NMP1L3402, Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 0

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Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of License Amendment Request to Adopt TSTF-582, Revision 0
ML21155A136
Person / Time
Site: Nine Mile Point Constellation icon.png
Issue date: 06/04/2021
From: David Gudger
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP1L3402, TSTF-582, Rev 0
Download: ML21155A136 (38)


Text

200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.90 NMP1L3402 June 4, 2021 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:

Response to Request for Additional Information by the Office of Nuclear Reactor Regulation to Support Review of Nine Mile Point Nuclear Station, Unit 1, License Amendment Request to Adopt TSTF-582, Revision 0

References:

1. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Application to Revise Technical Specifications to Adopt TSTF-582, Revision 0, 'Reactor Pressure Vessel Water Inventory Control,'" Revision 2, dated December 18, 2020
2. Email from M. Marshall (Senior Project Manager, U.S Nuclear Regulatory Commission) to R. Reynolds (Exelon Generation Company, LLC), "Nine Mile Point Nuclear Station, Unit 1-Request for Additional Information RE: Review of License Amendment Request to Revise Technical Specifications to Adopt TSTF-582," dated April 20, 2021 By letter dated December 18, 2020 (Reference 1), Exelon Generation Company, LLC (Exelon) requested to change The Nine Mile Point Unit 1 (NMP1) Technical Specifications (TS). The proposed amendment request is to adopt Technical Specification Task Force (TSTF) Traveler 582, "Reactor Pressure Vessel Water Inventory Control (RPV WIC) Enhancements," Revision 0.

On April 20, 2021 (Reference 2), the U.S. Nuclear Regulatory Commission (NRC) identified areas where additional information was necessary to complete the review. to this letter contains the NRCs request for additional information immediately followed by Exelons response. Attachment 2 contains the complete set of TS markups which supersedes, in its entirety, the TS markups provided in Reference 1. Attachment 3 contains the complete set of TS Bases markups (for information only) which supersedes, in its entirety, the TS Bases markups provided in Reference 1.

U.S. Nuclear Regulatory Commission Response t o Request for Additional Information Adopt TSTF-582, Revision 0 Docket No. 50-220 June 4, 2021 Page 2 Exelon has reviewed the information supporting a finding of no significant hazards consideration and the environmental consideration provided to the NRC in Reference 1. The additional information provided in this response does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration. Furthermore, the additional information provided in this response does not affect the bases for concluding that neither an environmental impact statement nor an environmental assessment needs to be prepared in connection with the proposed amendment.

There are no commitments contained in this response.

If you should have any questions regarding 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 4th day of June 2021.

Respectfully, David T. Gudger Senior Manager - Licensing Exelon Generation Company, LLC : Response to Request for Additional Information : Technical Specification Marked Up Pages : Technical Specification Bases Marked Up Pages (for information only) cc:

USNRC Region I Regional Administrator w/attachments USNRC Senior Resident Inspector - NMP USNRC Project Manager, NRR - NMP A. L. Peterson, NYSERDA

ATTACHMENT 1 Nine Mile Point Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-63 NRC Docket No. 50-220 Response to Request for Additional Information

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 1 of 17 Docket No. 50-220

RAI 1

The adaptation of the TSTF-582, which is based on the standard TS (STS), to the custom TSs used at Nine Mile Point 1 is unclear in the LAR. Please provide a comparison (e.g.,

crosswalk) of the changes in the STS found in TSTF-582 versus the proposed changes to Nine Mile Point 1 custom TS. This should include discussion of items that are in TSTF-582 but are not proposed in this LAR, as well as items that are specific to Nine Mile Point 1 TS but not in TSTF-582. Clearly identify the location of the changes in each document (e.g.,

LCO number and items changed.)

Exelon Response to RAI 1:

The following lists the Reactor Operating Conditions for the NMP1 Custom Technical Specifications (TS) and correlates them to the Standard TS (STS).

The NMP1 Reactor Operating Conditions are different than the STS. The STS terminology of MODES is not used in the NMP1 TS. The NMP1 instrumentation uses the position of the Reactor Mode Switch to enable functions. The table below correlates NMP1 Reactor Operating Condition to Mode Switch Position.

STS MODE NMP1 TS Reactor Operating Condition NMP1 Reactor Mode Switch Position 1 - Power Operation Power Operating Condition Run 2 - Startup Startup 3 - Hot Shutdown (>200F)

Shutdown Condition - Hot

(>212F)

Shutdown 4 - Cold Shutdown (200F)

Shutdown Condition - Cold (212F)

Shutdown or Refuel 5 - Refueling Refueling Condition Refuel No Mode Major Maintenance Condition (defueled)

No Required Position

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 2 of 17 Docket No. 50-220 The following table lists all the changes identified in TSTF-582 and provides a crosswalk between NMP1 Custom TS and STS for these changes, including administrative, design, and technical variations as requested in RAI 2. The crosswalk for the TS Bases changes are provided in this table for information only:

TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification 1.1, Definitions, TS 1.1-2 and TS 1.1-3 1.0, Definitions Section 1.34, Drain Time 8a TSTF-582 - Change to definition of Drain Time in accordance with TSTF.

LCO 3.3.5.2, Conditions A and B TS 3.3.5.2-1 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

New Note (c) 247f TSTF-582: New Note (c) has been added to modify the LCO requirement for Shutdown Cooling and Reactor Water Cleanup Isolation instrumentation.

This change incorporates the TSTF-582 LCO action to place the inoperable channel(s) in the tripped condition in accordance with TSTF-582 LCO 3.3.5.2, Condition A, Required Actions A.1 or A 2.1 and A.2.1. Added the action to take the action required by specification 3.6.2a for that parameter to require evaluation and potential actions of WIC Specification 3.1.9 based on calculated drain time.

The wording of the LCO requirement has been changed to match the wording within NMP1 Custom TS for Instrumentation Specification 3.6.2.

LCO 3.3.5.2, Condition C TS 3.3.5.2-1 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

247f TSTF-582: Note (e) is deleted in accordance with the deletion of Condition E in the TSTF.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 3 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification LCO 3.3.5.2, Condition D TS 3.3.5.2-1 TS 3.3.5.2-2 LCO 3.6.2m N/A N/A Condition D is not applicable to NMP1 design.

LCO 3.3.5.2, Condition E TS 3.3.5.2-3 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

247f TSTF-582: Note (e) is deleted in accordance with the deletion of Condition E in the TSTF.

SR 3.3.5.2, SR Notes TS 3.3.5.2-3 N/A N/A N/A Variation (Design): This Note is not in NMP1 TS.

SR 3.3.5.2.3 TS 3.3.5.2-3 TS 3.3.5.2-4 SR 4.6.2m Table 4.6.2m, Open Core Spray Discharge

Valves, Parameter (1)

Reactor Pressure 247d TSTF-582: Surveillance Parameter (1), Reactor Pressure, is deleted from this Surveillance Requirement in accordance with the TSTF.

Table 3.3.5.2-1, Function 1.a 3.3.5.2-5 LCO 3.6.2m Table 3.6.2m, Open Core Spray Discharge

Valves, Parameter (1)

Reactor Pressure 247b TSTF-582: Parameter (1) Reactor Pressure is deleted from this instrument specification in accordance with the TSTF. The TSTF and NMP1 markup remove the core spray valve permissive for opening. Although this change follows the intent of the TSTF, it is also a variation due to design.

Table 3.3.5.2-1, Function 1.b 3.3.5.2-5 N/A N/A N/A Variation (Design): Function 1.b is not in the NMP1 design.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 4 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Table 3.3.5.2-1, Function 1.c 3.3.5.2-5 N/A N/A N/A Variation (Design): Function 1.c is not in the NMP1 instrumentation specification.

Table 3.3.5.2-1, Functions 2.a, 2.b, and 2.c 3.3.5.2-5 N/A N/A N/A Variation (Design): These Functions are not in the NMP1 design.

Table 3.3.5.2-1, re-numbered Functions 1 and 2 3.3.5.2-5 LCO 3.6.2m Table 3.6.2m 247c TSTF-582: Re-numbered parameters Low-Low Reactor Water Level and Manual because of deleting Parameter (1) on page 247b in accordance with the TSTF.

Table 3.3.5.2-1, Footnote (a) 3.3.5.2-5 N/A N/A N/A Variation (Design): As stated above, Functions 1.b and 1.c are not in the NMP1 design. Therefore, this TSTF change is not applicable to NMP1.

Table 3.3.5.2-1, Function 1 TS 3.3.5.2-5 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

Note(b) 247f TSTF-582: Deleted Note (b) associated with Table 3.6.2m and SR 4.6.2m requirement for Core Spray Discharge Valve permissive that has been deleted in accordance with the TSTF. This aligns with the change on NMP1 TS page 247b.

Table 3.3.5.2-1 TS 3.3.5.2-5 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

247f Re-numbered Note (c) to Note (b) to reflect deletion of Note (b) above and revised the note to modify the Shutdown and Refuel mode applicability to only require the parameters when crediting the automatic isolation in calculating drain time.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 5 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Table 3.3.5.2-1, Footnote (a) 3.3.5.2-5 LCO 3.6.2m Notes for Tables 3.6.2m and 4.6.2m:

Note (d) and Note (e) 247f Deleted Note (d) and Note (e) associated with the LCO requirement for Core Spray Discharge valve permissive that has been deleted.

N/A N/A LCO 3.6.2m Table 3.6.2m 247c Variation (Administrative): Added Note (b) to the Shutdown and Refuel columns for the "Reactor Mode Switch Position in Which Function Must Be Operable." This note was previously contained as part of Note (c) and is now a separate clarification attached to the mode applicability column.

N/A N/A LCO 3.6.2m Table 3.6.2m 247c Variation (Design): Revised the "Minimum No. of Operable Instrument Channels per Operable Trip System" from 2 to 1. This proposed change reflects the NMP1 specific RPS design for Primary Coolant Isolation logic of a one-out-of-two taken twice logic.

One channel in each trip system will continue to provide the minimum isolation logic requirements.

This change is reflected in UFSAR Chapter VIII for description of NMP1 RPS Logic. TSTF-542 and 582, Table 3.3.5.2-1 reflect the minimum required channels per system for each parameter to maintain safety function. This is a correction to the original TSTF-542 submittal.

N/A N/A LCO 3.6.2m Table 3.6.2m 247c Variation (Administrative): The Manual parameter is deleted from Table 3.6.2m for the Primary Coolant Isolation function as it is determined not to be required in Shutdown Condition - Cold and Refuel Condition. See response to RAI 4.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 6 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification LCO 3.5.2, Required Action C.3 TS 3.5.2-2 LCO 3.1.9, RPV WIC Specifications 3.1.9.d(3) 79b Variation (Administrative): This change is similar to TSTF-582; however, NMP1 uses Reactor Building Emergency Ventilation System (RBEVS) in lieu of Standby Gas Treatment (SGT).

LCO 3.5.2, Required Action C.3 TS 3.5.2-2 LCO 3.1.9, RPV WIC Specifications 3.1.9.d(3) 3.1.9.e(4) 79b Variation (Administrative): Added site specific designation for a train of RBEVS to include "circuit" to make equivalent to TSTF-582 3.5.2 to actions C.3 and D.3 which use the term one standby gas treatment subsystem. This is in accordance with NMP1 TS 3.4.4 wording.

LCO 3.5.2, Required Action D.3 TS 3.5.2-3 LCO 3.1.9, RPV WIC Specification 3.1.9.e(3) 79b TSTF-582 - Change is in accordance with TSTF.

LCO 3.5.2, Required Action D.4 TS 3.5.2-3 LCO 3.1.9, RPV WIC Specification 3.1.9.d(3) 79b TSTF-582 - Change is in accordance with TSTF.

LCO 3.5.2, Required Action E TS 3.5.2-3 LCO 3.1.9, RPV WIC Specification 3.1.9.f 79c Variation (Technical)- Corrected error in Amendment 236. Logic of an "and" statement is not aligned with TSTF-582. Therefore, the change is to use an "or" connector. This change is now in accordance with LCO 3.5.2, Condition E, of both TSTF-542 & 582.

SR 3.5.2.2 TS 3.5.2-4 N/A N/A N/A NMP1 design does not include LPCI.

SR 3.5.2.5 3.5.2-5 SR 4.1.9, RPV WIC SR 4.1.9.c 79a 79b TSTF-582: SR 4.1.9.c is deleted in accordance with TSTF. Consequently, administrative changes are made to re-number the remaining SRs 4.1.9.d and 4.1.9.e to SRs 4.1.9.c and 4.1.9.d on NMP1 TS page 79b.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 7 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Revised SR 3.5.2.5 TS 3.5.2-6 N/A N/A N/A Variation (Technical): The SR requirement is not contained in the current TS as approved in Amendment 236 (TSTF-542).

Revised SR 3.5.2.7 TS 3.5.2-6 SR 4.1.9 SR 4.1.9.d 79b Variation (Administrative): SR 4.1.9.d states to verify the required core spray subsystem can be manually operated. Core spray is the ECCS system for NMP1 RPV WIC specification which is a variation to the TSTF. This SR already contains the phrase, "can be manually operated." Therefore, there is no change required.

N/A N/A Bases for 3.1.9 and 4.1.9 Bases page 79d, 4th paragraph 79d Variation - The sentence, "The necessary portions of the Service Water System and Ultimate Heat Sink capable of providing cooling are also required for a Core Spray subsystem," is deleted as this sentence was added in error during the implementation of Amendment 236 (TSFT-542).

LCO 3.6.1.3, Applicability TS 3.6.1.3-1 LCO 3.2.7 3.2.7, Applicability 108 NMP1 does not include the TSTF-582 reference to instrumentation specification that is being deleted; therefore, this change does not apply to NMP1.

LCO 3.6.1.3, Condition F TS 3.6.1.3-6 LCO 3.2.7 Specification 3.2.7.c 109 NMP1 does not include the TSTF-582 reference to instrumentation specification that is being deleted; therefore, this change does not apply to NMP1.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 8 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification LCO 3.6.1.3.G and 3.6.1.3.H TS 3.6.1.3-7 LCO 3.2.7 Specification 3.2.7.d Specification 3.2.7.e Specification 3.2.7.f 109 TSTF-582 - The three Specification have been deleted from the Reactor Coolant Isolation Valve specification to remove MODE 4 and 5 requirements. The PCIV specification will now be limited to MODES 1, 2, & 3 in the same manner as TSTF-582 specification for PCIVs 3.6.1.3. The specifications for inoperable PCIV penetration in MODES 4 & 5 (NMP modes Shutdown-Cold and Refuel) are now controlled by the WIC Instrumentation specification which then requires implementation of the actions within WIC Specification 3.1.9, where applicable, for associated drain time calculation, which recognizes the loss of the PCIV penetration for automatic isolation capability.

SR 3.6.1.3.1 SR 3.6.1.3.2 SR 3.6.1.3.7 SR 3.6.1.3.12 SR 3.6.1.3.13 SR 3.6.1.3.14 SR 3.6.1.3.15 TS 3.6.1.3-8 TS 3.6.1.3-11 TS 3.6.1.3-13 SR 4.2.7 SR 4.2.7.a through SR 4.2.7.d 108 109 NMP1 does not include the TSTF-582 reference to instrumentation specification that is being deleted; therefore, this change does not apply to NMP1.

SR 3.8.2.1 TS 3.8.2-3 N/A N/A N/A The NMP1 TS does not contain an AC Power -

Shutdown specification. Therefore, there is no change.

Bases 3.3.5.2, Background.

second paragraph 3.3.5.2A-1 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 9 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Bases 3.3.5.2, Background, first paragraph B 3.3.5.2A-2 LCO 3.6.2 and SR 4.6.2, Protective Instrumentation Bases for 3.6.2 and 4.6.2, Protective Instrumentation 248a TSTF-582: Change is in accordance with the TSTF.

Bases 3.3.5.2, Background, second paragraph B 3.3.5.2A-2 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change.

Bases 3.3.5.2, Applicable Safety Analysis, LCO, and Applicability, second paragraph B 3.3.5.2A-2 LCO 3.6.2 and SR 4.6.2, Protective Instrumentation Bases for 3.6.2 and 4.6.2, Protective Instrumentation, first paragraph 249 TSTF-582: Change is in accordance with TSTF.

Bases 3.3.5.2, Applicable Safety Analysis, LCO, and Applicability, B 3.3.5.2A-3 and B 3.3.5.2A-4 LCO 3.6.2 and SR 4.6.2, Protective Instrumentation Bases for 3.6.2 and 4.6.2, Protective Instrumentation, first paragraph 249a NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases 3.3.5.2, Actions, A.1, A.2.1, and A.2.2 B 3.3.5.2A-7 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 10 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Bases 3.3.5.2.

Actions C, D, and E B 3.3.5.2A-8 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases 3.3.5.2, Surveillance requirements B 3.3.5.2A-9 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases 3.3.2A, SR 3.3.5.2.3 B 3.3.5.2A-10 and B 3.3.5.2A-11 N/A N/A N/A NMP1 TS does not have Logic System Functional Testing. Therefore, there is no change required to the bases.

Bases 3.3.6.1, Action J.2 B 3.3.6.1A-26 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. NMP1 TS 3.6.2b requires isolation of shutdown cooling. Therefore, there is no change.

Bases 3.5.2, Applicable Safety

Analysis, second paragraph B 3.5.2-1 Bases for 3.1.9 and 4.1.9 Bases page 79d, 6th paragraph 79d TSTF-582 - Change is in accordance with TSTF.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 11 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Bases 3.5.2, LCO, second paragraph B 3.5.2-2 Bases for 3.1.9 and 4.1.9 Bases page 79d, 4th paragraph 79d TSTF-582: Change is in accordance with TSTF.

Bases 3.5.2, Applicability B 3.5.2-2 N/A N/A N/A NMP1 does not have RCIC. No change required to the Bases.

Bases 3.5.2, Actions, C.1, C.2, and C.3; also, D.2, D.3, and D.4 B 3.5.2-4 and B 3.5.2-6 N/A N/A N/A Variation (Administrative): The Reviewer's Note in TSTF-582 states that the bracketed text for the identified Actions applies to multiple unit sites with a shared secondary containment. NMP1 is a single unit design. Therefore, this TSTF change is not applicable to NMP1.

Bases 3.5.2, Required Action D.3, third paragraph B 3.5.2-6 Bases for 3.1.9 and 4.1.9 Bases page 79f, 5th paragraph, Action 3.1.9.e(3) 79f TSTF-582 - Change is in accordance with TSTF.

Bases 3.5.2, Required Action E.1 B 3.5.2-6 Bases for 3.1.9 and 4.1.9 Bases page 79f, 7th paragraph 79f Variation-Corrected error in Amendment 236.

Logic of an and connector is not correct.

Correction to the page uses an "or" connector and is now in accordance with the TSTF, T.S. 3.5.2, Action E, of both TSTF-542 & 582.

Bases SR 3.5.2.1, third paragraph B 3.5.2-8 N/A N/A N/A Variation (Administrative): The change to the definition to Drain Time is limited to NMP1 TS Section 1.1, Definitions. The NMP1 Bases does not include the TSTF Bases change.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 12 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Bases SR 3.5.2.1, second paragraph B 3.5.2-9 N/A N/A N/A Variation (Administrative): NMP1 Bases does not include this detail. N1-OP-34 will be revised to include the TSTF Bases change.

Bases SR 3.5.2.4, first paragraph B 3.5.2-11 N/A N/A N/A Variation (Technical): NMP1 TS does not contain this surveillance in RPV WIC. The SRs in TSTF-542, Revision 2, for LCO 3.5.2 are included in the new SR 4.1.9, except for an equivalent for SR 3.5.2.4 to verify the required ECCS injection/spray subsystem, the piping is filled with water from the pump discharge valve to the injection valve. The current SR 4.1.9.g is limited in applicability to greater than 212 degrees F; therefore, this surveillance is currently not required when in the Shutdown Condition - Cold or Refuel and is not being added. The system design and configuration is not susceptible to voiding and would not result in a system inoperability, as reported in the Generic Letter 2008-01 responses provided (References 4 and 5).

Bases SR 3.5.2.5 B 3.5.2-12 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases revised SR 3.5.2.5 B 3.5.2-13 N/A N/A N/A NMP1 TS does not contain this surveillance.

Therefore, there is no change required to the Bases.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 13 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification Bases revised SR 3.5.2.7 B 3.5.2-14 4.1.9 4.1.9.d 79b NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases 3.5.3, Surveillance Requirements, first paragraph B 3.5.3-8 N/A N/A N/A NMP1 TS does not have Logic System Functional Testing. Therefore, there is no change required to the Bases.

Bases, Applicability for LCO 3.6.1.3 B 3.6.1.3-3 and B 3.1.6.3-4 Bases for 3.2.7 and 4.2.7, Reactor Coolant System Isolation Valves Based page 115, 4th paragraph.

115 Deleted 4th paragraph since TS 3.1.9 now controls operability of RCIVs when below 212°F.

Bases, Actions, F.1 and F.2 B 3.6.1.3-11 N/A N/A N/A NMP1 TS does not contain the wording identified in TSTF-542 and TSTF-582. Therefore, there is no change required to the Bases.

Bases 3.6.1.3, Required Actions G.1 and H.1 B 3.6.1.3-12 Bases for 3.2.7 and 4.2.7, Reactor Coolant System Isolation Valves Based page 115, 5th paragraph.

115 Deleted reference to 3.2.7.e and 3.2.7.f to align with the deletion of Specifications 3.2.7.e and 3.2.7.f.

N/A N/A Bases for 3.2.7 and 4.2.7, Reactor Coolant System Isolation Valves Bases page 115a 115a Deleted 2nd full paragraph to align with the deletion of Specification 3.2.7.d.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 14 of 17 Docket No. 50-220 TSTF-582 Section TSTF-582 TS/Bases Page NMP1 TS NMP1 TS Section NMP1 TS Page Justification N/A N/A LCO 3.6.2 and SR 4.6.2, Protective Instrumentation Bases for 3.6.2 and 4.6.2, Protective Instrumentation, fourth paragraph 249 Variation (Design): This change corrects a previous error to reflect plant specific design of a one out of two, taken twice logic which meets the level of detail with the TSTF considering the plant-specific design.

N/A N/A LCO 3.6.2 and SR 4.6.2, Protective Instrumentation, Bases for 3.6.2 and 4.6.2, Protective Instrumentation, fifth paragraph 249 Variation: Note (e) was previously eliminated in Amendment 236 but not updated in the Bases. The deletion updates the Bases to the approved change in Amendment 236.

N/A N/A LCO 3.6.2 and SR 4.6.2, Protective Instrumentation, Bases for 3.6.2 and 4.6.2, Protective Instrumentation, second paragraph 249 This corrects the Bases to reflect the addition of Note (k) added for the implementation of TSTF-542.

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 15 of 17 Docket No. 50-220

RAI 2

Section 2.2 of Attachment 1 to the LAR describes optional changes and variations.

However, there are other variations in the TS markup pages that are not listed. For those items not included in Section 2.2 of the LAR, please identify and explain all variations from TSTF-582, including:

a. Editorial or administrative variations (all numbering/wording that differs from TSTF-582 but does not change requirements)
b. Design variations (explain where Nine Mile Point 1's design does not match the design assumed in TSTF-582 and why it is applicable) c.

Technical variations (a requirement that differs from that in TSTF-582 or in the current Nine Mile Point 1 TS.)

Exelon Response to RAI 2a, 2b and 2c:

A complete list of administrative, design and technical variations are provided in the crosswalk table in response to RAI 1 above. The response to RAI 1 and RAI 2 supersedes, in its entirety, Section 2.2 in Reference 1.

RAI 3

In the LAR, a list of improvements from TSTF-582 was discussed on pages 2 and 3 of. For numbers 5 and 6, please provide more detail of the proposed changes to Nine Mile Point 1 TS and how they compare to what is stated in TSTF-582.

Exelon Response to RAI 3:

In reference 1, six TS changes were listed. The following description of numbers 5 and 6 supersede in their entirety the description provided in Reference 1:

5.

TS 3.2.7d, 3.2.7e, and 3.2.7f are deleted. These specifications have been deleted from the Reactor Coolant Isolation Valve specification to remove Refuel and Shutdown-Cold (Mode 4 and 5 requirements in accordance with the TSTF-582 markups for TS 3.6.1.3 G and H). The Primary Containment Isolation Valve (PCIV) specification will now be limited to Startup and Run (Modes 1, 2, & 3 in TSTF-582 for PCIVs 3.6.1.3). The actions for inoperable PCIV penetration in Shutdown-Cold and Refuel (Modes 4 & 5 in TSTF-582) are now controlled by the WIC Instrumentation specification which then requires implementation of the actions within WIC specification 3.1.9 where applicable for associated drain time calculation, which recognizes the loss of the PCIV penetration

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 16 of 17 Docket No. 50-220 for automatic isolation capability. This change is not worded exactly but fulfills the same function as defined in the TSTF.

6.

The NMP1 TS are revised to follow the formatting of the custom TS which NMP1 is licensed. The proposed changes are made with the effort to follow the TSTF as closely as reasonable. Variations to the TSTF wording are identified in the response to RAI 1 above.

RAI 4

On Nine Mile Point 1 TS markup page 247c, please explain why "Manual" is a separate parameter from primary coolant isolation. Also, there are no annotations next to it like the other parameters. Which Table 3.6.2m notes apply to "Manual" when it is inoperable?

Exelon Response to RAI 4:

The separate Manual parameter is part of the original design for NMP1.

Upon further review, it is identified that the Manual parameter for the Primary Coolant Isolation function is not required for Shutdown Condition - Cold and Refuel Condition based on the applicability of the RPV WIC instrumentation required to be operable only when automatic isolation of the associated penetration flow path(s) are credited in calculating drain time.

Therefore, the Primary Coolant Isolation Manual parameter is being removed from Table 3.6.2m on TS page 247c and is in alignment with TSTF-582..

RAI 5

LAR appears to be missing information identified in TSTF-582. In the LAR, it appears that the equivalent for TSTF-582 STS 3.3.5.2 Action A is proposed TS 3.6.2m Table Note (c) which states:

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.

Please explain the apparent discrepancy between TSTF-582 STS 3.3.5.2 and proposed TS 3.6.2m Table Note (c). Additionally, correct or provide technical justification for this variation from TSTF-582.

Exelon Response to RAI 5:

New Note (c) has been revised to modify the LCO requirement for Shutdown Cooling and Reactor Water Cleanup Isolation instrumentation. This change incorporates the TSTF-582 LCO action to place the inoperable channel(s) in the tripped condition in accordance with TSTF-582 3.3.5.2.A Actions. Added the action to take the action required by specification 3.6.2a for that

Response to Request for Additional Information Adopt TSTF-582, Revision 0 Page 17 of 17 Docket No. 50-220 parameter to require evaluation and potential actions of WIC Specification 3.1.9 based on calculated drain time. The wording of the LCO requirement has been changed to match the wording within NMP1 Custom TS for Instrumentation Specification 3.6.2.

The response to RAI 5 and attached markup supersede, in its entirety, the markup of Note (c) in Reference 1.

ATTACHMENT 2 Nine Mile Point Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-63 NRC Docket No. 50-220 Technical Specification Marked Up Pages 8a 79a 79b 79c 109 247b 247c 247d 247f Total 9 pages

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:

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 -10 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 closed and administratively controlled

3.1.9 LIMITING CONDITION FOR OPERATION Reactor Pressure Vessel (RPV) Water Inventory Control Applicability:

Applies to the operating status of the core spray systems and Reactor Water Inventory Control when the reactor coolant temperature is less than or equal to 212°F.

Objective:

To assure the RPV water inventory is maintained -10 inches indicator scale.

Specification:

a.

Whenever irradiated fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F, drain time of RPV water inventory to

-10 inches indicator scale shall be ~36 hours and one core spray subsystem shall be operable except as specified in Specifications b through f below.

b.

If the required core spray subsystem becomes inoperable, the component shall be returned to an operable condition within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

c.

If Specifications a and b are not met, then immediately initiate action to establish a method of water injection capable of operating without offsite electrical power.

AMENDMENT NO, 236 4.1.9 SURVEILLANCE REQUIREMENT Reactor Pressure Vessel (RPV) Water Inventory Control Applicability:

Applies to the periodic testing requirements for the core spray system and RPV water inventory.

Objective:

To verify the operability of the core spray system and RPV water inventory.

Specification:

a.

Verify drain time ~36 hours in accordance with the Surveillance Frequency Control Program.

b.

Verify, for a required core spray subsystem, the downcomers in the suppression chamber have greater than or equal to three and one half foot of submergence or the condensate storage tank inventory is not less than 300,000 gallons, in accordance with the Surveillance Frequency Control Program.

c.

Verify for the required core spray subsystem, each manual power operated and automatic 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.

79a

LIMITING CONDITION FOR OPERATION

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 /> perform the following actions:

(1) Verify secondary containment boundary is capable of being established in less than the drain time, and (2) Verify each secondary containment penetration flow path is capable of being isolated in less than the drain time, 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, and (3) Initiate action to isolate each secondary containment penetration flow path or verify it can be manually isolated from the control room, and (4) Initiate action to verify one RBEVS is capable of being placed in operation.

AMENDMENT NO. 236 SURVEILLANCE REQUIREMENT

d.

Verify each valve credited for automatically isolating a penetration flow path actuates to the isolation position on an actual or simulated isolation signal, in accordance with the Surveillance Frequency Control Program.

e.

Verify the required core spray subsystem can be manually operated, in accordance with the Surveillance Frequency Control Program. Vessel spray may be excluded.

79b c.

d.

Reactor Building Emergency Ventilation System (RBVES) circuit circuit automatically or

LIMITING CONDITION FOR OPERATION

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 SURVEILLANCE REQUIREMENT 79c d or e

LIMITING CONDITION FOR OPERATION

c.

If Specifications 3.2.7a and b above are not met, initiate normal orderly shutdown within one hour and have reactor in the cold shutdown condition within ten hours.

d.

Whenever fuel is in the reactor vessel and the reactor coolant temperature is less than or equal to 212°F, the isolation valves on the shutdown cooling system lines connected to the reactor coolant system shall be operable except as specified in Specification 3.2.7.e 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 SURVEILLANCE REQUIREMENT

c.

In accordance with the Surveillance Frequency Control Program the feedwater and main-steam line power-operated isolation valves shall be exercised by partial closure and subsequent reopening.

d.

In accordance with the INSERVICE TESTING PROGRAM the feedwater and main steam line power-operated isolation valves shall be fully closed and reopened.

109

TABLE 3.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Parameter Minimum No.

of Tripped or Operable Trip Systems OPEN CORE SPRAY DISCHARGE VALVES (1)

Reactor Pressure 2

AMENDMENT NO. 236 Limiting Condition for Operation Minimum No. of Operable Instrument Channels per Operable Trip System 1 (d)(e)

Set Point

365 psig Reactor Mode Switch Position in Which Function Must Be Operable c

~

Q.

0 a;

"Cl

I
s 1::
I -

nl

.c Cl) -

fl)

It:

fl)

(a)(b)

(a)(b) c

I It:

247b

TABLE 3.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Parameter Minimum No.

of Tripped or Operable Trip Systems PRIMARY COOLANT ISOLATION (2)

Low-Low Reactor Water Level (a) Cleanup 2

(b) Shutdown Cooling 2

(3)

Manual 2

AMENDMENT NO. ~. 239 Limiting Condition for Operation Minimum No. of Operable Instrument Channels per Operable Trip System 2(c) 2(c) 1 Set Point

~ 5 inches (Indicator Scale)

~ 5 inches (Indicator Scale)

Reactor Mode Switch Position in Which Function Must Be Operable c

r:

Q.

0 "C

Q)

s
s

~

c

s -

C'G

.c Q) -

s rn 0::

rn 0::

(a)

(a)

(a)

(a)

(a)

(a) 247c (1) 1(c) 1(c)

(b)

(b)

(b)

(b)

Parameter OPEN CORE SPRAY DISCHARGE VALVES (1)

Reactor Pressure AMENDMENT NO. 236 TABLE 4.6.2m RPV WATER INVENTORY CONTROL INSTRUMENTATION Sensor Check Surveillance Requirement Instrument Channel Test Note 1 Instrument Channel Calibration 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.

(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.

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

AMENDMENT NO. 236 247f With the number of Operable channels less than required by the Minimum Number of Operable Instrument Channels per Operable Trip System requirement, immediately either

1. Place the inoperable channel(s) in the trip condition, or
2. a. Declare associated penetration flow path(s) incapable of automatic isolation, and
b. Initiate action to calculate drain time, and
c. Take the Action required by Specification 3.6.2a for that parameter.

(c)

Insert new Note (c)

(b)

ATTACHMENT 3 Nine Mile Point Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-63 NRC Docket No. 50-220 Technical Specification Bases Marked Up Pages (for information only) 79d 79f 115 115a 248a 249 249a Total 7 pages

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.

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.

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.

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) 79d aligned and from the control room 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.

considered an (an event that creates a drain path through multiple vessel penetrations located below -10 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.

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.

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 or automatically or

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 procedurally controlled. Using the longest closure time on the main-steam-line valves following a main-steam-line break (Section XV-C.1.0)(1l, 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 prevent clad damage. Closure times are discussed in Section Vl-D.1.0<1l.

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.

(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

BASES FOR 3.6.2 AND 4.6.2 PROTECTIVE INSTRUMENTATION A double-ended guillotine break of the Reactor Coolant System (RCS) is not postulated in Shutdown Condition - Cold or Refuel Condition 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.

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 considered considered an both trip systems (one channel in each) in Shutdown Condition - Hot and in Shutdown Condition - Cold in accordance with 3.6.2m

BASES FOR 3.6.2 AND 4.6.2 PROTECTIVE INSTRUMENTATION Table 3.6.2.m, Notes (c) and (d) reflect the drain time requirements that penetration flow paths capable of being isolated by valves will close automatically when actuated by RPV water level isolation instrumentation. In the event that the associated instrumentation channels for Cleanup and/or Shutdown Cooling become inoperable, the requirements of Technical Specification 3.1.9.d thru 3.1.9.f are applicable to verify that RPV water level is maintained above -10 inches indicator scale.

Manual initiation is available for scram, reactor isolation and containment isolation. In order to manually initiate other systems, each pump and each valve is independently initiated from the control room. Containment spray raw water cooling is not automatically initiated.

Manual initiation of each pump is required as discussed in 3.3.7 above.

Revision 46 (A236) 249a Note (c) reflects