ML063390165
| ML063390165 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/19/2006 |
| From: | Martin R NRC/NRR/ADRO/DORL/LPLII-1 |
| To: | Grissette D Southern Nuclear Operating Co |
| Martin R, NRR/DORL, 415-1493 | |
| References | |
| TAC MD3371 | |
| Download: ML063390165 (5) | |
Text
De cembe r 19 , 20 06 M r. D. E. Gri ss e tt e Vi ce Pre si den t So uthe rn N ucl ear Operati ng Co mpan y , Inc.P.O. B o x 1 2 9 5Bi rmin gham, AL 35 201-129 5
SUBJECT:
VOG T LE ELECTRI C GENERAT ING PLANT, UNIT 1 (VOG T LE) - SUM M ARY OF CONFERENCE CALL REGARDING THE 2006 FALL O UT AGE ST EAM GENE RA TO R TUBE IN SP EC TIO NS (TAC N O. M D3 371)De ar M r. Gris sette:On Octob er 1 8, 2 006 , the N ucl ear Re gula tory C ommis si on (NR C) staff pa rtic ip ated i n a con f eren ce cal l w ith S outh ern Nu cl ear Operati ng Co mpan y , Inc., rep rese ntati v es regardi ng ste am gen erat or inspect ion f inding s during the f all 2006 ref ueling outag e. T he NRC staf f is f orw ardi ng the en cl ose d s ummary for y our in f ormati on.
Sin ce r ely,/R A/
Ro bert M arti n, S eni or P roject M ana ger P l a n t L i ce n si n g B ra n ch I I-1 D i v i s i o n o f O p e r a t i n g R e a c t o r L i c e n s i n g Of f ic e o f N ucl ear Re acto r R egul ati on Do cket No. 50-424 E n cl o su re: Oc to b e r 1 8 C o n fere n ce C a l l S u mma ry c c w/e n c l: S e e n e x t p a ge De cembe r 19 , 20 06 M r. D. E. Gri ss e tt e Vi ce Pre si den t So uthe rn N ucl ear Operati ng Co mpan y , Inc.P.O. B o x 1 2 9 5Bi rmin gham, AL 35 201-129 5
SUBJECT:
VOG T LE ELECTRI C GENERAT ING PLANT, UNIT 1 (VOG T LE) - SUM M ARY OF CONFERENCE CALL REGARDING THE 2006 FALL O UT AGE ST EAM GENE RA TO R TUBE IN SP EC TIO NS (TAC N O. M D3 371)De ar M r. Gris sette:On Octob er 1 8, 2 006 , the N ucl ear Re gula tory C ommis si on (NR C) staff pa rtic ip ated i n a con f eren ce cal l w ith S outh ern Nu cl ear Operati ng Co mpan y , Inc., rep rese ntati v es regardi ng ste am gen erat or inspect ion f inding s during the f all 2006 ref ueling outag e. T he NRC staf f is f orw ardi ng the en cl ose d s ummary for y our in f ormati on.
Sin ce r ely, /RA/
Ro bert M arti n, S eni or P roject M ana ger P l a n t L i ce n si n g B ra n ch I I-1 D i v i s i o n o f O p e r a t i n g R e a c t o r L i c e n s i n g Of f ic e o f N ucl ear Re acto r R egul ati on Do cket No. 50-424 En cl osu re: Oc to b e r 1 8 C o n fere n ce C a l l S u mma ry c c w/e n c l: S e e n e x t p a ge DIST RIBUT IO N:P U B L IC P D II-1 R/FR i d sN rr L A M O'B ri e n R i d sN rr D o rl L p l 2-1 (E M a ri n o s) Ri dsOGCR p Ri dsA crsA cnw M ai lC ente rNrr DciCsg b(YDiaz-Cast ill o)
RidsNrr PM RM art in R i d sR gn2 M a i l C tr (S S h a e ff e r) AD AM S Acc ess io n N o.: M L06 339 016 5 NR R-1 06 OF FICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/LPL2-1/BC NA M E RM arti n M O'B rie n EM ari nos DA TE 12 /11 /06 12 /18 /06 12 / 1 9 /0 6 OFFICIAL RECORD CO PY Enclo sure OCT OBER 18, 2006, CO NFERENCE CALL SUM M ARY ST EAM GENERAT OR T UBE INSPECT IO NS V OG TL E E L E C TR I C G E N E R A TI N G P L A N T, U N I T 1 DOCK ET N O. 50-4 24 On Octob er 1 8, 2 006 , the N ucl ear Re gula tory C ommis si on (NR C) staff pa rtic ip ated i n a con f eren ce cal l w ith S outh ern Nu cl ear Operati ng Co mpan y , Inc., rep rese ntati v es, to d is cus s stea m genera tor (S G) i nsp ecti on acti v iti es at V ogtle E le ctri c Gen erati ng Pl ant, Un its 1 and 2, (Vog tle Unit 1 and Vogt le Uni t 2), part icularly thos e activities during the Vog tle Unit 1 f all ref ueling outag e (desig nate d 1R13). A summ ary of the inf orm ation discus sed dur ing the call a lo n g wit h so m e ba c k g r o u n d in f o r m a t io n is pr o vi d e d be lo w.Vog tle Unit 1 has f our m odel F SGs desig ned and f abrica ted by W est ing house. Each SG con tai ns 562 6 th ermal ly trea ted Al lo y 60 0 tu bes w ith an ou tsi de di ameter of 0.688 of an i nch and a nomi nal w al l thi ckness of 0.040 of an i nch. The tub es are hy drau li cal ly ex pan ded for the f ul l dep th o f the tub esh eet at e ach en d a nd are sup porte d b y a numb er o f sta in le ss stee l tube su p p o rt s. In t h e U-b e n d r e gi o n , th e t u b e s a re s u p p o rt e d b y a n ti-v i b ra ti o n b a rs. Th e t u b e s a re arran ged i n a square pi tch.Vo gtle Un it 1 S Gs be gan co mmerci al op erati on in 19 87. In 200 2, th ere w as an in adv erten t add iti on of pho sph ate to th e U ni t 1 and U ni t 2 SGs. In the spri ng of 200 4, V ogtle U ni t 2 pul le d tw o tu bes to in v esti gate cra ck-li ke i ndi cati ons at the ex pan si on trans iti on. A l abo ratory no n-des tructi v e e x ami nati on of both of these tub es in di cate d th at th ere w as no crac king at the ex pan si on trans iti on. D estru cti v e e x ami nati on of one of the se tube s c onfirmed the re w as no cra ck ing at the expansion tra nsition. In th e spring of 2005, Vog tle Unit 1 identif ied crack ing in bul ges w ith in the tub esh eet. N o c rack-li ke i ndi cati ons w ere f oun d d uri ng the fall 20 05 in spe cti on in V ogtle U ni t 2. D uri ng the rec entl y co mpl eted fall 20 06 SG tu be in spe cti ons at V o gt l e U n i t 1 , c r a c k-l i ke i n d i c a t i o n s w e r e i d e n t i fi e d a t t h e e x p a n s i o n t r a n s i t i o n. Th e s e fi n d i n gs are di scu sse d b el ow. The ne x t V ogtle U ni t 2 SG tu be in spe cti ons are sc hed ul ed f or th e spri ng of 200 7.During the 1R13 outag e, 100 per cent of the tube s in S Gs 2 and 3 w ere inspec ted wi th a bobbin coi l. In add iti on, the U-b end regi on of 50 perc ent of the row 1 and 2 tube s, a nd 100 pe rcen t of the di ngs an d d ents greate r tha n 5 v ol ts i n th e h ot l eg i n S Gs 2 and 3 w ere in spe cted w ith a ro ta ti n g p ro b e. Th e S Gs w e re c h e mi ca l l y c l e a n e d b e fore t h e t u b e i n sp e ct i o n s a n d t h e S Gs ope rate at a ho t l eg tempe rature of 61 8 F. o Du rin g 1R1 3, +P oi ntŽ i nsp ecti ons of the top of the tub esh eet regio n w ere pl ann ed f or 5 0 perc ent of the tube s i n S Gs 2 and 3. D uri ng thi s i ni tia l sampl e, i ndi cati ons of ou tsi de di ameter stress co rrosi on crac king w ere f oun d i n s ev eral tub es at th e b ottom o f the ex pan si on trans iti on regio n i n b oth SGs. A s a res ul t of f in di ng the se in di cati ons , the sc ope of i nsp ecti on at the top of the tube she et w as ex pan ded to in cl ude 10 0% o f the tub es in S Gs 2 and 3 and 25 pe rcen t of the tube s i n S Gs 1 and 4. The ex tent of thi s i nsp ecti on w as f rom 3 i nch es abo v e to 3 in che s bel ow the top of the tub esh eet. A s a res ul t of f in di ng i ndi cati ons i n th e i ni tia l sampl e i nsp ecti on in S Gs 1 and 4, the sco pe of the in spe cti on at th e to p o f the tub esh eet w as ex pan ded to in cl ude 100 pe rcen t of the tube s. At the time of the co nference ca ll , 10 i ndi cati ons ha d b een i den tifie d: 3 i n S G 1, 2 i n S G 2, 3 i n S G 3, and 2 in S G 4. The li cen see i ndi cate d th at e v al uati ons for othe r po ssi bl e i ndi cati ons , so me i n th e s lu dge p il e re gion , w ere sti ll on goin g in S G 4.For SGs 1, 2 an d 3 , the i ndi cati ons are pre domi nan tly l oca ted in l ow row , hi gh col umn tube s a l o n g th e p e ri p h e ry (b e tw e e n r o w s 1 t h ro u gh 6 a n d b e tw e e n c o l u mn s 1 0 3 t h ro u gh 1 1 9).In o rder to c onfirm th e i ndi cati ons , fiv e d iff eren t i nsp ecti on method s w ere use d: +P oi ntŽ, Ghent, 3 C oi l De lta , an d th e 0.080 an d 0.115 pa nca ke coi l. A ll of the i nsp ecti on method s con f irme d th e i ndi cati ons w ith the ex cep tio n th at s ome of the smal l ampl itu de si gnal s w ere not id enti f ie d w ith the 0.0 80 pan cake c oi l. Gi v en thes e re sul ts, th e l ic ens ee con cl ude d th at th ese i n d i ca ti o n s a re c ra cks. The l argest c rack-li ke i ndi cati on w as measu red to h av e a ci rcumferenti al ex tent of 180 de grees.The max imu m rep orted de pth w as 67 perc ent throu ghw al l. The in di cati on w ith the l argest ci rcumferenti al ex tent w as not the same in di cati on that had the max imu m de pth. The v ol tages a s s o c ia t e d wit h t h e in d ic a t io n s wer e ap p r o xi m a t e ly 0.2 vo lt s , al t h o u g h t h e r e wer e t wo i n d i ca ti o n s th a t h a d v o l ta ges o f 0.6 0 v o l ts a n d 0.7 3 v o l ts. A h i st o ri ca l r e v i e w o f th e +P o i n tŽd a ta for t h e t u b e s i n w h i ch t h e OD S C C i n d i ca ti o n s w e re d e te ct e d t h i s o u ta ge w a s p e rfor me d. This rev ie w di d n ot i den tify an y pre curs or s igna ls i n th ese tub es. The l ic ens ee state d th at i t ha d a le rted the in dus try (oth er l ic ens ees of pre ssu riz ed-w ater re a ct o rs) re gar d i n g th i s i ss u e. Al l tube s w ith cra ck-li ke i ndi cati ons w il l be pl ugg ed and sta bi li z ed. The li cen see co nsi dere d pulling a tube or tubes, but due to a maj or tu be-p ull proj ect ov ers eas, the licensee w as not able to p ul l a tu be giv en its ou tage sc hed ul e. The l ic ens ee w il l ev al uate pu ll in g a tu be duri ng the n e x t re fue l i n g o u ta ge. D u e t o t h e l o ca ti o n o f th e t u b e s w i th c ra ck-l i ke i n d i ca ti o n s i n r e l a ti o n t o the di v id er p la te, i t i s n ot c le ar w heth er p ul li ng a tube i s feasi bl e. W ith res pec t to si mil ar ope rati ng ex peri enc e, th e l ic ens ee in di cate d th at C oman che P eak U ni t 1 had first d etec ted outs id e d ia meter c irc umf eren tia l crac ks in a si mil ar re gion of the tub e b und le.The l i ce n se e a l so s ta te d t h e re w e re i n d i ca ti o n s n e a r th e t o p o f th e t u b e sh e e t th a t w e re id enti f ie d w ith the +P oi ntŽ p robe bu t no t co nfirmed w ith the Ghe nt, 3 C oi l De lta pro be or th e 0.08 0 c oi l. Thes e i ndi cati ons ha d v ol tages o f ap prox ima tel y 0.0 6 v ol ts to 0.0 8 v ol ts.In addit ion to crac k-lik e indications f ound dur ing the inspect ion, a v olume tr ic f law above the cold le g f lo w di stri buti on baff le mea suri ng 42 pe rcen t thro ugh-w al l w as dete cted i n o ne tube.T he indication w as att ribut ed to a loose part. +PointŽ inspections w ere per f orm ed at this e l e v a ti o n for a 2-t u b e b u ff e r su rr o u n d i n g th i s v o l u me tr i c fla w. N o p o ss i b l e l o o se p a rt s w e re identif ied during this inspect ion. Given the location of the indication, v isual i nspec tions could not be performed.
Other v ol umetri c i ndi cati ons w ere obs erv ed in S G 2, how ev er, th ey me asur ed less than 10-perc ent t hrou g h-wall.Insp ecti ons w ere performed on a s ampl e o f bu lges and ov erex pan si on in the tub esh eet regio n (i.e., from the top of the tube she et to 17 i nch es bel ow the top of the se con dary face o f the tube she et). No i ndi cati ons w ere f oun d d uri ng the se in spe cti ons.Ba sed on the i nformatio n p rov id ed, the NR C staff di d n ot i den tify an y tec hni cal i ssu es that w arran ted f ol lo w-up acti on at th is ti me.
Vog tle Electr ic Gener ating Plant, Units 1 & 2 cc: M r. D. E. Gri sse tte, V ic e P resi den t So uthe rn N ucl ear Operati ng Co mpan y , Inc.P.O. B ox 12 95 Bi rmin gham, AL 352 01-1 295 M r. N. J. Stri ngf el lo w M ana ger, Li cen si ng So uthe rn N ucl ear Operati ng Co mpan y , Inc.P.O. B ox 12 95 Bi rmin gham, AL 35 201-129 5M r. T. E. Tyn an, Genera l M ana ger Vo gtle El ectri c Gen erati ng Pl ant So uthe rn N ucl ear Operati ng Co mpan y , Inc.782 1 R iv er R oad W ay nes boro , GA 30 830 M r. Je f f rey T. Gasse r Ex ecu tiv e V ic e P resi den t So uthe rn N ucl ear Operati ng Co mpan y , Inc.P.O. B ox 12 95 Bi rmin gham, AL 352 01-1 295 M r. S tev en M. Ja ckson Senior Eng ineer - Power Supply M unicipal El ect ric Autho rity of Geor g ia 1470 Riv ered g e Park w ay, NW Atl anta , GA 30 328-468 4 M r. R eec e M cAl is ter E x e cu ti v e S e cr e ta ry Georgia P ubl ic S erv ic e C ommis si on 244 W ashing ton St., SW Atl anta , GA 30 334 M r. H arol d R ehe is , D ire ctor De partmen t of Na tural R eso urce s 205 B utl er S treet, SE , S ui te 1 252 Atl anta , GA 30 334 Attorn ey Gen eral Law D epa rtment 132 Ju di ci al B ui ld in g Atl anta , GA 30 334 M r. La uren ce Be rgen Og le thorp e P ow er C orpo rati on 210 0 E ast Ex cha nge P la ce P.O. B ox 13 49 Tucker, GA 300 85-1 349 A rt h u r H. D o mb y , E squ i re Tro u tma n S a n d e rs Na t ion s Ba nk Pla za 600 Peacht ree St reet , NE Su ite 52 00 Atl anta , GA 30 308-221 6 Re si den t Ins pec tor Vo gtle Pl ant 880 5 R iv er R oad W ay nes boro , GA 30 830 Of f ic e o f the C oun ty C ommis si one r Bu rke Co unty C ommis si on W ay nes boro , GA 30 830