ML14167A025

Summary of Telephone Conference Call Held on June 10, 2014, Between the U.S. Nuclear Regulatory Commission and Exelon Generation Company, LLC Concerning Draft Request for Additional Information, Set 33, Pertaining to the Byron and Braidwood

ML14167A025
Person / Time
Site:	Byron, Braidwood
Issue date:	06/24/2014
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: ML14167A025 (7)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 June 24, 2014 LICENSEE: Exelon Generation Company, LLC FACILITY: Byron Station, Units 1 and 2 Braidwood Station, Units 1 and 2

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON JUNE 10, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION, SET 33, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION (TAC NOS. MF1879, MF1880, MF1881, 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 June 10, 2014, to discuss and clarify the staffs draft request for additional information (DRAI),

Set 33, 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. 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/

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

ML14167A025 *concurred via email OFFICE LA:DLR* PM:RPB1:DLR BC:RPB1:DLR PM:RPB1:DLR NAME YEdmonds LRobinson YDiazSanabria LRobinson DATE 6/23/14 6/23/14 6/23/14 6/24/14

SUMMARY

OF TELEPHONE CONFERENCE CALL HELD ON JUNE 10, 2014, BETWEEN THE U.S. NUCLEAR REGULATORY COMMISSION AND EXELON GENERATION COMPANY, LLC CONCERNING DRAFT REQUEST FOR ADDITIONAL INFORMATION, SET 33, PERTAINING TO THE BYRON STATION AND BRAIDWOOD STATION, LICENSE RENEWAL APPLICATION (TAC NOS. MF1879, MF1880, MF1881, MF1882)

DISTRIBUTION EMAIL:

PUBLIC RidsNrrDlr Resource RidsNrrDlrRpb1 Resource RidsNrrDlrRarb Resource RidsNrrDlrRasb Resource RidsOgcMailCenter RidsNrrPMByron Resource RidsNrrPMBraidwood Resource LRobinson DMcIntyre, OPA EDuncan, RIII JBenjamin, RIII AGarmoe, RIII JMcGhee, RIII JRobbins, RIII VMitlyng, RIII PChandrathil, RIII

TELEPHONE CONFERENCE CALL BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2 LICENSE RENEWAL APPLICATION LIST OF PARTICIPANTS June 10, 2014 PARTICIPANTS AFFILIATIONS Lindsay Robinson U.S. Nuclear Regulatory Commission (NRC)

William Holston NRC John Hufnagel Exelon Generating Company, LLC (Exelon)

Al Fulvio Exelon Don Warfel Exelon Dylan Cimock Exelon Pete Tamburro Exelon Greg Lupia Exelon Alex Luga Exelon Ralph Wolen Exelon ENCLOSURE 1

DRAFT REQUEST FOR ADDITIONAL INFORMATION BYRON STATION, UNITS 1 AND 2, AND BRAIDWOOD STATION, UNITS 1 AND 2, LICENSE RENEWAL APPLICATION June 10, 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 June 10, 2014, to discuss and clarify the following draft request for additional information (DRAI), Set 33, concerning the Byron Station, Units 1 and 2, and the Braidwood Station, Units 1 and 2, license renewal application (LRA).

DRAI B.2.1.28-3b Applicability:

Byron Station (Byron) and Braidwood Station (Braidwood), all units

Background:

1. The response to RAI B.2.1.28-3a, dated May 15, 2014, stated that soil corrosion probes will not necessarily be installed at each cathodic protection survey test point; but rather, the soil corrosion probe assemblies will most often be installed away from existing cathodic protection test points. The response also stated that: selection of soil corrosion probe locations and utilization of the data will be subject to: (a) assistance in selection of the location(s) by NACE qualified cathodic protection experts; (b) location of the probes further from the impressed current anode bed than the buried pipe test point of interest; (c) evaluation of the difference in the respective locations between the soil corrosion probes and the existing test point by a NACE qualified cathodic protection expert to determine whether the difference in the relative data could be reasonably attributed to other significant site features (e.g., exposed large surface area tank bottoms, heavily congested areas of other buried piping, very large diameter pipes); and (d) cathodic protection effectiveness at the existing test point not being evaluated by use of data from the soil corrosion probes if the difference in the observed data could be attributed to adjacent site features. LRA Section B.2.1.28 was revised to cite NACE Internal Publication 05107, Report on Corrosion Probes in Soil or Concrete, as a reference to be considered during the application, installation, and use of the soil corrosion probes.

• Selection of soil corrosion probe locations and utilization of the data will be subject to assistance in selection of the location(s) by National Association of Corrosion Engineers (NACE) qualified cathodic protection experts.

• [g]enerally, both the soil corrosion probes and the permanent reference electrode are installed below-grade and in close proximity to the buried piping of interest.

• [i]n such situations, other adjacent convention test points exhibiting values less negative than -850mV could be evaluated, as applicable, in accordance with the criteria described above.

• A NACE qualified cathodic protection expert will evaluate the difference in the respective locations between the soil corrosion probes and the existing test point to determine whether the difference in the relative data could be reasonably ENCLOSURE 2

attributed to other significant site features (e.g., exposed large surface area tank bottoms, heavily congested areas of other buried piping, very large diameter pipes).

2. The response to RAI B.2.1.28-3a stated that soil corrosion probe data will only be used in locations where in-scope buried piping has been volumetrically examined.

Issue:

1. The staff noted that:

a. NACE offers four levels of qualification consisting of cathodic protection tester, cathodic protection technician, cathodic protection technologist, and cathodic protection specialist (NACE Courses CP 1 through CP 4). It is not clear to the staff what level of qualification will be required for individuals who determine locations of soil corrosion probes and the impact of localized site features.

b. Local soil conditions (e.g., moisture content, pH, resistivity) could be impactful.

For example, if the soil in the vicinity of the soil corrosion probe were less corrosive than at the buried pipe location of interest, the soil corrosion probe could under-predict the corrosion rate. The applicant did not address the impact of local soil conditions.

b. Given the use of the term generally in relation to the location of the installation of soil corrosion probes, it is not clear to the staff whether soil corrosion probes will be installed in close proximity to the buried piping of interest.

c. Based on its review of the response to RAI B.2.1.28-3a, the staff understands that a soil corrosion probe could be used to verify that effective cathodic protection has been provided to pipe segment locations remote from the probe.

The staff has the following concerns:

i. A NACE qualified cathodic protection expert will evaluate the impact of significant site features as they could affect cathodic protection effectiveness. However, the response did not state the factors that will be considered when evaluating the impact of local site features.

ii. The response did not state how local soil conditions (e.g., moisture content, pH, and resistivity) could be impactful. For example, if the soil in the vicinity of the soil corrosion probe were less corrosive than at other pipe segment locations, the soil corrosion probe could under-predict the corrosion rate at other points of interest along the pipe length.

NACE Internal Publication 05107 Section 3 recommends that the probe should be installed close to the pipe or structure. Appendix B to the NACE publication further recommends that the probe be installed 10 inches from the pipe. Beyond stating that probes will be located further from the impressed current anode bed than the buried pipe test point of interest, the applicant did not provide a basis for how locating the probes remote from the pipe location of interest would provide representative corrosion rates.

d. The applicant did not state the factors it will consider when evaluating the impact of local site features. NACE Internal Publication 05107 does not contain recommendations associated with the impact of local site features.

2. The staff noted that LRA Section B.2.1.28 was not revised to state that soil corrosion probe data will only be used in locations where in-scope buried piping has been volumetrically examined in conjunction with installation of the probes.

Request:

1. State: Please provide information to address the following issues:

a. The level of NACE cathodic protection qualification of the individuals involved in selecting soil corrosion probe locations and for determining the impact of localized site features

b. Whether soil corrosion probes will be installed in close proximity to the buried piping of interest, or state the basis for its location if installed remotely from the pipe of interest. how local soil conditions will be factored into use of the soil corrosion probe data

c. What factors will be considered when evaluating local site features including examples of how the factors would be applied.

d. How local soil conditions will be factored into use of the soil corrosion probe data.

the basis for how locating the probes remote from the pipe location of interest would provide representative corrosion rates In addition, make any applicable changes to LRA Section B.2.1.28.

2. Revise the Buried and Underground Piping program (LRA Section B.2.1.28) to state that soil corrosion probe data will only be used in locations where in-scope buried piping has been volumetrically examined in conjunction with installation of the probes.

Discussion: The applicant requested clarification on the staffs concern regarding the location of soil corrosion probes. The staff stated that the RAI response dated May 15, 2014, stated that soil corrosion probes and the permanent reference electrode are generally installed in close proximity to the buried piping of interest. The staffs concern regarding the effectiveness for the soil corrosion probes to provide accurate data for evaluating cathodic protection is that it needed to be located in close proximity to the pipe of interest. The applicant discussed their intention for soil corrosion probes location and provided examples of how they would address the impact of significant site features. Based on these explanations, the staff reviewed the RAI response dated May 15, 2014, and revised the DRAI B.2.1.28-3b. This question will be sent as a formal request titled: RAI B.2.1.28-3b.