ML20034B033

Summary of 900403 Meeting W/Util in Rockville,Md Re Status of Inservice Insp Activities at Facility.Agenda & Viewgraphs Encl

ML20034B033
Person / Time
Site:	Hatch
Issue date:	04/18/1990
From:	Crocker L Office of Nuclear Reactor Regulation
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9004250240
Download: ML20034B033 (45)

Text

{{#Wiki_filter:1 " a, i i , sy l

• f 0,

UNITED STATES ! 'i i NUCLE AR REGULATORY COMMISSION i i WASHINGTON, D. C. 20556 j ~r April 18, 1990 l l %, 4 p l i r l Docket No. 50-321 LICENSEE: Georgia Power Company I FACILITY:.Edwin I. Hatch Nuclear Plant, Unit 1 l l l

SUMMARY

OF APRIL 3, 1990 MEETING TO DISCUSS STATUS OF INSERVICE INSPECTION AT HATCH UNIT 1 On April 3, 1990, the NRC staff met with representatives of the licensee to discuss the results to date of-the current ISI I activities at Hatch, Unit 1. Meeting attendees are listed in i. The agenda for the meeting is at Enclosure 2. [ Mr. McElroy of GPC made the presentation for the licensee. Copies of his briefing slides are at Enclosure 3. Hatch Unit 1 is now in its 12th refueling / maintenance outage. The meeting was held at the request of the licensee to inform the staff of the rssults to j date of the inspection f or intergranular stress corrosion cracking (IGSCC) in the welds of the susceptible stainless steel piping. 1 The inspection is being conducted in accordance with the guidelines I of NUREG-0313, Rev. 2. As of the date of the meeting, GPC had 4 inspected about 62% of the Category C, D, E and F welds and planned to inspect more than 70% of the welds. The inspection has revealed ( two Category C welds with new indications and 5 of the 9 Category i F welds show some crack growth, all in the large, 29-inch piping. For the Category E welds, GPC had originally planned to inspect 25 of the 34 welds. Among the 25 welds inspected to date, changed IGSCC indications have been observed in 3 welds, and the licensee has expanded the scope of the inspection to include all Category i ? E welds. For the most part, the cracking problems appear to be limited to the large bore piping. The licensee plans to repair the welds showing new or larger indications by applying weld overlays. t Mr. Cowan of the General Electric Company briefed the group on the status of.1the hydrogen water chemistry program at Hatch. Copies of his briefing slides are at Enclosure 4._ Hydrogen additions are believed tsp be beneficial. both from the standpoint of reducing l l IGSCC in sensitized stainless steel piping and in improving fuel l performance. Tests have been underway at Hatch 1 since about i midway through Cycle 10. However, due to ALARA (as low as reasonably achievable) concerns, hydrogen has been added at only. l about half the rate calculated as necessary. The high radiation i levels that have resulted from hydrogen addition are believed l linked to the copper impurities in the coolant. During the current outage, the licensee is replacing the admiralty brass condenser tubes with titanium tubes, which is expected ultimately to. result i In in a significant decrease in copper impurities.in the system. I

turn, the lower level of copper in the coolant should allow i

hydrogen addition at a rate calculated to reduce stress corrosion cracking. 7 I 9004250240 900418 PDR ADOCK 05000321 hk)( Q PDC (, i

~4 'I n s R 2 During this outage, the licensee encountered radiation levels in the crywell that average about a factor of two higher than had l Dreviously been observed in the drywell during. shutdowns. Mr. l Cowan believes that the changes are most likely due to the hydrogen i addition program. The hydrogen addition induces oxide changes on primary system surfaces resulting in crud releases. Thas crud is 1 believed to have migrated to the recirculation system piping with j the attendant increases in radiation levels. Mr. Cowan feels that this is a transient phenomenon and that the dose rates should stabilize and then decrease, particularly af ter the admiralty brass j condenser tubes have been replaced. Mr. Riccardello of Structural Integrity Associates, the licensee's consultant, presented an analysis of the possible causes for the examination results observed thus far, including a discussion.of a the beneficial effects of the induction heating stress ' improvement i (lHS!) applied to many of the welds during the 1995/66 outage, and the anticipated effects of the hydrogen water chemistry. In general, it appears that !HS! is most effective for small bore l pipang, with less beneficial effects observed for the large bore piping. The hydrogen water chemistry program has been less l beneficial than had been hoped since the amount of hydrogen added was less than the amount calculated as necessary. However, after the copper has been removed from the system, the hydrogen addition rates can be increased to ef fective levels without encountering the ALARA concerns. A copy of Mr. Riccardella's br.iefing slides is at There was some discussion regarding the possibility of replacing the sensitized piping with material that is not susceptible to IGSCC. The licensee noted that this obviously had been considered. However, in view of the cost of such an effort in terms of time, dollars and man-rem, the licensee has opted for now to continue with the weld repairs as necessary to meet the guidelines of NUREG-0313. The licensee does not believe that the current level of repairs to the welds in the Unit i recirculation system piping present a problem for long term operation. It also was observed during the discussion that the new indications of cracks that have been observed could possibly be due, an part at least, to improved methods of inspection. The remaining IGSCC related work for this outage includes examination of 10 Category A welds in the Class i portion of the J reactor water cleanup (RWCU) system piping, examination of 7 Category G welds in the non-safety portion of the RWCU system, a scope expansion of 15 welds in the 29-inch piping and 6 welds in the 12-inch piping (all Category C welds). The licensee plans to repair 7 of the 29-inch welds with overlays. The designs for these overlays will be submitted for staff approval. i ..m. m. .,...r.,,_

( n 'I I 3 1 In addition to the IGSCC work, there are other code inspections still to be accomplished and there is considerable other work going i on in the drywell, notably rework of the recirculation pumps and 1 -motors and replacement of the drywell cooler coils. The extensive drywell work, coupled with. the higher. than expected radiation levels in the drywell, has resulted.In a larger accumulated dose j than originally planned. for the outage. To date, the _ non-p destructive examination (NDE) technicians have accumulated a total dose of 38 man-rem. The availability of qualified IGSCC_ inspectors could be a factor in completing the planned work on schedule. j 4s/ l Lawrence P. Crocker, Project Manager .] Project Directorate 11-3. t Division of Reactor Projects-!/II i -l Enclosures

1. Attendance List

2. Agenda

3. Briefing Slides (McElroy) 4.

Briefing Slides (Cowan)-

5. Briefing Slides (Riccardella) cc w/ enclosures See next page f

7h LAIPDII.3 PM PDII-3 D DII-3 RIngraf LCrocker DMatthews 4'/ p /90_ 4/ /J /90 4/ q /90

.q, ~~] Mr. W. G. Hairston, III Edwin I. Hatch Nuclear Plant, Georgia Power Company Units Nos l'and 2 cc: Mr. Ernest L. Blake, Jr. Mr. R. P. Mcdonald Shaw, Pittman, Potts and Trowbridge Executive Vice President - 2300 N-Street, N.W. Nuclear Operations Washington, D.C. 20037 Georgia Power-Company P.O. Box 1295 Mr. J. T. Beckham Birmingham, Alabama 35201 Vice President - Plant Hatch Georgia Power Company Mr. Alan R. Herdt, Chief P.O. Box'1295 Project Branch #3 Birmingham, Alabama 35201 U.S. Nuclear Regulatory Commission 101 Marietta Street, NW, Suite 2900 Mr. S. J. Bethay Atlanta, Georgia 30323 1 Manager Licensing - Hatch Georgia Power Company-P.O.-Box 1295 Mr. W. G. Hairston, III Birmingham, Alabama 35201 Senior Vice President - Nuclear Operations. i Mr. H. C. Nix Georgia Power Company General Manager, Nuclear Plant .P. O. Box 1295-Georgia Power Company-Birmingham, Alabama 35201 Route 1, Box 439 Baxley, Georgia 31513 Resident Inspector U.S. Nuclear Regulatory Commission Route 1, Box 725 Baxley, Georgia 31513 ,j Regional Administrator, Region II I U.S. Nuclear Regulatory Commission 101 Marietta Street, Suite 2900 . i Atlanta, Georgia 30323 j Mr. Charles H. Badger i Office of Planning and Budget Room 610 270 Washingtom Street, S.W. 1 Atlanta, Geo

30334 i

Mr.J.Leonardle&etter, Director Environmental Protection Division Department of Natural Resources 205 Butler Street, S.E., suite 1252 i Atlanta, Georgia 30334 -l i Chairman Appling County Commissioners i County Courthouse Baxley, Georgia 31513

-o ,t'

Enclosure 1

) ATTENDANCE LIST ISI RESULTS MEETING,-HATCH'l April 3, 1990 NAME REPRESENTING-POSITION-Larry Crocker NRR/PDII Project: Manager Frank Rinaldi NRR/PDII-3 Project Engineer C.Y. Cheng NRR/EMCB-Branch. Chief. J.J. Blake NRC-RII Section Chief J.L. Coley; NRC-RII Reactor Inspector W.H. Koo NRR/EMCB' Materials: Engineer G.K. McElroy GPC ' Licensing Engineer S.J.-Bethay GPC ,Mgr. Licensing - Hatch .1 K.I. Parcrewski NRR/EMCB Sr.. Chemical. Engineer R.A. Hermann NRR/EMCB Section Chief R.L.-Cowan GE Nuclear Energy Mge.-Chem'.' Technology P.C. Riccardella Struct. Integrity

Consultant to GPC-Associates Lynn Connor The NRC' Calendar' Robin Dyle SCS/SONOPCO:Proj.

Sr.~ Engineer-Gary Lofthus SCS/SONOPCO Proj. Level,III ISI' R.V. Syx, Jr. GPC Maintenance Support T.N. Epps SCS/SONOPCO Proj. Manager ITS i l l ? i .5k 3 l 4 l 4-v w ~ .wm n e-

c ?

h, :,[ Evnesune 12. NRC/GPC MEETING . UNIT 1 IGSCC INSPECTIONS-APRIL 3, 1990 1:00 3:30 WHITa FLINT BUILDING Room-I. MEETING PURPOSE /0VERVIEW McEl roy II. CLASS I IGSCC INSPECTIONS TO DATE-McEl roy; A. Initial Sample Inspections B. Inspection Results-III. EVALUATION OF INSPECTION RESULTS Riccardella IV. PROPOSED MITIGATING ACTIONS THIS OUTAGE McElroy V. SCOPE EXPANSION McElroy l VI. HYDR 0 GEN WATER CHEMISTRY Cowan. VII. FUTURE. PLANS /

SUMMARY

McElroy x.t - \\ i i . i

sok/

Eneasunc LV ' ; [ s-MEETING PURPOSE /0VERVIEW I o UNIT 1 CURRENTLY IN OUTAGE RETUBING/ REFUELING o UNIT 1 IGSCC INSPECTIONS HAVE SHOWN SOME WELDS.WITH CRACK GROWTH OR NEW INDICATIONS TOTAL OF TWO WELDS WITH NEW INDICATIONS-(CATEGORY C)- SEVERAL CAT F WELDS SHOWED SOME CRACK' GROWTH IHSI TREATMENT DURING 1985/86 0UTAGE " PARTIAL" HWC SINCEL1987 [ o GPC INSPECTED ALL CAT F AND EXPANDED SCOPE TO INSPECT ALL CAT E WELDS o GPC HAS INSPECTED 62% OF THELNUREG-0313, REV 2 CAT C, D, E, F WELDS, AND PLANS TO INSPECT OVER 70%

l o

MEETING PURPOSE: DISCUSS INSPECTION RESULTS AND EVALUATIONS OF'RESULTS DISCUS 5.FUTUREPLANS i f- 'f.

i NUREG-0313, REV. 2 CATEGORY F RESULTS WELDS WITH T9TAL ORIGINAL CHANGED IGSCC SCOPE SYSTEN 11ZI SCOPE INDICATIONS EXPANSION CON 9ENTS B31 12" 3 3 0 N/A INDICATIONS ARE EQUAL TO 0R BETTER THAM PRE-INSI-OR NO CHANGE FRON LAST-INSPECTION. 831 28" 5 5 5 N/A -INDICATIONS EITHER GREW OR NEW INDICATION. SEE INDICATION SupWIARY. E11 20" 1 1 0 N/A NO CHANGE FRON'LAST INSPECTION. TOTAL 9 9 9/5 N/A 5.0F 9 SHOW GROWTH TO BE OVERLAID.

e -w NUREG-0313,-REV. 2 CATEGORY E RESULTS WELDS WITH TRIAL ORIGINAL CHANGED IGSCC SCOPE-SYSTEM 11Zg cInc wins SCOPE INDICATION 1_ EXPANSION C0ffERIS ,m z. 831 12" 20 13 1 7 F-2 (BOAT SAMPLE) SCOPE EXPANSION INSPECTION COMPLETE 22" 4 4 1 0 ONE WELD WITH NEW AXIALS (22 BM-4). NO 0VERLAY . PENETRATION. 28" 6 5-0 1 SCOPE EXPANSION INSPECTION COMPLETE. E11 20" 1 l' 0 0 24" 3 2 1 1 ONE' WELD WITH REW AXIAL (24A-R-13). NO OVERLAY PENETRATION.: SCOPE. EXPANSION INSPECTION COMPLETE TOTAL: 34 25 .3 9

.~ ; o NUREG-0313, REV. 2 CATEGORY C RESUILTS WELDS WITH TOTAL ORIGINAL NEW IGSCC SCOPE ly.SIDI 11ZE CIRC'WELpS SCOPE INDICATIONS EXPAWSION(2) COPBIENTS B31 4* 4 0 N/A 0 12-27 5 0 6 T2 COMPLETE) SCOPE INCREASE INSPECTIONS'IN PROGRESSS. 22" 12(1) 0 N/A 0 28" 25 10 2- -15 SCOPE INCREASE INSPECTIONS IN PROCESS. Ell 20" 4 4: 0 -0 24" 3 2-0. O G31 6" 1 0 N/A 0 All .All 76'- 21 2 21 L(1)' INCLUDES EIGHT 22". SOLUTION ANNEALED'SWEEPOLET WELDS. .(2) UT ONLY.

i INSPECTION RESULTS/ EVALUATIONS + WELD 'NO. INDICATION DESCRIPTION DISPOSITION-i- CATEGORY C i t

1. 1831-1RC-28A-7 NEW CIRC. (4.9" LONG.75" OEEP); STD OVERLAY-L AND AXIAL (1/2 W)

-l l

2. 1831-1RC-28A-8 NEW CIRC. (13.5" LONG.45" DEEP) STD OVERLAY-AND AXIALS (1/2-W)

CATEGORY E

1. 1831-1RC-12AR-F-2 BEING -EVA LU4TED POTENTIAL BOAT SAMPLE-

2. 1831-1RC-22BM-4 NEW AXIALS 0.K. AS-IS

3. 1E11-1RHR-24A-R-13 NEW AXIALS 0.K. AS-IS-i-

CATEGORY F

1. IB31-1RC-28A-2 NEW CIRC (4" LONG.25" 0EEP)

STD OVERLAY

2. 1831-1RC-28A-4 NEW CIRCS (16.8 LONG.25 DEEP)

STD OVERLAY.

3. 1831-1RC-28A-6 NEW CIRCS (4.7 LONG.14' DEEP)

STD OVERLAY.

4. 1B31-1RC-288-10 NO NEW' CRACKS-EXISTING CRACKS STD OVERLAY ARE LONGER / DEEPER

5. IB31-1RCH288 NEW CIRC (.6 LONG.3 DEEP)-

STD OVERLAY AND NEW AXIALS (1/2W)- l 1 1 f l

-- 7 -- -

SUMMARY

OF NUREG-0313, REV. 2 WELDS / EXAMS TOTAL' 1990 COMPLETE NEW 0R TOTAL-CIRC. ORIG. THRU IGSCC PROPOSED WELQ1 SCOPE 3/30 INDICATIONS EXPANSION COMMENTS CAT A 19 10 3 0 0 CAT-B' 0 . CAT C 76 21 25(2) 2 17 -ALLL28"' ~2 12" COMPLETE-CAT D -12 11 10 0 0 CAT'E 34 25 34 3 9 (BOAT SAMPLE F-2 AND-REPAIR) _ CAT F 9 9 9 5 0-CAT G (1) 7 0 (1) APPROXINATELY 70 WELDS NOT WITHIN GPC SECTION XI ISI PROGRAM (NON-SAFETY RWCU OUTSIDE CONTAINMENT) j (2) INCLUDES 4 WELDS OF THE SCOPE EXPANSION l q 1

i n ~ l - IB31-IRC-4A-IA .lB 31-IRC-12AR-H IB31-IRC-12AR-J IB -12AR-G S_ECTION A-A IB31-lRC-12AR-K 3 3 lB31-IRC-12AR-F -3 9 c 3 -5 -5 -5. S' 5 3, 2, f "9 2j i ul ,)A z.) z) . 4'] g) 4' r 4-4 4-g a h h I. h h [' h IB31-lRC-28A I I 3 I 17 3 I ~ l 3BC-1 / 3BC-2 N IBC-l IBC-2 f ( J' V c l- = Y .i i. 9 .g/ 1 - -( i i 2 x y =SA 1931-lRC-22AM i ~ [_i'l413j 'w 1931-IRC-22AM l Ell-- 15 j f F060A L 12 gg , IEll-IRHR-24A-R PUNP JL B31-lRC-4A-10A I 93 l-p COOlA 's 14 _ \\ gl A . g3 g. ) NIB 7l-IRC-28A IMRC@ . FO3lAf) 5.: i B3l- +- U 6 7 -x / A 'l2 -13 s 10 FIGURE l 7 8 HATCH I STAINLESS STEEL PIPING LOOP A

~ ~ IB31-IRC-49-IA IB31-IRC-12BR-C IB31-IRC-12BR-D IBWlOl2BR-B SECTION A-A IB31-lRC-12BR-E 3 3 IB31-IRC-12BR-A 3 3 7 IG31-IRUCU-6-D h 2' 3 5 -5 -5 5 g ,J r yd

L_d, dL l

4 4 < t 2---. L 7' L gY f g) 4?gY gY 4~ 4 l 4 4' g I 's 5 4 I 1 I I l l l l l ll l e u I 4 i is 3 f = 3BC-1 2 5 IBC-1 IBC-2 jf l 3 = i (,4 ( i' 'v c'4-r 'v' fg if i - a i i i /I 1 2 4 -~ 2 IB31-IRC-22BM 17 [._ ' f "EIP 0" l IEll-IRHR-209-D 16 [ j g3 F0600 l . Lig i2 - l RC IEll-lRHR-249-R-PUMP j i _ IB31-IRC-49-LOA B31-f_ 0018 IB31-IRC-289 12 g3 - IB3HRC-28B IEHE-E / ,F0318 ) ) r x xs B31-t r 7 = o j ( ( F023B lh L 4 N' A '13 -14 l 'N 11 . FIGURE 2 HATCH I STAINLESS STEEL PIPING 8 9 10 l 'LOOPB ocw n L _.. c.. ~ .a. -. = ~ ~

a. EVALUATION 0F-INSPECTION RESULTS s o GROWTH IS EXPLAINABLE FOR FIVE 28" CAT F WELDS TWO OF THREE CAT E WELDS HAVE EXPLAINABLE CHANGES IN INSPECTION o RESULTS L 'f ONE CAT E WELD (F-2) REQUIRED' REPAIR DURINGIINITIAL OVERLAY o APPLICATION (1984) AT REPAIR LOCATION MAY BE CONFIRMED BY BOAT SAMPLE o ~TWO 28" CAT C WELDS HAVE NEW-CIRC INDICATIONS 'i POSSIBLY DUE TO LESS THAN OPTIMAL IHSI POSSIBLY DUE.TO INCIPIENT IGSCC PREVIOUSLY NOT OBSERVED (ONE-SIDEDEXAM) -l i NEW INDICATIONS DISCOVERED WERE NOT EXPECTED, BUT EXPLAINABLE I NO SAFETY CONCERN l 1

t GENERAL CONCLUSIONS i 3 PROBLEM LIMITED TO LARGE BORE PIPING (28') 1 o.IHSI IS VERY EFFECTIVE'FOR SMALL BORE < PIPING PARTIAL HWC HAS 'OT BEEN EFFECTIVE N o 1 I o FOR CATEGORY E'S, NO GROWTH INTO OVERLAY ISL EXPECTED o NOT A SAFETY CONCERN o OVERLAY CONTINUES.TO P30 VIDE EFFECTIVE MITIGATION l o INSPECTION TECHNIQUE AND INSPECTOR EXPERTISE CONTINUE T0-ENHANCE SENSITIVITY i RESULTS DO NOT INDICATE MAJOR PROBLEMS WITH UNIT 1~ l PIPE l~ RECIRC SYSTEM STILLLACCEPTABLE FOR LONG< TERM-OPERATION - i i l s-r i I I = d re W g4 eauw e w-, a m m .-s.,a a 4 w s4h m. msw m. v m o% .w m - a

i l MITIGATING ACTIONS THIS OUTAGE o STANDARD WELD OVERLAYS WILL BE APPLIED.T0 THE.FOLLOWINGfWELDS: i IB31-1RC-28A-2 SE T0 PIPE -1831-IRC-28A-4 ELBOW T0. PIPE 1831-1RC-28A-6 ELBOW TO PIPE l 1831-1RC-288-10 ELBOW TO PIPE A STANDARD WELD OVERLAY (1/2 W) WILL.BE APPLIED TO THE FOLLOWING' o WELDS: e 1831-1RC-28A-7 ELBOW TO VALVE + 1831-1RC-28A-8 VALVE TO PIPE IB31-1RC-288-8 -ELB0W TO VALVE 0VERLAY DESIGNS WILL BE FORWARDED'TO NRC PER NUREG-0313, REV.L2' REQUIREMENTS TOTAL UNIT 1 CAT E OVERLAYS WILL BE INCREASED FROM 34 T0'41 L l T k r b t -,#m ,,wr -m r-.= a._,.,m-_,_, mm

,ce.- s j F Figure l' 1 l A B ~' FLOW 4 45' MIN - o TYP Le o-A<5' $$$'e'ed"%' 555'e'/ $$$$"51' 5"e5??' h, t dee eched &ed r- %\\\\ / 7 } l (WELD -t A-2, A-4, A-6, B-10 F t I e 4 7 l l _....,_..,. ---- ~~ ~

+ n,=. I 1 I ] I' f l-f . g! = l 1 i A 45' MIN TYF! s o ss$s,o m isissi /. 4. 5.,,ff.5.5.5.5.5.5.5.5.5.5\\5,. i l 1 l' / i 'i i i l .[

e. WELD 1

i A-7, A-8, B-8 t I i i' r i O l' l!' l 8 s 6 4 .rE 4 L e - +... --.re.e,-- -...- _. -,. - --2,.,- -+,.w...- .m r- -w--. +----...--.,,v.

= - - - -.--

y e = -e+-*e -.w,

-c SCOPE EXPANSION l o GPC-HAS EXPANDED-CAT E SCOPE PER NUREG-0313 REV. 2 l o NUREG ALLOWS DISTRIBUTION ADJUSTMENT IF TECHNICALLY JUSTIFIED o THE NEW OR LARGER INDICATIONS IN CAT C AND F HAVE BEEN LIMITED l j TO THE 28" PIPE

o. HAVE SEEN NO CRACK GROWTH IN 12" CAT F AND NO CRACKS IN 12" l

CAT C WELDS EXAMINED THIS 0UTAGE o EXPANDED SCOPE' INCLUDES SIX 12": CAT C WELDS 3 DONE FOUR OF-EIGHT NON-0L 12" N0ZZLE TO SE WELDS DID ALL 12" N0ZZLE TO SE WELDS LAST OUTAGE 4 o DONE 10 0F 30 NON-OL 12" WELDS THIS OUTAGE, AND 10 WELDS-NOT INSPECTED ARE RISEN TO MANIFOLD WELDS o DONE 20 0F THE 27 12" CAT C WELDS EITHER LAST OUTAGE OR THIS l OUTAGE i i l i GPC INTENDS TO INSPECT SIX 12" WELDS AND THE~ REMAINING FIFTEEN 28" CATEGORY C WELDS AND DISPOSITION ANY NEW FINDINGS i 4 + ~ ., - -, - - -,,.. - ~. e

'{ FUTURE PLANS /

SUMMARY

(THIS DUTAGE) o REMAINING IGSCC RELATED WORK i EXAMS ON 10-CAT A RWCU (CLASS I) WELDS-(VOLUNTARY) EXAMS ON 7' CAT G RWCU (NON-SAFETY) WELDS. SCOPE EXPANSION OF FIFTEEN 28" AND SIX 12" CAT C-WELDS SEVEN 28" OVERLAYS TO BE APPLIED AND REINSPECTED 38-MAi!-REM ON NDE TECHNICIANS S0 FAR o REMAINING CODE INSPECTIONS o "PROACTIVE" DRYWELL WORK ON RECIRC PUMPS, MOTORS AND DRYWELL COOLERS 4 l o DRYWELL RADIATION LEVELS-HIGHER THAN ANTICIPATED GPC HAS A SIGNIFICANT AMOUNT OF IGSCC RELATED WORK.YET TO PERFOME IN ADDITION TO CODE INSPECTIONS' ALARA CONCERNS, PLUS AVAILABILITY OF QUALIFIED ~IGSCC INSPECTORS A PROBLEM

l I FUTURE' PLANS /

SUMMARY

u CONDENSER TUBE REPLACEMENT WILL BRING DOWN. COPPER LEVELS IN o FEE 0 WATER AND EVENTUALLY IN REACTOR VESSEL l j INDUSTRY STILL BELIEVES HWC WILL ARREST CRACK GROWTH / INITIATION! o '0NCE REQUIRED ECP-IS ACHIEVED l GE CAV SYSTEM INSTALLED IN UNIT 1-WILL PROVIDE CRACK GROWTH RATE, o DATA-FOR THE ACTUAL WATER ENVIRONMENTAL CONDITIONS o -N0 DEFINITE REGULATORY-LIMIT ON PERCENTAGE'0F SYSTEM'S WELDS' WHICH MAY BE OVERLAYED i EFFECTS'0F OVERLAY (I.E., SHRINKAGE STRESSES) GENERALLY LESS ON LARGE BORE PIPING SEVEN NEW OVERLAYS THIS OUTAGE t ONLY TWO NEW CRACKED WELDS o STRESS IMPROVEMENT (IHSI, MSIP) STILL-AVAILABLE APPLICATION ON CAT D WELDS BEING INVESTIGATED' REAPPLICATION OF SI POSSIBLE GPC.DOES NOT BELIEVE CURRENT LEVEL OF REPAIR IN UNIT 1 RECIRC [ SYSTEM IS PROBLEM FOR LONG TERM OPERATION GPC WILL CONTINUE TO STRIVE FOR EFFECTIVE HWC,.AND IN-THE INTERIM, CONTINUE TO INSPECT.PER NUREG 0313 AND MITIGATE-THROUGH SI, 0VERLAY

.o .[Nt b h rt ' -( j 4 1986 HWC MINI TEST RESULTS i l. O ECP UNDER NORMAL' WATER CHEMISTRY t i CONDITIONS HIGHER THAN OTHER BWRs-1 L HATCH to.150 V,SHE l OTHER BWRs 0 TO t0.050 V,SHE i O REQUIRED. H FOR IGSCC PROTECTION t 2 L (ECP -0.230 V,SHE) MUCH-HIGHER THAN EXPECTED 4 j 0.3 ppm FW H, Expected. 1.4 ppm FW H, Required O PRESENCE OF COPPER IN REACTOR-WATER-IDENTIFIED AS NEGATIVELY AFFECTING L H2 EFFICIENCY j O MAIN STEAM LINE N-16 DOSE RATES AT PROTECTION POTENTIAL TOO HIGH FOR EFFICIENT PLANT OPERATION 4x Normal Water Chemistry Background O COPPER CONCENTRATION IN HOTWELL SHOWED SLIGHT DOWNWARD TREND WITH CONTINUOUS H2 ADDITION aataggeg .._._,...;,~,,.._..,,._,..,

y A__ 0

2

,8 1 2 , '6 1 M )7 4' E. L P 1 x R E H PP / d O N-2 e C R m 1 ( u e ta \\ 0 R T W _1 e U s N o P D R x ' " a E 8 m PP x , 0 a O r m C a \\* u a m "

r G

u P 6 e c ~ e m 0 m z oc n w 4 o , 0 D 2 . 0 0 08 4 2 1 8 e. 2 1 0 1 -0 o O O CS O yh'O ga N $ k ~V $ oO n EoU g j I :.b i ) i

Edwin I. Hatch HWC Minitest i 5.0 B 4.0 m a g e 4 e i E a' 3.0 = 1 m e. 2 e .E 2.0 s g-D - o z e-e 1.0 : : =s ;_ e E t i i O.O ' - 'g g g g g g y 'g. g ,g g. O. 0 O. 4 7.8

1. 2 -

.1. 6 E '. 0 0 5 10 '15- ~20~ 25 30. 35 40 ?45 50 55 60 -65 70 ^ Hydrogen Addition Rote (SCFW) Feenimater hycVogen Concentratim 99W)- .-..-.s.- .a

g e: i. +' BASIS FOR " PARTIAL HWC" L I I O MINIMlZE N-16 DOSE RATE - ALARA CONCERNS L 4 O REDUCE' ECP FROM +0.150 -V,SHE TO' l 0.000.V,SHE BY INJECTING 22 SCFM (0.7 PPM) H lNTO FEEDWATER (2X;lNCREASE) a L IN MSLRM) l-REDUCES-CRACK GROWTH RATE OF ANY EXISTING 3 i' CR ACKS... CONFIRM WITH CAVS-DATA O MONITOR ECP OF STAINLESS STEEL AND EXPECT. POSSIBLE SLOW DECREASE TOWARD-I L PROTECTION POTENTIAL O MONITOR MAIN STEAM LINE RADIATION -MONITORS (MSLRM). IF' SUBSTANTIAL DRIFT DOWN, INCREASE' HYDROGEN INJECTION ~TO DECREASE.ECP 4 eetetces - =....

n...., i i s a ~l Effect of ECP on Crack Growth Rate PLEDGE - Hatch 1 - Type 304 SS Crack Growth Rate, mpy - - ~ - ' - / Hatch 1 Conductivity .7 1987 (0.148 uS/cm) ,[' 1988 (0.262 uS/cm) 3,/ 0.262 us/cm ..[5 1989 (0.112 uS/cm) ~ l 0.14 8 u S / c m .x

• 0.112 uS/cm 10

/ly s"- ~' i--- '--I 1 -400 -350 -300 -250 -200 -150 -100 -50 0 50 10 0-- 15 0 200-ECP, mV (SHE) K-25ksi/in EPR-15C/cm2 -u-1- i i - --

ey HWC OPERATIONAL HISTORY a INJECTION RATE TARGET MAINTAINEDLAT 22 SCFM THROUGH CYCLES 11 ANDc12-q PERIODIC ECP MEASUREMENTS OF-TYPE-304; STAINLESS STEEL NOTED ONLY SLIGHT DRIFT OF POTENTIALS TOWARD PROTECTION'- YEAR ggy 1986 0 V,SHE l m e 1990. -0.01 TO -0.05- ] CAVS MACHINE INSTALLED LATE IN 1989 HATCH-1 OPERATED'IN ENVIRONMENT OF SIGNIFICANT IGSSS SUSCEPTABILITY. DURING CYCLES-10,111,12 l-i

^ ] j HYDROGEN INJECTION HISTORY i CYCLE 10 e 1 l Mini Test I I t i: CERT Test Campaign 85 Days,28% of Cycle l " Steady State' H - / 2 CYCLE 11 i NWC-First?100 Days - " Steady State" H'2 September 15,1987 to E.O.C. CYCLE ~2 NWC First 50 Days l " Steady State" H January 27,1989 to E.O.C. 2 'STE ADY' STATE' H2 CONDITION L '22 scfm (0.7 ppm) approx. 80% l. 12 scfm (0.4' ppm) 20% 1 l 0 sofm some j-Cycled between 12 and 22 scfm approx. 3 times per week I for N-16 reduction _during maintenance / surveillance ....u.i i 4 r.- .--w -.e ,. ~ ..e-. ....r,-

4 y i L ) i HATCH 1 RADIATION LEVELS-l 0: DOSE RATES HAVE INCREASED 1 -o. Recirc dose rates now'> zine plant. curve-o At 160 mR/h, still low for-BWR~ Changes vary greatly from spot to spot' o Pattern typical of crud controlled buildup: o E O INCREASE LIKELY RELATED TO HWC Similar observations 'at Duane Arnold, o L Monticello, and FitzPatrick l l o HWC induces oxide changes on primary. system surfaces - resulting in crud releases I o Appears to be transient. phenomenon o. Dose rates should-stabilize - then decrease 4 s p g. .....m..- u-

---

e-w

e 9 e E.

l. HATCH UNIT //1 RAD LEVEL INCREASES IN DRYWELL 260 -

240 - 220 - y u 200 - 180 - 160 - x 75 fkx i '21 l9%q Wh fil 2:dh si d$ sh -114 127 147 156 8 CYCLE 10- . kTJ LYL E 1 @ CYCLE 12

o HWC PROGNOSIS AT HATCH-1 O REMOVAL OF COPPER SOURCE TERM (CONDENSER REPLACEMENT) WILL RESULT IN SHIFT FROM COPPER TO NON-COPPER PLANT BEHAVIOR O HATCH-2 DATA PROJECTS: FW Cu <0.1 ppb af ter approx.100 days RW Cu <2 ppb af ter approx. 300 days O PLANT WILL BE ABLE TO ESTABLISH IGSCC PROTECTION POTENTIAL WHEN REACTOR WATER COPPER IS IN THE RANGE OF 1-5 PPB Cu O CAVS DATA WILL PRECISELY MONITOR THE CHANGES ECP - Crack Growth Rate O AFTER PROTECTION POTENTIAL IS REACHED AT 22 SCFM INJECTION RATE, HYDROGEN INJECTION RATE CAN BE SLOWLY REDUCED ... MSLRM WILL THEN DECREASE TO 1.3 TO 1.5X-NWC BACKGROUND ....a.. R

6; HATCH 2 j RX. Cu SINCE REPLACEMENT OF CONDENSER 30 26-2 44 1 ^ 22-l l 00 a A 1 20* t v s 1 l l z 18-i O 16-Q N o e tr 14-s 5 12-i O i z 10-o O 8-6- 3 4-i 2-i 0 10 50 80 0 150 200 250 300 aso t DAYS ~ SINCE CYCLE STARTUP MX2CU90

(m m.ca S: -~ ~.. -q 1 APPARENT CRACK GROWTH. AND-l NEW INDICATIONS. DESPITE: j i 1 \\ l i

• IHSI TREATMENT OF WELDS DURING i

1985/86 OUTAGE i I i I

• HWC SINCE ~ MID-CYCLE 1986/87 I

5 I j i i I I I l i l k i STRUCTURAL l-INTEGRITY ' A$$QCI ATE S, INC g g. 014 P R l t l j. 1

,4 i 4 i EFFECTIVENESS OF STRESS REMEDIES 1 UNFLAWED WELDS i l

• SMALL DIAMETER - THIN WALL I

Large Residual Stress improvement on Pipe ID Laboratory Test Data Shows Major Benefit of IHSI on IGSCC (factor i of 10 improvement in IGSCC resistance)

• LARGE DIAMETER - THICK WALL l

Somewhat Smaller Residual Stress improvement on Pipe ID Laboratory Test on Similar Stress improvement Shows Benefit (factor of more than 5 improvement in IGSCC resistance) { ..i i STRUCTURAL INTEGRITY , o. o g no ' ASSOCI AT E S, INC, i %x

"O..y ' ~. 80- ,,, j e e eu - .. ~.. t*"d"l ' E "' la' i 20 e l 4 9 0 . e.......,,,,,, =

• e 1

. ~ ~ ~. 20< e e I.40' 9 a ~ e 5 a 60' 3 .no-Figure 5 - As-Welded and Post-IHSI Axial Residual Stresses' to ,,,,,, i o e me i e,e on g, .sa.,Ieaveem e,e m q l 40' l 20' I e 0 g e ~.. 20< g g 8 e e 40' I o e e g 60' o g 00' I s Figure 6 - As-Welded and Post-IHSI Hoop Residual Stresses 4 i

,a ,b

== <r sn ess a / \\ k / \\ { 38# ' / \\ / \\ g / / N r an l / N' l nn. / f s 3 / %g \\ / / im. j ~~~ e / / o-e am se e un as me as hade iMCOsette O Figure 7 - Transient Strain Measurements 1 i I l I i I t l~

P r '.. e b i, a g 1131{ ggj R s g gggh I h ,g i Ig II,! 11 ,I s-{}31 sx i L i I .s g a 4 g N s, S I , it A .s[ 1 {3 y ' pp a { J g i 1st a 1 1 aA tg g (( \\4' g,.4 ~ 11} \\ 1 } g 1 \\ 0 s i 6l ~ 8 R g s l R R i 6 o [(um et V S4'01 WML lism g 1 l = i .. ~,......

j i l 1 i j PLANT DATA ON STRESS IMPROVEMENT j i REMEDY EFFECTIVENESS l i t i ,l l j

• LIMITED CRACK EXTENSION IN *EVERAL j

BWR'S - Consistent with Laboratory j Observations on Flawed Pipe l i - Bounded by Fracture Mechanics l Analysis and Flaw Sizing Variability i i i l-i 1 i STRUCTURAL INTEGRITY j oo.oroaa ' AS$QCI ATE S. INC I i a .. _..--...~. --....,-..-..

i i RESIDUAL STRESS DISTRIBUTIONS i USED IN FLAW GROWTH ANALYSES (WITHOUT IHSI) i i I 60 l [ NUREG Residucl Stress High Residual Stress i - Los Residual Stress l l 40 3 N i \\ \\ e \\ l \\ \\ = 20 g s s s y 6 \\ s l b \\ 's g x 's_ ~ s s \\ / / s / i \\ / _20 s ys.w. bhk!h -400. 00 0;........ i......... 0.40 0.80 1.20 thickness (in) J STRUCTURAL INTEGRITY ASSOCI ATE S. INC. so.oseen ? ..J..- .-.__-,_.J.._,...

a. - '.

l PROJECTED CRACK GRWOTH WITHOUT IHSI OR HWC l (Weld 28-A-2) l 1.20 a l .~ 1.00 i 1 [ ,' 1990 Inspection l 0 i Results 5,30 ! / / 5 I [0.60 ~ r ~ l g ~ I e 1 .0 0.40 i I I

./

~,__--- i [l O.20 Hi h Residual Stress ( N REG 0313 Residual Stress 8 --- Low Residual Stress -

.: Mm1988 Inspection Results OIh[1ddbh''2ddbh$ddbh'4ddb5'5ddbh

h-Time (br) STRUCTURAL so.ossen INTEGRITY ' AS SOCI ATE S. INC_

, v.. y Pisure 4 PROJECTED CRACK GROWTH WITHOUT IHSI OR HWC (Weld 28-A-7) 1.20 3 (--- Hi h Residual Stress N REG 0313 Residual Stress - - Low Residual Stress 1.00 j 1990 Inspection I Results l 0.80 e 3 I D 4 I s 3 %0.60 $ I o / ~5 i e .I O0.40i / l ~~~ ~_____. / l t 0.20 1984 inspection Results 0.00-10000 20000 30000 40000 50000 60000 Time (br) l STRUCTURAL INTEGRITY ' ASSOCI ATES. INC. I

c...

4 J . ],,... I i PROJECTED CRACK GROWTH RATES l WITH IHSI RESIDUAL STRESSES i I 1 1.20 Low IHSI Residuct Stress j j 1 1.00 - ~ 0.80. m ._c .v l.c "c,0.60 :: ec .:tu E '~ ~ 00.402. l i 0.20, hy a l O.00 ' 'FtF'10000 20000 30000 40000 50000 C0000 Time (br) l l ? STRUCTURAL + INTEGRITY ' ASSOCI ATES. INC. so.onspn I

y....

i 4 i i ESTIMATED EFFECT OF IHSI ON 2 28" PIPE WALL RESIDUAL STRESSES l I. 60 1 i i I j NUREG Residual. Stress High Residual Stress - Low Residual Stress i l 4 0 m. \\ 3 \\ \\ \\ l l l \\ s 20 - g s c s \\ l i \\ s s \\ s g s m O' \\ s _ _ g_. N / / x / i WITH IHSI-2 \\ i -20 + r b;,$Nk. -40 . w.,,, i 0.00 F 0.40 0.80 1.20 thickness (In) l t STRUCTURAL l lNTEGRITY

• ASSOCI AT E S. INC.-

90*024PR I l-t 1 i 1 i

Fa .o ~ C. -o 4 DATED April 18, 1990 MEETING

SUMMARY

FOR EDWIN !. MATCH, UNIT 1 (APRIL 3, 1990) DISTRIBUTION M9eekselFJJew NRC POR Local PDR PD11-3 R/F Hatch R/F R. leerem 14-H-25 L. Crocker 14-H-25 ACRS (10) P-135 OGC-WF 15-9-18 E. Jordan MNBB-3302. F. Alme101 14-H-25 C. Y. Cheng 9-H-15 R. Hermann 9-H-15 W. Koo 9-H-15 K. Parcrewski 9-H-15 J. Blake Region !! J. Coley Region !! t s ? ( l \\! ?^ .} l l )Fo I it, -}}