ONS-2017-043, Technical Specification Bases Change 2017-01

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Technical Specification Bases Change 2017-01
ML17208A061
Person / Time
Site: Oconee  Duke Energy icon.png
Issue date: 07/20/2017
From: Teresa Ray
Duke Energy Carolinas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
ONS-2017-043
Download: ML17208A061 (14)
v • d • e


Text

Thomas D. Ray Vice President Oconee Nuclear Station Duke Energy ON01VP 17800 Rochester Hwy Seneca, SC 29672 0 864.873.5016 r 864.873. 4208 ONS-2017-043 Tom.Ray@duke-energy.com July 20, 2017 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington DC 20555-0001

Subject:

Duke Energy Carolinas, LLC Oconee Nuclear Station Docket Numbers 50-269, 50-270, and 50-287 Technical Specification Bases Change 2017-01 The attached change to the Oconee Nuclear Station Technical Specification Bases was processed in accordance with the provisions of TS 5.5.15, "Technical Specifications (TS) Bases Control Program."

Technical Specification Bases change 2017-01 revises TS 3.7.16 to require any temporary cooling train credited as a train of chilled water to be powered from a Keowee backed power supply during normal operation to prevent the need to swap power to this source following accident scenarios (e.g., loss of offsite power).

Any questions regarding this information should be directed to Boyd Shingleton, Oconee Regulatory Affairs, at (864) 873-4716.

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Thomas D. Ray Vice President Oconee Nuclear Station Attachments www.duke-energy.com

U.S. Nuclear Regulatory Commission July 20, 2017 Page 2 cc: Ms. Catherine Haney Administrator, Region II U.S. Nuclear Regulatory Commission, Region II Marquis One Tower 245 Peachtree Center Ave., NE, Suite 1200 Atlanta, GA 30'303-1257

(by electronic mail only)

U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-08B1A Rockville, MD 20852-2738 Mr. Eddy L. Crowe

  • Senior Resident Inspector Oconee Nuclear Station

ONS-2017-043 July 20, 2011 Attachments TSB List of Effective Pages (LOEPs), Rev. 014 LOEP 1-4 TSB 3. 7.16 Control Room Area Cooling Systems (CRAGS) Rev. 001 3.7.16 1 -7 www.duke-energy.com

CRAGS B3.7.16 B 3. 7 PLANT SYSTEMS B 3.7.16 Control Room Area Cooling Systems (CRAGS)

BASES BACKGROUND The CRAGS provides temperature control for the control areas.

The control area is defined as the control room, cable room, and equipment room for each unit. Units 1 and 2 have a shared control room, and Unit 3 has an independent control room. The cable and equipment rooms are independent for each unit. Th~ control rooms, cable rooms, and equipment rooms for each unit contain vital electrical equipment, such as 125 VDC Vital l&C Power and 120 VAC Vital l&C Power, which is essential for achieving safe shutdown on the units. A control area portion is defined as a cable room, equipment room, or control room, for which a set of redundant CRVS cooling trains is required. The control area portions are listed in the table below. Through the use of alternative air flow paths,' air handling units AHU-34 and AHU-35 provide redundant cooling to both Units 1 and 2 cable rooms.

The AH Us which cool the control areas are part of the CRVS for each unit. The Chilled Water System (WC) serves as the heat sink for the CRVS on all three units. The WC System consists of two redundant cooling trains which serve all three units.

UFSAR Section 9.4.1 (Ref. 1) requires that redundant air conditioning and ventilation equipment be available to assure that no single failure of an active component within the CRVS and WC System will prevent proper control area environmental control. During a LOOP event, power will be temporarily lost to the equipment within these systems. Upon restoration of power the equipment will be required to restart. This restart makes the equipment susceptible to a single active failure. Without redundant cooling capability, acceptable temperatures within the control area could be exceeded. This could result in the potential failure of vital electrical equipment which is needed for safe shutdown of the units.

OCONEE UNITS 1, 2, & 3 B 3.7.16-1 REV. 001 I

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CRAGS B3.7.16 BASES BACKGROUND The following table identifies each portion of the CRVS where (continued) redundancy is required:

Table B 3.7.16-1 CRVS Redundant Equipment Control Area Portion Associated CRVS Cooling Trains Unit 1&2 Control Room AHU-11 and AHU-12 Unit 1 Cable Room AHU-34 and AHU-35 Unit 1 Equipment Room AHU-22 and AHU-34 Unit 2 Cable Room AHU-34 and AHU-35

  • Unit 2 Equipment Room AHU-23 and AHU-35' Unit 3 Control Room AHUs 3-13 and 3-14 Unit 3 Cable Room t AHUs 3-11 and 3-12 Unit 3 Equipment Room AHUs 3-15 and 3-16 A single train will provide the required temperature control. The CRAGS operation to maintain control room temperature is discussed in the UFSAR, Section 9.4.1 (Ref. 1).

APPLICABLE The design basis of the CRAGS is to maintain control area temperature SAFETY ANALYSES to ensure cooling of vital equipment.

The CRAGS components are arranged in redundant trains. A single active failure of a CRAGS component does not impair the ability of the system to perform as designed. The CRAGS is designed to remove sensible and latent heat loads from the control area, including consideration of equipment heat loads to ensure equipment OPERABILITY.

The CRAGS satisfies Criterion 3 of the NRC Policy Statement.

OCONEE UNITS 1, 2, & 3 B 3.7.16-2 REV. 001 I

CRAGS B3.7.16 BASES (continued)

LCO Two redundant trains of the CRAGS and WC Systems train are required to be OPERABLE to ensure that at least one train in each system is available, assuming a single active failure disables the other train in one or both systems. Total system failure could result in the equipment operating temperature exceeding limits. A Train of CRVS consists of one of the redundant AH Us specified in Table B 3.7.16-1 for each of the three portions of the control area for an Oconee unit and associated ducts, dampers, instrumentation and controls. A single AHU can function as a component in more than one train on an Oconee unit and can function as a component on trains in multiple Oconee units. For example AHU-34, and its associated ducts, damper, instrumentation and controls, can simultaneously function as the AHU for a train of CRVS serving the Unit 1 cable room, the Unit 1 equipment room as well as the Unit 2 cable room.

The combination of AHU-34 and either AHU-11 or AHU-12 along with their associated* equipment constitutes a combination of equipment.which' can satisfy the requirement for one train of CRVS for Unit 1. Additionally, AHU-34 can simultaneously serve as the AHU for the portion of a Unit 2 CRVS train serving the Unit 2 cable room. AHU-35 in combination with either AHU-11 or AHU-12 alo*ng with their associated equipment constitutes a combination of equipment which can satisfy the requirement for one train of CRVS for Unit 2.

For the Units 1 and 2 cable and equipment rooms, a system of motorized dampers is provided to allow AHU-34 and AHU-35 to provide cooling to the opposite unit's cable and equipment rooms in the event of the loss of one of the AHU's. The flow path for cooling is accomplished by closing redundant dampers between the unit's cable and equipment rooms upon loss of the opposite units cable room AHU.

If AHU-34 fails, the dampers between the Unit 2 cable and equipment rooms will close, allowing AHU-35 to cool .both Units 1 and 2 cable and equipment rooms providing AHU-22 and AHU-23 are operating. If one or both of the dampers in the flow path, fail open, then both AHU's are inoperable for Unit 1. If both dampers close, an adequate flow path for OPERABILITY is maintained even if one of two motor operated dampers on Unit 1 fail closed. If the Unit 2 dampers fail closed, OPERABILITY is not affected for the AHU-34 failure scenario. OPERABILITY is not maintained if one or both of the fire dampers between cable rooms or equipment rooms is closed. Compensatory measures, such as opening the damper must be taken to maintain OPERABILITY.

If AHU-35 fails, the dampers between the Unit 1 cable and equipment rooms will close, allowing AHU-34 to cool both Units 1 and 2 cable and equipment rooms providing AHU-22 and AHU-23 are operating. If one or both of the dampers in the flow path, fail open, then both AHU's are OCONEE UNITS 1, 2, & 3 B 3.7.16-3 REV. 001 I

CRAGS B3.7.16 BASES LCO inoperable for Unit 2. If both dampers close, an adequate flow path for (continued) OPERABILITY is maintained even if one of two motor operated dampers on Unit 2 fail closed. If the Unit 1 dampers fail closed, OPERABILITY is not affected for the AHU-35 failure scenario. OPERABILITY is not maintained if one or both of the fire dampers between cable rooms or equipment rooms is closed. Compensatory measures, such as opening the damper and posting a fire watch must be taken to maintain OPERABILITY.

The CRACS is considered OPERABLE when the individual components that are necessary to maintain control area temperature are OPERABLE in both trains of CRVS and WC System. Each CRVS train listed in Table B 3.7.16-1 includes the associated ductwork, instrumentation, and air handling unit, which includes the fan, fan motor, cooling coils, and isolation dampers .. Each WC train consists of a chiller, chilled water pump, condenser service water pump, and associated controls. Although each chilled water pump is normally associated with, and aligned to, a specific chiller, any OPERABLE chilled water pump maybe aligned to any OPERABLE chiller to maintain one OPERABLE train when a component has been removed from service. The two redundant trains can include a temporarily installed full-capacity control area cooling train. Any temporary cooling train credited as a train of WC shall be powered from a Keowee backed power supply (e.g. 4kV Switchgear breaker 3TD-15) during normal operation to prevent the need to swap power to this source following accident scenarios (e.g. a LOOP). If the temporary cooling train is powered from Unit 3, 4kV switchgear breaker 3TD-15, it can be powered if the 3B Condenser Circulating Water (CCW) Pump Motor (powered from breaker 3TD-4) is not being used. In order to power the temporary cooling train as a train of WC through this source, two exhaust fans in the Unit 3 Switchgear Blockhouse must be available while the temporary train is being credited.

In addition, the CRACS must be OPERABLE to the extent that air circulation can be maintained.

APPLICABILITY In MODES 1, 2, 3, 4, and during movement of recently irradiated fuel assemblies (i.e., fuel that has occupied part of a critical reactor core within the previous 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />), the CRACS must be OPERABLE to ensure that the control area temperature will not exceed equipment OPERABILITY requirements.

OCONEE UNITS 1, 2, & 3 B 3.7.16-4 REV. 001

CRACS 83.7.16 BASES (continued)

ACTIONS With one CRVS train inoperable for the control area, action must be taken to restore the CRVS train to OPERABLE status within 30 days. In this Condition, the remaining OPERABLE CRVS train is adequate to maintain the control area temperature within limits. However, the overall reliability is reduced because a failure in the OPERABLE CRVS train could result in a loss of CRVS cooling function. The 30 day Completion Time is based on the low probability of a loss of CRVS cooling component and the time necessary to perform repairs to CRVS cooling equipment.

With one WC train inoperable for a control area portion, action must be taken to restore the WC train to OPERABLE status within 30 days. In this Condition, the remaining OPERABLE WC train is adequate to maintain the control area portion temperature within limits. However, the overall reliability is reduced because a failure in the OPERABLE WC train could result in a loss of CRACS cooling function. The 30 day Completion Time is based on the low probability of a loss of WC cooling component, and on the time necessary to perform repairs to WC cooling equipment.

With the control room area air temperature outside its limit, action must be taken to restore the air temperature to within the limit within 7 days. If the control room area air temperature exceeds its limit, the ability of a single train of CRACS to maintain control room area temperature may be affected. The Completion Time of 7 days is reasonable considering the remaining CRACS train available to perform the required temperature control function and the low probability of an event occurring that would require the CRACS operation during that time.

The Required Actions are modified by a Note that states LCO 3.0.4 is not applicable. In consideration of the redundant CRACS train available, the small variation in temperature expected between 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> surveillances, and the marginal impact small temperature variations may have on the ability of a CRACS train to maintain the control room temperature within limits, an exception to LCO 3.0.4 is applicable for this condition.

OCONEE UNITS 1, 2, & 3 B 3.7.16-5 REV. 001 I

CRACS B3.7.16.

BASES ACTIONS D.1 and D.2 (continued)

If the Required Actions and associated Completion Times of Conditions A, B, or Care not met in MODE 1, 2, 3, or 4, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner without challenging unit systems.

E.1 and E.2 During movement of recently irradiated fuel; if the inoperable CRACS train cannot be restored to OPERABLE status within the required Completion Time, the OPERABLE CRACS train must be placed in operation immediately. This action ensures that the remaining train is

'OPERABLE, that no failures preventing actuation will occur, and that any active failure will be readily detected. An alternative to Required Action E.1 is to immediately suspend activities that could release radioactivity that might require the isolation of the control room. This places the unit in a condition that minimizes accident risk. This does not preclude the movement of fuel to a safe position.

F.1 If both CRVS trains or both WC trains are inoperable during MODE 1, 2, 3 or 4, the CRACS may not be capable of performing the intended function and the unit is in a condition outside the accident analyses.

Therefore, LCO 3.0.3 must be entered immediately.

During movement of recently irradiated fuel assemblies, with two CRACS trains inoperable, action must be taken to immediately suspend activities that could release radioactivity that might require isolation of the control room. This places the unit in a condition that minimizes accident risk.

This does not preclude the movement of fuel to a safe position.

OCONEE UNITS 1, 2, & 3 B 3.7.16-6 REV. 001 I

CRACS B 3.7.16 BASES (continued)

SURVEILLANCE SR 3.7.16.1 REQUIREMENTS This SR verifies that the heat removal capability of the system is sufficient to maintain the temperature in the control room and cable room at or below 80°F and maintain the temperature in the electrical equipment*

room at or below 85°F. The temperature is determined by reading gauges in each area or computer points which are considered representative of the average area temperature. These temperature limits are based on operating history and are intended to provide an indication of degradation of the cooling systems. The limits are conservative with respect to equipment operability temperature limits.

The values for the SR are values at which the system is removing sufficient heat to meet design requirements (i.e., OPERABLE) and sufficiently above the values associated with normal operation during hot weather. The temperature in the equipment room is typically slightly higher than the temperature in the control room or cable room. Because of that, a higher value is specified for this area. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. UFSAR, Section 9.4.1.

OCONEE UNITS 1, 2, & 3 B 3.7.16-7 REV. 001 I

OCONEE NUCLEAR STATION TECHNICAL SPECIFICATIONS-BASES REVISED 05/18/17 LIST OF EFFECTIVE PAGES SECTION/PAGES REVISION NUMBER IMPLEMENTATION DATE TOC 000 09/03/14 B 2.1. l 000 05/31/12 B 2.1.2 000 02/06/14 B 3.0 000 10/20/11 B 3.1.1 000 05/16/12 B 3.1.2 000 05/16/12 B 3.1.3 000 06/02/99 B 3.1.4 000 07/23/12 B 3.1.5 000 05/16/12 B 3.1.6 000 07/23/12 B 3.1.7 000 07/23/12 B 3.1.8 000 05/16/12 B 3.2.1 000 05/16/12 B 3.2.2 000 05/16/12 B 3.2.3 000 05/16112 B 3.3.l 003 01117/17 B 3.3.2 000 12/14/04 B 3.3.3 000 12/10/14 B 3.3.4 000 12/10/14 B 3.3.5 000 12/10/14 B 3.3.6 000 12/10/14 B 3.3.7 000 12/10/14 B 3.3.8 000 05/16/12 B 3.3.9 000 05/16/12 B 3.3.10 000 05/16/12 B 3.3.11 001 01/17/17 B 3.3.12 000 05/16/12 Oconee Nuclear Station LOEP 1 Revision 014

OCONEE NUCLEAR STATION TECHNICAL SPECIFICATIONS-BASES REVISED 05118/17 LIST OF EFFECTIVE PAGES SECTION/PAGES REVISION NUMBER BASES REVISION DATE B 3.3.13 000 05/16/12 B 3.3.14 001 01/17117 B 3.3.15 000 05/16/12 B 3.3.16 000 05/16/12 B 3.3.17 000 05/16/12 B3.3.18 000 05/16/12 B 3.3.19 000 05/16/12 B 3.3.20 000 05/16/12 B 3.3.21 000 05/16/12 B 3.3.22 000 05116112 B 3.3.23 000 05/16/12 B 3.3.24 000 09/26/01 B 3.3.25 000 11/05/03 B 3.3.26 000 11/05/03 B 3.3.27 000 12/10/14 B 3.3.28 000 05/16/12 B 3.4.1 000 05/16/12 B 3.4.2 000 12/16/98 B 3.4.3 001 01/17/17 B 3.4.4 001 07114116 B 3.4.5 000 05/16/12 B 3.4.6 001 04/18/17 B 3.4.7 001 04/18/17 B 3.4.8 001 04/18/17 B 3.4.9 000 05/16/12 B 3.4.10 001 09/21/15 B 3.4.11 000 10/12/12 B 3.4.12 000 06/13/14 Oconee Nuclear Station LOEP2 Revision 014

OCONEE NUCLEAR STATION TECHNICAL SPECIFICATIONS-BASES REVISED 05/18/17 LIST OF EFFECTIVE PAGES SECTION/PAGES REVISION NUMBER BASES REVISION DATE B 3.4.13 001 01/17/17 B 3.4.14 001 09/21/15 B 3.4.15 001 11/24/15 B 3.4.16 001 08/23/16 B 3.5.1 000 05/16/12 B 3.5.2 003 04/18/17 B 3.5.3 003 04/18/17 B 3.5.4 000 05/16/12 B 3.6.l 001 01/17/17 B 3.6.2 001 01/17/17 B 3.6.3 000 05/16/12 B 3.6.4 000 05/16/12 B 3.6.5 002 04/18/17 B 3.7.l 002 01/17/17 B 3.7.2 000 11/13/12 B 3.7.3 001 09/21/15 B 3.7.4 002 01/17/17 B 3.7.5 001 09/21/15 B 3.7.6 000 05/16/12 B 3.7.7 000 12/10/14 B 3.7.8 000 05/16/12 B 3.7.9 000 08/28/14 B 3.7.10 003 01/17/17 B 3.7.lOa 001 01/17/17 B 3.7.11 000 05/16/12 B 3.7.12 000 05/16/12 B 3.7.13 000 08/19/10 B 3.7.14 000 05/16/12 Oconee Nuclear Station LOEP3 Revision 014

OCONEE NUCLEAR STATION TECHNICAL SPECIFICATIONS-BASES REVISED 05/18/17 LIST OF EFFECTIVE PAGES SECTION/PAGES REVISION NUMBER BASES REVISION DATE B 3.7.15 000 10/24/07 B 3.7.16 001 05/18117 B 3.7.17 001 01/17/17 B 3.7.18 000 06/15/06 B 3.7.19 001 03/10116 B 3.8.l 002 01/17117 B 3.8.2 000 04/07/11 B 3.8.3 001 01/17/17 B 3.8.4 000 12/18/07 B 3.8.5 000 05/16/12 B 3.8.6 000 05/16112 B 3.8.7 000 05/16112 B 3.8.8 001 01/17/17 B 3.8.9 001 01117/17 B 3.9.l 000 05/16/12 B 3.9.2 000 05/16/12 B 3.9.3 001 01/17/17 B 3.9.4 002 04/18117 B 3.9.5 001 04/18/17 B 3.9.6 000 05/16112 B 3.9.7 000 05/16/12 B 3.9.8 000 06/25/14 B 3.10.1 001 01/17/17 B 3.10.2 000 11/05114 Note: With the introduction of Fusion in June 2015, all controlled documents require a three-digit revision number. Thus, the revision numbers were set to "000" in the summer of 2015. As such, the revision dates for Revision 000 are based on the implementation dates for revisions in effect prior to this change.

Oconee Nuclear Station LOEP4 Revision 014

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