IR 05000280/1994016
| ML18153B021 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/14/1994 |
| From: | Blake J, Kleinsorge W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18153B020 | List: |
| References | |
| 50-280-94-16, 50-281-94-16, NUDOCS 9407290142 | |
| Download: ML18153B021 (10) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900 ATLANTA, GEORGIA 30323-0199 Report Nos.:
50-280/94-16 and 50-281/94-16 License~:
Virginia Electric and Power Company Glen Allen, VA 23060 Docket Nos.:
50-280 and 50-281 License Nos~:
DPR-32 and DPR-37 Facility Name:
Approved Scope:
Surry Power Station Units 1 and 2 lake, Chief and Process Section Branch Reactor Safety *
- SUMMARY 7/(7'~
"'ate Signed *
This routine, announced inspection was conducted in the areas of Chemically Enhanced Pressure Pulse Cleaning (PP/CC) treatment of the three Unit 2 Steam Generators (S/G)s, feedwater system leak, and flow accelerated corrosio Results:
Interviews, observ~tions and records review indicated that the Unit 2 S/G PP/CC project was well planned and executed, and appeared to be effectiv With the exception of the weakness noted concerning the aGcuracy of weld documentation, the licensee's actions related to the feedwater line failure were appropriate to the circumstance The licensee has established an effective program to maintain high energy carbon steel piping systems within acceptable wall thickness limit In the areas inspected, no violations or deviations were identified.
9407290142 940715 PDR ADOCK 05000280
~=------=-~-.
- Persons Contacted Licensee Employees REPORT DETAILS W. Benthall, Supervisor, Licensing
- *B. Graber, Licensing
- D. Hanson, Maintenance
- L. Moris, Radiation Protection
- J. Price, Assistant Station Manager
- E. Turko, Engineering
Other licensee employees contacted during this* inspection included engineers, operators, technicians, and administrative personne NRC Resident Inspectors
- M. Branch, Senior Resident Inspector S. Tingen, Resident Inspector
- Attended exit interview Acronyms and initialisms used throughout this report are listed in the last paragrap.
Steam Generator (S/G) Cleaning (92903)
_ Background In May 1993, Unit 2 noted small oscillations in "C" steam generator water leve By August 1993, the "C" S/G water level oscillations had enlarged to 15% to 20%.
Investigation indicated that the 11C 11 S/G level water level oscillations were independent of feedwater flow rate. It was determined that the water level oscillations were the result of density wave (hydrodynamic) instability, the root cause of which was blockage of flow area in the Tube Support Plates (TSPs), in particular the upper TSP In order to stabilize plant operation, the licensee incrementally decreased reactor powe By early November 1993, reactor power had dropped to 96%.
- ouring a forced outage in November 1993 (trip caused by a loss of power, to all three feedwater regulation valves), Westinghouse Company (H)
performed a pressure pulse cleaning treatment on "C" S/ The cleaning
. removed a certain amount of the blockage, but significant blockage remained. Subsequent to the outage the unit was stable at full powe S/G water level oscillations of 10% soon returned and reactor power was ramped back in 1% to 2% step It was evident that the pressure pulse cleaning treatment, performed by N, had not adequately corrected the S/G water level oscillation In late February 1994, the licensee started vender interviews, planning for a more aggressive cleaning proces By late March 1994, the licensee decided on Chemically Enhanced Pressure Pulse Cleaning (PP/CC) treatment
for the three Unit 2 S/G PP/CC is a process in which chemicals are selectively introduced into the S/Gs at varying temperatures, pH levels, and concentrati~ns to remove iron and coppe Due to system load demands, the licensee elected to perform PP/CC in June 199 The licensee solicited bids for PP/CC in March-April 199 The Unit 2 PP/CC outage ~ommented June 3, 199 W was selected to perform the PP/CC as the prime-contractor (the project manager and th~ provider of corrosion monitoring}.
The subcontractors were Vectra (provider of personnel and the majority *of the equipment} and DIS (provider of some equipment, chemicals and the chemical laboratory facility}.
The project was conducted under th~ umbrella of the W Quality Assurance Progra The WPP/CC process uses the EPRI/SGOG (described in EPRI NP.;.6354-M,
.
Qualification of PWR Steam Generator Chemical Cleaning for Indian Point-2, May 1989} chemical cleaning solvents at low temperature combined with*
pressure pulse cleaning to remove sludge buildup at the TSP elevation The main chemical ingredient used in PP/CC operation was the chelating agent ethylene diamine tetra-acetic acid (EDTA}.
Other major ingredients included corrosion inhibitors, ammonia, oxidizing agents, and hydrazin The PP/CC process included real-time insitu corrosion monitoring of the S/G The effectiveness-of the PP/CC process was monitored by inprocess chemical analysis of the cleaning solutions and-selected remote visual examinations of the S/G internal Inspection*-
To evaluate the PP/CC process in the areas of process control, personnel qualification, and protection of safety related equipment, the inspector conducted interviews with lfcensee and contractor personnel; jxamined selected records and video tape; and observed work activitie * Identificatio SSS 2.13.2-VIR-Ol 6/1/94
. 0-SSS 2.13.2-VIR-02 6/1/94 2-SSS 2.13.2-VIR-03 6/1/94 2-SSS 2.13.2-VIR-04 6/1/94 Documents Reviewed Revision ntle
. O Master Governing Procedure for Chemi-cally Enhanced Pressure Pulse Cleaning of Surry-2 Steam Generators
Steam Generator Equipment and Pressure Pulse Operation for Chemical Cleaning
Sampling and Analysis Procedure for Surry-2 Steam Generator Chemically*
Enhanced Pressure Pulse Cleanin Process Application and Termination for Surry-2 Steam Generator Chemically Enhanced Pressure Pulse Cleaning
Identification 2-SSS 2.13.2-VIR.,Q5 6/1/94 SECL-94-091 6/1/94 NSD-JLH-4028 SG-94-01-026 1/18/94 W STD-OP-1994-6823 5/27 /94
Documents Reviewed Revision Title,
O Set-Up and Operation of Corrosion Mon-itoring Equipment for Chemically En-hanced Pressure Pulse Cleaning
Safety Evaluation for:
Surry Unit 2 Steam Generator Chemic~lly Enhanced Pressure Pulse Cleaning Analysis of Performance and Hydrodynamic Stability for Water Level.
Oscillation in Surry Unit 2 Steam Gen-erators Corrosion Monitoring Application Code and System Qualification Procedure In addition to the documents indicated above the inspector examined
- documentation attesting to and certifying personnel qualifications and equipment calibration..
The inspecior viewed a video tape of remote visual examinationi of the internals of the "C" S/G, depicting before and after views of the top of the seventh TS Virtually all the deposits had been removed from the
surfaces of the TSPs, the quatrefoil flow passages, and the tube surfaces visible in. the limited field of vie *
A significant quantity of material was removed from the generators, which is indicated belo Materials Removed From Unit 2 S/G Copper Iron Sludge (Lbs.)
(Lbs.)
(Lbs.)
S/G A 350 2600 1i58 S/G B 470 3050 984 S/G C 500 3900 610 Total 1,320 9,550 2,852 The inspector conducted a walk-through inspection of the chemical handling facilities used for the PP /C The inspector noted the dikes erected to contain spills and to prevent the commingling of chemicals with the potential of synergistic reaction The inspector observed de-activation activitie *~
- Interviews, observations and records revie~ indi~ated that the Unit 2 PP/CC project was well planned and executed, and appeared to be effec-tiv Within the areas examined, no violations or deviations were identifie.
Feedwater System Pipe Leak (92903)
Background The licensee noted water on the floor adjacent to the 2A Feedwater heate On May 25, 1994, after isolation and cool-down of the 2A Feedwater heater, the insulation was removed exposing a through~wall hole in heater drain line 10"-WLD-101-301, at a 10" x 14" expande The hole was located at the 12:00 position in the heat affected zone of the weld connecting the h~rizontal expander to*a down directed 10" elbow (see Figure 1). The licensee cut out the carbon steel expander and elbow and re~laced the fittings with low alloy steel, 2jCr !Mo, fittings. At thi writing, the 1 i censee is conducting a meta 11 urgi ca 1 failure ana 1 ys i In 1992, prior to the implementation of the tHECMATE program, the licensee ultrasonically examined the elbow and expander on the Unit 1 "B" train line (in the same relative position as above).
The minimum wall thickn~ss value found, though acceptable then, would have been unaccept-able prior to the end of the next fuel cycle. The maximum ~oint of wear was approximately 16" to 20" down the extrados of the elbow at the 12:00
_position (see Figure 1).
Location of 199.!I Unit 2 F;11ilure
Location of 1992 Unit 1 Fallure Expander
Fccdwatcr Heater The licensee expanded the sample and examined the "A" train elbow and expande They were.found to be acceptable for continued service. The
Unit 1 "8" train elbow was replaced with a*low alloy steel, 2iCr lMo, fittin The Unit 1"8" train expander remains the original carbon stee The elbow and r~duce~ in the Unit 2 "8" train was ultrasonically examined
- in June 1994, and found to be acceptable for.continued service for
.
several cycle The licensee indicated that they intend to replace both 118 11 train fittings at the next Unit 2 refueling outage, when they replace the Unit 2 feedwater heater Inspection
. To evaluate the licensee's actions relative to* the balance of plant non-safety related feedwater system leak, the inspector conducted interviews with licensee personnel; examined the failure sites; examined the cut out elbow and expander; and.~xamined selected record~.
The inspector examined welder qualification arid certification documen-tation; Quality Control (QC) inspector qualification, certification, and*
. visual acuity documentation; welding filler material certified material test reports (CMTRs); and welding procedure specifitations (WPSs) and their associated procedure qualification records (PQRs); irivolved with the replacement of the failed Unit 2, carbon steel, 10 11 x 14 11 expander and the worn, 10 11 elbow with 2iCr lMo low alloy steel fitting The documents were examined for compliance with licensee procedures and Sections II and IX of the ASME B&PV Cod Welding Filler Material CMTRs Examined Type Size Heat/Lot N ER-BOS 82 ER-BOS 82 E-8018-82 E-8018-82 l/8
3/32
1/8" 3/32" F5409 F2874 412W1371 26847 As a result of the review of documentation for the wel~ing filler materials, discrepancies were identified on 11Weld Material.Field Control" forms issued by the licensee for welding filler material contro * o On "Weld Material Field Control 11 form Serial No~038590, the Heat and*
Purchase Order Numbers for electrode type E-7018 {minimum tensile
. strength 70 ksi carbon steel coated electrode) filler material was annotated when type E-8018-82 (80 ksi llCr-lMo steel coated elec~
trade) was issued and use o Electrode type E-8018 {mini~um tensile strength 80 ksi carbon steel coated electrode) was annotated on several 11Weld Material Field
. Control II forms, when Type E-8018-82 (80 ksi HCr-lMo steel coated electrode) was intende *
o Type ER-8018 (unknown type) was annotated on one "Weld Material Field Control" form, when Type ER-80S-B2 (80 ksi HCr-lMo steel bare rod) was intende The licensee documented the incorrect Heat and Purchase Order Numbers on a Station Deviation Report (DR) dated June 23, 1994 (DR number was not available at this writing). the licensee indicated that they would add the discrepant material types to that DR or institute a new D The
- licensee conducted an immediate investigation into this matte The licensee's preliminary results indicated that welding filler materials used were consistent with the materials specified in the applicable WP The errors were only in the documentation and did not affect plant equipmen The above discrepancies demonstrate a weakness concerning the accuracy of welding documentatio This is of concern because th~ same welding filler material i~sue stations, personnel and ~rocedures used for this non-safety related, balance-of~plant job, are employed for plant safety related wor Welder's Qualification Certification Documentation Examined GM 7784; KS 5016, DB 6994, KS 4632, and RT 0360 QC Inspector Certification and Documentation Examined GH MT-II; GAM Visual.Weld, SRW Visual Weld, and CWM Mechanical WPS WPS-508, Revision F
. 9/91 WPSs Examined PQR
.505, Revision A, 2/2/82 506, Revision A, 10/30/82 532, 8/27/90 533, 9/9/91 534, 9/9/91 The WPS examined above was properly supported by PQR The welds were made by properly qualified and certified welders, using appropriate
.
welding materials in accordance with properly qualified welding procedure specifications, and inspected by properly qualified and certified inspec-tors/examiner *
W.ith the exception of the weakness noted concerning the accuracy of weld documentation, the licensee's actions related to the feedwater line failure were appropriate to the circumstance Within the areas examined, no violations or deviations were identifie.
- 7 Flow Accelerated Corrosion (FAC) (49001)
The licensee his ~stablished a FAC inspection program which im~lements
- the CHECMATE EPRI (Electric Power Research Institute) computer code, industry experience, and previous inspection data as predictive tools for determining and prioritizing inspection locations. The inspector conducted interviews with licensee personnel and reviewed records as indicated belo Observations/Findings During Unit 1 Refueling Outage RFO 13, the lic~nsee planned to examine 121 locations in their Unit 1 FAC progra The licensee expanded the sample size to 137 locations and identified 16 FAC degraded components:
13 were replaced and three were repaire *
The:inspector examined the engineering evaluations for the 13 replaced component The observations were compared with the applicable proce-dure *
FAC Engineering Evaluations Examined Component,
Component System Disposition Identification Type 1-SD-PPS-598 6" Pipe Sch. XS Steam Drain Replaced 1-SD-PSF2-297
11 90° El bow Steam Drain Replaced Sch. 80 -
1-SD-PSFI-44
11 45° El bow Steam Drain Replaced Sch. XS 1-SD-PPS-597
11 Pipe Steam Drain.
Replaced Sch. XS 1-SD-PSF2-282
11 90° Elbow Steam Drai Replaced Sch. STD 1-SD-PSFl-45
11 45° Elbow
- Steam Drain Replaced Sch. 80 l-SD-PSF2:.299
11 90° Elbow Steam Drain Replaced Sch. XS 1-SD-PFS2-28 ° El bow Steam Drain Replaced Sch. 80 1-FW-PFS2-41
11 90° Elbow Feedwater Replaced
. Sch. 100 1-FW-PPS-27
11 Pipe Sc Feedwater Replaced 100 l-FW-PSF2-44
11 90° El bow Feedwate Replaced Sch. 100
FAC Engineering Evaluations Examined Component Component" System Disposition Identification Type l-CN-PFS2-122 18" 90*
0 El bow Condensate Replaced Sch. XS-l-CN-PPS-118 18" Pipe Sc *condensate Replaced XS Tne licensee is in the process of converting their CHECMATE data to CHECWORKS which operates,in the Microsoft Windows environmen Notwithstanding the feedwater system leak discussed above, the licensee has established an effective program to*maintain high-energy carbon steel piping systems within acceptable wall thickness limits;
Within the areas examined, no violations or dev1ations were identifie. * Exit Interview The inspection scope and results were summarized on June 24, 1993, with those persons indicated in paragraph I. The inspector described the areas inspected: Although reviewed during this inspection, proprietary information i.s not contained in this report. Dissenting comments were not received from the license.
Acronyms and Initialisms ASME B&PV CMTR CN Cr DPR DR
. EDTA EPRI FAC FW ksi Lb Mo N NRC p. PP/CC PQR QA QC Re American Society of Mechanical Engineers Boiler and Pressure Vessel Certified Material Test Report Condensate Chromium Demonstration Power Reactor Station Deviation Report Ethylene Diamine Tetra-Acetic Acid Electric Power Research Institute Flow Accelerated Corrosion Feedwater 10a Lbs. per square inch Pounds Molybdenum
_ Number Nuclear Regulatory Commission Professional Engineer Chemically Enhanced Power Pulse Cleaning ProGedure Qualification Record Quality Assurance Quality Control Revision
..
RFO S/G Sc SD SGOG STD TSP VA kl WPS XS
Refueling Outage Steam Generator Schedule Steam Drain Steam Generator Owners Group Standard Tube Support Plate Virginia Westinghouse Company Welding Procedure Specification Extra Strong_