IR 05000423/1989012

Insp Rept 50-423/89-12 on 890626-30.No Violations or Deviations Noted.Major Areas Inspected:Inservice Insp Program,Steam Generator Eddy Current Insps & Water Chemistry Results

ML20247L930
Person / Time
Site:	Millstone
Issue date:	07/21/1989
From:	Mcbrearty R, Strosnider J, Winters R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20247L888	List: IR 05000423/1989012 ML20247L885
References
50-423-89-12, IEIN-86-106, NUDOCS 8908010382
Download: ML20247L930 (9)

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U.S. NUCLEAR REGULATORY COMMISSION REGION I-Report N /89-12

- Docket N r License N NPF-49 Licensee: Northeast Nuclear Energy Company P. O. Box 270 Hartford, Connecticut Facility'Name: . Millstone Nuclear Power Station - Unit 3 Inspection At: Waterford, Connecticut Inspection Dates: June 26-30,1989 Inspectors: _e 7/4///9

/ A. McBrearty, Reactor Engineer, MPS, EB, date S, Region I h

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. Winters, Reactor Engineer, MPS, EB, 7/a/rt date S, Region I Approved by: . kb J. Strosnider, Chief,' Materials & Processes date D

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Section, Engineering Branch, DRS, RI Inspection Summary: Routine unannounced inspection on June 26-30, 1989 (Report No. 50-423/89-12).

Areas Inspected: Inservice inspection program, steam generator eddy current inspections and water chemistry results were inspecte Results: No violations or deviations were identified, s

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l DETAILS 1.0' Persons Contacted Northeast Nuclear Energy Company

• T. Burnes, Unit 3 Chemistry Supervisor

• C. Clement, Unit 3 Superintendent G. Closious, Manager, Quality Assurance K. Colgan, Eddy Current Specialist E. Grondahl, Chemist, Corporate Engineering

• J. Harris, Millstone Unit 3 Engineer

• L. Loomis, ISI Coordinator, Unit 3

• T. Lyons, Unit 3 Engineer

• D. MacNeill, NUSCO ISI Coordinator

• J. Waters, Chemistry Supervisor R. Wells, Manager, Nuclear Materials and Chemistry Ebasco Services Company R. Zieber, Supervisor, Nondestructive Examination United States Nuclear Regulatory Commission

• K. Kolaczyk, Resident inspector, Unit 3

• W. Raymond, Senior Resident Inspector

• Denotes those attending the exit meetin The 'nspectors also contacted other administrative and technical personnel during the inspectio .0 Introduction Millstone Unit 3 is a Westinghouse four loop pressurized water reactor that went into commercial operation on April 23, 198 It is currently in the first period of the first 10 year inspection interval. The first inspection interval is scheduled to end April 22, 199 The 1983 Edition through the Summer 1983 addenda of the ASME Code,Section XI is in effecc during this interva .0 References / Requirements Technical Specification paragraph 3/4.4.5 Steam Generators Steam Generator Owners Group - water chemistry guidelines

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'3 4.0 Inservice Inspection Program  !

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The 1989 outage,ISI plan and the ISI 10 year program were selected for ,

inspection to ascertain that scheduled items were examined and tha the schedule agreed with the 10 year plan and the current outage pla The inspector determined that the required examinations were completed and that changes to the program were documented. The. licensee intends to revise the program at the end of the outage. This revision is-intended ~to docunient the examinations completed during the outage and to show the program status regarding percent completed.

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The inspectors reviewed selected, inspections, including the ultrasonic-examina W a of tha. reactor vessel head welds, to determine that the appropric.e-examinations had ~oeen performed. In all cases the data indicated these examinations had been performed in accordance with the cont.....iLJ document '

In the case of the reactor vessel head the licensee's inspector reported two areas on the head that. appeared to be meridian welds not shown on the head drawing. Through subsequent investigation using both ultrasonic'and eddy. current techniques the licensee determined that these two areas were remnants of two attachment welds where lifting devices had been installed during head fabricatio ~ Conclusions The examinations which were scheduled and completed during the 1989 refueling outage complied with the inspection interval program. The licensee reported that'the program has been completed within the Code required limits for'the first inspection interval. The licensee's response to the reported extra meridian welds established that the existing drawings accurately depicted the true configuration of the hea .0 Personnel Certifications

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Qualification and certification records for EBASCO and Babcock and Wilcox personnel, the licensee's ISI and. eddy current testing vendors, were selected for inspection to ascertain that the technicians were certified in accordance with SNT-TC-1A, the governing document. In addition the inspector reviewed Pabcock und Wilcox procedure, 151-24, Revision 10, Administrative Prozedure for the Written Practice of Personnel Qualification in Eddy Current Examination. All records reviewed were found acceptabl .0 Steam Generator Eddy Current Inspection The minimum Technical Specification requirements for eddy current examination 3% of the total number of steam generator tubes in the

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L pl a nt'. This required testing' ofl676. tubes. The. licensee ~ elected to inspect approximately 45% of'theLtubes in both the "A" and "C" steam-

. generators using the standard bobbin coil. The sample chosen for each

' steam generator included the following:

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All known Model F damage regions:

Kori -2 dent region AVB Wear region

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' Suspect regions generic to all steam generators:

Row 1 U-bends All perimeter. tubes

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Millstone' Unit 3 specific ~ areas of interest:

Tubesheet irregularities All previously identified flaws

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'A general random pattern:

approximately 35% of tubes not included above Additional' tests using a rotating pancake coil were made on tubes including the following:

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tubesheet irregularities

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roll transitions in high carbon tubes

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ambiguous bobbin coil signals

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antivibration bar wear

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row I U-bends The results of this examination are shown in Table TABLE 1 EDDY CURRENT. EXAMINATION RESULTS Steam Generator Tubes Inspected Degraded Defective Category

"A" 2550 22 3 C2

"C" 2474 3 0 C1 The three defective tubes were plugged in accordance with the requirements of the Technical Specification, in addition one tube was plugged as a preventative measure due to a distorted eddy current signal. The degraded tubes were analyzed and it was determined that the indications were due to antivibration bar wear. The inspectors l verified that all tubes previously reported as degraded had been inspected during this outag '

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Conclusions The inspectors concluded that the licensee had performe'd inspections in.ex;ess of the Technical Specification requirements in order to determine the true condition of the steam generator .0 Data Analysis All eddy l current data were evaluated by two independent analyses. The primary analysis was performed by individuals with qualifications in accordance with SNT-TC-1A and licensee requirements specific to Millstone Unit 3. -The secondary analyses were performed using the Zetec CDS computer program monitored by a certified Level IIA individual. Differences between the two analyses resulted in a discrepancy report, which was then resolved by a qualified Level III analyst. If the differences were to be. resolved from pluggable to not

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pluggable a second lead analyst was required to approve the chang The licensee reported that this situation did not arise during this inspectio The licensee Level III from the corporate engineering staff was actively involved with the eddy current examinatio His function was to determine the tubes to be inspected, monitor the examinations as the tes-ing progressed and monitor the data analyses to assure that this was carried out in accordance with the established requirement This individual was the licensee's representative to assure the quality of the examinatio Conclusions The analyses of the eddy current data were performed with appropriate safeguards and licensee oversight to assure that all indications were found and properly dispositioned. The use of the computer screening during the secondary analyses assures that defects are not missed due to human erro .0 Eresion - Corrosion Control Program (IN 86-106)

Concern regarding erosion and corrosion of balance of plant piping systems has been heightened as a result of of the December 9, 1986 feedwater line rupture that occurred at Surry Unit This event was the subject of.NRC Information Notice 86-106 issued on Decen:ber 6, 1986 and a supplement issued on February 13, 198 The inspectors reviewed the licensee's actions with regard to the detection of erosion - corrosion in plant components. The inspection was conducted to determine the scope of the licensee's program and the results to date.

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The licensee's. erosion - corrosion program consists of selected

' portions of single and two phase high energy systems. The following plant systems are included in the program:

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Steam generator blowdown

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Condensate

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Extraction steam - 1st and 2nd point

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Extraction steam - 3rd and 4th point

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Auxiliary steam

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Moisture separator drain lines

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Feedwater

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HDL and HDH Cascading Feedwater Heater Drains

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Feedwater heater continuous vents Components of the program are ranked according to susceptibility to erosion - corrosion with the aid of the EPRI CHEC computer program for single phase systems, a program developed by the Massachusetts Institute of Technology for-two phase systems, manual calculations based on accepted equations and relationships, industry and plant specific experience and engineering judgement in combination with one or more of the aforementioned technique Inspection guidelines are provided by document EN 31125, Revision 1, Piping Inspection Program for Erosion - Corrosion. This document includes the selection criteria for systems to be examined, procedures for determining where to examine, how to establish a sampling program and how to expand the sampling pla During this outage 30 components were inspected for erosion -

corrosion. Of these 30 components 18 had previously been inspected and 12 new components were added. None were found that had thinned to the minimum design thicknes Conclusions The licensee is using the history available from other plants in selecting components to be included in the program. In addition a plant specific history is being developed through retesting of components. During each outage additional components are being added

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to the inspection coverage.

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9;0.' Primary and Secondary Water Chemistry Water chemistry data were reviewed as'part of this inspection. The methods of collecting and verifying the accuracy of these data were not included in the scope.of this inspectio s~

Primary water chemistry was stable throughout the second cycle

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indicating the' licensee had good control of the variables. governing:

water quality. Transients were ref.lected, as expected, by the lithium and pH dropping and the boron increasing during power reduction Secondary water. chemistry also was well controlled as shown in Table 2 with all parameters significantly below the EPRI guideline TABLE 2

, TYPICAL SECONDARY WATER CHEMISTRY RESULTS Parameter Blowdown EPRI ll) Blowdown Sodium (ppb) 5 20 ma Chloride (ppb) 1 20 ma Sulfate (ppb) 1 20 ma Cat Cond (umho/cm ) 0.08 0.8 ma Oxygen (ppb) 5 max.(2)

Hydrazine (ppb) 20 min.(2)

(1) Most values from in line monitors were below minimum detectable

' level (2) Feedwater sample The corporate chemistry department is actively involved in assisting the plant improve performance. The inspectors met with one of the

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corporate chemist and determined that several experiments were performed. One such experiment was the injection of nitrogen into the turbine. In this experiment it was established that this injection reduced the dissolved oxygen at the condensate pump discharge, and therefore in the secondary system. Another innovation was the purchase and.use of a Continuous Gas Partitioned used in conjunction with helium leak detection equipment to evaluate condenser gas removal efficiency. During the unexpected reactor trip on May 11, 1989 the plant personnel collected the required samples for determining hideout return in addition to the other data collection activities required during plant transient Conclusions The water quality at Millstone Unit 3 is significantly better than the EPRI guideline There appears to be excellent cooperation between the operating staff, the plant chemistry group and the corporate

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engineering group to allow innovations and experiments that lead to improved water qualit .0 Engineering

'The ' inspectors interviewed licensee engineering personnel and discussed corporate engineering involvement in various aspects of plant operations. From these interviews and reviewing the results of engineering projects the inspectors determined that corporate engineering has a significant role in assisting the plan The individuals were qualified and certified as required to perform these functions. For example, those engineers involved with the inservice inspection and steam generator. inspections were certified to Level III in the appropriate discipline In. the' area of water chemistry, engineering had recommended eight projects.for the improvement of water chemistry. These included changing the cation resin in the condensate polishing facility, i installation of a corrosion product sampler, and control of oxygen in the condensate storage tank. A project involving revir. ion of the chemistry data management system was reported as having been recently complete The engineering group is also active in the eddy current testing of-the steam generators. In this area engineering est,'blishes the extent of testing to be performed and is responsible-for the acceptance of the test dat In the performance of inservice inspection the engineering group is responsible for determining what testing is required and for the acceptance of the data. In addition engineering monitors the progress of this testing to assure that compliance to the requirements of the ten year program are satisfied. During the performance of the inservice inspection the licensee's engineering personnel review the data and as required verity these data by actual retesting of the ite Conclusions The licensee has been effectively using the corporate engineering group to support Millstone Unit Examples of this support int iuded improvements to the water treatment facilities, supervising the performance of the eddy current examinations of the steam generators, and supervising the progress of the inservice inspection ten year program. Engineering involvement is further demonstrated by the certified engineers verifying the data collected by vendors by actual retestin _ - -___ _- __ _ . ._ - _ _ _ _ _- _ ._ _

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9 l 11.0 Management Meetings Licensee management was informed of the scope and purpose of the inspection at the entrance at the beginning of the inspection. The findi.ngs of the inspection were discussed with licensee representatives during the course of the inspection and presented to licensee management at the June 30, 1989 exit interview (see paragraph ,

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1 for attendees).

At no time during the inspection was written material provided to the licensee by the inspector. The licensee did not indicate that proprietary information was involved within the scope of this inspection.

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