ML17163A047

From kanterella
Jump to navigation Jump to search
NRR E-mail Capture - (External_Sender) PSEG Entergy Presentation for June 20, 2017 Public Meeting to Discuss Proposed River Bend Control Building HVAC Technical Specification Change
ML17163A047
Person / Time
Site: Hope Creek, River Bend  PSEG icon.png
Issue date: 06/06/2017
From: Anissa Coates
Entergy Nuclear Operations
To: Lisa Regner
Plant Licensing Branch IV
References
Download: ML17163A047 (26)
v • d • e


Text

NRR-PMDAPEm Resource From: Coates, Alyson <alacey@entergy.com>

Sent: Tuesday, June 06, 2017 4:11 PM To: Regner, Lisa

Subject:

[External_Sender] RBS HVK Pre-Submittal Meeting Presentation.pdf - Adobe Acrobat Professional Attachments: RBS HVK Pre-Submittal Meeting Presentation.pdf Lisa, Please see the attached PowerPoint for the pre-submittal meeting on June 20th 10am. If you have any questions, please feel free to contact me.

Thank You Alyson L. Coates Sr. Engineer - Licensing River Bend Station 225-381-4630 1

Hearing Identifier: NRR_PMDA Email Number: 3556 Mail Envelope Properties (90CC84328BFC7F4FAB7905410BF7F88E2C723844)

Subject:

[External_Sender] RBS HVK Pre-Submittal Meeting Presentation.pdf - Adobe Acrobat Professional Sent Date: 6/6/2017 4:11:04 PM Received Date: 6/6/2017 4:11:43 PM From: Coates, Alyson Created By: alacey@entergy.com Recipients:

"Regner, Lisa" <Lisa.Regner@nrc.gov>

Tracking Status: None Post Office: litxmetsp001.etrsouth.corp.entergy.com Files Size Date & Time MESSAGE 249 6/6/2017 4:11:43 PM RBS HVK Pre-Submittal Meeting Presentation.pdf 190872 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

1 RIVER BEND STATION PRE-SUBMITTAL MEETING License Amendment Request (LAR): Technical Specification 3.7.7, "Control Building Air Conditioning (AC) System" June 20, 2017

2 OPENING REMARKS Tim Schenk Regulatory Assurance Manager River Bend Station

3 INTRODUCTIONS Tim Schenk Regulatory Assurance Manager River Bend Station

4 Agenda Introduction Tim Schenk - Reg. Assurance Manager Overview - HVC, HVK, SSW Tim Schenk - Reg. Assurance Manager Systems Current TS Requirements Tim Schenk - Reg. Assurance Manager Reason for Proposed Change Tim Schenk - Reg. Assurance Manager Description of Proposed Change Tim Schenk - Reg. Assurance Manager Technical Evaluation Tim Schenk - Reg. Assurance Manager Closing Comments Tim Schenk - Reg. Assurance Manager

5 OVERVIEW -

HVC, HVK, AND SSW SYSTEMS Tim Schenk Regulatory Assurance Manager River Bend Station

6 HVC System Design Control Building HVAC (HVC)

Two 100% capacity divisions / subsystems

  • Division I - HVC-ACU1A, HVC-ACU2A, & HVC-ACU3A
  • Division II - HVC-ACU1B, HVC-ACU2B, & HVC-ACU3B The HVC ACUs function to provide cooling, heating, ventilation to the following areas in the Control Building:

HVC-ACU1A/B

  • Main Control Room HVC-ACU2A/B
  • Standby Switchgear Rooms Cable Chase Rooms
  • Inverter Charger Rooms Battery Rooms HVC-ACU3A/B
  • Chiller Equipment Rooms The HVC ACUs are safety related and are supplied with Power from their respective safety related buss or Emergency Diesel Generator

7 HVC Diagram - Normal Flow Path -

1 of 2 Redundant Divisions

8 HVK System Design Control Building Chilled Water (HVK)

Four 100% capacity refrigeration compressors/chillers (2 per division / subsystem), associated valves, chilled water pumps, service water pumps, instrumentation, and compression tanks.

  • Division I - HVK-CHL1A & HVK-CHL1C
  • Division II - HVK-CHL1B & HVK-CHL1D The chilled water system functions during normal, shutdown, and accident conditions to supply chilled water to the cooling coils in HVC-ACU1A/B, HVC-ACU2A/B, and HVC-ACU3A/B.

The Normal Service Water system provides cooling water to the chiller condenser. In a DBA or loss of Normal Service Water the Standby Service Water system functions as the Ultimate Heat Sink.

The Standby Service Water system is also connected to the Chilled Water piping circuit and in the event both subsystems of HVK fail it can function as the cooling medium for HVC-ACU1A/B, HVC-ACU2A/B, and HVC-ACU3A/B.

The HVK Chillers are safety related and are supplied with power from their respective safety related buss or Emergency Diesel Generator

9 HVK Diagram - Normal Flow Path for 1 of 2 Redundant Divisions From Make- Temperature ACU3A - Chiller Up Water From Service Control Valve Equipment Rm Water Expansion Tank ACU1A - Main ACU2A - Battery, Control Room Switchgear, Inverter, and General Area To Service Water Chiller 1A Pump 1A Chiller 1C Pump 1C

10 HVC Diagram - Normal Flow Path -

1 of 2 Redundant Divisions

11 SSW System Design Standby Service Water (SSW)

Provides a reliable source of cooling water to plant auxiliaries that are essential for a safe reactor shutdown following a design basis Loss of Coolant Accident (LOCA)

Two 100% capacity, redundant piping subsystems which provide cooling for

1. Standby Diesel Generators (Div 1 and Div 2)
2. High Pressure Core Spray Diesel Generator (Div 3)
3. Auxiliary Building Room Unit Coolers
4. Containment Unit Coolers
3. Control Building Chilled Water - Condensers Each SSW subsystem is fully capable of supporting safe shutdown of the reactor.

Service water flow rate to the control building chilled water chillers is based upon heat removal requirements with the chilled water system at maximum capacity, i.e., maximum ambient temperature plus maximum heat gain from control building equipment.

Four 50% capacity, 7,690 gpm pumps, SWP-P2C is powered by Div 3 One Ultimate Heat Sink cooling tower and associated storage basin

12 Standby Service Water System

13 CURRENT TS REQUIREMENTS Tim Schenk Regulatory Assurance Manager River Bend Station

14 Current TS Requirements

  • The Control Room Air-Conditioning System is fully addressed by existing TS 3.7.3 requiring two control room AC subsystems to be operable with a required action to repair within 30 days of one required AC subsystem being inoperable.
  • Currently there is no TS addressing the following:

HVC-ACU2A/B

  • Standby Switchgear Rooms Cable Chase Rooms
  • Inverter Charger Rooms Battery Rooms HVC-ACU3A/B
  • Chiller Equipment Rooms
  • The equipment providing cooling to the above areas will be referred to as the Control Building AC (CBAC).

15 REASON FOR PROPOSED CHANGE Tim Schenk Regulatory Assurance Manager River Bend Station

16 Reason for Proposed Change

  • March, 24, 2015, the NRC completed its initial assessment of the circumstances surrounding a loss of control building ventilation due to HVK chillers, which occurred on March 9, 2015, at River Bend Station.
  • At the time, RBS considered the HVK a non-TS support system for all applications except the control room air conditioning system. In the event that one subsystem of HVK chilled water became nonfunctional, the supported divisional equipment was considered operable because cooling was maintained by the redundant support system. River Bends position was that this was supported by TS LCO 3.0.6.
  • On August 4, 2015, River Bend requested an Interpretation of Technical Specifications.
  • September 19, 2016, the NRC responded that the exception to LCO 3.0.2 allowed by LCO 3.0.6 can only be applied in a situation where both a supporting and a supported system have LCOs in TS, and that the supported system is rendered inoperable by the inoperable support system.

17 Reason for Proposed Change

  • Based on the NRC interpretation that the exception to LCO 3.0.2 allowed by LCO 3.0.6 can only be applied in a situation where both a supporting and a supported system have LCOs in TS, the loss of one subsystem of HVK could affect operability of the following; DC Sources - Operating (TS 3.8.4),

Inverters - Operating (TS 3.8.7), and Distribution Systems - Operating (TS 3.8.9)

  • TS 3.8.4 DC Sources - Operating is the most limiting TS LCO, with a Completion Time (CT) of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, else be in Mode 3 within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of one required battery charger on Division I or II being inoperable.

18 DESCRIPTION OF PROPOSED CHANGE Tim Schenk Regulatory Assurance Manager River Bend Station

19 Proposed Change RBS is requesting to add a new Technical Specification related to "Control Building Air Condition (AC) System".

This amendment will establish a Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to allow time to complete minor maintenance activities on the Control Building AC System equipment and thus reduce the need for unnecessary plant shutdowns.

20 TECHNICAL EVALUATION Tim Schenk Regulatory Assurance Manager River Bend Station

21 Proposed 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time Proposed 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time is based on

  • On the low probability of an event occurring resulting in a loss of all cooling to the building, the consideration that the remaining subsystem can provide the required protection, and the availability of alternate cooling methods.

22 TS 3.7.1 Standby Service Water (SSW) and Ultimate Heat Sink (UHS)

Per TS 3.7.1 in MODES 1, 2, and 3, the SSW System is required to be OPERABLE to support OPERABILITY of the equipment serviced by the SSW System required to be OPERABLE in these MODES. If one SSW subsystem is inoperable (Condition G), it must be restored to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> (TS 3.7.1 Condition G, Required Action G.1).

With the unit in this condition, the remaining operable SSW subsystem is adequate to perform the heat removal function.

However, the overall reliability is reduced because a single failure in the operable SSW subsystem could result in loss of SSW function

23 Conclusion

  • If one SSW subsystem is inoperable, cooling to both chillers in that subsystem (HVK-CHL1A and HVK-CHL1C OR HVK-CHL1B and HVK-CHL1D) would be unavailable. This will result in the loss of the ACUs in that subsystem (HVC-ACU1A ,HVC-ACU2A, and HVC-ACU3A OR HVC-ACU1B, HVC-ACU2B, and HVC-ACU3B).
  • The loss of one subsystem of Standby Service Water scenario has the same results as taking one subsystem of the CBAC system out of service, in addition to the many functions impacted by having one SSW subsystem inoperable.
  • The consequences of a Loss of CBAC is much more limited than the consequences of a Loss of Service Water.
  • Therefore, the CBAC proposed completion time 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is bounded by the scenario of one subsystem of Standby Service Water out of service.

24 CLOSING COMMENTS Tim Schenk Regulatory Assurance Manager River Bend Station

Retrieved from "https://kanterella.com/w/index.php?title=ML17163A047&oldid=2228635"