NMP1L3369, Application to Revise Technical Specifications to Adopt TSTF-582, Revision 0 Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements

Application to Revise Technical Specifications to Adopt TSTF-582, Revision 0 Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements

ML20353A401
Person / Time
Site:	Nine Mile Point
Issue date:	12/18/2020
From:	David Helker Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP1L3369
Download: ML20353A401 (26)

Text

200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.90 NMP1L3369 December 18, 2020 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-63 NRC Docket No. 50-220

Subject:

Application to Revise Technical Specifications to Adopt TSTF-582, Revision 0 "Reactor Pressure Vessel Water Inventory Control (RPV WIC)

Enhancements" Pursuant to 10 CFR 50.90, Application for amendment of license or construction permit, or early site permit, Exelon Generation Company, LLC (Exelon), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License No.

DPR-63 for Nine Mile Point Nuclear Station, Unit 1 (NMP1).

Exelon requests adoption of TSTF-582, Revision 0, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements." The TS related to RPV WIC are being revised to incorporate operating experience and to correct errors and omissions in TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control." provides a description and assessment of the proposed changes. Attachment 2 provides the existing TS pages marked up to show the proposed changes. Attachment 3 provides the existing TS Bases pages marked up to show revised text associated with the proposed TS changes and is provided for information only.

The proposed changes have been reviewed and approved by the sites Plant Operations Review Committee in accordance with the requirements of the Exelon Quality Assurance Program.

Exelon requests that this application be reviewed under the Consolidated Line Item Improvement Process (CLIIP).

Exelon requests approval of the proposed amendment by February 28, 2021, in support of the refueling outage scheduled to begin on March 22, 2021. Once approved, the amendment shall be implemented within 60 days.

There are no regulatory commitments contained in this submittal.

License Amendment Request Adopt TSTF-582 RPV WIC Enhancements Docket No. 50-220 December 18, 2020 Page 2 In accordance with 10 CFR 50.91, "Notice for public comment; State consultation,"

paragraph (b), Exelon is notifying the State of New York of this application for license amendment by transmitting a copy of this letter and its attachments to the designated State Official.

Should you have any questions concerning this submittal, please contact Ron Reynolds at (610) 765-5247.

I declare under penalty of perjury that the foregoing is true and correct. Executed on the 18th day of December 2020.

Respectfully, David P. Helker Sr. Manager, Licensing Exelon Generation Company, LLC Attachments: 1. Evaluation of Proposed Changes

2. Proposed Technical Specification Changes (Mark-Up)

3. Proposed Technical Specification Bases Changes (Mark-Up) -

For Information Only cc: USNRC Region I, Regional Administrator w/attachments USNRC Senior Resident Inspector, NMP "

USNRC Project Manager, NMP "

A. L. Peterson, NYSERDA "

ATTACHMENT 1 License Amendment Request Nine Mile Point Nuclear Station, Unit 1 Docket No. 50-220 Application to Revise Technical Specifications to Adopt TSTF-582, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements" EVALUATION OF PROPOSED CHANGES

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 1 of 6 Docket No. 50-220 Evaluation of Proposed Changes

1.0 DESCRIPTION

Pursuant to 10 CFR 50.90, Application for amendment of license or construction permit, or early site permit, Exelon Generation Company, LLC (Exelon), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License No. DPR-63 for Nine Mile Point Nuclear Station, Unit 1 (NMP1).

Exelon requests adoption of TSTF-582, Revision 0, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements" (Reference 1). The TS related to RPV WIC are being revised to incorporate operating experience and to correct errors and omissions in TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control" (Reference 2).

2.0 ASSESSMENT 2.1 Applicability of Safety Evaluation Exelon has reviewed the NRC safety evaluation for TSTF-582 provided to the Technical Specifications Task Force in a letter dated August 13, 2020 (Reference 3). This review included a review of the NRC staffs evaluation, as well as the information provided in TSTF-582. Exelon has concluded that the justifications presented in TSTF-582 and the safety evaluation prepared by the NRC staff are applicable to NMP1 and justify this amendment for incorporation of the changes to the NMP1 TS.

Exelon verifies that the required ECCS injection/spray subsystem can be aligned and the pump started using relatively simple evolutions involving the manipulation of a small number of components. These actions can be performed in a short time (less than the minimum Drain Time of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />) from the control room following plant procedures.

2.2 Optional Changes and Variations Exelon is proposing the following generic variations from the TS changes described in TSTF-582 or the applicable parts of the NRC staffs safety evaluation.

NMP1 TS are custom TS and, therefore, the wording and format varies slightly from the NRC Improved Standard Technical Specifications (NUREG-1433) shown in TSTF-582, Revision 0, and the applicable parts of the NRC's safety evaluation. These differences are administrative and do not affect the applicability of TSTF-582 to the NMP1 TS.

Note also that NMP1 uses different numbering and titles than the improved Standard Technical Specifications (STS) in several instances. These differences are administrative and do not affect the applicability of TSTF-582 to the NMP1 TS. The model application provided in TSTF-582 includes an attachment for typed, camera-ready (revised) TS pages reflecting the proposed changes. NMP1 is not including such an attachment due to the number of TS pages included in this submittal that have the potential to be affected by other unrelated license amendment requests and the straightforward nature of the proposed changes. Providing only mark-ups of the proposed TS changes satisfies the requirements of 10 CFR 50.90, "Application for amendment of license, construction permit, or early site permit," in that the mark-ups fully

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 2 of 6 Docket No. 50-220 Evaluation of Proposed Changes describe the changes desired. This is an administrative deviation from TSTF-582 with no impact on the NRC's model safety evaluation published on August 13, 2020. As a result of this deviation, the contents and numbering of the attachments for this amendment request differ from the attachments specified in the model application in TSTF-582.

TSTF-582, Description of the Proposed Change, identifies 12 Improvements, Corrections and TS Bases Corrections. None of the proposed TS Bases changes apply to NMP1 custom TS.

For this application, Improvements 1 through 4; and Correction 10 and the first bullet in Correction 11 are included in this submittal.

Specific Optional Changes to TSTF-582 are also proposed in this application. These optional changes address consistency issues and make further corrections to RPV WIC implemented with the adoption of Reference 2. These optional changes are as follows:

• Specification 3.1.9.d. (3): This Specification has the word "circuit" added and now reads as follows: "Verify one RBEVS circuit is capable of being placed in operation in less than the drain time." This is an optional change to the changes described in TSTF-582; however, this change aligns with NMP1 custom TS. This optional change is considered administrative providing clarity and completeness to the LCO and consistency with the NMP1 TS and does not impact the intent of TSTF-582; therefore, this change is acceptable.

• Specification 3.1.9.e. (3): This Specification has the words "automatically or" added and now reads as follows: "Initiate action to isolate each secondary containment penetration flow path or verify it can be automatically or manually isolated from the control room."

This is an optional change to the changes described in TSTF-582; however, this change aligns NMP1 TS with the wording in TSTF-582. This optional change provides clarity and completeness to the LCO and does not impact the intent of TSTF-582 and is therefore acceptable.

• Specification 3.1.9.e. (4): This Specification has the word "circuit" added and now reads as follows: "Initiate action to verify one RBEVS circuit is capable of being placed in operation." This is an optional change to the changes described in TSTF-582; however, this change aligns with NMP1 custom TS. This optional change is considered administrative providing clarity and completeness to the LCO and consistency with the NMP1 TS and does not impact the intent of TSTF-582; therefore, this change is acceptable.

• Specification 3.1.9.f: This Specification currently has an "and" statement that does not align with LCO 3.5.2.E in TSTF-582. This "and" statement was carried over in the implementation of the approved amendment for TSTF-542. Therefore, for correctness, this optional change will revise Specification 3.1.9.f to an "or" statement to say "Specifications d or e" and will read as follows: "Specifications d or e not met, or drain time is <1 hour, immediately initiate action to restore drain time to 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />." This optional change does not adversely impact the changes identified in TSTF-582 and is therefore acceptable.

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 3 of 6 Docket No. 50-220 Evaluation of Proposed Changes

• Table 3.6.2m, Primary Coolant Isolation parameter, Low-Low Reactor Water Level: The Minimum Number of Operable Instrument Channels per Operable Trip System is changed from 2 to 1 for Cleanup and Shutdown Cooling systems. This change aligns the system channel logic of one out of two taken twice. In addition, new Note (b) on Notes for Tables 3.6.2m and 4.6.2m is reworded to align with NMP1 custom TS. This optional change does not adversely impact the changes identified in TSTF-582 and is therefore acceptable.

3.0 REGULATORY ANALYSIS

3.1 No Significant Hazards Consideration Analysis Exelon Generation Company, LLC (Exelon), proposes changes to the Technical Specifications (TS), Appendix A of Renewed Facility Operating License No. DPR-63 for Nine Mile Point Nuclear Station, Unit 1 (NMP1).

Exelon requests adoption of TSTF-582, Revision 0, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements. The TS related to RPV WIC are being revised to incorporate operating experience and to correct errors and omissions that were incorporated into the plant TS when adopting TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control." TSTF-582 includes the following changes to the TS:

1. The Drain Time definition is revised to move the examples of common mode failure mechanisms to the Bases and seismic events are no longer considered a common mode failure mechanism.

2. The Drain Time definition exception from considering the Drain Time for penetration flow paths isolated with manual or automatic valves that are "locked, sealed, or otherwise secured" is revised to apply the exception for manual or automatic valves that are "closed and administratively controlled."

3. The TS are revised to eliminate the requirement for a manual ECCS initiation signal to start the required ECCS injection/spray subsystem, and to instead rely on manual valve alignment and pump start.

4. The TSs are revised to permit placing an inoperable isolation channel in trip as an alternative to declaring the associated penetration flow path incapable of automatic isolation.

5. Specifications 3.2.7.d, 3.2.7.e, and 3.2.7.f are deleted from the TS as the RPV WIC specification controls shutdown cooling.

6. The TS are revised to use wording in a manner consistent with the remainder of the TS. These changes are made for consistency and have no effect on the application of the TS.

Exelon has evaluated if a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 4 of 6 Docket No. 50-220 Evaluation of Proposed Changes

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

Response: No The proposed changes incorporate operating experience and correct errors and omissions that were incorporated into the plant TS when adopting TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control." Draining of RPV water inventory in Shutdown Condition-Cold and Refueling Condition is not an accident previously evaluated and, therefore, revising the existing TS controls to prevent or mitigate such an event has no effect on any accident previously evaluated. RPV water inventory control in Shutdown Condition-Cold and Refueling Condition is not an initiator of any accident previously evaluated. The existing and revised TS controls are not mitigating actions assumed in any accident previously evaluated.

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

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

Response: No The proposed changes incorporate operating experience and correct errors and omissions that were incorporated into the plant TSs when adopting TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control." The event of concern under the current requirements and the proposed change is an unexpected draining event. The TS have contained requirements related to an unexpected draining event during shutdown for over 40 years and this event does not appear as an analyzed event in the Updated Final Safety Analysis Report (UFSAR) for any plant or in the NRC's Standard Review Plan (NUREG-0800). Therefore, an unexpected draining event is not a new or different kind of accident not considered in the design and licensing bases that would have been considered a design basis accident in the UFSAR had it been previously identified.

None of the equipment affected by the proposed changes has a design function described in the UFSAR to mitigate an unexpected draining event in Shutdown Condition-Cold and Refueling Condition, although the equipment may be used for that purpose. Therefore, the proposed changes will not change the design function of the affected equipment. The proposed changes will affect the operation of certain equipment, such as the manual initiation function and related instrumentation to permit initiation of the required ECCS injection/spray subsystem, and the control of valves credited for preventing a draining event. However, these changes provide adequate protection to prevent or mitigate an unexpected draining event and do not create the possibility of a new or different kind of accident due to credible new failure mechanisms, malfunctions, or accident initiators not considered in the design and licensing bases.

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

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 5 of 6 Docket No. 50-220 Evaluation of Proposed Changes

3. Do the proposed changes involve a significant reduction in a margin of safety?

Response: No The proposed changes incorporate operating experience and correct errors and omissions that were incorporated into the plant TSs when adopting TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control."

The safety basis for the RPV WIC requirements is to protect Safety Limit 2.1.1.d. The proposed changes do not affect any specific values that define a safety margin as established in the licensing basis. The proposed changes do not affect a design basis or safety limit, or any controlling value for a parameter established in the UFSAR or the license. Therefore, the proposed changes do not significantly reduce the margin of safety.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above, Exelon concludes that the proposed changes present no 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.

3.2 Conclusion 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 Commissions 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.

4.0 ENVIRONMENTAL EVALUATION The proposed changes would change a requirement with respect to 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. The proposed changes do not involve (i) a significant hazards consideration, (ii) a significant change in the types 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. Accordingly, the proposed changes meet the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed changes.

License Amendment Request Attachment 1 Adopt TSTF-582 RPV WIC Enhancements Page 6 of 6 Docket No. 50-220 Evaluation of Proposed Changes

5.0 REFERENCES

1. TSTF-582, Revision 0, " Reactor Pressure Vessel Water Inventory Control (RPV WIC)

Enhancements," dated August 28, 2019 ADAMS Accession No. ML19240A260.

2. TSTF-542, Revision 2, "Reactor Pressure Vessel Water Inventory Control," dated March 14, 2016. ADAMS Accession No. ML16074A448.

3. Final Safety Evaluation of Technical Specifications Task Force Traveler TSTF-582, Revision 0, "Reactor Pressure Vessel Water Inventory Control (RPV WIC)

Enhancements," dated August 13, 2020. ADAMS Accession No. ML20219A317.

ATTACHMENT 2 License Amendment Request Nine Mile Point Nuclear Station, Unit 1 Docket No. 50-220 Application to Revise Technical Specifications to Adopt TSTF-582, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements" Proposed Technical Specifications Markup Pages 8a 79a 79b 79c 109 247b 247c 247d 247f

1. 34 Drain Time The drain time is the time it would take for the water inventory in and above the Reactor Pressure Vessel (RPV) to drain to

-10 inches indicator scale (7 4 inches above the top of the active fuel seated in the RPV) assuming:

a. The water inventory above -10 inches indicator scale is divided by the limiting drain rate;

b. The limiting drain rate is the larger of the drain rate through a single penetration flow path with the highest flow rate, or the sum of the drain rates through multiple penetration flow paths susceptible to a common Mode failure (e.g.,

seismic event, loss of normal power, single human error}, for all penetration flow paths below -10 inches indicator scale except:

closed and administratively controlled

1. Penetration flow paths connected to an intact closed system, or isolate by manual or automatic valves that are locked, sealed, or otherwise secured in the closed position, blank flanges, or other devices that prevent flow of reactor coolant through the penetration flow paths;

2. Penetration flow paths capable of being isolated by valves that will close automatically without offsite power prior to the RPV water level being equal to -1 O inches indicator scale when actuated by RPV water level isolation instrumentation; or

3. Penetration flow paths with isolation devices that can be closed prior to the RPV water level being equal to the

-10 inches indicator scale by a dedicated operator trained in the task, who is in continuous communication with the control room, is stationed at the controls, and is capable of closing the penetration flow path isolation device without offsite power.

c. The penetration flow paths required to be evaluated per paragraph b are assumed to open instantaneously and are not subsequently isolated, and no water is assumed to be subsequently added to the RPV water inventory;

d. No additional draining events occur; and

e. Realistic cross-sectional areas and drain rates are used.

A bounding drain time may be used in lieu of a calculated value.

AMENDMENT NO. 236 Ba

LIMITING CONDITION FOR OPERATION SURVEILLANCE REQUIREMENT 3.1.9 Reactor Pressure Vessel (RPV) Water Inventory 4 .1.9 Reactor Pressure Vessel (RPV) Water Inventory Control Control Applicability: Applicability:

Applies to the operating status of the core spray systems Applies to the periodic testing requirements for the and Reactor Water Inventory Control when the reactor core spray system and RPV water inventory.

coolant temperature is less than or equal to 212°F.

Objective:

Objective:

To assure the RPV water inventory is maintained -10 To verify the operability of the core spray system inches indicator scale. and RPV water inventory.

Specification: Specification:

a. Whenever irradiated fuel is in the reactor vessel a. Verify drain time ~36 hours in accordance and the reactor coolant temperature is less than or with the Surveillance Frequency Control equal to 212°F, drain time of RPV water inventory to Program.

-10 inches indicator scale shall be ~36 hours and one core spray subsystem shall be operable except b. Verify, for a required core spray subsystem, the as specified in Specifications b through f below. downcomers in the suppression chamber have greater than or equal to three and one half foot

b. If the required core spray subsystem becomes of submergence or the condensate storage inoperable, the component shall be returned to an tank inventory is not less than 300,000 gallons, operable condition within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. in accordance with the Surveillance Frequency Control Program.

c. If Specifications a and b are not met, then immediately initiate action to establish a method of c. Verify for the required core spray subsystem, water injection capable of operating without offsite each manual power operated and automatic electrical power. valve in the flow path, that is not locked, sealed or otherwise secured in position, is in the correct position, in accordance with the Surveillance Frequency Control Program.

AMENDMENT NO, 236 79a

LIMITING CONDITION FOR OPERATION SURVEILLANCE REQUIREMENT

d. If drain time <36 hours and ~8 hours, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> d. Verify each valve credited for automatically perform the following actions: isolating a penetration flow path actuates to the

c. isolation position on an actual or simulated (1) Verify secondary containment boundary is isolation signal, in accordance with the capable of being established in less than the Surveillance Frequency Control Program.

drain time,

e. Verify the required core spray subsystem can be and manually operated, in accordance with the (2) Verify each secondary containment penetration flow d. Surveillance Frequency Control Program. Vessel path is capable of being isolated in less than the spray may be excluded.

drain time, circuit and (3) Verify one RBEVS is capable of being placed in operation in less than the drain time.

e. If drain time <8 hours, immediately perform the following actions:

(1) Initiate action to establish an additional method of water injection with water sources capable of maintaining RPV water level above -1 O inches indicator scale for ~ 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> without offsite electrical power, and (2) Initiate action to establish secondary containment boundary, automatically or and (3) Initiate action to isolate each secondary containment penetration flow path or verify it can be manually isolated from the control room, circuit and (4) Initiate action to verify one RBEVS is capable of being placed in operation.

AMENDMENT NO. 236 79b

d or e LIMITING CONDITION FOR OPERATION SURVEILLANCE REQUIREMENT

f. Specifications d and e not met, or drain time is

<1 hour, immediately initiate action to restore drain time to <?:36 hours.

AMENDMENT NO. 236 79c

LIMITING CONDITION FOR OPERATION SURVEILLANCE REQUIREMENT

c. If Specifications 3.2.7a and b above are not met, c. In accordance with the Surveillance Frequency initiate normal orderly shutdown within one hour Control Program the feedwater and main-steam and have reactor in the cold shutdown condition line power-operated isolation valves shall be within ten hours. exercised by partial closure and subsequent reopening.

d. Whenever fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F, d. In accordance with the INSERVICE TESTING the isolation valves on the shutdown cooling system PROGRAM the feedwater and main steam line lines connected to the reactor coolant system shall be power-operated isolation valves shall be fully operable except as specified in Specification 3.2.7.e closed and reopened.

below.

e. In the event any shutdown cooling system isolation valve becomes inoperable whenever fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F, the system shall be considered operable provided that, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, at least one valve in each line having an inoperable valve is in the mode corresponding to the isolated condition.

f. If Specifications 3.2.7.d and 3.2.7.e above are not met, immediately initiate action to restore the valve(s) to operable status.

AMENDMENT NO. 142, 197, 222, 233, 236 109

TABLE 3.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Limiting Condition for Operation Minimum No. of Operable Instrument Reactor Mode Switch Minimum No. Channels per Position in Which of Tripped or Operable Function Must Be Parameter Operable Trip Systems Trip System Set Point Operable c

~

~

0 "C

I U) a;

I Cl) a::

~

c.

I ftS U) c

I a::

OPEN CORE SPRAY DISCHARGE VALVES

( 1) Reactor Pressure 2 1(d)(e)  ;:: 365 psig (a)(b) (a)(b)

AMENDMENT NO. 236 247b

TABLE 3.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Limiting Condition for Operation Minimum No. of Operable Instrument Reactor Mode Switch Minimum No. Channels per Position in Which of Tripped or Operable Function Must Be Parameter Operable Trip Systems Trip System Set Point Operable c

(1)  :!=

0 "C

s

.c rn G>

s G>

a::

a.

s t:

C'G rn c

s a::

PRIMARY COOLANT ISOLATION 1(c)

(2) Low-Low Reactor Water Level (b)

(b)

(a) Cleanup 2 2(c)  ::?: 5 inches (a) (a) 1(c) (Indicator Scale)

(b)

(b)

(b) Shutdown Cooling 2 2(c)  ::?: 5 inches (a) (a)

(Indicator Scale)

(3) Manual 2 1 (a) (a)

(2)

AMENDMENT NO. ~. 239 247c

TABLE 4.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Surveillance Requirement Instrument Instrument Channel Parameter Sensor Check Channel Test Calibration OPEN CORE SPRAY DISCHARGE VALVES (1) Reactor Pressure Note 1 AMENDMENT NO. 236 247d

NOTES FOR TABLES 3.6.2m AND 4.6.2m (a) The Parameters in this table are only applicable in the Shutdown Condition - Cold and Refuel. See Table 3.6.2b or Table 3.6.2d for Parameter applicability in the Shutdown Condition - Hot.

(b) The instrumentation that allows for injection of the Core Spray System is not required to be operable if there is no fuel in the reactor vessel.

(b)

(c) Applicable when automatic isolation of the associated penetration flow path(s) is credited in calculating drain time . With one or more channels inoperable, immediately

1. Declare associated penetration flow path(s) incapable of automatic isolation, and

2. Calculate drain time.

(d) Associated with the subsystem of Core Spray required to be Operable per Specification 3.1.9, Reactor Pressure Vessel (RPV) Water Inventory Control.

(e) With the number of Operable channels less than required by the Minimum Number of Operable Instrument Channels per Operable Trip System requirement, place the inoperable channel in a tripped condition within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, or Immediately, declare the associated Core Spray subsystem per Specification 3.1.9 inoperable.

Insert new Note (c)

Note 1: Surveillance intervals are specified in the Surveillance Frequency Control Program unless otherwise noted in Table 4.6.2m.

(c) With the number of Operable channels less than required by the Minimum Number of Operable Instrument Channels per Operable Trip System requirement, either

1. Place the inoperable channel(s) in the trip condition, or

2. Take the Action required by Specification 3.6.2a for that parameter.

AMENDMENT NO. 236 247f

ATTACHMENT 3 License Amendment Request Nine Mile Point Nuclear Station, Unit 1 Docket No. 50-220 Application to Revise Technical Specifications to Adopt TSTF-582, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements" Proposed Technical Specifications Bases Markup Pages 79d 79f 115 115a 248a 249

BASES FOR 3.1.9 AND 4.1.9 Reactor Pressure Vessel (RPV) Water Inventory Control The RPV contains penetrations below -1 O inches indicator scale (7 4 inches above top of active fuel) that have the potential to drain the reactor coolant inventory to below -10 inches indicator scale. If the water level should drop below -10 inches indicator scale, the ability to remove decay heat is reduced, which could lead to elevated cladding temperatures and clad perforation.

The Core Spray System performance is evaluated for the entire spectrum of break sizes for a postulated loss of coolant accident (LOCA).

Both systems (at least one subsystem in each system) are required to operate to limit peak clad temperatures below 2200°F (10 CFR 50.46(a)(1)(i) model) for the worst case line break (recirculation discharge line break). It is reasonable to assume, based on engineering judgment, while in the cold shutdown or refueling conditions, one Core Spray subsystem can maintain adequate reactor vessel water level.

The RPV water level must be controlled when in the cold shutdown or refueling conditions to ensure that if an unexpected draining event should occur, the reactor coolant water level remains above -10 inches indicator scale. The Limiting Condition for Operation (LCO) requires the drain time of RPV water inventory to -1 O inches indicator scale to be ~36 hours. A drain time of 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> is considered reasonable to identify and initiate action to mitigate unexpected draining of reactor coolant. An event that could cause loss of RPV water inventory and result in the RPV water level reaching -10 inches indicator scale in greater than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> does not represent a significant challenge to core uncovery and can be managed as part of normal plant operation. aligned and from the control room One Core Spray subsystem is required to be operable and capable of being manually started to provide defense-in-depth should an unexpected draining event occur. The Core Spray subsystem consists of one motor driven pump set (two pumps in series), piping, and valves to transfer water from the torus to the RPV. The necessary portions of the Service Water System and Ultimate Heat Sink capable of providing cooling are also required for a Core Spray subsystem. Management of gas voids is important to Core Spray subsystem operability. Operability of the Core Spray subsystem includes any necessary valves, instrumentation, or controls needed to manually align and start the subsystem from the control room.

RPV water inventory control is required when in the cold shutdown or refueling conditions. RPV water inventory control is required whenever irradiated fuel is in the reactor vessel. an considered A double-ended guillotine break of the Reactor Coolant System (RCS) is not postulated when in the cold shutdown or refueling conditions, due to the reduced RCS pressure, reduced piping stresses, and ductile piping systems. Instead, an event is considered in which single operator error or initiating event allows draining of the RPV water inventory through a single penetration flow path with the highest flow rate, or the sum of the drain rates through multiple penetration flow paths susceptible to a common mode failure (e.g., seismic event, loss of normal power, single human error).

The RPV water level must be controlled when in the cold shutdown or refueling conditions, to ensure that if an unexpected draining event should occur, the reactor coolant water level remains above -10 inches indicator scale.

Revision 4 7 (A236) (an event that creates a drain path through multiple vessel penetrations located below -10 79d inches indicator scale, such as loss of normal power, or a single human error).

BASES FOR 3.1.9 AND 4.1.9 Reactor Pressure Vessel (RPV) Water Inventory Control Action 3.1.9.d(3) requires verification of the capability to place one RBEV circuit in operation in less than the drain time. The required verification confirms actions to place an RBEV circuit in operation are preplanned and necessary materials are available. Verification that an RBEV circuit can be placed in operation must be performed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The required verification is an administrative activity and does not require manipulation or testing of equipment.

With the drain time less than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, mitigating actions are implemented in case an unexpected draining event should occur.

Action 3.1.9.e(1) requires immediate action to establish an additional method of water injection augmenting the Core Spray subsystem required by the LCO. The additional method of water injection includes the necessary instrumentation and controls, water sources, and pumps and valves needed to add water to the RPV or refueling cavity should an unexpected draining event occur. For Action 3.1.9.e(1 ), either the Core Spray subsystem or the additional method of water injection must be capable of operating without offsite electrical power. The additional method of water injection may be manually initiated and may consist of one or more systems or subsystems. The additional method of water injection must be able to access water inventory capable of being injected to maintain the RPV water level above -10 inches indicator scale for ~36 hours. The additional method of water injection and the Core Spray subsystem may share all or part of the same water sources. If recirculation of injected water would occur, it may be credited in determining the required water volume.

Action 3.1.9.e(2) requires that actions be immediately initiated to establish the secondary containment boundary. With the secondary containment boundary established, one RBEV circuit is capable of maintaining a negative pressure in the secondary containment with respect to the environment. The secondary containment penetrations form a part of the secondary containment boundary.

Action 3.1.9.e(3) requires that actions be immediately initiated to verify that each secondary containment penetration flow path is isolated or to verify that it can be manually isolated from the control room.

automatically or Action 3.1.9.e(4) requires that actions be immediately initiated to verify that at least one RBEV circuit is capable of being placed in operation. The required verification is an administrative activity and does not require manipulation or testing of equipment.

or If the Required Actions and associated Completion times of Specifications 3.1.9.d and 3.1.9.e are not met or if the drain time is less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, actions must be initiated immediately to restore the drain time to ~36 hours. In this condition, there may be insufficient time to respond to an unexpected draining event to prevent the RPV water inventory from reaching -10 inches indicator scale. Note that the Actions of 3.1.9.e are also applicable when drain time is less than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

Revision 4 7 (A236) 79f

BASES FOR 3.2.7 AND 4.2.7 REACTOR COOLANT SYSTEM ISOLATION VALVES The list of reactor coolant isolation valves is contained in the procedure governing controlled lists and has been removed from the Technical Specifications per Generic Letter 91-08. Revisions will be processed in accordance with Quality Assurance Program requirements.

Double isolation valves are provided in lines which connect to the reactor coolant system to assure isolation and minimize reactor coolant loss in the event of a line rupture. The specified valve requirements assure that isolation is already accomplished with one valve shut or provide redundancy in an open line with two operative valves. Except where check valves are used as one or both of a set of double isolation valves, the isolation valves shall be capable of automatic initiation. Valve closure times are selected to minimize coolant losses in the event of the specific line rupturing and are 1

procedurally controlled . Using the longest closure time on the main-steam-line valves following a main-steam-line break (Section XV-C.1.0)( l, the core is still covered by the time the valves close. Following a specific system line break, the cleanup and shutdown cooling closing times will upon initiation from a low-low level signal limit coolant loss such that the core is not uncovered. Feedwater flow would quickly restore coolant levels to 1

prevent clad damage. Closure times are discussed in Section Vl-D.1.0< l.

Closure of the isolation valves in lines which connect to the reactor coolant system also minimizes potential leakage paths from the primary containment in the event of a loss-of-coolant accident. For each emergency cooling system condensate return line penetration, this isolation function is accomplished either by (a) Type C leak rate testing both the inboard and outboard isolation valves, in which case the emergency cooling closed loop outside containment (CLOC) configuration does not apply, or (b) Type C leak-rate-testing one valve and the closed system piping outside primary containment. In this case CLOC configuration applies. The closed system boundary includes the emergency cooling system main process piping and connected branch lines up to and including the first branch line isolation valve.

In addition, whenever fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F (encompassing the cold shutdown and refueling operating conditions), closure of the shutdown cooling system isolation valves ensures that the reactor vessel water level does not drop below the top of the active fuel during a vessel draindown event caused by a leak or line break in the shutdown cooling system.

It is not intended that compliance with Technical Specification actions would prevent changes in modes or other specified conditions that are part of a shutdown of the unit. Accordingly, if during a plant shutdown any shutdown cooling system isolation valve becomes inoperable for closing while placing shutdown cooling in operation, it is recommended not to take the action specified in 3.2.7.b to isolate one valve in the line having the inoperable valve within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This is because, once the line is isolated, the Technical Specifications preclude unisolating the line unless it is for the purpose of demonstrating operability of the inoperable valve. It is, therefore, recommended to take the action specified in 3.2.7.c within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> (instead of the action specified in 3.2.7 .b) and proceed with the shutdown actions using shutdown cooling as necessary to reduce reactor coolant temperature to less than 212°F within the following 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />. Thereafter, the actions specified in 3.2.7.e and 3.2.7.f would need to be met. An inoperable shutdown cooling isolation valve may be opened with the shutdown cooling permissives met (reactor pressure ..:; 120 psig and temperature :::;; 350°F) in order to comply with the shutdown actions specified in 3.2.7.c.

During plant operation, the isolation valves in the shutdown cooling system are normally closed. In lieu of performing Type C leak rate testing on these isolation valves, a water seal is provided to prevent containment atmosphere leakage through these valves in the event of an accident

1) UFSAR AMENDMENT NO. 142, 145, Revision 2(A17J), e (A181), 24 (A1Q7), J8, 40 115

BASES FOR 3.2.7 AND 4.2.7 REACTOR COOLANT SYSTEM ISOLATION VALVES requiring primary containment isolation. The seal water, supplied from the core spray system, would pressurize the piping between the inboard and outboard isolation valves. To prevent a spurious or inadvertent valve opening from defeating the water seal, the motor-operated shutdown cooling system isolation valves are required to be de-activated (power is removed) during normal plant operation. Thus, the motor-operated shutdown cooling system isolation valves are considered operable when the valves are closed and de-activated and the water seal is capable of performing its function.

When the shutdown cooling system is placed in service for plant cooldown (with reactor pressure :-:; 120 psig and temperature ~ 350°F}, power for the motor-operated isolation valves must be restored and the valves opened. Should a loss of coolant accident occur at this time, failure of an isolation valve to close upon receipt of an isolation signal could cause a loss of the water seal. The risk associated with this potential single failure has been determined to be acceptable based on the low probability of a core damage event occurring during shutdown cooling system operation(2l.

Specification 3.2.7.d requires operability of the shutdown cooling system isolation valves whenever fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F. If any isolation valve becomes inoperable, Specification 3.2.7.e requires that, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, at least one valve in each line having an inoperable valve is in the mode corresponding to the isolated condition. However, if the shutdown cooling function is needed to provide core cooling, isolating the shutdown cooling line is not desirable. Specification 3.2.7.f allows the shutdown cooling line to remain unisolated provided Drain Time is ~ 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. If Drain Time is less than 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, then Specification 3.1.9 applies. In addition, with the reactor coolant temperature less than or equal to 212°F, the water seal function is not required to consider the shutdown cooling system isolation valves operable since primary containment integrity is not required with reactor coolant temperature less than or equal to 215°F.

Results obtained during closure testing are not expected to differ appreciably from closure times under accident conditions as in most cases, flow helps to seal the valve.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

With (2) Letter from G. E. Edison (NRG) to B. R. Sylvia (NMPC) dated March 20, 1995, Issuance of Amendment for Nine Mile Point Nuclear Station Unit No. 1 (License Amendment No. 154).

Revision 24 (A197), 37, 38, 39, 40, 41 (A222), 47 (A236) 115a

BASES FOR 3.6.2 AND 4.6.2 PROTECTIVE INSTRUMENTATION Each reactor operating condition has a related reactor mode switch position for the safety system. The instrumentation system operability for each mode switch position is based on the requirements of the related safety system. For example, the specific high drywell pressure trip systems must be tripped or operable in the applicable Operating Condition for core spray, containment spray, automatic depressurization or containment isolation functions.

In instrumentation systems where two trip systems are required to initiate action, either both trip systems are operable or one is tripped .

Having one trip system already tripped does not decrease the reliability in terms of initiating the desired action. However, the probability of spurious actuation is increased. Certain instrument channels or sensor inputs to instrument channels may be bypassed without affecting safe operation. The basis for allowing bypassing of the specified SRM's, IRM's, LPRM's and APRM's is discussed in Volume I (Section Vll-C.1.2)*. The high area temperature isolation function for the cleanup system has one trip system. There are three instrument channels; each has four sensor inputs. Only two instrument channels are required since the area covered by any one sensor is also covered by a sensor in one of the other two instrument channels. The shutdown cooling system also has one trip system for high area temperature isolation. However, since the area of concern is much smaller, only one instrument channel is provided. Four sensors provide input to the channel. Since the area covered is relatively small only three of the four sensors are required to be operable in order to assure isolation when needed.

The RPV contains penetrations below -10 inches indicator scale that have the potential to drain the reactor coolant inventory to below

-10 inches indicator scale. If the water level should drop below -10 inches indicator scale, the ability to remove decay heat is reduced, which could lead to elevated cladding temperatures and clad perforation. Safety Limit 2.1.1.d and 2.1.1.e contain the requirements for the RPV water level to prevent such elevated cladding temperatures.

With the unit in the Shutdown Condition - Cold or Refuel Condition, RPV water inventory control is not required to mitigate any events or accidents evaluated in the safety analyses. RPV water inventory control is required in these conditions to protect Safety Limit 2.1.1.d, 2.1 .1.e and the fuel cladding barrier to prevent the release of radioactive material should a draining event occur. Under the definition of drain time, some penetration flow paths may be excluded from the drain time calculation if they will be isolated by valves that will close automatically without offsite power prior to the RPV water level being equal to -10 inches indicator scale when actuated by RPV water level isolation instrumentation.

The purpose of the RPV Water Inventory Control Instrumentation, Table 3.6.2m, is to support the requirements of LCO 3.1.9 and SR 4.1 .9, "Reactor Pressure Vessel (RPV) Water Inventory Control," and the definition of drain time. There are functions that are required for manual initiation or operation of the Core Spray system required to be Operable by LCO 3.1.4 and other functions that support automatic isolation of Shutdown Cooling and Cleanup system penetration flow path(s) on low RPV water level.

• FSAR; Letter, R.R. Schneider to A. Giambusso, dated November 15, 1973 AMENDMENT NO. 142, Revision 46 (A236) 248a

considered BASES FOR 3.6.2 AND 4.6.2 PROTECTIVE INSTRUMENTATION considered A double-ended guillotine break of the Reactor Coolant System (RCS) is not postulated in Shutdown Condition - Cold or Refuel Condition an due to the reduced RCS pressure, reduced piping stresses, and ductile piping systems. Instead, an event is postulated in which a single operator error or initiating event allows draining of the RPV water inventory through a single penetration flow path with the highest flow rate, or the sum of the drain rates through multiple penetration flow paths susceptible to a common mode failure (e.g., seismic event, loss of normal power, single human error). It is assumed, based on engineering judgment, that while in Shutdown Condition - Cold or Refuel Condition, one low pressure ECCS injection/spray subsystem can be manually initiated to maintain adequate reactor vessel water level.

Table 3.6.2b requires that the low-low reactor vessel water level instrumentation that initiates isolation of the Main Steam, Cleanup and Shutdown Cooling system be operable with the reactor mode switch in the Shutdown position. Two trip systems must be operable or in the tripped condition in the hot shutdown condition . If one low-low water level instrument channel in a required Trip System becomes inoperable and cannot be restored or placed in the tripped condition within the allowed time, the associated shutdown cooling line should be isolated.

However, if the shutdown cooling function is needed to provide core cooling, isolating the shutdown cooling line is not desirable.

Table 3.6.2d requires that the high drywell pressure and low-low reactor water level instrumentation Parameters for Start Core Spray Pumps and the reactor pressure instrumentation Parameter for Open Core Spray Discharge Valves be operable with the reactor mode switch in the shutdown or refuel positions. This is modified with a note clarifying applicability is only in the Shutdown Condition - Hot.

Table 3.6.2m requires that the low-low reactor vessel water level instrumentation that initiates isolation of the main steam and Cleanup and Shutdown Cooling system be operable with the reactor mode switch in the Shutdown or Refuel position. In the Shutdown Condition -

Cold and Refuel Condition, only one trip system (with two instrument channels) must be operable so long as shutdown cooling system integrity is maintained. System integrity is maintained provided the piping is intact and no maintenance is being performed that has the potential for draining the reactor vessel through the system.

both trip systems (one channel in each)

Table 3.6.2m, Note (e}, allows the shutdown cooling line to remain unisolated and the system to remain in service provided action is immediately initiated to restore the channel to operable status. The alternative action is to immediately initiate action to isolate the shutdown cooling system, which may require that alternate decay heat removal capabilities be provided. The term "immediately" means that the action should be pursued without delay and in a controlled manner. Either of these actions must continue until the channel is restored to operable status or the shutdown cooling system is isolated.

AMENDMENT NO. 142, Revision 24 (A197), 46 (A236) 249