ML19319A679
| ML19319A679 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/01/1976 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19319A675 | List: |
| References | |
| NUDOCS 7911210625 | |
| Download: ML19319A679 (8) | |
Text
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REACTCR CCOLM ahei
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- STEAM GENERATCRS I.DfITING CCNDITION FOR CPERATICN 3.4.5.1 Primary-to-secondary leakage thrcugh the steam generator : tes shall be 14,4:ed to 1 Gal ctal for all steam generators.
'3.4.5.2 Each stesa generator shall be CFERABLE with a water level between
.( ) and ( ) inches.
IAPPLICABILITY: MODES 1, 2, 3 and 4.
ACTICN_:
With any steam generator tube leakage greater than the above a.
limit reduce the leakage rate within four hours or be in col <f shutdown within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
b.
With one or more steam generators inoperable due to steam generatcr tube imperfections, restore the inoperable genera :or(s) to CPERASLE status prior to increasing T above 200 4.
avg c.
With one or acre steam generators incperable due to the water level being cutside the limits, be in at least HOT STANCBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in CCLD SHUTDOWN within the nex 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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SURVEILLANCE RECUIREMENTS I
y.4.5.0 Each steam generator shall be demonstrated CPERABLE by perfomance
- of the follcwing augmenta inservice inspection prygram and the requirements
! of Specification 4.0.5.
- l4.4.5.1..
Steam Generator Samole Selection and Inscection - Each stean generator snail ce cetaminec CPERABLE curing snutccwn oy selecting and
- insoecting at least the minimum number of steam generators specified "n Table
,t-1.
l4.4.5.2Steam Generator Tube Samole Selection and Insoection - The steam
' enerator tuce minimum sampie si:s, inspection result classificaticn, nd the corresponding action required shall be as specified in Table 4.4-2.
jhe inservice inspection of steam generator tubes shall be per#crmed at the
, frequencies specified in 'Specificatien 4.4.5.3 and the inspected tubes shall be verified acceptable per the acceptance criteria of Specifica:icn 1.4.5.4 jThe tuces selected for each inservice inscecticn shall include at least 3:
of the te.al number of tubes in all steam generators; the tubes selected '
for these inspections shall be selected on a randem basis except:
a.
-Where excerience in similar plants with similar water chemistry indicates critical areas to be inspected, then at least 5C% of the tubes inspected shall be frcm these critical areas.
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.S&W-STS 3/4 4-6 June 1, 1976 7911210$ M
REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)_
b.
The first inservice inspection (subsequent to the preservice inspection) of each steam generator shall include:
1.
All nonplugged tubes that preyfously had detectable wall penetrations (p20%), and 2
Tabes in those areas where experience has indicated poten-ttal problems.
c.
The second and third inservice inspecticts may be less than a full tube inspection by concentrating (selecting at least 50%
of the tubes to be inspectedl 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:
Category 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 total tubes inspected are degraded tubes.
CJ More than 10% of the total tubes inspected are degraded tubes or more than 1% of tite inspected tubes are defective.
Note:
In all inspections, greviously degraded tubes must exfitttt significant.L>10%). further wall penetrations to be included tn the above percentage calculations.
4,4,5,3 Inscection Frecuencies - The aboye required inserYice itspections of steam generator tuces snall be perfornd at the following frequencies:
a, Tfte first inserYice inspection shall be performed after 6 Effective Full Power Months but within 24 calendar months of tuitial critica1 tty.
Subsequent inservice inspections shall be B&W-STS 3/4 4-7 June 1. IS76 He
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REACTOR C00LAtiT SYSTEM SURVEILLAtlCE REQUIREME?iTS (Continued) performed at intervals of not less than 12 nor more than 24 calendar months after the previous inspection.
If two consecu-tive inspections following service under AVT conditions, not including the preservice inspection, result in all inspection results falling into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional degradation has occurred, the inspection interval may be extended to a maximum of once per 40 months, b.
If the inservice inspection of a steam generat:r conducted n accordance with Table 4.4-2 requires a third sample inspection whose results fall in Category C-3, the inspection frequency shall be reduced to at least once per 20 months.
The reduction in inspection frequency shall apply until a subsequent inspection demonstrates that a third sample insrsection is not required.
c.
Additional, unscheduled inservice i.saections shall be performed on each steam generator in accordance with the first sample inspection specified in Table 4.4-2 during the shutdown subsequent to any of the following conditions.
1.
Primary-to-secondary tubes leaks (not including leaks originating frem tube-to tube sheet welds) in excess of the limits of Specification 3.4.5.1, 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.
4.4.5.4 Acceptance Criteria a.
As used in this Specification:
1.
Imoerfection means an exception to the dimensions, finish or contour of a tuce frcm that required by fabrication drawings or specifications. Eddy-corrent testing indications Below 20% of the ncminal tube wait thickness, if detac:able, may 5'e considered as imperfections.
B&W-STS 3/4 4-8 Jene 1, lE76
REACTOR COOLANT SYSTEM SURVEILLANCE REOUIREMENTS (Continued) 2.
Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a tube.
3.
Degraded Tube means a tube containing imperfections >20%
of tne nominal wall thickness caused by degradation.
4.
% Degradation means the percentage of the tube wall thicxness affected or removed by degradation.
5.
Defect means an imperfection of such severity that it exceeds the plugging limit. A tube containing a defect is defective. Any tube which does not permit the passage of the eddy-current inspection probe shall be deemed a defective tube.
6.
plugging Limit means the imperfection depth at or beyond wnien tne tuce shall be removed frcm re vice because it may become unserviceable prior to the next inspection and is equal to 40% of the ncminal tube wall thickness.
7.
Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its structural 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 4.4.5.3.c, above.
8.
Tube Inscection means an inspection of the steam generator tuce from tne point of entry completely to the point of exit.
b.
The steam generator shall be determined OPERABLE after completing the corresponding actions (plug all tubes exceeding the plugging limit and all tubes containing through-wall cracks) required by Table 4.4-2 4.4.5.5 Recorts a.
Following each inservice inspection of steam generator tuces, the number of tubes plugged in each steam generator shall be reported to the Commission within 15 days.
b.
The complete results of the steam generator cube inservice inspection shall be included in the Annual Operating Report for the pericd in which this inspection was cenpleted. This report shall include 3&W-ST3 3/4 4-9 June 1, 1975
REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 1.
Number and extent of tubes inspected.
2.
Location and percent of wall-thickness penetration for each indication of an imperfection.
3.
Identification of tubes plugged.
c.
Results of steam generator tube inspections which fall into Category C-3 and require prompt notificaticn of the Ccamission shall be reported pursuant to Specification 6.9.1 prior to resumption of plant operation. The written followup of this report shall provide a description of investigations conducted to determine cause of the tube degradation and corrective measures taken to prevent recurrence.
4.4.5.6 The steam generator shall be demonstrated OPERABLE by verifying steam generator level to be within limits at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
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B&W-STS 3/4 4-10 June 1, 1976
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tn TABLE 4.4-1 MINIMUM NUMilER OF STEAM GENERATORS TO BE INSPECTED DUlllNG INSEHVICE INSPECTION j,
Pseservice Inspection No Yes No. of Steam Generators per Unit Two Itwee Four Two liwee Four us 4
First inservice Ingnection All One Two Two y
a Secoms & Subsequent inservice inspections Oc '
OneI One One 2
3 Table Notation:
- 1. The isiservice irispection may be limited to one steam generator on a sotating scheduto encornpassing 3 N % of the tubes (where N is the number of steam generators (si the plant) if the sesults of the fisst or swevious inspections inihcate that all steasii gesieratoss aso pesforening isi a hke masmer. Note that usuler some circumstances. the operating corwhisons in one os mose steasn gerieratoss may be fousui to lee more severe staan those in other stearn generators. Usules sucts ciscurn-stesues ilus sassiple Sevissente stiall be snoilified to insgiect stic suost severe cosidstioris.
2.
The other steam generator sion insgiected during the first iriservice inspictiuri staall be isispected. Ti.e third asul suliscinuesit g
mspections stuiuid follow the isutsuctions described in I above.
n
- 3. Ea.h of the other two steaan generatoes not ingiected dusing the lust inseswice inspectiec < hall be inspected duaisuj the secosul.sud thiad inspections. T he tousth and subsequent isupections shall follow the us.uctums descsibed m I shove.
N Os
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'l Ey T ABLE 4.4-2 "i.
v STEAM GENEHATOR TIMIE INSPECTION IST SAMPLE INSPECTION 2ND SAMPL E INSPEC110N 3RD SAMPLE INSPECTION d
Saniple Size Hesult Action Required Hesult Action Hutuised Hesult Action Heguised A sninimum of C-1 None N/A N/A N/A N/A S Tulses per S. G.
1-C-2 Plug defective tulaes C-1 None N/A N/A 4
88'8 I'ig>ect adstational Plug defective sulses C-1 None 2S tubes in this S. G.
C-2 and ingiect additional C-2 Plug defective tules 4S suites in this S. G.
Peeform action for C-3 C-3 result of fisse sample Pesfoten action for C-3 C-3 result of first N/A N/A sarnple R
C-3 Impact all tubes in All other sinis S. G., plug de-S. G.s are None N/A N/A 4
fective tubes and C-1 inspect 2S tubes in go"'8 3 g 5 each other S. G.
Pesforni action for N/A N/A to C-2 but sio C-2 result of second additional w,pi, Prornpt notification S. G. are to NHC pursuant C-3 to specification Additional inspect all tubes in 6 9.1 S. G. is C-3 cach S. G. and plug defective tut.es.
I'sornpt su,tshcation N/A N/A to NilC pussuant to specification 6.9.1 n
89 N
g,3 Where H is the riurnhet of steasu generatoes ist the uriit, asul si is the number of stea<n generators inspected a
a dusing an ingnection a
a.
REACTOR COOLANT SYSTEM BASES 3/4.4.4 PRESSURIZER A steam )ubble in the pressurizer ensures that the RCS is not a hydraulically solid system and is capable of acccmodating pressure surges during operation. The steam bubble also protects the pressurizer code safety valves and power operated relief valves against water relief.
The low level limit is based on providing enough water volume to prevent a pressurizer icw level or a reactor coolant system low cressure condition that would actur.te the Reactor protection System or the Engineered Safety Feature Actuation System as a result of a reactor scram. The high level limit is based on providing enough steam volume to prevent a pressurizer high level as a result of any transient.
The power operated relief valves and steam bubble function to relieve RCS pressure during all design transients. Operation of the power operated relief valves minimizes the undesirable opening of the spring-loaded pressurizer code safety valves.
3/4.4.5 STEAM GENERATORS 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 pengram for inservice inspection of steam generator tubes is based on a modificition of Regulatory Guide 1.83, Revision 1.
Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event that there is evidence of mechanical 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 degracation so that corrective measures can be taken.
The plant is expected to be operated in a manner such that the secondary coolant will be maintained within those chemistry limits found to result in segligible corrosion of the steam generator tubes.
If the secondary coolant chemistry is not maintained within these chemistry limits, localized corrosion may likely result in stress corrosion cracking.
The extent of cracking during plant operation would be limited by the limita: ion of steam generator tube leakage between the primary coolant system and the secondery coolant system (primary-to-secondary leakage = 1 GpM).
Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads S&W-STS B 3/4 4-2 June 1,1975
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s REACTOR COOLANT SYSTEM BASES imposed during nonnal operation and by postulated accidents.
Operating plants have demonstrated that primary-to-secondary leakage of 1 GPM can be detected by monitoring the secondary coolant. Leakage in excess of this limit will require plant shutdcwn and an unscheduled inspection, during which the leaking tubes will be located and plugged.
Wastage-type defects are unlikely with proper chemistry the treatment of the secondary coolant. However, even if a defect should develop in service, it will be found during scheduled inservice s?,aam generator tube examina tions.
Plugging will be required for 40% of the tube nominal wall thickness. Steam generator tube inspections of operatir; plants have demonstrated the capability to reliably detect degradat.icn that has penetrated 20% of the original tube wall thickness.
Whenever the results of any steam generator tubing insarvice inspec-tion fall into Category C-3, these results will be prcmptly reported to the Connission pursuant to Specification 6.9.1 prior to resumption of plant operation.
Such cases will be considered by the Commissien on a case-by-case basis and may result in a requirement for analysis, labora-tory examinations, tests, additional edd-current inspection, and re-vision of the Technical Specifications, if necessary.
The steam generator water level limits are consistent with the initial assumptions in the FSAR.
34W-STS 3 3f4 4-3 June 1, 1975
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