RS-14-166, Response to NRC Request for Additional Information, Set 25 Dated May 19, 2014, Related to the Byron Station, Units 1 and 2 and Braidwood Station, Units 1 and 2, License Renewal Application

Response to NRC Request for Additional Information, Set 25 Dated May 19, 2014, Related to the Byron Station, Units 1 and 2 and Braidwood Station, Units 1 and 2, License Renewal Application

ML14157A151
Person / Time
Site:	Byron, Braidwood
Issue date:	06/05/2014
From:	Gallagher M Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-14-166
Download: ML14157A151 (8)

Text

10 CFR 50 10 CFR 51 10 CFR 54 RS-14-166 June 5, 2014 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Response to NRC Request for Additional Information, Set 25, dated May 19, 2014, related to the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application

References:

1. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon) to NRC Document Control Desk, dated May 29, 2013, "Application for Renewed Operating Licenses"

2. Letter from Lindsay R. Robinson, US NRC to Michael P. Gallagher, Exelon, dated May 19, 2014, "Request for Additional Information for the Review of the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application, Set 25 (TAC NOS. MF1879, MF1880, MF1881, and MF1882)"

In Reference 1, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 (BBS). In Reference 2, the NRC requested additional information to support staff review of the LRA.

Enclosure A contains the response to this request for additional information.

Enclosure B contains updates to sections of the LRA affected by the response.

There are no new or revised regulatory commitments contained in this letter.

June 5, 2014 U.S. Nuclear Regulatory Commission Page 2 If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on _tJ_6_-_t>_S'_- Z. "I</-

Respectfully,

~~

Vice President - License Renewal Projects Exelon Generation Company, LLC

Enclosures:

A Response to Request for Additional Information B. Updates to affected LRA sections cc: Regional Administrator - NRC Region Ill NRC Project Manager (Safety Review), NRR-DLR NRC Project Manager (Environmental Review), NRR-DLR NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station NRC Project Manager, NRR-DORL-Braidwood and Byron Stations Illinois Emergency Management Agency - Division of Nuclear Safety

RS-14-166 Enclosure A Page 1 of 3 Enclosure A Byron and Braidwood Stations (BBS), Units 1 and 2 License Renewal Application Response to Request for Additional Information RAI 3.5.2.3.15-1

RS-14-166 Enclosure A Page 2 of 3 RAI 3.5.2.3.15-1 Applicability:

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

Background:

License renewal application (LRA) Table 3.5.2-15, Structural Commodity Group: Structural Commodity Group Summary of Aging Management Evaluation, includes two plant-specific aging management review (AMR) items: lead (Pb) penetrations seals that are exposed to (1) indoor uncontrolled air and (2) indoor air with borated water leakage. The LRA identifies that there are no aging effects that are applicable to the exposure of these seals to these environments. The AMR items cite generic Note J, which states that neither the component nor the materials and environment are evaluated in the Generic Aging Lessons Learned (GALL)

Report. The AMR items also a reference a plant-specific Note 9 on the AMR table, which states:

This material and environment applies to the lead wool used for packing penetrations for radiation shielding. Operating experience has shown the air-indoor uncontrolled and air with borated water leakage environments to contain insignificant quantities of moisture, humidity, condensation, and contaminants during normal operation. Therefore, there are no aging effects associated with the lead material in the normal dry, air - indoor uncontrolled and air with borated water leakage environments.

Per Title 10 of the Code of Federal Regulations (10 CFR) 54.21(a)(3), the licensee is required to demonstrate that the effects of aging will be adequately managed during the period of extended operation for each structure or component that is scoped in for license renewal in accordance with the requirements in 10 CFR 54.4 and has been screened in for an AMR in accordance with the requirement in 10 CFR 54.21(a)(1). Since the applicant has identified air with borated water leakage environment as an applicable environment for these seal materials, the applicant must evaluate the seal materials applicable aging effects under exposure to the both containment air environment and postulated sources of borated water.

Issue:

The applicable plant-specific AMR item in LRA Table 3.5.2-15 identifies the indoor air with borated water leakage environment as an applicable environment for these containment penetration seals. However, plant-specific Note 9 for the AMR item only addressed the impacts of moisture, humidity, condensation and impurity contaminants in the containment air would have on the lead (Pb) seal materials (i.e., lead packing wool). The plant-specific Note for the AMR item did not address the impact that borated water would have on these seal materials if the borated water were to leak onto these penetration seal materials. It is not clear to the staff whether the aging effect of loss of material due to boric acid corrosion would not be considered if the lead packing wool is exposed to an indoor air with borated water leakage environment.

RS-14-166 Enclosure A Page 3 of 3 Request:

Provide the technical basis as to why loss of material due to boric acid corrosion of the lead packing wool used in the penetration seals has not been identified as an aging effect requiring management for the applicable AMR item in LRA Table 3.5.2-15. Amend the application, accordingly, if it is determined that loss of material due to postulated boric acid corrosion is an applicable aging effect requiring management for these penetration seals.

Exelon Response:

The lead (Pb) material (i.e., lead packing wool) identified for penetration seals in LRA Table 3.5.2-15 was included to account for a description in UFSAR Section 12.3.2.3 related to the potential use of lead wool as one of a series of higher density materials that might be used for penetration shielding. However, based on further review of plant drawings and design specifications, as well as a review of over 10 years of operating experience at Byron and Braidwood, no instances were identified of lead packing wool used as a penetration seal material. As a result, LRA Section 3.5.2.1.15 is revised to remove lead material and LRA Table 3.5.2-15 is revised to remove the lead material for penetration seals with an intended function of Shielding, as shown in Enclosure B of this letter.

During this review of penetration seals, it was identified that elastomeric penetration seals in LRA Table 3.5.2-15 should also have included an intended function of Shielding. Therefore, LRA Table 3.5.2-15 is also revised to add elastomer material to penetration seals with a Shielding intended function, as shown in Enclosure B of this letter.

RS-14-166 Enclosure B Page 1 of 3 Enclosure B Byron and Braidwood Stations, Units 1 and 2 License Renewal Application (LRA) updates resulting from the response to the following RAI:

RAI 3.5.2.3.15-1 Note: To facilitate understanding, the original LRA pages have been repeated in this Enclosure, with revisions indicated. Existing LRA text is shown in normal font. Changes are highlighted with bolded italics for inserted text and strikethroughs for deleted text.

RS-14-166 Enclosure B Page 2 of 3 As a result of the response to RAI 3.5.2.3.15-1 provided in Enclosure A of this letter, LRA Section 3.5.2.1.15, Structural Commodity Group, page 3.5-19, is revised as shown below.

Changes are highlighted with strikethroughs for deleted text.

3.5.2.1.15 Structural Commodity Group Materials The materials of construction for the Structural Commodity Group components are:

Aluminum Aluminum Bolting Calcium Silicate Carbon Steel Carbon and Low Alloy Steel Bolting Ceramic Fiber Elastomer Fiberglass Foamed Plastic Galvanized Steel Galvanized Steel Bolting Glass Grout Lead Mineral Fiber PVC Polymers Stainless Steel Stainless Steel Bolting

RS-14-166 Enclosure B Page 3 of 3 As a result of the response to RAI 3.5.2.3.15-1 provided in Enclosure A of this letter, LRA Table 3.5.2-15, Structural Commodity Group, pages 3.5-256 and 3.5-263, is revised as shown below. Changes are highlighted with bolded italics for inserted text and strikethroughs for deleted text.

Table 3.5.2-15 Structural Commodity Group (Continued)

Component Intended Material Environment Aging Effect Aging Management NUREG-1801 Table 1 Item Notes Type Function Requiring Programs Item Management Penetration Seals Shielding Elastomer Air - Indoor Loss of Sealing Structures Monitoring III.A6.TP-7 3.5.1-72 A Uncontrolled (B.2.1.34)

Air with Borated Loss of Sealing Structures Monitoring III.A6.TP-7 3.5.1-72 A Water Leakage (B.2.1.34)

Grout Air - Indoor Cracking, Loss of Bond, Structures Monitoring III.A3.TP-26 3.5.1-66 A, 8 Uncontrolled and Loss of Material (B.2.1.34)

(Spalling, Scaling)

Air with Borated Water Cracking, Loss of Bond, Structures Monitoring III.A3.TP-26 3.5.1-66 A, 8 Leakage and Loss of Material (B.2.1.34)

(Spalling, Scaling)

Lead Air - Indoor None None J, 9 Uncontrolled Air with Borated Water None None J, 9 Leakage Plant Specific Notes: (continued)

9. Not Used. This material and environment applies to the lead wool used for packing penetrations for radiation shielding. Operating experience has shown the air-indoor uncontrolled and air with borated water leakage environments to contain insignificant quantities of moisture, humidity, condensation, and contaminants during normal operation. Therefore, there are no aging effects associated with the lead material in the normally dry, air - indoor uncontrolled and air with borated water leakage environments.