ML20040F361

Reactor Water Clean-Up Sys Temporary Repair of Nonisolable Intergranular Stress Corrosion Cracking

ML20040F361
Person / Time
Site:	Quad Cities
Issue date:	01/28/1982
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20040F356	List: ML20040F355 ML20040F361
References
PROC-820128, NUDOCS 8202090116
Download: ML20040F361 (85)

Text

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OUAD CITIES STATION UNIT 2 REACTOR WATER CLEAN-UP SYSTEM TEMPORARY REPAIR OF NON-ISOLABLE IGSCC REVISED JANUARY 28, 1982 The following revisions were made and affect the Appendices only:

1.

Onsite Review Report with Final Approval 2.

Offsite Review Report 3.

Description of Analytical Effort 8202090116' 820128 PDR ADOCK 05000265 P

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Y TABLE OF CONTENTS Introduction History of Problem Previous NRC Discussions

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Schedule Inspection and Flaw Characterization Inspection Procedures Inspection Results Edison Review of Inspection Characterization of Flaws Design of Repair Repair Assumptions / Philosophy Circumferential Flaw Repair Axial Flaw Repair Sock-o-let Repair Analysis of Repair Repair Procedures Welding -

Inspection -

Temporary Support -

Back-Up Measures Freeze Plug Clamps for Overlay and Sleeve Restrain of 2-inch Line Administrative Control Technical Evaluation of Repair l

Crack Extension During Welding Crack Extension Post Welding Material Selection Isolation During Repair Mock-Up Safety Evaluation

- Leak Detection

.[. On-Site Review Off-Site Review Quality Assurance Appendices.

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INTRODUCTION Unit 2 experienced a 15-week refueling outage which ended on December 26, 1981.

~ On January 2,1982, a step increase of 0.5 gallons per minute was observed.

This was attributed at the time to a possible valve. packing leak. On January 15, 1982 the 2B Reactor Recirculation MG Set was tripped due to a problem with the exciter brushes. At that time the decision was made to rectify a low oil level alarm for the 2B Reactor Recirculation Pump motor that had previously annunciated, and to identify the existing drywell leakage. As a result a drywell entry was made. While the Operating Engineer was in the drywell, he noticed that water was coming out from the insulation around the Reactor Water Clean-Up System suction piping. The unit was shut down.

Since the unit has been shutdown there have been several discussions with the NRC, the last one being a conference call on January 23, 1982 between Region III, NRR, and the Station.

As of this date, we are proceeding with a repair program that we are here to discuss today. We have obtained the materials, welding machines and manpower that are necessary for the repair, and a mock-up of the repair is in progress.

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er INSPECTION AND FLAW CHARACTERIZATION

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s INSPECTION AND FLAW CHARACTERIZATION Subsequent to the discovery of a leaking crack on the pipe side of weld joint S-14, UT inspection program was initiated to examine two adjacent welds, S-15 and S-16 (see the attached iso.).

As a result of discovering linear indication on these two welds, the program was expanded to inspect all butt welds in the RWCU line up to the outboard isolation valve.

Radiation levels are very high in this area (400 - 800 mR per hour), and required 17.9 Man Rea exposure, and the UT examination was limited to discovery of flaws on the isolable side. However, the welds on the non-isolable side were examined thoroughly, sometimes by three different UT inspectors. Common-wealth Edison's three UT inspectors, including the Level III inspector, evaluated the results of contractors work and where needed personally examined some welds for verification of other inspectors test results.

Based on these examinations, it was discovered that:

1.

Eight out of eleven butt welds downstream of the inboard isolation valve (isolable) had UT reflectors indicative of cracks.

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2.

None of the four welds outside the containment had any unacceptable indications.

3.

Four out of ten butt welds upstream from the inboard isolation valve showed UT indications.

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4.

All axial cracks were found on the elbow side of the welds.

5.

All circumferential cracks were found in the HAZ of the pipe.

- Test results are summarized in the attached table.

The attached isometric drawing shows the locations of the welds identified in the summary table.

While the UT inspectors were performing inspections on the piping butt welds, one of the inspectors observed a droplet of water on the socket weld which attaches the 2-inch reactor drain line to the Sock-o-let on the RWCU line (Weld F-1A).

Subsequent visual and high temperature penetrant examination failed to reveal any linear indications indicative of through-wall crack.

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INSPECTION & FLAbl CHARACTER *lZATION QUAD C.lTlE S c.).Q lT;. d.,

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S-19 PIK - ELBW CIRC. - PIK StML 3

S-18 EUDI - PIR CIRC. - PIK 1-1/2 - 2 IIDI LW G F-17 PI K - ELBOW AXIAL - ELBOW SIE 50% T.W. ~1/2 - 3/4 ING LDNG S-16 EUBl - PIK CIRC. - PIR HIG1 RAD - NO SIZING a

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SP DESIGN OF REPAIR e

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l DESIGN OF REPAIR Repair Assumptions / Philosophy.

The repair described in this section and in the repair program, which is an Appendix to this report is based on two assumptions.

The non-isolable section of the line cannot be replaced due to fuel storage concerns.

The fix is temporary, i.e. a permanent repair will be performed during the Spring 1983 outage.

The basic philosophy of the repair is to create a new pressure boundary using IGSCC resistant materials (as identified in NUREG-0313 Revision 1 such as low carbon materials and weld metal). Implicit in this philosophy is that each flaw identified has developed to a thru-wall crack. Secondarily the weld pad repairs offer a favorable residual stress distribution.

DESIGN OF REPAIR Circumferential Flaw Repair The circumferential flaw repair (Figure 1) uses a low carbon stainless steel sleeve around the flawed weld extending six inches on either side.

The sleeve will be machined from wrought material, split and welded around the pipe using full penetration welds. The sleeve ends will be welded to the pipe using partial penetration welds with cover fillets.

The sleeve will allow space for the existing weld crown.

Axial Flaw Repair The axial flaw repair (Figure 2) establishes a " cast - in place" pipe sleeve from weld metal.

In addition to the favorable compressive residual stress pattern, the Type 308L weld metal is resistant to propagation of the IGSCC crack.

Sock-o-let Repair If required, a sleeve will be provided around the sock-o-let connecting the two-inch drain line to the six-inch RWCU line. This repair is shown

,_ in Figure 3.

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Analysis of Repairs The stress analysis and flaw propagation calculations necessary to justify the repairs are contained in an Appendix to this report.

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9' REPAIR PROCEDURES l

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REPAIR PROCEDURES Welding Procedures Weld Overlay:

CECO Automatic Welding Procedure WPS-8-8-DA.

Sleeve Welds:

Axial Seam Welds using Mechanical Incorporated Procedure WPS-800A.

Circumferential welds using Mechanical Incorporated Procedure WPS-800A.

Sock-o-let Welds:

Axial seams welds using Mechanical Incorporated Procedure WPS-800A.

Circumferential welds using Mechanical Incorporated Procedure WPS-800A.

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REPAIR PROCEDURES Inspection Procedures The following procedures will be used to verify quality of the repair:

Welding Overlay:

PT of the first pas.t CECO procedure.

UT of the joint - if successfully developed by CECO from the mock-ups.

i Sleeve Welds:

PT of the welds - CECO procedure.

UT of the welds - CECO standard procedure.

Sock-o-let Welds:

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.i of the welds - CECO procedure.

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. REPAIR PROCEDURES Temporary Supports During the course of the repair, the non-isolable piping is being supported with temporary restraints. The supports will account for normal pipe / water weight, repair equipment weight, and relocation of existing restraints.

Restraints will be removed or relocated to provide welder / welding equipment accessibility. Prior to removal / relocation of existing restraints, the temporary support system will be installed.

Two existing restraints are affected by the repair. Spring hanger 1202-W-110 located on the isolable piping, was disengaged to allow piping replacement.

Valve MO 2-1201-2 was secured with chain hoists prior to disengagement of 1202-W-110. Reetraint 1202-M-107 will be removed to allow access to welds S9 and S10. Temporary blocking will be pisced near the downstream guide 1202-G-109, and chain hoists will be placed upstream'of weld S9 to account for removal of 1202-M-107.

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REPAIR PROCEDURES Back-Up Measures In the event that leakage occurs during the repair, back-up measures have been established to stop the leak, and allow repairs to proceed. Mechanical clamps have been designed for each generic repair zone and freeze plug equipment is immediately available on-site. For a given leak, the clamp will stop the flow allowing the freeze plug to be established.

The freeze plug equipment wil be standard liquid nitrogen freezing equipment sized as required. Each leak scenario has been considered to assure that plugging can be accomplished for each scenario.

The mechanical clamping devices have been designed for the pipe sleeve, the weld overlay, and the sock-o-let sleeve. The pipe sleeve clamp is a 6-inch bolted sleeve lined with a rubber membrane. An alternate clamp capable of encompassing the pipe and the pipe sleeve is also in preparation.

Clamping for the weld overlay consists of various widths of standard pipe clamps combined with a rubber membrane.

The sock-o-let sleeve clamp, installed prior to the start of sleeve

- installation, consists of a pipe clamp around the 2-inch line, which will be tied to the six-inch RWCU line with cable.

This clamp will prevent any displacement during a postulated break in the sock-o-let, thus limiting any leakage to a small and manageable amount. -

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1 x so,ciai hign-strengtn ductiie iron 2 tugs witn mutuaiiv supporting siiding 3 ruii circumference. singie or moitinie alloy lug utilizes a strength efficient fingers to assure proper bolt alignment section ctainless steel bands available computer-aided design that's not only while tightening. Permits maximum in 7%" 10",12%".15",20" and 30" stronger, but lighter and easier to install.

torque without bending of bolts, widths.

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resists pull-out and provides gasket pressure and prevents maximum band retention.

crimping.

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pipe surfaces.

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REPAIR PROCEDURES Administrative Control A detailed procedure for control of operational support of this repair has been written and is appended to this report.

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W TECHNICAL EVALUATION OF REPAIR l

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TECHNICAL EVALUATION OF REPAIR Crack Extension Durina Welding The risk of causing a failure of the RWCU line during welding is non-existent due to the very high toughness of austenitic stainless steel.

Studies by EPRI and General Electric on austenitic stainless steel have shown that flaws very much larger than those detected in the RWCU line would be stable under normal and upset operating conditions. The repairs will be performed with 23 psig pressure in the pipe, and with the shutdown cooling the only system operating (intermittently) within the drywell. Stresses from these sources are insignificant.

Welding stresses could be significantly high in the localized weld regions.

The attachments for the sleeve repair to the circumferential flaw in weld F6 will be located several inches away from the existing weld. There will be no significant thermal or mechanical stressing of the existing weld during sleeve attachment. The weld overlay repairs to the axial flaws could conceivable cause some extension of the flaws. Such extension could only take place with very high tensile stress present at the edge of the flaw. The stresses from welding are highly localized and any extension would be arrested in a very short distance due to the reduced stress field. A nearby through-wall flaw has the potential of extending radially to produce a small leak. Low heat input will be used in depositing the first layer over the flaw regions to minimize penetration and stresses. --

TECliNICAL EVALUATION OF REPAIR In the unlikely event that a small leak occurs, a rubber-lined mechanical clamp will be available to seal off the leak. Freeze plug equipment will be available. With a freeze plug in place and the line drained to stop leakage, a localized,epair to seal the leak would be performed. Once the leak is sealed off, the freeze plug would be allowed to melt and the repair completed as originally planned.

The sleeve repair to the sock-o-let will be attached to the 6-inch RWCU line and to the 2-inch drain line above the existing socket weld. The attachment weld to the 6-inch line will not tie into the existing sock-o-let weld. There will be no significant thermal or mechanical stressing of the existing welds during sleeve attachment.

i Due to the uncertainty of the condition causing the water droplet noted during examination, a strap clamp will be applied prior to attaching the sleeve. The strap clamp will supplement the existing rigid support on the 2-inch line to mechanically restrain the 2-inch line from pulling out of the sock-o-let in the very unlikely event of failure.

If leakage were to occur during repair, attempts will be made to accomplish freeze plug isolation to permit completion of the repair.

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' TECHNICAL EVALUATION OF REPAIR t

Crack Extension Post Welding IGSCC can only occur when the cambination of sensitization, tensile stress, and aggressiveness of the environment is sufficient to cause it.

The sleeve repairs will not change the degree of sensitization or the environment near the existing welds. The effect on residual stresses of adding the sleeves is uncertain, but it is not expected that any significantly increased tensile stresses will result. Crack extension may occur during operation, but this is not of concern as the sleeves are desig ed as new, independent pressure boundaries around the existing welds. The sleeves can accomodate complete separation of the existing welds. If through-wall penetration occurs, the annulus between the sleeve and pipe will be wetted with primary water. The Type 304L sleeve material and Type 308L weld metal will resist initiation of IGSCC during service. It is extremely unlikely that IGSCC could initiate in the existing pipe near a sleeve attachment weld and propagate through pipe material under the weld to produce a crack. Even if such a crack were to occur, the result would be a detectable leak, and no tisk of pipe breakage would be presented.

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TECHNICAL EVALUATION OF REPAIR The weld overlay repairs to the axial flaws will be performed by depositing circumferential stringer beads. The deposition will be accomplished in layers with each layer completed before beginning the next layer.

Circumferential stringer beads will produce a constrictive force as the underlying pipe, due to weld metal shrinkage. The accumulated effect of the stringer beads comprising the overlay will be to produce compressive circumferential residual stresses under the overlay. As the overlay will extend well beyond the existing axial flaws, propagation of these flaws during operation would be mitigated by the changed residual stress pattern.

Also, crack extension in the axial direction would be mitigated due to the absence of butt veld sensitization from the original butt weld and the reduced residual tensile stresses beyond the heat affected zone of the original weld. Even if crack extension were to occur, the crack would be arrested in the radial direction by the IGSCC resistant weld metal overlay.

In the very unlikely event of extension in the axial direction to beyond the weld overlay, the result would be a detectable leak, and no risk to pipe breakage would be presented.

The weld overlay could produce residual tensile stresses at the inside surface of the existing pipe near the ends of the overlay. The magnitude of these stresses is reduced by tapering the ends of the overlay.

IGSCC is unlikely to occur at these transition regions as significant sensitization is not expected at the inside surface. The overlay will be applied at low heat input and the water present inside the pipe will produce rapid cooling.

The degree of sensitization produced by the weld overlay process wil), be evaluated by a representative mock-up and metallurgical testing.

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4 TECHNICAL EVALUATION OF REPAIR Materials Selection The materials which will be used to accomplish the repair have been selected to provide a high resistance to IGSCC. The wrought material for the sleeves is Type 304L stainless steel having 0.035 percent carbon and meeting the mechanical requirements of regular Type 304. The consumable welding material is Type 308L stainless steel. Type 304L and Type 308L stainless steel are listed as acceptable materials in NUREG 0313 Revision I for construction of piping systems.

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TECHNICAL EVALUATICN OF REPAIR Isolation Durina Repair The repairs to the non-isolable portion of the RWCU line will be performed without establishing isolation. The only feasible means of 3 clation is by creating a freeze plug upstream of the repair areas. The reasons for performing the repairs without a freeze plug are as follows:

1.

The pipe will not be severed during the repairs so that a large diameter potential leak path will not exist.

2.

The risk of creating a major leak during welding is non-existent due to the very high toughness of austenitic stainless steel.

3.

A freeze plug would require continuous monitoring by personnel to assure no degradation of the plug. The radiation field where the personnel would be present is approximately 600 - 800 mR per hour at one foot. The accumulated man-rem for continuous monitoring is contrary to the ALARA concept.

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TECHNICAL EVALUATION OF REPAIR i

Mock-Up The proposed repair of axial cracks on the elbow side of the elbow to pipe joint calls for deposition of weld metal on the 0.D. surface to produce a weld pad approximately 6 inches long and 1/2 inch thick.

Commonwealth Edison has used this particular mechanized welding equipment previously at Dresden. CECO has the required procedures and is familiar with the equipment; however, we propose to conduct a mock-up study to evaluate the following:

1.

Feasibility of using mechanized welding on elbows:

A new elbow will be welded to a straight length of pipe for conducting this test. The test spool piece then will be pad welded to produce a weld pad approximately 6 inches long (3 inches on either side of the butt weld). Any difficulties in using mechanized welding in negotiating elbow contours and set-up problems will be investigated.

TECHNICAL EVALUATION OF REPAIR 2.

Evaluation of quality of weld metal:

The pad welded mock-up sample will be examined by VT, PT and RT methods.

The NDE results will be evaluated to ASME Section III Class I acceptance standards.

The test sample will then be sectioned for metallurgical examination.

The heat affected zone (HAZ), quality of weld deposit and the bond along the fu. ion line will be thoroughly investigated. Microstructure in 'the HAZ will be eval'uated using ASTM A 262 practice A.

The degree of sensitization (DOS) observed will be compared with DOS generally observed in a typical butt welded sample.

3.

UT inspectibility of the pad weld.

A section of the pad welded sample will be retained for the development of a UT procedure. Attempts will be made to apply the latest UT technology

.to develop a UT procedure to inspect the production welds. Since results of our attempt will be known only after performir ; this trial run, there is no committment at this time to ultrasonically examine J_.

the production pad weld. - - -

l TECHNICAL EVALUATION OF REPAIR 4.

Extension of existing crack during pad weld repair.

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The elbow to pipe joint (F-17) removed from service will be utilized for this purpose. The weld joint will be radiographed to locate the crack. The pipe will be filled with water and pad welded on the 0.D.

to produce a 6 inch - 1/2 inch thick pad.

After the first layer is laid down, the weld layer will be prepared for a thorough PT examination.

PT will be performed to determine if the existing flaw has broken through the weld layer.

If the crack does not break thru, subsequent weld passes will be deposited.

If the crack breaks thru the first layer, the mock-up test will be terminated and the position on repair will be re-evaluated.

The completed weld repair will be examined by radiography. Original and final radiographs will be compared to determine if any significant crack extension has occurred.

5.

Concern over welding on marginally sensitized material.

From previous metallurgical investigations, it is possible that the l,

elbow material may be in a slightly sensitized condition. Concern has been raised over degradation of this slightly sensitized material due to additional welding.

It is not possible to section the contaminated elbow and prepare for merallographic samples in a reasonable period of time. the consequences of crack extension under the overlay is addressed in ' Technical Evaluation of Repair' section of this report.

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SAFETY EVALUATION Leak Detection - To ensure that any postulated additional cracking will be

- detected prior to potential pipe rupture, leakage within the drywell is closely monitored. Reactor coolant leakage in the drywell is monitored in 4

accordance with the appended Quad-Cities Station Procedure QOS 1600-7.

The procedure ensures adequate leak detection, and the performance of this procedure is shown in the attached tabulation of leakage monitored at Unit 2.

The procedure did identify the additional leakage due to the through wall IGSCC in the isolatable portion of the reactor water clean-up system. This leakage was well below limits, but the change in leakage was identified for this small defect.

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'lAFETY EVALUATION

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DAILY U-2 DRYWELL FLOOR DRAIN SUMP PUMP READINGS GAL PER

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12/26/81 0 gal 0.00 gpm 12/27'/81 300 gal 0.02 gpm START UP FOLLOWING REFUEL OUTAGE t

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12/28/81 280 gal 0.19 gpm 12/29/81 330 gal 0.23 gpm 12/30/81 370 gal 0.26 gpm

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12/31/81

' 410 gal 0.28 gpm 01/01/82 770 gal 0.53 gpm 01/02/624 1420 gal 0.99 gpm 01/03/82 1090 gal 0.7& gpm SCRAM RECOVERY

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01/04/8'2 1590 gal 1.10 gpm x

4 01/05/82 1650 gal 1.15 gpm

- 0.1/06/82.

1670 gal 1.16 gpm 01/07/82 1700 gal 1.18 gpm 01/08/82 1710 gal 1.19 gpm 01/09/82 1810 gal 1.26 gpm 01/10/82 2030 gal 1.41 gpm 01/11/82 1950 gal 1.35 gpm j

' 01/12/82 1930 gal 1.34 gpm 01/13/82 1820 gal l.26 gpm 01/14/82 2020 gal 1.40 gpm 01/15/82 If:30 sal 1.17 spm 01/16/82 120 gd1 0.08 gpm UNIT SHUT DOWN HIGHEST 4 HOUR PERIOD WAS 480 GAL CR 2 GPM (01/14/82). TECHNICAL SPECIFICATION LIMIT FOR UNIDENTIFIED LEAKAGE IS 5 GPM.

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J SAFETY EVALUATION Onsite Review An on-site review of this proposed repair to the Unit 2 Reactor Water Clean-Up System IGSCC was conducted and recorded in Review Report Number 82-05.

This review report is appended.

l Off-Site Review An off-site review was conducted and the report is appended.

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QUALITY ASS 1RANCE i

I All work will be performed in accordance with the Commonwealth Edison Company Quality Assurance Manual.

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i TABLE OF APPENDICES i

QOS 1600-7, Reactor Coolant Leakage in the Drywell On-Site Review No. 82-05 Off-Site Review

'4 Repair Program (Included in On-Site Review)

Administrative Control Procedure for Repair of Non-Isolatable Unit 2 Clean-Up Pipe in Drywell.

Calculations and Analysis 1. _ _, - _ _

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QOS 1600-7 Revision 3

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PIACTOR COOLANT LEAKAGE IN THE DRYWELL June 1981 S.R.

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PURPOSE

' The purpose.of this procedure is to detect and monitor identified and unidentified leakage in the drywell.

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REFERENCES 1.

None.

C. -PREREQUISITES 1

1.

None.

L D.

PRECAUTIONS 9

1.

None.

E.

LIMITITIONS AND ACTIONS 1.

In the event that any one or more the following criteria are exceeded, commence an orderly shutdown if:

The volume pumped from the drywell floor drain sump in a four hour a.-

period is equal to or greater than:

(1) 1200 gallons (5 gpm).

(2) 480 gallons greater than the previous 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> pump down.-

l The volume (A gallons) pumped from the drywell floor drain sump at b.

the end of any four hour period when averaged with the previous five a gallons is greater than twice the average of the previous six A gallons.

The volume pumped from the :drywell equipment dra'in :: ump in an IJ c.

.eight' hour perio'd. is equal to or. greatar-than 9600 gallons (20

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'gpm).

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If leakIage.is excessive. hut below limits, notifv* the Shif t Eng.n--r to contact Rad Protection to perform a dryvell qanifold sample siirvey to' idedtify the leakage source.

2.

If either integrator reading has drifted free the end of one pump to f

the start of the next write a work request to cor. rect it.

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' APPROVED AUG 21 1981.

Q. C. C. S. R.

F

.B*.

QOS 1600-7 R;visien 3 I

F.

PROCEDURE 1.

Drywell equipment drain sump.

Pump down the drywell equipment drain sump twice a shift (approxi,

a.

mately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />).

I b.

Record drywell equipment drain sump integrator readings, 901-4(902-4),

on QOS 1600-S13 immediately before and af ter pumping the sump.

I Transfer the sum o'f the pumping for the shift to the Operation's c.

Department Weekly Summary of Daily Surveillance, QOS 005-SI.

d.

Compare the volume pumped against the limiting criteria. if unacceptable, notify the Shif t Engineer and refer to Technical Specification 3.6.D.

2.

Drywell floor drain sump.

Pump down the drywell floor drain sump every four hours.

a.

b.

Record drywell floor drain sump integrator readings, 901-4(902-4),

on QOS 1600-S9 immediately before and after pumping the sump.

c.

Close isolation valves immediately after pump trips on low level.

l d.

Record integrator reading and a gallons pumped on the " Unit Drywell Floor Drain Sump Data Sheet".

Average the latest A gallons with the five previous recorded g

e.

g gallons and record the new calculated 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> average.

f.

Once a shift (approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) transfer the sum of the pumping for the shift on Operation's Department Weekly Summary of Daily Surveillance QOS 005-S1 item 2.

)

g.

Compare the volume pumped per four hours against the limiting criteria.

If unacceptable, notify the Shift Engineer to contact Rad Protection to perform a drywell air manifold sample and refer y

to. Technical Specification 3.6.D.

c.

h5 G.

CHECKLISTS'-

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y 1.

Operat. ion's Depa.rtment Wekly Seaary of Daily Sur.vei..aacie :C3 005-S1_

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QOS' IUD [0-S9, Unit Drywell Floo'r Drain Sump D'ata Sheet.

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2.

3.

QOS 1600-S13, Unit Drywell Equipment Drain Sump Data Sheet.

H.

TECHNICAL SPECIFICATION REFERENCES 1.

Section 3.6.D.

0-APPROVID 12 2.

Section 4.6.D.

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y.

Revisicn 1 May 1975 QUAD-CITIES STATION ONSITE REVIEW ASSIGNMENT DATE 1/22/82 REVI EW NO.

82-05 REVIEW PARTICIPANTS:

L. Gerner W. Burkamper R. Bax T. Tamiyn J..Tietz CONSULTANTS:

R. Gal tonde (OAD)

G. Schuite (NSD-Maint)

R. Taminga (NSD-Maint)

T. Spry (NST-Maint)

J. Gavula (NUTECH)

E. Hemzy (Of f-Si te Staf f)

D. Pitcairn (NUTECH) s ASSIGNMENT:

P,rovide 10 CFR 50.59 Safety Evaluation of Proposed Repair Program for Unit 2 Reactor Water Cleanup System Pipe Cracks in the Dryweli M K STATIONSUPERINTEtIDENT APPRO,VED 1 (final) s SEP 5 1975 Q.C.Q.S.R.

~

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QAP 1400-T2 QUAD-CITIES STATION.

R; vision 2.

ON-SITE REVIEll REPORT February 1977 R iference information:

OSR Recuest Oricinator:

OSR No:

27-C[

Station X

Off-Site Review Review Date:

/ J A/r2.-

NLA Other

/!J.

P z.

NFS Was Request Complete:

'RequesJ Date:

SNED Yes No (Attach material submitted)

'"I'"'

UWW 77v0 keec%r IAle Yir C/es p - Q Cyz 7 &'

hE iMc Repir f

Reason For Review:

Tech. Spec. 6.l.G.2.a (On-Site)

Tech. Spec. 6.1.G.I.a (Off-Site)

Other:

NRC Bulletin Deviation

,k AIR Request Station

'X On-Site Reference Materials (attach):

Safety Evaluation X,

Procedures Affected Tech Spec Pages MOD Number FSAR Pages AIR Number QA Manual Pages Other Off-Site Completion Info:

i f3If%2-W h Check List Complete X

Advance Notification

'f24 Forward to Off-Site X

Date Off-Site Review Humber Person b-Disposition:

RoutinI5 Report X

Of f-Si te Review for Concurrence (T.S. 6.1 G.2.a. (5))

X.

AIR issued (#

)

NRC Submittal Needed Technical Specification Change A.. P P R t 'i V r.' ;,

Unreviewed Safety question

[

Other No Further Acticn M 9 9A]977 Other W-G. C. S. R.

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NOV. 6 l-1-81 OSR FUPN - 1 RECORD OF REQUEST FOR OFFSITE REVIEW 5 etion quad-cities Onsite Review No. 82-05 Suomitted.by G. Tietz Date 1/22/82

~

Test or experiment not involving an unreviewed safety question.

Proposed test or experiment invo.1ving an unreviewed safety question Proposed change to procedure, equipment or system involving.an unreviewed safety question.

Proposed change to Tech. Spec. or license.

Unanticipated deficiency of design or operation of safety related structures, systems, or. components.

Proposed change to GSEP.

Referral by T. S. Supervisor, Station Superintendent, Division Vice X

President fluclear Stations, or Manager of Quality Assurance The Unit Two R' actor Water Clean-U'p System

~

g..Adoitional subject description:

e b

Piping Repalr Supporting documents attached:

Safety Evaluation, M. C. Strait' Letter of Jrnuary 22, 1982, to N. J. Kalivianakis, Repair Program COM 3402-002 Rev. I Repair Program COM 3402-003 Rev. O, Baseline Data Figure 65-11 l

l Date required for Offsitd Review comp 1'etion:

Date Received by Senior Participant 3ffsite Review No.

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,v.---....,- c -*---.-

s Quad-Citics Station On-Sito Rsview No. 82-5 7

r Unit Two Reactor Water Clean-up Piping Repair

SUMMARY

The Unit Two Reactor Water Clean-up piping butt welds inside the Drywell on line 2-1202-6"-A, from the RHRS Shutdown Cooling Suction tie-in to penetration

~

X-14 were UT examined by CONAM and G.E., an'd the data obtained were verified by OAD. The indications found were divided into two. categories; 1)

Isolable, downstream of isolation valve MO-2-1201-2 and; 2) Non-isolable, upstream of the isolation valve.

There were 8 indications discovered on the 11 buttwelds on the isolable portion.

Seven of these eight welds had circumferential Indications on the pipe side HAZ. One weld (12S-S17) and an axial Indication on the elbow side of the weld.

Of the 10 butt': welds on the non-Isolable line, four indications were found. A circumferential crack Indication was found in the HAZ of one side of the pipe to pipe weld 125-F6. Axial flaws were found in the elbow side of the elbow to pipe welds 125-59 and 125-S10. Three axial crack Indications were found in the elbow side of the elbow to valve weld 125-F12.

A visual observation of the sockolet weld to bottom vessel drain line 2-1265-2"-A l

revealed this may also have a possible flaw. This weld will be PT examined to confirm the visual observation.

The repair to the Isolable portion of this line consists of replacing the eqisting piping from isolation valve MO-2-1201-2 to the containment penetration.

The original routing and pipe supports will be utilized. New piping will consist of stainless steel type 304L having the mechanical properties of type 304 stainless steel.

{

i

2 The repair to the non-Isolable portion of line 2-1202-6"-A consists of three separate methods. The first method will install a welded sleeve around the pipe-to-p!pe weld 125-F6. This sleeve will encompass the entire Heat

,Affected Zone, HAZ, of weld 125-F6, and consist of two halves welded together

~ longitudinally with a full penetration weld and a circumferential partial penetrat:on weld to the pipe.

The axial flaws will be repaired using an automatic welding machine to lay a pad of weld material over the Indicated flaws.

Should the two inch sockciet weld require repair, a sleeve will be installed which covers the crack.

The sleeve will consist of two halves welded longitudinally, full penetration weld to the six-inch pipe, and circumferential partial penetration welds to the two-inch pipe.4' Temporary pipe ' restraints shall be provided to assure the integrity of the socolet welds during the sleeve I ns tal lation.

' 'The following 10 CFR 50.59 Safety Evaluation is provided for the proposed repair program for the~ non-Isolable weid flaws:

1 1.

The probability of an occurrence or the consequence of an accident, or j

malfunction of equipment impo-tant to safety as previously evaluated 1

in the FSAR is not increased.

The pipe f rom the RHRS Shutdown Cooling tie-In to the MO-2-1201-2 valve will remain In' tact and will not be cut open during this repair. All 6

welding will be performed on the external pipe surfaces, thus maintaining primary coolant boundary integrity. To mitigate the consequences of a i

highly improbable pipe leak, the following measures will be taken:

i a.

A pipe clamp will be available to expeditiously plug a small leak, freeze plug equipment will then be utilized to isolate the line prior to commencing further repairs.

b.

The LPCI Mode of RHRS, both Core Spray subsystems, and a Condensate Feedwater flow path with pumping capability will be operable.

c.

Current Standby Diesel Generator Technical Specifications will apply.

l The repair program will be performed and documented in accordance with the Commonwealth Edison Company Quality Assurance Program as approved by the NRC and the AIA.

Detailed installation and inspection procedures will l*

be written and approved to execute this repair program in a manner consistent with the highest quality of safety-related work.

Quality Control, Quality Assurance, and the ANI will provide evaluations and hold points throughout the program.

The sleeve installation, weld overlay and sockolet' sleeve are being evaluated to meet ASME Section t il Stress allowables.

The piping section to be repaired serves as a primary coolant pressure boundary; however, the Reactor is in the Cold Shutdown condition with normal water level. Therefore, only head pressure (approximately 23 psig) is seen at the pipe elevation.

Since this piping system does not involve an engineered safeguard system, it is not being j

structurally degraded during the repair program, and the Reactor is shut-down, no adverse safety implications are presented.

2.

The possibility for an accident or malfunction of a different type than any previously evaluated in the FSAR is not created.

The repair program will utilize established materials, procedures, welding techniques, -and examination methods that have been utilized previously.

No new nor unapproved methods or materials will be used.

During the next refueling outage, a permanent repair will be implemented.

Protection for personnel involved with the repair work will be afforded proper radiological protective practices to assure that personnel exposures will be ALARA.

l l

'3 The margin of safety, as defined in the basis for any Technical Specification is not reduced.

The safety limit of maintaining Reactor water level greater than 12 inches above TAF with the Reactor in cold shutdown will be maintained.

Redundant water level instrumentation will remain operable, and routine surveillance will continue to be performed.

Secondary containment, SBGTS, Reactor Building vent isolation capability, and all low-pressure ECCS will be operable per Techni cal Specification requi rements.

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12S414 N

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Figure 61-11.

Reactor Cleanup (Ref. Dwst 2-1202-ED-1 & 2) i

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3 RECOMMENDATI ON It is the conclusion of the On-Site Review Committee that the above repair program is technically feasible and sound. When NUTECH, the ANI, the NRC and Commonwealth Edison OAD,'SNED, TSN, NSD-Maint., and QA organizations have concurred with this program, the repair will be initiated.

The above Safety Evaluation is hereby approved, and it is recommended that the repair program be carried out to completion.

9 l

1

(

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1

i January 22,1982

Subject:

Reactor-Vater Clean-up Line Repair Program CON-3402-002, Rev.1, l

Dated January 19, 1982 I

Mr. I.J. 'Kalivianatis, SEED has reviewed the subject progras and concur with the requirements. However, we would like to emphasize that the new pipe should be routed identical to the old pipe routing. There has been an analysis of the old routing which would apply to.the new pipin no dimensions are changed. This will save time, cecause l

supports cosid be 1 sed.

Ifyouhave to confirm the nS pipe reuting is the same as the old pipe.

any questions or consents, please contact us.

l r

R5CEIVED Ja 2r82 M.C. Strait

=

A (Aest, %

= %,

4

$ E*LE e%

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Approved:

i

.S. Abel SEED Manager 1

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15090

s. :

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fdayy l6:~Di5 Ag f/ -

py Ctal-3462-002 e s nevision 1

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- January 19,1982

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y/Ed RECEIVED

1. 1 RDAIR PROGM REACTOR R TER CLEAN-UP LIE s

gg /

c ruanneaamei QUAD CITIES UNIT 2 C"'

A.~ Description of Repair This program addresses the replacement of the 6* HPS schedule 805 Reactor Water Clean Up Line, Lins No. 2-1202-6'A.~ The line will be replaced f:w the inboard isolation valve, valve no. 2-1201-2, domatnam to the dryvell penetration to the insert pipe. Pup pieces at the valve and at the penetration vill be left in place to simplify the replacement.

8.

Jurisdictional Concerns

1. The maintenance of nuclear power cesponents is addressed g

in Section VIII of the Illinois Boiler Safety Act, N

1978, which references the ASME Boiler and Pressure i

Vessel Code, Sections III and H.

In addition, p

10CFR50 dictates the use of ASE Section H for the repair.

2. This epair program shall be submitted to the Authorized Nuclear Inspector. In addition, this program is subject to review by all enforcement and regulatory authorities havingjurisdictionattheplant.

3.

The repair shall meet the requirements (f ASE Section H, 1977 Edition up to and including the Summer 1978 Addenda.

j C. Code of Construction i

The Reactor Water Clean-Up Line downstream of the isolation valve was designed, fabricated, examined and tested in accordance with USAS B31.1.0-1967 and..trgent

& Lundy Specification R-2330.

D. Code of Repair

~

This repair shall be performed in accordance with the original code of Construction and Design Specification referenced in Section C, except as modified in Section F of this program.

Yl

....._i.

I. Flav Description and Failure Mode tvaluaQ-

~ ~

1. The flaws are cire n ferential and Icogitudinal stress' corrosion cracks' located in the dryvell

. between the inboard isolation valve and the.dryvell.

j I

2. The initial flav was revealed by water leakage.

subsequent flaws were revealed by ultrasonic testing.

~3. The failure node is intergranular stress corrosion cracking. In order to prevent future occurrence RECEIVED of this type of failure, low carbon stainless steel will be used as replacement material.

ggi.82 F.

Repair Requirements

_ s too.r..oa.,

• ~ ~ " ~ ' =

j

1. Material D Admm. & T.cn.

E P.r.onn.f

a. Existing:

l (1) The existing pipe is ASTM A312 TP 304.

(2) The existing fittings are ASTM A403, Gr. W 304.

b. New natarial shall meet the requirements of USAS 331.1.0-1967 and'shall be as follows:

I (1) pipe: ASME Sk312 TP 304L with physical

.e

• l properties.necting the requirements of tr 304.

(2) fittings: ASME SA-403, Gr. W 304 with carbon content limited to 0.0354 anxima.

1

2. Fabrication.

x,r.....

.;7

a. All veIding shall be performed in acco$$ nice'vith veldinifprocedure specifications

.been

=>1 M al in accordance with ASME,

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3

.srs.

b. A111iil8ers shall be qualified in with Ass sei: tion IX.

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' p,ic s-

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c. The ?

is exempt fra postweld t.

3 F

3. Testing 5 7

-G Q

sure test shall"be perf ce

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A systen vith INA-5000 of AES Sectics shallhe~

ormedat1.10sinesths'

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4. sondestructive tramination

a. All velds shall be visually examined, 11guld i

penetrant avanined and radiographically examined in accordance with Ccunonwealth Edison Special Process Procedures.

b. All velds shall be ultrasonically eramined to establish a new preservice record.

RECEIVED

5. Code Stamping

.%1 'e2 Code stamping of the replacement is not required a Q shall not be performed.

_A tw gg, '

s e%.,,.,

_c r u.,m.,,,e,,

G. Quality Assurance U "#

All work shall be performed in accordance with the perhanical Incorporated Quality Assurance Program as um.. -

it interfax s with Connonwealth Edison's Quality Ass'rance u

Program.

5.

Records

1. Code Data Report An ASME Section II NIS-1 Form shall be prepared and shall be signed by the Authorized Nuclear Inspector.

2. Documentation Permanent records to be maintained by Quad Citica Station ares

a. Certified Material Test Reports for all material,

b. Welding Procedure Specifications and Qualification Records.

c. Welder Qualification Records j

f.d. Wendestructive Examination Reports l

~

-e.

Rondestructive Examination Procedures and

~

~

PersonnelQualifications

f. 0,capleted Station Traveler g'

Repair Program

^

h. As-built Drawings of sketches of the repair l'.

Code Data Report for the repair

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1

ynl'82 ID/QC@ a w supu _

COM-3402-003 g

Revision 0 5 gyneet January 20, 1982

"""""" ~3 Admin. & Tech.

REPAIR PROGRAM

~

3#g-NON-ISOIATABLE PORTION OF

~

REACIOR WATER CLEAN-UP LINE 5

QUAD-CITIES UNIT 2 A.

Des M N Ion of Repair This program addresses the repair of the 6" NPS schedule 80S Reactor Water Clean Up Line, Line No. 2-1202-6"A.

These repairs are located between the tie-in to the 20" recirculation line and the inboard isolation valve (2-1201-2).

B.

Jurisdictional Concerns 1.

The maintenance of nuclear power components is addressed in Section VIII of the Illinois Boiler Safety Act, Vessel Code, Sections III and II.

In addition,10CFR50 dictates the use of ASME Sectio'n II for the repairs.

2.

This rep' air progran shall be submitted to the Authorized Nuclear Inspector.

In addition, this' program is subject to review by all enforcement and regulatory authorities having jurisdiction at the E

plant.

3.

The repair shall meet the requirenents of ASME Section IX,1977 Edition up to and including the Summer 1978 Addenda.

C.

Code of Construction The Reactor Water Clean-Up Line from the reactor vessel to the isolation valve was designed, fabricated, examined and tected in accordance with the 1965 Edition of ASME Section I with the Winter 1966 Addenda and Sargent &

Lundy Specification R-2330.

D.

Code of Repair This repair shall be performed in accordance with the original Code of Construction and Design Specification referenced in Section C, except as modified in Section F of this program.

E.

-Flaw DeIscription and Failure Mode Evaluation

-1.

The flaws are circumferential and logitudinal stress corrosion cracks located in the drywell between the inboard isolation valve and the reactor.

2.

The flaws were revealed by ultrasonic examination.

_t_

3.

The failure mode is intergranular stress corrosion cracking. In order to prevent future occurrence of this type of failure, low carbon stainless steel and stainless steel weld metal will be used as repair material.

F.

Repair Requirements 1.

, Material a.

Existing:

(1) The existin's pipe is AS'Di A312 TP 304.

(2) The existing fittings are AS'Di A403, Gr. WP304, b.

New material shall meet the following:

(1)

Pipe: ASME SA-312 Tp 304L with physical properties meeting the requirements of TP 304.

(2) Plate: ASME SA-240 Type 304L with physical properties meeting the requirements of TP 304.

Rolled plate shall be solution annealed.

(3) kielding material: Type 30814tainless steel.

(4) Bar stock:

Type 3041. stainless steel.

2.

Fabrication a.

All welding shall be perfomed in accordance with welding procedure specifications which have been qualified in accordance with ASME Section IX.

b.

All welders shall be qualified in accordance with ASME Section IX.

c.

The repair is exempt from postweld heat treatme: t.

3.

Testing An initial service leak test shall be perfomed.

4.

Nondestructive Examination All full penetration butt welds shall be visually examined, liquid a.

penetrant examined and ultrasonically examined in accordance with i

Commonwealth Edison Special Process Procedures.

b.

All other welds shall be visually and liquid penetrant examined in accordance with Commonwealth Edison Special Process Procedures.

5.

Code Stmping Code stuping of the repair is not required and shall not be perfomed.

G.

Quality Assurance All work shall be perfomed in accordance with the Mechanical Incorporated Quality Assurance Program as it interfaces with Commonwealth Edison's Quality Assurance Progra.

H.

Records 1.

Code Data Report An ASME Section II NIS-1 Form shall be prepared and shall be signed by the Authriized Nuclear Inspector.

2.

Documentation Pemanent records to be maintained by Quad-Cities Station are:

a.

Certified Material Test Reports for all material.

b.

Welding Procedure Specifications and Qualification Records.

c.

Welder Qualification Records.

d.

Nondestructive Examination Reports.

e.

Nondestructive Examination Procedures and Personnel Qualifications, f.

Completed Station Traveler.

g.

Repair Program.

h.

As-built drawings of sketeches of the repair.

1.

Code Data Report for the repair.

l ID/ DAILY-D REACTOR WATER CLEANUP SYSTDi REPAIR DESCRIPTION A.

Findings 1.

The initial leak was noted in weld S-14 (ref. drwg. ISI-119).

2.

UT exam of all 6" KWCU butt welds between the 20" shutdown cooling suction header to the outboard isolation valve (outside containment) was performed.

3.

Within containnent 8 of 11 butt welds downstrean of the inboard isolation valve had UT reflectors indicative of cracks.

4.

Seven of these 8 velds had circunferential indications on the pipe side HAZ. One weld (F17) had an axial indication on the elbow side of the weld.

5.

No indications were found in welds outside containment.

6.

The isolable portion of the RWCU line within containment will be

<3 replaced with Type 304L stainless steel having.035 max. carbon and meeting the mechanical requirements of regular Type 304 7.

The non-isolable side has 10 butt welds.

The ultrasonic examination found indications in 4 of the welds.

8.

A circunferential crack indication approximately 95% through wall and 1-1/2" in length was found in the HAZ of one side of the pipe to pipe weld identified F6.

9.

Longitudinal crack indications were formed in the elbow side of the elbow to pipe welds designated S9 and S10.

These indications were approxmistely 3/4" long and 50% of wall.

10.

Three longitudinal crack indications were found in the elbow side of the elbow to valve weld F12.

These indications were approximately 3/4" long and 50% to 95% of wn11.

11.

A suspected leak was noted at a 2" branch line to sockolet weld.

The sockolet to 6" line weld is designated FIA.

12.

Weld F5 had been armnined under the ISI program during the recent refueling outage and again at this time. The weld was found to be accep table.

B.

Repair The pipe to pipe joint F6 containing the circumferential crack indication will be repaired using a sleeve as shown in Figure 1.

The sleeve will provide an independent pressure boundary around and to either side of the existing weld F6.

Partial penetration welds as shown in Fig. NB-4244(d)2

~,

---.w-

...,. ~

of ASME Section III will be used for the ciressaferential welds of the pipe sleeve. The final sleeve dimensions and attachment weld size will be detemined by stress analysis. The sleeve material will be Type 304L stainless steel with 0.035 max carbon and having anchanical properties of Type 304. The sleeve provides pressure boundary integrity for mechanically separated.6" pipe sections.

The longitudinal crack indications in the elbows at joints 59, S10, and

~

- F12 will be repaired by depositing veld metal 360' around and to either

)

side of the existing welds (F approximately 6" long and 1/2,igure 2). The weld depcsited bands will be i

thick although final dimensions will be determined by stress analysis.

The bands will provide pressure boundaries 1

independent of the of the underlying original veld joints.

The suspected leak in the 2" side of the sockolet will be repaired with a sleeve as shown in Figure 3.

This sleeve similar to a standard type sockolet will provide an independent pressure boundary around the entire existing sockolet by attaching to the 6" RWCU line and to the 2" drain line above the sockolet.

The repairs to the non isolable portion of the RWCU line are temporary and the line will be replaced at the next refueling outage planned for the spring of 1983.

I C.

Technical Evaluations The crack indications in all instances are assumed to be intergranular stress corrosion cracking (IGSCC).

The sleeve repairs are straight forward in establishing an independent pressure boundary around the welds with indications.

IGSCC is associated with the weld heat affected zones (HAZ) of Type 304 stainless steel. The existing crack indications may propagate in the heat affected zones and become through wall; however, the conditions for IGSCC only exist in the HAZ vhere sensitization has occurred due to the heat of welding and residual stresses due to velding are relatively high. The sleeve designs can accanodate canplete separation of the existing velds. The type 304L sleeve material is highly resistant to IGSCC in the valded condition and is listed as an acceptable material in RUREG 0313 Rev. 1.

The weld deposited bands over the longitudinal crack indications are similar to sleeves and provide independent pressure boundaries around the existing velds. Longitudinal IGSCC cracks should not propagate significantly beyond the HAZ due to the absuce of sensitization and the reduced weld residual stresses. The lengths of the longitudinal crack indications in the RWCU line are similar to those found in the

- investigation of the Qoad-Cities Unit 2 core spray piping.

"'he shrinkage of the weld metal during deposition of the bands is expected to produce compressive ciretsaferential stresses in the underlying base and weld metal. Compressive residual stresses should mitigate propagation of the existing indications. Wald metal has proven to be highly resistant to propagation of IGSCC. Therefore even if the existing crack indications should propagate through wall, they would be arrested by the weld metal bands.

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January 25, 1982 Quad" Cities Offsite Review 82-3

Subject:

Unit Two Reactor Water Clean-up System Piping Repair Background and Discussions On Thursday, January 14, 1982 Quad Cities Unit 2 er.rerienced a B Recirculation Pump MG set trip resulting from improper exciter brush seating reducing reactor power to approxi-mately 50%.

After repair of brushes and subsequent pump restart, a low oil level alarm was received on the lower motor bearing necessitating a drywell entry for inspection.

During the inspection, leakage was detected from a clean-up system 6" line weld located at an elbow downstream of the inboard M.0.

isolation valve.

Pri.or to the Recirqulation MG set trip an upward trend had been detected on the drywell floor drain sump input-indicating.

some additional unidentified leakage.over normal.

-The unit.was

.' ' ~ ~,.

immediately shutdown for a determination of the' extent'of'th'e leakage and repair.

On Sunday, January 24, 1982 three Nuclear Safety personnel att' ended a briefing meeting at the station to review the safety significance of the proposed repair.

During the station briefing and subsequent telecons, the repair program was determined to be adequate based on the technical expertise involved and in conformance with the ASME Code methods allowed for repair.

The station onsite review lists those Company personnel involved in the development of the repair program.

Conclusion Offsite Review concurs with the pro' gram presented in Quad Cities OnSite Review 82-05 for the Unit 2 reactor water clean-up system pipe repair.

Offsite Review believes that the present leak detection methods are adequate for detecting future pipe cracks and recommends that because the pipe configuration of Unit 1 is the same as Unit 2, Offsite Review recommends a visual inspection of Unit 1 clean-up system at pressure during the next outage.

c

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.-,o 2-Participants /Discialines

-E.

Budzichowski a,'a,c,h E. Budzi'chowski J. S. Kolanowski a,b,c Senior Participant 1

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Supervisor of Offsite Review and Investigative Function 4

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e ni R.KUISTOR 7. J JJLm Aa4 DATE PJQUESTED Autho.t:ad copies held by:

Per:anent Procedure Change !!eeded i l)J0.

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Shift Eng. T.C. Log 5.

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n Administrative Procedure for Unit Two Reactor Water Clean-up Pipe Repair Upstream of MO-2-1201-2 A.

Purpose The purpose of this procedure is to outline the method to provide

'~

administrative instructions, procedures, and guidelines to assure that the repair of the non-Isolable section of the Unit Two Reactor Water Clean-up Pipe is carried out in a manner that will assure the safety of the Reactor and plant personnel.

B.

Re fe rences 1.

Quad-Cities Station On-Site Review 82-05, including 10 CFR 50 59 Safety Evaluation.

2.

Repai r Program COM-3402-003, Revision 0, dated January 20, 1982, including repair description.

3 Work Request Package Q17244, with associated travelers, procedures, and supporting documentation.

4.

Quad-Cities Station Operating Surveillance Procedures QOS 005-2 (Normal Control Room inspection) and QOS 005-51 (Weekly Summary of Daily Surveillance).

5 Commonwealth Edison Company quality Assurance Manual.

6.

Abnornal Operating Procedures QGA-1 (Large Line Break inside Containment) and QGA-2 (Small Leak Inside Containnent), and QGA-18 (Loss of Feedwater).

7 Operating Procedures QOP 1000-5 and 1000-12.

C.

Prerequisites 1.

Pr.ior to initiating the repair programs and procedures outlined in On-Site Review 82-05 and Work Request Package Q17244, the following prerequisites must be satisfied:

a.

An Operating Engineer shall be on-site at all times during the repair program.

~

b.

The LPCI Mode of RHRS shall be operable at all times, including RHR pumps and valves constituting the injection paths being in thei r nornel configurations.

2 c.

Both Core Spray subsystems shall be operable at all times, including the Core Spray pumps and valves constituting the injection paths being in their normal configuration.

d.

Both the 1/2 and 2 Diesel Generators shall be operable.

Technical Specification 3 9.E.2 (Diesel Generator preventative maintenance for one and one-half hours) may be applied during this clean-up pipe repair period.

e.

A Condensate-Feedwater System flow path shall be available, with pumping capability.

f.

Suppression Pool water le*<el within Technical Specification limits (between -2 inches and +2 inches).

g.

Contaminated Condensate Storage Tanks at sufficient levels to provide backup water to Suppression Pool for Core Spray and LPCI.

h.

Secondary Containment shall be in effect with both SBGT Systems operable and the capability for Reactor Building Ventilation isolation in effect.

I.

Reactor water temperature being properly controlled utilizing the intermittent operation of the Shutdown Cooling Mode of RHRS in accordance with QOP 1000-5.

J.

Reactor water level shall be closely monitored at all times during this repair program from all Control Room Reactor Water Level instrumentation.

Normal Control Room inspection procedure, QOS 005-2, shall govern this item, and procedure QOS 005-S1 shall be used to document the normal routine level instrument checks.

k.

The control switches on panel 902-4 for the Drywell floor and Equipment Drain Sump Pumps shall be kept in pull-to-lock, except when the sumps are pumped every four hours, per procedures.

3 i

=

1.

Clamps for 6 inch ID pipe and freeze-seal equipment available.

Clamp assembly installed to restrain 2 inch bottom vessel drain pipe to the 6 inch clean-up lines.

The Master Electrician or Electrical Foreman will inspect the m.

set-up, installation, and arrangement of all welding machines.

The Operating Engineer will verify that the electrical load from the machines is compatible with present bus loads.

n.

Communications will be established between the Control Room and the Drywell.

Normal communications will be maintained using radios or the P. A. System.

Backup communications are provided by the dial phones in the Drywell, and adjacent 'o the desk out-side the Drywell.

Radiation surveys and air samples taken to assure proper raoiation o.

exposure planning and management to keep doses ALARA.

p.

The Shift Engineer shall be notified just prior to the initiation of welding on each axial crack (welds 59, S10, and F12).

2.

Prior to starting welding on the non-isolable section of clean-up system piping inside the Drywell, a detailed training session shall be held, and documented as per Attachment 1:

a.

Supervisory personnel shall be instructed on the condition of the Reactor, the level of water in the Reactor, the piping configuration with respect to the Reactor, and the impilcations of a leak in the system.

b.

Supervisory personnel shall be instructed in the organization out-line and malfunction procedure given in Attachnent 2.

4 c.

Experienced personnel shall be available to use the freeze-seal equipment.

~

4 d.

Supe cvisory personnel shall be instructed in the use of the pipe clamp devices.

THE AtovE t'tECEGV (StTES At.E 90 cow EWT Go op AMCMmENT

'I BY THE.

ofER.AT t PG E96 ft.

D.

Precautions 1.

Monitor Reactor water level throughout the repair period.

2.

All personnel in the area of the repair will wear the proper protective clothing and respiratory equipnent, as prescribed by Radiation Protection.

The RCT on duty at the Drywell has responsibility to ensure radiation exposures are properly documented.

The ALARA Coordinator shall evaluate the shielding effectiveness throughout the repair program, based on dose received and work conditions.

Periodic air samples and area surveys shall be taken.

Exposure approvals shall be compilance with QRP 100-1, Radiation Control Standards.

3 Strict enforcement of and adherence to the Out-Of-Service procedure involving the Unit Two Clean-up System is necessary.

E.

Limitations and Actions 1.

If during the repair, a critical step is I,n progress at shift change of the repair personnel, the critical path operation shall be completed prior to the shif t change.

2.

A shift log shall be maintained by a cognizant CECO supervisor at the Drywell.

Significant items should be logged, including time, description, and any necessary corrective or supplementary. actions taken.

Status of the repair should be understood by all supervisory personnel.

3 Surveillance on plant systems and components in accordance with the Technical Specifications is permissible upon concurrence with the Operating Engineer.

4.

Whenever the Reactor is n. the Shutdown condition with irradiated fuel in the Reactor vessel the water level shall not be less than that corresponding to 12 inches above the top of the active fuel when it is seated in the core, (Technical Specifications)

F.

Procedure 1.

Perform the repair program in accordance with the Work Package.

2.

A pipe leak caused by the welding processes is very unlikely.

However, to mitigate the consequences of a leak should it occur on the 6 inch line, a pipe clamp is available to be installed on the line adjacent to the location of the weld deposit areas.

Upon the discovery of a t

l leak, the following is to be performed:

l l

l

.o 5

As quickly as possible, remove the welding apparatus from the a.

area.

b.

Install the clamp over'the leak and tighten down on the bolts sufficiently to slow down and stop the leak. The water in the pipe will be at approximately 23 psig pressure (with 30 inches Reactor water level Indicated).

c.

Initiate malfunction procedure as per Attachment 2.

d.

Using freeze-seal equipment, install freeze plug in line upstream of the leak using approved procedure.

After leakage has stopped, remove clamp and continue with repair.

e.

NOTE Water leakage of a minor quantity will flow to the Drywell floor drain sump.

Routine pumping of the sump will keep it from overflowing.

There will be no likely response on the Reactor water level instrumentation for a small leak.

3 To mitigate the consequences of a leak from the 2 inch bottom vessel drain line where it ties into the 6 inch clean-up line, the, following is to'be performed:

a.

As quickly as possible, remove the welding apparatus from the area.

b.

Tighten down on straps to br.ing 2 inch pipe into the sockolet.

This should reduce the leakage, c.

Initiate malfunction procedure as oer Attachment 2.

d.

Steps will be taken to stop the leak.

4.

Should a highly unlikely catastrophic failure occur that causes significant leakage that cannot be stopped, perform the following:

a.

Initiate malfunction procedure as per Attachment 2.

Isolate the Reactor Buildi.ng Vent System and START an SBCTS train.

b.

Using the Condensate-Feedwater System, add water to the Reactor vessel as follows:

(1)

START, or verify running a Condensate-Condensate Booster Pump.

(2)

Verify Feedwater Heater isolation valves are OPEN.

(3)

OPEN a Feedwater isolation valve, either MO-2-3205A or MO-2-3205B.

^

.o 6

(4)

Use low flow Feedwater Regulator A0-2-643 to control Reactor vessel level.

(5)

Avoid water level drop to Group 11 Isolation / Reactor scram level (+8 inches) or ECCS Initiation level (-59 inches).

(6)

Pump water f rom the Suppression Pool to the Condenser Hotwell using procedure q0P 1000-12.

b.

If a Condensate-Feedwater malfunction occurs, Core Spray or LPCI must be used to fill the vessel.

Refer to QGA-18.

(1)

Core Spray:

(a)

START either 2A or 2B Core Spray Pump.

(b) OPEN Injection valve M0-2-1402-25A/B to admit water to the vessel.

(c)

Core Spray injection valves cannot be throttled; there-fore, to stop flow, the pump must be shut off and then re-started to add water to the vessel again.

(d) l~nitiate redundant' Core Spray Loop, if necessary, using

~

above steps.

(2)

LPCI:

(a) On loop that is not being used for shutdown cooling, START an RHRS pump and OPEN Injection valve MO-2-1001-29A/B.

(b) Throttle flow using valve MO-2-1001-28A/B to maintain desi red water level.

START the other RHR pump in that loop if more flow is needed.

l (c)

Initiate additional flow capacity by terminating shut-down cooling and starting up the redundant LPCI Inj ection loop.

G.

Checklists

1., Training Documentation.

2., Organization Outline.

H.

Technical Specification References 1.

Section 1.1.D.

2.

Section 3 5.F.2.

3 Section 3 7.C.I.

ATTACHMENT 1 Supervisory Personnel Training for Non-Isolable Unit Two Reactor Water Clean-up Pipe Repair 1.

I have received training on the condition of the Reac, tor, Reactor water level, Clean-up Piping configuration, and implications of system leakage.

SIGNATURE DATE 2.

I have been instructed in the organizational outline and malfunction p rocedu re.

SIGNATURE DATE 3

I have been instructed in the use of the pipe clamp devices.

SIGNATURE DATE I

I INSTRUCTOR DATE 1 (final)

ATTACHMENT 2 Unit Two Reactor Water Clean-up System Repair - Non-Isolable Portion Organization Outilne Manpower Requirement /Shif t Supervisor: Ceco 1

Mechanical, incorporat'ed I

Welders / Pipe Fitters: Mechanical, incorporated As Necessary Radiation Protection:

Ceco 1

Extra:

(1) Authorized Nuclear inspector (2) NDE Personnel (3)

Ceco Q.C. and Ceco Q.A.

Malfunction Procedure if a malfunction should occur, both the Ceco and Mechanical, Incorporated Supervisors should be promptly notified.

For a small leak, either, or both of these personnel should enter the Drywell, in rubber gear (if necessary) and administer the installation of the pipe clamp.

They should then summon the personnel to Install the freeze-seal on the pipe.

The RCT should dress-up and enter the Drywell to assess the leak from a personnel contamination and exposure viewpoint. The Control Room should be notified of the problem, who will notify the Shift Engineer.

For a large leak, either or. both supervisors and the RCT should enter the Drywell in rubber gear to assess the situation.

Personnel should be evac-uated from-the Drywell in this case.

The Control Room must be promptly notified to initiate Reactor water level restoration.

4 4

1 (final)

ATTACHMENT 3 Operating Engineer Checklist for Procedure Prerequisites DAY

• I 2

3 4

5 6

7 8

9 10 11 12 13 14 i

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Oper Eng On-Site l

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Torus Level Normal l

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CCST Level Normal 8.

Secondary Cont in Effect l

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Rx Water Temp Normal i

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Rx Water Level Normal l

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DW Sump pumps in PTL (except during pumping) j I

13 Clamps Available i

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14.

Freeze-seal Equip Available i

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15 Welding Machine Setup Inspected i

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16.

Communications Established l

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I 17 Rad Surveys & Air Samples Current I

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Shif t Engineer informed 19 Supervisory Personnel Trained

• Use addltional sheets if necessary.

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MECHANicA L REsrRAtMT l

OrP 800-8 F.ev i s i or, 1

.j FREEZE SEAL PP.0CEDURE August 1973 8

USillG JACKETS

.+

A.

PURPOSE i

The purpose of this procedure is to outline the method to freeze scol a pipe using Jacket:, and liquid ni trogen (LN ).

7 S.

REFERENCES FOR REFERENCE ONLY 1.

None.

C.

PREREQUISITES 1.

Before freeze sealing a pipe, the normal operating pressure and te pera-ture of the system should be reduced as low as possible in accor.'r.ce with the approved cooldown procedure.

The pressure of tha syste.--

should be reduced to atmospheric and the pipe cooled to ambient te pera-ture. When it is impractical to attain atmospheric pressure and ambient temperature, the following maximum conditions shall prev. ail:

a.

Ambient Temperature - 1100F.

0 b.

System W ter Temperature - 200 F.

Maximum Jifferential pressure across freeze,:193 c.

(1)

Stainless Steel - 200 psi.

(2)

Cartan anJ Lew Alloy ",.ce! - O psi.

(Pressure may be highar with idaintenanca E.,; i ne:e r a; r-2.

Material anJ components needed to freeze seal pi:e Adequate supply of liquid nitrogen (LN ).

2 a.

b.

Freeze chambers of proper size.

c.

Heat transfer cement (Dow, Corning 340 heat sink compound) er (Thermon).

d.

3/8" copper tubing with rubber refrigeration insulation and fittings.

Thermometers with remote bulbs (two or more).

e.

t.

Insulation to provide minimum two inches on chamber.

4PPROVED 9

Duct tape.

h.

Tools / supplies pursuant to individual seal.

SEP1li,973

' Q. C. C. S. R.

- = -

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PRECUATIONS 1.

A man should be assigned to control each freeze.

He should haer r.,

other duties.

2.

The same man may control two freezes if they are in close proximit/

and he has no other duties.

3 The man assigned a freeze raust not leave his post.

The foreman is responsible to provide a relief when required.

4.

Precautions should be taken to protect both perso: nel and material in the event that the ice plug should be blown out of t! e pipe, e.c.

u.e freeze area should be located so that a pipe elbv., or bend lies b t.. <.n the freeze area and the location where the, pipe will be cut.

5 Because of its low temperature, liquid N2 can desirey human tissur Precautions nust be taken to co/er exposed parts of the body.

U... r insulated (non porous) gloves, a face shield and protective clot:.in;.

6.

The work arca must be adequately ventilated to insure an oxygen content of at least ICt by volo.ac.

E.

LlHITATIONS AND ACTIONS 1.

When two ice plugs are to be uccd to Isolate a single pipe se: i c r.,

they must be located greater than 30 pipe-diareters cpart.

2.

No freeze seal shall be applici less than 20 pipe-diameters frcr.

closed valve or other component that blocks the f!., ^f exp

iu.

water as the ice plug forms.

3 The freeze area must not incluce any fittings.

4.

The pipe must be full of water before initiating treeze seal Om:r.;-ir.r.

5 The ice plug must be completely melted before the pipe is restored c:.

service.

If it is not allowed to melt completely, pressure

y. ta:..

insid the pipa up in the pipe, or the Ice plug may damage a ccmponent if it breaks loose.

6.

Freeze sealing carbon and low alloy steel.

To insure against br'ittle fracture when freezing water in carbon and low al'.oy steel pipe, the following must be observed:

The pressure in the p.ipe most be reduced to zero before a: tem:2:ing a.

a freeze seal, b.

The lowest temperature to which the material can be subjected :s h

-40 F.

A.o P P O V E D SEP 141978 Q. c. O. S. R.

(-

l CMP 800-8 o

F.evision I O

e The pipe must be adequately supported (teeporary pipe supports ray c.

be used to supplement permanent pipe hangers), and must not te subjected to any shock or impact forces.

F.

IRCCEDURE bottles from main storage tank:

I.

Filling Lil2 flotify Shif t Engineer prior to filling.

[

a.

b.

The following safety precautions must be observed:

(1)

Do not inhale gas vapors.

(2)

Personnel must wear gloves and entire arm must be covered.

0 (Liquid is at -320 F; will boil at -280 F.)

If below 50" H 0, check with Main-c.

Check level of main tank.

2 tenance Engineer before filling any bottles.

NOTE Level will drop approximately 2" H O for each 160 2

ii ter, (42 ga1lon). bottle fi11ed.

d.

Hook up t.attle to fill connection.

(Inspect bottic for damage).

NOTE l

Main tant supply is at 120 - 140#; bottle relief is set at 22#.

e.

Open vent on bottle to vent gas.

(Stay clear of vent and r:li f valve.)

f.

Open fill valve on bottle (1 turn), then sloat y crack ope. n.

tank valve, (1/4 - 1/2 turn).

Slowly feed nitrogen through bottle to cool it down.

g.

h.

Fill slowly until level indicator shows full.

Fill slow enough c.o that relief does not open'.

(Keep bottle pressure between 15 -

20 pounds).

NOTE Normal.perating pressure for these bottles is 170 psig, which is above main storage tank pressure of 140 psig, so there is little danger of bottle APPROVED y

bursting even if the 22 psig relief lifts.

SEP 141978 Q. C. o. s. R.

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nv.

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Close till valve on main tank, then close valve on bottic and quickly,fi:, connect fill hose, making sure to de pressurize l i r:u through connector before removing.

J.

Closu ve,it on bottle.

k.

Secure equipment.

gg y Und 2.

Installation of Freeze Chambers HORl70"iAL VERTICAL M

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ifeat Tran ter cumpvund is applied to cover 1.C. of.,

cha. L a halved b.iore insta l la t ic;r. cn pi pe.

t.

C ha.abe r h.1ves are tecured on pipe with exhausts at highest ;; int using bu:.c clamps, band-its, or cloth reir. forced tape.

c.

Temperature bulbs are located 3/4" to 1" f rc:n the chamber.

d.

Chambers are insulated with 2 layers of spun fiberglass and extends a t least 6 inches beyond the chamber.

c.

LN2 piping arrangement fr m bottle to chamber should be as follows:

APPROVED SEP 141978 Q.C.O.S.R.

,4,

QMP 800-8

~

I'.evision I FORREFERBCE DEY i

,; b o'*AGy C!s MW

,( **l Q

O.~nz;

' UGab t/dt 2 Q, nf y.

r-u

.s, f

.r O d c;~ IAft.it.;~;-

LW1 1

ao m.c,

1 l.W O?. TANT Each sid of the chan.ber must have its own throttiing valve.

a.

b.

The L N Lottle i..anifold is optional, if one is not u:cd, the 2

supply line m.y te connected directly to a LM2 bottic at poin: A.

c.

Coonect Iine tc a LICUID valve on bottic.

d.

ProviJe tur add;tional cr.h:iust capability if area is not ven t i l a t.:J.

3 LN Freeze f.ntructions 2

a.

Establishi.ig a freeze sca!.

(1)

Op.:n all valves in supply line to allow maximum flow to seal chambers.

(2)

Adjust thethrottlinhvalveforonesideofthechamberto equalize the splashing and. overflow between the two chambers.

(Keep one of the throttle valves open full at all times.)

Use the root valve to control splashing / overflow f rom bot: 5 chambers sinaltanecusIy.

(3)

Wn.n both ta.nperocures are less than -10 F, shut the root valve.

A freeze is now established.

4PPROVED

-S-SEP 141978 Q. C. O. s a,

QMP 800-8 Pevision 1 b.

Maintainisig a freeze scal.

(1) When the highest temperature reaches -10 F, open the root valve until both char:bers are overflewing with Lil2 or until the lowest temperature is not lower than -400F, then shut the rcia t valve.

f;0TE 00 fl0T ATTEMPT TO "THROTTI.E" THE Lil2 TO MAINTAir A TEMPERA 10n.

G.

C HEC 1'L I STS 1.

Freeze Seal Data Sheet QMF 800-S4.

2.

Table For Freeze Seals QMP 800-T1.

3 Freeze Seal t.og QtlP C00-SS.

H.

TECH:11 CAL SPECIFICATIO:: REFERE!!CES

~

1.

None.

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WPPROVED SEP 141978 Q. C. O. S. R.

.:;; (final)

- -.a

,--.J:!'.27Li.L,?QWJ*} - -- -

=,.,

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QMP 800-54 Revision 1 FREEZE SEAL DATA S!!EET August 1978 t.

PLAtillit1G This section must be completed before seal application for each freeze R

, location.

y

' Location : o.

1 2

3 l

4 l

Pipe Spcol.flo.

t ca. SI:c (inches)

Elevttion 11 I

IJ Locction a

l Vert. or Foci:.

i Sei ric Ciacs Pipc' Spool Inspcetion Re<;ui rcr: cats:

Visu:1 5 ".:TCH OF LOC A.T"M _

lt:asurcmentt Pentrant Test (Cefore & Af ter)

I (Req'd for Cict. I)

RREVERg (Attach all results) u g

lj.

liaintain freeze

. Thaw and re-freeze 9U Total LN2 requirements (calculate)

Itake arrangements for change area and Radiation Protection ecverage.

etails of INTERiti OR BACKUP ISOLATION T,

L1 APPROVED

- g SEP 141978 n

H O <- n e -

QMP 800-54 Revision 1 ll.

Chamber installation (to be completed by foreman).

Initial wh.en complete.

INITIAL COMPLETIOM Location flo.

1 2

3 i

4 Pipe Spool Inspection Complete

• Temp. bulb location verified i

- Installed r, insulated per Dug. A c

N e

4 Lt!2 supply & exhaust inspected l

E Indicate quanti ty of L!!2 on hand E

Verbal approvcl to s tcrt f re.cac(.s) obtair,ed fror SM f t Eng inc.:r.

Foren:n Dcte Tins 11-1.

Establish :nd maintcia fre 2 per instructien;.

1.

l!a i n t.. i n te..gerc:ure icg fc/ each 1ccr: ?o: (cttach).

f 2.

Ob tain ver'2ai a, proval frcm 5:ii f t Engineer to cpen sys te.m.-

t Foremen Date Tirre r

?!OTE:. Keep Shift Er. _ *ncer infomed of ins tniia tion or removc' of b.cEu:

Isolation, th. ting and re-freezing operaticr.s.

IV.

When work is ccmplete, disassemble freeze chem!:crs.

Initial t; hen comp!ete.

IfflTI AL C0!:P!.c.T!0!;

Location flo.

1 I

2 1

3 4

l Pipe spool cleaned

• l Pipe spool. inspection complete n

Insulation re-installed I

i i

I Piping released for service a

1 FOR REFBCE 01.Y

'l Freeze equip. returned to locker 8

• IMP 0i; TANT Use onl/ approved cleaning solvents to cleon stainless steal piping.

(Denatured Alcohol, Acetone and Sovasol f5 are approyed for such use.)

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V.

Work completed by:

Date Mechanic (s)

Foreman 9

APPRGVED d (final) 8 9 1 4 }97D o

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FORREIBENCE OHl.Y e,., 800_Ss 1

I Revision 1 FREEZE SEAL LOG August 1973 a

APPROVED Dato Ucrk Request flo.

SEP 141973 Locat ion' flo.

i G. C. O. C. R.

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-Exhaust' 0;,po,1 te Exhaust 0,posite E"hz.u s t O p p:.c. i t.

Time End.

End Time End End Time End End

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Temo.

Tero.

Tem::.

Temp.

Te.mm.

Te l

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I J' NOTES:

1.

Establish and maintain f reeze per written instritctions.

Ul

,2.

Record ter.parature readings every 10 minutes.

3 tiotify Foreman ir.wediately if eithar teeparature cannot be raintained belo.:

+200F.

4.

Do not trap LH2 between tuo closed valves.

~

.3 5

Take frequent oxygen readings.

r:otify foreman if 02 percentcge decreases to 18't.

Secure freeze and Icave area if 02 percentage decreases to.10f.. (f i na l ),

n n

qttP.800-T1 e

Revision 2 TAELE FOR FREEZE SEALS September 1978 3

Minimum tiec and refrigerant required for making freeze seals in horizontal or vertical stainless steel pipe.

l Pipe Min. Jacket Hin. Time Hin. fl Size Length (Lbs.)2 (Min.)

(Inch)

(Inch)*

1/2 4

3 6

t 1

5 5

10 1-1/2 6

to 30 2

7 20 40 3

9 40 50 4

11 70 60 J: ch t length.i r the di s tanc ' '

-^t.

the iat d._ edger e.f the 3s' sing tc.r :

or shcp febr' nte.d con nincr.

P t.

hCTES:

(1)

Freczc-sesiing teicc,'? rete: Und time at:

c. nces varv w!;h th2 h,

u h

s i tu., t i en.

I n terp r$.t the Care.

(2)

Time re;uircran*.= cre for tempera-tures (water, pipe end aret.) of hl 70 F.

A longer time will Le required C

when cny of these ter.:::cratures is above 700F.

(3)

Minimu-a arounts oF tij, arc for making the shal; amount does n:- include maintaining the seal.

7 (4)

Times are based en no flow through the freeze seal.

6 F

a WPPROVEO u

SdP141973 nN Q. C. O. S. n.

b (final) n.

i

- e Description of Analytical Effort to Support Implementation of Temporary Fixes for Quad Cities 2 RWCU System Pipe Cracks 1.0 Pipe Sleeve 1.1 Strength / load capacity comparison for fix versus

-original configuration 1.2 Stress analysis for region of temporary fix using axisymmetric thin shell of revolution mathematical model.

1.3 Loads applied to model taken from piping analysis of system performed for IE bulletin 79-14.

1.4 Stresses from analysis compared to allowable stress values from ASME Code Subsection NC.

1.5 Analysis to assess stress and fatigue effects of differential thermal expansion between sleeve and pipe.

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1.6 Fracture mechanics analysis of pipe to sleeve weld to evaluate susceptibility of weld to intergranular stress corrosion cracking.

2.0 Sockolet 2.1 Strength / load capacity comparison for fix versus original configuration.

2.2 Analysis to assess stress and fatigue effects of differential thermal expansion between sleeve and pipe.

2.3 Fracture mechanics analysis of pipe to sockolet sleeve weld to evaluate susceptibility of weld to intergranular stress corrosion cracking.

3.0 Welu overlay 3.1 Strength / load capacity comparison for fix versua original configuration 4

3.2 Analysis to assess stress and fatigue effect of differential thermal expansion between pipe and weld overlay.

3.3 Fracture mechanics analysis of weld overlay to evaluate susceptibility of_ weld to intergranular stress corrosion cracking.

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Strength Comparison of Temporary Pipa Sleeve Fix Versus Original Confirguration i

Orjginal Tempgrary Quantity Configuration Flx Weld Cross-Sectional Area 8.4 16.6 (in. 2 )

Weld Moment of Inertia 40.5 90.8 (in.4)

Sleeve /Pi,e Cross Sectional 8.4 13.8 Area (in.2}

Sleeve / Pipe Moment of 40.5 105.3 Inertia (in. 4 )

m 4

h l

l

o 4

i E of pipe

& sleeve n

d t=0.432"

=

b i

v di e

~

~

t=0. 56 25" - -*-

l t=0.432" 4

To iP M

R=3.0965" R=3.9063" MathematicalModelofPipe/SleeveTemporaryEfx g

I w

n-,

-n.,..-.

o Piping Analysis Forces Used in Stress Analysis of Temporary Fix Seismic Maximum Fo.ce Anc c r

Gravity Thermal Combined g

ent Component plus OBE Fx

-20.

423.

768.

1191.

(Axial)

F Y

588.

-90.

324.

912.

(Shear)

F z

-10;

-301.

153.

464.

(Shear)

'~

MX

-7344.

-19,056.

16,368.

42,768.

(Torsion)

My 4260.

-22,872.

16,680.

39,552.

(Bending)

Mz 15,792.

-13,500.

25,608.

41,400.

(Bending)

,, Notes:

b' 1)

Internal pressure of 1250 psi also used in stress analysis of temporary fix

.o Stresses in Region of Temporary Fix Excluding Pioe/ Sleeve Differential Thermal Expansion Stresses Membrane Plus Membrane Bending Component Calc.

Allowable Calc.

Allowable Pipe s.O 15.9 40.5 47.7 Sleeve 5.1 15.9 29.5 47.7 Weld 3.6 9.5' 15.8 17.7 Notes

_ l) Allowable stresses for pipe and sleeve taken from ASME Subsection NC.

2) Allowable weld stresses based on a joint efficiency g,

factor of 0.60 for shear and 0.74 for tension f

.x

(

, Strength Comparison of Sockolet Sleeve Versus' Original Confiauration s

Original Temporary Quantity Configuration Fix at base 4.6 7.2 Weld Cross-

~~

Sectional. Area (in. 2 )

at top, 1.3 2.6 s

I at bai,e.

5.1, 14.8 Weld Moment T-of Inertia

~

(in.4)

-l 0.9 1.9 at top, s.

s at base

'4.5 7.2 Sleeve /Sockole t Cross Sectiona]

N Area (in.2) at top 2. 2' 5.2

~

s tibase 5.1 14.8 Sleeve /Sockolet Cross Sectional insee s(in.4),

'-i "

s llwrir r ferm a \\

at:tcP 2.0 5.6 u

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k.. l 4

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4.

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,x Strength Compraison of Weld Overlay Fix Versus Original Configuration Original Temporary Quantity Configuration Fix Cross Sectional Area (in.2) 8.4 11.2 Moment of Inertia (in.4) 40.5 71.4

=

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l l

l

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