IR 05000259/1993040
| ML18037A589 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/10/1993 |
| From: | Blake J, Kleinsorge W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18037A588 | List: |
| References | |
| 50-259-93-40, 50-260-93-40, 50-296-93-40, NUDOCS 9312140081 | |
| Download: ML18037A589 (14) | |
Text
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+y*~0 UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIHTASTREET, N.W., SUITE 2900 ATLANTA,GEORGIA 303234199 Report Nos.:
50-259/93-40, 50-260/93-40, and 50-296/93-40 Licensee:
Tennessee Valley Authority 6N 38A Lookout Place 1101 Market 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:
Brown Ferry I, 2, and
Inspection Cond ct 993 Inspector:
W)
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e tor ate vgne Approved by.
Jero e
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a e, e
Ma r's and Process Section En in ering Branch D vision of Reactor Safety
/c l~
ate zgne SUMMARY Scope:
This routine, announced inspection was conducted in the area of Inservice Inspection (ISI).
Results:
The licensee's ISI Coordinator, and Level III examiner were actively involved in the resolution of technical issues and ensuring that all quality objectives were properly addressed by examiners.
Identification and resolution of technical issues are being handled in an effective manner.
In the areas inspected, no violations or deviations were identified.
9312140081 931118 PDR ADOCK 05000259
REPORT DETAILS Persons Contacted Licensee Employees
- F. Froscello, Inservice Inspection (ISI)
- J. Johnson, Manager, guality Assurance (gA)
- J. Haddox, Manager, Nuclear Engineering
- R. Moll, Acting Manager, Operations
- J. Rupert, Manager, Engineering and -Modifications
- J. Scalice, Plant Hanager
- T. Shriver, Manager, Nuclear Assurance and Licensing
- P. Salas, Hanager, Licensing
- R. Wells, Manager, Compliance Licensing
- J. Whitaker, ISI Level III Examiner
- 0. Zeringue, Site Vice President Other licensee employees contacted during this inspection included craftsmen, engineers, technicians, and administrative personnel.
Other Organizations General Electric Nuclear Services
- 0. Bragg, GERIS 2000 Project Manager C. Minor, Level III Examiner R. Seals, BFN Reactor Pressure Vessel (RPV) Project Manager Hartford Steam Boiler
"A. Ladd, Authorized Nuclear Inservice Inspector (ANII)
NRC Resident Inspectors C. Patterson, Senior Resident Inspector
- J. Hunday, Resident Inspector
- R. Musser, Resident Inspector G. Schnebli, Resident Inspector
- Attended exit Interview Inservice Inspection (ISI)
Background Browns Ferry Units I and 3 are in an extended shutdown 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 I received its Operating License December 20, 1973, and declared commercial operations
~j
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 commer-cial 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 1 and 3 is the ASME BKPV Code,Section XI, 1974 Edition with Addenda through the Summer 1975 (74S75) for everything except technique.
The applicable code for technique is the ASME BRPV Code Section XI, 1986 Edition and no Addenda.
The applicable code for ISI, for Unit 2 is the ASME BSPV Code,Section XI, 1986 Edition without Addenda.
For the Reactor Pressure Vessel (RPV) inspections, ASME BSPV Code Section XI, 1989 Edition with Addenda through 1991, which implements the Appendix VIII. "Performance Demonstration For Ultrasonic Examination Systems",
is being used for guidance only.
The Tennessee Valley Authority (TVA) and General Electric's (GE)'s performance demonstration for qualification of automatic ultrasonic examination personnel, procedures, and equipment for inspection from the I.D. of the vessel, were conducted in the spirit of Appendix VIII.
'a ~
Observation of Work and Work Activities, Unit 3 (73753)
The inspector observed work activities, reviewed certification records of NDE equipment and materials, and reviewed NDE personnel qualifications for personnel who had been utilized in the ISI examinations during this outage.
The observations and reviews conducted by the inspector are documented below.
Activities Observed Ultrasonic Examination (UT)
The inspector observed examiners perform equipment calibrations and ultrasonic examinations for the areas listed below.
The examina-tions were observed to determine whether approved procedures were being followed, if examination personnel were knowledgeable of the
'xamination method and operation of the test equipment, whether welds were properly scanned, and whether, examination results and evaluations of the results were recorded, plotted, and dispositioned correctly.
The applicable procedures for the examinations were GE-UT-700, GE-UT-701, GE-UT-400, and GE-UT-401.
Personnel and equip-ment certifications were verified by the inspector.
The following ISI examinations were observed by the inspector:
Ultrasonic Examinations/System Calibrations Observed Identification Area Activity Weld C-2-3 Patch'utomated Data Acquisition
Nozzle N4E Nozzle N4F Inner Radius Inner Radius Automated Equipment Setup, Calibra-tion and, Data Acquisition Automated Equipment Setup
'elds are subdivided into inspection patches to accommodate computer data storage.
The inspector reviewed the certification documentation for the following UT equipment:
Transducers S/N 92-826,92-827, 92-828, 92-829~
92 839~
92 840~
92 841~
92 842>>
92 852~
92 853~
92 854~
92 855>>
92-865, and 92-866; Thermometer S/N L00437CL.
The inspector reviewed the certification, qualification, and visual acuity documentation for following UT examiners:
ROF UT-II, JCG UT-II, CAN UT-III and TK UT-III.
The examinations were performed satisfactorily.
b.
Review of Ultrasonic Data and Evaluations Unit 3 (73755)
The inspector reviewed data for the inspection patches on Weld C-1-2, listed below, to determine whether:
data was consistent with the acceptance criteria; data recording, evaluation, and disposition of findings were accomplished in accordance with the applicable exami-,
nation procedures.
Ins ection Patch No.
BF-116 BF-117 BF-118 BF-119 BF-120 BF-121 BF-122 BF-123 Documentation for the examination patches listed above was excel-lent.
Evaluation and disposition of recorded indications by the analyst was also performed satisfactorily.
Within the areas examined, no violations or deviations were identifie Licensee Event Report (LER)
(Closed-Unit 2 Only)
LER 260/88-037:
Inadequate Design Control Proce-dures In HVAC Duct Work Pursuant to deficiencies identified at Watts Bar Nuclear (WBN) Plant, the licensee conducted walkdown inspections of Heating Ventilating and Air Conditioning (HVAC) duct work at the Browns Ferry Nuclear (BFN) Plant.
The licensee discovered that the duct work had discrepancies between the design assumptions and the duct work test results and/or design stan-dards.
The licensee determined the cause of these conditions to be inadequate design controls in place at the time the HVAC systems were originally designed.
As reported in NRC Inspection Report (IR) 50-259,260,296/91-06, the licensee performed a walkdown and evaluation of the systems affected.
Repairs or modifications as necessary, to meet the required criteria for operability were completed.
The NRC staff reviewed the licensee's actions and determined them acceptable for Unit 2 restart as documented in NUREG-1232, Vol.3, Supp.2.
The analysis conducted for Unit 2 refuel-ing and restart used stresses that were deemed satisfactory for "interim" operation.
Approximately 12,000'f duct and 509 existing supports were qualified to the interim design criteria.
"Long term" operation criteria were established and documented in TVA General Design Criteria BFN-50-C-1704.,
and approved by NRC letter dated July 16, 1992.
The licensee evaluated the 12,000'f duct and 509 supports qualified to the "interim" operability criteria, for qualification to the "long term" operability criteria.
This evaluation compelled the installation of or modifications to 113 HVAC supports.
No modification to ducts was required.
Ten Design Change Notices (DCN)s were issued to effect this work.
The 113 supports have been modified or installed.
To address the issue of inadequate design controls for future design work, the licensee issued the below listed procedures.
The generic issue of inadequate design control for existing designs at BFN, is addressed in
"The Browns Ferry Nuclear Performance Plan of The Tennessee Valley Authority", Revision 2 (NPP).
The walkdowns, evaluations, modifications, and installations indicated above, apply to seismic Class I HVAC duct work only.
The NPP indicated that the program to evaluate seismic spectral interactions of seismic Class 2 features installed over seismic Class I features including HVAC duct work, will be conducted following the resolution of Unresolved Safety Issue A-46, utilizing the techniques developed by Seismic gualifi-cation Utility Group (SHRUG).
To evaluate the adequacy of the licensee's actions the inspector conduct-ed interviews with licensee personnel, reviewed the procedures listed below, and conducted a walkdown inspection of eleven selected modified HVAC supports listed belo J
Procedures Reviewed Identification Revision Title NEP-3.1 NEP-3.2 SEP-9.5.6 Calculations Design Input Design Verification HVAC Supports Examined Identification Drawing No.
Sup ort Location 1-SWHVAC-92-37 1-47B930-44 1-SWHVAC-94-07 1-47B930-38 Control Control 1-SWHVAC-94-15 1-47B930-42-1 Control 1-SMHVAC-92-0113 1-SWHVAC-71-40 1-47B930-63 1-47B930-31 1-SWHVAC-71-41 1-47B930-32 1-SMHVAC-132-07 1-47B930-50 1-SWHVAC-132-01 1-47B930-51 Control Control Control Control Control 1-SMHVAC-80-28 1-47B930-192 Control 1-SMHVAC-80-31 1-47B930-190 Control 1-SMHVAC-71-17 1-47B930-190 Control Bay Floor el.
593'ay Floor el.
593'ay Floor el.
593'ay Floor el.
593'ay Floor el.
606'ay Floor el.
606'ay Floor el.
606'ay Floor el.
606'ay Floor el.
617'ay Floor el.
617'ay Floor el.
617'his LER is considered closed for Unit 2 only, it remains open for Unit Nos.
1 and 3 pending the completion of the walkdowns, evaluations, modifications/installations to the HVAC duct work in those units.
Within the areas examined, no violations or deviations were identified.
4.
Review of Actions Taken by TVA for a Reported Steam Leak in the 4" Extraction Steam Line -
Followup - Unit 2 (49001)
As reported in NRC IR 50-259,260,296/93-38, on October 6, 1993, TVA notified NRC that they had experienced a steam leak in a weld joining a weld-o-let to a 4" drain line.
Because the 4" line was spraying steam and the radiation levels were high in Unit 2, the licensee ultrasonically examined the same fittings in Unit 1 and plans to examine the Unit 3 fittings as part of their regularly scheduled Erosion/Corrosion (E/C)
program, to determine whether E/C was the mechanism for the failure in Unit 2.
The licensee made an entry into the high radiation area in
Unit 2, ultrasonically examining the weld-o-let to pipe weld and pipe at 90'ntervals, at the weld, one inch down from the weld, and two inches down from the weld.
Eight of the eleven readings taken, wer e below nominal pipe wall thickness (0.237"), three of those eight were below 8735 of nominal wall thickness (0.207").
The lowest wall thickness reading was 0. l63" measured two inches down from the weld and 180'rom the hole.
All eleven readings were well above design minimum wall of 0.0187".
Approximately one man rem of dose was received in the Unit 2 examination effort.
The licensee affected an online repair to the hole using furmanite.
The licensee has ultrasonically investigated the piping on Unit l.
Unit I was chosen because it was thought to have the same pipe configuration, operational time, and the worst chemistry conditions.
The configuration of the Unit 2 piping is as follows:
a vertical 4" weld-o-let is welded to a horizontal 24" pipe run at the 6:00 o'lock position, the lower end of the weld-o-let is welded to a vertical 4" diameter pipe section approximately 2J" long, the lower end of the 4" pipe is welded to a 4"x4"x3" tee with the through 4"x4" leg in the vertical position.
The Unit I configuration is the same as the Unit 2 configuration except that the 4" weld-o-let is welded directly to the 4"x4"x3" tee.
The licensee applied a grid to the Unit I tee and ultrasonically examined the same.
A review of the data, for a pattern indicative of E/C was inconclusive because of the nonuniform nature of the cross section of tee pipe fittings.
All readings were above 87j% of the nominal wall thickness which is 0.207".
As the original leak was noted by an auxiliary operator, while preforming a weekly task, it is the licensee's view that any future leaks in the same location should be similarly identified.
The licensee indicated that they would determine the extent of degradation in this area of Unit 2 during the next refueling outage, scheduled for October 1994, and replace piping as appropriate.
The licensee further indicated that the same area in Unit 3 will be thoroughly evaluated in the normal course of the Unit 3 E/C program.
It is the inspector's view that the hole was probably a weld defect that was opened up by E/C, because the hole appeared on the weld, a location which is thicker than the surrounding piping.
There appears to be reasonable assurance that the piping will remain intact for the remainder of this fuel cycle because of the following: it took six operation cycles for the leak to appear; the piping in this area is well above the design minimum wall value of 0.0187" and; the leaking weld has been encapsulated by a furmanite fixture.
Within the areas examined, no violations or deviations were identifie Exit Interview The inspection scope and results were summarized on October 29, 1993, with those persons indicated in paragraph 1.
The inspector described the areas inspected.
Although reviewed during this inspection, proprietary information is not contained in this report.
No dissenting comments were received from the licensee.
Acronyms and Initialisms ANII ASHE BLPV BFN DCN DPR E/C el.
NPP NRC P. E.
WBN Authorized Nuclear Inservice Inspector American Society of Mechanical Engineers Boiler and Pressure Vessel Browns Ferry Nuclear Plant Design Change Notice Demonstration Power Reactor Erosion Corrosion Elevation General Electric Company General Electric Remote Inspection System Heating, Ventilating and Air Conditioning Inside Diameter Inspection Report Inservice Inspection Licensee Event Report Nondestructive Examination Number Browns Ferry Nuclear Performance Plan of The Tennes-see Valley Authority Nuclear Regulatory Commission Professional Engineer Quality Assurance Reactor Pressure Vessel Serial Number Seismic Qualification Utility Group Supplement Tennessee Valley Authority Ultrasonic Volume Watts Bar Nuclear Plant