ML20199A929

Core Shroud Insp Plan Unit 1 B112R1 Outage April 1998

ML20199A929
Person / Time
Site:	Brunswick
Issue date:	01/22/1998
From:	Gore P, Langdon J, Yemma L CAROLINA POWER & LIGHT CO.
To:
Shared Package
ML20199A926	List: BSEP-98-0015, Provides Plans for re-inspection of Core Shroud for Unit 1. Reinspections Planned for Upcoming Refueling Outage 11,which Is Presently Scheduled to Begin on 980425,per GL 94-03 ML20199A929
References
PROC-980122, NUDOCS 9801280124
Download: ML20199A929 (9)

Text

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d ENCLOSURE 1 BRUNSWICK STEAh! ELECTRIC PLANT, UNIT NO.1 4-DOCKET NO. 50 325/ LICENSE NO. DPR-71 CORE SHROUD RE-INSPECTION PLAN 4

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. CORE SHROUD INSPECTION PLAN UNIT 1 Bil2R1 OUTAGE APRIL 1998 t

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9801280124 980123 PDR ADOCK 05000325 P PDR v 1-

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Core Shroud l Inspection Plan Unit 1 B112R1 Outage April 1998 Prepared by:

Phil Gore John Langdon Larry Yemma January 20,1998 Recommended b) Md Date: /!31I 98 y f Approved by:  % Date: NZ/38

4 Core Shroud Inspection Plan Brunswick Steam Electric Plant, Unit No 1 Refueling Outage 11 (B112RI), April 1998

SUMMARY

OF B112R1 INSPECTION PLANS The scope of re-inspection for the Brunswick Steam Electric Plant (BSEP), Unit No.1 Refueling Aage 11 (i.e., Bl12111) core shroud is based on several factors. Results of previous inspections

,4dormed on both BSEP, Unit Nos. I and 2. as well as results within the industry, are key inputs into the inspection plan. Follow-up actions and commitments established from the last inspection are also included in the determination of the inspection scope. Guidance on shroud inspections and flaw evaluation contained in the Boiling Water Reactor Vessel Intemals Program (BWRN IP) documents BWRVIP-01, " Core Shroud Inspection and Haw Evaluation Guideline, Revision 2," and BWRVIP-07, " Guidelines for Reinspection of BWR Core Shrouds," is also used.

Analysis of weld HI ultrasonic testing (UT) data from BSEP, Unit No.1 Refueling Outage 10 (i.e., Bl 11 Rl), performed using only the remaining ligament of the core shroud plate, concluded that the H1 weld was qualified for one additional cycle of operation. Preliminary analysis has

, been performed which takes credit for the additional ligament from the reinforcing fillet weld.

! The finalized analysis will demonstrate that weld H1 has sufficient structural margin for additional operating cycle (s). Therefore, no inspections of weld H1 are currently planned for the ,

l Bl12R1 outage. However,if the additional analysis of weld H1 concludes that the weld must be l-re-inspected to assure operability for an additional cycle, BSEP will re-inspect the weld during the B112R1 outage. Since welds H2 and H3 were structurally replaced with 12 clamps during BSEP, Unit No.1 Refueling Outage 8 (i.e., B109RI), these welds no longer requin :pection.

Seven of the twelve weld H2/H3 repair clamps will be visually inspected, which will complete the initial inspection of all 12 clamps installed. Analysis of the B111R1 UT inspection results for welds H4, H5, H6A, H6B, and H7 concluded that these welds do not require re-inspection during the 'B112RI outage. No inspections of weld H8 orshroud support legs are planned since inspection tooling and techniques have not been fully developed that will work on the BSEP type shroud. Since no flaws were found on weld H9 during BSEP, Unit No.1 Refueling Outage 9 (i.e., B110Rl) inspection, this weld does not need re-inspection in the B112R1 outage. Each shroud weld is discussed in further detail herein with respect to inspection history, results, and analytical conclusions.

INSPECTION HISTORY In the B109RI outage,100 percent of the outside and inside surfaces of weld H1 was visually (VT) inspected. Cracking was found on 74 percent of the outside surfaces and no cracking was found on the inside surfaces. Eight locations were also UT inspected, with the crack depths ranging from less than 0.3 to a maximum of 0.7 inches. In the B110RI outage,4 of the 8 areas UT inspected in the B109R1 were again UT inspected with no significant crack depth gowth noted. In the B111R1 outage,100 percent of the accessible areas of weld H1 were UT inspected.

4 This weld presents unique challenges to UT inspection since the shroud head hold down bolt lugs prevem access to most areas on the upper side of the weld. These lugs limited the overall UT coverage of the upper side of the weld to 18.8 percent. The UT was performed on the upper side of weld 111 in 28 locaties uniformly distributed arouno the circumference of the weld.

Cracking, initiating exclusively on the outside surfaces on the ring side of the weld, was found in 98.2 percent of the area with aepths from 0.32 to 0.66 inches. No cracking was found initiating from the inside surfaces on the ring side of the fillet weld heat affected zene.

The lower side of weld 111 was UT inspected in 79.6 percent of the area. Tweh e percent of the area was found cracked, with depths ranging from 0.18 to 0.67 inches. The guide rod brackets and core spray piping prevent access to some areas of the weld. Analysis ; i J e data showed the weld has sufiicient structural margin to operate for one cycle without conswn. tion for the additional ligament from the reinforcement fillet weld. CP&L has since measured the size of the fillet weld using the UT data :nd is currently performing additional analysis of weld H1 that includes the structural ligament from the fillet weld. Preliminary analysis has concluded that weld 111 has sufficient structural margin to operate for muhiple cycles before re-inspection.

Therefore, no inspections of weld H1 are planned for the Bi12R1 outage. The analysis justifying additional cycle (s) of operation for weld H1 will be submitted to the NRC as specified by BWRVIP-01 for plant specific evaluations.

Welds H2 and 113 were structurally replaced with twelve clamps during the B109R1 outage; therefore, no inspection of these welds is required. In the B110R1 outage, two of the clamps were VT inspected with no indications noted. In the B111R1 outage, three of the clamps were VT . pected with no indications noted. The seven remaining clamps will be VT inspected during the B112RI outage, thereby bringing the total clamps inspected to all 12.

In the B109R1 outage, weld H4 was 100 percent VT inspected on the inside surfaces and 45 percent on the outside surfaces with :.o circumferential cracking noted. Jet Pumps prevented inspection of the remaining areas on the outside surfaces. In the B111R1 outage, UT inspection was perfonned on 100 percent of the accessible areas with 77.6 percent of the total weld covered.

Circumferential cracking was found in 8.1 percent of the inspected area with depths ranging frem El to 0.62 inches. The guide rod brackets, core spray piping andjet pumps prevented accem m some areas of the weld. Analysis shows the weld is qualified to operate for multiple cycles In the B109R1 outage, weld H5 was 100 percent VT inspected on the inside surfaces and 45 percent on the outside surfaces with five circumferential cracks found. Two locations were selected for depth measurement and growth monitoring in future outages with the crack ends

, punch marked and depth measurements taken with UT. The depths ranged from less than 0.3 to 0.6 inches. Jet pumps prevented inspection of tl.e remaining areas on the outside surfaces. In the B110R1 cutage, these two areas were re-inspected with VT and UT with no significant growth in length or depth noted. In the B111R1 outage, UT inspection was performed on 100 percent of the accessible areas with 76.8 percent of the total weld covered. Circumferential cracking was found in 25 percent of the inspected area with depths ranging from 0.1 to 0.2 inches. The guide rod brackets, core spray piping and jet pumps prevented access to some areas of the weld.

Analysis shows the weld is qualified to operate for multiple cycles.

In the B109RI outage, weld H6A was VT inspected on 45 percent of the outside surfaces with no circumferential cracking noted, inaccessibility prevented inspections on the inside surfaces.

During the B110R1 outage, UT inspection was performed in three areas covering approximately 10 percent of the weld Circumferential cracking was found at two locations with the maximum depth being 0.35 inches. Jet pumps and guide rod brackets prevented inspection of additional areas. In the Bl11R1 outage. UT inspection was performeo on 100 percent of the accessible areas with 76.6 percent of the total weld inspected. Circumferential cracking was found in 5.8 percent of the area with depths ranging from 0.1 to 0.35 inches. Analysis shows the weld is qualified to operate for multiple cycles.

In the B109R1 outage, weld H6B was VT inspected on 45% of the outside surfaces with no circumferential cracking noted. Inaccessibility prevented inspections on the inside surfaces. In the B110R1 outage, UT inspection was performed in three areas covering approximately 10 percent of the weld. Circumferential cracking was found at three locations with the maximum depth being 0.55 inches. Jet pumps and guide rod brackets prevented inspection of additional areas. In the B111R1 outage, UT inspection was performed on 100 percent of the accessible areas with 77.8 percent of the total weld inspected. Circumferential cracking was found in 8.9%

of the area with depths ranging from 0.19 to 0.52 inches. Analysis shows the weld is qualified to operate for multiple cycles.

In the B109R1 outage, weld H7 was VT inspected on 17 percent of the outside surface with no circumferential cracking noted. Inaccessibility prevented inspections on the inside surfaces. In the B111 R1 outage, UT inspection was performed on 100 percent of the accessible areas with 76.8 percent of the weld inspected. Circumferential cracking was found in 1.6 percent of the area with depths ranging from 0.1 to 0.37 inches. Analysis shows the weld is qualified to operate for multiple cycles.

No inspections have been performed, or are planned during the B112R1 outage, for weld H8.

This weld presents significant accessibility challenges since access to the upper side of the weld

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is very restricted due to thejet pump diffusers, core spray piping and guide rod brackets. Access to the lower side of the weld has even more restrictive access due to the jet pump baffle plate and the need to disassemble fuel cells for access from the bottom ht.ad region. Additionally, no inspection techniques and tooling have been completely developed. While some inspection tooling is available, it will not work at BSEP due to the clamps installed around welds H2 and H3. When the inspection tooling and techniques are available, CP&L plans to inspect this weld consistent with BWRVIP guidance.

During the B110R1 outage, weld H9 was UT inspected in 100 percent of the accessible areas.

A total of 99 percent of the weld was inspected with no cracking noted. Analysis shows the weld

is qualified to operate for multiple cycles.

There currently are no inspection equipment or techniques available for inspecting the core support legs. When these inspection tooling and techniques are available, these areas will be inspected consistent with BWRVIP guidance.

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1 A summary of the inspection history and plans for each weld, and for the clamps, is described in

Table 1.-

i INSPECTION SCOPE EXPANSION if any unusual findings are found during the VT inspection of the seven clamps, the remaining clamps will be inspected to determine the extent of any changes, a

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TABL BSEP Unit 1 Refueling Outage 11 (B112R1) Co2 PLANNED WELD INSPECTIONS PLANNED INSPECTION METil0D B109R1 None planned.1996 analysis concluded that rutticient stmetural margins existed to operate v cycle without consideration of the VTinspected 100% of outside and in HI structural margin from the. utforcement fillet weld. Since that analysis N/A cracking found on'/4% of the outsid<

was performed, the size of the nilet weld was determined from the UT cracking found on the inside surfaces data. Additional analysis of this weld is being performed that includes were UTinspected for crack depth u the ligament from the 111% we.d Tids analysis is expected to conclude to 0.7 inches.

that weld 111 has sufficici. structural margm to operate for additional cycle (s) without inspection. Therefore, BSEP is not planning to inspect this weld during the Bl)2R1 outage.

Replaced with clan H2 & 113 None planned Replaced wi'h clamps in B109RI outage. N/A H4 None planned.1996 analy, sis concluded tlut sufficient structund VTinspected 100%of theinside surf margins exist and any anticipated growth of flaws will not impact N/A outside surfaces with no circumfereni structural margins. pumps prevented inspection of the re surfaces.

H5 Nonc planned.1996 analysis concluded that suffic!cnt structural VT inspected 100% of the inside surt, margins exist and any anticipated growth of flaws will not impact N/A I outside surfaces with five circumfereI structaral margins. I Two locations were selected for crach growth measurements and growth md outages. Depths ranged from less thai Jet pumps prevented inspection of tiu the outside surfaces.

H6A None planned.1996 analysis conduded that sulficient structura! Vfinspected 45% of outside surfact margins exist and any anticipated growth of flaws will not impact N/A circumferential cracking noted. Jet 3 structural margins, inspection of the remaining areas on i

'Ihe inside surfaces were inaccessible H6B None planned.1996 analysis concluded that sufficient structural VTinspected 45%of outside surfact margins exist and any anticipateo growth of flaws will not impact N/A cirwmferential cracking noted. Jet g structural margms. inspection of the remaining arcas on <

The inside surfaces were hiaccessible H7 None planned. 1996 analysis concluded the sufficient stmetural VTinspected 17% of the outside surt margins exist and any anticipated growth of flaws will not impact circumferential cracking noted. Jet p structural margms. N/A inspectien of the remaining areas on i inside surfaces were inaccessible.

H8 None planned. Awaiting BWRVIP developmcat of inspection N/A No inspections performed.

tools /tecluilques.

H9 None planned.1995 analysis concluded that sufficient structura! N/A Ne inspedions performed.

margins exist.

Shroud None planned. BWRVIP developing inspection tools and techniques. No inspections performed. Tooling i support N/A legs Shroud Inspect seven clamps for general appearance, missing parts, and No inspections performed.

clamps integrity of tack u elds. Will bring the total number of clamps inspected Vr to 12 of the 12 totalinstalled.

lAPERTURE-M, ' CARD

} Shroud Re-inspection and Inspection History dibsbttn(dn_

7T@TtWreD,td PREVIOUS INSPECTION RESULTS B110R1 BillRI [

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%c surfaces with UT re-inspected four of the eight areas UT inspected 18.8% of the upper side of the weld was UT inspected

surfaces and no during the B 109RI outage with no significant growth with 98.2% of the area cmcked with dep'hs from 0.32 to Eightlocations noted. 0.66 inches. 79.6% of the lower side of the weld was UT fu depths from 0.3 inspected with 12% of the area cracked with cicpths from 0.18 to 0.67 inches. These inspections constitute 100% of the accessible areas.

P5 N/A N/A sces and 45% of the No inspections performed UT inspected 100% of accessible areas with 77.6% of the ial cracks noted. Jet total weld inspected. Cracking found in 8.1% of the naining outside inspected areas with depdis ranging from 0.1 to 0.62 inches. "The guide rod brackets, mre spray piping and jet pumps prevented access to some areas of the weld.

ices and 45% cf the UT and VT inspected the two areas selected for creck UT inspected 100% of the accessible areas with 76.8% of itial cracks noted, length and depth growth monitoring in the B109RI the total weld inspected. Cracking found in 25% of the length and depth outage. No significant powth was noted. inspected areas with dep hs ranging from 0.1 to 0.2 nitoring in future inches. The guide rod brackets, core spray piping and jet i 0.3 to 0.6 inches. pumps prevented access to some areas of the weld.

remammg areas on s with no UT inspected three areas totaling approximately 10% of UT inspected 100% of the accessible areas with 76.8% of imps prevated the weld with cracking noted at two locations with a the total weld inspected. Cracking found in 25% of the he outside surfaces. maximum depth of 0.35 inches. Jet pumps and guide rod inspected areas with depths ranging from 0.1 to 0.2 brackets prevented inspection of additional areas. inches. The guide rod brackets, core spray piping andjet pumps prevented access to some areas of the weld.

s with no UT inspected three areas totaling approximately 10% of UT inspected 100% of accessible areas with 77.8% of the unps prcvated the weld with cracking noted et three locations with a total weld inspected. Cracking found in 8.9% of the he outside surfaces. maximum depth of 0.55 incher, 'et pumps and guide rod inspected area with depths ranging from 0.19 to 0.52 brackets prevented inspection or additional areas. inches. The guide rod brackets, core spray piping and jet pumps prevented access to some areas of the weld.

ace with no No inspections performed. UT inspected 100% of the acccisible areas with 76.8% of imps prevented the total wcld inspected. Cracking found in 1.6% of the he outside surfaces. Inspected area with depths ranging from 0.1 to 0.37 inches. The guide rod brackets, core spray piping and jet pumps prevented access to some areas of the weld.

Fo inspections performed. No inspections perfonned.

UT inspeded 99% of weld with no indications notod. No inspections performed.

ot available. No inspections perfonned. Tooting not available. No inspections performed. Tooling not available.

VT inspected two clamps with no indicatio is noted. VT inspected three clamps with no indications noted

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ENCLOSURE 2 i

BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO 1 l DOCKET NO. 50-325/ LICENSE NO. DPR-71  !

3- CORE SHROUD RE-INSPECTION PLAN LIST OF REGULATORY COMMITMENTS L

The following table identifies those actions committed to by Carolina Power & Light (CP&L) e

Company in this document. Any other actions discussed in the submittal represent intended or planned actions by CP&L. They are described for the NRC's information and are not regulatory .

i commitments. Please notify the Manager - Regulatory Affairs at the Brunswick Steam Electric ,

3 . Plant of any questions regarding this document or any associated regulatory commitments.

Committed

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Commitment date or

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outage

1. Submit the plant-specific evaluation an analysis that demonstrates '2/27/98 weld H1 has sufficient structural margin to operate for multiple cycles before re-inspection is necessary.

. Submit the results of BSEP, Unit No. I Refueling Outage 11 core 2.- _Within 30 day shroud re-inspections following l completion -

ofthe

- re-inspections, t

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