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Category:Technical Specification
MONTHYEARRA-23-0279, Supplement to Application to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 and Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power2023-11-0202 November 2023 Supplement to Application to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 and Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power RA-18-0190, License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b2023-02-16016 February 2023 License Amendment Request to Revise Technical Specifications to Adopt Risk-Informed Completion Times TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b RA-22-0091, Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2023-02-16016 February 2023 Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RA-22-0118, License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies2023-02-0101 February 2023 License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies RA-22-0080, Independent Spent Fuel Storage Installation, McGuire, Units 1 & 2, Independent Spent Fuel Storage Installation, Request for an Exemption to the Requirements of Certificate of Compliance No. 1031 for the NAC Magnastor Storage System2022-04-0707 April 2022 Independent Spent Fuel Storage Installation, McGuire, Units 1 & 2, Independent Spent Fuel Storage Installation, Request for an Exemption to the Requirements of Certificate of Compliance No. 1031 for the NAC Magnastor Storage System RA-21-0302, Application to Revise Technical Specifications to Adopt TSTF-569, Rev. 2, Revise Response Time Testing Definition2022-02-24024 February 2022 Application to Revise Technical Specifications to Adopt TSTF-569, Rev. 2, Revise Response Time Testing Definition RA-20-0107, Duke Energy Progress, LLC, and Duke Energy Carolinas, LLC, Application to Revise Technical Specifications to Adopt TSTF-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position2022-01-18018 January 2022 Duke Energy Progress, LLC, and Duke Energy Carolinas, LLC, Application to Revise Technical Specifications to Adopt TSTF-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position RA-21-0027, Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections2021-09-16016 September 2021 Application to Revise Technical Specifications to Adopt TSTF-577, Revised Frequencies for Steam Generator Tube Inspections RA-20-0207, Duke Energy - Application to Revise the Technical Specification for Engineered Safety Feature Actuation System (ESFAS) Instrumentation2020-12-0303 December 2020 Duke Energy - Application to Revise the Technical Specification for Engineered Safety Feature Actuation System (ESFAS) Instrumentation RA-19-0006, License Amendment Application to Relocate Technical Specification Unit/Facility Staff Qualification ANSI N18.1-1971, ANSI/ANS-3.1-1978 and ANSI/ANS-3.1-1981 Requirements to the Duke Energy Corporation Quality Assurance Program Description2019-07-0808 July 2019 License Amendment Application to Relocate Technical Specification Unit/Facility Staff Qualification ANSI N18.1-1971, ANSI/ANS-3.1-1978 and ANSI/ANS-3.1-1981 Requirements to the Duke Energy Corporation Quality Assurance Program Description RA-18-0232, Proposed Editorial Error Correction of Technical Specification (TS) 3.0, Surveillance Requirement Applicability, SR 3.0.5 and Proposed Removal of Expired TS Footnotes from the MNS2019-02-0505 February 2019 Proposed Editorial Error Correction of Technical Specification (TS) 3.0, Surveillance Requirement Applicability, SR 3.0.5 and Proposed Removal of Expired TS Footnotes from the MNS RA-18-0166, Supplement to Non-Voluntary License Amendment Request (LAR) to Correct Non-Conservative Technical Specification 3.4.11 - PORVs2018-09-13013 September 2018 Supplement to Non-Voluntary License Amendment Request (LAR) to Correct Non-Conservative Technical Specification 3.4.11 - PORVs ML18191A5452018-07-10010 July 2018 Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages RA-18-001, Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages2018-07-10010 July 2018 Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages RA-18-000, Duke Energy Progress, LLC and Duke Energy Carolinas, LLC - Submittal of License Amendment Application to Remove Heaters from Ventilation System Technical Specifications2018-05-10010 May 2018 Duke Energy Progress, LLC and Duke Energy Carolinas, LLC - Submittal of License Amendment Application to Remove Heaters from Ventilation System Technical Specifications RA-18-0001, Duke Energy Progress, LLC and Duke Energy Carolinas, LLC - License Amendment Application to Remove Heaters from Ventilation System Technical Specifications2018-05-10010 May 2018 Duke Energy Progress, LLC and Duke Energy Carolinas, LLC - License Amendment Application to Remove Heaters from Ventilation System Technical Specifications ML18130A8072018-05-10010 May 2018 Duke Energy Progress, LLC and Duke Energy Carolinas, LLC - Submittal of License Amendment Application to Remove Heaters from Ventilation System Technical Specifications RA-17-0005, Application to Revise Technical Specifications to Adopt TSTF-545, Revision 3, TS Inservice Testing Program Removal & Clarify SR Usage Rule Application to Section 5.5 Testing2017-11-0707 November 2017 Application to Revise Technical Specifications to Adopt TSTF-545, Revision 3, TS Inservice Testing Program Removal & Clarify SR Usage Rule Application to Section 5.5 Testing RA-17-0045, Supplement: Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules.2017-10-12012 October 2017 Supplement: Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules. ML17237A0492017-08-17017 August 2017 Technical Specification Bases - List of Effected Sheets ML17237A0482017-08-17017 August 2017 Technical Specification Bases (Rev. 150) ML17237A0462017-08-17017 August 2017 Document Transmittal Form Regarding Technical Specification Changes - Amendment Nos. 296/275 ML17186A0682017-06-26026 June 2017 Tech Spec Bases - List of Affected Sections ML17186A0672017-06-26026 June 2017 Revision 151 to Tech Spec Bases - B 3.6.13 and B 3.6.14 ML17186A0662017-06-26026 June 2017 TS 3.6.13 Amendment 292/271 and TS 3.6.14 Amendment 294/273 ML17186A0692017-06-26026 June 2017 Issue Tech Spec - List of Affected Pages ML17136A2792017-05-0303 May 2017 Technical Specification Leep, Rev. 109 ML17136A2782017-05-0303 May 2017 Technical Specification Bases - Loes, Rev. 133 ML17136A3612017-05-0303 May 2017 Technical Specification Bases, Revision 149 ML17136A3602017-05-0303 May 2017 Technical Specification Amendment Nos. 285/264 ML17124A3682017-04-19019 April 2017 Tech Spec Bases List of Effected Pages ML17124A3712017-04-19019 April 2017 Bases B 3.5.1 - Accumulators ML17094A6722017-03-29029 March 2017 Issue Selected License Commitment Cslcl 16.7.14 Revision ML17094A6732017-03-29029 March 2017 Issue SLC List of Effected Pages ML17090A4522017-03-23023 March 2017 Revision to Technical Specification 3.3.2 - Amendment 293/272 ML17090A4512017-03-23023 March 2017 Revision to Technical Specification 3.8.1 - Amendment 293/272 ML17090A4352017-03-22022 March 2017 Technical Specification Bases ML17090A4502017-03-22022 March 2017 Revision to Technical Specification Bases - B 3.6.15 ML17094A6702017-03-15015 March 2017 Issue MNS-SLC-16.9.15. Snubbers MNS-16-092, License Amendment Request to Revise Technical Specifications Section 5.5.2, Containment Leakage Rate Testing Program for Permanent Extension of Type a and Type C Leak Rate Test Frequencies2016-12-19019 December 2016 License Amendment Request to Revise Technical Specifications Section 5.5.2, Containment Leakage Rate Testing Program for Permanent Extension of Type a and Type C Leak Rate Test Frequencies ML16305A1442016-10-20020 October 2016 Issue MNS Technical Specification 5.5 RA-16-0019, Duke Energy Progress - Application to Revise Technical Specifications to Adopt TSTF-522, Revision 0, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month Using the Consolidated Line Item Improvement Proces2016-09-27027 September 2016 Duke Energy Progress - Application to Revise Technical Specifications to Adopt TSTF-522, Revision 0, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month Using the Consolidated Line Item Improvement Process ML16265A5312016-08-30030 August 2016 Issue MNS Tech Spec Bases List of Effective Sections ML16265A5322016-08-30030 August 2016 Technical Specification Bases 3.6.14 Revisions, List of Revisions and Dates ML16250A0142016-08-29029 August 2016 Amendment 287 ML16243A3492016-08-23023 August 2016 Mccguire, Units 1 and 2, Revision 143 to Issue MNS Technical Specification Bases 3.3.1 ML16243A3482016-08-23023 August 2016 Technical Specification 3.3.1, Reactor Trip System (RTS) Instrumentation. ML16243A3512016-08-23023 August 2016 Revision 105 to Technical Specifications List of Effective Pages ML16243A3502016-08-23023 August 2016 Revision 129 to Technical Specification Bases ML16243A3572016-08-18018 August 2016 Technical Specification Bases Revision 001, List of Revised Sections 2023-02-16
[Table view] Category:Bases Change
MONTHYEARRA-23-0279, Supplement to Application to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 and Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power2023-11-0202 November 2023 Supplement to Application to Adopt Risk-Informed Completion Times TSTF-505, Revision 2 and Application to Adopt 10 CFR 50.69, Risk-informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power RA-22-0091, Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements2023-02-16016 February 2023 Application to Revise Technical Specifications to Adopt TSTF-554, Revision 1, Revise Reactor Coolant Leakage Requirements RA-22-0118, License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies2023-02-0101 February 2023 License Amendment Request to Revise Restrictive Technical Specification Surveillance Requirement Frequencies RA-21-0302, Application to Revise Technical Specifications to Adopt TSTF-569, Rev. 2, Revise Response Time Testing Definition2022-02-24024 February 2022 Application to Revise Technical Specifications to Adopt TSTF-569, Rev. 2, Revise Response Time Testing Definition RA-20-0107, Duke Energy Progress, LLC, and Duke Energy Carolinas, LLC, Application to Revise Technical Specifications to Adopt TSTF-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position2022-01-18018 January 2022 Duke Energy Progress, LLC, and Duke Energy Carolinas, LLC, Application to Revise Technical Specifications to Adopt TSTF-541, Add Exceptions to Surveillance Requirements for Valves and Dampers Locked in the Actuated Position RA-18-0232, Proposed Editorial Error Correction of Technical Specification (TS) 3.0, Surveillance Requirement Applicability, SR 3.0.5 and Proposed Removal of Expired TS Footnotes from the MNS2019-02-0505 February 2019 Proposed Editorial Error Correction of Technical Specification (TS) 3.0, Surveillance Requirement Applicability, SR 3.0.5 and Proposed Removal of Expired TS Footnotes from the MNS RA-18-0166, Supplement to Non-Voluntary License Amendment Request (LAR) to Correct Non-Conservative Technical Specification 3.4.11 - PORVs2018-09-13013 September 2018 Supplement to Non-Voluntary License Amendment Request (LAR) to Correct Non-Conservative Technical Specification 3.4.11 - PORVs ML18191A5452018-07-10010 July 2018 Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages RA-18-001, Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages2018-07-10010 July 2018 Attachment 2 - McGuire Technical Specification 3.8.1 Bases Marked Up Pages RA-17-0045, Supplement: Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules.2017-10-12012 October 2017 Supplement: Application to Revise Technical Specifications to Adopt TSTF-529, Clarify Use and Application Rules. ML17237A0462017-08-17017 August 2017 Document Transmittal Form Regarding Technical Specification Changes - Amendment Nos. 296/275 ML17237A0482017-08-17017 August 2017 Technical Specification Bases (Rev. 150) ML17237A0492017-08-17017 August 2017 Technical Specification Bases - List of Effected Sheets ML17186A0662017-06-26026 June 2017 TS 3.6.13 Amendment 292/271 and TS 3.6.14 Amendment 294/273 ML17186A0672017-06-26026 June 2017 Revision 151 to Tech Spec Bases - B 3.6.13 and B 3.6.14 ML17186A0682017-06-26026 June 2017 Tech Spec Bases - List of Affected Sections ML17186A0692017-06-26026 June 2017 Issue Tech Spec - List of Affected Pages ML17136A3612017-05-0303 May 2017 Technical Specification Bases, Revision 149 ML17136A3602017-05-0303 May 2017 Technical Specification Amendment Nos. 285/264 ML17136A2792017-05-0303 May 2017 Technical Specification Leep, Rev. 109 ML17136A2782017-05-0303 May 2017 Technical Specification Bases - Loes, Rev. 133 ML17124A3682017-04-19019 April 2017 Tech Spec Bases List of Effected Pages ML17124A3712017-04-19019 April 2017 Bases B 3.5.1 - Accumulators ML17094A6722017-03-29029 March 2017 Issue Selected License Commitment Cslcl 16.7.14 Revision ML17094A6732017-03-29029 March 2017 Issue SLC List of Effected Pages ML17090A4522017-03-23023 March 2017 Revision to Technical Specification 3.3.2 - Amendment 293/272 ML17090A4512017-03-23023 March 2017 Revision to Technical Specification 3.8.1 - Amendment 293/272 ML17090A4352017-03-22022 March 2017 Technical Specification Bases ML17090A4502017-03-22022 March 2017 Revision to Technical Specification Bases - B 3.6.15 ML17094A6702017-03-15015 March 2017 Issue MNS-SLC-16.9.15. Snubbers RA-16-0019, Duke Energy Progress - Application to Revise Technical Specifications to Adopt TSTF-522, Revision 0, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month Using the Consolidated Line Item Improvement Proces2016-09-27027 September 2016 Duke Energy Progress - Application to Revise Technical Specifications to Adopt TSTF-522, Revision 0, Revise Ventilation System Surveillance Requirements to Operate for 10 Hours Per Month Using the Consolidated Line Item Improvement Process ML16265A5312016-08-30030 August 2016 Issue MNS Tech Spec Bases List of Effective Sections ML16265A5322016-08-30030 August 2016 Technical Specification Bases 3.6.14 Revisions, List of Revisions and Dates ML16250A0142016-08-29029 August 2016 Amendment 287 ML16243A3482016-08-23023 August 2016 Technical Specification 3.3.1, Reactor Trip System (RTS) Instrumentation. ML16243A3502016-08-23023 August 2016 Revision 129 to Technical Specification Bases ML16243A3512016-08-23023 August 2016 Revision 105 to Technical Specifications List of Effective Pages ML16243A3492016-08-23023 August 2016 Mccguire, Units 1 and 2, Revision 143 to Issue MNS Technical Specification Bases 3.3.1 ML16243A3572016-08-18018 August 2016 Technical Specification Bases Revision 001, List of Revised Sections ML16243A3552016-08-17017 August 2016 Renewed Facility Operating License, Amendment 284 ML16243A3522016-08-17017 August 2016 Technical Specification 3.4.18, Amendment Nos. 284/263, Steam Generator (SG) Tube Integrity. ML16243A3542016-08-17017 August 2016 Technical Specification Bases 3.4.18, Revision 144, Steam Generator (SG) Tube Integrity RA-16-0007, Duke Energy Carolinas, LLC, Application to Revise TS to Adopt TSTF-427, Revision 2, Allowance for Non Technical Specification Barrier Degradation on Supported System Operability Using the Consolidated Line Item Improvement Process2016-06-23023 June 2016 Duke Energy Carolinas, LLC, Application to Revise TS to Adopt TSTF-427, Revision 2, Allowance for Non Technical Specification Barrier Degradation on Supported System Operability Using the Consolidated Line Item Improvement Process ML16139A5572016-05-10010 May 2016 Technical Specification Bases 3.3.1 Rev. 001, Revision 141 ML16139A5552016-05-10010 May 2016 Technical Specification Bases 3.9.3, Revision 001, Revision 142 MNS-16-020, License Amendment Request Removal of Superseded Technical Specification Requirements2016-05-0505 May 2016 License Amendment Request Removal of Superseded Technical Specification Requirements MNS-16-015, License Amendment Request (LAR) for One-Time Extension of Appendix J Type a Integrated Leakage Rate Test Interval2016-02-18018 February 2016 License Amendment Request (LAR) for One-Time Extension of Appendix J Type a Integrated Leakage Rate Test Interval ML16056A2432016-02-18018 February 2016 Emergency Action Level Technical Bases Document Redline MNS-16-016, Emergency Action Level Technical Bases, Revision 1 Redline. Part 1 of 22016-02-18018 February 2016 Emergency Action Level Technical Bases, Revision 1 Redline. Part 1 of 2 ML16056A2452016-02-18018 February 2016 Emergency Action Level Technical Bases, Revision 1 Redline. Part 2 of 2 2023-02-16
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1*Distribution:
- 1. AREVA NP 2. BLUE DOT LIBRARY 3. MCG DOC CNTRL MISC MAN 4. MCG OPS PROCEDURE GP 5. MCG PLANT ENG. LIBR.6. MCGRPAD PROT 7. OPS HUMAN PERFORMANCE
-8. OPS TRNG MGR.9. QATS-10. RESIDENT NRC INSPECT 11. SCIENTECH CLEARWIR, FL 12. SERV BLDG FILE ROOM -13. U S NUC REG WASHINGTON, DC 14. USNRC 15. WESTINGHOUSE ELECTRIC CO LLC Duke Energy DOCUMENT TRANSMITTAL FORM Facility:
MCGUIRE NUCLEAR STATION SUBJECT MNS-TSB-B 3.1.3 RCS MODERATOR TEMPERATURE COEFFICIENT-REV 136 Date: 7128/2015 Document Transmittal
- TR-NUC-MC-000332 Purpose: Issue Released By: 13225 Haaers Ferry Road Document Manaaement MGO2M Huntersville, NC 28078 MNSDCRMc@duke-eneray.corn Page 1 of 1 1: DocumentID.
.....41 1 1 18 9 1 ii 213115 ILICN -MC -MNS-TSB-B 311.3 -136 -ISSUED "YI YI YI YI YI FIE FIE FIE FIE FIE FY" YI YI YI YI Remarks: PLEASE DISTRIBUE THIS TO TSB MANUAL HOLDERS REFERENCE TRANSM1T~AL TR-NUC-MC000287---FOR DISTRIBUTION ENTITIES MTC B 3.1.3 BASES B 3.1 REACTIVITY CONTROL SYSTEMS B 3.1.3 Moderator Temperature Coefficient (MTC)BASES BACKGROUND According to GDC 11 (Ref. 1), the reactor core and its interaction with the Reactor Coolant System (RCS) must be designed for inherently stable power operation, even in the possible event of an accident.
In particular, the net reactivity feedback in the system must compensate for any unintended reactivity increases.
The MTC relates a change in core reactivity to a change in reactor coolant temperature (a positive MTC means that reactivity increases with increasing moderator temperature; conversely, a negative MTC means that reactivity decreases with increasing moderator temperature).
The reactor is designed to operate with a negative MTC over the largest possible range of fuel cycle operation.
Therefore, a coolant temperature increase will cause a reactivity decrease, so that the coolant temperature tends to return toward its initial value. Reactivity increases that cause a coolant temperature increase will thus be self limiting, and stable power operation will result.MTC values are predicted at selected burnups during the safety evaluation analysis and are confirmed to be acceptable by measurements.
Both initial and reload cores are designed so that the MTC is less than zero when THERMAL POWER is at RTP. The actual value of the MTC is dependent on core characteristics, such as fuel loading and reactor coolant soluble boron concentration.
The core design may require additional fixed distributed poisons to yield an MTC at or near BOC within the range analyzed in the plant accident analysis.
For some designs, the burnable absorbers may burn out faster than the fuel depletes early in the cycle. This may cause the boron concentration to increase with burnup early in the cycle and the most positive MTC not to occur at BOC but somewhat later in the cycle. For these core designs, the predicted difference between the BOC MTC, and the most positive MTC is used to adjust the BOC measured MTC to ensure that the MTC remains less than the limit during the entire cycle. The end of cycle (EOC)MTC is also limited by the requirements of the accident analysis.
Fuel cycles that are designed to achieve high burnups or that have changes to other characteristics are evaluated to ensure that the MTC does not exceed the EOC limit.The limitations on MTC are provided to ensure that the value of this coefficient remains within the limiting conditions assumed in the UFSAR accident and transient analyses.McGuire Units 1 and 2 B3131Rvso o 3 B3.1.3-1 Revision No. 136 MTC B 3.1.3 BASES BACKGROUND (continued)
If the LCO limits are not met, the unit response during transients may not be as predicted.
The core could violate criteria that prohibit a return to criticality, or the departure from nucleate boiling ratio criteria of the approved correlation may be violated, which could lead to a loss of the fuel cladding integrity.
The SRs for measurement of the MTC at the beginning and near the end of the fuel cycle are adequate to confirm that the MTC remains within its limits, since this coefficient changes slowly, due principally to changes in RCS boron concentration associated with fuel and burnable absorber depletion.
APPLICABLE The acceptance criteria for the specified MTC are: SAFETY ANALYSES a. The MTC values must remain within the bounds of those used in the accident analysis (Ref. 2); and b. The MTC must be such that inherently stable power operations result during normal operation and accidents, such as overheating and overcooling events.The UFSAR, Chapter 15 (Ref. 2), contains analyses of accidents that result in both overheating and overcooling of the reactor core. MTC is one of the controlling parameters for core reactivity in these accidents.
Both the most positive value and most negative value of the MTC are important to safety, and both values must be bounded. Values used in the analyses consider worst case conditions to ensure that the accident results are bounding (Ref. 2).The consequences of accidents that cause core overheating must be evaluated when the MTC is positive.
Such accidents include the rod withdrawal transient from any power level (Ref. 3), turbine trip, and loss of forced reactor coolant flow. The consequences of accidents that cause core overcooling must be evaluated when the MTC is negative.
Such accidents include sudden feedwater flow increase and steam line break.In order to ensure a bounding accident analysis, the MTC is assumed to be its most limiting value for the analysis conditions appropriate to each accident.
The bounding value is determined by considering rodded and unrodded conditions, whether the reactor is at full or zero power, and whether it is the BOC or EOC life. The most conservative combination appropriate to the accident is then used for the analysis (Ref. 2).MTC values are bounded in reload safety evaluations assuming steady state conditions at BOC and EOC. An EOC measurement or McGuire Units 1 and 2 B3132Rvso o 3 B3.1.3-2 Revision No. 136 MTC B83.1.3 BASES APPLICABLE SAFETY ANALYSES (continued) analytical check (Ref. 5) of the EOC MTC is conducted at conditions when the RCS boron concentration reaches approximately 300 ppm. The measured or calculated value may be extrapolated to project the EOC value, in order to confirm reload design predictions.
MTC satisfies Criterion 2 of 10 CFR 50.36 (Ref. 4). Even though it is not directly observed and controlled from the control room, MTC is considered an initial condition process variable because of its dependence on boron concentration.
LCO LCO 3.1.3 requires the MTC to be within specified limits of the COLR to ensure that the core operates within the assumptions of the accident analysis.
During the reload core safety evaluation, the MTC is analyzed to determine that its values remain within the bounds of the original accident analysis during operation.
Assumptions made in safety analyses require that the MTC be less positive than a given upper bound and more positive than a given lower bound. The MTC is most positive at or near BOC; this upper bound must not be exceeded.
This maximum upper limit occurs at or near BOC, all rods out (ARO), hot zero power conditions.
For some core designs, the burnable absorbers may burnout faster than the fuel depletes early in the cycle. This may cause the boron concentration to increase with burnup early in the cycle and the most positive MTC not occur at BOC, but somewhat later in the cycle. For these core designs, the predicted distance between the BOC MTC, and the most positive MTC is used to adjust the BOC measured MTC to ensure that the MTC remains less than the limit during the entire cycle. At EOC the MTC takes on its most negative value, when the lower bound becomes important.
This LCO exists to ensure that both the upper and lower bounds are not exceeded.During operation, the condition of the upper LCO limit at BOC is ensured through measurement.
The lower LCO limit at EOC is ensured either analytically or through measurement.
The Surveillance checks at BOO and EOC on MTC provide confirmation that the MTC is behaving as anticipated so that the acceptance criteria are met.The LCO establishes a maximum positive value that cannot be exceeded.The BOO positive limit and the EOC negative limit are established in the COLR to allow specifying limits for each particular cycle. This permits the unit to take advantage of improved fuel management and changes in unit operating schedule.McGuire Units 1 and 2 B3133Rvso o 3 B 3.1.3-3 Revision No. 136 MTC B 3.1.3 BASES APPLICABILITY Technical Specifications place both LCO and SR values on MTC, based on the safety analysis assumptions described above.In MODE 1, the limits on MTC must be maintained to ensure that any accident initiated from THERMAL POWER operation will not violate the design assumptions of the accident analysis.
In MODE 2 with the reactor critical, the upper limit must also be maintained to ensure that startup and subcritical accidents (such as the uncontrolled control rod assembly or group withdrawal) will not violate the assumptions of the accident analysis.
The lower MTC limit must be maintained in MODES 2 and 3, in addition to MODE 1, to ensure that cooldown accidents will not violate the assumptions of the accident analysis.
In MODES 4, 5, and 6, this LCO is not applicable, since no Design Basis Accidents using the MTC as an analysis assumption are limiting when initiated from these MODES.ACTIONS A.1 If the BOO MTC limit is violated, administrative withdrawal limits for control banks must be established to maintain the MTC within its limits.The MTC becomes more negative with control bank insertion and decreased boron concentration.
A Completion Time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provides enough time for evaluating the MTC measurement and computing the required bank withdrawal limits.Using physics calculations, the time in cycle life at which the calculated MTC will meet the LCO requirement can be determined.
At this point in core life Condition A no longer exists. The unit is no longer in the Required Action, so the administrative withdrawal limits are no longer in effect.B.._If the required administrative withdrawal limits at BOC are not established within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the unit must be brought to MODE 2 with keff < 1.0 to prevent operation with an MTC that is more positive than that assumed in safety analyses.The allowed Completion Time of 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.C...1 Exceeding the EOC MTC limit means that the safety analysis assumptions for the EOC accidents that use a bounding negative MTC value may be invalid. If the EOC MTC limit is exceeded, the plant must McGuire Units 1 and 2 B3134Rvso o 3 B 3.1.3-4 Revision No. 136 MTC B 3.1.3 BASES ACTIONS (continued) be brought to a MODE or condition in which the LCO requirements are not applicable.
To achieve this status, the unit must be brought to at least MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.The allowed Completion Time is reasonable, based on operating experience, for reaching the required MODE from full power conditions in an orderly manner and without challenging plant systems.SURVEILLANCE SR 3.1.3.1 REQUIREMENTS This SR requires measurement of the MTC at BOC prior to entering MODE 1 in order to demonstrate compliance with the positive MTC LCO.Meeting the limit prior to entering MODE 1 ensures that the limit will also be met at higher power levels.The BOC MTC value for ARO will be inferred from isothermal temperature coefficient measurements obtained during the physics tests after refueling.
If appropriate, the ARO value is adjusted to account for any increase in the MTC early in the cycle. The ARO value can then be directly compared to the BOC MTC limit of the LCO. If required, measurement results and predicted design values can be used to establish administrative withdrawal limits for control banks.SR 3.1.3.2 In similar fashion, the LCO demands that the MTC be less negative than the specified value for EOC full power conditions.
This measurement may be performed at any THERMAL POWER, but its results must be extrapolated to the conditions of RTP and all banks withdrawn in order to make a proper comparison with the LCO value. Because the RTP MTC value will gradually become more negative with further core depletion and boron concentration reduction, a 300 ppm SR value of MTC should necessarily be less negative than the EOC LCO limit. The 300 ppm SR value is sufficiently less negative than the EOC LCO limit value to ensure that the LCO limit will be met when the 300 ppm Surveillance criterion is met.SR 3.1.3.2 is modified by three Notes that include the following requirements:
- a. The SR is not required to be performed until 7 effective full power days (EFPD) after reaching the equivalent of an equilibrium RTP all rods out (ARO) boron concentration of 300 ppm for the reasons discussed above. Measurement of the MTC may be suspended for the current operating cycle provided the benchmark criteria McGuire Units 1 and 2 B3135Rvso o 3 B 3.1.3-5 Revision No. 136 MTC 8 3.1.3 BASES SURVEILLANCE REQUIREMENTS (continued) specified in DPC-NE-1 007-PA and the Revised MTC Prediction specified in the COLR are satisfied.
- b. If the 300 ppm Surveillance limit is exceeded, it is possible that the EOC limit on MTC could be reached before the planned EOC.Because the MTC changes slowly with core depletion, the Frequency of 14 EFPD is sufficient to avoid exceeding the EOC limit.c. The Surveillance limit for RTP boron concentration of 60 ppm is conservative.
If the measured MTC at 60 ppm is more positive than the 60 ppm Surveillance limit, the EOC limit will not be exceeded because of the gradual manner in which MTC changes with core burnup.REFERENCES
- 1. 10 CFR 50, Appendix A, GDC 11.2. UFSAR, Chapter 15.3. UFSAR, Section 15.4.4. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).
- 5. DPC-NE-1 007-PA, "Conditional Exemption of the EOC MTC Measurement Methodology.
McGuire Units 1 and 2831-6RvsoNo16 B3.1.3-6 Revision No. 136