IR 05000250/1988006
| ML17342B250 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 03/23/1988 |
| From: | Adamovitz S, Kahle J, Ross W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML17342B249 | List: |
| References | |
| 50-250-88-06, 50-250-88-6, 50-251-88-06, 50-251-88-6, NUDOCS 8804080240 | |
| Download: ML17342B250 (21) | |
Text
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'UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 'MARIETTAST., 'N.W.
ATLANTA,GEORGIA 30323 MAR 3 l l988 Report No.:
50-250/88-06, 50-251/88-06 Licensee:
Florida Power and Light Company 9250 West Bagler Street Miami, FL 33102 Docket Nos.:
50-250, 50-251 Facility 'Name:
Turkey Point License Nos.:
Inspection Con Inspectors:
W. J.
o M
ch 7-11, 1988 Date Signed e
amovitz Approved by:
J.
B.
Ka e,
ection C ief D vision of Radiation Safety,and Safeguards ate S gned Z~~ dV D te igned SUMMARY Scope:
This routine, unannounced inspection was conducted in the area of plant
chemistry and corrosion.
A Results:
No violations or deviations were identified.
8804080240 88033i PDR ADOCK 05000250
DCD'
REPORT DETAILS Persons Contacted Licensee Employees
- C
- E
- L M.
K.
E.
p.
A.
E.
p.
D.
- J
- L
- LE p.
R.
NRC
- D. Brewer
- Attended exit interview Baker, Plant Manager Baker, Superintendent, Land Utilization Bladow, Superintendent, Quality Assurance Cooper, Supervisor, Nuclear Training Department Craig, Steam Generator Program Manager English, Chemistry Supervisor Fulford, Corrosion Engineer, General Engineering Gould, Staff Specialist, Nuclear Energy Services Lapierre, Chemistry Instructor, Nuclear Training Department Logiudice, Chemistry Instructor, Nuclear Training Department Meils, Chemistry Department Supervisor Odom, Site Vice President Pearce, Operations Superintendent Umbaugh, Chemistry Supervisor Vollmar, Chemistry Supervisor Woodard, Water Treatment Specialist, Chemistry Resident Inspector Exit Interview The inspection scope and findings were summarized on March 11, 1988, with those persons indicated in Paragraph 1 above.
The inspector described the areas inspected and discussed in detail the inspection findings.
No dissenting comments 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 inspection.
Licensee Action on Previous Enforcement Matters This subject was not addressed in the inspection.
Plant Chemistry (79701)
This inspection was a
reassessment of the licensee's capability to maintain the integrity of plant components, especially the reactor coolant pressure boundary, through the prevention of corrosion.
The last inspection in this area was made on April 6-10, 1987, at the beginning of what were to be extensive shutdowns for both units during most of the remainder of the year.
Consequently, during this inspection emphasis was
Oi
placed on the current status of principal components of the secondary system, the licensee's chemistry control program, and actions being taken by the licensee to monitor and to prevent thinning of carbon steel pipes and subsequent transport of solid corrosion products to the steam generators.
Status of Components During this phase.of the inspection the design and operability of components of the secondary cooling system were reviewed as to their effectiveness in preventing ingress of potential contaminants or in removing such contaminants before they could initiate corrosion within the steam generators.
(1)
Main Condenser and Condenser Cooling Water System As discussed in earlier inspection reports, the high salt content of condenser cooling water and the integrity of barriers against ingress of this water provided by the titanium condenser tubes are subjects that require continual vigilance by the licensee.
Through discussion with the Superintendent of Land Utilization, the inspector was informed of continuing efforts to provide cooling water that help maintain optimum vacuum in tke main condenser and adequate cooling by Service Water Systems.
These efforts involved dredging of cooling canals to increase water flow and reduce siltation and the removal of vegetation that inhibits air cooling of the water in the canals.
Because of the extensive periods. when neither unit of the plant was operating, quantitative results, in terms of temperature changes or salt content of the cooling water, had not been established during the past year.
An Amertap tube-cleaning system had been installed in the Service Water System of Unit 3 to help remove calcium salt scale from heat exchanger tubes.
No water leak had been observed in the condensers of either units, and eddy current tests of the condenser tubes of Unit 3, during its refueling outage in April 1987, did not identify any indications that required plugging of a tube.
The extent to which hydriding of the condenser tubes had changed since the last. inspection had not been determined because inservice inspection tests had not been performed, except during the refueling outages.
The licensee had continued to investigate the causes of tube hydriding and had established a voltage on the cathodic protection system less than the 750 millivolt (versus a silver/silver chloride electrode)
threshold that allows 'hydriding to occur.
Efforts were still being made to reduce air inleakage into the condenser to less than 6 standard cubic feet per minute (SCFM).
During this inspection the leak rates were
SCFM for Unit 3 and
SCFM for Unit 4.
A highly sensitive heat sensor was being
used effectively to detect air leaks by monitoring, the cooling effect of inrushing air.
(2)
Water Treatment Plani As discussed in previous reports, the water treatment plant (WTP) provides another potential pathway for contaminants to enter the secondary cooling water.
Since the last inspection in this area the WTP had deteriorated to the extent that it frequently had to be shutdown because of inefficient cleanup of the raw water (from 'the Dade County Water system).
During mos't of this inspection the WTP was shutdown, and steam generator blowdown had to be secured when the level of makeup water in the Demineralized Water Storage Tank dropped to approximately eight feet.
Loss of blowdown subsequently resulted in a buildup of impurities in the steam generators that briefly exceeded the Action Level 1 limit for cation conductivity (0.8 umho/cm)
before the WTP became operable again.
The inspector was informed that several steps had been or will be taken to increase the effectiveness of the WTP.
These actions include the following:
A member of the Chemistry Department had been designated WTP Coordinator with responsibilities to recommend and pursue design and operational improvements.
Major modifications on the WTP are to be made in April 1988.
The various beds (sand, charcoal, and ion exchange resins)
in the WTP will be replaced with new material.
The effectiveness of the current practice of using WTP operators on a rotational, as opposed to long-term, schedule was under review.
During the periods when the WTP will be inoperable (as well as when the output of the WTP needs augmenting)
makeup water will be processed by mobile demineralizer units contracted from vendors.
(3)
Condensate Cleanup System The inspector reviewed with cognizant personnel the licensee's policy and practice of bypassing the condensate polishers when the units are operating at full power.
This decision had been made on the basis of the licensee's belief that the filter, demineralizers would not be effective in protecting the feedwater and steam generators from significant inleakage of the highly saline condenser cooling water in the event of a serious
(4)
condenser tube leak.
Also, 'after the level of purity for teedwater.recommended by the Steam Generator Owners Group (SGOG)
was achieved during plant startup, by use of the polishers, further use of the polishers would continually contaminate the feedwater through leakage of ion-exchange resin powder.
These resin "fines" would subsequently thermally degrade in the steam generators to form corrosive sulfur-containing chemical species.
The inspector observed that w'hen the yolishers were bypassed and the steam generator water was being blown.down at a rate less than 100 gpm -per steam generator, the cation conductivity of the steam generator water had been maintained as low as 0.30 umho/cm.
This level of contaminants was considerably less than the 0.8 umho/cm limit recommended by the SGOG, and therefore, was acceptable.
However, as discussed earlier, whenever steam generator blowdown had to be secured and condensate makeup minimized, the purity of the steam generator water quickly deteriorated through the concentrating effect of the steam generators.'lthough the licensee was maintaining good chemistry control when blowdown was available, even purer secondary coolant is being achieved at other PWRs in Region II through continual use of condensate polishers and effective retention of resin fines.
Consequently, the inspector emphasized the value of continuing to investigate ways of reducing the leakage of resin "fines" when the condensate polisher are in use.
Steam Generators The inspector was informed that ten percent of the tubes in each steam generator of Unit 3 had been eddy current tested during the 1987 outage.
Only one tube had to be plugged as the result of these tests.
Plans were being made to eddy current test 100 percent of the tubes in one Unit 4 steam generator and 25 percent of the tubes in the other two steam generators during the upcoming refueling outage.
During the Unit 3 refueling outage all three steam generators were sludge lanced.
Less than 100 pounds of iron oxide sludge was removed from each steam'generator.
These relatively small amounts of sludge were indicative of'ffective prestartup cleanup of both the high-pressure (steam and drain) carbon steel pipe and the low-pressure carbon steel components of the secondary coolant system.
Also, these weights indicated relatively low rates of general corrosion and corrosion product transport as will be discussed in the next part of this report.
As discussed previously in this report steam generator blowdown was being used to maintain the purity of steam generator water within limits recommended by the SGOG.
The blowdown system was
'5 designed to remove as much as 600 gpm of water from each steam generator; however, the blowdown rate was usually maintained at approximately 100 gpm per steam generator in order to conserve water and thermal energy since all blowdown water was being wasted.
As discussed earlier," even this blowdown rate exceeded the designed makeup capacity of the WTP when both units were operating.
Consequently the inspector and Chemistry personnel reviewed the feasibility of reducing the blowdown rate further if the purity of the feedwater (and steam generator water) could be reduced to approximately 0. 1 umho/cm.
This level of purity has been achieved or bettered at most PWRs in Region II.
Thinning of Carbon Steel Pipe Through discussions with cognizant personnel from the licensee's corporate and plant staffs the inspector reviewed actions being taken to prevent pipe thinning in single-phase (water)
and two-phase (wet steam)
systems.
In an effort to prevent loss of pipe integrity from erosion the licensee's Inservice Inspection (ISI) Program had been revised to include single-phase systems as well as two-phase systems.
Loss of metal from carbon steel pipe as the result of general corrosion was. being addressed through proposed changes in the chemistry control program that would provide better pH control in steam and drain pipe.
One positive result of bypassing the condensate polishers was that the pH of the feedwater and steam generator water could be elevated without detrimentally affecting the demineralizers through expedited loading with ammonia.
During this inspection the pH of water in the steam generators was approximately 9.3.
According to SGOG guidelines the pH could be raised as high as 9.5 (Some plants in Region II maintain a
pH range of 9.5 to 9.6).
Since general corrosion of carbon steel pipe is inhibited at the higher pH ranges the action taken by the licensee was considered appropriate.
The inspector was informed that consideration is being given to substituting morpholine for ammonia to control pH.
Although morpholine has been used for this purpose for many years it was not considered as effective as ammonia when the All-volatile-Treatment (AVT) Chemistry Control program was selected by the SGOG and the Electric Power Research Institute (EPRI)
to minimize various corrosion'echanisms observed in the steam generators of PWRs.
However, recent EPRI reports have shown that lower fractionation of morpholine in the steam phase may increase its retention in the water phase of two-phase systems and, thereby, may provide a less corros'ive environment in the pipes that carry extraction steam or in the drains from the Moisture Separator Reheaters (MSRs).
The inspector encouraged the licensee, as part of its response to NRC BuTletins and Not'ices related to pipe thinning, to continue investigating possible actions
"that would reduce erosion/corrosion of pipe and transport of iron oxides to the steam generators.
(6)
Conclusions The following components of the secondary coolant system require priority attention from the licensee to ensure that the level of chemistry control recommended by the SGOG can be maintained:
integrity of the main condenser tubes design and operation of the WTP
.
functions of the condensate cleanup system and the steam generator blowdown system in achieving and maintaining high purity secondary coolant general oxidation of carbon steel pipe that results in pipe thinning and transport.of sludge to steam generators:
b.
Status of the Licensee's Chemistry Program During previous inspections the licensee's capability to control plant chemistry was considered to have been adversely affected by inadequate development of elements and activities essential to meet chemistry objectives.
Consequently, the second objective of this
, inspection'was to review and assess progress being made to develop an overall program that is consistent with the SGOG guidelines.
This part of the inspection consisted of discussions with members of the Chemistry, Training, and guality Assurance Departments and walkdowns of sampling facilities, laboratories, operational facilities (WTP and condensate polisher control rooms),
and the licensee's new training laboratory.
(1)
Staffing After the'major reorganization that had taken place in early 1987 the Chemistry Department had made significant progress in resetting goals and reassigning responsibilities for upgrading all of the elements of a Chemistry Control program.
A major impediment to these efforts was that the size of the Chemistry staff did not permit much time for activities other than the basic, routine analyses.
Four of the thirteen Chemistry technicians had been detailed to special problem areas (e.g.,
water treatment plant and reducing condenser air inleakage).
Two Chemistry technicians were assigned to each of three shifts.
The inspector was informed that approximately four technicians were lost each year through normal attrition, and contractor
personnel were to be used until a full complement of sixteen technicians could be 'hired "and trained.
Training The Chemistry Department was stHl considered to be deficient in personnel who were academically trained analytical chemists and/or were familiar with corrosion technology.
However, significant progress had been made in these areas through self-study during the last year.
These and other weaknesses
'identified by internal and outside auditors had been factored
.
into a
new training program, developed by the Training Department.
Since the last inspection two qualified instructors
.
(in radiochemistry and in non-radioanalytical chemistry)
had
.
been added to the Training Department Staff, and classroom and laboratory training modules had been developed to address known deficiencies as well as other training and retraining needs.
This formal training had not been effectively initiated, however, because members of the Chemistry staff could not be spared from their daily duties.
This situation was discussed in depth with licensee personnel but no satisfactory resolution was identified other than increasing the size of the Chemistry staff.
(3)
The inspector observed that instructions in the use of new analytical instrumentation and operation of the condensate polishers was being scheduled with vendor personnel as instructors:
Finally, the inspector attended several
"shift changeover" meetings and observed that these brief sessions were being used effectively to exchange information within the Chemistry staff, to discuss specific problem areas, and to permit supervisors to provide instructions and guidance on current responsibilities.
Procedures The inspector observed 'that the preponderance of all analyses of key chemical parameters in the secondary system, both control and diagnostic, were being performed with either inline analytical -instruments or state-of-the-art.
manually operated instruments.
Most of the procedures involving these instruments were based on vendor instructions.
Many backup analyses, however, continued to be based on standard analytical procedures described in chemistry literature on standard methods of analysis.
The inspector was informed that, as part of an overall plant improvement program, all chemistry procedures were under review and revision.
The number of procedures identified as necessary for chemistry/corrosion control had been increased from 130 to approximately 300.
The effectiveness and value of this
chemistry procedure upgrade program was considered to be questionable, however, since only one person had been detailed to this task.
The rapid changes and advances that have been made, and which 'are continuing to be made, in power plant analytical chemistry as the result of ongoing activities by the SGOG, FPRI, and the power plant industry would appear to require considerably more priority be given to maintaining procedures up-to-date.
As an example of these changes, the Chemistry staff was considering implementing new primary chemistry control guidelines, recently published by EPRI, in order to reduce the levels of out-of-core radiation throughout the reactor coolant
'system.
Physical Facilities In Inspection Report 87-17 (dated Nay 1, 1987)
the licensee's efforts to upgrade the chemistry laboratory had been recognized.
The improved laboratory facilities had been used effectively during 1987 to locate state-of-the-art analytical instrumentation as well as to provide better working space for Chemistry technicians.
Among the new instruments was an atomic absorption spectrometer that fulfilled a perceived need for a, backup analyzer for lithium.
In addition, the Chemistry staff had a
new ion chromatograph and a
new Total Organic Analyzer that will enhance capabilities to diagnose problems associated with the WTP as well as to monitor trace contaminants of 'the secondary coolant.
The Chemistry Department had new offices and meeting facilities in a building that had been completed during the past year.
In addition, laboratory space had been provided adjacent to the Chemistry= Department offices and
'was being equipped with radiochemical and non-radiochemical instrumentation for training purposes.
The Chemistry Department's capability for monitoring control and diagnostic parameters in the steam generator blowdown had been significantly enhanced through tj>e installation of two inline monitoring panels (one for each unit).
These panels were located near the sampling taps on the mezzanine level of the Turbine Building and had been tied in with the existing sampling lines from the steam generators.
These panels were equipped with analyzers and readout meters and recorders for the following chemical variables.
specific conductivity cation conductivity pHchloride sodium dissolved oxygen
'k ck
These monitors were being serviced on a monthly schedule by Westinghouse personnel.
c.
Non-radiological Confirmatory Measurement Program In an effort to evaluate the Chemistry Department's equality Control Program and to provide an opportunity. for the inspector to observe the analytical technique of licensee Chemistry Technicians, the inspector requested the Chemistry Supervisor to have a series of samples analyzed.
These liquid samples had been prepared for the NRC by the Brookhaven Na'tional Laboratory to be consistent with samples of reactor coolant and secondary coolant normally encountered in a
PWR.
Because of the work load of the Chemistry Staff and the inoperability of the ion chromatographs during the period of the inspection only a
few of the samples were analyzed while the inspector was onsite.
The licensee will transmit the results to the inspector when all samples have been analyzed.
The results will be reviewed by NRC and reported in a subsequent report.
Inspector Followup Item 84-06-01 During the initial inspection in this area (February 6-10, 1984)
concern was expressed
"over the licensee's procedure for obtaining most grab samples for the secondary water system at an outdoor sample panel that is not protected from such adverse environmental conditions as rain and salt spray."
Also, the outdoor sampling sink did not provide fot dispositioning radioactive water in case a
primary-secondary leak occurred.
Consequently, under such conditions, steam generator blowdown samples could not be taken.
This item had been discussed during all subsequent inspections, and the licensee's response was that the deficiency was recognized but could not be corrected because of budgetary constraints.
During this inspection.the inspector was informed that resolution of this deficiency had been made Item Nos.
102 and 103 on the Turkey Point Nuclear Plant Integrated Schedule ("Secondary Chemistry Inline Monitors" for Units 3'nd 4)
and currently are scheduled for completion in h;ovember 1991 and November 1992 respectively.
These activities will be performed in conjunction with the construction of a new secondary chemistry laboratory, i.e.,
Item No.
146,
"Chemistry Cold Laboratory Chemical Equipment" to be completed in March 1992.
Based on information provided to the inspector (Integrated Schedule Modification Worksheet (B),
October 23, 1987)
priorities and completion dates were based on eleven factors (predominantly related to safety and reliabi'lity significance)
used to rate benefits to the plant and to the licensee's electrical generation requirements.
Since IFI 84-06-01 was opened two temporary corrective actions had been taken.
In 1985 a plexiglass enclosure was constructed around some of the
sampling points.
In 1987 two modular on-line monitors were installed for steam generator blowdown samples, as was discussed earlier in this report.
The subject of sampling was discussed in depth wi.th Chemistry Supervision and Plant Management personnel.
The licensee was aware that all aspects of chemistry control must be considered in meeting the stringent guidelines recommended by SGOG, EPRI, and Westinghouse.
Eventually, the new laboratory and inline monitors, along with the current state-of-the-art analytical instrumentation and the computerized data management system that soon will be installed, will provide the Chemistry Department with the best resources available for processj'analytical chemistry control.
However, until all of these improvements have been completed, the licensee must continue to be aware that erroneous data can result from contamination of grab samples taken at the outdoor sink.
Such an incident occurred during this inspection when grab samples were taken for analyses of chloride in steam generator blowdown while it was raining.
On the basis of the temporary corrective actions taken, the long-term corrective actions budgeted for in the Integrated Schedule, and the licensee's comprehension of this.issue IFI 84-06-01 is hereby closed.
t