NL-16-0108, Units 1 and 2, License Amendment Request to Correct Non-Conservative Technical Specification Allowable Values for the Condensate Storage Tank Low Level Transfer Function

Units 1 and 2, License Amendment Request to Correct Non-Conservative Technical Specification Allowable Values for the Condensate Storage Tank Low Level Transfer Function

ML18180A396
Person / Time
Site:	Hatch
Issue date:	06/29/2018
From:	Gayheart C Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-16-0108
Download: ML18180A396 (23)

Text

~ Southern Nuclear Cheryl A. Gayheart Regulatory Affairs Director 40 Inverness Center ParkwJy Post Office Box l 295 Bim1ingham. AL 352~2 205 992 53 l 6 tel 205 992 760 I fa' cagayhea@~outhemco com JUN 2 9 2018 Docket Nos.: 50-321 NL-16-0108 50-366 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Edwin I. Hatch Nuclear Plant- Units 1 and 2 License Amendment Request to Correct Non-Conservative Technical Specification Allowable Values for the Condensate Storage Tank Low Level Transfer Function Ladies and Gentlemen:

Pursuant to 10 CFR 50.90, Southern Nuclear Operating Company (SNC) hereby requests an amendment to the Technical Specifications (TS) for the Edwin I. Hatch Nuclear Plant (HNP),

Units 1 and 2. The proposed change increases the Allowable Values (AV) specified in TS Table 3.3.5.1-1 for automatic transfer of the High Pressure Coolant Injection (HPCI) pump suction alignment from the condensate storage tank (CST) to the suppression pool for Units 1 and 2. The proposed change also increases the AV specified in TS Table 3.3.5.2-1 for automatic transfer of the Reactor Core Isolation Cooling (RCIC) pump suction alignment from the CST to the suppression pool for Unit 1.

SNC has reviewed the proposed change in accordance with 10 CFR 50.91 (a)(1) using the criteria in 10 CFR 50.92(c), and has determined that the change involves no significant hazards consideration.

The Enclosure provides a description and assessment of the proposed change, including the no significant hazards consideration analysis, regulatory requirements, and environmental considerations. Attachment 1 provides the existing TS pages marked to show the proposed change. Attachment 2 provides revised (clean) TS pages.

This license amendment request (LAR) is required to correct a non-conservative TS. Currently plant operations are administratively controlled as described in NRC Administrative Letter (AL) 98-10, "Dispositioning of Technical Specifications That Are Insufficient to Assure Plant Safety."

In accordance with the guidance in AL 98-10, this LAR is required to resolve non-conservative TS and is not a voluntary request from a licensee to change its licensing basis. Therefore, this request is not subject to 'forward fit' considerations as described in the letter from S. Burns (NRC) to E. Ginsberg (NEI), dated July 14,2010 (ADAMS Accession Number ML01960180).

Approval of the proposed amendment is requested by June 25, 2019. Once approved, the amendment will be implemented within 90 days.

In accordance with 10 CFR 50.91, SNC is notifying the state of Georgia of this license amendment request by transmitting a copy of this letter to the designated state official.

U. S. Nuclear Regulatory Commission NL-16-0108 Page 2 This letter contains no NRC commitments. If you have any questions, please contact Jamie Coleman at 205.992.6611.

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

Executed on June t-'1 , 2018.

C. A. Ga he Regulato ffairs Director Southern Nuclear Operating Company

Enclosure:

Description and Assessment of Proposed Change Attachments 1. Existing TS Pages Marked to Show the Proposed Change

2. Revised (Clean) TS Pages cc: NRC Regional Administrator NRC NRR Project Manager- Hatch NRC Senior Resident Inspector- Hatch Georgia - State Department of Natural Resources - Director of Environmental Protection SNC Document Control A-Types: CHA02.004

Edwin I. Hatch Nuclear Plant - Units 1 and 2 License Amendment Request to Correct Non-Conservative Technical Specification Allowable Values for the Condensate Storage Tank Low Level Transfer Function Enclosure Description and Assessment of Proposed Change

Enclosure to NL-16-01 08 Basis for Proposed Change ENCLOSURE Description and Assessment of the Proposed Change

Subject:

License Amendment Request to Correct Non-Conservative Technical Specification Allowable Values for the Condensate Storage Tank Low Level Transfer Function

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Analysis 4.3 Conclusions

5. ENVIRONMENTAL CONSIDERATION

6. REFERENCES ATTACHMENTS:

1. Existing TS Pages Marked to Show the Proposed Change

2. Revised (Clean) TS Pages E-1

Enclosure to NL-16-0108 Basis for Proposed Change 1.0 Summary Description The proposed change increases the Allowable Values (AV) specified in Technical Specification (TS) Table 3.3.5.1-1 for automatic transfer of the High Pressure Coolant Injection (HPCI) pump suction alignment from the condensate storage tank (CST) to the suppression pool for Units 1 and 2. The proposed change also increases the AV specified in TS Table 3.3.5.2-1 for automatic transfer of the Reactor Core Isolation Cooling (RCIC) pump suction alignment from the CST to the suppression pool for Unit 1. The proposed change is being made to address air entrainment and vortexing concerns for the Unit 1 and 2 HPCI pumps and Unit 1 RCIC pump when they are aligned to take suction from the CST.

2.0 Detailed Description 2.1 System Design and Operation The HPCI system is part of the Emergency Core Cooling Systems (ECCS). Upon receipt of an initiation signal, the HPCI pump automatically starts and injects water, taken from either from the CST or suppression pool, into the Reactor Coolant System (RCS). Although the suppression pool provides the credited source of water for the HPCI system, the system is normally aligned to take suction from the CST.

The RCIC system is not part of the ECCS. Upon receipt of an initiation signal, the RCIC pump automatically starts and injects water, taken from either from the CST or suppression pool, into the RCS. The system is normally aligned to take suction from the CST.

Low water level in the CST introduces the possibility of air entrainment in the HPCI and RCIC pump suctions. To prevent this, if the water level in the CST falls below a preselected level, both valves on the HPCI suction line from the suppression pool automatically open, and then the valve on the HPCI suction line from the CST automatically closes. Similarly, if the water level in the CST falls below a preselected level for the RCIC pump, both valves on the RCIC suction line from the suppression pool automatically open, and then the valve on the RCIC suction line from the CST automatically closes. These automatic suction transfers ensure that an adequate supply of makeup water is available to the HPCI and RCIC pumps. For both the HPCI and RCIC pumps, the pump suction valves are interlocked so that both suppression pool suction valves must be open before the CST suction valve automatically closes in order to prevent losing pump suction.

Two level switches are used to detect low water level in the CST and initiate the HPCI suction valve transfer. Either switch can cause the suppression chamber suction valves to open.

Similarly, two level switches are used to detect low water level in the CST and initiate RCIC suction valve transfer, with either switch capable of initiate opening of the suppression chamber suction valves. The level switches that initiate the HPCI automatic CST suction transfer function are separate and unique from the level switches for the RCIC automatic CST suction transfer function. The TS 3.3.5.1-1 and TS 3.3.5.2-1 Condensate Storage Tank Level - Low Function AVs are provided to ensure adequate pump suction head is available to the HPCI and RCIC pumps when they are aligned to take suction from the CST.

E-2

Enclosure to NL-16-01 08 Basis for Proposed Change The HPCI and RCIC suction pipes separately enter the CST horizontally and terminate at the CST wall. The HPCI and RCIC pump suction lines connect to the CST near the bottom of the tank and are not equipped with vortex suppressor devices. The azimuths of the HPCI and RCIC suction line penetrations through the CST sidewall are sufficiently separated to preclude interaction of vortex effects. Physical dimensions and configuration details of the Unit 1 and 2 CSTs are summarized in Table 1, located at the end of the Enclosure.

Each HNP Unit has a separate, dedicated CST. System demands on the CST other than HPCI and RCIC draw from the CST through internal standpipes that are set at a level so that approximately 100,000 gal are below the standpipe inlets and unavailable to these other systems. As a result, approximately 100,000 gal. of the 500,000 gal. CST capacity are held in reserve for use exclusively by the HPCI and RCIC systems. The HPCI suction line for each unit is positioned such that approximately 80,000 gal are available below the internal CST standpipes for the non-HPCI/RCIC demands. The RCIC suction line for each unit is positioned such that approximately 98,000 gal are available below the internal CST standpipes for non-HPCI/RCIC demands.

The HPCI system is not credited as the primary success path in the FSAR Chapter 15 accident analysis of loss of coolant accidents, or the SAFERIGEST-LOCA analysis (Reference 1) for HNP Units 1 and 2. Additionally, HPCI system operation is not credited for any other DBA or transient analysis in HNP FSAR Chapter 15, although it is mentioned in the HNP Unit 1 and 2 safety analysis as an option for a number of design basis accidents (DBAs).

The RCIC system is not an Engineered Safety Feature System and is not credited in the safety analysis for any DBA. However, availability of the CST water supply to the RCIC system, and the availability of sufficient condensate inventory from the CST for the required Station Blackout (SBO) coping duration is identified as an assumption in the SBO coping analysis. Availability of the automatic RCIC suction transfer function from the CST to the suppression pool is also assumed. HPCI availability is not required in the SBO analysis. The proposed AV change for automatic transfer of the RCIC suction line does not result in a change to the instrument setpoint for this function, and therefore does not adversely affect the validity of these assumptions.

The CST is non-safety related, and no credit is taken in the safety analysis for the CST as a makeup water source for the HPCI or RCIC systems, or any other plant systems.

2.2 Current Technical Specification Requirements The Allowable Values for the Condensate Storage Tank Level - Low ECCS instrumentation function associated with automatic transfer of the HPCI pump suction alignment from the CST to the suppression pool are provided as Function 3.d in TS Table 3.3.5.1-1. The current Unit 1 and Unit 2 AVs are 2.58 ft., and 2.61 ft., respectively.

The Allowable Value for the Condensate Storage Tank Level- Low ECCS instrumentation function associated with automatic transfer of the RCIC pump suction alignment from the CST to the suppression pool is provided as Function 3 of TS Table 3.3.5.2-1. The current Unit 1 AV is 0.87 ft. No change to the Unit 2 AV for the Condensate Storage Tank Level - Low is necessary or requested.

E-3

Enclosure to NL-16-01 08 Basis for Proposed Change 2.3 Reason for Proposed Change During review and evaluation of instrument elevation survey data it was determined that level switch setpoints and TS AVs associated with the CST Water Level - Low instrument functions that initiate automatic transfer of the HNP Unit 1 HPCI and RCIC pump suctions from the CST to the suppression pool were non-conservative and could result in air entrainment and vortexing prior to completion of the suction transfer. It was also determined that the setpoint calculations for these instrument functions did not take into account the necessary reduced voltage assumptions associated with post-accident operation, when the battery chargers may be not available, for the DC motor operated valves associated with the suction transfer lines. It was subsequently concluded that these same conditions were also applicable to the Unit 2 HPCI pump automatic suction transfer from the CST to the suppression pool.

The HPCI and RCIC pump suction valves from the CST to the suppression pool are direct current powered motor operated valves. The reduced voltage assumptions have the effect of increasing valve stroke times and extending the time required to complete execution of the HPCI and RCIC suction transfer from the CST to the suppression pool, which results in additional inventory depletion from the CST prior to completion of the suction alignment transfer.

As a result, the instrument setpoints were determined to not be sufficient to prevent vortexing and air entrainment in the HPCI and RCIC suctions lines when aligned to the CST during low CST water level conditions. This condition was reported in HNP Unit 1 Licensee Event Report 2009-001, "Pump Suction Swap for HPCI and RCIC Non-conservative with Respect to Technical Specification Requirements," and revised setpoints were implemented pending revision of the TS.

This license amendment request (LAR) is required to correct a non-conservative TS. Currently, plant operations are administratively controlled as described in NRC Administrative Letter (AL) 98-10, "Dispositioning of Technical Specifications That Are Insufficient to Assure Plant Safety."

In accordance with the guidance in AL 98-10, this LAR is required to resolve non-conservative TS and is not a voluntary request from a licensee to change its licensing basis. Therefore, this request is not subject to 'forward fit' considerations as described in the letter from S. Burns (NRC) to E. Ginsberg (NEI), dated July 14, 2010 (ADAMS Accession Number ML01960180}.

2.4 Description of the Proposed Change The proposed change revises the AVs in TS Table 3.3.5.1-1 (Function 3.d) for the HPCI automatic pump suction transfer from the CST to the suppression pool.

• For HNP Unit 1, the proposed change increases the AV from greater than or equal to 2.58 feet above the bottom of the CST, to greater than or equal to 3.52 feet above the bottom of the CST.

• For HNP Unit 2, the proposed change increases the AV from greater than or equal to 2.61 feet above the bottom of the CST, to greater than or equal to 3.25 feet above the bottom of the CST.

The proposed change revises the AV in TS Table 3.3.5.2-1 (Function 3) for the RCIC automatic pump suction transfer from the CST to the suppression pool.

E-4

Enclosure to NL-16-01 08 Basis for Proposed Change

• For HNP Unit 1, the proposed change increases the AV from greater than or equal to 0.87 feet above the bottom of the CST, to greater than or equal to 1.0 feet above the bottom of the CST.

• No change is proposed to the HNP Unit 2 AV.

3.0 Technical Evaluation Revised AVs were calculated for automatic transfer of the HPCI pump suction alignment from the CST to the suppression pool for HNP Units 1 and 2, and for automatic transfer of the RCIC pump suction alignment from the CST to the suppression pool for HNP Unit 1. These AVs were determined based on revised analytical limits that were developed using a more rigorous hydraulic modeling methodology, and consideration of HPCI and RCIC suction valve stroke times under design basis conditions.

The primary technical reference used as the basis for determining the revised AVs for automatic realignment of the HNP Unit 1 and 2 HPCI and RCIC pump suctions is Calculation Note FAI/09-19, Rev. 1 (Reference 2). Proprietary and non-proprietary versions of this document were previously docketed in response to Requests for Additional Information in support of a License Amendment Request for the Joseph M. Farley Nuclear Plant (ADAMS Accession Number ML14167A493) (Reference 3).

Calculation Note FAI/09-19 performed a comparison of air intrusion test data obtained from scale model simulations of the D.C. Cook Refueling Water Storage Tank. The purpose of these comparisons was to evaluate air intrusion data obtained from physical testing of various tank suction piping configurations with critical submergence values predicted using models developed by Harleman, et. al. (Reference 4), and Lubin and Springer (Reference 5).

The D.C Cook simulation was modeled using a horizontal suction pipe with a vertical opening, located just above the tank floor, and with no vortex suppression devices. This configuration is similar to the configuration of the HPCI and RCIC suction lines from the CSTs for HNP Unit 1 and 2.

The D.C. Cook tests were performed in both transient (open loop) and steady-state (closed loop) modes in which the water level in a tank was decreased at a given flow rate until air intrusion into the horizontal suction pipe was observed. The test results were documented in terms of: 1) when a steady stream of air bubbles was first detected in the downcomer of the suction piping, and 2) when the gas void fraction was estimated to be 2% of the downcomer cross-sectional flow area. As shown on Figure 3 of Calculation Note FAI/09-19, there is very little difference between the onset of air intrusion (gray triangular data points) and the conditions that resulted in an estimated void fraction of 2% (red and gray square data points). The D.C.

Cook test method, configuration, and dimensions are described and shown in Section 2.0 and Figure 2 of Calculation Note FAI/09-19.

Air entrainment data from the D.C. Cook testing is represented on Figure 3 of Calculation Note FAI/09-19 in terms of the dimensionless water submergence (S/D) as a function of the Froude number, where S is the height of water above the bottom of the suction pipe, and D is the suction pipe diameter. The dimensionless Froude number is defined as U/[g D] 0*5 , where U is the one-dimensional superficial velocity, g is the acceleration of gravity, and D is the pipe internal diameter. The figure also provides a comparison of the air entrainment data from the D.C. Cook testing with the critical submergence values predicted by the Harleman and E-5

Enclosure to NL-16-01 08 Basis for Proposed Change Lubin-Springer methods. The experimental observations from the D.C. Cook testing demonstrate that both methods provide conservative prediction of the onset of air intrusion in tank suction piping.

The Harleman correlation has been previously demonstrated to provide a conservative basis for determining the minimum submergence for pump suction lines necessary to prevent air intrusion. Use of the Harleman correlation was previously approved by the NRC in a similar licensing application for the Joseph M. Farley Nuclear Plant (ADAMS Accession Number ML14155A302) (Reference 6).

The Harleman correlation was used to determine the critical submergence analytical limits for the HNP Unit 1 and 2 HPCI and RCIC CST suction line automatic transfer functions. These analytical limits were then used as an input to the calculations that were performed to determine the proposed TS AVs and their associated instrument setpoints. The Harleman correlation is presented on page 17 of 24 of Calculation Note FAI/09-19 and defines suction line submergence as the height of water above the centerline elevation for a vertical suction opening, as shown in Figure 5(b) of the calculation note. The Harleman correlation for a horizontal suction line with a vertical opening is given as:

SID= 0.75 [NFr] 0*4 + 0.5 or equivalently:

Where:

S = Height of water above bottom of suction pipe SH =Height of water above suction pipe centerline D = suction pipe diameter NFr = Froude number Calculation of analytical limits, allowable values, and instrument setpoints for the automatic HPCI and RCIC suction transfer was performed based on the Harleman correlation.

Additionally, the following hydraulic model assumptions were made:

HPCI Assumptions

• Full rated HPCI and RCIC flow from the CST was assumed for the duration of the HPCI suction transfer and was not reduced based on valve throttling during transition.

• RCIC and HPCI are both assumed to be operating at full flow for the duration of transfer.

• CST and suppression pool valve stroke times are based on reduced, post-accident voltage.

• Transfer time is based on the sum of the longest suppression pool suction valve stroke time and CST suction valve stroke time.

RCIC Assumptions

• Full rated RCJC flow from the CST was assumed for the duration of the RCIC suction transfer and was not reduced based on valve throttling during transition.

• No HPCI flow from the CST was assumed during the RCIC suction transfer since the HPCI suction transfer will have completed prior to initiation of the RCIC suction transfer.

• CST and suppression pool valve stroke times are based on reduced, post-accident voltage.

E-6

Enclosure to NL-16-01 08 Basis for Proposed Change

• Transfer time is based on the sum of the longest suppression pool suction valve stroke time and CST suction valve stroke time.

The HPCI and RCIC suction valve stroke times were developed using the BWROG DC Motor Method, which predicts the stroke time under design basis conditions. The method accounts for effects such as degraded voltage and elevated temperature by using an incremental approach to evaluate the valve stroke. The stroke time is determined by summing the times for all of the stroke increments.

The proposed TS AVs were developed using analytical limits that were determined using the Harleman correlation and the hydraulic model assumptions described above, and applying the appropriate instrument uncertainties, other than drift, which is applied to the AV to determine the nominal trip setpoint. Provisions for margin are included in the TS AVs to reduce the possibility of exceeding an AV during operations.

It is noted that the currently installed instrumentation that provides initiation of the automatic HPCI suction transfer on low CST level consists of magnetic level switches. The proposed increase in TS AVs for the HPCI suction transfer functions will result in instrument setpoints that are higher than the upper level taps for these instruments, and that would be outside the adjustable range of the installed instruments without a significant modification to the CSTs to relocate the upper level taps. As a result, a design change has been developed to change the HPCI instruments from magnetic level switches to pressure switches. The pressure switches will be installed in the lower tap for the existing level instrumentation and will not require structural modification of the CSTs. This instrumentation change is not included within the scope of the change for which approval is requested. The plant modification implementing the instrument change will be performed and controlled under the provisions of 10 CFR 50.59.

There are no changes to the CST level instrumentation type for the RCIC suction transfer function.

4.0 Regulatory Evaluation 4.1 Applicable Regulatory Requirements/Criteria The HNP Unit 1 construction permit was received under the seventy (70) general criteria identified in 32 FR 10213, published July 11, 1967 (ML043310029). The following NRC requirements and guidance documents were evaluated for their applicability to the proposed change.

HNP Unit 1 Equivalent: 1967 GOG Criterion 37- Engineered Safety Features Basis for Design Engineered safety feature shall be provided in the facility to back up the safety provided by the core design, the reactor coolant pressure boundary, and their protection systems. As a minimum such engineered safety features shall be designed to cope with any size reactor coolant pressure boundary break up to and including the circumferential rupture of any pipe in that boundary assuming unobstructed discharge from both ends.

HNP Unit 1 Equivalent: 1967 GOG Criterion 44 - Emergency Core Cooling System Capability E-7

Enclosure to NL-16-01 08 Basis for Proposed Change At least two emergency core cooling systems, preferably of different design principles, each with a capability for accomplishing abundant emergency core cooling, shall be provided. Each emergency core cooling system and the core shall be designed to prevent fuel and clad damage that would interfere with the emergency core cooling function and to limit the clad metal-water reaction to negligible amounts for all sizes of breaks in the reactor coolant pressure boundary, including the double-ended rupture of the largest pipe. The performance of each emergency core cooling system shall be evaluated conservatively in each area of uncertainty. The systems shall not share active components and shall not share other features or components unless it can be demonstrated that (a) the capability of the shared feature or component to perform its required function can be readily ascertained during reactor operation, (b) failure of the shared feature or component does not initiate a loss-of-coolant accident, and (c) capability of the shared feature or component to perform its required function Is not impaired by the effects of a loss-of-coolant accident and is not lost during the entire period this function Is required following tan accident.

HNP Unit 2 was licensed under the current 10 CFR Part 50 Appendix A GDCs. The following GDC is applicable to Unit 2:

Criterion 33-Reactor coolant makeup A system to supply reactor coolant makeup for protection against small breaks in the reactor coolant pressure boundary shall be provided. The system safety function shall be to assure that specified acceptable fuel design limits are not exceeded as a result of reactor coolant loss due to leakage from the reactor coolant pressure boundary and rupture of small piping or other small components which are part of the boundary. The system shall be designed to assure that for onsite electric power system operation (assuming offsite power is not available) and for offsite electric power system operation (assuming onsite power is not available) the system safety function can be accomplished using the piping, pumps, and valves used to maintain coolant inventory during normal reactor operation.

There are no regulatory requirements associated with use of the CST as the non-safety related suction source for HPCI or RCIC as an RCS makeup source. The design basis, safety related source of water for these systems is the suppression pool. The proposed change ensures the automatic transfer from the CST to the suppression pool occurs without adversely impacting HPCI or RCIC system availability or operation. Therefore, the proposed change is consistent with the requirements of the applicable GDC.

10 CFR 50.36, Technical Specifications, Criterion 3, requires that Technical Specification limiting condition for operation be established for:

A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

10 CFR 50.36, Technical Specifications, Criterion 4 requires that Technical Specification limiting condition for operation be established for:

E-8

Enclosure to NL-16-0108 Basis for Proposed Change A structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety There are no regulatory requirements associated with use of the CST as the non-safety related suction source for HPCI or RCIC . The design basis, safety related source of water for these systems is the suppression pool. The proposed change ensures the automatic transfer from the CST to the suppression pool occurs without adversely impacting HPCI or RCIC system availability or operation. Therefore, the proposed change is consistent with the requirements of 10 CFR 50.36.

4.2 No Significant Hazards Determination Analysis Southern Nuclear Operating Company (SNC) requests a License Amendment for Plant Hatch, Units 1 and 2 Technical Specifications (TS). The proposed changes increase the Allowable Values (AV) specified in TS Table 3.3.5.1-1 for automatic transfer of the High Pressure Coolant Injection (HPCI) pump suction alignment from the condensate storage tank (CST) to the suppression pool for Units 1 and 2. The proposed change also increases the AV specified in TS Table 3.3.5.2-1 for automatic transfer of the Reactor Core Isolation Cooling (RCIC) pump suction alignment from the CST to the suppression pool for Unit 1.

SNC has evaluated whether or not a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of Amendment," as discussed below.

1. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed change ensures the HPCI and RCIC pump automatic suction transfer functions from the CST to the suppression pool occur without introducing the possibility of vortex formation or air intrusion in the HPCI or RCIC pump suction path. The water level of the CTS on automatic suction transfer of the HPCI and RCIC systems to the suppression pool is not an initiator or precursor to any accident previously evaluated.

The CST water source is not assumed to mitigate the consequences for any design basis accident, but is assumed as a water source for the RCIC when mitigating a station blackout event. The revised AV will ensure the RCIC can perform this function.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed change ensures the HPCI and RCIC pump automatic suction transfer functions from the CST to the suppression pool occur without introducing the possibility of vortex formation or air intrusion in the HPCI or RCIC pump suction path. HPCI, RCIC, and CST design functions are unaffected by this change. The change to the HPCI and RCIC automatic suction transfer functions would not create the possibility of any credible failure mechanism not considered in the design and licensing basis.

E-9

Enclosure to NL-16-01 08 Basis for Proposed Change Additionally, no new credible failure modes for the CST are introduced by the proposed changes.

Therefore, the proposed changes do not create the possibility of a new or different kind of accident from any previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No The proposed change ensures the HPCI and RCIC pump automatic suction transfer functions from the CST to the suppression pool occur without introducing the possibility of vortex formation or air intrusion in the HPCI or RCIC pump suction path. The applicable margins of safety are the AVs for the HPCI and RCIC pump automatic suction transfer functions. The proposed change increases the margin of safety by revising the affected AVs to address more severe circumstances than considered in the current AVs. The proposed change does not exceed or alter a design basis or safety limit.

Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Based upon the above, SNC concludes that the proposed amendment presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a finding of no significant hazards consideration is justified.

4.3 Conclusion In conclusion, based on the considerations discussed above, SNC concludes: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 Environmental Consideration A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed change does not involve: (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any effluent that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed change.

6.0 References

1) GE Nuclear Energy, "Hatch Units 1 and 2, SAFERIGEST-LOCA Loss-of-Coolant Accident Analysis," NEDC-32720P, March 1997.

E-10

Enclosure to NL-16-01 08 Basis for Proposed Change 2} Fauske and Associates, Inc., "Vortex Evaluation for Vogtle and Farley RWSTs and Hatch CSTs", FAI/09-19, Rev. 1, dated April2014.

3) Letter from C.R. Pierce (SNC) to Document Control Desk (NRC), Joseph M. Farley Nuclear Plant - Units 1 and 2, Supplement to Response for Additional Information Regarding Condensate Storage Tank Minimum Level License Amendment Request, NL-12-0867, dated June 16, 2014, (ADAMS Accession Number ML14167A493)

4) Harleman, D. R. (1959). "Selective Withdrawal from a Vertically Stratified Fluid".

Proceedings, Eighth Congress of the International Association for Hydraulics Research, pp 10-C-1 to 10-C-16.

5) Lubin, B.T and Springer (1967}, The Formation of a Dip on the Surface of a Liquid Draining From a Tank", Journal of Fluid Dynamics, 29, pp 385-390.

6) Letter from S.A. Williams (NRC) to C.R. Pierce (SNC), Joseph M. Farley Nuclear Plant, Units 1 and 2, Amendment Regarding Minimum Condensate Storage Tank Level Technical Specification (TAC NOS ME9293 and ME9294), dated August 15, 2014, (ADAMS Accession Number ML14155A302)

E-11

Enclosure to NL-16-01 08 Basis for Proposed Change Table 1 Dimensions and Values Used in Hydraulic Model Calculations Parameter Unit 1 Unit 2 CST Values CST, inside diameter (ft) 46.5 43.9375 Bottom elevation (ft) 1 130.0 130.0 HPCI I RCIC Pump Suction Pipe Values HPCI pump CST suction centerline elevation (ft) 131.0 131.0 HPCI pump CST suction pipe inside diameter (in) 14.376 15.624 HPCI suction line CST penetration azimuth 182° 165° (degrees)

RCIC pump CST suction centerline elevation (ft) 130.5 NIA RCIC pump CST suction pipe inside diameter (in) 5.761 NIA RCIC suction line CST penetration azimuth 88° 240° (degrees)

HPCI I RCIC Pump Suction Valve Stroke Times HPCI suction transfer valve stroke time, total 229.3 159 (sec)

RCIC suction transfer valve stroke time, total (sec) 94 NIA HPCI I RCIC Pump Values HPCI pump design flow (gpm) 4,250 4,250 RCIC pump design flow (gpm) 400 400 Notes:

1 Corresponds with instrument zero E-12

Attachment 1 Existing TS Pages Marked to Show the Proposed Change

ECCS Instrumentation 3.3.5.1 Table 3.3.5.1-1 {page 3 of 5)

Emergency Core Cooling System Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTIONA.1 REQUIREMENTS VALUE

3. High Pressure Coolant Injection (HPCI) System

a. Reactor Vessel Water 1, 4 B SR 3.3.5.1.1 ~ -47 inches Level- Low Low, 2(d), 3(d) SR 3.3 .5. 1.2 Level2 SR 3.3.5. 1.4

• SR 3.3.5.1.5

b. Drywell Pressure - High 1, 4 B SR 3.3.5.1.1 ~ 1.92 psig 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5 c

T

c. Reactor Vessel Water 1, 2 SR 3.3.5.1.1 5 56.5 inches Level- High , Level 8 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

d. Condensate Storage 1, 2 D SR 3.3.5.1.3 ~~

Tank Level - Low 2(d), 3(d) SR 3.3.5.1.5

e. Suppression Pool 1, 2 D SR 3.3.5.1.1 ~ 154 inches Water Level - High 2(d), 3(d) SR 3.3.5. 1.2 SR 3.3.5. 1.4 SR 3.3.5. 1.5

f. High Pressure Coolant 1, E SR 3.3.5.1.1 <:605 gpm Injection Pump 2(d), 3(d) SR 3.3.5.1.2 and Discharge Flow - Low SR 3.3.5.1.4 ~ 865 gpm (Bypass) SR 3.3.5.1.5 (continued)

(d) With reactor steam dome pressure > 150 psig.

HATCH UNIT 1 3.3-41 Amendment No. 266 I

RCIC System Instrumentation 3.3.5.2 Table 3.3.5.2-1 (page 1 of 1)

Reactor Core Isolation Cooling System Instrumentation CONDITIONS REQUIRED REFERENCED CHANNELS FROM PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION FUNCTION ACTIONA.1 REQUIREMENTS VALUE

1. Reactor Vessel Water Level - 4 B SR 3.3.5.2.1 01:-47 inches Low Low, Level 2 SR 3.3.5.2.2 SR 3.3.5.2.4 SR 3.3.5.2.5

2. Reactor Vessel Water Level - 2 c SR 3.3.5.2.1 s 56.5 inches High, Level 8 SR 3.3.5.2.2 SR 3.3.5.2.4 SR 3.3.5.2.5

3. Condensate Storage Tank 2 D SR 3.3.5.2.3 Level- Low SR "3.3.5.2.5

4. Suppression Pool Water 2 D SR 3.3.5.2.3 s 151 inches Level- High SR 3.3.5.2.5 HATCH UNIT 1 3.3-47 Amendment No. 266

ECCS Instrumentation 3.3.5.1 Table 3.3.5.1-1 (page 3 of 5)

Emergency Core Cooling System Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTIONA.1 REQUIREMENTS VALUE

3. High Pressure Coolant Injection (HPCI) System

a. Reactor Vessel Water 1' 4 B SR 3.3.5.1.1 2! -47 inches Level- Low Low, 2(d), 3(d) SR 3.3.5.1.2 Level2 SR 3.3.5.1.4 SR 3.3.5.1.5

b. Drywell Pressure - High 1' 4 B SR 3.3.5.1.1 s 1.92 psig 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1 .5

c. Reactor Vessel Water 1' 2 c SR 3.3.5.1.1 s 56.5 inches Level - High, Level 8 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

d. Condensate Storage Tank Level - Low 1'

2(d), 3(d) 2 D SR 3.3.5.1.3 SR 3.3.5.1.5 2! ~

e. Suppression Pool 1' 2 D SR 3.3.5.1.1 s 154 inches Water Level - High 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

f. High Pressure Coolant 1' E SR 3.3.5.1.1 <: 590 gpm Injection Pump 2(d), 3(d) SR 3.3.5.1.2 and Discharge Flow - Low SR 3.3.5.1.4 s 845 gpm (Bypass) SR 3.3.5.1.5 (continued)

(d) With reactor steam dome pressure > 150 psig.

HATCH UNIT 2 3.3-41 Amendment No. 210

Attachment 2 Revised (Clean) TS Pages

ECCS Instrumentation 3.3.5.1 Table 3.3.5.1-1 (page 3 of 5)

Emergency Core Cooling System Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTIONA.1 REQUIREMENTS VALUE

3. High Pressure Coolant Injection (HPCI) System

a. Reactor Vessel Water 1, 4 B SR 3.3.5.1.1 ~ -47 inches Level - Low Low, 2(d), 3(d) SR 3.3.5.1.2 Level2 SR 3.3.5.1.4 SR 3.3.5.1 .5

b. Drywell Pressure - High 1, 4 B SR 3.3.5.1.1 s 1.92 psig 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1 .5

c. Reactor Vessel Water 1, 2 c SR 3.3.5.1.1 s 56.5 inches Level- High, Level 8 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

d. Condensate Storage 1, 2 D SR 3.3.5.1.3 ~ 3.52 ft Tank Level -Low 2(d), 3(d) SR 3.3.5.1.5

e. Suppression Pool 1, 2 D SR 3.3.5.1.1 s 154 inches Water Level - High 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

f. High Pressure Coolant 1, E SR 3.3.5.1.1 ~ 605 gpm Injection Pump 2(d), 3(d) SR 3.3.5.1.2 and Discharge Flow - Low SR 3.3.5.1.4 s 865 gpm (Bypass) SR 3.3.5.1.5 (continued)

(d) With reactor steam dome pressure > 150 psig.

HATCH UNIT 1 3.3-41 Amendment No.

RCIC System Instrumentation 3.3.5.2 Table 3.3.5.2-1 (page 1 of 1)

Reactor Core Isolation Cooling System Instrumentation CONDITIONS REQUIRED REFERENCED CHANNELS FROM PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION FUNCTION ACTION A.1 REQUIREMENTS VALUE

1. Reactor Vessel Water Level - 4 B SR 3.3.5.2.1 ~ -47 inches Low Low, Level2 SR 3.3.5.2.2 SR 3.3.5.2.4 SR 3.3.5.2.5

2. Reactor Vessel Water Level - 2 c SR 3.3.5.2.1 s 56.5 inches High, Level 8 SR 3.3.5.2.2 SR 3.3.5.2.4 SR 3.3.5.2.5

3. Condensate Storage Tank 2 D SR 3.3.5.2.3 ~ 1.0 ft Level - Low SR 3.3.5.2.5

4. Suppression Pool Water 2 D SR 3.3.5.2.3 s 151 inches Level- High SR 3.3.5.2.5 HATCH UNIT 1 3.3-47 Amendment No.

ECCS Instrumentation 3.3.5.1 Table 3.3.5.1-1 (page 3 of5)

Emergency Core Cooling System Instrumentation APPLICABLE CONDITIONS MODES REQUIRED REFERENCED OR OTHER CHANNELS FROM SPECIFIED PER REQUIRED SURVEILLANCE ALLOWABLE FUNCTION CONDITIONS FUNCTION ACTIONA.1 REQUIREMENTS VALUE

3. High Pressure Coolant Injection (HPCI) System

a. Reactor Vessel Water 1' 4 B SR 3.3.5.1.1 <: -47 inches Level - Low Low, 2(d), 3(d) SR 3.3.5.1.2 Level2 SR 3.3.5.1.4 SR 3.3.5.1.5

b. Drywell Pressure - High 1' 4 B SR 3.3.5.1.1 s 1.92 psig 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

c. Reactor Vessel Water 1' 2 c SR 3.3.5.1.1 s 56.5 inches Level - High, Level 8 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

d. Condensate Storage 1' 2 D SR 3.3.5.1.3  ;:: 3.25 ft Tank Level - Low 2(d), 3(d) SR 3.3.5.1 .5

e. Suppression Pool 1' 2 D SR 3.3.5.1.1 s 154 inches Water Level - High 2(d), 3(d) SR 3.3.5.1.2 SR 3.3.5.1.4 SR 3.3.5.1.5

f. High Pressure Coolant 1' E SR 3.3.5.1.1 <: 590 gpm Injection Pump 2(d), 3(d) SR 3.3.5.1.2 and Discharge Flow - Low SR 3.3.5.1.4 s 845 gpm (Bypass) SR 3.3.5.1.5 (continued)

(d) With reactor steam dome pressure> 150 psig.

HATCH UNIT2 3.3-41 Amendment No.