IR 05000324/1989041
| ML19351A595 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/01/1989 |
| From: | Blake J, Coley J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML19351A591 | List: |
| References | |
| 50-324-89-41, 50-325-89-41, IEIN-88-002, IEIN-88-2, NUDOCS 8912190395 | |
| Download: ML19351A595 (10) | |
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NUCLEAR REGULATORY COMMISSION UNITED STATES -
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REolONil 101 MARIETTA STREET.N.W.
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ATLANTA, GEORot A 30323 4'
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= Report Nos.: 50-325/89-41 and 50-324/89-41
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Licensee:
Carolina Power and Light Company.
P. O. Box-1551-
.Raleigh, NC 27602 Docket Nos.:
50-325 and 50-324 License Nos.:
DPR-71 and DPR-62 l Facility Name:
Brunswick 1 and 2
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Inspection povember-6-9,1989
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k8 I-Inspect ':
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o y Dat Signed
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LApprov d b.
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J. J Blake, Chief.
Date Signed t rials and Processes Section n neering Branch Division of Reactor Safety-i SUMMARY
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Scope:
This routine, unannounced inspection was conducted in the areas of review of'
General Electric's (GE) revised nondestructive examination (NDE) procedures for the recirculation system pipe replacement program, observation of ultrasonic.
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examinations performed on the recirculation system replacement pipe, review of radiographic film of outage repair welds, review of records pertaining to crack indications identified on the feedwater header and the core spray T-box piping, review of licensee's program for Torus Corrosion'(NRC Information Notice 88-82)
and followup on NRC Open enforcement items.
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.Results:
. GE had revised their NDE procedures to meet ASME Code requirements. Work and examination activities were proceeding effectively on the recirculation system pipe replacement project.
Review of CP&L radiographs revealed film to be acceptable and a strong quality control program for assuring quality.
However, welding-Quality is deteriorating at the Brunswick facility.
Numerous-weld repairs with the potential to sensitize austenitic materials were required, before acceptable weld quality was obtained.
Senior CP&L Management was aware of the welding problem and corrective actions are in process.
In the areas inspected, violations or deviations were not identified.
8912290395 89120[
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PDR ADOCK 05000324 G
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REPORT DETAILS
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1.
Persons Cont. acted Licensee Employe'es
- R. E. Helme, Manager, Technical Support
- J. R. Holder, Manager, Outage Management and Modifications
- M. A. Jones, Manager, On-Site Nuclear Safety
- L. E. Jones, Manager, QA/QC
- R. M. Poulk, Supervisor, Regulatory Programs
- W. W. Simpson, Manager, Control and Administration
- R. B. Starkey, Plant Manager
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Other licensee employees contacted during this inspection included craftsmen, engineers, technicians, and administrative personnel.
- Attended exit interview
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2.
Review of Nondestructive Examination (NDE) PronKhres - Units 1 and 2 (57050, 57060, 57070, and 57090)
During a previous NRC inspection (Region II Inspection Report No. 50-325, 324/89-35) NDE procedures to be used by CP&L's vendor (GE) for the recirculation system pipe replacement program were found to be in nonconformance with the minimum requirements of the applicable ASME Code.
In addition, the procedures were lacking substance and clarity.
This finding was listed as an example in a violation which dealt with inadequate procedures for welding and NDE. The apparent failure however, was that the licensee's progransnatic review process had broken down allowing these procedures to be released to production without proper technical review, and editing, and Code inspector approval.
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On November 6, 1989 the inspector returned to the site to determine if the i
GE procedures had been adequately revised for the critical nature of the l
work activitias of their intended use and to determine specifically if CP&L's corporate radiographic procedure adequately implemented current applicable Code requirements as identified in the GE radiographic procedure. The following GE and CP&L procedures were reviewed:
Procedure Identification Procedure Title GE-CPL-25.0 Rev. 2 Visual Examination General Procedure GE-CPL-26.0 Rev. 2 Liquid Penetrant Examination General Procedure
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Procedure Identification Procedure Title (cont'c)
GE-CPL-27.0 Rev. 2 Radiographic Examination of Welds GE-CPL-28.0 Rev. 1 Magnetic Particle Examination Procedure
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CP&L Corporate QA Procedure Radiographic Examination NPEP-101, Rev. 12
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The inspector's review of the revised NDE procedures revealed that CP&L and GE had effectively revised the GE procedures.
The procedures presently incorporate clerity and substance.
Minimum ASME Code require-
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ments had been included and all but one of the procedures (Liquid
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Penetrant. Examination) had been approved by the Code inspector.
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inspector's review of the CP&L Corporate radiographic procedure revealed that the licensee has been addressing current Code requirements for each facility as required and the procedure met minimum ASME Code requirements.
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However, this procedure could provide improved clarity both as require-ments related to specific sites and instructions to radiographic examiners. The CP&L Level III examiner recognized that improvements could be made and intends to assess methods of strengthening this procedure for clarity in the near future.
Within the areas examined, violations or deviations were not identified.
3.
Observatfun of Ultrasonic Examination Work Activities - Unit 2(57080)
The inspector observed ultrasonic examinations performed on a recircula-tion system replacement riser pipe to determine whether the ultrasonic examination procedure and the examination activities met CP&L/GE examina-tion intent and contract requirements. The examinations observed were not required by the ASME Code.
However, the licensee's intent for performing these examinations was to obviate possible examination inaccuracies resulting from material variations during subsequent examinations, therefore, the examinations observed exhibited enhanced inspection methods.
Recirculation system downcomer pipe serial No. 8 was examined for lamina-tion, thickness, and ultrasonic beam angle deviations.
The inspection area included scanning 360' for 12 inches on both the upstream and downstream ends of the pipe.
Each downcomer was to receive the ultrasonic examination verifications which would be unique to the pipe serial number for future reference.
GE's inservice inspection (ISI) procedure No. GE-UT-106 Rev. O " Procedure for Manual Ultrasonic Examination of Pressure Retaining Welds in Ferritic and Austenitic Piping and Components" was used for Calibration and examination parameters with enhanced instruc-tions from CP&L's Corporate QA Department. The examinations were performed with properly certified examiners who conducted a through examination of the inspection area and correctly recorded the values obtained.
These examinations revealed that the 316NG stainless steel was sound material with very little deviation from the known true values.
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Within the areas examined, violation or deviations were not identified.
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4.
Review of R6diographs for Outage Repair, Replacement and Modification Activities - Unit 2 (57090)
The inspactor reviewed the radiographs listed below to determine whether they were examined, evaluated and maintained in ac;ordance with applicable commitments and code requirements.
The applicable code for this review was the 1986 Edition of the Code,Section III and Section V.
Radiographs
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of the following welds were examined:
System Weld Identification Diameter HPCI
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HPCI 2E41-425 14 inches HPCI 2E41-371 14 inches
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The inspector'S review of the above radiographs as well as radiographs reviewed in NRC Inspection Report 50-325,324/89-36 and in-process film of rejected welds revealed that the licensee's Quality Control is conducting radiographic examinations and evaluations in a very effective manner.
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However, welding skills are declining at the Brunswick site.
Numerous required weld repairs are shown on many of the radiographs and weld root conditions even on acceptable film are less than would be desired in order to minimize potential for inservice failures.
In addition numerous repairs to welds can sensitize austenitic materials leaving the materials susceptible to intergranular stress corrosion cracking (IGSCC).
The inspector contacted a welding instructor f rom the Brunswick weld test shop to determine why the weld reject level was so high and welding quality in general was declining.
The welding instructor stated that the problem was not in the certification process because welders qualifying on austenitic materials are given qualification tests with limitations similar to those that they will encounter in the field and their test coupons are examined with radiography.
The instructor stated however, that the licensee is aware of the high reject level and actions are being taken by the licensee to have the welders certify on three consecutive test coupons before allowing them to be certified for production welding.
In addition the instructor stated that, new filler materials used to weld austenitic stainless steel material such as the 316L insert ring will not nelt at emperages normally used by welders and the differences are significant.
For instance a normal insert ring for austenitic stainless steel would properly melt at 100 amps.
However, an amperage of 150 amp would be required to properly fuse a 316L insert ring for 316NG base materials.
This high amperage creates shrinkage cracks in the root pass.
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P The instructor also listed the following as causes for the decline in welding skills:
l Low pay
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Drug testing
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Lack of pride in work
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During the inspector's exit meeting this item was discussed with plant management who were well aware of the decline in welding.
Management indicated that their discussions with other utilities revealed this to be a generic problem to the nuclear industry.
One method management stated
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that is being considered to improve the quality of welding at the site is l
to contract a major welding contractor to perform the welding.
The inspector will continue to review the licensee progress to resolve this issue.
- Within the areas examined, violations or deviations were not identified.
5.
Invessel Inspection - Review of Records, Unit 2(73755)
Duringtheinvesselexaminationofthefourcoresprayteeboxwelds,two at 90 and two at 270', one indication associated with IGSCC was recorded on the 90* (right side) tee box weld.
The indication had also been detected by visual examination and sized with ultrasonic during the previous outage of Unit 2.
This outage the licensee performed ultrasonic examinations on all four T-boxes and performed a liquid penetrant excmination on the weld which had the crack indication. The indication is presently 4.9 inches in length on r
the inside surface and 1.9 inches in length on the outside surface.
Previously this was recorded at 3.5 inches in length on the inside surface and 1.75 inches in length on the outside surface.
Therefore, this indication has grown 1.4 inches in length on the inside surface and.250 inch in length on the outside surface.
The other three T-box welds were
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examined by the manual ultrasonic technique and no recordable indications were identified in these welds.
Also during previous visual invessel examinations of the feedwater sparger flow holes cracks had been identified and liquid penetrant examinations performed to accurately determine their length. During the present outage the liquid penetrant examination was repeated and numerous linear indica-tions were detected, some of which were not previously recorded.
The inspector reviewed the inspection data and photographs of the reported indications from both the previous outages and the present outage.
The information reviewed by the inspector will be transmitted by CP&L to GE's Nuclear Energy Engineering for further evaluation.
Within the areas examined, violations and deviations were not identified.
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6.
NRC Information Notice No. 88-82, " Torus Shells With Corrosion and in BWR Containments" - Review of Licensee's Actions Degraded Coating (92701)
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- Units 1 and 2
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On October 14, 1908, NRC Information Notice No. 88-02 alerted licensees to the discovery of suppression pool steel shells with corrosion and degraded coatings in BWR containments.
It was expected that recipients would
review the information provided in the notice for applicability to their f acilities and consider actions, as appropriate, to avoid similar problems.
The NRC staff considered the reported torus corrosion degrada-tion significant because the neasured corrosion rates of torus shells were greater than the corrosion rates assumed as part of the original design.
The notice recognized that many licensees perform periodic visual inspections of the suppression pool steel shells or liners in accordance
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with their technical specifications, but the methods used by licensees
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vary.
Some licensees examine only those portions of the torus above the water line, and others employ divers or use cameras to inspect submerged surfaces.
Such inspections can only detect general degradation.
The information notice suggested that the most effective way to detect
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localized degradation such as pitting is to drain the torus and inspect
under dry conditions.
CP&L response regarding applicability of the corrosion problem identified in the information notice was simply that
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they had a torus corrosion monitoring program (Periodic test - 20.5.2).
However, the inspector's review of this program revealed it to be weak in
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The program did not have corrosion test plates below the sludge l
layer, b.
The test specimens were homogenous plates and not representative of material corrosion rates accelerated by welding.
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The test plates represented a general area corrosion rate rather than localized corrosion rate verification addressed in the information
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notice.
As a result of the inspector's review of the torus corrosion monitoring
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program a meeting was requested by the inspector with cognizant plant
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l personnel to determine if a visual inspection of the torus was performed by any other mechanism such as periodic paint inspections.
Discussions with cognizant plant personnei revealed that no paint inspections are performed.
In fact, much of the torus is not painted and that is why the licensee started. the corrosion monitoring program.
In addition, the licensee stated that, during a recent annual INPO audit, an issue was
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raised over the potential for significant corrosion damage to the torus liner.
The concern was primarily based on the experience of one of the INP0 auditors and his background with the torus corrosion events at the Oyster Creek Nuclear Station.
Also since Brunswick Unit I had recently
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encountered a moderate chloride intrusion INP0 was concern over its effects on the torus lines.
In order to properly address the INPO concern the licensee conducted a Torus Corrosion Review, Memorandum Serial No. BSEP/89-0833 dated August 24, 1989.
This memorandum compares the
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Oyster Creek Nuclear Station experience to the conditions at Brunswick and
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basically concludes that the conditions at the two plant can not be compared. However, the memorandum stated that, the submerged areas of the torus liner had not been inspected in approximately five years, and some
general pitting has been identified on some of the half-submerged test coupons.
The memorandum also acknowledged that the corrosion monitoring program did not address all locations, and the specific water chemistry of the sludge mat area is unknown.
In addition the memorandum identified that new issues such as microbiological 1y induced corrosion (MIC) were not s
considered when the corrosion program was established.
Although, the bacteria that is suspected of causing MIC has been identified in some l
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water systems at Brunswick, the torus has not been tested.
The memorandum recommended the following immediate actions be taken for the present Unit 2 outage:
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Inspect present coupons in accordance with PT-20.5.2 as early in the
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outage as possible in order that corrective actions will not impact the outage schedule.
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Send a diver down into the torus to inspect the liner condition below the sludge layer, quantify the size and extent of the sludge layer and obtain a water sample in the sludge mat area.
The above actions have been performed this outage.
However, the NRC information Notice alludes to the fact that these methods may be
ineffective in identifying localized corrosion pitting.
In addition the memorandum made several long term recommendations and action items which should be considered for Unit I and Unit 2.
These long term recommendations consisted of the following:
Begin a sampling program for iron reducing microbes and periodically obtain water chemistry samples of the sludge mat area.
i Assign a permanent CP&L coordinator to further research the torus condition.
The coordinator should work closely with the Metallurgy Lab, BSEP Chemistry group, and System Engineer to develop a conclusive long term position on the actions that should be triken.
Tech Support recommended that this individual operate in the Nuclear Engineering Department.
Specifically, the assigned coordinator should; (1) Develop and implement a more representative coupon program. The current program is reasonably comprehensive, however, areas
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1 below the sludge blanket are not considered and the current program is running short on coupons.
(2) Evaluate the need and benefits of a thorough torus inspection on a long (such as once every ten year) periodic basis.
The inspection would involve draining and cleaning the torus for j
weldment and wall thickness inspection.
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As stated in NRC Information Notice 88-82, a periodic drain down and visual inspection of the torus below the water line is recommended as the best method of identifying localized corrosion degradation. The inspector also encouraged the licensee to consider their latter recommendation particularity based on the fact that many areas below the water line in the torus are unpainted.
This information notice will remain an active issue at the Brunswick site until management and engineering determine what corrective steps will be necessary to insure that localized corrosion degradation will be adequately and timely identified.
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I Within the areas examined, violations and deviations were not identified.
7.
Followup on Corrective Acticns to NRC Enforcement Items - Units 1 and 2 (92702)
a.
(Closed) Severity Level IV Violation 50-324/87-30-01, failure to Adequately Complete First Inspection Intervsl Hydrostatic Testing.
CP&L letter of response dated October 29, 1987 has been reviewed and determined to be acceptable by Region II.
The inspector held discussions with CP&L's Project Engineer for Inservice Inspection and I
l examined the corrective actions as stated in the letter of response.
The inspector concluded that CP&L had determined the full extent of
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the subject noncompliance, performed the necessary survey and follow-up actions to correct the present conditions and developed the necessary corrective actions to preclude recurrence of similar circumstances.
The corrective action identified in the letter of response have been implemented.
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(Closed) Severity Level IV Violation 50-324/87-30-02, Failure to Issue Nonconformance Report on Licensee Identified Code Discrepancy.
CP&L letter of response dated October 29, 1987 has been reviewed and determined to be acceptable by Region II.
The inspector held discussions with CP&L's Project Engineer for Inservice Inspection and examined the corrective actions as stated in the letter of response.
The inspector concluded that CP&L had determined the full extent of the subject noncompliance, performed the necessary survey and follow-up actions to correct the present conditions and developed the
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The corrective action identified in the letter of
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(Closed) Severity Level IV Violation 50-324/87-30-03 and 50-325/87-30-01, Inadequate Hydrostatic Test Procedures CP&L letter of response dated October 29, 1987 has been reviewed and determined to be acceptable by Region II.
The inspector held i
discussions with CP&L's Project Engineer for Inservice Inspection and examined the corrective actions as stated in the letter of response.
The inspector ~ concluded that CP&L had determined the full extent of the subject noncompliance, performed the necessary survey and follow-up actions to correct the present conditions and developed the i
necessary corrective actions to preclude recurrence of similar
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circumstances.
The corrective action identified in the letter of
response have been implemented.
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8.
Followup on NRC Open Item - Unit 1 (92701)
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(0 pen) Inspector Followup Item 50-325/88-26-01, " Enhance ENP-16 and Repair and Replacement ENP (In Preparation) to Reflect Managements Position for Obtaining Prior Approval for Relief Request"
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CP&L has updated ENP-16 to include obtaining prior approval for relief request.
However, the Repair and Replacement ENP has not been
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formally approved.
The new completion date for the Repair and Replacertent ENP is December 29, 1989.
This item will. remain open until the Repair and Replacement ENP can be reviewed by NRC.
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b.
(Closed) Inspector Followup Item 50-325/89-15-02, " Radiographic Indicator in Weld 251, Station 4-5" This item dealt with an inspector concern over an indication in a weld root that was darker in density than the surrounding area. The indication was in an area that had previously been rejected for lack of penetration and the indication appeared to be a part of the L
original defect.
The inspector had requested that the licensee l
perform an enhanced inspection utilizing ultrasonics to size the indication.
As a result of radiographic procedure review problems
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I identified 'in the Inspection Report 50-325, 324/89-35 and declining welding skills observed at the Drunswick plant NRC Management directed the inspector to reexamine this indication to ASME Code acceptance criteria and take any necessary and appropriate action.
The inspector's review of the radiographic indic6 tion revealed that the indication could not be classified as unacceptable to the ASME Code because the re-flow of metal during the subsequent weld repairs had feathered the indication into the adjacent material.
The inspector also considered the indication too small for ultrasonic
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sizing to be of value.
Discussions with CP&L's Outage and Modifica-tions Manager revealed that this valve (FO-13) is presently scheduled to be removed during the upcoming Unit 1 outage on Plant Modification Instruction 89-071.
The CP&L Manager also stated that if anything precluded the valve (weld) being removed during the June 1990 outage i
CP&L would perform enhanced radiography to profile the root condi-tions.
The inspector considered the licensee's concern over a general welding conditions at Brunswick and their commitment to go beyond ende requirements and perform enhanced radiography of this weld if necessai7 during the June 1990 outage to be sufficient for closure of this item.
9.
Exit Interview The inspection scope and results were sunnarized on November 9,1989, with those persons indicated in paragraph 1.
The inspector described the areas inspected rand discussed in detail the inspection results.
Proprietary information is not contained in this report. Dissenting comments were not received from the licensee.
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