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Category:Meeting Briefing Package/Handouts
MONTHYEARML20184A2872020-07-0101 July 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and General Design Criterion 33, PM-0720-70785, Revision 0 ML20150C5172020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled NRC Public Meeting Presentation: Boron Redistribution and Associated Design and DCA Changes, PM-0620-70336, Revision 0 ML20150C8812020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and Associated Design and DCA Changes, PM-0620-70244, Revision 0 ML20099H0802020-04-0808 April 2020 LLC - Submittal of Presentation Materials Entitled NRC Public Meeting: Revisions to Nuscale'S EPZ Sizing Methodology Topical Report, PM-0420-69598, Revision 0 ML20094H6742020-04-0303 April 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation NuScale Topic-Probabilistic Risk Assessment with a Focus on Emergency Core Cooling System Analysis PM-0420-69559, Revision 0 ML20072H3272020-03-0909 March 2020 LLC - Public Meeting Presentation: Topic - Emergency Core Cooling System Boron (ECCS) Distribution, PM-0320-69218, Revision 0 ML20069A9692020-03-0505 March 2020 ACRS Full Committee Presentation: NuScale Topical Report, Loss-of-Coolant Accident Evaluation Model, PM-0320-69138, Revision O ML20069A1632020-03-0505 March 2020 ACRS Full Committee Presentation: NuScale Topical Report-Rod Ejection Accident Methodology, PM-0320-69146, Revision 0 ML20069A1542020-03-0404 March 2020 ACRS Full Committee Presentation: NuScale Topical Report- Non-Loss-of-Coolant Accident, PM-0320-69141, Revision 0 ML20066G2802020-03-0303 March 2020 LLC, Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale Topic - Hydrogen Monitoring, PM-0220-69071, Revision 0 ML20066G2772020-02-28028 February 2020 ACRS Full Committee Presentation: NuScale - Steam Generator Design, PM-0220-69051, Revision 0 ML20054A9622020-02-19019 February 2020 ACRS Subcommittee Presentation: NuScale Topical Report - Non-Loss-of-Coolant Accident, PM-0220-68852, Revision 0 ML20054B6342020-02-17017 February 2020 Nuscale - ACRS Subcommittee Presentation: NuScale Topical Report - Rod Ejection Accident Methodology, PM-1019-67365, Revision 0 ML20054A4062020-02-17017 February 2020 ACRS Subcommittee Presentation: NuScale Topical Report- Loss-of-Coolant Accident Evaluation Model, PM-0220-68917, Revision 0 ML20035C7892020-02-0404 February 2020 Nuscale - ACRS Subcommittee Presentation, FSAR, Steam Generator Design ML19340B5912019-12-0606 December 2019 Public Meeting - NuScale Incorporated by Reference (Ibr) Slides ML19324C8362019-11-13013 November 2019 LLC Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale Source Term Methodology Application, PM-1119-67928, Revision 0 ML19204A2772019-07-22022 July 2019 Discussion Topic July 22, 2019 Public Meeting to Discuss Interface Requirement Associated with the NuScale Design Certification Application ML19190A0882019-07-0303 July 2019 LLC Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation, NuScale FSAR Chapter 20, Mitigation of Beyond-Design-Basis Events, PM-0719-66189, Revision 0 ML19169A1662019-06-14014 June 2019 Mitigation of Beyond-Design-Basis-Events, NuScale FSAR Chapter 20, PM-0619-65964, Revision 0 ML19135A0642019-05-0909 May 2019 LLC - Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale FSAR Chapter 21, Multi-Module Design Considerations, PM-0519-65533, Revision 0 ML19134A0742019-05-0909 May 2019 LLC Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale FSAR Chapter 19, Probabilistic Risk Assessment and Severe Accident Evaluation, PM-0519-65372, Revision 0 ML19105A1352019-04-11011 April 2019 ACRS Presentation: NuScale Chapter 5, Reactor Coolant System and Connecting Systems Overview, PM-0419-65159, Revision 0 ML19098A7802019-04-0202 April 2019 LLC - Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Chapter 9, Auxiliary Systems, PM-0319-64807, Revision 0 ML19079A2382019-03-20020 March 2019 Enclosure 1: ACRS Presentation: NuScale Chapter 9, Auxiliary Systems, PM-0319-64807, Revision 0 ML19073A0482019-03-11011 March 2019 LLC - ACRS Presentation Chapter 10 - Steam and Power Conversion System, PM-0219-64501, Revision 1 ML19073A0512019-03-11011 March 2019 ACRS Presentation Chapter 11 - Radioactive Waste Management, PM-0219-64543, Revision 1 ML19050A1632019-02-20020 February 2019 Enclosure 1: ACRS Presentation Chapter 11 - Radioactive Waste Management, PM-0219-64543, Revision 0 ML19053A5182019-02-19019 February 2019 Nuscale - Dhrs and ECCS Logic Changes, PM-0219-64563, Revision 0 ML19045A3062019-02-12012 February 2019 PM-0219-64475-NP, Revision 0, Reactor Vessel Flange Tool (Rft) Design Plan and Schedule. ML19042A0732019-02-0505 February 2019 Nuscale - Chapters 2 and 17 ACRS Full Committee, PM-0219-64333, Revision 0 ML19024A2042019-01-23023 January 2019 ECCS Valve DCA Demonstration Testing, PM-0119-64160-NP, Revision 0 ML18362A1422018-12-19019 December 2018 Enclosure 2: Absorption Coefficient for Pool Water and Reactor Building Floor Interaction, PM-1218-63882, Revision 0 ML18347A2032018-12-18018 December 2018 Enclosure 1: ACRS Presentation Chapter 17 - Quality Assurance and Reliability Assurance, PM-1218-63732, Revision 0 ML18347A2072018-12-18018 December 2018 ACRS Presentation Chapter 2 - Site Characteristics and Site Parameters, PM-1218-63753, Revision 0 ML18331A1602018-11-20020 November 2018 Enclosure 2: Addressing Component Fatigue for NuScale DCA, November 20, 2018 ML18338A1032018-11-14014 November 2018 Nuscale - LTC RAI Closure Plan, PM-1118-63594-NP, Revision 0, Nonproprietary Version ML18235A3152018-08-23023 August 2018 LLC - Presentation Materials Entitled ACRS Presentation: NuScale Instrumentation and Controls Design Overview, PM-0618-60212, Revision 0 ML18222A1932018-08-0808 August 2018 Enclosure 1: NuScale Accident Source Terms Methodology Options PM-0818-61166, Revision 0 ML18213A1572018-08-0101 August 2018 Risk-Informed Review of NuScale Initial Test Program, PM-0718-61123, Revision 0 ML18220A8742018-07-25025 July 2018 Enclosunuscale CIRLT-RAI 9474 ML18205A3182018-07-24024 July 2018 NRC Staff Questions for the August 1, 2018 Public Meeting with NuScale on ITP ML18116A4422018-04-24024 April 2018 Enclosure 2: NuScale Power Comprehensive Vibration Assessment Program - Audit Report Summary Discussion, Revision 0, PM-0218-58803-NP (Non-Proprietary Version) ML18090A0032018-04-0202 April 2018 Handout for the April 2, 2018 Public Meeting to Discuss NuScale Plans to Respond to the NRC Staff RAIs Related to Sections 3.7 and 3.8 ML18085A0722018-03-26026 March 2018 NRC Staff Questions for April 9, 2018 Public Meeting with NuScale on DCA Chapter 20 ML18037A6732018-02-0808 February 2018 PM-0218-58480, Revision 0, Shutdown Capability of the NuScale Power Module. ML18019A1612018-01-23023 January 2018 LLC - Shutdown Capability of the NuScale Power Module ML18019A1632018-01-23023 January 2018 Source Term Revision, Revision 0, PM-0118-58201 2020-07-01
[Table view] Category:Slides and Viewgraphs
MONTHYEARML20184A2872020-07-0101 July 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and General Design Criterion 33, PM-0720-70785, Revision 0 ML20150C8812020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Topic - Boron Redistribution and Associated Design and DCA Changes, PM-0620-70244, Revision 0 ML20150C5172020-05-29029 May 2020 LLC Submittal of Presentation Materials Entitled NRC Public Meeting Presentation: Boron Redistribution and Associated Design and DCA Changes, PM-0620-70336, Revision 0 ML20133J9142020-05-11011 May 2020 LLC Submittal of Presentation Materials Entitled Public Meeting Presentation: Topic - Emergency Core Cooling System (ECCS) Boron Distribution, PM-0420-69511, Revision 0 ML20099H0802020-04-0808 April 2020 LLC - Submittal of Presentation Materials Entitled NRC Public Meeting: Revisions to Nuscale'S EPZ Sizing Methodology Topical Report, PM-0420-69598, Revision 0 ML20097F1922020-04-0606 April 2020 Nuscale Power, LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: Nuscale Topic - Hydrogen/Oxygen Monitoring, PM-0420-69518, Revision 0 ML20094H6742020-04-0303 April 2020 LLC Submittal of Presentation Materials Entitled ACRS Full Committee Presentation NuScale Topic-Probabilistic Risk Assessment with a Focus on Emergency Core Cooling System Analysis PM-0420-69559, Revision 0 ML20072H3272020-03-0909 March 2020 LLC - Public Meeting Presentation: Topic - Emergency Core Cooling System Boron (ECCS) Distribution, PM-0320-69218, Revision 0 ML20069A1632020-03-0505 March 2020 ACRS Full Committee Presentation: NuScale Topical Report-Rod Ejection Accident Methodology, PM-0320-69146, Revision 0 ML20069A9692020-03-0505 March 2020 ACRS Full Committee Presentation: NuScale Topical Report, Loss-of-Coolant Accident Evaluation Model, PM-0320-69138, Revision O ML20069A1542020-03-0404 March 2020 ACRS Full Committee Presentation: NuScale Topical Report- Non-Loss-of-Coolant Accident, PM-0320-69141, Revision 0 ML20066G2802020-03-0303 March 2020 LLC, Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale Topic - Hydrogen Monitoring, PM-0220-69071, Revision 0 ML20066F4672020-02-28028 February 2020 Enclosure 1: ACRS Subcommittee Presentation: NuScale FSAR Topic- Resolution of Chapter 15 Phase 2 Open Items, PM-0220-69062, Revision 0 ML20066G2772020-02-28028 February 2020 ACRS Full Committee Presentation: NuScale - Steam Generator Design, PM-0220-69051, Revision 0 ML20054A9622020-02-19019 February 2020 ACRS Subcommittee Presentation: NuScale Topical Report - Non-Loss-of-Coolant Accident, PM-0220-68852, Revision 0 ML20054A4062020-02-17017 February 2020 ACRS Subcommittee Presentation: NuScale Topical Report- Loss-of-Coolant Accident Evaluation Model, PM-0220-68917, Revision 0 ML20054B6342020-02-17017 February 2020 Nuscale - ACRS Subcommittee Presentation: NuScale Topical Report - Rod Ejection Accident Methodology, PM-1019-67365, Revision 0 ML20035C7892020-02-0404 February 2020 Nuscale - ACRS Subcommittee Presentation, FSAR, Steam Generator Design ML19340B5912019-12-0606 December 2019 Public Meeting - NuScale Incorporated by Reference (Ibr) Slides ML19324C8362019-11-13013 November 2019 LLC Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale Source Term Methodology Application, PM-1119-67928, Revision 0 ML19192A1662019-07-10010 July 2019 Presentation Entitled, Evaluation Methodology for Stability Analysis of the NuScale Power Module. ML19169A1662019-06-14014 June 2019 Mitigation of Beyond-Design-Basis-Events, NuScale FSAR Chapter 20, PM-0619-65964, Revision 0 ML19135A0642019-05-0909 May 2019 LLC - Submittal of Presentation Materials Entitled ACRS Subcommittee Presentation: NuScale FSAR Chapter 21, Multi-Module Design Considerations, PM-0519-65533, Revision 0 ML19105A1352019-04-11011 April 2019 ACRS Presentation: NuScale Chapter 5, Reactor Coolant System and Connecting Systems Overview, PM-0419-65159, Revision 0 ML19105A1312019-04-10010 April 2019 Enclosuacrs Presentation: Chapter 4, Reactor Overview, PM-0419-65096, Revision 0 ML19098A7802019-04-0202 April 2019 LLC - Submittal of Presentation Materials Entitled ACRS Full Committee Presentation: NuScale Chapter 9, Auxiliary Systems, PM-0319-64807, Revision 0 ML19073A0482019-03-11011 March 2019 LLC - ACRS Presentation Chapter 10 - Steam and Power Conversion System, PM-0219-64501, Revision 1 ML19073A0512019-03-11011 March 2019 ACRS Presentation Chapter 11 - Radioactive Waste Management, PM-0219-64543, Revision 1 ML19073A0532019-03-11011 March 2019 Enclosure 1: ACRS Presentation Chapter 12 - Radiation Protection, PM-0219-64534, Revision 1 ML19050A1632019-02-20020 February 2019 Enclosure 1: ACRS Presentation Chapter 11 - Radioactive Waste Management, PM-0219-64543, Revision 0 ML19053A5182019-02-19019 February 2019 Nuscale - Dhrs and ECCS Logic Changes, PM-0219-64563, Revision 0 ML19050A3982019-02-13013 February 2019 Enclosure 1: ACRS Presentation Chapter 10 - Steam and Power Conversion System, PM-0219-64501, Revision 0 ML19045A3062019-02-12012 February 2019 PM-0219-64475-NP, Revision 0, Reactor Vessel Flange Tool (Rft) Design Plan and Schedule. ML19042A0732019-02-0505 February 2019 Nuscale - Chapters 2 and 17 ACRS Full Committee, PM-0219-64333, Revision 0 ML19024A2042019-01-23023 January 2019 ECCS Valve DCA Demonstration Testing, PM-0119-64160-NP, Revision 0 ML18360A1782018-12-19019 December 2018 Enclosure 2: Presentation Titled, Addressing Component Fatigue for NuScale Dca. ML18362A1422018-12-19019 December 2018 Enclosure 2: Absorption Coefficient for Pool Water and Reactor Building Floor Interaction, PM-1218-63882, Revision 0 ML18347A2032018-12-18018 December 2018 Enclosure 1: ACRS Presentation Chapter 17 - Quality Assurance and Reliability Assurance, PM-1218-63732, Revision 0 ML18347A2072018-12-18018 December 2018 ACRS Presentation Chapter 2 - Site Characteristics and Site Parameters, PM-1218-63753, Revision 0 ML19025A2212018-12-18018 December 2018 Enclosure 2: Slides Titled, Basis for an Rft Stand COL Item, PM-1218-63892-NP, Revision 0, Non-Proprietary Version ML18331A1602018-11-20020 November 2018 Enclosure 2: Addressing Component Fatigue for NuScale DCA, November 20, 2018 ML18338A1032018-11-14014 November 2018 Nuscale - LTC RAI Closure Plan, PM-1118-63594-NP, Revision 0, Nonproprietary Version ML18235A3152018-08-23023 August 2018 LLC - Presentation Materials Entitled ACRS Presentation: NuScale Instrumentation and Controls Design Overview, PM-0618-60212, Revision 0 ML18222A1932018-08-0808 August 2018 Enclosure 1: NuScale Accident Source Terms Methodology Options PM-0818-61166, Revision 0 ML18213A1572018-08-0101 August 2018 Risk-Informed Review of NuScale Initial Test Program, PM-0718-61123, Revision 0 ML18220A8742018-07-25025 July 2018 Enclosunuscale CIRLT-RAI 9474 ML18156A1262018-06-0101 June 2018 LLC Submittal of Presentation Materials Entitled, ACRS Presentation Chapter 8 Overview, for Use During a Public Meeting on June 6, 2018 ML18156A1272018-05-31031 May 2018 LLC Submittal of Presentation Materials Entitled NuScale Power Containment Leak Rate Test Program, PM-0518-59978, Revision 1 ML18116A4422018-04-24024 April 2018 Enclosure 2: NuScale Power Comprehensive Vibration Assessment Program - Audit Report Summary Discussion, Revision 0, PM-0218-58803-NP (Non-Proprietary Version) ML18037A6732018-02-0808 February 2018 PM-0218-58480, Revision 0, Shutdown Capability of the NuScale Power Module. 2020-07-01
[Table view] |
Text
NuScale Nonproprietary Shutdown Capability of the NuScale Power Module Derick Botha Darrell Gardner February 8, 2018 PM-0218-58480
- *; NUSCALE Revision
- O Copyright 2018 by NuScale Power, LLC. *.:. .~ POWER-Template #: 0000-21727-F01 R2
Acknowledgement & Disclaimer This material is based upon work supported by the Department of Energy under Award Number DE-NE0000633.
This report was prepared as an account of work sponsored by an agency of the United States (U.S.) Government. Neither the U.S.
Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the U.S.
Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the U.S.
Government or any agency thereof.
2 PM-0218-58480 ~ *; NUSCALE Revision : O Copyright 2018 by NuScale Power, LLC. ,;.- POWER-Template#: 0000-21727-F01 R2
Outline
- NuScale Reactivity Control Systems
- Exemption Review Criteria
PM-0218-58480 Revision : O Copyright 20 18 by NuScale Power, LLC.
GDC 27 Exemption
- NuScale has identified the possibility of a return to power condition under very limited conditions and assumptions
- Passive cooldown to low RCS temperatures is unique to NuScale design
- This condition was evaluated against the General Design Criterion NuScale did not identify a need for an exemption and believes current design satisfies the GDC
- Draft GDCs explicitly required systems to make core "subcritical "
- Final GDCs revised by the Commission to address "controlling reactivity changes" to assure acceptable radiological consequences
- NuScale design approach is consistent with literal language and intent of final GDCs
- NuScale submitted a white paper on reactivity control (L0-1116-51829 , Nov 2016) and addressed compliance with GDC 26 and 27 reactivity control functions
- protection function: rapid power reduction to protect fuel, assuming WRSO , to protect fuel (AOOs under GDC 26) or to maintain core cooling capability to mitigate the consequences of accidents (DBAs under GDC 27)
- shutdown function : capability to hold the core subcritical under cold conditions 4
PM-0218-58480 Revision : 0 Copyright 2018 by NuScale Power, LLC.
GDC 27 Exemption
- NRC staff position (ML16116A083, Sep 2016) is that an exemption from GDC 27 is required
- design departs from precedent (i .e., long-term shutdown with WRSO)
- NuScale complied with staff position and applied for exemption to GDC 27
- whether or not an exemption is required, NuScale believes the design solution and safety demonstration are unchanged
- Exemption and FSAR establish PDC 27
- Regulations require NuScale to define the PDCs for the design , and relation of the design bases to the PDCs
- PDC 27 addresses precedent by explicitly defining requirement for long-term shutdown following postulated accident: NuScale design assures long-term shutdown with all rods in , but recriticality with WRSO would not exceed CHF :
- The reactivity control systems shall be designed to have a combined capability of reliably controlling reactivity changes to assure that under postulated accident conditions and with appropriate margin for stuck rods the capability to cool the core is maintained.
- Following a postulated accident, the control rods shall be capable of holding the reactor core subcritical under cold conditions, without margin for stuck rods, provided the specified acceptable fuel design limits for critical heat flux would not be exceeded by the return to power.
5 PM-02 18-58480 Mfftiao*: . N USCALE Revision: O Copyright 2018 by NuScale Power, LLC.
- POWER-Template # : 0000-2 1727-F0 1 R2
NuScale Reactivity Control Systems
- NuScale uses two primary reactivity control systems
- safety-related control rods and nonsafety-related chemical volume and control system (CVCS)
- The selected reactivity control systems are consistent with NuScale design objectives for passive safety and simplicity
- design does not use ECCS makeup with boron - typically the only safety-related boron injection for PWRs
- Following transients, RCS passively cools down to low temperatures - not just to "hot shutdown"
- Control rods alone maintain shutdown through entire RCS temperature range
- Assuming certain low probability conditions, there is a possibility of a return to power after a trip concurrent with a control rod malfunction (stuck rod) late in core life (low boron concentration) and at low decay heat (core has cooled significantly),
the small core with high control rod worth could experience a return to power if the highest worth rod is stuck out and AC power is not available to operate the active CVCS system
- in all cases , reactor immediately shuts down after a trip using only control rods , even with WRSO
- the reactor remains shut down under cold conditions with reliance only on control rods
- indefinitely with WRSO during first 70 percent of equilibrium fuel cycle, or
- for 30 days (typical) assuming WRSO while decay heat remains above 100 kW* (negative reactivity feedback from voiding in the core lim its return to power) 6 PM-0218-58480 --.-** NUSCALE Revision : O Copyright 20 18 by NuScale Power, LLC . ,: POWER-Template # : 0000-21727-F 01 R2
Exemption Review Criteria
- NuScale believes maintaining core cooling is the design objective of reactivity control systems in GDC 27 (postulated accidents)
- the "safety concern " for a return to power event is that it could challenge heat removal system capability such that the core is insufficiently cooled resulting in core damage
- maintaining peak cladding temperature limits is considered sufficient to maintain core cool ing
- core cooling is conservatively demonstrated by maintaining CHF limits
- NRC's proposed criteria for an exemption to GDC 27 is conservative
- maintain AOO acceptance criteria (CHF) and restrict frequency to less than that of an AOO (not expected in the life of a module) 7 PM-0218-58480 '; NUSCALE Revision : O Copyright 2018 by NuScale Power, LLC. ,: POWER-Template # : 0000-21727-FO1 R2
Design Evaluation Deterministic Evaluation Probabilistic Evaluation (Chapter 15)
Purpose Evaluate safety Evaluate shutdown reliability Conservative 1. WRSO with limiting shutdown margin 1. eves failure on demand vs . less likely extended assumptions 2. MTC unavailability of eves and CFDS
- 3. Cooldown rate 2 . Occurs throughout cycle vs . latter 30% of cycle
- 4. Xenon and boron concentration 3. No decay heat after restart vs . more likely decay
- 5. No credit for non-safety systems heat levels to prevent return to power Probability =1 under Ch 15 assumptions <1 E-6 per reactor module year
=O that all assumptions will actually occur Event 1. Return to power at 2+ hrs with DHRS 1. Return to power during DHRS cooldown is progression cooldown prevented
- 2. ECCS actuates resulting in subcriticality 2 . Without AC power, ECCS actuates after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />
- in less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> if AC and DC power is 3. Remains shut down until decay heat reduces to <
lost, or 100 kW
- after 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with DC power available 4. Sufficient time to restore function to eves or
- 3. Limiting condition for ECCS heat removal and CFDS to prevent a return to power CHF is subcriticality with maximum decay heat Criteria CHF limit not exceeded Not expected to occur during the life of a module 8
PM-02 18-58480 cea';* NUSCALE Revision : 0 Copyright 2018 by NuScale Power, LLC. .:* POWER-Temp1ate # : 0000-21727-FO 1 R2
Design Evaluation
- The capacity of the NuScale passive heat removal systems (DHRS, ECCS) are sufficiently sized to ensure the core remains cooled, irrespective of control rod performance
- core is protected after a return to power with a WRSO, or even after a failure to trip the reactor (ATWS)
- NuScale safely controls reactivity through natural, predictable, and reliable phenomena (negative void and reactivity feedback)
- using additional systems to increase shutdown reliability will increase design complexity, reduce overall reliability and likely safety
- licensed designs had to ensure subcriticality, using deterministic assumptions including a WRSO , to maintain core cooling (limit heat production within the capacity of decay heat removal systems) .
- DHRS heat removal characteristic in combination with negative moderator coefficient leads to self-limiting condition
- higher power-> higher moderator temperature-> negative moderator feedback
- ECCS heat removal characteristic in combination with moderator density decrease due to voiding leads to self-limiting condition
- higher power-> lower moderator density due to voiding-> negative density feedback 9
PM-0218-58480
,___,... N USCALE Revision : 0 Copyri ght 2018 by NuScale Power, LLC . ,__..,,: POWER-Temp late # : 0000-21727-F0 1 R2
Summary
- NuScale is pursuing an exemption from GDC 27 consistent with NRC staff position
- Reactivity control systems are consistent with design objectives for simplicity and passive safety and provide
- rapid shutdown to protect fuel
- reliable capability to maintain subcriticality under cold conditions
- passive heat removal that protects against control rod malfunctions
- alignment with the NRC's advanced reactor policy statement (73 FR 26349 ; October 14, 2008) for an advanced reactor design
- A return to power with a WRSO is a benign low probability event with no radiological consequences 10 PM-02 18-58480 :* ";* NUSCALE Revision : O Copyright 2018 by NuScale Power, LLC. **.:. : *POWER-Template # : 0000-21727-F0 1 R2
Backup Slides Reactor Power (Peak Power Case, EDSS Available) 14 12 10
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320 300 280 0 2000 4000 6000 8000 10000 12000 14000 Time (sec) 11 PM -0218-58480 Revision : 0 Copyright 2018 by NuScale Power, LLC.
Backup Slides Simplified eves Diagram X
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Design Overview: Passive Decay Heat Removal System
- Decay heat passively removed via the steam generators and OHR heat condensers to the reactor pool
- OHR system is composed of two independent and redundant trains (1 of 2 trains needed) NOTTO SCALE 13 PM-0218-58480
- ';* NUSCALE Revision: 0 Copyrig ht 20 18 by NuScale Power, LLC. *.:. ,;* POWER-Template # : 0000-21727-F01 R2
Design Overview: ECCS and Containment Heat Removal
+ t t +
provided without the need for safety-related injection
- Reactor vent valves and feactor recirculation valves --r--;-~ --+--l-+- containment vessel open on emergency core reactor pool cooling system (ECCS) actuation signal
- condensing steam on inside surface of containment vessel reactor recirculation-+-+-- ~ reactor recirculation convection to the pool fluid valves valves on outside vessel wall NOTTO SCALE 14 PM-0218-58480 ';* NUSCALE Revisio n: 0 Copyright 2018 by NuScale Power, LLC. ,:. POWER~
Tem plate #: 0000-21727-FO 1 R2
.,*** **** POWER' 6650 SW Redwood Lane, Suite 210 Portland, OR 97224 971 .371 .1592 1100 NE Circle Blvd., Suite 200 Corvallis, OR 97330 541 .360.0500 11333 Woodglen Ave., Suite 205 Rockville, MD 20852 301 . 770.0472 6060 Piedmont Row Drive South, Suite 600 Charlotte, NC 28287 980.349.4804 1933 Jadwin Ave., Suite 130 Richland, WA 99354 151 Floor Portland House Bressenden Place London SW1 E 58H United Kingdom
+44 (0) 2079 321700 http://www. nuscalepower.com WTwitter: @NuScale_Power 15 PM-0218-58480
- NUSCALE Revision : 0 Copyright 2018 by NuScale Power, LLC. ,' POWERN Template # : 0000-21727-FO 1 R2