ML20197A842
| ML20197A842 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 12/12/1997 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML19317C807 | List: |
| References | |
| NUDOCS 9712230218 | |
| Download: ML20197A842 (13) | |
Text
I 3.1.6 LenkOga-Specification If the total reactor coolant leakage rate exceeds 10 gpm, the 3.1.6.1 l
reactor shall be shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.2 If unidentified reactor coolant 3eakage (exceeding normal evaporative losses) enceeds 1 gpm or if any reactor coolant Icakage is evaluated as unsafe, the reactor shal.1 be shut-down within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.3.a If it is determined that any reactor coolant leakage exists f
through a non-isolable fault in a reactor coolant system strength boundary (such as the reactor vassel, piping, valve i
the reactor shall body, etc., except. steam generator tubes),
be shutdown ano a cooldown to the cold shutdown condition shall be initiated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.3.b If the leakage through the tubes of any one steam generator equals or exceeds 150 gallons per day (0.104 gpm), a reactor l
shutdown shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the reactor shall be in the cold shutdotrn condition within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
I 3.1.6.4 Deleted 3.1.6.5 L: tion to evaluate the safety implication of reactor coolant leakage shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of detection.
The nature, as well as the magnitude of the leak, shall be considered in this evaluation. The safety evaluation shall assure that the exposure of offsite personnel to radiation is within the guidelines of 10CFR20.
3.1.6.6 If reactor shutdown is required per specification 3.1.0.,
3.1.6.2, or 3.1.6.3 the reactor shall not be restarter until the leak is repaired or until the problem is otherwit.e corrected.
S.1.6.7 Whcn the reactor is at power operation, three reactor cool-ant leak detection systems of different operating principles shall be in operation. One of taese systems is sensitive to radioactivity and consists of a radioactive gas detector and an air particulate activity detect.or.
Both of these instru-ments may be out-of-service simultaneously for a period of no more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided two other means are available to detect leakage and reactor building air samples are taken and analyzed in ths laboratory at least once per shifts other-wise, be in at least Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
3.1.6.8 Loss of reactor coolant through reactor coolant pump seals and system valves to.onnecting systems which Amendment No. M,M4,MS,M4,449, 17 9712230218 971212 PDR ADOCK 05000313 P
A tuba insp:etien (pursu:nt to Sp;cificatien 4.18.5.o.9) shc11 bv perforned on each selected tube.
If any selected tubs do:s not perndt the passage of the eddy current probe for a tube inspection, this shall be recorded and an aujacent tube shall be selected and subjected to a tube inspection.
Tubes in the following groups may be excluded from the first 3.
random sample if all tubes in a group in both steam generators are inspected. The inspection may be concentrated on those portions of the tubes whe..
imperfections were pratiously found. No credit will be taken for these tubee in meeting minimum sample size requirements. Where only a portion of the tube is inspected, the remainder of the tube will be subjected to the random inspection.
(1)
Group A-1: Tubes within one, two or three rows of the open inspection lane.
(2)
Group A-2: Unplugged tubes with sleeves installed.
(3)
Group A-3: Tubes in the wedge-shaped group on either side of the lane region (Group A-1) as.
defined by Tigure 4.10.1.
Indications left in service as a result of application of 4.
the upper tubesheet voltage-based repair criteria shall be inspected by bobbin and rotating coil probes during all subsequent refueling outages.
Implementation of the steam generator upper tubesheet voltage-based b.
repair criteria requires a 100% bobbin coil inspe-tion of the upper If a 100% bobbin coil examination of the upper tubesheet tubesheet.
is performed, the results of this examination may be excluded from the first random sample.
The second and third sample inspections during each inservice c.
inspection as required by Table 4.10-2 may be less than a full tube inspection by concentrating the inspection on those areas of the tube sheet array and on those portions of the tubes where tubes with imperfections were previously found.
The results of each sample inspection shall be classified into one of the following three categories:
Inspection Results Category Less than 5% of the total tubes C-1 inspected are degraded tubes and none of the inspected tubes are defective.
One or mote tubes, but not mort C-2 than 1% of the total tubes inspected, are defective, or between 5% and 10% of the total tubes inspected are degraded tubes.
Mare than 10% of the total C-3 tubes inspected are degraded tubes or more than 1% of the inspected tubes are defective.
Amendmen!
, C4, M, M, M6, H4, 110k
tha first samplo insp;etien sp3cificd in Tcblo 4.18-2.
If the degradation mechanism which cs'ased the leak is limited to a specific portion of the tube length, the inspection per this parugt sph may be limited to the af fected portion of the tube length.
If the results of this inspection fall into the C-3 category, all of the tubes in the same group in the other steam generator will also be similarly inspected.)
2.
A seismic occurrence greater than the Operating Basis Earthquake, 3.
A loss-of-coolant accident requiring actuation of the engineered safeguards, or 4.
A main steam line or feedwater line break.
4.10.5 Acceptat.co criteria a.
As used in this specification:
1.
Tubing or Tube means that portion of the tube or sleeve which forna the primary system to secondary system pressure boundary.
2.
Imperfection means an exception to the dimensions, finish or contour of a tube from that required by fabrication drawings or specifications.
Eddy current testing indications below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.
3.
Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either the inside or outside of a tube.
4.
Degraded Tube means a tube containing imperfections s 20% of the nominal wall thickness caused by degradation, except where all degradation has been spanned by the installation of a sleeve.
5.
6 Degradation means the percentage of the tube wall thickness affected or removed by degradation.
6.
Defect means an imperfection of such severity that it exceeds the plugging limit except where the imper fection has been spanned by the installation of a sleeve. A tube containing a defect in its prcssure boundary is defective.
7.
Plugging Limit means the imperfection depth at or beyond which the tube shall be restored to serviceability by the installation of a sleeve or removed from service because it nay become unserviceable prior to the next inspections it is equal to 40% of the nominal tube wall thickness. This definition does not apply to the upper tubesheet volumetric indications for which the voltage-based repair criteria are being applied.
Refer to specification 4.18.5.a.10 for the repair lindt applicable to these indications.
1 Amendment No. G4,41,66,446,144, 110m
i 8.
Unserviceablo describes tho conditien of a tube if it Iceks cr cont: ins o defect 1 ergo cntugh to offect its strusturcl integrity in the event of an operating Basis Earthquake, a loss-of-coolant accident, or a steam line or feedwater line break as specified in specification 4.18.4.c.
i 9.
Tube Inspection means an inspection of the steam generator tube from the point of entry completely to the point of exit.
- 10. Tubesheet Limit is used for the disposition of an alloy 600 ot3G tube for continued service that is experiencing predominately volumetric CDIGA located from 2.75 inches from the secondary face of the upper tubesheet to but not including the roll transition. The plugging limit within l
this portion of the tubesheet is based on maintaining steam r
generator tube serviceability as described belows a.
steam generator tubes, whose degradation is attributed to volumetric ODIGA within the upper tubesheet with a bobbin voltage s 1.18 volts, minus an allowance for growt.h over the next operating cycle, will be allowed to stay in service. Tubes with indications that exceed this i
limit will be repaired or plugged.
b.
The determination that an indication is volumetric ODIGA will be based on rotating coil examination.
If the indication can be characterized as crack-like (either as axial or circumferential) the steam genarator tube shall be repaired or plugged, b.
The steam generator shall be determined operable after completing the corresponding actions (plug or sleeve all_ tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.18-2.
l l
Amendment No. M,M, M,4M,H4,449, 110ml t
--o
4.18.6 Reports rollowing each inservice inspection nf steam generator tubes, the complete results of the inspection shall be reported to the NRC.
This report, to be submitted within 45 days of inspection completion, shall includes a.
Number and extent of tubes inspecteds b.
Location and percent of wall-thickness penetration for each indication of an imperfections and c.
Identification of tubes plugged and tubes sleeved.
This report shall be in addition to a Special Report (per Specification 6.12.5.d) required for the results of steam generator tube inspections which fall into Category C-3 as denoted in Table 4.18-2.
The Commission shall be notified of the results of steam generator tube inspections which fall into Category C-3 prior to resumption of plant operation. The written Special Report shall provide a description of investigations conducted to deterndne cause of the tube degradhtion and corrective measures taken to prevent recurrence.
For implementation of the upper tubesheet voltage-based repair criteria, notify the Commission prior to returning the steam generator to service if any of the following conditions arises Leakage through an upper tubesheet volumetric ODIGA indication a.
is detected during in-situ leak testing, or b.
Upper tubesheet indications previously left in service, on average, show signs of growth beyond that seen in the previous cycle, based on the results of the bobbin voltage data analysis from the current and previous inspections.
Bases The surveillance requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained. The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.63, Revision 1.
Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event th at there is evidence of mechanical damage or progressive dogradation due to design, manufacturing errors, or inservice conditions that lead to corrosion.
Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.
The voltage-based repair limit of SR 4.18 implements the criteria derived from BAW-10226P,
- Alternate Repair Criteria for Volumetric outer Diameter Intergranular Attack in the Tubesheets of once Through Steam Generators."
The voltage-based repair limits are not applicable to other forms of once through steam generator (OTSG) tube degradation nor are they applicable to outer diameter intergranular attack (ODIGA) that occurs at other locations within the OTSGs. Additionally, the repair criteria apply only to indications where the degradation mechanism is dominantly volumetric.
Upper tubesheet indications, for the purpose of this specification, are defined as indications within the upper tubesheet located 2.75 inches from the secondary face to but not including the roll transition.
Amendment No. 44,44, 46, M6, Me, Me, 110n
bad-20226P cvaluated tho p:tcntici for tube burst cnd cccident infuced l
1eakage as a result of applying the voltag3-b: sed rcpair critoric to i
volumetric ODIGA within the tubasheet.
Because of the c?n9traint of rf t t
~
f, OT5G tube radial displacement within the tubesheet, burst pres 4 o einv that of an unflawed tube is precluded.
To assure acceptable accident int,ced leakage, worst case s 4.eeA accident loads were applied to 29 samples with volumetric a 347. Vet t bobbin indications ranging from 0.04 to 1.62 volts.
Nona et *WS u flaws showed signs of leakage as a result of these loads. Ma additional four laboratory specimens created by electrodisch4473 machining were also testing. None of these additional samples leaked under worst case combined accident loads.
Therefore, it was concluded that volumetric CDIGA flaws with eddy current indication up to 1.62 volts will not leak under accident conditions, and that this is an acceptable threshold value to use to assume zero accident leakage.
The voltage threshold value must be adjusted, as appropriate, to account for eddy current measurement uncertainties associated with the chosen eddy current technique.
In addition, an appropriats allowance must be nade for growth of the indications in order to ensure that the indication amplitude does not exceed the threshold value prior to the next planned inspection. This adjustment can be expressed by the followit; equations Vn = V,..n.is - Vuor - Vorowth 3
where Vu = Repair limit (volta)
Vne..n.te = Threshold voltage (1.62 volts)
Eddy current measurement uncertainty Vung
=
Growth over one fuel cycle (volts)
Va,.46
=
The eddy current uncertainty is discussed in BAW-10226P and is equal to 0.44 volts.
By performing eddy current inspections consistent with the guidance found in Appendix A to RAW-10226P this uncertainty value will be bounding for ANO-1.
Therefore the AHO-1 repair limit ist Vn = 1.62 - 0.44 volta - Va, 4n Vu = 1.18 volta - Va,,wtn trom growth rate studies performed on ANO-1 eddy current data collected from 1993 through 1996 the upper tubesheet volumetric ODIGA indic.stions have shown an average growth rate of zero volts. To account for potential growth in the future, growth rate studies will be conducted each outage.
The growth rate studies will compare the eddy current bobbin voltage values for the same indications from the previous inspection to that of the current inspection.
Both the average growth and the 95% upper tolerance values will be calculated.
For conservatism the 95% upper tolerance growth rate limit will be used in the establishment of the voltage-based repair limit.
To further enhance the leakage data base and to demonstrate the conservatism of the voltage-based repair limit, four of the larger accessible tubesheet volumetric ODIGA indications with a bobbin voltage measurement of > 1.0 volts will be in-situ leak tested each outage the voltage-based repair criteria is applied.
Amendment No.
110n1
W '+
i MARKUP OF CURRENT ANO-1 TECliNICAL SPECIFICATIONS (FOR INFO ONLY)
3.1.6 Le ktg3 Specification 3.1.6.1 If the total reactor coolant leakage rate exceeds 10 gpm, the reactor shall be shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.2 If unidentified reactor coolant leakage (exceeding normal evaporative losses) exceeds 1 gpm or if any reactor coolant leakage is evaluated as unsafe, the reactor shall be shut-down within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.3.a If it is determined that any reactor coolant leakage exists through a non-isolable fault in a reactor coolant system strength boundary (such as the reactor vessel, piping, valve body, etc., except steam generator tubes), the reactor shall be shutdown and a cooldown to the cold shutdown condition shall be initiated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
3.1.6.3.b If the leakage through the tubes of any one steam generator l
equals or exceeds ligbre gallons per day (0 1A1447 gpm)*,
a reactor shutdown shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the reactor shall be in the cold shutdown condition within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
^ Thie-limit-4 a: h::n ::6 :d-to-444-ge11+ne-per-day (0.1 p F
--4e:- th: emainder-ef-eyele-44, 3.1.6.4 Deleted 3.1.6.5 Action to evaluate the safety implication of reactor coolant leakage shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of detection.
The nature, as well as the magnitude of the leak, shall be considered in this evaluation.
The safety evaluation shall assure that the exposure of offsite personnel to radiation is within the guidelines of 10CTR20.
3.1.6.6 If reactor shutdown is required per Specification 3.1.6.1, 3.1.6.2, or 3.1.6.3 the reactor shall not be restarted until the leak is repaired or until the problem is otherwise corrected.
3.1.6.7 When the reactor is at power operation, three reactor cool-ant leak detection systems of different operating principles shall be in operation. One of these systems is sensitive to radioactivity and consists of a radioactive gas detector and an air particulate activity detector.
Both of these instru-ments may be out-of-service simultaneously for a period of no more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided two other means are available to detect leakage and reactor building air samples are taken and analyzed in the laboratory at least once per shifts other-wise, be in at least Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
3.1.6.0 Loss of reactor coolant through reactor coolant pump seals and system valves to connecting systens which Amendment No. M,444,H4,M 4,449,
l A tube it:pe:tica (pursu:nt to Sp Sific tirn 4.18.5.c.9) sh:11 b) performed on each selected tube.
If any sele:ted tube do:s_n:t permit the passage of the eddy current proba for a tube inspection, this shall be recorded and an adjacent tube shall be selected and subjected to a tube inspection.
3.
Tubes in the following groups may be excluded from the first random sanple if all tubes in a group in both steam generators are inspected. The inspection may be concentrated on those portions of the tubes where imperfections were previously found.
No credit will be taken for these tubes in meeting minimum sample size requirements. Where only a portion of the tube is inspected, the remainder of the tube will be subjected to the random inspection.
(1) Group A-1: Tubes within one, two or three rows of the open inspection lane.
(2)
Group A-2: Unplugged tubes with sleeves installed.
(3)
Group A-3: Tubes in the wedge-shaped group on either side of the lane region (Group A-1) as defined by Figute 4.18.1.
4.
Indications le_ft in service as_a regult of neglicat!on of illt ilRRer__tubigh3yt voltsal;;hgjed repair criteria shaRg3 inpoected bv_bobbyn__and rotatina coil propig,,,gurina_ ell ggbseauent refueltna outaaesi kA 1[gpigmentation of the steartagpgggigt,ypp3Lluhrsheet volj;aae-bsa_e_d ggp11r cri te rigle,qq1ren a 100% bobbin coi:, inspigtion of the _urpag igb M get.
If a_100% bobbin coil examAnat:,on of the upper tubesheet LP P3I1Rupsd, _the regults-of this examinat:<on may be exc' uded f rom lhg !11st raMRIL,gp2piga gb.
The second and third sample inspections during each inservice inspection as required by Table 4.18-2 may be less than a full tube inspection by concentrating the inspection on those areas of the tube sheet array and on those portions of the tubes where tubes with imperfections were previously found.
The results of each sample inspection shall be classified into one of the following three categories:
Cateaory Inspection Results C-1 Less than 5% of the total tubes inspected are degraded tubes and none of the inspected tubes are defective.
C-2 One or more tubes, but not more than 1% of the total tubes inspected, are defective, or between 5% and 10% of the t>tal tubes inspected are degraded tubes.
j C-3 More than 10% of ths total tubes inspected are degraded tubes or more than 1% of the inspected cubes are defective.
I l
Amendment No. 34,44,46,446,444.
110k l
1
tho first samplo inspetticn cpecified in T blo 4.18-2.
If the degradation mechanism which caused tha 1cOk 10 limited to a specific portion of the tube length, the inspection per this paragraph may be limited to the affected portion of the i
tube length.
If the results of this inspection fall into the C-3 category, all of the tubes in the same group in the other steam generator will also be similarly inspected.)
2.
A seismic occurrence g.-eater than the operating Basis Earthquake, 3.
A loss-of-coolant accident requiring actuation of the engineered safeguards, or 4.
A main steam line or feedwater line break.
4.18.5 Acceptance criteria a.
As used in this specification 1.
Tubing or Tube means that portion of the tube or sleeve which forms the primary system to secondary system pressure boundary.
2.
Imperfection neans an exception to the dimensions, finish or contour of a tube from that required by fabrication drawings or specifications.
Eddy current testing indications below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.
3.
Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either the inside or outside of a tube.
4.
Degraded Tube means a tube containing imperfections s 20% of the nominal wall thickness caused by degradation, except where all degradation has been spanned by the installation of a sleeve.
5.
% Degradation means the percentage of the tube wall thickness affected or removed by degradation.
6.
Defect means an imperfection of such severity that it exceeds the plugging limit except where the imperfection has been spanned by the installation of a sleeve. A tube containing a defect in its pressure boundary is detective.
7.
Plugging Limit means the imperfection depth at or beyond which the tube shall be restored to serviceability by the installation of a sleeve or removed from service because it may become unserviceable prior to the next inspections it is equal to 40% of the nominal tube wall thickness._ Thig peMD,[1,lSn_ dom _nqLayfly to the_upp3r tukepheet volugg dg
$.. ag2D839I Wl.11Sh. the voltage-hapid_tgpair crjm DalDg_MPiled.
ReLetto spe g a_ tion 4.10.b a.10 for t(g repair limit _gyplicable to these indications.
Amendment No. G4,41,46,446,144, 110m
8.
Unservie?able de: crib:s tha c:nditicn of c tube if it 100k3 i
or contains a defect 1crg3 cc ugh to cffccc ito ctructurcl 1
a i
integrity in the event of an Operating Basis Earthquake, loss-of-coolant accideat, or a steam line or feedwater line i
break as specified in Specification 4.18.4.c.
9.
Tube Inspection means an inspection of the steam generator tube f rom the point of entry completely to the point of exit.
1L _.Tubisheet Limit is used for the discotition of an allov 600 OTSG tube for continggd service that is egpegigging pJedominpitly volumetric Op,1CA located f rom 2.75 inhet from the secondtuv face of the_vpper tubesheet. to but nel licludina tiie ro;.1 transition. T1e cluaaina
,imit watnin t ais portion __of the tubybiet is Dased__on ma10tainina sagg 21D1ptor tube serviceabilitvas descyibed belows a s...Sttaa.gggytor tukts. whose degggc,jglion is attributed
$2My[netric ODIGA._ within the upptt t.Mhtshett wild bobbin voltage s 1.18 volts. minus an allowance for crowth py,3g Jd}3_DEKl_9Pfl111pc cycle. will be allowed to stav in_ serv 11e.
Tubes with indications that exceed this 1.11 nit w[11 be repaired or olugggdA p,,.
The_detegnination that an indiration is vo1Mmetric ODIGA will be based on rotatina coil examination.
If the gdication.can be characterized as crack-like (either as AK11.1 or circumferential) the steam cenerator tube shall ki_I.fraired or_pluag,eA b.
The steam generator shall be determined operable after completing the corresponding actions (plug or sleeve all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.18-2 -*4+h th: fel4 ewing-ene:ption:
2 Tubee-with-4ntergeomel*e-etteek-indlee44ene-within th upper tuh:
eh::t with-+he-petent4*4-ef-theeu;h x:11 d:pthe-ge::ter then--the ylgging-14ml t = y ::=in-4n-eeevi+e-fer - t he cemelad:: ;f cy:sle-14,.
f l
Amendment No. 24,4+,66,444,444,444, 110ml
4.18.6
- Reports, j
ro11owing each inservice inspection of steam generator tubes, the complete results of the inspection shall be teported to the NRC.
This report, to be submitted within 45 days of inspection completion, shall include I
a.
Number and extent of tubes inspected; b.
Location and percent of wall-thickness penetration for each indication of an imperfections and c.
Identification of tubes plugged and tubes sleeved.
This report shall be in addition to a special Report (per Specification 6.12.5.d) required for the results of steam generator tube inspections which fall into category C-3 as denoted in Table 4.18-2.
The connission shall be notified of the results of steam generator tube inspections which fall into Category C-3 prior to resumption of plant operation.
The written Special Report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence, for implementation of the upper tubesheet voltaae-based repair criteria.
B2111YMSAUlt l1}on orior _to returningabe steam _uenerator to servigg,,11 ggy_of the.followina conditions arise t Leakaae through an uoper tubesheet volumetric ODIGA indication a.
is detected _durina in-situ Itak testigg ggI Upper tubenheet indis411ons oreylau.siv lef t in service, on b.
aveg,assu h9w sigaf&towth beyond thAt seen in the prevap,yg s
evele. based on the results of the bobbin voltaae data anahvsis f rom the curre.nt and orevious ingpectiong2 Bases The surveillance requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained. The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1.
Inservice inspection of steam generator tubing is essential in order to naintain surveillance of the conditions of the tubes in the event that there is evidence of nachanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that lead to corrosion.
Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.
The voltaas-hash!1diptit of SR 4.18 itqplements the criteria derived from BAW-10226P. " Alternate Repair Criteria for Volumetric Octer Diameter JJ11, fdggnu1 r Attack in ti g,,,,,I,y),gsheets of Once Throuch Steam Generators."
A l
Ihe voltaae-b3.3.tdatpALLJlmits are not applicable to other forms of once through steem_aeggrator (OJ1G) tube degy3a.daj;1on_nor_ ate._1hev applisakte_t2 a
oyter dQ331gr interganular_aqa,c_k (ODIGA) that occurs _at other_Loppf,1,ong o
within the OTSGs. Additionally, the repair criteria ao,piv only to Andications where the_dentadelion mechanism is domLns_nt.ly volumetrig2 Mpper tubenheet :.ndicationc. for the ourogge.of this snteifg elion, are defined as indira.tions_within the uppgI 1@gg}Ltit._J2 gated 2.75 inches f rom the secondarv face to but not uncludino the roll transitiont Amendmen'. No. 44,44,86,446,444,174, 110n
PM -1022fP evaluated the potenti,31 for tube burst and accident induced lith. age _al,A_usult of applylga_the__ voltage-hased repai r criteria _tn volumatrac ODIGA within_the tuk_t, sheet.
Bgigge of the_ggnetraint of the gIso_ tube radial disple_c3 pent within_the _tubtsbetteburst_prennutes below that of an unflawed tube is precaugge, To eaaure acespigble acciltnt _i114911dilige. wo;ALERai,Spahj,Did accident loads were applietto 29Jfgg6t#_with volumetric Op19A with hfbbinindj,Sp&ons rggg[Do f tpfn 0.04 to lai2 volth,None of thes_t i aws showed s:,gns of ItakagLgLa result of theep Ioads.__An Add 131SMA 19E.Akb.21A19JLJP3SAMAL.SA1911d kY intS11SA11EhiL21 gghiglgg_were also t9 sling.
H ong,pLth e a t>JAllignal_g.aryl e s l e aked WA42,s w.2rst esse co,rgblagd _ accidig1,,1 gads.
Thertiggg it_was conglyggd 1,ga,Lypl,ymfiric ORIGA flaws with mddv_ currer t :,ndicglion up to 1.62 volta will rion feak under accident cond:,tions, arc that this is en acceptablg threshohd value to use t2 A17BIR ggio acci_sent le.akggf,a, The voltaae threshold value must be adiusted. as appl,ppriate, t2 account 12r eddy current measurement ungictainties assoc:,ated with the chosen SMdL.SMEI1nt tech 124e- _ In adgg. an appgppnggllp_wance must be D
ude f or_ growth of the_11gigp1(gnt_11Lorder to ensure th.at the irigqallga appl 11gde dorp _not eyceecl the thrpho1Lyf1MS. prior to the next plannfj 1_nspection. This adiustment can_ be expressed by the f%19wiria eaga_11ont Vn = h..sm-h -Emu Y.h1I.A Vn = Rep,gir limit (volt 11 b..e = Threshold volt ARe- (1.62.. volts) h = Eddy current meangrement uncertainty V w = Growth over one fusL,gysle (volts)
Ihe eddy _q9tttnt_.MnstLtainty_la_41scussed in_pw.-19226E__agd it fauJ1.12 0.44 volts.
By_ performing _e_ddy_gug.Lgggj ngpActions co,ngle_ tent with the ggianc.t_J,ound in _ App 3ndix A to BAW-10226P this uncertaintv__value will be bounctino for ANO-1.
ThtInfore the ANO-1. rep 31r_11glL ig,l, W = 1. 62 - 0. 4 4 volts - E ~u W = 1.18 volt s - Em.s ZISE, gIpyth rate studjga,p3rformed_on_ANP-1_iddy current _ dain_sgliegrad irom 1993 thtoggh 1996 the uppy,,1uAep,hget volumttric ODIQLindicationa have shown an R%21gge atowth rate of_Ifro volts. To account for potential growth in the future, crowth rate sti.idies wil? be conducted each outaaeg The crowth rate studits_will comgare the_ eddy current bnkbin voltage ymlues f or the same indications f rom the_ previous inspecti.on to that of iht,ggIIgnt :,nspection.
Both th,e__ average _ growth agg _the. 95%__uppgg, tolerance values will be gg},gglpled.
For conservatism the 95% ypp3,g 1Eatance arowth rate __ limit _wi Q be_used in the establishment of thg yR11.ege-based _rgy,gir limit 1 To further_enhBDee the leahigsdalg,,,,Ags.And to demonstrate the SSA!!1LYAtism of the voltage-base <LIf2 air limit. four o,f the larger ASSigalk11,1HkifAtal,,yslp331 gig,,0 DIM _indint190s with a _bokbin voltagt geAMrement_pf > 1.0 voJJa_will_ke 1n-sitq_letk_trated each outage _the Y211A g t-h
- 8 t4_ter gir_c r11m rJf_1g_applis43.
Amendment No. 44,4,66,M6,Me,Me, 110n i
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