RS-13-274, Response to NRC Requests for Additional Information, Set 5, Dated November 22, 2013, Related to License Renewal Application

Response to NRC Requests for Additional Information, Set 5, Dated November 22, 2013, Related to License Renewal Application

ML13353A627
Person / Time
Site:	Byron, Braidwood
Issue date:	12/19/2013
From:	Gallagher M Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-13-274, TAC MF1879, TAC MF1880, TAC MF1881, TAC MF1882
Download: ML13353A627 (23)

Text

10 CFR 50 10CFR51 10 CFR 54 RS-13-274 December 19, 2013 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 Requests for Additional Information, Set 5, dated November 22, 2013, related to the Braidwood Station, Units 1 and 2 and Byron 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 November 22, 2013, "Requests for Additional Information for the Review of the Byron Nuclear Station, Units 1 and 2, and Braidwood Nuclear Station, Units 1 and 2, License Renewal Application - Set 5 (TAC NOS. MF1879, MF1880, MF1881, AND MF1882)

In the Reference 1 letter, 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 the Reference 2 letter, the NRC requested additional information to support the staffs' review of the LRA.

Enclosure A contains the responses to these requests for additional information.

Enclosure B contains updates to sections of the LRA (except for the License Renewal Commitment List) affected by the responses.

December 19, 2013 U.S. Nuclear Regulatory Commission Page 2 Enclosure C provides an update to the License Renewal Commitment List (LRA Appendix A, Section A.5) associated with the response to RAI 2.1-3. There are no other new or revised regulatory commitments contained in this letter.

If you have any questions, please contact Mr. AI Fulvio, Manager, Exelon License Renewal, at 610-765-5936.

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

Executed on /2 -/? -,20/J Respectfu Ily,

~~L Michael P. Gallagher Vice President - License Renewal Projects Exelon Generation Company, LLC

Enclosures:

A: Responses to Requests for Additional Information B: Updates to affected LRA sections C: License Renewal Commitment List Changes cc: Regional Administrator - NRC Region III 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-13-274 Enclosure A Page 1 of 9 Enclosure A Byron and Braidwood Stations (BBS), Units 1 and 2 License Renewal Application Responses to Requests for Additional Information RAI 2.1-1 RAI 2.1-2 RAI 2.1-3

RS-13-274 Enclosure A Page 2 of 9 RAI 2.1-1 Applicability:

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

Background:

Title 10 of the Code of Federal Regulations (10 CFR) 54.4, Scope, states, in part:

(a) Plant systems, structures and components [SSCs] within the scope of this part are -

(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following functions -

(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.

Issue:

During the on-site scoping and screening methodology audit, the staff determined that the applicant had used a plant equipment database, which provides the component quality classification, as an information source to identify SSCs within the scope of license renewal.

However, the staff determined that not all components identified as safety-related in the plant equipment database were included with the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

Request:

The staff requests that the applicant provide a basis for not including components identified as safety-related within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

Indicate if the review concludes that use of the scoping methodology precluded the identification of SSCs that should have included within the scope of license renewal in accordance with 10 CFR 54.4(a). Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a) criteria. List any additional SSCs included within the scope of license renewal as a result of the review, and any structures and components (SCs) for which aging management reviews are performed.

Exelon Response:

During the scoping phase of the development of the Byron and Braidwood license renewal application the PassPort equipment database was used as one of many sources to identify systems and structures within the scope of license renewal. The PassPort equipment database was not used to make component level scoping determinations. The scoping methodology requires the identification of all systems that perform a safety-related function for inclusion within the scope of license renewal in accordance with scoping criterion 10 CFR 54.4(a)(1). Once the systems that perform a safety-related intended function are identified, the applicable system-level safety-related intended functions are determined based on a review of a number of sources including the UFSAR, design basis documents (e.g., engineering drawings, evaluations, and calculations), and the maintenance rule database. Based on the system safety-related intended functions, the components required for the system to perform the safety-

RS-13-274 Enclosure A Page 3 of 9 related intended functions are identified and included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

As a confirmatory method to ensure that all systems that perform a 10 CFR 54.4(a)(1) function are identified, the component-level safety classification field in the PassPort equipment database was reviewed. Per the Byron and Braidwood scoping methodology, if a system includes components that are identified as safety-related in the PassPort equipment database, then the system is included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1) with the following exceptions:

1. Systems with Safety-Related Boundary Components: If the safety-related components in an otherwise nonsafety-related system are required to support the safety-related function of an interfacing system, then the safety-related components may be reassigned to the interfacing system for license renewal aging management review. The remainder of the nonsafety-related system is not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1). This is consistent with the Byron and Braidwood scoping methodology in that license renewal systems are made up of station equipment grouped together by common function. For cases such as this, the specific components that are classified as safety-related are included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

2. Systems with Components with Incorrect PassPort Equipment Database Classifications:

In the process of the development of the license renewal application a limited number of discrepancies were identified related to the safety classification of individual components in the PassPort equipment database at Byron and Braidwood. During the review of the component level safety-classification field in PassPort, certain systems that are classified as nonsafety-related in other sources (e.g., UFSAR) were identified as containing a limited number of components that were classified as safety-related in the PassPort equipment database. The components identified during this review were then evaluated to determine if they perform any safety-related function. If the components do not perform a safety-related function, then the system was not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

All component level safety classification discrepancies identified during the development of the license renewal application have been entered into the corrective action program.

Components that have been identified as incorrectly classified as safety-related in the PassPort equipment database but do not perform or support any safety-related function are not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

3. Systems with Components with Conservative PassPort Equipment Database Classifications: As described in Section 3.1.1 of NEI 95-10, components that are not relied on to perform any safety-related function described in 10 CFR 54.4(a)(1) may be classified as safety-related because of plant-specific considerations and preferences.

Therefore, a component may not meet the requirements of 10 CFR 54.4(a)(1) although it is designated as safety-related for plant-specific reasons. If the only safety-related components in an otherwise nonsafety-related system are conservatively classified as safety-related but do not perform a safety-related function then the system would not be included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

RS-13-274 Enclosure A Page 4 of 9 Components that have been identified as conservatively classified as safety-related in the PassPort equipment database but do not perform or support any safety-related function are not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

Other than the exceptions stated above, the Byron and Braidwood scoping methodology requires all systems that include safety-related components be included within the scope of license renewal in accordance with scoping criterion 10 CFR 54.4(a)(1). The scoping methodology did not preclude the identification of any SSCs that should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a). No additional scoping evaluations have been performed to address the 10 CFR 54.4(a) criteria. No additional SSCs have been included within the scope of license renewal as a result of the review and, therefore, no additional aging management reviews have been performed.

RS-13-274 Enclosure A Page 5 of 9 RAI 2.1-2 Applicability:

Byron and Braidwood, all units

Background:

10 CFR 54.4, Scope, states, in part, (a) Plant systems, structures and components [SSCs] within the scope of this part are -

(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following functions -

(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.

(2) All nonsafety-related systems, structures and components whose failure could prevent satisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of this section.

Issue:

During the on-site scoping and screening methodology audit, the staff determined that certain equipment that was no longer required had been placed in an abandoned state. The applicant indicated that activities had been performed to confirm that abandoned equipment that initially contained fluids, and is in the proximity of safety-related SSCs, has been verified to be drained.

Request:

The staff requests that the applicant provide a basis for not including abandoned equipment within the scope of license renewal in accordance with 10 CFR 54.4(a). Indicate if the review concludes that use of the scoping methodology precluded the identification of SSCs that should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a).

Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a) criteria.

List any additional SSCs included within the scope of license renewal as a result of the review, and any structures and components (SCs) for which aging management reviews are performed.

Exelon Response:

The basis and methodology for not including abandoned equipment within the scope of license renewal is that the abandoned equipment did not meet any of the scoping criteria as delineated in 10 CFR 54.4(a). Abandoned equipment is not relied on to perform any function delineated in 10 CFR 54.4(a)(1) or (a)(3) as it is non-operational. However, failure of abandoned equipment could potentially impact the performance of the safety-related function of surrounding equipment if the abandoned equipment contains water, steam, or oil. The abandoned equipment that has been excluded from scope has been vented, fluids drained, and isolated, and therefore this equipment does not perform any intended function for license renewal. This information was verified through review of documents including drawings, procedures, and design change packages, as well as discussions with site personnel.

RS-13-274 Enclosure A Page 6 of 9 Any abandoned equipment located in an area containing safety-related equipment, that was not verified to be drained of fluids is within the scope of license renewal in accordance with 10 CFR 54.4(a)(2).

The methodology to identify and exclude abandoned equipment was used sparingly, such that only three (3) instances were identified where abandoned equipment was not included within the scope of license renewal for Byron and Braidwood.

A review of this issue was performed and it was concluded that the use of this scoping methodology did not preclude the identification of systems, structures, and components (SSCs) which should be included within scope of license renewal in accordance with 10 CFR 54.4(a)(2).

There are no additional scoping evaluations required, no additional SSCs to be included within the scope of license renewal and no additional aging management programs to be credited.

RS-13-274 Enclosure A Page 7 of 9 RAI 2.1-3 Applicability:

Byron Nuclear Station, Units 1 and 2

Background:

10 CFR 54.4, Scope, states, in part, (a) Plant systems, structures and components [SSCs] within the scope of this part are -

(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following functions -

(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.

(2) All nonsafety-related systems, structures and components whose failure could prevent satisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of this section.

Issue:

During the on-site scoping and screening methodology audit, the staff reviewed the license renewal application, license renewal implementing documents, as-built drawings, and current licensing basis documentation. The staff determined that the containment access facility hallway structure that is immediately adjacent to the containment extension structure (within the scope of license renewal in accordance with 10 CFR 54.4(a)(1)) is not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(2).

Request:

The staff requests that the applicant provide a basis for not including the containment access facility hallway structure, which is located adjacent to containment extension structure (within the scope of license renewal in accordance with 10 CFR 54.4(a)(1)), within the scope of license renewal in accordance with 10 CFR 54.4(a)(2). The staff requests that the applicant perform a review of this issue and indicate if the review concludes that use of the scoping methodology precluded the identification of SSCs that should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a). Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a) criteria. List any additional SSCs included within the scope of license renewal as a result of the review and SCs for which aging management reviews are performed.

RS-13-274 Enclosure A Page 8 of 9 Exelon Response:

Although this RAI indicates that is applicable to Byron Nuclear Station, Units 1 and 2 only, the response addresses Byron Station, Units 1 and 2 and Braidwood Station, Units 1 and 2, as it is applicable to all four units.

The Containment Access Facility (CAF) structures at Byron and Braidwood Stations, Units 1 and 2, are nonsafety-related structures that provide staging and storage for personnel and equipment to facilitate entry into the radiologically controlled Containment Structure during refueling outages. Each of the four units has a CAF structure. The CAF structure consists of a main CAF building and a CAF hallway structure. The main CAF building is nonsafety-related and provides support, shelter, and protection for nonsafety-related systems, structures, and components (SSCs) that do not perform an intended function for license renewal. The CAF hallway structure connects each main CAF building to the respective containment extension structure, as it is referred to in the Issue section of this Request for Additional Information. The containment extension structure is an exterior structural feature described in LRA Section 2.4.4, Containment Structure, as the shielding outside of the personnel lock and equipment hatch.

The shielding outside of the personnel lock and equipment hatch consists of reinforced concrete shield walls that encompass the personnel lock and equipment hatch. These walls provide radiation and outdoor missile shielding for the personnel lock and equipment hatch. The enclosed CAF hallway structures are nonsafety-related, commercially designed, single story, steel framed structures with concrete foundations and slabs on grade, which are separate from the Containment Structure foundation, previously evaluated as part of the Containment Access Facilities in LRA Table 2.2-1, Comment 1. The personnel lock and equipment hatch are integral parts of the Containment Structure located at grade level, leading outdoors, and are included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).

During the license renewal scoping evaluation of the CAF hallway structures, current licensing basis documents were reviewed consistent with the methodology described in LRA Section 2.1.

As a result of this review, it was concluded that the purpose of the CAF hallway structures is to provide shelter and protection to plant personnel transitioning from the Containment Structure, outside of the personnel lock and equipment hatch, to the main CAF buildings during refueling outages. Additionally, although the CAF hallway structure siding and flashing are connected to safety-related structures, it was determined that the CAF hallway structures do not provide structural support to the three foot thick reinforced concrete walls of adjacent safety-related structures. Therefore, since the CAF hallway structures do not support a safety-related 10 CFR 54.4(a)(1) function or provide structural support to safety-related structures, the CAF hallway structures were not included within the scope of license renewal in accordance with 10 CFR 54.4(a)(2).

Due to the location of the CAF hallway structures with respect to the safety-related structures, spatial interaction between the buildings was considered. Byron and Braidwood UFSAR Section 3.3.2.3 was reviewed and found to provide a description of the evaluation of the collapse of the CAF hallway structures, referred to as the equipment staging structures adjacent to the emergency hatch, on safety-related structures under tornado loadings. It was concluded that although the nonsafety-related CAF hallway structures were not designed for tornado loading conditions, their collapse and failure during a tornado event would not adversely affect the structural integrity of any safety-related structures. Furthermore, missiles generated as a result of the collapse of CAF hallway structure were evaluated and determined to be less critical

RS-13-274 Enclosure A Page 9 of 9 than those considered in UFSAR Subsection 3.5.1.4. At the time of the original scoping evaluation of the CAF hallway structures, this tornado loading analysis was considered to bound the failure of the structures due to age-related reasons as the loads imparted on safety-related structures in a tornado event would exceed the loads experienced as a result of the potential collapse of the structures due to aging. In addition, the potential failure modes of the CAF hallway structures due to tornado loads are not limited by any design features, such that the effects of age-related degradation of the CAF hallway structures cannot exceed the results of this tornado analysis. Therefore, the scoping methodology did not preclude SSCs from being included within the scope of license renewal in accordance 10 CFR 54.4(a)(2).

However, the Staff's concern is recognized relative to the absence of a formal analysis, evaluation, or calculation documenting the potential age-related failure effect of the CAF hallway structures on nearby safety-related structures. Based on a review of this issue, the portions of the CAF hallway structures that are in contact with, or immediately adjacent to, safety-related structures at Byron and Braidwood Stations will be included within the scope of license renewal under 10 CFR 54.4(a)(2). The CAF hallway structures are now evaluated as part of the Containment Structure as an additional exterior structural feature. The effects of aging on the structural elements of the CAF hallway structures, including the concrete, metal framing, and metal and fiberglass panels used for siding, will be managed by the Structures Monitoring program. The roofs of the CAF hallway structures are addressed under the Structural Commodity Group, as noted under the description of the Containment Structure on page 2.4-27.

LRA Section 2.4.4, 3.5.2.1.4, Table 2.2-1, Table 2.4-4, Table 3.5.2-4, and Sections A.2.1.34 and B.2.1.34 are revised to reflect this change as shown in Enclosure B. The Byron and Braidwood LRA Table A.5 Commitment List, Item 34, is also revised to include the CAF hallway structures as part of the Structures Monitoring program, as shown in Enclosure C.

An additional review of structures evaluated as part of the Miscellaneous Not In-Scope Structures was performed to determine whether the scoping methodology precluded the inclusion of any structures which perform an intended function in accordance with 10 CFR 54.4(a). The list of structures evaluated as part of the Miscellaneous Not In-Scope Structures is included in LRA Table 2.2-1, "Plant Level Scoping Results", Comment 1, on pages 2.2-4 and 2.2-5. Based upon this review, it was verified that none of the listed structures perform a function in accordance with 10 CFR 54.4(a). Additionally, the only nonsafety-related structures that are not within the scope of license renewal but are in contact with a safety-related structure are station security features, which are part of the listed Security Structures.

Site security features are required by 10 CFR 73, do not provide an intended function in accordance with 10 CFR 54.4(a), and are managed by 10 CFR 73.46(g). Therefore, no additional SSCs, other than the CAF hallway structures as discussed above, have been included within the scope of license renewal and no additional aging management reviews are required.

RS-13-274 Enclosure B Page 1 of 10 Enclosure B Byron and Braidwood Stations, Units 1 and 2 License Renewal Application (LRA) updates resulting from the response to the following RAI:

RAI 2.1-3 Note: To facilitate understanding, portions of the original LRA 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-13-274 Enclosure B Page 2 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section Table 2.2-1, "Plant Level Scoping Results," Comment 1, page 2.2-5, is revised as shown below.

Additions are indicated with bolded italics; deletions are shown with strikethroughs.

Table 2.2-1 Plant Level Scoping Results Comments:

1. The Miscellaneous Not In-Scope Structures are nonsafety-related and provide support, shelter, and protection for nonsafety-related systems, structures, and components (SSCs) that do not perform an intended function for license renewal. These nonsafety-related structures are also separated from safety-related SSCs such that the structures failure would not impact a safety-related function. Therefore, the following structures are not within the scope of license renewal: Acid Pump House, Bottle Gas Storage Area, Construction Offices (Braidwood), Containment Access Facilities, Contractors Facility (Byron), Decontamination Facility (Braidwood), Dry Cask Storage Structures, Electrical/Instrument Maintenance Building, Environmental Protection Facility (Byron),

FIN Team/Records Management Vault Building (Braidwood), Generator Stator Water Cooling Equipment Building (Byron), Illinois Emergency Management Agency Monitoring Facility, Level B Storage Building, Meteorological Tower, Miscellaneous Oil Handling Structures, Old Steam Generator Facility, Security Structures, Sewage Treatment Plant, Spare Building (Braidwood), Training Facilities, Warehouse Buildings, and Waste Treatment Facilities.

The Containment Access Facility (CAF) structure, associated with each of the four units, consists of a main CAF building and an associated CAF hallway. The portions of the containment access facility hallway that are in contact with, or immediately adjacent to, safety related structures are evaluated with the Containment Structure. The remaining portions of the Containment Access Facility (e.g., the main CAF building) is evaluated as part of the Miscellaneous Not In-Scope Structures. The main CAF building is nonsafety-related and provides support, shelter, and protection for nonsafety-related systems, structures, and components (SSCs) that do not perform an intended function for license renewal.

RS-13-274 Enclosure B Page 3 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section 2.4.4, pages 2.4-25 and 2.4-26, is revised as shown below. Additions are indicated with bolded italics; deletions are shown with strikethroughs.

2.4.4 Containment Structure Description Exterior Structural Features:

In addition, the Containment Structure includes the following exterior structural features: a tendon access gallery, a buttress and walkway enclosure, and shielding outside of the personnel lock with equipment hatch, and the portions of the containment access facility hallway that are in contact with, or immediately adjacent to, the shielding outside of the personnel lock with equipment hatch.

Tendon Access Gallery - The annular reinforced concrete tendon access gallery is below the base slab of the containment buildings. The tendon gallery provides access to the bottom of the tendon anchorage and provides shelter and protection to the tendon anchorage.

Buttress and Walkway Enclosure - The exterior buttress and walkway enclosures contain the ladders and access platforms that provide access to the tendon anchorages at the vertical buttresses and around the outside edge of the dome. The exterior buttress and walkway enclosures provide shelter and protection to the tendon anchorage. The ladders and access platforms inside of these enclosures, on the outside of the containment building wall, while providing access to the tendon anchorages for inspection, do not perform an intended function and their failure would not impact a safety-related function.

Shielding Outside of the Personnel Lock with Equipment Hatch - The personnel lock with equipment hatch is equipped with a concrete external shielding to allow access into the containment building for personnel and large equipment. The external shielding is evaluated as a containment building element and acts as a radiation and missile shield.

Containment Access Facility Hallway - The containment access facility hallway provides shelter and protection to the shielding outside of the personnel lock with equipment hatch.

RS-13-274 Enclosure B Page 4 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section 2.4.4, Table 2.4-4, page 2.4-31, is revised as shown below. Additions are indicated with bolded italics.

Table 2.4-4 Containment Structure Components Subject to Aging Management Review Component Type Intended Function Metal decking and framing (Outside Structural Support Containment in Buttress and Walkway Enclosure, and Containment Access Facility Hallway)

Metal panels (Buttress and Walkway Shelter, Protection Enclosures, and Containment Access Facility Hallway)

Miscellaneous steel (catwalks, stairs, Structural Support handrails, ladders, vents and louvers, platforms, etc.)

Penetration Bellows (Containment Pressure Boundary Boundary) Shelter, Protection Structural Support Penetration sleeves (Guard pipe for fuel Pressure Boundary transfer tube) Shelter, Protection Structural Support Water retaining boundary Penetration sleeves (Guard pipe for Pressure Boundary recirculation sump effluent pipe) Shelter, Protection Structural Support Water retaining boundary Penetration sleeves (in refueling cavity for Shelter, Protection instruments) Structural Support Water retaining boundary Personnel airlock, equipment hatch Pressure Boundary Shelter, Protection Pipe Whip Restraints and Jet Pipe Whip Restraint Impingement Shields (Energy Absorbing Material)

Precast Panel (Containment Access Shelter, Protection Facility Hallway) - (Byron only)

Prestressing system (Grease cap at Shelter, Protection tendon anchorage)

RS-13-274 Enclosure B Page 5 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section 3.5.2.1.4, pages 3.5-6 and 3.5-7, is revised as shown below. Additions are indicated with bolded italics.

3.5.2.1.4 Containment Structure Materials The materials of construction for the Containment Structure components are:

• Carbon Steel

• Carbon and Low Alloy Steel Bolting

• Coatings

• Concrete Block

• Elastomer

• Fiberglass (Byron only)

• Galvanized Steel

• Galvanized Steel Bolting

• Lubrite

• Reinforced concrete

• Silicone

• Stainless Steel

• Stainless Steel Bolting Aging Effect Requiring Management The following aging effects associated with the Containment Structure components require management:

• Change in Material Properties

• Cracking

• Cracking and Distortion

• Cracking, Loss of Bond, and Loss of Material (Spalling, Scaling)

• Cumulative Fatigue Damage

• Increase in Porosity and Permeability, Cracking, Loss of Material (Spalling, Scaling)

• Increase in Porosity and Permeability, Loss of Strength

RS-13-274 Enclosure B Page 6 of 10

• Loss of Coating Integrity

• Loss of Leaktightness

• Loss of Material

• Loss of Material (Spalling, Scaling) and Cracking

• Loss of Mechanical Function

• Loss of Preload

• Loss of Prestress

• Loss of Sealing

RS-13-274 Enclosure B Page 7 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Table 3.5.2-4, Containment Structure, pages 3.5-154, 3.5-162, and 3.5-168, is revised as shown below. Only those line items affected by the revision are shown below. Additions are indicated with bolded italics.

Table 3.5.2-4 Containment Structure (Continued)

Component Intended Material Environment Aging Effect Aging Management NUREG-1801 Table 1 Item Notes Type Function Requiring Programs Item Management Metal decking and Structural Support Carbon Steel Air - Outdoor Loss of Material Structures Monitoring III.A4.TP-302 3.5.1-77 A framing (Outside (B.2.1.34)

Containment in Galvanized Steel Air - Outdoor Loss of Material Structures Monitoring III.A4.TP-274 3.5.1-82 C Buttress and (B.2.1.34)

Walkway Enclosure, and Containment Access Facility Hallway)

Metal panels Shelter, Protection Carbon Steel Air - Outdoor Loss of Material Structures Monitoring III.A4.TP-302 3.5.1-77 A (Buttress and (B.2.1.34)

Walkway Enclosures, and Containment Access Facility Hallway)

Precast Panel Shelter, Protection Fiberglass Air - Outdoor Change in Material Structures Monitoring J, 16 (Containment Properties (B.2.1.34)

Access Facility Hallway) - (Byron only)

Table 3.5.2-4 Containment Structure (Continued)

Plant Specific Notes: (continued)

16. This material has a potential to experience a change in material properties in an air-outdoor environment. The Structures Monitoring (B.2.1.24) program is credited to manage the aging effects applicable to this component type, material, and environment combination.

RS-13-274 Enclosure B Page 8 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section A.2.1.34, page A-36, is revised as shown below. Additions are indicated with bolded italics.

A.2.1.34 Structures Monitoring The Structures Monitoring program is an existing program that was developed to implement the requirements of 10 CFR 50.65 and is based on NUMARC 93-01, Rev. 2 Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, and Regulatory Guide 1.160, Rev. 2 Monitoring the Effectiveness of Maintenance at Nuclear Power Plants. The program includes elements of the Masonry Walls (A.2.1.33) program. The program relies on periodic visual inspections and monitoring of the condition of structures and structural components, structural bolting, component supports, and masonry block walls to ensure that aging degradation leading to loss of intended functions will be detected and that the extent of degradation can be determined. The inspections are conducted on a frequency not to exceed five (5) years.

The Structures Monitoring aging management program will be enhanced to:

1. Add the following structures;

a. Radwaste and Service Building Complex

i. Radwaste Building ii. Original Service Building

b. Turbine Building Complex

c. Yard Structures

i. Transformer foundations ii. Valve and line enclosures

d. Fire protection structures-features

i. Transformer fire barrier walls ii. Fuel oil storage tank berm

e. Containment structure features

i. Containment access facility hallway

RS-13-274 Enclosure B Page 9 of 10 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Section B.2.1.34, pages B-222 and B-223, is revised as shown below. Additions are indicated with bolded italics.

B.2.1.34 Structures Monitoring Program Description The Byron and Braidwood Structures Monitoring program is an existing condition monitoring program that was developed to implement the requirements of 10 CFR 50.65 and is based on NUMARC 93-01, Rev. 2 Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants, and Regulator Guide 1.160, Rev. 2 Monitoring the Effectiveness of Maintenance at Nuclear Power Plants. The program includes elements of the Masonry Walls (B.2.1.33) program. As a result, the program elements incorporate the requirements of NRC IEB 80-11, Masonry Wall Design, and the guidance in NRC IN 87-67, Lessons Learned from Regional Inspections of Licensee Actions in Response to IE Bulletin 80-11. The structures and structural components are inspected by qualified personnel in accordance with station procedures which will be enhanced for consistency with ACI 349.3R. Concrete structures are inspected for indications of deterioration and distress including evidence of leaching, loss of material, cracking, and a loss of bond, as defined in ACI 201.1R, Guide for Making a Condition Survey of Existing Buildings.

Steel components are inspected for loss of material due to corrosion. Masonry walls are inspected for cracking and loss of material. Elastomers will be monitored for hardening, shrinkage and a loss of sealing. Fiberglass will be monitored for change in material properties. Environments include air-outdoor, air-indoor (uncontrolled), concrete, condensation, treated water, raw water, waste water, water-flowing, and groundwater and soil.

The program also includes provisions for periodic testing and assessment of groundwater chemistry and inspection of accessible below grade concrete structures.

A de-watering system is not relied upon to control settlement in the design of the BBS foundations.

Inspection frequency for the in-scope structures will not exceed 5 years, with provisions for more frequent inspections when conditions are observed that have a potential for impacting an intended function. Unacceptable conditions, when found, are evaluated or corrected in accordance with the corrective action program.

Enhancements Prior to the period of extended operation, the following enhancements will be implemented in the following program elements:

1. Add the following structures; a) Radwaste and Service Building Complex

i. Radwaste Building

RS-13-274 Enclosure B Page 10 of 10 ii. Original Service Building b) Turbine Building Complex c) Yard Structures

i. Transformer foundations ii. Valve and line enclosures d) Fire protection structures-features

i. Transformer fire barrier walls ii. Fuel oil storage tank berm e) Containment structure features

i. Containment access facility hallway

RS-13-274 Enclosure C Page 1 of 2 Enclosure C Byron and Braidwood Stations (BBS) Units 1 and 2 License Renewal Commitment List Changes This Enclosure identifies new or revised commitments made in this document and is an update to the Byron and Braidwood Station (BBS) LRA Appendix A, Table A.5 License Renewal Commitment List. Any other actions discussed in the submittal represent intended or planned actions and are described to the NRC for the NRCs information and are not regulatory commitments. Changes to the License Renewal Commitment List are as a result of the Exelon response to the following RAI:

RAI B.2.1-3 Notes:

• To facilitate understanding, portions of the original License Renewal Commitment List have been repeated in this Enclosure, with revisions indicated.

• Existing LRA text is shown in normal font. Changes are highlighted with bold italics for inserted text.

RS-13-274 Enclosure C Page 2 of 2 As a result of the response to RAI 2.1-3 provided in Enclosure A of this letter, LRA Table A.5, Item 34, page A-85, is revised as shown below. Additions are indicated with bolded italics.

A.5 License Renewal Commitment List PROGRAM OR IMPLEMENTATION NO. COMMITMENT SOURCE TOPIC SCHEDULE 34 Structures Monitoring Structures Monitoring is an existing program that will be enhanced to: Program to be enhanced prior Section A.2.1.34 to the period of extended

1. Add the following structures: operation. Exelon Letter

a. Radwaste and Service Building Complex RS-13-274

i. Radwaste Building RAI 2.1-3 ii. Original Service Building 12/19/2013

b. Turbine Building Complex

c. Yard Structures

i. Transformer foundations ii. Valve and line enclosures

d. Fire protection structures-features

i. Transformer fire barrier walls ii. Fuel oil storage tank berm

e. Containment structure features

i. Containment access facility hallway