ML14140A385
| ML14140A385 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 05/28/2014 |
| From: | Robinson L License Renewal Projects Branch 1 |
| To: | Exelon Generation Co |
| Robinson L, 415-4115 | |
| References | |
| TAC MF1879, TAC MF1880, TAC MF1881, TAC MF1882 | |
| Download: ML14140A385 (8) | |
Text
May 28, 2014 LICENSEE: Exelon Generation Company, LLC FACILITY: Byron Station, Units 1 and 2 Braidwood Station, Units 1 and 2
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE CALL HELD ON MAY 15, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION, SET 27, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION AND RESPONSES FOR REQUEST FOR ADDITIONAL INFORMATION B.2.1.30-3 AND B.2.1.29-1, DATED APRIL 17, 2014 (TAC NOS. MF1879, MF1880, MF1881, AND MF1882)
The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Company, LLC (Exelon or the applicant), held a telephone conference call on May 15, 2014, to discuss and clarify the staffs draft request for additional information (DRAI),
Set 27, concerning the Byron Station, Units 1 and 2, and the Braidwood Station, Units 1 and 2, license renewal application. The telephone conference call was useful in clarifying the intent of the staffs DRAIs.
In addition, the staff discussed the responses for request for additional information (RAI)
B.2.1.30-3 and RAI B.2.1.29-1, dated April 17, 2014. Specifically, for the response to RAI B.2.1.30-3, the staff requested that the applicant consider revising the updated final safety analysis report (UFSAR) supplement associated with the ASME Section XI, Subsection IWL with certain information provided in the RAI responses. The applicant agreed to update the UFSAR supplement accordingly. With regard to the response to RAI B.2.1.29-1, the staff requested clarifying information, which the applicant provided.
provides a listing of the participants, and Enclosure 2 contains a listing of the DRAIs discussed with the applicant, including a brief description on the status of the items. The applicant had an opportunity to comment on this summary.
/RA Richard Plasse for/
Lindsay Robinson, Project Manager Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket Nos. 50-454, 50-455, 50-456, and 50-457
Enclosures:
- 1. List of Participants
- 2. List of Draft Request for Additional Information cc w/encls: Listserv
ML14140A385 *concurred via email OFFICE LA:DLR* PM:RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME IKing LRobinson (RPlasse for) YDiazSanabria LRobinson (RPlasse for)
DATE 5/28/14 5/28/14 5/28/14 5/28/14 TELEPHONE CONFERENCE CALL BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS May 15, 2014 PARTICIPANTS AFFILIATIONS Lindsay Robinson U.S. Nuclear Regulatory Commission (NRC)
Alice Erickson NRC Sam Cuadrado NRC Angela Buford NRC William Holston NRC John Hufnagel Exelon Generating Company, LLC (Exelon)
Al Fulvio Exelon Albert Piha Exelon Casey Muggleston Exelon Jim Annett Exelon Paul Cervenka Exelon Don Warfel Exelon Ralph Wolen Exelon Don Brindle Exelon ENCLOSURE 1
DRAFT REQUEST FOR ADDITIONAL INFORMATION BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION May 15, 2014 The U.S. Nuclear Regulatory Commission (NRC or the staff) and representatives of Exelon Generation Company, LLC (Exelon or the applicant), held a telephone conference call on May 15, 2014, to discuss and clarify the following draft request for additional information (DRAI),
Set 27, concerning the Byron Station, Units 1 and 2, and the Braidwood Station, Units 1 and 2, license renewal application (LRA).
DRAI B.2.1.16-1a Applicability:
Byron Station (Byron) and Braidwood Station (Braidwood), all units
Background:
The applicants response, dated March 13, 2014, to Request 1 for request for additional information (RAI) B.2.1.16-1 states that the Fire Water System program will be enhanced to include non-destructive examinations (NDE) capable of detecting internal flow blockage (e.g.,
digital radiography) or internal visual inspections. The response also states that inspections will be performed by opening a flushing connection at the end of one [emphasis added by NRC]
main in each structure containing in-scope water-based fire suppression systems.
Issue:
The staff notes that the National Fire Protection Association (NFPA) 25, Section 14.2.2, requires an internal inspection of every other wet pipe system (in buildings with multiple wet pipe systems) and that the alternate systems (not inspected during the previous inspection) be inspected during the next inspection. Since the response only stated that one main in each structure will be opened, it is not clear whether there are multiple wet pipe systems in any of the structures containing in-scope fire water systems and, if so, whether all wet pipe systems will be inspected as stated in NFPA 25.
The staff also notes that LR-ISG-2012-02 AMP XI.M27 Table 4a limits the alternative NDE methods, which are permitted by NFPA 25, Sections 14.2.1.1 and 14.3.2.3, to those that can ensure that flow blockage will not occur. Because of its similarity to raw water applications in fire water systems, the staff further notes that the Electric Power Research Institute (EPRI)
TR-102063, Guide for the Examination of Service Water System Piping, cites radiography as an effective NDE method capable of measuring the extent of occlusions or biofouling conditions.
Although the EPRI guide includes ultrasonic testing, the discussion of its capability is limited to wall thickness measurement. Because the response proposes digital radiography as an example and not the only method, it was not clear how other NDE methods, if used, would be shown to ensure that flow blockage will not occur demonstrated to be capable of detecting flow blockage.
ENCLOSURE 2
Request:
- 1. State whether there are multiple wet pipe systems in any of the structures containing in-scope fire water systems and, if there are, confirm that internal inspections will be conducted as stated in NFPA 25, Section 14.2.2, or provide the basis for not conducting the internal inspections on every other wet pipe system every 5 years.
- 2. If NDE methods other than digital radiography are used, state how the other NDE methods will be demonstrated to be capable of detecting flow blockage.
Discussion: The applicant requested clarity on the staffs concern. The applicant requested the last sentence of the issue section be edited as shown by the strikethrough and underlined portion of the text. This question will be sent as part of the formal request titled: RAI B.2.1.16-1a.
DRAI B.2.1.16-1b Applicability:
Byron and Braidwood
Background:
RAI B.2.1.16-1 requested that either: (a) it is confirmed that follow-up volumetric examinations will be conducted whenever internal fire water system visual inspections detect surface irregularities indicative of material loss below nominal wall thickness [emphasis added by NRC]; or (b) the bases be provided for why the visual inspection alone will provide reasonable assurance that the current licensing basis intended functions of in-scope components will be met.
The applicants response, dated March 13, 2014, to RAI B.2.1.16-1 states that noticeable deposits in excess of a normal oxide layer, which could be indicative of wall loss below nominal, are documented; inspection results that are unusual or unexpected (e.g., surface irregularities indicative of significant loss of material [emphasis added by NRC]) are documented in the corrective action program for evaluation; and, based on the results of the evaluation, appropriate corrective actions are taken including repair, replacement, or follow-up volumetric examinations to quantify the remaining wall thickness, as applicable.
Issue:
The staff noted that LR-ISG-2012-02 AMP XI.M27 states that, [i]nternal visual inspections used to detect loss of material are capable of detecting surface irregularities that could be indicative of wall loss below nominal pipe wall thickness due to corrosion and corrosion product deposition. Where such irregularities are detected, followup volumetric examinations are performed. Based on the wording surface irregularities indicative of significant loss of material, it is not clear to the staff that surface irregularities indicative of wall loss below nominal would be documented in the corrective action program. It is also not clear to the staff that volumetric wall thickness measurements would be conducted when visual inspection results reveal surface irregularities that could be indicative of wall loss below nominal pipe wall thickness.
Request:
- 1. State whether surface irregularities indicative of wall loss below nominal would be documented in the corrective action program.
- 2. State whether volumetric wall thickness measurements would be conducted when visual inspection results reveal surface irregularities that could be indicative of wall loss below nominal pipe wall thickness.
- 3. If not, state the basis for the portion(s) of the response that represent an exception to LR-ISG-2012-02 AMP XI.M27.
Discussion: The applicant requested clarity on the staffs concern. The applicant discussed their concern with the staffs position of using below nominal wall thickness as the basis for conducting follow-up inspections. The staff decided to keep the question as written and not make any edits. This question will be sent as part of the formal request titled: RAI B.2.1.16-1b.
DRAI 3.5.2.10-1
Background:
Title 10 of the Code of Federal Regulations (10 CFR) Part 54.21 (a)(3) states that for structures and components (SCs) subject to an aging management review (AMR) it shall be demonstrated that the effects of aging will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis (CLB) for the period of extended operation (PEO).
LRA Table 3.5.2-10, Main Steam & Auxiliary Feedwater Tunnels and Isolation Valve Rooms Summary of Aging Management Evaluation, states that polymer blowout panels exposed to air-indoor (uncontrolled) or air-outdoor will be managed for change in material properties by the Structures Monitoring Program. The AMR items cite generic note J, which states that neither the component nor the material and environment combination is evaluated in NUREG-1801, Generic Aging Lessons Learned (GALL) Report, Revision 2. The AMR items also cite plant specific note 1, which states that the blowout panels are constructed of extruded polystyrene.
Issue:
Although the scope of the Structures Monitoring Program has been enhanced to include inspection of blowout panels, the parameters monitored or inspected and acceptance criteria for this material have not been specified in the program elements. Unlike GALL Report aging management programs (AMPs) XI.M36, External Surfaces Monitoring of Mechanical Components and XI.M38, Inspection of Internal Surfaces in Miscellaneous Piping and Ducting Components, GALL Report AMP XI.S6, Structures Monitoring Program, does not include examples of inspection parameters for polymeric components. Based on the staffs review of this material exposed to an air-indoor and air-outdoor environment, the staff noted that at high temperatures, this material may begin to degrade. The staff does not have sufficient information to conclude that the visual inspections performed under the Structures Monitoring Program would identify a change in material properties, prior to a loss of intended function.
Request:
State how the visual inspections performed under the Structures Monitoring Program would identify a change in material properties for these components, and provide the acceptance criteria by which they would be evaluated.
Discussion: The applicant requested clarity on the staffs concern. No edits were proposed.
This question will be sent as part of the formal request titled: RAI 3.5.2.10-1.