IR 05000272/1991003
| ML18095A855 | |
| Person / Time | |
|---|---|
| Site: | Salem, Hope Creek  |
| Issue date: | 03/20/1991 |
| From: | Gray E, Kaplan H, Patnaik P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML18095A854 | List: |
| References | |
| 50-272-91-03, 50-272-91-3, 50-311-91-03, 50-311-91-3, 50-354-91-05, 50-354-91-5, NUDOCS 9104090130 | |
| Download: ML18095A855 (5) | |
Text
. U. S. NUCLEAR REGULATORY COMMISSION
REGION I
50-311/91-03 50-272/91-03 Report No /91-05 50-272 50-311 Docket No License Nos. DPR-70, DPR-75, NPF-57 Licensee:
Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 0803 Facility N~me: Salem Nuclear Generating Station
,~Creek Nuclear Generating Station Inspection At:
Hancocks Bridge, New Jersey Inspection Conducted:
January 16-17 and January 17-18 1991 Inspectors:
Pat Patnaik, Reactor Engineer, MPS, EB, DRS, RI He!/o~J.p*/i.~r Reactor Engineer MPS, EB, DRS, RI Approved by: f /~~
E. HaroldGra;Chief, Materials and Processes Section, EB, DRS, RI date J-).(J -'l J date
- date Inspection Summary:
A routine unannounced inspection was performed from January 16-17 at the Salem Generating Station and January 17-18, 1991 at the Hope Creek Station, Report Nos. 50-272/91-03, 50-311/91-03 and 50-354/91-05).
Areas Inspected:
The areas covered were water chemistry control at Salem and investigation of inservice inspection indications on the reactor coolant recirculation piping at Hope Cree Results:
No violation or deviation was identifie QPDR ADOCK 05000272 PDR
OETAI LS 1.0 Persons Contacted Public Service Electric and Gas Company Salem:
- V.Polizi
- M. Morr.on i
- A. Orticelle
- T. Cellmer
- E. H. Villar J. Wray
- G. Slaby
- G. Dziuba
- G. Suey M. Alpaugh
- R. Dolan B. Preston D. Smith Hope Creek:
- T. Spenser
- R. Griffit *J. Perrin
- W. Maher
- R. W. Brandt Operations Manager Technical Department Manager Maintenance Manager Radiation Protection and Chemistry Manager Station Licensing Engineer Radiation Protection Supervisor Plant System Operation Chemistry Supervisor Chemistry Supervisoi Senior Staff Engineer *
Licensing Engineer Principal Engineer, Radiation Protection Services Manager, Licensing Station Licensing Engineer Project Manager Manager, Quality Control Metallurgical Consultant Sy*stem Engineer Inspection Services Engineer United States Nuclear Regulatory Commission T. Johnson
- S. M. Pindale S. Barr
- K. Lathrop R. Harris P. Peterson Senior Resident Inspector Resident Inspectbr Resident Inspector Resident Inspector NOE Technician NOE Technician
- Denotes those attending the exit meetin The inspectors also contacted other administrative and technical personnel during the inspectio.0 References/Requirements
Technical Specifications - Salem Nuclear Generating Station Units 1 and *
Updated Final Safety Analysis Report - Salem Nuclear Generating
- Station Units 1 and *
PWR Secondary Water Chemistry Guidelines, Revision 1 EPRI NP-5056-SR
ASME Boiler and Pressure Vessel Code Section XI, 1983 Edition including 1983 Summer Addend. Purposi The purpose of this inspection was to investigat~ the recent inservice inspection indications in the rea~tor recirculation piping of the Hope Creek Generating Station and to review the program for control of
. water chemistry in the primary and in the secondary systems of Salem Nuclear Generating Statio.0 Inservice Inspection (ISI) Indications in the Reactor Recirculation Piping (Hope Creek)
During the present ISI period, three liquid penetrant test (PT) indications were found on the outside diameter surface of two, 28-inch diameter x 1.35-1.40 inch wall pipe butt-welds.* The welds were located in loops A and B of the primary coolant recirculation piping syste The applicable ASME Code,Section XI, is the 1983 edition* including the 1983 Summer Addend The PT indications, which ranged in length from 1\\ inches to 7\\ inches, were oriented i~ a circumferential direction and located approximately in the center of the s~ainless steel wel The welds were coincidently the same welds in both loops and identified as -shop welds on drawing ISO 795 E 47 After failing to remove the indications by light grinding, the indications were completely removed from both welds by excavating the areas to a depth of 7/16 inch (32% of wall).. After liquid penetrant eiamination to assure absence of defects, the cavities were weld repaired with type 308 filler material using the Tungsten Inert Gas (TIG) welding proces Prior to excavation, a ~ inch wide x 1\\ inch long boat sample was removed for metallurgical examinatio Preliminary.results as reviewed by the inspector indicated that the defect was a hot short crack, typical of welding defects found in stainless steel weld Initial findings from records generated by the licensee and General Electric Company (G~) regarding the fabrication history of the welds in the recircu-lation piping system indicated £hat the type 304 stainless steel spool pieces were made by Associated Piping and Engineering, Compton, CA in 198 The records also showed that the spool pieces, which contained 12-inch and 28-inch welds, were solution annealed after welding at 1925°F-1960°F followed by water quenchin Although no welding procedure had been retrieved, GE reported that to the best of their knowledge, the subject welds were made using the TIG process for.the root pass, followed by a co~er pass deposited by the manual metal arc process, with subsequent fill layers by an automatic submerged arc (flux/wire) proces The latter process because of its location, with respect to the hot short cracks, js apparently responsible for the defects because of the low ferrite levels (0.1%-1.9%) found in the boat sample even though certified test reports of the filler materials used by Associated Piping (AP) showed ferrite levels of 6-12%.
The low ferrite level~ may have been the result of the solution treatment employed by AP after welding which could have reduced the as-deposited
ferrite levels to the levels found in the boat sample, or to dilution from base metal and/or weld flux effect Other causes for the. cracking suggested by GE were:
1) a non-optimum weld width to depth ratio and 2) a high deposition rat The licensee also reported that 1) a review of liquid penetrant records showed no reportable indications and 2) a review of production radiographs showed no rejectable indication The licensee also reported that the defects were not detected by the present ASME Section XI ISI ultrasonic examination, principally because the UT method used (shear wave) is geared to finding intergranular stress corrosion cracks (IGSCC) on the inside diameter surface as well as flaws in the bottom third of the wel The hot short cracks in this case were found in the upper third of the wel \\
In order to determine the extent of the problem and to *assure integrity
. of the recircul~tion piping system, the li~ensee proceeded to liquid penetrant test all 36 similar welds (100%) in the recirculating syste There was no other rejectable indication foun The licensee also ultrasonically tested eight additional welds (five 28 11 and three 12 11 d.iameter piping) using a high angle longitudinal refractive wave metho This method was validated in the presence of the inspectors using an EPRI furnished mock-up containing weld defects similar to and at the same level as those found in the recirculation ~iping weld No rejectable indications were reported in any of the eight weld The licensee also inspected seven longitudinal seams in the adjoining pipe section using ultrasonic and liquid penetrant test There were no reportable liquid penetrant indications, except for one isolated group of small (<~ inch) randomly, oriented indications which were removed by light grindin *
The licensee 1 s proposed inspection progra~ for the next outage will include seven welds which will consist of two of the original cracked welds now repaired, a weld which exhibited a minor ultrasonic indication and four of the higher stressed welds similar in fabrication history to the welds that exhibited hot crackin.0 Water Chemistry Control (Salem Units 1 and 2)
The water chemistry control program was reviewed to determine whether the licensee is adequately controlling the quality of plant process wat~r to ensure long-term integrity of the reactor coolant pressure boundar Water chemistry data were reviewed to determine whether the completed chemical analysis were within the establ{shed limits and corrective actions were taken when chemical variables have exceeded the limit The method of collecting and verifying the accuracy of these data, was not included in the scope of this inspectio Details of Review The inspector interviewed cognizant personnel and discussed the control of primary and secondary water chemistry in the plant system The results of the controls for secondary water chemistry were also reviewed for the
past yea With regard to the secondary water, the inspector verified that the licensee employes the Chemistry Performance Index (CPI) which is a weighted average of three principal corrosion causing, impur1ty concen-trations (conductivity, sodium and oxygen) divided by the EPRI upper specification limit During cycle 8 of Salem Unit No. 1, the year-to-date CPI was 0.25 and during Cycle 5 of Salem Unit No. 2, the CPI was 0.2 The CPI goal for Salem is 0.17 against the industry median of 0.2 The control of pH in secondary water is governed by ammoni The licensee attempts to maintain a pH of 8.5 to 9.0 in feedwater during Mode 1 operatio The control of secondary water chemistry was satisfactory from the data reviewed during the inspectio Any out-of-normal limit of secondary water chemistry is detected and corrected in accordance with Procedure N AOP-COND-1 11Condenser Tube Leak.
The inspector's review of the procedure indicates that the procedure does not address out-of-normal chemistry due to ingress of impurities into the feedwater originating from within the system during weld repairs, plant modification or component replacemen The 1 i censee agreed to revi e.w and revise the AOP-COND-1 procedure to address any out-of-norma 1 chemistry in 1 i ght of specific parameters s 11ch as pH, specific conductivity and/or impurities and the corrective action required to bring respective values within normal limit The primary water chemistry data were reviewed for compliance to Procedure No. CH-3.8.020 "Sampling Schedule and Chemistry Specifications."
In order to control pH, Salem Unit 1 uses the Westinghouse Coordinated Lithium Program and Unit 2 uses the Modified Lithium Progra Following the next outage, Unit 1 will also use the Modified Lithium Progra This program will raise pH at operating temperature and pressure which will result in reduced transport of radioactive corrosion products from the cor Hence, the balance of reactor coolant system will have less contaminant The inspector found that the charts which provide lithium concentration as a function of boron concentration are not part of the governing procedure and are uncontrolled document Although the graph of lithium concentration vs. boron concentration is a part of the procedure, the operator routinely uses the charts to increase or decrease lithium level in the reactor coolant syste The licensee agreed to incorporate the ch~rts of lithium vs. boron concentration into the Procedure CH-3.8.02 The licensee has an INPO accredited training program for chemistry technicians and the training of personnel is on schedul The inspector reviewed reports on surveillances conducted by the licensee's Quality Assurance Departmen The coverage of the chemistry program by the Quality Assurance Department was determined to be satisfactory.*
6.cr Management Meetings The licensee's management was informed of the scope and purpose of the inspection at the entrance meeting on January 16, 199 The findings of the inspection were discussed with licensee representatives during the course of the inspection and presented to licensee's management at the exit meetings on January 17 and 18, 1991 (see Paragraph 1 for attendees).