ML19052A142

Correction to License Amendment No. 198 Related to Adoption of TSTF-542, Reactor Pressure Vessel Water Inventory Control

ML19052A142
Person / Time
Site:	Monticello
Issue date:	03/11/2019
From:	Robert Kuntz Plant Licensing Branch III
To:	Church C Northern States Power Company, Minnesota
Kuntz R, 415-3733
References
EPID L-2017-LLA-0360
Download: ML19052A142 (5)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 March 11, 2019 Mr. Christopher Church Site Vice President Monticello Nuclear Generating Plant Northern States Power Company - Minnesota (NSPM) 2807 West County Road 75 Monticello, MN 55362-9637

SUBJECT:

MONTICELLO NUCLEAR GENERATING PLANT-CORRECTION TO LICENSE AMENDMENT NO. 198 RELATED TO ADOPTION OF TSTF-542, REACTOR PRESSURE VESSEL WATER INVENTORY CONTROL (EPID L-2017-LLA-0360)

Dear Mr. Church:

On October 29, 2018, the U.S. Nuclear Regulatory Commission (NRC) issued Amendment No. 198 to Facility Operating License No. DPR-22 for the Monticello Nuclear Generating Plant (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18250A075). The amendment revised the technical specification to adopt Technical Specification Task Force (TSTF} Travel 542, "Reactor Pressure Vessel Water Inventory Control," in response to Northern States Power Company, doing business as Xcel Energy (Xcel) request dated October 20, 2017 (ADAMS Accession No. ML17293A280), as supplemented by letters dated June 1, 2018 (ADAMS Accession No. ML18157A056), and September 11, 2018 (ADAMS Accession No. ML18254A046).

During Xcel's review of the amendment, it identified an error in the NRC staff's safety evaluation on page 26. In the safety evaluation, the following paragraph reads:

The NRC staff finds acceptable that the deletion of Functions 1.f and 2.f, CS/LPCI pump start time delay relay low reactor steam dome, bypass time channels. The Bypass Timer channels allow the CS and LPCI pumps to start on Reactor Vessel Water Level - Low Low after the time delay times out, even if the reactor steam dome pressure is above its permissive setpoint. NRC staff finds the deletion of the two Bypass Timer permissive functions consistent with TSTF-542 since they are no longer needed in Modes 4 and 5. These functions do not have an equivalent described in the STS. The purpose of these time delays is to provide sufficient time for the operator to inhibit any unnecessary automated data system actuation. The deletion of Function 1.f is further described under Variation 7, (Section 3.5. 7 of this SE).

The paragraph erroneously refers to the purpose of the time delays. The paragraph has been updated to delete the sentence describing the purpose of the delays.

C. Church The proposed correction does not change any of the conclusions in the safety evaluation associated with the amendment, and does not affect the associated notice to the public.

Enclosed, please find corrected safety evaluation page 26.

If you have any questions regarding this matter, I can be reached at (301) 415-3733 or Robert.Kuntz@nrc.gov.

Robe F. Kun , nior Project Manager Plant Licensing Branch Ill Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-263

Enclosure:

Corrected Page 26 to the Safety Evaluation cc: via ListServ

ENCLOSURE MONTICELLO NUCLEAR GENERATING PLANT FACILITY OPERATING LICENSE DPR-22 DOCKET NO. 50-263 AMENDMENT NO. 198 CORRECTED PAGE TO SAFETY EVALUATION

The NRC staff finds acceptable that the deletion of Functions 1.f and 2.f, CS/LPCI pump start-time delay relay low reactor steam dome, bypass time channels. The Bypass Timer channels allow the CS and LPCI pumps to start on Reactor Vessel Water Level - Low Low after the time delay times out, even if the reactor steam dome pressure is above its permissive setpoint. NRC staff finds the deletion of the two Bypass Timer permissive functions consistent with TSTF-542 since they are no longer needed in Modes 4 and 5. These functions do not have an equivalent described in the STS. The deletion of Function 1.f is further described under Variation 7, (Section 3.5.7 of this SE).

3.5 Staff Evaluation of Proposed Technical Variations The licensee proposed the following technical variations from the TS changes described in TSTF-542 or the applicable parts of the NRC staffs SE for TSTF-542. The licensee stated in the LAR that these variations do not affect the applicability of TSTF-542 or the NRC staffs SE for TSTF-542 to the proposed license amendment. The NRC staff evaluated each variation below.

3.5.1 Variation 1, Table 3.3.5.1-1, Core Spray Pump Discharge Flow - Low (Bypass)

NUREG-1433, Table 3.3.5.1-1, Function 1.d, Core Spray Pump Discharge Flow- Low (Bypass), is not included in the MNGP TSs. As a result, this function is not being included in TS 3.3.5.3, RPV WIC, Table 3.3.5.3-1.

In Reference 2, the licensee stated that each MNGP CS subsystem is equipped with a minimum flow bypass line that contains a restricting orifice and locked open manual isolation valve to ensure the pump will not overheat when the associated injection valve is not fully open. The minimum flow line contains no instrumentation or active components and continuously diverts a portion of the core spray pump discharge back to the drywell suppression pool regardless of reactor system pressure or position of the injection valve.

The NRC staff has determined that the above CS Function 1.d, Table 3.3.5.1-1, noted in STS, is not a function in the MNGP TS and is not included as part of the proposed TS changes the support TSTF-542. NRC staff reviewed the RAI response (Reference 2) which indicates there is adequate protection from pump overheating via the installed minimum flow bypass line that does not require instrumentation or active components; therefore, the NRC staff finds Variation 1 acceptable.

3.5.2 Variation 2, Table 3.3.5.1-1, Manual Initiation The MNGP TS, Table 3.3.5.1-1, ECCS system instrumentation, does not include functions for manual initiation of CS and LPCI. Since the TS does not include this feature, proposed Table 3.3.5.3-1 does not include manual initiation functions for CS and LPCI. In addition, TS Table 3.3.5.3-1 does not include a SR for a logic system functional test since it applies only to the manual initiation function.

As an alternative to NUREG-1433, SR 3.5.2.8, which demonstrates ECCS injection/spray actuation on a manual initiation signal, the licensee proposes that TS 3.5.2, RPV WIC, include a new SR 3.5.2.5 to verify the required CS or LPCI subsystem can be manually operated through the manipulation of the subsystem components from the control room. This alternative is justified by the fact that a draining event is a slow evolution when compared to a design basis

ML19052A142 OFFICE DORL/LPL3/PM DORL/LPL3/LA DORL/LPL3/BC DORL/LPL3/PM NAME RKuntz SRohrer DWrona RKuntz DATE 2/25/19 2/25/19 3/8/19 3/11/19