ML14350B371
| ML14350B371 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 12/16/2014 |
| From: | Jennivine Rankin Plant Licensing Branch III |
| To: | Miksa J Entergy Nuclear Operations |
| References | |
| TAC MF4569 | |
| Download: ML14350B371 (4) | |
Text
NRR-PMDAPEm Resource From: Rankin, Jennivine Sent: Tuesday, December 16, 2014 1:32 PM To: MIKSA, JAMES P (jmiksa@entergy.com); ERICKSON, JEFFREY S (JERICKS@entergy.com)
Cc: Venkataraman, Booma
Subject:
Request for Additional Information - Palisades Nuclear Plant 2014 Steam Generator Tube Inspection Report (MF4569)
Attachments: Palisades-Steam Gen tube inspection final RAIs.docx Mr. Miksa and Mr. Erickson, By letter dated August 5, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14218A548), Entergy Nuclear Operations, Inc. (ENO, the licensee) submitted information summarizing the results of the 2014 steam generator tube inspections performed at Palisades Nuclear Plant. These inspections were performed during refueling outage 23 in January - February, 2014. In a letter dated April 30, 2014 (ADAMS Accession No. ML14093A243), the U.S. Nuclear Regulatory Commission (NRC) staff summarized a conference call with the licensee regarding the 2014 steam generator tube inspections.
A draft request for information (RAI) was sent to you on December 8, 2014. A clarification telephone call was held on December 16, 2014. It was agreed that ENO will respond to these RAIs by March 31, 2015. Please treat this e-mail as transmittal of formal RAIs. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-1530 or via email at Jennivine.rankin@nrc.gov.
- Thanks, Jennie Jennie Rankin, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation 1
Hearing Identifier: NRR_PMDA Email Number: 1768 Mail Envelope Properties (Jennivine.Rankin@nrc.gov20141216133100)
Subject:
Request for Additional Information - Palisades Nuclear Plant 2014 Steam Generator Tube Inspection Report (MF4569)
Sent Date: 12/16/2014 1:31:34 PM Received Date: 12/16/2014 1:31:00 PM From: Rankin, Jennivine Created By: Jennivine.Rankin@nrc.gov Recipients:
"Venkataraman, Booma" <Booma.Venkataraman@nrc.gov>
Tracking Status: None "MIKSA, JAMES P (jmiksa@entergy.com)" <jmiksa@entergy.com>
Tracking Status: None "ERICKSON, JEFFREY S (JERICKS@entergy.com)" <JERICKS@entergy.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 1310 12/16/2014 1:31:00 PM Palisades-Steam Gen tube inspection final RAIs.docx 28445 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:
Recipients Received:
REQUEST FOR ADDITIONAL INFORMATION REGARDING THE JANUARY-FEBRUARY 2014 STEAM GENERATOR TUBE INSPECTIONS PALISADES NUCLEAR PLANT DOCKET NO. 50-255 By letter dated August 5, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14218A548), Entergy Nuclear Operations, Inc. (the licensee) submitted information summarizing the results of the 2014 steam generator tube inspections performed at Palisades Nuclear Plant. These inspections were performed during refueling outage 23 in January-February, 2014. In a letter dated April 30, 2014 (ADAMS Accession No. ML14093A243), the U.S. Nuclear Regulatory Commission (NRC) staff summarized a conference call with the licensee regarding the January-February 2014 steam generator tube inspections. The NRC staff has reviewed the information provided and determined that additional information is required in order to complete its review.
- 1. There are several instances in the report where it does not appear the results were properly communicated and/or the technical details were not fully understood. Please clarify the following:
- a. Item g on page 3 of 156 indicates, in part, that the results of the condition monitoring are provided in Table 6. Table 6 does not have the indicated information; however, it appears the results are provided further down on the page. In addition, on page 3 of 156 there is a discussion about the accident induced leakage performance criteria. The following statements were made:
Leakage did not exceed the 0.3 gallon per minute (gpm) accident induced leakage limit. Primary-to-secondary leak rate measured using condenser off-gas (Xenon-135) was measured at 0.0003 gpm for the start of operating cycle 23, finished at <0.0001 gpm and had a decreasing trend over the cycle.
No leakage was predicted for either operating or accident conditions for the 2012 to 2014 operating cycle due to observed SG tube degradation in the 2014 refueling outage. All plugs installed were Alloy 690 in the Palisades SGs post-operation and are either Westinghouse ribbed mechanical plugs or Areva mechanically rolled plugs. The Westinghouse plugs are leak-tight for all plant conditions. The Areva roll expansion provides a leak-limiting seal between the plug and tube wall.
Accident induced leakage is the primary-to-secondary leakage that occurs during a design basis accident. As a result, this value is calculated based, in part, on inspection results. Other sources of accident induced primary-to-secondary leakage are leakage past plugs and other repairs. In addition, implementation of alternate repair criteria may also be a source of accident induced leakage particularly when the criteria eliminates the need to inspect certain locations of the tube.
- 1) Therefore, please clarify whether or not the first sentence in the above quote was intended to indicate that the calculated leakage from all potential sources of accident induced leakage did not exceed the 0.3 gpm accident induced leakage limit.
- 2) Please confirm that the second sentence in the above quote was simply a statement regarding operational leakage.
- 3) Please clarify that the third sentence in the above quote only includes the contribution to the accident induced leakage associated with the observed degradation mechanisms.
- 4) Please confirm that the accident induced leakage associated with the Areva roll expanded plugs (i.e., leak limiting plugs) was combined with the accident induced leakage associated with implementation of the C* alternate repair criteria and the accident induced leakage from all other sources (presumably zero for the observed degradation mechanisms based on the third sentence in the above quote) for comparison against the 0.3 gpm accident induced leakage limit.
- b. Please clarify that Tables 4A, 4B, and 4C provide all of the service induced indications.
If not, please provide any service induced indications not included in those tables (e.g.,
the wear indications associated with possible loose parts). Please ensure the location, orientation (if linear), and measured sizes (if available) of all service induced indications are provided (since it does not appear that such information was provided for some of the indications such as wear associated with possible loose parts). The staff notes that the statements that Table 4A provides the location and measured sizes of service induced indications and the majority are a result of axial and circumferential outside diameter stress corrosion cracking indications is misleading since Table 4A only provides a subset of service induced indications and only includes axial and circumferential outside diameter stress corrosion cracking indications.
- c. Please confirm that the tubes in SG A row 134, column 75 and SG A row 133, column 74 had wear attributed to a loose part since the last sentence indicates that these tubes had no wear indications from the loose part. It was not clear which tubes were being referred to by the reference to these tubes.
- d. The headings for the tables on pages 152 through 156 reference the 2012 refueling outage. Please clarify.
- 2. Please discuss the nature of the restriction in the tube in row 3, column 112 in steam generator E-50B. For example, has the condition changed with time?
- 3. Please summarize the number of indications of wear detected and how many tubes are affected (e.g., 10 indications of wear at the eggcrate supports in 8 tubes, 35 indications of wear at the diagonal bars in 22 tubes, etc.).
- 4. Please discuss whether an inspection of the plugs was performed. If so, please discuss the results of the inspection (e.g., all plugs were present in the proper location and no degradation was observed).