ML20090K440

Applicant Exhibit A-97,consisting of Testimony of Je Cavender,We Rogers,Dh Llewellyn & Lr Barnes Re in Camera Witness 2 Allegations Concerning Accuracy of Radiographs

ML20090K440
Person / Time
Site:	Catawba
Issue date:	12/15/1983
From:	Barnes L, Cavender J, Llewellyn D, Rogers W DUKE POWER CO.
To:
References
A-097, A-97, NUDOCS 8405240205
Download: ML20090K440 (9)

Text

_ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ ___

77 r

/41A'N s v UCm

.. /b UNITED STATES OF AMERICA 67 43  % \)

\

NUCLEAR REGULATORY COMMISSIO 7 "9.? i BEFORE THE ATOMIC SAFETY AND LICENSINk N6 y

'g In the Matter of ) ~1 HG

) -x DUKE POWER COMPANY, et al. ) Docket Nos. 50-413 (Catawba Nuclear Station,

- -- ) 50-414

)

Units 1 and 2) )

TESTIMONY OF J. E. CAVENDER, W. E. ROGERS, D. H. LLEWELLYN, AND L. R. BARNES REGARDING IN CAMERA WITNESS #2's ALLEGATIONS CONCERNING ACCURACY OF RADIOGRAPHS 1 Q. PLEASE STATE YOUR NAMES, YOUR BUSINESS ADDRESSES, AND 2 PROFESSIONAL QUALIFICATIONS.

3 A. Mr. Cavender: My name is John E. Cavender. My business 4 address is P.O. Box S3189, Charlotte, N. C. 28242. I am a 5 Nondestructive Examination Examiner (NDE) Level III. My

@ 6 responsibilities include training and qualification of NDE personnel, 7 the development and approval of NDE procedures, and the periodic 8 review of NDE records. A copy of my professional qualifications is 9 attached to Applicants' testimony addressing the Board's Question 10 Concerning the Containment Spray System.

11 12 Mr. Rogers: My name is W. E. (Bill) Rogers. My business 13 address is Catawba Nuclear Station, P. O. Box 223, Clover, S. C.

14 29710. My current position is Welding Superintendent. I am 15 responsible for Welding at Catawba. My department consist of 16 approximately 550 employees. Prior assignments have included 17 Welding General Foreman, Welding Foreman, Welding Inspector, and 18 Welder with Duke Power. A copy of my professional qualifications nen88ra8aara o

d _

'1 .is attached to Applicants' testimony addressing In Camera Witness 2 .#2's Allegations Concerning Foreman Override.

3 4 Mr. Llewellyn: My' name is D. H. Llewellyn. My business address 5 is Catawba Nuclear Station, P. O. Box 223, Clover, S. C. 29710.

6 My present position is group leader of Technical Support - Welding.

7 A copy of my professional qualifications is attached to Applicant's 8 testimony addressing In Camera Witness #2's Allegations Concerning 9 Foreman Override.

10 11 Mr. Barnes: My name is L. R. Barnes. My business address is 12 Catawba Nuclear Station, P. O. Box 223, Clover, S. C. 29710.

13- My current position is Planning and Control Manager of construction 14 at Catawba Nuclear Station. A copy of my professional i

15 qualifications is attached to Applicants' testimony addressing the .

16 Board's Question Concerning the Containment Spray System.

17 18 Q. ARE YOU FAMILIAR WITH IN CAMERA WITNESS #2's ALLEGATION 19 THAT RADIOGRAPHS WERE BEING INACCURATELY INTERPRETED i 20- AND THAT THIS COULD HAVE RESULTED IN UNACCEPTABLE 4

21 DEFECTS IN WELDS?

l l-22 A. Yes. We have reviewed his testimony. As support for his allegation-23 the witness' major concerns include the following:

24 (1) ~ Although he is "no radiographer", he states that in attempting 25 to correct -welds which radiographers have determined ' are 26 deficient, at times he could not find the defect noted by the O 27 radiographer or would find a defect .in a location in the weld

)

l l

l t,

~

• ]f NJ 1 other than that noted. Also , he alleges that at times 2 radiographs of corrected welds would point out defects not 3 noted in the earlier radiographs.

4 5 (2) The witness alleges that in early 1982, Mr. Pridmore (one of 6 the "better welders" in Henry Best's crew) had informed him 7 of a weld in the Unit I reactor building which had passed a 8 radiograph inspection in 1960 and in early 1982 had been 9 rejected by a visual welding inspector. [M 10 11 Q. HAVE YOU INVESTIGATED THE ALLEGATION?

12 A. Yes. This investigation consisted of a review of relevant portions 13 of records regarding this issue and discussions with Level I and II 14- radiographers, welders , welder foremen, welder general foreman, 5 and the welder superintendent.

16 17 Q. WHAT WAS THE RESULT OF YOUR INVESTIGATION?

18 A. From our investigation, we determined that radiographers at the 19 Catawba site are qualified to do their job, that adequate controls 20 are in effect to assure that radiographs are accurately interpreted 21 and that unacceptable weld defects are identified and repaired.

22 Furthermore, to the best of our knowledge, there are no defective 23 welds. in the Catawba plant. Factors providing support for' this 24 determination include those noted below.

25 1. There are three levels of radiography certification, i.e. ,

26 Level I inspectors (assist in making radiographs), Level 27 II inspectors (may make radiographs on their own and

~. . . .. - .-

I l

. 1

[b 1 2

may interpret them if assigned to an interpreter's position) and Level III examiners (may also perform I

3 functions including administering qualification exams) .

4 The Level I radiographers at the Catawba site are 5 certified only after an extensive and thorough period of' 6 instruction (on the average about 6 months) culminating 7 in a comprehenrive written and practical examination 8 during which they must prove their abilities. To be 9 selected as a candidate for Level II testing and 10 certification, the Level I radiographer must train for a 11 minimum of nine additional months during which time his 12 work is checked to assure that he is completely qualified 13 and that he has sound, basic interpretive skills. The 14 Level II certification is awarded only after another very 15 extensive written and practical exams (e.g. , the practical 16 exam lasts about 2 days). Even after certification, the 17 Level' II radiographers must still undergo an 18 " apprenticeship" before being considered to fill an 19 interpreter's position at Duke. (No Level II QC 20 interpreters at Catawba have had less than 3 years 21 experience, and no Level II QA interpreters at Catawba 22 have had less than 8 years experience.) Further, even 23 af ter being assigned an interpreter's position, the work 24 of the Level II radiographer (like all other certified l 25 radiographers assigned radiographer positions) is i I

26 ' reviewed at least annually and every three years he must i

~O-C/

l 27 undergo a recertification. In short, the radiographers at l

_ _ _ _ _ .I

/~ 1 Catawba are well-trained and highly skilled employees

'2 whose proficiency is. continuously reconfirmed. JEC.

3 4 2. QA Procedure M-4 paragraph 4.7 requires that every 5 radiograph be reviewed and evaluated by a certified NDE 6 Level II Inspector. Procedure NDE-10 paragraph 18 7 requires that the inspector verify that the radiograph is 8 properly exposed and has adequate coverage for 9 interpretation, and that he interprets the radiograph to 10 identify any indications of weld defects which would be 11 rejectable under ASME III NB-5320 or NC-5320, as 12 appropriate, for the weld. In addition, QA Procedure 13 NDE-10 Paragraph 17.2 requires that a separate .avel II 14 inspector check the interpretations of the first inspector 15 for accuracy. If it is determined that a rejectable defect 16 exists , QA Procedure M-4 requires that the weld be 17 rejected until corrections are made and the weld is again 18 radiographed and accepted by two certified Level II 19 Inspectors. This rejection cycle will continue until 20 acceptance is achieved. After total acceptance by two 21 certified NDE Level II film interpreters, procedure M-4 22 paragraph 4.11 requires that ASME Code weld records be 23 made available for review by the Authorized Nuclear 24 Inspector. If he should find a rejectable defect , the i

25 entire cycle begins again. In addition , the Level III 26 inspector periodically reviews the work of the two 27 interpreters. Significantly, In Camera Witness #2 has not 28 identified any weld which is defective or any specific weld 1

t .

h. I which he questions. In short, procedures require b 2 thorough and independent review of all radiographs by at 3 least two qualified inspectors and periodic checks of these 4 reviews by a third Level III Inspector and the Authorized 5 Nuclear Inspector. JEC, LRB .

6 7 3. With regard to In Camera Witness #2's concerns regarding 8 not finding defects or finding defects in locations other 9 than that identified by the Level II radiography 10 reviewers, there are several possible explanations for 11 this. First, when a welder cuts into a weld using an air 12 arc to remove an identified defect, he quite likely will 13 remove the metal so quickly that some defects may be 14 removed before he sees them. When blending out a 15 smooth repair area, he might also come across a small 16 area of porosity or slag that he might consider to be a 17 defect , but because of its size may be acceptable under 18 the Code. JEC, WER, -

19 20 Second, the actual process of radiographing and 21 providing the welder information on any identifiable defect 22 will, in many cases, result in a shift in the observed 23 location of the defect. To explain, when a defect is 24 identified on a radiograph, the interpreter prepares, on a 25 piece of translucent plastic, a tracing of the radiograph 26 showing the location and nature of the rejectable defect 27 by referencing it to location numbers around the 28 circumference of the weld. Prior to repairing the weld,

• p 1 the welder should align the location numbers on the 2 tracing to the corresponding locations on the weld which 3 were marked during radiography. Failure to carefully 4 and accurately align the location numbers and weld 5 configuration can result in improperly marking the defect 6 locatior. on the weld , i.e., shifting of the defect. In 7 addition, the geometrical relationship between the source 8 used in radiography, the defect, and the film can result 9 in the defect location on the tracing being displaced from 10 the actual defect location on the weld circumference. In 11 any event, the allegations that defects pointed out by 12 radiographs may not be found by the welder, or may not 13 be found in the precise locations noted, provides no basis 14 for concluding that rejectable defects in welds are not 15 being identified and corrected. The witness has not 16 pointed out any welds where this is the case. (It should 17 be noted that we raised this issue with many other 18 welders at Catawba and they stated that this was not an 19 area of concern). In any event, because radiographs of 20 areas of weld repair are done on not only the area of 21 concern but also on the two adjacent areas, any rejectable 22 defects not corrected in the initial repair effort will be 23 identified in the subsequent radiograph. While this could 24 lead to a greater expenditure of Duke resources, it is not 25 a situation affecting plant safety. JEC, WER, DHL.

.26 27 4. With regard to In Camera Witness #2's concern that new 28 radiographs of welds which had previously been corrected

y-4 D'

Q -1 reflected defects in areas which were not repaired, there

. 2 are several possible explanations. First, the new i

3 radiograph may have been made using more sensitive film 4 than was used originally. (The Code requires that film

-5. have a certain minimum sensitivity, but we sometimes use 6 more sensitive film ' to aid the interpreter to evaluate 7 This is completely in accordance I borderline indications.)  !

8 with the Code and is not indicative of faulty ['

9 interpretation of the initial radiograph or rejectable n

10 " defects" slipping by the process. JEC.

Y 11 i 12 A second possible explanation regarding "new" defects in 13 reradiographed welds is the practice of opening a small i 14 hole through the weld on the opposite side from the 15 repair area so that the interior side of the repair can be 16 observed during welding in order to avoid root defects.

17 This " viewing port" must be rewelded, and its area 18 reradiographed to assure no defects are present. This f 19 appears to be the situation that the In Camera Witness #2 20 is referring to on Tr. 291. JEC, WER.

21 22 A third possible explanation regarding "new" defects in 23 reradiographed welds is that if a defect is repaired near l

24 a location marker; not only is the area - in which - the 25' repair was made. reradiographed, but also - the adjacent 26 area in order to assure complete coverage. This different 27 radiograph geometry could detect a previously undetected .

28 . indication . Because of Duke's conservative policy this I

-, ,_, _ , .,m,._. _ _ - , - _ . - _ , . .

e.

.O

(

1 new indication would receive appropriate attention. JE C ,

2 WER.

3 4 The significant point regarding this concern is that while r 5 more welder time may be needed to repair defects in areas 6 where originally no defects were noted, or defects which 7 " suddenly" appear in locations other than where they 8 were reported, in neither case is the interpretative skill

9 of the reviewer called into question or the final adequacy 10 of the weld at issue. It should be noted that we asked 11 many welders at. Catawba if they had a concern similar to 12 the witness and in no case did any respond that they 13 did. JEC, WER.

14 15 5. With regard to In Camera Witness #2's concerns regarding 16 the rejected weld of Mr. Prid more (identified as 17 INC56-8), this incident was docum nted on nonconforming 18 item report 12549. The report and subsequent discussions 19 revealed that the NDE Level III Inspector had evaluated 20 this weld ~ and determined that the radiograph was

_ 21 accurately interpreted and that the weld was acceptable.

l 22 However, in that there was some disagreement (of whh.h I

l 23 thh hard h:: alrady h--A +- " =y) regarding the l 24 weld , Duke chose the conservative approach and took 25 appropriate action. Specifically, some additional grinding 26 was done on the weld , it was reinspected and G

l b 27 reradiographed and determined to meet requirements of l

28 ASME III NC-4424(e). JEC, DHL, LRB.

.g.

l

G~

/

A /

n )/ / . .-

,8M,? Q ',)'g l/ 9/ /f e .,.<

8 "y f e' /

! 7'

.$y?4h,i  ! '

/ ,

sp{////l/)?:Qf

.; '?' l ,/ ,/

4N5 ,f ,' ,/,! ,

/j' I C l c';/,,/,//}Q c ,e

'W' _$

G J ,/

, /

r O