Text

License Amendment Request for Technical Specification (TS) 3.4.12, Low Temperature Overpressure Protection (LTOP) System
	ML14043A167
Person / Time
Site:	McGuire, Mcguire
Issue date:	01/28/2014
From:	Capps S; Duke Energy Carolinas
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	MNS-14-003
	Download: ML14043A167 (43)
	v • d • e

Steven D. Capps Vice President "ZOENERGY. McGuire Nuclear Station Duke Energy MG01VP 1 12700 Hagers Ferry Road Huntersville, NC 28078 o: 980.875.4805 f: 980.875.4809 Steven. Capps@d uke-energy.com Licensing Change Proposal: 0003 Serial: MNS-14-003 January 28, 2014 10 CFR 50.90 U. S. Nuclear Regulatory Commission Washington, DC 20555-0001 Attention: Document Control Desk

Subject:

Duke Energy Carolinas, LLC (Duke Energy)

McGuire Nuclear Station, Units 1 and 2 Docket Nos. 50-369 and 50-370 License Amendment Request for Technical Specification (TS) 3.4.12, "Low Temperature Overpressure Protection (LTOP) System" Pursuant to 10 CFR 50.90, Duke Energy is submitting a License Amendment Request (LAR) to McGuire Facility Operating Licenses NPF-9 and NPF-1 7 and the subject TS. An error was made during McGuire's conversion to Standard Technical Specifications in TS 3.4.12.

Condition G incorrectly references Condition E. As currently written, TS 3.4.12 Required Actions F.2 and G.1 collectively require that an operable Residual Heat Removal (RHR) suction relief valve be aligned within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and that a Reactor Coolant System vent path greater than 2.75 square inches be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months if one of two Power Operated Relief Valves (PORVs) is inoperable in accordance with Condition E. Both actions are overly restrictive since either action is sufficient to compensate for the loss of one PORV. As such, Condition G is being corrected to eliminate the reference to Condition E so that alignment of an operable RHR relief valve is sufficient to compensate for the loss of one PORV.

The enclosure provides Duke Energy's evaluation of the LAR which contains a description of the proposed TS change, the technical analysis, the regulatory evaluation, the determination that this LAR contains No Significant Hazards Considerations, and the basis for the categorical exclusion from performing an Environmental Assessment/Impact Statement.

Attachment 1 provides the current McGuire's TS pages, marked-up to show the proposed changes. Reprinted TS pages will be provided to the NRC upon issuance of the approved amendment. Attachment 2 provides the pre-STS TS pages. Attachment 3 provides the original conversion STS marked-up pages showing the error. Attachment 4 provides the current McGuire's TS Bases pages, marked-up to show the proposed changes. Attachment 4 is provided for information only.

Duke Energy requests approval of this LAR within one year of its submittal date. The NRC's standard 30-day implementation grace period will be sufficient to implement this LAR. There are no regulatory commitments contained in this LAR. The McGuire's Updated Final Safety Analysis Report does not require to be updated due to this LAR.

www.duke-energy.com

U. S. Nuclear Regulatory Commission January 28, 2014 Page 2 In accordance with Duke Energy internal procedures and the Quality Assurance Topical Report, the proposed amendment has been reviewed and approved by the McGuire Plant Operations Review Committee.

Pursuant to 10 CFR 50.91, a copy of this LAR has been forwarded to the appropriate North Carolina state official.

There are no regulatory commitments contained in this letter or its enclosure/attachments.

Please direct any questions you may have in this matter to P. T. Vu at (980) 875-4302.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on January 28, 2014.

Very truly yours, Steven D. Capps Enclosure/attachments

U. S. Nuclear Regulatory Commission January 28, 2014 Page 3 xc:

Victor McCree Administrator, Region II U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 John Zeiler NRC Senior Resident Inspector McGuire Nuclear Station Jason Paige (addressee only)

NRC Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 G9A Rockville, MD 20852-2738 W. L. Cox, III Section Chief Division of Environmental Health, Radiation Protection Section North Carolina Department of Environmental and Natural Resources 1645 Mail Service Center Raleigh, NC 27699-1645

ENCLOSURE EVALUATION OF PROPOSED CHANGES

Subject:

License Amendment Request to Revise Technical Specification 3.4.12 Conditions and Required Actions - Low Temperature Overpressure Protection (LTOP) System 1.0

SUMMARY

DESCRIPTION 2.0 DETAILED DESCRIPTION

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration Determination 4.3 Conclusions

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

ATTACHMENTS:

1. Current Technical Specification Page Markups

2. Pre-STS Technical Specification Pages

3. Original Conversion STS Page Markups

4. Current Technical Specification Bases Page Markups

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 1 of 8 1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, Duke Energy is submitting a License Amendment Request (LAR) to McGuire Facility Operating Licenses NPF-9 and NPF-17 and Technical Specification (TS) 3.4.12 - Reactor Coolant System (RCS) Low temperature Overpressure Protection (LTOP)

System.

An error was made during McGuire's conversion to Standard Technical Specifications (STS) in TS 3.4.12. Condition G incorrectly references Condition E. As currently written, TS 3.4.12 Required Actions F.2 and G.1 collectively require that an operable Residual Heat Removal (RHR) suction relief valve be aligned within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and that a Reactor Coolant System vent path greater than 2.75 square inches be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months if one of two Power Operated Relief Valves (PORVs) is inoperable in accordance with Condition E. Both actions are overly restrictive since either action is sufficient to compensate for the loss of one PORV. As such, Condition G is being corrected to eliminate the reference to Condition E so that alignment of an operable RHR relief valve is sufficient to compensate for the loss of one PORV.

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 2 of 8 2.0 DETAILED DESCRIPTION TS 3.4.12 Conditions E, F and G currently specify:

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. One PORV inoperable in E.1 Suspend all operations Immediately MODE 5 or 6. which could lead to a water solid pressurizer.

AND E.2 Restore PORV to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months OPERABLE status.

F. Required Action and F.1. Verify RCS cold leg 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months associated Completion temperature > 174 0 F (Unit Time of Condition E not 1) or > 89 0 F (Unit 2).

met.

AND F.2 Verify RHR suction relief 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months valve is OPERABLE and the suction isolation valves are open.

G. Two PORVs inoperable. G.1 Depressurize RCS and 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months establish RCS vent of OR >2.75 square inches.

Required Action and associated Completion Time of Condition C, D, E, or F not met.

OR LTOP System inoperable for any reason other than Condition A, B, C, D, E, or F.

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 3 of 8 Based on the above requirements, when Condition E required actions and associated completion times are not met, all three Required Actions F.1, F.2 and G1 have to be performed.

Prior to conversion to STS, only Required Actions F.1 and F.2, or G.1 had to be performed (see Pre-STS TS 3.4.9.3 Action d in Attachments 2 and 3).

Required Actions F.2 and G.1 are overly restrictive in that Required Action F.2 restores redundancy with one PORV and one RHR suction relief valve, and further action by Required Action G.1 is not necessary. This proposed LAR modifies TS 3.4.12 Condition G by deleting the reference to Condition E so that when Condition E required actions are not met, only Condition F is entered and Condition G is not entered.

The revised Condition G is:

G. Two PORVs inoperable. G.1 Depressurize RCS and 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months establish RCS vent of OR >2.75 square inches.

Required Action and associated Completion Time of Condition C, D, or F not met.

OR LTOP System inoperable for any reason other than Condition A, B, C, D, E, or F.

3.0 TECHNICAL EVALUATION

The RCS Overpressure Protection System prevents the RCS from exceeding the pressure/temperature limits of 10 CFR 50, Appendix G, for periods of water solid operation during startup and shutdown. The maximum RCS pressure is limited by providing a low pressure setpoint interlocked with reactor coolant temperature to actuate the PORV.

The protection provided by this system is required for periods of water solid operation during startup and shutdown. Therefore, the PORV low pressure setpoint is enabled by the operator as plant conditions dictate. A key-lock switch, located on the main control board, is provided for each train of PORVs to enable the low pressure setpoint.

The PORVs are used to provide protection against exceeding 10 CFR 50 Appendix G limits during periods of water solid operation. Analyses have shown that one PORV is sufficient to prevent violation of these limits due to anticipated mass and heat input transients. However, redundant protection against such over-pressurization events is provided through the addition of low pressure setpoints to two PORV's. Since this protection is required only during low

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 4 of 8 temperature water solid operation, the low pressure setpoint is enabled by the operator at reactor coolant loop temperature below 300'F. The low pressure setpoint is interlocked with reactor coolant loop temperature to minimize the possibility of inadvertent actuation.

Administrative control is exercised to prevent inadvertent overpressurization when the RCS is water solid during startup or shutdown. Operating procedures for startup and shutdown are written such that the sequence of operations assures that the unit is maintained within the TSs.

Additionally, these procedures contain precautions and limitations which are specified to emphasize sequences or combinations of unit conditions which are critical to the control of pressure in the RCS.

As RCS temperature approaches the temperature setpoint during plant cooldown but before collapse of the pressurizer steam bubble, an annunciator alerts the operator that plant conditions require low temperature overpressure protection. The operator places each key-lock switch to the LOW PRESSURE position to enable the PORV low pressure setpoint.

Should a pressure excursion occur while in the low pressure mode with plant temperature below the temperature setpoint, system pressure in excess of the PORV low pressure setpoint would be relieved to the pressurizer relief tank. An annunciator in the Control Room would alert the operator to system overpressure in this condition.

When system temperature rises above the temperature setpoint during plant heatup, the RCS Overpressure Protection System is automatically disarmed, and an annunciator alerts the operator that low temperature overpressure protection is no longer required. The operator then returns each key-lock switch to the NORMAL position.

The permissive signal which allows the operator to enable the PORV to respond to the low pressure setpoint and the annunciator which alerts the operator that the low pressure mode is required are derived from the RCS wide range temperature instrument. Additionally, the temperature permissive signal functions as an interlock to prevent inadvertent actuation of the PORVs during normal operation and, also, to automatically remove the low pressure setpoint when system temperature is above the low temperature setpoint.

With one of the two PORVs inoperable in Mode 5 or in Mode 6, all operations which could lead to a water solid pressurizer must be suspended immediately and the completion time to restore two valves to operable status is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If the preceding actions are not met, then alternative actions are necessary to establish the required redundancy in relief capacity.

To establish the above required redundancy in relief capacity, Required Action F.2 currently requires to verify that the RHR suction relief valve is operable and the suction isolation valves are open within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , and Required Action G.1 currently requires depressurizing the RCS and establishing a RCS vent of > 2.75 square inches within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Required Actions F.2 and G.1 are overly restrictive since either action is sufficient to compensate for the loss of one PORV. As such, Condition G is being corrected to eliminate the reference to Condition E so that alignment of an operable RHR suction relief valve is sufficient to compensate for the loss of one PORV. LTOP calculations support the use of the RHR suction relief valve as an alternative to one PORV.

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 5 of 8

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/Criteria:

1) Regulatory Requirements The regulatory basis for TS LCO 3.4.12 is to control RCS pressure at low temperatures so the integrity of the reactor coolant pressure boundary (RCPB) is not compromised by violating the P/T limits of 10 CFR 50 Appendix G. The ASME Code forms the basis for the requirements of this appendix. The reactor vessel material is less tough at low temperatures than at normal operating temperature. As the vessel neutron exposure accumulates, the material toughness decreases and becomes less resistant to pressure stress at low temperatures. RCS pressure, therefore, is maintained low at low temperatures and is increased only as temperature is increased.

10 CFR 50, Appendix G - This appendix specifies fracture toughness requirements for ferritic materials of pressure-retaining components of the reactor coolant pressure boundary of light water nuclear power reactors to provide adequate margins of safety during any condition of normal operation, including anticipated operational occurrences and system hydrostatic tests, to which the pressure boundary may be subjected over its service lifetime.

ASME Section III, Division 1 - This section addresses the rules for construction of nuclear facility components and supports. The components and supports covered by Section III are intended to be installed in a nuclear power system that serves the purpose of producing and controlling the output of thermal energy from nuclear fuel and those associated systems essential to safety of nuclear power system.Section III provides requirements for new construction of nuclear power system considering mechanical and thermal stresses due to cyclic operation. Deterioration, which may occur in service as result of radiation effects, corrosion, or instability of the material, is typically not addressed.

Division 1- Metallic Components o Subsection NB Class 1 components (Those components that are part of the fluid-retaining pressure boundary of the reactor coolant system. Failure of this pressure boundary would violate the integrity of the reactor coolant pressure boundary)

" Reactor Pressure Vessel

" Pressurizer Vessel

" Steam Generators

" Reactor Coolant Pumps

" Reactor Coolant Piping

" Line Valves

" Safety Valves Generic Letter 88 The purpose of this letter is to call the licensee attention to Revision 2 to Regulatory Guide 1.99, "Radiation Embrittlement of Reactor Vessel Materials," which became effective May 1988. It will be used by the NRC in reviewing submittals regarding pressure-temperature (P-T) limits and for analyses other than pressurized thermal shock (PTS) that require an estimate of the embrittlement of reactor vessel beltline materials.

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 6 of 8 Generic Letter 90 The purpose of this generic letter is to advise pressurized water reactor (PWR) licensees and construction permit (CP) holders of the staff positions delineated in Enclosures A and B to this letter. Enclosure A presents the staff position resulting from the resolution of Generic Issue 70 (GI-70), "Power Operated Relief Valve and Block Valve Reliability." Enclosure B presents the staff position resulting from the resolution of GI-94, "Additional Low-Temperature Over Pressure Protection for Light-Water Reactors."

2) Regulatory Guidance UFSAR 5.2.2.3 - The power operated relief valves are also used to provide protection against exceeding 10 CFR 50 Appendix G limits (including ASME Code Case N-514), as defined by McGuire TS Figures 3.4.3-1 and 3.4.3-2 during periods of water solid operation. Analyses have shown that one PORV is sufficient to prevent violation of these limits due to anticipated mass and heat input transients. However, redundant protection against such over-pressurization events is provided through the addition of low pressure setpoints to two PORV's.

UFSAR 7.6.17.1 - The RCS Overpressure Protection System prevents the RCS from exceeding the pressure/temperature limits of 10 CFR 50, Appendix G, for periods of water solid operation during startup and shutdown. The maximum RCS pressure is limited by providing a low pressure setpoint interlocked with reactor coolant temperature to actuate the PORV.

4.2 No Significant Hazards Consideration Determination:

An error was made during McGuire's conversion to Standard Technical Specifications in TS 3.4.12 - Low Temperature Overpressure Protection (LTOP). Condition G incorrectly references Condition E. As currently written, TS 3.4.12 Required Actions F.2 and G.1 collectively require that an operable Residual Heat Removal (RHR) suction relief valve be aligned within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and that a Reactor Coolant System (RCS) vent path greater than 2.75 square inches be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months if one of two Power Operated Relief Valves (PORVs) is inoperable in accordance with Condition E. Both actions are overly restrictive since either action is sufficient to compensate for the loss of one PORV. As such, Condition G is being corrected to eliminate the reference to Condition E so that alignment of an operable RHR suction relief valve is sufficient to compensate for the loss of one PORV. LTOP calculations support the use of the RHR suction relief valve as an alternative to one PORV.

Duke Energy has concluded that operation of McGuire Units 1 & 2, in accordance with the proposed LAR does not involve a significant hazards consideration. Duke Energy's conclusion is based on its evaluation, in accordance with 10 CFR 50.91 (a)(1), of the three standards set forth in 10 CFR 50.92(c) as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No.

The proposed change has no effect on the probability or consequences of an accident previously evaluated since adequate low temperature overpressure protection of the RCS is being maintained.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 7 of 8

2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed change does not involve the addition or modification of any plant equipment. The proposed change does not involve a change in the operational limits or the design capabilities of the LTOP system. The LTOP system remains capable of protecting the RCS against low temperature overpressurization.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does the proposed amendment involve a significant reduction in the margin of safety?

Response: No.

Margin of safety is related to the confidence in the ability of the fission product barriers to perform their design functions during and following an accident situation. These barriers include the fuel cladding, the reactor coolant system, and the containment system. The performance of the fuel cladding, the reactor coolant system and the containment system will not be adversely impacted by the proposed change since the ability of the LTOP system to prevent a challenge to the integrity of a fission product barrier has not been adversely impacted by the proposed change.

Therefore, the proposed change does not involve a significant reduction in the margin of safety.

Based on the above, Duke energy concludes that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c),

and, accordingly, a finding of "no significant hazards consideration" is justified.

4.3

Conclusions:

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

5.0 ENVIRONMENTAL CONSIDERATION

Duke Energy has determine that the proposed amendment would change requirements with respect to the installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. Duke Energy has evaluated the proposed change and has determined that the proposed change does not involve (i) a significant hazards consideration, (ii) a significant change in the types of or significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. As discussed above, the proposed change does not involve a significant hazards consideration and the

U. S. Nuclear Regulatory Commission Enclosure January 28, 2014 Page 8 of 8 analysis demonstrates that the integrity of the RCS pressure boundary is not affected.

Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), an environmental assessment of the proposed change is not required.

6.0 REFERENCES

1 McGuire License Amendments 184/166, Full Conversion to Standard Technical Specifications (NUREG-1431, Revision 1), September 30, 1998.

2 McGuire TS 3.4.12 Bases, Revision 115, "Low Temperature Overpressure Protection System."

3 McGuire UFSAR Section 5.2.2, Revision 17, "Overpressurization Protection."

4 McGuire UFSAR 7.6.17, Revision 17, "Reactor Coolant System Overpressure Protection System for Low Pressure/Temperature, Water Solid conditions."

5 U.S. Code of Federal Regulations, 10 CFR 50, Appendix G, "Fracture Toughness Requirements."

6 ASME Section III, Division 1, "Rules for Construction of Nuclear Facility Components and Supports."

7 U.S. NRC, Generic Letter 88-11, "NRC Position on Radiation Embrittlement of Reactor Vessel Materials and its Impact on Plant Operations."

8 U.S. NRC, Generic Letter 90-06, "Resolution of Generic Issues 70, "PORV and Block Valve Reliability," and 94, "Additional Low-Temperature Over Pressure Protection for Light-Water Reactors."

9 McGuire Safety Evaluation Report, NUREG-0422, March 1, 1978, Section 5.2.2, "Overpressurization Protection."

10 McGuire Supplement No. 1 to Safety Evaluation Report, May 1978, Section 5.2.2, "Overpressure Protection."

ATTACHMENT 1 Current Technical Specification Page Markups

LTOP System 3.4.12 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.12 Low Temperature Overpressure Protection (LTOP) System LCO 3.4.12 An LTOP System shall be OPERABLE with a maximum of one centrifugal charging pump or one safety injection pump capable of injecting into the RCS and the accumulators isolated and either a or b below:

a. Two power operated relief valves (PORVs) with lift setting < 385 psig or

b. The RCS depressurized and an RCS vent of_> 2.75 square inches.

- --NOTE ------------------------

A PORV secured in the open position may be used to meet the RCS vent requirement provided that its associated block valve is open and power removed.

APPLICABILITY: MODE 4 when any RCS cold leg temperature is < 300°F, MODE 5, MODE 6 when the reactor vessel head is on.

NOTE.----------- --

Accumulator isolation is only required when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed by the P/T limit curves provided in Specification 3.4.3.

McGuire Units 1 and 2 3.4.12-1 Amendment Nos. 184/166

o- . LTOP System 3.4.12 ACTIONS

NOTE----.

LCO 3.0.4.b is not applicable when entering MODE 4.

CONDITION REQUIRED ACTION COMPLETION TIME A. Two centrifugal charging A. 1 --------- NOTE-------

pumps capable of Two centrifugal charging injecting into the RCS. pumps may be capable of injecting into the RCS OR during pump swap operation for < 15 minutes.

One centrifugal charging pump and one safety Initiate action to verify a Immediately injection pump capable maximum of one centrifugal of injecting into the RCS. charging pump or one safety injection pump is OR capable of injecting into the RCS.

Two safety injection pumps capable of OR injecting into the RCS.

A.2.1 Verify RHR suction relief Immediately valve is OPERABLE and the suction isolation valves are open.

AND A.2.2.1 Verify RCS cold leg Immediately temperature > 174 0 F (Unit

1) or > 89 0 F (Unit 2).

OR A.2.2.2Verify RCS cold leg Immediately temperature > 74 0 F and cooldown rate < 20'F/ hr (Unit 1), or > 74 0 F and cooldown rate < 6 0 °F/hr (Unit 2).

OR (continued)

McGuire Units 1 and 2 3.4.12-2 Amendment Nos. 221/203

LTOP System 3.4.12 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME A. (continued) A.3 Verify two PORVs secured Immediately open and associated block valves open and power removed.

OR A.4 Depressurize RCS and Immediately establish RCS vent of > 4.5 square inches.

OR A.5.1 Depressurize RCS and Immediately establish RCS vent of

> 2.75 square inches.

AND A.5.2 Verify two PORVs are Immediately OPERABLE.

B. An accumulator not B. 1 Isolate affected 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months isolated when the accumulator.

accumulator pressure is greater than or equal to the maximum RCS pressure for existing cold leg temperature allowed in Specification 3.4.3.

C. Required Action and C.1 Increase RCS cold leg 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months associated Completion temperature to > 300 0 F.

Time of Condition B not met. OR C.2 Depressurize affected 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months accumulator to less than the maximum RCS pressure for existing cold leg temperature allowed by Specification 3.4.3.

D. One PORV inoperable in D.1 Restore PORV to 7 days MODE 4. OPERABLE status.

(continued)

McGuire Units 1 and 2 3.4.12-3 Amendment Nos. 214/195

LTOP System 3.4.12 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E. One PORV inoperable in E.1 Suspend all operations Immediately MODE 5 or 6. which could lead to a water solid pressurizer.

AND E.2 Restore PORV to 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months OPERABLE status.

F. Required Action and F.1. Verify RCS cold leg 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months associated Completion temperature > 174 0 F (Unit Time of Condition E not 1) or > 89°F (Unit 2).

met.

AND F.2 Verify RHR suction relief valve is OPERABLE and 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months the suction isolation valves are open.

G. Two PORVs inoperable. G.1 Depressurize RCS and 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months establish RCS vent of OR > 2.75 square inches.

Required Action and associated Completion j1 Ie of Condition C, D, or F not met.

OR LTOP System inoperable for any reason other than Condition A, B, C, D, E, or F.

McGuire Units 1 and 2 3.4.12-4 Amendment

LTOP System 3.4.12 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.12.1 Verify a maximum of one centrifugal charging pump or In accordance with one safety injection pump is capable of injecting into the the Surveillance RCS. Frequency Control Program SR 3.4.12.2 Verify each accumulator is isolated. In accordance with the Surveillance Frequency Control Program SR 3.4.12.3 Verify RHR suction isolation valves are open when the In accordance with RHR suction relief valve is used for overpressure the Surveillance protection. Frequency Control Program SR 3.4.12.4 -------------- NOTE ------------------------------------

Only required to be performed when complying with LCO 3.4.12.b.

Verify RCS vent > 2.75 square inches open. In accordance with the Surveillance Frequency Control Program SR 3.4.12.5 Verify PORV block valve is open for each required In accordance with PORV. the Surveillance Frequency Control Program (continued)

McGuire Units 1 and 2 3.4.12-5 Amendment Nos. 261/241

LTOP System Fr- 3.4.12 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.4.12.6 ----------------- NOTE -------------------

Not required to be met until 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS cold leg temperature to < 300 0 F.

Perform a COT on each required PORV, excluding In accordance with actuation. the Surveillance Frequency Control Program SR 3.4.12.7 Perform CHANNEL CALIBRATION for each required In accordance with PORV actuation channel. the Surveillance Frequency Control Program McGuire Units 1 and 2 3.4.12-6 Amendment Nos. 261/241

ATTACHMENT 2 Pre-STS Technical Specification Pages

REACTOR COOLANT SYSTEM OVERPRESSURE PROTECTION' SYSTEMS LIMITING CONDITION FOR OPERATION 3.4.9.3 As a minimum, a Low Temperature Overpressure Protection (LTOP) System shall be OPERABLE as follows:

a. A maximum of one Centrifugal Charging (NV) pump or one Safety Injection (NI) pump capable of injecting into the Reactor Coolant System (RCS) with all remaining NV and NI pump motor circuit breakers open or the discharge of the remaining NV and NI pumps isolated from the RCS by at least 2 valves with power removed#

AND

b. All accumulators isolated AND

c. One of the following conditions met:

1. Two PORVs with a lift setting of _<385 psig OR

2. The RCS depressurized with a vent of ý 2.75 square inches.

APPLICABILITY: MODE 4 when the temperature of any RCS cold leg is less than or equal to 300 0 F, MODE 5, and MODE 6 when the head is on the reactor vessel.

ACTION:

a. With two or more Charging (NV) or Safety Injection(NI) pumps capable of injecting into the RCS*, immediately initiate action to restore a maximum of one NI or one NV pump capable of injecting into the RCS.

Two Charging pumps (NV or NI) maybe capable of injecting into the RCS during pump swap operation for __15 Minutes.

One Safety Injection pump and one Charging pump, or two Charging pumps may be operated concurrently provided:

1. RHR suction relief valve (ND-3) is OPERABLE, and the RHR suction isolation valves (ND-i and ND-2) are open and one of the following conditions is met:

a. RCS cold leg temperature is greater than 1670 F or

b. RCS cold leg temperature is greater than 1070 F and cooldown rate is less than 200 F per hour.

OR

2. Two PORVs secured in the open position with their associated block valves open and power removed.

McGUIRE - UNIT 1 3/4 4-33 Amendment No. 166

REACTOR COOLANT SYSTEM LIMITING CONDITION FOR OPERATION (Continued)

ACTION: (continued)

b. With an accumulator not isolated, isolate the affected accumulator within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . If required action is not met, either:

1. Depressurize the accumulator to less than the maximum RCS pressure for the existing cold leg per Specification 3/4.4.9 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , OR

2. Increase RCS cold leg temperature to greater than or equal to 3000 F within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

c. With one PORV inoperable in MODE 4, restore the inoperable PORV to OPERABLE status within 7 days. If required action is not met, depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

d. With one PORV inoperable in MODES 5 or 6, suspend all operations which could lead to a water-solid pressurizer. Restore the inoperable PORV to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If required action is not met, either:

1. Ensure RCS temperature is greater than 1670 F, and ND-3 is OPERABLE, and ND-1 and ND-2 are open within one hour.

OR

2. Depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

e. With the LTOP system inoperable for any reason other than a., b., c.,

or d. above, depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

f. In the event that either the PORVs or the RCS vent are used to mitigate an RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstance initiating the transient, the effect of the PORVs or vent on the transient, and any corrective action necessary to prevent recurrence.

g. The provisions of Specification 3.0.4 are not applicable.

McGUIRE - UNIT 1 3/4 4-34 Amendment No. 166

REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS 4.4.9.3.1 Each PORV shall be demonstrated OPERABLE by:

a. Performance of an ANALOG CHANNEL OPERATIONAL TEST on the PORV actuation channel, but excluding valve operation, at least once per 31 days;

b. Performance of a CHANNEL CALIBRATION on the PORV actuation channel at least once per 18 months; and

c. Verifying the PORV isolation valve is open at least once per 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months when the PORV is being used for overpressure protection.

4.4.9.3.2 Once every 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months s*, verify that an RCS vent of Ž 2.75 square inches is open when the vent is used for overpressure protection.

4.4.9.3.3 Once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , verify that each accumulator is isolated and that only one NV or NI pump is capable of injecting into the RCS.

4.4.9.3.4 Once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , verify that RHR suction isolation valves ND-1 and ND-2 are open when RHR suction relief valve ND-3 is being used for overpressure protection.

4.4.9.3.5 Once every 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , verify that the PORV block valve is open for each required PORV.

Except when the vent pathway is provided with a valve which is locked, sealed, or otherwise secured in the open position, then verify these valves open at least once per 31 days.

A PORV secured in the open position may be used to meet this vent requirement provided that its associated block valve is open and power is removed.

McGUIRE - UNIT I 3/4 4-35 Amendment No. 166

REACTOR COOLANT SYSTEM OVERPRESSURE PROTECTION SYSTEMS LIMITING CONDITION FOR OPERATION 3.4.9.3 As a minimum, a Low Temperature Overpressure Protection (LTOP) System shall be OPERABLE as follows:

a. A maximum of one Centrifugal Charging (NV) pump or one Safety Injection (NI) pump capable of injecting into the Reactor Coolant System (RCS) with all remaining NV and NI pump motor circuit breakers open or the discharge of the remaining NV and NI pumps isolated from the RCS by at least 2 valves with power removed#

AND

b. All accumulators isolated AN AND

c. One of the following conditions met:

1. Two PORVs with a lift setting of

385 psig OR

2. The RCS depressurized with a vent of ! 2.75 square inches.

APPLICABILITY: MODE 4 when the temperature of any RCS cold leg is less than or equal to 300°F, MODE 5, and MODE 6 when the head is on the reactor vessel.

ACTION:

a. With two or more Charging (NV) or Safety Injection(NI) pumps capable of injecting into the RCS*, immediately initiate action to restore a maximum of one NI or one NV pump capable of injecting into the RCS.

Two Charging pumps (NV or NI) maybe capable of injecting into the RCS during Z-pump swap operation for

15 Minutes.

One Safety Injection pump and one Charging pump, or two Charging pumps may be operated concurrently provided:

1. RHR suction relief valve (ND-3) is OPERABLE, and the RHR suction isolation valves (ND-1 and ND-2) are open and one of the following conditions is met:

a. RCS cold leg temperature is greater than 1670 F or

b. RCS cold leg temperature is greater than 1070 F and cooldown rate is less than 20' F per hour.

OR

2. Two PORVs secured in the open position with their associated block valves open and power removed.

McGUIRE - UNIT 2 3/4 4-33 Amendment No. 148 S.,T '..a".

REACTOR COOLANT SYSTEM LIMITING CONDITION FOR OPERATION (Continued)

ACTION: (continued)

b. With an accumulator not isolated, isolate the affected accumulator within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . If required action is not met, either:

1. Depressurize the accumulator to less than the maximum RCS pressure for the existing cold leg per Specification 3/4.4.9 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , OR

2. Increase RCS cold leg temperature to greater than or equal to 3000 F within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

c. With one PORV inoperable in MODE 4, restore the inoperable PORV to OPERABLE status within 7 days. If required action is not met, depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

d. With one PORV inoperable in MODES 5 or 6, suspend all operations which could lead to a water-solid pressurizer. Restore the inoperable PORV to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If required action is not met, either:

1. Ensure RCS temperature is greater than 1670 F, and ND-3 is e.OPERABLE, and ND-1 and ND-2 are open within one hour.

I*F OR

. Depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

.e. With the kTOP system inoperable for any reason other than a., b., c.,

or d. above, depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

f. In the event that either the PORVs or the RCS vent are used to mitigate an RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstance initiating the transient, the effect of the PORVs or vent on the transient, and any corrective action necessary to prevent recurrence.

g. The provisions of Specification 3.0.4 are not applicable.

McGUIRE - UNIT 2 3/4 4-34 Amendment No. 148

iI, . .... ...i '* _

_.*- o... .

"A. .

REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS 4.4.9.3.1 Each PORV shall be demonstrated OPERABLE by:

a. Performance of an ANALOG CHANNEL OPERATIONAL TEST on the PORV actuation channel, but excluding valve operation, at least once per 31 days;

b. Performance of a CHANNEL CALIBRATION on the PORV actuation channel at least once per 18 months; and

c. Verifying the PORV isolation valve is open at least once per 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months when the PORV is being used for overpressure protection.

4.4.9.3.2 Once every 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months s*, verify that an RCS vent of _ 2.75 square inches is open when the vent is used for overpressure protection.

4.4.9.3.3 Once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , verify that each accumulator is isolated and that only one NV or NI pump is capable of injecting into the RCS.

4.4.9.3.4 Once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , verify that RHR suction isolation valves ND-1 and ND-2 are open when RHR suction relief valve ND-3 is being used for overpressure protection.

4.4.9.3.5 Once every 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , verify that the PORV block valve is open for each required PORV.

Except when the vent pathway is provided with a valve which is locked, sealed, or otherwise secured in the open position, then verify these valves open at least once per 31 days.

A PORV secured in the open position may be used to meet this vent requirement provided that its associated block valve is open and power is removed.

McGUIRE - UNIT 2 3/4 4-35 Amendment No. 148

ATTACHMENT 3 Original STS Conversion Technical Specification Page Markups (Included in Duke Energy letter to the NRC dated May 27, 1997 and approved by the NRC letter dated September 30, 1998)

REACTOR COOLANT SYSTEM LIMITING CONDITION FOR OPERATION (Contimuid)

ACTION: (c contnued I te~~ (A7141.

B (B With an accumulator not isoaeiso1-":e the-affected accumulator c

within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . If required action is not met, either:

c.a1 Depressurize the accumulator to less than the maximum ,4%.._A pressure for the existing cold leg per Specification/o.4.<4 .

within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , OR C- . Increase RCS cold leg temperature to greater than t Ca 3000 F within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

. , With one PORV inoperable in MODE 4, restore the inoperable PORV to OPERABLE status within 7 days. If required action is not met, c_*4J-,G depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

C""ýý;. 1E With one PORV inoperable in MODES 5 or 6, suspend all operations which could lead to a water-solid pressurizer. Restore the inoperable PORVYto OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If required action is not met, either:

F.I.*' F.2.D Ensure RCS temperature is greater than 167* F, and ND-3 is OPERABLE, and ND-1 and ND-2 are open within one hour.

OR 4 *. Depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

A. , C,cj

,c .<V K LTOP system inoperable for any reason other than ý- ' .,J M Nbove, depressurize the RCS and vent through at least a2.475 square lClvan-+ u thin 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

-L f*.In the eifnt that.either the I)Rs or the RCS ven are used to LA./*.

T~ovs. Po, *" \ iti~gg* an RCS p!esure tr ~sient, a Special R port shall be Inoperable,

pre at~ nd submitted to *he Commission purs; -'t to Speciftcatid\

,OIL 6 T0y2 withnin 30 days. *Ae report shall des ~be the circumstan*

--.. .

itating the transtidt, the effect of th POR~s or vent on tke \

, .nt, and any ctive action to prevent re rrence.

slouThe pro ions of Spec 3.0.4cnot applicable. "cation . ... .

A.Cj D,rz F NOTE:

McGUIRE - UNIT 1 3/4 4-34 Amendment No. 166

.. :~

REACTOR COOLANT SYSTEM LIMITING CONDITION FOR OPERATION (Continued)

ACTION: (continued) ( - .f., j, -. '.- '

(' iS With an accumulator not iso ate*-so ate the affected accumulator

_- - within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . If required action is not met, either:

.1 (. Depressurize the accumulator to less than the maximum pressure for the existing cold leg per Specification .L4-i within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , OR CA ( Increase RCS cold leg temperature to greater than OA' 300* F within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

(0 With one PORV inoperable in MODE 4, restore the inoperable PORV to OPERABLE status within 7 days. If required action is not met, ca ft) depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

~9 With one PORV inoperable in MODES.5 or 6, suspend all operations which could lead to a water-solid pressurizer. Restore the inoperable PORV to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . If required S action is not met, either:

_ 2. ) Ensure RCS temperature is greater than 1670 F, and NO-3 is OPERABLE, and ND-i and ND-2 are open within one hour.

OR 6J (V Depressurize the RCS and vent through at least a 2.75 square inch vent within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .A LTOP system inoperable for any reason other than 7 ,

wye, depressurize the RCS and vent through at least a 2.7 ich vent-within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

mitigate prepared agrRCS pressureto transi*nt, hd submitted a Special theyjonuission Rep rt pursuap( shall be to.Specification 6.9.2 wi lihin 30 days. The rfort shall descri e the circumstance,/

initiarng the transient, te effect of the *0RVs or vent on thf trans ent, and an" 4rrct~ve action necess"Av to Drevent recuren STheprovins of pcif~ tion 3.0.4( not applicable.

McGUIRE - UNIT 2 314 4-34 Amendment No. 148

.ýe-3 J; 9

ATTACHMENT 4 Current Technical Specification Bases Page Markups (For Information Only)

lee C4A 1ý a-'- r~k 0-LTOP System B 3.4.12 B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.12 Low Temperature Overpressure Protection (LTOP) System BASES BACKGROUND The LTOP System controls RCS pressure at low temperatures so the integrity of the reactor coolant pressure boundary (RCPB) is not compromised by violating the pressure and temperature (P/T) limits of 10 CFR 50, Appendix G (Ref. 1). The reactor vessel is the limiting RCPB component for demonstrating such protection. This specification provides the maximum allowable actuation logic setpoints for the power operated relief valves (PORVs) and LCO 3.4.3, "RCS Pressure and Temperature (P/T) Limits," provides the maximum RCS pressure for the existing RCS cold leg temperature during cooldown, shutdown, and heatup to meet the Reference 1 requirements during the LTOP MODES.

The reactor vessel material is less tough at low temperatures than at normal operating temperature. As the vessel neutron exposure accumulates, the material toughness decreases and becomes less resistant to pressure stress at low temperatures (Ref. 2). RCS pressure, therefore, is maintained low at low temperatures and is increased only as temperature is increased.

The potential for vessel overpressurization is most acute when the RCS is water solid, occurring only while shutdown; a pressure fluctuation can occur more quickly than an operator can react to relieve the condition.

Exceeding the RCS P/T limits by a significant amount could cause brittle cracking of the reactor vessel. LCO 3.4.3 requires administrative control of RCS pressure and temperature during heatup and cooldown to prevent exceeding the specified limits.

This LCO provides RCS overpressure protection by having a minimum coolant input capability and having adequate pressure relief capacity.

Limiting coolant input capability requires all but one centrifugal charging pump or one safety injection pump incapable of injection into the RCS and isolating the accumulators. The pressure relief capacity requires either two redundant PORVs or a depressurized RCS and an RCS vent of sufficient size. One PORV or the open RCS vent is the overpressure protection device that acts to terminate an increasing pressure event.

With minimum coolant input capability, the ability to provide core coolant addition is restricted. The LCO does not require the makeup control McGuire Units 1 and 2 B 3.4.12-1 Revision No. 115

NA 71B LTOP System 3.4.12 BASES BACKGROUND (continued) system deactivated or the safety injection (SI) actuation circuits blocked.

Due to the lower pressures in the LTOP MODES and the expected core decay heat levels, the makeup system can provide adequate flow via the makeup control valve. If conditions require the use of more than one centrifugal charging pump for makeup in the event of loss of inventory, then pumps can be made available through manual actions.

PORV Requirements As designed for the LTOP System, each PORV is signaled to open if the RCS pressure reaches 385 psig when the PORVS are in the "lo-press" mode of operation. If the PORVs are being used to meet the requirements of this specification, then RCS cold leg temperature is limited in accordance with the LTOP analysis. For cases where no reactor coolant pumps are in operation, this temperature limit is met by monitoring of BOTH the Wide Range Cold Leg temperatures and Residual Heat Removal Heat Exchanger discharge temperature. These temperatures are the most representative of the fluid in the reactor vessel downcomer region. The LTOP actuation logic monitors both RCS temperature and RCS pressure. The signals used to generate the pressure setpoints originate from the safety related narrow range pressure transmitters. The signals used to generate the temperature permissives originate from the wide range RTDs on cold leg C and hot leg D. Each signal is input to the appropriate NSSS protection system cabinet where it is converted to an internal signal and then input to a comparator to generate an actuation signal. If the indicated pressure meets or exceeds the bistable setpoint, a PORV is signaled to open.

This Specification presents the PORV setpoints for LTOP. Having the setpoints of both valves within the limits ensures that the Reference 1 limits will not be exceeded in any analyzed event.

When a PORV is opened in an increasing pressure transient, the release of coolant will cause the pressure increase to slow and reverse. As the PORV releases coolant, the RCS pressure decreases until a reset pressure is reached and the valve is signaled to close. The pressure continues to decrease below the reset pressure as the valve closes.

RCS Vent Requirements Once the RCS is depressurized, a vent exposed to the containment atmosphere will maintain the RCS at containment ambient pressure in an RCS overpressure transient, if the relieving requirements of the transient do not exceed the capabilities of the vent. Thus, the vent path must be McGuire Units 1 and 2 B 3.4.12-2 Revision No. 115

LTOP System BASES BACKGROUND (continued) capable of relieving the flow resulting from the limiting LTOP mass or heat input transient, and maintaining pressure below the P/T limits. The required vent capacity may be provided by one or more vent paths.

The vent path(s) must be above the level of reactor coolant, so as not to drain the RCS when open.

APPLICABLE Safety analyses (Ref. 4) demonstrate that the reactor vessel is SAFETY ANALYSES adequately protected against exceeding the Reference 1 P/T limits. In MODES 1, 2, and 3, and in MODE 4 with RCS cold leg temperature exceeding 300 0 F, the pressurizer safety valves will prevent RCS pressure from exceeding the Reference 1 limits. At about 300OF and below, overpressure prevention falls to two OPERABLE PORVs or to a depressurized RCS and a sufficient sized RCS vent. Each of these means has a limited overpressure relief capability.

The actual temperature at which the pressure in the P/T limit curve falls below the pressurizer safety valve setpoint increases as the reactor vessel material toughness decreases due to neutron embrittlement. Each time the P/T curves are revised, the LTOP System must be re-evaluated to ensure its functional requirements can still be met using the PORV method or the depressurized and vented RCS condition.

Any change to the RCS must be evaluated against the Reference 4 analyses to determine the impact of the change on the LTOP acceptance limits.

Transients that are capable of overpressurizing the RCS are categorized as either mass or heat input transients, examples of which follow:

Mass Input Type Transients

a. Inadvertent safety injection; or

b. Charging/letdown flow mismatch.

Heat Input Type Transients

a. Inadvertent actuation of pressurizer heaters;

b. Loss of RHR cooling; or McGuire Units 1 and 2 B 3.4.12-3 Revision No. 115

LTOP System oB 3.4.12 BASES APPLICABLE SAFETY ANALYSES (continued)

c. Reactor coolant pump (RCP) startup with temperature asymmetry within the RCS or between the RCS and steam generators.

The following are required during the LTOP MODES to ensure that mass and heat input transients do not occur, which either of the LTOP overpressure protection means cannot handle:

a. Rendering all but one centrifugal charging pump or one safety injection pump incapable of injection;

b. Deactivating the accumulator discharge isolation valves in their closed positions; and

c. Disallowing start of an RCP if secondary temperature is more than 50°F above primary temperature in any one loop. LCO 3.4.6, "RCS Loops-MODE 4," and LCO 3.4.7, "RCS Loops-MODE 5, Loops Filled," provide this protection.

The Reference 4 analyses demonstrate that either one PORV or the depressurized RCS and RCS vent can maintain RCS pressure below limits when only one centrifugal charging pump or one safety injection pump are actuated. Thus, the LCO allows only one centrifugal charging pump or one safety injection pump OPERABLE during the LTOP MODES. Since neither one PORV nor the RCS vent can handle the pressure transient from accumulator injection when RCS temperature is low the LCO also requires the accumulators isolation when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed in LCO 3.4.3.

The isolated accumulators must have their discharge valves closed and power removed.

Fracture mechanics analyses established the temperature of LTOP Applicability at 300 0 F.

The consequences of a small break loss of coolant accident (LOCA) in LTOP MODE 4 conform to 10 CFR 50.46 and 10 CFR 50, Appendix K (Refs. 5 and 6), requirements by having a maximum of one centrifugal charging pump OPERABLE and SI actuation enabled.

McGuire Units 1 and 2 B 3.4.12-4 Revision No. 115

LTOP System SV B3.4.12 BASES APPLICABLE SAFETY ANALYSES (continued)

PORV Performance The fracture mechanics analyses show that the vessel is protected when the PORVs are set to open at or below the specified limit. The setpoints are derived by analyses that model the performance of the LTOP System, assuming the limiting LTOP transient of one centrifugal charging pump or one safety injection pump injecting into the RCS. These analyses consider pressure overshoot and undershoot beyond the PORV opening and closing, resulting from signal processing and valve stroke times. The PORV setpoints at or below the derived limit ensures the Reference 1 P/T limits will be met.

The PORV setpoints will be updated when the revised P/T limits conflict with the LTOP analysis limits. The P/T limits are periodically modified as the reactor vessel material toughness decreases due to neutron embrittlement caused by neutron irradiation. Revised limits are determined using neutron fluence projections and the results of examinations of the reactor vessel material irradiation surveillance specimens. The Bases for LCO 3.4.3, "RCS Pressure and Temperature (P/T) Limits," discuss these examinations.

The PORVs are considered active components. Thus, the failure of one PORV is assumed to represent the worst case, single active failure.

RCS Vent Performance With the RCS depressurized, analyses show a vent size of 2.75 square inches is capable of mitigating the allowed LTOP overpressure transient.

The capacity of a vent this size is greater than the flow of the limiting transient for the LTOP configuration, one centrifugal charging pump or one safety injection pump OPERABLE, maintaining RCS pressure less than the maximum pressure on the P/T limit curve.

The RCS vent size will be re-evaluated for compliance each time the P/T limit curves are revised based on the results of the vessel material surveillance.

The RCS vent is passive and is not subject to active failure.

The LTOP System satisfies Criterion 2 of 10 CFR 50.36 (Ref. 7).

McGuire Units 1 and 2 B 3.4.12-5 Revision No. 115

LTOP System BASES LCO This LCO requires that the LTOP System is OPERABLE. The LTOP System is OPERABLE when the minimum coolant input and pressure relief capabilities are OPERABLE. Violation of this LCO could lead to the loss of low temperature overpressure mitigation and violation of the Reference 1 limits as a result of an operational transient.

To limit the coolant input capability, the LCO permits a maximum of one centrifugal charging pump or one safety injection pump capable of injecting into the RCS and requires all accumulator discharge isolation valves closed and immobilized when accumulator pressure is greater than or equal to the maximum RCS pressure for the existing RCS cold leg temperature allowed in LCO 3.4.3.

The elements of the LCO that provide low temperature overpressure mitigation through pressure relief are:

a. Two OPERABLE PORVs (NC-32B and NC-34A); or A PORV is OPERABLE for LTOP when its block valve is open, its lift setpoint is set to the specified limit and testing proves its automatic ability to open at this setpoint, and motive power is available to the valve and its control circuit.

b. A depressurized RCS and an RCS vent.

An RCS vent is OPERABLE when open with an area of

_>2.75 square inches.

Each of these methods of overpressure prevention is capable of mitigating the limiting LTOP transient.

The LCO is modified with a note that specifies that a PORV secured in the open position may be used to meet the RCS vent requirement provided that its associated block valve is open and power removed.

With the PORV physically secured or locked in the open position with its associated block valve open and power removed, this vent path is passive and is not subject to active failure.

APPLICABILITY This LCO is applicable in MODE 4 when any RCS cold leg temperature is

< 3000F, in MODE 5, and in MODE 6 when the reactor vessel head is on.

The pressurizer safety valves provide overpressure protection that meets the Reference 1 P/T limits above 300 0 F. When the reactor vessel head is off, overpressurization cannot occur.

LCO 3.4.3 provides the operational P/T limits for all MODES.

LCO 3.4.10, "Pressurizer Safety Valves," requires the OPERABILITY of McGuire Units 1 and 2 B 3.4.12-6 Revision No. 115

LTOP System 0B 3.4.12 BASES APPLICABILITY (continued) the pressurizer safety valves that provide overpressure protection during MODES 1, 2, and 3, and MODE 4 above 300°F.

Low temperature overpressure prevention is most critical during shutdown when the RCS is water solid, and a mass or heat input transient can cause a very rapid increase in RCS pressure when little or no time allows operator action to mitigate the event.

The Applicability is modified by a Note stating that accumulator isolation is only required when the accumulator pressure is more than or at the maximum RCS pressure for the existing temperature, as allowed by the P/T limit curves. This Note permits the accumulator discharge isolation valve Surveillance to be performed only under these pressure and temperature conditions.

ACTIONS A Note prohibits the application of LCO 3.0.4.b to an inoperable LTOP system. There is an increased risk associated with entering MODE 4 from MODE 5 with LTOP inoperable and the provisions of LCO 3.0.4.b, which allow entry into a MODE or other specified condition in the Applicability with the LCO not met after performance of a risk assessment addressing inoperable systems and components, should not be applied in this circumstance.

A.1, A.2.1, A.2.2.1, A.2.2.2, A.3, A.4, A.5.1, and A.5.2 With two centrifugal charging pumps, safety injection pumps, or a combination of each, capable of injecting into the RCS, RCS overpressurization is possible.

To immediately initiate action to restore restricted coolant input capability to the RCS reflects the urgency of removing the RCS from this condition.

Two pumps may be capable of injecting into the RCS provided the RHR suction relief valve is OPERABLE with:

1. RCS cold leg temperature > 174 0 F (Unit 1), or

2. RCS cold leg temperature > 89 0 F (Unit 2), or

3. RCS cold leg temperature > 74 0 F and cooldown rate < 200 F/hr (Unit 1),

or

4. RCS cold leg temperature > 74 0 F and cooldown rate < 6 0 °F/hr (Unit 2),

or

5. two PORVs secured open with associated block valves open and power removed, or

6. a RCS vent of > 4.5 square inches, or McGuire Units 1 and 2 B 3.4.12-7 Revision No. 115

o * *"'Pol7e, LTOP BSystem 3.4.12 BASES ACTIONS (continued)

7. a RCS vent of > 2.75 square inches and two OPERABLE PORVs (the RCS vent shall not be one of the two OPERABLE PORVs).

For cases where no reactor coolant pumps are in operation, RCS cold leg temperature limits are to be met by monitoring of BOTH the WR Cold Leg temperatures and Residual Heat Removal Heat Exchanger discharge temperature. With both PORVS and block valves secured open, or with an RCS vent of 4.5 square inches, there are no credible single failures to limit the flow relief capacity. For the RHR relief valve to be OPERABLE, the RHR suction isolation valves must be open and the relief valve setpoint at 450 psig consistent with the safety analysis. The RHR suction relief valves are spring loaded, bellows type water relief valves with pressure tolerances and accumulation limits established by Section III of the American Society of Mechanical Engineers (ASME) Code (Ref. 3) for Class 2 relief valves.

Required Action A.1 is modified by a Note that permits two centrifugal charging pumps capable of RCS injection for < 15 minutes to allow for pump swaps.

B.1, C.1, and C.2 An unisolated accumulator requires isolation within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . This is only required when the accumulator pressure is at or more than the maximum RCS pressure for the existing temperature allowed by the P/T limit curves.

If isolation is needed and cannot be accomplished in 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , Required Action C.1 and Required Action C.2 provide two options, either of which must be performed in the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . By increasing the RCS temperature to > 300 0 F, an accumulator pressure of 639 psig cannot exceed the LTOP limits if the accumulators are fully injected.

Depressurizing the accumulators below the LTOP limit also gives this protection.

The Completion Times are based on operating experience that these activities can be accomplished in these time periods and on engineering evaluations indicating that an event requiring LTOP is not likely in the allowed times.

D.1 In MODE 4 when any RCS cold leg temperature is <3000 F, with one PORV inoperable, the PORV must be restored to OPERABLE status McGuire Units 1 and 2 B 3.4.12-8 Revision No. 115

LTOP System Mo Y-'B C~-Lei~ 3.4.12 BASES ACTIONS (continued) within a Completion Time of 7 days. Two PORVS are required to provide low temperature overpressure mitigation while withstanding a single failure of an active component.

The Completion Time considers the facts that only one of the PORVs is required to mitigate an overpressure transient and that the likelihood of an active failure of the remaining valve path during this time period is very low.

E.1 and E.2 The consequences of operational events that will overpressurize the RCS are more severe at lower temperature (Ref. 8). Thus, with one of the two PORVs inoperable in MODE 5 or in MODE 6 with the head on, all operations which could lead to a water solid pressurizer must be suspended immediately and the Completion Time to restore two valves to OPERABLE status is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

The Completion Time represents a reasonable time to investigate and repair several types of relief valve failures without exposure to a lengthy period with only one OPERABLE PORV to protect against overpressure events.

F.1 and F.2 If the Required Actions and associated Completion Times of Condition E are not met, then alternative actions are necessary to establish the required redundancy in relief capacity. This is accomplished by verifying that the RHR relief valve is OPERABLE and the RHR suction isolation valves open and the RCS cold leg temperature > 174 0 F (Unit 1) or > 89 0 F (Unit 2). For cases where no reactor coolant pumps are in operation, RCS cold leg temperature limits are to be met by monitoring of BOTH the WR Cold Leg temperatures and Residual Heat Removal Heat Exchanger discharge temperature. The Completion Time of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months reflects the importance of restoring the required redundancy at lower RCS temperatures.

G.1 The RCS must be depressurized and a vent must be established within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months when:

McGuire Units 1 and 2 B 3.4.12-9 Revision No. 115

LTOP System B 3.4.12 BASES ACTIONS (continued)

a. Both required PORVs are inoperable; or

b. A ,9,uired Action and associated Completion Time of Condition C D, or F is not met; or

c. The LTOP System is inoperable for any reason other than Condition A, B, C, D, E, or F.

The vent must be sized > 2.75 square inches to ensure that the flow capacity is greater than that required for the worst case mass input transient reasonable during the applicable MODES. This action is needed to protect the RCPB from a low temperature overpressure event and a possible brittle failure of the reactor vessel.

The Completion Time considers the time required to place the plant in this Condition and the relatively low probability of an overpressure event during this time period due to increased operator awareness of administrative control requirements.

SURVEILLANCE SR 3.4.12.1 and SR 3.4.12.2 REQUIREMENTS To minimize the potential for a low temperature overpressure event by limiting the mass input capability, all but one centrifugal charging pump or one safety injection pump are verified incapable of injecting into the RCS and the accumulator discharge isolation valves are verified closed and power removed (See Ref. 10).

The centrifugal charging pump and safety injection pump are rendered incapable of injecting into the RCS through removing the power from the pumps by racking the breakers out under administrative control. An alternate method of LTOP control may be employed using at least two independent means to prevent a pump start such that a single failure or single action will not result in an injection into the RCS. This may be accomplished through two valves in the discharge flow path being closed.

The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

SR 3.4.12.3 The RHR suction relief valve shall be demonstrated OPERABLE by verifying the RHR suction isolation valves are open and by testing it in McGuire Units 1 and 2 B 3.4.12-10 Revision No.X

v ,LTOPBSystem 3.4.12 BASES SURVEILLANCE REQUIREMENTS (continued) accordance with the Inservice Testing Program. This Surveillance is only required to be performed if the RHR suction relief valve is being used to meet the Required Actions of this LCO.

The RHR suction valves are verified to be opened. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

The ASME OM Code (Ref. 9), test per Inservice Testing Program, verifies OPERABILITY by proving proper relief valve mechanical motion and by measuring and, if required, adjusting the lift setpoint.

SR 3.4.12.4 The RCS vent of _>2.75 square inches is proven OPERABLE by verifying its open condition.

The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

The passive vent arrangement must only be open to be OPERABLE.

This Surveillance is required to be performed if the vent is being used to satisfy the pressure relief requirements of the LCO 3.4.12b.

SR 3.4.12.5 The PORV block valve must be verified open to provide the flow path for each required PORV to perform its function when actuated. The valve must be remotely verified open in the main control room. This Surveillance is performed if the PORV satisfies the LCO.

The block valve is a remotely controlled, motor operated valve. The power to the valve operator is not required removed, and the manual operator is not required locked in the inactive position. Thus, the block valve can be closed in the event the PORV develops excessive leakage or does not close (sticks open) after relieving an overpressure situation.

The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

McGuire Units 1 and 2 B 3.4.12-11 Revision No. 115

LTOP System el, B3.4.12 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.12.6 Performance of a COT is required within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS temperature to _<300OF and periodically on each required PORV to verify and, as necessary, adjust its lift setpoint. The COT will verify the setpoint is within the allowed maximum limits. PORV actuation could depressurize the RCS and is not required. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Frequency considers the unlikelihood of a low temperature overpressure event during this time.

A Note has been added indicating that this SR is required to be met 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after decreasing RCS cold leg temperature to < 3001F. The test must be performed within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months after entering the LTOP MODES.

SR 3.4.12.7 Performance of a CHANNEL CALIBRATION on each required PORV actuation channel is required to adjust the whole channel so that it responds and the valve opens within the required range and accuracy to known input. The Surveillance Frequency is based on operating experience, equipment reliability, and plant risk and is controlled under the Surveillance Frequency Control Program.

McGuire Units 1 and 2 B 3.4.12-12 Revision No. 115

S I.p LTOP System NOJdA. B 3.4.12 BASES REFERENCES 1. 10 CFR 50, Appendix G.

2. Generic Letter 88-11.

3. ASME, Boiler and Pressure Vessel Code, Section II1.

4. UFSAR, Section 5.2.

5. 10 CFR 50, Section 50.46.

6. 10 CFR 50, Appendix K.

7. 10 CFR 50.36, Technical Specifications, (c)(2)(ii).

8. Generic Letter 90-06.

9. ASME Code for Operation and Maintenance of Nuclear Power Plants.

10. Duke letter to NRC, "Cold Leg Accumulator Isolation Valves", dated September 8, 1987.

McGuire Units 1 and 2 B 3.4.12-13 Revision No. 115

v t e Letter Sequence Request
TAC:MF3444, (Approved, Closed)
Initiation Request Acceptance Administration Questions 23 September 2014 Answers Results Approval Other:
MONTHYEAR2014-12-11 [Table View]

MNS-14-003, License Amendment Request for Technical Specification (TS) 3.4.12, Low Temperature Overpressure Protection (LTOP) System

Text

Subject:

Subject:

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

Conclusions:

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

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MNS-14-003, License Amendment Request for Technical Specification (TS) 3.4.12, Low Temperature Overpressure Protection (LTOP) System

Text

Subject:

Subject:

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

SUMMARY

3.0 TECHNICAL EVALUATION

4.0 REGULATORY EVALUATION

Conclusions:

5.0 ENVIRONMENTAL CONSIDERATION

6.0 REFERENCES

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