ML102871088

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7.6 Vibration Due to Cutting Tendons
ML102871088
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Site: Crystal River Duke Energy icon.png
Issue date: 03/12/2010
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Download: ML102871088 (36)
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7.6 Vibrations due to cutting tendons under tension (piano effect)

==

Description:==

The procedure used to remove the tendons from the sleeves that intersect the SGR opening is as follows, taken from FM 7.6 Exhibit 1 which contains excerpts of the Engineering Change package relating to tendon detensioning, and FM 7.6 Exhibit 2 which contains excerpts of the Precision Surveillance Corporation (PSC) field manual:

1. Degrease tendon sleeves;
2. Cut tendons using a plasma torch;
3. Pull tendons using a coiler machine.

An important point to note is that the tendon cutting is performed without releasing the tension. A plasma torch is slowly applied to the wire button-heads until the wire yields and snaps in a tensile fracture. The sudden release of energy has a "piano effect" in the wire that can result in additional stresses and/or vibrations in the concrete.

Data to be collected and Analyzed:

1. Tendon cutting procedure (FM 7.6 Exhibit 1 and FM 7.6 Exhibit 2);
2. Calculate amount of energy released by cutting one wire (FM 7.6 Exhibit 3 is a calculation of the energy released when plasma cutting 1 wire, 20 wires, and a whole tendon at once);
3. Finite Element Modeling (FEM) analysis to determine the vibration induced additional forces on the concrete (FM 7.6 Exhibit 4 is an Abaqus analysis of the vibration frequency and amplitude upon plasma cutting 20 wires at once).

3/12/2010 Page 1of 3 Draft 1

Verified Supporting Evidence:

a. None Verified Refuting Evidence:
a. The FEM impact energy analysis determined that the excitation force due to the energy released by 20 wires plasma cut at once induces stresses and/or vibration responses that are very low, and therefore considered an insignificant contributor to either cracking, delamination or propagation of any preexisting cracks (FM 7.6 Exhibit 3 and FM 7.6 Exhibit 4);
b. The operation of plasma cutting the tendons under load is now standard industry practice and has been used successfully in many Steam Generator Replacement (SGR) concrete containment opening jobs (FM 7.6 Exhibit 5 is an email from Paul Smith, PSC president, FM 7.6 Exhibit 6 is an interview with Gary Goetsch, PSC superintendant, and FM 7.6 Exhibit 7 is an interview with Cliff Peters, Bechtel superintendent, on the topic).

Discussion:

Experience from suspension bridges indicates large energy release potential in tendons that can be sufficient to cut through the entire bridge deck underneath. With this in mind, the approach of plasma cutting tendon wires under load, used in the nuclear containment industry needs closer review.

The main reason for plasma cutting under load is that it is a faster process compared to de-tensioning the tendons before cutting the wires. This latter approach is to release the load first and then either plasma cut or grind the wires. Additionally, the grinding process can result in flashing and can complicate the wires removal out of the anchor-heads. This particular issue was encountered during this SGR job on vertical tendon 34V13 (FM 7.6 Exhibit 8 shows the addition to the Engineering Change package to allow plasma cutting of the detensioned tendon 34V1 2 after it could not be pulled out of the button-head).

The calculations performed by PII show that releasing 20 wires at once generates only a small additional stress in the concrete structure. One important difference with the suspension bridges experience is that the cut wires are not flying long distances before hitting the concrete, thereby not gaining additional energy from a heavy object falling down.

3/12/2010 pII eTr-y CurrFiduIi.idl, 2OO- 201 Page 2 of 3 Draft 1 D to t....

==

Conclusion:==

The vibration induced by plasma cutting the tendons under tension (piano effect) did not contribute to the delamination.

3/12/2010 , -- ; !, 2N Page 3 of 3 Draft 1 n

FM 7.6 Exhibit 1 page 1 of 5 PCHG-DESG Engineering Change 0000063016R163 D.1 Installation Package D1.1 This EC will create and repair an opening in the Reactor Building wall. This opening is necessary for the transport of the old and replacement OTSG during the Steam generator replacement outage. The following is an over view of the activities required to accomplish these activities:

Pre-Outage:

1. Mock-ups and associated training of craft for complex work activities required for the creation and restoration of the access Opening.
2. Staging tendon upper support frames onto the Reactor Building roof and attaching the tendon work platforms.
3. Partial degreasing of 30 vertical tendons in and around the Opening prior to Plant shutdown.
4. Installation of a temporary work platform (a.k.a. "chipping platform") as described in EC #63022.
5. Survey and layout the basic geometry of the Opening, and shallow saw cutting of the Opening.
6. Deleted
7. Tendon anchorage inspections per ASME Section Xl, Subsection IWL.
8. Disable sump pumps SDP-3A and 3B and Install temporary sump pump(s) in the tendon gallery sump. Test the temporary pumps to ensure that they are operable and deliver at least 300gpm.
9. Saw cutting of the perimeter of the containment access opening.

Modes 5 and 6:

10. Tendon anchorage inspections per ASME Section Xl, Subsection IWL.
11. Detensioning, removal and final degreasing of 10 vertical and 17 hoop tendon's from within the Opening (mode 5 or 6).
12. Hydrodemolition of the 42" thick concrete containment wall from within the Opening.
13. Radiological and environmental testing and disposal of the hydrodemolition effluent (wastewater and concrete rubble)
14. Cutting and removal of the steel reinforcement bars (rebar) within the Opening; drilling of pilot holes in liner plate for cut line layout.
15. Cutting and removal of tendon sheathing within the Opening.
16. Perform core boring in accordance with AI-480, ASTM C-42 and Attachment Z65.

Defueled Prior To Removal and reinstallation of the OTSG:

17. Cutting and removal of the steel liner plate at the Opening, about liner plate cut line.

FM 7.6 Exhibit 1 page 2 of 5 All welding shall be performed per NGGM-PM-0003, Corporate Welding Manual.

Station security shall be notified at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to breaching the liner plate so that they may evaluate and implement compensatory measure.

Notify Operations and RP and insure the following has been accomplished prior to commencing the liner plate cut:

o Appropriate radiological postings installed outside the access Opening o Personnel monitoring and air monitoring equipment (radiological) installed and operational outside access Opening.

o Satellite de-contamination facility established (Ref. RP Task Plan) o A 12" wide strip of paint on either side of the liner plate cut line has been removed.

o Inside face of the liner plate must be decontaminated as practical.

o Satellite de-contamination facility established Obtain a fire barrier breach permit per site procedure CP-137, Fire and HELB Barrier Breaches, Additional attachment welds on the metallic liner may be required to attach construction aids to the liner. These construction aids may include pads that will be permanently welded to the liner to support lifting rings and lugs.

D.2.2 Detail required sequencing of steps This section will be broken up by major activity. The handoffs from one activity to another will be identified.

D.2.2.1 Tendon Degreasing, Detensioning, Removal, Reinstallation and Retensioning

FM 7.6 Exhibit 1 page 3 of 5 Refer to PSC Manual "Post Tensioning System Field and Quality Control Procedure Manual" (Attachment Z23) for additional guidance in removal, inspection and reinstallation of tendons.

Note: The intent of all of the instructions contained in this document must be transferred to the work order instructions, clearly, accurately and in their entirety. However, CR3 procedures will always take precedence over the PSC F&Q Quality Control Procedures.

The methodology and requirements for Calibration of all tools and equipment shall be evaluated, reviewed and approved by Progress Energy (CR3) Nuclear Assessment Section (NAS).

1. Tendon Service Platform installation
a. Install four Upper Support Frames (USF) supplied by Precision Surveillance Corporation (PSC) as directed by PSCs supervisory representative and in accordance with the information contained in the PSC design calculation contained in Attachment Z34. Note that all platform tie-down material/equipment will be supplied by PSC.
b. Each USF shall be initially placed on the reactor building roof rails above the equipment hatch (approximate AZ 150), following the safe load path drawing (see attachment G01).
c. Each of the four USFs will support a suspended work platform (2-8'xlO' and 2-nominallO'x20' platforms). Each work platform is lifted over the equipment hatch shield structure at AZ 150 degrees, and attached to its respective USF with cables.
d. After a work platform has been attached to its respective USF it will be proof load tested per the requirements of Section E00.
e. The suspended work platforms come in two sizes. The 8' x 10' platforms (and USFs) will be moved and staged at buttresses 2 and 5 and the nominal 10' x 20' platform will be placed at buttresses 3 and 4 with the restrictions listed below in f.
f. The USF and platform combination for buttress numbers 2, 3 and 5 will be rolled clockwise around the roof (from their initial position at approximate AZ 150 degrees) and must be lowered to their temporary storage location on top of the intermediate building roof. They cannot be staged at buttress numbers 2 or 3 until Mode 5. Note that the platform at buttress number 5 may be temporarily stored on the IB roof if required until Mode 5. The platform sequence is buttresses 5 first followed by buttress 2 and finally buttress 3.
g. The USF and platform combination for Buttress number 4 shall be rolled counterclockwise from its initial position at AZ 150 degrees to the east side of buttress # 4. It may be staged at buttress #4 during any Mode.

FM 7.6 Exhibit 1 page 4 of 5

2. Tendon Degreasing and Tendon Removal
a. Partially degrease the following vertical tendons prior to shutdown (Refer to drawing 421-347 for tendon location):
i. 34V8 thru 34V17 (within the opening),

ii. 45V22 thru 45V24 and, 34V1 thru 34V7 (about buttress #4 and adjacent to the opening) iii. 23V1 thru 23V3 and 34V18 thru 34V24 (about buttress #3 and adjacent to the opening)

b. After partially degreasing the vertical tendons, perform the required ASME Section XI, subsection IWL inspections of the tendon anchorage components either before the outage or during the outage dependent on labor needs, and the following requirements:
1. The following two vertical tendon anchorages (inside the opening) including the surrounding concrete require a detailed visual inspection per IWL prior to ram detensioning (Refer to Drawing 421-347 and Ref. 4.19 for location):

34V12 and 34V13

2. The anchorage components of the following 8 remaining vertical tendons that are being removed from the opening do not require IWL inspections, except for the concrete surrounding the tendon bearing plates that must be inspected to IWL requirements prior to detensioning:

34V8 thru 34V11 and 34V14 thru 34V17 The anchorage components of hoop tendons that are being removed do not require IWL inspections, except for the concrete surrounding the tendon bearing plates that must be inspected to IWL requirements.

However, craft personnel are to look at the tendon assembly after cleaning and prior to cutting the buttonheads for removal and note any obvious deficiencies that may question the integrity of the tendon assembly. Any questionable deficiencies should be referred to the IWE/

IWL Responsible Engineer.

c. Two vertical adjacent tendons (, 34V12 and 34V13) (Refer to drawing 421-347 for location) may be removed from within the opening after the reactor has shutdown (after entering Mode 5) and prior to the start of concrete hydrodemolition of the 42" thick containment wall and saved for possible re-use.

These two tendons will be detensioned with a hydraulic ram, the buttonheads removed with a hand grinder, coiled and then saved as

FM 7.6 Exhibit 1 page 5 of 5 a contingency to ensure that replacement vertical tendons of sufficient length are available in the event that a new replacement tendon is identified as being too short. If it is determined that one or more of these three original tendons must be reused, then the tendon(s) will be sent to PSC for restoration.

Note that Tendon 34V1 3 may be plasma cut directly above the bottom anchor head.

One wire will be removed from each of the two tendons, its length measured as accurately as possible, recorded, and this information sent to engineering for evaluation.

d.

e. With the plant in Mode 5 or 6 the following tendons can be removed:
i. 8 vertical tendons 34V8 thru 34V1 1 and 34V14 thru 34V17 (Ref.

to drawing 421-347 for location).

ii. 17 hoop tendons 42H27 thru 42H34 and 53H27 thru 53H35 - (Ref. drawing 421-347 for locations) iii. After the hoop and vertical tendons have been removed from within the opening, the open tendon sheaths shall be degreased to the extent practical.

f. The remaining 8 vertical tendons to be removed from within the opening (34V8 thru 34V1 1 and 34V14 thru 34V17) will be destructively detensioned by plasma cutting the buttonheads at the lower anchorage in the tendon gallery. The tendon is then coiled-up at the upper anchorage (RB roof) and banded, removed from the coiler, wrapped in plastic and lifted to the ground by the mobile crane.
g. Hoop tendons to be removed from within the opening will be destructively detensioned by plasma cutting the buttonheads at the smaller work platforms located at buttress numbers 2 and 5. The tendon is then coiled-up at either buttress number 3 or 4 and banded, removed from the coiler, wrapped in plastic and lifted to the ground by the mobile crane.
h. After a tendon is removed, attach a temporary protective bearing plate cover to the bearing plate, over the open tendon sheath void (hoops only) to prevent further debris from entering the tendon sheaths.

Alternatively the grease cap can be replaced using the old gaskets.

i. Tendon removal activities are completed
3. Tendon Detensioning around the access opening
a. After the old steam generators have been transported out and the new steam generators into containment, and the Horizontal Transfer Structure is no longer required to support lifting the steam generators, the following tendons shall be detensioned:
i. 45V22 thru 45V24 and, 34V1 thru 34V7 (about buttress #4 and adjacent to the opening)

Lxhibit 22 page 1 of 8 I-M (.b FM (.b Exhibit page 1 of 8 Precision Surveillance Corporation 3468 Watling Street Phone: (219) 397-S826 East Chicago, IN 46312 Fax: (219) 397-5867

. -Email: Info@psctendon.com http://www.psctendon.com CONTROLLED MANUAL NO: N1013-POST TENSIONING SYSTEM FIELD AND QUALITY CONTROL PROCEDURE MANUAL FOR PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER NUCLEAR UNIT 3 STEAM GENERATOR REPLACEMENT PROJECT CONTAINMENT BUILDING TENDON INSTALLATION REVISION A AUGUST 29, 2008 REVISION A JUNE 24, 2009 REVISION A AUGUST 19, 2009 REVISION A SEPTEMBER 16, 2009 QA MANAGER 09/16/09 Prepared by Title Date PROJECTMANAGER, PE. 09/16/09 Approved by Title Date A~-7 PRESIDENT 09/16/09 Approved by Title Date

9M~ 1 19 EFkbk;a+ f) 0--

FIELD AND QUALITY CONTROL WO-DAC'IMANUAL ACKNOWLEDGEMENT OF RECEIPT FORM August 29, 2008 Page 1 of 1 Revision 0 Revision 2. 8/19/2009 Revision 3. 9/16/2009 This page shall be removed, and mailed or faxed to:

Precision Surveillance Corporation Phone: 219-397-5826 Quality Assurance Fax: 219-397-5867 3468 Watling Street East Chicago, IN 46312 The return of this Acknowledgement form from Control Manual Number:

will indicate acknowledgement-of-receipt for document control purposes. Failure to return this page or otherwise provide similar acknowledgement, SHALL be just cause for terminating the controlled status of this manual.

RETURN OF THIS FORM DOES NOT CONSTITUTE APPROVAL OF THE CONTENTS HEREIN, If this page is stamped "UNCONTROLLED MANUAL", it is not necessary to return.

Date of Submittal:

Date of Receipt:

The individual acknowledging Name:

receipt will be considered the Name:

permanent holder of this manual. Signature:

For more information regarding

Title:

responsibility of the attendant of this manual, refer to the Manual Company:

Control Policy Statement.

Project:

Contract:

Field and Quality Control Procedure Manual Issue Date 08-29-08 Revision //* 09-16-09

rII A 7 ^ _ '-- ' ^. /- ,I" FIELD AND QUALITY CONTROL FLIEV'Lf'IANUAL INDEX STATUS SHEET August 29, *2008 PsC PrEcision Surveillance Corporation Page 1 of 2 Revision 0 Revision 2. 8/19/2009 Revision 3. 9/16/2009 ORIGINAL ISSUE REVISED STATUS SECTION PAGES REV. DATE REV. DATE PREFACE Title 1 0 08-29-08 3 09 09 Receipt - To be returned 1 0 08-29-08 3 09 09 Index Status Sheets 2 0 08-29-08 3 09 09 Definitions 4 0 08-29-08 Personnel Safety 5 0 08-29-08 PROCEDURES F&Q 1.0 - Purpose 2 0 08-29-08 F&Q 2.0 - Scope 3 0 08-29-08 F&Q 3.0 - Receiving, Handling 5 0 08-29-08 and Storage Data Sheet F&Q 3.0 1 0 08-29-08 Data Sheet F&Q 3.OA 1 0 08-29-08 F&Q 3.1 - Equipment Proof Test 4 0 08-29-08 Data Sheet F&Q 3.1 1 0 08-29-08 F&Q 5.0 - Tendon Initial Degreasing 4 0 08-29-08 1 08 09 Data Sheet F&Q 5.0 1 0 08-29-08 1 06-24-09 F&Q 6.0 - Tendon Detensioning/Removai for Possible 0 09-16-09 Reuse Data Sheet F&Q-6.0 1 0 09-16-08 Data Sheet F&Q 6.OA 1 0 09-16-08 Figure 1.0 - Tendon Wire Puller 1 0 09-16-08 F&Q 8.0- Plasma Tendon Detension 5 0 I08-29-08 Data Sheet F&Q 8.0 1 0 08-29-08 1 06-24-09 F&Q 8.1 - Ram Tendon Detension 6 0 08-29-08 Data.Sheet F&Q 8.1 1 0 08-29-08 1 06-24-09 F&Q 10.0 - Tendon Removal 4 0 08-29-08 F&Q 11.0 - Tendon Void Cleaning 4 0 08-29-08 F&Q 13.0 - Tendon Installation 5 0 08-29-08 1 06-24-09 Data Sheet F&Q 13.0 1 0 08-29-08 Spec. EW10i 1 0 08-29-08 103 INDEX.CR3.SGR.F&QREV3.doc

FM 7.6 Exhibit 2 Daae 4 of 8 PSC PROCEDURE F&Q 8.0 PLASMA CUTTING TENDON DETENSIONING August 29, 2008 Page 1 of 5 Revision P Precision Surveillance Corporation PROGRESS ENERGY FLORIDA, INC.

CRYSTAL RIVER NUCLEAR UNIT 3 STEAM GENERATOR REPLACEMENT PROJECT PRECISION SURVEILLANCE CORPORATION FIELD AND QUALITY CONTROL PROCEDURE PLASMA CUTTING TENDON DETENSIONING

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Title 08/29/08 Date PROJECTMANAGER, P.E. 08/29/08 Approved by - Title Date PRESIDENT 08/29/08 Approved by Title Date

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11 F&Q8.0CR3.SGR.doc

FM 7.6 Exhibit 2 Daae 5 of 8 PSC PROCEDURE F&Q 8.0 PLASMA CUTTING TENDON DETENSIONING August 29, 2008 Page 2 of 5 Revision 0 1.0 PURPOSE I 1.1 This procedure will establish the requirements for plasma cutting de-tensioning of tendons at Crystal River Unit 3 for the vertical and horizontal tendon work during the Steam Generator Replacement Project.

2.0 SCOPE 2.1 The tendons to be de-tensioned by plasma cutting shall be as specified in PSC Procedure F&Q 2.0 or Owner Work Package.

2.2 The de-tensioning sequence shall be as specified in Owner Work Package.

3.0 RESPONSIBILITY 3.1 Owner Field Construction Personnel shall be responsible for the physical activities and recording of documentation associated with this procedure.

4.0 QUALIFICATIONS 4.1 Owner Field Construction Personnel shall be fit by skill, training and/or experience to perform these duties.

5.0 EQUIPMENT 5.1 Plasma cutting equipment.

5.2 Shim, anchor head and button head catcher.

5.3 Miscellaneous Tools, wrenches, ratchets, sockets, shackles, come-alongs, etc.

5.4 Plastic bags, plastic sheeting (Visqueen), rags, buckets or drums for waste grease.

6.0 PRECAUTIONS 6.1 As in other heavy construction, care should be exercised while working from scaffolds, platforms, ladders, high or restricted access locations. Respect for the safety and well-being of the other trades and personnel in the area must be observed, especially during hoisting operations.

6.2 During plasma cutting operations, care should be taken to wear prescribed protective equipment such as proper eye protection, gloves, and to avoid burns from the plasma cutting and electrical shock.

6.3 Grease is flammable, during plasma cutting operations all Fire Watch restrictions and precautions are to be followed.

111 F&Q8.0.CR3.SGR

FM 7.6 Exhibit 2 ipaae 66 of of 88 FM 7.6 Exhibit 2 pacie PSC PROCEDURE F&Q 8.0 PLASMA CUTTING TENDON DETENSIONING August 29, 2008 Page 3 of 5 Revision 0 6.4 During plasma cutting operations, at the end of the tendon being cut a shim and button head catcher is to be in place as directed by the Owner Site Shift Superintendent to catch any projectile button heads.

6.5 On the opposite end of a tendon end that is being plasma cut care should be taken when the grease cap is removed as it could contain loose shims which could fall when the cap is removed.

CAUTION DO NOT STAND UNDER LOADS WHILE STATIONARY OR DURING HOISTING.

DO NOT PERMIT OTHERS TO STAND UNDER LOADS.

DO NOT THROW OR DROP OBJECTS.

DURING PLASMA CUTTING WEAR PROTECTIVE EQUIPMENT, AVOID BURNS AND ELECTRICAL SHOCK.

6.6 The wire used for the tendons has a minimum breaking strength of 240,000 pounds per square inch. This means that each 7mm diameter wire is capable of withstanding a minimum breaking load of 14,317 pounds. Multiply this by 163 wires in a tendon and you are dealing with forces in excess of two million pounds per tendon.

CAUTION (When plasma cutting on a tendon to be removed and scrapped)

NEVER CONNECT A WELDING GROUND, PERFORM WELDING ON, OR STRIKE AN ARC NEAR A STRESSED TENDON WHICH IS NOT BEING SCRAPPED.

NEVER APPLY AN OPEN FLAME TO THE BUTTONHEADS, THE WIRES OR ANCHORAGES OF A STRESSED TENDON EXCEPT FOR THE END OF THE TENDONS THAT ARE TO BE PLASMA CUT AND SCRAPPED.

NEVER STRIKE THE BUTTONHEADS, THE WIRES OR THE ANCHORAGES OF A STRESSED TENDON WITH A HAMMER OR ANY OTHER METAL OBJECT.

6.7 The above actions could cause a button head or wire to fail. During tendon tensile testing, broken wires or button heads have been observed to penetrate hard lumber in excess of 4 inches in thickness, about the equivalent of a .32 caliber bullet.

7.0 QUALITY CONTROL DOCUMENTATION AND HOLD POINTS 7.1 There are no Quality Control Documentation (QCD) points or HOLD POINTS in this procedure.

111 F&Q8.0.CR3.SGR

FM 7.6 Exhibit 2 ~aae 7 of 8

!~a 7 f FM 7.6 Exhibit 2 PSC PROCEDURE F&Q 8.0 PLASMA CUTTING TENDON DETENSIONING August 29, 2008 Page 4 of 5 Revision 0 ELO PREREQUISITES 8.1 Prior to removing a grease cap/tendon end protection assure that the proper tendon is being worked on.

8.2 Prior to de-tensioning vertical tendons that are to be removed from the void, grease is to have been drained and or blown from the tendon.

8.3 On the opposite end of the tendon to be plasma cut the grease cap is to be removed.

The grease cleaned out of the cap and from around the anchorage and shims. A keeper plate is installed to the anchor head to hold the button heads in place during plasma cutting. The grease cap is replaced and tightened down. Care should be taken when this grease cap is removed after plasma cutting as it could contain loose shims which could fall when the cap is removed.

L0 PROCEDURE 9.1 If not previously done, remove the grease cap or end protection from the end being de-tensioned.

9.2 ANCHORAGE CLEANUP 9.2.1 Grease shall be removed from the tendon end. Bristle brushes and rags with suitable quantities of Viscosity Oil, Viscor Industrial No. 16A solvent or Owner approved equivalent to dilute and wash away the grease may also be required.

This cleanup must be sufficient to permit plasma cutting of button heads as verified by Superintendent.

9.3 TENDON DE-TENSIONING 9.3.1 During plasma cutting the grease cap at the other end not being cut is to remain on. The button heads of the tendon are to be plasma cut one at a time, if possible, until all the button heads are cut.

9.4 TENDON SHIM PROTECTION 9.4.1 Shims removed from a tendon shall be kept in matched pairs and protected from the elements by covering with plastic or placing in a temporary storage container until sent to storage.

10.0 DOCUMENTATION 10.1 The items requiring documentation in this procedure shall be documented by the assigned field construction person of the working crew on Data Sheet F&Q 8.0 attached to this procedure or as required by Owner Work Package.

111 F&Q8.0.CR3.SGR

FM 7.6 Exhibit 2 pacle pane 88 of of 88 FM 7.6 Exhibit 2 PSC PROCEDURE F&Q 8.0 PLASMA CUTTING TENDON DETENSIONING August 29, 2008 Page 5 of 5 Revision 0 11.0 QUALITY CONTROL 11.1 There is no quality control inspection or documentation required by this procedure.

12.0 NOTIFICATION 12.1 Owner Shift Superintendent shall be notified if there are any problems encountered with the plasma cutting operations.

13.0 ATTACHMENTS 13.1 Data Sheet F&Q 8.0.

111 F&Q8.0.CR3.SGR

FM 7.6 Exhibit 3 page 1 of 1 Calculation Energy per Wire Tendon Force 1,635 kips Young's Modulus, E 2.90E+07 psi Guaranteed UTS 240 ksi Wire Diameter 0.276 in (7 mm)

Wire Area 0.0596 inA2 Wires per Tendon 163 Force per wire 10,013 Ibf (70% x 240 ksi x 0.0596 inA2)

Wire length 1,884 in (157 ft)

Elongation, A=FL/AE 10.91 in Wire Strain Energy per wire, U=1/22FA 54,641 Ib.in 4,553 lb.ft Wire Strain Energy per 20 wires, U=Y2FA 1,092,818 lb.in 91,068 lb.ft Wire Strain Energy per tendon, U=1/2FtF 8,906,464 Ib.in 742,205 lb.ft calculations by Henric Larsson and Patrick Berbon, PII

FM 7.6 Exhibit 4 page 1 of 11 Vibration Analysis of the Crystal River Unit 3 Reactor Containment Structure February 23, 2010 Rev. 1 Summary:

The analysis presented here is part of the root cause investigation by Performance Improvement International of the Reactor Building Containment Wall failure during the Steam Generator Replacement (SGR).

This analysis considers the entire Reactor Building and does not include the detail modeling that may predict local stress concentrations. Further, the wall at the SGR opening location is assumed to be intact in this analysis.

The vibration of the Reactor Building due to the following loads are modeled and analyzed:

. Shock load of plasma cutting 20 post-tensioned wires; The result of this analysis is:

1. The resonant frequencies of the structure are:
a. 4.43 Hz - Swaying of Reactor Building
b. 6.42, 7.48 & 8.37 Hz- Vibration frequencies of Wall Panels between buttresses
2. The modal analysis compares favorably to physical testing (7.4 Hz calculated vs. 7.3 Hz measured).
3. The shock load of cutting 20 individual Wire Strands of one Hoop Tendon at one time induces vibrations with displacements less than 7 x 10.3 inch and tensile stresses less than 11 psi in the concrete.

1

FM 7.6 Exhibit 4 page 2 of 11 Analysis Objective The objective of the presented analysis is to study the following two loads for vibrations of the Reactor Containment Structure:

1. Shock load of plasma cutting 20 wires of one Hoop tendon at a time Modeling Approach and Properties The geometry of the Crystal River Plant Unit No. 3 Containment structure was modeled based on references I though 10. Abaqus version 6.9-1 Finite Element Analysis software was used to model and analyze the structure.

The following components of the structure are included in the model:

1. Concrete base (cylindrical geometry)
2. Concrete wall panels and buttresses (6 panels and 6 buttresses)
3. Concrete dome
4. Interior steel liner (3/8 inch thick wall and roof, 1/4 inch floor)
5. 144 Vertical Tendons (24 ea x 6 Bays) equally spaced around 360 degrees
6. 282 Hoop Tendons (47 ea x 6 Pairs of Bays)

The concrete structure is modeled using the 8-node linear brick elements with incompatible modes, C3D81, for accurate bending representation. The steel liner is modeled using the 4-node linear shell element S4. The vertical and horizontal tendons are modeled using the 2-node truss element T2D2. The truss elements are embedded in the solid concrete elements with a prescribed initial stress.

The Tendons are made up of 163 individual wire strands, each with a diameter of 7 mm). The Tendons are modeled as being tensioned to 1,400 kip force which results in a prescribed stress of roughly 144,000 lb/in2 .

The Modulus of Elasticity and Mass Density of the concrete is based on Reference 11. The Poisson's Ratio of the concrete is based on Reference 12:

0 Ec= 4.287 x 106 lb/in2 Vc =0.2 3

  • Pc = 150 lb/ft The steel Tendon and Liner properties are taken as:

E= 30 x 106 lb/in2 E

vs = 0.29 3

  • Ps = 0.282 Ibm/in The bottom of the concrete base is fixed in all translational degrees of freedom.

2

FM 7.6 Exhibit 4 page 3 of 11 Finite Element Model Description The model consists of three types of Finite Elements:

1. Continuum Solid Elements (C3D81) representing the concrete structure
2. Structural Shell Elements (S4) representing the steel Liner Interior
3. Structural Truss Elements (T2D2) for the representation of the Vertical and Hoop Tendons Figure 1 depicts the mesh of the concrete structure and the steel liner.

Figure 1: Finite Element Mesh of the ReactorBuilding. The exterior shown on left and the interiorliner mesh shown on the right.

3

FM 7.6 Exhibit 4 page 4 of 11 Figure 2 shows the mesh of the Vertical and Hoop Tendons and the location on the solid structure.

Figure 2: Vertical and Hoop Tendons shown separatelyon the left and where they are embedded in the concrete solid structure on the right.

4

FM 7.6 Exhibit 4 page 5 of 11 Frequency Analysis The frequency analysis is performed after a static baseline analysis which includes the tensioning of the Tendons and the application of gravity acceleration.

The following vibration modes and associated natural frequencies are found:

  • Mode 1 & 2 (4.43 Hz): Swaying of the structure (increasing vibration amplitude with height)

" Mode 3 (6.42 Hz): Radial vibration of the panels of the cylindrical structure. The mode is three panels deflecting in as the other three are deflecting out (every other in and every other out)

" Mode 4 (6.57 Hz): Radial vibration of the cylindrical structure - similar to Mode 3 but rotated 30 degrees such that the buttresses are mostly vibrating instead of the panels

  • Mode 5 & 6 (7.48 Hz): Radial vibration of the cylindrical structure with two peaks and two valleys in the circumferential direction

" Mode 7 & 8 (8.37 Hz): Radial vibration of the cylindrical structure with four peaks and four valleys in the circumferential direction

" Mode 9 (8.88 Hz): Twisting of the structure around the vertical centerline.

  • Mode 10 & 11 (12.1 Hz): vibration of the cylindrical structure with five peaks and five valleys in the circumferential direction.

5

FM 7.6 Exhibit 4 page 6 of 11 Experimental Validation of Frequency Analysis The natural frequencies of the Containment Structure were measured by Crystal River Unit 3 Personnel (Reference 13). Accelerometers and two types of excitations were employed: (1) hammer impact, and (2) movement of the Polar Crane and lifting equipment during the installation of the Replacement Steam Generator.

The hammer test mostly excites the following frequencies: 7.3 Hz and 15 Hz where the 15 Hz is likely the first harmonic of the 7.3 Hz vibration. However, careful inspection of the spectrum plot of the wall between Buttress 2 and 3 (in Ref. 13) indicates a small peak around 4 Hz. Typically, hammer impact tests may excite more high frequencies than low frequencies. It is likely that the hammer impact test is not exciting the very low frequency associated with the swaying of the structure. In order to excite the tower swaying modes (Mode 1 & 2) a higher amount of energy that a hammer can produce may be needed.

The inspection of the spectrum that was collected during the movement of the crane clearly shows a peak at around 4 Hz. The movement of the crane will likely produce much higher energies and able to excite the bending vibration modes (Mode 1 & 2).

The frequency analysis of the Finite Element Model indicates that the following set of vibration modes exists of the radial vibration of the wall panels (between buttresses):

" Mode 3 (6.42 Hz)

" Mode 5 & 6 (7.48 Hz)

  • Mode 7 & 8 (8.37 Hz)
  • Mode 10 & 11 (12.1 Hz)

The three closely spaced natural frequencies of the model (6.42, 7.48 and 8.37 Hz) produce the average frequency 7.4 Hz. Depending on what the resolution of the test instrument is and the amount of averaging used, it is likely that the test was unable to resolve the closely spaced frequencies in this range.

It is concluded that the FEA model is likely a good approximation of reality (7.4 Hz calculated vs. 7.3 Hz measured).

6

FM 7.6 Exhibit 4 page 7 of 11 Transient Dynamic Analysis of Cutting Hoop Tendon Wires This analysis is studying the transient dynamic response of the whole structure from the shock load of cutting 20 individual strands of wires of one Hoop Tendon at one time.

The cutting of Hoop Tendons will likely induce higher vibrations than the release of Vertical Tendons.

This is based on the fact that the Hoop Tendons will release a radial force which tends to induce panel radial vibrations. Hence, there is no need to study the cutting of Vertical Tendons.

The Hoop Tendon chosen to be cut in the simulation is located at the bottom of the SGR opening between Buttress 3 and 5.

This model, as the previous model of the Hydro Blasting load case, is a modal dynamic transient analysis based on the first 50 modes of free vibration. Damping equal to 2% of the critical damping for each of the 50 modes was used to absorb the energy released. The transient analysis is performed for the duration of 0.1 second after the cutting event.

The result here is the perturbation due to the release of the Tendon Wires only. Static stresses, deformation and strains due the gravity and Tendon tensions are present but not shown in the perturbation results. The load of the cutting event was applied by an equivalent distributed load in the opposite direction.

Figures 6 though 8 depict the deflection, stress, and strain, respectively, due to the shock load.

7

FM 7.6 Exhibit 4 page 8 of 11 Figure 6: Displacement Magnitude Contours (inch) due to the event of cutting 20 individualwires of one Tendon at one time.

8

FM 7.6 Exhibit 4 page 9 of 11 Figure 7: Max PrincipalStress Contours (psi) due to the event of cutting 20 individual wires of one Tendon at one time.

9

FM 7.6 Exhibit 4 page 10 of 11 Figure8: Max PrincipalStrain Contours (inch/inch) due to the event of cutting 20 individual wires of one Tendon at one time.

The dynamic response of cutting 20 wires of one Tendon at one time results in:

0 Maximum Principal Stress of about 11 psi in tension and 2.4 psi in compression.

SI Maximum Displacement of about 7 x 10'3 in (= 7 mil = 0.2 mm)

SI Maximum Strain of about 2.5 x 10-6 (= 0.00025 %)

The hypothetical shock load that results of cutting one complete Hoop Tendon at one time results in the Maximum Principal Stress of about 90 psi in tension.

10

FM 7.6 Exhibit 4 page 11 of 11 References

1. Gilbert Associates, Inc., 1970, drawing "Reactor Building Exterior Wall - Concrete Outline"
2. Florida Power, Final Safety Analysis Report, Revision 31.3, Figure 5-2 "Reactor Building Typical Details"
3. Florida Power, Final Safety Analysis Report, Revision 31.3, Figure 5-18 "Base - Cylinder Junction Detail"
4. Florida Power, Final Safety Analysis Report, Revision 31.3, Figure 5-21 "Reactor Building Segments"
5. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 13 Layout"
6. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 42 Layout"
7. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 53 Layout"
8. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 64 Layout"
9. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 51 Layout"
10. Florida Power, 1998, drawing "IWE/IWL Inspection Hoop Tendon 62 Layout"
11. MPR Associates, Inc., 11/3/2009, "Radial Pressure at Hoop Tendons", Calculation No. 0102-0906-0135
12. Progress Energy, 11/8/1985, "Design Basis Document for the Containment", Rev. 6
13. Memorandum from Virgil W. Gunter, CR3 Systems Engineering, 11/14/2009, "Report of CR3 Containment Structure Vibration Monitoring and Impact Testing"
14. Telephone Interview with Dave McNeill (Mac&Mac, Vancouver), 10/28/2009. Documented in "10 28 interview Dave MacNeil.pdf" 11

FM 7.6 Exhibit 5 page 1 of 1 Miller, Craig L From: Paul Smith [PSmith@psctendon.com]

Sent: Monday, January 18, 2010 11:33 AM To: Portmann, Rick Cc: Miller, Craig L

Subject:

RE: PSC F&Q 8.0

Rick, Ever since Byron in 1997 where it was determined that replacing tendons, and not trying to re-use them, provided significant time advantages "destructive detensioning" or using plasma cutting to destroy the buttonheads has been the preferred method of detensioning. This approach is now industry practice and was successfully used at:

Braidwood ANO unit 2 Oconee Units 1, 2 & 3 Turkey Point units 3 & 4 ANO unit 1 Fort Calhoun TMI.

If you have any questions or require further information please do not hesitate to contact me.

Regards Paul From: Portmann, Rick [mailto: Rick.Portmann@pgnmail.com]

Sent: Monday, January 18, 2010 9:59 AM To: Paul Smith Cc: Miller, Craig L

Subject:

PSC F&Q 8.0 Paul - The question was asked whether the flame cutting tendon removal process (Ref. PSC 8.0) was a standard industry practice and where it has been used at other plants. If you could reply or have any questions please give me a call 352-464-7846 or Craig Miller 352-795-6486 x 1026. Thanks, Rick 1

FM 7.6 Exhibit 6 page 1 of 1 Interview with Gary Goetsch, PSC supervisor over tendon detensioning October 24, 2009 Marci Cooper and Craig Miller

" What was done and sequence?

o De-tensioned 2 vertical top center- night shift performed per plan o Absolutely no sequence for the plasma cuts o He had asked Mr. Peters (Bechtel) when came on job what sequence to be used -was told no sequence per plan, any sequence was ok to cut o Started plasma cutting with 3 crews - lon vertical, I on B2-4, 1 on B3-5

  • What was observed or noted?

o Was very smooth cut - by that means that are relieving 1.2-1.4 million lbs.

each. The cuts and self-relieving very smooth, because shims still in place behind grease cans so unloaded evenly -. if not, they would have slipped out.

o When asked if some tendons did not self-relieve as cutting, he said he didn't recall or know - did not have machine cut effect or wouldn't still have shims tight o When asked what he normally see's, he indicated could be either way, i.e.,

start cutting and subsequent tendons self-relieve as pick up more load, or some don't and cut. Either way can be smooth

" How many jobs like this has he done and what was similar or different in other experiences?

o This is I Ith. SGRjob o This is the first and only one where did this way - no sequence to cutting and not de-tensioning some tendons outside the cut area before cutting o Usually, cut within the opening per specified sequence - e.g., cut one, skip two, cut one, skip two, go up and then alternate back down o Then after all done in the opening, detension around the opening, e.g., 5 on either side and 20 across top, before cut containment o Knew (the CR-3 plan) was a bad idea o S&L did some model that said would take the load o He was told the reason for doing this way at CR-3 was to avoid having to use the polar crane o His concern would be stress loads around concrete

" What was duration of cutting activity?

o Cut from one end of platform, pull tendon out other; then start on next.

Except for verticals, no platform changes. Cut straight across o Roughly 1 to 1 '/2 tendons per shift, roughly 4 days to complete - finished around 10/2 on last cut 9/30

  • Some reports that others detension in opening before cut - how does that match with your experience?

o Have to cut under tension if plasma cut. Otherwise would relax.. .would have to probably grind, would take days and days to cut. Just from schedule standpoint would not do o Others plasma cut under tension

FM 7.6 Exhibit 7 page 1 of 1 10/28/2009 Interview Gary Goetsch and Clifford Peters Present: Gary Goetsch (PSC), Clifford Peters (Bechtel), Craig Miller, Chong Chiu, Patrick Berbon 1- Assymetry lift-off values PB: The data show an asymmetry in the lift-off values when measured at different buttresses on the same cable. Is that usual?

GG: We (PSC) do surveillance testing on many plants. It is usual to measure differences in lift-off values.

The difference is typically less pronounced that at CR3.

CP: The difference at CR3 is more than usually observed.

2- Operator discrepancy PB: When you do the lift-off test, is there possibility of operator discrepancy?

CP: The force increment is only about 20psi. There will be a different reaction time but it cannot account for the large force difference observed at CR3.

3- Have you observed de-tensioning at other plants?

GG: De-tensioning is occasionally found during routine maintenance. However, "runs" of de-tensioned tendons, such as the ones observed at CR3, are rare.

CP: Has been involved in 25 surveillance tests together with PSC and can only recall re-tensioning at Calvert Cliff.

GG: In the case of VC summer, re-tensioning was done on the vertical tendons at the time of life extension analysis to go beyond 40 years because de-tensioning was progressing faster than expected.

4- When you pulled out the tendons, did you observe any corrosion?

CP: It is all in the documentation on the tendon removal package. Did not observe loss of grease in any tendon. Some corrosion was observed on tendon cap, where water migrated in gap. No corrosion on gasket surfaces or on tendons.

FM 7.6 Exhibit 8 page 1 of 5 PCHG-DESG Engineering Change 0000063016R163 D.1 Installation Package D1.1 This EC will create and repair an opening in the Reactor Building wall. This opening is necessary for the transport of the old and replacement OTSG during the Steam generator replacement outage. The following is an over view of the activities required to accomplish these activities:

Pre-Outage:

1. Mock-ups and associated training of craft for complex work activities required for the creation and restoration of the access Opening.
2. Staging tendon upper support frames onto the Reactor Building roof and attaching the tendon work platforms.
3. Partial degreasing of 30 vertical tendons in and around the Opening prior to Plant shutdown.
4. Installation of a temporary work platform (a.k.a. "chipping platform") as described in EC #63022.
5. Survey and layout the basic geometry of the Opening, and shallow saw cutting of the Opening.
6. Deleted
7. Tendon anchorage inspections per ASME Section XA, Subsection IWL.
8. Disable sump pumps SDP-3A and 3B and Install temporary sump pump(s) in the tendon gallery sump. Test the temporary pumps to ensure that they are operable and deliver at least 300gpm.
9. Saw cutting of the perimeter of the containment access opening.

Modes 5 and 6:

10. Tendon anchorage inspections per ASME Section Xl, Subsection IWL.
11. Detensioning, removal and final degreasing of 10 vertical and 17 hoop tendon's from within the Opening (mode 5 or 6).
12. Hydrodemolition of the 42" thick concrete containment wall from within the Opening.
13. Radiological and environmental testing and disposal of the hydrodemolition effluent (wastewater and concrete rubble)
14. Cutting and removal of the steel reinforcement bars (rebar) within the Opening; drilling of pilot holes in liner plate for cut line layout.
15. Cutting and removal of tendon sheathing within the Opening.
16. Perform core boring in accordance with AI-480, ASTM C-42 and Attachment Z65.

Defueled Prior To Removal and reinstallation of the OTSG:

17. Cutting and removal of the steel liner plate at the Opening, about liner plate cut line.

FM 7.6 Exhibit 8 page 2 of 5 All welding shall be performed per NGGM-PM-0003, Corporate Welding Manual.

Station security shall be notified at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to breaching the liner plate so that they may evaluate and implement compensatory measure.

Notify Operations and RP and insure the following has been accomplished prior to commencing the liner plate cut:

o Appropriate radiological postings installed outside the access Opening o Personnel monitoring and air monitoring equipment (radiological) installed and operational outside access Opening.

o Satellite de-contamination facility established (Ref. RP Task Plan) o A 12" wide strip of paint on either side of the liner plate cut line has been removed.

o Inside face of the liner plate must be decontaminated as practical.

o Satellite de-contamination facility established Obtain a fire barrier breach permit per site procedure CP-1 37, Fire and HELB Barrier Breaches, Additional attachment welds on the metallic liner may be required to attach construction aids to the liner. These construction aids may include pads that will be permanently welded to the liner to support lifting rings and lugs.

D.2.2 Detail required sequencing of steps This section will be broken up by major activity. The handoffs from one activity to another will be identified.

D.2.2.1 Tendon Degreasing, Detensioning, Removal, Reinstallation and Retensioning

FM 7.6 Exhibit 8 page 3 of 5 Refer to PSC Manual "Post Tensioning System Field and Quality Control Procedure Manual" (Attachment Z23) for additional guidance in removal, inspection and reinstallation of tendons.

Note: The intent of all of the instructions contained in this document must be transferred to the work order instructions, clearly, accurately and in their entirety. However, CR3 procedures will always take precedence over the PSC F&Q Quality Control Procedures.

The methodology and requirements for Calibration of all tools and equipment shall be evaluated, reviewed and approved by Progress Energy (CR3) Nuclear Assessment Section (NAS).

1. Tendon Service Platform installation
a. Install four Upper Support Frames (USF) supplied by Precision Surveillance Corporation (PSC) as directed by PSCs supervisory representative and in accordance with the information contained in the PSC design calculation contained in Attachment Z34. Note that all platform tie-down material/equipment will be supplied by PSC.
b. Each USF shall be initially placed on the reactor building roof rails above the equipment hatch (approximate AZ 150), following the safe load path drawing (see attachment G01).
c. Each of the four USFs will support a suspended work platform (2-8'xlO' and 2-nominall0'x20' platforms). Each work platform is lifted over the equipment hatch shield structure at AZ 150 degrees, and attached to its respective USF with cables.
d. After a work platform has been attached to its respective USF it will be proof load tested per the requirements of Section E0O.
e. The suspended work platforms come in two sizes. The 8' x 10' platforms (and USFs) will be moved and staged at buttresses 2 and 5 and the nominal 10' x 20' platform will be placed at buttresses 3 and 4 with the restrictions listed below in f.
f. The USF and platform combination for buttress numbers 2, 3 and 5 will be rolled clockwise around the roof (from their initial position at approximate AZ 150 degrees) and must be lowered to their temporary storage location on top of the intermediate building roof. They cannot be staged at buttress numbers 2 or 3 until Mode 5. Note that the platform at buttress number 5 may be temporarily stored on the IB roof if required until Mode 5. The platform sequence is buttresses 5 first followed by buttress 2 and finally buttress 3.
g. The USF and platform combination for Buttress number 4 shall be rolled counterclockwise from its initial position at AZ 150 degrees to the east side of buttress # 4. It may be staged at buttress #4 during any Mode.

FM 7.6 Exhibit 8 page 4 of 5

2. Tendon Degreasing and Tendon Removal
a. Partially degrease the following vertical tendons prior to shutdown (Refer to drawing 421-347 for tendon location):
i. 34V8 thru 34V17 (within the opening),

ii. 45V22 thru 45V24 and, 34V1 thru 34V7 (about buttress #4 and adjacent to the opening) iii. 23V1 thru 23V3 and 34V18 thru 34V24 (about buttress #3 and adjacent to the opening)

b. After partially degreasing the vertical tendons, perform the required ASME Section Xl, subsection IWL inspections of the tendon anchorage components either before the outage or during the outage dependent on labor needs, and the following requirements:
1. The following two vertical tendon anchorages (inside the opening) including the surrounding concrete require a detailed visual inspection per IWL prior to ram detensioning (Refer to Drawing 421-347 and Ref. 4.19 for location):

34V12 and 34V13

2. The anchorage components of the following 8 remaining vertical tendons that are being removed from the opening do not require IWL inspections, except for the concrete surrounding the tendon bearing plates that must be inspected to IWL requirements prior to detensioning:

34V8 thru 34V11 and 34V14 thru 34V17 The anchorage components of hoop tendons that are being removed do not require IWL inspections, except for the concrete surrounding the tendon bearing plates that must be inspected to IWL requirements.

However, craft personnel are to look at the tendon assembly after cleaning and prior to cutting the buttonheads for removal and note any obvious deficiencies that may question the integrity of the tendon assembly. Any questionable deficiencies should be referred to the IWE/

IWL Responsible Engineer.

c. Two vertical adjacent tendons (, 34V12 and 34V13) (Refer to drawing 421-347 for location) may be removed from within the opening after the reactor has shutdown (after entering Mode 5) and prior to the start of concrete hydrodemolition of the 42" thick containment wall and saved for possible re-use.

These two tendons will be detensioned with a hydraulic ram, the buttonheads removed with a hand grinder, coiled and then saved as

FM 7.6 Exhibit 8 page 5 of 5 a contingency to ensure that replacement vertical tendons of sufficient length are available in the event that a new replacement tendon is identified as being too short. If it is determined that one or more of these three original tendons must be reused, then the tendon(s) will be sent to PSC for restoration.

Note that Tendon 34V13 may be plasma cut directly above the bottom anchor head.

One wire will be removed from each of the two tendons, its length measured as accurately as possible, recorded, and this information sent to engineering for evaluation.

d.

e. With the plant in Mode 5 or 6 the following tendons can be removed:
i. 8 vertical tendons 34V8 thru 34V1 1 and 34V14 thru 34V17 (Ref.

to drawing 421-347 for location).

ii. 17 hoop tendons 42H27 thru 42H34 and 53H27 thru 53H35 - (Ref. drawing 421-347 for locations) iii. After the hoop and vertical tendons have been removed from within the opening, the open tendon sheaths shall be degreased to the extent practical.

f. The remaining 8 vertical tendons to be removed from within the opening (34V8 thru 34V1 1 and 34V14 thru 34V17) will be destructively detensioned by plasma cutting the buttonheads at the lower anchorage in the tendon gallery. The tendon is then coiled-up at the upper anchorage (RB roof) and banded, removed from the coiler, wrapped in plastic and lifted to the ground by the mobile crane.
g. Hoop tendons to be removed from within the opening will be destructively detensioned by plasma cutting the buttonheads at the smaller work platforms located at buttress numbers 2 and 5. The tendon is then coiled-up at either buttress number 3 or 4 and banded, removed from the coiler, wrapped in plastic and lifted to the ground by the mobile crane.
h. After a tendon is removed, attach a temporary protective bearing plate cover to the bearing plate, over the open tendon sheath void (hoops only) to prevent further debris from entering the tendon sheaths.

Alternatively the grease cap can be replaced using the old gaskets.

i. Tendon removal activities are completed
3. Tendon Detensioning around the access opening
a. After the old steam generators have been transported out and the new steam generators into containment, and the Horizontal Transfer Structure is no longer required to support lifting the steam generators, the following tendons shall be detensioned:
i. 45V22 thru 45V24 and, 34V1 thru 34V7 (about buttress #4 and adjacent to the opening)
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