ML13297A307

Issuance of an Amendment Regarding Changing Technical Specification Table 3.3-4 for Degraded Voltage Time Delay Values

ML13297A307
Person / Time
Site:	Harris
Issue date:	12/17/2013
From:	Andrew Hon Plant Licensing Branch II
To:	Kapopoulos E Progress Energy Carolinas
Hon A
References
TAC MF0308
Download: ML13297A307 (19)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON , D.C. 20555-0001 Decer:tber 17, 2013 Mr. Ernest J. Kapopoulos Site Vice President Shearon Harris Nuclear Power Plant 5413 Shearon Harris Road New Hill, NC 27562-0165

SUBJECT:

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 - ISSUANCE OF AN AMENDMENT REGARDING TECHNICAL SPECIFICATION TABLE 3.3-4 FOR DEGRADED VOLTAGE TIME DELAY VALUES (TAC NO. MF0308)

Dear Mr. Kapopoulos:

The U.S. Nuclear Regulatory Commission (NRC) has issued the enclosed Amendment No. 143 to Renewed Facility Operating License No. NPF-63 for the Shearon Harris Nuclear Power Plant Unit 1 (HNP). The amendment changes the HNP Technical Specifications (TSs) in response to your application dated November 29, 2012. In response to the NRC staff request, the licensee provided supplemental information by letters dated January 3 and June 4, 2013 (Agencywide Documents Access and Management System Accession numbers ML13003A214 and ML13156A061 ).

This amendment revises TS Table 3.3-4 associated with 6.9 kilovolt Emergency Bus Secondary Undervoltage time delay values to resolve a nonconservative TS .

A copy of the related safety evaluation is enclosed. A notice of issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

~ ~...___--

Andrew Hon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-400

Enclosures:

1. Amendment No. 143 to NPF-63

2. Safety Evaluation cc w/enclosures: Distribution via ListServ

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON , D.C. 20555-0001 DUKE ENERGY PROGRESS. INC.

DOCKET NO. 50-400 SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 143 Renewed License No. NPF-63

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Carolina Power & Light Company (now Duke Energy Progress, Inc., the licensee), dated November 29, 2012, as supplemented by letters dated January 3, and June 4, 2013, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) , and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specifications, as indicated in the attachment to this license amendment; and paragraph 2.C.(2) of Renewed Facility Operating License No. NPF-63 is hereby amended to read as follows:

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, as revised through Amendment No.143 , are hereby incorporated into this license.

Duke Energy Progress, Inc. shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3. This license amendment is effective as of the date of its issuance and shall be implemented within 90 days.

FOR THE NUCLEAR REGULATORY COMMISSION ie. ~~

lant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to Renewed Facility Operating License No. NPF-63 and the Technical Specifications Date of Issuance: December 17, 2013

ATTACHMENT TO LICENSE AMENDMENT NO. 143 RENEWED FACILITY OPERATING LICENSE NO. NPF-63 DOCKET NO. 50-400 Replace the following pages of the Renewed Facility Operating License and Appendix "A" Technical Specifications (TSs) with the enclosed pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove License NPF-63 License NPF-63 Page4 Page4 TS Page TS Page 3/4 3-34 3/4 3-34

C. This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect, and is subject to the additional conditions specified or incorporated below.

(1) Maximum Power Level Duke Energy Progress, Inc. is authorized to operate the facility at reactor core power levels not in excess of 2948 megawatts thermal (1 00 percent rated core power) in accordance with the conditions specified herein.

(2) Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, as revised through Amendment No. 143, are hereby incorporated into this license. Duke Energy Progress, Inc. shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan .

(3) Antitrust Conditions Duke Energy Progress, Inc. shall comply with the antitrust conditions delineated in Appendix C to this license.

(4) Initial Startup Test Program (Section 14)1 Any changes to the Initial Test Program described in Section 14 of the FSAR made in accordance with the provisions of 10 CFR 50.59 shall be reported in accordance with 50.59(b) within one month of such change .

1The parenthetical notation following the title of many license conditions denotes the section of the Safety Evaluation Report and/or its supplements wherein the license condition is discussed .

Renewed License No. NPF-63 Amendment No. 143

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS SENSOR TOTAL ERROR FUNCTIONAL UNIT ALLOWANCE (TA) ~ .lli) TRIP SETPOINT ALLOWABLE VALUE

9. Loss of Offsite Power

a. 6.9 kV Emergency Bus N.A. N.A. N.A. <:: 4830 volts with a <:: 4692 volts with a Undervoltage- Primary s 1.0 second time time delays 1.5 (Loss of Voltage) delay seconds

b. 6.9 kV Emergency Bus N.A. N.A. N.A. <:: 6420 volts with a <:: 6392 volts with a Undervoltage - Secondary s 12.88 second s 13.21 second time (Degraded Voltage) time delay (with delay (with Safety Safety Injection). Injection).

<:: 6420 volts with a <:: 6392 volts with a s 57.89 second s 59 .62 second time time delay delay (non-accident).

(non-accident).

10. Engineered Safety Features Actuation System Interlocks

a. Pressurizer Pressure, P-11 N.A. N.A. N.A. <:: 2000 psig <:: 1988 psig Not P-11 N.A. N.A. N.A. s 2000 psig s 2012 psig

b. Low Low Tavg , P-12 N.A. N.A. N.A. <:: 553°F <:: 549.3°F SHEARON HARRIS - UNIT 1 3/4 3-34 Amendment No. 143

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON , D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 143 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-63 DUKE ENERGY PROGRESS, INC.

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400

1.0 INTRODUCTION

By letter dated November 29, 2012 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML123350104), as supplemented January 3 and June 4, 2013 (ADAMS Accession Nos. ML13003A214 and ML13156A061 ), Carolina Power & Light Co.

(CP&L, the licensee; now Duke Energy Progress, Inc.) requested an amendment to Operating License Number NPF-63 for Shearon Harris Nuclear Power Plant, Unit 1 (HNP).

The license amendment revises Technical Specification (TS) Table 3.3-4 associated with 6.9 kilovolt (kV) Emergency Bus Secondary Undervoltage (degraded voltage) time delay values to resolve a nonconservative TS item, identified in the Nuclear Regulatory Commission (NRC)

Inspection Report 05000400/2011008. Specifically, the licensee amendment revises the time delay values (allowable and trip setpoints values) of degraded voltage relays (DVRs) when subjected to a degraded voltage condition coincident with a safety injection signal associated with a loss-of-coolant accident (LOCA), and a sustained degraded voltage condition without an accident. The revised DVR time delay values will support the LOCA analysis timeline assuming the LOCA occurs concurrent with a sustained degraded voltage condition .

The supplements dated January 3, and June 4, 2013 provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the staff's initial proposed no significant hazards consideration determination as published in the Federal Register on November 12, 2013 (78 FR 67405).

2.0 REGULATORY EVALUATION

The proposed amendment would revise TS Table 3.3-4 associated with 6.9 kV Emergency Bus Secondary Undervoltage time delay values to resolve a nonconservative TS. The proposed amendment would revise the degraded voltage function in TS Table 3.3-4, Functional Unit 9-Enclosure

Loss-of-Offsite Power (LOOP), 6.9 kV Emergency Bus Undervoltage- Secondary. Specifically, the amendment would:

1. Revise the Allowable Value with voltage greater than or equal to (~) 6392 volts with a time delay less than or equal to (:5) 18 seconds (with Safety Injection) to s 13.21 second time delay. This includes an editorial change to make the word structure of the requirement consistent with the existing verbiage of the other criteria in that section of the table.

2. Revise the Allowable Value with voltage ~ 6392 volts with a ::;; 60 second time delay (without Safety Injection) to::;; 59.62 second time delay.

3. Revise the Trip Setpoint with voltage ~ 6420 volts with a ::;; 16 second time delay (with Safety Injection) to::;; 12.88 second time delay.

4. Revise the Trip Setpoint with voltage ~ 6420 volts with a ::;; 54 second time delay (without Safety Injection) to ::;; 57.89 second time delay.

5. Add clarifications to the functional unit descriptions such that the primary setpoints apply to loss of voltage condition and the secondary setpoints apply to degraded voltage condition.

6. Revise clarifications for the degraded voltage allowable value and trip setpoint to change "without safety injection" to "non-accident."

2.1 Regulatory Requirements The staff considered the following regulatory requirements.

Title 10 of the Code of Federal Regulations (1 0 CFR) Part 50, "Domestic Licensing of Production and Utilization Facilities," establishes the fundamental regulatory requirements.

Specifically Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50 provides criteria for the necessary design, fabrication, construction, testing, and performance requirements for structures, systems, and components important to safety.

General Design Criterion (GDC) 17, "Electric power systems," requires, in part, that an onsite electrical power system and an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for each system shall be to provide sufficient capacity and capability to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated accidents. The LOOP instrumentation settings and control in the TSs assures proper operation of safety-related loads as required by GDC 17.

GDC 13, "Instrumentation and Control," requires that instrumentation be provided to monitor variables and systems and that controls be provided to maintain these variables and systems within prescribed operating ranges.

GDC 20, "Protection System Functions," requires that the protection system be designed to initiate the operation of appropriate systems to ensure that specified acceptable fuel design limits are not exceeded.

Section 36 of 10 CFR, Part 50, Technical Specifications," requires the TSs shall be included by applicants for a license authorizing operation of a production or utilization facility. It states in 10 CFR 50.36(c) that TSs include items in five specific categories related to station operation.

These categories are (1) Safety limits, limiting safety system settings, and limiting control settings, (2) Limiting conditions of operation (LCOs), (3) Surveillance requirements (SRs),

(4) Design features, and (5) Administrative controls. The proposed changes to TSs, discussed in this safety evaluation, are within the LCOs and the SRs categories.

2.2 Regulatory Guidance:

The staff considered the following guidance:

The staff considered Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants (NUREG-0800), Branch Technical Position (BTP} 8-6, March 2007 (similar to the previous BTP PSB-1, July 1981) "Adequacy of Station Electric Distribution System Voltages." This BTP states that the TSs should include LCOs, SRs, trip setpoints, and maximum and minimum allowable values for the first level of undervoltage protection (LOOP) relays and the second level (degraded voltage) protection sensors and associated time delay devices.

The staff considered the regulatory guidance provided in Regulatory Guide (RG) 1.1 05, "Setpoints for Safety-Related Instrumentation," Revision 3, issued December 1999, (ADAMS Accession No. ML993560062), which describes a method that the NRC staff considers acceptable for complying with the agency's regulations for ensuring that setpoints for safety-related instrumentation are initially within and will remain within the TS limits.

RG 1.105 endorses Part I of Instrument Society of America (ISA) Standard 67.04-1994, "Setpoints for Nuclear Safety-Related Instrumentation," subject to NRC staff's clarifications. The staff used this guide to establish the adequacy of the licensee's setpoint calculation methodologies and the related plant surveillance procedures.

3.0 TECHNICAL EVALUATION

According to HNP's updated final safety analysis report (UFSAR), Section 8.3, 6.9 kV safety-related Class 1E Buses 1A-SA and 1B-SB supply power to equipment essential for safe shutdown of the plant. These two buses receive power from the upstream nonsafety-related Buses 1D and 1E, which are fed from offsite power. In case of loss of offsite power or sustained offsite degraded voltage conditions, 6.9 kV Class 1E buses are fed from emergency diesel generators (EDGs).

The two 6.9 kV Class 1E buses are provided with two sets of undervoltage protection: Loss of Voltage Relaying (primary undervoltage protection) and Degraded Voltage Relaying (secondary

undervoltage protection). Each DVR is connected to two distinct time delay relays. The first time delay relay, termed as the short-term time delay relay (2-1 ), provides a time delay long enough to accommodate the longest motor starting time. At the expiration of the short-term time delay, during a LOCA concurrent with a sustained degraded voltage condition event, the emergency buses get automatically separated from the offsite power; the loads on emergency buses are shed; the EDG output breaker is closed ; and the emergency loads are sequenced back onto the emergency buses. The second time delay relay, termed as the long-term time delay relay (2-2), provides a time delay based on the maximum time for which the most sensitive load can perform its safety function without impairment at the sustained degraded voltage. If sustained degraded voltage conditions continue to exist without a coincident accident, the automatic tripping actions are initiated after expiration of the relay 2-2 time delay.

In the NRC Inspection Report 05000400/2011008, dated August 9, 2011 (ADAMS Accession No. ML112220337), the inspectors identified that the licensee had not analyzed whether electrical equipment needed to respond to an accident would be energized by the EDGs within the time considered in the accident analysis if a degraded voltage condition existed concurrent with an accident. In particular, the following is stated in the inspection report (page 12, Example 2: Degraded Voltage Time Delay Not Analyzed for Consistency with the Accident Analysis):

Branch Technical Position (BTP) PSB-1, [July 1981] Position 8.1 (b) states that two separate time delays shall be selected for the degraded voltage relays; one that is in effect when a safety injection actuation signal (SIAS) is present, and another that is in effect in the absence of a SIAS. PSB-1 also requires that the selection of undervoltage and time delay setpoints be based on an analysis of the voltage requirements of Class 1E loads. TS Table 3.3-4 establishes the Allowable Value for the Secondary Loss of Offsite Power (degraded voltage) relay time delay with Safety Injection as

s; 18 seconds. (Note that the Allowable Value is the acceptable as-found value during a surveillance and that the actual time delay during an event could be longer than 18 seconds, considering errors such as M&TE [measurement and test equipment]

accuracy).

UFSAR 8.3.1.1.2.11 states that the time delay associated with the undervoltage relays will be consistent with the maximum time delay considered in the design basis accident analysis. The UFSAR statement is consistent with guidance provided to HNP by the NRC in a letter to J.A. Jones (CP&L) dated 11/21/1978. CP&L Letter M.A. McDuffie to NRC dated August 31, 1982 stated, "The time delay associated with the undervoltage relays shall be consistent with the maximum time delay considered in the design basis accident analysis and shall prevent spurious tripping due to short time transient conditions."

Attachment J of Calculation E2-0005.09, which analyzed the time delays for the degraded voltage relays, provided several time lines for ECCS [emergency core cooling system] response times. These timelines included 10 seconds for EDG start time but did not consider the time delay associated with the degraded voltage relays that provide the permissive for the EDG supply breaker for the safety buses to close. The team noted that UFSAR Table 15.6.5-3 indicated that for a large break Loss of Coolant Accident (LOCA), high pressure safety injection (HPSI) and low pressure safety injection

(LPSI) were assumed to occur at 29 seconds after the SIAS signal. The team was concerned that, considering an approximately 18+ seconds time delay before the safety

. buses were transferred to the EDGs, in addition to sequencer time delays (i.e.,

5.5 seconds for RHR [residual heat removal] pumps), and pump acceleration time, the accident analysis assumptions may not be satisfied. In response to the team's inquiries, the licensee was not able to provide formal analysis that demonstrated that the time delay specified in TS Table 3.3-4 was consistent with 29 seconds for HPSI and LPSI assumed in the accident analysis.

To resolve the above concern in the inspection report, the licensee has proposed to revise the maximum degraded voltage time delay values to be consistent with the design-basis-accident analysis. The licensee has also updated the UFSAR including the LOCA accident analysis in December 2012. The current UFSAR Table 15.6.5-1 indicates that, for a large break LOCA with a LOOP event, the allowable high head safety injection (HHSI) pump delay is 29 seconds and the allowable low head safety injection (LHSI) pump delay is 37 seconds.

Proposed changes to the TS Table 3.3-4, Functional Unit 9 The main proposed change in the LAR is to lower the short-term time delay associated with the DVR (relay 2-1) Trip Setpoint (with SIAS) from~ 16 seconds to~ 12.88 seconds and the short-term time delay associated with the DVR (relay 2-1) Allowable Value (with SIAS) from

~ 18 seconds to~ 13.21 seconds, so that flows from HHSI and LHSI pumps are ensured within the accident analysis timings of 29 seconds and 37 seconds, respectively.

In the LAR, the licensee stated that the maximum short-term DVR time delay analytical limit is 13.3 seconds, which will support the design basis limiting peak cladding temperature LOCA timeline for safety functions. Uncertainties including accuracy, calibration tolerance, M&TE error, and drift contribute to a total loop uncertainty (TLU) of 0.42 seconds. The maximum analytic limit of 13.3 seconds is reduced by the TLU value of 0.42 seconds to yield the maximum trip setpoint of 12.88 seconds. The as-left tolerance, instrument drift, and M&TE error contribute to a group as-found tolerance (AFT) of 0.33 seconds. The group AFT of 0.33 seconds is added to the maximum trip setpoint of 12.88 seconds to yield the maximum allowable value of 13.21 seconds.

Another proposed change in the LAR is to revise the long-term time delay associated with the DVR (relay 2-2) Trip Setpoint (without SIAS) from~ 54 seconds to~ 57.89 seconds, and the long-term time delay associated with the DVR (relay 2-2) Allowable Value (without SIAS) from

~ 60 seconds to~ 59.62 seconds. This change is proposed because in the current TS, the Allowable Value (without SIAS) is equal to the Analytical limit of 60 seconds and, therefore, does not have any allowance for measure uncertainty in the Allowable Value of 60 seconds.

In the LAR, the licensee stated that the maximum long-term DVR time delay analytical limit is 60 seconds, based upon the specification that HNP motors are capable of "riding through" voltage transients of 75 percent of motor nameplate voltage for a minimum of 60 seconds.

Uncertainties including accuracy, calibration tolerance, M&TE error, and drift contribute to a TLU of 2.11 seconds. The maximum analytic limit of 60.0 seconds is reduced by the TLU value of 2.11 seconds to yield the maximum trip setpoint of 57.89 seconds. The as-left tolerance, instrument drift, and measurement equipment error contribute to a group AFT of 1.73 seconds.

The group AFT of 1. 73 seconds is added to the maximum trip setpoint of 57.89 seconds to yield the maximum allowable value of 59.62 seconds.

Other proposed changes in TS Table 3.3-4 are editorial.

Overall, the TS Table 3.3-4 (Function Unit- Loss of Offsite Power) will have the following proposed changes (the current and revised time delay values are underlined):

1. Revise the Allowable Value with voltage ~ 6392 volts with a < 18 second time delay (with Safety Injection) to :5 13.21 second time delay. This includes an editorial change to make the word structure of the requirement consistent with the existing verbiage of the other criteria in that section of the table.

2. Revise the Allowable Value with voltage ~ 6392 volts with a < 60 second time delay (without Safety Injection) to< 59.62 second time delay.

3. Revise the Trip Setpoint with voltage ~ 6420 volts with a < 16 second time delay (with Safety Injection) to :5 12.88 second time delay.

4. Revise the Trip Setpoint with voltage ~ 6420 volts with a < 54 second time delay (without Safety Injection) to< 57.89 second time delay.

5. Add clarifications to the functional unit descriptions such that the primary setpoints apply to loss of voltage condition and the secondary setpoints apply to degraded voltage condition.

6. Revise clarifications for the degraded voltage allowable value and trip setpoint to change "without safety injection" to "non-accident."

The staff evaluated the maximum and minimum analytical limits of DVR time delay relays (with and without SIAS). The staff also evaluated the derivation of the TS Trip Setpoint and Allowable Values based on the analytical limits.

3.1 Maximum Analytical Limit of Short Term DVR Time Delay (Relay 2-1) (with SIAS):

In its letter dated January 3, 2013, the licensee stated that high head and low head injection are key mitigating safety functions in the UFSAR analysis of large break LOCA. If oftsite power is lost due to concurrent LOCA and degraded voltage condition at the analytic limit of 13.3 seconds, the EDGs can provide power to LHSI and HHSI pumps resulting into LHSI flow at 26.3 seconds and HHSI flow at 27.3 seconds, which are less than the allowable timings (i.e.,

37 seconds for LHSI flow and 29 seconds for HHSI flow) considered in the current large break LOCA/LOOP analysis (UFSAR Table 15.6.5-1}. The licensee also provided a copy of the Calculation No. E2- 0005.09, Revision 4, "Degraded Grid Voltage Protection for 6.9kV Busses 1A-SA and 1B-SB," which provides the calculations for the proposed DVR time delays. In of this calculation, the licensee provided timelines for safety injection actuated equipment response times during a simultaneous occurrence of an accident and a degraded voltage condition. Based on a maximum analytical limit of 13.3 seconds for the short-term DVR (relay 2-1) time delay, the response times of Engineered Safety Features (ESF) equipment are

found within the analyzed equipment response times in case of accident concurrent with the LOOP scenario analyzed in Chapter 15 of UFSAR. As indicated in the Calculation No.

E2-0005.09, Revision 4, the licensee will implement a plant modification (EC 84101) to achieve necessary response time of ESF equipment.

Based on the review of Attachment 0 of the Calculation, No. E2-0005.09, Revision 4, the staff finds that the maximum analytical limit of 13.3 seconds for the short-term DVR time delay, in case of concurrent large break LOCA and degraded voltage conditions, is acceptable.

3.2 Minimum Analytical Limit of Short Term DVR Time Delay (Relay 2-1) (with SIAS):

To meet the intent of BTP PSB-1, the minimum time delay of the short term DVR time delay (relay 2-1) should be long enough to establish the existence of a sustained degraded voltage condition (i.e., a time longer than a motor starting transient, so as not to cause spurious actuation during starting of large motors). In the Calculation No. E2-0005.09, Revision 4, the licensee stated that the Normal Service Water start time of 10 seconds is bounding and establishes the minimum analytical limit for the degraded voltage time delay with SIAS. A margin of 0.5 seconds is added to this minimum time delay value to account for potential future plant changes. Thus the minimum analytical limit for the short term DVR time delay (relay 2-1) is 10.5 seconds.

The staff has reviewed the licenee's analysis and finds that the minimum analytical limit of 10.5 seconds for the short term DVR (relay 2-1) time delay is reasonable and acceptable, as it meets the intent of BTP PSB-1.

3.3 Maximum and Minimum Analytical Limits of Long Term DVR Time Delay (Relay 2-2)

(without SIAS):

For the long term DVR time delay (relay 2-2), the licensee has selected 60 seconds as the maximum analytical value. The licensee stated that this maximum analytical value is based on HNP motors capable of "riding through" voltage transients of 75 percent of motor nameplate voltage for a minimum of 60 seconds. The DVR time delay relay should provide at least a minimum time for operator action, and should be less than the maximum analytical value.

Based on this criterion and engineering judgment, the licensee selected 50 seconds as the minimum analytical value of time delay.

According to BTP PSB-1, the second time delay (without SIAS) should be of limited duration such that the permanently connected Class 1E loads will not be damaged. Following this delay, if the operator has failed to restore adequate voltage, the Class 1E distribution system should be automatically separated from the offsite power system.

Based on its review of the licensee's submission, the staff finds that the above maximum and minimum analytical limits for the long term DVR (relay 2-2) time delay meet the intent of BTP PSB-1 and are reasonable, and therefore acceptable.

3.4 Short Term DVR Time Delay (Relay 2-1) Setpoint Relay 2-1 controls the short term DVR time delay. The maximum analytical limit for the short term DVR time delay is 13.3 seconds. The current nonconservative allowable value is less than

(<) 18 seconds and the proposed allowable value is< 13.21 seconds. The current nonconservative trip setpoint is <16 seconds and the proposed trip setpoint is <12 seconds.

The staff reviewed the Relay 2-1 setpoint calculation in Section 3.0 of the LAR and in Section 4.2.4 and related attachments of HNP calculation E2-0005.09, Revision 4, submitted as an attachment to the supplemental letter dated January 3, 2013 (ADAMS Accession No. ML13003A214).

HNP calculated the Limiting Trip Setpoint by subtracting the TLU from the analytical limit as documented in Attachment I of HNP calculation E2-0005.09, Revision 4. The staff verified the TLU calculation and found the TLU conservative, but noted that there was no basis for the drift value.

HNP documented the value used for drift was an assumed value. The licensee confirmed via an August 22, 2013, email to aU. S. NRC Project Manager that the assumed value was derived from HNS procedure EGR-NGGC-0153, "Engineering Instrument Setpoints." The procedure, which is incorporated by reference in Table 1.6-4 of the HNP UFSAR, allows the use of an assumed 1-percent value for drift in cases where no other data is available. The procedure also requires the licensee to verify and update the assumed value, if needed, when recorded surveillance data becomes available.

The licensee similarly calculated values for the minimum short term DVR time delay based on a 10.5 second minimum analytical limit using the same TLU and AFT values used for maximum time delay. The licensee chose to add different amounts of margin to the maximum and minimum time delays. The differing amounts of margin are acceptable because for both minimum and maximum time delays, the limiting trip setpoints and allowable values are conservative without the additional margin. The maximum time delay margin is 0.88 seconds and the minimum time delay margin is 1.08 seconds. Figure 1 shows a graphical representation of the all the short term DVR time delay setpoints and margins.

The staff reviewed the licensee's allowable calculations and found that the proposed allowable value of 13.21 seconds and limiting trip setpoint of 12.88 seconds are conservative and meet the criteria of RG 1.1 05. The nominal trip setpoint of 12 seconds, which includes additional margin, is not listed in the TS.

Upper Analytical Limit= 13.3 seconds TI.U (0.42 *A FT Upper Allowable Value (132ls)

AIT(0.33)

Al Max Allowable Setpoint (12.88)

Margin (0.88s)

Setpoint 12 s Margin (1.08s)

~

Min Allowable Setpoint (10.92)

AIT(0.33)

TI.U (0.42)

, *AFT Lower Allowable Value {10.59s)

Lower Analvtical Limit = 10.5 seconds Figure 1- Short Term DVR Time Delay Setpoint Values (Relay 2-1) 3.5 Long Term DVR Time Delay (Relay 2-2) Setpoint Relay 2-2 controls the long term DVR time delay. The maximum analytical limit for the long term DVR time delay is 60 seconds. The licensee included accuracy, calibration tolerance, M& TE and drift in calculating the TLU of 2.11 seconds. The licensee determined the Limiting Trip Setpoint (LTSP) on subtracting 2.11 seconds from the analytical limit. The calculated LTSP is 57.89 seconds. The licensee's AFT calculation included as-left tolerance, instrument drift, and measurement equipment error. The licensee's calculated AFT is 1.73 seconds. The allowable value was calculated by adding the AFT to the LTSP. The calculated allowable value is 59.62 seconds. The licensee chose a nominal trip setpoint of 54 seconds, which includes 3.89 seconds of additional margin and is conservative.

The licensee similarly calculated values for the minimum long term DVR time delay based on a 50 seconds minimum (lower) analytical limit using the same TLU and AFT values used for maximum time delay. The licensee chose to add different amounts of margin to the maximum and minimum time delays. The differing amounts of margin are acceptable because for both minimum and maximum time delays, the limiting trip setpoints and allowable values are conservative even without the additional margin. The maximum time delay margin is 3.89 seconds and the minimum time delay margin is 1.89 seconds. Figure 2 shows a graphical representation of the all the long term DVR time delay setpoints and margins.

The staff reviewed the Relay 2-2 long term DVR time delay setpoint calculation in Section 3.0 of the LAR and in Section 4.2.5 and related attachments of HNP calculation E2-0005.09, Revision 4, submitted as an attachment to the supplemental letter dated January 3, 2013 (ADAMS Accession No. ML13003A214) .

The staff found that the proposed allowable value of < 59.62 seconds and limiting trip setpoint of

< 57.89 seconds are conservative and meet and the criteria of RG 1.1 05. The nominal trip setpoint of 54 seconds, which includes additional margin, is not listed in the TS.

Upper Analytical Limit = 60 seconds

,AfT UJ¥1" Allowable Value (59.62s)

TLu (2.11)

AFT (1.73)

Max Allowable Setpoint (57.89)

Margin (3 .89s)

Setpoint 54 Margin (1 .89s)

Min Allowable Setpoint (52.11)

AFT(l.73)

TLU (2 .11)

• AFT Lower Allowable Value (50.38s)

Lower Analvtical Limit= 50.0 seconds Figure 2- Long Term DVR Rime Delay Setpoint Values (Relay 2-2)

The staff also reviewed the other editorial TS changes and finds that the changes are administrative in nature and do not change the intent of the TS, and therefore acceptable.

3.6 Technical Specifications Task Force (TSTF) 493, Revision 4 The licensee stated in the license amendment request (LAR) that they previously adopted TSTF 493 for Limiting Safety System Settings (LSSSs). Although the DVR time delay relay setpoints are not limiting safety system settings, the licensee stated in the LAR that they followed the TSTF 493 method for calculating these setpoints because it is conservative.

The staff reviewed the licensee's method for calculating the allowable value, limiting trip setpoint, and AFT and found that they were consistent with the goals of TSTF 493. The staff also found that the DVR time delay relay is not an LSSS and the additional TSTF 493 TS notes are not required.

3.7 Summary The NRC staff's review finds that the proposed changes to the TS Table 3.3-4 associated with 6.9 kV Emergency Bus degraded voltage time delay values meets Commission guidance for allowing TS changes. The staff found the licensee performed the setpoint calculations for nominal trip setpoint, as-left tolerance and AFT to be in conformance with the requirements of RG 1.1 05. Furthermore, the staff found setpoint changes and changes to the TS comply with GDC 13, GDC 17, GDC 20, 10 CFR 50.36, and TSTF 493, Revision 4. The staff finds that the proposed changes toTS Table 3.3-4, Functional Unit 9- "Loss-of-Offsite Power (LOOP), 6.9 kV Emergency Bus Undervoltage - Secondary provide reasonable assurance of the availability of required safety equipment needed to shut down the reactor and keep it in a safe condition following a degraded voltage condition and an accident, and as such comply with 10 CFR 50.36 and GDC 17. Therefore, the proposed TS changes are acceptable.

4.0 REGULATORY COMMITMENTS There are no regulatory commitments in the license amendment request dated November 29, 2012.

5.0 STATE CONSULTATION

In accordance with the Commission's regulations, the North Carolina State official was notified of the proposed issuance of the amendments. The State official had no comments.

6.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (78 FR 67405) . Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51 .22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

7.0 CONCLUSION

The NRC has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) there is reasonable assurance that such activities will be conducted in compliance with the NRC'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.

Principal Contributor: Adakou Foli Stephen Wyman Date: December 17, 2013

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• STSB/BC NAME JDion AHon BCiayton JZimmerman REIIiott DATE 11/21/13 11/21/13 11/14/13 11/22/13 12/16/13 OFFICE EICB/BC OGC LPL2-2/BC LPL2-2/PM NAME JThorp

• BMizuno JQuichocho AHon DATE 11/22/13 12/3/13 12/17/13 12/17/13