ML24215A201

LLC, Response to SDAA Audit Question Number A-16.3.3-1

ML24215A201
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Site:	05200050
Issue date:	08/02/2024
From:	NuScale
To:	Office of Nuclear Reactor Regulation
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Response to SDAA Audit Question Question Number: A-16.3.3-1 Receipt Date: 09/18/2023 Question:

Throughout the SDAA generic TS and Bases, when referring to MPS instrumentation Functions, be editorially consistent in capitalization (use title case) and use a non-breaking hyphen in names of Functions 9, 12, 16, 19, and 24; i.e., Low-Low.

9.a.

Low-Low Pressurizer Pressure RTS actuation 9.b.

Low-Low Pressurizer Pressure DWSI actuation 12.a. Low-Low Pressurizer Level CIS actuation 12.b. Low-Low Pressurizer Level CVCSI actuation 16.a. Low-Low RCS Flow RTS actuation 16.b. Low-Low RCS Flow DWSI actuation 19.a. Low-Low Main Steam Pressure RTS actuation 19.b. Low-Low Main Steam Pressure SSI actuation 19.c. Low-Low Main Steam Pressure DWSI actuation 23.a. Low Reactor Pressure Vessel Riser Level ECCS actuation 24.a. Low-Low RPV Riser Level ECCS actuation If the intended convention is actually to not use a hyphen in Low Low, be consistent; but recommend using a non-breaking space.

If the intended convention is actually to not use title case for Function name references, and to just use title case when the name is listed in a Section 3.3 Function table or is a discussion heading in the Bases, be consistent.

NuScale Nonproprietary NuScale Nonproprietary

Response

NuScale revises the bases to SDAA Technical Specification Section 3.3.1 to consistently specify Low Low without the use of a hyphen and to correct improper use of title case capitalization.

Markups of the affected changes, as described in the response, are provided below:

NuScale Nonproprietary NuScale Nonproprietary

MPS Instrumentation B 3.3.1 NuScale US460 B 3.3.1-14 Draft Revision 2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued) 5.

When the N-2H interlock is not active, the operating bypass is automatically removed for the following:

the High Power Range Positive Rate reactor trip; the High Power Range Positive Rate DWSI actuation; the High Power Range Negative Rate reactor trip; and the High Power Range Negative Rate DWSI actuation.

Reactor Tripped Interlock, RT-1 The Reactor Tripped Interlock, RT-1 is active when both divisional reactor trip breakers indicate open. The RT-1 interlock is required to be active for the ESFAS interlocks T-2, T-3, and L-1.

FWIV Closed Interlock, V-1 The FWIV Closed interlock, V-1 is active when one FWIV indicates closed.

1.

When the V-1 interlock is active, an automatic operating bypass is established for the Low Main Steam Superheat reactor trip.

2.

When the V-1 interlock and the T-3 interlock are active, or the containment level interlock, L-1, is active, an automatic operating bypass is established for the Low Low Main Steam Pressure Secondary System Isolation actuation.

3.

When the V-1 interlock or the L-1 interlock are active, the operating bypass is established for the Low Main Steam Superheat Secondary System Isolation actuation.

4.

When the V-1 interlock is not active, the operating bypass is automatically removed for the Low Main Steam Superheat reactor trip.

5.

When the V-1 interlock or the T-3 interlock are not active, and L-1 is not active, the operating bypass is automatically removed for the Low Low Main Steam Pressure Secondary System Isolation actuation.

MPS Instrumentation B 3.3.1 NuScale US460 B 3.3.1-15 Draft Revision 2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

Wide Range RCS Tcold Interlock, T-1 The Wide Range (WR) RCS Cold Temperature (Tcold) T-1 interlock is active when Wide Range Tcold is greater than approximately 290 °F.

When the T-1 interlock is active, an automatic operating bypass is established for the Low Temperature Overpressure Protection actuation.

When the T-1 interlock is not active, the operating bypass is automatically removed for the Low Temperature Overpressure Protection actuation.

Wide Range RCS Thot Interlock, T-2 The WR RCS Hot Temperature (Thot) T-2 interlock is active when WR RCS Thot is less than approximately 200 °F and RT-1 is active.

1. When the T-2 interlock is active, an automatic operating bypass is established for the Low Pressurizer Level trip for Secondary System Isolation actuation

2. When the T-2 interlock is active, an automatic operating bypass is established for the Low Low Pressurizer Level trip for the following:

CVCS Isolation actuation; and Containment System Isolation actuation.

3. When the T-2 interlock and containment level interlock, L-1, are not active, the operating bypass is automatically removed for the Low Pressurizer Level trip Secondary System Isolation actuation

4. When the T-2 interlock and containment level interlock, L-1, are not active, the operating bypass is automatically removed for the Low Low Pressurizer Level trip for the following:

CVCS Isolation actuation; and Containment System Isolation actuation.

Wide Range RCS Thot Interlock, T-3 The WR RCS Thot T-3 interlock is active when WR RCS Thot is less than approximately 340 °F.

MPS Instrumentation B 3.3.1 NuScale US460 B 3.3.1-16 Draft Revision 2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

1. When the T-3 interlock is active, an automatic operating bypass is established for the following:

Low Low Pressurizer Pressure Reactor Trip; High Narrow Range Containment Pressure trip for Secondary System Isolation actuation, Containment System Isolation actuation, DHRS actuation, CVCS Isolation actuation, and Pressurizer Heater trip; Low Pressurizer Pressure Pressurizer Line isolation actuation; and All Automatic Reactor Trip Signals for Demineralized Water System Isolation actuation.

2. When the T-3 interlock is not active, the operating bypass is automatically removed for the following:

Low Low Pressurizer Pressure Reactor Trip; High Narrow Range Containment Pressure for Secondary System Isolation actuation, Containment System Isolation actuation, DHRS actuation, CVCS Isolation actuation, and Pressurizer Heater trip; Low Pressurizer Pressure Pressurizer Line isolation actuation; and All Automatic Reactor Trip Signals for Demineralized Water System Isolation actuation.

Narrow Range RCS Thot Interlock, T-4 The Narrow Range RCS Thot T-4 interlock is active when Narrow Range RCS Thot is less than approximately 500 °F.

1. When the T-4 interlock is active, an automatic operating bypass is established for the following:

Low Pressurizer Pressure Reactor trip; Low Pressurizer Pressure DWSI actuation;

MPS Instrumentation B 3.3.1 NuScale US460 B 3.3.1-18 Draft Revision 2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

Containment Level Interlock, L-1 The Containment Level Interlock L-1 is active when Containment Level is greater than approximately 45 ft. and RT-1 is active.

1. When L-1 is active, an automatic operating bypass is established for the following:

Low Low Main Steam Pressure Secondary System Isolation actuation; Low Main Steam Superheat Secondary System Isolation actuation; Low Pressurizer Level Secondary System Isolation actuation; Low Low Pressurizer Level Chemical and Volume Control System Isolation actuation; and Low Low Pressurizer Level Containment System Isolation actuation.

2. When the L-1 interlock and the WR RCS Thot interlock, T-2, are not active, the operating bypass is automatically removed for the following:

Low Pressurizer Level Secondary System Isolation actuation; Low Low Pressurizer Level Containment System Isolation actuation; and Low Low Pressurizer Level Chemical and Volume Control System Isolation actuation.

3. When the L-1 interlock and the WR RCS Thot interlock, T-3, or the FWIV Closed interlock, V-1, are not active, the operating bypass is automatically removed for the Low Low Main Steam Pressure Secondary System Isolation actuation.

4. When the L-1 interlock and the FWIV Closed interlock, V-1, are not active, the operating bypass is automatically removed for the Low Main Steam Superheat Secondary System Isolation actuation.

MPS Instrumentation B 3.3.1 NuScale US460 B 3.3.1-43 Draft Revision 2 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

10. Reactor Pressure Vessel Riser Level Reactor Pressure Vessel (RPV) riser level is measured by four level sensors (one per separation group).

a. Low RPV Riser Level - ECCS Actuation (Table 3.3.1-1 Function 23.a)

The lLow RPV rRiser lLevel ECCS actuation protects against unintended changes in RCS inventory such as a LOCA when operating at RCS temperatures above the T-5 interlock. The Low RPV rRiser lLevel setpoint actuates ECCS upon riser uncovery.

Actual setpoints are established in accordance with the Setpoint Program.

Four lLow RPV Riser Level actuation channels are required to be OPERABLE when operating in MODES 1 and 2 with RCS temperature above the T-5 interlock. In MODES 1 and 2 below the T-5 interlock and MODE 3 when not PASSIVELY COOLED, the Low Low RPV Riser Level actuation ensures the ECCS actuation safety function will be performed. In MODE 3 when PASSIVELY COOLED, and in MODES 4 and 5, the function is fulfilled.

Four channels are provided to permit one channel in trip or bypass indefinitely and still ensure no single random failure will disable this trip Function.

b. Low Low RPV Riser Level - ECCS Actuation (Table 3.3.1-1 Function 24.a)

The lLow lLow RPV rRiser lLevel ECCS actuation protects against unintended changes in RCS inventory such as a LOCA. The lLow lLow RPV rRiser lLevel setpoint actuates ECCS before upper riser hole unncovery. Actual setpoints are established in accordance with the Setpoint Program.

Four lLow lLow RPV Riser Level actuation channels are required to be OPERABLE when operating in MODES 1 and 2, and in MODE 3 when not PASSIVELY COOLED. In MODES 1 and 2 and MODE 3 when not PASSIVELY COOLED, the Low Low RPV Riser Level actuation ensures the ECCS actuation safety function will be performed. In MODE 3 when PASSIVELY COOLED, and MODES 4 and 5, the function is fulfilled.