ML19080A218

Request for Additional Information Monticello License Amendment Request to Remove Note TS LCO 3.5.1

ML19080A218
Person / Time
Site:	Monticello
Issue date:	03/21/2019
From:	Robert Kuntz Plant Licensing Branch III
To:	Loeffler R Northern States Power Co
References
Download: ML19080A218 (3)

Text

NRR-DMPSPEm Resource From: Kuntz, Robert Sent: Thursday, March 21, 2019 10:46 AM To: Loeffler, Richard A.

Subject:

Request for additional information RE: Monticello license amendment request to remove note TS LCO 3.5.1 Mr. Loeffler, By letter dated November 12, 2018 (ADAMS Accession No. ML18317A172), pursuant to Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR 50.90), the Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (NSPM, or the licensee), submitted a license amendment request (LAR) for Monticello Nuclear Generating Plant (MNGP). The LAR proposes to delete a note associated with the Limiting Condition for Operation (LCO) 3.5.1 of Technical Specification (TS) Section 3.5.1, "ECCS

[Emergency Core Cooling System] - Operating." The NRC staff has determined that additional information is required for it to complete its review. During a clarification call held March 21, 2019 a 30 day response is expected. Therefore a response is expected by April 21, 2019. If a response cannot be provided by April 21, 2019 contact me to discuss.

Robert Kuntz Senior Project Manager (DC Cook, Monticello, and Prairie Island)

NRC/NRR/DORL/LPL3 (301)415-3733 REQUEST FOR ADDITIONAL INFORMATION DELETION OF THE NOTE ASSOCIATED WITH TECHNICAL SPECIFICATION 3.5.1 FOR MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 By letter dated November 12, 2018 (ADAMS Accession No. ML18317A172), pursuant to Section 50.90 of Title 10 of the Code of Federal Regulations (10 CFR 50.90), the Northern States Power Company, a Minnesota corporation, doing business as Xcel Energy (NSPM, or the licensee), submitted a license amendment request (LAR) for Monticello Nuclear Generating Plant (MNGP). The LAR proposes to delete the following note associated with the Limiting Condition for Operation (LCO) 3.5.1 of Technical Specification (TS) Section 3.5.1, "ECCS [Emergency Core Cooling System] - Operating":

Low pressure coolant injection (LPCI) subsystems may be considered OPERABLE during alignment and operation for decay heat removal with reactor steam dome pressure less than the Residual Heat Removal (RHR) shutdown cooling supply isolation interlock in MODE 3, if capable of being manually realigned and not otherwise inoperable.

In order to complete its review, the Nuclear Regulatory Commission (NRC) staff requests responses to the following request for additional information (RAI).

RAI Regulatory Basis:

1

AEC Proposed General Design Criterion (GDC) 6, Reactor Core Design (Category A), states:

The reactor core shall be designed to function throughout its design lifetime, without exceeding acceptable fuel damage limits which have been stipulated and justified. The core design, together with reliable process and decay heat removal systems, shall provide for this capability under all expected conditions of normal operation with appropriate margins for uncertainties and for transient situations which can be anticipated, including the effects of the loss of power to recirculation pumps, tripping out of a turbine generator set, isolation of the reactor from its primary heat sink, and loss of off-site power.

The corresponding 10 CFR 50, Appendix A, GDC Criterion 34, Residual heat removal, states in part:

A system to remove residual heat shall be provided. The system safety function shall be to transfer fission product decay heat and other residual heat from the reactor core at a rate such that specified acceptable fuel design limits and the design conditions of the reactor coolant pressure boundary are not exceeded.

Background

Updated Safety Analysis Report (USAR) Section 10.2.4.3 states:

The reactor shutdown cooling system is placed into operation during a normal plant cooldown when reactor dome pressure is below 81.8 psig. Operation of this portion of the RHR system for shutdown cooling does not compromise the ability of the RHR system to operate in the low pressure coolant injection system (LPCI) mode. During shutdown, the probability of requiring LPCI operation is very low. However, if LPCI operation is required, the operator can manually terminate shutdown cooling and start LPCI operation from the main control room.

The LAR states that:

NSPM does not have an analysis to demonstrate that realignment of an RHR subsystem from SDC to the LPCI mode does not result in thermal-hydraulic transients which could potentially challenge the system under certain scenarios during realignment to the LPCI for injection.

The Bases for TS 3.5.1, under the title APPLICABILITY, states:

All ECCS subsystems are required to be OPERABLE during MODES 1, 2, and 3, when there is considerable energy in the reactor core and core cooling would be required to prevent fuel damage in the event of a break in the primary system piping. In MODES 2 and 3, when reactor steam dome pressure is 150 psig, ADS [Automatic Depressurization System] and HPCI [High Pressure Coolant Injection] are not required to be OPERABLE because the low pressure ECCS subsystems can provide sufficient flow below this pressure.

Request The last sentence in USAR Section 10.2.4.3 states that, However, if LPCI operation is required, the operator can manually terminate shutdown cooling and start LPCI operation from the main control room. The USAR statement allows for the realigning of SDC to the LPCI mode, however the LAR states that NSPM does not have an analysis that supports this realignment and hence the change proposed in the LAR. Clarify if alignment to LPCI would still be permitted and describe any changes to plant operation based on the proposed amendment.

2

Hearing Identifier: NRR_DMPS Email Number: 876 Mail Envelope Properties (Robert.Kuntz@nrc.gov20190321104500)

Subject:

Request for additional information RE: Monticello license amendment request to remove note TS LCO 3.5.1 Sent Date: 3/21/2019 10:45:50 AM Received Date: 3/21/2019 10:45:00 AM From: Kuntz, Robert Created By: Robert.Kuntz@nrc.gov Recipients:

"Loeffler, Richard A." <Rick.Loeffler@xenuclear.com>

Tracking Status: None Post Office:

Files Size Date & Time MESSAGE 5480 3/21/2019 10:45:00 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received: