ML060120127
| ML060120127 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 02/17/2006 |
| From: | Richard Laufer Plant Licensing Branch III-2 |
| To: | Kansler M Entergy Nuclear Operations |
| SHea J, 415-1388, NRR/DLPM | |
| References | |
| TAC MC8288 | |
| Download: ML060120127 (14) | |
Text
February 17, 2006 Mr. Michael R. Kansler, President Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SUBJECT:
PILGRIM NUCLEAR POWER STATION RELIEF REQUEST NO. PRR-05, (TAC NO. MC8288)
Dear Mr. Kansler:
By letter dated June 29, 2005, Entergy Nuclear Operations, Inc. (the licensee), requested relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, 1998 Edition, Appendix VIII, Supplement 10.
The Nuclear Regulatory Commission staff has concluded that the proposed alternatives to the ASME Code requirements in PRR No. 5 are acceptable and will provide an acceptable level of quality and safety. The results are provided in the enclosed safety evaluation. Pursuant to 10 CFR 50.55a(a)(3)(i), the proposed alternative is authorized for the Pilgrim Nuclear Power Stations (Pilgrim) fourth 10-year inservice inspection interval, which ends on June 30, 2015.
If you have any questions regarding this approval, please contact the Pilgrim Project Manager, James Shea, at 301-415-1388.
Sincerely,
/RA/
Richard J. Laufer, Chief Plant Licensing Branch I-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-293
Enclosure:
As stated cc w/encl: See next page
ML060120127 *See SE dated 10/12/05 OFFICE LPL1-1/PM LPL1-1/LA EMCB OGC LPL1-1/BC NAME JShea SLittle TChan* MBupp RLaufer DATE 02/02/06 02/02/06 10/12/05 02/16/06 02/17/06 Pilgrim Nuclear Power Station cc:
Regional Administrator, Region I Secretary of Public Safety U. S. Nuclear Regulatory Commission Executive Office of Public Safety 475 Allendale Road One Ashburton Place King of Prussia, PA 19406-1415 Boston, MA 02108 Senior Resident Inspector Director, Massachusetts Emergency U. S. Nuclear Regulatory Commission Management Agency Pilgrim Nuclear Power Station Attn: James Muckerheide Post Office Box 867 400 Worcester Road Plymouth, MA 02360 Framingham, MA 01702-5399 Chairman, Board of Selectmen Mr. William D. Meinert 11 Lincoln Street Nuclear Engineer Plymouth, MA 02360 Massachusetts Municipal Wholesale Electric Company Chairman P.O. Box 426 Nuclear Matters Committee Ludlow, MA 01056-0426 Town Hall 11 Lincoln Street Mr. Michael A. Balduzzi Plymouth, MA 02360 Site Vice President Entergy Nuclear Operations, Inc.
Chairman, Duxbury Board of Selectmen Pilgrim Nuclear Power Station Town Hall 600 Rocky Hill Road 878 Tremont Street Plymouth, MA 02360-5508 Duxbury, MA 02332 Mr. Stephen J. Bethay Office of the Commissioner Director, Nuclear Assessment Massachusetts Department of Entergy Nuclear Operations, Inc.
Environmental Protection Pilgrim Nuclear Power Station One Winter Street 600 Rocky Hill Road Boston, MA 02108 Plymouth, MA 02360-5508 Office of the Attorney General Mr. Bryan S. Ford One Ashburton Place Manager, Licensing 20th Floor Entergy Nuclear Operations, Inc.
Boston, MA 02108 Pilgrim Nuclear Power Station 600 Rocky Hill Road Director, Radiation Control Program Plymouth, MA 02360-5508 Commonwealth of Massachusetts Executive Offices of Health and Ms. Charlene D. Faison Human Services Manager, Licensing 174 Portland Street Entergy Nuclear Operations, Inc.
Boston, MA 02114 440 Hamilton Avenue White Plains, NY 10601
Pilgrim Nuclear Power Station cc:
Mr. Gary J. Taylor Mr. Travis C. McCullough Chief Executive Officer Assistant General Counsel Entergy Operations Entergy Nuclear Operations, Inc.
1340 Echelon Parkway 440 Hamilton Avenue Jackson, MS 39213 White Plains, NY 10601 Mr. John T. Herron Mr. John M. Fulton Sr. VP and Chief Operating Officer Assistant General Counsel Entergy Nuclear Operations, Inc. Entergy Nuclear Operations, Inc.
440 Hamilton Avenue 440 Hamilton Avenue White Plains, NY 10601 White Plains, NY 10601 Mr. Danny L. Pace Ms. Stacey Lousteau Vice President, Engineering Treasury Department Entergy Nuclear Operations, Inc. Entergy Services, Inc.
440 Hamilton Avenue 639 Loyola Avenue White Plains, NY 10601 New Orleans, LA 70113 Mr. Brian OGrady Mr. James Sniezek Vice President, Operations Support BWR SRC Consultant Entergy Nuclear Operations, Inc. 5486 Nithsdale Drive 440 Hamilton Avenue Salisbury, MD 21801 White Plains, NY 10601 Mr. Michael D. Lyster Mr. John F. McCann BWR SRC Consultant Director, Nuclear Safety Assurance 5931 Barclay Lane Entergy Nuclear Operations, Inc. Naples, FL 34110-7306 440 Hamilton Avenue White Plains, NY 10601 Mr. Michael J. Colomb Director of Oversight Entergy Nuclear Operations, Inc.
440 Hamilton Avenue White Plains, NY 10601
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELIEF REQUEST NO. PRR-5 PILGRIM NUCLEAR POWER STATION DOCKET NO. 50-293
1.0 INTRODUCTION
By letter dated June 29, 2005, Agencywide Documents Access and Management System (accession number ML052990495), Entergy Nuclear Operations, Inc., (the licensee), submitted the Pilgrim Nuclear Power Station (Pilgrim) fourth interval 10-year Inservice Inspection (ISI) program plan and associated relief requests. In Pilgrim relief request PRR-5, the licensee has requested relief from requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components, 1998 Edition, related to the ultrasonic examination of dissimilar metal welds. The proposed relief would authorize the use of an alternative to the ASME Code,Section XI, Appendix VIII, Supplement 10, requirements for ultrasonic examination requirements of dissimilar metal welds during the Pilgrim fourth ISI 10-year interval.
2.0 REGULATORY EVALUATION
In accordance with 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components must meet the requirements set forth in ASME Code,Section XI, Rules for Inservice Inspection of Nuclear Power Plants Components to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that all inservice examinations and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of ASME Code,Section XI, incorporated by reference in 10 CFR 50.55a(b) on the date 12 months prior to the start of the 10-year interval. For Pilgrim, the ISI Code of record for the fourth ISI interval is the 1998 Edition of the ASME Code,Section XI with the 2000 Addenda.
In accordance with 10 CFR 50.55a(g)(6)(ii)(C), the implementation of Supplements 1 through 8, 10 and 11 of Appendix VIII to Section XI, 1995 Edition with the 1996 Addenda of the ASME Code is required on a phased schedule ending on November 22, 2002. Supplement 10 was included in the last phase of implementation and was required to be implemented by November 22, 2002. Additionally, 10 CFR 50.55a(g)(6)(ii)(C)(2) requires licensees implementing the 1989 Edition and earlier editions of Section XI of the ASME Code to implement the 1995 Edition with the 1996 Addenda of Appendix VIII and supplements to Appendix VIII of Section XI of the ASME Code.
Alternatives to requirements may be authorized or relief granted by the Nuclear Regulatory Commission (NRC) pursuant to 10 CFR 50.55a(a)(3)(i), 10 CFR 50.55a(a)(3)(ii), or Enclosure
10 CFR 50.55a(g)(6)(i). In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance is impractical for the facility. Pursuant to 10 CFR 50.55a(g)(4)(iv), ISI items may meet the requirements set forth in subsequent editions and addenda of the ASME Code that are incorporated by reference in 10 CFR 50.55a(b),
subject to the limitations and modifications listed therein, and subject to Commission approval.
Portions of editions and addenda may be used provided that related requirements of the respective editions and addenda are met.
The licensee submitted the request, pursuant to 10 CFR 50.55a(a)(3)(i), as a proposed alternative to the implementation of ASME Code,Section XI, Appendix VIII, Supplement 10 for the fourth ISI interval for Pilgrim which began July 1, 2005 and ends June 30, 2015.
2.1 Components For Which Relief Is Requested The requested relief from the Supplement 10 requirements applies to pressure-retaining piping welds subject to examination using procedures, personnel, and equipment qualified to ASME Code,Section XI, Appendix VIII, Supplement 10 criteria.
2.2 ASME Code Requirements The licensee requested relief from the requirements of ASME Code,Section XI, Appendix VIII, Supplement 10, the implementation of which is required in accordance with 10 CFR 50.55a(g)(6)(ii)(C).
The licensee proposed alternatives to the following Supplement 10 requirements:
Item 1 - Paragraph 1.1(b) states, in part - Pipe diameters within a range of 0.9 to 1.5 times a nominal diameter shall be considered equivalent.
Item 2 - Paragraph 1.1(d) states - All flaws in the specimen set shall be cracks.
Item 3 - Paragraph 1.1(d)(1) states - At least 50-percent of the cracks shall be in austenitic material. At least 50-percent of the cracks in austenitic material shall be contained wholly in weld or buttering material. At least 10-percent of the cracks shall be in ferritic material. The remainder of the cracks may be in either austenitic or ferritic material.
Item 4 - Paragraph 1.2(b) states, in part - The number of unflawed grading units shall be at least twice the number of flawed grading units.
Item 5 - Paragraph 1.2(c)(1) and 1.3(c) state, in part - At least 1/3 of the flaws, rounded to the next higher whole number, shall have depths between 10-percent and 30-percent of the nominal pipe wall thickness. Paragraph 1.4(b) distribution table requires 20-percent of the flaws to have depths between 10-percent and 30-percent.
Item 6 - Paragraph 2.0, first sentence states - The specimen inside surface and identification shall be concealed from the candidate.
Item 7 - Paragraph 2.2(b) states, in part - The regions containing a flaw to be sized shall be identified to the candidate.
Item 8 - Paragraph 2.2(c) states, in part - For a separate length sizing test, the regions of each specimen containing a flaw to be sized shall be identified to the candidate.
Item 9 - Paragraph 2.3(a) states - For the depth sizing test, 80-percent of the flaws shall be sized at a specific location on the surface of the specimen identified to the candidate.
Item 10 - Paragraph 2.3(b) states - For the remaining flaws, the regions of each specimen containing a flaw to be sized shall be identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region.
Item 11 - Table VIII-S2-1 provides the false call criteria when the number of unflawed grading units is at least twice the number of flawed grading units.
2.3 Relief Requested Pursuant to the alternative provisions in 10 CFR 50.55a(a)(3)(i), the licensee proposed the following for the remaining portion of the fourth ISI interval for Pilgrim. The proposed alternative will be implemented through the Electric Power Research Institute (EPRI) -
Performance Demonstration Initiative Program (PDI).
2.4 Licensees Proposed Alternative and Basis Paragraph 1.1(b) proposed alternative:
"The specimen set shall include the minimum and maximum pipe diameters and thicknesses for which the examination procedure is applicable. Pipe diameters within a range of 1/2 in. (13 mm) of the nominal diameter shall be considered equivalent. Pipe diameters larger than 24 in. (610 mm) shall be considered to be flat. When a range of thicknesses is to be examined, a thickness tolerance of +/-25-percent is acceptable."
Technical Basis - The change in the minimum pipe diameter tolerance from 0.9 times the diameter to the nominal diameter minus 0.5-inch provides tolerances more in line with industry practice. Though the alternative is less stringent for small pipe diameters, they typically have a thinner wall thickness than larger diameter piping. A thinner wall thickness results in shorter sound path distances that reduce the detrimental effects of the curvature. This change maintains consistency between Supplement 10 and the recent revision to Supplement 2.
Paragraph 1.1(d) proposed alternative:
"At least 60-percent of the flaws shall be cracks, the remainder shall be alternative flaws.
Specimens with intergranular stress corrosion cracking (IGSCC) shall be used when available.
Alternative flaws, if used, shall provide crack-like reflective characteristics and shall be limited to the case where implantation of cracks produces spurious reflectors that are uncharacteristic of actual flaws. Alternative flaw mechanisms shall have a tip width of less than or equal to 0.002
in. (.05 mm). Note, to avoid confusion, the proposed alternative modifies instances of the term cracks or cracking to the term flaws because of the use of alternative flaw mechanisms.
Technical Basis - As illustrated below, implanting a crack requires excavation of the base material on at least one side of the flaw. While this may be satisfactory for ferritic materials, it does not produce a useable axial flaw in austenitic materials because the sound beam, which normally passes only through base material, must now travel through weld material on at least one side, producing an unrealistic flaw response. In addition, it is important to preserve the dendritic structure present in field welds that would otherwise be destroyed by the implantation process. To resolve these issues, the proposed alternative allows the use of up to 40-percent fabricated flaws as an alternative flaw mechanism under controlled conditions. The fabricated flaws are isostatically compressed which produces ultrasonic reflective characteristics similar to tight cracks.
Paragraph 1.1(d)(1) proposed alternative:
"At least 80-percent of the flaws shall be contained wholly in weld or buttering material. At least one, and a maximum of 10-percent of the flaws shall be in ferritic base material. At least one, and a maximum of 10-percent of the flaws shall be in austenitic base material."
Technical Basis - Under the current ASME Code, as few as 25-percent of the flaws are contained in austenitic weld or buttering material. Recent experience has indicated that flaws contained within the weld are the likely scenario. The metallurgical structure of austenitic weld material is ultrasonically more challenging than either ferritic or austenitic base material. The proposed alternative is, therefore, more challenging than the current ASME Code.
Paragraph 1.2(b) proposed alternative:
"Detection sets shall be selected from Table VIII-S10-1. The number of unflawed grading units shall be at least one and a half times the number of flawed grading units."
Technical Basis - New Table VIII-S10-1 provides a statistically based ratio between the number of unflawed grading units and the number of flawed grading units. The proposed alternative reduces the ratio to 1.5 times. This reduces the number of test samples to a more reasonable number from the human factors perspective. However, the statistical basis used for screening personnel and procedures is still maintained at the same level with competent personnel being successful and less skilled personnel being unsuccessful. The acceptance criteria for the statistical basis are in Table Vlll-S10-1.
Paragraph 1.2(c)(1) and 1.3(c) proposed alternative:
The proposed alternative to the flaw distribution requirements of Paragraph 1.2(c)(1) (detection) and 1.3(c) (length) is to use the Paragraph 1.4(b) (depth) distribution table (see below) for all qualifications.
Flaw Depth Minimum
(% Wall Thickness) Number of Flaws 10-30% 20%
31-60% 20%
61-100% 20%
Technical Basis - The proposed alternative uses the depth sizing distribution for both detection and depth sizing because it provides for a better distribution of flaw sizes within the test set.
This distribution allows candidates to perform detection, length, and depth-sizing demonstrations simultaneously utilizing the same test set. The requirement that at least 75-percent of the flaws shall be in the range of 10 to 60-percent of wall thickness provides an overall distribution tolerance. The distribution uncertainty decreases the possibilities for testmanship that would be inherent to a uniform distribution. It must be noted that it is possible to achieve the same distribution utilizing the present requirements, but it is preferable to make the criteria consistent.
Paragraph 2.0 first sentence proposed alternative:
"For qualifications from the outside surface, the specimen inside surface and identification shall be concealed from the candidate. When qualifications are performed from the inside surface, the flaw location and specimen identification shall be obscured to maintain a "blind test".
Technical Basis - The current Code requires that the inside surface be concealed from the candidate. This makes qualifications conducted from the inside of the pipe impractical. The proposed alternative differentiates between inside diameter (ID) and outside diameter (OD) scanning surfaces, requires that they be conducted separately, and requires that flaws be concealed from the candidate.
Paragraph 2.2(b) and 2.2(c) proposed alternative:
"... containing a flaw to be sized may be identified to the candidate."
Technical Basis - The current ASME Code requires that the regions of each specimen containing a flaw to be length sized shall be identified to the candidate. The candidate shall determine the length of the flaw in each region (Note, that length and depth sizing use the term "regions" while detection uses the term "grading units" - the two terms define different concepts and are not intended to be equal or interchangeable). To ensure security of the samples, the proposed alternative modifies the first "shall" to a "may" to allow the test administrator the option of not identifying specifically where a flaw is located. This is consistent with the recent revision to Supplement 2.
Paragraph 2.3(a) and 2.3(b) proposed alternative:
"... regions of each specimen containing a flaw to be sized may be identified to the candidate."
Technical Basis - The current ASME Code requires that a large number of flaws be sized at a specific location. The proposed alternative changes the "shall" to a "may" which modifies this from a specific area to a more generalized region to ensure security of samples. This is consistent with the recent revision to Supplement 2. It also incorporates terminology from length sizing for additional clarity.
Table VIII-S2-1 acceptance criteria proposed alternative:
Table VIII-S 2 10-1 PERFORMANCE DEMONSTRATION DETECTION TEST ACCEPTANCE CRITERIA Detection Test False Call Test Acceptance Criteria Acceptance Criteria No. of No. of Maximum Flawed Minimum Unflawed Number Grading Detection Grading of False Units Criteria Criteria Calls 5 5 10 0 6 6 12 1 7 6 14 1 8 7 16 2 9 7 18 2 10 8 20 15 3 2 11 9 22 17 3 3 12 9 24 18 3 3 13 10 26 20 4 3 14 10 28 21 5 3 15 11 30 23 5 3 16 12 32 24 6 4 17 12 34 26 6 4 18 13 36 27 7 4 19 13 38 29 7 4 20 14 40 30 8 5 Technical Basis - The proposed alternative is identified as new Table VIII-S10-1. It was modified to reflect the reduced number of unflawed grading units and allowable false calls. As a part of ongoing ASME Code activities, Pacific Northwest National Laboratory (PNNL) has reviewed the statistical significance of these revisions and offered the revised Table VIII-S10-1.
3.0 TECHNICAL EVALUATION
The licensee proposed to use the program developed by PDI. The Nuclear Regulatory Commission (NRC) staffs evaluation of the PDI program is discussed below.
Paragraph 1.1(b):
The ASME Code requirement of 0.9 to 1.5 times the nominal diameter are equivalent was established for a single nominal diameter. When applying the ASME Code-required tolerance to a range of diameters, the tolerance rapidly expands on the high side. Based on the current requirements, a 5-inch outer diameter pipe would be equivalent to a range of 4.5-inch to 7.5-inch diameter pipe. Under the proposed PDI guidelines, the equivalent range would be reduced to 4.5-inch to 5.5-inch diameter pipe. Additionally, with the current ASME Code requirements, a 16-inch nominal diameter pipe would be equivalent to a range of 14.4-inch to 24-inch diameter pipe. The proposed PDI guidelines would significantly reduce the equivalent range to between 15.5-inch and 16.5-inch diameter pipe. The difference between the ASME Code and the proposed PDI program for diameters less than 5-inches is not significant because of a shorter metal path and beam spread associated with smaller diameter piping.
The NRC staff reviewed the licensees technical basis for the proposed alternative and agrees with the licensees assessment that the alternative provides tolerances more in-line with industry practice. Based on the discussion as presented above, the NRC staff finds the proposed alternative will provide more conservative tolerance results for a range of piping diameters in comparison to the current ASME Code requirements. The NRC staff also finds that the differences in tolerance results for smaller diameter piping are not significant.
Therefore, the NRC staff finds the proposed alternative acceptable.
Paragraph 1.1(d):
The ASME Code requires all flaws to be cracks. Manufacturing test specimens containing cracks free of spurious reflections and telltale indicators is extremely difficult in austenitic material. To overcome these difficulties, the EPRI developed a process for fabricating flaws that produce ultrasonic acoustic responses similar to the responses associated with actual cracks. EPRI presented its process at public meetings held June 12 through 14, 2001, and January 31 through February 2, 2002, at EPRIs non-destructive examination (NDE) Center located in Charlotte, North Carolina.
The NRC staff attended the meetings and determined that the process parameters used for manufacturing fabricated flaws demonstrated the ability to produce acoustic responses similar to those associated with actual cracks. In addition, the NRC staff reviewed the licensees technical basis and agrees with the licensees assessment. Therefore, the NRC staff concludes that the proposed alternative adequately demonstrates that ASME Code requirements are met.
Paragraph 1.1(d)(1):
The ASME Code requires that at least 50-percent of the flaws be contained in austenitic material and at least 50-percent of the flaws in the austenitic material shall be contained fully in
weld or buttering material. This means that at least 25-percent of the total flaws must be located in the weld or buttering material. Industry experience shows that flaws identified during ISI of dissimilar metal welds are more likely to be located in the weld or buttering material. The grain structure of austenitic weld and buttering material represents a much more stringent ultrasonic scenario than that of a ferritic material or austenitic base material. Flaws in austenitic base material that are free of spurious reflectors and telltale indicators are difficult to create.
The NRC staff finds the proposed 80 percent or greater alternative to the ASME Code requirement of at least 50 percent of the flaws be contained in the weld metal or buttering material provides a testing scenario reflective of industry experience and minimizes difficulties associated with telltale reflectors common to placing flaws in austenitic base material.
Therefore, the NRC staff finds the proposed alternative provides a more rigorous inspection than that required by the ASME Code and, therefore, is acceptable.
Paragraph 1.2(b):
The ASME Code requires that detection sets meet the requirements of Table VIII-S2-1, which specify the minimum number of flaws in a test set to be 5 with 100-percent detection. The ASME Code also requires the number of unflawed grading units to be two times the number of flawed grading units. The proposed alternative would follow the detection criteria of the table beginning with a minimum number of flaws in a test set being 10, reducing the number of false calls to one and a half times the number of flawed grading units.
The NRC staff reviewed the licensees technical basis and finds that the proposed alternative satisfies the pass/fail objective established in ASME Code,Section XI, Appendix VIII for performance demonstration acceptance criteria.
Paragraph 1.2(c)(1), Paragraph 1.3(c):
The ASME Code requires, for detection and length sizing, that at least 1/3 of the flaws be located between 10-30-percent through the wall thickness and 1/3 located greater than 30-percent through the wall thickness. The remaining 40-percent would be located randomly throughout the pipe wall thickness. The proposed alternative sets the distribution criteria for detection and length sizing to be the same as the depth sizing distribution, which stipulates that at least 20-percent of the flaws be located in each of the increments of 10-30-percent, 31 percent, and 61-100-percent. The remaining 40-percent would be located randomly throughout the wall thickness. With the exception of the 10-30-percent increment, the proposed alternative is a subset of the ASME Code requirements. The 10-30-percent increment would be in the subset if it contained at least 30-percent of the flaws.
The NRC staff reviewed the licensees technical basis for the proposed alternative. The NRC staff finds the change simplifies the assembly of test sets for detection and sizing qualifications and, based on industry experience, is more indicative of actual conditions in the field. In addition, the NRC staff finds the proposed alternative does not significantly deviate from, or reduce the level of, detection and length sizing from that required in the ASME Code.
Therefore, the NRC staff finds the alternative is acceptable.
Paragraph 2.0:
The current Code requires that the inside surface be concealed from the candidate. This makes qualifications conducted from the inside of the pipe impractical. The proposed alternative differentiates between ID and OD scanning surfaces, requires that they be conducted separately, and requires that flaws be concealed from the candidate. The NRC staff concludes that the intent behind the concealment of the ID is to assure that tests conducted from the outside are blind examinations that do not provide location information to the examiner. The NRC staff concludes that the licensees alternative to conceal the OD surface from the candidate for examinations performed from the ID meets the same intent to perform a blind examination and is, therefore, acceptable.
Paragraph 2.2(b) and 2.2(c):
The ASME Code requires that the region of flaws added to the test set for length sizing be identified to the candidate. The proposed alternative would make identifying the location of additional flaws an option.
The NRC staff finds that the proposed alternative will provide an additional element of difficulty to the testing process, since the candidate would be expected to demonstrate the skill of detecting and sizing flaws over a larger area in comparison to a specific region. The NRC staff finds the alternative, if utilized, would require the demonstration of a higher level of skill than that currently required by the ASME Code and is, therefore, acceptable.
Paragraph 2.3(a):
The ASME Code requires that 80-percent of the flaws be sized in a specific location that is identified to the candidate. The proposed alternative permits detection and depth sizing to be conducted separately or concurrently. In order to maintain a blind test, the location of flaws cannot be shared with the candidate. For depth sizing that is conducted separately, allowing the test administrator the option of not identifying flaw locations makes the testing process more difficult.
The NRC staff finds that the proposed alternative will provide an additional element of difficulty to the testing process, since the candidate would be expected to demonstrate the skill of detecting and sizing flaws in an unknown location. The NRC staff finds the alternative, if utilized, would require the demonstration of a higher level of skill than that currently required by the ASME Code and is, therefore, acceptable.
Paragraph 2.3(b):
The ASME Code requires that the region of flaws added to the test set for depth sizing shall be identified to the candidate. The proposed alternative would make identifying the region of flaws an option.
The NRC staff finds that the proposed alternative will provide an additional element of difficulty to the testing process since the candidate would be expected to demonstrate the skill of finding and sizing flaws in an area larger than a specific location. The NRC staff finds the alternative, if
utilized, would require the demonstration of a higher level of skill than that currently required by the ASME Code and is, therefore, acceptable.
Table VIII-S2-1 acceptance criteria:
The ASME Code requirements, discussed in Paragraph 1.2(b) above, are based on statistical parameters for screening personnel. The proposed alternative increases the minimum number of flawed grading units and reduces the number of unflawed grading units while maintaining the same statistical parameters as the ASME Code.
The NRC staff finds that the proposed alternative provides the same pass/fail screening criteria used to develop the test size tables in Appendix VIII are also used to create the PDI alternative Supplement 10, Table VIII-S10-1. Therefore, the NRC staff determined that the alternative does not significantly impact the false call criteria established in the table and, therefore, is acceptable.
4.0 CONCLUSION
The NRC staff has reviewed the licensees submittal and determined that, in accordance with 10 CFR 50.55a(a)(3)(i), the proposed alternative program will provide an acceptable level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the NRC staff authorizes the proposed alternative under Pilgrim Relief Request Number PRR-5, for the fourth ISI interval.
All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in this relief request remain applicable, including third party review by the Authorized Nuclear Inservice Inspector.
Principal Contributor: T. Steingass Date: February 17, 2006