IR 05000259/1992042
| ML18036B121 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/28/1992 |
| From: | Blake J, Coley J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18036B120 | List: |
| References | |
| 50-259-92-42, 50-260-92-42, 50-296-92-42, NUDOCS 9301190040 | |
| Download: ML18036B121 (11) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323
'JAN -5 l993 Wp*yW Report Nos.:
50-259/92-42, 50-260/92/42, and 50-296/92-42 Licensee:
Tennessee Valley Authority 3B Lookout Place 1101 Harket Street Chattanooga, TN 37402-2801 Docket Nos.:
50-259, 50-260, and 50-296 License Nos.:
DPR-33, DPR-52, and DPR-68 Facility Name:
Browns Ferry 1, 2, and
Inspection Conducted:
December 7-11, 1992 Inspector:
J.
L.
oley Jr.
Reactor Inspector Approved by:
J. J.
Bla Chief Haterials and Processes Section Engineering Branch Division of Reactor Safety SUHHARY Date Signed Jz zs gK ate Signed Scope:
This special, announced inspection was conducted at the General Electric Company (GE) Service Center and the Frank W. Hake Associates President Island facility in Hemphis, Tennessee.
The purpose of the inspection was to continue the surveillance initiated in NRC Inspection Report 50-259,260,296/92-40, of TVA's "performance demonstration" activities for the automated ultrasonic inspection, personnel, procedures, and equipment that is scheduled to be used to examine the Reactor Pressure Vessel (RPV) shell welds of the three Browns Ferry units.
These examinations will be performed in accordance with NRC's new rule for augmented examination of RPV shell welds,
[10 CFR 50.55a (g) (6) (ii) (A)] which became effective on September 8,
1992.
Specific areas examined or discussed with the licensee this inspection included: observation of the final system calibrations for the "Performance Demonstration" activities, review of ultrasonic'data for GE's proposed statistical analysis calibration verification method, review of practice examination data, reviewed status of calibration block certifications, reviewed status of O.D. vessel examination coverage, and held discussions with TVA/GE regarding the jet pump adapter to shroud weld susceptibility to intergranular stress corrosion cracking (IGSCC).
9301190040 930105 PDR ADOCK 05000259
Results:
The activities examined by the inspectors were genera] ly well planned, implemented, and documented by TVA.
Review. of detection data for each examiner, obtained during practice examinations, revealed that the TVA and GE procedures, equipment, and personnel should be capable of achieving the high level of confidence in UT examinations that Appendix VIII of the ASME Code mandates for the nuclear industry.
TVA's proactive commitment to quality for the integrity of the reactor vessel I.D. examinations was demonstrated by the ongoing performance demonstration activities observed in Memphis.
Identification and resolution of technical issues are being handled in an effective manne REPORT DETAILS Persons Contacted Licensee Employees
- F. Leonard, Level III Examiner
- D. Massey, Regulatory Engineer T. Stockman, Level III Examiner
- C. White, guality Assurance (gA)
General Electric Company (GE)
- 0. 'Bragg Jr.,
GERIS 2000 Project Manager
- C=. Minor, Level III Examiner
- T. Brinkman, Project Manager, Application Technology
- H. Sodemann, gA Specialist Electric Power Research Institute (EPRI)
E., Kietzman, Manager, Heavy Section Laboratory Frank W. Hake Associates R. Applebaum, Manager Support Services
- Attended the exit interview Inservice Inspecti'on (ISI)
a.
Background Browns Ferry Units 1 and 3 are in an extended shut down status, in the third, 40-month period,. of the first, ten-year interval.
Unit 2 is operating in the third, 40-month period,. of the-first, ten-year interval (P3, Il) which is scheduled to end February 23, 1993.
Unit 1 received its Operating License December 20, 1973, and declared commercial oper'ations on August 1, 1974.
Unit 2 received its Operating License on August 2, 1974; and declared commercial operations on March 1, 1975.
Unit 3 received its Operating License on August 18, 1976, and declared commercial operations on March 1, 1977.
(While the ten-year inspection interval would normally end on the tenth anniversary of the date of commercial operations, these three units are still considered to be in their first, ten-year ISI inspection interval because the ASME code allows for the extension of inspection intervals to compensate for extended outages.)
The applicable code for ISI, for Units
and 3 is the ASME B&PV.Code;Section XI, 1974 Edition with Addenda through the Summer 1975 (74S75) for everything except technique.
The applicable code for technique is the
o
ASME B&PV Code Section XI, 1986 Edition and no Addenda.
The applicable code for ISI, for Unit 2 is the ASME B&PV Code,Section XI, 1986 Edition without Addenda.
For the planned Reactor Pressure Vessel (RPV) inspections, ASME B&PV Code Section XI, 1989 Edition with Addenda through 1991,- which implements the Appendix VIII "Performance Demonstration For Ultrasonic Examination Systems", will be used for guidance only.
TVA's performance demonstration for qualification of automatic ultrasonic examination personnel, procedures, and equipment for inspection from the I.D. of the vessel, are being conducted in the spirit of Appendix VIII.
The licensee has, contracted General Electric Company (GE) to conduct automated ultrasonic (UT) examinations of the Reactor Pressure Vessels (RPVs) using the GERIS, and GERIS 2000 Data Acquisition -Systems, under the umbrella of the GE guality Assurance Program.
GE Engineering and their San Jose California based'ervices, including the qualification program is covered by the GE BWR gA program as described.in GE Topical Report NEDO-11209.
'On and off site ISI services are covered by GE Nuclear Projects guality Assurance Manual, (AM-OOl.
The inspector reviewed the ISI program documents, examination procedures, personnel and equipment certifications, and observed the start of the
"Performance Demonstration gualification Examinations" during the preceding inspection conducted 'on November 16-20, 1992 and. reported in Inspection Report Nos. 50-259/92-40, 50-260/92-40, and 50-296/92-40.,
b.
Observation of Work and Work Activities Units 1, 2 and-3, (73753)
(1)
When the inspector arrived at the GE Service Center in Memphis Tennessee, he was informed that the GE examiners had completed
.
acquiring data for'the final test specimen and the only remaining activities for the GERIS acquisition system was to verify the final calibrations and to insure that the system did not save any of the test specimen data on the computer's hard drive.
This precaution is taken because the perfoirmance demonstration philosophy requires that
.
NDE personnel.
and equipment demonstrate'qualification on "blind" test samples.
At the present time there is only a limited number of test specimens with implanted flaws available for qualification of-examiners.
Therefore, the TVA security plan goes to great lengths
- to insure that no information on the flaws in these test specimens would be compromised.
The insp'ector observed the final ultrasonic system calibrations and also observed the licensee verify that the GE's GERIS 2000 computer program had not. stored any examination data taken on the test specimens.
(2)
As delineated in NRC Inspection Report 50-259,260,296/92-40 dated December 9,
1992, GE had 'proposed an alternate method to perform the GERIS 2000 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> calibration verification checks but had not obtained the Code Inspectors'pproval.
The proposed, alternative
'alibration verification check methodology would allow calibration
verifications to be performed using statistical analysis of the material's ultrasonic noise level, on designated reference patches of the reactor vessel.
The inspector held discussions with TVA and GE to determine what actions were being taken to obtain approval for the new method, or how GE was intending to meet Code-required calibration verification checks without taking their scanning fixture out of the reactor vessel every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
TVA stated that another meeting had been held with the Code Inspector but that technical issues concerning computer storage and comparison of calibration data still remained unresolved.
In addition GE had presented the proposed calibration verification methodology to the ASME Code Working Group for action in their November 30 thru December 4,
1992, meeting.
No action was taken on GE's request.
GE therefore, has decided to use'
,calibration block consisting of several curve radii that can be put in the reactor vessel to perform the verification checks in accordance with the ASHE Code.
GE will continue to seek approval for the statistical analysis method because it would save time and be much more economical to perform.
The inspector reviewed data obtained to determined the standard deviations at. various decibels of attenuation.
All the data reviewed was well within the Code allowable variance.
GE plans to seek approval for a Code Case which would allow this method of performing calibration verification checks for reactor vessel inspection's performed with automated systems.
(3)
NRC Inspection Report 50-259,260,296/92-40 reported that. the inspector had review preliminary detection data obtained during practice examinations.
During this inspection the inspector reviewed the final practice examination data for all examiners to be qualified for detection.
As stated previously, this data revealed that TVA/GE procedures, equipment, and personnel should be capable of achieving the high level of confidence in UT examinations that Appendix VIII of the ASHE Code mandates for the nuclear industry.
'owever, one area of concern was identified involving the fact that, indications on the outer extremity of the test specimens were consistently being plotted inboard of their actual position.
This problem has not been totally resolved, but preliminary investigation tends to indicate that the difference in measurement is cause by the calibration block being made out of flat plate and the practice specimens being made out of rolled plate:
The inspector emphasized that the problem needed to be resolved before the data is plotted for the performance demonstration specimens, because at that point, the amount of deviation stated in the programmatic procedure would be all the tolerance the examiners would be expected to have.
(4)
The inspector also questioned the licensee about what progress had been made to resolve the Browns Ferry calibration block material concerns addressed by the inspectors in NRC Inspection Report 50-
'
259.,
260, 296/92-40.
The licensee stated that, at the present time TVA is considering using the Phipps Bend calibration block because it is a vessel drop-out (curved plate with as-weld clad surface)
and the clad was applied by the strip method.
This is the same method used to clad Units 2 and 3.
Unit I clad however was applied using the 6 wire method.
The decision as to what will be used on Unit I, is still unresolved at this time.
Within the areas examined, no violation or deviation was identified.
Discussion
- Examination Limitations The present examination requirements for the Browns Ferry reactor vessels require l00% ultrasonic testing of the reactor vessels.
Performance demonstration activities for the ID automated ultrasonic examinations of the reactor vessels are in the spirit of Appendix VIII to Section XI of the ASHE Code, 1989 Edition with Addenda through 1991.
However, TVA's qualification effort in Hemphis is for examinations performed from the I.D. of the reactor vessel only.
The new rule emphasizes that in order to obtain essentially 100% coverage of the reactor vessel'shell welds, both O.D.
and I.D. examinations may be required.
During a previous inspection, (92-40)
GE was performing a survey to determine how much additional examination coverage could be obtained from the O.D. of the reactor vessel.
= This information was to be reported to NRR as requested.
During this inspection GE was in Hemphis preparing the draft report for the licensee.
The inspector met with the Project Hanager of the activity to obtain a reasonable estimate of the examination coverage that GE could obtain without removal of insulation for examination of the bottom shell weld to lower vessel head or modification of the ultrasonic scanning fixture.
GE's final estimates of inspection coverage percentage were lower than expected, and 'it is now apparent that the licensee will have to,seek-Code Relief for some of the weld coverage which cannot be inspected by the combination of I.D. and O.D. examinations.
The estimate of coverage improves considerably if the insulation is removed from the bottom weld.
This is not planned however, and. the licensee's justification will be delineated in their request for relief.
Since the licensee's relief request submittal, with justification for not removing the insulation, has not been received, the inspector made the presumption that the insulation will be removed and the weld will be examined.
Using that presumption, the inspector noted that the bottom shroud plate is approximately 5-inches below the bottom shell weld, and if the insulation was removed, the shroud welds could be scanned for radial cracking at the same time and re-examination of the weld could be scheduled with the 10 year vessel inspection.
IGSCC in Shroud Hanway Hole Access Cover welds has been. a problem for BWR's.
=The inspector was concerned as to whether GE had determined the susceptibility of the jet-pump-adapter to shroud-plate welds to intergranular stress'orrosion cracking (IGSCC).
GE provided the inspector with drawings concerning the
weld joint design; however, these drawings had depicted a weld symbol which was not conclusive in determining whether the weld would be highly susceptible to IGSCC.
The inspector requested that GE provide information as to these welds'susceptibility.
At the conclusion of the inspection thi's information had not been received.
The inspector also discussed with TVA and GE that they consider post examination qualification of their O.D. examiners since documentation of the capability of the O.D. inspection methods by some means such as a
modified performance demonstration would establish the reliability of the examination data;
'(The inspector acknowledged that at this time this is not a requirement.)
Within the areas examined, no violation or deviation was identified..
Exit interview:
The inspection scope and results were summarized on December ll, 1992, with those persons indicated in paragraph 1.
The inspectors described the areas inspected, Although reviewed during this inspection, propri-etary information is not contained in this report.
Dissenting comments were not received from the licensee.
Acronyms and Initialisms ANII ASME BNF BKPV BWR EPRI GE GERIS I.D.
,
NRR O.D.
QA QAM QC RPV TVA UT Authorized Nuclear Inservice Inspector American Society of Mechanical-Engineers Browns Ferry Nuclear Facility Boiler and Pressure Vessel Boiling Wa'ter Reactor
,Electric Power Research Institute General Electric Company General Electric Remote Inspection System Inside Diameter Inservice Inspection Nondestructive Examination-Nuclear Regulatory Commission Nuclear Reactor Regulation Outside Diameter Quality Assurance Quality Assurance Manual Quality Control Reactor Pressure Vessel Tennessee Valley Authority Ultrasonic
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