ONS-2014-021, Licensing Basis for the Protected Service Water System - Response to Request for Additional Information (RAI) No. 190; Revised Responses to RAI Nos. 134 and 165; License Amendment Request (LAR) 2008-07 - Supplement 8

Licensing Basis for the Protected Service Water System - Response to Request for Additional Information (RAI) No. 190; Revised Responses to RAI Nos. 134 and 165; License Amendment Request (LAR) 2008-07 - Supplement 8

ML14055A068
Person / Time
Site:	Oconee
Issue date:	02/14/2014
From:	Batson S Duke Energy Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
ONS-2014-021
Download: ML14055A068 (19)

Text

SCOTT L.BATSON DUKE DUEG Vice President ENERGY. Oconee Nuclear Station Duke Energy ONOI VP / 7800 Rochester Hwy Seneca, SC 29672 ONS-2014-021 864-873-3274 864-873-4208 fax 10 CFR 50.90 Scott.Batson@duke-energy.com February 14, 2014 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852-2746

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station, Units 1, 2, and 3 Docket Numbers 50-269, 50-270, and 50-287, Renewed Operating Licenses DPR-38, DPR-47, and DPR-55 Licensing Basis for the Protected Service Water System - Response to Request for Additional Information (RAI) No. 190; Revised Responses to RAI Nos. 134 and 165; License Amendment Request (LAR) 2008 Supplement 8

References:

1. Letter from T. Preston Gillespie, Jr., Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "Tornado and High Energy Line Break (HELB) Mitigation License Amendment Requests (LARs) -

Responses to Request for Additional Information," dated December 16, 2011.

2. Letter from T. Preston Gillespie, Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U.S. Nuclear Regulatory Commission, "Licensing Basis for the Protected Service Water System - Responses to Request for Additional Information," dated July 11, 2012.

3. Letter from T. Preston Gillespie, Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U.S. Nuclear Regulatory Commission, "Licensing Basis for the Protected Service Water System - Responses to Request for Additional Information," dated November 2, 2012.

4. Letter from Roy P. Zimmerman, Director, NRC Office of Enforcement, "Notice of Violation and Confirmatory Order Related to a Fire Protection Program License Condition (Oconee Nuclear Station, Units 1, 2, and 3)," dated July 1, 2013.

5. NRC RAI email from Richard Guzman (NRC) to Timothy D. Brown (Duke Energy) dated November 22, 2013.

6. Letter from Scott L. Batson, Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "Responses to Request for Additional Information Item Nos. 172 through 189; License Amendment Request (LAR) 2008 Supplement 7," dated December 18, 2013.

www.duke-energy.com Aoof

U. S. Nuclear Regulatory Commission February 14, 2014 Page 2 References (continued):

7. NRC RAI email from Richard Guzman (NRC) to Timothy D. Brown (Duke Energy) dated January 28, 2014.

By letter dated December 16, 2011, Duke Energy Carolinas, LLC (Duke Energy),

submitted a consolidated License Amendment Request (LAR) for the Oconee Nuclear Station (ONS) proposing revisions to the High Energy Line Break (HELB) licensing bases (Ref. 1). As part of the reconstituted HELB program effort, the LAR introduced and credited into the HELB licensing basis a Protected Service Water (PSW) System for mitigation of certain HELBs at the station.

Associated with both the HELB LAR and subsequent National Fire Protection Association (NFPA) 805 enforcement actions (Ref. 4), the Staff has requested additional information related to the PSW System. Duke Energy responses to these requests were submitted as LAR 2008-07 Supplements 1 through 7.

On January 28, 2014, the Staff requested additional information regarding the design of the penetrations in the Unit 3 south Auxiliary Building wall to manhole 7 (Ref. 7). This is provided in the response to new RAI 190.

Duke Energy is also revising its prior responses to RAls Nos. 134 and 165. These RAIs are related to the environmental qualification (EQ) of PSW components. These changes are necessary since the qualified radiation values for the High Pressure Injection (HPI) system's 5.0 kV motor operated manual transfer switches are being revised as a result of walkdowns associated with PSW cable routing work where radioactive sources were identified that have the potential for providing Loss of Coolant Accident (LOCA) dose.

The 5.0 kV manual disconnect/alignment switches are being removed since they are not required to be in the EQ Program.

The responses are contained in the Enclosure to this letter. The changed areas made to earlier responses are denoted by revision bars in the right hand margin and replace in their entirely, the earlier responses made to the Staff. It should also be noted that in an effort to address the RAls clearly, some of the responses may contain direct calculation numbers and content. Duke Energy will continue to control and revise the information provided from these calculations through its normal design and engineering change processes.

If you have any questions in regard to this letter, please contact Stephen C. Newman, Regulatory Affairs Lead Engineer, Oconee Nuclear Station, at (864) 873-4388.

U. S. Nuclear Regulatory Commission February 14, 2014 Page 3 I declare under penalty of perjury that the foregoing is true and correct. Executed on February 14, 2014.

Sincerely, Scott L. Batson Vice President Oconee Nuclear Station

Enclosure:

Revised Responses to RAI Nos. 134 and 165; Response to RAI No. 190.

U. S. Nuclear Regulatory Commission February 14, 2014 Page 4 cc: (w/enclosure)

Mr. Richard Guzman, Senior Project Manager (by electronic mail only)

U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation 11555 Rockville Pike Rockville, MD 20852 Mr. Victor M. McCree, Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30303-1257 Mr. Eddy Crowe NRC Senior Resident Inspector Oconee Nuclear Station Ms. Susan E. Jenkins, Manager Radioactive & Infectious Waste Management SC Dept. of Health and Environmental Control 2600 Bull St.

Columbia, SC 29201

ENCLOSURE Revised Responses to RAI Nos. 134 and 165; Response to RAI No. 190

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 2 RAI 134 [EEEB251 In its letter dated January 20, 2012, the licensee referenced the Institute of Electrical and Electronics Engineers (IEEE) Standard (Std.) 323-1974 and 323-1983, "Standards for Qualifying Class 1E equipment for Nuclear Power Generating Stations," and noted that these standards were used in the design of electrical equipment for the PSW System. The staff review noted that the design of some of the PSW System electrical equipment are based on the IEEE Std. 323-1974 while others are based on the IEEE Std. 323-1983. The NRC has not endorsed the IEEE Std. 323-1983 for satisfying the EQ requirements of 10 CFR 50.49. Explain how and why the IEEE Std. 323-1983 was applied, in lieu of the IEEE Std. 323-1974, in the design of the PSW System electrical equipment.

Duke Energy Response:

Backgqround:

For the different versions of the IEEE Standard 323 (1974 vs. 1983), Duke Energy's Environmental Qualification (EQ) Program is established in accordance with IEEE 323-1974 at fleet level as outlined in Duke Energy Nuclear System Directive (NSD) 303 (Environmental Qualification Program - Rev. 5) for the EQ Program in compliance with the NRC EQ Regulation, 10CFR50.49. This is to remain in alignment with the NRC endorsement of that version as noted in Regulatory Guide 1.89 Revision 1.

Oconee Specific Applications Related To This RAI Response:

All new electrical equipment procured for the Oconee Nuclear Station (ONS) Protected Service Water (PSW) System and project was purchased via procurement specifications that referenced IEEE 323-1974 as the basis to be used for environmental qualification. This was completed in the original Revision 0 of procurement specifications which required an EQ inspection and sign-off, and technical requirements documents (TRDs) which elected to have an EQ inspection and sign-off. Following the issuance of these procurement documents at Revision 0 and selection of various equipment vendors, several vendors responded via deviation / exception requests to Duke Energy's referenced requirement of using IEEE 323-1974 for environmental qualification.

They stated a justification for the use IEEE 323-1983 based on various factors including the specified environmental conditions (EQ MILD versus HARSH), radiation levels, etc. In each of these deviation / exception requests, Duke Energy reviewed, documented, and processed approval for the use of the 1983 standard. These reviews were documented and tracked to completion via a revision to the referenced procurement specification or TRD to reflect this reference change. Each deviation allowing the use of IEEE 323-1983 versus the 1974 version was reviewed and inspected by EQ personnel. For equipment that remained specified and qualified in accordance with IEEE 323-1974, there are no additional documentation requirements with respect to this RAI response.

The 5.0 kV manual disconnect/alignment switches are used to select either the "A" or "B"High Pressure Injection (HPI) pump to inject into the Reactor Coolant System (RCS) following a PSW event. The normal HPI pump motor power path is not routed through the 5.0 kV manual disconnect/alignment switch; therefore, the failure of this switch would not affect the ability of the HPI system to mitigate a Loss of Coolant Accident (LOCA). Per the EQ Program guidelines, the 5.0kV manual disconnect/alignment switches are not required to mitigate a LOCA which creates the HARSH environment in the installed location and their failure would not affect the ability of the HPI system to mitigate a LOCA; therefore, these switches will not be included in the EQ Program.

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 3 The 5.0KV motor operated manual transfer switches are already included in the EQ Program and are being qualified by the vendor in accordance with IEEE 323-1974. The switches are located in the Auxiliary Building at Elevation 771' and provide an electrical power connection to the HPI system from the PSW system. The normal HPI pump motor power path is routed through the motor operated transfer switches and the transfer switches' only requirement under LOCA conditions is to not change position from the normal power path position.

The radiation requirement total integrated dose (TID) for the 5.0 kV motor operated manual transfer switches utilize a 40-year normal dose plus one year accident (LOCA) dose. These doses have been revised to a value of 1.33E3 and 2.16E6 RADs respectively. The switches would not be required to operate under the listed one year accident dose; however, they would be required to remain in the normal, i.e., Engineering Safeguards Position, during and after a LOCA. The test reports will qualify the switches to IEEE 323-1974 via testing and analysis for the worst case radiation values plus the elevated temperature testing for accident temperature considerations. These additions will be processed via the Duke Energy Engineering Change Program with appropriate EQ reviews.

The 40-year normal dose value of 1.33E3 RADs was revised based on 3-years of monthly survey data. The post-accident radiation value of 2.16E6 RADS comes from post-accident piping in the Low Pressure Injection (LPI) hatch areas and streaming of post-accident dose from the pipe room directly below. During PSW walk downs for Room 119 (Hatch Area - Units 1 &

2) and room 159 (Hatch Area - Unit 3), it was observed that isolated LPI piping in the hatch areas would experience mixing and back leakage with Emergency Core Cooling System (ECCS) piping. Historical post-accident shielding calculations were completed prior to consideration of back leakage. The streaming component resulted from unshielded ECCS pipe without attenuation through an open stairwell from the pipe room directly below. These issues have been addressed through Duke Energy's corrective action program.

Generic Considerations On The Use Of Different Versions Of IEEE 323 Related To This RAI

Response

With respect to the actual differences between the 1974 version and the 1983 version of IEEE 323, there were no new requirements established under the 1983 version as compared to the 1974 version. The same qualification testing and analysis elements are in both versions. The following is noted in the foreword of IEEE 323-1983:

"This revision to IEEE 323-1974 was made to clarify its requirements and imposes no additional requirements for qualifying Class 1E equipment."

This has been reviewed on multiple occasions internal to Duke Energy's EQ Program along with various industry meeting discussions. It is further documented via industry documents such as EPRI Report TR-1 00516 "Nuclear Power Plant Equipment Qualification Reference Manual".

Key clarifications included in IEEE 323-1983 are the considerations for MILD environment qualification and documentation, extending methods for qualified life evaluations, extrapolation of qualification via similarity analysis, and clarifications on accident environments and profiles for Loss of Coolant Accidents (LOCAs) and High Energy Line Breaks (HELBs).

Summary:

Duke Energy has originally specified IEEE 323-1974 as the reference and basis for qualifying the new electrical equipment for the Oconee PSW System. Over the course of procuring and testing this new electrical equipment, it has been requested to perform most of the qualification testing in accordance with IEEE 323-1983 versus the 1974 version on certain PSW System equipment. A majority of these requests were supplied by the equipment vendors to take advantage of the MILD environment guidance that is provided via IEEE 323-1983. Since there

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 4 are no new requirements established by the 1983 version, it was determined there were no concerns with different standards for the above listed reasons. All PSW equipment placed in the EQ program will be qualified to IEEE 323-1974.

RAI 165 [EEEB25]

In its responses dated January 20 and July 11, 2012, to the Staff's RAIs 62 and 134

[EEEB25] respectively related to the Environmental Qualification (EQ) of the PSW equipment, the licensee stated that a new 5.0 kilo Volt (kV) Manual Disconnect Switches and 5.0 kV Motor Operated Disconnect Switches were added to the EQ program and these switches were qualified in accordance with IEEE Std. 323-1983. The switches were added due to a radiation requirement total integrated dose (TID) utilizing a 40.0 year normal dose plus one year accident (design basis event) dose of 1.6E3 RADs. However, the licensee did not address EQ of the cables, cable connections and other components that will be connected to these two new switches located in the same EQ zone for a radiation TID dose requirement. Provide a summary table showing all PSW electrical equipment in the EQ zone (where these two new switches will be installed) including cables, cable connections, their safety qualification (i.e., safety-related or non- safety-related), IEEE Std. and versions used for EQ, environmental conditions they have been qualified for (temperature, radiation, pressure, humidity etc.).

Duke Energy Response:

Table 165-1 (shown below) lists the Protected Service Water (PSW) equipment/components in the same Environmental Qualification (EQ) Zone as the new 5.0 kV manual disconnect/alignment switches(1/2/3HPISXALGN001) and 5.0 kV motor operated manual transfer switches 1/2/3HPISXTRN001 & 002). Medium voltage cables are used for power feeds to and from the manual alignment switches and the motor operated transfer switches. The medium voltage connections to the various switches are made with Burndy un-Insulated lugs and 3M stress cones. The motor operated transfer switches utilize 125 VDC as the incoming control voltage and then converts the 125 VDC to 24 VDC for actual control component usage.

The low voltage control cables (125 VDC and below in this application) connect the control power and/or indication/control circuits to and from the manual alignment switches and the motor operated transfer switches, utilizing Thomas & Betts (T&B) Tefzel insulated connectors.

The alignment switches are used to select either the "A" or "B" High Pressure Injection (HPI) pump to inject into the Reactor Coolant System (RCS) following a PSW event. The normal HPI pump motor power path is not routed through the 5.0 kV manual disconnect/alignment switch; therefore, the failure of this switch would not affect the ability of the HPI system to mitigate a Loss of Coolant Accident (LOCA). Per the EQ Program guidelines, the 5.0KV alignment switches are not required to mitigate a LOCA which creates the HARSH environment in the installed location and their failure would not affect the ability of the High Pressure Injection (HPI) system to mitigate a LOCA; therefore, these switches will not be included in the EQ Program as previously stated, and Table 165-1, Item 3, column 2 has been revised from a "YES" to a "NO" response.

The 5.0KV motor operated manual transfer switches are already included in the EQ Program and are being qualified by the vendor in accordance with IEEE 323-1974. The switches are located in the Auxiliary Building at Elevation 771' and provide the electrical power connection to the HPI system from the PSW system. The normal HPI pump motor power path is routed

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 5 through the motor operated transfer switches and the transfer switches' only requirement under LOCA conditions is to not change position from the normal power path position.

The radiation requirement total integrated dose (TID) for the 5.0 kV motor operated manual transfer switches utilizes a 40-year normal dose plus one year accident (LOCA) dose. These doses have been revised to a value of 1.33E3 and 2.16E6 RADs respectively. The switches would not be required to operate under the listed one year accident dose; however, they would be required to remain in the normal, i.e., Engineering Safeguards Position, during and after a LOCA. The test reports will qualify the switches to IEEE 323-1974 via testing and analysis for the worst case radiation values plus the elevated temperature testing for accident temperature considerations. These additions will be processed via the Duke Energy Engineering Change Program with appropriate EQ reviews.

The 125 VDC Power Panel (1/2/3PSWPL2DC) that provides control power to the 5kV motor operated transfer switches is located in the same EQ Zone as the transfer switches but are not in the EQ Program because the panel supply (125 VDC) to the motor operated transfer switches is not required to be available during the LOCA event since the transfer switch is not required to change position during the LOCA event.

The 5kV motor operated transfer switches are included in Environmental Qualification Maintenance Manual (EQMM) Section EQMM-1393.01-N1O-01. The commodities component type parts (i.e. cables, connectors, stress cones, etc.) are covered by Duke Energy EQ Document number EQMM- 1393.01-MOl-00, which covers Commercial Grade/Approved Vendor Items.

Based on revised normal and accident dose values in the ONS Auxiliary Building, 771' elevation, Rooms 119 and 159, which are the location of the 5.0 kV motor operated manual transfer switches, these 1/2/3HPISXTRN001 & 002 transfer switches and the associated Adalet/PLM cable terminators will be re-qualified to a 40-year normal radiation value of 1.33E3 RADS and a 1-year accident (LOCA) radiation value of 2.16E6 RADS via submittal of a new Qualification Report from the Vendor.

The 40-year normal dose value of 1.33E3 RADs was revised based on 3-years of monthly survey data. The post-accident radiation value of 2.16E6 RADS comes from post-accident piping in the Low Pressure Injection (LPI) hatch areas and streaming of post-accident dose from the pipe room directly below. During PSW walk downs for Room 119 (Hatch Area - Units 1 &

2) and room 159 (Hatch Area - Unit 3), it was observed that isolated LPI piping in the hatch areas would experience mixing and back leakage with Emergency Core Cooling System (ECCS) piping. Historical post-accident shielding calculations were completed prior to consideration of back leakage. The streaming component resulted from unshielded ECCS pipe without attenuation through an open stairwell from the pipe room directly below. These issues have been addressed through Duke Energy's corrective action program.

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 13 RAI-190 (EMCB-11)

Background:

" The Oconee UFSAR, Section 3.2.1.1.1 designates portions of the Auxiliary Building that house engineered safeguards systems, control room, fuel storage facilities and radioactive materials as Class 1 structure. Section 3.2.1.1.2 of the UFSAR designates Oconee Turbine and Auxiliary Buildings (except as included in Class 1) as Class 2 structures.

• Section 2.0 "Design Input" of Calculation OSC-9211 references Section 3.2.1.1 of the UFSAR and establishes that the exterior south wall of Unit 3 Auxiliary Building is classified as Class 1 structure.

• Section 4.1 "Load Combinations" of Calculation OSC-921 1, references Table 3-23 of the UFSAR for design basis load conditions used in Calculation OSC-9211 for structural evaluation of the exterior south wall of Unit 3 Auxiliary Building. Table 3-23 is referenced in Section 3.8.4.5 of the UFSAR for the design of those portions of the Auxiliary Building housing the facilities listed in Section 3.8.4.1 of the UFSAR.

• Section 4.2 "Acceptance Criteria" of Calculation OSC-921 1, references Section 20.2.3 of Specification OSS-0254.00-00-3007, Revision 4 "Design Basis Specification of the Auxiliary Building" for acceptance criteria for Class 1 reinforced concrete structures. Section 4.2 of Calculation OSC-9211 also references Section 3.8.5 of the UFSAR which is related to non-Class 1 structures and where a 33 percent increase, for wind and seismic load combinations, in allowable stress limits is allowed for the design of Class 2 structures.

Issue:

There is an apparent inconsistency in Section 4.2 of Calculation OSC-9211 where it is established that the exterior south wall of Unit 3 Auxiliary Building is classified as Class 1 and it is acknowledged that structural acceptance criteria for Class 1 structures will be used; but, in contrary, the UFSAR section related to non-Class 1 structures is referenced for use.

Request for Additional Information:

a. Provide further clarification related to the seismic classification and the structural acceptance criteria applicable to the exterior south wall of Unit 3 Auxiliary Building evaluated in Calculation OSC-921 1.

b. Section 4.1 "Load Combinations" of Calculation OSC-921 1, references Table 3-23 of the UFSAR for design basis load conditions used in Calculation OSC-9211 for structural evaluation of the exterior south wall of Unit 3 Auxiliary Building. Contrary to the UFSAR, Table 3-23, Calculation OSC-9211 excludes design basis earthquake from load combination LC1. Provide further clarification and reconcile the exclusion of design basis earthquake.

c. Static soil pressure and hydrostatic loads are permanent loading conditions for the exterior south wall of Unit 3 Auxiliary Building evaluated in Calculation OSC-9211. Provide further clarification and reconcile the exclusion of these loading conditions from Maximum Hypothetical Earthquake load combination LC3.

d. Calculation OSC-9211 considers self-weight of the wall, self-weight of floor slab at elevation 796'-6", and self-weight of concrete masonry wall at elevation 796'-6". It is also stated in Calculation OSC-9211 that loads from floors above elevation 796'-6" will be transferred through Auxiliary Building columns to the foundation. Confirm that equipment loading plus any other permanent loading, either attached directly to the

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 14 south wall of Unit 3 Auxiliary Building or supported on the floor slab at Elevation 796'-

6", have been properly taken into account in Calculation OSC-9211.

e. As assumed in Calculation OSC-9211, the existing reinforcing bars have been cut/removed to construct the new opening. The Auxiliary Building design basis code of record, ACI 318-63, requires that the calculated tension or compression in any reinforcing bar at any section must be developed on each side of that section by proper embedment length, end anchorage, or hook. Provide further information and demonstrate that there is sufficient embedment length of reinforcing bars to develop the flexural moment demand, in the horizontal and vertical directions, in the areas adjacent to the new opening.

f. Provide further information and demonstrate that the flexural and shear capacity of concrete spanning the width of the new opening is adequate to resist the maximum flexural moment and shear force demand.

Duke Energy Response The issues raised in this RAI have been entered into Oconee Nuclear Station's Corrective Action Program. Subsequently, Oconee Station Calculation (OSC) 9211 has been revised to provide clarification, as required, for the issues included in RAI-190. The response to each lettered item in RAI-190 will include references to the page and section number in OSC-921 1, Revision 2, where the response may be validated.

RAI-190.a: The subject Auxiliary Building (AB) wall is considered to be Seismic Class 1 for the purposes of qualifying its modification in OSC-9211. The acceptance criteria applied in OSC-921 1, revisions 1 and 2 are from the Oconee UFSAR, Section 3.8.4.5.

[OSC-9211: page 4A, Sec. 2.0 (Rev. 1); page 9A, Sec. 4.2 (Rev. 1); page 66, Sec. 2.0 (Rev. 2)]

RAI-190.b: In the preparation of OSC-921 1, Revision 1, it was considered that seismic load cases would not control. This consideration was based on conclusions drawn in OSC-921 1, Revision 0. On this basis OSC-921 1, Revision 1, configured the analysis load combination LCl to include the entire "normal" load cases required by Load Condition A but excluded the OBE load case. There was no further discussion or demonstration in OSC-921 1, Revision 1, regarding "normal" loads controlling the design. OSC-9211, Revision 2, has been, originated, reviewed and approved and includes the required OBE load case as well as demonstrating that "normal" loads control the design.

[OSC-921 1: page 66, Sec. 1.0 (Rev. 2); page 67, Sec. 9.1 (Rev. 2); page 82, Sec. 10.0 (Rev. 2); page D11, App. D (Rev. 2)]

RAI-190.c: OSC-921 1, Revision 1, analysis load combination LC3, corresponding to UFSAR Load Condition D, includes load case EQ2. Load case EQ2 represents the MHE soil and hydrostatic load on the subject AB wall. Load case EQ2 is also included in OSC-921 1, Revision 2, analysis load combination LC3.

[OSC-9211: page 29A, Sec. 6.2.4.2 (Rev. 1); page A23, App. A (Rev. 1); page D11, App. D (Rev. 2)]

Enclosure - Responses to Request for Additional Information - Supplement 8 February 14, 2014 Page 15 RAI-1 90.d: In OSC-921 1, revisions 1 and 2, permanent equipment loading is accounted for by applying the applicable acceleration factor to one-half the live load. The basis for using one-half the live load as a proxy for the permanent equipment load is in specification OSS-0027.00-00-0009, Specification for the Evaluation of Support/Restraintsand Equipment StructuralAttachment Loads at Oconee Nuclear Station (Including Keowee Hydro Station), page A2 and A6. In the OSC-9211 analysis model this is accomplished by applying appropriate load factors to the live load case.

[OSC-9211: page 30A, Sec. 6.2.4.3 (Rev. 1); page 67, Sec. 9.1 (Rev. 2); p. Dl, App. D (Rev. 2)]

RAI-190.e: In OSC-921 1, revision 2, bond stress in the bars adjacent to the opening is evaluated for the terminated horizontal and vertical reinforcing. The bond stress is evaluated at a distance from the opening equal to the effective depth of the section, d, at d/2, and at 12in. In all cases the bond stress is well below the allowable stress limit and the bars can develop the flexural moment demand.

[OSC-921 1: pages 73 - 76, Sec. 9.5 (Rev. 2)]

RAI-190.f: OSC-92 11, Revision 2, evaluates the "beam" section which spanned the opening prior to the placement of concrete and grout in the opening. The "beam" is shown to be adequate to withstand the combined in- and out-of-plane flexural moment and shear force demand.

[OSC-921 1: pages 77 - 82, Sec. 9.6 (Rev. 2)]