 1. Data sheets SQ11.1 for H13-03 Buttress 1 and Buttress 3 Topical Report 213 Attachment 1 Page 87 of 110 Exelon Generation. | |||
Evaluation of As-Found Force for H13-03 PREPARED BY SUBJECT Michael Grimni Evaluation of H13-03 As-Found Force Approvals Responsible Engineer: | |||
Howard Hill Preparer: | |||
Michael Grimm Independent Reviewer: | |||
Sean Taylor Manager: MarkTorborg 1645620-02 PAGE 6 of 6 Date: See EDMS Date: See EDMS Date: See EDMS I Date: See EDMS, Topical Report 213 Attachment 1 Page 88 of 110 ExeLon Generation. | |||
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 1 of 5 Plates in the Reactor Building Tendon Buttresses | |||
===1.0 Reason=== | |||
for Evaluation/Scope The purpose of this technical evaluation is to evaluate the "as-found" condition of the embedded plates in the reactor building tendon buttress concrete. | |||
During the 4 0 th Year Tendon Surveillance general concrete examination, several embedded steel plates were identified as "pulling away" from the concrete. | |||
The embedded plates identified in these data sheets are shown on drawing 421030.This constitutes a new recordable indication' that needs to be addressed, and evaluated for acceptability. | |||
This evaluation was screened per HU-AA-1212. | |||
Review of attachment 2 of HU-AA-1212 identified no risk factors; however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation The 4 0 th Year Tendon Surveillance was performed at Three Mile Island (TMI) during the Fall of 2013.The surveillance began on September 23, 2013 and Precision Surveillance Corporation (PSC) left site on December 4, 2013. The surveillance completed on January 31, 2014 with the receipt of the corrosion protection medium (CPM) and tendon wire test results. Additional CPM tests are in process; hcýwever, these are follow-up actions to the original surveillance As part of the surveillance, PSC conducted a general concrete visual examination of the accessible exterior reactor building surfaces. | |||
These inspections were documented in the PSC surveillance report submitted to TMI on February 4, 2014.Subsequent to the receipt of the surveillance report, the Responsible Engineer (RE), Howard Hill, performed a review for his agreement/concurrence with the conclusions reached by PSC. This review is part of the RE duties and is included as part of the final TMI Engineering Topical Report issued to the NRC within 90 days of he surveillance completion. | |||
The Topical Report is required to be submitted by April 31, 2014. During this review the RE identified that the PSC data sheets for the concrete visual inspection identified new recordable indications of several embedded steel plates pulling away from the concrete surface. The indications were reported on Tendon Buttresses 3, 4, 5, and 6.The embedded plates in question are depicted on drawing 421030, Reactor Building Concrete Exterior Wall Concrete Outline. Detail A of this drawing shows the details of the embedded plates (Figure 1, below). Figure 2, below, shows the locations of the embedded plates on the tendon buttress.Topical Report 213 Attachment 1 Page 89 of 110 Exeton Generation. | |||
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 2 of 5 Plates in the Reactor Building Tendon Buttresses | |||
,-68" 6 3 8NELSON ANCHO01 5TUD5 ?.'O",c,) ~ k : .d 38F(CONTI N)DSTAiL "A" Figure 1: Details of Embedded Steel Plates Figure 2: Location of Embedded Plates Topical Report 213 Attachment 1 Page 90 of 110 Exelon Generation. | |||
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 3 of 5 Plates in the Reactor Building Tendon Buttresses The embedded steel plates do not run the entire length of the tendon buttress but are primarily above the rooflines of the adjacent buildings. | |||
: 1. Buttress 1 -Elevation 369' to 436'2. Buttress 2 -Elevation 405' to 436'3. Buttress 3 -Elevation 403' to 436'4. Buttress 4 -Elevation 400' to 436'5. Buttress 5 -Elevation 305' to 436'6. Buttress 6 a. North Side -Elevation 341' to 436'b. South Side -Elevation 305' to 436'Upon discovery, an attempt was made to conduct an interview with the inspector to determine what the exact phenomena observed was. The inspector who performed the concrete visual inspections was a temporary contractor for PSC and no longer works for the company. A phone interview conducted with his direct supervisor indicated that the inspector identified several locations where the embed plates were bulging from the concrete surface, no photographs were available of this condition. | |||
Following the phone interview, the Tendon and ISI prigram engineers conducted a walk down of the tendon buttresses in question to view and photograph the indications. | |||
The walk down did not reveal any indications where the embedded plates were bulging or pulling away from the concrete.However, several locations where the embedded plates overlap were observed, as shown in Figure 3, below. The overlap locations are consistent with the locations where the inspector identified the embed plates pulling away, as documented in the PSC Inspection Report.Topical Report 213 Attachment 1 Page 91 of 110 Exelon Generation. | |||
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 4 of 5 Plates in the Reactor Building Tendon Buttresses Figure 3: Overlap of Embedded Steel Plates In these locations the overlapping embedded plates have grouting around them. The grouting is uncracked with no significant degradation noted. This implies that the overlap is the installed condition of the emlIedded plates and that no significant degradation has occurred.I 3.0 Conclusion/Findings Based on the walk down performed by Programs Engineering and discussions with both PSC and the Responsible Engineer, Howard Hill, it is determined that the embedded plates are in the installed condition with no degradation. | |||
These findings, as documented in this evaluation, determine that there is no recordable indication, and no further evaluation for acceptability is required.4.0 References | |||
: 1. CC-AA-309-101, Engineering Technical Evaluations | |||
: 2. HU-AA-1212, Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Review 3. ASME Section XI 2004 Edition No Addenda, Boiler and Pressure Vessel Code, Division 1 Rules for Inspection and Testing of Components of Light-Water Cooled Plants 4. REP-1091-510, Final Report for the 2013 Tendon Surveillance at TMI 5.0 Attachments | |||
===5.1. General=== | |||
Concrete NDE Data Sheets Topical Report 213 Attachment 1 Page 92 of 110 Exeton Generation As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 5 of 5 Plates in the Reactor Building Tendon Buttresses I AzRoLM T Preparer: | |||
Michael Grim m Independent Peer Reviewer: | |||
Se an Taylor Responsible Engineer: | |||
Howard Hill Manager: Mark Torbor-Date: __//_O"___ | |||
Date: Ai25 16A Date: Aw Date:_____ | |||
I Topical Report 213 Attachment 1 Page 93 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01626566 Linked ARs Aff Fac: Three Mile AR Type: CR Status: APPROVED Island Aff Unit: 01 Owed To: A5551CAP Due Date: 04/30/2014 Aff System: 153 Event Date: 02/26/2014 CR 4/D Disc Date: 02/26/2014 Level/Class: | |||
How H02 Orig Date: 02/26/2014 Discovered: | |||
Action Request Details | |||
==Subject:== | ==Subject:== | ||
TENDON GREASE SAMPLE ACID NUMBER EXCEEDS ACCEPTANCE | TENDON GREASE SAMPLE ACID NUMBER EXCEEDS ACCEPTANCE CRITERIA | ||
== Description:== | == Description:== | ||
On February 26, 2014 TMI received the initial acid number test | |||
* i-f J~Examiner: James L Newaiob II &M/ 9 I [ ff/'Mf / Level: l Oate 04-09- | Originator: | ||
MICHAEL GRIMM Supv Contacted: | |||
Mark Torborg Condition | |||
== | |||
Description:== | |||
On February 26, 2014 TMI received the initial acid number test results from Precision Surveillance Corporation (PSC). The official lab report will be included in a revision to the PSC Surveillance Report. PSC reported that 7 of the 10 samples tested for acid number, did not meet the PSC acceptance criteria of <0.500. The seven samples reported to TMI were: 1. D-303 (North): 0.530 2, H13-03 (Buttress 3): 0.530 3. H13-08 (Buttress 1): 1.06 4. H13-10 (Buttress 3): 0.530 5. H35-02 (Buttress 3): 1.06 6. V-32 (Gallery): | |||
2.64 7. V-108 (Gallery): | |||
0.530 A follow-up phone call with the PSC Quality Assurance Manager revealed that the above test results were confirmatory test numbers, which agreed with the initial test results.Samples D-303, H13-03, H13-10, and V-108 are acceptable per Exelon procedure ER-AA-330-006, which has an acceptance criteria of <1 for the acid number. N# additional actions are required for these tendons.Samples H13-0ý, H35-02, and V-32 do not meet the <1 acid number requirement. | |||
Immediate actions taken: Notified Responsible Engineer Issued IR Recommended Actions: 1. Include formal discussion of acid number results in the Tendon Surveillance Topical Report (Grimm, March 31, 2014)2. Define additional actions to be taken during the 45th Year Tendon Surveillance in 2019 in accordance with TS 4.4.2.1.4 (Grimm, March 31, 2014)What activities, processes, or procedures were involved?Topical Report 213 Attachment 1 Page 94 of 110 Laboratory analysis of tendon filler grease samples. The acid number tests were a follow-up action driven by Exelon procedure ER-AA-330-006 and the vendor (PSC) surveillance procedure for grease sample base number tests below the reporting limit of 0.50.Why did the condition happen?Unknown. This condition is new and has not been previously identified in prior tendon surveillances at TMI.What are the consequences? | |||
None Tendon filler grease sample testing is performed to verify there is no evidence of filler grease degradation that could result in the corrosion of the tendon wire or anchorage comlionents and lead to future failure of the tendon components. | |||
The reported acid number results indicate that the grease in these 3 tendons has become acidic and may not be fully effective in performing its intended corrosion prevention function. | |||
While there is evidence that the filler grease has degraded, the surveillance indicates that no active corrosion is occurring on the three tendons in question.Visual inspections were conducted on each of the three tendon anchorages (H13-08 Buttress 1, H35-02 Buttress 3, and V-32 Gallery) with the following results: 1. No free water was found during end cap removal, this includes in the end cap and on the anchorage components. | |||
: 2. No anchorage component (including the shims, buttonheads, anchorheads, bearing plate, and bushing) exhibited a corrosion category above "A", which indicates no visible rust.3. There were no protruding buttonheads identified, and all three tendons had 169 effective wires.4. Other than the base and acid numbers, grease testing results were within acceptable limits for chlorides, nitrates, sulfides, and moisture cojnent.Lift offs were conducted on H35-02 and V-32 with acceptable resultsl H35-02 had a lift-off of 1216 kips, which was greater than the predicted value of 1093 kips. V-32 had a lift-off of 1181.27 kips which was greater than the predicted value of 1176 kips. No lift-off was conducted on H13-08 as the Buttress 3 end of the tendon was inaccessible due to the Reactor Building Flood Seal.Additionally, during original manufacture the tendon wires were coated with Visconorust 1601 Amber, which provides another layer of corrosion protection in addition to the filler grease. Given the results of the surveillance it is reasonable t 9 conclude that there is no active corrosion on the tendon com lpnents (anchorage or wire) and that the tendons in question will contilue to perform their function through the next surveillance in 2019.Were any procedural requirements impacted?No. Exelon procedure ER-AA-330-006 requires notification of the responsible engineer and evaluation of the condition for follow-up actions and acceptability. | |||
A formal discussion of this condition will be included in the surveillance topical report, and will address the required follow-up actions during the 45th Year Tendon Surveillance. | |||
Were there any adverse physical conditions? | |||
There are no adverse physical conditions in the plant. Based on the surveillance results discussed above, it is reasonable to conclude that the structural integrity of the Reactor Building Containment has not been challenged. | |||
The Limiting Condition for Operation concerning structural integrity is provided in TS 3.19.1 and states: Topical Report 213 Attachment 1 Page 95 of 110 "With the structural integrity of the containment not conforming to the inservice tendon surveillance program requirements of 4.4.2.1 for the tendon lift off forces, perform an engineering evaluation of the structural integrity of the containment to determine if COLD SHUTDOWN is required. | |||
The margins available in the containment design may be considered during the investigation. | |||
If the acceptability of the containment tendons cannot be established within 48 hours, restore the structural integrity to within the limits within 24 hours or be in at least HOT STANDBY within the next 6 hours and in COLD SHUTDOWN within the following 30 hours." As the surveillance results indicate acceptable lift-off values with no observable degradation to the tendon components that could challenge the pre-stressing ability of the tendons, the Reactor Building Containmelt retains its structural integrity. | |||
Additionally there is reasonable evidence to conclude that no degradation will be experienced to challenge the structural integrity prior to performance of the next scheduled tendon surveillance in 2019.List of knowledgeable individuals: | |||
Mike Grimm Howard Hill Sean Taylor John Piazza Repeat or similar condition? | |||
No Operable Basis: The Containment Structure remains operable. | |||
Tech Spec 3.19 specifically covers the tendon lift off forces and does not cover corrosion protection.Tech Spec 4.4.2.1 statqs that the Inservice Tendon Surveillance program for structural integrity a rd corrosion protection conforms to ASME code requirements. | |||
As noted in the IR, tendon filler grease sample testing is performed to verify there is no evidence of filler grease degradation that could result in the corrosion of the tendon wire or anchorage components and lead to future failure of the tendon components. | |||
While there is evidence that the filler grease has degraded, the surveillance indicates that no active corrosion is occurring on the three tendons in question.As the surveillance results indicate acceptable lift-off values with no observable degradation to the tendon components that couly challenge the pre-stressing ability of the tendons, the Reactor Building Co tainment retains its structural integrity. | |||
l 1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability? | |||
TS, ER-AA-330-006 | |||
: 3. Describe the function of the SSC and basis for operability/availability determination. | |||
Functions are listed below. As discussed in the IR, the containment structure continues to meet its design requirements. | |||
: 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103. | |||
: 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO Topical Report 213 Attachment 1 Page 96 of 110 153-MOl : Exterior wall provides jet fuel fire barrier. Part of the original design basis (153).153-M02 Provide aircraft protection (153).153-M03 : Provide environmental protection for systems and components (153).153-M04 Provide protection from groundwater (153).153-MO5 Provide protection from turbine generated or other missiles (153).153-M06 Provide radiation shielding from fission products in the RB (153).153-M07 Provide train or channel separation (153).153-M08 : Withs nd short-term tornado loading including tornado-generated missiles (153). T 153-NO1 Provide fire barrier (153).153-N02 Provide personnel access to systems and components (153).153-N03 : THE SHIELD BARRIER WITH THE STEEL PLATING ACTS TO RESTRICT A RELEASE OF POST ACCIDENT FISSION PRODUCTS 153-ROl Contain fission products to prevent radioactive release (153).153-R02 Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 Maintain structural integrity (153).153-R04 Provide fluid containment (153).153-RO5 Provide pressure boundary integrity for internal pressure.153-RO6 Provide protection from flooding (153).153-R07 Provide support for systems and components (153)Reportable Basis: This does not meet any reporting thresholds. | |||
Functional Basis: Reviewed by: EDWARD M CARRERAS 02/26/2014 22:24:24 CST Reviewer Comments: EMC Reviewed by: EDWARD M CARRERAS 02/27/2014 02:56:47 CST Reviewer Comments: SOC ReviLwed by: CAROLYN J FLORY-MAGATZ 02/28/2014 10:00:10 CST SOC Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 02/27/14). | |||
Close to actions created. (McDowell 2/28/14) (SOC 2/28/14)Topical Report 213 Attachment 1 Page 97 of 110 Assign #: 01 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority: | |||
Assigned To: Due Date: 03/03/2014 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition: | |||
Sec Grp: Assignment Details subject/Description: | |||
TENDON GREASE SAMPLE ACID NUMBER rXCEEDS ACCEPTANCE CRITERIA Assignment Completion In Progress Notes: Completion Notes: 0 Topical Report 213 Attachment 1 Page 98 of 110 Assign #: 02 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: GRIMMX Due Date: 04/30/2014 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 03/31/2014 Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
Include formal discussion of acid number results in the T endon Surveillance Topical Report (Grimm, March 31, 2014)Assignment Completion In Progress Notes: A formal discussion of the acid number results and the conclusions from the associated IR 1626566 was included in Topical Report 213 section 3.6.No further actions are required.-Michael Grimm 4/09/2014 Move assignment to correspond with the due date for the Tendon Surveillance Topical Report. This assignment can't be closed until the Topical Report is signed off and submitted. | |||
Michael Grimm 3/26/2014 Completion Notes: Topical Report 213 Attachment 1 Page 99 of 110 Assign #: 03 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority: | |||
Assigned To: GRIMMX Due Date: 04/30/2014 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 03/31/2014 Unit Condition: | |||
Sec Grp: Assignment Details Subject/Description: | |||
Define additional actions to be taken during the 45th Yea r Tendon Surveillance in 2014 in accordance with TS 4.4.2.1.4 (Grimm, March 31, 2014)Assignment Completion I In Progress Notes: Section 5.2 of Topical Report 213 documents the follow-up actions to be taken during the 45th Year Surveillance. | |||
During the 45th Year Surveillance the tendon anchorage components of H13-08 Buttress 1, H35-02 Buttress 3, and the Gallery end of V-32 will be visual inspected for corrosion and the tendon duct will be pumped through with new Corrosion Protection Medium. No further actions are required.-Michael Grimm 4/09/2014 Move due date to 4/30/14 which is the submittal date for the tendon surveillance Topical Report to the NRC. This assignment can't be closed until the report is submitted. | |||
Michael Grimm 3/26/14 Completion Notes: Topical Report 213 Attachment 1 Page 100 of 110 1@to Exelkn.ER-AA-335-019 Revision 0 Nuclear ATTACHMENT 4 ASME IWL (Class CC) Containment Concrete Detailed or General Visual Examination NDE Report Station I Three Mile Island Uni It Date: 104-09-14 ReportNo: | |||
/A System[ 153 1 Component: .SE Quad of ring girder (Above Butressg3 | |||
& 2) WO No(s).: R2163325-87 Location: | |||
Building: | |||
COO. E(ev. t6 0 1 N/A Rowl NA Azimuth/Radius Exam Type: 1Z Detailed Visual Type Of Exam: E]Direct i[-General Visual lRemote MI l Type: Outside ConialnmentConcrete Design Drawing(s) | |||
TMII-0014 REV. I Visual Aids: Orion Apex 102mm, Model 9823 Optical Tube Assembly telescope with 26m5m Simus Eye Piece, 45 Degree Correct Image Diagonal adaptor & Correct Image Finder Scope Surface: DD 00 10I Surface / Comp~onents Coaled: F1 YES NO Illumination Used I Attribute RI NRI 10 tExplanation | |||
/ Comments .-Cracks (Characterize and Size) q See attached sheets for photos of degraded areas Exposed Reinforcing Steel 4 No changes noted from 2006 Inspoction other than evidence of a Expospd 'Metallic Items (Other) _ N1 leak area gatting larger.Evidence Of Greaes Leakage 4 Photos and videos taken of exam volume.-.Evldence-.lMolsture | |||
..-. .... .--4 .......Videos avallable If.requested,..-.-........ | |||
-.Leaching Or Chemical Attack 1 Photos and Videos supplied to ISI program owner: Mike Grimm Sehlements Or dflections Degraded Patches or epairs .P opouts, Voids, Honeycomb | |||
,.Spells i, ,_,_ __,_, Cold Joint Unes 4 Corrosion Staining 'Scaling I Ousting 'Coating Deterioration | |||
'Abrasion, Cavitaton, Wear .4 Air Velds I Bug Holes. I 4- REACTOR BUILDING TENdON SURV. (oT005278) | |||
OthIer lain ) --NDE VT-1 BE QUAD RING GIRDER Reasulte Legend; -1 il -Recordable Indieatii NRI -No Recordabl Indliatlons 10 -Information Only Supplemental Information: | |||
UYes [No El S[ ketch ,Photo ZVldeo E] Other (Describe): | |||
IIi~~~ | |||
* i-f J~Examiner: | |||
James L Newaiob II &M/ 9 I [ ff/'Mf / Level: l Oate 04-09-14 Further Evaluation Required: | |||
YesU k;?-/.z Additional Aotionswzi r- -ldcc-,5 rxv7oc x. -~ ýi:4A )(Action ReqlUeat, .k Order, Issue Repeod. etc. f;l dorCoetve Action) Suspect Aras shall be dlsposflloned by a Responsible Enlteer Reviewer, i2_Mike Grmiml Date 04-10-14 ANti: Data " , Page 1 of iO Topical Report 213 Attachment 1 Page 101 of 110 ER-AA-335-019 Revision 0 a I 7 I I 5 H AR64 tXAmidei~7 I j I. 1 I I ,"i '.S a'I"~2u t L ~I- I 17,.$r.-1 z.iZ S. j b l~5 C I!r v pepa v 9 ha H AI -4 c. :3'F ::-I ~ I, 2-* Ird I H 1' .Ad.2302~~ ;41 1 I 'lz-IH* *'C2" , 0, t 4 VV.4. 13-a It ok ;.I 4 -!A#r it -: D..2L~ A.2LI~e~-ill..11,2- I I. J*4~4.'.14 ~I 4)-I 4 Page 2 of 10 Topical Report 213 Attachment 1 Page 102 of 110 ER-AA-335-019 Revision 0~iuurn Page 3 of 10 Topical Report 213 Attachment 1 Page 103 of 110 ER-AA-335-019 Revision 0 THREE MILE ISLAND UNIT 1 OUTSIDE CONTAINMENT CONCRETE ARFA II\JPFCTFF) nN I1q11A FRfnM, F1nlKF TFNfnlN rm-'In TC) r)-9nl1 RINC IriFrp Paue 4 of 10 Topical Report 213"Attachment 1 Page 104 of 110 ER-AA-335-019 Revision 0 Pane 5 of 10 Topical Report 213-Attachment 1 Page 105 of 110 ER-AA-335-0 1 9 Revision 0 0 I Page 6 of 10 Topical Report 213 Attachment 1 Page 106 of 110 ER-AA-335-019 Revision 0 Page 7 of 10 Topical Report 213 Attachment 1 Page 107 of 110 ER-AA-335-019 Revision 0 0 Topical aO Page 108 of 110 ER-AA-335-019 Revision 0 Page 9 of 10 Topical Report 213 Attachment 1 Page 109 of 110 ER-AA-335-019 Revision 0 ORION APEX 102mm, MODEL 9823 OPTICAL TUBE ASSEMBLY TELESCOPE WITH 25mm SIRUS EYE PIECE, 45 DEGREE CORRECT IMAGE DIAGONAL ADAPTER AND CORRECT IMAGE FINDER SCOPE.ENTIRE AREA INSPECTED USING THE SCOPE ABOVE REFERENCE REMOTE VISUAL EXAMINATION DEMONSTRATION | |||
# TMI-02-09 VISUAL ACUITY CARD USED AT START OF THE INSPEC TION AND AT THE END MAX DISTANCE CHECK WAS 75' I INSPECTION PERFORMED FROM -40' TO 60' ON TOP OF THE TURBINE BUILDING ROOF ENTIRE EXAM VOLUME ALSO RECORDED USING A SONY "HANDYCAM" HD 30X EXTENDED ZOOM CAMCORDER PHOTOS TAKEN USING A SONY "CYBERSHOT" 12.1 MEGA PIXEL CAMERA PHOTOS TAKEN DURING 2006 INSPECTION WERE USED TO VERIFY ANY CHANGE IN CONDITIONS SEVERAL AREAS NOTED AS HAVING DEGRADATION, CRACKED & MISSING GROUT, STAINING, MINOR CHIPS, PEELING, POPOUTS. OVERALL NO CHANGE FROM 2006 EXCEPT FOR A LEAK AREA IDENTIFIED IN THE PHOTOS ABOVE.Page 10 of 10 Topical Report 213 Attachment 1 Page 110 of 110}} |
Latest revision as of 09:24, 11 October 2018
ML14189A285 | |
Person / Time | |
---|---|
Site: | Three Mile Island ![]() |
Issue date: | 04/30/2014 |
From: | Grimm M D, Hill H T, Sherrie Taylor, Torborg M Exelon Generation Co |
To: | Office of Nuclear Reactor Regulation |
Shared Package | |
ML14189A283 | List: |
References | |
TMI-14-061 | |
Download: ML14189A285 (159) | |
Text
Topical Report No. 213 Revision 0 Page 1 of 49 Topical Report 213 40th Year Reactor Building Tendon Surveillance (Period 10)(Rev 0)Responsible Engineer DateýA;Reviewer Design Verification Required?Section Manager Dote EJYes DgNo Date 4W-#
Topical Report No. 213 Revision 0 Page 2 of 49 Table of Contents 1. PURPOSE AND INTRODUCTION p4 2.
SUMMARY
OF WORK PERFORMED AND INSPECTION RESULTS p6 2.1. Work Performed p6 2.1.1. Sample Selection p6 2.1.2. Post-Tensioning System Testing and Examination p7 2.1.3. Containment Surface Examination p8 2.2. Inspection Results p9 2.2.1. Post-Tensioning System p9 2.2.2. Containment Surface p11 3. POST-TENSIONING SYSTEM TESTS AND EXAMINATION p12 3.1. Examination Sample Selection p12 3.2. Tendon Forces p14 3.2.1. Individual Tendon Forces p14 3.2.2. Group Mean Forces p17 3.2.3. Projected Group Mean Forces p18 3.2.4. Control Tendon Force Trends p27 3.3. Tendon Elongations and Re-Tensioning p29 3.3.1. Elongations p30 3.3.2. Re-Tensioning p31 3.4. End Anchorage Condition p32 3.4.1. Corrosion p32 3.4.2. Physical Damage p33 3.4.3. Missing Button Heads p33 3.4.4. Unseated Button Heads p34 3.4.5. Free Water p34 3.4.6. Concrete Within Two Feet of Bearing Plate p34 3.4.7. Shim Gaps p35 Topical Report No. 213 Revision 0 Page 3 of 49 3.5. Specimen Wire Test Results p36 3.6. Corrosion Protection Medium Test Results p37 3.7. Corrosion Protection Medium Removal / Replacement p39 3.8. Tendon End Anchorage Cover Examination p41 3.9. Topical Report No. 203 Examination and Test Commitments p42 4. CONTAINMENT SURFACE EXAMINATIONS
4.1. Overall
Concrete Surface Condition 4.2. Topical Report No. 203 Follow-up Examinations p43 p43 p43 5. REPAIRS AND FOLLOW-UP EXAMINATIONS p45 5.1. Repairs p45 5.2. Follow-Up Examinations During 45th Year Surveillance (Period 11)p45 6. CONCLUSIONS p46 7. REFERENCES p48 ATTACHMENT 1: Engineering Technical Evaluations and Issue Reports ATTACHMENT 2: Final Report for the Three Mile Island Unit 1 4 0 th Year Containment Building Tendon Surveillance ATTACHMENT 3: Exelon Approval of PSC Procedures and Personnel Topical Report No. 213 Revision 0 Page 4 of 49 1. PURPOSE AND INTRODUCTION This topical report documents the performance and results of the 4 0 th Year (Period 10) Reactor Building In-Service Inspection.
The Reactor Building in-service inspection (ISI), referred to herein as surveillance, is performed at 5 year intervals to demonstrate the continued structural integrity of the reactor building.The 4 0 th year Surveillance was conducted on site from September to December 2013, with lab tests being performed during January and February of 2014 and the final visual examinations on April 15, 2014. The surveillance, in its entirety, was performed in the examination window between March 2013 and March 2015, time window defined by the earliest start and latest finish dates specified in the governing code, ASME Section Xl, Subsection IWL, as cited in USNRC Regulation 10CFR50.55a.
This topical report also serves as the Engineering Evaluation Report required by 10CFR50.55a and the ASME Boiler and Pressure Vessel Code,Section XI, Sub-Section IWL, Article IWL-3310.
The ISI Summary Report, consisting of the NIS-1 and NIS-2 forms, identified in Subsection IWA-6000 and required by 10CFR50.55a, are separate documents.
The 4 0 th year surveillance includes, for the first time, two distinct sets of randomly selected tendons. One set is selected from the population of tendons not de-tensioned during the 2009 steam generator replacement (SGR) outage. The other set, identified as SGR tendons, is selected from the population of tendons de-tensioned and re-tensioned (or replaced) during that outage. The selection of tendons for the SGR set follows Subsection IWL requirements and the additional requirements, imposed by TMI procedures.
The random sample of tendons drawn for this surveillance includes hoop tendons initially tensioned from a single-end during construction.
As this is the first time since the second inspection period, special considerations were made as discussed later in this report.The Surveillance, performed per Technical Specification 4.4.2.1, conforms to the requirements of Subsection IWL of Section Xl of the ASME Boiler and Pressure Vessel Code, as incorporated by reference into 10CFR50.55a.
The Surveillance meets the requirements as described in the Updated Final Safety Analysis Report (UFSAR) and is performed in accordance with TMI-1 Surveillance Procedure 1301-9.1, in addition to Exelon Corporate Procedures ER-AA-330-005, ER-AA-330-006, ER-AA-335-001, and ER-AA-335-019.
The actual implementation of the surveillance is conducted using approved vendor procedures.
The Surveillance is comprised of the measurements, examinations, tests and related activities identified in Section 2. Surveillance activities also included replacement of one hoop tendon end cap gasket to eliminate a corrosion protection medium leak.Measurements, examinations and tests on randomly selected tendons are performed on a regular basis (5 year frequency as required be Subsection IWL)
Topical Report No. 213 Revision 0 Page 5 of 49 throughout the life of the plant. Complete examination of the containment exterior as specified in Sub-Section IWL, examination of tendon end anchorage caps and tendon force trend extrapolation commenced with the Period 7 surveillance (performed in 2000) in accordance with requirements introduced in a 1996 amendment to 10CFR50.55a.
The Period 10 surveillance is the fifth to be conducted per 10CFR50.55a and Sub-Section IWL. The Period 7, Period 8, Period 9 and 2010 Augmented Surveillances are documented in topical Reports No. 136, 183, 203 and 204, respectively.
The 2010 augmented surveillance addressed a small sample of the tendons affected (de-tensioned
/ re-tensioned or replaced) by steam generator replacement activities.
The remainder of this topical report is divided into the following sections: Section 2, Summary of Work Performed and Inspection Results, is a synopsis of Surveillance activities and findings.Section 3, Post-Tensioning System Examinations and Tests, describes measurements, tests, and examinations performed on post-tensioning system components (except bearing plate and end cap examinations performed as a part of the overall containment exterior examination), tabulates results, provides a detailed development of tendon force trend extrapolation and includes evaluations of conditions that do not meet acceptance criteria.
Post-tensioning system follow-up examinations and tests as defined in topical Report 203 are also covered in this section.Section 4, Containment Surface Examinations, describes the examination process, discusses examination findings and includes evaluations of conditions that do not meet acceptance criteria.
Containment surface follow-up examinations as defined in Topical Report 203 are also covered in this section.Section 5, Repairs and Follow-Up Examinations, is a summary list of required repair work and damage / deteriorated area re-examinations to be performed during the 4 5 th year surveillance.
Section 6, Conclusions, summarizes overall conclusions regarding containment integrity as demonstrated by the Surveillance.
Section 7, References, identifies the documents that govern the performance of the Surveillance and are cited in this report.Attachment 1, Engineering Technical Evaluations and Issue Reports, includes the issue reports written for conditions found during Surveillance activities and their evaluations.
Attachment 2, Final Report for the Three Mile Island Unit 1 4 0 th Year Containment Building Tendon Surveillance, is the Vendor Surveillance Report complete with data sheets and applicable procedures.
Attachment 3, Exelon Approval of PSC Procedures and Personnel, provides the designation of the Responsible Engineer, approval of the PSC Surveillance procedure, and approval of the PSC quality control personnel.
Topical Report No. 213 Revision 0 Page 6 of 49 2.
SUMMARY
OF WORK PERFORMED AND INSPECTION RESULTS The work performed during the 4 0 th year surveillance and the results of these examinations and tests are summarized in 2.1 and 2.2 below.2.1 Work Performed The 4 0 th year surveillance consisted of testing and visual examination of a randomly selected sample of post-tensioned tendons and a visual examination of the accessible containment exterior.2.1.1 Sample Selection Sub-Section IWL requires that tendons impacted by repair / replacement activities be treated as a separate population for sampling and examination purposes.
This population includes those tendons (subsequently identified-as SGR tendons) that were de-tensioned
/ re-tensioned or replaced in 2009 to accommodate the access opening for installation of new steam generators.
SGR tendons are sampled and examined as required by Subsection IWL-2521.2 and Table IWL-2521-2.
The remaining tendons are sampled and examined in accordance with Subsection IWL-2520.The SGR tendons are H46-28 through H46-42 inclusive, H51-28 through H51-42 inclusive and V113 through V1 57 inclusive for a total of 30 hoops and 45 verticals.
Table IWL-2521-2 specifies that at least 4% of each type, hoop or vertical, be examined during the first two inspections following the repair /replacement work. The 4 0t year ISI was the 2 nd inspection, the first being the augmented inspection in 2010. Consequently, 2 vertical and 2 hoop SGR tendons were selected for examination during this ISI. The SGR tendons consist of both de-tensioned/re-tensioned and replacement tendons, and as good practice one tendon from each of these populations was included in both the vertical and horizontal group selection.
The non-SGR tendon group sample size is, as specified in Table IWL-2521-1, the lesser of 5 tendons or 2% of the non-SGR population but at least 3 tendons, with one tendon in each group being the previously designated control tendon and the remainder randomly selected.
The 4 0 th year Surveillance included additional tendons identified for follow-up examination during previous surveillance reports.The following table lists, for each group, the total number of tendons, the number of SGR tendons, the number of non-SGR tendons and the corresponding minimum required sample sizes.0 Topical Report No. 213 Revision 0 Page 7 of 49 Table I -1: Number of Tendons and Sampling Requirements
- Group Vertical Hoop Dome Number of Tendons in Group 166 330 147 Number of SGR Tendons 45 30 0 Number of Non-SGR Tendons 121 300 147 SGR Tendon Sample Size 2 2 0 Non-SGR Tendon Sample Size 3 5 31 Discussion of the specific tendon selection is covered in Section 3.One tendon in each non-SGR group and one in each of the SGR groups were randomly selected from among the non-control tendons for de-tensioning and removal of a wire for tensile testing. As a good practice, one of the SGR tendons selected for wire removal was from the new tendon population and the other from de-tensioned/re-tensioned population.
In addition to the sample tendons discussed above, the following tendon end anchorages were designated for limited examination (reasons noted)." V-84: The tendon gallery end anchorage was examined for bearing plate corrosion in accordance with the Topical Report 203 (Reference 28)follow-up actions. As the end cap had to be removed for this activity, a complete visual examination of anchorage components was done and corrosion protection medium (CPM) samples were taken and tested." H42-47: The Buttress 2 end cap gasket was replaced.
Examination activities were limited to observations for free water and to ensure complete CPM coverage of anchorage components prior to cap re-installation.
2.1.2 Post-Tensioning System Examinations and Tests Examinations and tests consisted of the following activities, with exceptions as noted. These were performed in accordance with TMI Surveillance Procedure 1301-9.1, in addition to Exelon Corporate Procedures ER-AA-330-005, ER-AA-330-006, ER-AA-335-001 and ER-AA-335-019, which incorporate the applicable requirements of the 2004 Edition (no Addenda) of the ASME Boiler and Pressure Vessel Code, Section Xl, Subsection IWL and the additional requirements specified in 1OCFR50.55a(b)(2)(viii).
The surveillance procedures also incorporate applicable requirements from the UFSAR. The actual implementation of surveillance activities is conducted in accordance with the approved vendor procedures.
1 Four (4) dome tendons were selected for examination during the 40th Year Surveillance Topical Report No. 213 Revision 0 Page 8 of 49" Collection of corrosion protection medium (CPM) samples from both ends of each tendon (samples are not taken if an end cap is removed solely for the purpose of gasket repair) and laboratory tests conducted to determine water content, concentration or corrosive ions (chlorides, nitrates, and sulfides), and reserve alkalinity (base number). Further tests are conducted for the acid number where the base number is determined to be below the reporting threshold of 0.50." Visual examination of end anchorage hardware (button heads, anchor heads, shims and bearing plates) and concrete within 2 feet of the bearing plate edge.* Measurements of end anchorage force using the Lift-Off procedure described in Surveillance Procedure 1301-9.1." De-tensioning of one tendon in each non-SGR group (vertical, hoop and dome) and each SGR group (vertical and hoop only), extraction of a test wire for visual examination and performance of tensile tests on specimens cut from the removed test wire.* Re-tensioning of the de-tensioned tendons with measurement of elongations at several loads (Pre-Tension Force (PTF), 1/3 Overstress Force (OSF), 2/3 OSF, and OSF).* Refilling of tendon ducts and end caps with CPM (the quantities of CPM removed and replaced are measured and documented).
Additionally, all tendon end anchorage covers (End Caps) were examined for damage and CPM leakage in accordance with the requirements of ASME Section Xl, Article IWL-2510(c).
2.1.3 Containment
Surface Examination The entire accessible exterior surface of the containment was visually examined in accordance with ASME Section Xl, Subsection IWL-2510 using a General Visual (defined by TMI procedure as a VT-3C) technique.
This examination was performed directly (without optical aids) and remotely using binoculars.
The tendon anchorage end caps and bearing plates were examined at the same time.The specific conduct of this inspection is governed by ER-AA-330-005, ER-AA-335-019, and the approved vendor procedures.
The concrete was examined for evidence of cracking, spalling, efflorescence and other types of damage / deterioration as identified in ACI 201.1 R (Reference 1).This examination was also focused, as specified in IWL-2510(c), on CPM seepage through the concrete.The Bearing plates were examined for detached or missing coatings and corrosion.
Topical Report No. 213 Revision 0 Page 9 of 49 Areas with possible damage or degradation as identified during general visual examination were re-examined using a Detailed Visual (defined by TMI procedure as a VT-IC) technique in accordance with IWL-2310(b).
Topical Report No. 203, Section 5.3, specifies the detailed visual examinations on concrete surfaces to be performed as follow-up examinations during the 4 0 th Year Surveillance.
The specific examinations are as follows: " The grout overlay of previously exposed reinforcing steel on the vertical face of the ring girder sector in the southeast quadrant." The tendon gallery ceiling area including base mat concrete, tendon bearing plates, and tendon end caps for evidence of CPM leakage, effects of ground water seepage on concrete and steel items, deterioration of previously documented exposed reinforcing, and other damage or deterioration.
- The lower wall, above the base mat, for evidence of increased CPM leakage through the vertical cracks.2.2 Inspection Results Summary The results of the 4 0 th Year (Period 10) Reactor Building Surveillance are summarized below.2.2.1 Post-Tensioning System The results of the post-tensioning system examinations, measurements and tests met all prescriptive acceptance criteria except as noted below. The results are summarized as follows: " All tendon forces were above 95% of predicted value. Hoop tendon H13-03 was lift-off tested from only one buttress.
This test is valid as the tendon was originally single-end stressed from the tested buttress.* The vertical, hoop, and dome tendon normalized group mean forces were above the minimum required values. As the SGR tendon forces are significantly greater than those documented for the other sample tendons, these are, for conservatism, not included in the vertical and hoop tendon group means." The 95% lower confidence limits on vertical, hoop and dome tendon force trends projected through the latest date for the completion of the 4 5 th year Surveillance are above the minimum required forces." Elongations measured during the re-tensioning of de-tensioned tendons were within 10% of the "as-installed" construction values.* End anchorage hardware items were free of active corrosion, cracking, and distortion.
Some tendons; i.e. V84, V115 and V1 36 tendon gallery bearing plates, exhibited minor rust which does not show evidence of progression (not active). A number of tendon gallery bearing plates are frequently wetted by ground water seepage between the gallery walls and Topical Report No. 213.Revision 0 Page 10 of 49 the Reactor Building base mat. This has caused minor corrosion.
There is no significant loss of metal, and at the present time, no need to take remedial action other than re-examination during the 4 5 th year surveillance." As-found button head conditions were, with 3 exceptions, as documented during construction.
Two button heads at the Buttress 4 end of H24-15 were found unseated and one buttonhead was found missing at the gallery end of SGR tendon V-1 36 (all buttonheads were intact at the top end). These conditions were deemed to have no structural significance and were accepted by evaluation.
- The tensile strength and elongation (at failure) of all wire test samples was above the minimum required values.* Water content, corrosive ion (chlorides, nitrates, and sulfides)concentration, and reserve alkalinity (base number) of all corrosion protection medium samples met acceptance criteria, except as noted below.o 9 CPM samples had base numbers less than the 0.50 reporting threshold and required further tests for their acid number.o 3 of the 10 acid number tests resulted in acid numbers in excess of the acceptance limit of 1. These 3 samples were accepted by evaluation.
- No free water was found at tendon anchorages.
5" Concrete adjacent to the tendon end anchorages was free of cracks over 0.01 inches wide.* The differences between the quantities of corrosion protection medium removed from sample tendons and the quantities replaced were, with 3 exceptions, within 10% of net duct volume. The 3 exceptions, involving"as-found" under-fill of the dome tendon ducts, were accepted by evaluation." All tendon end anchorage covers (end caps) were free of damage and, with one exception, free of corrosion.
The single exception consisted of light, dry rust covering part of a dome tendon end cap. CPM was observed to be leaking from 6 dome and 3 hoop end caps. All leakage noted was minor (estimated quantities lost on the order of 0.1 liter or less)and was deemed to require no corrective action at the present time.* Several shim pairs were found to have gaps in excess of the specified maximum, and the gaps were restored to an acceptable condition or accepted by evaluation.
Technical evaluations showed that the "as-found" reduced bearing area was sufficient to carry the maximum expected tendon load, with a bearing stress below the material allowable.
These evaluations concluded that no further examination is required at this time.0 Topical Report No. 213 Revision 0 Page 11 of 49 2.2.2 Containment Surface The Reactor Building concrete surfaces and tendon anchorage bearing plates were generally free of damage and deterioration.
Minor corrosion was noted on the V84, V115, and V1 36 bearing plates in the tendon gallery, a result of ground water seepage between the gallery outer wall and the Reactor Building base mat.As the loss of metal is not significant, remedial action, other than re-examination during the 4 5 th year surveillance, is not considered necessary at this time.Minor seepage of corrosion protection medium (CPM) through vertical cracks in the lower wall was found to be continuing at a nominal rate unchanged from that observed during the 3 5 th year surveillance.
This is expected since most of the CPM in the TMI tendon ducts is of an older formulation that liquefies at relatively low temperatures.
Most of the seepage was noted in the area below the equipment access hatch. Ducts in this area curve around the opening, and are thusly flexible and not fabricated for leak tightness.
The seepage, which has no structural significance, is monitored and corrective actions will be taken to top off the vertical tendon CPM levels when seepage rates warrant.
Topical Report No. 213 Revision 0 Page 12 of 49 3. POST-TENSIONING SYSTEM TESTS AND EXAMINATIONS The following tests and examinations were performed to assess the continuing quality and integrity of the post-tensioning system.* Measurement of tendon end anchorage forces.* Measurement of tendon elongations during re-tensioning.
- Measurement of wire test specimen strength and elongation at failure.* Chemical analysis to determine corrosion protection medium test specimen water content, reserve alkalinity (base number), and concentration of corrosive ions (chlorides, nitrates, and sulfides)." Visual examination of the post-tensioning system components, as well as the concrete adjacent to the bearing plates, to detect accumulation of free water, corrosion, deformation, cracking, wire breakage, shim gaps, and wire button head failures." Visual examination of the tendon end anchorage covers (end caps) to detect damage and corrosion protection medium leakage.All but the last of the above tests and examinations involved a small sample of the total tendon population as covered in Section 2. In accordance with ASME Section XI, Subsection IWL, Article IWL-251 0, 100% of the end caps were examined.3.1 Examination Sample Selection Five sample sets were selected for examination, from two tendon populations.
The larger population included tendons that were not de-tensioned during the 2009 steam generator replacement (SGR) outage and met the sample size requirements of Table IWL-2521.1.
The smaller population included the tendons affected by the SGR and conformed to the size requirements of Table IWL-2521-2.Tendons, except control tendons, initially selected for tests and examinations were randomly picked from populations (non-SGR and SGR) that included all tendons not examined during a prior surveillance.
Control tendons (the SGR population does not include control tendons) are common to consecutive surveillances.
The non-SGR population consists of three sample sets; vertical, hoop, and dome tendons. For the 4 0 th Year Surveillance; 3 vertical, 5 hoop and 4 dome tendons were selected.
The SGR population consists of two sample sets;vertical and hoop tendons. For the 4 0 th Year Surveillance; two vertical and two hoop tendons were selected.
As a good practice both the SGR sample sets included one de-tensioned/re-tensioned and one new tendon.The following tendons, which are listed in TMI Surveillance Procedure 1301-9.1, Attachment 2, were included in the initially selected samples. Control tendons and new SGR tendons are identified by the notations
'(control)'
or '(new)'following the tendon number.
Topical Report No. 213 Revision 0 Page 13 of 49* Non-SGR Tendons o Verticals:
V-32 (control tendon), V-108, V-159 (wire)o Hoops: H13-03 (wire), H13-08, H24-15, H35-02, H62-26 (control tendon)o Domes: D-143, D-225 (control tendon), D-237 (wire), D-303* SGR Tendons" Verticals:
V-115, V-136 (new, wire)o Hoops: H46-34 (new), H51-40 (wire)One tendon in each non-SGR group and one in each of the SGR groups was randomly selected from among the non-control tendons for de-tensioning and removal of a wire for tensile testing. These are identified above by the notation'(wire)' following the tendon number. As a good practice, one of the SGR tendons selected for wire removal is new and the other is de-tensioned/re-tensioned.
Of the non-SGR tendons listed above, two hoops and one dome were determined to be inaccessible at one end. Each was replaced in the sample by the nearest undisturbed (i.e., not yet subjected to lift-off), fully accessible tendon.The replaced tendon was examined to the extent practical as specified in Section Xl, Subsection IWL-2521.1.
The basis for declaring the tendon inaccessible and designating a replacement tendon is as follows:* H13-08: Access to the Buttress 3 end of this tendon is partially obstructed by the Reactor Building Flood Seal. The flood seal is not removable.
The Buttress 3 end of H13-07 falls within the concrete cut-out in the floor and does not allow access of a stressing ram. The flood barrier, which was located directly below the Buttress 3 anchorage of H13-09, prevented installation of a ram at this location.
The nearest undisturbed and fully accessible tendon is H13-10, and was designated as the replacement tendon for H 13-08." H24-15: Access to the Buttress 4 end of H24-15 was restricted by safety related conduit and piping in the immediate area. Two additional considerations were that the transport of the stressing ram to the tendon buttress was impaired by safety related motor control centers (MCC), and that the dose rates in the area were high when the safety related equipment was not required to function due to fuel movements.
Due to the high dose rates and concern for repositioning/damaging safety related components, it was determined that the Buttress 4 end of H24-15 and the adjacent anchorages in the seal injection room were inaccessible for ram installation.
The first tendon adjacent to H24-15 outside of the seal injection room was H24-18. This tendon was determined to be inaccessible on the Buttress 4 end due to interferences with the Auxiliary Building roof. Tendon H24-19, H24-20, and H24-21 were all tested during Topical Report No. 213 Revision 0 Page 14 of 49 previous surveillances.
The closest undisturbed replacement tendon for H24-15 was determined to be H24-22.D-143: During surveillance activities it was determined that stressing ram access to one end of tendon D-143 was obstructed by a permanently mounted seismic monitor. The nearest undisturbed and fully accessible tendon was found to be D-146, which was designated as the replacement tendon. D-145 and D-141 were tested in previous surveillances, and D-142 and D-144 had the same interference as D-143.In addition to the above, the following tendons were designated for examination or corrective action at the end anchorages." V-84: The tendon gallery end anchorage was examined for bearing plate corrosion in accordance with a Topical Report 203 (Reference
- 28) follow-up action. As the end cap had to be removed for this activity, a complete visual examination of the anchorage components was performed and corrosion protection medium (CPM) samples were taken and tested.* H42-47: The Buttress 2 end cap gasket was replaced to eliminate CPM leakage. Examination activities were limited to ensuring complete CPM coverage of anchorage components prior to end cap re-installation.
3.2 Tendon
Forces Tendon end anchorage forces were measured using the lift-off technique described in Surveillance Procedure 1301-9.1.
The actual performance of lift-offs was conducted in accordance with the approved vendor procedures.
Forces were measured at both ends of hoop (except as noted) and dome tendons and at the top end of vertical tendons.Acceptance criteria cover individual tendon forces, and for the non-SGR tendons, group mean forces and projected group mean force trends. The SGR tendons were recently tensioned to a nominal 70% of the Guaranteed Ultimate Tensile Strength (GUTS) lock-off force and have current lift-off forces well above those of the non-SGR tendons. Therefore the SGR tendon lift-off forces are excluded from group mean forces and the group mean force trends. Individual tendon forces, group mean forces, group mean force trends, and the associated acceptance criteria are discussed in the following sections.3.2.1 Individual Tendon Forces Table 3-1 lists the measured end anchorage forces, average tendon forces, predicted forces, and the lower acceptance limits (there is no stated upper acceptance limit) for non-SGR tendon population.
Table 3-2 lists this information for the SGR tendon population.
The lower acceptance limit is equal to 95% of the tendon's predicted force. Predicted forces are documented in Calculation C-1101-153-E410-046.
Topical Report No. 213 Revision 0 Page 15 of 49 Measured End Anchorage and Predicted Forces for Non-SGR Tendons Table 3 -1: Tendon "d .. Meisuired Mean End Predicted" 95% of Predicted Force, kip ,. orce, KiFo p ,Force, kip Force, kip rc -kip Force, k ,..V32 Top 1,181 1,181 1,176 1,117 V108 Top 1,225 1,225 1,155 1,097 V159 Top 1,154 1,154 1,149 1,092 B-1 1,230 H13-03 /A 2 N/A 1,141 1,084 B-3 N/A B-1 1,140 H 13-10 1,150 1,097 1,042 B-3 1,161 B-2 1,143 H24-15 B-2 j_1,143 _ N/A 1,073 1,019 B-4 N/A 3 B-2 1,136 H24-22 1,161 1,137 1,080 B-4 1,186 B-3 1,216 H35-02 1,216 1,093 1,038 B-5 1,216 B-6 1,117 H62-26 1,126 1,099 1,044 B-2 1,136 S 1,219 D143 N/A 1,153 1,095 E N/A 4 S 1,173 D146 1,184 1,110 1,055 E 1,195 W 1,099 D225 1,106 1,061 1,008 E 1,114 W 1,191 D237 1,167 1,088 1,034 SE 1,144 N 1,181 D303 1,200 1,142 1,085 SE 1,219 2 Lift-off force at the B-3 end of H31-03 not measured.3 B-4 end of H24-15 not accessible for lift-off measurement.
4 East end of D143 not accessible for lift-off measurement.
Topical Report No. 213 Revision 0 Page 16 of 49 Table 3 -2: Measured End Anchorage and Predicted Forces for SGR Tendons Tendon E.. nd Measured Mean End Predicted 95%:of Predicted Teo Ed Force, kip Force, kip Force; kip' Forcekip.V115 Top 1,378 1,378 1,306 1,241 V136 Top 1,335 1,335 1,311 1,245 B-4 1,457 H46-34 1,397 1,232 1,170 B-6 1,338 B-5 1,286 H51-40 -_1,341 1,198 1,138 B-I 1,396 Hoop and dome tendon forces are, with three exceptions (H13-03, H24-15, D143) computed as the average of both end anchorage lift-off measurements.
Vertical tendon forces are documented as the force measured at the top end; the gallery end force is not measured.Sample tendon H13-03 is one of 14 hoop tendons that were originally tensioned from a single-end during construction.
Due to a miscommunication during the surveillance, H13-03 was de-tensioned from the Buttress 1 end prior to performance of a lift-off on the Buttress 3 end. Therefore, the force in this tendon is reported as two values. One is the lift-off force measured at Buttress 1. The other is the mean force determined using the "as-found" shim stack heights and re-tensioning (this tendon was de-tensioned for wire removal) elongations.
The mean force calculation is documented in Technical Evaluation 1645620, included in Attachment 1.The H13-03 predicted forces are based on the initial lock-off force documented for the Buttress 1 end in construction records. Therefore, the single end anchorage force measured at Buttress 1 is used in the assessment of current force against predicted value as shown in Table 3-1. The current and projected group means are based on the mean force computed using shim stack height and re-tensioning elongations.
The Technical Evaluation compares the computed average pre-stress force to a modified version of the predicted force to demonstrate the average force is within expected limits.As previously discussed, hoop tendon H24-15 was determined to be inaccessible for lift-off at the Buttress 4 end, and was replaced by an alternate tendon H24-22.H24-15 was single-end tensioned during construction from the Buttress 2 end; it was determined to be in keeping with the intent of ASME Section Xl Subsection IWL to measure the anchorage force at Buttress 2. This lift-off value is for information only, and provides assurance that the tendon's pre-stressing force is not degraded.As shown in Tables 3-1 and 3-2, all tendon forces (including that listed for the Buttress 2 end of H24-15) exceed predicted values and are well above the lower acceptance limit (95% of predicted value). H13-03 meets the acceptance criteria Topical Report No. 213 Revision 0 Page 17 of 49 as discussed above. This demonstrates that the predictions for individual tendon forces are based on a conservatively high estimate of overall time dependent losses resulting from the combined effects of concrete creep, concrete shrinkage, and tendon wire stress relaxation.
3.2.2 Group
Mean Forces As previously discussed, SGR tendon forces are well above those in the remaining tendons, and are thusly not included in the vertical and hoop tendon group mean forces.The mean force in each group of tendons must be equal to or greater than the minimum required force for the group as stated in section 9.3.1 of Surveillance Procedure 1301-9.1.
The minimum required force values are:* Vertical Tendons: 1,033 kip* Hoop Tendons: 1,108 kip* Dome Tendons: 1,064 kip During construction of the containment, individual tendons were tensioned to anchorage forces between 70% and 74% of GUTS. Differences in initial seating force are expected to be reflected in the lift-off force measured throughout the life of the structure.
Also, as tendons were tensioned in sequence, force in any tendon falls (elastic shortening loss) during the subsequent tensioning of tendons in the same group.Surveillance samples are quite small, nominally 2% of the tendons in each group.For this reason, there is a relatively high probability that the samples will consist of tendons initially tensioned to the high end or the low end of the acceptance range and / or tendons tensioned close to the beginning of the sequence or end of the sequence.
Consequently, the sample mean force calculated using measured end anchorage forces has a high probability of deviating significantly from the true group mean.Therefore, measured forces are adjusted (normalized) to account for initial tensioning force and stressing sequence.
Calculation C-1101-153-E410-046 describes the normalization procedure and lists the adjustments for all TMI tendons.Table 3-4 lists average tendon forces, adjustments, normalized forces, and the group mean normalized forces. The individual tendon forces, other than that for H13-03 are those shown in Table 3-1. The 1,076 kip force listed for H13-03 is the mean value computed in previously cited Technical Evaluation 1645620. As noted above, group mean value computations exclude SGR tendon forces which are, as shown in Table 3-1, all significantly above those listed for non-SGR tendons. Also, the group means exclude the H24-15 and D143 single-end lift-offs, which were measured and reported in Table 3-1 for information only. All Topical Report No. 213 Revision 0 Page 18 of 49 group mean normalized forces are above the minimum required values as summarized in Table 3-3.Table 3 -3: Group Mean vs. Minimum Mean Force Group MeaIn Normalized Force (kips) Minimum Required Mean (kips)Vertical 1,195 1,033 Hoop 1,133 1,108 Dome 1,170 1,064 Table 3 -4: Normalized Tendon and Group Mean Forces Tendon Measured force, kip Adjustment, kip Normalized force, kip V32 1,181 -7 1,174 V1 08 1,225 14 1,239 V159 1,154 20 1,174 Vertical Group -Mean Normalized Force 1,195 Tendon Measured force, kip Adjustment, kip Normalized force, kip-.H 13-03 -40 1,036 H13-10 1,150 4 1,154 H24-22 1,161 -37 1,124 H35-02 1,216 8 1,224 H62-26 1,126 2 1,128 Hoop Group -Mean Normalized Force 1,133 Tendon Measured force, kip, .Adjustment, kip Normalized force, kip D146 1,184 -4 1,180 D225 1,106 45 1,151 D237 1,167 19 1,186 D303 1,200 -35 1,165 Dome Group -Mean Normalized Force 1,170 3.2.3 Projected Group Mean Forces ASME Section Xl, Subsection IWL-3221.1(c) requires projecting the trends of tendon forces to determine whether or not group means are expected to remain 5 Computed mean as discussed in Section 3.1 Topical Report No. 213 Revision 0 Page 19 of 49 above the minimum required values until the time of the next scheduled surveillance.
Topical Report No. 136, which documents the results of the 2 5 th year surveillance, develops the procedure used to extrapolate tendon force trends. As explained in that report, the projection uses the tendon force data acquired during the 1 0th year and later surveillances.
It does not use data from the 1 st, 3 rd, and 5 year surveillances for two reasons. First, the trends of the forces measured during those early surveillances appear to differ significantly from the trends established by the data recorded during the later surveillances.
Second, the later (1 0 th year forward) surveillances are more completely documented, which ensures that the correct force values are used in trend development.
As discussed in Topical Report No. 136, the force data for all three groups exhibit a considerable degree of scatter. As a result, fitted lines or curves do not necessarily provide meaningful representations of force trends. Therefore, the forecasted forces are not determined as the ordinates of the regression curves, but are reported as the 95% lower confidence levels computed using the postulated log-linear relationship between force and time. The basis for using the confidence level approach is extensively discussed in the cited topical report.Figures 3-1, 3-2, and 3-3 are log-linear plots for the vertical, hoop, and dome group tendon forces measured from the 1 0 th year through the latest surveillance.
The data scatter, which is typical, is evident in these plots. The plots include log-linear trend lines for reference; however, the magnitude of the scatter is such that these fitted trends cannot necessarily be considered meaningful (note that the hoop tendon trend, Fig 3-2, shows force increasing with time). The Lower Confidence Limit (LCL) values are also displayed on the plots.
Topical Report No. 213 Revision 0 Page 20 of 49 Table 3 -5: Summary of Vertical Tendon Forces Surveillance YearI Sincet SIT, Years- Tendon' Force, kipo V14 1,243 V30 1,193 10 11.2 V32 1,196 V84 1,189 V160 1,192 V19 1,187 V21 1,196 V22 1,171 15 15.6 V23 1,175 V50 1,213 V83 1,196 V85 1,179 V32 1,210 20 20.6 V78 1,306 V126 1,209 V32 1,193 25 25.5 V40 1,202 V114 1,189 V164 1,181 V32 1,190 V53 1,222 V66 1,178 V137 1,218 V140 1,144 V141 1,207 V11 1,206 V32 1,175 V90 1,200 V132 1,206 V32 1,181 40 39.6 V108 1,225 V159 1,154 Topical Report No. 213 Revision 0 Page 21 of 49 1350 1.300 1 250-X1 200 -U-.1 150 0 U.1 100 1 050 1 00 20 25 30 35 Ln (T, Years Since SIT)Figure 3 -1: Vertical Tendon Force Projection Table 3 -6: Summary of Hoop Tendon Forces 40 45 Surveillance Year Time Since SIT, Years Tendon Force, kip H13-35 1,191 H 13-36 1,066 H13-37 1,182 10 11.2 H24-26 1,173 H35-26 1,156 H62-26 1,145 H62-30 1,152 H24-29 1,072 H24-30 1,139 H24-31 1,114 15 15.6 H24-51 1,142 H46-34 1,177 H62-13 1,088 H62-26 1,128 Topical Report No. 213 Revision 0 Page 22 of 49 SuriVeillance Year Time Since Years Tendon H24-40 1,132 H35-23 1,200 20 20.6 H35-47 1,192 H62-26 1,161 H62-49 1,163 H13-50 1,159 H35-33 1,169 25 25.5 H46-37 1,129 H51-43 1,170 H62-26 1,136 H13-11 1,218 H35-49 1,201 30 30.6 H46-25 1,121 H62-18 1,105 H62-26 1,120 H13-41 1,151 H24-33 1,123 35 35.6 H46-50 1,131 H51-49 1,154 H62-26 1,141 H13-03 1,076 H13-10 1,150 40 39.6 H24-22 1,161 H35-02 1,216 H62-26 1,126 Topical Report No. 213 Revision 0 Page 23 of 49 11.250 1 200_l 150 U.tLA 1 100 1 050 20 40 25 30 35 Ln (T, Years Since SIT)Figure 3 -2: Hoop Tendon Force Prediction Table 3 -7: Summary of Dome Tendon Forces Surveillance Year Time Since SIT, Years Tendon Force, kip D133 1,107 10 11.2 D225 1,125 D314 1,290 D145 1,220 15 15.6 D347 1,183 D141 1,164 20 20.6 D225 1,120 D248 1,202 D102 1,280 25 25.5 D225 1,104 D313 1,120 D213 1,094 30 30.6 D225 1,120 D230 1,149 Topical Report No. 213 Revision 0 Page 24 of 49 D122 1,119 D225 1,088 35 35.6 D322 1,135 D342 1,150 D146 1,184 D225 1,106 40 39.6____D237 1,167 D303 1,165 1 .350 1 300 1 250 1,200 1,150 0 UL 1,100 1 050 1 000 20 2.5 30 35 40 Ln (T, Years Since SIT)Figure 3 -3: Dome Tendon Force Prediction 4.5 S Topical Report No. 213 Revision 0 Page 25 of 49 The tendon forces listed in Tables 3-5, 3-6 and 3-7 (and plotted in Figures 3-1 through 3-3) are used to compute 95% lower confidence limits projected through March 2020 (46 years after the SIT and the latest date for the completion of Surveillance 11). These limits, also plotted in Figures 3-1, 3-2 and 3-3, were 6 computed using the following procedures.
LCL(X)= (a0+b) (X-tO.0 5 , 2) (Se) 1+ "[X-X ]2)Where, with all summations from 1 to n: 1. LCL(X) is the lower confidence limit on Y at an abscissa value of X.2. a is the intercept of the least squares fit trend line a=(Ym-b)Xm n XM= xi Xm=-n 3. Xi and Yi are data sets where: X i = In(ti) and Yi = tendon force (kips)4. b is the slope of the least squares fit trend line b =SX-, 5. to.0 5 , n-2 is the t statistic for a 95% confidence level and (n-2) degrees of freedom 6. Se is the standard error of the estimate Se = [tsn(ng- 2)Sx]6 The procedure shown is that developed in Reference
- 15. The 95% LCL's on the projected means for the three groups are above the minimum required values, which provides a significant degree of confidence that actual mean forces will be above minimum required levels in March 2020 (T = 46 years), the latest date for completion of the 4 5 th Year Surveillance.
Topical Report No. 213 Revision 0 Page 26 of 49 7. n is the number of data sets used in the LCL Calculation Sy n~X I (xi)2= nI(XiY 1) -[( x 1) (Y3]The lower confidence limits (LCL's) on group means at T = 46 years and the corresponding lower limit on group mean are listed below.Table 3 -8: 95% LCL vs. Minimum Mean Force Group 95% LCL on GroupMean, kip Lower Limit, kip.Vertical 1,178 1,033 Hoop 1,129 1,108 Dome 1,079 1,064 Vertical, hoop and dome LCL forces at T = 46 years are above are above the corresponding lower limits. This supports the conclusion that actual group mean forces will continue to be acceptable through the period ending in March 2020, the latest date for completion of the 4 5 th year surveillance.
Topical Report No. 213 Revision 0 Page 27 of 49 3.2.4 Control Tendon Force Trends One tendon in each group is designated as a control tendon and is, barring exceptional circumstances, included in each consecutive surveillance sample to provide information on the time dependent behavior of individual post-tensioning elements.
Control tendons are not de-tensioned.
The control tendons and consecutively measured (not normalized) forces are listed in the table below.Prior to the 1 0 th year surveillance, all sample tendons were de-tensioned and re-tensioned; control tendons were not designated until after the 5 th year surveillance.
As previously stated, the SGR sample groups do not include control tendons.Table 3 -9: Control Tendon Forces , ..:~~~oSurveillance Year I Period Tendon. ..... =.. ... .. .1 oth:f .ýj 81h. / 5 20t" ...... 'tth /7 30. /8 1Wl 9 40"oth 10 V-32 1,196 N/A 1,210 1,193 1,190 1,180 1,181 H62-26 1,145 1,128 1,161 1,136 1,120 1,148 1,126 D-225 1,125 1 N/A 1,120 1,104 1,120 1,093 1,106 There is no clear trend to the above forces, which fluctuate in a random manner over a relatively narrow range. The fluctuations, which probably result from temperature changes, tendon force redistribution and small measurement errors, tend to mask the expected trend (a slow, linear decrease with the logarithm of time).The measured forces, measured force trend line (log-linear fit to the force data)and predicted force trend line are shown for each of the control tendons in Figures 3-4 through 3-6. These plots exhibit the following consistent features.* Trend lines fitted to the measured forces all have flatter slopes than the predicted force trend lines and, as expected, all fitted trend lines have negative slopes.0 4 0 th year surveillance measured forces are above predicted values.* The log-linear trends of measured forces are above the predicted force trends, both at the time of the 4 0 th year surveillance and at all future times.
Topical Report No. 213 Revision 0 Page 28 of 49 1,300 1,250 a.0 1,200 1,150 1,100 1,050 1,250 1,200 1,150 2L 1,100.0 1,050 1,000 10 100 Time, T, Years Since SIT (log scale)Figure 3 -4: Vertical Control Tendon V-32 10 100 Time, T, Years Since SIT (log scale)Figure 3 -5: Hoop Control Tendon H62-26 Topical Report No. 213 Revision 0 Page 29 of 49 1,250 1,200 1,150 1,100 0: 0.1,050 1,000 1u 100 Time, T, Years Since SIT (log scale)Figure 3 -6: Dome Control Tendon D-225 These plots provide a positive indication that tendon forces are currently decreasing at a lower than expected rate and support the conclusion that mean tendon forces will remain above minimum required values, through March 2020, the latest date for completion of the 4 5 th year surveillance.
3.3 Tendon
Elongations and Re-Tensioning One tendon in each group for both populations (non-SGR and SGR) was de-tensioned to allow removal of a wire for testing. Tendon elongations were measured during the subsequent re-tensioning and compared to original construction values to verify that the tendons were intact and that there were no obstructions to tendon motion within the ducts. Following the elongation measurements at Overstress Force (OSF), nominally 80% of GUTS, each tendon was seated, in accordance with Subsection IWL requirements, at a force between that predicted for the time of the surveillance and 70% of GUTS, except for vertical tendon V-136 (IR 1569458).Tendons V-136 (SGR), V-159, H13-03, H51-40 (SGR) and D-237 were de-tensioned for wire removal.
Topical Report No. 213 Revision 0 Page 30 of 49 3.3.1 Elon-gations Elongations measured during initial tensioning and re-tensioning are normalized to account for differences between the pre-tension force (PTF) and over stress force (OSF) applied during original construction or SGR work, those applied during the 10thsurveillance, and differences in the number of wires (one was removed from each tendon for testing prior to re-tensioning).
Normalizing construction (or SGR) and surveillance values in this manner allows for the direct comparison of the elongations regardless of differences in PTF, OSF, and number of wires. Normalized elongations are expressed as inches per kip per wire.Elongations are acceptable if:-0.1 < dR = (A2-A"i)
_ 0.1, where: An1 1. An1 is the normalized elongation determined for original stressing 2. An 2 is the normalized elongation determined for re-tensioning
- 3. dR is the fractional difference of the normalized elongation The pertinent information from initial construction tensioning and the 40th year surveillance re-tensioning is tabulated for each of the sample tendons below.These tabulations also list the calculated normalized elongation rates. Original stressing data is as listed on the tendon stressing cards completed during construction and maintained as permanent plant records.Table 3 -10: Tendon Elongation Tendon Time Frame Parameter
_'Td__V-436 V-159 H13-03 H5140 D-237 Original Fosf, kip 1,587 1,473 1,593 1,589 1,519 Construction dosf, in 15.3 Note 1 Note 1 18.0 6.6 or Fptf, kip 199 208 208 200 208 SGR dptf, in 4.3 Note 1 Note 1 7.3 16.0 as Wires, N, 169 169 169 169 169 Applicable Fosf -Fptf, kip 1,388 1,265 1,385 1,389 1,311 from Stressing dosf-dpff, in 11.0 12.3 9.8 10.7 9.4 Cards Ani, in / (kip / wire) 1.34 1.64 1.20 1.30 1.21 Note 1: Only the difference (net elongation) between individual dosf and dptf values is shown on the V-159 and H13-03 stressing cards. Individual dosf and dptf values are not listed.
Topical Report No. 213 Revision 0 Page 31 of 49ýTendon, Time Frame Parameter
'H13 V-136 V \&59. H13-03 V-136 D-237 Fosf, kip 1,567 1,463 1,463 1,583 1,509 dosf, in 16.0 18.3 18.0 19.0 14.6 Fptf, kip 197 206 207 199 201 2013 dptf, in 4.0 6.0 8.5 8.7 5.6 Surveillance Wires, Nw 167 168 168 168 168 Fosf- Fptf, kip 1,370 1,257 1,256 1,384 1,308 dosf- dpff, in 12.0 12.3 9.5 10.3 9.0 An 2 , in / (kip/ wire) 1.46 1.64 1.27 1.25 1.16 dR = (An 2-AnA)/Anl 1J0.090 1J0.000 1j0.058 -0.038 -0.041 In the above table: 1. Fos is the overstress force (two end average for hoop and dome tendons)2. dosf is the overstress reference distance (two end sum for hoop and dome tendons)3. Fptf is the pre-tension force (two end average for hoop and dome tendons)4. dptf is the pre-tension reference distance (two end sum for hoop and dome tendons)5. An is the normalized elongation
= (dosf -dptf) X Nw / (Fosf -Fptf)All of the above dR values are between the limits of-0A1 and +0.1 and are acceptable.
Tendon H13-03 was single end tensioned during construction but re-tensioned at both ends during the surveillance.
3.3.2 Re-Tensioning After elongations at OSF were measured, tendons (with the exception of V-1 36)were reseated at forces between those predicted for the time of the surveillance and 70% of specified minimum ultimate strength in accordance with Subsection IWL-2523.3.
Final lock-off forces documented in the surveillance data sheets are listed below with the applicable lower and upper limits.
Topical Report No. 213 Revision 0 Page 32 of 49 0 Table 3 -11: Tendon Re-Tensioning Lower Limit Upper Limit'Tendon Lock-Off Force (kips)Predicted Force (kips) 70% GUTS (kips)V-1 36 1,315 1,414 1,377 V-159 1,149 1,205 1,385 H 13-03 1,141 1,272 1,385 H51-40 1,211 1,368 1,385 D-237 1,088 1,224 1,385 All final lock-off forces except that documented for V-1 36, are between the specified limits. The V-1 36 lock-off force of 1,414 kip, equivalent to 72% GUTS, resulted from an incorrect interpretation of the procedural requirements as summarized on the data sheet. The responsible engineer evaluated the out of range force, and as the lock-off was below the 74% GUTS upper limit allowed when this tendon was tensioned during the SGR outage, concluded that it could be left "as-is". Resolution of the procedure deviation and the SGR tensioning force limits are documented in IR 1569458 (Attachment
- 1) and SGR Calculation 38455-CALC-C-008 (Reference 31), respectively.
3.4 End Anchorage Condition All sample tendon end anchorages except the H13-08 Buttress 3 anchorage which is partially encased by the Reactor Building flood seal, were visually examined for evidence of corrosion, physical damage, missing buttonheads, unseated buttonheads, and the presence of free water. In addition, concrete surrounding each anchorage was examined out to a distance of two feet beyond the bearing plate edge (or to the edge of the adjacent bearing plate if closer than 2 ft) to detect cracks >0.01 inches in width, spalls, and other indications of damage or deterioration.
Examination acceptance criteria and the inspection results are listed below.These cover all Surveillance tendon end anchorages, including V-84 Gallery, except H 13-08 Buttress 3.3.4.1 Corrosion* Acceptance Criterion No evidence of active corrosion Topical Report No. 213 Revision 0 Page 33 of 49* Examination Results No corrosion was found on wires 7 , buttonheads, or stressing washers.Small patches of light, dry, tightly adhering rust was observed on a few shims and bearing plates. All documented rust patches were acceptable by examination; i.e., none required evaluation.
3.4.2 Physical
Damage" Acceptance Criterion Anchor heads, shims and bearing plates are free of cracks, deformation, and other signs of physical damage.* Examination Results No cracks, deformation, or other signs of physical damage were found.3.4.3 Missing Button Heads" Acceptance Criterion No missing button heads not previously documented (no specific criterion set for button heads that detach during surveillance operations)." Examination Results End anchorage examinations uncovered only one missing buttonhead, which is documented as a missing wire at the V-136 gallery end (all buttonheads were present at the top end). The data sheet documenting the condition of this anchor head at the completion of pre-stressing during the SGR outage, notes that there are 169 seated wires. Therefore, it was concluded that the buttonhead detached while in service (a rare but not unknown event), allowing the wire to pull through the anchor head.The CPM drained from the end cap and tendon duct during surveillance activities, was heated and strained.
The buttonhead was not recovered, and due to its size (-0.25 inch diameter), could have been caught in and discarded with the cleaning cloths used to remove CPM from the anchorage components after end cap removal.The condition was evaluated and determined to be acceptable as documented in IR 1567224 (Attachment 1).7 Short segments of some wires were visible when tendons were de-tensioned for wire removal Topical Report No. 213 Revision 0 Page 34 of 49 3.4.4 Unseated Button Heads" Acceptance Criterion No unseated buttonheads not previously documented (no specific criterion set for buttonheads that are unseated following re-tensioning).
- Examination Results End anchorage examinations uncovered only two unseated buttonheads, both at the Buttress 4 end of H24-15. One was estimated to be 0.2 inches off of its seat and the other 0.3 inches. These were not noted in the original construction records. All buttonheads at the Buttress 2 end were found fully seated.H24-15 was a single-end tensioned tendon, and the original stressing was performed from the Buttress 2 end. As the tendons are twisted at the time of fabrication to enhance strain equalization among the wires, it is possible that near the Buttress 4 end, the force was transferred to the protruding wires through friction resulting from the twist and the buttonheads did not seat. This is a phenomenon that is occasionally seen in 2400 hoop tendons tensioned at both ends (TMI tendons span a nominal 1200).An engineering evaluation concluded that the condition is acceptable as-found and that there is no need for a continuity test to demonstrate that the unseated wires are intact. The evaluation is documented in IR 1565440 (Attachment 1).3.4.5 Free Water" Acceptance Criterion No evidence of free water inside the end cap, on anchorage components, or CPM enclosed by the cap.* Examination Results End anchorage examinations uncovered no evidence of free water either inside the end caps, on components, or CPM enclosed by the caps.3.4.6 Concrete Within Two Feet of Bearing Plate" Acceptance Criterion No concrete cracks wider than 0.01 inches.* Examination Results End anchorage concrete examinations uncovered a number of minor shrinkage cracks radiating from the corners of bearing plates. All were reported as less than 0.01 inches wide and are acceptable.
Topical Report No. 213 Revision 0 Page 35 of 49 3.4.7 Shim Gaps Acceptance Criterion During the 4 0 th Year Surveillance TMI fully implemented the guidance provided in Exelon corporate procedure ER-AA-330-006 for the first time.Previous surveillances utilized only the guidance in TMI procedure 1301-9.1 for the conduct of surveillance activities and the approval of vendor procedures.
ER-AA-330-006, unlike 1301-9.1, provides acceptance criteria for the maximum shim gap. Shim gaps, while observed, were not measured and recorded in previous surveillances.
ER-AA-330-006 specifies the following: "The gap between shim halves for the first set of shims under anchorhead shall not exceed an average of 0.25". A maximum gap of 0.50" is acceptable at one gap location if other side of shim halves is in contact. The remaining shims are allowed a maximum gap of 0.50" at each location of shim halves." Examination Results Gaps in excess of the allowable 0.25 inch average were found at the following anchorages:
H24-22: Documented in IR 1567897 (included in Attachment 1), the shims were found with a 1 inch gap on the top and in contact on the bottom. This shim gap was restored to the ER-AA-330-006 acceptable limits and evaluated for "as-found" acceptance in order to determine past operability.
No further actions were required.H13-08: Documented in IR 1579266 (included in Attachment 1), the shims were found with a 1 inch gap on the top and in contact on the bottom. The shim gap was determined to be acceptable as-found.
No evaluation was performed for this tendon end as it was bounded by the H24-22 evaluation.
D-143: Documented in IR 1569980 (included in Attachment 1), the shims were found with a 1 inch gap on the top and in contact on the bottom.Efforts to reset the shim gap to the 0.25 inch allowable were unsuccessful due to interferences at the tendon anchorage.
The final "as-left" shim gap was 0.5 inches on top and 0.25 inches on bottom (average gap of 0.375 inches). Both the "as-found" and "as-left" shim gaps were evaluated as acceptable and no further actions were required.Technical evaluations determined that the observed over limit gaps would not result in excessive bearing stresses at the maximum expected tendon pre-stressing force. Therefore, no further inspections were required on other anchorages.
The maximum evaluated shim gaps for each tendon Topical Report No. 213 Revision 0 Page 36 of 49 group will be documented in a procedure revision prior to the next surveillance.
The evaluations are discussed in Attachment
1.3.5 Specimen
Wire Test Results A sample for wire examination and testing was removed from one sample tendon in each of the non-SGR and SGR groups. Each wire was visually examined over its entire length for corrosion, pitting, and physical damage. Test specimens were then cut from near each end and the middle of the sample wires. These were tested in accordance with ASTM A370 (Reference
- 4) to determine tensile strength and elongation at failure.The visual examinations, documented on data sheets 10.2 in Attachment 2, verified that all five specimen wires were free of corrosion, pitting, and physical damage. As no corrosion was found, there was no need to cut an additional test specimen from the most corroded section of wire as specified in surveillance procedures.
The tensile strength of all 15 test specimens exceeded the specified lower limit of 240 ksi (GUTS), and the elongations at failure exceeded the lower limit of 4%.The test results are tabulated below.Table 3 -12: Tendon Wire Test Results Tendon TestSample Tensile Strength (ksi) Elongation at Failure (%)V-136 1 262.8 4.2 SGR 2 262.0 5.4 New 3 263.4 4.7 1 249.4 5.7 V-159 2 251.6 5.0 3 253.5 4.8 1 258.9 5.8 H13-03 2 258.5 6.2 3 257.8 5.8 1 248.2 5.2 H51-40 2 249.7 5.8 SGR 3 248.8 5.0 1 259.6 5.2 D237 2 254.7 5.2 3 253.5 5.1 S Topical Report No. 213 Revision 0 Page 37 of 49 3.6 Corrosion Protection Medium Test Results Samples of corrosion protection medium (CPM) were collected from both ends of each Surveillance tendon as well as from the gallery end of V-84. Laboratory tests were performed on these samples to determine the characteristics listed (with acceptance limits) below. Surveillance procedure ER-AA-330-006 identifies the process and standardized tests used during the laboratory analysis.Table 3 -13: CPM Test Criteria Characteristic Acceptance Limit Water Content Not to Exceed 10% by weight Water Soluble Chlorides Not to Exceed 10 ppm Water Soluble Nitrates Not to Exceed 10 ppm Water Soluble Sulfides Not to Exceed 10 ppm Ry0.508 for originally installed CPM Reserve Alkalinity (Base Number) 1.foVicnrs20-P
>-1 7.5 for Visconorust 2090-P4 Table 3-14 lists the laboratory test results which are documented in the laboratory report included in Attachment
- 2. As shown in the table, 9 CPM samples had base numbers <0.50 and required an acid number test. An additional acid number test was performed on a V108 field end sample which had a base number of 0.52. Of the10 samples, 3 had acid numbers testing above the acceptance limit of 1. IR 1626566 was issued to document the acid number results, and determined that there was no current concern from the degraded CPM. Follow-up visual examinations during the 4 5 th Year Tendon Surveillance, in addition to pump-through with new CPM, will correct this issue.8 If the base number for originally installed CPM is <0.50 (the laboratory's reporting limit), then an acid number test is performed as described in ER-AA-330-006.
The acid number must be <1 to be acceptable.
Topical Report No. 213 Revision 0 Page 38 of 49 Table 3 -14: CPM Test Results.... .... ;: ' w ater En Chlorides, Nitrates, Sulfides, Content, Base Acid iTendon Ed "otet NueSlles ..Ai.PPM p .p ppm Number Number Shop <0.50 <0.50 <0.50 <0.10 53.1 N/A Field <0.50 <0.50 <0.50 0.20 <0.500 2.64'Shop N/A N/A N/A N/A N/A N/A V-84 Field <0.50 <0.50 <0.50 <0.10 1.61 N/A Shop <0.50 <0.50 <0.50 <0.10 26.9 N/A V-108 Field 0.50 <0.50 <0.50 <0.10 0.520 0.530 Shop <0.50 <0.50 <0.50 0.28 57.9 N/A Field <0.50 <0.50 <0.50 <0.10 28.4 N/A Shop <0.50 <0.50 <0.50 <0.10 45.9 N/A V-136 Field <0.50 <0.50 <0.50 0.22 35.2 N/A Shop <0.50 <0.50 <0.50 <0.10 26.3 N/A V1 59 Field 0.50 <0.50 <0.50 0.19 <0.500 <0.50 Shop 0.50 <0.50 <0.50 0.31 <0.500 <0.50 Field 0.50 <0.50 <0.50 <0.10 <0.500 0.530 H13-08 Shop 0.50 <0.50 <0.50 <0.10 <0.500 1.06'Field N/A N/A N/A N/A N/A N/A H13-10 Shop <0.50 <0.50 <0.50 0.10 1.98 N/A Field 0.50 <0.50 <0.50 <0.10 <0.500 0.530 Shop 0.50 <0.50 <0.50 <0.10 1.44 N/A H24-15 Field 0.50 <0.50 <0.50 <0.10 2.26 N/A Shop 0.50 <0.50 <0.50 0.10 <0.500 <0.50 H24-22 Field 0.50 <0.50 <0.50 <0.10 3.70 N/A H35-02 Shop 0.50 <0.50 <0.50 <0.10 2.72 N/A Field 0.50 <0.50 <0.50 <0.10 <0.500 1.06'9 Acid Numbers >1 were evaluated and accepted under IR 1626566 Topical Report No. 213 Revision 0 Page 39 of 49L ..,% ..... W ,!Chlorides, Nitrates, Sulfides, Base Acid Tendon End ppm ppm ppm Content, N H63Sh P <0.5 pM0 <0.5 <0%.1 5.Number Numb/A dShop <0.50 <0.50 <0.50 <0.10 56.4 N/A Field <0.50 <0.50 <0.50 <0.10 50.4 N/A H51-40 Shop <0.50 <0.50 <0.50 <0.10 46.6 N/A Field <0.50 <0.50 <0.50 <0.10 48.2 N/A H62-26 Shop <0.50 <0.50 <0.50 <0.10 42.1 N/A Field <0.50 <0.50 <0.50 <0.10 47.9 N/A D-143 Shop 0.50 <0.50 <0.50 <0.10 1.02 N/A Field 0.50 <0.50 <0.50 <0.10 1.02 N/A Shop 0.50 <0.50 <0.50 <0.10 2.08 N/A D-1 46 Field 0.50 <0.50 <0.50 <0.10 1.90 N/A D225 Shop <0.50 <0.50 <0.50 <0.10 38.4 N/A Field <0.50 <0.50 <0.50 <0.10 38.1 N/A D-237 Shop 0.50 <0.50 <0.50 <0.10 2.06 N/A Field <0.50 <0.50 <0.50 <0.10 34.6 N/A D-303 Shop 0.50 <0.50 <0.50 <0.10 <0.500 0.530 Field 0.50 <0.50 <0.50 <0.10 1.04 N/A 3.7 Corrosion Protection Medium Removal I Replacement
--re .. ........When CPM was removed from tendon sheathing and end anchorage areas, it was collected in containers, measured, and recorded.
After examinations were completed, new CPM was poured or pumped into the sheathing and end caps.The quantity of CPM replaced was measured and recorded for comparison.
The difference in these quantities provides the information to assess the acceptability of both the level of CPM fill prior to removal and the level following replacement.
If the amount replaced is significantly less than the amount removed, the level is low and must be increased.
If the amount replaced is significantly greater than the amount removed the condition must be evaluated to determine the reason for, and acceptability of, the "as-found" under-filled condition.
Quantities of CPM removed and replaced during the 4 0 th year surveillance are documented in Attachment 2 and listed in Table 3-15. All differences (absolute values), except as noted, are less than the 10% of the tendon net duct volume allowable difference specified in ASME Section Xl, Subsection IWL-3221.4.
Topical Report No. 213 Revision 0 Page 40 of 49 Table 3 -15: CPM Quantities Removed/Replaced o "a~rntity qQuantity Absolute.
.NetDDuct %.Rmoved (gal), Replaced (gal) Difference (gal) Volume (gal) Diff.V-32 14.0 16.4 2.4 120.4 2.3 V-84 8.0 8.8 0.8 120.0 0.7 V-108 18.5 18.6 0.1 120.3 0.1 V-115 14.0 16.4 2.4 119.0 2.0 V-136 12.0 13.3 1.3 121.6 1.1 V-159 74.0 77.8 3.8 119.9 3.2 H13-03 9.7 15.0 5.3 109.7 4.8 H13-08 4.5 5.3 0.8 110.7 0.7 H13-10 8.0 11.5 3.5 110.7 3.2 H24-15 12.0 12.9 0.9 110.9 0.8 H24-22 8.5 11.3 2.8 110.1 2.5 H24-47 3.0 5.3 2.3 110.1 2.1 H35-02 8.7 10.6 1.9 110.1 1.7 H46-34 9.8 10.6 0.8 109.8 0.7 H51-40 7.4 11.1 3.7 109.1 3.4 H62-26 10.0 11.1 1.1 110.1 1.0 D-143 19.5 70.7 51.2 85.4 60.0 D-146 15.5 63.2 47.7 81.0 58.9 D-225 8.2 10.2 2.0 97.5 2.1 D-237 20.8 65.4 44.6 92.8 48.1 D-303 9.8 11.5 1.7 80.3 2.1 The amounts of CPM replaced in dome tendons D-143, D-146, and D-237 exceeded the amounts removed by more than 10% of the net duct volume as noted in Table 3-8 and listed below.10 Gasket repair only (Buttress 2 end)
Topical Report No. 213 Revision 0 Page 41 of 49 Table 3 -16: Dome Tendons Exceeding Acceptance Limit Tendon % Differen'e D-143 60.0%D-146 58.9%D-237 48.1%The percentages noted show that there was void space in the dome tendon ducts. This condition was evaluated and concluded to be acceptable without corrective action for the following reasons: " Dome ductwork consists of Schedule 40 pipe segments with sealed joints, making the ducts essentially impervious to water intrusion." No water was found at any of the 10 dome tendon anchorage areas examined." There was no evidence of corrosion on either anchorage components or the test wire pulled from D-237.* The end caps, the lowest point of the dome tendons and the most susceptible to water intrusion, were found completely filled with CPM and were thusly protected from corrosion.
The full evaluation is documented in IR 1585403 (Attachment 1).3.8 Tendon End Anchorage Cover Examination Tendon end anchorage covers (end caps) were examined as specified in ASME Section Xl, Subsection IWL-2510(c) for damage, deformation, and CPM leakage.The results of this examination are documented on Data Sheets 8.5 in Attachment 2 and summarized below.* No end caps show signs of deformation or other damage.* With one exception, no end caps show signs of corrosion.
The cap at the east end of D-243 is lightly rusted, but not pitted, over roughly one quarter of its surface.* There is minor CPM leakage from the tendon ends noted below. Each of these locations has an estimated quantity of CPM accumulation in the area of the leak less than 0.1 Liters. Oil (separated from the CPM formulation) seeping in small quantities through threaded connections is not considered to constitute CPM leakage and is not reported.
Topical Report No. 213 Revision 0 Page 42 of 49 Table 3 -17: Quantity of CPM Leakage Tendon Numberi- Anchloirage" CPM Le akage.r D-102 Southwest
<1 oz D-104 Southwest
<1 oz D-105 Southwest
<1 oz D-113 Northeast
<2 oz D-115 Northeast
<2 oz D-229 Unspecified
-2 oz (oil stain)H13-51 Unspecified
-1 oz H13-55 Unspecified
-3 oz H35-25 Buttress 5 <2 oz The light rust on the D-243 end cap and the CPM leakage listed above are considered to have no structural significance.
All of these reported conditions are concluded to be acceptable as-is and no corrective action or additional examinations are required at this time.3.9 Topical Report No. 203 Follow-up Examinations Topical Report No. 203 (Reference
- 28) Section 5.3 directed a re-examination of the V-84 bottom bearing plate during the 4 0th Year Surveillance.
The end cap was removed and the bearing plate as well as other anchorage hardware items examined for free water, corrosion, and damage. In addition, CPM samples were taken for testing.There was no free water evident in the end cap or on the anchorage components.
The only corrosion observed was an area of light rust at the outside (furthest from containment) edge of the bearing plate. No damage to either the end cap or the load bearing anchorage components was found. The condition of the V-84 bottom anchorage is, in essence, unchanged from the "as-left" condition following the 3 5 th year examination in 2009.The condition of the V-84 bottom end anchorage is acceptable "as-found", and no corrective action or additional examinations are required.
Topical Report No. 213 Revision 0 Page 43 of 49 4. CONTAINMENT SURFACE EXAMINATIONS The accessible exterior surface of the containment was examined using the general visual technique defined in Section Xl, Subsection IWL-2310(a).
Detailed visual examinations were performed in areas showing signs of possible damage or degradation.
The detailed visual examination technique was performed in accordance with Subsection IWL-2310(b).
Examination results are documented in Attachment 2 on ER-AA-336-019 Attachment 4 and specific vendor data sheets with supplemental descriptions and sketches as applicable.
The results are summarized in the following sections.4.1 Overall Concrete Surface Condition The overall concrete surface shows no evidence of damage or degradation other than some non-structural degradation consisting of grout patches degradation in several areas, minor spalling of the surface concrete at sharp edges, and spalling adjacent to embedded steel plates.There are numerous small shrinkage cracks on the concrete surface reported as less than 0.01 inches wide and below the recording threshold.
Several cracks on the tendon gallery ceiling were reported with widths <0.015 inches, all of which were previously documented.
As previously documented, CPM is seeping through small vertical cracks in areas of the lower wall that are visible in the alligator pit region; this condition is essentially unchanged from that documented during prior surveillances.
Data sheets included in Attachment 2 identify areas on Tendon Buttresses 3, 4, 5, and 6 where embedded steel plates are pulling away from the concrete.
A follow-up walk-down conducted by engineering determined that these embedded steel plates are not pulling away from the concrete, but were in fact originally installed in the concrete with an overlap. This was evidenced by the lack of cracking and degradation in the grouting and concrete surrounding the embedded steel plate overlaps.
The formal evaluation is included in Attachment
1.4.2 Topical
Report No. 203 Follow-up Examinations Topical Report No. 203 directed a detailed visual re-examination of three containment exterior surface areas during the 4 0 th Year Surveillance.
These areas are documented below with their results., The grout overlay of ring girder reinforcing steel once exposed by an extensive spall of cover concrete on the southeast facing sector and repaired in 2006 was examined for grout deterioration or detachment from the concrete substrate.
The grout overlay was found to be fully intact, with no evidence of degradation or separation from the underlying concrete.
Topical Report No. 213 Revision 0 Page 44 of 49* The tendon gallery ceiling was examined for indications that the extent of previously documented leaching, cracking, and spalling that exposed the underlying reinforcement is not increasing.
The gallery ceiling condition does not appear to have changed since the 3 5 th Year Surveillance in 2009. The extent of leaching, cracking, and spalling is unchanged.
Further, the condition of the exposed base mat reinforcing steel is unchanged, with only minor corrosion noted.* The lower wall in the alligator pit area was examined for indications that the rate of CPM seepage through vertical cracks is increasing with time.The extent of CPM leakage areas and the quantities of CPM observed on the lower wall and top of the base mat at the wall-to-mat juncture are unchanged.
It is concluded that the CPM seepage is a steady phenomenon and is not increasing significantly with time.All areas identified in Topical Report No. 203 for detailed visual examination during the 4 0 th Year Surveillance were found to be unchanged.
The grout overlay repair to the exposed reinforcing steel on the southeast sector of the ring girder was done after the completion of the 3 0th Year Surveillance.
The repaired area currently shows no sign of damage or deterioration.
These detailed visual examinations, expanded to include the exposed surfaces of all tendon gallery ceiling bearing plates, will be performed again during the 4 5 th Year Surveillance.
Topical Report No. 213 Revision 0 Page 45 of 49 5. REPAIRS AND FOLLOW-UP EXAMINATIONS
5.1 Repairs
The results of the surveillance show that no repair to either the concrete or the post-tensioning system is necessary at the present time.5.2 Follow-up Examination During 4 5 th Year Surveillance (Period 11)Detailed visual examinations will be performed in the following areas during the 4 5 th Year Surveillance.
- The grout overlay of previously exposed reinforcing steel on the vertical face of the ring girder SE quadrant for degradation and separation from the underlying concrete." The tendon gallery ceiling area; including base mat concrete, tendon bearing plates, and tendon end caps for evidence of CPM leakage, the effects of ground water seepage onto concrete and steel items, deterioration of previously documented exposed reinforcing steel, and other damage or deterioration." The lower wall above the base mat will be examined to determine if corrosion protection medium seepage through the previously documented vertical cracks is increasing." Tendon anchorage assemblies, noted below, for evidence of corrosion.
Pump-through of new CPM in the tendon ducts will be used to correct a possible degraded CPM condition (test sample acid numbers >1).o H13-08 Buttress 1 o H35-02 Buttress 3 o V-32 Gallery Topical Report No. 213 Revision 0 Page 46 of 49 6. CONCLUSIONS The following conclusions are based on, and supported by, evaluation of the surveillance results.* The force in each individual sample tendon exceeds the lower acceptance limit (95% of the predicted value); no sample tendon force exceeds the implied upper limit of 74% GUTS (the limit imposed during initial and Steam Generator Replacement Project tensioning)." Vertical, hoop and dome sample tendon mean normalized forces are above the minimum required values." The 95% lower confidence limits on vertical, hoop, and dome tendon force trends are forecast to remain above minimum required levels through March 2020, the deadline for completion of the 4 5 th year surveillance.
- Control tendon lift-offs exhibit relatively little scatter; vertical, hoop and dome control tendon trends indicate that forces are decreasing more slowly than predicted.
- Elongations (normalized to account for wire stress at PTF and OSF)measured during the re-tensioning of de-tensioned tendons are all within 10% of previously measured values." All examined tendon end anchorage hardware is free of active corrosion, cracks, and distortion.
Observed corrosion is limited to light, dry rust on end caps, bearing plates, and shims. No corrosion was found on wires or anchorheads." With two exceptions, all examined wire button heads are seated. Two wires at the Buttress 4 end of H24-15 were found unseated.
This condition, which has no structural significance, was accepted by evaluation and requires no corrective action or further examination." With one exception, all button heads are intact. One wire was found to be missing at the bottom end of SGR tendon V-136. This condition, which has no structural significance, was accepted by evaluation and requires no corrective action or further examination.
- Several shim pairs were found to have gaps that exceeded the specified limit. These were corrected or evaluated for continued service. All observed gaps were such that bearing area was still sufficient to carry the maximum expected tendon load without generating bearing stresses in excess of the allowable values for the shim material.
No additional examinations are required at the present time.* The difference between the quantities of CPM removed from sample tendons and quantities replaced were, with 3 exceptions, within 10% of the tendon net duct volume. The 3 exceptions, all involving "as-found" Topical Report No. 213 Revision 0 Page 47 of 49 under-fill of the dome tendon duct, were determined to be acceptable by evaluation." Corrosion protection medium samples meet specified limits on water content and concentrations of corrosive ions (chlorides, nitrates, and sulfides).
All CPM samples, save for 9, met the reserve alkalinity (base number) requirements.
An acid number test was conducted on the 9 samples below 0.50 reserve alkalinity and on one additional sample with a base number of 0.52. Three were found with acid numbers greater than the acceptance limit of 1. The 3 sample failures were accepted by evaluation with follow-up actions during the 4 5 th Year Surveillance." No free water was detected at tendon end anchorages; showing that water intrusion is not an issue.* Tendon wire samples meet the specified limits on ultimate strength and elongation at failure.* Concrete surrounding tendon bearing plates is free of damage, deterioration, and cracks exceeding 0.010 inches in width.* Concrete surfaces are free of damage and degradation.
The deterioration of grout patches, as noted in various areas, has no structural significance.
The few concrete cracks that exceed the threshold width of 0.010 inches (none exceed 0.015 inches) were previously documented, accepted by evaluation, and reported as unchanged from previous surveillances." Tendon end caps are free from damage, and with one exception, free from corrosion.
The corrosion observed consisted of light, dry rust with no noticeable loss of metal." Conditions in areas identified for detailed visual examination in Topical Report 203 have not changed since the 3 5 th year surveillance in 2009.Detailed visual examination of these areas is recommended again during the 4 5 th Year Surveillance.
Topical Report No. 213 Revision 0 Page 48 of 49 7. REFERENCES The following documents (applicable sections noted) were used in the development of this report and /or are specifically referenced herein.1. ACI 201.1 R-92, Guide for Conducting a Visual Inspection of Concrete in Service, Published by the American Concrete Institute.
- 2. ACI 349.3R-96, Evaluation of Existing Nuclear Safety-Related Concrete Structures, Published by the American Concrete Institute.
- 3. ASME Boiler and Pressure Vessel Code (2004 Edition with no Addenda),Section XI, Sub-Sections IWA and IWL.4. ASTM A370, Standard Test Methods and Definitions for Mechanical Testing of Steel Products.5. ASTM D974, Standard Test Method for Acid and Base Number by Color-Indicator Titration.
- 6. Calculation C-1101-153-E410-028, Rx Building Tendons, Minimum Required Prestressing Forces, Revision 0, 10 Feb 99.7. Calculation C-1 101-153-E410-046, TMI-1 RB Post Tensioning System ISI Program Tendon Force Prediction, Revision 0, 6 Oct 2010.8. ER-AA-330-005, Visual Examination of Section XI Class CC Concrete Containment Structures, Revision 10, 6 Sept 2013.9. ER-AA-330-006, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems, Revision 7, 12 Sept 2013.10. ER-AA-335-001, Qualification and Certification of Nondestructive Examination (NDE) Personnel, Revision 6, 31 July 2012.11. ER-AA-335-019, Visual Examination of ASME IWL Class CC Containment Components, Revision 0, 10 April 2012.12. Gilbert / Commonwealth Letter (with attachments)
G/C/TMI-1 CS/1 6616 dated 27 Dec 88, Transmitting Tendon Stressing Record Data (ECD C-310055).13. Miller, Irwin and John E. Freund, Probability and Statistics for Engineers, Prentice-Hall, 1965 14. PSC Procedure N1091, Post Tensioning System In-Service Inspection Manual, Revision 0, 3 Sept, 2013.15. TMI -Unit 1 UFSAR Section 5.7.5, Revision 22 16. TMI -Unit 1 Technical Specification Sections 3.19.1 & 4.4.2.1 17.TMI -Unit 1 Surveillance Procedure 1301-9.1, RB Structural Integrity Tendon Surveillance, Revision 23A, 30 Sept 2013.
Topical Report No. 213 Revision 0 Page 49 of 49 18. TMI -Unit 1 EER JO # 162193, Rx Building Tendons, Minimum Required Prestressing Forces.19. TMI -Unit 1, Reactor Containment Building / First Tendon Surveillance test / One Year After SIT, GAI Report No. 1880, 29 Sep 75 20. TMI -Unit 1, Second Tendon Surveillance Test of Reactor Containment Building / Three Years After SIT, VSL Corp. Report No. GQL 0204, Dec 77.21.TMI -Unit 1, Containment Building Tendon Surveillance Test report for Third Period (5 Years After SIT), TDR No. 229, 27 Mar 81.22. TMI Vendor Manual VM-TM-2485.
- 23. Topical Report 025, Reactor Building Tendon Surveillance Test I Inspection Period 4 (10 Years), 27 Aug 85.24. Topical Report 069, Reactor Building Fifteen year Tendon Surveillance Test (Inspection Period 5), 2 May 90.25. Topical Report 093, Reactor Building Twenty Year Tendon Surveillance Test (Inspection Period 6), 22 Mar 95.26. Topical Report 136, 2 5 th Year Reactor Building Tendon Surveillance (Period 7), Revision 1, 31 Jul 01.27. Topical Report No. 183, 3 0 th Year Reactor Building Tendon Surveillance (Period 8), Revision 0, 10 Mar 2005.28. Topical Report No. 203, 3 5 th Year Reactor Building Tendon Surveillance (Period 9), Revision 0, 19 April 2010.29. Topical Report No. 204, 2010 Augmented Reactor Building Tendon Surveillance, Revision 1, 13 June 2012.30. United States Code of Federal Regulations, Title 10, Part 50, Subpart 50.55a (1OCFR50.55a).
31.38455-CALC-C-008, Determination of Losses in New and Re-Tensioned Tendons, Revision 8, 9 Jan 2010.
ATTACHMENT 1 Engineering Technical Evaluations and Issue Reports Table of Contents 1. IR 1541172: 4 0 th Year Surveillance Tendon Tensioned from Single End p02 2. IR 1567897: Shim Gap Identified on H24-22 Buttress 4 p20 3. IR 1579266: Shim Gap Identified on Hoop Tendon H 13-08 p29 4. IR 1569980: Shim Gap Identified on Dome Tendon D-143 p34 5. IR 1565440: Tendon H24-15 had 2 Wires Protruding from Anchor Head p44 6. IR 1567224: Tendon V136 Missing 1 Wire p 4 8 7. IR 1569458: Lock-Off Force in Tendon V-136 Exceeded Acceptance Criteria p58 8. IR 1572452: Dome Tendon D-143 Identified to be Inaccessible p63 9. IR 1585403: Tendon Regreasing Exceeded Acceptance Limits p66 10. IR 1587456: Surveillance Tendon De-tensioned Before Lift-off Completed p75 11. Ev luation of the As-Found Condition of Embedded Ste l Plates in the Reactor Building Tendon Buttresses p89 12. IR 1626566: Tendon Grease Sample Acid Number Exceeds Acceptance Criteria p94 13. Ring Girder Southeast Quadrant Follow-up VT-1 C p101 Topical Report 213 Attachment 1 Page 1 of 110 0Go Back Print I New Search I Home AR Number: 01541172 Linked ARs Aff Fac: Three Mile AR Type: CR Status: APPROVED Island Aff Unit: 01 Owed To: A5551CAP Due Date: 09/30/2014 Aff System: 153 Event Date: 07/29/2013 CR 4/D Disc Date: 07/29/2013 Level/Class:
How H02 Orig Date: 07/30/2013 Discoverld:
Action Request Details
Subject:
i 40TH YEAR SURVEILLANCE TENDON TENSIONED FROM SINGLE END
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
John Piazza/Mark Torborg Condition
==
Description:==
Random sample selection was performed to establish RB tendon population for the 40th year tendon surveillance scheduled in TIR20. Hoop tendons, H24-15 and H13-03, were selected for examination and lift-off testing.Stressing cards indicate that these tendons are two of 14 hoop tendons that were single end tensioned during construction.
It is industry practice to tension horizontal hoop tendons from both ends and the perform lift-off testing from both ends. With single end tensioning the potentiaI exists that lower pre-stressing forces were achieved and subsequ nt lift-off testing may yield stressing forces below the ASME Section XI Subsection IWL-3220 Code Acceptance Criteria.If results of lift-off testing do not meet acceptance criteria, the condition must be evaluated for continued operation and additional testing will need to be performed on adjacent tendons. In the case of H24-15 the next adjacent accessible tendons are H24-18 and 19. These tendons were also single end tensioned.
The adjacent tendons for H13-03 were tensioned from both ends.An additional concern is that the contracted MPRjanalysis for the acceptability of reduced force tendons assumes a11 TMI hoop tendons are dual end tensioned.
Immediate actions taken: Conducted phone call with Responsible Engineer (Howard Hill), Corporate ISI Program Engineer (Gene Navratil), TMI Design Manager (John Piazza), TMI Programs Manager (Mark Torborg) and TMI ISI Program Engineer (Michael Grimm) to discuss options for inspection of tendon H24-15 and path going forward for the MPR analysis.Reviewed single end tensioned tendons to determine if any were previously surveilled (ex. H24-19).Recommended Actions: 1. Work with Howard Hill to develop flow chart for decision making when inspecting single end tensioned tendons. (Sean Taylor -9/30/2013)
Topical Report 213 Attachment 1 Page 2 of 110
- 2. Walkdown the 14 single end tensioned tendons to determine accessiblity of both ends. (Michael Grimm -8/30/2013)
- 3. Revise procedure 1301-9.1 to incorporate single end tensioned tendon inspection methodolgy. (Sean Taylor -9/30/2013)
- 4. Work with Howard Hill to provide calculations of reduced force estimates for the 14 single end tensioned tendons for the MPR analysis.(Sean Taylor -9/30/2013)
- 6. Determine if calculation C-1101-153-E410-046 required revision, and initiate revision accordingly. (Sean Taylor -9/30/2013)
- 7. Rev~iew original design basis/calculations for single end tensioning justification. (Dave Yerkes -9/30/2013)
What activities, processes, or procedures were involved?Tendon Surveillance planning activities including review of tendon data and force curves.Why did the condition happen?During construction Inryco single end tensioned 14 hoop tendons because of accessibility issues. Gilbert Associates reviewed/approved single end tensioning.
What are the consequences?
The potential exists that the 14 single end tensioned tendons will have a reduced pre-stress force below predicted values in calculation C-1101-153-E410-046 and below the ASME Section XI Subsection IWL-3220 code acceptance criteria of 95% of predicted force. This will result in additional tendons requiring lift off testing. Additionally the MPR analysis being performed for the acc ptance of reduced forces in adjacent tendons may be affected by the redu1ed pre-stress tendons.Review of H24-19 (originally single end tensioned) surveillance in year 3, indicates that though the pre-stress after the Structural Integrity Test was lower than similar hoop tendons (double end tensioned), the difference was minimal and has no consequence with respect to containment structural integrity.
This IR is to identify potential additional scope. It does not imply a deficient condition with the containment building.Were any procedural requirements impacted?
I Site procedure 1301-9.1 and corporate procedure ER-AA-330-P6 do not address the condition where a hoop tendon was only single enltensioned.
Were there any adverse physical conditions?
There is the possibility of reduced pre-stressing forces in the 14 single end tensioned hoop tendons. However, review of H24-19 (single end tensioned tendon) in subsequent surveillance indicates that the reduction was minimal and did not impact containment structural integrity.
List of knowledgeable individuals:
John Piazza Mark Torborg Gene Navratil Michael Grimm Howard Hill Repeat or similar condition?
Topical Report 213 Attachment 1 Page 3 of 110 No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: CRAIG W SMITH 07/30/2013 14:23:06 CDT Reviewer Comments: There are no operability, reportability, or functionality concerns.Additional lift off testing may be neeyed to evaluate as found condition.
If not stisfactory, additional IR will bý requied to document condition.
SOC Reviewed by: MELISSA L MORLEY 08/01/2013 09:40:11 CDT SOC Comments: Close to actions created (MGF 8/1/13) (SOC 8/1/13)0 Topical Report 213 Attachment 1 Page 4 of 110 Assign #: 01 AR #: 01541172 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 08/04/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details I/Subject/Description:
40TH YEAR SURVEILLANCE TENDON TENSIONED FROM SINGLE END Assignment Completion I I In Progress Notes: Completion Notes:-1 Topical Report 213 Attachment 1 Page 5 of 110 Single End Tensioned Hoop Tendon Discussion Page 1 of 3 9/5/2013 TMI-1 4 0 th Year Containment (RB) In-Service Inspection (ISl)Measurement
& Evaluation of Force in Single End Tensioned Hoop Tendons The following discussion and flow chart address issues unique to the treatment of the single-end tensioned hoop tendons randomly selected for examination during the 4 0 th year Reactor Building (RB) Inservice Inspection (ISI). Single-end tensioned tendons are not addressed in ISI program documents or ASME Section XI Subsection IWL and, with one exception, have not been previously included in the random examination samples. Single end tensioned hoop tendon H24-19, the exception, was included in the 3 rd year (after the 1976 Structural Integrity Test (SIT)) ISI surveillance Oample. During that examination, lift-off forces were measured at both ends of H24-19. The average of the measured end anchorage forces was reported to have met the acceptance criterion (at or above 95% of the predicted value determined for a double end tensioned tendon).II The tendon sample randomly selected for examination during the 4 0 th year RB in-service inspection includes 2 hoop tendons, H13-03 and H24-15, tensioned at only one end during construction.
It has been determined that both ends of H13-03 are currently accessible for lift-off measurement.
Subsequent to selection, H24-15 has been determined inaccessible due to access restrictions to the Seal Injection Room. H24-22, double end tensioned, has replaced H24-15 for this surveillance.
H24-15 shall be examined per the requirements of this document and the attached flow chart.During construction, 14 hoop tendons were single end tensioned.
The mean force in a single end tensioned hoop tendon is calculated to be about 6.5% less than that in a hoop tendon tensioned at both ends. The RB design calculations do not account for the associated reduction in mean hoop pre-stressing force. The RB is pre-stre sed by 330 hoop tendons and if 14 of these are 6.5% below the level specified in the design, the overall reduction in mean hoop pre-stressing force is 6.5
- 14 / 330 -0.3%.The 0.3% overall reduction would be relatively insignificant if the 14 tendons were well distributed around the circumference and height of the RB wall. However, 5 of the 14 single end tensioned hoops are in the Hxx-03 group, one is in the adjacent Hxx-04 group and 3 are closely spaced in the H24-xx group. As a consequence, there is a -3' high band low on the RB wall that has a possible significant shortfall in pre-stressing force.The reduced pre-str ssing force in these localized regions may have struc ural significance when the reduction iý evaluated against the design criteria.
For this reason, 'lit is important to measure, where possible, the force at both anchorages of each single end tensioned random sample tendon. Having data for both ends of said tendons will greatly facilitate any required evaluation of structural conditions in the localized regions.If a single end tensioned hoop tendon is only accessible at one end, lift-off at the accessible end should be measured for confirmatory information, this is not a code required examination.
The lift-off force will be evaluated but, if it is below 0.95 of the forecast value, subsequent actions will be as specified by the Responsible Engineer (RE). In addition, the originally designated sample tendon will be replaced with the nearest tendon in the same buttress grouping that is accessible at both ends. TMI site procedure (1301-9.1) requirements will apply to the replacement tendon whether it is single or double end tensioned (a requirement for additional evaluation is discussed in the subsequent paragraph).
Topical Report 213 Attachment 1 Page 6 of 110 Single End Tensioned Hoop Tendon Discussion Page 2 of 3 9/5/2013 The following flow chart identifies actions to take depending both on the accessibility of single-end tensioned random sample hoop tendons and on the results of the lift-off measurements.
The flow chart includes an action to evaluate the condition if the average (both ends) lift-off force determined for a single end tensioned hoop tendon is below 84% of the predicted force (which is based on double end tensioning).
As noted above, the mean force in a single end tensioned tendon is expected to be about 93.5% of that in a double end tensioned tendon. If the average lift-off force determined for a single end tensioned tendon is below 90% of this expected value or, below 0.935
- 0.9 = 0.84 of the predicted force, additional engineering evaluation is deemed necessary.
If the lift-off is above 0.84 the acceptance and evaluation criteria of 1301-9.1 shall apply.Topical Report 213 Attachment 1 Page 7 of 110 Single End Tensioned Hoop Tendon Discussion Page 3 of 3 9/5/2013 Tendon Lift-Off Measurement Flow Chart Is random sample, replacement No or adjacent hoop tendon single o Proceed per end tensioned?
1301-9.1 Select as replacement the nearest tendon accessible at both ends.Yes A F Is tendon accessible for lift-off measurements at both ends?4 Yes Measure single end lift-off.V Is average (both ends)lift-off force below 0.84 times predicted force?Yes RE to evaluate.Topical Report 213 Attachment 1 Page 8 of 110 A walkdown was performed on the single end tensioned tendons. Several tendons could not be accessed due to current plant conditions, i.e. scaffold builds, temporary RCAs, etc. A follow-up assignment will be issued to verify accessibility of these tendons prior to annotation in procedure 1301-9.1.A follow-up assignment will be issued to document the following walkdown as an attachment to 1301-9.1. While the single end tensioned tendons determined to be inaccessible during this walkdown will remain in population, they can be diagnosed from the pictures, or those taken during the follow-up walkdown, as inaccessible or accessible based on the rams available for the surveillance.
If the ram technology is the same as it was for the 4 0 th year surveillance, then these inaccessible tepdons will remain inaccessible and an adjacent tendon will be selected.The seal injection room, will be annotated in the procedure as inaccessible, as current equipment can't access the room because of space restrictions around the motor control centers.Disposition of Single End Tensioned Tendons 1. Summary a. Accessible Tendons i. H24-18 ii. H24-19 iii. H62-44 iv. H 13-03 b. Inaccessible Tendons i. H24-15 ii. H13-12 iii. H51-20 iv. H46-03 v. H24-03 c. Indeterminate due to current access restrictions
-Conduct additional walkdown i. H62-24 -Turbine Building RCA Restriction ii. H3p2 Turbine Building RCA Restriction ii. H 5-03 -Access to part of alligator pit iv. H35-04 -Access to part of alligator pit v. H62-03 -Access to part of alligator pit II. H24-15 a. Scheduled in T1R20 b. End Locations i. Buttress 2-Turbine Building 322' Elevation Topical Report 213 Attachment 1 Page 9 of 110 ii. Buttress 4-Auxiliary Building 305' Elevation -Seal Injection Room Topical Report 213 Attachment 1 Page 10 of 110
- 1. The seal injection room is inaccessible as the rams can't fit around the MCCs 2. Additional clearance issues exist with safety related conduit in front of the tendon end cap 111. H-24-18 a. Not Scheduled b. End Locations i. Buttress 2 -Turbine Building 322' Elevation 1. Inaccessible due to piping obstruction ii. Buttress 4 -Above Auxiliary Building Roof Topical Report 213 Attachment 1 Page 11 of 110
- 1. Last Tendon above roof line -accessible IV. H24-19 a. This tendon was inspected during 3 d Year Surveillance
- i. Lift-Off was conducted from both ends.ii. Tendon passed surveillance
-no issues identified V. H62-24 a. Not Scheduled b. End Locations i. Buttress 2 -Turbine Building 346' Elevation 1. Indeterminate accessibility
-Roped off RCA area due to scaffold construction
- a. Appears to be inaccessible due to Fire Service Piping 2. Will need to re-assess when access is available ii. Buttress 6- RB Exterior Above Equipment Hatch 1. Accessible with Work Platform VI. H62-34 a. Not Scheduled b. End Locations Topical Report 213 Attachment 1 Page 12 of 110
- i. Buttress 2 -Turbine Building 365' Elevation 1. Indeterminate accessibility
-roped off RCA due to scaffold construction
- 2. Will need to re-assess when access is available ii. Buttress 6 -RB Exterior above Equipment Hatch 1. Accessible with work platform VII. H62-44 a. Not Scheduled b. End Locations i. Buttress 2 -Below Roof line of Turbine Building.Tendon is accessible ii. uttress 6- RB Exterior 1. Accessible from Work Platform VIII. H 13-012 a. Not Scheduled b. End Locations i. Buttress 3 -Turbine building 302' Elevation outside of Personnel Hatch Topical Report 213 Attachment 1 Page 13 of 110
- 1. Accessible ii. Buttress 1 -Intermediate Building 295' Elevation 1. Inaccessible due to piping interference
- c. Note: This tendon deforms around the personnel hatch.IX. H51-20 a. Not Scheduled b. End Locations i. Buttress 1- Intermediate Building 322' Elevation 1. Inaccessible due to pipe interference ii. Buttress 5- RB exterior above Auxiliary Building 1. Accessible with Work Platform X. H46-03 a. Not Scheduled b. End Locations i. Buttress 6- Alligator Pit Topical Report 213 Attachment 1 Page 14 of 110
- 1. Accessible ii. Buttress 4- Auxiliary Building 281' Elevation 1. Inaccessible due to pipe interference XI. H24-03 a. Not Scheduled b. End Loca ions i. Buttress 4 -Auxiliary Building 281' Elevation I Topical Report 213 Attachment 1 Page 15 of 110
- 1. Inaccissible due to pipe interference and contaminated area ii. Buttress 2 -Alligator Pit 1. Indeterminate
-will need to identify in an additional walkdown XII. H35-04 a. Not Scheduled b. End Locations i. Buttress 3 -Alligator Pit 1. Indeterminate -will need to id ntify in an additional walkdown ii. Buttress 5- Alligator Pit Topical Report 213 Attachment 1 Page 16 of 110
- 1. Accessible XIII. H35-03 a. Not Scheduled b. End Locations i. Buttress 3 -Alligator Pit 1. Indeterminate
-will need to identify in an additional walkdown ii. Buttress 5 -Alligator Pit 1. Accessible XIV. H 62-03 a. Not Scheduled b. End Locations i. Buttress 6 -Alligator Pit Topical Report 213 Attachment 1 Page 17 of 110
- 1. Accessible ii. Buttress 2 -Alligator Pit 1. Indeterminate-will need to identify in an additional walkdown XV. H 13-03 a. Scheduled T1R20 b. End Locations i. Buttress 3 -Alligator Pit 1. Accessible ii. Buttress 1 -Alligator Pit Topical Report 213 Attachment 1 Page 18 of 110
- 1. Accessible Topical Report 213 Attachment 1 Page 19 of 110 0Go Back Print I New search I Home AR Number: 01567897 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/31/2013 Aff System: 153 Event Date: 10/03/2013 CR 4/D Disc Date: 10/03/2013 Level/Class:
How H02 Orig Date: 10/04/2013 Discovered:
Action Request Details
Subject:
SHIM GAP IDENTIFIED ON H24-22 BUTTRESS 4
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
John Piazza/Mark Torborg Condition
==
Description:==
During tendon surveillance activities on Hoop Tendon H24-22 at Buttress 4 a shim gap measuring linch was identified, with the opposite side of the shims measuring zero. This shim gap is in excess of the 0.25 inch average allowed per procedure ER-AA-330-006.
Immediate actions taken: IR initiated e The shim gap was reset to meet de 1 ign requirements after lift-off.Briefed Responsible Engineer on the condition Recommended Actions: Evaluate the pre-existing condition.
What activities, processes, or procedures were involved?Conduct of tendon surveillance activities.
Why did the condition happen?During original construction the shim gap was not set properly.What are the consequences?
The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components.
The shim gap has since been reset. The anchorage components exhibited no evidence of degradation.
Tendon H24-22 Buttress 4 has been fully restored to the design requirements.
Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of ER-AA-330-006.
Were there any adverse physical conditions?
The AISC allowable design bearing stress of 90% of yield was exceeded at the time of original construction, the yield stress was not exceeded.Relaxation of the tendon and the corresponding loss of prestress during Topical Report 213 Attachment 1 Page 20 of 110 the first year of service, resulted in a reduction in the bearing stress, and thereafter, 90% yield criteria was met.The shim gap has been reset to an acceptable average width of 0.25 inches or less, and the lift off test was performed satisfactory, restoring H24-22 Buttress 4 to teh as-designed condition.
List of knowledgeable individuals:
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition?
Yes IR 1014485 written on 1/10/2010.
Non conforming shim gaps on three tendons during the final stressing inspections of the steam generator replacement tendons.Operable Basis: Reportable Basis: Functional Basis: Reviewed by: CRAIG W SMITH 10/05/2013 12:10:45 CDT Reviewer Comments: There are no operability, reportability, or fj nctionality concerns.The shim gap has since been reset. The arýchorage components exhibited no evidence of degradation.
Tendon H24-22 Buttress 4 has been fully restored to the design requirements.
Initial engineering evaluation has determined tendon continued to maintain design function in as found condition.
Action to Engineering to document formal evaluation when complete.
If evaluation does not reach satisfactory conclusion, a separate IR should be generated.
SO( Reviewed by: DIANE M SCHNEIDER 10/08/2013 09:40:56 CDT SO Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/07/13).
10/07/2013
-Per S/M Comments:
The shim gap has since been reset. The anchorage components exhibited no evidence of degradation.
Tendon H24-22 Buttress 4 has been fully restored to the design requirements.
Initial engineering evaluation has determined tendon continued to maintain design function in as found condition.
Action to Engineering to document formal evaluation when complete.
If evaluation does not reach satisfactory conclusion, a separate IR should be generated.
D. Hockley Close to comments and action taken and created. (benson 10/8/13) (SOC 10/08/13)Topical Report 213 Attachment 1 Page 21 of 110 1 0 Topical Report 213 Attachment 1 Page 22 of 110 Assign #: 01 AR #: 01567897 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/09/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/l!escription:
SHIM GAP IDENTIFIED ON H24-22 BUTTRESS 4 Assignment Completion In Progress Notes: Completion Notes: t 4 Topical Report 213 Attachment 1 Page 23 of 110 Exelon Generation.
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 1 of 5 1.0 Reason for Evaluation/Scope This is evaluation is being performed to document the acceptability of a non-conforming condition that was identified during the TMI-1 4 0 th year In-service Inspection of the Reactor Building post-tensioning system (tendons).
During the as-found examination of surveillance hoop tendon H24-22 (a non Steam Generator Replacement Project affected tendon) end anchorage at buttress 4, the top side shim gap was found to be 1 linch. The shim halves were in sensible contact at the bottom. tAfter the lift-off measurement was completed, the shims were realigned to restore the gaps between shim halves to 0.25 inches, which is compliant with the requirements specified in Par. 4.4.1.5.A of Exelon Corporate Procedure ER-AA-330-006, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section XI 2004 Edition Subsection IWL, to evaluate and document the acceptability of the as-found condition for tendon H24-22, as well as to establish criteria for the maximum allowable shim gap for hoop tendons to be used in future inspections.
This evaluation was screened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, SuIsection IWL.2.0 Detailed Evaluation As documented in IR 1567897, the shim stack on hoop tendon H24-22 was found with a 1 inch gap on one side and no gap on the other side. During lift-off testing of the tendon, technicians restored the shim gap to the acceptable 0.25 inches average gap in accordance with ER-AA-330-006.
This evaluation provides the maximum allowable shim gap assuming the highest as-found hoop tendon lift-off force. This evaluation may be used for the acceptance of additional hoop tendon shim gaps assuming the maximum issumed lift-off force is not exceeded.2.1. As-Found Condition The post-tensioning system vendor (INRYCO) manual, VM-TM-2485, provides relatively detailed instructions for tendon installation and stressing.
However, these instructions do not address shim gap, suggesting that the implied warranty of good workmanship would result in shim halves being pushed into contact either with each other or with the tendon wire bundle.The manual includes a drawing (identified only by title as 170 Wire Split Shim / Part No.101006), also present in TMI Electronic Document Management System (EDMS) as PS-01. This drawing shows a maximum material removal of 0.25 inches along the line where the 10 inch square shim blank is flame cut in half. Drawings are available for all shims sizes. The smallest Topical Report 213 Attachment 1 Page 24 of 110 Exelon Generation, Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 2 of 5 shim, 10 gauge, shows dimensions for the cut gap as a maximum of 0.125 inches. Although manufacturing tolerances allow for the flame cut to remove up to 0.25 inches along the centerline, a conservative assumption of 0.125 inches is used for the purposes of this evaluation as it provides the greatest reduction in bearing surface area making it a bounding condition.
A 5.625 inch diameter center hole is cut through the shim blank before the blank is cut in half.This is sufficient to clear the wire bundle maximum diameter (diameter varies with angular position due to the anchor head hole pattern) at the anchor head exit. If 0.125 inches are removed along the cut line when the shim blank is split, the shim halves may not necessarily close against each other when placed around the wire bundle. Depending on the orientation of the anchor head relative to the shim parting line, shim halves may be separated by up to 0.125 inches when pushed into contact with the wires.American Institute of Steel Construction (AISC) specifications (which covers TMI's post-tensioning system components) limit steel bearing stress to 90% fv, where fy is the minimum tensile yield stress specified for the material.
Shims 0.25 inches and larger are cut from ASTM A 36 plate (per the previously cited shim drawing) which has a minimum required tensile yield of 36 ksij Therefore, the AISC bearing limit for this material is 0.90
- 3 1 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate Tensile Strength (GUTS), or 1,394 kips, per TMI Updated Final Safety Analysis Report, Chapter 5 Appendix 5B. This seating force requires an area of 1,394 / 32.4 = 43.02 in 2 between the anchor head and the shim in contact with the anchor head. To ensure a bearing area of at least 43.02 in 2 , the average shim gap, computed using the expression discussed in Section 2.2 of this evaluation, cannot exceed a value of 0.21 inches, which is 0.085 inches greater than the cut gap of 0.125 inches.The 1 inch gap observed at the top of the H24-22 buttress 4 shim stack results in a net bearing area of about 42 in 2.At the design tendon seating force of 1,394 kip (0.70 GUTS), the resulting bearing stress would be close to 1,394 / 42 = 33.2 ksi or about 92% f,.While it is conservative to limit bearing to 90% fv, this conservatism is provided by AISC to account for unknown variations in loads and material properties.
Construction records show that H24-22 was seated at an average (of both ends) force of 1,458 kips and not 70% GUTS (1,394 kips). If both ends of the tendon are treated as having equal seating forces, the initial anchor head to shim bearing stress at the buttress 4 end would have been about 34.8 ksi, or 97% f,. While this stress exceeds the AISC limit of 90% fv, it is still below the minimum specified Topical Report 213 Attachment 1 Page 25 of 110 Exelon Generation.
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 3 of 5 material yield and well below the actual material yield. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load, which was verified by visual inspection of the shim stack.Tendon forces are currently well below the initial seating levels (lift-oft at the shop end of H24-22 was 1,186 kips) due to the effects of elastic shortening and time dependent losses. At this time, bearing stress at all hoop tendon anchor head to shim interfaces should be under 32.4 ksi (90% fy for A 36 material), assuming that bearing areas are not significantly less than 42 in'.The bearing stress at the buttress 4 end of H24-22 with the as-found 1 inch shim gap was 1,186 kips / 42 in 2 = 28.2 ksi, which is well below the 90% fy level of 32.4 ksi. Still, there is no current design basis for reducing the required bearing area to anything less than that needed at initial tensioning.
For this reason, it is important to show with confidence that shim gaps are acceptable based on the initial design requirements.
This is done below.2.2. Maximum Evaluated Acceptable Shim Gap The subsequent evaluation applies only to hoop tendons. Vertical and Dome (Evaluation 1569980-02)
Tendons will require a separate evaluation.
At the present time, hoop tendon forle levels are well below initial lock-off values. The expected current mean hoop tendon force level, determined by the trend of surveillance measurements is 1,150 kips. The greatest mean anchorage force observed in hoop tendons examined during surveillances 4 through 9 (surveillance years 10 through 35) is 1,218 kips. This value was computed as the average of the 1,201 kips and 1,235 kips forces measured at the anchorages of hoop tendon H13-11 during Surveillance 8 (3 0 th year) in 2004. On the basis of these trended and measured tendon force levels, it is reasonable to conclude that any easured dome tendon anchorage force from this time forwa 1d will not exceed 1,235 kips. If a im gap is found in a dome tendon with a lift-off exceeding this 1,235 kips criteria, a separate evaluation shall be conducted to determine its acceptability.
The minimum required shim bearing area required to support a tendon anchorage force of 1,235 kips is 1 k10 =M ng .The anchor head to shim bearing area, Ab, is effectively equal to the value computed using the following expression:
Where; -6 Id c) i Where;Topical Report 213 Attachment 1 Page 26 of 110 Exelon Generation.
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 4 of 5-ý m %,S75 Inc.,, which is the Anchor Head Diameter dz -5,I25 .'-,, which is the Shim Hole Diameter d, = 0.25 i.P.,, which is the assumed width of the shim cut line G, is the sum of the top and bottom shim gap widths Substituting the above values, rounded to the nearest 0.01 inches, into the expression for Ab gives:--%.15D ---01z) % -C 44'For a required bearing area of 38.12 in 2 , the sum (G) of the top and bottom gaps may not exceed = ,,, .9, this value is reduced to 1.4 inches for conservatism.
Using the conservative value of 1.4 inches for G, mean gap width (G / 2) cannot exceed 0.70 inches.3.0 Conclusion/Findings Based on the above computation, the conclusion of this evaluation is that a mean shim gap width _0.70 inches is acceptable for hoop tendons. This conclusion is considered to be valid unless a current or future measurement of a dome tendon anchorage force exceeds 1,235 kips.There is no evidence that hoop tendon average shim galls in excess of 0.70 inches have been observed during prior examinations.
In addition, during the present surveillance a total of 35 hoop, vertical, and dome end anchorages will be examined.
Of these, 28 ends are randomly selected sample tendons (including 4 Steam Generator Replacement (SGR) tendons) that have not been previously examined since initial installation.
The remaining seven have been previously examined.It is expected that the results of the examinations performed during the present surveillance will show that the 0.7 ihch mean gap between the H24-22 shim stack halves is an ano naly and that mean gaps found aý the anchorages of the remaining surveillance sample dome t ndons will be smaller.As is shown above, a mean gap of 0.70 inches is acceptable for hoop tendons. If the remaining hoop tendon end anchorage examinations do not uncover a larger gap and if no hoop tendon end anchorage lift-off force is found to exceed 1,235 kips, conditions with respect to shim gap will be considered acceptable and no further evaluation will be required.In summary, based on the computation presented in this evaluation, it is concluded that a mean dome tendon shim gap < 0.70 inches is acceptable for an end anchorage force < 1,235 kips. As the Topical Report 213 Attachment 1 Page 27 of 110 Exelon Generation.
Evaluation of Shim Gap 1567897-02 at H24-22 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-22 Shim Gap 5 of 5 lift-off measured on H24-22 was 1,186 kips, which is less than 1,235 kips, the as-found shim gap is acceptable.
4.0 References
- 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection ond Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structurol Integrity Tendon Surveillance
- 4. AISC Handbook 5. IR 1569980 6. TMI-1 UFSAR Chapter 5, Appendix 5B 5.0 Attachments None Approvals Responsible Engineer:
Howard Hill Date: See EDMS Preparer:
Michael Grimm Date: See EDMS V Independent Reviewtr:
Sean Taylor Date: Sle EDMS Manager: MarkTorborg Date: See EDMS 0 Topical Report 213 Attachment 1 Page 28 of 110 0 Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01579266 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/06/2013 Aff System: 153 Event Date: 10/31/2013 CR 4/D Disc Date: 10/31/2013 Level/Class:
How H02 Orig Date: 10/31/2013 Discovered:I Action Request Details
Subject:
SHIM GAP IDENTIFIED ON DOME TENDON H13-08
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
During tendon surveillance activities on Hoop Tendon H13-08 a shim gap measuring 1 inch was identified, with the opposite side of the shims measuring 0.125 inches. This shim gap is in excess of the 0.25 inch average allowed per PSC procedure SQ 8.0 Revision 1 and corporate procedure ER-AA-330-006.
This condition was previously evaluated for Hoop Tendon H24-22 Buttress 4 (IR 1567897) and Dome Tendon D-134 (IR 1569980);
both tendons were determined to be acceptalle.
Tendon H13-08 is undergding visual examination only as it was determined to be inaccessible during pre-outage walk downs. There are no plans to restore this shim gap to the 0.25 inch acceptable gap.The evaluation of shim gaps for hoop tendons was completed previously for Hoop Tendon H24-22 Buttress 4 under IR 1567897. At construction the design lock-off force was 1394 Kips which results in a bearing force 92%of yield. The allowable design bearing force per the AISC manual is 90%of yield.Lift-off data from past tendon surveillances shows tljat pre-stressing force decreases rapidly over the first couple years oflservice and then more slowly during the remaining lifetime.
During thl 40 year life of the TMI Unit 1 containment building the highest as-found lift-off force for a hoop tendon was 1218 Kips. It was determined in the evaluation of H24-22 in IR 1567897 that a maximum shim gap average of 0.7 inches was acceptable for service at an as-found force of 1218 Kips.As H13-08 has not had a lift-off performed, the maximum observed lift-off force for the life of the plant is assumed. The as-found shim gap average was 0.6 inches. Therefore the shim gap average is below the allowable shim gap and acceptable for continued service.Immediate actions taken: IR initiated Briefed Responsible Engineer on the condition Topical Report 213 Attachment 1 Page 29 of 110 PSC issued NCR-N1091-005 Recommended Actions: Create action to close to evaluation in IR 1567897 once completed (Michael Grimm)What activities, processes, or procedures were involved?Conduct of tendon surveillance activities.
Why did the condition happen?During original construction the shim gap was not set properly What are the consequencWs?
The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components.
The anchorage components exhibited no evidence of degradation.
Tendon H13-08 could not be restored to the as-designed condition as the tendon will not undergo a lift-off test and will remain' under tension.Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of PSC procedure SQ 8.0 Revision 1 or corporate procedure ER-AA-330-006.
Were there any adverse physical conditions?
The AISC allowable design bearing stress of 90% of yield was exceeded at the time of original construction; however the yield stress was not exceeded.
Relaxation of the tendon and the corresponding loss of pre-stress during the first year of service, resulted in a reduction of the bearing stress, and thereafter, the 90% yield criterion was met.The shim gap could not be reset to the as-designed cond tion as no lift-off test was performed and the bearing assembly renjained under tension.List of knowledgeable individuals:
Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar Yes IR 1569980 for shim gap on Dome Tendon D-143 IR 1567897 for shim gap on Hoop Tendon H24-22.IR 1014485 written on 1/10/2010.
Non conforming shim gaps on three tendons during the final stressing inspections of the steam generator replacement tendons.Operable Basis: Reviewed TS 3.19 and 4.4.2. This 'as found' shim gap was in excess of the 0.25 inch average allowed per ER-AA-330-006.
As documented in the IR, It was determined in the evaluation of H24-22 in IR 1567897 that a maximum shim gap average of 0.7 inches was acceptable for service at an as-found force of 1218 Kips. The as-found shim gap average was 0.6 inches.Topical Report 213 Attachment 1 Page 30 of 110 Therefore the shim gap average is below the allowable shim gap and acceptable for continued service.1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability?
TS 3.19, 4.4.2, 1301-9.1, ER-AA-330-006
- 3. Describe the function of the SSC and basis for operability/availability determination.
See below 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103.
- 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO I The following functions are maintained even with the deviation in shim gaps: 153-ROl : Contain fission products to prevent radioactive release (153).153-R02 : Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural integrity (153).Reportable Basis: This is not reportable IAW the Exelon Reportability Manual.Functional Basis: See operability basis SOC Jeviewed by: CRYSTAL A WARLOW 11/04/2013 09:47:40 CST SOC Comments: REACTOR BUILDING Close to action created. (benson 11/1/13)11/03/2013
-Unchecked Shift Review Complete Radio Button because the shift needs to address the TS=Yes Required Modes. D. Hockley Not a CCF. Close to action created. (SOC 11/04/13)Reviewed by: BRADLEY A PARFI-T 11/01/2013 16:19:17 CDT Reviewer Comments:
I See operability and reportability basis.Reviewed by: EDWARD M CARRERAS 11/03/2013 13:44:45 CST Reviewer Comments: Added required modes. EMC 11/3/13 Topical Report 213 Attachment 1 Page 31 of 110 Assign #: 01 AR #: 01579266 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 11/05/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
ISHIM GAP IDENTIFIED ON DOME TENDON H13-08 Assignment Completion In Progress Notes: Completion Notes: 4 Topical Report 213 Attachment 1 Page 32 of 110 Assign #: 02 AR #: 01579266 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: GRIMMX Due Date: 12/06/2013 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 12/06/2013 Unit Condition:
Sec Grp: Assignment Details Subject/Description:
Ensure that evaluation under IR 1567897 satisfactorily co vers this issue. Create additional actions as needed.Assignment Completion In Progress Notes: The condition observed on this tendon is addressed under technical evaluation 1567897-02 as the condition is bounded by the evaluation.
No further actions are required.-Michael Grimm 11/27/2013 Completion Notes: Topical Report 213 Attachment 1 Page 33 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01569980 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 11/15/2013 Aff System: 153 Event Date: 10/09/2013 CR 4/D Disc Date: 10/09/2013 Level/Class:
How H02 Orig Date: 10/09/2013 Discovered:
Action Request Details
Subject:
SHIM GAP IDENTIFIED ON DOME TENDON D-143
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
During tendon surveillance activities on Dome Tendon D-143 a shim gap measuring 1 inch was identified, with the opposite side of the shims measuring zero. This shim gap is in excess of the 0.25 inch average allowed per PSC procedure SQ 8.0 Revision 1 and corporate procedure ER-AA-330-006.
The as-found condition corresponds to a bearing stress of 81% of yield., which is less than the 90% of yield strength design criteria.This condition wos previously evaluated for Hoop Tendon H24-22 Buttress 4 (IR 1567897) a Id determined to be acceptable.
After lift-off the shim gap was adjusted, but was unable to be restored to the required 0.25 inch average gap required by procedure due to interference from the wire bundle. The as-left condition of the shim stack is 0.5 inch gap on top and 0.25 inch gap on the bottom. This condition is acceptable as the bearing stress is 78% of yield.Immediate actions taken: IR initiated The shim gap was reset to the smallest ga 3 achievable with the wire bundle interference (the shims are in contact withl the wire bundle).Briefed Responsible Engineer on the condition PSC issued NCR-N1091-004 Recommended Actions: Document evaluation of the pre-existing and as-left condition What activities, processes, or procedures were involved?Conduct of tendon surveillance activities.
Why did the condition happen?During original construction the shim gap was not set properly.What are the consequences?
Topical Report 213 Attachment 1 Page 34 of 110 The shim gap is important in maintaining the bearing stresses within the allowable design limits of the anchorage components.
Per AISC the design criteria for the bearing stress should be 90% of yield. With the as-found shim gap, the bearing stress at time of construction was 9 2% of yield and 81% of yield with the as-found lift-off.
The bearing stress of the anchorage assembly never exceeded the yield strength of the material.The anchorage components exhibited no evidence of degradation.
Tendon D-143 could not be restored to the as-designed condition, the as-left shim gap is 0.5 inch on top and 0.25 inch on the bottom. The as-left condition corresponds to bearing stress of 78% of yield.Were any procedural requirements impacted?The shim gap does not meet the acceptance criteria of PSC procedure SQ 8.0 Revision 1 or corporate procedure ER-AA-330-006.
Were there any adverse physical conditions?
The AISC allowable design bearing stress of 9 0% of yield was exceeded at the time of original construction; however the yield stress was not exceeded.
Relaxation of the tendon and the corresponding loss of pre-stress during the first year of service, resulted in a reduction of the bearing stress, and thereafter, the 90% yield criterion was met.The shim gap could not be reset to the as-designed condition due to interference with the wire bundle. The as-left condition of the shim stack has a 0.5 inch gap on top and 0.25 inch gap on the bottom, an average of 0.375 inches. This condition is below the 90% yield criteria (actual is 7 8% of yield) with the current pre-stress in the tendon (1218.68 kips), and is therefore acceptable for continued service.List of knowledgeable individuals:
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition?
Yes IR 1567897 for shim gap on Hoop Tendon H24-22.IR 1014485 written on 1/10/2010.
Non conforming shim gaps on three tendons during the final stressing inspections of the stearn generator replacement tendons. /Operable Basis: Reviewed TS 3.19 and 4.4.2. This 'as found' shim gap was in excess of the 0.25 inch average allowed per ER-AA-330-006.
As docuimented in the IR, this corresponds to a bearing stress of 81% of yield., which is less than the 90% of yield strength design criteria.
The shim gap has been adjusted but cannot attain the desired final average gap. The as-left condition results in an acceptable bearing stress of 78% of yield.1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability?
TS 3.19, 4.4.2, 1301-9.1, ER-AA-330-006
- 3. Describe the function of the SSC and basis for operability/availability determination.
See below Topical Report 213 Attachment 1 Page 35 of 110
- 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103.
- 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO The following functions are maintained even with the deviation in shim gaps: 153-ROl : Contain fission products to prevent radioactive release (153).153-R02 : Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural lintegrity (153).Reportable Basis: This does not meet any reporting thresholds.
Functional Basis: Reviewed by: EDWARD M CARRERAS 10/09/2013 19:29:22 CDT Reviewer Comments: Engineering to document an evaluation of the pre-existing and as-left condition for this tendon. Generate an IR, as needed, if results require additional actions.SOC Reviewed by: DIANE M SCHNEIDER 10/11/2013 09:30:25 CDT SOC Comments:
S REACTOR BUILDING This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/10/13).
Close to action created. (benson 10/10/13) (SOC 10/11/13)0 Topical Report 213 Attachment 1 Page 36 of 110 S Assign #: 01 AR #: 01569980 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/14/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
SHIM GAP IDENTIFIED ON DOME TENDON D-143 Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 37 of 110 Exeton Generation.
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY J SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 1 of 6 1.0 Reason for Evaluation/Scope This evaluation is being performed to document and evaluate for acceptability a non-conforming condition that was identified during the TMI-1 4 0 th year In-service Inspection of the Reactor Building post-tensioning system (tendons).
During the as-found examination at the buttress 4 end of surveillance dome tendon D-143, the top side shim gap was found to be 1 inch. The shim halves were in sensible contact at the bottom. After the lift-off measurement was completed, the shims were realigned to restore the gaps between halves to 0.5 inches on the top and 0.25 inches on the bottom. It was not possible to reduce the gaps further. Both the as-found mean gap of 0.5 inches and the resulting as-left mean gap of 0.375 inches exceed the 0.25 inches limit specified in Par.4.4.1.5.A of Exelon Corporate Procedure ER-AA-330-006, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section Xl, 2004 Edition, Subsection IWL, to evaluate and document the acceptability of both the as found and as left conditions of tendon D-143, as well as establish criteria for the maximum allowable shim gap for dome tendons to be used in future inspections.
This evaluation was screened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section XI, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation As documented in IR 1569980, the shim stack on dome tendon D-143 was found with a 1 inch gap on top and no gap on the bottom. During lift-off testing of the tendon, technicians attempted to restore the shim gap to the acceptable 0.25 inches average gap as provided in ER-AA-330-006.
Due to interferences with the wire bundle, the as-left shim gap was 0.5 inches on top and 0.25 inches on the bottom, for an average of 0.375 inches gap. This evaluation provides the maximum acceptable shim gap assuming the highest as-found dome tendon lift-off force. This evaluation may be used for the acceptance of additional dome tendon shim gaps assuming the maximum assumed lift-off force is not exceeded.2.1. As-Found Condition The post-tensioning system vendor (INRYCO) manual, VM-TM-2485, provides detailed instructions for tendon installation and stressing.
However, these instructions do not address the presence of shim gaps, suggesting that the implied warranty of good workmanship of the shims would result in shim halves being pushed into contact either with each other or with the tendon wire bundle, resulting in a gap consistent with manufacturing tolerances.
Topical Report 213 Attachment 1 Page 38 of 110 ExeLon Generation.
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 2 of 6 The manual includes a drawing (identified only by title as 170 Wire Split Shim / Part No.101006). This drawing shows a maximum material removal of 0.25 inches along the line where the 10 inch square shim blank is cut in half (flame cut). Drawings are available for all shims sizes. The smallest shim, 10 gauge steel, shows dimensions for the cut gap as a maximum of 0.125 inches. Although manufacturing tolerances allow for the flame cut to remove up to 0.25 inches along the centerline, a conservative assumption of 0.125 inches is used for the purposes of this evaluation as it provides the greatest reduction in bearing surface area making it a bounding condition.
A 5.625 inch diameter center hole is cut through the shim blank before the blank is cut in half.This is sufficient to clear the wire bundle maximum diameter (diameter varies with angular position due to the anchor head hole pattern) at the anchor head exit. If 0.125 inches is removed along the cut line when the shim blank is split, the shim halves may not necessarily close against each other when placed around the wire bundle. Depending on the orientation of the anchor head relative to the shim parting line, shim halves may be separated by up to 0.125 inches when pushed into contact with the wires.American Institute of Steel Construction (AISC) specifications (which covers TMI's post-tensioning system components) limit steel bearing stress to 90% fy, where fy is the minimum tensile yield stress specified for the material.
Shims 0.25 inches and larger are cut from ASTM A 36 plate (per the previously cited shim drawing) which has a minimum required tensile yield of 36 ksi. Therefore, the AISC bearing limit for this material is 0.90
- 36 = 32.4 ksi.All tendons were initially tensioned to a nominal force of 70% Guaranteed Ultimate Tensile Strength (GUTS), or 1,394 kips, per TMI Updated Final Safety Analysis Report, Chapter 5 Appendix 5B. This seating force requires an area of 1,394 / 32.4 = 43.02 in 2 between the anchor head and the shim in contact with the anchor head. To ensure a bearing area of at least 43.02 in 2 , the average shim gap, computed using the expression discussed in Section 2.2 of this evaluation, cannot exceed a value of 0.21 inches, which is 0.085 inches greater than the cut gap of 0.125 inches.The 1 inch gap observed at the top of the H24-02 Buttress 4 end shim stack results in a net bearing area of approximately 42 in 2.At the design tendon seating force of 1,394 kip (70%GUTS), the resulting bearing stress would be approximately 1,394 / 42 = 33.2 ksi or about 92%fy.While it is conservative to limit bearing to 90% fy, this conservatism is provided by AISC to account for unknown variations in loads and material properties.
Construction records show that D-143 was seated at an average (of both ends) force of 1,394 kips = 70% GUTS. If both Topical Report 213 Attachment 1 Page 39 of 110 Exelon Generation.
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT I PAGE Michael Grimm Evaluation of D-143 Shim Gap 3 of 6 ends of the tendon are treated as having equal seating forces, the initial anchor head to shim bearing stress at the shop end would have been approximately 33.2 ksi, or 92% fy, as stated in the previous paragraph.
While this stress exceeds the AISC limit of 90% fy, it is still below minimum specified material yield and well below the actual material yield. Therefore, it can be assumed that the shim stack did not yield under the initial tendon load, which was verified by visual inspection of the shim stack.Tendon forces are currently well below the initial seating levels (lift-off at the shop end of D143 is 1,219 kip) due to the effects of elastic shortening and time dependent losses. At this time, bearing stress at all dome tendon anchor head to shim interfaces should be under 32.4 ksi (90%fy for A 36 material), assuming that bearing areas are not significantly less than 42 in 2.The bearing stress at the shop end of D143 with the as-found I inch shim gap was about 1,218 / 42= 29 ksi which is well below the 90% fy level of 32.4 ksi. Still, there is no current design basis for reducing the required bearing area to anything less than that needed at initial tensioning.
For this reason, it is important to show with confidence that shim gaps are acceptable based on the initial design requirements.
This is done below.2.2. Maximum Evaluated Acceptable Shim Gap The subsequent evaluation applies only to dome tendons. Vertical and Hoop Tendons will require a separate evaluation.
At the present time, dome tendon force levels are well below initial lock-off values. The expected current mean dome tendon force level, determined by the trend of surveillance measurements is 1,121 kips. The greatest mean anchorage force observed in dome tendons examined during surveillances 4 through 9 (surveillance years 10 through 35) is 1,290 kips. This value was computed as the average of the 1,286 kip and 1,294 kip forces measured at the anchorages of dome tendon D-314 during Surveillance 4 (l 0 th year) in 1984. On the basis of these trended and measured tendon force levels, it is reasonable to conclude that any measured dome tendon anchorage force from this time forward will not exceed 1,294 kips. If a shim gap is found in a dome tendon with a lift-off exceeding this 1,294 kips criteria, a separate evaluation shall be conducted to determine its acceptability.
The minimum required shim bearing area required to support a tendon anchorage force of 1,294 kip is 1294kips -39.94 in 2.The anchor head to shim bearing area, Ab, is effectively (90%*36 ksi)equal to the value computed using the following expression:
7r (d,2 -d 2)G Ab -dc(d- dh) -(2_dcd. in 2 Where;Topical Report 213 Attachment 1 Page 40 of 110 Exeton Generation, Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 4 of 6 da = 9.375 inches, which is the Anchor Head Diameter dj, = 5.625 inches, which is the Shim Hole Diameter d, = 0.125 inches, which is the assumed width of the shim cut line G, is the sum of the top and bottom shim gap widths Substituting the above values, rounded to the nearest 0.01 inches, into the expression for Ab gives: Ab 7 (9.382 -5.622) _ 0.12(9.38
-5.62) -(-0.12) 9.38 =44.97 -4.69G i71 2 For a required minimum bearing area of 39.94 in 2 , the sum (G) of the top and bottom gaps may not exceed (44973994)
= 1.07 inches, this value is reduced to 1.0 inches for conservatism.
4.69 Using the conservative value of 1.0 inches for G, mean gap width (G / 2) cannot exceed 0.50 inches.3.0 Conclusion/Findings Based on the computation performed in section 2.2, the conclusion of this evaluation is that a mean shim gap width < 0.50 inches is acceptable for dome tendons. This conclusion is considered to be valid unless a current or future measurement of a dome tendon anchorage force exceeds 1,294 kip.There is no evidence that dome tendon average shim gaps in excess of 0.50 inches have been observed during prior examinations.
In addition, during the present surveillance a total of 35 hoop, vertical and dome end anchorages will be examined.
Of these, 28 ends are randomly selected sample tendons (including 4 Steam Generator Replacement (SGR) tendons) that have not been previously examined since initial installation.
The remaining seven have been previously examined.It is expected that the results of the examinations performed during the present surveillance will show that the 0.5 inch mean gap between the D-143 shim stack halves is an anomaly and that mean gaps found at the anchorages of the remaining surveillance sample dome tendons will be smaller.As is shown above, a mean gap of 0.50 inches is acceptable for dome tendons. If the remaining dome tendon end anchorage examinations do not uncover a larger gap and if no dome tendon end anchorage lift-off force is found to exceed 1,294 kips, conditions with respect to shim gap will be considered acceptable and no further evaluation will be required.In summary, based on the computation presented in this evaluation, it is concluded that a mean dome tendon shim gap < 0.50 inches is acceptable for an end anchorage force < 1,294 kip. As the lift-off measured on D-143 was 1,219 kips, which is less than 1,294 kips, the as-found shim gap is Topical Report 213 Attachment 1 Page 41 of 110 Exelon Generation.
Evaluation of Shim Gap 1569980-02 at D-143 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of D-143 Shim Gap 5 of 6 acceptable.
Based on this same analysis and reasoning, the as-left shim gap of 0.375 inches is acceptable for continued service of tendon D-143.4.0 References
- 1. ASME Section X1, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance
- 4. AISC Handbook 5. IR 1569980 6. TMI-1 UFSAR Chapter 5, Appendix 5B 5.0 Attachments None Topical Report 213 Attachment 1 Page 42 of 110 Exelon Generation.
Evaluation of Shim Gap at D-143 Anchorage PREPARED BY SUBJECT Michael Grimm Evaluation of D-143 Shim Gap Approvals Responsible Engineer:
Howard Hill (See EDMS)Preparer:
Michael Grimm (See EDMS)Independent Reviewer:
Sean Taylor (See EDMS)I Manager: Pat Bennett (See EDMS)1569980-02 PAGE 6 of 6 Date: Date: Date: Date: l Topical Report 213 Attachment 1 Page 43 of 110 0Go Back Print I New Search I Home 0 Go Back Print j New Search Home AR Number: 01565440 Linked ARs Aft Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5552CAP Due Date: 12/20/2013 Aff System: 153 Event Date: 09/30/2013 CR 4/D Disc Date: 09/30/2013 Level/Class:
How H02 Orig Date: 09/30/2013 Discovered:
Action Request Details
Subject:
TENDON H24-15 HAD 2 WIRES PROTRUDING FROM ANCHOR HEAD
Description:
Originator:
MARVIN H ESPENSHADE Supv Contacted:
Howard Stein Condition
==
Description:==
While performing a visual inspection on tendon H24-15 it was discovered by QV personnel that there was 2 wires protruding about 0.25" above the anchor head. Per the vendors procedure an NCR-N1091-001 was written for engineering to evaluate and comment on a corrective action if required.Immediate actions taken: Generated this IR to capture that engineering reviews the NCR-N1091-001 for resolution on protruding 2 wires.Recommended Actions: Assignment to engineering (Mike Grinm and Howard Hill) to reviews the NCR-N1091-001 for any resolutions that may be required.Operable Basis: Discussed issue with Engineering.
The 2 protruding wires represent a potential issue where the cables are not tensioned.
Numerous wires exist in the anchor head and per engineeing up to 12 cables can be detensioned before the structural integrity of the tendon is challenged.
Reasonable assurance exists that tendon H24 remains capable of performing its design function.Reportable Basis: This is not reportable IAW the Exelon Reportability manual.Functional Basis: Reviewed by: JOSEPH W KULASINSKY 09/30/2013 12:39:26 CDT Reviewer Comments: JWK SOC Reviewed by: LINDA C WITTER 10/01/2013 09:42:22 CDT SOC Comments: REACTOR BUILDING(#1)
This condition does not meet definition for CCF. Close to action created (MGF 10/01/13) (SOC 10/01/13)0 Topical Report 213 Attachment 1 Page 44 of 110 Assign #: 01 AR #: 01565440 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/05/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
TENDON H24-145 HAD 2 WIRES PROTRUDING FROM ANCHOR HEAD Assignment Completion In Progress Notes: Completion Notes: t Topical Report 213 Attachment 1 Page 45 of 110 Exelon Generation.
Evaluation of Unseated Buttonheads 1565440-02 at H24-15 Buttress 2 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-15 Unseated Buttonheads 1 of 2 1.0 Reason for Evaluation/Scope This evaluation is performed to document the acceptability of the condition observed at the Buttress 2 end of the hoop tendon H24-15 during the 40th Year Tendon Surveillance.
IR 1565440 was issued to document that 2 buttonheads were protruding on H24-15 during the as-found visual examination of the tendon. The buttonheads were protruding
0.1 inches
beyond the seating surface. Hoop tendon H24-15 was single-end stressed durin, construction from the Buttress 4 end.This evaluation was screened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During the as-found visual examination of hoop tendon H24-15 two protruding buttonheads were found. The buttonheads were protruding
0.1 inches
from the seating surfaces and IR 1565440 was written to document the non-conforming condition.
During examination it was noted that the buttonheads did not move when pushed or pulled, which indicates that the wires are not broken close to the anchorhead.
The observed condition is nct unexpected for the non-tensioned end of a curved single enc tensioned tendon. Due to tendon twist (nominally one turn per 40 feet of length) and the effect of the curved duct, contact friction results in a gradual transfer of force between wires. In extreme cases, the load in one or more wires is completely transferred to other wires along the tendon length. In these cases, the affected wires are essentially load-free at the non-tensioned end. Thusly buttonheads on theses wires may remain unseated after tensioning at the far end is completed.
This frictional force transfer phenomenon does not affect the total force in the tendon, only its distribution among wires. Therefore, the observed ccnndition, which is occasionally found at the anchorages of single-end tensioned, curved tendons, nd more rarely at the anchorages of tendons tensioned from both ends, does not degrade the performance of the post-tensioning system.3.0 Conclusion/Findings In light of the above discussion, it is concluded that the unseated button heads at the H24-15 Buttress 2 end are acceptable as-is. No corrective action, further evaluation or additional examination is required.4.0 References
- 1. ASME Section Xl, Subsection IWL, 2004 Edition Topical Report 213 Attachment 1 Page 46 of 110 ExelonGeneration.
Evaluation of Unseated Buttonheads 1565440-02 at H24-15 Buttress 2 Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H24-15 Unseated Buttonheads 2 of 2 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance
- 4. IR 1565440, Tendon H24-15 had 2 Wires Protruding from Anchor Head 5.0 Attachments None Approvals Responsible Engineer:
Howard Hill Date: EDMS Preparer:
Michael Grimm Date: EDMS Independent Reviewer:
Sean Taylor Date: EDMS Manager: MarkTorborg Date: EDMS t Topical Report 213 Attachment 1 Page 47 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01567224 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/13/2013 Aff System: 153 Event Date: 10/03/2010 CR 4/D Disc Date: 10/03/2010 Level/Class:
How H02 Orig Date: 10/03/2013 Discovered:
Action Request Details
Subject:
TENDON V136 MISSING 1 WIRE.Description:
Originator:
MARVIN H ESPENSHADE Supv Contacted:
Butch Espenshade Condition
==
Description:==
While performing the 40 year tendon surveillance V136 had a missing wire identified on the bottom end. The top had no protruding wires visible.NCR-N1091-002 was generated for engineering to evaluate the as found condition.
Immediate actions taken: Generated this IR to track that engineering(Mike Grimm & Howard Hill)perform an evaluation of NCR-N1091-002 Recommended Actions: Engineering to perform NCR-N1091-002 evaluation on missind wire.Operable Basis: Discussed issue with Engineering.
The missing wire does not impact the operability of the tendon. 169 wires exist in each tendon and per engineering up to 12 wires can be missing, or detensioned, before the structural integrity of the tendon is challenged.
Reasonable assurance exists that tendon V136 remains capable of performing its design function with one wire missing.Reportable Basis: This is not reportable I W the Exelon Reportability manual.Functional Basis: SOC Reviewed by: CRYSTAL A WARLOW 10/04/2013 09:26:03 CDT SOC Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/03/13).
Close to action created. (benson 10/4/13) (SOC 10/04/13)Reviewed by: CRAIG W SMITH 10/03/2013 14:07:35 CDT Reviewer Comments: There are no operability, reportability, or functionality concerns.Topical Report 213 Attachment 1 Page 48 of 110 Assign #: 01 AR #: 01567224 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/08/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
TENDON V136 MISSING 1 WIRE.Assignment Completion In Progress Notes: Completion Notes: t Topical Report 213 Attachment 1 Page 49 of 110 V136 Evaluation and Recommendation 1567224-02 Page 1 of 4 131004 Vertical Tendon V136 Discontinuous Wire Evaluation and Recommendation 11 October 2013 During the as-found visual examination of the V136 bottom end anchor head, one wire button head was observed to be missing. The V136 stressing card completed by SGT at the end of the steam generator replacement outage identifies 169 effective wires; i.e., no missing button heads. The button head was not found in the CPM removed from the V136 hardware.
HovIever, the search for the button head did not includý heating and sieving the CPM. Passing the CPM through a % inch mesh is required by Par. 11.4 of PSC Procedure SQ 8.0, Anchorage Inspection.
During the late 2010 augmented surveillance of Steam Generator Replacement (SGR)tendons, two wires were observed to be protruding above the top anchor head of one vertical.
Subsequent examination determined that both wires had broken at a point close to the bottom face of the top anchor head. As this condition was not documented on the SGT stressing cards, it was concluded that these wires fractured after the as-left examination of the anchor head, i.e., after the application of the Original Stressing Force (OSF) load and final seating of the anchor head on the shim stack and, probably, after re-installation of the end cap.As noted in the above paragraphs, three SGR tendon wires have been found to be discontinuous (two fractured and one for a reason yet to be determined).
The metallurgical report on the evaluation of the br ken wires found in 2010 concluded that these were somehow bent and significantly ov rstressed to the point of eventual failure during installation and / or stressing.
It is important to establish the reason for the apparent failure of the discontinuous wire in V136 and, in particular, to show that there is not a generic issue associated with the SGR tendons; i.e., to show that the breaks found in 2010 and the current discontinuity represent unique, isolated and unrelated events. As the initial search of the removed CPM did not uncover a broken wire segment, it is tentatively concluded that one of the following condillions exists.(1) The button head was incompletely formed and, over time, pulled through the anchor head.(2) The button head detached (a not uncommon phenomenon that generally results from a problem with button header adjustment or operation) and, due to its small size, was missed during the search through the CPM removed from the tendon hardware (some was drained directly into a drum and not searched).
(3) The wire was not button headed at the bottom end, an unlikely but not impossible QC oversight.
Topical Report 213 Attachment 1 Page 50 of 110 V1 36 Evaluation and Recommendation 1567224-02 Page 2 of 4 131004 Condition (2) is considered to be the most likely. Therefore, it is recommended that all of the CPM removed from V136, including the CPM drained directly into the drum, be thoroughly searched by heating and: (1) Trying to retrieve the button head with a magnet and/or;(2) Pumping all heated CPM through a sieve If a detached button head is recovered, this should be sent off for metallurgical examination.
I I If a button head is not recovered, it will be necessary to remove the discontinuous wire for visual and, probably, metallurgical examination to establish cause (continuity test).While at this point it could be postulated that the cause is either a defective button head or no button head, the cause remains indeterminate until the button head or wire is retrieved.
The cause of the break is required to determine if there is a generic issue applicable to the SGR tendons and if corrective actions are required.The discontinuous wire can be identified through the continuity test procedure described in PSC Procedure SQ 10.5 (the tendon must be de-tensioned first). Once it is identified, it can be removed from the tendon by the procedure employed for test wire removal.The current condition of V-136 with 167 effective wires (removal of test wire and loss of an ad litional load carrying wire) does not represent an op rability concern. The tendon is co npletely capable of performing its design function an carrying a pre-stressing load in excess of the required 1033 kips, the current pre-stress on V-136 is 1414 kips.Topical Report 213 Attachment 1 Page 51 of 110 V136 Evaluation and Recommendation 1567224-02 Page 3 of 4 131004 N1091 PSC PROCEDURE SQ 8.0 ANCHORAGE INSPECTION Data Sheet 8.OA 09103/13 Page 1 of I Revision 0 Project: TMI 2013 TENDON SURVEILLANCE Ig UNIT 1 (7.13)Tendon No.: V -, Tendon End:
' Field ANCHORAGE INSPECTION CRITERIA IR As-Found 0 Post De-Tensioning I Pre-Wire Removal [3 Post Re-Tensioning Q.C. Signoff 9.0 & 10,0 CORROSION
& CRACK INSPECTION (9.2) Buttonheads Level: (10.1) Cracks [] Yes 1 7 , No MI N/A (9.2) Anchorhead Level- (10.1) Cracks r'0 Yes 12) RNo Q N/A (9.2) Shims Level: (10.1) Cracks E] Yes 12) No [O N/A (9.2) Bearing Plate Level: (10.1) Cracks [3 Yes [] No 0 N/A ,o-- I)llLCoisroon Leye of C rquims a NCR. {1CoSe a sketch of the cracks on Sketch Sheet 8,0 and Inate a NCR.11.0- PUTTONHEAD IN.PECTION D Offsize (Malformed)
ProtrudIngfunseated
' wire/butlonheads 0 Broken/missing wire/buttonheads
- Pevlousty idenriied as missing 00000000 00000000000 Dlsconllnuous-removed this 000000000000
,,, surveillance.
O2 O0000000000 vira(s) removed during this I 0000000000000C0 suverllance for testing 0000000000000 00000000000000 0000000000000 q 00000000000000 (11.2)Anchorieaddl.D.
Iq oooo00o oooooooo/Located on Sketch [&,Yes [INo 000000000000 (11.4) Missing Buttonheads Found; 00000000000 OO OO 00000000-Yes W No Quantity:.
1 0000000 Additional Information:
(12.2) Number of Protruding Buttonheads (w):(18.31 Illumiaion a 4 2e -2 U (12.3) Number of Missing Buttonheads (0, g _): (12.4) Total of Protruding
+ Missing Buttonheads:
-(12.6) Continuity Test Requested?
0 Yes EJ No (12.5) Total # of Effective Buttonheads Seated: Wtres Identified?
E] Yes E) No (12.7) Overall Results [l Acceptable I. Un-Acceptable Customer Notified NCR#* rJ .CO. -/..QC Reviewed:
Level: Date: 18 SQ 8.O.TMl.13 1Sl Topical Report 213 Attachment 1 Page 52 of 110 V136 Evaluation and Recommendation 1567224-02 Page 4 of 4 131004 NONCONPORMANCE/
CORRECTIVE ACTION REPORT FORMV HOLD TAG NO.: #/A NC ICA NO.: ,Vee- At/01( -a t ?NONCONFORMANCE.,1:
AdA -4ki,4 I n~N f~4 44o heAd-%4 /A Alt%# /p/evst1ily repodAed.
ier Psc proceeck4re SO t -o sec, t3.' wle-u I e~o ne0re n,,.S5,?j wjt5 or &NoV-HWhCA d~ 5 1f die-4C(e 8~go. CKXO-A% 10, 6#8j0. 'Aq 6ý j / A (AfillelY
~ Jjg /fic vo .2-J'I'S S 4 w /f., 0 ,,, 0- -,F-Aitl!E,n
-4 V I i';Cl APPARENT CAUSE KNOWN: Uj YES MMO IF YES, DESCR~IBE:
RECOMMENDED CORRECTIVE ACTION: Cl;w4 4,> .ANY NONCONFORMING ITEM TO BE REPAIRED SHALL HAVE AN APPROVED REPAIR PROCEDURE.
CORRECTIVE ACTION TO PREVENT RECURRENCE:
j #_ INITIATOR:
TITLE DATE: SIGNIFICANT CONDITION:
El YES 9 NO IF YES. REFER TO OAM SECTION 15, APPROVAL COMMENTS: SIGN & DArE: /- 2-Za __/EXELON AP ROVAL REQUIRED 0 YES N- NO ENGINEER D All IQA DATE COMMENTS: DISTRIBUTION DISPOSITION COMPLETED El QASECT'ION 0 VICE PRESIDENT E VENDOR SIGNED: Cl CE SECTION Fj CONTR. MGMT. 0_ _ TITLE: l ENGINEERING
[3 EXELON El _ DATE: 43 OA o'rMI. 3 ISI Topical Report 213 Attachment 1 Page 53 of 110 Assign #: 03 AR #: 01567224 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: GRIMMX Due Date: 12/13/2013 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 12/13/2013 Unit Condition:
Sec Grp: Assignment Details Subject/Description:
Track completion of follow-uplactivites for V-136 Track follow up activities as follows: 1.Retrieve button head from grease using strainer or magnet or; 2. Retrieve broken wire from tendon using a continuity test Assignment Completion In Progress Notes: Grease was heated and run through a strainer.
The buttonhead was not found. This assignment is closed to 1567224-04, technical evaluation that accepts the tendon condition as is.-Michael Grimm 11/27/2013 Completion Notes: Topical Report 213 Attachment 1 Page 54 of 110 Exelon Generation.
Evaluation of Missing Buttonhead 1567224-04 at V-136 Lower Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of V-136 Missing Buttonhead 1 of 3 1.0 Reason for Evaluation/Scope This evaluation is being performed to evaluate the acceptability of a condition in which a buttonhead was found missing on the lower anchorage of vertical tendon V-136 during the 40th Year Tendon Surveillance.
Previously, under assignment 1567224-02, it was identified that while this condition does not represent a failure of the tendon, efforts should be taken to retrieve either the missing buttonhead or the broken wire for evaluation.
Assignment 1567224-03 tracked the completion of activities to locate the missing buttonhead.
This included heating the grease removed from V-136 and draining it through a Y4" strainer/filter in accordance with PSC procedure SQ8.0. The buttonhead was not recovered during this activity.
This evaluation will demonstrate that while the buttonhead was not recovered the condition is acceptable and no further actions are required to retrieve the broken wire.This evaluation was screened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors, however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section XI, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During visual examination of the bottom anchorage of vertical tendon V-136 one buttonhead was observed to be missing. The top anchorage was found with 169 buttonheads, which alig rs with the SGT stressing cards from 2J09, indicating 169 buttonheads for both the top and bottom dlnchorages.
This indicates the 168 observed buttonheads on the bottom anchorage is a post-construction condition.
The corrosion protection medium (CPM) removed from the bottom end of V136 was searched for the broken wire stub and/or buttonhead.
Since nothing was found, it can be concluded that the wire itself did not break, as any length of wire attached to the buttonhead would have made the missing piece larger and easier to find. Additionally, since the as-left examination records from 2009 show 169 acceptable button heads following tensio ing, it can be concluded that the missing wire did not have a significantly undersized button head ýhat may have pulled through the drilled hole in the anchor head.This leads to the conclusion that the button head detached from the wire. Per the Responsible Engineer this is a rare, but not an unheard of condition, which usually results from an imperfection in the forming process inducing an area of weakness due to excessive cold working. Since the button head itself is quite small, it could have easily been missed in the search for a stub wire or, possibly, caught on one of the rags used to wipe CPM from the anchor head.As stated above, detached button heads are rare, isolated events, that are not indicative of a generic condition; either at an individual anchor head or across a set of anchorages regardless of crew and Topical Report 213 Attachment 1 Page 55 of 110 Exelon Generation.
Evaluation of Missing Buttonhead 1567224-04 at V-136 Lower Anchorage PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of V-136 Missing Buttonhead 2 of 3 hydraulic dies. For this reason, there is no concern that additional instances of detached buttonheads at the anchorages of other SGR replacement tendons exist in sufficient numbers to degrade containment integrity.
To date, eight anchorages at the ends of SGR replacement tendons have been examined with no evidence of other detached buttonheads.
The current condition of V-136 with 167 effective wires (removal of test wire and loss of an additional load carrying wire due to a missing buttonhead) does not represent an operability concern. The tendon is completely capable of performing its design function and carryinL a pre-stressing load in excess of the required 1033 kips as each tendon wire is capable of carrying a load of 11.77 kips or 1966 kips total with 167 wires. The current pre-stressing force on V-136 in the as-left condition is 1414 kips.3.0 Conclusion/Findings For the above reasons, it is concluded that the missing buttonhead at the bottom anchorage of V136 is an isolated finding and does not represent current or potential future degradation of the TMI-1 pre-stressing system. The loss of a single effective vertical tendon wire is an insignificant condition with respect to the structural integrity of the Reactor Building and the ability of the tendon to perform its design function.
Therefore, the condition is deemed acceptable as-is and no further examinations or evaluations are required.
However, as the broken wire was not retrieved during the 4 0 th Year Tendon Surveillance, it is recommended that an additional visual examination be performed on the bottom anchorage of vertical tendon during the 4 5 th year Tendon Surveillance (scheduled for 2018). This is to provide ye rfication that the missing wire found at the V136 bottom anchorage was the result of a unique and isolated event.4.0 References
- 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revi ion 23A, RB Structural Integrity Tendon Surveillance
- 4. IR 1567224, T"ndon V-136 Missing 1 Wire T 5.0 Attachments None S Topical Report 213 Attachment 1 Page 56 of 110 Exelon Generation.
Evaluation of Missing Buttonhead at V-136 Lower Anchorage PREPARED BY SUBJECT Michael Grimm Evaluation of V-136 Missing Buttonhead 1567224-04 PAGE 3 of 3 Approvals Responsible Engineer:
Howard Hill Preparer:
Michael Grimm Independent Reviewer:
Sean Taylor Manager: MarkTorborg Date: EDMS Date: EDMS Date: EDMS Date: EDMS Topical Report 213 Attachment 1 Page 57 of 110 0Go Back Print I New Search I Home AR Number: 01569458 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 11/07/2013 Aff System: 153 Event Date: 10/07/2013 CR 4/D Disc Date: 10/07/2013 Level/Class:
How H02 Orig Date: 10/08/2013 Discovered:
Action Request Details
Subject:
, LOCK-OFF FORCE IN TENDON V-136 EXCEEDED ACCEPTANCE CRITERIA
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
John Piazza/Mark Torborg Condition
==
Description:==
During tendon surveillance activities, selected tendons are de-tensioned (pre-stressing force is removed) and a wire sample is taken from the tendon. The tendons are then re-stressed to within plus 6%/minus 0% of the as-found lift off force or 7 0% of the Guaranteed Ultimate Tensile Strength (GUTS), whichever is less, by procedure 1301-9.1 and PSC Vendor Procedures.
During re-stressing activities vertical tendon V-136 was locked-off at 1414 kips. This value exc eds the 7 0% GUTS value allowed by procedure as determined by the effecti e number of wires. This condition was identified during the data sheet review by the Responsible Engineer.V-136 has 167 effective wires (one broken, one removed for testing), 70%GUTS corresponds to 8.24 kip per effective wire or 1376 kips. The lock-off value of 1414 kips corresponds to 72% GUTS.This condition has no impact on the ability of the tendon to perform its function and does not compromise the tendon integrity as it does not exceed the Guaranteed Ultimate Tensile Strength of the tendon wire material.
The lock-off force of 1414 kips restores the tendon pre-stress to the as-left condition during the Steam Generator lReplacement Project, 71% GUTS, which was performed by a different procedure with different acceptance criteria.Immediate actions taken: IR initiated NCR issued by PSC Recommended Actions: Revision to PSC procedure SQ 11.0 to clarify requirement to not exceed 7 0%GUTS during re-tensioning.
What activities, processes, or procedures were involved?Review of Tendon Surveillance data sheets by the Responsible Engineer.Why did the condition happen?Topical Report 213 Attachment 1 Page 58 of 110 During re-tensioning activities PSC restored the tendon to the as-found condition instead of the 70% GUTS condition as required by the procedure.
What are the consequences?
There are no adverse consequences on the containment or the tendon. The tendon is capable of performing its intended design function and is within the guaranteed strength of the material.Were any procedural requirements impacted?The lock-off force exceeded the acceptance criteria of both the approved PSC Vendor Procedures and the TMI Surveillance Procedure 1301-9.1.Were there any adverse physical conditions?
There arý no adverse physical conditions.
The tendon stress is higher than the acceptable value; however it is well within the guaranteed strength of the tendon material.
The containment and the tendon are capable of performing their design functions in this condition.
List of knowledgeable individuals:
John Piazza Mark Torborg Michael Grimm Sean Taylor Howard Hill Repeat or similar condition?
No Operable Basis: Reviewed TS 3.19 and 4.4.2. Tendon V-136 is tensioned slightly greater than desired. However, this does not compromise its ability to perform its intended function.
Applied forces are greater than the minimum required by procedure (1033 Kips) and lust slightly greater than the upper target of 1376 Kips. The as left corresponds to 72% GUTS which is well below the ultimate yield strength of the tendon.As noted in the IR, this condition has no impact on the ability of the tendon to perform its function and does not compromise the tendon integrity as it does not exceed the Guaranteed Ultimate Tensile Strength of the tendon wire material.
The lock-off force of 1414 kips restores the tendon pre-stress to the as-left condition during the Steam Generator Replacement Project, 71% GUTS, which was performed by a different procedure with different cceptance criteria..Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability?
TS 3.19, 4.4.2, 1301-9.1 3. Describe the function of the SSC and basis for operability/availability determination.
See below 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103.
- 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO The following functions are maintained even with the slightly greater applied force on this tendon.Topical Report 213 Attachment 1 Page 59 of 110 153-ROl Contain fission products to prevent radioactive release (153).153-R02 Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 : Maintain structural integrity (153).Reportable Basis: This does not meet any reporting thresholds.
Functional Basis: Reviewed by: EDWARD M CARRERAS 1/08/2013 23:39:35 CDT Reviewer Comments: Added Reactor Building as the component ID. Engineering review is required.SOC Reviewed by: DIANE M SCHNEIDER 10/10/2013 09:52:14 CDT SOC Comments: REACTOR BUILDING(#1)
This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/09/13).
HU has been adressed with the PSC crew (Kaplan,BD 10/10/13).
Close to actions taken/created. (benson 10/10/13) (SOC 10/10/13)Topical Report 213 Attachment 1 Page 60 of 110 Assign #: 01 AR #: 01569458 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/13/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details SubjectlDescription:
LOCK-OFF FORCE IN TENDON V-136 EXCEEDED ACCEPTANCE CRITERIA Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 61 of 110 Assign #: 02 AR #: 01569458 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: STEIHX Due Date: 10/18/2013 Schedule Ref: Prim Grp: A5520MS Orig Due Date: 10/18/2013 Unit Condition:
Sec Grp: Assignment Details Subject/Description: (Steinj Verify (PSC) has revised PSC procedure SQ 11.0 to clarify requirement to not exceed 70% GUTS during re-tensioning.
Create additional action as needed.Assignment Completion, In Progress Notes: Completion Notes: 9.8.3 Lock-off Force (LOF) -That force at which the tendon load is transferred to the shim stack from the ram. If the detensioned tendon had an accepted lift-off force greater than its Predicted Force obtained in PSC Procedure SQ 9.0 the Lock-Off Force shall be the as found lift-off force within a tolerance of minus 0% and plus 6%. If the detensioned tendon had a lift-off force less than its Predicted Force obtained in PSC Procedure SQ 9.0 the Lock-Off Force shall be the Predicted Force from PSC Procedure SQ 9.1 within a tolerance of minus 0% and plus 6%. Lock-off Force is not to exceed 70% of G.U.T.S. (1394 kips for a 169 wire tendon, or 8.25 kips per wire).Topical Report 213 Attachment 1 Page 62 of 110 0 Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01572452 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5520CAP Due Date: 11/14/2013 Aff System: 153 Event Date: 10/15/2013 CR 4/D Disc Date: 10/15/2013 Level/Class:
How H02 Orig Date: 10/15/2013 Discovered:
Action Request Details
Subject:
DOME TENDON D-143 IDENTIFIED TO BE INACCESSIBLE
==
Description:==
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
The tendons selected for examination during the 40th Year Tendon Surveillance were walked down prior to the start of the surveillance to identify any tendons that were inaccessible.
During the walk down dome tendon D-143 was not identified as inaccessible.
During the performance of surveillance activities, it wa-s identified that an installed Seismic Box, with Accelerometer, created an interference with the hydraulic ram, making the tendon inaccessible for surveillance.
Per the requirements of ASME Section XI Subsection IWL-2541.1 the closest tendon, not previously inspected, shall be selected as a s bstitute.
The inaccessible tendon shall have a visual examination and a grease sample taken for analysis.The nearest accessible tendon for surveillance is D-146.Immediate actions taken: Verified condition in field Wrote this IR Recommended Actions: 1. Add replacemerlt tendon D-146 to the scope of the surveillance for examination (lift-off, visual, and grease sample).2. Perform visual examination and take a grease sample from D-143.3. Identify why the condition was not identified during pre-surveillance walk downs.What activities, processes, or procedures were involved?Tendon surveillance activities on Dome Tendons.Why did the condition happen?Pre-surveillance walk down of tendon did not identify the interference.
What are the consequences?
Tendon is inaccessible, and additional adjacent tendon is required to be selected and examined.
The inaccessible tendon is examined to the extent possible.Were any procedural requirements impacted?Topical Report 213 Attachment 1 Page 63 of 110 No Were there any adverse physical conditions?
No List of knowledgeable individuals:
Mark Torborg Butch Espenshade Howard Stein Mike Grimm Repeat or similar condition?
Yes Pre surveillance tendons H24-15 and H13-08 were identified to be inaccessible and alternate tendons were selected for exa mination.Operable Basis: Reportable Basis: Functional Basis: Reviewed by: ROBERT R BRADY 10/16/2013 04:01:45 CDT Reviewer Comments: Reviewed by Operations for operability and reportability.
This issue has no impact on the ability to safely operate the plant, to achieve or maintain the plant in a safe shutdown condition, or to mitigate the effect of any accident condition.
This is a process issue that does not identify an equipment deficiency that affects operability of any SSC. There are no operability or reportability concerns.SOC Reviewed by: CR4STAL A WARLOW 10/18/2013 09:46:55 CDT SOC Comments: REACTOR BUILDING This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 10/16/13).
Recommended Actions 1 &2 should go to Maintenance Support (Howard Stein)for scheduling.
and Recommended action 3 should go to Maintenance Support (Butch Espenshade) for review of how it was missed.Followup to Maint CR to address actions. (SOC 1 /17/13)RA#1 -Completed 10/17/2013.
RA#2 -Scheduled under existing work order for 10/18/2013.
RA#3 -Walkdowns were done prior to ability to be at the tendon with use of inspection platform.
Interference was not seen during walkdown due to the inaccessiblity Close to comments and actions taken. (Smokowicz 10/17/13) (SOC 10/18/13)10/16/2013
-Per the IR Originator's request, corrected Tendon Nos.throughout the IR. D. Hockley Reviewed by: JONATHAN J SMOKOWICZ 10/17/2013 16:12:06 CDT Reviewer Comments: Topical Report 213 Attachment 1 Page 64 of 110 Assign #: 01 AR #: 01572452 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 10/20/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
DOME TENDON D-143 IDENTIFIED TO BE INACCESSIBLE Assignment Completion In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 65 of 110 0 Go Back Print New Search I Home AR Number: 01585403 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5551CAP Due Date: 12/30/2013 Aff System: 153 Event Date: 11/14/2013 CR 4/D Disc Date: 11/14/2013 Level/Class:
How H02 Orig Date: 11/14/2013 Discovered:
Action Request Details
Subject:
TENDON REGREASING EXCEEDED ACCEPTANCE LIMITS
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
John Piazza Condition
==
Description:==
The tendon population selected for inspection during the 40th year tendon surveillance included four dome tendons. Of the four dome tendons, one was found to be inaccessible during the conduct of surveillance activities (IR 1572452), and a replacement was selected.
All five dome tendons had end caps removed and inspection activities performed:
D-143 D-146 D-237 D-22 During the conduct of the surveillance activities, the bulk filler grease that protects the tendons from corrosion drains from the tendon conduit.The grease is collected in drums and the amount removed is measured.
The tendon duct is then refilled with grease after inspection activities are completed.
Per procedure 1301-9.1, the regreasing is required to be with-0/+10% of the total tendon duct volume. Reference AR Evals A2238266-02 and 04 for the computed tendon duct volumes.During refill activities, three dome tendons took more the +10% duct volume to fill.D-143 .+59.94% grease fill D-146 .+58.84% grease fill D-237 .+48.08% grease fill It is noted that no grease leakage was noted from the dome area of the containment building prior to the conduct of inspection activities.
Additionally no water was found in the grease removed from the dome tendons. A wire sample was taken from D-237 and no corrosion was noted on the wire surface.Immediate actions taken: Contacted Responsible Engineer Wrote IR Recommended Actions: Topical Report 213 Attachment 1 Page 66 of 110
- 1. Evaluate cause of the condition and acceptability for continued service.What activities, processes, or procedures were involved?Tendon Surveillance Activities
/ regreasing Why did the condition happen?The condition is a result of original construction greasing.
The grease was pumped into the tendon duct using the opposite end cap as the vent point. As the dome is spherical, the high point of the tendon duct is at a higher elevation than the vent location.
Dome tendons that run along the outer edges of dome have less of an elevation difference and as a result will have a smaller grease void.What are the consequences?
The consequences of the grease void is that a section of the dome tendons is not covered by bulk filler grease. There are no adverse consequences on the containment as these three dome tendons were tested satisfactorily.
The lift-off and grease visuals were acceptable and as expected.
A wire sample was pulled from D-237 and did not show signs of corrosion.
Were any procedural requirements impacted?The grease refill did not meet the acceptance criteria of 1301-9.1.Were there any adverse physical conditions?
There are no adverse physical conditions in the containment.
The dome tendons are performing their functions as demonstrated by the acceptable lift-off tests. Additinally there is no noted grease leakage from the dome tendons and there was no water found in the tendon grease or end caps.Additionally there was no corrosion found on the wire sample taken from D-237 which stands as a representative sample. The tendon wires were coated in Viscon rust 1601 Amber, that per UFSAR section 5.2.2.3.7 provides protectifon from corrosion prior to bulk grease filling.List of knowledgeable individuals:
Michael Grimm Sean Taylor Howard Hill Repeat or similar condition?
No Operable Basis: As stated in ht body of the IR there are nooperability issues with the containment.
Reportable Basis: There are o reportability concerns Functional Basis: Reviewed by: MARKO MALINEN 11/14/2013 21:02:26 CST Reviewer Comments: MPM SOC Reviewed by: CRYSTAL A WARLOW 11/16/2013 10:47:32 CST SOC Comments: Close to action created (BBalliet 11/15/13) (SOC 11/16/13)Topical Report 213 Attachment 1 Page 67 of 110 I I Topical Report 213 Attachment 1 Page 68 of 110 Assign #: 01 AR #: 01585403 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 11/19/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
TENDON REGREASING EXCEEDED ACCEPTANCE LIMITS Assignment Completion In Progress Notes: Completion Notes:.t Topical Report 213 Attachment 1 Page 69 of 110 Exeton Generation.
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 1 of 5 1.0 Reason for Evaluation/Scope During tendon bulk filler grease (Corrosion Protection Medium (CPM)) refill activities in the dome tendons during the TMI Unit 1 40th Year Tendon Surveillance, the quantity of refill tendon grease was found to exceed the acceptance criteria specified in Exelon Procedure ER-AA-330-006 Revision 7, section 4.4.4.1, states: I I"The absolute difference between quantity of corrosion protection medium (sheathing filler grease)removed and amount replaced shall not EXCEED 10% of net duct volume." I I The purpose of this evaluation is to evaluate this condition for its affect on containment integrity and to determine its acceptability for continued service. This evaluation is conducted in accordance with CC-AA-309-101, Engineering Technical Evaluations, and ASME Section XI 2004 Edition, Subsection IWL.This evaluation wasscreened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors; however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation As IR 1585403 documents, dome tendon regreasing activities conducted during the TMI Unit 1 4 0 th Year Tendon Surveillance resulted in grease fill exceeding the acceptance criteria of PSC procedure SQ 12.1 and Exelon procedure ER-AA-330-006 of 10% of the total net duct volume. The actual quantities of grease replaced are shown below in table 1.Table 1: Grease Replacement Volumes% Difference Net Duct Grease Added' tal Grease Total Duct Volume Te don Volume 1 (Gallons)
Replaced (Gallons) (Gallons)D143 59.94% 51.2 70.69 85.4 D146 58.84% 47.7 63.16 81.0 D237 48.08% 44.6 65.37 92.8 Notel: Net duct volume is gross volume of duct, trumpets and end caps less the volume of tendon wire, anchor heads and shims.Note 2: Grease added is the difference between the grease removed during surveillance activities and that pumped back into the tendon a Topical Report 213 Attachment 1 Page 70 of 110 Exelon Generation.
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 2 of 5 As there has been no evidence of significant leakage at the tendon end caps as evidenced from Topical Report 150, it can be concluded that the tendon ducts did not drain during their 40 year service life. Thusly this implies that the tendon ducts were not completely filled at the time of construction.
TMI does not have high point vents for the dome tendons; as such the observed condition is not unexpected.
I I During construction, dome tendon ducts were generally filled with CPM in pairs. The supply hose from the pump was connected at the end of one tendon and the return (to the hot CPM reservoir) hose at the nearby end of an adjacent tendon. A third hose was connected to the far ends of the two tendons. CPM was pumped through the two tendons until the CPM exiting the end cap at the return end reached a specified temperature.
At that point, the supply and return hoses were isolated by valves and the end caps sealed by threaded plugs inserted through the fittings used to attach the hoses.This procedure ensured that the duct on the inlet side of both tendons was filled to the high point and that the end caps on the outlet ends were filled. But, since the hot, fluid CMP flowed freely from the high points to the outlet end caps, the air voids on the outlet sides of the ducts were not necessarily purged. As a consequence, it is expected that dome tendon ducts have significant air voids trapped between the duct high points and the end caps on the return ends.It should be noted that while this condition is not 4 uexpected, past tendon surveillances at TMI have not reported grease voids in excess of the acceptance criteria.
This may be due to limitations within the procedure used for grease refill, or these three tendons could be an anomaly from original plant construction.
As the number of confirmed dome tendons affected by this condition is small, and the lack of high point vents to allow for the filling of the duct, it is desired to show by evaluation that the dome tendons will continue to perform acceptably for the remainder of plant life.Unlike typical Bechtel containments, the TMI Unit 1 containment uses schedule 40 pipe for the tendon duct than rolled spiral seam sheet metal. As such the pipe du ts are impervious to water penetration and are well protected from exterior corrosion by the suriounding alkaline concrete environment.
Since water penetration is not an issue with the TMI design, it is not necessary to fill tendon duct with bulk filler grease (CPM) as the entry point for water into the tendon duct is at the low points (tendon end caps). During initial tendon greasing, grease was pumped through the tendon duct from one end until a constant stream of grease exited the opposite side, ensuring that the tendon end caps are filled with CPM. This is sufficient for preventing water intrusion into the tendon end cap and lower portions of the tendon duct, and thusly into the upper portions.Additionally, during construction, the TMI tendons were coated with a hard wax-like corrosion preventive material, Visconorust 1601 Amber, as referenced in the TMI Updated Final Safety Analysis Report section 5.2.2.3.7.
Further during CPM pump through, the tendon wires would Topical Report 213 Attachment 1 Page 71 of 110 Exelon Generation.
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 3 of 5 experience some CPM coating. Therefore, the tendon wire maintains some corrosion protection against the initial environment within the tendon duct.The dome area above the ring girder is well drained with no areas in which rain water or snow melt can collect in significant quantity, percolate into the concrete, and accumulate around the tendon ducts. To date 72 TMI-1 dome tendon anchorages (both ends of 36 dome tendons) have been examined under the containment ISI program. Forithe life of the plant (40 years), no significant water intrusion has been noted, and all grease samples taken from the dome tendons have met the acceptance criteria in procedure ER-AA-330-006.
Test wires have been removed from 10 tendons and examined.
No significant corrosion has been found and all wire samples have had satisfactory tensile tests. This provides convincing evidence that water intrusion and wire corrosion are not areas of concern for the TMI Unit 1 dome tendons.Additional industry Operating Experience (OPEX) on tendon grease voids was reviewed for applicability to TMI. Both Crystal River Unit 3 (OE 169794 and 178114) and South Texas (CE 121945)have identified grease replacements that exceeded the acceptance criteria on their vertical tendons.Both plants reported that the conditions did not pose a containment integrity issue, and no tendon degradation was observed.3.0 Conclusion/Findings The above discussion supports the conclusion that the observed shortfall of CPI does not have an adverse impact on the dome tendon integrity.
The geometry of the dome and the rigid pipe duct ensure that tendons are fully protected from water intrusion.
The shop coating of Visconorust 1601 Amber on the tendon wires and further coating during CPM installation ensures that the bare tendon wire is not exposed to a possibly moist atmosphere in those segments of duct that are not completely filled with CPM. Extensive examinations conducted to date provide conclusive evidence that there has been no degradation of the TMI Unit 1 dome tendon wires, and scheduled future examinations are expected to yield similar results. Therefore it is concluded that the as-found grease void condition in the dome tendons is acceptable for continued operation and no further inspection or repair activities are required It this time.4.0 References
- 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance
- 4. TMI-1 UFSAR Chapter 5 5. IR 1585403, Tendon Regreasing Exceeded Acceptance Limits 6. Tendon Surveillance Topical Reports 7. InRyco Drawings PS-xx series Topical Report 213 Attachment 1 Page 72 of 110 ExeLon Generation.
Evaluation of Dome Grease Voids 1585403-02 that Exceed Acceptance Criteria PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 4 of 5 5.0 Attachments None Topical Report 213 Attachment 1 Page 73 of 110 INEMW Exeton Generation.
Evaluation of Dome Grease Voids that Exceed Acceptance Criteria 1585403-02 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of 4 0 th Year Surveillance Dome Grease Voids 5 of 5 Approvals Responsible Engineer:
Howard Hill Preparer:
Michael Grimm Independent Reviewer:
Sealn Taylor Manager: Mark Torborg Date: EDMS Date: EDMS Date: EDMS I Date: EDMS Topical Report 213 Attachment 1 Page 74 of 110 Full Action Request Report Page I of 5 O Go Back Print I New Search Home AR Number: 01587456 Linked ARs Aff Fac: Three Mile AR Type: CR Status: COMPLETE Island Aff Unit: 01 Owed To: A5520CAP Due Date: 12/20/2013 Aff System: 153 Event Date: 11/18/2013 CR 4/D Disc Date: 11/19/2013 Level/Class:
How H02 Orig Date: 11/19/2013 Discovered:
Action Request Details
Subject:
SURVEILLANCE TENDON DE-TENSIONED BEFORE LIFT-OFF COMPLETED
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
The random tendon selection for the TMI Unit 1 40th Year Tendon Surveillance included Hoop Tendon H13-03. H13-03 was originally tensioned from a single-end (Buttress
- 1) during construction due to interferences and as such it is expected that the opposite end (Buttress
- 3) will have a lower lift-off force.IR 1541172 was put in previously for another single-end tensioned tendon (H24-15) to declare the tendon inaccessible as it was not possible to ccess both ends of the tendon. Per ASME Section XI, 2004 Editioln, ubsection IWL-3000 the average lift-off value from both ends shiall be used for comparison to the acceptance criteria.
This implies that All tendons should have the lift-off test performed from both ends. TMI has proceduralized that all dome and hoop tendons shall have lift-off tests performed from both ends, only vertical tendons are exempt from this requirement.
Per Exelon procedure and ASME Section XI, it was determined that any hoop tendon not accessible from both ends, regardless of how the tendon was originally stressed, would be declared inaccessible.
TMI has taken a further stance that information only lift-offs will be performed on single-end tensioned tendons inaccessible from the opposite end to comply with the intent of ASME Section XI, Subsection IWL-2521 which states that the tendon anc orage shall be examined to the extent practical.
Due to questions raised around this issue during the planning phase of the tendon project, a decision tree flow diagram was issued to PSC under assignment 1541172-02.
This decision tree was intended to provide a visual representation to aide PSC and Exelon personnel with determining the best course of action for various conditions (such as this one) during the surveillance.
During the pre-surveillance walkdowns it was identified that both ends of H13-03 were accessible for lift-off testing. As a result, this tendon was not declared inaccessible and PSC was instructed to test the tendon, de-tension, and re-tension the tendon from both buttresses.
Once in the field for performance of the surveillance on H13-03, PSC identified that they could not in fact couple their ram to the tendon to perform the lift-off measurement.
PSC did not stop work, and continued to de-tension the tendon from one end, after lift-off was performed from the Topical Report 213 Attachment 1 Page 75 of 110 http://eamgenco.ceco.com/cap/serv let/ReportFu I IA RServ let 4/10/2014 Full Action Request Report Page 2 of 5 accessible end. This course of action was not proscribed by the decision tree and is counter to PSC procedure SQ9.0 which states: "The tendon will have been monitored for tendon force as required of PSC Procedure SQ9.0. The De-tensioning shall continue from that point where the final or third liftoff was taken. The tendon shall not be de-tensioned until the liftoffs are documented.
The ram will still be coupled to the anchorage that all Hoop tendons are to have lift-off tests performed from both ends." In addition, the measurement of the lift-off on H13-03 was counter to PSC procedure SQ9.0 which states the following: "Monitoring of Tendon Force can be performed on both ends of a tendon in a nimultaneous and controlled manner or on one tendon end at a titne, independent of the opposite end of the tendon. These procedures have been developed so that they apply to one end of the tendon. Every effort should be made to measure lift-off at opposite ends of a tendon at the same time.If this is prohibited by plant conditions (i.e., one end is accessible only with the plant operating and the other only when the plant is shut down), then measurements must be made as close together in time as possible and under similar temperature regimes. Adequate communication shall be maintained between both ends of the tendon during the taking of lift-off readings for simultaneous stressing operations.
Vertical tendon monitoring of force is to be performed from one end, top end, only unless the tendon was double end stressed during original installation." As H13-03 is not a vertical tendon the lift-off testing of a single-end is not acceptable.
Further PSC procedure SQ10.0 specifies that both ends of a tendon be de-tensioned in unison except single-end stressed vertical tendons. Thus the de-tensioning of H13-03 from one end violated the procedure SQ10.0.Finally PSC and TMI do not havr a procedure that allows for or addresses the re-tensioning of hoop tend d ns from a single-end.
PSC procedure SQ12.0 states that "Retensioning of te' dons shall be performed on both ends of a hoop and dome tendon, or, single end of a vertical tendon which are only retensioned from the top end. Where it is not possible to perform simultaneous stressing of a tendon, Exelon Engineering shall be notified in writing to provide resolution for such conditions." Immediate actions taken: IR initiated PSC personnel modified the ram jib arm to allow access tp the Buttress 3 end of H13-03.Recommended Actions: 1. Maintenance Support to address Human Performance issue 2. Engineering to perform technical evaluation to determine the average as-found tendon pre-stressing force.3. Maintenance to submit vendor FMS What activities, processes, or procedures were involved?Conduct of tendon surveillance activities.
Why did the condition happen?Failure to comply with procedure Topical Report 213 Attachment 1 Page 76 of 110 http://eaiigenco.ceco.com/cap/servlet/ReportFuIlARServ let 4/10/2014 Full Action Request Report Page 3 of 5 What are the consequences?
Per the intent of ASME Section XI, subsection IWL and TMI engineering position the lift-off of H13-03 does not constitute a code exam as it was not taken from both ends of the tendon. However, the as-found average pre-stressing force in the tendon can be determined through a computation using the tendon elongation during re-tensioning activities.
Were any procedural requirements impacted?PSC procedures SQ9.0, SQ10.0, and SQ12.0 were violated during the performance of surveillance activities on H13-03. Further engineering was not notified of the non-conforming condition.
Were there any adverse physical conditions?
None. The plant is currently in Cold Shutdown, however, it is acceptable to have one h~op tendon de-tensioned while the plant is in operation.
List of knowledgeable individuals:
Mark Torborg Michael Grimm, Sean Taylor Howard Hill Repeat or similar condition?
No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: BRADLEY A PARFITT 11/20/2013 11:39:55 CST Reviewer Comments: Reviewed by Operations for operability and reportability.
This issue has no impact on the ability to safely operate the plant, to achieve or maintain the plant in a safe shutdown condition, or to mitigate the effect of any accident condition.
This issue does not identify an equipment deficiency that affects operability or functionality of any SSC. the as-found average pre-stressing force in the tendon can be determined through a computation using the tendon elongation during re-tensioning activities.
The tendon will be retensioned prior to heat up, however, it is acciptable to have one hoop tendon de-tensioned while the plant is i h opera ion. This issue is not reportable because this condition doesn't meet 6r exceed any reportability criteria of the Exelon Reportability Reference Manual.SOC Reviewed by: CRYSTAL A WARLOW 11/21/2013 09:56:12 CST SOC Comments: Tendon surveillances are complete.
HU addressed with contractor.
Action created to submit FMS for contractor.
Close to actions created/taken (Smokowicz 11/21/2013)
Action created for RA#2. (Lytle 11/21/13)Close to actions taken/created. (SOC 11/21/13)Topical Report 213 Attachment 1 Page 77 of 110 http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet 4/10/2014 Full Action Request Report Page 4 of 5 Assign #: 01 AR #: 01587456 0 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 11/24/2013 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
SURVEILLANCE TENDON DE-TENSIONdD BEFORE LIFT-OFF COMPLETED Assignment Completion In Progress Notes: Completion Notes: 0 Topical Report 213 Attachment 1 Page 78 of 110 http://eam-genco.ceco.comn/cap/servlet/ReportFulIARServlet 4/10/2014 Full Action Request Report Page 5 of 5' Assign #: 02 AR #: 01587456 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: STEIHX Due Date: 12/20/2013 Schedule Ref: Prim Grp: A5520MAINT Orig Due Date: 12/20/2013 Unit Condition:
Sec Grp: Assignment Details I Subject/Description:
Submit FMS for vendor PSC Assignment Completion In Progress Notes: Surveillance Tendon H 13-03 De-tensioned before Liftoff of other Tendon End Contract & Procedure The 40th Year Tendon Surveillance was performed by Precision Surveillance Corp. The surveillance process followed an approved Procedure that incorporated both Station and Corporate requirements.
N1091 PSC Procedure SQ 10.0, Section 8.0 Detensioning the Tendon, provides direction for this activity.Procedure SQ 10.0, Section 8.0 Detensioning the Tendon"Both ends of a tendon shall be de-tensioned in unison unless otherwise directed by the PSC Superintendent." The H13-03 hoop tendon was only tensioned from one (1) end during Station construction as confirmed by the shim on the side that PSC initially detensioned being a proximately 14 inches thick whereas the opposite end shim thickness was he minimal 2 inches thickness for a non-tensioned end.Based on this finding, PSC elected only to detension from one end (following the Procedure).
Per direction from the Station via Howard Hill (consulting engineer), PSC retensioned H13-03 from both ends.Recommendations
- 1) Insure that Station requirements are made clear in the Procedure (which was updated, reviewed and approved by the Station).2) Clearly define during the walkdown as well as confirm via the Schedule Description for each tendon when a tendon is to be retensioned from both ends. Secondly, a Summary Scope 9 f Work should be developed that clearly describes what is to be performed for elch tendon to be surveyed.As-Built Tendon Card Shows one end was stressed.Completion Notes: 0 Topical Report 213 Attachment 1 Page 79 of 110 http://eamgenco.ceco.com/cap/servlet/ReportFullARServlet 4/10/2 014 Full Action Request Report Page I of 3 0 Go Back Print I New Search Home AR Number: 01645620 Linked ARs Aff Fac: Three Mile AR Type: CR Status: APPROVED Island Aff Unit: 01 Owed To: A5551CAP Due Date: 05/10/2014 Aff System: 153 Event Date: 04/09/2014 CR / Disc Date: 04/09/2014 Level/Class:
How H02 Orig Date: 04/10/2014 Discovered:
Action Request Details
Subject:
REVISION REQUIRED FOR TECHNICAL EVALUATION 1587456-03
==
Description:==
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
During the preparation of the 40th Year Tendon Surveillance Topical Report 213 it was identified that an alternate method for computing the average tendon pre-stressing force would provide a more conservative result for trending purposes.
The average pre-stressing force in the tendons is used to demonstrate that the expected tendon pre-stressing force will be greater than the minimum required pre-stressing force at the time of the next tendon surveillance.
This IR is written to supersede the original technical ev luation.Immediate actions taken: Revised the technical evaluation Issued IR Recommended Actions: Close to actions taken.What activities, processes, or procedures were involved?Preparation of the 40th Year Tendon Surveillance Topical Report 213.Why did the con lition happen?A different methodology was used in the preparation of the original evaluation under IR 1587456-03 that was not as conservative.
A more conservative approach was utilized in the revision of the technical evaluation.
What are the consequences?
None, the force computed in the technical evaluation is not used for acceptance of the tendon's as-found condition, but is utilized in the hoop tendon force trend to predict the expected pre-stressing force at the time of the next surveillance.
Were any procedural requirements impacted?No Were there any adverse physical conditions?
None List of knowledgeable individuals:
Topical Report 213 Attachment 1 Page 80 of 110 http://eamngenco.ceco.com/cap/servlet/ReportFullARServ let 4/14/20 14 Full Action Request Report Page 21 of 3 Mike Grimm Sean Taylor Mark Torborg Repeat or similar condition?
No Operable Basis: Reportable Basis: Functional Basis: Reviewed by: JOSEPH W KULASINSKY 04/10/2014 13:28:54 CDT Reviewer Comments: The information in the Tech Eval is not used to determine surveillance testing acceptance criteria.
Reasonable assurance exists that the RB tendons remain operable.
There are no reportability or functionality concerns.SOC Reviewed by: RANDY E HESS 04/11/2014 10:53:43 CDT SOC Comments: Close to action created. (benson 4/11/14)Topical Report 213 Attachment 1 Page 81 of 110 http://earngenco.ceco.comn/cap/servlet/ReportFullARServlet 4/14/2014 Full Action Request Report Page 3 of 3 Assign #: 01 AR #: 01645620 Aff Fac: Three Mile Island Assign Type: TRKG Status: AWAIT/C Priority:
Assigned To: Due Date: 04/15/2014 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details Subject/Description:
REVISION REQUIRED FOR TECHNICAL EVALUATION 158ý456-03 Assignment Completion I I In Progress Notes: Completion Notes: Topical Report 213 Attachment 1 Page 82 of 110 http://eai-genco.ceco.co-n/cap/servlet/ReportFullARServlet 4/14/2 014 Exelon Generation.
Evaluation of As-Found Force 1645620-02 for H 13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 1 of 6 1.0 Reason for Evaluation/Scope The purpose of this evaluation is to determine the as-found average pre-stress force in hoop tendon H13-03. H13-03 was single-end stressed during plant construction due to access restrictions during the construction process. Prior to the 4 0 th Year Tendon Surveillance it was determined that both ends of H13-03 were accessible for testing and the tendon was not declared inaccessible.
During surveillance activities, safety related conduit was found to be in the way of the ram jib arm and as a result the Buttress 3 end was not tested. Further H13-03 was de-tensioned without informing engineering, reference IR 1587456 for complete description.
ASME Section XI 2004 Edition No Addenda Subsection IWL, Subsection IWL-2522(a) requires that"The pre-stressing force in all inspection sample tendons shall be measured by lift-off or an equivalent test." The force in a curved tendon is normally documented as the average of the lift-off values measured at the individual ends. However, this is not mandated in IWL. A technically acceptable alternative, i.e., "equivalent test", for tendons that are de-tensioned/re-tensioned is to compute tendon mean force using the as-found shim stack height, the re-tensioning force/elongation data, tendon length, tendon area and elastic modulus of the wire.This evaluation will analytically determine the as-found average pre-stressing force on tendon H13-03. The computed mean force will be used in the hoop tendon normalized group mean force and mean force trend projections.
The H13-03 predicte force (C-1101-153-E410-046) is based on the single end (Buttress
- 1) lock-off force as documentedIon the stressing cards. Therefore, force measured at the tensioned end of H13-03 (Buttress 1), and not the computed mean, is compared to the predicted value for the purpose of determining the acceptability of time dependent losses (which are normally assumed to be relatively proportional at all points along the tendon length)experienced by this tendon. Therefore, special considerations are required to compare the "as-found" and predicted forces. These considerations are discussed the following evaluation.
This evaluatio was screened per HU-AA-1212.
Review of attachment 2 of H -AA-1212 identified no risk f hoever, as this evaluation pertains to a safety related componeft, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation During the 40th Year Tendon Surveillance hoop tendon H13-03 was lift-off tested from one end and then detensioned.
This single end lift-off provides the data needed to establish time dependent losses and the acceptability of these as determined by comparing this lift-off force to the predicted value. The predicted value, taken from Calculation C-1101-153-E410-046, is based on the "as-installed" lock-off force, which was performed from one end (Buttress 1). For this reason it is reasonable to use the single-end lift-off measurement from Buttress 1 for direct comparison with Topical Report 213 Attachment 1 Page 83 of 110 ExeLon Generation.
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 2 of 6 the predicted force to determine time dependant losses. However, it is prudent to compare the average "as-found" force computed in the following evaluation with a modified version of the predicted force.2.1. Development of single-end tensioned acceptance criteria During construction of the TMI Unit 1 Containment Building 14 hoop tendons were found to be inaccessible from one end, and were thusly single-end tensioned.
Correspondance between Inland-Ryerson (Inryco), Gilbert Associates (GAI), and GPU Nuclear shows acceptance the acceptance of this condition with the acknowledgement of reduced pre-stressing forces in the affected tendons.However, during the original tendons selection for surveillance (TMI selected all 40 years of surveillance tendons at the same time shortly after original construction), the single-end tensioned tendons were not included in the surveillance population due to their accessibility.
As a result the original pre-stressing force calculation, DC-5390-225.01-SE, did not address the difference in the predicted tendon force.During the revision of the predicted force calculation to include the steam generator replacement (SGR) tendons and a complete listing of all TMI tendons as a result of the incorporation of the IWL requirements into the surveillance, no consideration was given to single-end tensioned tendons outside of identifying which tendons were single-end stressed.
At the start of the 40th Year Tendon Surveillance in 201 it was identified that two tendons selected for examination vere originally single-end tension4d.
While one of these tendons was eventually ruled to be ia ccessible, it was deemed prudent to develop guidance to help in the disposition of these tendons. This guidance included a flow-chart for determining accessibility, lift-off measurements, and methodology for evaluating the results.The main conclusion from the guidance was that the predicted force values developed for the single-end tensioned tendons were not representative of the expected average pre-stressing force in the single-end tensioned tendons. It was expected that single-end tensioned tendons would have a predicted pre-stress force approximately 5% less than that in double-end tensioned tendons.This led to a modified predicted force of 93. % of the originally calculated predicted force (1,013.5 kips), with the 95% of predicted force acceptance criteria being equal to 88% of the original predicted force (954 kips).Further evaluation of the single-end tensioned tendons and their effect on the pre-stressed containment structure for the period of extended operation will be evaluated in an MPR analysis.The forces developed in this analysis will be utilized for future surveillances as applicable, and additional guidance will be incorporated into the TMI Surveillance Procedure, 1301-9.1, to address single-end tensioned tendons.Topical Report 213 Attachment 1 Page 84 of 110 Exelon Generation.
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 3 of 6 2.2. Computation of the "As-Found" Average Pre-Stressing Force While the actual surveillance test results are acceptable for determining time dependent losses, the"as-found" average pre-stressing force is required to compute the normalized group mean pre-stressing force, the group mean trend to demonstrate acceptability until the next surveillance, and to compare to the modified predicted force developed in section 2.1. The mean force in an individual hoop tendon can be represented as the average of lift-off forces measured at the individual ends approach) or computed directly as outlined below The method of computing the as-found average tendon pre-stress force is as follows: 1. Using the force (F,) and elongation (Xi) data recorded at Buttresses 1 and 3 during re-tensioning, where i represents the buttress number, plot the average end force (Favg) against the total tendon elongation (Xtotal).avg F + F 3 XtotaI= X 1 + X 3 The plot is represented by a linear trend line; represented as follows: F = mX + b 2. Extrapolate the plot back to zero force to determine the zero-stress clearance (X 0) between the bearing plate and anchor head for both tendon ends.X =--3. Subtract X 0 from the total "as-found" shim stack height (hs)to get the "as-found" tendon elongation (Xf). The "as-found" shim stack height will be the same as the "as-installed" shim stack height. Then divide by tendon length (L) to get the mean "as-found" tendon strain (Ema).hs = h 1 + h3 Xf = h, -Xo xr 4. Computý mean as-found tendon force (Fm) using the tendon modulus oý elasticity (E) and the cross sectional area of the tendon (A).F.= ()(E)(A)E = 29x103ksi T/r 2 A = (Nvires) 2 In accordance with PSC procedure SQl.0, Retension Tendons, the pre-stress force in the tendons is taken at four separate elongations as the tendon is taken to 80% of the Guaranteed Ultimate Tensile Strength (GUTS), referred to as the overstress condition.
This is done from both ends simultaneously and the tendon elongation and force are recorded on data sheet SQl1.1. Table 1 Topical Report 213 Attachment 1 Page 85 of 110 ExeLon Generation.
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 4 of 6 shows the pre-stressing forces and corresponding elongations recorded during re-tensioning of H13-03. The total elongation and the average pre-stress force are computed in table 1.Table 1: Tendon Pre-Stressing Force for Recorded Tendon Elongations Buttress 1 Buttress 3 H13-03 Elongation Force Elongation Force Total Elogation Average Force (inches) (kips) (inches) (kilýs) (inches) (kips)4.4 206.04 4.1 207.2 8.5 206.62 6.8 800.28 6.2 797.59 13 798.935 8.2 1199.18 7.65 1201.15 15.85 1200.165 9.3 1462.37 8.7 1462.72 18 1462.545 The total elongation is then plotted in figure 1 versus the average pre-stressing force. A linear trend line is fitted to the data to show the as-found tendon condition.
Tendon Elongation vs. Pre-Stressing Force 2000:1500 100 4 500 y = 133.12x -924.92 0 I I I I I I I I 0 2 4 6 8 10 12 14 Tendon Elongation (inches)I I I 16 18 20 Figure 1: Plot of the total tendon elongation versus the average pre-stressing force.Using the linear trend equation X 0 is found to be 6.95 inches. Tendon H13-03 had 169 wires in the"as-found" condition and the corresponding tendon area (A) is 8.30 in 2.The total shim height (hj)from measurements taken by PSC and recorded on data sheets 8.OA and 8.0B is 15.3 in. The tendon length (L), as recorded on test wire examination data sheet 10.2, is 155 ft and 6 in, or 1,866 in.Using this data, the "as-found" mean strain (Em) is found to be 4.47x10-3 , and the respective "as-found" mean pre-stressing force (Fm,) is 1,076 kips.The measured lift-off at Buttress 1 was recorded on PSC data sheet 9.0 as 1,230 kips. The T = 39.5 (years after the March 1974 RB SIT) prediction for force at the Buttress 1 end of H13-03 is 1,141 kip.S Topical Report 213 Attachment 1 Page 86 of 110 Exelon Generation.
Evaluation of As-Found Force 1645620-02 for H13-03 PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of H13-03 As-Found Force 5 of 6 The measured force exceeds that predicted and, therefore, meets the acceptance criterion (measured force at least 95% of predicted (1,084 kips)), and is used to show the time-dependant pre-stessing losses are acceptable.
Additionally, the computed average tendon force (1,076 kips) is equivalent to 94.3% of the predicted pre-stressing force, which exceeds the modified predicted force (1,013.5 kips) discussed in section 2.1. Therefore, both the Buttress 1 measured lift-off force and the computed average pre-stressing ftrce are acceptable in the "as-found" condition.
The comparison of the computed average pre-stressing force to the modified predicted force is included for reference only.The computed average pre-stressing force will be further utilized in the 4 0 th Year Tendon Surveillance Topical Report for computation of the Hoop Tendon Group Mean Pre-Stressing Force and the Group Mean Pre-Stressing Trend.3.0 Conclusion/Findings As the above computation shows, the as-found mean pre-stressing force in hoop tendon H13-03 is 1,076 kips, or 94.3% of the predicted tendon pre-stress force, which is greater than the modified predicted force developed in section 2.1. Additionally, as the "as-found" lift-off force measured at Buttress 1 was 1,141 kips, which is greater than 95% of the predicted tendon pre-stress force the tendon's "as-found" condition is acceptable.
The average pre-stressing force, computed in the above evaluation, will be used in the 4 0 th Year Tendon Surveillance Topical Report for computling the mean hoop tendon force as w~ll as determining the hoop tendon force trend until the next surveillance.
No additional actions are required.4.0 References
- 1. ASME Section Xl, Subsection IWL, 2004 Edition 2. ER-AA-330-006 Revision 7, Inservice Inspection and Testing of the Pre-Stressed Concrete Containment Post Tensioning Systems 3. 1301-9.1 Revision 23A, RB Structural Integrity Tendon Surveillance
- 4. IR 1587456, Surveillance Tendon Detensioned Befor Lift-Off Completed 5. PSC Inspection Manual N1091 6. C-1101-153-E410-046, TMI-1 RB Post Tensioning System ISI Program Tendon Force Prediction
- 7. DC-5390-225.01-SE, Surveillance Tendon Selection Reactor Bldg. Post Tensioning System Tendon Selection and Force vs. Time Curves Surveillances 6 through 10 5.0 Attachments
- 1. Data sheets SQ11.1 for H13-03 Buttress 1 and Buttress 3 Topical Report 213 Attachment 1 Page 87 of 110 Exelon Generation.
Evaluation of As-Found Force for H13-03 PREPARED BY SUBJECT Michael Grimni Evaluation of H13-03 As-Found Force Approvals Responsible Engineer:
Howard Hill Preparer:
Michael Grimm Independent Reviewer:
Sean Taylor Manager: MarkTorborg 1645620-02 PAGE 6 of 6 Date: See EDMS Date: See EDMS Date: See EDMS I Date: See EDMS, Topical Report 213 Attachment 1 Page 88 of 110 ExeLon Generation.
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 1 of 5 Plates in the Reactor Building Tendon Buttresses
1.0 Reason
for Evaluation/Scope The purpose of this technical evaluation is to evaluate the "as-found" condition of the embedded plates in the reactor building tendon buttress concrete.
During the 4 0 th Year Tendon Surveillance general concrete examination, several embedded steel plates were identified as "pulling away" from the concrete.
The embedded plates identified in these data sheets are shown on drawing 421030.This constitutes a new recordable indication' that needs to be addressed, and evaluated for acceptability.
This evaluation was screened per HU-AA-1212.
Review of attachment 2 of HU-AA-1212 identified no risk factors; however, as this evaluation pertains to a safety related component, it requires an independent review. An additional review has been performed by the Responsible Engineer, Howard Hill, as required by ASME Section Xl, 2004 Edition, Subsection IWL.2.0 Detailed Evaluation The 4 0 th Year Tendon Surveillance was performed at Three Mile Island (TMI) during the Fall of 2013.The surveillance began on September 23, 2013 and Precision Surveillance Corporation (PSC) left site on December 4, 2013. The surveillance completed on January 31, 2014 with the receipt of the corrosion protection medium (CPM) and tendon wire test results. Additional CPM tests are in process; hcýwever, these are follow-up actions to the original surveillance As part of the surveillance, PSC conducted a general concrete visual examination of the accessible exterior reactor building surfaces.
These inspections were documented in the PSC surveillance report submitted to TMI on February 4, 2014.Subsequent to the receipt of the surveillance report, the Responsible Engineer (RE), Howard Hill, performed a review for his agreement/concurrence with the conclusions reached by PSC. This review is part of the RE duties and is included as part of the final TMI Engineering Topical Report issued to the NRC within 90 days of he surveillance completion.
The Topical Report is required to be submitted by April 31, 2014. During this review the RE identified that the PSC data sheets for the concrete visual inspection identified new recordable indications of several embedded steel plates pulling away from the concrete surface. The indications were reported on Tendon Buttresses 3, 4, 5, and 6.The embedded plates in question are depicted on drawing 421030, Reactor Building Concrete Exterior Wall Concrete Outline. Detail A of this drawing shows the details of the embedded plates (Figure 1, below). Figure 2, below, shows the locations of the embedded plates on the tendon buttress.Topical Report 213 Attachment 1 Page 89 of 110 Exeton Generation.
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 2 of 5 Plates in the Reactor Building Tendon Buttresses
,-68" 6 3 8NELSON ANCHO01 5TUD5 ?.'O",c,) ~ k : .d 38F(CONTI N)DSTAiL "A" Figure 1: Details of Embedded Steel Plates Figure 2: Location of Embedded Plates Topical Report 213 Attachment 1 Page 90 of 110 Exelon Generation.
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 3 of 5 Plates in the Reactor Building Tendon Buttresses The embedded steel plates do not run the entire length of the tendon buttress but are primarily above the rooflines of the adjacent buildings.
- 1. Buttress 1 -Elevation 369' to 436'2. Buttress 2 -Elevation 405' to 436'3. Buttress 3 -Elevation 403' to 436'4. Buttress 4 -Elevation 400' to 436'5. Buttress 5 -Elevation 305' to 436'6. Buttress 6 a. North Side -Elevation 341' to 436'b. South Side -Elevation 305' to 436'Upon discovery, an attempt was made to conduct an interview with the inspector to determine what the exact phenomena observed was. The inspector who performed the concrete visual inspections was a temporary contractor for PSC and no longer works for the company. A phone interview conducted with his direct supervisor indicated that the inspector identified several locations where the embed plates were bulging from the concrete surface, no photographs were available of this condition.
Following the phone interview, the Tendon and ISI prigram engineers conducted a walk down of the tendon buttresses in question to view and photograph the indications.
The walk down did not reveal any indications where the embedded plates were bulging or pulling away from the concrete.However, several locations where the embedded plates overlap were observed, as shown in Figure 3, below. The overlap locations are consistent with the locations where the inspector identified the embed plates pulling away, as documented in the PSC Inspection Report.Topical Report 213 Attachment 1 Page 91 of 110 Exelon Generation.
As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 4 of 5 Plates in the Reactor Building Tendon Buttresses Figure 3: Overlap of Embedded Steel Plates In these locations the overlapping embedded plates have grouting around them. The grouting is uncracked with no significant degradation noted. This implies that the overlap is the installed condition of the emlIedded plates and that no significant degradation has occurred.I 3.0 Conclusion/Findings Based on the walk down performed by Programs Engineering and discussions with both PSC and the Responsible Engineer, Howard Hill, it is determined that the embedded plates are in the installed condition with no degradation.
These findings, as documented in this evaluation, determine that there is no recordable indication, and no further evaluation for acceptability is required.4.0 References
- 1. CC-AA-309-101, Engineering Technical Evaluations
- 2. HU-AA-1212, Technical Task Risk/Rigor Assessment, Pre-Job Brief, Independent Third Party Review, and Post-Job Review 3. ASME Section XI 2004 Edition No Addenda, Boiler and Pressure Vessel Code, Division 1 Rules for Inspection and Testing of Components of Light-Water Cooled Plants 4. REP-1091-510, Final Report for the 2013 Tendon Surveillance at TMI 5.0 Attachments
5.1. General
Concrete NDE Data Sheets Topical Report 213 Attachment 1 Page 92 of 110 Exeton Generation As-Found Condition of Reactor Building Embed Plates PREPARED BY SUBJECT PAGE Michael Grimm Evaluation of the As-Found Condition of Embedded Steel 5 of 5 Plates in the Reactor Building Tendon Buttresses I AzRoLM T Preparer:
Michael Grim m Independent Peer Reviewer:
Se an Taylor Responsible Engineer:
Howard Hill Manager: Mark Torbor-Date: __//_O"___
Date: Ai25 16A Date: Aw Date:_____
I Topical Report 213 Attachment 1 Page 93 of 110 0Go Back Print I New Search I Home 0 Go Back Print New Search Home AR Number: 01626566 Linked ARs Aff Fac: Three Mile AR Type: CR Status: APPROVED Island Aff Unit: 01 Owed To: A5551CAP Due Date: 04/30/2014 Aff System: 153 Event Date: 02/26/2014 CR 4/D Disc Date: 02/26/2014 Level/Class:
How H02 Orig Date: 02/26/2014 Discovered:
Action Request Details
Subject:
TENDON GREASE SAMPLE ACID NUMBER EXCEEDS ACCEPTANCE CRITERIA
Description:
Originator:
MICHAEL GRIMM Supv Contacted:
Mark Torborg Condition
==
Description:==
On February 26, 2014 TMI received the initial acid number test results from Precision Surveillance Corporation (PSC). The official lab report will be included in a revision to the PSC Surveillance Report. PSC reported that 7 of the 10 samples tested for acid number, did not meet the PSC acceptance criteria of <0.500. The seven samples reported to TMI were: 1. D-303 (North): 0.530 2, H13-03 (Buttress 3): 0.530 3. H13-08 (Buttress 1): 1.06 4. H13-10 (Buttress 3): 0.530 5. H35-02 (Buttress 3): 1.06 6. V-32 (Gallery):
2.64 7. V-108 (Gallery):
0.530 A follow-up phone call with the PSC Quality Assurance Manager revealed that the above test results were confirmatory test numbers, which agreed with the initial test results.Samples D-303, H13-03, H13-10, and V-108 are acceptable per Exelon procedure ER-AA-330-006, which has an acceptance criteria of <1 for the acid number. N# additional actions are required for these tendons.Samples H13-0ý, H35-02, and V-32 do not meet the <1 acid number requirement.
Immediate actions taken: Notified Responsible Engineer Issued IR Recommended Actions: 1. Include formal discussion of acid number results in the Tendon Surveillance Topical Report (Grimm, March 31, 2014)2. Define additional actions to be taken during the 45th Year Tendon Surveillance in 2019 in accordance with TS 4.4.2.1.4 (Grimm, March 31, 2014)What activities, processes, or procedures were involved?Topical Report 213 Attachment 1 Page 94 of 110 Laboratory analysis of tendon filler grease samples. The acid number tests were a follow-up action driven by Exelon procedure ER-AA-330-006 and the vendor (PSC) surveillance procedure for grease sample base number tests below the reporting limit of 0.50.Why did the condition happen?Unknown. This condition is new and has not been previously identified in prior tendon surveillances at TMI.What are the consequences?
None Tendon filler grease sample testing is performed to verify there is no evidence of filler grease degradation that could result in the corrosion of the tendon wire or anchorage comlionents and lead to future failure of the tendon components.
The reported acid number results indicate that the grease in these 3 tendons has become acidic and may not be fully effective in performing its intended corrosion prevention function.
While there is evidence that the filler grease has degraded, the surveillance indicates that no active corrosion is occurring on the three tendons in question.Visual inspections were conducted on each of the three tendon anchorages (H13-08 Buttress 1, H35-02 Buttress 3, and V-32 Gallery) with the following results: 1. No free water was found during end cap removal, this includes in the end cap and on the anchorage components.
- 2. No anchorage component (including the shims, buttonheads, anchorheads, bearing plate, and bushing) exhibited a corrosion category above "A", which indicates no visible rust.3. There were no protruding buttonheads identified, and all three tendons had 169 effective wires.4. Other than the base and acid numbers, grease testing results were within acceptable limits for chlorides, nitrates, sulfides, and moisture cojnent.Lift offs were conducted on H35-02 and V-32 with acceptable resultsl H35-02 had a lift-off of 1216 kips, which was greater than the predicted value of 1093 kips. V-32 had a lift-off of 1181.27 kips which was greater than the predicted value of 1176 kips. No lift-off was conducted on H13-08 as the Buttress 3 end of the tendon was inaccessible due to the Reactor Building Flood Seal.Additionally, during original manufacture the tendon wires were coated with Visconorust 1601 Amber, which provides another layer of corrosion protection in addition to the filler grease. Given the results of the surveillance it is reasonable t 9 conclude that there is no active corrosion on the tendon com lpnents (anchorage or wire) and that the tendons in question will contilue to perform their function through the next surveillance in 2019.Were any procedural requirements impacted?No. Exelon procedure ER-AA-330-006 requires notification of the responsible engineer and evaluation of the condition for follow-up actions and acceptability.
A formal discussion of this condition will be included in the surveillance topical report, and will address the required follow-up actions during the 45th Year Tendon Surveillance.
Were there any adverse physical conditions?
There are no adverse physical conditions in the plant. Based on the surveillance results discussed above, it is reasonable to conclude that the structural integrity of the Reactor Building Containment has not been challenged.
The Limiting Condition for Operation concerning structural integrity is provided in TS 3.19.1 and states: Topical Report 213 Attachment 1 Page 95 of 110 "With the structural integrity of the containment not conforming to the inservice tendon surveillance program requirements of 4.4.2.1 for the tendon lift off forces, perform an engineering evaluation of the structural integrity of the containment to determine if COLD SHUTDOWN is required.
The margins available in the containment design may be considered during the investigation.
If the acceptability of the containment tendons cannot be established within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, restore the structural integrity to within the limits within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />." As the surveillance results indicate acceptable lift-off values with no observable degradation to the tendon components that could challenge the pre-stressing ability of the tendons, the Reactor Building Containmelt retains its structural integrity.
Additionally there is reasonable evidence to conclude that no degradation will be experienced to challenge the structural integrity prior to performance of the next scheduled tendon surveillance in 2019.List of knowledgeable individuals:
Mike Grimm Howard Hill Sean Taylor John Piazza Repeat or similar condition?
No Operable Basis: The Containment Structure remains operable.
Tech Spec 3.19 specifically covers the tendon lift off forces and does not cover corrosion protection.Tech Spec 4.4.2.1 statqs that the Inservice Tendon Surveillance program for structural integrity a rd corrosion protection conforms to ASME code requirements.
As noted in the IR, tendon filler grease sample testing is performed to verify there is no evidence of filler grease degradation that could result in the corrosion of the tendon wire or anchorage components and lead to future failure of the tendon components.
While there is evidence that the filler grease has degraded, the surveillance indicates that no active corrosion is occurring on the three tendons in question.As the surveillance results indicate acceptable lift-off values with no observable degradation to the tendon components that couly challenge the pre-stressing ability of the tendons, the Reactor Building Co tainment retains its structural integrity.
l 1. Is the SSC operable? (Y/N) YES If inoperable, list tech spec and LCO action.2. What licensing documents were reviewed to evaluate operability?
TS, ER-AA-330-006
- 3. Describe the function of the SSC and basis for operability/availability determination.
Functions are listed below. As discussed in the IR, the containment structure continues to meet its design requirements.
- 4. Is the SSC available (Paragon)? (Y/N) YES 5. Does this deficiency require Operations to take compensatory actions?(Y/N) NO If yes, then perform an initial screening for Operator work around/challenge per OP-AA-102-103.
- 6. Is an operability evaluation or technical evaluation being requested?(Y/N) NO Topical Report 213 Attachment 1 Page 96 of 110 153-MOl : Exterior wall provides jet fuel fire barrier. Part of the original design basis (153).153-M02 Provide aircraft protection (153).153-M03 : Provide environmental protection for systems and components (153).153-M04 Provide protection from groundwater (153).153-MO5 Provide protection from turbine generated or other missiles (153).153-M06 Provide radiation shielding from fission products in the RB (153).153-M07 Provide train or channel separation (153).153-M08 : Withs nd short-term tornado loading including tornado-generated missiles (153). T 153-NO1 Provide fire barrier (153).153-N02 Provide personnel access to systems and components (153).153-N03 : THE SHIELD BARRIER WITH THE STEEL PLATING ACTS TO RESTRICT A RELEASE OF POST ACCIDENT FISSION PRODUCTS 153-ROl Contain fission products to prevent radioactive release (153).153-R02 Maintain containment integrity during normal ops and after the SSE (DBE)153-R03 Maintain structural integrity (153).153-R04 Provide fluid containment (153).153-RO5 Provide pressure boundary integrity for internal pressure.153-RO6 Provide protection from flooding (153).153-R07 Provide support for systems and components (153)Reportable Basis: This does not meet any reporting thresholds.
Functional Basis: Reviewed by: EDWARD M CARRERAS 02/26/2014 22:24:24 CST Reviewer Comments: EMC Reviewed by: EDWARD M CARRERAS 02/27/2014 02:56:47 CST Reviewer Comments: SOC ReviLwed by: CAROLYN J FLORY-MAGATZ 02/28/2014 10:00:10 CST SOC Comments: REACTOR BUILDING Added bldg component ID. This IR identified deficiency does not meet the definition of a CCF (Kaplan,BD 02/27/14).
Close to actions created. (McDowell 2/28/14) (SOC 2/28/14)Topical Report 213 Attachment 1 Page 97 of 110 Assign #: 01 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: TRKG Status: COMPLETE Priority:
Assigned To: Due Date: 03/03/2014 Schedule Ref: Prim Grp: ACAPALL Orig Due Date: Unit Condition:
Sec Grp: Assignment Details subject/Description:
TENDON GREASE SAMPLE ACID NUMBER rXCEEDS ACCEPTANCE CRITERIA Assignment Completion In Progress Notes: Completion Notes: 0 Topical Report 213 Attachment 1 Page 98 of 110 Assign #: 02 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: GRIMMX Due Date: 04/30/2014 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 03/31/2014 Unit Condition:
Sec Grp: Assignment Details Subject/Description:
Include formal discussion of acid number results in the T endon Surveillance Topical Report (Grimm, March 31, 2014)Assignment Completion In Progress Notes: A formal discussion of the acid number results and the conclusions from the associated IR 1626566 was included in Topical Report 213 section 3.6.No further actions are required.-Michael Grimm 4/09/2014 Move assignment to correspond with the due date for the Tendon Surveillance Topical Report. This assignment can't be closed until the Topical Report is signed off and submitted.
Michael Grimm 3/26/2014 Completion Notes: Topical Report 213 Attachment 1 Page 99 of 110 Assign #: 03 AR #: 01626566 Aff Fac: Three Mile Island Assign Type: ACIT Status: COMPLETE Priority:
Assigned To: GRIMMX Due Date: 04/30/2014 Schedule Ref: Prim Grp: A5551NESPR Orig Due Date: 03/31/2014 Unit Condition:
Sec Grp: Assignment Details Subject/Description:
Define additional actions to be taken during the 45th Yea r Tendon Surveillance in 2014 in accordance with TS 4.4.2.1.4 (Grimm, March 31, 2014)Assignment Completion I In Progress Notes: Section 5.2 of Topical Report 213 documents the follow-up actions to be taken during the 45th Year Surveillance.
During the 45th Year Surveillance the tendon anchorage components of H13-08 Buttress 1, H35-02 Buttress 3, and the Gallery end of V-32 will be visual inspected for corrosion and the tendon duct will be pumped through with new Corrosion Protection Medium. No further actions are required.-Michael Grimm 4/09/2014 Move due date to 4/30/14 which is the submittal date for the tendon surveillance Topical Report to the NRC. This assignment can't be closed until the report is submitted.
Michael Grimm 3/26/14 Completion Notes: Topical Report 213 Attachment 1 Page 100 of 110 1@to Exelkn.ER-AA-335-019 Revision 0 Nuclear ATTACHMENT 4 ASME IWL (Class CC) Containment Concrete Detailed or General Visual Examination NDE Report Station I Three Mile Island Uni It Date: 104-09-14 ReportNo:
/A System[ 153 1 Component: .SE Quad of ring girder (Above Butressg3
& 2) WO No(s).: R2163325-87 Location:
Building:
COO. E(ev. t6 0 1 N/A Rowl NA Azimuth/Radius Exam Type: 1Z Detailed Visual Type Of Exam: E]Direct i[-General Visual lRemote MI l Type: Outside ConialnmentConcrete Design Drawing(s)
TMII-0014 REV. I Visual Aids: Orion Apex 102mm, Model 9823 Optical Tube Assembly telescope with 26m5m Simus Eye Piece, 45 Degree Correct Image Diagonal adaptor & Correct Image Finder Scope Surface: DD 00 10I Surface / Comp~onents Coaled: F1 YES NO Illumination Used I Attribute RI NRI 10 tExplanation
/ Comments .-Cracks (Characterize and Size) q See attached sheets for photos of degraded areas Exposed Reinforcing Steel 4 No changes noted from 2006 Inspoction other than evidence of a Expospd 'Metallic Items (Other) _ N1 leak area gatting larger.Evidence Of Greaes Leakage 4 Photos and videos taken of exam volume.-.Evldence-.lMolsture
..-. .... .--4 .......Videos avallable If.requested,..-.-........
-.Leaching Or Chemical Attack 1 Photos and Videos supplied to ISI program owner: Mike Grimm Sehlements Or dflections Degraded Patches or epairs .P opouts, Voids, Honeycomb
,.Spells i, ,_,_ __,_, Cold Joint Unes 4 Corrosion Staining 'Scaling I Ousting 'Coating Deterioration
'Abrasion, Cavitaton, Wear .4 Air Velds I Bug Holes. I 4- REACTOR BUILDING TENdON SURV. (oT005278)
OthIer lain ) --NDE VT-1 BE QUAD RING GIRDER Reasulte Legend; -1 il -Recordable Indieatii NRI -No Recordabl Indliatlons 10 -Information Only Supplemental Information:
UYes [No El S[ ketch ,Photo ZVldeo E] Other (Describe):
IIi~~~
- i-f J~Examiner:
James L Newaiob II &M/ 9 I [ ff/'Mf / Level: l Oate 04-09-14 Further Evaluation Required:
YesU k;?-/.z Additional Aotionswzi r- -ldcc-,5 rxv7oc x. -~ ýi:4A )(Action ReqlUeat, .k Order, Issue Repeod. etc. f;l dorCoetve Action) Suspect Aras shall be dlsposflloned by a Responsible Enlteer Reviewer, i2_Mike Grmiml Date 04-10-14 ANti: Data " , Page 1 of iO Topical Report 213 Attachment 1 Page 101 of 110 ER-AA-335-019 Revision 0 a I 7 I I 5 H AR64 tXAmidei~7 I j I. 1 I I ,"i '.S a'I"~2u t L ~I- I 17,.$r.-1 z.iZ S. j b l~5 C I!r v pepa v 9 ha H AI -4 c. :3'F ::-I ~ I, 2-* Ird I H 1' .Ad.2302~~ ;41 1 I 'lz-IH* *'C2" , 0, t 4 VV.4. 13-a It ok ;.I 4 -!A#r it -: D..2L~ A.2LI~e~-ill..11,2- I I. J*4~4.'.14 ~I 4)-I 4 Page 2 of 10 Topical Report 213 Attachment 1 Page 102 of 110 ER-AA-335-019 Revision 0~iuurn Page 3 of 10 Topical Report 213 Attachment 1 Page 103 of 110 ER-AA-335-019 Revision 0 THREE MILE ISLAND UNIT 1 OUTSIDE CONTAINMENT CONCRETE ARFA II\JPFCTFF) nN I1q11A FRfnM, F1nlKF TFNfnlN rm-'In TC) r)-9nl1 RINC IriFrp Paue 4 of 10 Topical Report 213"Attachment 1 Page 104 of 110 ER-AA-335-019 Revision 0 Pane 5 of 10 Topical Report 213-Attachment 1 Page 105 of 110 ER-AA-335-0 1 9 Revision 0 0 I Page 6 of 10 Topical Report 213 Attachment 1 Page 106 of 110 ER-AA-335-019 Revision 0 Page 7 of 10 Topical Report 213 Attachment 1 Page 107 of 110 ER-AA-335-019 Revision 0 0 Topical aO Page 108 of 110 ER-AA-335-019 Revision 0 Page 9 of 10 Topical Report 213 Attachment 1 Page 109 of 110 ER-AA-335-019 Revision 0 ORION APEX 102mm, MODEL 9823 OPTICAL TUBE ASSEMBLY TELESCOPE WITH 25mm SIRUS EYE PIECE, 45 DEGREE CORRECT IMAGE DIAGONAL ADAPTER AND CORRECT IMAGE FINDER SCOPE.ENTIRE AREA INSPECTED USING THE SCOPE ABOVE REFERENCE REMOTE VISUAL EXAMINATION DEMONSTRATION
- TMI-02-09 VISUAL ACUITY CARD USED AT START OF THE INSPEC TION AND AT THE END MAX DISTANCE CHECK WAS 75' I INSPECTION PERFORMED FROM -40' TO 60' ON TOP OF THE TURBINE BUILDING ROOF ENTIRE EXAM VOLUME ALSO RECORDED USING A SONY "HANDYCAM" HD 30X EXTENDED ZOOM CAMCORDER PHOTOS TAKEN USING A SONY "CYBERSHOT" 12.1 MEGA PIXEL CAMERA PHOTOS TAKEN DURING 2006 INSPECTION WERE USED TO VERIFY ANY CHANGE IN CONDITIONS SEVERAL AREAS NOTED AS HAVING DEGRADATION, CRACKED & MISSING GROUT, STAINING, MINOR CHIPS, PEELING, POPOUTS. OVERALL NO CHANGE FROM 2006 EXCEPT FOR A LEAK AREA IDENTIFIED IN THE PHOTOS ABOVE.Page 10 of 10 Topical Report 213 Attachment 1 Page 110 of 110