IR 05000280/1985023
| ML18143B369 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/31/1985 |
| From: | Blake J, Ross W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18143B367 | List: |
| References | |
| 50-280-85-23, 50-281-85-23, NUDOCS 8508130467 | |
| Download: ML18143B369 (11) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323 Report Nos.:
50-280/85-23 and 50-281/85-23 Licensee:
Virginia Electric and Power Company Richmond, VA 23261 Docket Nos.:
50-280 and 50-281 Facility Name:
Surry 1 and 2
- 12, 1985 License Nos.:
DPR-32 and DPR-37 Approved by: -.---.-...........,..-;:.,,c.,,:,,,c::;;,..-...;-'r-!~:-,-"T---:"---------- Chief En ne ing Branch Division of Reactor Safety SUMMARY Scope:
This routine, unannounced inspection entailed 40 inspector-hours on site in the areas of plant chemistry and inservice testing of pumps and valve Results:
No violations or deviations were identifie ~g~g~BO PDR ADOC~
PDR G
REPORT DETAILS Persons Contacted Licensee Employees
- R. F. Saunders, Station Manager
- H. L. Miller, Assistant Station Manager
- E. S. Grecheck, Superintendent, Technical Services J. W. Ogren, Corporate Director Operations and Maintenance Support
- W. A. Thornton, Corporate Supervisor System Chemistry W. Hagan, Supervisor Water Management L. G. Miller, Assistant Supervisor Chemisty R. Blount, Supervisor, Inservice Inspection, Engineering Other licensee employees contacted included chemistry, and technician NRC Resident Inspectors D. J. Burke
- M. Davis
~ *Attended exit interview Exit Interview The inspection scope and findings were summarized on July 12, 1985, with those persons indicated in paragraph 1 abov The inspector described the areas inspected and discussed in detail the inspection findings listed belo No dissenting comments were received from the license (Closed) Inspector Followup Item 50-280, 281/84-16-0l Evaluation of Secondary Water Chemistry Program (Section 5.d).
(Closed) Inspector Followup Item 50-280, 281/84-16-02 Leakage of Primary Water Into the Component Cooling Water System (Section 5.d).
The licensee did not identify as proprietary any of the material provided to or reviewed by the inspector during this inspectio.
Licensee Action on Previous Enforcement Matters This subject was not addressed in the inspectio.
Unresolved Items Unresolved items were not identified during this inspectio *
2 Plant Chemistry (79501 and 79502)
As a result of its continuing concern for steam generator tube integrity, the NRC staff has recently issued recommehded actions and review guidelines that are directed toward the resolution of unresolved safety issues regarding this subject (see Generic Letter 85-02 dated April 17, 1985.) One recommended action is as follows:
11 Licensees and app 1 i cants shoul ct have a secondary water chemistry program (SWCP) to minimize steam generator tube degradatio The specific p 1 ant program shoul ct incorporate the secondary water chemistry guide 1 i nes in the Steam Generators Owners Group (SGOG) and Electric Power Research Institute (EPRI) Special Report EPRI-NP-2704, 11 PWR Secondary Water Chemistry Guidelines, 11 October 1982, and should address measures taken to minimize steam generator corrosion, including materials selection, chemistry limits, and control method In addition, the specific plant procedures should include progressively more stringent corrective actions for out-of-specification water chemistry condition These corrective actions should include power reductions and shutdowns, as appropriate, when excessively corrosive conditions exis Specific functional individuals should be identified as having the responsibility/authority to interpret plant water chemistry information and initiate appropriate p 1 ant act ions to adjust chemistry, as necessar The reference guidelines were prepared by the Steam Generator Owners Group Water Chemistry Guidelines Committee and represented a consensus opinion of a significant portion of the industry for state-of-the-art secondary water chemistry control.
Reference Section 2.5 of NUREG-0844 In a parallel action, the NRC Office of Inspection and Enforcement has developed two new Inspection Procedures to verify that the design of a plant provides conditions that ensure long term integrity of the reactor coolant pressure boundary and to determine a licensee 1s capability to control the chemical quality of plant process water in order to minimize corrosion and occupational radiation exposur The objectives of these new procedures were partially met during a previous inspection of the two Surry units, (see Inspection Report 84-16 dated June 6, 1984).
The results of that inspection indicated that the capability to prevent ingress of corrosive contaminants into the three steam generators of each unit had been significantly improved through design modifications made in the secondary water cycle that were implemented when the original steam generators were being replaced in 1979-198 The licensee was also in the process of revising the procedures and directives of the Surry secondary water chemistry program to incorporate the SGOG guideline This followup
inspection consisted of a reassessment of the licensee 1s activities in these two areas and a review of problems that were attributed to water chemistry during the past yea Plant Design and Operation At the time of this inspection, Unit 1 was operating at full power and Unit 2 was restarting after a refueling outag During the refueling outages for both units during the past year the licensee continued to make major changes in the secondary water cycle to improve the protection of the steam generator from corrosion and tube fai 1 ur These changes and the status of the major components of the secondary water cycle are summarized as follows:
(1)
Main Condensers (2)
An audit of analyses made on condensate water while the units were at power during March-July 1985 indicated that water 1 eakage through the retubed condensers was minima (Instrumentation for monitoring inleakage of condenser cooling water from the James River through continuous determination of sodium in each water box has not yet been installed.) Condensate chemistry parameters were within SGOG/EPRI guide 1 i nes and approximated the purity of demineralized wate The inspector was informed that three percent of the titanium condenser tubes were eddy-current tested during the last refueling outage As discussed in Inspection Report 84-16 some of these tubes have been damaged by mechanical wear, but no tube failure from corrosion has been observe Air leakage into the hotwells has been encountered, especially when the units are at low power leve The licensee continues to rely on a contractor to identify the sources of air inleakage and is attempting to maintain inleakage of less than 5 SCFM to protect the low-pressure turbines from corrosion as well as to minimize the dissolved oxygen content of the condensat Condensate Makeup Water System The licensee provides a supply of high quality water for primary and secondary coolants and other demands by purification of water taken from deep wells on site and from the James Rive The water treatment process consists of flash evaporation of the raw water followed by demineralization of the distillat Although the flash evaporators were retubed recently, the desired efficiency has not been achieve Consequently, approximately 50 percent of the purified water is currently being produced by a mobile water treatment p 1 ant that has been contracted for unt i 1 the p 1 ants systems can be made fully effectiv *
(3) Condensate Polishers (4)
During the previous inspection, the inspector observed that through the use of full-flow deep-bed demineralizers the quality of the feedwater was being maintained at a high leve An audit of recent operational data indicated that normally this quality st i 11 remains very goo However, two prob 1 ems have been encountered during the past yea Polishers bed 28 in Unit 2 has a weld crack that allows water to leak into the lower plenum of the tank, and this bed has been out of service since the end of the last fuel cycl Consequently, now when a bed is generated there is no replacement bed available and, consequently, part of the condensate flow is not polishe This shortcoming has been especially troub 1 esome during startup cleanup of the condensate when cleanup of hotwell water is neede The licensee considers this to be maintenance deficienc Also, early break-through of sodium has been encountered frequently because of i nsuffi ci ent rinsing of aged resin during the regeneration phas During this inspection period, three demineralized beds were being replaced with new resin in an effort to eliminate this proble There is evidence, in hideout return studies, that sulfate ions are continually being 1thrown 1 from the polishers bed This is a generic problems that is caused by cross contamination of anion and cation resins when they are regenerated with sulfuric acid and sodium hydroxid The licensee is testing two additional types of resins to determine if better physical separation can be achieve Also the use of inert resin to separate the cation and anion beds is still being considere The licensee informed the inspector that consideration is also being given to installing a Graver CONESEP external regeneration system for the same purpos In the CONESEP process the lower (heavier) cation resin beads are removed from the bottom of a conical shape tank until a monitor indicates contamination by the less dense anion resin bead The licensee informed the inspector that although its goal is to ultimately achieve such a clean secondary system that polishing will not be needed, there are no plans to bypass the demineralizers to eliminate throw of sulfat Instead, the polishers will continue to be used as protection against a sudden loss of integrity of the condenser and inleakage of the brackish James River water that is used for condenser coolin Feedwater System During the past year, the licensee has initiated two positive actions to minimize the transport of corrosive soluble and solid contaminants to the steam generato As part of the p 1 ant I s operating procedure for restarting a unit from cold shutdown, specified chemistry limits must be met before power level may be increased above five percent and, subsequently, above 30 percen These I chemistry holds I enables the water in the low-pressure (condensate/feedwater) lines, and, subsequently, in the high pressure (steam and condensate drain) lines, to be cycled back through the hotwell and condensate polishers until the specified purity is achieve Even these 1 holds 1 failed to prevent contamination of the steam generator water during the startup of Unit A significant increase in cation conductivity and chloride occurred while this unit was at -60 percent power and was thought to have been caused by transport of soluble chloride from a section of pipe downstream of the heater drain pump when drain water was initially pumped forward to the feedwater pump The contaminated section of pipe had been installed during the refueling outage and had not been previously flushed during the startup cleanu Although this incident was unique and probably will never reoccur, it emphasizes the need to monitor the water in the drain tank before it is pumped forward during startu In a separate action to minimize buildup of sludge in steam generators, the licensee has begun to replace a 11 copper-containing alloys in the secondary water syste During the most recent refueling outages the moisture separator re heaters were replaced with stainless steel tube Similar replacement of the tubes in the feedwater heaters is scheduled to begin during the next refueling outage By this means the licensee hopes to eliminate stress corrosion of steam generator components through processes that have been attributed to plating of copper or the presence of copper oxide in sludge that is deposited on the surfaces of steam generator tubes, tube sheets, and tube support plate (5)
Steam Generators The steam generators in both units were sludge-lanced during the most recent refueling outage The results indicated that as the result of continual use of condensate polishers and steam generators blowdown, the amount of solids had been kept to very low level; i.e., a total of 62 pounds of sludge was removed from Unit 1 and 184 pounds from Unit (Only 2.5 pounds were removed from steam generator 18).
The licensee believes that the sludge lancing technique was efficient and that these small quantities o sludge represent the true condition of the steam generator Most of the sludge was identified as oxides of iron, copper, nickel and minor metals and to represent oxidation products of the principal constituents of the carbon-steel pipe and copper-alloy tubes that are used throughout the secondary water cycl The sludge from Unit 1 also contained several hundred parts-per-million of phosphat Although the Surry units originally contro 11 ed secondary chemistry with phosphates, the licensee
cannot exp 1 ai n the presence of phosphate in the new steam generator There was also small amounts of 11 non-metallic beads
that apparently consisted of carbonaceous materia 1 of unknown origi During the last refueling outage for Unit 2, the licensee repaired (by grinding) cracks that had been observed in the steam generators' transition-zone upper-girth weld These welds were part of the original steam generators, and the cracks have been attributed to chemical pitting and to stress corrosion cracking prior to the rep 1 acement of the 1 ower sect ions of the steam generators in 197 The inspector was informed that in the period before the steam generators were rep 1 aced, the steam generator water frequency contained 25 ppb or more of dissolved oxygen and 300-400 ppm of chlorid There is further evidence that these welds cracks may have continued to propagate (through static stress or fatigue) even after chemistry control was improve In an effort to prevent similar residual buildup of corrosive ions in the steam generators the licensee continually blows down the steam generators during plant operatio In addition, plant operating procedures now include a 12-hour 'chemistry hold' when the temperature of the steam generator water drops to 350°F during a unit shutdown. During this 1hold 1 blowdown is continued in order to remove contaminants that are solubilized as 'hideout return' as the temperature decrease The inspector observed that at the end of these 1holds 1 the concentration of sulfate in the blowdown still remained as high as 800 pp Consequently, even longer 1holds 1 would have been beneficial for cleansing the steam generators of this corrosive specie (6) Main Steam System and Turbines In an effort to eliminate any environment for further stress corrosion cracking in low-pressure turbine disks, the licensee has installed new rotors in all of the low-pressure turbines at the Surry statio The disks on the new rotors were designed to have less stress levels than before and, thus, be more resistant to stress corrosion that was theorized to have been initiated by condensation of steam and precipitation of trace amounts of corrosive salts and oxide As will be discussed later, the licensee's capability to monitor the purity of the main steam has also been improve (7)
Summary:
The inspector concluded that the licensee is continuing to take positive steps to make the design of the secondary water system conducive to the elimination of corrosive environments, especially in the steam.generator However, very 1 itt 1 e progress had been made during the past year in resolving problems associated the
- production of condensate makeup wate The units operated by this licensee are unique in Region II in their use of flash evaporators to obtain high purity wate Most of the problems associated with the condensate cleanup system during the past year were attributed to delays in repairing one polisher vessel in Unit 2 and to the use of aged resins with degraded ion-exchange characteristic The licensee is pursuing several avenues to eliminate the 1throw 1 of sulfate and to maintain the concentration of all key chemistry parameters in the steam generator to less than 20 pp Scope and Adequacy of the Licensee 1s Water Chemistry Program Since the inspector 1s previous inspection (May 1984) the licensee has completed the revision of administrative and chemistry procedures so that the Surry secondary water chemistry program is now consistent with the recommendations of the SGOG/EPRI guide 1 i ne The inspector reviewed the following key procedures (Periodic Tests) that now incorporate specified limits or acceptance criteria for key control parameters as well as the action that must be taken by members of the Chemistry Section if a limit is exceede The few discrepancies between the requirements of these procedures and the recommendations of the SGOG/EPRI guidelines were explained satisfactorily by the license PT-38. 38 l-PT-38.41 1-PT-38.42 1-PT-38. 45 Chemistry Sampling-Steam Generator Secondary Wet Layout (Unit 1)
Main Steam System (Unit 1)
Steam Generator and Feedwater Secondary Systems (Unit 1)
Condensate System (Unit 1)
As a result of this review (and a review of Chemistry Admi ni strati ve Procedures as discussed in the next section of this report) the inspector believes that this licensee is meeting all of the technical recommendations of the SGOG/EPRI guidelines (and NRC Generic Letter 85-02).
As will be discussed later, additional attention should be given to implementing the SGOG/EPRI recommendations related to staffing and maintenanc Implementation of the Surry Water Chemistry Program The inspector reassessed the 1 i censee I s capability for making the chemical measurements necessary for control of the chemical quality of the secondary coolant and for implementing other requirements of the Surry Water Chemistry Progra This evaluation was again based on discussions with licensee personnel, review of procedures, observation of calibrations and chemistry tests, and an audit of results obtained during the past yea (1) In conjunction with the revision of Periodic Tests the licensee has developed a series of Chemistry Admi ni strati ve Procedures (CAPs) to provide detailed information and instruction related to the various responsibilities of the Chemistry Sectio These documents reference guidance provided by the Nuclear Steam Supply System (NSSS), vendor (Westinghouse), Electric Power Research Institute (EPRI), Institute of Nuclear Power Operations (INPO),
and the licensee's corporate chemistry group and are to be used by Chemistry Technicians to fully comprehend their duties and the interface of the Chemistry Section with other departments of the statio The inspector observed that a formal on-the-job tratning program had been developed to qualify all Chemistry personnel on the new, state-of-the-art, ion-chromatograph and atomic absorption spectro-mete A Senior Technician has been detailed for this instruction as well as for maintaining these instruments operable and for setting-up new on-line ion chromatographs in the near futur Another Senior Technician has been detailed to upgrade training in quality control based on CAP In compliance with the SGOG/EPRI guidelines that corrective action should be taken in a timely manner, the licensee now has at least two members of the Chemistry Section on duty at all time Procedures for notifying pl ant management and the Ope rat i ans Department of abnormal chemistry events are detailed in CAP (2)
The licensee has entered into a long-term steam generator maintenance agreement with Westinghouse that will significantly affect the implementation of the Surry Water Chemistry Progra Plans are underway to install several types of in-line analytical instrumentation and monitors to supplement the current schedule of 1grab 1 sample The inspector expressed two concerns related to this upgrade progra Currently, because of maintenance problems, most of the chemistry monitors on the board in the Control Room are inoperabl The inspector was told by Operations personnel that they would depend on personnel from the Chemistry Section or Water Treatment Section to alert the Control Room of any devia-tions from normal chemistry and to make recommendations for corrective actio At present, the Chemistry Section does not have any readouts or al arms for i n-1 i ne monitor If new i n-1 i ne instrumentation is to be installed, the alarms and monitors should be located where they will result in timely corrective action being taken - as recommended by the SGOG/EPRI guideline The SGOG/EPRI guidelines al so address ti me ly maintenance of instruments and other components that are needed to control and monitor secondary water chemistr It is the inspector's opinion that the licensee needs to place considerably more attention and resources in this area to ensure that abnormal chemistry events
can be recognized and corrected promptl The addition of new in-line instrumentation will only add to this work loa (3) The licensee has developed the capability to trend key chemistry parameters with a compute Consequently, both graphical and numerical data are available to plant management for diagnosing and controlling transients in secondary water chemistr The inspector took advantage of this capability to audit the licensee I s control of key chemical parameters during the past yea As reported earlier, chemistry control was considered to be very good except during power excursions (hideout return) and during isolated chemistry transient The cause of most of the transients were readily explained by Chemistry Section personne However, a significant increase in the chloride concentration in only one steam generator occurred on June 29, 1985 while Unit 2 was returning to power, and its cause could not be determined with certaint The licensee believes the high chloride concentration may have resulted from decomposition of an organic cleaner, Inhibisol, that had inadvertently been left in this steam generator after the girth weld repairs had been complete The inspector considered this to be a quality control proble With the high sensitivity that is now available with ion chromato-graphy the licensee is attempting to identify all anions that contribute to the cation conductivity of steam generator wate These studies, when correlated with the measured cation conductivity of the main steam, indicate that a large percentage of anionic species volatilize with the steam and, thus, may consist, in part, of organic or inorganic carbon compound This information will be of use in establishing what species are carried over to the low-pressure turbine rotor (4) The inspector observed three Chemistry Technicians while they performed analyses of routine samples by means of ion chromato-graphy, atomic absorption, flame photometry, spectrophotometry, conductivity bridge, and pH mete All activities, including calibrations of instruments and procedures, were considered to have been performed properly and in a professional manne (5) During this phase of the inspection, no violations or deviations were i dent ifi e c Inspector Followup Items (IFI)
As a result of this inspection, the following followup items have been close ~--
IFI 50-280, 281/84-16-01 11 Evaluation of Secondary Water Chemistry Program.
This item is closed on the basis of new information that is summarized in Section 5.b of this repor IFI 50-280, 281/84-16-02 11 Leakage of Primary Water Into the Component Cooling Water System.
During the latter part of his previous inspec-tion the inspector became aware that primary coolant was leaking into the component cooling water syste In the interim this leak has been stopped; however, the component cooling water remains contaminated with reactor cooling wate.
Inservice Testing of Pumps and Valves The inspector continued a review of the licensee 1 s activities for implementing the requirements of Section XI of the ASME code to test safety-related pumps and valve Attention was primarly directed to the licensees procedures for stroke-timing valves and to the summary listing of results from valve stroke-time test To the extent -0f this review, no deviations or violations were identifie The inspector did question the licensee 1s policy and procedures for establishing reference and maximum stroke times and discussed the NRC staff 1 s position that stroke times are to be used to establish the operability of only a specific valve rather than the system that includes the valv After reviewing procedures (Periodic Tests) in which the maximum allowable stroke time was considerably longer (by a factor of 10 to 100)
than the measured stroke time, the inspector requested that the maximum stroke times be reviewed to ensure that they were of magnitudes that would allow trends in degradation of the valves to be identified.