IR 05000255/2015009

IR 05000255/2015009; on 02/23/2015 - 02/27/2015; Palisades Nuclear Plant; Problem Identification and Resolution (One Sample)

ML15089A198
Person / Time
Site:	Palisades
Issue date:	03/26/2015
From:	Dave Hills NRC/RGN-III/DRS/EB1
To:	Vitale A Entergy Nuclear Operations
References
IR 2015009
Download: ML15089A198 (17)

Text

UNITED STATES rch 26, 2015

SUBJECT:

PALISADES NUCLEAR PLANT - PROBLEM IDENTIFICATION AND RESOLUTION (ONE SAMPLE) INSPECTION REPORT 05000255/2015009

Dear Mr. Vitale:

On February 27, 2015, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection consisting of one problem identification and resolution review sample at your Palisades Nuclear Plant. The enclosed report documents the results of this inspection, which were discussed on February 27, 2015, with you and other members of your staff.

This inspection was an examination of activities conducted under your license as they relate to problem identification, resolution, and compliance with the Commissions rules and regulations and the conditions of your license. Within these areas, the inspection involved examination of selected procedures, representative records, and interviews with personnel.

Based on the results of this inspection, two NRC-identified findings of very-low safety significance (Green) were identified. The findings involved violations of NRC requirements.

However, because of the very-low safety significance, and because the issues were entered into your Corrective Action Program, the NRC is treating these issues as Non-Cited Violations (NCVs) in accordance with Section 2.3.2 of the NRC Enforcement Policy.

If you contest the subject or severity of these NCVs, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555 0001, with copies to the Regional Administrator, Region III; the Director, Office of Enforcement, U.S.

Nuclear Regulatory Commission, Washington, DC 20555-0001; and the NRC Resident Inspector at Palisades Nuclear Plant. In accordance with Title 10 of the Code of Federal Regulations (10 CFR) 2.390, Public Inspections, Exemptions, Requests for Withholding, of the NRC's "Rules of Practice," a copy of this letter, its enclosure, and your response (if any) will be available electronically for public inspection in the NRCs Public Document Room or from the Publicly Available Records (PARS)

component of the NRC's Agencywide Documents Access and Management System (ADAMS).

ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Sincerely,

/RA/

David E. Hills, Chief Engineering Branch 1 Division of Reactor Safety Docket No. 50-255 License No. DPR-20

Enclosure:

IR 05000255/2015009; w/Attachment: Supplemental Information

REGION III==

Docket No: 50-255 License No: DPR-20 Report No: 05000255/2015009 Licensee: Entergy Nuclear Operations, Inc.

Facility: Palisades Nuclear Plant Location: Covert, MI Dates: February 23 through 27, 2015 Inspector: M. Holmberg, Reactor Inspector Approved by: David E. Hills, Chief Engineering Branch 1 Division of Reactor Safety Enclosure

SUMMARY OF FINDINGS

Inspection Report 05000255/2015009; 02/23/2015 - 02/27/2015; Palisades Nuclear Plant;

Problem Identification and Resolution (One Sample).

This report covers a one-week period of announced baseline inspections by a regional inspector. Two Green findings were identified by the inspector. These findings were considered Non-Cited Violations (NCVs) of U.S. Nuclear Regulatory Commission (NRC)regulations. The significance of inspection findings is indicated by their color (i.e., Greater than Green, or Green, White, Yellow, Red), and determined using Inspection Manual Chapter (IMC) 0609, Significance Determination Process dated June 2, 2011. Cross-cutting aspects are determined using IMC 0310, Aspects Within the Cross-Cutting Areas dated December 4, 2014. All violations of NRC requirements are dispositioned in accordance with the NRCs Enforcement Policy dated July 9, 2013. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, Reactor Oversight Process, Revision 5, dated February 201

NRC-Identified

and Self-Revealed Findings

Cornerstone: Initiating Events

• Green: The inspector identified a finding of very-low safety significance with an associated NCV of Title 10, Code of Federal Regulations (CFR) Part 50, Appendix B,

Criterion XVI, Corrective Action, for the licensees failure to establish measures to assure that the cause of the ultrasonic examination leakage path indications and crack indications identified in the J-groove welds of the reactor pressure vessel head penetration nozzles 29 and 30 (a significant condition adverse to quality) was determined. Specifically, the licensee did not complete adequate causal investigations to assure the cause of this significant condition adverse to quality was determined. The licensee entered this issue into the Corrective Action Program (CAP), and initiated an action to conduct a root cause investigation for this issue.

The issue was more than minor in accordance with IMC 0612, Appendix B, Issue Screening, because it adversely affected the Initiating Events cornerstone attribute of equipment performance and procedure quality. The inspector also answered Yes to the more than minor screening question, If left uncorrected, would the performance deficiency have the potential to lead to a more significant safety concern? Specifically, the inspector determined that this issue was more than minor because, if left uncorrected, the licensee would have reduced the frequency of reactor vessel head nozzle penetration examinations which could result in the failure to detect primary water stress corrosion cracking (PWSCC). Undetected PWSCC could increase the risk for through-wall leakage and design basis events such as a loss-of-coolant accident (LOCA). The inspector determined that the finding was of very-low safety significance based on answering No to the IMC 0609, Appendix A, Exhibit 1-Initiating Events Screening Questions for LOCA Initiators. Although this performance deficiency occurred more than 10 years ago, it was representative of current licensee performance because in the November 19, 2014, Licensee Event Report Cancelation Letter, the licensee again failed to assure that the cause of the reactor pressure vessel nozzle crack indications in the J-groove welds was determined. Therefore, the finding had a cross-cutting aspect in the area of Problem Identification and Resolution because the licensee failed to assure the cause was determined for the reactor pressure vessel nozzle crack indications in the J-groove welds, and this decision was not consistent with an organization that thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance (IMC 310-Item P.2). (Section 4OA2.1.b(1))

• Green: The inspector identified a finding of very-low safety significance with an associated NCV of 10 CFR Part 50, Appendix B, Criterion IX Control of Special Processes, for the licensees failure to use qualified personnel and procedures for the dye penetrant (PT) examinations of the J-groove welds at nozzles 29 and 30 used to characterize crack indications. Consequently, no quality records existed to validate or confirm the size or extent of the cracking identified in these welds. The licensee documented the use of the unqualified PT examination for characterizing the reactor pressure vessel nozzle J-groove weld cracks in the CAP, and was developing corrective actions at the conclusion of the inspection.

The issue was determined to be more than minor in accordance with IMC 0612,

Appendix B, Issue Screening, because it adversely affected the Initiating Events cornerstone attribute of equipment performance and procedure quality. Further, if left uncorrected, it would become a more significant issue. Specifically, the licensee had based the risk evaluation of the nozzle cracking on the results of the unqualified PT examination, and if this result was not correct, the risk significance of past plant operation with these cracks may have been greater than assumed. Additionally, the licensee had considered the results from this PT examination, as part of the evaluations identified in their November 19, 2014, letter that concluded the flaws identified were caused by embedded weld defects, and not PWSCC. Based upon this revised cause determination, the licensee had elected to reduce the scheduled vessel head examinations, and this reduced inspection schedule may not be adequate to identify PWSCC prior to experiencing a through-wall leak. The inspectors determined that the finding was of very low safety significance based on answering No to the IMC 0609,

Appendix A, Exhibit 1-Initiating Events Screening Questions for LOCA Initiators. The finding did not have a cross-cutting aspect because it was not indicative of current licensee performance due to the age of the performance deficiency.

(Section 4OA2.1.b(2))

Licensee-Identified Violations

No violations were identified.

REPORT DETAILS

OTHER ACTIVITIES

Cornerstones: Initiating Events

4OA2 Identification and Resolution of Problems

.1 Selected Issue Follow Up Inspection: Revised Cause Evaluation - Reactor Vessel Head

J-Groove Weld Defects

a. Inspection Scope

On February 20, 2004, the U.S. Nuclear Regulatory Commission (NRC) issued an update to Order EA 03-009, First Revised NRC Order Establishing Interim Inspection Requirements for Reactor Pressure Vessel (RPV) Heads at Pressurized Water Reactors (PWRs). In this Order, the NRC stated, The RPV heads of PWRs have penetrations for control rod drive mechanisms (CRDMs) and instrumentation systems.

Nickel-based alloys (e.g., Alloy 600) are used in the penetration nozzles and related welds. Primary coolant water and the operating conditions of PWR plants can cause cracking of these nickel-based alloys through a process called primary water stress corrosion cracking (PWSCC). The susceptibility of RPV head penetrations to PWSCC appears to be strongly linked to the operating time and temperature of the RPV head.

Problems related to PWSCC have, therefore, increased as plants have operated for longer periods of time. In this Order, the NRC established augmented RPV head examination requirements to identify PWSCC which included application of ultrasonic examination (UT) and/or surface examination techniques (e.g., eddy current or dye penetrant [PT] examinations) of the entire wetted surface of the J-groove weld, and the wetted surface of the RPV head penetration nozzle base materials. These augmented RPV requirements were subsequently incorporated into Title 10, Code of Federal Regulations (CFR) 50.55a (g)(6)(ii)(D), Augmented Inservice Inspection Requirements:

Reactor Vessel Head Inspections, and included the requirement to perform a demonstrated volumetric (e.g., UT) or surface leak path assessment through all J-groove welds.

On October 16, 2004, during examination of the RPV head CRDM nozzles in accordance with Order EA 03-009, the licensee identified UT leak path and crack indications in the J-groove weld at nozzles 29 and 30, and reported this condition to the NRC in Licensee Event Report (LER) 2004-002-00, Leak Path Indications Identified in RPV Head Nozzle Penetrations. The licensee subsequently repaired the affected nozzles, and the RPV was returned to service. The licensee attributed the cause of this cracking to PWSCC, and, therefore, in accordance with Order EA 03-009, conducted volumetric examinations of the RPV head CRDM nozzles during each subsequent refueling outage.

On November 19, 2014, the licensee issued Letter PNP 2014-100, Cancellation of LER 2004-002-00, Leak Path Indications Identified in RPV Head Nozzle Penetrations).

In this letter, the licensee cancelled LER 2004-002 after re-evaluation of the cause for the flaw indications identified in penetrations 29 and 30. In this letter, the licensee also reported its intent to reduce the frequency of the RPV head CRDM nozzle examinations to every other refueling outage.

In accordance with guidance in Inspection Procedure (IP) 71152, defects and non-conforming materials, parts, or components may present a substantial safety hazard, and should be reviewed to ensure licensee corrective actions comply with 10 CFR Part 50, Appendix B. The inspector reviewed records related to the RPV nozzles 29 and 30 J-groove weld cracks to confirm that adequate corrective actions had been completed for this issue. Specifically, the inspector verified the following attributes during review of the licensee's records related to the affected RPV nozzles:

• Complete and accurate identification of the problem in a timely manner commensurate with its safety significance and ease of discovery;

• Consideration of the extent of condition, generic implications, common cause and previous occurrences;

• Evaluation and disposition of operability/reportability issues;

• Classification and prioritization of the resolution of the problem, commensurate with safety significance;

• Identification of the apparent and/or contributing causes of the problem; and

• Identification of corrective actions, which were appropriately focused to correct the problem.

This review constituted one in-depth problem identification and resolution sample as defined in IP 71152-05.

a. Findings

(1) Failure to Determine the Cause of Head Penetration Nozzle J-Groove Weld Cracking

Introduction:

The inspector identified a finding having very-low safety significance (Green), and an associated Non-Cited Violation (NCV) of 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, for the licensees failure to establish measures to assure that the cause of the UT leakage path indications and crack indications identified in the J-groove welds of the RPV head penetration nozzles 29 and 30 (a significant condition adverse to quality [SCAQ]) was determined. Specifically, the licensee did not complete adequate causal investigations to assure the cause of this SCAQ was determined.

Description:

On February 26, 2015, during the review of the November 19, 2014, Letter PNP 2014-100, Cancellation of LER 2004-002-00, Leak Path Indications Identified in RPV Head Nozzle Penetrations, the inspector identified that the licensee had not completed a root cause investigation to support its conclusion that the cause of the defects identified in the J-groove welds of RPV head penetration nozzles 29 and 30 in 2004 was due to embedded welding defects. Consequently, the licensees corrective action to reduce the frequency of non-destructive examinations may not be sufficient to identify the presence of J-groove weld cracking prior to developing a through-wall pressure boundary leak. The inspector was concerned that a through-wall pressure boundary leak at a J-groove weld could lead to wastage of the RPV head material, and increase the risk for a LOCA.

On December 9, 2004, the licensee reported in LER 2004-002-00, that the UT leak path indications identified on October 16, 2004, in the Inconel buttering of the J-groove weld on RPV head CRDM nozzles 29 and 30 were a condition that resulted in a principle safety barrier being seriously degraded in accordance with 10 CFR 50.73(a)(2)(ii)(A).

In LER 2004-002, the licensee stated, Additional metallurgical examinations were not performed on the indications; however, based on industry experience, the cause of the two penetration cracks is believed to be PWSCC.

In 2004, the licensees Corrective Action Program (CAP) was described in Revision 6 of procedure FP-PA-ARP-01 Action Request Process. Section 4.15 of this document defined a SCAQ as Conditions where nuclear safety or personnel safety is significantly threatened or already has been compromised. A problem that meets one or more of the following criteria, and is addressed as a Level A issue in the CAP4.15.2 Conditions which are reportable to the NRC under 10 CFR Part 71, 10 CFR 50.72 (requiring an LER), and 10 CFR 50.73. The licensee documented Discontinuities Exist in the UT Signal for Penetrations 29 and 30, in condition report (CR)-PLP-2004-06822, and documented PWSCC Identified on Reactor Head Penetrations, in CR-PLP-2004-06978. Both of these CRs were classified as Level A significance in accordance with procedure FP-PA-ARP-01. The issues identified in these CRs also met the procedure FP-PA-ARP-01 definition of an SCAQ, because this condition was required to be reported to the NRC in accordance with 10 CFR 50.73. In CR-PLP-2004-06822, the licensee stated, The issue manager and the reactor head inspection team in combination with the Electric Power Research Institute and other industry peers are working on the root cause (analysis of the indications). I would not recommend a parallel root cause investigation. The licensee closed this CR on October 18, 2004, without additional cause investigation/evaluation. Similarly, the licensee closed CR-PLP-2004-06978 on January 5, 2006, without completing an investigation to determine the cause of the J-groove weld crack indications. Specifically, a root cause evaluation had not been completed by the licensees reactor head inspection team or by the Electric Power Research Institute for the crack indications identified in RPV nozzle penetrations 29 and 30 as was stated in CR- PLP-2004-06822.

On November 19, 2014, the licensee issued Letter PNP 2014-100, Cancellation of LER 2004-002, Leak Path Indications Identified in Reactor Pressure Vessel Head Nozzle Penetrations (VHP). In this letter, the licensee reported that the flaws identified in the Palisades reactor VHP nozzles were not caused by PWSCC. Instead, the licensee concluded these flaws were caused by the original welding process (embedded welding defects), and as such did not represent a safety barrier being seriously degraded. The licensees conclusions in Letter PNP 2014-100 were based upon a supporting document PLP-RPT-14-00071, Review of RPV Crack Indication in CRDM Penetration J-Groove Welds. In this document, the licensee stated, Inspections at Palisades from 2004 to 2012 have shown no evidence of PWSCC. This is in contrast to PWSCC experience at other plants. Affected vessel heads typically have shown cracking at multiple nozzles, multiple cracks at each nozzle, and significant crack growth between refueling outages. The licensees reviews documented in PLP-RPT-14-00071 were done in accordance with their design control process which did not define a level of rigor for determining the cause for a condition. If the licensee had instead elected to apply the CAP, it would have defined the level of effort (e.g., rigor) required for conducting a causal investigation of this issue.

The inspector and staff in the Office of Nuclear Reactor Regulation reviewed PNP 2014-100, and the supporting document PLP-RPT-14, and concluded that these documents did not provide an adequate basis to exclude PWSCC as a cause for the flaws identified in the J-groove welds at RPV head nozzles 29 and 30, and, therefore, did not provide an adequate basis to reduce the RPV head penetration nozzle examination frequency. Specifically, the inspector and staff in the Office of Nuclear Reactor Regulation identified that these licensee documents did not:

• Include analysis of material samples of the J-groove welds with crack indications still present in the at RPV nozzles 29 and 30. Metallurgical examinations of material removed from J-groove welds has been successfully implemented at other commercial power reactor sites to confirm the cause of cracks identified in J-groove welds or nozzles (reference LER 50-455/2007-001-00, RPV Head CRDM Penetration Nozzle Weld Indication Due to an Initial Construction Weld Defect Allowing the Initiation of PWSCC.)

• Explain an alternative cause for the UT leak-path indications identified at VHP 29 and 30 and the presence of this UT leakage path indicates that a through-wall leak occurred in these J-groove welds. The NRC has confirmed the effectiveness of the UT leak path method for identification of leakage through the J-groove weld into the annulus between the RPV head penetration nozzle, and the RPV head low-alloy steel (reference NUREG/CR 7142, Ultrasonic Phased Array Assessment of the Interference Fit and Leak Path of the North Anna Unit 2 Control Rod Drive Mechanism Nozzle 63 with Destructive Validation).

• Explain how the indications identified in the nozzles 29 and 30 presumed to be embedded welding defects and open to the J-groove surface (as revealed by the initial PT examinations) did not result in a PWSCC initiation site. Specifically, welding defects open to the surface and reactor coolant environment have been shown to create an atypical corrosion environment that serves to initiate PWSCC (reference LER 50-455/2007-001-00, and LER 50-339/2002-001).

• Review applicable industry experience gained from PWSCC in J-groove welds as documented in NRC Information Notices (INs), and LERs related to PWSCC identified by other nuclear plants. Instead, the licensee relied on industry reports that provided a summary level of information extracted from LERs or NRC INs related to PWSCC. In particular, the licensee did not consider operating experience documented in NRC IN 2003-11 (Supplement 1), Leakage Found on Bottom-Mounted Instrumentation Nozzles. Specifically, this IN describes an experience at the South Texas Project (STP) where two lower head bottom mounted instrument vessel penetrations experienced leakage cause by PWSCC that was confirmed through destructive metallurgical examinations of a physical sample removed from an affected J-groove weld. Subsequent inservice examinations at STP Unit 1 have not identified any new PWSCC flaws, which does not change the fact that the original J-groove weld flaw was caused by PWSCC. This operating experience example contradicts the licensees conclusion that absent identification of leakage or new flaws following the original discovery of cracks in VHP nozzles 29 and 30 J-groove welds means that these cracks were not caused by PWSCC. Additionally, the results from STP indicate that fabrication flaws (i.e., welding flaws) can be a significant contributing factor to cracking (reference NUREG/CP-0191, Proceedings of the Conference on Vessel Penetration Inspection, Crack Growth and Repair).

The licensee documented the failure to perform a root cause evaluation for the J-groove weld cracking into the CAP (CR-PLP-2015-00883), and initiated an action to conduct a root cause investigation for this issue. Additionally, the licensee issued CR-PLP-2015-00880 to track a planned action to withdraw the November 19, 2014, letter to cancel LER 2004-002-00.

Analysis:

The inspector determined that failure to assure the cause was adequately determined for the RPV nozzle crack indications in the J-groove welds of RPV head penetrations 29 and 30 was contrary to 10 CFR Part 50, Appendix B, Criterion XVI Corrective Action, and was a performance deficiency.

The inspector determined that this issue was more than minor in accordance with Inspection Manual Chapter (IMC) 0612, Appendix B, Issue Screening, dated September 7, 2012, because it adversely affected the Initiating Events Cornerstone attribute of equipment performance and procedure quality. The inspector also answered Yes to the more than minor screening question, If left uncorrected, would the performance deficiency have the potential to lead to a more significant safety concern?

Specifically, the inspector determined that this issue was more than minor because, if left uncorrected, the licensee would have reduced the frequency of RVH nozzle penetration examinations which could result in a failure to detect PWSCC. Undetected PWSCC could increase the risk for through-wall leakage and design basis events such as a LOCA.

The inspectors determined the finding could be evaluated using the Significance Determination Process (SDP) in accordance with IMC 0609, SDP, 0609.04, Initial Characterization of Findings, dated June 19, 2012,and Appendix A, Exhibit 1-Initiating Events Screening Questions, dated June 19, 2012.

Questions 1 and 2 of the LOCA Initiator Section of Exhibit 1 asked; if after a reasonable assessment of degradation, could the finding result in exceeding the reactor coolant system leak rate for a small LOCA?, or could the finding have likely affected other systems used to mitigate a LOCA resulting in a total loss of their function (e.g., Interfacing System LOCA)? In this case, the licensee had not yet reduced the frequency of examinations necessary to detect PWSCC degradation of RPV nozzles, and thus had not yet impaired the ability of the RPV to perform the design functions (e.g., pressure retaining boundary) so the inspector answered these questions No, and this issue screened as having very-low risk significance (Green).

Although this performance deficiency occurred more than 10 years ago, it was representative of current licensee performance because in the November 19, 2014, LER cancelation letter, the licensee again failed to assure that the cause of the RPV nozzle crack indications in the J-groove welds was determined. Therefore, the inspector determined that this finding had a cross-cutting aspect in the area of Problem Identification and Resolution. Specifically, the licensees failure to assure the cause was determined for the RPV nozzle crack indications was not consistent with an organization that thoroughly evaluates issues to ensure that resolutions address causes, and extent of conditions commensurate with their safety significance (IMC 310 - Item P.2).

Enforcement:

Title 10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, requires, Measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and non-conformances are promptly identified and corrected. In the case of SCAQ, the measures shall assure that the cause of the condition is determined and corrective action taken to preclude repetition. The identification of the SCAQ, the cause of the condition, and the corrective action taken shall be documented and reported to appropriate levels of management.

Contrary to the above, from October 16, 2004, through January 5, 2006, the licensee failed to establish measures to assure that the cause of a SCAQ identified on October 16, 2004 was determined. Specifically, the licensee failed to complete investigations, to assure the cause of the UT leakage path indications and crack indications identified at the J-groove welds of RPV head penetration nozzles 29 and 30 (a SCAQ) was determined. Because this violation was of very-low safety significance, was not repetitive or willful, and was entered into the licensees CAP as CR-PLP-2015-00883, this violation is being treated as an NCV, consistent with Section 2.3.2 of the NRC Enforcement Policy (NCV 05000255/2015009-01; Failure to Determine the Cause of Head Penetration Nozzle J-Groove Weld Cracking).

(2) Unqualified Non-Destructive Examinations of J-Groove Welds 29 and 30

Introduction:

The inspector identified a finding having very-low safety significance (Green), and an associated NCV of 10 CFR 50 Appendix B, Criterion IX Control of Special Processes, for the licensees failure to use qualified personnel and procedures for the PT examinations of the J-groove welds at nozzles 29 and 30 used to characterize crack indications. Consequently, no quality records existed to validate or confirm the size or extent of the cracking identified in these welds.

Description:

On February 26, 2015, during review of the records related to the identification of flaws in the RPV J-groove welds in 2004, the inspector identified that unqualified PT examinations had been used to characterize the weld flaws. Specifically, during the grinding operation to remove these weld flaws; in-process PT examinations had been performed. The grinding operation was subsequently abandoned due to the licensees decision to implement a repair at these nozzles; however, the in-process unqualified PT results were subsequently used to establish the J-groove weld flaw dimensions and locations as reported to the NRC in LER 2004-002. The inspector was concerned that failure to conduct PT examinations with qualified personnel and procedures, could result in inaccurate results that affected the licensees previous risk evaluations and/or result in an incorrect conclusion for the cause of this cracking.

On October 14, 2004, the licensee identified UT signals at penetrations 29 and 30 indicative of leakage between the RPV head and nozzle. This UT examination was completed to comply with NRC Order EA-03-009 which required, in part, that an assessment be made to determine if leakage has occurred through the J-groove weld into the annulus between the RPV head penetration nozzle, and the RPV head low-alloy steel. On October 15, 2004, to confirm this UT result, the licensee documented in Work Request 299801, the results of PT examinations conducted on the surface of the J-grooves welds at penetrations 29 and 30 using qualified personnel following a Code qualified PT procedure. These examinations identified small rounded indications in the penetration nozzle 29 and 30 J-groove welds.

On October 16, 2004, as documented in Work Request 299801, the licensee performed several grinding operations, and PT examinations during the attempts to remove the rounded indications identified in the J-groove welds at penetrations 29 and 30. Based upon discussions with the licensees engineering staff, the personnel performing the grinding steps also conducted in-process PT examinations for informational purposes (e.g., to show grinding was, or was not successful in flaw removal), and these staff did not have PT examination training qualifications, and did not follow a Code qualified PT procedure. The grinding operation was subsequently abandoned because the licensee decided to implement a repair at these nozzles, and a final Code qualified PT was not performed (e.g., using a procedure qualified to an applicable Code or Standard such as the American Society of Mechanical Engineers Code Section V).

While the unqualified PT examinations were sufficient for the in-process J-groove weld grinding operation, the licensee subsequently, and inappropriately, used the results of the unqualified PT examinations for other purposes. Specifically, on December 9, 2004, the licensee issued LER 2004-002-00, that reported the UT leak path indications identified on October 16, 2004, in the Inconel buttering of the J-groove weld on RPV head CRDM nozzles 29 and 30 as a condition that resulted in a principle safety barrier being seriously degraded in accordance with 10 CFR 50.73 (a)(2)(ii)(A). In this LER, the licensee stated, The PT exam showed minor surface indications that required further evaluation. During grinding activities on penetration 29, an approximately 1/4-inch long axial crack was identified perpendicular to the fusion line of the J-weld. During grinding activities on penetration 30, a circumferential crack, approximately 1 inch long, was identified adjacent to the fusion line of the J weld. Based upon discussions with the licensees engineering staff, the flaw dimensions reported in LER 2004-002-00 were taken from the in-process PT examinations that occurred on October 16, 2004, however no record existed to identify how the flaw dimensions or locations as reported in the LER were determined. In LER 2004-002-00, the licensee concluded that the safety significance of this cracking was minimal due to the size and orientation of the cracks, and that the cracks were small and tight. However, the size, extent, or configuration (e.g., branching) of the cracking identified could have been different than reported because of the unqualified PT process used to detect these flaws. Additionally, in PLP-RPT-014-00071, Review of RPV Crack Indication in CRDM Penetration J-Groove Welds, the licensee had considered the flaw dimensions, locations and configurations reported in LER 2004-002-00 to support the November 19, 2014, decision to cancel LER 2004-002-00.

In response to this finding, the licensee documented the use of an unqualified PT examination for characterizing the RPV nozzle J-groove weld cracks in CR-PLP-2015-00879, and documented the use of the unqualified PT results in PLP-RPT-014-00071 in CR-PLP-2015-882, and was developing corrective actions at the conclusion of the inspection.

Analysis:

The inspector determined that the licensees failure to use qualified personnel and procedures for the PT examination of the J-groove welds at nozzles 29 and 30 was a performance deficiency.

The performance deficiency is more than minor in accordance with IMC 0612, Appendix B, Issue Screening dated September 7, 2012, because it adversely affected the Initiating Events Cornerstone attribute of equipment performance and procedure quality. Further, if left uncorrected, it would become a more significant issue.

Specifically, the licensee had based the risk evaluation of the nozzle cracking on the results of the unqualified PT examination, and if this result was not correct, the risk significance of past plant operation with these cracks may have been greater than assumed. Additionally, the PT examination results were considered in the evaluation supporting the licensees conclusions that the J-groove weld flaws identified in 2004 were caused by embedded weld defects and not PWSCC (reference licensee report PLP-RPT-14-00071 Review of RPV Crack Indication in CRDM Penetration J-Groove Welds). Based upon this revised cause determination, the licensee elected to reduce the frequency of RPV nozzle examinations which may not be adequate to identify PWSCC prior to experiencing a through-wall leak.

The inspector determined the finding could be evaluated using the SDP in accordance with IMC 0609, SDP, Attachment 0609.04, Initial Characterization of Findings, dated June 19, 2012, and Appendix A, Exhibit 1-Initiating Events Screening Questions, dated June 19, 2012. Questions 1 and 2 of the LOCA Initiator Section of Exhibit 1 asked if after a reasonable assessment of degradation, could the finding result in exceeding the reactor coolant system leak rate for a small LOCA?, or could the finding have likely affected other systems used to mitigate a LOCA resulting in a total loss of their function (e.g., Interfacing System LOCA)? In this case, the licensee had not yet reduced the frequency of examinations necessary to detect PWSCC degradation of RPV nozzles, and thus, had not yet impaired the ability of the RPV to perform the design functions (e.g., pressure retaining boundary) so the inspector answered these questions No, and this issue screened as having very-low risk significance (Green).

The inspector did not identify a cross-cutting aspect associated with this finding because it was not indicative of current licensee performance due to the age of the performance deficiency.

Enforcement:

Title 10 CFR Part 50, Appendix B, Criterion IX, Control of Special Processes, requires that measures shall be established to assure that special processes, including welding, heat treating, and non-destructive testing, are controlled and accomplished by qualified personnel using qualified procedures in accordance with applicable codes, standards, specifications, criteria, and other special requirements.

Contrary to the above, on October 16, 2004, the licensee performed non-destructive testing (PT examinations) of the J-groove welds at penetration nozzles 29 and 30 using personnel and procedures not qualified in accordance with a Code or standard.

Because this violation is of very-low safety significance, and was entered into the CAP (CR-PLP-2015-00879 and CR-PLP-2015-882), this violation is being treated as an NCV consistent with Section 2.3.2 of the NRC Enforcement Policy (NCV 05000255/

2015009-02, Unqualified Non-Destructive Examinations of J-Groove Welds 29 and 30).

4OA6 Management Meetings

.1 Exit Meeting Summary

On February 27, 2015, the inspector presented the inspection results to Mr. A. Vitale, and other members of the licensee staff. The licensee acknowledged the issues presented. The licensee confirmed that none of the potential report input discussed was considered proprietary.

ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Licensee

A. Vitale, Site Vice President

B. Dotson, Regulatory Assurance

P. Russell, Engineering Director

K. OConnor, Design and Programs Engineering Manager

T. Fouty, Engineering Supervisor

LIST OF ITEMS

Opened

05000255/2014009-01 NCV Failure to Determine the Cause of Head Penetration Nozzle J-Groove Weld Cracking (Section 4OA2.1)

05000255/2014009-02 NCV Unqualified Non-Destructive Examinations of J-Groove Welds 29 and 30 (Section 4OA2.1)

Closed

05000255/2014005-01 NCV Failure to Determine the Cause of Head Penetration Nozzle J-Groove Weld Cracking (Section 4OA2.1)

05000255/2014009-02 NCV Unqualified Non-Destructive Examinations of J-Groove Welds 29 and 30 (Section 4OA2.1)

Discussed

None