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Title 10 of the CFR 50.55a(g)(6)(ii) states that the Commission may require the licensee to follow an augmented inservice inspection program for systems and components for which the Commission deems that added assurance of structural reliability is necessary. | Title 10 of the CFR 50.55a(g)(6)(ii) states that the Commission may require the licensee to follow an augmented inservice inspection program for systems and components for which the Commission deems that added assurance of structural reliability is necessary. | ||
Under this section, 10 CFR 50.55a(g)(6)(ii)(D) defines the requirements for reactor vessel head inspections. | Under this section, 10 CFR 50.55a(g)(6)(ii)(D) defines the requirements for reactor vessel head inspections. | ||
Title 10 of the CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC if: (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The licensee, in accordance with 10 CFR 50.55a(a)(3)(ii), has requested relief from the demonstrated volumetric leak path inspection requirements of 10 CFR 50.55a(g)(6)(ii)(D)(3). | Title 10 of the CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC if: (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The licensee, in accordance with 10 CFR 50.55a(a)(3)(ii), has requested relief from the demonstrated volumetric leak path inspection requirements of 10 CFR 50.55a(g)(6)(ii)(D)(3). | ||
3.0 TECHNICAL EVALUATION 3.1 Component for Which Relief Was Requested There are 53 American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1 vessel head penetration nozzles and associated welds identified by item number B4.20 of Code Case N-729-1 , Table 1. Enclosure | |||
-2 3.2 Regulatory Requirement Title 10 of the CFR 50.55a(g)(6)(ii)(D)(3) requires, in part, a licensee to perform a demonstrated volumetric or surface leak path assessment through all vessel head penetration nozzle J-groove welds. 3.3 Proposed Alternative The licensee's proposed alternative is to perform a vOlumetric leak path inspection using the same techniques used to satisfy the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004. 3.4 Licensee's Basis The licensee notes that while industry has initiated efforts to accomplish a generic demonstration of the volumetric leak path assessment technique, the extent of remaining tasks will likely preclude successful completion in time to support the upcoming spring 2009 refueling outage at PNP. The licensee also states that performance of alternative surface examinations of each J-groove weld would be a significant hardship due to the personnel exposure associated with the inspections in a locked high radiation area and high contamination area without a compensating increase in the level of quality and safety. The licensee provided details on several enhancements to the volumetric leak path inspection technique which have been developed over the past five years, including the previously completed baseline inspection data available for assessment comparison. | ===3.0 TECHNICAL=== | ||
3.5 Staff Evaluation ASME Code Case N-729-1 did not include a vOlumetric leak path assessment as part of the long term re-inspection plans for reactor pressure vessel upper head penetration nozzles and their associated welds. The NRC staff believed this omission was, in part, due to the difficulty for ASME members to establish qualification requirements for this inspection technique. | |||
EVALUATION | |||
===3.1 Component=== | |||
for Which Relief Was Requested There are 53 American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1 vessel head penetration nozzles and associated welds identified by item number B4.20 of Code Case N-729-1 , Table 1. Enclosure | |||
-2 3.2 Regulatory Requirement Title 10 of the CFR 50.55a(g)(6)(ii)(D)(3) requires, in part, a licensee to perform a demonstrated volumetric or surface leak path assessment through all vessel head penetration nozzle J-groove welds. 3.3 Proposed Alternative The licensee's proposed alternative is to perform a vOlumetric leak path inspection using the same techniques used to satisfy the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004. 3.4 Licensee's Basis The licensee notes that while industry has initiated efforts to accomplish a generic demonstration of the volumetric leak path assessment technique, the extent of remaining tasks will likely preclude successful completion in time to support the upcoming spring 2009 refueling outage at PNP. The licensee also states that performance of alternative surface examinations of each J-groove weld would be a significant hardship due to the personnel exposure associated with the inspections in a locked high radiation area and high contamination area without a compensating increase in the level of quality and safety. The licensee provided details on several enhancements to the volumetric leak path inspection technique which have been developed over the past five years, including the previously completed baseline inspection data available for assessment comparison. | |||
===3.5 Staff=== | |||
Evaluation ASME Code Case N-729-1 did not include a vOlumetric leak path assessment as part of the long term re-inspection plans for reactor pressure vessel upper head penetration nozzles and their associated welds. The NRC staff believed this omission was, in part, due to the difficulty for ASME members to establish qualification requirements for this inspection technique. | |||
The NRC staff determined that surface examination of all associated penetration J-groove welds was necessary as a defense-in-depth approach to detect leakage through the J-groove weld. The NRC staff presented this position in the proposed rule to mandate upper head inspections in accordance with ASME Code Case N-729-1. During the public comment period, several stakeholders noted hardships in performing this examination, and some stakeholders requested the option of performing a vOlumetric leak path assessment which would provide a similar defense-in-depth inspection to detect leakage through the J-groove weld. The staff found the stakeholder's request had merit and amended the final rule. However, due to the question regarding the effectiveness of the examination technique raised during the development of ASME Code Case N-729-1, the NRC staff included the requirement for a demonstrated volumetric leak path assessment in the final rule. On November 24,2008, the NRC staff held a public meeting with representatives from Nuclear Energy Institute and industry to discuss generic activities going forward to demonstrate the volumetric leak path inspection technique. | The NRC staff determined that surface examination of all associated penetration J-groove welds was necessary as a defense-in-depth approach to detect leakage through the J-groove weld. The NRC staff presented this position in the proposed rule to mandate upper head inspections in accordance with ASME Code Case N-729-1. During the public comment period, several stakeholders noted hardships in performing this examination, and some stakeholders requested the option of performing a vOlumetric leak path assessment which would provide a similar defense-in-depth inspection to detect leakage through the J-groove weld. The staff found the stakeholder's request had merit and amended the final rule. However, due to the question regarding the effectiveness of the examination technique raised during the development of ASME Code Case N-729-1, the NRC staff included the requirement for a demonstrated volumetric leak path assessment in the final rule. On November 24,2008, the NRC staff held a public meeting with representatives from Nuclear Energy Institute and industry to discuss generic activities going forward to demonstrate the volumetric leak path inspection technique. | ||
A meeting summary with presentation slides is available in ADAMS under document accession number ML090560434. | A meeting summary with presentation slides is available in ADAMS under document accession number ML090560434. |
Revision as of 14:43, 14 October 2018
ML090770034 | |
Person / Time | |
---|---|
Site: | Palisades ![]() |
Issue date: | 04/07/2009 |
From: | James L M Plant Licensing Branch III |
To: | Entergy Nuclear Operations |
Chawla M L, NRR/DORL, 415-8371 | |
References | |
TAC ME0606 | |
Download: ML090770034 (5) | |
Text
UNITED NUCLEAR REGULATORY WASHINGTON, D.C. 20555-0001 Apri 1 7, 2009 Vice President, Operations Entergy Nuclear Operations, Inc. Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530 PALISADES NUCLEAR PLANT -EVALUATION OF RELIEF REQUEST TO PERFORM VOLUMETRIC LEAK PATH ASSESSMENT OF REACTOR PRESSURE VESSEL UPPER HEAD PENETRATION NOZZLE (TAC NO. ME0606)
Dear Sir or Madam:
By letter dated February 6, 2009 (Agencywide Document Access and Management System (ADAMS) Accession No. ML090370840), Entergy Nuclear Operations, Inc. (the licensee), requested U.S. Nuclear Regulatory Commission (NRC) authorization for relief from the requirements of Title 10 of the Code of Federal Regulations (CFR) 50.55a(g)(6)(ii)(D)(3) for the 2009 spring refueling outage at Palisades Nuclear Plant (PNP). The submittal requests relief from the requirement to perform an NRC approved demonstrated volumetric leak path assessment of each reactor pressure vessel (RPV) upper head penetration nozzle. The relief request proposes an alternative to use a previously NRC authorized volumetric leak path technique used under the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004, which was revoked by rulemaking dated September 10, 2008 (73 FR 52742). The NRC staff has reviewed the licensee's relief request Nondestructive Examination-Leak Path. On the basis of the information submitted, the staff concludes that the proposed alternative provides reasonable assurance of structural integrity of the RPV upper head and implementation of additional requirements would result in hardship without a compensating increase in the level of quality and safety. Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the staff authorizes this alternative for the 2009 spring refueling outage at PNP.
Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ UNITED NUCLEAR REGULATORY WASHINGTON, D.C.
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION VOLUMETRIC LEAK PATH ASSESSMENT ENTERGY NUCLEAR OPERATIONS, INC. RELIEF REQUEST FOR PALISADES NUCLEAR PLANT DOCKET NUMBER 50-255
1.0 INTRODUCTION
By letter dated February 6,2009, Entergy Nuclear Operations, Inc. (the licensee), requested U.S. Nuclear Regulatory Commission (NRC) authorization for relief from the requirements of Title 10 of the Code of Federal Regulations (CFR) 50.55a(g)(6)(ii)(D)(3) for the 2009 spring refueling outage at Palisades Nuclear Plant (PI'JP). The submittal requests relief from the requirement to perform an NRC approved demonstrated volumetric leak path assessment of each reactor pressure vessel (RPV) upper head penetration nozzle. The relief request proposes an alternative to use a previously NRC authorized volumetric leak path technique used under the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004, which was revoked by rulemaking dated September 10, 2008 (73 FR 52742).
2.0 REGULATORY EVALUATION
Title 10 of the CFR 50.55a(g)(6)(ii) states that the Commission may require the licensee to follow an augmented inservice inspection program for systems and components for which the Commission deems that added assurance of structural reliability is necessary.
Under this section, 10 CFR 50.55a(g)(6)(ii)(D) defines the requirements for reactor vessel head inspections.
Title 10 of the CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the NRC if: (i) the proposed alternatives would provide an acceptable level of quality and safety, or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The licensee, in accordance with 10 CFR 50.55a(a)(3)(ii), has requested relief from the demonstrated volumetric leak path inspection requirements of 10 CFR 50.55a(g)(6)(ii)(D)(3).
3.0 TECHNICAL
EVALUATION
3.1 Component
for Which Relief Was Requested There are 53 American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Class 1 vessel head penetration nozzles and associated welds identified by item number B4.20 of Code Case N-729-1 , Table 1. Enclosure
-2 3.2 Regulatory Requirement Title 10 of the CFR 50.55a(g)(6)(ii)(D)(3) requires, in part, a licensee to perform a demonstrated volumetric or surface leak path assessment through all vessel head penetration nozzle J-groove welds. 3.3 Proposed Alternative The licensee's proposed alternative is to perform a vOlumetric leak path inspection using the same techniques used to satisfy the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004. 3.4 Licensee's Basis The licensee notes that while industry has initiated efforts to accomplish a generic demonstration of the volumetric leak path assessment technique, the extent of remaining tasks will likely preclude successful completion in time to support the upcoming spring 2009 refueling outage at PNP. The licensee also states that performance of alternative surface examinations of each J-groove weld would be a significant hardship due to the personnel exposure associated with the inspections in a locked high radiation area and high contamination area without a compensating increase in the level of quality and safety. The licensee provided details on several enhancements to the volumetric leak path inspection technique which have been developed over the past five years, including the previously completed baseline inspection data available for assessment comparison.
3.5 Staff
Evaluation ASME Code Case N-729-1 did not include a vOlumetric leak path assessment as part of the long term re-inspection plans for reactor pressure vessel upper head penetration nozzles and their associated welds. The NRC staff believed this omission was, in part, due to the difficulty for ASME members to establish qualification requirements for this inspection technique.
The NRC staff determined that surface examination of all associated penetration J-groove welds was necessary as a defense-in-depth approach to detect leakage through the J-groove weld. The NRC staff presented this position in the proposed rule to mandate upper head inspections in accordance with ASME Code Case N-729-1. During the public comment period, several stakeholders noted hardships in performing this examination, and some stakeholders requested the option of performing a vOlumetric leak path assessment which would provide a similar defense-in-depth inspection to detect leakage through the J-groove weld. The staff found the stakeholder's request had merit and amended the final rule. However, due to the question regarding the effectiveness of the examination technique raised during the development of ASME Code Case N-729-1, the NRC staff included the requirement for a demonstrated volumetric leak path assessment in the final rule. On November 24,2008, the NRC staff held a public meeting with representatives from Nuclear Energy Institute and industry to discuss generic activities going forward to demonstrate the volumetric leak path inspection technique.
A meeting summary with presentation slides is available in ADAMS under document accession number ML090560434.
During the meeting industry representatives provided a presentation on advances in the volumetric leak path
-assessment technique over the past five years. The industry described a living program being run by both major inspection vendors to ensure effective examinations were being performed.
The industry representatives noted that recent concerns raised by the Office of Nuclear Reactor Research contractors, including questions regarding the interpretation of signal data, were being incorporated into a generic standards document for use by inspectors in the field. The industry representatives explained that since baseline examinations have been performed on all RPV upper head penetration nozzles throughout the United States pressurized water reactor fleet, that there would be significant enhancement in analyzing future inspection results. The industry representatives also stated their intention to provide details of each of these enhancements to the NRC in a guideline in the spring of 2009, but that this information was already being put into use by vendors in the field. Further, industry representatives discussed activities to complete an industry generic demonstration of the volumetric leak path technique, but they did not expect to complete the project in time to support the spring 2009 outage at PNP. Surface examination of the entire wetted surface of each J-groove weld is an option for the licensee under the requirements of 10 CFR 50.55a(g)(6)(ii)(D)(3).
However, the licensee has noted that these inspections would be required in a high radiation area of nearly 3 rem/hour and a contact dose rate of 5 rem/hour.
Further the design of the nozzles prevents easy access and limits the ability to deploy remote tooling. This would require additional manual activity within these high radiation areas. The NRC staff finds that the licensee has provided sufficient plant specific information regarding the weld surface condition and personnel radiological dose exposure that the NRC staff concludes that compliance with these provisions would constitute a hardship upon the licensee.
Given this hardship and the delay in implementation of a generic demonstration of the volumetric leak path technique, the licensee's alternative is to implement a volumetric leak path assessment of each penetration nozzle and associated weld in accordance with the previous requirements of the First Revised NRC Order EA-03-009, additionally being informed by the current activities to perform a generic demonstration of the inspection technique.
The NRC staff finds that given the licensee's hardship to perform a surface leak path assessment, this volumetric leak path assessment technique, as described in the licensee's proposed alternative, currently provides a best effort defense-in-depth inspection beyond the required bare metal visual inspection to identify leakage through each J-groove weld. Further, the NRC staff concludes that the licensee's proposed alternative provides reasonable assurance of public health and safety, and compliance with the additional requirements would result in hardship without a compensating increase in the level of quality and safety.
4.0 CONCLUSION
The NRC staff has reviewed the licensee's basis and concludes that the licensee's proposed alternative provides reasonable assurance of public health and safety, and compliance with the additional requirements would result in a hardship without a compensating increase in the level of quality and safety. Therefore, in accordance with 10 CFR 50.55a(a)(3)(ii) the NRC authorizes the licensee's proposed alternative for the spring 2009 refueling outage at PNP. All other 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.
April 7, 2009 Vice President, Operations Entergy Nuclear Operations, Inc. Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530
SUBJECT:
PALISADES NUCLEAR PLANT -EVALUATION OF RELIEF REQUEST TO PERFORM VOLUMETRIC LEAK PATH ASSESSMENT OF REACTOR PRESSURE VESSEL UPPER HEAD PENETRATION NOZZLE (TAC NO. ME0606)
Dear Sir or Madam:
By letter dated February 6, 2009(Agencywide Document Access and Management System (ADAMS) Accession No. ML090370840), Entergy Nuclear Operations, Inc. (the licensee), requested U.S. Nuclear Regulatory Commission (NRC) authorization for relief from the requirements of Title 10 of the Code of Federal Regulations (CFR) 50.55a(g)(6)(ii)(D)(3) for the 2009 spring refueling outage at Palisades Nuclear Plant (PNP). The submittal requests relief from the requirement to perform an NRC approved demonstrated vOlumetric leak path assessment of each reactor pressure vessel (RPV) upper head penetration nozzle. The relief request proposes an alternative to use a previously NRC authorized volumetric leak path technique used under the requirements of the First Revised NRC Order EA-03-009, dated February 20, 2004, which was revoked by rulemaking dated September 10, 2008 (73 FR 52742). The NRC staff has reviewed the licensee's relief request Nondestructive Examination-Leak Path. On the basis of the information submitted, the staff concludes that the proposed alternative provides reasonable assurance of structural integrity of the RPV upper head and implementation of additional requirements would result in hardship without a compensating increase in the level of quality and safety.
Therefore, pursuant to 10 CFR 50.55a(a)(3)(ii), the staff authorizes this alternative for the 2009 spring refueling outage at PNP. IRA! Lois M. James, Chief Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-255
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ DISTRIBUTION PUBLIC LPL3-1 r/f RidsAcrsAcnw_MailCTR Resource RidsNrrDirsltsb Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl3-1 Resource RidsNrrPMPalisades Resource RidsNrrLABTully Resource RidsOgcRp Resource RidsRgn3MailCenter Resource S. Campbell, R-III ADAMS Accession No ML090770034