Information Notice 1997-88, Experiences During Recent Steam Generator Inspections

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Experiences During Recent Steam Generator Inspections
ML031050020
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant  Entergy icon.png
Issue date: 12/16/1997
From: Roe J
Office of Nuclear Reactor Regulation
To:
References
IN-97-088, NUDOCS 9712120012
Download: ML031050020 (11)


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 December 16, 1997 NRC INFORMATION NOTICE 97-88: EXPERIENCES DURING RECENT STEAM

GENERATOR INSPECTIONS

Addressees

All holders of operating licenses for pressurized-water reactors (PWRs) except those who have

permanently ceased operations and have certified that fuel has been permanently removed

from the reactor.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform

addressees about findings from recent inspections of steam generator tubes and secondary- side internal components. It is expected that recipients will review the information for

applicability to their facilities and consider actions, as appropriate, to avoid similar problems.

However, suggestions contained in this information notice are not NRC requirements; therefore, no specific action or written response is required.

Description of Circumstances

Recent inspections of steam generator tubes and secondary-side internal components have

identified a number of concerns related to the degradation of these components. The relevant

findings associated with these concerns are discussed below.

Degradation of Secondary-Side Internal Components

In May 1997, the licensee for the Shearon Harris Nuclear Power Plant found that four

perforated, carbon steel ribs in a steam generator had been extensively damaged. The ribs are

welded to the feedwater impingement plate which shields the steam generator tubes from direct

impact of the feedwater flow. The licensee concluded that the high flow velocities of the

feedwater had eroded the ligaments between the perforations on the ribs.

During the spring 1997 refueling outage, Southern California Edison Company, the licensee for

the San Onofre Nuclear Generating Station, Unit 3 (SONGS-3), discovered degradation of the

steam generator tube eggcrate supports. The damage was confined to the periphery of the

supports. The damage existed in both steam generators on both the hot-leg and cold-leg sides

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_~ 7-88 ecember 16,1997 but was more extensive on the hot-leg side. The licensee concluded that excessive deposits on

the steam generator tubes and supports were responsible for changes in flow velocities and

water chemistry on the secondary side of the steam generator. The erosion/corrosion damage

mechanism resulting from these changes subsequently damaged the eggcrate supports. The

deposits were removed by chemical cleaning during the outage. With nominal secondary-side

properties restored, further erosion/corrosion is not expected because of better control of

secondary-side chemistry conditions.

Eddy current inspection of steam generator tubes gathers limited information on secondary-side

conditions that could challenge the structural and leakage integrity of tubes. The erosion of

secondary-side steam generator components could potentially lead to loose parts. In addition, erosion of the eggcrate supports as observed at SONGS-3 could reduce the lateral restraint of

the tubes and could increase the potential for flow-induced vibration of the tubes. Because of

these experiences, other utilities have visually inspected the secondary side of steam

generators to assess the Integrity of internal components. Such inspections could promote

early detection and mitigation of secondary-side component degradation.

Deficiencies In Inservice Inspections

Qualification of Eddy Current Depth Sizing Techniques

Attempts to qualify eddy current techniques for estimating the depth of intergranular attack

(IGA) and stress-corrosion cracking (SCC) in steam generator tubes have had limited success.

Entergy, the licensee for Arkansas Nuclear One, Unit 1 (ANO-1), developed a technique to

estimate the depth of volumetric IGA In once-through steam generator (OTSG) tubes. The

technique was qualified using data primarily from Crystal River Nuclear Plant, Unit 3 (CR-3)

tube specimens and supplemented with data from ANO-1 tube specimens. The licensee

applied the technique to IGA indications in the upper tubesheet crevice. Destructive

examination of several tubes revealed that the technique underestimated the depth of the

indications by as much as 50 percent of through-wall depth. The tube specimen data obtained

from CR-3 contained Indications from the lower regions of the tube bundle above the lower

tubesheet. The environment in that region differs considerably from the environment In the

upper tubesheet crevice. Because of the differences in the environments in which the IGA

degradation developed and the licensee's reliance on data obtained from CR-3, the resulting

sizing technique developed in the qualification process yielded nonconservative depth

estimates when applied to the degradation In the ANO-1 OTSGs.

Entergy's experience illustrates some of the potential difficulties in qualifying and applying eddy

current depth-sizing techniques. Because eddy current Inspection methods are sensitive to a

number of variables, the qualification process should consider all of these variables. Although

Entergy assumed that the IGA indications from ANO-1 and CR-3 were of similar morphology, other factors, such as the conductivity of the degradation, were not considered in the

development of the sizing technique. Also, because the tube specimens were obtained over a

period of many years, it may have been appropriate to address changes In the degradation that

may have occurred over time. Validation of developed depth-sizing techniques through sizing

and subsequent destructive examination could address each of these factors.

~~\,...i9748

-Zcember 16, 1997 Inaccuracies in the Location of Indications

In June 1997, Duke Power shut down William B. McGuire Nuclear Station, Unit 2, because of

an increasing primary-to-secondary leak. A steam generator tube was leaking approximately

13.2 cm [5.2 inches] above the second cold-leg tube support plate. During the preceding

refueling outage, the general bobbin coil probe Inspection Identified an Indication in this same

area. At that time, in accordance with procedure, the licensee inspected the area with a

rotating pancake coil (RPC) probe from 12.7 cm [5 Inches] below to 2.5 cm [1 inch] above the

location at which the bobbin coil probe detected an indication. The RPC probe inspection did

not confirm the indication and the tube was returned to service. After the primary-to-secondary

leak occurred and was located, the licensee reexamined the Inspection data from the previous

refueling outage and concluded that the RPC data were actually not acquired over the area of

interest. Although the area containing the degradation should have been, and appeared to

have been, inspected with the RPC probe, the measurement from the second support plate to

the indication location was Inaccurate which resulted in the indication not being inspected.

Several licensees have provisions in their eddy current inspection program that reduce the

possibility of leaving a defective tube in service as was done at McGuire Unit 2. Instead of

attempting to position a rotating probe at a particular location relative to a support, data are

collected between two support locations that bound the section of tubing containing the

indication which should guarantee that the area of interest is inspected. Other methods that

minimize probe positioning Inaccuracies include: (1) using axial encoders during data

acquisition, (2) establishing consistent settings in the data analysis software, and (3) using

sharp reflectors sufficiently spaced in the calibration standard to more accurately calibrate the

probe translation speed.

Potential Inability to Detect Cracks at Locations with Dents Less Than 5 Volts

To better detect cracks at dented locations, the Electric Power Research Institute (EPRI)

recommends the use of supplemental eddy current probes (e.g., Cecco or RPC) on dents

greater than 5 volts. At Sequoyah Nuclear Plant, Unit 1; Diablo Canyon Nuclear Power Plant, Unit 1; and Maine Yankee Atomic Power Station, inspection of dents less than 5 volts with RPC

probes have detected crack indications that were not detected with the bobbin coil probe. The

dents were at tube support plate intersections. The indications Initiated from both the inside

and outside diameter of the tube and were both circumferential and axial in nature. Apparently, eddy current signal distortion from the dents hindered detection with the bobbin coil probe.

These inspection findings call into question the adequacy of the 5-volt threshold recommended

by EPRI. The licensee for Sequoyah Unit 1 has surveillance requirements in the plant's

technical specifications which require an RPC Inspection of dents less than 5 volts. Such

requirements may improve the ability to detect cracks in tubes with dents less than 5 volts.

Vv7-88 D-tecember 16, 1997 Indications Identified in Welded Tubesheet Sleeves

In the 1995 refueling outages at Zion Nuclear Plant, Units 1 and 2, eddy current inspections of

welded tubesheet sleeves identified a number of indications that were not detected by visual or

ultrasonic inspection methods. The sleeved tubes containing eddy current indications were

returned to service on the basis that the visual and ultrasonic inspections did not confirm the

indications. This was documented in a nonconformance report, however, a formal safety

evaluation to assess the significance of the eddy current indications was not performed. In

January 1996, inspections of welded sleeves at the Prairie Island Nuclear Plant, Unit 1, found

61 indications similar to those found at Zion. Metallurgical evaluations of sleeve/tube

assemblies removed from Prairie Island revealed that the indications were the result of weld

conditions caused by Improper surface preparation during the sleeve installation process.

Subsequent inspections of sleeve welds at other plants with welded tubesheet sleeves showed

similar indications.

The initial sleeve weld acceptance criteria are based primarily on an ultrasonic test examination

to demonstrate an adequate sleeve weld joint. Although indications were detectable using eddy

current methods, this testing was performed only to provide a baseline for future examinations.

The experience with welded sleeves indicates a combination of visual, ultrasonic, and eddy

current techniques may be needed to provide comprehensive coverage of areas susceptible to

defects. Although the alternative inspection techniques did not identify the presence of the

eddy current indications at Zion, the significance of the indications detected by eddy current

was indeterminate because the nature of the degradation and the sensitivity of visual and

ultrasonic inspection techniques to the indications was unknown.

The experience with welded CE sleeves highlights the importance of adequately qualifying the

capabilities of each inservice inspection technique and addressing the root cause of new modes

of steam generator tube degradation. Because the capabilities of the ultrasonic and visual

inspection techniques to detect the weld zone defects had not been assessed, negative

inspection results (i.e., lack of confirmation) should not have been considered sufficient

evidence to conclude that the sleeved tubes with the eddy current indications were acceptable

per the plugging limits specified in the technical specifications.

High Voltage Growth of Outer-Diameter Stress Corrosion Crack (ODSCC) Indications

The Joseph M. Farley Nuclear Plant, Unit 1, applies a voltage-based steam generator tube

repair criteria to ODSCC indications conforming to the guidance in NRC Generic Letter

(GL) 95-05, "Voltage-Based Repair Criteria for Westinghouse Steam Generator Tubes

Affected by Outside-Diameter Stress-Corrosion Cracking." During a routine tube inspection in

April 1997 at Farley Unit 1, data analysts identified a bobbin coil indication with a voltage

amplitude of approximately 14 volts. The voltage of the indication was 1.46 volts at the

previous inspection and was not anticipated based on an operational assessment completed

during the prior refueling outage. The operational assessment also did not predict the

distribution of higher voltage indications identified during the subsequent inspection. Because

the operational assessment underestimated the magnitude and number of higher voltage

December 16, 1997 indications, the calculated end-of-cycle (EOC) conditional tube burst probability was lower than

would be calculated using the actual inspection results.

Commonwealth Edison (Corn Ed) similarly identified a number of higher voltage ODSCC

indications in an inspection at Braidwood Station, Unit 1, that were not anticipated based on the

licensee's previously completed operational assessment. Consequently, the EOC main steam

line break (MSLB) tube leakage predicted as part of the assessment (26.5 liters per minute

(Ipm) [6.99 gpm]) was lower than the leak rate predicted using actual EOC inspection results

(45.5 Ipm [11.5 gpm]). At a meeting with the NRC on July 23, 1997, Corn Ed presented its

conclusion that the voltage growth of ODSCC indications is dependent on the initial voltage of

the indications. GL 95-05 recommended a methodology for projecting the distribution of

indications (i.e., the number and voltage) which assumed that the growth rate for indications left

in service was Independent of the initial indication voltage. The use of this assumption was

contingent upon the licensee having demonstrated that the methodology predicted distributions

of indications which were conservative when compared to operating experience. Using voltage- dependent growth rates, Corn Ed was able to improve the accuracy of the EOC MSLB tube

leakage estimation.

The findings discussed above identify instances where the methodology discussed in GL 95-05 was shown to be nonconservative with respect to operating experience. Braidwood 1 is unique

in that it has a voltage-based criteria value greater than other licensees which permits higher- voltage indications to remain in service. However, the nonconservatism identified by Corn Ed

may have implications for other licensees using voltage-based repair criteria. Licensees

utilizing the methodology may wish to address the implications of this issue in future operational

assessments.

Continued Degradation Growth In Plugged Tubes

Eddy current inspection of tubes recently removed from the retired McGuire, Unit 1 steam

generators found that the bobbin coil voltage for indications had increased even after the tubes

were plugged. Of the 12 crack-like indications examined, 10 had apparently initiated from the

outside diameter (OD) of the tube and 2 from the inside diameter. The inspections revealed

increases in the bobbin coil voltages ranging from 0.3 to 6.1 volts since the tubes had been

plugged. Increases in RPC voltage were also noted. Because the results are preliminary and

are based entirely on nondestructive inspection data, it is not certain whether the indications

had grown after the tubes were plugged, however, these results suggest that the indications did

change in some way after the tubes were plugged.

During the spring 1997 refueling outage at Braidwood 1, Corn Ed found that 49 of 85 Blocked"

tubes (also plugged) had circumferential cracks at the tubesheet expansion transition area.

The tubes had been locked by expanding them above and below certain tube support plate

intersections In support of the use of voltage-based repair criteria. Inspections of the tube

expansion-transitions completed before the plugging verified that no Indications were present in

the tubes.

December 16, 1997 The inspection findings discussed above suggest that steam generator tubes remain

susceptible to stress corrosion cracking (SCC) even after they have been plugged. Although

the susceptibility to SCC of plugged tubes should be less than that for tubes remaining In

service, many of the factors associated with the development of SCC remain unchanged

(e.g., material susceptibility). The consequences of continued degradation of plugged tubes

include the potential for complete severance of the tube and the potential for creation of loose

parts, both of which could damage inservice tubes. Some utilities have installed tube stabilizers

in tubes with outside-diameter-initiated circumferential defects before plugging them, which may

lessen the potential to damage inservice tubes.

Discussion

As PWRs continue to age, new modes of steam generator degradation continue to appear.

Historically, verification of tube integrity has focused on degradation which directly affected the

tubes. However, the recent findings at Shearon Harris and San Onofre illustrate the importance

of considering the Impact of other modes of degradation on the integrity of steam generator

tubes. Although inspection practices generally focus on locations In steam generator tubes

where degradation has previously been identified, the examples presented here demonstrate

that degradation taking place elsewhere in steam generators could potentially challenge the

integrity of the tubes.

Because of improved inspection capability, specifically improvements in probes and data

analysis software, earlier detection and perhaps more accurate sizing of tube degradation is

possible. However, problems with tube inspections continue to occur. As discussed, these

problems may arise from inadequate qualification of data analysis procedures or from errors

associated with the acquisition of inspection data. It remains Important for licensees to assess

the significance of indications with respect to the qualification of the inspection techniques and

the manner in which the indications were detected. Such practice Is consistent with regulatory

requirements in Criteria IX and XVI of Appendix B to 10 CFR Part 50. The conclusions from

these assessments may dictate revisions to inspection procedures and repair of tubes.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

W. Roe, Acting Director

Zion of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Phillip J. Rush, NRR Eric J. Benner, NRR

301-415-2790 301-415-1171 E-mail: pjr1@nrc.gov E-mail: ejbl@nrc.gov

Attachment: List of Recently Is ued NRC Information Notices

14y4 p

KU ,achment

..

IN 97-88 December 16, 1997 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

97-87 Second Retrofit to 12/12/97 All industrial radiography

Industrial Nuclear Company licensees

IR 100 Radiography Camera, to Correct Inconsistency In

10 CFR Part 34 Compatibility

97-86 Additional Controls for 12112/97 Registered users of the Model

Transport of the Amersham No. 660 series packages, and

Model No. 660 Series Nuclear Regulatory Commission

Radiographic Exposure Devices industrial radiography licensees

97-85 Effects of Crud Buildup 12/11/97 All holders of OLs for pressurized- and Boron Deposition on water reactors, except those

Power Distribution and licensees who have permanently

Shutdown Margin ceased operations and have

certified that the fuel has been

permanently removed from the

reactor vessel

97-84 Rupture in Extraction 12/11/97 All holders of OLs for nuclear

Steam Piping as a power reactors except those

Result of Flow-Accelerated who have permanently ceased

Corrosion operations and have certified

that fuel has been permanently

removed from the reactor vessel

95-49, Seismic Adequacy of 12110/97 All holders of OLs for nuclear

Sup. 1 Thermo-Lag Panels power reactors

97-83 Recent Events Involving 12/05/97 All holders of OLs for pressurized- Reactor Coolant System water reactors, except those

Inventory Control During licensees who have permanently

Shutdown ceased operations and have

certified that fuel has been

permanently removed from the

reactor vessel

OL = Operating License

CP = Construction Permit

7-88 K Member 16,1997

  • 1 The inspection findings discussed above suggest that steam generator tubes remain

susceptible to stress corrosion cracking (SCC) even after they have been plugged. Although

the susceptibility to SCC of plugged tubes should be less than that for tubes remaining in

service, many of the factors associated with the development of SCC remain unchanged

(e.g., material susceptibility). The consequences of continued degradation of plugged tubes

include the potential for complete severance of the tube and the potential for creation of loose

parts, both of which could damage inservice tubes. Some utilities have installed tube stabilizers

in tubes with outside-diameter-initiated circumferential defects before plugging them, which may

lessen the potential to damage inservice tubes.

Discussion

As PWRs continue to age, new modes of steam generator degradation continue to appear.

Historically, verification of tube integrity has focused on degradation which directly affected the

tubes. However, the recent findings at Shearon Harris and San Onofre illustrate the importance

of considering the Impact of other modes of degradation on the integrity of steam generator

tubes. Although inspection practices generally focus on locations in steam generator tubes

where degradation has previously been identified, the examples presented here demonstrate

that degradation taking place elsewhere in steam generators could potentially challenge the

integrity of the tubes.

Because of improved inspection capability, specifically improvements in probes and data

analysis software, earlier detection and perhaps more accurate sizing of tube degradation Is

possible. However, problems with tube inspections continue to occur. As discussed, these

problems may arise from inadequate qualification of data analysis procedures or from errors

associated with the acquisition of inspection data. It remains Important for licensees to assess

the significance of indications with respect to the qualification of the inspection techniques and

the manner in which the indications were detected. Such practice is consistent with regulatory

requirements In Criteria IX and XVI of Appendix B to 10 CFR Part 50. The conclusions from

these assessments may dictate revisions to Inspection procedures and repair of tubes.

This Information notice requires no specific action or written response. If you have any

questions about the information Inthis notice, please contact one of the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

original signed by

Jack W. Roe, Acting Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Phillip J. Rush, NRR Eric J. Benner, NRR

301-415-2790 301415-1171 E-mail: pjrl@nrc.gov E-mail: ejbl@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: 97-88.IN

  • SEE PREVIOUS CONCURRENCE

To receive a copy of this document, Indicate In the box C=Copy wlo attachmen losureE wit attachmentlenclosure N=No copy

OFFICE PECB EMCB EMCB (A) C:EMCB

NAME EBenner PRush* CBeardslee* ESullivan*

DATE 11/20/97 109/09/97 09/10/97 /97 OFFICE (A) D:DE l SC:PECB C:PECB D:DRPM l

NAME GLainas* RDennig* SRichards*JRoer"'Z/

DATE 09/19/97 11/21 /97 12/03/97 12/08/97 OFFICIAL RECORD COPY

'7-

- ,6ember , 1997 The inspection findings discussed above suggest that steam generator tubes remain

susceptible to stress corrosion cracking (SCC) even after they have been plugged. Although

the susceptibility to SCC of plugged tubes should be less than that for tubes remaining in

service, many of the factors associated with the development of SCC remain unchanged

(e.g., material susceptibility). The consequences of continued degradation of plugged tubes

include the potential for complete severance of the tube and the potential for creation of loose

parts, both of which could damage inservice tubes. Some utilities have installed tube stabilizers

in tubes with outside-diameter-initiated circumferential defects before plugging them, which may

lessen the potential to damage inservice tubes.

Discussion

As PWRs continue to age, new modes of steam generator degradation continue to appear.

Historically, verification of tube integrity has focused on degradation which directly affected the

tubes. However, the recent findings at Shearon Harris and San Onofre illustrate the importance

of considering the impact of other modes of degradation on the integrity of steam generator

tubes. Although inspection practices generally focus on locations In steam generator tubes

where degradation has previously been identified, the examples presented here demonstrate

that degradation taking place elsewhere in steam generators could potentially challenge the

integrity of the tubes.

Because of improved inspection capability, specifically improvements In probes and data

analysis software, earlier detection and perhaps more accurate sizing of tube degradation Is

possible. However, problems with tube inspections continue to occur. As discussed, these

problems may arise from inadequate qualification of data analysis procedures or from errors

associated with the acquisition of inspection data. It remains important for licensees to assess

the significance of indications with respect to the qualification of the inspection techniques and

the manner in which the indications were detected. Such practice Is consistent with regulatory

requirements In Criteria IX and XVI of Appendix B to 10 CFR Part 50. The conclusions from

these assessments may dictate revisions to inspection procedures and repair of tubes.

This information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Jack W. Roe, Acting Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Phillip J. Rush, NRR Eric J. Benner, NRR

301-415-2790 301-415-1171 E-mail: pjrl@nrc.gov E-mail: ejbl@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\EJB1\SGINFO.WPD

  • SEE PREVIOUS CONCURRENCE

To receive a copy of this document, indicate In the box C=copy wlo attachmenVenclosure E=Copy with attachment/enclosure N = No copy

OFFICE PECB EMCB EMCB l (A)C:EMCB l

NAME EBenner PRush* CBeardslee* ESullivan*

DATE 11/20/97 09/09197 09/10/97 /97 OFFICE (A) D:DE SC:PECB C:PECB DQRPM

NAME GLainas* RDennig* SRichards J

DATE 09/19/97 11/21 /97 01'/5/97 'P 97 pFFICIAL REPORD COPY

11A~ /&i///97

IN 97-xx

November xx, 1997 Page of 6 severance of the tube and the potential for creation of loose parts, both of which could damage

inservice tubes. Some utilities have installed tube stabilizers in tubes with outside-diameter- initiated circumferential defects before plugging them, which may lessen the potential to

damage inservice tubes.

Discussion

As PWRs continue to age, new modes of steam generator degradation continue to appear.

Historically, verification of tube integrity has focused on degradation which directly affected the

tubes. However, the recent findings at Shearon Harris and San Onofre illustrate the importance

of considering the impact of other modes of degradation on the integrity of steam generator

tubes. Although inspection practices generally focus on locations in steam generator tubes

where degradation has previously been identified, the examples presented here demonstrate

that degradation taking place elsewhere in steam generators could potentially challenge the

integrity of the tubes.

Because of improved Inspection capability, specifically Improvements in probes and data

analysis software, earlier detection and perhaps more accurate sizing of tube degradation is

possible. However, problems with tube inspections continue to occur. As discussed, these

problems may arise from inadequate qualification of data analysis procedures or from errors

associated with the acquisition of inspection data. It remains important for licensees to assess

the significance of indications with respect to the qualification of the inspection techniques and

the manner in which the indications were detected. Such practice is consistent with regulatory

requirements in Criteria IX and XVI of Appendix B to 10 CFR Part 50. The conclusions from

these assessments may dictate revisions to inspection procedures and repair of tubes.

This Information notice requires no specific action or written response. If you have any

questions about the information in this notice, please contact one of the technical contacts listed

below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager.

Jack W. Roe, Acting Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contacts: Phillip J. Rush, NRR

301-415-2790

E-mail: pjrl@nrc.gov

Eric J. Benner, NRR

301-415-1171 E-mail: ejbl@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\EJB1\SGINFO.WPD

  • SEE PREVIOUS CONCURRENCE

To receive a copy of this document indicate in the box C=Copy Wo attachmentlenclosure E=Copy Wth attachment/enclosure NNo copy

OFFICE JPECB l EMCB EMCB (A)C:EMCB

NAME EBenne PRush* CBeardslee* ESullivan*

DATE 11/20/97 09/09197 09/10/97 09/12/97 OFFICE (A) D:DE l SC:PECB A C:PECB l D:DRPM Il

NAME GLainas* RDennig8( SRichards JRoe

DATE 09/19/97 10/497 10/ /97 091 /97 OFFICIAL RECORD COPY

!

IN97-xx

September xx, 1997 Technical contacts: Phillip J. Rush, NRR

301-415-2790

E-mail: pjrl@nrc.gov

Eric J. Benner, NRR

301-415-1171 E-mail: ejbl@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\EJB1\SG-INFO.WPD

  • SEE PREVIOUS CONCURRENCE

To receive a copy of this document, Indicate In the box C=Copy w/o attachment/enclosure E=Copy with attachment/enclosure N = No copy

OFFICE PECB EMCB f EMCB I1 (A) C:EMCB I ET

NAME EBenner _ __PRush_ _ _ CBeardslee (&~ ESullivan a

DATE 09/ t/97 09107197 109/_ _ _97__ 09/f1/97 OFFICE (A) :DE PECB f (A) C:PECBI D:DRPM

NAME GLa s EGoodwin RDennig JRoe

DATE 997 09/ /97 09/ /97 109/ /97

1A k ,!f OFFICIAL RECORD COPY