15-16. October 2008, Vienna, Austria

1. Thank You, It’s a pleasure to be here. My name is Mihaly Czibula, Im senior eng. in Paks NPP, in the ISI section. Today I’m going to talk about our experience on regulatory acceptance of inspection qualification requirements. During the previous presentation Mr. Somogyi already has mentioned the status of the hungarian inspection qualifications. So I’m going to focus on the authority aspect of it.Thank You, It’s a pleasure to be here. My name is Mihaly Czibula, Im senior eng. in Paks NPP, in the ISI section. Today I’m going to talk about our experience on regulatory acceptance of inspection qualification requirements. During the previous presentation Mr. Somogyi already has mentioned the status of the hungarian inspection qualifications. So I’m going to focus on the authority aspect of it.

2. 2 Inspection Qualifications Subjects Mechanized UT of the longitudinal welds of main coolant loop piping Mechanized UT of the circumferential welds of main coolant loop piping At the end of 2000, the Hungarian Atomic Energy Authority Safety Directorate requested to perform inspection qualification activities at Paks Nuclear Power Plants. As Mr. Somogyi mentioned the firs qualification was a pilot exercise, and based on the experience of this pilot qualification Paks continued the qualification activity. In 2007 Paks NPP’s In-service inspection section planned to start the 8th and the 9th inspection qualifications parallel.At the end of 2000, the Hungarian Atomic Energy Authority Safety Directorate requested to perform inspection qualification activities at Paks Nuclear Power Plants. As Mr. Somogyi mentioned the firs qualification was a pilot exercise, and based on the experience of this pilot qualification Paks continued the qualification activity. In 2007 Paks NPP’s In-service inspection section planned to start the 8th and the 9th inspection qualifications parallel.

3. 3 Inspection Qualifications Arrangements Fracture Mechanics Calculations on DN 500 primary main coolant pipeline, Qualification Target Flaw Size Calculation Specimen selection options: 4 m length DN 500 Greiswald Specimen of main circulation tubing, without any type of defects - Paks NPP’s property DN 500 Specimen included circumferential and longitudinal welds, with artificial defects - owned by the Finnish Fortum Welmat RPV nozzle-specimen with circumferential weld - Paks NPP’s property Laboratory experiments and inspections on specimens with the P-Scan 4+8 channels UT equipment and AWS-4D scanner So we started the arrengements: At first NPP had Qualification Target Flawsize calculation made by the experts We had 3 specimen selection options... So we started the arrengements: At first NPP had Qualification Target Flawsize calculation made by the experts We had 3 specimen selection options...

4. 4 Picture number one...Picture number one...

5. 5 The Selected Specimen 4 m length DN 500 Greiswald Specimen of main coolant pipe testpiece, both for inspection qualification and practical exam The testpiece was cut in two part to turn the artificial defects according to the calculated qualification target flaw size The Finnish specimen was transported back The 4 m length main coolant pipe testpiece was accepted both for the inspection qualification and the practical exam. The 4 m length main coolant pipe testpiece was accepted both for the inspection qualification and the practical exam.

6. 6 Inspection Qualifications In the middle of 2007, the 8th and 9th qualification work were started Paks NPP finalized the Technical Specification in time according to fracture mechanics calculation-based discontinuities parameters Approval of Qualification Body had been received, as usual Specimen and the artificial defect according to qualification target flawsize manufacturing was started, as usual In October, the permission from the authority was received not as usual... The Hungarian Atomic Energy Authority’s request pointed out a discrepancy.The Hungarian Atomic Energy Authority’s request pointed out a discrepancy.

7. 7 The Discrepancy Up to that time, the qualification target flaw size was determined based on the fracture mechanics calculation used for the Technical Specification of the Inspection Qualification in Hungary. For this reason the mechanized UT of the longitudinal and circumferential welds of main coolant loop piping Technical Specification’s qualification target flawsize was determined based on the result of fracture mechanics calculation. However in March of 2007 a new ASME adapted Two-Level Criterion Document was submitted by the Paks NPP to HAEA, where the registration limits of the relevant inspections were modified from the previous regulations. The new ASME based (IWB 3514-2) acceptance limits didn’t agree with the fracture mechanics results

8. 8 Two-Level Evaluation Concept Level 1 Evaluation: analog signal basis Level 2 Evaluation: ASME basis Before I go further, I would like to clarify what the Two-Level Criterion Document means in the UT practice. The 2-level expression refers to the Two-Level Evaluation Concept In Hungary the evaluation of UT is based on a comparison between the amplitude and that amplitude given by a reference flat bottom hole reflector. The registration level is usually equal to that of the construction. The acceptance level is equal with the reference level plus 12 dB. Only if the amplitude exceeds this acceptance level the sizing and fracture mechanics calculation have to be performed. But the FBH equivalent sizing cant calculate into the real phisics dimensions, so they are incompatible fracture mechanics input data. Before I go further, I would like to clarify what the Two-Level Criterion Document means in the UT practice. The 2-level expression refers to the Two-Level Evaluation Concept In Hungary the evaluation of UT is based on a comparison between the amplitude and that amplitude given by a reference flat bottom hole reflector. The registration level is usually equal to that of the construction. The acceptance level is equal with the reference level plus 12 dB. Only if the amplitude exceeds this acceptance level the sizing and fracture mechanics calculation have to be performed. But the FBH equivalent sizing cant calculate into the real phisics dimensions, so they are incompatible fracture mechanics input data.

9. 9 Qualification Target Flawsize and Two-Level Criterion Document (ASME IWB 3514-2) After this short explanation now I would like to turn back to the discrepancy between the qualification target flawsize as the static calculation result and the ASME regulation. Let see the numbers! So it seems, that the Qualification Target Flawsize is app. 3-five-times bigger than the ASME registration limit. After this short explanation now I would like to turn back to the discrepancy between the qualification target flawsize as the static calculation result and the ASME regulation. Let see the numbers! So it seems, that the Qualification Target Flawsize is app. 3-five-times bigger than the ASME registration limit.

10. 10 HA4543 - Authority’s Decision ‘Inspection Qualification process must be extended taking into consideration the requirements of the Two-Level Criterion Document and the inspection capability must be demonstrated also on the level of acceptance limits of Two-Level Criterion Document.’ I tryed to translate the original sentence. For the analysis of the decision Paks NPP called for a 3 party reconciliation between the authority, NPP, and the Hungarian Inspection Qualification Body, in order to clarify the situation and determine the further steps.I tryed to translate the original sentence. For the analysis of the decision Paks NPP called for a 3 party reconciliation between the authority, NPP, and the Hungarian Inspection Qualification Body, in order to clarify the situation and determine the further steps.

11. 11 Qualification Work According to the plan: The Authority’s decision didn’t relate to the Technical Specification and any elements of the Qualification Dossier. As a result of the reconciliation the qualification work was continued. Because the Authority’s decision didn’t relate to the Technical Specification and any elements of the Qualification Dossier. They asked for a supplementary qualification extension as an enclosure of the Qualification Dossier. At the end on May 13. 2008 the Qualification Certificate has been issued. As a result of the reconciliation the qualification work was continued. Because the Authority’s decision didn’t relate to the Technical Specification and any elements of the Qualification Dossier. They asked for a supplementary qualification extension as an enclosure of the Qualification Dossier. At the end on May 13. 2008 the Qualification Certificate has been issued.

12. 12 Supplementary Technical Analysis Paks NPP didn’t have main coolant pipe specimen with IWB 3514-2 like reflectors Re-evaluation of the Finnish Fortum etalon mechanized UT data from spring of 2007 same UT equipment same probes same inspection procedure (except of the evaluation procedure) The re-analysis showed that inspection also efficient on the ASME acceptance limits, but: Detection probability slightly lower The sizing accuracy not worse RMS error still acceptable At the end on May 13. 2008 the Qualification Certificate has been issued. Let see how the Let see how the

13. 13 Thx, for your attention and with that I’m happy to take any question.Thx, for your attention and with that I’m happy to take any question.