NMP2L2746, Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2

Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, Provide Risk- Informed Extended Completion Times - RITSTF Initiative 4b, Revision 2

ML20276A019
Person / Time
Site:	Nine Mile Point  (NPF-069)
Issue date:	10/02/2020
From:	David Gudger Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NMP2L2746
Download: ML20276A019 (11)

Text

200 Exelon Way Kennett Square, PA 19348 www.exeloncorp.com 10 CFR 50.90 NMP2L2746 October 2, 2020 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License No. NPF-69 NRC Docket No. 50-410

Subject:

Supplemental Information for Nine Mile Point Nuclear Station, Unit 2, to Adopt TSTF-505, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," Revision 2

References:

1. Letter from D. Gudger (Exelon Generation Company, LLC) to U.S.

Nuclear Regulatory Commission, "License Amendment Request to Revise Technical Specifications to Adopt Risk Informed Completion Times TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," dated October 31, 2019 (ML19304B653)

2. Letter from R. Guzman (Senior Project Manager, U.S. Nuclear Regulatory Commission ) to K. Langdon (Vice President Nine Mile Point Nuclear Station), "Nine Mile Point Nuclear Station, Unit 2-Issuance of Amendment Regarding Extension of Completion Time for an Inoperable Division 1 or Division 2 Diesel Generator (TAC No. ME3736)," dated October 31, 2011 By letter dated October 31, 2019 (Reference 1), Exelon Generation Company, LLC (Exelon) requested to change the Nine Mile Point Nuclear Station, Unit 2 (NMP2) Technical Specifications (TS). The proposed amendment would modify TS requirements to permit the use of Risk Informed Completion Times in accordance with TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b," (ADAMS Accession No. ML18183A493).

In Attachment 2 to Reference 1, Exelon provided a markup of the Completion Time for Required Action 3.8.1.B.4 on TS page 3.8.1-3. This markup removed a previously NRC approved TS change (Amendment 138 ML112299155) (Reference 2) pertaining to the 14-day Completion Time for restoring the required Division 1 or Division 2 Diesel Generator to operable status. This markup eliminated a NMP2 variation to TSTF-505, Revision 2. In Exelon Generation

U.S. Nuclear Regulatory Commission Supplemental Information TSTF-505, Risk-Informed Extended Completion Times October 2, 2020 Page 2 to Reference 1, Exelon provided the TS Bases markups for Required Action 3.8.1.B.4 on pages B 3.8.1-10 through B 3.8.1-13.

to this letter provides supplemental information identifying this change as a variation to TSTF-505, Revision 2. Attachment 2 provides the TS markup reflecting the revised change in the Completion Time on TS page 3.8.1-3. This revised change maintains the Completion Time approved by Amendment 138 for Required Action 3.8.1.B.4. In addition, Attachment 3 provides the applicable TS Bases pages are revised to reflect this supplemental information.

This variation is identified and justified in Attachment 1 to this letter. The supplemental information provided in Attachment 1 has no further impacts on other attachments or enclosures to Reference 1.

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 supplemental information provided in this letter does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration.

Furthermore, the supplemental information provided in this letter 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 2nd day of October 2020.

Respectfully, David T. Gudger Senior Manager - Licensing Exelon Generation Company, LLC Attachments: 1) Supplemental Information

2) Markup of TS Page

3) Markup of TS Bases Pages 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 2 Renewed Facility Operating License NPF-69 Docket No. 50-410 SUPPLEMENTAL INFORMATION

U.S. Nuclear Regulatory Commission Supplemental Information TSTF-505, Risk-Informed Extended Completion Times Docket No. 50-410 Page 1 of 1 Variation:

Technical Specification (TS) 3.8.1.B.4 - AC Sources Operating.

The TS Completion Time for TS 3.8.1.B.4 is a variation to TSTF-505, Revision 2. The Completion Time states 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from discovery of an inoperable Division 3 DG AND 14 days. This Completion Time was implemented as a result of Amendment 138 (ML112200155) dated October 31, 2011, which extended the Completion Time for an inoperable Division 1 or Division 2 Emergency Diesel Generator (EDG) from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days and 17 days from discovery of failure to meet LCO. The Second Completion Time of 17 days from discovery of failure to meet LCO was removed from this TS Completion Time as a result of Amendment 159 (ML16281A596) dated November 22, 2016. Therefore, this variation to TSTF-505, Revision 2, is justified through the implementation of Amendments 138 and 159.

Precedent:

Braidwood Station, Units 1 and 2, and Byron Station, Unit Nos. 1 and 2 - Issuance of Amendments Nos. 206, 206, 212, and 212, RE: Adoption of TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4B," dated March 30, 2020.

TS and TS Bases Markups The Risk Informed Completion Time is applied to Required Action 3.8.1.B.4 separately for the Division 3 EDG and the Division 1 and 2 EDGs as shown in the attached markup of TS page 3.8.1-3. Accordingly, the corresponding TS Bases pages are attached to reflect this change. The TS and TS Bases markups replace the markups provided in and Attachment 3, respectively, to the original submittal dated October 31, 2019 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML19304B653).

ATTACHMENT 2 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License NPF-69 Docket No. 50-410 SUPPLEMENTAL INFORMATION Markup of TS Page 3.8.1-3

ACTIONS CONDITION B.

(continued)

NMP2 REQUIRED ACTION 8.2 Declare required feature(s), supported by the inoperable DG, inoperable when the redundant required feature(s) are inoperable.

AND B.3.1 Determine OPERABLE DG(s) are not inoperable due to common cause failure.

OR B.3.2 Perform SR 3.8.1.2 for OPERABLE DG(s).

AND B.4 Restore required DG to OPERABLE status.

OR AC Sources - Operating 3.8.1 COMPLETION TIME 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from discovery of Condition B concurrent with inoperability of redundant required feature(s) 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 24 hours 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> from discovery of an inoperable Division 3 DG In accordance with L/

P1AND the Risk Informed Completion Time 14 days Program blf

/

V (continued)

OR In accordance with the Risk Informed Completion Time Program 3.8.1-3 Amendment 91, 138, 159

ATTACHMENT 3 Nine Mile Point Nuclear Station, Unit 2 Renewed Facility Operating License NPF-69 Docket No. 50-410 SUPPLEMENTAL INFORMATION Markup of TS Bases Pages (for information only)

B 3.8.1-10 through B 3.8.1-13

BASES ACTIONS Alternatively, a Completion Time can be determined in accordance with the Risk Informed Completion Time Program.

NMP2 AC Sources - Operating B 3.8.1 B.2 (continued) required feature. Additionally, the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, reasonable time for repairs, and low probability of a OBA occurring during this period.

B.3.1 and B.3.2 Required Action B.3.1 provides an allowance to avoid unnecessary testing of OPERABLE DGs. If it can be determined that the cause of the inoperable DG does not exist on the OPERABLE DG(s}, SR 3.8.1.2 does not have to be performed. If the cause of inoperability exists on other DGs, the other DGs are declared inoperable upon discovery, and Condition E or G of LCO 3.8.1 is entered, as applicable.

Once the failure is repaired, and the common cause failure no longer exists, Required Action B.3.1 is satisfied. If the cause of the initial inoperable DG cannot be confirmed not to exist on the remaining DG(s), performance of SR 3.8.1.2 suffices to provide assurance of continued OPERABILITY of those DG(s).

In the event the inoperable DG is restored to OPERABLE status prior to completing either B.3.1 or B.3.2, the Deficiency Event Report Program will continue to evaluate the common cause possibility. This continued evaluation, however, is no longer under the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> constraint imposed while in Condition B.

According to Generic Letter 84-15 (Ref. 9), 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonable time to confirm that the OPERABLE DG(s) are not affected by the same problem as the inoperable DG.

In Condition B, the remaining OPERABLE DGs and offsite circuits are adequate to supply electrical power to the onsite Class 1 E distribution system. Although Condition B applies to a single inoperable DG, several Completion Times are specified for this Condition.

The first Completion Time applies to an inoperable Division 3 DG.

The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time takes into account the capacity and capability of the remaining AC sources, a reasonable time for repairs, and the low probability of a OBA occurring during this period...._

(continued)

B 3.8.1-10 Revision 0, 35 (A 138)

BASES ACTIONS NMP2 B.4 (continued)

AC Sources - Operating B 3.8.1 This Completion Time begins only "upon discovery of an inoperable Division 3 DG" and, as such, provides an exception to the normal "time zero" for beginning the allowed outage time "clock" (i.e., for beginning the clock for an inoperable Division 3 DG when Condition B may have already been entered for another equipment inoperability and is still in effect).

The second Completion Time (14 days) applies to an inoperable Division 1 or Division 2 DG and is a risk-informed Completion Time based on a plant-specific risk analysis. The extended Completion Time would typically be used for voluntary planned maintenance or inspections but can also be used for corrective maintenance.

However, use of the extended Completion Time for voluntary planned maintenance should be limited to once within an operating cycle (24 months) for each DG (Division 1 and Division 2). When utilizing an extended DG Completion Time (greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and up to 14 days), the compensatory measures and configuration risk management controls listed below shall be implemented. For planned maintenance utilizing an extended Completion Time, these measures and controls shall be implemented prior to entering Condition B. For an unplanned entry into an extended Completion Time, these measures and controls shall be implemented without delay.

a.

The other two DGs are operable and no planned maintenance or testing activities are scheduled on those two DGs.

b.

No planned maintenance or testing activities are scheduled in Scriba Substation, the NMP2 115 kV switchyard, or on the 115 kV power supply lines and transformers which could cause a line outage or challenge offsite power availability.

c.

The HPCS system is operable and no planned maintenance or testing actiVities are scheduled.

d.

The RCIC system is operable and no planned maintenance or testing activities are scheduled.

e.

The NMP2 and Nine Mile Point Unit 1 (NMP1) diesel-driven fire pumps and the cross-tie between the NMP2 and NMP1 fire protection water supply systems are available to provide a backup cooling water supply to the Division 3 DG and no planned maintenance or testing activities are scheduled.

(continued)

B 3.8.1-11 Revision 0, 35 (A 138)

BASES ACTIONS NMP2 B.4 (continued)

AC Sources - Operating 8 3.8.1

f.

The Division 1 and Division 2 Residual Heat Removal (RHR) pumps and the LPCS pump are operable and no planned maintenance or testing activities are scheduled.

g.

Both divisions of the redundant reactivity control system and the standby liquid control system (equipment required for mitigation of Anticipated Transients Without Scram (ATWS) events) are operable and no planned maintenance or testing activities are scheduled.

h.

The stability of existing and projected grid conditions will be confirmed prior to planned entry into the extended DG Completion Time by contacting the Transmission System Operator (TSO).

i.

Operating crews will be briefed on the DG work plan. As a minimum, the briefing will include the important procedural actions that could be required in the event a loss of offsite power, station blackout, or fire condition occurs.

j.

The extended DG Completion Time will not be entered for planned maintenance if severe weather conditions (high winds, tornado, or heavy snow/ice) with the potential to degrade or limit offsite power availability are present, or if official weather forecasts are predicting such conditions to occur.

k.

Except for the room housing the inoperable DG, no hot work permits will be active for the control building or the normal switchgear rooms.

I.

A portable generator is available as a temporary backup source of AC power to one of the Division 1 or Division 2 battery chargers and is pre-staged within the protected area near the NMP2 control building.

m.

Four portable power supplies are available for use to facilitate operation of safety relief valves to maintain reactor coolant system pressure control for an extended station blackout condition and are verified to be functional.

If one or more of the above measures and controls are not met while in the extended Completion Time, enter the condition into the corrective action program, follow applicable Required Actions, manage the risk in accordance with the configuration risk management program, and initiate actions to restore the measure(s) or control(s) without delay.

(continued) 8 3.8.1-12 Revision G, 35 (A 138)

BASES ACTIONS NMP2 AC Sources - Operating B 3.8.1 B.4 (continued)

Similar to Required Action B.2, the Completion Time of Required Action B.4 allows for an exception to the normal "time zero" for beginning the allowed outage time "clock."

This exception results in establishing the "time zero" at the time the LCO was initially not met, instead of the time Condition B was entered.

Alternatively, a Completion Time can be determined in accordance with c.1 and c.2 the Risk Informed Completion Time Program.

Required Action C.1 addresses actions to be taken in the event of concurrent failure of redundant required features.

Required Action C.1 reduces the vulnerability to a loss of function. The Completion Time for taking these actions is reduced to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> from that allowed with only one division without offsite power (Required Action A.2). The rationale for the reduction to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is that Regulatory Guide 1.93 (Ref. 8) allows a Completion Time of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for two required offsite circuits inoperable, based upon the assumption that two complete safety divisions are OPERABLE.

When a concurrent redundant required feature failure exists, this assumption is not the case, and a shorter Completion Time of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is appropriate. These features are designed with redundant safety related divisions (i.e.,

(continued)

B3.8.1-13 Revision 0, 35 (J\\138), 50 (A159)