ML19210D734

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LLC Supplemental Response to NRC Request for Additional Information No. 520 (Erai No. 9642) on the NuScale Design Certification Application
ML19210D734
Person / Time
Site: NuScale
Issue date: 07/29/2019
From: Rad Z
NuScale
To:
Document Control Desk, Office of New Reactors
References
RAIO-0719-66472
Download: ML19210D734 (32)
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RAIO-0719-66472 July 29, 2019 Docket No.52-048 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738

SUBJECT:

NuScale Power, LLC Supplemental Response to NRC Request for Additional Information No. 520 (eRAI No. 9642) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 520 (eRAI No. 9642)," dated March 20, 2019
2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 520 (eRAI No.9642)," dated May 16, 2019 The purpose of this letter is to provide the NuScale Power, LLC (NuScale) supplemental response to the referenced NRC Request for Additional Information (RAI).

The Enclosure to this letter contains NuScale's supplemental response to the following RAI Question from NRC eRAI No. 9642:

16-65 This letter and the enclosed response make no new regulatory commitments and no revisions to any existing regulatory commitments.

If you have any questions on this response, please contact Rebecca Norris at 541-602-1260 or at rnorris@nuscalepower.com.

Sincerely, Zackary W. Rad Director, Regulatory Affairs NuScale Power, LLC Distribution: Gregory Cranston, NRC, OWFN-8H12 Samuel Lee, NRC, OWFN-8H12 Getachew Tesfaye, NRC, OWFN-8H12 : NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9642 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0719-66472 :

NuScale Supplemental Response to NRC Request for Additional Information eRAI No. 9642 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9642 Date of RAI Issue: 03/20/2019 NRC Question No.: 16-65 Paragraph (a)(11) of 10 CFR 52.47 and paragraph (a)(30) of 10 CFR 52.79 state that a design certification (DC) applicant and a combined license (COL) applicant, respectively, are to propose technical specifications (TS) prepared in accordance with 10 CFR 50.36 and 50.36a.

10 CFR 50.36 sets forth requirements for TS to be included as part of the operating license for a nuclear power facility.

The following observations are a followup to the response to RAI 506-9614, Question 16-50.

In Revision 2 of DCA Part 4, the applicant revised Section 1.1 by omitting the RTS and ESF response time definitions and defined terms; the applicant also revised the Section 3.3 response time Surveillances and associated Bases, which are quoted below. In these quotations, underlined and lined-through text indicate staff recommended additional editorial corrections to the Surveillance statements and associated Bases. Following the quoted material for each SR, the staff has provided its observations about shaded text. The applicant is requested to address each of the observations below.:

SR 3.3.1.3 Verify channel required response time is within limits. l 24 months The Bases for SR 3.3.1.3 state:

This SR 3.3.1.3 verifies that the individual channel actuation response times are less than or equal to the maximum values assumed in the accident analysis. The channel actuation response time is the time from when the process variable exceeds its setpoint until the output from the channel analog logic reaches the input of the MPS NuScale Nonproprietary

digital logic. Response time testing criteria are included in FSAR Chapter 7.

Channel response time may be verified by any series of sequential, overlapping or total channel measurements, including allocated sensor response time, such that the channel response time is verified. Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications. ...

Observations on SR 3.3.1.3 and associated Bases:

1. The word required is unnecessary in the Surveillance statement.
2. In the Bases phrase, channel actuation response time, the word actuation is unnecessary and inconsistent with SR 3.3.1.3, which uses the phrase channel response time.
3. The phrase accident analysis is used in the Bases for SR 3.3.1.3, but the phrase safety analysis is used in the corresponding similar sentences in the Bases for SR 3.3.2.2 and SR 3.3.3.2. This appears to be inconsistent.
4. In the Bases, consider modifying the reference FSAR Chapter 7 to say FSAR Section 7.2 (Ref. 1).
5. The channel response time verified by SR 3.3.1.3 appears to span the channels process sensor to the channels output from the analog to digital converter, and excludes the comparison of the digital signal with the channel trip setpoint in the SFM.

SER Section 7.2 gives the staffs evaluation of the digital response time verification testing.

6. When channel response time is meant, the Bases should use the full phrase for clarity, not just response time, which is more general. Consider discussing the overlappingcomponent response times in an MPS instrument channel (e.g., sensor response time is already called out).
7. Regarding allocated MPS instrument channel component response times, the last NuScale Nonproprietary

sentence of the definitions of the W-AP1000-STS defined terms RTS Response Time and ESF Response Time states:

In lieu of measurement, response time may be verified for selected components provided that the components and methodology for verification have been peviously reviewed and approved by the NRC.

Unless the staff has previously reviewed and approved the components and methodology for response time verification [by allocation] as a part of the NuScale DCA review, as documented in SER Chapter 7, the above quoted SR 3.3.1.3 Bases statement, Allocations for sensor response times may be obtained from records of test results, vendor test data, or vendor engineering specifications. may need to be designated as a COL action item.

SR 3.3.2.2 Verify required response time is within limits. l 24 months The Bases for SR 3.3.2.2 state:

This SR ensures that the response times of the two RTS divisions are verified to be less than or equal to the maximum values assumed in the safety analysis. Individual component response times are not modeled in the analyses. The analyses model the overall or total elapsed time, from the point at which the process variable exceeds the trip setpoint value at the sensor to the time at which the [reactor trip breakers (RTBs)]

open. Total response time may be verified by any series of sequential, overlapping, or total channel measurements.

... The maximum digital time response is described in the FSAR. This SR encompasses the response time of the RTS division from the output of the equipment interface modules until the RTBs are open. ...

Observations on SR 3.3.2.2 and associated Bases:

NuScale Nonproprietary

1. The word required is unnecessary in the Surveillance statement.
2. The phrase accident analysis is used in the Bases for SR 3.3.1.3, but the phrase safety analysis is used in the corresponding similar sentences in the Bases for SR 3.3.2.2 and SR 3.3.3.2. This appears to be inconsistent.
3. In the Bases, consider modifying the reference to FSAR to say FSAR Section 7.2 (Ref. 1).
4. Consider whether it would be more accurate to say total division measurements in place of total channel measurements.
5. The RTS division response time verified by SR 3.3.2.2, appears to span the analog output of the RTS EIM to the divisions two RTBs, and excludes verification of the digital time response, which appears to span the components from receipt of the digital process signal, to the setpoint comparison in the SFM, through the SVM, and through the priority logic of the RTS EIM. SER Section 7.2 gives the staffs evaluation of the digital response time verification testing.
6. Consider discussing in the Bases the overlapping digital component response times in an RTS division and how maximum digital time response is verified.

SR 3.3.3.2 Verify required pressurizer heater breaker response time is within limits. l 24 months The Bases for SR 3.3.3.2 state:

This SR ensures that the pressurizer heater breaker opening response times are verified to be less than or equal to the maximum values assumed in the safety analysis. Individual component response times are not modeled in the analyses. The analyses model the overall or total elapsed time, from the point at which the process variable exceeds the trip setpoint value at the sensor to the time at which the ESF NuScale Nonproprietary

component actuates. Total response time may be verified by any series of sequential, overlapping, or total channel measurements.

Response times of the sensors are tested in accordance with LCO 3.3.1 , MPS Instrumentation. The maximum digital time response is described in the FSAR. This SR encompasses the response time of the ESFAS from the output of the equipment interface modules to the loss of voltage at the output of the pressurizer heater breaker.

The response time of valves actuated by the ESFAS are verified in accordance with the IST program, and LCO 3.4.6, "Chemical and Volume Control System Isolation Valves," LCO 3.4.10, "LTOP Valves," LCO 3.5.1, "ECCS," LCO 3.5.2, "DHRS," LCO 3.6.2, "Containment Isolation Valves," LCO 3.7.1, "MSIVs," and LCO 3.7.2, "Feedwater Isolation."

Observations on SR 3.3.3.2 and associated Bases:

1. The word required is unnecessary in the Surveillance statement.
2. The phrase accident analysis is used in the Bases for SR 3.3.1.3, but the phrase safety analysis is used in the corresponding similar sentences in the Bases for SR 3.3.2.2 and SR 3.3.3.2. This appears to be inconsistent.
3. In the Bases, consider modifying the reference to FSAR to say FSAR Section 7.2 (Ref. 1).
4. Consider whether it would be more accurate to say total division measurements in place of total channel measurements.
5. The ESFAS division response time verified by SR 3.3.3.2, appears to span the analog output of the pressurizer heater breaker EIM to the divisions two pressurizer heater breakers, and excludes verification of the digital time response, which appears to span the components from receipt of the digital process signal, to the setpoint comparison in the SFM, through the SVM, and through the priority logic of the pressurizer heater breaker EIM. Also excluded is the digital portion of the ESFAS division for the other ESF Logic and Actuation functions. See SER Section 7.2 for the staffs evaluation of the digital response time verification testing.

NuScale Nonproprietary

6. Consider discussing in the Bases the overlapping digital component response times in an ESFAS division and how maximum digital time response is verified.
7. Consider clarifying in the Bases for the following SRs for Inservice Testing Program ESFAS valve actuations (The Frequency of In accordance with the Inservice Testing Program is taken to mean 24 months for these SRs.) that the valve "isolation (or

'closure') time" or "open actuation time" (the time to stroke closed or stroke open, respectively) is included in the ESF Function's overall response time. Also, the word "required" is not needed because it is redundant to "within limits.":

SR 3.4.6.2 Verify the required isolation time of each automatic power operated CVCS valve is within limits.

SR 3.4.10.2 Verify the open actuation time of each RVV is within limits.

SR 3.5.1.2 Verify the open actuation time of each RVV and RRV is within limits.

SR 3.5.2.4 Verify the open actuation time of each DHRS actuation valve is within limits.

SR 3.6.2.3 Verify the isolation time of each automatic containment isolation valve is within limits except for valves that are open under administrative controls.

Note that the staff is tracking the exception to SR 3.6.2.3 as an open item under RAI 197-9051 (ML17237C008), Question 16-28, which is described in SER Section 16.4.8.5, Proposed exceptions to meeting certain surveillances for isolation valves and circuit breakers.

SR 3.7.1.2 Verify isolation time of each MSIV and MSIV bypass valve is within limits on an actual or simulated actuation signal.

NuScale Nonproprietary

SR 3.7.2.2 Verify the closure time of each FWIV and FWRV is within limits on an actual or simulated actuation signal.

BACKGROUND DISCUSSION ENGINEERED SAFETY FEATURE (ESF) RESPONSE TIME In Revision 1 of DCA Part 4, GTS Section 1.1, Definitions, included the W-STS definition of ESF RESPONSE TIME with changes related to the NuScale designs lack of ESF pumps and Class 1E diesel generators, as indicated in the following mark up of the W-STS definition:

The ESF RESPONSE TIME shall be that time interval from when the monitored parameter exceeds its actuation setpoint at the channel sensor until the ESF equipment is capable of performing its safety function (i.e., the valves travel to their required positions, pump discharge pressures reach their required values, etc.). Times shall include diesel generator starting and sequence loading delays, where applicable.

The response time may be measured by means of any series of sequential, overlapping, or total steps so that the entire response time is measured. In lieu of measurement, response time may be verified for selected components provided that the components and methodology for verification have been previously reviewed and approved by the NRC.

Because these changes resulted in an ESF RESPONSE TIME definition appropriate for the NuScale design, the staff considered the changes acceptable. However, in Revision 1 of DCA Part 4, Section 3.3, Instrumentation, did not use the ESF RESPONSE TIME defined term, but did use the RTS RESPONSE TIME defined term, even though Section 1.1 did not include its definition. Section 3.3 stated the response time Surveillances as follows:

SR 3.3.1.3 Verify channel RESPONSE TIME is within limits. l 24 months SR 3.3.2.2 Verify RTS RESPONSE TIME is within limits. l 24 months SR 3.3.3.2 Verify required RESPONSE TIME is within limits. l 24 months NuScale Nonproprietary

In RAI 506-9614 (ML18289A751), Question 16-50, the staff requested that the applicant provide justification for not including response time defined terms and their definitions in GTS Section 1.1, and in response time SRs in Section 3.3. In its response (ML18347A619) to RAI 506-9614, Question 16-50, the applicant explained in detail the reasons the STS response time definitions are not suitable for the NuScale instrumentation design, and how the response time for the digital signal processing is verified during factory acceptance testing of the MPS as described in associated inspections, tests, analyses, and acceptance criteria listed in [Revision 2 of DCA Part 2,] Tier 1, Table 2.5-7 of the FSAR. The response also stated:

The self-testing features of the design will notify operators of failures that could impact system function, however degradation of the system response time cannot occur. An OPERABLE MPS has a defined digital response time that does not change and does not require further verification.

Pending completion of its review of the applicants response, the staff is tracking the omission of the response time definitions and the adequacy of the proposed response time verification Surveillances as an open item under RAI 506-9614, Question 16-50. The staff is tracking the completion of the disposition of the above observations under this RAI question.

NuScale Response:

Supplemental NRC Clarification Question Discussed During Public Meeting on July 24, 2019 The proposed [response time] definitions do not explicitly require measurement of the response time from sensor to actuated component because they leave out the assumed (or allocated) time for MPS digital logic processing. This must be explicitly specified in the SRs somehow because the proposed definitions do not address entire response time. The Bases do not clearly explain how the entire response time is verified. But, just adding more explanation in the Bases is not sufficient, because the essential content of each STS response time definition is to verify the entire RT and ESF actuation response time --- from monitored variable value reaching the sensor Functions nominal setpoint until the end device completes repositioning to its actuated position.

NuScale Nonproprietary

Supplemental Response A definition for TOTAL RESPONSE TIME was added to the proposed technical specifications.

Response time testing Surveillance Requirements and the associated Bases were modified to address the staff comments as discussed in the meeting.

Impact on DCA:

The Technical Specifications have been been revised as described in the response above and as shown in the markup provided in this response.

NuScale Nonproprietary

Definitions 1.1 1.1 Definitions SHUTDOWN MARGIN (SDM) SDM shall be the instantaneous amount of reactivity by which the reactor is subcritical or would be subcritical from its present condition assuming:

a. Moderator temperature is 420 °F; and
b. All control rod assemblies (CRAs) are fully inserted except for the single CRAassembly of highest reactivity worth, which is assumed to be fully withdrawn.

However, with all CRAs verified fully inserted by two independent means, it is not necessary to account for a stuck CRA in the SDM calculation. With any CRA(s) not capable of being fully inserted, the reactivity worth of these affected CRAassemblies must be accounted for in the determination of SDM.

THERMAL POWER THERMAL POWER shall be the total reactor core heat transfer rate to the reactor coolant.

TOTAL RESPONSE TIME TOTAL RESPONSE TIME is the sum of the CHANNEL RESPONSE TIME, the allocated MPS digital time response, and the ACTUATION RESPONSE TIME. The TOTAL RESPONSE TIME is the time interval from when the monitored parameter exceeds its actuation setpoint at the channel sensor until the actuated component is capable of performing its safety function (i.e., the valves travel to their required positions, breakers are open, etc.)

NuScale 1.1-6 Draft Revision 3.0

MPS Instrumentation 3.3.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.3.1.2 -------------------------------NOTES---------------------------

1. Adjust Neutron Monitoring System (NMS) nuclear instrument channel when absolute difference is

> 1% RTP.

2. Not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reaching 15% RTP.
3. If the calorimetric heat balance is < 50% RTP, and if NMS nuclear instrumentation channel indicated power is:
a. lower than the calorimetric measurement by

> 1%, then adjust the NMS nuclear instrumentation channel upward to match the calorimetric measurement.

b. higher than the calorimetric measurement, then no adjustment is required.

Compare results of calorimetric heat balance to NMS In accordance with nuclear instrument channel output. the Surveillance Frequency Control Program SR 3.3.1.3 -------------------------------NOTE-----------------------------

Neutron detectors are excluded from response time testing.

Verify channel required response timeCHANNEL In accordance with RESPONSE TIME is within limits. The CHANNEL the Surveillance RESPONSE TIME is combined with the allocated Frequency Control MPS digital time response and the ACTUATION Program RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

NuScale 3.3.1-6 Draft Revision 3.0

Reactor Trip System Logic and Actuation 3.3.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.2.1 NOTE Not required to be met for reactor trip breakers that are open.

Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program SR 3.3.2.2 NOTE Not required to be met for reactor trip breakers that are open.

Verify requiredACTUATION RESPONSE TIME In accordance with response time is within limits. The ACTUATION the Surveillance RESPONSE TIME is combined with the allocated Frequency Control MPS digital time response and the CHANNEL Program RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.3.2.3 NOTE Not required to be met for Class 1E isolation devices that have isolated 1E circuits from non 1E power.

Perform CHANNEL CALIBRATION on each In accordance with Class 1E isolation device.Verify associated Class 1E the Surveillance isolation devices are OPERABLE. Frequency Control Program SR 3.3.2.4 NOTE Not required to be met for reactor trip breakers that are open.

Verify each RTB actuates to the open position on an In accordance with actual or simulated actuation signal. the Surveillance Frequency Control Program NuScale 3.3.2-2 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME G. As required by Required G.1 ----------------NOTE--------------

Action B.1 and Heater(s) may be referenced in energizedPressurizer heater Table 3.3.3-1. breakers may be closed intermittently under manual OR administrative controls.

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Both divisions of Pressurizer Heater trip Open pressurizer heater actuationde energization breakers.De energize fFunction inoperable. Pressurizer Heaters.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.3.1 Perform ACTUATION LOGIC TEST. In accordance with the Surveillance Frequency Control Program SR 3.3.3.2 NOTE Not required to be met for pressurizer heater breakers that are open or closed under manual control.

Verify required pressurizer heater breaker response In accordance with timeACTUATION RESPONSE TIME is within limits. the Surveillance The ACTUATION RESPONSE TIME is combined Frequency Control with the allocated MPS digital time response and the Program CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

NuScale 3.3.3-4 Draft Revision 3.0

Chemical and Volume Control System Isolation Valves 3.4.6 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.4.6.1 Verify [required] valves accumulator pressures are In accordance with within limits. the Surveillance Frequency Control Program.

SR 3.4.6.2 NOTE Not required to be met for valves that are closed or open under administrative controls.

Verify the required isolation timeACTUATION In accordance with RESPONSE TIME of each automatic power operated the INSERVICE CVCS valve is within limits. The ACTUATION TESTING RESPONSE TIME is combined with the allocated PROGRAM MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.4.6.3 Verify each automatic CVCS valve that is not locked, In accordance with sealed, or otherwise secured in position, actuates to the Surveillance the isolation position on an actual or simulated Frequency Control actuation signal except for valves that are open under Program administrative controls.

NuScale 3.4.6-3 Draft Revision 3.0

LTOP Valves 3.4.10 SURVEILLANCE REQUIREMENTS NOTE Not required to be met for valves that are open.

SURVEILLANCE FREQUENCY SR 3.4.10.1 Verify each RVV actuates to the open position on an In accordance with actual or simulated actuation signal. the Surveillance Frequency Control Program SR 3.4.10.2 Verify the open actuation timeACTUATION In accordance with RESPONSE TIME of each RVV is within limits. The the INSERVICE ACTUATION RESPONSE TIME is combined with the TESTING allocated MPS digital time response and the PROGRAM CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.4.10.3 Verify the inadvertent actuation block function for In accordance with each RVV. the Surveillance Frequency Control Program SR 3.4.10.4 Verify the inadvertent actuation block setpoint is In accordance with within limits for each RVV. the INSERVICE TESTING PROGRAM NuScale 3.4.10-2 Draft Revision 3.0

ECCS 3.5.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 NOTE Not required to be met for valves that are open.

Verify each RVV and RRV actuates to the open In accordance with position on an actual or simulated actuation signal. the Surveillance Frequency Control Program SR 3.5.1.2 NOTE Not required to be met for valves that are open.

Verify the open actuation timeACTUATION In accordance with RESPONSE TIME of each RVV and RRV is within the INSERVICE limits. The ACTUATION RESPONSE TIME is TESTING combined with the allocated MPS digital time PROGRAM response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.5.1.3 Verify the inadvertent actuation block function of each In accordance with RVV and RRV. the Surveillance Frequency Control Program SR 3.5.1.4 Verify the inadvertent actuation block setpoint is In accordance with within limits for each RVV and RRV. the INSERVICE TESTING PROGRAM NuScale 3.5.1-2 Draft Revision 3.0

DHRS 3.5.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.2.1 Verify [required] valves accumulator pressures are In accordance with within limits. the Surveillance Frequency Control Program SR 3.5.2.2 Verify DHRS heat exchangersloops are filled. In accordance with the Surveillance Frequency Control Program SR 3.5.2.3 -------------------------------NOTE--------------------------------

Not required to be performed for DHRS loop with associated FWIV open.

Verify SG level is > [5]% and [65]% In accordance with the Surveillance Frequency Control Program SR 3.5.2.43 Verify that each DHRS actuation valve actuates to In accordance with the open position on an actual or simulated actuation the Surveillance signal. Frequency Control Program SR 3.5.2.54 Verify the open actuation timeACTUATION In accordance with RESPONSE TIME of each DHRS actuation valve is the INSERVICE within limits. The ACTUATION RESPONSE TIME is TESTING combined with the allocated MPS digital time PROGRAM response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

NuScale 3.5.2-2 Draft Revision 3.0

Containment Isolation Valves 3.6.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.2.1 Verify [required] valves accumulator pressures are In accordance with within limits. the Surveillance Frequency Control Program SR 3.6.2.2 ---------------------------------NOTE------------------------------

Valves and blind flanges in high radiation areas may be verified by use of administrative means.

Verify each containment isolation manual valve and In accordance with blind flange that is located outside containment and the Surveillance not locked, sealed, or otherwise secured and is Frequency Control required to be closed during accident conditions is Program closed, except for containment isolation valves that are open under administrative controls.

SR 3.6.2.3 Verify the isolation timeACTUATION RESPONSE In accordance with TIME of each automatic containment isolation valve the INSERVICE is within limits except for valves that are open under TESTING administrative controls. The ACTUATION PROGRAM RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.6.2.4 Verify each automatic containment isolation valve In accordance with that is not locked, sealed, or otherwise secured in the Surveillance position, actuates to the isolation position on an Frequency Control actual or simulated actuation signal except for valves Program that are open under administrative controls.

SR 3.6.2.5 Verify the combined leakage rate for all containment In accordance with bypass leakage paths is 0.6 La when pressurized the Containment to 951 psia. Leakage Rate Testing Program NuScale 3.6.2-3 Draft Revision 3.0

MSIVs 3.7.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.1.1 Verify [required] valves accumulator pressures are In accordance with within limits. the Surveillance Frequency Control Program SR 3.7.1.2 Verify isolation timeACTUATION RESPONSE TIME In accordance with of each MSIV and MSIV bypass valve is within the INSERVICE limits on an actual or simulated actuation signal. TESTING The ACTUATION RESPONSE TIME is combined PROGRAM with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.7.1.3 Verify each MSIV and MSIV bypass valve leakage In accordance with is within limits. the INSERVICE TESTING PROGRAM NuScale 3.7.1-3 Draft Revision 3.0

Feedwater Isolation 3.7.2 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.7.2.1 Verify [required] FWIV accumulator pressures are In accordance with within limits. the Surveillance Frequency Control Program.

SR 3.7.2.2 Verify the closure timeACTUATION RESPONSE In accordance with TIME of each FWIV and FWRV is within limits on the INSERVICE an actual or simulated actuation signal. The TESTING ACTUATION RESPONSE TIME is combined with PROGRAM the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME.

SR 3.7.2.3 Verify each FWIV and FWRV leakage is within In accordance with limits. the INSERVICE TESTING PROGRAM NuScale 3.7.2-3 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.1.2 A periodic calibration (heat balance) is performed when THERMAL POWER is above 15%. The Linear Power Level signal and the nuclear instrumentation system addressable constant multipliers are adjusted to make the nuclear power calculations agree with the calorimetric calculation if the absolute difference is 1%. The value of 1% is adequate because this value is assumed in the safety analysis. These checks (and, if necessary, the adjustment of the nuclear power signal) are adequate to ensure that the accuracy is maintained within the analyzed error margins.

The power level must be above 15% RTP to obtain accurate data. At lower power levels, the accuracy of calorimetric data is questionable.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

The Surveillance is modified by three Notes. The first Note indicates that the neutron monitoring system nuclear instrument channel must must be calibrated when the absolute difference is > 1% when compared to the calorimetric heat balance. The second Note indicates that this Surveillance need only be performed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reaching 15%

RTP. The 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after reaching 15% RTP is required for unit stabilization, data taking, and flow verification. The secondary calorimetric is inaccurate at lower power levels. A third Note is provided that permits operation below 15% RTP without adjusting the instrument channel as long as the indicated nuclear instrument power is conservatively higher than the calorimetric heat balance results. This third Note is an exception to the first Note and only applies when below 15% RTP.

SR 3.3.1.3 This SR 3.3.1.3 measuresverifies that the individual channel actuation response timesCHANNEL RESPONSE TIMES. are less than or equal to the maximum values assumed in the accident analysis. The channel actuation response time is the time from when the process variable exceeds its setpoint until the output from the channel analog logic reaches the input of the MPS digital logic.The CHANNEL RESPONSE TIME is combined with the allocated MPS digital time response and the ACTUATION RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. Response time testing criteria are included in FSAR Chapter 7.

NuScale B 3.3.1-59 Draft Revision 3.0

RTS Logic and Actuation B 3.3.2 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.2.2 This SR measuresensures that the ACTUATION RESPONSE TIMEresponse time of the RTS divisions are verified to be less than or equal to the maximum values assumed in the safety analysis. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. Individual component response times are not modeled in the analyses. The analyses model the overall or total elapsed time, from the point at which the process variable exceeds the trip setpoint value at the sensor to the time at which the RTBs open. Total TOTAL RESPONSE TIMEresponse time may be verified by any series of sequential, overlapping, or total divisionchannel measurements.

Response times of the sensorsCHANNEL RESPONSE TIMES are tested in accordance with LCO 3.3.1. The maximum digital time response is described in the FSAR. This SR encompasses the ACTUATION RESPONSE TIMEresponse time of the RTS division from the output of the equipment interface modules until the RTBs are open.

A note provides an allowance for the SR so that it does not need to be met for reactor trip breakers that are open. This allowance permits continued operation when a trip breaker may not be able to satisfy the requirements of the SR but is already open. When a reactor trip breaker is open it has performed its safety function.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

NuScale B 3.3.2-5 Draft Revision 3.0

ESFAS Logic and Actuation B 3.3.3 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.3.2 This SR measuresensures that the pressurizer heater breaker opening response timesACTUATION RESPONSE TIMES. are verified to be less than or equal to the maximum values assumed in the safety analysis. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. Individual component response times are not modeled in the analyses. The analyses model the overall or total elapsed time, from the point at which the process variable exceeds the trip setpoint value at the sensor to the time at which ESF component actuates. Total response timeTOTAL RESPONSE TIME may be verified by any series of sequential, overlapping, or total divisionchannel measurements.

Response times of the sensorsCHANNEL RESPONSE TIMES are tested in accordance with LCO 3.3.1. The maximum digital time response is described in the FSAR. This SR encompasses the response time of the ESFAS from the output of the equipment interface modules to the loss of voltage at the output of the pressurizer heater breaker.

The response timeACTUATION RESPONSE TIME of valves actuated by the ESFAS are verified in accordance with the IST program, and LCO 3.4.6, "Chemical and Volume Control System Isolation Valves," LCO 3.4.10, "LTOP Valves," LCO 3.5.1, "ECCS," LCO 3.5.2, "DHRS," LCO 3.6.2, "Containment Isolation Valves," LCO 3.7.1, "MSIVs," and LCO 3.7.2, "Feedwater Isolation."

A note provides an allowance for the SR so that it does not need to be met for pressurizer heater breakers that are open in their actuated position. This allowance permits continued operation when a pressurizer heater trip breaker is open because it has performed its safety function.

The note also allows intermittent closure of the breakers under manual control when the SR is not met because the slowly occurring nature of the phenomena the automatic heater trip breakers mitigate.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

NuScale B 3.3.3-11 Draft Revision 3.0

CVCS Isolation Valves B 3.4.6 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.6.2 Verifying that the isolation ACTUATION RESPONSE TIMEtime of each automatic power operated CVCS isolation valve is within limits is required to demonstrate OPERABILITY. The isolation time test ensures that the valve will isolate in a time period less than or equal to that assumed in the safety analysis.The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. Isolation time is measured from output of the module protection system equipment interface module until the valves are isolated.

A Note is provided that indicates that the SR is not required to be met when valves are closed or open under administrative controls. This is acceptable because of the slowly occurring nature of the design basis events the CVCS isolation function mitigates. The Surveillance Frequency of this SR is in accordance with the INSERVICE TESTING PROGRAM.

SR 3.4.6.3 This Surveillance demonstrates that each automatic CVCS isolation valve actuates to the isolated position on an actual or simulated actuation signal. This Surveillance is not required for valves that are locked sealed, or otherwise secured in the isolated position under administrative controls. The actuation logic is tested as part of Engineered Safety Features Actuation System Actuation and Logic testing. An exception to the SR is provided for valves that are opened under administrative controls. This is acceptable because of the slowly occurring nature of the design basis events the CVCS isolation function mitigates.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. FSAR Chapter 15, Transient and Accident Analysis.

NuScale B 3.4.6-5 Draft Revision 3.0

LTOP Valves B 3.4.10 BASES ACTIONS (continued)

B.1 and B.2 With two closed RVVs inoperable, overpressurization is possible. Four hours to restore the closed RVV to OPERABILITY or open the RVV permits evaluation of the condition and completion of the action required to assure an LTOP condition cannot occur in a deliberate manner. The RCS vent to the containment atmosphere with two RVVs open prevents an overpressure condition from occurring.

C.1 and C.2 With three closed inoperable RVVs the RCS does not have overpressure protection. The Completion Time considers the urgency of removing the RCS from this condition, the time required to place the plant in this Condition in an orderly manner without challenging plant systems, and the relatively low probability of an overpressure event during this time period.

SURVEILLANCE A Note is provided to indicate that the surveillance requirements are not REQUIREMENTS required to be met for valves that are open. This merely clarifies the intent of the surveillance testing applicability and is consistent with the LCO requirement that each closed RVV be OPERABLE.

SR 3.4.10.1, SR 3.4.10.2, SR 3.4.10.3, and SR 3.4.10.4 The ability of the RVVs to perform their LTOP safety function requires the same testing as required for them to perform their ECCS function. The bases for these surveillance requirements are the same as those specified in LCO 3.5.1, Emergency Core Cooling System however they only apply to the RVVs.

Actuation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are open. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis.

In addition to verification that the valves will perform as designed, the inadvertent actuation block must be verified to function at a setpoint that will not prevent LTOP actuation if needed.

NuScale B 3.4.10-5 Draft Revision 3.0

ECCS B 3.5.1 BASES SURVEILLANCE SR 3.5.1.1 REQUIREMENTS Verification that the RVVs and RRVs are OPERABLE by stroking the valves open ensures that each train of ECCS will function as designed when these valves are actuated. One RVV is designed to be actuated by either division of the MPS and it must be verified to open from each division without dependence on the other. The RVVs and RRVs safety function is to open as described in the safety analysis. A Note is provided indicating that the SR is not required to be met for a valve that is open. This Note is necessary to allow a valve to be credited with performing its safety function when it may not be able to satisfy the SR requirements. When an ECCS valve is open it has performed its safety function.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.5.1.2 Verifying that the open actuation timeACTUATION RESPONSE TIME of each RVV and RRV is within limits is required to demonstrate OPERABILITY. The open actuation time test ensures that the valve will open in a time period less than or equal to that assumed in the safety analysis. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. The opening times are as specified in the INSERVICE TESTING PROGRAM. One RVV is designed to be actuated by either division of the MPS and its actuation time must be tested from each division without dependence on the other.

Actuation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are open.

A Note is provided indicating that the SR is not required to be met for a valve that is open. This Note is necessary to allow a valve to be credited with performing its safety function when it may not be able to satisfy the SR requirements. When an ECCS valve is open it has performed its safety function.

Frequency of this SR is in accordance with the INSERVICE TESTING PROGRAM.

NuScale B 3.5.1-6 Draft Revision 3.0

DHRS B 3.5.2 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.5.2.54 Verifying that the open actuation timeACTUATION RESPONSE TIME of each DHRS actuation valve is within limits is required to demonstrate OPERABILITY. The open actuation time test ensures that the valve will open in a time period less than or equal to that assumed in the safety analysis. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. The opening times are as specified in the INSERVICE TESTING PROGRAM. Each looptrain of DHRS contains two actuation valves, one actuated from each division of the MPS ESFAS actuation logic.

Actuation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are open.

Frequency of this SR is in accordance with the INSERVICE TESTING PROGRAM.

REFERENCES 1. FSAR Section 5.4, "Reactor Coolant System Component and Subsystem Design."

2. FSAR Section 10.3, "Main Steam System."
23. FSAR Chapter 15, Transient and Accident Analysis.

NuScale B 3.5.2-8 Draft Revision 3.0

Containment Isolation Valves B 3.6.2 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.2.3 Verifying that the isolation timeACTUATION RESPONSE TIME of each automatic containment isolation valve is within the limits is required to demonstrate OPERABILITY. The isolation time test ensures the valve will isolate in a time period less than or equal to that assumed in the safety analysis. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis. Isolation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are isolated.

An exception to the SR is provided for valves that are open under administrative control.

The isolation time and Frequency of this SR are in accordance with the INSERVICE TESTING PROGRAM.

SR 3.6.2.4 Automatic containment isolation valves close on a containment isolation signal to minimize leakage of fission products from containment and to maintain required RCS inventory following a DBA. This SR ensures each automatic containment isolation valve will actuate to its isolation position on an actual or simulated actuation signal. The Surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. An exception to the SR is also provided for valves that are open under administrative control.

The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

NuScale B 3.6.2-7 Draft Revision 3.0

MSIVs B 3.7.1 BASES SURVEILLANCE SR 3.7.1.1 REQUREMENTS This SR [applies to valves with actuators that incorporate pressurized accumulators as a source of stored energy. The SR] verifies adequate pressure in the accumulators required for MSIV and main steam line bypass isolation valve OPERABILITY. The pressure limits required for OPERABILITY, including consideration of temperature effects on those limits, applicable to the valve accumulators are established and maintained in accordance with the INSERVICE TESTING PROGRAM.

The Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.7.1.2 This SR measuresverifies the safety related and non-safety related MSIV and MSIV Bypass Valve closure timesACTUATION RESPONSE TIMES are within limits on an actual or simulated actuation signal. Isolation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are isolated. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis.

The isolation time is assumed in the accident and containment analyses.

The MSIVs and MSIV Bypass Valves are not tested at power to reduce the likelihood of an unplanned transient due to valve closure when the unit is generating power. As the MSIVs are not tested at power, they are exempt from the ASME OM Code (Ref. 6) requirements during operation in MODES 1 and 2.

The Frequency is in accordance with the INSERVICE TESTING PROGRAM.

This test is typically conducted during shutdown conditions or with the unit at reduced operating temperatures and pressures before their OPERABILITY is required by the Applicability of this LCO.

NuScale B 3.7.1-12 Draft Revision 3.0

Feedwater Isolation B 3.7.2 BASES ACTIONS (continued) and deactivated automatic valve, closed manual valve, or blind flange. An inoperable FWIV/FWRV may be utilized to isolate the line only if its leak tightness has not been compromised. This action returns the system to a condition in which at least one valve in the affected flow path is performing the required safety function. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is a reasonable amount of time to complete the actions required to close the FWIV, or FWRV, which includes performing a controlled unit shutdown without challenging plant systems.

D.1, and D.2 If the FWIVs and FWRVs cannot be restored to OPERABLE status, or closed, or isolated within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 2 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, in MODE 3 and PASSIVELY COOLED within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, to reach the required unit conditions from full power conditions in an orderly manner.

SURVEILLANCE SR 3.7.2.1 REQUIREMENTS This SR [applies to valves with actuators that incorporate pressurized accumulators as a source of stored energy. The SR] verifies adequate pressure in the accumulators required for feedwater isolation valve OPERABILITY. The pressure limits required for OPERABILITY, including consideration of temperature effects on those limits, applicable to the valve accumulators are established and maintained in accordance with the INSERVICE TESTING PROGRAM. The Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.7.2.2 This SR measuresverifies that the closure timeACTUATION RESPONSE TIME of each FWIV and FWRV is within limits, on an actual or simulated actuation signal. Isolation timeACTUATION RESPONSE TIME is measured from output of the module protection system equipment interface module until the valves are isolated. The ACTUATION RESPONSE TIME is combined with the allocated MPS digital time response and the CHANNEL RESPONSE TIME to determine and verify the TOTAL RESPONSE TIME is less than or equal to the maximum values assumed in the safety analysis.

NuScale B 3.7.2-4 Draft Revision 3.0

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