IR 05000566/1981006
| ML20009D791 | |
| Person / Time | |
|---|---|
| Site: | Yellow Creek  |
| Issue date: | 06/16/1981 |
| From: | Coley J, Herdt A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20009D787 | List: |
| References | |
| 50-566-81-06, 50-566-81-6, 50-567-81-06, 50-567-81-6, NUDOCS 8107240352 | |
| Download: ML20009D791 (6) | |
Text
F
{
..
,'
c,c.,%
UNITED STATES U"
NUCLEAR HEGULATORY COMMISSION
^
E REGION ll
$
.a #
o 101 MARIETTA ST., N.W., SUITE 3100
' D g ATLA *JTA. GEORGIA 30303
+....
Report Nos. 50-566/81-06 and 50-567/81-06 Licensee: Tennessee Valley Authority 500A Chestnut Street Chattanooga, TN 37401 Facility Name:
Yellow Creek Docket Nos. 50-566 and 50-567 License Nos. CPPR-172 and CPPR-173 Inspection at Combustion Engineering Inc., Plant, Chattanooga, Tennessee Inspector:
\\N At 6 - /$ -8 /
J. L. CN ey
%
Date Signed Accompanying Personnel:
A. R. Herdt, IE:II J. H. Gieske, NRC Consultant K. V.- Cook, NRC Consuitant J. Smith, NRC Consultant J. R. Gleim, NRR Approved by:
~/[
/
A. R. Herdt, Section Chief Date Signed Engineering Inspection Branch Engineering and Technical Inspection Di' vision SUMMARY Inspection on May 7-8, 1981 Areas Inspected This special announced inspection involved 26 inspector-hours on site in the areas of preservice inspection of Unit 2, reactor vessel outlet nozzle utilizing collimated beam ultrasonic transducers, and followup on previously identified inspector items.
Results Of the two aren inspected, no violations or deviations were identified.
.
8107240352 810618 PDR ADOCK 05000566 O
PDR i-
r'
q
-
.
,
REPORT DETAILS 1.
' Persons Contacted Licensee Employees
- G. J. Pitzl, TVA-Nuclear Power, Supervisor, Metals Applications
- M. E. Gothard, TVA-Nuclear Power, ISI Level III Examiner
- G. L Belew, TVA-Nuclear Power, Supervisor, Codes and Standards R. H. Daniel, TVA-Nuclear Power, Supervisor, Baseline and ISI
- D. J. Etzler, TVA-ENDES, Metallurgical Engineer
- D. E. Robertson, TVA-ENDES, Mechanica' Engineer Associate Other Organizations
- M. L. Rice, Hartford Steamboiler Inspection, Authorized Nuclear Inspector
- W. A. Stone, Jr., CE-Chattanooga, Manager Nuclear Quality Assurance
- W. R. Mc
Dearman,
CE-Chattanooga, Manager NDE Development
- L. Woods, CE-Chattanooga, Component Design Engineer
- T. E. McMahon, CE-Windsor, Assistant Project Manager
- Attended exit interview 2.
Exit Interview The inspection scope and findings were summarized on May 8, 1981 with those persons indicated in paragraph 1 above. The inspectors described the areas inspected and discussed in detail the inspection findings including the supplement data, requested in inspector followup item 567/81-01-03,
" Demonstration of Equivalent UT",
paragraph 6.d.
of this report.
No dissenting comments were received from the licensee.
3.
Licensee Action on Previous Inspection Findings (Closed)DeficiencyNos. 566/80-17-01 and 567/80-17-05, Failure to establish responsibilities for PSI when inspections are conducted in the vendor shops.
TVA-YC letter of response dated December 23, 1980, has been reviewed and determined to be acceptable by Region II. The lqspectc.' also reviewed the changes to the Operational Quality Assurance Manual and concluded that TVA had determined the full extent of the subject noncompliance.
(Closed) Unresolved ~ Item No. 567/80-17-02, Lack of documentation for personnel qualifications to procedures being used. This item dealt with the inspector concern that NDE personnel records did not include a statement
.
.
-
,
,
-,
--
,
_ -, _
f,
..
.
_
.
indicating satisfactory completion of training / indoctrination to the employer's written examination procedure.
Combustian Engineering has subsequently qualified their NDE inspection personnel to the examination procedure used for -the inspection of the R/V nozzles, and furnished TVA a statement of this training to be included in the personnel records of the certified individuals.
4.
Unresolved Items Unresolved items were not identified during this inspection.
5.
Preservice Inspection - Ultrasonic Inspection' of Unit 2 Reactor Vessel 0 Outlet Nozzle The inspectors witnessed the partial inspection of the 0 outlet nozzle (weld No. 02-001-015) for the Unit 2 reactor vessel. This examination was performed to re-establish the base line data for the 0 +180 outlet nozzles.
- A Krautkramer-Branson 6000 ul't asonic instrument was used for this inspec-tion.
The re-examination was first conducted using two compressional wave (normal) transducers (1 inch diameter, 2.25 MHz).
One transducer was positioned to produced a 5 refracted angle in steel and the other trans-ducer was positioned to produced a 20 refracted angle in steel.
CE then intended to reinsnect both nozzles using compressional wave transducers (1 inch diameter, 2.25 MHz)-which had-spherical lens attached. The purpose of the spherical lens was to try to collimate the beam divergency of the transducer. The collimated beam transducers were also positioned to produce a 5* and 20 refracted angle in steel.
The purpose for performing both inspections, was to compare the results and to establish equivalent or superior performance of the collimated beam transducer with regards to flaw sizing using the amplitude based techniques of the ASME Code Section XI 1974 edition through the summer 1975 addenda.
The inspector had witnessed CE's Manual ultrasonic inspection of the 0 and 180 outlet nozzles using the collimated beam transducers on January 16, 1981. A compe.rison of the UT results obtained from the manual scan using the collimated beam transducer verses the manual scan using normal probes or the baseline automated UT using normal probes, revealed an ap' proximate four to one reduction in defect size when the collimated beam transducer was used. In at least one case a reduction in applitude was observed that made a previously reported baseline discontinuity with an amplitude of 62%
DAC, a length of 2 inches and a 2a dimension of 1.18 inches nonrecordable.
The inspector considered the differences in flaw amplitude and sizing excessive and could not be attributed totally to beam divergency, surface conditioning or coupling variations.
This inspector's concern was docu-mented in Inspector Followup Item No. 50-567/81-01-03.
-
p
--
.
-.
.
The~ licensee had notified Region II that the re-inspection of the 0 and 180 nozzles would be performed using the automatic ultrasonic equipment on May 7, 1981. The licensee assumed this was a ASME Code Section XI inspection and
~
was seeking to obtain assurance from NRC that augmented inspections would
.not be required in future inservice inspections. As a result Region II
. arranged -.to have NDE consultants available that were knowledgeable experts in' the field of ultrasonics, ~ particularly in the study of beam divergency.
'
In-addition, engineers highly experienced in ultrasonic testing from Region II, Region IV and NRR were available on May 7, to witness the nozzle re-examination.
The licensee re-examinations, however, did not occur on schedule and by the end of' the day (May 7) CE had only. accomplished the reinspection of one half of~the diameter of the 0 nozzle using the normal
~
transducers. In addition, the licensee /CE was vague when questiened con-
- cerning the analytical and experimental data taken by CE to support the collimated beam transducer. When it became apparent that the inspector would not. have. the opportunity to witness the comparison examinations
'
during this visit, the. licensee /CE was requested to set up on one previously recorded indication that had been detected using the original autcmatic system to compare this single -indication with the data received with the KBI' 6000 using a normal. probe and then with data acquired usi g the
,collimated beam technique. Calibrations were also witnessed by the inspec-tor. 'The results'of this indication comparison revealed that the amplitudes-were. equivalent --(collimated beam being slightly larger), the indication length was approximately h" smaller and a 2a diamension was approximately h" smaller. It should be. emphasized however, that this was rough data and no final conclusion could be reached from this limited examination. Since the inspector could not witness the comparison examinations or have access to the analytical and. experimental data at this time the collimated beam transducer Lequivalence.or superiority _could not be determined. The licensee's assump-tion _ however, that sinc.e the ASME Code does not specifically prohibit a
.'
technique, the technique is then in accordance with the code is not neces-sarily, correct.
The inspector questioned if the licensee felt that the data taken to establish Table'IWB-3512.1 (acceptance criteria) was derived using any other method than a normal transducer. The licensee agreed that fractured mechanics 'used to establish Table IWB-3512.1 would have to j.
consider the: state-of-the-art in ultrasonic sizing at the time and the a
collimated ' beam transducer would - not have been used.
The inspector
' concluded thatL there was a minimum amount of data that should be made j
available to NRC ~ for evalu tion in order to determine the equivalence of this examination and before any assurance could be made that NRC would not require additional augmented inservice inspections. The data required is
~ discussed in detail in _ Inspector Followup Item 567/81-01-03. This matter
'
,,
appears under paragraph 6.d. of this report.
!
Within the' areas examined, no violations of deviations were identified.
L (
i.
.
t i(:
F,
.
.
.
6.
Inspector Followup Items a.
(Closed) Inspector Followup Item 567/80-17-04. Confusing radiographic interpretation records. Two observations were noted in this item; (1)
a review of radiographs of a longitudinal seam on Unit 2 reactor vessel revealed radiographic indications in the base metal area.
The radio-graphic interpreter had made a notation on the x-ray acceptance form that the indications were due to surface conditions, with no further explanation; and (2) a review of radiographs of a circumferential weld seam on primary piping revealed two complete sets of radiographs and two completed radiographic acceptance forms. There was no explanation or instructions for the two complete sets of radiographs. Only after asking the radiographic interpreter was it learned that both sets of film were needed to accept the weld.
CE's Level III examiner had taken the initiative to correct this apparent problem by issuing an Interoffice Memorandum dated October 29, 1980, and addressed all applicable CE divisions.
This memo required appropriate supervisor personnel to ensure that: (1) a brief descrip-tion of the cause of the surface condition and action to be taken be documented on the radiographic reader's sheet; and (2) in addition, to avoid confusion and to assist personnel who will be reviewing the film in future years, the radiographic interpreters were instructed to make brief notations of unusual or unique conditions on the radiographic acceptance form. This corrective action appears to be adequate at this time and this item is considered closed.
b.
(Closed) Inspector Followup Item 567/80-17-03, Removal of weld splatter on surfaces to be ultrasonically examined.
This item dealt with an
~
inspector's observation that weld splatter was on a surface that had just received an ultrasonic examination.
The inspector did not question the UT coverage since it was apparent that the transducer could be oscillated around the weld splatter. However, the inspector was concerned that the UT examiners would perform an examination on a surface which had weld splatter since this condition could limit the inspection. The licensee removed the weld splatter and retested the area in question. In addition, a critique was held with all UT exam-iners and this item was the topic of discussion.
This training was documented for NRC review.
c.
(Closed) Inspector Followup Item 567/80-17-01, Revision 5 to UT Proce-dure NIP-1138.
This item dealt with Nuclear Energy Services' (NES)
technique for inspecting areas with a normal straight beam transducer where a back reflection cannot be obtained (reactor head flange). NES has elected to use a more critical examination utiitzing side drill holes, however, NES procedure NIP-1138 which was written specifically for the reactor head flange did not address this technique. Revision 5
.
W-p
...
.
9.,
~v e
--+w,
.
T F
--
"
f t.
,
.
.
-to the licensee /NES Procedure (NIP 1138) reflected this practice. The inspector reviewed this incorporated chang'e and this item is considered closed.
-d.
(0 pen) Inspector ~ Followup Item 50-567/81-01-03, Demonstration of Equivalent UT. The inspector attended a UT demonstration at Combustion Engineering in Chattanooga, Tennessee on January 16, 1981. The purpose was to demonstrate the results of'a collimited beam transducer using manually operated UT equipment on discrepancies found in the outlet nozzles of Yellow Creek's Reactor 7essel for Unit 2.
The discrepancies
'had previously been rejected whel. the automated system using a normal beam transducer had been used.
The results of this demonstration indicated, hat the discontinuities sized much smaller than previously reported using a normal probe. The sizing difference appeared to be attributed to the beam spread on the reflective surface of the discontinuities. Using the collimated beam
. transducer, the discontinuities appear to be acceptable. The inspector noted, however, that the amplitude for the discontinuity on weld No.
02-001-015 located at 165 had dropped from the recorded 62% DAC when the collimated probe was used.
This discontinuity had a recordable length of two inches and a 2a dimension of 1.18 inches when measured with a normal probe using the automated system. The 40% DAC reading would make this discontinuity nonrecordable. However, this decrease in
' amplitude is not consistent with the concept of the collimated beam transducer.
The collimated transducer should give equivalent on greater amplitudes forL the area / distance relationship. The licensee felt the difference encountered could be the result of variables associated with the manual scanning process.
The licensee stated that the nozzles would be reinspected using the automated system and the collimated beam trans-ducer.
The variables will be eliminated at this time and an accurate comparison of the area / distance / amplitudes relationships can be made.
Region II was notified that the re-examination noted above would be conducted on May 7, 1981. The inspector and consultants were present at CE on May 7-8, 1981 to witness the reinspection of the 0 and 180 nozzles utilizing both a normal transducer and a collimated beam transducer.
Results of both examinations were to be compared.
The licensee /CE, however, had not performed 50% of the normal beam exami-nation on one nozzle by the end of the first day and it was apparent that the inspector would not have the opportunity to witness both examinations even on one nozzle. In addition, the licensee /CE did not have any analytical or experimental data available for the inspector to review.
The -inspector informed the licensee /CE that there was a minimum amount of data that would be necessary in order to ensure that an adequate com,,arison of UT techniques could be made. The following information was requested:
k
-
..
..
.
-..
A graph (or plot) of data showing the comparison between the normal and collimated transducers for sizing on side drilled holes and flat bottom holes on laboratory test performed in water using a disc; laboratory test performed on steel mockups; test performed in steel on flaws (actual data) under the following conditions:
(1) 50% DAC-(2) 50% max amplitude (laboratory tests above only)
mf-(3) 20% max amplitude (laboratory tests aboya only)
(4) 20% DAC-e.
In addition, the following data was requested on the 0 and 180 nozzles. Plots of 2.a dimension versus 1 dimension for each indication in the nozzles and far each inspection angle (0, 5 and 20 ).
List maximum DAC values recorded for each indication and show 50% CAC recordings ~ and 20% DAC recordings for both the normal and collimated beam transducers.
.This item will continue to be identified as followup item No. 50-567/
1-01-03, Demonstration of equivalent UT.
.
-'- -