IR 05000302/1988021

Insp Rept 50-302/88-21 on 880711-15.No Violations or Deviations Noted.Major Areas Inspected:Plant Chemistry, Corrosion Control & Pipe Thinning

ML20207G575
Person / Time
Site:	Crystal River
Issue date:	08/05/1988
From:	Kahle J, Marston R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20207G569	List: IR 05000302/1988021 ML20207G564
References
50-302-88-21, NUDOCS 8808240165
Download: ML20207G575 (12)

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UNITED STATES g?pm CEcoq%g

NUCLEAR REGULATORY COMMISSION

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REGION H I I 0 101 MARIETTA ST RE ET, f ATLANTA, GEORGI A 30323 5% kk--)

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Alle 0 81988 Report No.: 50-302/88-21 Licensee: Florida Power Corporation 3201 34th Street, South St. Petersburg, FL 33733 Docket No.: 50-302 License No.: DPR-72 Facility Name: Crystal River 3 Inspection Conducted: July 11-15, 1988 Inspect : b R/ R. Marston b Alb.](e 6 8 Date Signed

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l Accompanying e sonnel: W. J. Ross Approved by: CfM m.J1[1 k [fp J; . Kahle, Scction Chief Date Signed

,Di ision of Radiation Safety and Safeguards SUMMARY Scope: This routine, unannounced inspection was conducted in the areas of plant chemistry (Inspection Module 79701), corrosion control and pipe thinning, e

Results: Major improvements were found in corrosion control and plant operation since the last inspection in these areas as the result of the following activities: successful removal of corrosion products from the once-through steam generators (OTSG); increased surveillance and maintenance related to the main condenser; replacement of copper-nickel alloy tubes in the moisture seoarator reheaters; and improved training and quality control within i the Chemistry Departmen The chemistry program had been strengthened through

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the promulgation of a corporate policy statement that endorsed water chemistry guidelines recommended by the Steam Generator Owners Group and the Electric l Power Research Institute (SG0G/EPRI).

NRC concerns related to pipe thinning; i.e., IE Notice 86-106, etal., were being actively addresse Within the areas inspected, no violations or deviations were identifie One ,

Inspector Followup Item (IFI) was close l l

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REPORT DETAILS Persons Contacted Licensee Employees J. Barrett, Nuclear Engineering Specialist, Plant Engineering-B. Crane, Engineer, Plant Engineoring P. Elsburg, Training Supervisor P. Ezell, Environmental Specialist

• B. Hickel, Manager Nuclear Plant Operations J. Payne, Nuclear Chemistry Supervisor

• J. Roberts, Assistant Superintendent, Nuclear Chemistry and Radiological  ;

Protection (Chem / Rad)

S. Robinson, Superintendent, Chem / Rad R. Stewart, Engineer, Performance Engineering

• D. Worley, Nuclear Chemistry Manager Other licensee employees contacted included Nuclear Chemistry technician NRC Resident inspectors

• P. Holmes-Ray

• J. Tedrow

• Attended erit interview Plant Chemistry (79701)

This inspection was a continuation of a program designed to assess the .

licensee's capability to prevent degradation of the primary coolant  !

pressure boundary particularly, as well as other plant systems, as the .I result of corrosion / erosion. During previous inspections at Crystal River ;

Unit 3 (CR-S), the major areas of concern had been related to plant i systems and chemistry control; i.e., deterioration of the efficiency of l the OTSGs due to reduced water flow caused by corrosion products plugging l the flow orifices; inleakage of saline condenser cooling water into '

condenser hotwells; and limitations in expertise and resources available to the Chemistry Department, l

During this site visit, the inspector reviewed and re-evaluated the 1 performance of components and systems included within the secondary I coolant cycle as well as the effectiveness of the chemistry contro program for preventing loss of integrity of the OTSG tubes, q Corrponents and Systems i

By means of discussions with cognizant itembers of the Chemistry and Engineering Departments and through an audit of chemistry data, the i

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2 inspector reviewed the performance of the major components of the secondary cooling system during the interval since the last inspection in this area in March 1987 (Inspection Report No. 50-302/87-08).

(1) Main Condenser As the result of increased surveillance and maintenance programs, the effectiveness of the copper-nickel alloy condenser tubes as barriers against insress of saline condenser cooling water had been markedly improved. Only two minor leaks had occurred but were isolated quickly. Consequently, the purity of the condensate in the hotwells remained high, e.g., cation conduer.ivity was typically less than 0.1 umho/cm and sodium concentrations were less than 1 pp The improved integrity of the condenser was attributed to two factors: epuxy had been applied periodically to the tube sheets to reduce leaks at tube to tube sheet joints; and the eddy current test surveillance program hed been upgraded so that 100% of the 41,672 tubes are to be tested each refueling outag During the last inspections all tubes with indications of greater than 80% through-wall cracks had been plugge A sumary of the status of the condenser tubes as of May 19, 1988, was as follows:

Waterbox A B C D Tubes Plugged 857 471 225 278 60-80% 181 81 417 37 40-60% 1987 1337 1275 845 less than 40% 7393 8529 8501 9258 Although there were indications of microbiological induced corrosion (MIC) on some stainless steel components of the main cooling water lines (90-inch concrete pipe), no corrosion attributable to MIC or to macrobiological species (such as clams) had been observed in the condenser. The licensee credited the Amertap tube cleaning system for preventing problems from these organism Inieakage of air into the condenser hotwell had been reduced !

from a typical leak rate of 16-18 SCFM during earlier fuel cycles to 10-14 SCFM in Cycle 7. This improver.ont was ;

attributed to work performed by a recently formed ' leak j detection team.' The licensee believed that a faulty gland seal i on the low pressure turbine wes the main scurce of the remaining l air leaks, and this seal will be replaced during the next refueling outage that is scheduled for September 198 !

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The concentration of dissolved oxygen in the hotwell water was highest (5-10 ppb) during the startup of. a fuel cycle and continued to decrease to less than or equal to 1 ppb as the cycle progresse (2) Service Water Systems The- inspector was informed that subsequent to coatir.g the waterboxes and the piping of Service Water heat exchangers with polyurethane in 1985 damage to the heat exchanger tubes had been small. However, the licensee continued to clean debris from the tubes and water boxes approximately every forty days. No MIC had been observed in Service Water component (3) Water Treatment Plant and Water Makeup System

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During previous inspections, the licensee had been having difficulty keeping the purity of condensate makeup water at the level recommended by the SGOG/EPRI. In an effort to ensure an ecceptable level of purity for both condensate makeup and for emergency feedwater the licensee had completed the following program during the last refueling outage:

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Water that was pumped from an onsite well and demineralized in a dedicated system at the site of CR-1 and CR-2 was subsequently stored in the CR-3 Demineralized Storage Tank (DWST). During the last outage the control board used to monitor the quality of the product had been upgraded with new inline instrumentation. Typically the product had a cation conductivity less than or equal to 0.07 umho/cm during the first six months of 198 A floating roof had been installed in the DWST to prevent ingress of air and to maintain a low concentration of dissolved oxygen in the DWST water (100-200 ppb during the first six months of 1988).

However, the purity of the DWST water continued to degrade with storage increase fromtime 0.07(e.g., the cation umho/cm to 0.2 conductivity

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. The to licensee had initiated a study to identify and eliminate the source of contaminatio A new Condensate Storage Tank (CST) had been constructed to help guarantee a supply of high purity water for the Emergency Feedwater System (EFS). This tank was equipped with a nitrogen sparger to minimize the concentration of dissolved oxyge In addition, this water was being treated with ammonia and hydrazine to ensure that all water pumped into the OTSGs via the EFS would be of equal quality to the feedwate '

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l The former CST, which was not equipped to . prevent ingress of- -

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air, was being utilized as a surge tank for demineralized water inventor The concentration of dissolved oxygen was being kept-less than 10 ppb by batch addition of hydrazine to this tan (4) Condensate Polishers As the result of reduced inleakage of condenser cooling water, the deep-bed condensate demineralizers were essentially being loaded only with ammonia during the current fuel cycle. Since the mixed bed resins were still capable of retaining such

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potentially corrosive species as sodium, chloride, and sulfate ions the resins had not had to be- replaced since the start of Fuel Cycle 7. Such an extension of the useable life of the resin beds represented a very significant improvement, both i technically and economically, in the operation of the condensate cleanup system, i I

The quality of the polisher effluent had remained very high; ,

e.g. , cation conductivity = 0.06 - 0.07 umho/cm, chloride less '

than 1 ppb, sodium approximately 1-2 ppb, sulfate typically less '

than 5 ppb or non-detectable). j All volatile treatment (AVT) control of the feedwater was being I maintained at a pH level of 9.00 - 9.35 and nondetectable i concentrations of dissolved oxygen by the injection of hydrazine I alone. Sufficient amonia to maintain this pH was being formed !

through thermal decomposition of hydrazine, consequently, the !

injection of additional amonia was not require I (5) Once-Through-Steam-Generators During previous inspections, the operation of the OTSGs had been j observed to be adversely affected by accumulation of solid I corrosion products (mostly iron oxide in the form of magnetite) l l in the broached openings between tubes and tube support plate !

As a consequence, power penalties that exceeded ten percent had l been incurred. During the last refueling outage, the licensee l i attempted to remove the plugging material by the use of a 1 l modified "pressure-pulse" technique that had been used (with less than the desired results) during an earlier refueling outage (see Inspection Report No. 50-302/85-10).

Before and after the "pressure-pulse" cleaning, the licensee had removed 150-175 pounds of magnetite from the lower tube-sheet of each OTSG by an improved lancing technique. Both the cleaning and lancing operations were more successful than in 1985 and the plant had been operating at full power (2500 MW th) since the ,

beginning of Cycle 7 (except for a 1-day shutdown caused by a feedwater pump trip). However, the plugs appeared to be reforming, and the licensee believed that additional load limits

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might be necessary within three of four months unless the OTSGs were cleaned agai '

The amounts of corrosion products removed from the four OTSGs at CR-3 were relatively small in comparison to the sludge removed from many recirculating steam generators in NRC Region I Also, the licensee of another Babcock-and Wilcox nuclear power-plant in Region 11 had chemically removed several thousand-pounds of iron oxide from OTSGs that had previously been-subjected to the pressure-pulse cleaning treatment and ,

subsequently sludge lanced. Consequently, the fonnation of new i blockages may be indicative of magnetite adhering to tubes, tube support plates, and other structural components of the OTSG The licensee stated that although it is attempting to remain I abreast of chemical cleaning technology there were no plans to - l chemically clean the CR-3 OTSGs. Because of the paucity of l information related to the use of the' chemical cleaning methods i developed by EPRI and other utilities the inspector requested i that the licensee keep the NRC informed if plans to use chemical j cleaning on the OTSGs or any other safety-related system are  :

made in the futur l

As the result of eddy current test during the last refueling outagc, .the licensee had plugged two OTSG tubes where I indications of mechanical damage had been observe !

(6) Moisture Separator Reheaters (MSRs)

During the last refueling outage, the original copper-nickel MSR tubes had been replaced with tubes fabricated from stainless steel. This action was taken to improve the efficiency of the

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MSRs; however, it also accomplished the removal of the only copper alloy components (other than the main condenser tubes) in the secondary coolant syste Even though the MSRs drain back to the hotwell so that water is eventually polished before

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becoming feedwater, the elimination of this potential source of copper corrosion products was considered to be beneficial to the protection of the OTSG (7) Pipe Thinning and Transport of Corrosion Products

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During his last inspection, the inspector had been informed that

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several actiuns were planned to minimize loss of metal from pipes and heat exchangers tubes in the secondary coolant system.

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These proposed actions were partially in response to NRC concerns that had resulted from the Surry pipe rupture in December 1986 (e.g. Information Notice 86-106) and partially were designed to reduce the transport of corrosion products to the ')TSG _ _ - - _ _ _ - _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ - _ - _ _ _ _ _ _ _

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A special task force was subsequently fonned to address this issu With the assistance of a contractor an analyses of potentially vulnerable (to erosion /corrosiva) pipe sections had been identified. During the last refueling outage forty of

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these candidate sections of both single phase and two-phase lines had been inspected by ultrasonic methods. Three regions were identified as having detectable thinning. Using a conservative assumption that the original pipe thickness had been 110% of nominal (thus increasing the apparent wear rate),

the licensee replaced these suspicious sections in the feedwater bypass line and in two regions of the extraction steam line A more comprehensive surveillance program was Seing developed for use during future refueling outages. Also the use of alloy steel for replacement of ^ inned carbon steel piping was being considered for future repines, in an effort to reduce pipe thinning caused by general corrosion, the AVT chemistry control program had been modified to increase the upper limit for feedwater pH to 9.3 This action was taken on the theory that general corrosion of carbon steel is decreased as the environment becomes less acidic. Even higher pH limits were considered but were rejected for two reasons. Higher pH levels would cequire greater concentretions of ammonia, which, in turn, would increase the probability titat the copper-nickel condenser tubes would be degraded through ammonia reactice with copper. Alto, increased concentrations of ammonia in the condensate might reduce the efficiency of the condensate polishers as barriers against potentially corrosive catior.s if a leak occurred in a condenser tub The licensee had also planned a study related to corroshn product transport mechanisms; however, this program had not been starte The inspector and licensee personnel discussed the results of other corrosion product transport studies that had been performed since the issuance of Information Notice (IN) 86-10 In the context of this discussion the replacement of copper alloy MSR tubes was considered to be a positive action. The principal pathway at CR-3 for corrosion products to be transported the OTSGs was concluded to be through extraction steam lines and high pressure feedwater drains to the feedwate (8) Conclusion The licensee had been successful in operating CR-3 in a manner that facilitated good corrosion contro The key to this success was considered to be the positive actions taken in many areas during the last refueling outage. Improvement in the integrity of the condenser had reduced tha urgency for possible

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major maintenance on or replacement of the tube bundle However, the benefits to be gained from the installation of titanium condenser tubes were still being investigate Upgrading of the condenser eddy current test program to 100% of the tubes is consistent with the intent of Generic Letter 85-0 The decreased probability of condenser leaks had given increased flexibility to AVT chemistry control of the secondary coolant system as well as increased operational life to the condensate polisher The licensee had been successful in restoring the designed cooling capability of the OTSGs through removal of magnetite from tube-tube support plate openings, b. Chemistry Control Program As addressed in the initial inspection per Module 79701 (Inspection Report No. 50-302/84-08 dated April 17, 1984), the licensee's cheristry control program had been developed to meet the general requirements of Technical Specification (TS) 7.1.6 as well as specific req'lirements of such TSs as 4.1.2.8, 4.1.2.9, 4.4.7, and 4.9.1.2. Later (1986), a new Compliance Procedure (CP-138, Secondary Water Chemistry Guidelines) was implemented, partly in response to the NRC staff's recommendation in Generic Letter 85-02 that each PWR liccr.me incorporate the guidelines developed by the SG0G/EPRI into their chemistry progra ;

During this inspection, the inspector was provided with a copy of i corporate policy statement entitled "Endorsement of Water Chemistry Guidelines." This statement, dated May 22, 1987, documented ~an i endorsement of the SG0G/EPRI guidelines and "agreement in principal i with tne cpera+.ing philosophy" of these guidelines. These actions l were considsred to fully meet the intent of the chemistry recomendations in Generic Letter 85-0 )

i Through discussions with managerial, supervisory, and technical members of the Nuclear Chemistry and Radioicgical Protection Department (Chem / Rad), through audits of chemistry data, and through inspections of chemistry sampling facilities (in-line monitors) and laboratories the inspector reassessed four major elements of the licensee's chemistry program; i.e., staffing, training, quality

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control, and facilities / instrumentatio (1) Sth*fing The Chemistry Department had continued tc experience difficulties in establishing a stable and qualified staff of supenisors, technicians, and . support chemists / chemical engineers. Since the last inspection several changes had been made in management positions: the Acting Superintende..? of

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Chem / Rad had been confirmed in this position; the former Chemistry Hanger had been promoted to Assistant Superintendent of Chem / Rad with new responsibilities in health physics and radwaste control in addition to Chemistry; and the former Staff Chemist had returned from the disbanded 0TSG Task Force to-become the new Chemistry Manage In addition, a new Chief Technician had been appointed; however, this individual was to

. be transferred out of the Chemistry Department. At the time of this inspection there were eight unfilled positions for l technicians, and the licensee was using temporary contract l personnel until the open positions could be filled with trained FPC employees. The inspector was informed that efforts were undemay to add a chemist / chemical engineer to the staff to provide support for OTSG activities as well as to assist with nother chemistry responsibilitie (2) Training l Even ' hough the chemistry staff was short of personnel the

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technicians were still organized in six shift Consequently, each technician continued to be available for four weeks ea year for training by the Training Department. As the result, i approximately half of the basic chemistry program of 224 hours0.00259 days <br />0.0622 hours <br />3.703704e-4 weeks <br />8.5232e-5 months <br /> had been completed by several technicians during the past yea The Training Department was developing lesson plans for a i followup curriculum for many of the basic chemistry subject l This two phase program was being reviewed monthly by supervisory l personnel from both the Training and Plant Chemistry Departmen The inspector was informed that the goals of the on-the-job training program was to fully qualify two technician specialists in the theory, operation, and. maintenance of each state-cf-the-art instrument used to analyze grab samples; e.g.,

ion chromatograph, atomic absorption spectrophotomete However, all technicians would eventually be qualified in the use of these instrument (3) Quality Control The development of an effective chemistry quality control program had progressed appreciably in the last year as the result of the additional emphasis and resources given to this area in 198 The major remaining weakness perceived by the inspector was the inability to convert to computerized data to more useable control chart The inspector perforvd an independent evaluation of the capability of chemis y technicians to monitor the most important chemistry variables normally used for control and diagnostic purpose Aqueous solutions of these variables had been prepared for this use by the Brookhaven National

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Laboratory. The CR-3 Chemistry Manager was requested to have these samples analyzed in the same manner as routine plant grab samples. The inspector periodically monitored these activities so as to evaluate the technicians' technique and accuracy. All of the analyses had not been completed by the end of the inspection period; however, a preliminary assessment of the results indicated that an acceptable level of accuracy and precision was being achieved it. most analyses. The final data will be.sent to and reviewed by the inspector, and an evaluation will be included in a later inspection repor (4) Facilities / Instrumentation The inspector performed a "walk-down" of the Chemistry Department's "secondary sampling room" and the laboratories used to analyze grab samples. Except for two observations no major difference from previous inspections were foun On the positive side, an additional laboratory had been acquired for analytical instrumentation, thereby, improving the working environment and providing more space for permanently locating these instruments. On the negative side, environmental control of the laboratories was being maintained with a temporary cooling system while major repairs were being performed on the permanent cooling syste As the result, the ambient temperature in the laboratories was not ideal for the operation of analytical and radiochemistry counting equipmen (5) Conclusiun During the past year, the Chemistry Departmeat had fulfilled its

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basic responsibilities ' to monitor and control chemistr However, this success was achieved with minimal staff resources and even better results are expected with additional personnel and continuing trainin One area in which additional resources were considered to be needed was in the implementation of new EPRI guidelines for reducing out-of-core radiation levels through modifications of primary coolant chemistry control. The licensee is the first in Region 11 to take this action, therefore, operational experience at other plants, for comnarison purposes, is currently limite Also, industry .xperience during the last year has shown that all licensees should have the capability to protect the components of the NSSS and the balance of plant from corrosion

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during extended outages. This licensee had been -invrstigating the use of both wet and dry layup procedures for this purpose; however, implementing procedures had not been writte Finally, corrosion research efforts initiated by EPRI and the SG0G are generating large amounts of information to help all utilities to foresee and prevent new corrosion problems. These and other I

demands on personnel resources and expertise are considered

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desirable evolutions of the guidance provided by EPRI and the SG0G guidelines to which a corporate commitment has been mad A.t the conclusion of.this phase of ine inspection no violations or deviations had been identifie No violations or deviations were identifie . Action On Previous Inspection Findings And Information Notices (92701, 92717) (Closed) IFI 302/86-16-01, Determine That Upper Measurements on New Meteorological-(Met) Tower are Within the Thermal Boundary layer i

During a previous inspection, the inspector noted that the new primary met tower was closer to the Gulf than the old (now backup) .

met tower. The inspector stated that under seabreeze conditions, the upper instrument level on the new tower might be above tW thermal internal boundary layer (TIBL), which was formed separating the ,

advected sea boundary layer from the land boundary laye The inspector reviewed a study conducted by a vendor for FPC which was published in March 1988. Section 4.2 of the study discussed the thermal boundary layer evaluatio The study concluded. u eing conservative modeling, that the boundary layer could interwet the two met towers during unstable atmospheric condition Because the !

boundary increased in height with distance from the shore it was ,

possible that the primary tower could be intersected by the boundary interface while the b W9 tower was totally. immersed in the TIB This could cause same differences in the measured parameters between the towers, primarily upper level temperature and temperature lapse rates. The licensee representative stated that stability indices could be calculated from wind direction deviations rather than from :

the tempetsture lapse rat . (Closed) Information hotice 88-22, Disposal of Sludge from Onsite l t Treatment Facilities l

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The inspector reviewed documentation which showed that the 1 information Notice had been received and assigned for evaluatio '

' (Closed) Information Notice 88-31, Steam Generator Tube Rapture Analysis Deficiency

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The inspector reviewed documentation which showed that the problem referenced in the Information Notice was not relevant to Crystal j River-3 because of its STSG desig )

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11 Exit Interview The inspection scope and results were sunnarized on July 15, 1988, with those persons indicated in Paragraph 1. The inspector described the areas inspected and discussed the inspection findings. No dissenting coments were received from the licensee. The licensee did not identify as proprietary any of the material provided to or reviewed by the inspector during this inspectio ,

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