ML19343A077

Draft Value/Impact Statement for Proposed Reg Guide Sc 705-4.Proposed Guide Should Be Issued for Comment.Guide Provides Addl Guidelines to Existing ASME Code Procedures

ML19343A077
Person / Time
Issue date:	07/29/1980
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
Shared Package
ML19343A076	List: ML19343A074 ML19343A077 ML19343A078 ML19343A079
References
RTR-REGGD-1.150, TASK-OS, TASK-SC-705-4 REGGD-01.XXX, REGGD-1.XXX, NUDOCS 8009110364
Download: ML19343A077 (17)

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i i t O i for determining the location, dimensions, orientation, and growth rate of flaws. l The lack of standardization in the use of UT equipment ano procedures 1 leads to uncertainty in the results obtained. For example, transducer charac-I teristics such as beam spread, damping characteristics, and frequency for i peak response are not defined, and there is no provision to keep track of these from one examination to the other. Stellarly, characteristics of (ther UT system components such as pulser, receiver, amplifier, and video display screen may vary from one examination to another, and all these charac-teristics can influence the magnitude of the flaw Indications. Therefore, well-defined criteria for supplementary UI procedures are needed so that g it will be possible to characterize flaws correctly, estimate flaw growth, I and have reproducible results from inspections performed at different times using different equipment. In many instances, the rate of flaw growth can be even more important l than the flaw size. For example, if a flaw is found in an RPV nozzle or belt line region and it can be demonstrated without doubt that the flaw will not grow and has not been growing, a rather large flaw can be tolerated. This is also a potential problem for cases where it is probable that no crack exists, but there is a cluster of small rounded inclusions that must be monitored by flaw growth techniques to ensure acceptable behavior. But if the rate of flaw growth is expected to be large or is uncertain, even a small flaw may be of concern. For corparison of results to deter-l mine growth rate, the UT procedures should be such that results of succes-l sive UT examinations can be compared and flaw growth determined. With present procedures, ti.ese results cannot be compared because of variation in instru-ment characteristics. UT instrument characteristics depend on the character- '4 istics of the instrument's dif ferent components, and variation in the charac-l teristics of calibration blocks can also affect results. Culdelines are needed so that uncertainties in the flaw characterization and resulting delays in the licensing process may be reduced. There is a need to specify and standardize required performance of most UT system compo-nents to achieve better consistency in UT results. 18 e w n. __[,,~~ I

t I This proposed guide will provide supplementary procedures with the objective of improving conventional UT procedures, as-defined in the B&PV Code. This guide Is based partially on the ir. formation available in liter-ature on both U.S. and European procedures and partly on the judgment of the NRC staf f and their consultants. On the basis of support work being performed at the Oak Ridge National Laboratory, the staff plans to issue a revision to this guide that should further leprove flaw characterization. The use of new techniques such as holography or synthetic aperture laaging of flaws by UT, which have not been introduced to practice and could considerably increase the cost of inservice examination, is not being pro-posed here.

1. 3 Value/ Impact of Proposed Action 1.3.1 NRC Reporting of UT examination results as indicated in this guide would help the NRC staff and their consultants to better assess the results of the data. NRC staf f time for review of reported data and interpretation of Indications is likely to be reduced.

1.3.2 Other Covernment Agencies Not appilcable, unless the government agency is an appilcant, such as j TVA.

1. 3. 3 Industry the value/ impact on fr.dustry of the proposed regulatory guide positions is stated by each position in the appendix to this value/ impact statement.

Some highlights of the value and lupact of the proposed regulatory guide positions are stated below. 1.3.3.1 value. The proposed regulatory gulde is a sct.eduled milestone in the technical activity of Task A-14 as defined by NRR and specifies supple-mentary procedures that will lead to the following advantages: l

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missing large flaws and ensuring greater safety for the pubile, industrial workers, and other government employees, 1.3.3.2 Impact. There will be ejor impact in the following three areas a. Quality control of the UT equipment At present, requirements in the ASME Code for quality control of UT equipment are marginal; for example, there are no direct require-ments to control the quality of UT transducers. Criterton XII, " Control of Measuring and Test Equipment," of Appendix 8. " Quality Assurance Criterla for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CfR Part 50 requires, la part, that measures be estabitshed to ensure that instruments used in activities affect-Ing quality are properly controlled, calibrated, and adjusted at specified periods to maintain accuracy within necessary limits. The recommendations of this guide will help to bring about uniform-ity in the quality control procedures among different companies and will ensure that quality control measures are taken to ensure reliability and reproducibility of UT results. No new UT equipment will be needed to follow the recommendations of this gulde. However, the quality control measures recommended for UT equipment will impose extra cost burdens that are difficult to estimate without feedback from industry. b. Increase in examination Pine e This guide would recommend, for the first time, that indications with significant length of Indication travel (larger than the standard calibration holes) or with significant depth dimensions be recorded. It is not expected that the slag tyr.e of flaws, ~ which are common among welds, or geometric reflectors will give m significant traveling Indications within the guidelines proposed. Hence, no substantiai increase in recorded indications as a result of this recommendation is expected; however, 419 exact increase is difficult to predict or~ estimate. m 9 g e i 21 / } I g _

.. _ ~. _. _._ g 'a.. \\ Reporting of Indications associated with flaws larger than 1 inch y (indications larger than 1 inch plus beam spread at 20% DAC level) is also new. RPV welds are examined by radiography, and no flaws larger than three quarters of an inch are acceptable in these welds. Because of this acceptance length, only new service-induced { flaws larger than 1 inch, of which there should not be many, are I expected to be picked up and reported as a result of this recommendation. Because of the above two new reporting recommendatlons, there may be an increase in examination time and dollar cost that is difficult to estimate. Thlt will depend on how many significant flaws are detected and how large and complex they are, a c. Radiation exposure Recommendations of this guide apply to the examination of RPV welds and RPV nozale welds. RPV welds are usually examined by automated equipmens, and data are collected on tape. Therefore, no increase in radiation exposure is anticipated as a sesult of the regulatory guide positions addressing RPV weld examinations. 6 RPV nozzle welds are sometimes examined by automated equipment but in most cases by manual UT. An increase in radiation exposure to examination personnel may be expected while RPV nozzles are being manually examined. The probable percent increase in examina-tion time or radiation exposure is impossible to estimate without field data and research effort. Requirements for reporting travel-Ing Indications and Indications associated with flaws larger than 1 inch may lead to an increase in occupational exposi.re in those cases in which the above Indications are found and additional examination is required. The magnitude of this additional exposure can only be assessed on a case-by-case basis. It s'muld be noted that radiation levels at vessel norile regions are reported to 22 i 4 n-,

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i a m n n o f d e o a i e i d a u i e y b n r b n r m s m d t a t m o n c a h e s a o , c o s i t f e e n i c y c n n o i n z e h a e e m t m r p s s a n n e is o a o a r o t o e h t x f r o A d t e e g d n i d t i f d l h s n o t h n e o, s m c c o y e e a y e o i o . t r d p l t g t u h p 1 e m n a s g a m nl i n a i imi e o i e o t n d f r t l l r T a l x e o s i s ir a a s t o d o g m c e e a o s h s u a r s e u d a q a e h a e p p u a. n re 1t d v v o r T a a n. R, e e n r e n o o n d R n iv w i g t a u C c e p h n o i e e s e t o t d g y e s N i s r it a o n n s e r t r. i a e c . s e e h i n i i E n u n t u d r o s t s b t e r m s H o i e o r r n n 1 a S 3 h e v f p o a i l s q n, e h s e a t t u 6 x e A 2 / l h e w c l n s s e is i a f s h g e e a u o t e e s b i n R n i s i r e h r o e s y t n v r e c e t 0 b a e o o u v o e is v d c r i g c d t d v u m r e o 2 d e t n e l e e s l e t c e c i r d r t u e l t a e t s le o c c h A t i e u s c s e e 5 e n p i s p t r is i i i i iv o g i b e n c n d r b d r h c s a v t n u n e e t e e t t a r e t d s V a s 0 c o O d e p v a l o R r i h u P n c y t i e n p n d d n u ml o l h o o f a r a r o c e e t o l n b t r o s o e w a g t v r a u le it P m w t e t n l i se c s p n a n e a s ,i A t u f i i i o r n i t l c b l e g r a q o h a A e t e b e o f e e v n u l n e g s e h u t s r r l d a r r a r i t P c l n i p e o H a i ig r e t n a d e h f f C c t o r d u r p c i i h r O i a a e u l t a c o v le t o e A n e v d m a s o e a g o 4 i t i D n r l b c f y e R h e s o h e h t i t P e l e a o e i c e o o t h P c t e s 3 r r n h e T i 1 N ig D T e r A T A u e P o e d t h v c e c g lu 1 2 i d n e r t n l i c n o p f a a t e t 4 e s u ga a 1 g I i w 2 2 a o 2 n I b I

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2. 3 Cy arison of Technical Alternatives leposing inservice examination of RPY welds by the use of holography, synthetic aperture imaging technique, or acoustic emission, which are stfil in the stage of prototype development and which have not been proved ef fective for fleid use, would not be justifiable on the basis of either cost or effectiveness.

2.4 Comparison of Procedural Alternatives leaving the situation as is would mean that continuert attention and manpower would have to be devoted by the NRC staff to investt 4te the uncer-0 tainties associated with flaw growth on a case-by-case basis. The low level of confidence in the present techniques means that excessive margins will continue to be used in the, law-accepiance criteria. Also unnecessary cutting and repair attempts to remove suspected flaws may result. The procedures recommended in this guide have been siown to be effective in practice, altheirJh they are not in general use in the United States. Including these procedures as regulatory guide recommendations should result in their wider use and consequently their improvement. Af ter these proce-dures have been accepted by the industry, we will seek their inclusion in the ASME Code. Some of these procedures have already been sent to the ASME for consideration and inclusion in the present ASME Code procedures for ultrasonic examinations.

2. 5 Decision on Ternnical and Procedural Alternattves l

On the basis of the above, it appears desirable to issue a regulatory t guide to provide recosaendations for improving ASME Code procedures. These recommendations, which are based on the advanced state-of-the-art Uf proce-dures in current use by some organizations, would improve flaw detectability and characterization without imposing new unproved techniques for flaw detection on industry. b e e 24 ...,- - p-r - -

l f 3. STATUTORY CONSIDERATIONS 3.1 NRC Authority this guide would fall under the authority and safety requirements of the Atomic Energy Act. In particular under $50.55a, " Codes and Standards " of 10 CTR Part 50, which requires in part that structures, systems, and components be designed, f abricated, erected, constructed, tested, and inspected te quality standards commensurate with the importance of the safety function to be performed. t 3.2 Need for NEPA Assessment The proposed action is noc a major action, as defined by 10 CFR 51.5(a)(10), and does not require an environmental impact statement. 4. RftATIONSHIP 10 OTHfR (XISTING OR PROPOSED REGULAll0NS OR PotICIES Recommendations of this guide would be supplemental to the requirements of Section XI, " Rules for Inservlce Inspection of Nuclear Power Plant Compo-nents," of the ASME Code, which is adopted by $50.55a, " Codes and Standards," of 10 CfR Part 50. 5. SIM4ARY This proposed guide was inttf ated as a result of a request from the Divi-slon of Operating Reactors, NRR. It forms a part of Task A-14, as defined by NRR, and is identified as a ellestone in the technical activity of Task A-14. Preliminary results of the round robin UT examination procedures following ASME Code procedures indicate a need for additto. sal guidelines to the existing ASML Code procedures to control equipment performance, calibra-tion block, and scanning procedures to get better reproducibility of results and detectability of through-thickness flaws. 9 25 I .,m sn _ ,s-,-

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I Minimum A'ME Code requirements do not specify the details of recording requirements that are essential to evaluate flaws. This deficiency in the Code rules makes it difficult for the NRC staff or their consultants to review, analyze, and assess the UT data to determine the flaw size and cvaluate the system safety when the data are made available to NRC at a later date. The present data obtained from ui equipment of uncertain, unspecified performance lead to discussions and delays in the review pro-cess resulting in loss of MAC staff time and loss of plant availability and power generation capacity for the utilities. These situations definitely 'need to be avolded as often as possible. This guide is almea at athleving this purpose by issuing recommendations that will be supplementary to the culsting ASME Code UT procedures. The issue remains whether to wait for encourage improv e the development of adu.ced NDE techniques and continue with the present ASME Code procedures resulting in uncertaintles, delays, and discussions -the present stat [o7 t d rt E U $nventiona.i'Ui.~ The dect-cr t ptialz -- - ~...-, slon appears to be obil ss that we should use conventional UT based on ~ ~ % cngineering judgment until some new techniques for flaw detection and sizing kleu can be proved effective in the field. This proposed guide is aimed at pro-elding the recommendatlons needed to improve on the ASME Code UI requlrements until proven advanced MDE techniques are available. j 26 1 1 -i

I ~ I = i APPENDIX TO C2 AFT VAltK/INPACT STATEMENT Values that will result from this proposed regulatory guide are much easier to perceive than the impact, whlch is very dlf ficult to assess because j the Lind of statistical data needed to determine the real impact is sim. y not available at this time. One way in which we hope to estimate the impact is through Industry feedtack af ter the guide has been issued for comunent. We have made an attempt, in a qualitative manner, to estimate the value/ Impact of regulatory guide positions, position by position, as follows: 1. INSTRtNf MT PERf 0RMANCE CHECKS Recording the characteristics of the UI examination system will be useful in later analysis for determining the location, dimensions, orienta-tion, and growth rate of flaws. System performance checks to determine the characteristics of the ultrasonic testing (UT) system wlit be made.at Interv is close enough that each UT examination may be correlated with a particular system performance check. This will help to compara results. I These determinations will help make it possible to judge whether differences In observations made at different times are due to changes in Instrument characteristics or are due to real changes in the flaw size and characteristics. It is recommended that, as a alnlaum, instrument checks should be vertfled before and after esamining all the welds that need to be exaelned in a reactor pressure vessel during one outage. l Performance of these instrument checks is likely to add a few thousand dollars to test equipment cost and to take 1 to 2 hours of examination time before and after each RPV examination. By estimating the examiner's salary to be about $50 per hour, these checks should not cost more than $100 each time they are performed. The use of the examination equipment is seldom scheduled so close that there is not even a few hours between examinations; therefore, the idle time on the equipment Is not Ilkely to increase, and 21 ., -.. - me. - __., _ 7 1

t 4 A 'I hence the cost differe1tlal of insurance and depreciation on the equipment has not been included in the above calculations. No additional radiation exposure is expected because of it 's position. 2. cat 16 RATION l' I According to this position, system calibration should be checked to j verify the distance-amplitude correction (DAC) curve, as a minimum, before 6 and af ter each reactor pressure vessel (RPV) examination (or each week the system is in use, whichever is lass) er each time any component (e.g., transducer, cable, connnector, pulser, or receiver) in the examination system is changed. g up to the Summer 1975 Addenda, Subarticle I-4230, Appendix 1, Section XI. ASME B&PV Code, which applied to the inspection of the RPV, required calibra-tion using the basic calibration block each 4 hours. However, the present (1977) rules of Article 4 (T-433), Section V, which are referenced by Sec-tion XI and now apply to the examination of the RPV, require calibration against the callbration block only " prior to use of the system." It is e considered that the present (1977) ASME Code rules are not adequate to con-trol potential problems in the variation of instrument performance charac-teristics. Therefore, the recommended calibration before and af ter each ewamination is a more rellahle approach to instrument performance checks. The ?l.ove position is not a ratchet on previously accepted 1975 Code rules on this item but is a ratchet if 1977 rules are considered. l Considesing the requirements of Article 4, Section V (1977), the above position will mean a calibration check each week the system is in use or before and af ter each RPW examination, whichever is less, instead of before each examination. Calibration check agalnst the calibration block takes 15 to 30 minutes for manual UI and automated UI equipment where prowlsion is made to calibrate the equipment without having to remove the transducers of from the rotating scanning are of the mechantred scanner. In some cases, transducers have to be removed from the scanning are for callbration of the UT instrument; in these cases, calibration check may take from 30 to 60 minutes. The added cost of the above may range from $25 to $50 in terms 28 wwe W "V%" V y y,, r

l et additional time spent by the examiner. This cost is calculated using a $50 per hour wa0e rate and would occur each week or once for each RPV examina-I tion, depending on whether or not the examination is completed in less than a week. No additional radiation exposure is espected because of this position. 3. NEAR-SURFACE EXAMfMAi!ON AND SURFACE RE50tuTION This position recommends that an estimation of the capability to ef fec-tlwely detect defects at the metal front and back surfaces of the actual component should be made and reported. This will not require any additional calibration or examination time but will simply require an estimate of this capability by the examiner, which will be reported to NRC. This may take 4 hours of ef fort and may cost around $200 for each RPV examinations report sent to NRC. This calculation is based on assuming $50 per hour wages for the examiner. No additional radiation exposure is expected because of this position. 4. BEAN PROFILE Ihis position recosamends that the beam profile (for each search unit l dsed) should be determined if any significant flaws are detected during t the RPV examination. Assuming that no more than three search units are Ilkely to be used during an RPV exam ration, this step is Ilkely to require no more than 2 hours of examination time. Therefore, this beam profile determination should cost no more than $100 for each RPV examination based on a $50 per hour wage rate. No additional radiation exposure is expected because of this position. 5. SCANNING WELD-NETAL INTER M This position recommends that the beam angles used to scan welds should be based on weld / parent metal ir.terface geometry and at least one of these angles should be such that the beam is almost perpendicular (115 degrees e 29 ? +.-_.-,.y.-- --. - 2

O I to the perpendicular) to the weld / parent metal interface, unless it car be demonstrated that larGe (Code-unacceptable) planar flaws unfavorably oriented 1 can be detected by the UT technique. On the basis of Information available, it appeart Bat it is difficult *0*I to detect large planar flaws (e.g., service-induced fatigue or stress corroston cracks) oriented at right angles to the surface, using the ASME Code UT procedure. However, the option is being provided to demonstrate that such flaws can be located by conventional methods or by using new advances in Uf techniques. In these cases, the technique will be acceptable as a volumetric examination method. Otherwise, the use of high-intensity radt-ography or tandem probe UT should be considered, among others. The above type of flaws is the most significant yet most difficult to detect. Because of this, the present recommendations are being made despite their potential lupact on cost and radiation esposure. The potential Impact may be as follows: 8 a. Fatra NRC staff time may be needed to evaluate the effectiveness af UI techniques, on a generic bas!s, to detect perpendicular planar flaws. After techniques are recognized to accomplish the above, NRC staff time that is being spent currently on evaluating problems on a plant-by plant basis is expected to be reduced considerably. b. Reactor downtime may increase, depending on the examination time differentials between the conventional and refined techniques. This may, however, be offset by a reduction in the downtime needed currently to evaluate data by NRC experts on a case-by-case basis that sometimes require further clarifications and reexaminations.8.10 " Probability of Detecting Planar Defects in Heavy Walt Welds by Ultrasonic lechniques According to falsting Codes," Dr. Ing. Hans-Jurgen Meyer, Quality l Department of M.A.N., Nurnberg, D 8500 Nurnberg 115. 8" Interim Technical Report on BWR Feedwater and Control Rod Drive Return Line Nottle Cracking," NURtG-0312, July 1977, p. 3. I" Analysis of the Ultrasonic Examinations of PVRC Weld Specimens 155, 202, and 203," R. A. Suchanan, Pressure Vessel Research Committee (PVRC) Report. August 1976. " Summary of the Detection and Evaluation of Ultrasonic Indications - Edwin Hatch Unit 1 Reactor Pressure Vessel," January 1972. Georgia Power Company. 30 ,w --n me

h l q I I c. Additional cost might be incurred in changes needed to add trans-ducers or data gathering capability to esisting automated equipment er.to automate current manuel emanimettons. Automation of current manual tech-i nlques is likely to reduce radiation exposure to personnel L 6.' SillIIG AIS RECORDING Of IISICAll0NS 6.1 Traveline Indicattens f This position recommends the recording of traveling indications. If RPV welds do not have any indications in the welds whose travel Indication i on the screen is larger than the indication en the screen from the calibra-tien holes (1/2" hole for 12* weld thickness, 3/8" hele for 8" thickness), this recommendation will not result in any more recording of ladicattens. If the RPV welds being emasined have several indications with travel in excess of the calibration hele diameter, the exaelnatten and recording time will be increased for investigation of these flaws, depending on the number of these indications. Slag faciusions in welds are generally long cylln-drical defects and do not have much depth unless they are asseclated with shrinkage or service-induced cracks. These slag inclusions are not expected to increase the number of Indications that will be recorded. Increase in examination time will depend on the number, size, and compleulty of geceetry of through-thickness indications. For RPV girth er nogale welds where examination is performed by auto-mated equipment and data are recorded on tape, this position will mean no e increase in examination time er radiation exposure; but interpretation, analysis, and reporting time for these depth indications will increase. The entra burden la teres of dellar cost will depend on the number, size, and complenity of flaws, and there is no rational basis or data available at this time to estimate the increase in cost of examination. For RPV welds, mostly nortle welds, where examination is performed manually and data are not recorded on tape, this position will mean entra examination time and increased radiation exposure to the emasiners. Increase in dollar cost and radiation exposure will depend again on the h I 31 i m %m s-

8 I number, size, and complexity of indications, and there is no basis or data avaManle to estimate this increase. 4 6.2 Nontravelina Indications ihls position also recommends the recording of nontraveling indication., above 20% DAC level, that persist for a distahce of more than 1 inch plus the beam spread. According to NS-5320, Radiographic Acceptance Standards, Section III, Olvision I, A5ME B&PV Code, 19FF edition, flaws larger than 3/4 of an inch for weld thicknesses above 2-1/4 inches are not acceptable. Because of this requirement, it is expected that no flaws larger than 3/4 of an inch in length are present in the RPV welds, and if indications are detected that suggest flaws larger than 3/4 of an inch, there is a strong possiblitty that these may be service-Induced flaws. Service-induced flaws are rare in RPV welds, and it is therefore not expected that additional Indications would have to be recorded becatse of this position. However, if such indications (over 1 inch) are detected, examination time for auto-I mated recording and examination time plus radiation exposure for manual UT examinations wl11 be increased. There is no rational basis or data available to estimate the impact of this part (6.2) of this regulatory posillon. t 7. REPORIING OF RESUti5 This position recommends that the areas required to be examined by the ASME Code that have not been effectively examined and an s.timate of error band in slain 0 the flaws should be brought to the attention of the NRC when the results are reported. This effort will take about 5 hours in report-writing time. The dollar cost for this ef fort is estimated to be $250 based on a $50 per hour wage rate. l IMPlfMfNTAIlON It should be noted that recosmandations of this guide are not intended to apply to preservice examination tests already completed. However, the N 32 ..- M

)ll Il1lll -l I - Y l = i. t c g e i e n l s r v b m t o i i e o e b s l t m t n a u ss b u I o r o o g l i he n o t o p r i v . c p a t d d t id s n r e e t a i c ic c i r s o o o r e e v u b i e. d t c v d a a a r n f s n o t e i n i t e t s m o o r n e e o c t n p a r c r a o r c p i f o n i e i v t f h r e i t t ini s i d m p n t e s a oi e s g w r s e r wi n a i i a s e e v e e l t e s d i h F s a b n a c t a l o v e e i l r t .d r v t l e a e e r a a e s t l o h c w e e a f c p i d f o i e r m d t t t n b t r n o i r e e n d d 3 i y t d e e l e n a i o m s u 3 h a l d u e o t s s h w e a n e s t g d o d a s i i t i i e a e n t e u a t u t g a g b h s e a s c t n p i e i s d e e s m e h l n i l w c d h u o i r t b i t o h l o w s r f r g f e e o p n o e o h W id i s n c t t s nl s n it a i h lt o e n e n o v o e o u r c i a r t d c o. t a t t a n i f y d e d a f e s a n r f n f r e m e p i e s i h i e m r m t d t s m e r m l T i e o t u o u e l e c n c c s b . b i s e I o r r d s c e e n r e w w i s c e a y e E l a s u i h a h D o o l t l st N w l p f f 0 l:

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UNITED STATES p ggy NUCLEAR REGULATORY COMMisslON o b o WASHINGTON, D. C. 20555 h' i, f JUL 3 o.i:410 i s.

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MEMORANDUM FOR: R. J. Budnitz, Director, RES R. J. Mattson, Director, DST, (5) N. C. Moseley, Director, DROI, IE H. D. Thornburg, Director, DRCI, IE H. Shapar, Director, ELD FROM: W. M. Morrison, AD/GES, DES, SD P

SUBJECT:

REGULATORY GUIDE REVIEW REQUEST Your assistance is requested in reviewing the enclosed document and pro-viding me with your coanents and recommendations. The following is a sum-mary of this request. 1.

Title:

Draft Regulatory Guide SC 705-4, Division 1, Draft.1, July 1980, " Ultrasonic Testing of Reactor Vessel Welds During Inservice Examination" 2. SD Task No.: SC 705-4. 3. SD Task Leader: V. S. Goel, SCSB, DES 4. Cogni:: ant Individuals: M. Hum, DE; C. Cheng, DL; J. Collins, IE. 5. Requested Action: Review and comment and make recommendations. 6. Requested Completion Date: AugustT. 28, 1980 7.

Background:

The revision to the proposed guide reflects the influence of public comments received during the 60-day comment period. A large number of coments were received on this guide. Resolution of the com-ments is based on the advice received from our consultants at the Oak Ridge National Laboratories, Sandia Laboratory, Albuquerque, and members of NRC staff. d' / glo;20 l} g 00 ?ny ?.

5'." ag g 1980 ~ Those Listed 2 8.

Enclosures:

1. Draft Regulatory Guide " Ultrasonic Testing of Reactor Vessel Welds During Inservice Inspection." 2. Public Comments to the proposed guide. 3. Resolution of public comments. 4. VIS-Value/ Impact Statement. (-{Y{ cW4 cn1 W. M. Morrison, Assistant Director for General Engineering Standards Division of Engineering Standards Office of Standards Development

Enclosures:

As~ stated cc: L. Frank -C. Cheng D. G. Eisenhut l A. Taboada R. Bosnak R. H. Vollmer E. Baker H. Brammer G. Knighton i E. Brown B. Liaw G. Georgiev M. Hum W. Rutherford R. Gamble W. Collins W. Hazelton R. Hermann K. Hoge l J. Henderson F. Almeter K. Wichman R. Msttu CONTACT: V. S. Goel 443-5997 i 1 t L.m j

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. ~. - (INDTD INDljd> TRIM 39yDTcoMpast ixc f W OUALITY ASSURANCE THROUGH NONDESTRUCTIVE TEST!.NG CHARLESTON DIVI 5 TON 3409 RIDC. W %* STREET CHARLESIO,$DIGPftsf C. ::9405 ' 44 ;'a $ July 19, 1979

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3 I g U.S. Nuclear Regulatory Con =tission p !373 Washington, D.C. 20555

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,""~" sb Act: Docketing & Service 3 ranch _ m ./ Y / o '# ' Ref: Draf t on Ultrasonic Testing of Reactor Vessel Welds during IS, ~ coc=ents on. To Whom It May Concern: Upon review and consideration on the above proposed Regulatory Guide, I am pleased to see some practical, state of the art, applications to ultrasonic testing of reactor vessel welds. Specific comments are listed below: 1. Calibration of scanning speed. It is my feeling that static calibration for manual scanning is more repeatable than calibrating while =oving the transducer. Since I do not have any experience with automatic scanning, I do not know from experience that the same would be true for aucccacic scanning. Scanning at an increased (2X or 6d3) sensitivity level enhances the resolution, detectability, and makes up for any slight dif ferences.

• Ghen a DAC curve is to be used for the detection of flaws (established statically or by a =oving transducer) utiliring automatic scanning equip-ment or manual scanning, the DAC calibration curve should be VERIFIED by scanning over the reference standards at the scanning speed (=anual or automatic).

2. Near-Surface Examination and Surface Resolution. How will near and far surfaces degradation be determined? 3. Scanning Weld-Metal Interface. If the beam angle is based on the weld / parent =ecal interface geo=etry (and within j 15 degrees), then is it necessary chat the other or second angle beam be used? Within some established limits if the interogatory beam is within some toleranca to weld prep angle, does the second angle give you the additional assurance of detection? , G. '.c.iuiled h* *n~f. 99flod4 ws %I .t -74 'G 4a Dl%I510% ? A% 4.%% AH iGAs Dtt i.410% AL34M L %TH AW'M 4 Di' i. im W e**i4934 e 9121136-5*J4 !14i *?J.1:u E

1 Thank you for the opportunity to coc=ent upon this regulatory guide. Sincerely, n 'h 4fk I.I T L Robert L. Moore Tirector of Quality Assurance RLM/dkb O e J m

r m l...- Q^.. p Washington Public Power Supply System A JCINT CPERATING AGENCY 00CxET Nu c ta g*g g' =msonoauu,)3 g g, W E C %. s iSOS) 375 5000 P. O. Se s 9 6 8 2000 G80. WAensMefem War Ricnkamp. Wasnamerom 99332 r%~. August 6,1979 gi - cv, uW 2 1 ,8 AUG pg jgI3 > 4 -~ Mr. Samuel J. Chilk, Secretary U.S. Nuclear Regulatory Commission i-D/, g Washington D.C. 20555 }

Subject:

COMMENTS ON NRC DRAFT REGULATORY GUIDE e, /#y AND VALUE/ IMPACT STATEMENT FOR ULTRASONIC TESTING OF REACTOR VESSEL WELDS DURING INSERVICE EXAMINATION, SC-705-4

Dear Mr. Chilk:

The Washington Public Power Supply System has reviewed the subject Regulatory Guide and submits for your consideration the attached corm:ents. Very truly yours, 0 V D. L. RENBERGER Assistant Director-Technology DLR:FJ:ct Attachment u.-~wsc=e...:J$.tw.& r ?,s u hfo " 3 pte qqo7i<1005I qq s A 19o9aso3% pse

AttachmInt .~ 1. Item "B, Discussion", page 3 - The reference examples cited as a basis for inconsistent characterization of flaws were conducted in accordance with the 1970 Edition of Section XI. The techniques referenced in this early inspection Code have been revised in the 1974 Edition of Section XI and later addenda. A data base should be formulated based on current techniques and proposed improvements should be judged against the current techniques. Item "B-2, Calibration", page 4 - Regardless of the frequency of calibration of the ultrasonic instrument, the existing requirements of the Code still require examinations to be repeated if an instru-ment is found to be out of calibration. The amount of economic risk to the examiners due to re-examination costs is directly pro-portional to the length of time between calibration checks. The amount of risk that examiners and utilities should be allowed to bear in regard to having to repeat examinations should not be discussed in a regulatory guide, as it has no bearing on the valid-ity of the final examination results. Furthermore, no consideration seems to have been given to the potential drawbacks of frequently removing and reinstalling remote equipment for recalibration, such j as increasing the potential for damage, inaccurate positioning, and so on' In fact, such a requirement may indeed cause or worsen the very problem the guide is addressing. 3. Item "S-2.b, CaTibration. Check-Simulator", page 5 - Much of the remote automated inspection equipment, for reactor vessels, in use today is complex and cumbersome. To require a full calibration of this . equipment every four hours can be very costly in time and additional radiation exposure; up to 2 hours for two or more people to disassemble, calibrate, and re-assemble. It is suggested that if the Commission finds' it necessary to address calibration frequencies, that a full calibration on the basic calib. ration block using all the required basic reflectors be performed at each change of examination personnel, not to exceed 12 hours, and that the use of simulators be encouraged p for intermediate (four hour) checks,. 4. Iten "B-2.d(l), Calibration Check-Scanning Speed", page 5 - Although there may be a relationship between scanning speed and the ability to detect indications, evidence exists which shows that the relation-ship is not as one sided as the Guide implies. That is; in some cases. signal responses are detected at the faster scanning speeds (dynamic) which cannot be confirmed, when static conditions are used for evaluation. The references to contact force appear to limit the Guide to other than PWR immersion testing from the ID; where, the measured water path distance is very carefully controlled and force is not a factor. If this is the case the Guide should be revised to clearly state the exception. e <_ 1 -i

O. / 5. Item "B-2.d(2), Calibration Check-3econdary DAC", page 6 - The Guide should be revised to clearly state that secondary DAC curves need i not be generated unless required. Where electronic DAC systems are used, this requirement may not exist. 6. Item "B-7, Reporting of Results", page 10 - The inclusion of stress corrosion cracks in the heat affected zone as a type of flaw occurrig in reactor vessels is puzzling. This type of flaw is known in piping applications but its occurrance in reactor vessels subject to this Guide is challenged. Both the 1974 Edition of ASME Section XI, including Summer 1975 Addenda and the 1977 Edition of ASME Section V, Article 4 require the reporting of areas of nonexamination due to geometry. The Regulatory Guide appears to be redundant in this area and offers no improvement in recording of geometric obstructions. ASME Section XI requires the examination of a full volume of material to con-stitute a test. If this volume is not fully examined, alternative techniques are permitted provided they provide demonstrated equivalence or superiority. Again the Guide appears redundant and further; it implies the postulation of defects in areas of nonexamination which are not substantiated. 7. Item "C-1.1, Screen Height Linearity", page 11 - The words "a means should be devised... ' are out of place in a Regulatory Guide. The Guide should provide a positive method for meeting the require-ments that would be acceptable to the Commission, and not set the stage for confusion and differences of opinion, both in industry and the Commission itself. 8. Item "C-1.2, Amplitude Control Linearity", page 11 - This item should i permit the use of Appendix 1 to the 1974 Edition of ASME Section XI including the _ summer 1975 Addenda in addition to Article 4 of ASME Section V as stated. 9. Item "C-1.3, Frequency-Amplituce Curve", page 11 - The inclusion of this parameter in the Guids suggests that it is important. Since this parameter measr.rement is non-existent in existing Code requirements, its value is challenged unless significant data is provided to support its value. 10. Item "C-1.5, Scanning Weld Metgl Interface" - The requirement to direct sound beams within t 15 to the perpendicular may be difficult to achieve when scanning perpendicular to reactor vessel longitudinal seams due to the vessel cu; 7ature. The ability to perform this test should be supported with refracted angle calcula-tipns based on existing reactor vessel sizes and including ID it.mersion tests of PWR vessels. ~ 11. Item "C-6, Sizing" - The importance of 20". DAC sizing should be supported by statistical field data..To dilute the evaluation effort just to take more data is expensive and time consuming and considered - unwarranted without some basis for the additional effort. We are confident that it is not the intent of the Ccanission to require the l generation of data without due justification. I

b. . 9 12. Value Impact Item 1.3.3.2(b), page 22 - The comparison between radio-graphy and ultrasonics is totally false and misleading. These two techniques are to some extent complementary and not absolutely equivalent with respect to flaw detection capability, as is inferred stating no flaws are expected to be detected which exceed radio-graphic acceptance standards. 13. Value Impact Item 1.3.3.2(c), " Radiation Exposure", page 22 - The statement that "The probable percent increase in examination time or radiation exposure is. impossible to estimate withott field data and research effort." is true. For that reason, it is unclear how the Commission can warrant issuing the guide, thus increasing the radiation exposure burden of the utility by some unknown amount, without any proven benefit to the public or the industry.. This action would not be consistent with the posture taken by the NRC on ALARA, prior to any implementation where radiation exposure increase is inevitable but, according to the draft guide, of unknown magnitude. 14. Appendix to Value/ Impact Statement - This appendix ignores the time of surveillance personnel, e.g., Authorized Inspector Quality Assurance, and Technical Surveillance, in all of its projected time and dollar estimates. The costs provided will be at least tripled if a thorough estimate of time and dollars is provided. O e S )

t NUCLEAR ENERGY SERVICES, INC. 4 NES DIVISION ~ SHELTER RCCK ACAD I \\. -\\ CAN8URY. CcNN. C15810 .b t[n g .a 4 (203) 748-3581 ac 9 I973 6~2 2 5 AUG e.M } August 3, 1979 Ref. No. 45-075 '"' e k cut was s ~ g E ED ihui ~* Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: Docketing and Service Branch

Dear Sir:

The U.S. N.R.C. issued a Draft Regulatory Guide entitled, " Ultrasonic Testing of Reactor Vessel Welds During Inservice Examination" for public comment. Nuclear Energy Services, Inc. has reviewed the draft and its Value/ Impact Statement and submits the attached comments for consideration. NES is vitally interested in the evolving requirements for Inservice Inspection. We would be eager to discuss details of specific items with representatives of the Commission. Very truly yours, NUC ENERGY SERVICES, INC. NES IVISION 0 ~ // / +w Georg T. Hamilton Vice President GTH:bb Enc. W cc: W. J. Manion L. A. Johnson K. F. Schmidt Acknowledad ty emd.. 4 J. L. Walker F. T. Carr p

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s, s s COMMENTS ON PROPOSED REGULATORY GUIDE ON RpV EXAMINATIONS Nuclear Energy Services (NES) has reviewed the draft Regulatory Guide entitled " Ultrasonic Testing of Reactor Vessel Welds During Inservice Examination". Although NES is in agreement with the broad objective to improve the effective detection of relevant vessel defects, we have numerous questions and comments on the impact of the proposed Regulatory Guide. i l NES is a major ISI contractor and has performed, or is under contract to perform, PSI or ISI examinations on twenty-one (21) domestic reactor pressure vessels. Our comments on Preservice Inspections are based on experience gained from examining twelve (12) vessels. Comments on inservice inspections are estimates based on preservice vessel inspections and extensive ISI on piping and components. The comments are organized into e three sections: (a) Comments and questions regarding the Discussion section of the draft Regulatory Guide. 1 (b) Comments and questions regarding the Regulatory Position. (c) Comments on the Value/ Impact statement. 1.~ Discussion Section 1.1 The introductory paragraph states the desirability to compare results from one ultrasonic examination to the other so that flaw growth rates may be estimated. Comment: This philosophy is not currently reflected in the ASME Code, Section XI, which intends to have each examination stand alone. How does the NRC intend to resolve this difference? 1.2 Paragraphs 2b and c raise doubts about the validity of a simulator for calibration checks, but no I position is taken in Section C of the Guide. Comment: What is the significance of discussed items which are not addressed in the Regulatory position? Prohibition of electronic simulators could result in a 10% increase in the time required for performing PSI and ISI and there is no evidence that we know of indicating that their use is detrimental.

u.- p .i

. - 1.3 Paragraph 2d (1) indicates a preference for dynamic

-calibration, but no position is taken in Section C of the Guide. I Comment: What is the significance of discussed items which are not addressed in the Regulatory Position? Dynamic calibration will require development of scanning bridges or other positioning devices which can represent scan motions on the vessel. Different motions are necessary for OD and ID exams of shell ) courses, lower head, and nozzle areas. Differences in the curvature and surface finish between calibration blocks and vessel areas could change the dynamic performance. 1.4 Paragraph 2d (2) recommends the use of a secondary DAC curve when points on the primary DAC curve fall below 20% of the full screen height, but no position is taken in Section C of the Guide. Comment: What is the significance of discussed items l which are not addressed in the Regulator-Position? j It should be pointed out that the use of electronic DAC eliminates the need for a secondary DAC. 4 1.5 Paragraph 5 indicates the desirability of monitoring j the back reflection amplitude from a straight beam transducer for reductions greater than 50%. Any such area should be successively scanned in increments of 1150 until the reduction is explained. However, no i i position is taken in Section C of the Guide. Comment: What is the significance of discussed items which are not addressed in the Regulatory Position? Back reflections are not monitorable in several areas of the vessel where opposite side tapers exist and signal losses occur due to cladding, surface conditions, geometry, etc. Examination of areas at angles 115 will require the development of new scan fixtures for automated systems and will consume significzut time and radiation exposure to evaluate many nonrelevant indications. i 1.6 Paragraph 6 states that only signals with a total transducer travel movement greater than the beam l spread should be considered significant, but no l position is taken in Section C of the Guide. 1 Comment: What is the significance of discussed items

s , which are not addressed in the Regulatory position? Most of the. vessel indications recorded in current examinations are spot indications with sizes less than the beam spread. Considerable time and effort is expended, however, at locating, sizing and recording these indications in accordance with Section II requirements. 2. Regulatory position 2.1 paragraph 1.1 requires demonstration of proportionality of electronic DAC signal response to different sizes of reflectors at 1/4, 1/2 and 3/4 T depths. Comment: This statement is open to broad inter-pretation as to its meaning and intent. Assuming that this means a two signal linearity check, some guidance should be given as to what the limits are for measurement positions; e.g., 1/4 T + 1/8 T, 1/2 T + 1/8 T, etc., or if 1/4 T and 1/Y T, 1/2 T and 3/4 T, etc. are acceptable to demonstrate the required proportionality. Could this be clarified? 2.2 paragraph 1.3 requires preparation of a frequency-amplitude c,urve for the ultrasonic instrument system. Comment: Experience has indicated that the trans-ducer type, cable length and type and instrument controls used have a significant effect on the frequency-amplitude response of the UT system. Spectrum analyzers would be needed at job locations to perform the measurements before and after each vessel exam. NES has no data to indicate the need for frequent frequency-amplitude curves. However, if data exists to establish the need to check these curves before and after each vessel examination, then the checks should actually be done more frequently so as not to endanger the validity of work performed on the entire vessel. 2.3 Paragraph 1.4 requires a photographic record of the unloaded instrument initial pulse. Comment: What function is the photographed initial pulse tg serve? Is there data to substantiate that it is a valid technique for determining instrument performance? 2.4 paragraph 2 requires measures to protect calibration

g

' block surface and hole reflective conditions between uses and to document any polishing performed.

Comment: ASME Code changes have required the use of new or modified calibration blocks between PSI and ISI along with changes in the calibration techniques. Such changes can compromise measures taken to protect the condition of the original block. 2.5 Paragraph 5 rgquires UT examinations with at least one angle +15 from the weld prep unless it can be demonstrated that planar flaws are adequately detected at larger angles. As discussed in an earlier section of the Guide, most vessel welds have essentially a0 00 preparation, and examination at angles near 75 are undesirable. Otherwise, alternate examination techniques should be used. Comment: This section provides three options.

First, a demonstration program could be undertaken for which relevant planar flaws must be examined at different orientations.

The surface condition of these flaws will have a major impact on their detection, but the relevant surface conditions of the flaws are also undefined. Some guidance should be provided as to what constitutes effective detection of planar flaws. Secondly, examinations could be attempted at larger angles but examination equipment has been designed 6 for 45 and 60 angles. Larger angles require a larger scan area. This both impacts the examination time and the scanning equipment. As an example, for an 11 inch thick shell course, the perpendicular scanincreasesfromabout2g_to75incheg to 41 inches when the angle increases from 60 OD vessel scanners and track systems have been designed to 0 obtain the scan coverage for 60. The larger angle will require new scanning equipment and tracks which may not even be installable in plants near completion or in operation. Furthermore, a number of welds have weld prep surfaces at angles greater than 90 due to tapers or lower head curvature. These welds could not be examined with-current techniques since angles over 80 would be required. Examination is achievable from one side only. The third option is a commitment to radiography, tandem-probe UT or other volumetric techniques. This proposes a major adjustment in the technical approach to ISI. e

. Major changes will be needed in equipment, personnel, procedures and programs. The sensitivity of RT to tight vertical or near vertical planar flaws in an i 11 inch thick shell is very questionable. Fairdew probe UT would be affected by need to bounce off cladding. NES recommends a government sponsored R&D program to establish the ability of present ultrasonic techniques to detect planar flaws along the weld / parent metal interface prior to implementing the requirements of the Regulatory Guide. It should also be pointed out 1 that examinations at new angles would not be easily correlated to early exams which conflicts with other i desires of the_ Guide. Additionally, ISI is supposedly j directed toward detection of service induced flaws (fatigue cracks) which would extend from or to the 1 0 nearest surface and could be detected with a 45 test. The tests at +15 of the weld interface would be looking for fabrication flaws which should have already been detected in the Section III inspection. 2.6 Sizing. paragraph 6 of the Regulatory position requires sizing of indications exceeding 20% DAC on I separate criteria depending on whether they are traveling or stationary. Comment: To implement the sizing criteria, all data generated at greater than 20% DAC would have to be evaluated. past practice indicates that_this would 1 increase the quantity of data by a factor of 10 and i ~ nearly double the number of recorded indications. Justification was not presented in the discussion section to form a basis for the additional effort involved. Can the basis for this requirement be stated? In regard to non-traveling indications, is it the NRC's position that geometric indications exceeding 2 20% DAC be fully recorded in accordance with this paragraph? 3. Value/ Impact 3.1 Instrument performance Checks ~ 3.1.1 Ultrasonic instruments screen height 1,inearity. 3.1.1.1 Checking at the setting used during examinations will require procedural changes to assure compliance. J .,. ~ ~

,e ' Value - Desirable addition to the system checks. Cost Estimate - One time cost for Q.C. procedure modification of $700. Cost per examination would t be on the order of $100. 3.1.1.2 Demonstration of electronic DAC for proportionality to different sizes of reflectors at 1/4, 1/2, and 3/4 T depths. Value - Unknown. Cost Estimate - Initial R&D program $10,000. Performance checks - 2 X 1 hour X S200 per hour = $400 per examination plus possible cost for additional calibration blocks. 3.1.2 Amplitude Control Linearity - no cost impact from present practice. 3.1.3 Frequency-Amplitude Curve - Value - Unknown. Cost Estimate - Spectrum analyzers, oscilliscopes and related equipment is estimated to cost about $1,000 per job. Generation of frequency-amplitude curves is estimated as follows: Manual instruments $600 X 2 Automated instrument $800 X 2 Total cost per job $3,800. 3.1.4 Pulse Shape Value - Practice has indicated that variations in instrument pulse shape has little value in evaluating indicar. ions and that system frequency, beam profile, and DAC response are more important measures of instrucent performance. 1 Cost - Equipmr.. costs have been prorated under the Frequency.'.m litude Requirement. Measure-ments are estir...ed to cost about S400 per job plim the indirect costs of maintaining records, etc.

Major changes will be needed in equipment, personnel, procedures and programs. The sensitivity of RT to tight vertical or near vertical planar flaws in an 11 inch thick shell is very questionable. Fairdew l probe UT would be affected by need to bounce off i cladding. NES recommends a government sponsored R&D program to establish the ability of present ultrasonic techniques to detect planar flaws along the weld / parent metal 1 interface prior to implementing the requirements of the Regulatory Guide. It should also be. pointed out a that examinations at new angles would not be easily correlated to early exams which conflicts with other desires of the Guide. Additionally, ISI is supposedly directed toward detection of service induced flaws (fatigue cracks) which would extend from or to the nearestsurfaceandcougdbedetectedwitha45 test. The tests at +15 of the weld interface would be looking for fabrication flaws which should have already been detected in the Section III inspection. 2.6 Sizing. Paragraph 6 of the Regulatory Position requires sizing of indications exceeding 20% DAC on separate criteria depending on whether they are traveling or stationary. Comment: To implement the sizing criteria, all data generated at greater than 20% DAC would have to be evaluated. Past prac.tice indicates that this would increase the quantity of data by a factor of 10 and nearly double the number of recorded indications. Justification was not presented in the discussion section to form a basis for the additional effort involved. Can the basis for this requirement be stated? In regard to non-traveling indications, is it the NRC's position that geometric indications exceeding 20% DAC be fully recorded in accordance with this paragraph? 3. Value/ Impact 3.1 Instrument Performance Checks 3.1.1 Ultrasonic instruments screen height lipearity. 3.1.1.1 Checking at the setting used during examinations will require procedural char;es to assure compliance.

s

3.2 The paragraph on calibration requires protection of calibration blocks and hole characteristics from change bet. ween uses.

Value - Protection of reflector conditions is a valuable requirement so long as the Code and regula-tions do not mandate a block or calibration change between examinations. Cost - Methods for protecting block reflectors are not well established, but would likely involve application and removal of protective coatings and Q.A. of block storage, handling, etc. EstLnated at $1,000 per job. 3.3 The paragraph on surface resolution requires an estimate of front and back surf ace volumes with limited or no examination due to near surface resolution, gating, cladding interfaces and surface roughness. Value - Recording of these estimated volumes will not directly result in improved examinations, but will probably lead to Laproved equipment and techniques i as a result of pressure to reduce these volumes. Cost - Recording this information will require procedure changes estimated at a cost of $4,000 per unit. Recording of volumes will add to examination time by about 300 man hours for a full vessel examination. This will cost about $14,000 per vessel inspection and result in about 3.0 man-rem of additional exposure. 3.4 Beam Profile requirements will not add to current 1, examination costs. 3.5 Scanning Weld-Metal Interface 4 Value - Unknown. 0 Cost - For examination, at angles within +15 of the interface, the impact is significant. Assuming a 700 angle was dictated by the weld / parent metal interface, the scanning distance would be increased by 50%. In addition, the 00 scan would have to.be extended to cover the additional base material for l laminations. T 1 The increased scanning distances noted would result j in an estimated increase to the RPV examination time i of 25% of total scanning time required at a cost of 1 about $40,000. A corresponding increase in radiation 4 .,n--- n-- n.-

exposure'would be incurred.

To provide suitable calibration blocks for these high angle calibrations, an expenditure of upwards of $20,000 could be expected. since existing code blocks are not large enough for 4 0 calibration at angles above 60. It should also be pointed out that the majority of automated scanners for OD exams are designed around 0 the Section XI 45 and 60 examination requirements. Existing equipment would require redesign and modification. Significant cost impacts could be anticipated for this effort on the order of $50,000- $100,000 par plant if modification is possible. For ID examinations,.new transducer fixtures would be required at a cost of $5,000-$10,000. In summary, the costs involved in using a 700-750 angle would 4 likely increase vessel examination costs by $50,000 to $150,000 depending on the reactor type and current examination system. Among the alternativeg, exam on planar flaws along the the demonstration of the effectiveness of a 60 weld prep would be less expensive, but could result I in the use of increased angles anyway. The parameters are not yet adequately defined to pursue such an approach. ~ Radiography would be viable'for portions of a pWR vessel where radiation levels are low enough to result in an effective radiograph. The underwater, high energy equipment and set up of film in the vessel annulus will be very costly. Estimates have not been generated. Radiography is not a viable alternative l for BWR's since ID access is limited by permanent core support structures. Alternative UT techniques would similarly require significant development and acceptance. In addition to the higher costs for either alternate ultrasonics or radiography, the costs for unused 1 equipment currently on hand would also have to be included in a thorough cost analysis. i 3.6 Sizing Value - Data has not been presented to evaluate the value of the add; tonal sizing requirements. 1 Cost - Application of the 20% DAC sizing, separate rules for traveling and stationary indications, and recording at multiple intervals will result in a 50% increase in examination time and costs using current 4 ?

.o. . equipment. This cost could exceed $100,000 per vessel examination and impact other non ISI schedules during a plant cutage. Development of new equipment to automatically process the increased data quantities and perform automatic sizing could eliminate schedule

impacts, but potentially increase the total ISI costs.

3.7 Reporting of Results Value - Reporting results from critical parameters is essential. - The value of the parameters required by the Regulatory Guide have been separately evaluated. Cost - The additional engineering costs in defining and reporting error bands and unexamined volumes is estimated to cost about $10,000 per vessel examination. 3.8 Cost Summary The total impact of the proposed Regulatory Guide is expected to nearly double the cost of a reactor vessel examination. Costs for OD exams are estimated to increase by about $315,000; costs for ID exams by about $250,000. 4 i l l L 1-

,[ s Wayne H. Jens. Assis: ant vce 7 escem f Vamng Acatess _J31 W 9.g Seavec Acao = J%, 3bi ga'n 4)f26 117 e est por m MuuaER ) p DLE

g. M Jtily 31, 1979 EF2 - 45752 p

b~ TN ~ 91973 % - Secretary of the C:mnissica AN Decketir4 and Service Branch ce j.s J U. S. IAlclear Regulatory C:mnissicn Washington, D. C. "20555 3r 4 <Ja Gentlernen:

Subject:

Cuu.a.i_s en the Draft Regulatcry Guide, " Ult'wenic Testirg of Fw+m Vessel Welds During Inservice Examination." We have reviewed the subject draft guide in depth ard wish to make the following m.mn.s. OVERVIsf The nain ccccern of the NRC is the lack of repr*hility of Ur results frem cne examiratien to the next exaniratien of the same wld. Rourd rebin tests m-Mad i:r.ependently by EPRI ard FVRC tend to substantiate this c=ncern. The draft regulatcry guide addresses this problem with exmssive requiments for instrt.:nent checks, m14hratica scWes, ard sizing ard reportLW cf irdica-tiens. In cur' cpinica, the curran.W.ts of Secticn V cf the A5ME Code are adequate. Six specific areas are identified in the draft doct.nent: 1. Instrurent perfcz nance checks. 2. m14hratien of Ur system. 3. Near Surface Examiratien and surface resolution. 4. Beam profile. s 5. Scanning Weld-4stal Interface. 6. Sizing of drdicaticns. 6 Ac'<r.o=4d;2f b/ cord.. P D!LrfG 09 l '7 00 I(l p b rL M9092505I.2

( .e ..~. Secretary of the Ca mission July 31, 1979 Page 2 'Ihe IRC positions in these six areas, if accepted, will result in nore costly ard lengthy RPV e. mirations. Furtbarrere, in cur u opinion, the suggested changes w.111 not achieve tFa desind result. We believe the basic problem is the variation in m14hration tec%. niques between different contracters, or lack of sufficient cali-bration, as the case might be. The following paragraphs give detailed cxxments on each of the tRC positiens. DEDTTJn CONENIS PRC Position C-1 (pages 10-12) 'Ihis position exceeds the require-nents of Paragraph T-431, Section V,1977 Code for instrutent cali-bration. The extra requirements are the f.va.cy arglitude curve and the pulse shape recnrd of the equignent. 'Ihis infor: nation is not essential to aralyze the conplete Ur systen. tRC Pesitien C-2 (page 12) - ;qain, this position is exmssive ard expensive. Secticn V mila for basic m14hraticn of the Ur systen prior to start of examiration of a given thickrass range and allows 2 m14hration checks of the sweep range and CAC curve during the re-m=4rhe of the examiration. If the m1ihraticn checks are nct with-in the limits of Paragraph T-433, Sectica V,1977 Code, corrective measures must be taken. The BRC position.%m extra m1ihrations ~ vhich is tire consuning and expensive when testing apV welds reretely with, autcrnated equipnent. tRC Positien C-3 (pages 12 and 13) - Fermi II vessel examirations will be per h =d frczn the CD surface. It is well kncwn that a dead bard exists directly under a tenaar used in contact testing. Kncwing the volume of material in this dead hard is of questicrable value especially when it is near the CD surface. BRC Pesition C-4 (page 13) - The proposed requirerent is excessive. Bean spread data at 1/2T or 3/4T is all tFat is racessary to esta-blish beam profile for a given tredar. No useful purpose is served by repeating the process several times. BRC Positien C-5 (page 13) - Beam angles of 45 and 60 are generally used per Section V. Fewever, other pairs of beam angles are pe.r-mitted per paragraph T-441.4.3 in Section V,1977 Code, provided there is a neasured difference of at least 10 degrees betean tF4 beams. Consequently, this positice does not offer any inprovecent. Furtherrere, the alterrate technigt.es su;;ested are not practical at this time. Tard.em-prebe Ur e.xamiration is not reliable due to the u.sedictable bean scattaring caused by the clad-metal interface. I

Secretary of the Ccmnission July 31, 1979 Page 3 l l NRC Position C-6_ (page 14) 'Ihis is an excessive requi_=mst. Fmd. code calls for sizing of through wall diwnsiens per para-graph T-441.8.2 when reflec+x exmeds 50% DAC. Preposed change would require sizing at 10%, 20%, 50% and 100% D7c. Ths.s would increase the ti:e and experra of the examiration. SIM ORY In conclusion, we believe that the draft guide does not offer any inprovernent over the curitantly applicable ASME: Section V.Ind XI Standards, other than doubling the paper work and the exaainatien time. We, therefore, suggest that tlw draft guide be w-2 drawn and any real need for iq:rovenent be subnitted through e ASE for inc=rporatien into the applicable Code. Sin, y, I Waym H Jens M M c/dk F l i l i I i l \\ .z. i i i i

a. Lambort o MacGill o Themaa, Inc. r gg Testing

• Engineering
• Service
• Trcining 771 East 8rokaw Road San Jose.Ca. 95112 408-297-8766 July 30, 1979 79-TGL-153 00CxC ttun&9 m

mmeouPR-E m 3om.MA we \\ \\ mission 9-AUG 91979 > {2 Secretary of the U.S. Nuclear Regulatory Ccemission O le Of.7 's"~. lT' Washington, D.C.' 20555 s.*.= 3 Attention: Docketing and Service Branch g Gentlemen: Lambert, MacGill, Thomas, Inc. offers the following in re-sponse to solicitation for comments concerning Task SC 705-4, " Ultrasonic Testing of Reactor Vessel Welds during Inservice Examination." Introduction L'ambert, MacGill, Thomas, Inc. is a privately held corpora-tion founded in 1977 by senior engineers and specialists in the nondestructive examination of nuclear components and systems. The experience of the company principals spans 27 calendar years and includes work at most of the power re-actors, fuel manufacturing facilities, and hot laboratories in the United States. Because of this lengthy and diversified experience I feel qualified to offer these comment;s on Task SC 705-4 for your consideration. General The draft regulatory guide, rather than stating requirements for vessel examination, requests data and is in effect an outline for a development program. It requires the examina-tion agency and the utility to perform extensive data gathering wis hout identifying a specific need for the data, offering rules for its use once gathered, or setting methods for its collection and presentation. Rather than reducing the amount of examinations and evaluations required by the licensing p::'a-cess it appears this regulatory guide will significantly in-crease them, primarily due to the number of trivial' operations added, each required its own lengthy paperwork support. g gwedpd by cad - cf, qqo9No156 p+

Secretary of the Commission July 30, 1979 Page 2 In an attempt to justify this added activity the writers must first establish that ultrasonic testing is not reliable, and to do this they have drawn carefully selected references from the literature, choosing most from foreign sources while neg-lecting those state-of-the-art inputs from American technology which find ultrasonic testing to be a reliable examination method not only for nuclear applications but in aircraft, ship, structural and piping construction, and maintenance. Their conclusion that there is a basic problem of reliability with the ultrasonic method, which can be solved by data gathering, is difficult to accept. Perhaps because of this the regulatory guide is laced with escape words and phrases such as "may be", " desirable", " partly due", "should be considered", and so forth, when setting forth arguments for these increased activities. It appears that the draft regulatory guide has been prepared not to improve this method but to increase understanding and a,cceptance of it within the NRC. The use of a regulatory guide for this purpose is doubly unfortunate. There is not only a tremendous cost involved ensuing from performing work which does not contribute to the timely completion of an al-ready expensive product and the delay associated with bringing a multitude of trivial audit points into the licensing chain, but by concentrating heavily on peripheral technical points the NRC ignores the most basic and continuing problem concern-ing nondestructive examination in the nuclear industry, that of personnel competency and corporate responsibility. Discussion A few specific comments are offered to illustrate the above observation that the guide addresses itself to very minor points and data gathering. A. Comments on the Discussion Portion of the Draft Comment 1 to In practice, the DAC, curve is most Page 6, Para. (2) often terminated becluse of a poor Secondary DAC signal-to-noise ratio. Increasing i gain does not improve this situa-tion. A regulatory guide should recognize this condition and state l at what point a DAC should be ter-mina'ed, as was done at one time L

T -T Secretary of the commission July 30, 1979 Page 4 researchers to prepare procedures for its use in evaluation. Unless this is done, beam profiling on a routine basis will continue to be waste. Should a beam profile be required for an evaluation of an in-dication it can be performed on se-lected transducers at that time. Comment 5 to This section, tutorial in tone, is Page 9, Para. (6) extremely vague and the effects on Sizing examination time may be extreme. How shall the one inch be measured since beam spread varies with metal path? Is the 20% of DAC indication level required to be continuous or intermittent as one indication is traversed? What scanning and re-cording sensitivity is now required? What about the effect of vessel cur-vature on beam spread? B. Comments to the Regulatory Position Portion of the Draft. Comment 1 to The regulatory guide should first Page 11, Para. (1.3) state which frequency response curve Frequency Amplitude is required, the transducer, instru-Curve ment, or system; then the guide should define an acceptable response. Until this is done, this type of work is only very expensive data collection. It will enlarge the instrumentation system appreciably and introduce an entire new Quality Assurance area into the examination. i l l l ~W 4 -y-.- 'w' g. vw s .w.v w--v-----eg- ,-v,y y-p w- =*-*19 p-sv

Secretary of the Commission July 30, 1979 Page 3 in ASME XI, Appendix I (Summer 1975, I-4423). The guide does not state that the use of two sensitivities implies scanning at two sensitivi-ties, thereby doubling either the test time or the equipment required. Comment 2 to Surface changes to a block are Page 6, Para. (4) easily measured and have reproduc-Calibration Holes ible effects. The regulatory guide should state acceptable limits to these effects as well as all block tolerances. A requirement for un-changed surface condition implies a measurement, maintenance, and documentation program on each block. More serious surface changes may happen to the vessel. Comment 3 to The relation between frequency.and Page 7, Para. (3) resolution is well established as Near Surface Exami-are the effects of plastic or liquid nation and Surface delay lines upon the ultrasonic beam. Resolution A regulatory guide should state re-quirements to ensure coverage on all tests, as is done in structural welding codes. Without this, the requirement for a best estimate in-vites individual interpretation which may or may not be accepted by the NRC. Comment 4 to The regulatory guide should specify Page 7, Para. (4) acceptable beam profiles. The ASME Beam Profile procedures reccmmended in this draf t have been in effect some time and several years of measurement of this parameter should already have gener-ated sufficient data for competent

T -T Secretary of the Commission July 30, 1979 Page 5 Comment 2 to The basis for the requirement that Page 12, Para..(3) a beam be almost perpendicular to Near Surface Exam-the weld interface is not clear. ination and Surface The discontinuities to be detected Resolution with this beam orientation are con-tained within the weld and arise and should be detected and corrected during fabrication. These are not a major consideration in inservice inspection. It is surely more in-portant to detect-fatigue or stress corrosion cracking which first ap-pears at the material surface and results in a corner reflector. The writers should also note that vessel curvature prevents an angle beam from being within 15 of the perpen-dicular on many vessel longitudinal welds. Comment 3 to Traveling indications are indeed Page 14, Para. (6.6) highly significant, but this para-Traveline Indications graph is not consistent with Page 9, Para. (6), and neither considers corner reflectors which represent the most significant type of indi-cation. The ASME procedures required in Paragraph 4 of the Regulatory position use the 50% of DAC point as a reference level for beam spread determination and are therefore not compatible with this paragraph.- Finally, there is no standard for evaluating low level indications. These are examples to illustrate the contention that the draft -guide is not technicar.ly suitable to be applied in the field. It does not possess sufficient precision to fulfill its function and will result in excessive attention to details and technical

t "T' 31 Secretary of the Commission July 30, 1979 Page 6 curiousities which have to date not been shown to have any identifiable effect on an ultrasonic examination. Attempts to fulfill the requirements of this guide will be entirely subject to the interpretation of individuals which will result in a lack of consistency thereby diluting efforts to maintain uniform performance standards. If we are all playing different games, hcw do you determine the winner? It is~ essential that the NRC, through its regulatory guides, set explicit standards to be met in the field. When this is done the so-called inconsistencies of ultrasonic testing will begin to disappear. Then the more serious problem of per-formance evaluation can be attacked. In other sensiti7e areas regulated or controlled by the government (the military, commercial aircraft, and ship repair) firms and individuals must be directly approved by the regulating authority. Only in the energy field has unrestricted " price only" competition been allowed. The results of this policy have been horren-dous, and yet the regulatory guide unfortunately ignores this entire situation. A final comment. The value statement assumes that positive results will be obtained and that more uniform data reporting will result from the implementation of the regulatory guide. To say the least, this assumption does not appear warranted. It appears rather that Unplementation of this guide will further complicate the licensing process, without clear bene-fit. In this way through the years we have so slowed nuclear development that the energy crisis is largely a nuclear cri-sis. I* the many plants that have been cancelled or set back were now on line and operating, our country would not now be at the mercy of those who hate it. What value is it to re-gain energy independence? Sincerely, h _ AA. i T. G. Lambert TGL/gd [ cc: NRC Contact File o_

. _ = _. e,... DUEE POWER COMPAYY ELECTRIC CENTER. BoI 33189. CnRI.OTrE. N. C. 25242 L. C. D A a b .J:n==.

=,,

,n t N. U'k.sT r;;e. ;;;r,. _ N eccu.n-h, Q July 24,1979 'S AU6 9 0 CC M SM J'~ 3 N

• W W \\ y Secretary of the Comission

.U. S. Nuclear Regulatory Comission Washington, D..C. Attention: Docketing and Services Branch

Subject:

Proposed Regulatory Guide Coments Duke File: A-12.16-2

Dear Sir:

Attached are coments from our engineering staff concerning the proposed Regulatory Guide entitled "Ultransonic Testing of Reactor Vessel Welds During Inservice Inspection." Ver truly yours, / . C. Dail, Vice-resident Design Engineering Department ELM / cam MW@d by cag,,g~/d........, Attachment -~ Yfdf//QQ37

COMMENTS ON DRAFT REGULATORY GUIDE AND VALUE/ IMPACT STATEMENT ENTITLED " ULTRASONIC TESTING OF REACTOR VESSEL WELDS DURING INSERVICE INSPECTION." Note: The numbers on the comments below correspond to the paragraph numbers contained in the proposed Regulatory Guide i 8.2.a. The DAC curve is a function of vertical linearity of the UT instrument and acoustic properties of the test specimen. Checking three points on the DAC curve implies that DAC is a function of through wall depth. This is not so. B.2.d.(1) The connents concerning transducer contact force are not of concern when the calibration and examination are done by immersion techniques. This is particularly true for PWR's. The distinction between PWR and BWR should be clearer. Calibrating using a moving transducer does not add significantly to the probability of detection or repeatability of the examination when one considers the relative velocities of scan speed and the speed of scund through the material. Also the fact that the examinations are performed at a minimum of two times the DAC curve sensitivity. B.2.d.(1) It appears that this wording would apply to the BWR contact exam-ination technique only. This should be clarified. In both the BWR and PWR examination the ' scanning sensitf vity is a minimum of 2x DAC. This shouTd more than compensate for the referenced " loss of received signal" effect. B.2.d.(2) Using the secondary DAC should be no problem as long as all of the following are met: a. Adjusting the instrument gain for the lower end of DAC curve has no deleterious effect on the front end of the DAC curve. b. Adjusting the gain setting is not to be interpreted as requiring a separate calibration. c. Secondary DAC's are used for sizing only. Not allowing the above stipulations would double the time calibrations and examinations. In nearly all instances this would be critical j path time. In any case however, we are scanning at relatively slow speeds and at 2x DAC curve sensitivity so the necessity for doing i this is questionable. B.3. In general this does not apply to PWR examinations and many of the near fielS effects encountered in BWR examinations may be compensated for by using various transducer shoes. Exact determination of sound dispersion at the cladding / vessel wall is probalistic at best and should not really be considered as deterministic as the regulatory guide suggest. I i ..~. - - - - - -..

J B.4. The detennination of beam profile would probably require additional calibration due to the non linearity of sound characteristics and the long metal paths encountered during reactor vessel examination; Also the ASME code does not fully address beam profile, so an acceptable technique for doing this should preceed the issuance of a regulatory guide which requires it to be done. B.5. The longer metal paths required to do this will probably require a new set of calibration blocks. B.S. Who will determine the acceptability of the alternate techniques referenced in this paragraph. B.6. Requiring the sizing of indications 20% DAC (in addition to 50% and 100%)appearsto'be rather arbitrary thus adding to examination time without establishing any increase in safety margins. B.7. This would be a redundant regulation since all reactor vessel examinations are documented in tte preservice and inservice inspection reports. These reports are filed with the appropriate regulatory agencies and are kept for the life of the plant. C.l.l. Screen height linearity is an instrument variable and as such is independent of variables such as material type and sound path. And two signals of the proper ratio could be used for this purpose. Requiring the unnecessary use of the calibration block would add to the length of the examination without increasing safety margins. C.l.3. The primary concern regarding the Frequency-Amplitude curve is that it gives you no useable information. The calibration block and DAC curve is the method for standardizing the UT system. The regulatory guide is also unclear on what frequency-amplitude curve is being requested. Transducer output, transducer response to reflected sound, and instrument response (receiver, amplifier, or CRT) are all possibilities. The DAC curve sculd include the effects of all of these responses. C.l.4. In addition to requiring additional equipment (Oscilloscope and camera), a pulse shape does not enhance the examination. Here again the DAC curve will-provide the best check for overall system conformance between successive exams. C.2. Calibration is adequately covered by existing Codes and Code case N-211 i (which allows shift change a automated examination without an additional calibration.) This area could be easily covered by referencing the appropriate codes. t 3 k 4 L

} C.3. The regulatory guide does not state what would be an effective way of estimating the front and back surfacu volumes not examined. This could lead to arbitrary standards and non uniform enforcement. Also the distinction between immersion and contact testing needs to be .ddressed. C.3. See Connent k.7 .3.a.,b.,c.&d. (a) Electronic gate: The method by which the gate is to be related to the material volume is not stated. Will recording gate settings suffice? The standards and enforcement comment of 16 above applies. (b) Decay time: Distinction between innersion and contact technique needs to be considered. Who will determine acceptable method for doing this? Also standards and enforcement comment of 16 applies. (c) & (d) Clad-weld metal interfaces and surface roughness. Who will determine acceptable methods for doing this? Standards and en-forcement comments of 16 apply. C.5. In general this is a good concept; however, it must be evaluated to determine the optimum trade off between the flaw orientation and total sound path travel aspects of the examination. Who will determine acceptability of alternate NDE te0:niques? Standards and enforcement comments of C'.3. apply. C.5. See Comment B.7. C.6.1. Will interpolation of travel distance on the horizontal baseline be allowed e.g. if the indication is at S/8t will the travel determination be made relative to the 1/2t, 3/4t, or 5/8t (interpolated) depth? The wording "at a depth similar to the flow depth" is unclear and further complicates the matter. Also note that sizing at 20% DAC and 50% DAC of course doubles the sizing requirement. C.6.2. This adds considerably to the recording requirements, e.g. a one inch indication which meets or exceeds DAC would require 35 recording points (10, 20, 50,100, 50, 20,10% DAC indexed at 1/4 inch increments.) C.7. See Comment B.7. C.7.a. What would be the basis for such an estimate? l i ,,. -,,., -. -..,. -. ~ - -.,,. - -. -,.

~'.- Durr PowEn CO>iPANY Powzu Ben.ntwo 422 SouTn Caracu Srazzr, Caiazorrz N. C. asa4a wiwu. c. maa ca.sa. August 3, 1979 37/', ",",'f;""',,, of/A7 mtwn '"'*'* $'[.els' 2 g N E3 / Secretary of the Conmission g U. S. Nuclear Regulatory Commission = Washington, D. C. 20555 4 Attention: Docketing and Service Branch 6 eeermo \\ usmac

Subject:

Draft Regulatory Guide and Value/I= pact State =ent' 8; AUG 91979 > -j! Ultrasonic Testing of Reactor Vessel Welds During e;a;f,,7 g Inservice Fu mination k s=== J 7

Dear Sir:

The following represents Duke Power Co=pany's co= cents on the Value/I= pact Stata=ent for the subject Draft Regulatory Guide. Paragraoh h Draft Value/I=cact ': tate =ent 1.3.3. 2.a. 21 Section V as referenced by Section XI is more than "carginal." Si= ply requiring the use of the non=andatory appendices would be adequate. In regards to the UT transducers, each DAC curve demonstrates adequate quality. 1.3.3.2.b. 21 This ite= is difficult to predict especially when considering the =ultiple DAC's and lowered recording levels. 1.3.3.2.b. 22 This is not so. There could easily be indica-tiens of this si:e range missed by RT yet detected by UT. 1.3.3.2.c. 23 The area around RPV noz=les is extre=ely congested and it is i= probable that significant shielding could be installed. 2.2 23 An ASME Code is a = ore desirable =eans of acco=- p11shing the stated purpose of this proposed regulatory guide. Aenendix to Draft Value/I=cact Statements 1. 27 Since most of these checks will be done on the vessel (in order to avoid having to reset the inspection tool), downti=e cost vill be .pn(L 19 09 /7 @ b$ esee w cas.ddh~.MM - - ~ ~ pve 19o9aga 3 cq

-s Secretary of the Commission August 3, 1979 Page Two Paragraph h Appendix to Draft Value/Imoact Statements (Cont'd) 1. 27 significant-along the order of $8000-$10,000 per hour-not $50 per hour. Additionally the cost figura does not include the cost for the remainder of the reactor vessel examination crew which could be another 2 or 3 people. 2. 28 The time to perform this operation is understated by a facto of 2 to 3. More importantly though the cost figure igo;res downtime cost of $8000 to $10,000 per hour p*ius the cost for the remainder of the inspection crew. 1 l 3. 29 Cost estimate does not include downtime costs and aud additional crew costs. 4. 29 Cost estimate does not include downtime costs and additional crew costs. 7. 32 Since we have little idea of how much data will be acquired it is unreasonable to estimate analysis and report cost. Also this requirement to file a separate report incurs considerably more admin 4=tra-tive processing costs (clerical, licensing, etc.) Finally it is a redundant requirement. (See commant B.7. Imolementation 7. 32-This paragraph is tantamount to a threat on the part of the NRC and has no factual basis. It appears that some basis for this may be contained under 1.3.3.2 (b) and (c) pp. 21-22 of the DRAFT VALUE/ IMPACT STATEMENT PORTION of the proposed Regulatory Guide; however, we do not agree in this area (see Comment 1.3.3.2.b.) and also do not agree here. The estimated cost of a report PSI for those units which could qualify would be on the order of $200,000 per unit. Additionally only those units without an operating 3 history could repeat the PSI, i.e. Oconee 1, 2 and 3 and possibly the McGuire units would be forced to follow the " service induced" assumption for l indications. This of course could lead to extensive forced shutdowns for analysis and unnecessary repair.- j The costs of direct labor and materials plus down-time could be enor=ous without any increase of safety to the public. Ia L- ~- c.

Secretary of the Commission August 3, 1979 Page Three In summary then, we feel these coments need to be addressed before the Regulatory Guide is ready for final review. Very truly yours, fegg winiam o. P rher, ar. RFJ:ses H =

I G E N E R A L h El.E CTRIC suctExa eOwEn SYSTEMS D I V I S I O' N GENERAL ELECTRIC COMPANY,175 CURTNER AVE., SAN JOSE CAUFORNIA 95125 MC 682 (408) 925-5722 p ~ RHS-05$-79 // MFN-282-79 c.m ul whtua ) Q ,3 u s** WD RE < M A3 N, DEC 71973 > b November 26, 1979 A 5 er;fo L2 U. S. Nuclear Regulatory Commission 0 g Secretary of the Commission Washington, D.C. 20555 4 Attention: Chief, Docketing and Service Section Gentlemen:

SUBJECT:

GENERAL ELECTRIC COMMENTS ON DRAFT REGULATORY GUIDE SC 705-4, " ULTRASONIC TESTING OF REACTOR VESSEL WELOS OURING IN-SERVICE EXAMINATION," DATED MAY 1979

Reference:

Letter, R. H. Buchholz to Secretary of the Commission, August 15, 1979 This letter summarizes our meeting of November 1,1979 with Dr. Goel, other members of the NRC Staff, and Consultants to discuss General Electric's comments in the referenced letter. As 'a result of our meeting, we now have a better understanding of the NRC position that the principal intent of this Regulatory Guide is to promote standardization of equip-ment parameters and reporting in order to permit meaningful third party; evaluations of in-service examination data. The following changes to the draft would resolve the comments of our August 15, 1979 letter: The " Discussion" should clearly state that the Reg Guide is intended o to supplement ASME Section XI, not to impose new requirements and will aid the NRC staff in performing third party evaluations of examination data. The " Regulatory Position" should include a statement that applica-o bility is to reportable indications only. Positions C.1.3 and C.1.4 should be clarified'to permit the licensee's o examination agency to use any of the common industry methods to measure these parameters as long as it is adequately documented in the examination record and that these measurements may be performed in the laboratory, before and after examination, provided that the identical equipment combination (i.e. instrumentation and search unit) is used. hW en..nc.vist'h/ cardlM N y 199 3/c) IP

GENERALh ELECTRIC U. S. Nuclear Regulatory Cochnission Page 2 The Reg Guide should also indicate that th'e intent is to aid third-party evaluations when different equipment is used to record indica-tions on subsequent examinations, and not to qualify systems for use. o Position C.5 should not be applied to operating plants since the concern is fabrication flaws. This type of examination, if performed, should be applied during vessel fabrication or pre-service examination when any flaws can still be corrected. o Position C.6 should reference ASME Section XI recording levels. If the Staff believes that 20% DAC recording levels are justified, in spite of the increased occupational exposures, then these require-4 ments should be incorporated in the Code. ? For Positions C.6.1-and C.6.2, the recording criteria should be the samt. o Positions C.7 and C.3 both refer to estimating and reporting volumes of material which have not been examined. It should be clarified that this is aimed at large volumes (1-2 inches or greater in depth), especially near surfaces where an examiner may " gate-out" material to avoid surface noise, and that it does not apply to the cladding if the majority of the base volume is examined. Position C.7 should indicate that the "best estimates" of flaw sizing error band are needed to aid third party evaluations. The position should state that it is not the intent to have examination agencies report directly to the NRC. We appreciate the Staff's interest in meeting with us and believe that these modifications would sufficiently clarify the intent and applicability of this Regulatory Guide. If you have any questions regarding this letter, please contact Vic Kovacevic at (408) 925-2996. Very truly yours, VIlbLLt&k R. H. Buchholz, Manager BWR Systems Licensing i s dHB:daj/760-761 cc: L. S. Gifford I

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gy %f,,3 2"y,y,*mo" m........ Secretary of the Commission / e=ber 17, 1979 U. S. Nuclear Regulatory Commission Q Attention Docketing and Services Section ksgj \\ Washington, DC 20555 Centlemen: We are pleased to submit our cecments on draft Proposed Regulatory Guide " Ultrasonic Testing of Reactor Vessel Welds During In-Service Examination," NRC Task SC 705-4, dated May 1979. SECTION B Paragraoh 2a The status of. Article 4 (T-432.1.2), Section V of the ASME Code, 1977 Edition should remain unchanged. The philosophy behind the use of only one point on Distance-Amplitude Correction curve (DAC) for a calibration check is to guard against possible instrument drif t - either gain or sweep, or any inadvertent change of the instrument controls - all of which would be i==ediately obvious with a one point check. Paragraoh 2b The use of mechanical or electronic simulators should be allowed in accordance with Subarticle T-432.1.3 of Article 4, ASME V, 1977 Edition. It is true that efte mechanical or electronic si=ulator could be any device that provides an electrical signal. However, it is,not necessarily true that uncertainty results. A mechanical simulator can provide a reference j signal, which, though undefined from a quantitative point of view, will at least remain constant and, therefore, useful for the purpose for which it is intended. It is used for purposes of cparison only. l fl.0/ t PDN $ 00 II(o o/5 / N ... 1, ~".. l, N

P SC 2 December 17, 1979 Paragraph 2e (1) We recommend that the electronic simulator parameters, which are required to be defined in Subarticle T-432.1.3 of Article 4, ASME 7,1977 Edition, be limited to stability with respect to both time and pulse height. There is no need to define any of the electronic parameters of the electronic simulator except for stability. Defining the pulse voltage in terms of a standard source of reference is meaningless. The important factor is that the pulse height

oduced on the screen be correlated with the original calibration on the has.

calibration block durine the original calibration, as called for in Subarticle T-432.1.3 of Artiels 4, Section 7 ASME Code, 1977 Edition. Thus, a stable reference will be established, against which any change in test parameters can be determined.

Paragraph 2e (2) We recommend that the status of Subarticle T-432.1.3, Section 7 of the ASME Code, 1977 Edition, remain unchanged. Checking transducer sensitivity, either separately or in combination with the entire test system, will not affect the problems cited, which will exist either way. If sensitivity of the transducer is defined as amplitude of signal resulting from a standard reflector, then it is not important, as signal height can be adjusted to any convenient value. Thus, adjustment of the instrument gain can be used to compensate for any deficiency in transducer sensitivity. Signal amplitudes are meaningful only for compara-tive purposes under similar test conditions and are, therefore, independent of such factors as transducer sensitivity. SECTION C Paragraphs 1.1. and 1.2 4 Determination of screen height and amplitude linearities should not be limited to the methods outlined in Article 4. Optional. methods should be allowed, providing that equivalency or superiority can be de=onstrated. Paragraph 1.3 Frequency-Amplitude :urves are useful, at the time of purchase of a trans-ducer, simply to verify the normal frequency of the unit. This should ba supplied by the vendor. Aside from this one purpose, the data called for in this paragraph appears to have no value. Paragraph 1.4 The purpose served by a record of the unloaded pulse shape is not clear. Such information would bear little relationship to the loaded pulse shape, which would vary unpredictably when loaded with different transducers. Reference to." test point at which it is obtained" is irrelevant, as no test point is involved.

~. SC 3 December 17, 1979 Paragraoh 4 We suggest that caution be exercised when using beam profile in an attempt to size flaws. When the flaw is smaller than the sound beam diameter, the relationship between beam profile and flaw is, at best, somewhat nebulous. When the area of the flaw is large, as compared to the sound beam diameter, the boundary can be determined by the half peak amplitude cathod to a fair degree of accuracy, but this determination is independent of beam spread, or profile. Placing undue reliance on the use of beam profile in sizing of flaws may well result in a false sense of confidence in the results obtained, particularly if they are to be used for purposes of stress analysis. Alhough Article 4 of Section V of the ASMI Code outlines a procedure for the determination of beam profile, the value of these data is unclear. Stone & Webster Engineering Corporation appreciates this opportunity to contribute to the improvement of this Proposed Regulatory Guide. Very truly yours, ~ OQ0_ om L ' S. 3. Jacobs Chief Licensing Engineer DWR: MAT I

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Lt 5 N"b!lIIh I II Houston. Texas 7/001 August 6, 1979 , 9. p Dg'[.% " O NSL-67 CY Mr. Samuel J. Chilk ~ A U# Secretary of the Commission U. S. Nuclear Regulatory Co==ission Washington, D. C. 20555 Attn: Docketing and Service Branch Re: Draft Regulatory Guide and Value/ Impact Statement; " Ultrasonic Testing of Reactor Vessel Welds During Inservice Inspection" (Task SC 705-4)

Dear Sir:

Houston Lighting & Power Company has reviewed the draft Regulatory Guide " Ultrasonic Testing of Reactor Vessel Welds During Inservice Inspection" and its associated value/ impact statement. An attachment is provided with our co=ments for your consideration in preparation of the next revision of this draft guide. ~ In su= mary, HL6P's comments on the proposed guide concern positions which should be revised in order to provide = ore specificity with regard to recording and evaluation requirements. These comments are discussed in more detail in the attachmen't to this letter. Please feel free to contact us should you have any questions. Very truly yours, YJon G. White, P. E. Supervising Engineer Nuclear Safety 5 Licensing BAN /jp A:kneffW"rme...R(yy Attachment .~. cc: E. A. Turner

1. C. Henson

" ".4Q W. M. Menger F. Herring J. R. Sumpter R. A. Fra:ar R. L. Baron R. D. Gauny M. M. DiGenova p .(),f rjcf;o f o A N g Toolig0joLl zg

b,* e e ATTACBEhT HLSP CO2ENTS ON DRAFT REGUL\\ TORY GUIDE AND VALUE/ IMPACT STATEMENT: " ULTRASONIC TESTING OF REACTOR VESSEL WELDS DURING INSERVICE EXM1INATION" Position C.6'" Sizing" Paragraph 6.2 states that all continuous, signals that are 20% of DAC with transducer travel moveme: t of more than one inch plus the beam spread should be considered significant a'nd should be recorded and investigated further. This section of the guide should be revised to provide a concise definition of the term "all continuous signals." Section XI of the ASME code presently requires recording of geometric reflections but does not state to what extent. If it is the intent of the guide to lower the recording level to 20% of DAC and to record all con-tinuous signals including metallurgy / geometric, the scope of the vessel inspection will increase by a significant amount. Certain vessel belt line welds could possibly require examination from the outside diameter, thus causing a significant increase in personnel radiation exposure. This would be applicable pri:::arily to Combustion Engineering vessels which inherently contain welds with " beam redirection" effects associated with the interface between strip cladding and three wire cladding. Recording of such reflectors each 1/4 inch, as stated in Position c.6.2.a, would possibly extend plant outage time during inservice examinations by one day to one week. These increased examination requirements, and resultant additional radia-tion exposure, could more than offset the potential values of reduced licensing time and reduced radiation exposure discussed in Section 1.3.3.1 items (e) and (g) of the value/ impact statement. This potential for significant financial impact due to plant downtime and increased radiation exposure possibly in conflict with the ALARA criteria of Regulatory Guide 8.8 should be considered carefully before issuance of the next revision of this draft guide. ~ \\ i l l i 9 4 e a 0

o EBASCO SERVICES INC0RPQRATED U T I:.I T Y c c N s U I.T AN T s E N G I N E.c a s - CCNsrRUCrQRs TWO RECTOR STREET NEWYORK. N.Y 10006 =..s. ....... co r ,g. c i.rga;t, August 16, 1979 1 9'T I g p gjhity.A.L Euti . g 0h [ h C c Secretary of the Co _.ssion Q' N 97 f U.S. Nuclear Regulatory Cc==ission Washington, DC 20555 p e*g ~ s w., Attention: Docketing and Service Sectico

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Subj ect: Draft Division 1 Regulatory Guide SC705-4, May 1979 " Ultrasonic Testing Of Reactor Vessel Welds During Inservice Examination" Gentle =en: Ebasco Serviceshas reviewed the subject draf t regulatory guide and attached draft value/i= pact statement and has the following coc=ents: Section B In the third sentence of the first paragraph the word "large" should be deleted when describing types of flaws to be reliably detected. The reasons for this are as noted in the " Draft Value/I= pact State =ent" Section 1.2, third and fourth paragraphs. Section B.2 Appendix I, Article I, I-4230. Section II of the ASME Code, 1974 edition, states that instrument calibration for perfor=ance charact-eristics is to be verified at the beginning of each axa=ination rather than each day of ey=mination. Please rcvise the sentence accordingly. Value/I=eace Section 1.3.3.1.g There appears to be an isufficient basis for concluding that this guide vill reduce radiation exposure. Although exposure to personnel performing repairs =ay be reduced, exposure to exa=iners would =est likely increase due to the =any inspections perfor=ed during plant life. This dose c:ust be considered against the perceived dose reduction due to a lover incidence of repair before any conclusion can be =ade. I a:dcd td h7 curd..Y(......Q. A 5 p>' 1 top []Oah0 o Il 9 pv 8a

EBASCO SERVICES IMCSEFORAtED 2-August 16, 1979 Secretary of the Co=iission Ebasco hopes these comments will be considered carefully and would welco=e the opportunity to participate in any discussion with the h"AC on the proposed ' guide. Very truly yours, [ E.' d'Donnell O.fef Engineer Ntclear Licensing EPO:. TSP:ke O O 4 em r -o m n

OC.-ti HU 4CIi2 e HARVEY E. SCHCCK. JR. NM AM ~ MANAGCMENT CDNSULTING IN Pacouc7 ArsuRANCES h, P. C. SCX 43C g h HACDCNFIELO. N. J. CBC33 t(N ,gTct.c, Nonces >Aza-vzsa %v h @0& If 3 August 24, 1979 = b Docketing and Service 3 ranch es"- Secretary U.S. Nuclear Regulatory Coernission WASHINGTON D.C. 20555 Go N Re: Task SC 705-4, Division 1, May 1979 Ultrasonic Testing of Reactor Vessel Welds Durint Inservice Exam. The following concents are offered as requested for consideration: i

1. The proposed rule could be i= proved to identify the relatwtship for criteria relating to design of product, design of testing, and actual quality assurance housekeeping practices.

For product design it is customary for deviations of given magnitude to be allowed with specific controls. Obviously the testing on tracking of possible changes in such allowed deviations requires a firm design base for the deviation and the techniques used for its monitoring. The proposal provides some g'o'od thoughts but requires expansion for human variability control, where human observation is used. This reproducibility c=nfidence must be related to the initial acceptable limits for deviation and exa=ination frequency. Design of testing must be identified as to tracking control vs discovery. The Proposal limits use of new techniques which could well be restricted for tracking but oot discouraged for discovery application, especially in new areas such as surface where there may have been limitations in the previously acceptable techniques. For the actual quality assurance practices there must be clear identification of levels of requirements used for tracking as opposed to new discovery practices. Obviously with the requirement for exchange of defect inferntion there cust be very careful control of such new technique data into the system required in B.7 Reporting of Results. 2. For the quality control of =easuring and test equipment, Criterion XII, it has always been the understanding of the undersigned that this would cover not only the proposed addition, as discussed on Page 21, but also the relationship with the human element using the equipment and associated equipment and facilities with their hardware, software, and fir =vare. Thank you for the opportunity of offering cournent., Cordially, bp H rve'y Schock cb " Y % sy e. g., g ly," "_ 4 ~~ p rf9)op9oiM-en 9 00 iib oo @ - -.}}