ASME Code Update.ASME Code Update – TG Appendix VIII • Revise Supplement 11 to Address Pre-Emptive Overlays – Supplement 11 and the implementing relief request provide requirements

ASME Code Update

PDI/NRC Meeting

December 2009

Mike Gothard Senior Project Manager

ASME Code Update – TG Appendix VIII

• Revise Supplement 11 to Address Pre-Emptive Overlays

– Supplement 11 and the implementing relief request provide requirements for full structural overlays where the examination volume consists of the weld overlay and the base material for a depth of ¼t. Pre-emptive overlays are not full structural, so the examination volume is expanded to ½t of base material as a result of the thinner weld Additionally new examination

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result of the thinner weld. Additionally, new examination requirements associated with measuring the shadowing effect of embedded flaws must be addressed. Once technical details are finalized, a new implementing relief request, Code Case, and Code change must be prepared. This project is currently awaiting completion of the technical basis and Code updates (e.g., Code Case N-770-1).

• Prepare Supplement Defining PDA Duties/Responsibilities

– Most Appendix VIII performance demonstrations are conducted in accordance with the program developed by the Performance Demonstration Initiative (PDI) and administered by the Electric Power Research Institute (EPRI). However, the Code provides no guidance for defining the duties and responsibilities of the performance demonstration administrator (PDA) or for

ASME Code Update – TG Appendix VIII (Cont.)


performance demonstration administrator (PDA) or for establishing supplemental criteria for activities such as control of qualification expansions, additions of equipment, or software revisions. Due to pending vendor hardware and software modifications, this project was delayed in 2009, and priority was shifted to addressing qualification requirements for equipment upgrades.

• Revise Supplement 10/14 to Address Onlays and Inlays

– Onlays and inlays are a mitigation activity, primarily intended for pressurized water reactor (PWR) nozzles. It is similar to the corrosion-resistant cladding

i l li d t th i l ti i i i

ASME Code Update – TG Appendix VIII (Cont.)


previously applied to the recirculation piping in a boiling water reactor (BWR). Once technical details are finalized, an implementing relief request, Code Case, and Code change must be prepared. This project is currently awaiting completion of the technical basis.

• Address Unclad Components in Appendix I-3000

– Appendix I-3000 provides coverage requirements for ultrasonic examinations; however, it does not differentiate between clad and unclad components. The proposed revision corrects this oversight and

id f i d l it Th C d h i

ASME Code Update – WG PQ&VE


provides for increased clarity. The Code change is prepared for approval.

• Incorporate Code Case N-639 into Appendix I, Supplement 1

– Section XI, Appendix I, Supplement 1 provides no guidance when calibration blocks of the same material specification, product form, and heat treatment

diti th t i l t b i d

ASME Code Update – WG PQ&VE (Cont.)


condition as the material to be examined are unavailable. This guidance is contained in Code Case N-639, and this action incorporates that guidance into the Code, as modified by RG 1.147. The Code change is prepared for approval.

• Define Significant Digits Applicability

– IWA-3200 provides requirements for significant digits in limiting values (that is, rounding). Typically, these calculations are performed to calculator or spreadsheet accuracy without limiting the intermediate

fi l l IWA 3200 d t if h (f



or final values. IWA-3200 does not specify when (for example, before during or after intermediate or final calculations) limiting values is appropriate. It is the contention of the proposed inquiry that IWA-3200 is applicable only when the values are being intentionally limited. The inquiry has passed SG NDE with the admonition to do no harm and will be sent to General Requirements.

• Examination of Materials

– Under action item BC95-142, Section V revised Article 4 so it addresses weld examination and Article 5 so it addresses material examinations. This causes a problem for the examination of the inside radius

ti f RPV l S ti V id thi



sections of non-RPV nozzles. Section V considers this to be a materials examination in accordance with Article 5. I-2400 still refers to Article 4 and needs to be revised. A Code interpretation 09-754 and Code revision were approved at the August 2009 ISI Standards Committee.

ASME Code Update – WG ISIO

• Reduce Non-RPV Examination Volume to Inner 1/3t for ISI—Record Number -7-1853

– This Code Case proposes to allow a reduction from 100%t to inner 1/3t for subsequent inservice examinations following completion of a full volume

i i i i i ti f RPV


preservice or prior inservice examination of a non-RPV pressure vessel using procedures, personnel, and equipment qualified in accordance with Appendix VIII, in lieu of Article 4 of Section V per I-2120. The Code Case is at the WG ISC for approval.

ASME Code Update – WG ISIO (Cont.)

• Eliminate Threads in Flange Examination

– Volumetric examination of the threads in a flange is typically performed using manual ultrasonic examination techniques. The closure head is raised several feet off the vessel to shield the examiner from

i di ti It i i h tl


excessive radiation exposure. It is an inherently dangerous operation, which is conducted during critical path, with no evident failure mechanism, and it should be eliminated. The Code change is prepared; the action is tabled awaiting development of a technical basis at some future date.


• Clarify Examination Requirements for Non-Standard Nozzle Inside Corner Regions

– Guidance is needed by the utilities concerning the examination requirements for the nozzle inside corner regions with nonstandard configurations, that is, not lik IWB 2500( d) IWC 2500( d) E l f


like IWB-2500(a-d) or IWC-2500(a-d). Examples of these nonstandard configurations include the inlet and steam outlet nozzles of replacement steam generators and the stand-by liquid control nozzle in a BWR. This project was tabled awaiting development of a technical basis at some future date.


• Reduce RPV Examination to ½ Inch for ISI

– Code Case N-613-1 reduced the examination volume for nozzle-to-vessel welds from ½ t to ½ inch. This Code action applies that concept to the remaining Class 1 vessel welds. The technical basis relies on the i d fid i th bilit f A di


increased confidence in the capability of Appendix VIII’s qualified ultrasonic examinations to detect and correctly reject unacceptable flaws. A Code Case has been prepared. The technical basis must be upgraded.


• Revise N-613-1 to Reduce Nozzle Boss Examination Volume to ½ Inch

– Despite the reduction in the nozzle-to-vessel weld examination volume from ts/2 to 1/2 inch, Figure 1 of Code Case N-613-1 continues to extend the

i ti l t t /2 th l b id f


examination volume to ts/2 on the nozzle-boss side of the weld. This is inconsistent with the other figures. For nozzles examined from the bore, this results in excess scanning during critical path. Additionally, this area is virtually impossible to examine from the outside, resulting in unwarranted reductions in examination coverage. The Code Case was approved at SG NDE awaiting SG WCS.

ASME Code Update – Open items

• CRC – Has it’s time come?

• HDPE – Code Case N-755-1 (18MB file).

– Current NDE is Visual (exposed surface and during Hydro (1.5X).

– Does it need Volumetric?


oes t eed o u et c

• Appendix D – Surface preparation - should it go into Section III? Doug Henry is Liaison between III and XI.

• Couplant – PDI tap versus Nuclear plant

Supplement 11 Review item

• 2.0 CONDUCT OF PERFORMANCE DEMONSTRATIONSThe specimen inside surface and identification shall be concealed from the candidate. All examinations shall be completed prior to grading the results and presenting the results to the candidate. Divulgence of particular specimen results or candidate viewing of unmasked specimens after the performance demonstration is prohibited. The overlay fabrication flaw test and the base metal flaw test may be performed separately.2.1 Detection Test. Flawed and unflawed grading units shall be randomly mixed. Although the boundaries of specific grading units shall not be revealed to the candidate, the candidate shall be made aware of the type or types of grading units (base metal or overlay fabrication) that are present for each specimen.

Why is the candidate being made aware of the type of grading unit that are present in each i ? I thi t d th t ti ? Th t t i d t b bli d d thi


specimen? Is this to speed up the testing process? The test is supposed to be blind and this statement seems to be telling the inspector what flaw locations they are to be focusing their inspections. This would seem to me initially to lead to a biased test.

• Comment: This is left over from the old days. (Prior to Appendix VIII) There are samples that were designed to be PSI samples only in the original sample set. There is no weld under the overlay and they were designed specifically to evaluate procedures and personnel performance on the detecting and sizing of fabrication type flaws. We also have the samples from the old program that contain grown IGSCC that were designed specifically to be ISI samples that do not have flaws in the overlay. Having them do meaningless examinations on these blocks does not add value, but they are very good samples and excluding them from the test sets would not be a good idea. The majority of the other samples we fabricated and added to the test sets are dual purpose ISI and PSI and the candidates do full examinations on them. The entire test set contains a Code compliant distribution of flawed and unflawed units. These grown IGSCC samples and the early PSI samples are very valuable and a important part of the technical basis for the program. I do not know if the sentence actually is needed in the Code we could handle this administratively just as easy.

Together…Shaping the Future of Electricity


Documents

ASME Code Update.ASME Code Update – TG Appendix VIII • Revise Supplement 11 to Address Pre-Emptive Overlays – Supplement 11 and the implementing relief request provide requirements