Text

LLC Response to NRC Request for Additional Information No. 512 (Erai No. 9634) on the NuScale Design Certification Application
	ML19056A587
Person / Time
Site:	NuScale
Issue date:	02/25/2019
From:	Rad Z; NuScale
To:	; Document Control Desk, Office of New Reactors
References
	RAIO-0219-64635
	Download: ML19056A587 (88)
	v • d • e

RAIO-0219-64635 February 25, 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 Response to NRC Request for Additional Information No.

512 (eRAI No. 9634) on the NuScale Design Certification Application

REFERENCES:

1. U.S. Nuclear Regulatory Commission, "Request for Additional Information No. 512 (eRAI No. 9634)," dated November 29, 2018

2. NuScale Power, LLC Response to NRC "Request for Additional Information No. 512 (eRAI No.9634)," dated January 10, 2019

3. NuScale Power, LLC Response to NRC "Request for Additional Information No. 512 (eRAI No.9634)," dated January 16, 2019

4. NuScale Power, LLC Response to NRC "Request for Additional Information No. 512 (eRAI No.9634)," dated January 29, 2019 The purpose of this letter is to provide the NuScale Power, LLC (NuScale) response to the referenced NRC Request for Additional Information (RAI).

The Enclosure to this letter contains NuScale's response to the following RAI Questions from NRC eRAI No. 9634:

16-60-45 16-60-60 16-60-65 16-60-66 16-60-75 16-60-76 16-60-79 16-60-80 16-60-81 16-60-82 Other portions of the NuScale response to question 16-60 were previously provided is References 2, 3, and 4.

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

NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

RAIO-0219-64635 If you have any questions on this response, please contact Carrie Fosaaen at 541-452-7126 or at cfosaaen@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 : eRAI No. 9634, Question 16 Cross-Reference Table : NuScale Response to NRC Request for Additional Information eRAI No. 9634 NuScale Power, LLC 1100 NE Circle Blvd., Suite 200 Corvalis, Oregon 97330, Office: 541.360.0500, Fax: 541.207.3928 www.nuscalepower.com

Attachment 1:

RAIO-0219-64635 eRAI No. 9634, Question 16-60 02/25/2019 Cross-Reference Table Page 1 of 3 NuScale NRC RAI Sub-Tracking paragraph NuScale Letter Submittal Letter Number Number No. Date Accession Number 16-60-1 1 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-2 2 pending 16-60-3 3 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-4 4 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-5 5 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-6 6 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-7 7 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-8 8 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-9 9 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-10 10 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-11 11 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-12 12 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-13 13 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-14 14 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-15 15 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-16 16 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-17 17 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-18 18 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-19 18 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-20 19 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-21 20 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-22 21 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-23 22 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-24 23 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-25 24 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-26 25 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-27 26 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-28 27 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-29 28 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-30 29 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-31 29 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-32 29 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-33 30 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-34 30 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-35 31 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-36 32 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-37 33 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-38 34 RAIO-0119-64111 January 10, 2019 ML19010A409

Attachment 1:

RAIO-0219-64635 eRAI No. 9634, Question 16-60 02/25/2019 Cross-Reference Table Page 2 of 3 NuScale NRC RAI Sub-Tracking paragraph NuScale Letter Submittal Letter Number Number No. Date Accession Number 16-60-39 35 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-40 36 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-41 37.1 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-42 37.2 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-43 37.3 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-44 38 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-45 39 RAIO-0219-64635 February 25, 2019 pending 16-60-46 40 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-47 41 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-48 42 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-49 43 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-50 44 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-51 45 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-52 Tracking number 16-60-52 not used 16-60-53 46 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-54 47 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-55 48 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-56 49 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-57 50 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-58 51 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-59 52 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-60 53 RAIO-0219-64635 February 25, 2019 pending 16-60-61 54 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-62 55 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-63 55 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-64 56, 57, 58 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-65 59 RAIO-0219-64635 February 25, 2019 pending 16-60-66 60 RAIO-0219-64635 February 25, 2019 pending 16-60-67 61 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-68 62 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-69 63 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-70 64 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-71 65 RAIO-0119-64178 January 16, 2019 ML19016A374 16-60-72 66 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-73 67 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-74 68 RAIO-0119-64111 January 10, 2019 ML19010A409 16-60-75 69 (i - iv) RAIO-0219-64635 February 25, 2019 pending 16-60-76 69 (v) RAIO-0219-64635 February 25, 2019 pending 16-60-77 70 pending

Attachment 1:

RAIO-0219-64635 eRAI No. 9634, Question 16-60 02/25/2019 Cross-Reference Table Page 3 of 3 NuScale NRC RAI Sub-Tracking paragraph NuScale Letter Submittal Letter Number Number No. Date Accession Number 16-60-78 71 RAIO-0119-64281 January 29, 2019 ML19029B572 16-60-79 72 RAIO-0219-64635 February 25, 2019 pending 16-60-80 73 RAIO-0219-64635 February 25, 2019 pending 16-60-81 74 RAIO-0219-64635 February 25, 2019 pending 16-60-82 75 RAIO-0219-64635 February 25, 2019 pending

RAIO-0219-64635 :

NuScale Response to NRC Request for Additional Information eRAI No. 9634 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.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-45

39. In Revision 2 of DCA part 4, on GTS page 3.4.1-2, SR 3.4.1.2 says "Verify RCS cold temperature is less than or equal to the limit specified in the COLR." However, on Bases page B 3.4.1-4, the basis for SR 3.4.1.2 begins, "This surveillance demonstrates that the average RCS temperature remains less than or equal to the limit specified in the COLR. Also notice that LCO 3.4.1.b and Condition A refer to RCS cold temperature limits. The applicant is requested to reconcile these statements. Also, in Revision 2 of DCA part 4, Required Action C.1 of Subsection 3.4.1 should state "Be in MODE 2."; and not "Be in Mode 2."

In the November 6, 2018, public meeting conference call with NuScale, the staff acknowledged that the June 12, 2018, response to RAI 457-9501, Question 15-12, discussed the relationship between RCS average temperature and RCS cold temperature, as follows:

... Core flow is a function of thermal power, given the flow resistance of the reactor coolant system (RCS) and the elevation difference between the core and the steam generators that provide the heat sink. FSAR Table 5.1-2, "Primary System Temperatures and Flow Rates,"

lists the nominal operating parameters of the RCS at various power levels, including primary flow and RCS temperatures.

LCO 3.4.2, "RCS Minimum Temperature for Criticality," establishes the minimum temperature at which thermal energy may be generated in the reactor core. Critical operations will begin at approximately 425ºF, with the average RCS temperature rising to approximately 543ºF, and then remaining constant from about 15% of rated thermal power (RTP) to full power.

In this design with a constant average RCS temperature above 15% RTP, the RCS hot and cold temperatures vary as a function of reactor power. This is illustrated in FSAR Table 5.1-NuScale Nonproprietary

2 by the core delta-T column. By specifying the average RCS temperature (Tavg), the reactor power, and the RCS flow resistance, the RCS maximum and minimum temperatures are established. LCO 3.4.1 establishes a cycle-specific, COLR- defined limit on RCS cold temperature that includes consideration of the initial conditions in the Chapter 15 analyses.

Based on these physical relationships and the methodology used to establish the limits in the COLR, LCO 3.4.1 will protect the RCS pressure ranges and average RCS temperature shown in Table 15.0-6 for all design basis events, including LOCA, non- LOCA, and peak containment pressure analyses....

Despite the above explanation, SR 3.4.1.2 still says "Verify RCS cold temperature is less than or equal to the limit specified in the COLR."

For a given thermal power, and best estimate flow, Revision 2 of DCA part 2, FSAR Table 5.1-2, "Primary System Temperatures and Flow Rates," lists percent of rated thermal power (RTP) (100% = 160 MWt); percent mass flow (100% = 587.0 Kg/s); and cold, average, and hot RCS temperatures. For thermal power at or above 15% RTP, average temperature is kept constant at 543.3 °F, and the corresponding cold and hot RCS temperatures are listed as 496.6

°F and 590.1 °F, respectively.

Revision 2 of DCA part 2, FSAR Table 15.0-6, "Module Initial Conditions Ranges for Design Basis Event Evaluation," lists the variation in these parameters' initial values assumed in the design basis event safety analyses:

Thermal Power 102% RTP RCS mass flow at 100% RTP 535-670 kg/s (mid-range value 602.5 kg/s)

RCS average temperature 535-555 °F (at normal operating conditions 545 °F)

The applicant is still requested to explain why the Bases for SR 3.4.1.2 still refers to verifying average RCS temperature being less than or equal to the limit specified in the COLR.

Also, please explain how the RCS cold, average, and hot temperature limits will be presented in the COLR. Please revise the Bases to clarify how this Surveillance verifies Tavg is within COLR limits by verifying Tcold is within COLR limits.

NuScale Nonproprietary

NuScale Response:

The Bases of SR 3.4.1.2 have been revised to indicate that the minimum RCS cold temperature is verified to be within its limit. FSAR Tier 2, section 4.4.3.2 and Figure 4.4-9 provides a illustration of the relationships between the temperatures.

The core operating limits report will be developed by the COL applicant as required by COL Action Item 16.1-1. The presentation of limits may be tabular, graphical, or in other form. The form of presentation will be defined at that time.

See also the supplemental response to RAI 15-12 provided January 11, 2019 (ML19011A310).

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

RCS Pressure, Temperature, and Flow Resistance CHF Limits B 3.4.1 BASES APPLICABLE SAFETY ANALYSES (continued)

The NSP2 and NSP4 correlation limits are used for comparison to conditions representative of normal operation, operational transients, anticipated operational occurrences, and accidents other than events that are initiated by rapid reductions in primary system inventory. The Hench-Levy correlation is used to evaluate events for which analyses postulate a rapid reduction in primary system inventory. An assumption for the analysis of these events is that the core power distribution is within the limits of LCO 3.1.6, Regulating GroupBank Insertion Limits; LCO 3.2.1, "Enthalpy Rise Hot Channel Factor (FH)," and LCO 3.2.2, AXIAL OFFSET (AO).

The flow resistance in the RCS directly affects the reactor coolant natural circulation flow rate established by THERMAL POWER, RCS pressure, and RCS temperature. The safety analyses assume flow rates that are based on a conservative value of flow resistance through the RCS.

Therefore the resistance must be verified to ensure that the assumptions in the safety analyses remain valid.

The pressurizer pressure operating limit and the RCS cold temperature limit specified in the COLR, as shown on the Analytical Design Operating LimitsThermal Margins Limit Map in FSAR Tier 2, Figure 4.4-9 (Ref. 2),

correspond to operatinganalytical limits, with an allowance for steady state fluctuations and measurement errors. These are the analytical initial conditions assumed in transient and LOCA analyses.

The RCS CHF parameters satisfy Criterion 2 of 10 CFR 50.36(c)(2)(ii).

LCO This LCO specifies limits on the monitored process variables, pressurizer pressure and RCS cold temperature to ensure the core operates within the limits assumed in the safety analyses. It also specifies the limit on RCS flow resistance to ensure that the RCS flow is consistent with the flow assumed in the safety analyses. These variables are contained in the COLR to provide operating and analysis flexibility from cycle to cycle.

Operating within these limits will result in meeting CHFR criterion in the event of a CHF-limited transient.

NuScale B 3.4.1-2 Draft Revision 3.0

RCS Pressure, Temperature, and Flow Resistance CHF Limits B 3.4.1 BASES SURVEILLANCE SR 3.4.1.1 REQUIREMENTS This surveillance demonstrates that the pressurizer pressure remains greater than or equal to the limit specified in the COLR. Required Action A.1 allows a Completion Time of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to restore parameters that are not within limits and the Surveillance Frequency is sufficient to ensure the pressure can be restored to a normal operation, steady state condition following load changes and other expected transient operations. The surveillance frequency is sufficient to regularly assess for potential degradation and to verify operation is within safety analysis assumptions.

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

SR 3.4.1.2 This surveillance demonstrates that the average RCS cold temperature remains less than or equal to the limit specified in the COLR. Required Action A.1 allows a Completion Time of 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months to restore parameters that are not within limits, and the Surveillance Frequency is sufficient to ensure the temperature can be restored to a normal operation, steady state condition following load changes and other expected transient operations. The surveillance frequency is sufficient to regularly assess for potential degradation and to verify operation is within safety analysis assumptions.

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

SR 3.4.1.3 Verification that the RCS flow resistance is less than that assumed in the safety analysis is accomplished by performing measurements of RCS flow rate under controlled conditions. Assuring the RCS flow resistance remains less than or equal to the limit specified in the COLR after each refueling provides assurance that the safety analysis assumptions regarding the relationship between expected RCS flow, reactor power, RCS pressure, and RCS temperature remains accurate. The flow rate used to determine RCS flow resistance may be determined by installed instrumentation, thermodynamic analyses, or by other methods.

The SR is modified by a Note that permits operation for up to 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months at greater than 50% RTP to permit the unit to establish conditions that permit measurements of RCS flow that allow evaluation of the RCS flow resistance. This is acceptable because the testing must be completed NuScale B 3.4.1-4 Draft Revision 3.0

RCS Pressure, Temperature, and Flow Resistance CHF Limits B 3.4.1 BASES SURVEILLANCE REQUIREMENTS (continued) before exceeding 75% RTP which provides margin to safety analysis limits that are established at 100% RTP, and due to the low likelihood of a design basis event during the time allowed to perform testing.

The frequency requires this surveillance to be performed once after each refueling. The potential for iInadvertent changes that might impact on flow resistance areis most likely to occur during refueling operations. Other credible changes to flow resistance are slow developing phenomena and unlikely to change significantly between performances of the surveillance.

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

2. FSAR Section 4.4, "Thermal and Hydraulic Design."

NuScale B 3.4.1-5 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-60

53. In Revision 2 of DCA part 4, on Page B 3.1.4-4, SRs section, the third paragraph of the Bases for SR 3.1.4.1, says that "The SR is modified by a Note that permits it not to be performed for rods associated with an inoperable rod position indicator. The alignment limit is based on rod position indicator which is not available if the indicator is inoperable. LCO 3.1.7,

'Rod Position Indication,' provides Actions to verify the rods are in alignment when one or more rod position indicators are inoperable." The surveillance column Note states, "Not required to be performed for rods associated with inoperable rod position indicator." Since the Rod Position Indication (RPI) System has two analog indicators for each control rod assembly (CRA or "rod"),

and loss of one indicator reduces position accuracy by one half (+/- 6 steps instead of +/- 3 steps),

which is apparently considered insufficient for concluding that the affected CRA's rod group alignment limit is met, the surveillance column Note functions as a required action to immediately enter LCO 3.1.7, which is a highly unusual construct; in addition, one must read the Bases for Subsection 3.1.4 to know that the Note actually means this. The staff observes that the CE-STS equivalent SR 3.1.4.1 does not include such a Note.

The applicant is requested (i) to change the presentation of SR 3.1.4.1 to omit the Note, and rephrase the surveillance statement to say:

SR 3.1.4.1 Verify the two rod position indicators of each CRA together indicate that the position of the individual CRAs CRA is within the CRA's rod group alignment limit. l 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and (ii) to add Action A as follows (ignore formatting issues):

NuScale Nonproprietary

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One or more CRAs with one A.1 Enter applicable Immediately or both rod position indicators Conditions and Required inoperable.

Actions of LCO 3.1.7, "Rod Position Indication."

B. One or more CRAs B.1.1 Verify SDM to be within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months inoperable. limits OR specified in the COLR.

One or more CRAs not within OR 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months alignment limits.

B.1.2 Initiate boration to restore SDM to within limit.

AND B.2 Be in MODE 2. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and (iii) to make appropriate changes to the Actions and SRs sections of the Bases for Subsection 3.1.4.

NuScale Nonproprietary

(iv) The applicant is also requested to clarify the sixth paragraph of the Background section of the Bases for Subsection 3.1.7 on page B 3.1.7-1 as indicated:

The axial position of shutdown group CRAs and regulating group CRAs are determined by two separate and independent systems: the Counter Position Indication (CPI)

System (CPI) (commonly called group step counters) and the Rod Position Indication (RPI)

System.

(v) The applicant is also requested to clarify the seventh paragraph, third sentence of the Background section of the Bases for Subsection 3.1.7 on page B 3.1.7-2 as indicated:

The CRA CPI Position Indication System is considered highly precise (+/- 1 step or +/- {3/8} inch).

(vi) The applicant is also requested to clarify the third sentence of the eighth paragraph of the Background section of the Bases for Subsection 3.1.7 on page B 3.1.7-2 as indicated; also describe that each of the two RPI channels is associated with just one of the data systems:

To increase the reliability of the RPI system, the inductive coils of a CRA's two RPI channels are alternately connected to two independent data systems. Each RPI channel is associated with just one of the data systems.

NuScale Response:

With regard to items (i), the proposed change is not needed as if one or both rod position indicators are inoperable it would result in failure to meet the associated LCO limit even if alternative means were available to confirm the rod position. Rewording the SR to imply an OPERABILITY requirement already addressed in LCO 3.1.7 would not be consistent with the Writer's Guide for Improved Standard Technical Specifications, and would establish an error trap for the operating staff due to the unusual nature of the SR.

With regard to items (ii) and (iii), NuScale disagrees with the inclusion of a new Condition and Required Action that merely provides a pointer to another Condition and Required Action that already exist and specify the required actions. The purpose of the Conditions and Required Actions that accompany LCOs are not to provide cross-reference for locating requirements.

NuScale Nonproprietary

With regard to item (iv), the terms used to refer to arrangement of the CRAs in two banks (regulating and shutdown) with two groups each were clarified in the response to other RAI 16-60-30 and 16-60-31 submitted on January 29, 2019 in NuScale letter RAIO-0119-64281 (ML19029B572).

With regard to item (v), the proposed change was incorporated in the response to RAI 16-60-21 submitted on January 29, 2019 in NuScale letter RAIO-0119-64281 (ML19029B572).

With regard to item (vi), changes to the Bases were made to improve the clarity of the description provided in the identified paragraph.

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

Rod Position Indication B 3.1.7 BASES BACKGROUND (continued)

CRAs are determined by two separate and independent systemsmeans: the Counter Position Indicatorsion System (CPIs)

(commonly called bankgroup step counters) and the Rod Position Indicatorsion (RPIs) System.

The Counter Position IndicationCPI counts the commands sent to the CRDM gripper coils from the Control Rod Drive System (CRDS) that moves the CRAs. There is one step counter for each CRDM. The CRA Position Indication SystemCPI is considered highly precise

(+/- 1 step or +/- {3/8} inch). If a CRA does not move one step for each command signal, the step counter will still count the command and incorrectly reflect the position of the CRA.

The RPI function of the CRDS provides a highly accurate indication of actual CRA position, but at a lower precision than the step counters.

This system is based on inductive analog signals from a series of coils spaced along a hollow tube with a center to center distance of 1.125 inches, which is equivalent to 3 steps. To increase the reliability of the RPI system, the inductive coils of a CRA's two RPI channels are alternately connected to two separate data systems. Each RPI channel is associated with just one of the data systems. Thus, if one system fails, the RPI will go on half accuracy with an effective coil spacing of 2.25 inches, which is 6 steps. Therefore, the normal indication accuracy of the RPIs System is +/- 3 steps (+/- 1.125 inches),

and the accuracy with one channel of RPI out-of-service is +/- 6 steps

(+/- 2.25 inches).

APPLICABLE The regulating and shutdown bank groups CRA position accuracy is SAFETY essential during power operation. Power peaking, ejected CRA worth, ANALYSES or SDM limits may be violated in the event of a Design Basis Accident (Ref. 2), with regulating or shutdown bankgroup CRAs operating outside their limits undetected. Therefore, the acceptance criteria for CRA position indication is that CRA positions must be known with sufficient accuracy in order to verify the core is operating within the group sequence, overlap, design peaking limits, ejected CRA worth, and within minimum SDM (LCO 3.1.5, Shutdown BankGroup Insertion Limits, LCO 3.1.6, Regulating Bankgroup Insertion Limits). The CRA positions must also be known in order to verify the alignment limits are preserved (LCO 3.1.4, Rod Group Alignment Limits). CRA positions are continuously monitored to provide operators with information that assures the unit is operating within the bounds of the accident analysis assumptions.

NuScale B 3.1.7-2 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-65

59. In Revision 2 of DCA part 4, Subsection 3.3.1: The applicant is requested to revise (i) Required Action C.1, as indicated, because the Table 3.3.1-1 table matches a Condition to each MPS instrumentation Function (It appears that using "channel(s)" in the equivalent Required Action C.1 of W-AP1000- STS Subsections 3.3.1 and 3.3.8 is an error.)

Also note that the removal of "(s)" is consistent with the separate condition entry example of Example 1.3-5:

C.1 Enter the Condition referenced in Table 3.3.1-1 for the channel(s) affected Function. l Immediately (ii) Required Action F.1, as indicated, for consistency with similar action statements related to inoperable channels of the CVCS isolation actuation Function, or the isolation valves the CVCSI Function closes:

F.1 Isolate the CVCS charging and letdown flow paths to the Reactor Coolant System (RCS).

l 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months The applicant is requested to explain whether the intent of this action is to isolate all CVCS flow paths listed in LCO 3.4.6, "CVCS Isolation Valves"; if not, then explain which flow paths must be isolated, and why; and explain why the other flow paths are not required to be isolated.

Consider whether meeting the action, as written, is sufficient to ensure the CVCSI actuation Function would be satisfied. Compare Subsection 3.3.3, Required Action F.1. Also the phrasing NuScale Nonproprietary

Subsection 3.3.4 Required Action F.1 ("Isolate the flow paths from the CVCS to the Reactor Coolant System ...") should also be made consistent with similar actions.

NuScale Response:

(i) The Condition is correct as written. The Actions to be entered are listed to the right of the Required Channels column in Table 3.3.1-1. Conditions A, B, and C are written by reference to channel inoperability. Condition A applies when one channel is inoperable.

Condition B applies when two channels are inoperable. Condition C applies when Conditions A or B are not met or when three or more channels are inoperable. The NuScale design certification application does not utilize nor does NuScale have knowledge of the application or adequacy of the W-AP1000-STS other than NUREG-2194, Rev. 0 as published.

(ii) The Required Action applies to all four flow paths between the chemical volume and control system (CVCS) and the reactor coolant system (RCS). The actuation logic is shown at FSAR Tier 2, Figure 7.1-1v and 7.1-1w, and the valve locations in the plant design are shown on Figure 6.2-4, Containment System Piping and Instrumentation Diagram.

The CVCS isolation actuated valves are the

RCS injection valves,

RCS discharge valves,

Pressurizer spray valves, and the

High point degasification valves.

LCO 3.3.1, Required Action F.1 has been modified to require the isolation of the flow paths between the CVCS and the Reactor Coolant System. Corresponding changes were made to Required Action E.1 of LCO 3.3.3 and Required Action F.1 of LCO 3.3.4.

The Bases are also modified to reflect this change and to clearly indicate that all four CVCS connections to the RCS are isolated by this actuation.

The phrase charging and letdown was not used because these terms are not consistent with the system design names for the flow paths, nor would they clearly describe the applicability to all four of the CVCS connections that the Required Action applies to.

NuScale Nonproprietary

Note that some of these changes slightly modified the previous changes described in the NuScale response to RAI 16-60-41 (ML19010A409).

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

MPS Instrumentation 3.3.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. As required by Required D.1 Open reactor trip breakers. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and referenced in Table 3.3.1-1.

E. As required by Required E.1 Reduce THERMAL POWER 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and to below the N-2L interlock.

referenced in Table 3.3.1-1.

F. As required by Required F.1 --------------NOTE----------------

Action C.1 and CVCS fFlow path(s) may be referenced in unisolated intermittently Table 3.3.1-1. under administrative controls.

Isolate the CVCS flow paths 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months between the CVCS and the to the Reactor Coolant System (RCS).

G. As required by Required G.1 --------------NOTE---------------- 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and Pressurizer Heater breakers referenced in may be closed intermittently Table 3.3.1-1. under administrative controls.

Open pressurizer heater breakers H. As required by Required H.1 Isolate demineralized water 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Action C.1 and flow path to RCS.Isolate referenced in dilution source flow paths in Table 3.3.1-1. the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.1-3 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 ACTIONS (continued)

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

Action B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.3-1. under administrative controls.

OR --------------------------------------

Both divisions of Isolate the flow path from 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Demineralized Water the demineralized water Supply Isolation storage tank to the reactor actuation fFunction coolant systemIsolate inoperable. dilution source flow paths in the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

F. As required by Required F.1 ----------------NOTE--------------

Action B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.3-1. under administrative controls.

OR --------------------------------------

Both divisions of CVCS Isolate theCVCS charging 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Isolation actuation and letdown flow paths fFunction inoperable. between the CVCS to and the Reactor Coolant System by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.3-3 Draft Revision 3.0

Manual Actuation Functions 3.3.4 ACTIONS (continued)

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

Action A.1 or B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.4-1. under administrative controls.

Isolate the flow path from the 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months demineralized water storage tank to the Reactor Coolant SystemIsolate dilution source flow paths in the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

F. As required by Required F.1 ---------------NOTE--------------

Action A.1 or B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.4-1. under administrative controls.

Isolate the flow paths 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months betweenfrom the CVCS andto the Reactor Coolant System by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.4-2 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES ACTIONS (continued)

If the Required Actions associated with this Condition cannot be completed within the required Completion Time, the unit must be brought to a MODE or other specified condition where the Required Actions do not apply. This is accomplished by isolating all fourthe CVCS flow paths to and from the RCS. The allowed Completion Time of 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months is reasonable, based on operating experience, for aligning the system in an orderly manner.

Required Action F.1 is modified by a Note that allows isolated penetration flow paths to be unisolated intermittently under administrative controls.

These administrative controls consist of stationing a dedicated operator at the device controls, who is in continuous communication with the control room. In this way, the penetration can be rapidly isolated when a need for isolation is indicated. This allowance permits the isolation signal to be reset when appropriate conditions exist to do so.

G.1 Condition G is entered when Condition C applies to Functions that result in automatic removal of electrical power from the pressurizer heaters as listed in Table 3.3.1-1.

If the Required Actions associated with this Condition cannot be completed within the required Completion Time, the unit must be brought to a MODE or other specified condition where the Required Actions do not apply. This is accomplished by opening the power supply breakers to the pressurizer heaters. The allowed Completion Time for G.1 of 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months is reasonable, based on operating experience, for reaching the required conditions in an orderly manner.

The Action is modified by a Note that permits the heaters to be energized intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator at the breaker controls, who is in continuous communication with the main control room. In this way, the pressurizer heaters can be de-energized when a need for de-energization is indicated. This permits the unit to continue to operate while in the Condition.

NuScale B 3.3.1-46 Draft Revision 3.0

ESFAS Logic and Actuation B 3.3.3 BASES ACTIONS (continued)

With one division of actuation logic inoperable, the redundant signal paths and logic of the OPERABLE division provide robust capability to automatically actuate the CVCSI if required.

F.1 requires the isolation of all fourflow paths from the CVCS flow paths to and from the reactor coolant system within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months of entering the Condition. The Action is modified by a Note that permits the flow path(s) to be unisolated intermittently under administrative controls. This Note limits the likelihood of an event by requiring additional administrative control of the CVCS flow paths. These administrative controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the main control room. In this way, the flow path(s) can be isolated when a need for isolation is indicated. This permits the unit to continue to operate while in the Condition.

G.1 If Required Action B.1 directs entry into Condition G as specified in Table 3.3.3-1, or if both divisions of the pressurizer heater trip actuation fFunction are inoperable then the unit is outside its design basis ability to automatically mitigate some design basis events.

With one division of actuation logic inoperable, the redundant signal paths and logic of the OPERABLE division provide sufficient capability to automatically actuate the PHT if required.

G.1 requires de-energization of the pressurizer heaters within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months of entering the Condition. This action limits the time the unit may continue to operate with limited or inoperable PHT automatic actuation logic. The Action is modified by a Note that permits the heaters to be energized intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator at the breaker controls, who is in continuous communication with the main control room. In this way, the pressurizer heaters can be de-energized when a need for de-energization is indicated. This permits the unit to continue to operate while in the Condition.

The completion time was established considering the likelihood of a design basis event that would require automatic de-energization.

NuScale B 3.3.3-8 Draft Revision 3.0

Manual Actuation Functions B 3.3.4 BASES ACTIONS (continued)

The Completion Times are reasonable because the credited automatic actuation fFunction remains OPERABLE as specified in LCO 3.3.3, and alternative means of manually initiating the safety function remain available, e.g., manually initiating individual MPS division trip logic and component-level actuations.

E.1 If Required Actions A.1 or B.1 direct entry into Condition E as specified in Table 3.3.4-1, then Action E.1 requires the dilution sourceDWSI flow paths to be isolated if the mManual aActuation fFunction is not restored within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . The Action includes a Note that permits the flow path to be opened intermittently under administrative controls. This permits operation of the unit while actions to restore the actuation fFunction are underway.

The Completion Times are reasonable because the credited automatic actuation function remains OPERABLE as specified in LCO 3.3.3, and alternative means of manually initiating the safety function remain available, e.g., manually initiating individual MPS division trip logic and component-level actuations.

F.1 If Required Actions A.1 or B.1 direct entry into Condition F as specified in Table 3.3.4-1, then Action F.1 requires the four CVCSI flow paths to and from the reactor coolant system be isolated if the mManual aActuation fFunction is not restored within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . The Action includes a Note that permits the flow path to be opened intermittently under administrative controls. This permits operation of the unit while actions to restore the actuation fFunction are underway.

The Completion Times are reasonable because the credited automatic actuation function remains OPERABLE as specified in LCO 3.3.3, and alternative means of manually initiating the safety function remain available, e.g., manually initiating individual MPS division trip logic and component-level actuations.

NuScale B 3.3.4-4 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-66

60. In Revision 2 of DCA part 4, Subsection 3.3.1, Table 3.3.1-1, Function 24 title. The applicant is requested to consider revising the title to say 24. High Wide Range RCS Pressure

- Low Temperature Overpressure Protection; also make conforming changes to the Bases on page B 3.1.1-38, paragraph 10.a. Since the wide range RCS pressure is measured at the steam space near the top of the reactor vessel does this mean the steam space near the top of the pressurizer? If so, why not say wide range pressurizer pressure instead of wide range RCS pressure?

NuScale Response:

The proposed changes were not incorporated. The descriptions and names provided are consistent with their usage in the plant design as shown in FSAR Tier 2, Table 7.1-2. The use of Wide Range RCS Pressure APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY portion of the bases for 3.3.1 is to describe the input device that is used to evaluate whether an LTOP actuation is needed. The sensor descriptions are not necessarily incorporated into the functions described after each sensor grouping. For example, the first listing is for Excore Nuclear Power, however sections a. through f. do not incorporate this name in any of the described signals.

The NuScale design does not include a separate pressurizer vessel. The LTOP function is required to be OPERABLE whether the upper region of the RCS is acting as a steam-filled pressurizer or contains other media (gas or liquid). The variable of concern is the wide range RCS pressure and actuation occurs based on wide range RCS pressure as described in the bases of 3.3.1 and based on this the term RCS pressure is retained.

NuScale Nonproprietary

Impact on DCA:

There are no impacts to the DCA as a result of this response.

NuScale Nonproprietary

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-75

67. A response is not required because the applicant stated in an email dated November 12, 2018, to follow up the November 6, 2018, public meeting conference call, that it would address this item in Part 2, Item 10 of a supplemental response to RAI 197-9051, Question 16-28, and in Revision 3 of DCA part 4. In Revision 2 of DCA part 4, Table 3.3.3-1 Footnote (c), and Table 3.3.4-1 Footnote (d) modify the Modes 2 and 3 Applicability of actuation Function 3.3.3.6, "Pressurizer Heater Trip," and manually actuated Function 3.3.4.7, "Pressurizer Heater Trip,"

respectively. These footnotes state:

Not required when pressurizer heater trip breakers are open and deactivated.

Subsection 3.3.1, Table 3.3.1-1 Footnote (f) modifies the Modes 2 and 3 Applicability of MPS instrumentation Functions that initiate a "Pressurizer Heater Trip" (PHT) 7.c PHT on "High Pressurizer 1, 2(f), 3(f)

Pressure" Modes PHT on "Low Pressurizer GG Mode 8.d 1(g)

Pressure" G Modes PHT on "Low Low Pressurizer 9.d Pressure" 1, 2 NuScale Nonproprietary

11.b PHT on "Low Pressurizer Level" Modes 1, 2(f), 3(f) G PHT on "Low Low Pressurizer 12.d Modes 1, 2(f), 3(f) G Level" PHT on "High NR RCS Hot 13.c Modes 1, 2(f), 3(f) G Temperature" PHT on "High Main Steam 17.c Modes 1, 2(f), 3(f) G Pressure" PHT on "Low Main Steam 18.c Mode 1(b) E Pressure" PHT on "Low Low Main Steam 19.c Modes 1, 2(f) G Pressure" 20.c PHT on "High Steam Superheat" Mode 1 G 21.c PHT on "Low Steam Superheat" Mode 1 G PHT on "High NR Containment 22.e Modes 1, 2(f), 3(f) G Pressure" PHT on "Low AC Voltage to ELVS 25.e Modes 1, 2(f) M BCs" PHT on "High Under-the-Bioshield 26.e Modes 1, 2(f), 3(f) M Temp."

NuScale Nonproprietary

Table 3.3.1 Footnote (f) states:

(f) With pressurizer heater trip breakers closed.

(i) The applicant is requested to explain why Table 3.3.3-1, Footnote (c), and Table 3.3.4-1, Footnote (d), are different from Table 3.3.1-1, Footnote (f). Else, make the phrasing consistent.

(ii) The applicant is requested to explain the significance of "open and deactivated" in Table 3.3.3-1, Footnote (c), and Table 3.3.4-1, Footnote (d).

(iii) The applicant is requested to explain why the Required Actions for inoperable PHT related Functions are phrased differently. Else, make the statements consistent. These differences are evident in the following quotations:

LCO 3.3.1 Required Action:

"E.1 Reduce THERMAL POWER to below the N-2L interlock. l 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months " "G.1 Open pressurizer heater breakers. l 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months " "M.5 Open pressurizer heater breakers. l 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months " LCO 3.3.3 Required Action:

"G.1 De-energize pressurizer heaters. l 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months " LCO LCO 3.3.4 Required Action:

"G.1 De-energize affected pressurizer heaters. l 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months " (i) The applicant is requested to revise the Note for LCO 3.3.3 Required Action G.1 and the (almost) identical Note for LCO 3.3.4 Required Action G.1 as indicated:

Pressurizer heater breakers Heater(s) may be energized closed intermittently under manual administrative controls.

NuScale Nonproprietary

The applicant is also requested to explain why it has not proposed the same Note for LCO 3.3.1, Required Actions G.1 and M.5.

NuScale Response:

The Notes to LCO 3.3.3, ESFAS Logic and Actuation, Required Action G.1, and LCO 3.3.4, Manual Actuation Functions have been modified.

A similar Note has been added to Required Action G.1 of LCO 3.3.1, Module Protection System Instrumentation. A Note was not added to Condition M Required Actions because the Completion Time of 96 hours0.00111 days 0.0267 hours 1.587302e-4 weeks 3.6528e-5 months provides adequate time to reach a MODE or other specified Condition in which the requirement no longer applies using normal means of operation of the pressurizer heater breakers. No additional allowance is needed during this period so the Note is not proposed for inclusion in Condition M.

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

MPS Instrumentation 3.3.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. As required by Required D.1 Open reactor trip breakers. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and referenced in Table 3.3.1-1.

E. As required by Required E.1 Reduce THERMAL POWER 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and to below the N-2L interlock.

referenced in Table 3.3.1-1.

F. As required by Required F.1 --------------NOTE----------------

Action C.1 and CVCS fFlow path(s) may be referenced in unisolated intermittently Table 3.3.1-1. under administrative controls.

Isolate the CVCS flow paths 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months between the CVCS and the to the Reactor Coolant System (RCS).

G. As required by Required G.1 --------------NOTE---------------- 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and Pressurizer Heater breakers referenced in may be closed intermittently Table 3.3.1-1. under administrative controls.

Open pressurizer heater breakers H. As required by Required H.1 Isolate demineralized water 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Action C.1 and flow path to RCS.Isolate referenced in dilution source flow paths in Table 3.3.1-1. the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.1-3 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES ACTIONS (continued)

If the Required Actions associated with this Condition cannot be completed within the required Completion Time, the unit must be brought to a MODE or other specified condition where the Required Actions do not apply. This is accomplished by isolating all fourthe CVCS flow paths to and from the RCS. The allowed Completion Time of 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months is reasonable, based on operating experience, for aligning the system in an orderly manner.

Required Action F.1 is modified by a Note that allows isolated penetration flow paths to be unisolated intermittently under administrative controls.

These administrative controls consist of stationing a dedicated operator at the device controls, who is in continuous communication with the control room. In this way, the penetration can be rapidly isolated when a need for isolation is indicated. This allowance permits the isolation signal to be reset when appropriate conditions exist to do so.

G.1 Condition G is entered when Condition C applies to Functions that result in automatic removal of electrical power from the pressurizer heaters as listed in Table 3.3.1-1.

If the Required Actions associated with this Condition cannot be completed within the required Completion Time, the unit must be brought to a MODE or other specified condition where the Required Actions do not apply. This is accomplished by opening the power supply breakers to the pressurizer heaters. The allowed Completion Time for G.1 of 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months is reasonable, based on operating experience, for reaching the required conditions in an orderly manner.

The Action is modified by a Note that permits the heaters to be energized intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator at the breaker controls, who is in continuous communication with the main control room. In this way, the pressurizer heaters can be de-energized when a need for de-energization is indicated. This permits the unit to continue to operate while in the Condition.

NuScale B 3.3.1-46 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 0.00167 hours 9.920635e-6 weeks 2.283e-6 months 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 manualadministrative control.

Verify required pressurizer heater breaker response In accordance with time is within limits. the Surveillance Frequency Control Program NuScale 3.3.3-4 Draft Revision 3.0

Manual Actuation Functions 3.3.4 ACTIONS (continued)

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

Action A.1 or B.1 and Heater(s) may be referenced in energizedPressurizer heater Table 3.3.4-1. breakers may be closed intermittently under administrative controls.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months De energize affected pressurizer heaters.Open pressurizer heater breakers.

H. As required by Required H.1 Open two reactor vent Immediately Action A.1 or B.1 and valves.

referenced in Table 3.3.4-1.

I. As required by Required I.1 Be in MODE 2. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action A.1 or B.1 and Referenced in AND Table 3.3.4 1.

I.2 Be in MODE 3 with RCS 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months temperature below the T-2 interlock.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.4.1 Perform actuation device operational test. In accordance with the Surveillance Frequency Control Program NuScale 3.3.4-3 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-76

69. (v) The surveillance statement of SR 3.3.3.4 defines an acronym, PHTB, which stands for "pressurizer heater trip breaker"; however, PHTB is used nowhere else in the GTS. Likewise, the Bases for SR 3.3.3.4 t defines PHTB, using it twice in the first two sentences, but nowhere else. The applicant is requested to (A) not define and not use PHTB; and (B) consistently refer to the 'pressurizer heater trip breakers' or the 'pressurizer heater breakers' in the Section 3.3 Actions and SRs, and Bases. (The staff observes that the Bases for LCO 3.3.3, Background section, defines the acronym, PHT, which stands for "Pressurizer Heater Trip"; PHT can be used to refer to the ESFAS PHT logic and actuation Function; it can also be used in reference to a PHT breaker. PHT is not used in Subsection 3.3.3, however.)

NuScale Response:

The description and use of the 'PHTB' acronym have been revised in technical specification section 3.3 as described in the RAI.

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

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 2 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

7. High Pressurizer Pressure

a. RTS 1, 2(a), 3(a) 4 D

b. DHRS 1, 2, 3(e) 4 I

c. Pressurizer Heater Trip 1, 2(f), 3(f) 4 G

d. DWSI 1, 2(a), 3(a) 4 H

8. Low Pressurizer Pressure

a. RTS 1(g) 4 D

b. DHRS 1(g) 4 D

c. CVCSI 1(g) 4 F

d. Pressurizer Heater Trip 1(g) 4 G

e. DWSI 1(g) 4 H

9. Low Low Pressurizer Pressure

a. RTS 1, 2(a) 4 D

b. DHRS 1, 2 4 I

c. CVCSI 1, 2 4 F

d. Pressurizer Heater Trip 1, 2 4 G

e. DWSI 1, 2(a) 4 H (a) When capable of CRA withdrawal.

(e) When not PASSIVELY COOLED.

(f) With pressurizer heater trip breakers closed.

(g) With narrow range RCS hot temperature above the T-4 interlock.

NuScale 3.3.1-9 Draft Revision 3.0

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 3 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

10. High Pressurizer Level

a. RTS 1, 2(a), 3(a) 4 D

b. CVCSI 1, 2, 3 4 F

c. DWSI 1, 2(a), 3(a) 4 H

11. Low Pressurizer Level

a. RTS 1, 2(a), 3(a) 4 D

b. Pressurizer Heater Trip 1, 2(f), 3(f) 4 G

c. DWSI 1, 2(a), 3(a) 4 H

12. Low Low Pressurizer Level

a. DHRS 1, 2, 3(h) 4 N

b. CIS 1, 2, 3(h) 4 L

c. CVCSI 1, 2, 3(h) 4 F

d. Pressurizer Heater Trip 1, 2(f), 3(f) 4 G

13. High Narrow Range RCS Hot Temperature

a. RTS 1 4 D

b. DHRS 1, 2, 3(e) 4 I

c. Pressurizer Heater Trip 1, 2(f), 3(f) 4 G

d. DWSI 1 4 H

14. Low RCS Flow

a. DWSI 1, 2, 3 4 H (a) When capable of CRA withdrawal.

(e) When not PASSIVELY COOLED.

(f) With pressurizer heater trip breakers closed.

(h) With RCS temperature above the T-2 interlock and containment water level below the L-1 interlock.

NuScale 3.3.1-10 Draft Revision 3.0

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 4 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

15. Low Low RCS Flow

a. RTS 1, 2(a), 3(a) 4 D

b. CVCSI 1, 2, 3 4 F

c. DWSI 1, 2(a), 3(a) 4 H

16. Low RPV Riser Level

a. ECCS 1, 2, 3 4 I

17. High Main Steam Pressure

a. RTS 1, 2(a) 4 per SG D

b. DHRS 1, 2, 3(e) 4 per SG I

c. Pressurizer Heater Trip 1, 2(f), 3(f) 4 per SG G

d. DWSI 1, 2(a) 4 per SG H

18. Low Main Steam Pressure

a. RTS 1(b) 4 per SG E

b. DHRS 1(b) 4 per SG E

c. Pressurizer Heater Trip 1(b) 4 per SG E

d. DWSI 1(b) 4 per SG H (a) When capable of CRA withdrawal.

(b) With power above the N-2H interlock.

(e) When not PASSIVELY COOLED.

(f) With pressurizer heater trip breakers closed.

NuScale 3.3.1-11 Draft Revision 3.0

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 5 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

19. Low Low Main Steam Pressure

a. RTS 1, 2(a) 4 per SG D

b. DHRS 1, 2 4 per SG K

c. Pressurizer Heater Trip 1, 2(f) 4 per SG G

d. DWSI 1, 2(a) 4 per SG H

20. High Steam Superheat

a. RTS 1 4 per SG D

b. DHRS 1 4 per SG D

c. Pressurizer Heater Trip 1 4 per SG G

d. DWSI 1 4 per SG H

21. Low Steam Superheat

a. RTS 1 4 per SG D

b. DHRS 1 4 per SG D

c. Pressurizer Heater Trip 1 4 per SG G

d. DWSI 1 4 per SG H (a) When capable of CRA withdrawal.

(f) With pressurizer heater trip breakers closed.

NuScale 3.3.1-12 Draft Revision 3.0

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 6 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

22. High Narrow Range Containment Pressure

a. RTS 1, 2(a), 3(a) 4 D

b. DHRS 1, 2, 3(e) 4 I

c. CIS 1, 2, 3(i) 4 L

d. CVCSI 1, 2, 3(i) 4 F

e. Pressurizer Heater Trip 1, 2(f), 3(f) 4 G

f. DWSI 1, 2(a), 3(a) 4 H

23. High Containment Water Level

a. ECCS 1, 2, 3(e) 4 I

24. High RCS Pressure - Low Temperature Overpressure Protection

a. LTOP 3(k) 4 J

25. Low AC Voltage to ELVS Battery Chargers

a. RTS 1, 2(a), 3(a) 4 per bus M

b. DHRS 1, 2, 3(e) 4 per bus M

c. CIS 1, 2, 3 4 per bus M

d. DWSI 1, 2(a), 3(a) 4 per bus M

e. Pressurizer Heater Trip 1, 2(f) 4 per bus M (a) When capable of CRA withdrawal.

(e) When not PASSIVELY COOLED.

(f) With pressurizer heater trip breakers closed.

(i) With RCS temperature above the T-3 interlock.

(k) With wide range RCS cold temperature below the LTOP enable temperature specified in the PTLR (T-1 interlock) and more than one reactor vent valve closed.

NuScale 3.3.1-13 Draft Revision 3.0

MPS Instrumentation 3.3.1 Table 3.3.1-1 (page 7 of 7)

Module Protection System Instrumentation APPLICABLE MODES OR OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS CHANNELS CONDITIONS

26. High Under-the-Bioshield Temperature

a. RTS 1, 2(a), 3(a) 4 M

b. DHRS 1, 2, 3 4 M

c. CIS 1, 2, 3 4 M

d. DWSI 1, 2(a), 3(a) 4 M

e. Pressurizer Heater Trip 1, 2(f), 3(f) 4 M (a) When capable of CRA withdrawal.

(f) With pressurizer heater trip breakers closed.

NuScale 3.3.1-14 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 SURVEILLANCE REQUIREMENTS (continued)

SR 3.3.3.3 -------------------------------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 required In accordance with Class 1E isolation deviceVerify associated Class 1E the Surveillance isolation devices are OPERABLE. Frequency Control Program SR 3.3.3.4 -------------------------------NOTE--------------------------------

Not required to be met for pressurizer heater trip breakers that are open or breakers closed under administrative controls.

Verify each pressurizer heater trip breaker (PHTB) In accordance with actuates to the open position on an actual or the Surveillance simulated actuation signal. Frequency Control Program NuScale 3.3.3-5 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 Table 3.3.3-1 (page 1 of 1)

ESFAS Logic and Actuation Functions APPLICABLE MODES OR ACTUATION OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS DIVISIONS CONDITIONS

1. Emergency Core 1, 2, 3(a) 2 C Cooling System (ECCS)

2. Decay Heat 1, 2, 3(a) 2 C Removal System (DHRS)

3. Containment 1, 2, 3(b) 2 D Isolation System (CIS)

4. Demineralized 1, 2, 3 2 E Water Supply Isolation (DWSI)

5. CVCS Isolation 1, 2, 3 2 F (CVCSI)

6. Pressurizer Heater 1, 2(c), 3(c) 2 G Trip

7. Low Temperature 3(d) 2 A Overpressure Protection (LTOP)

(a) Not PASSIVELY COOLED.

(b) With any RCS temperature above the T-2 interlock.

(c) Not required when Pressurizer Heater trip breakers are open and deactivated.With pressurizer heater breakers closed.

(d) With wide range RCS cold temperature below the LTOP enable temperature specified in the PTLR (T-1 interlock) and more than one reactor vent valve closed.

NuScale 3.3.3-6 Draft Revision 3.0

Manual Actuation Functions 3.3.4 Table 3.3.4-1 (page 1 of 1)

Manual Actuation Functions APPLICABLE MODES OR MANUALLY ACTUATED OTHER SPECIFIED REQUIRED FUNCTION CONDITIONS DIVISIONS CONDITIONS

1. Reactor Trip System 1, 2(a), 3(a) 2 C

2. Emergency Core 1, 2, 3(b) 2 D Cooling System

3. Decay Heat Removal 1, 2, 3(b) 2 D System

4. Containment Isolation 1, 2, 3(c) 2 I System

5. Demineralized Water 1, 2, 3 2 E Supply Isolation

6. CVCS Isolation 1, 2, 3 2 F System

7. Pressurizer Heater 1, 2(d), 3(d) 2 G Trip

8. Low Temperature 3(e) 2 H Overpressure Protection (a) When capable of CRA withdrawal.

(b) When not PASSIVELY COOLED.

(c) With any RCS temperature above the T-2 interlock.

(d) Not required when pressurizer heater trip breakers are open and deactivated.With pressurizer heater breakers closed.

(e) With wide range RCS cold temperature below the LTOP enable temperature specified in the PTLR (T-1 interlock) and more than one reactor vent valve closed.

NuScale 3.3.4-4 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

MODES 2 and 3 when capable of CRA withdrawal. In MODES 2 and 3, with no capability of withdrawing any CRA, the reactor will remain subcritical. In MODES 4 and 5 the reactor is subcritical with the CRDMs and CVCS incapable of affecting the reactivity in the unit.

Four High Pressurizer Pressure DHRS channels are required to be OPERABLE when operating in MODES 1 and 2, and MODE 3 without PASSIVE COOLING in operation. When PASSIVE COOLING is established sufficient cooling for decay heat loads is met. In MODES 4 and 5 the reactor is subcritical and passively cooled.

Four Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODES 2 and 3 with the pressurizer heater trip breakers closed. In MODES 2 and 3 with the pressurizer heater trip breakers open and in MODES 4 and 5 this 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.

The High Pressurizer Pressure DHRS and Pressurizer Heater Trip determination logic is automatically bypassed when containment water level is above the L-1 interlock and automatically enabled when containment water level is below the L-1 interlock.

b. Low Pressurizer Pressure - Reactor Trip, Demineralized Water System Isolation, Decay Heat Removal System Actuation, CVCS Isolation, and Pressurizer Heater Breaker Trip The Low Pressurizer Pressure trip is designed to protect against RCS line breaks outside of containment, CRA drop, and protect the RCS subcooled margin against flow instability events.

The RTS and ESFAS Low Pressurizer Pressure setpoint is approximately 1720 psia. Actual setpoints are established in accordance with the Setpoint Control Program. Four Low Pressurizer Pressure reactor trip and ESFAS channels are required to be OPERABLE when operating in MODE 1 with RCS hot temperature above the T-4 interlock. In MODE 1 with RCS hot temperature below the T-4 interlock and in MODES 2, 3, 4, and 5 the RCS temperatures are well below T-4 and with the reactor subcritical the heat input will be insufficient to reach T-4. Four NuScale B 3.3.1-25 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

OPERABLE when operating in MODE 1, and MODES 2 and 3 when capable of CRA withdrawal. In MODES 2 and 3 with no capability of withdrawing any CRA, and in MODES 4 and 5 the reactor will remain subcritical. Four Low Pressurizer Level Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1, and MODES 2 and 3 with the pressurizer heater trip breakers closed. In MODES 2 and 3 with the pressurizer heater trip breakers open and in MODES 4 and 5 this 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.

c. Low Low Pressurizer Level - Decay Heat Removal System Actuation, Containment Isolation, CVCS Isolation, and Pressurizer Heater Trip The Low Low Pressurizer Level trip provides protection for:

Steam system piping failures inside and outside containment;

Radiological consequences of failure of small lines carrying primary coolant outside the containment vessel;

Loss-of-coolant accidents outside the containment vessel; and

Steam generator tube failure.

Four Low Low Pressurizer Level Containment Isolation and CVCSI trip channels are required to be OPERABLE when operating in MODES 1, and 2, and MODE 3 when RCS temperature is above the T-2 interlock. In MODE 3 with RCS temperature below the T-2 interlock, and in MODES 4 and 5, the reactor will remain subcritical.

The Low Low Pressurizer Level Containment Isolation and CVCSI trip channels are automatically bypassed when the RCS temperature is below the T-2 interlock. The Low Low Pressurizer Level Containment Isolation and CVCSI trip channels are automatically enabled when RCS temperature is above the T-2 interlock.

Four Low Low Pressurizer Level DHRS trip channels are required to be OPERABLE when operating in MODES 1 and 2, and MODE 3 NuScale B 3.3.1-28 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

The High RCS Hot Temperature trip causes a reactor trip, DWSI, DHRS actuation, and a pressurizer heater trip. The DHRS and Pressurizer Heater Trip actuation is automatically bypassed when containment water level is above the L-1 interlock and automatically enabled when containment water level is below the L-1 interlock.

Four High Narrow Range RCS Hot Temperature reactor trip and DWSI channels are required to be OPERABLE when operating in MODE 1. In MODES 2, 3, 4, and 5 the reactor is subcritical.

Four High Narrow Range RCS Hot Temperature DHRS channels are required to be OPERABLE in MODES 1 and 2, and MODE 3 without PASSIVE COOLING in operation. In MODE 3 with PASSIVE COOLING in operation, sufficient cooling for decay heat loads is met. In MODES 4 and 5 the reactor is subcritical and passively cooled.

Four Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODES 2 and 3 with the pressurizer heater trip breakers closed. In MODES 2 and 3 with the pressurizer heater trip breakers open and in MODES 4 and 5 this 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.

5. RCS Flow RCS Flow is measured by four sensors (one per separation group located such that they measure the RCS flow below the steam generator region of the reactor vessel downcomer.

a. Low RCS Flow - Demineralized Water System Isolation The Low RCS Flow trip ensures boron dilution cannot be performed at low RCS flowrates where the loop time is too long to be able to detect the reactivity change in the core within sufficient time to mitigate the event.

The Low RCS Flow trip causes the demineralized water supply isolation valves to be closed. Four Low RCS Flow trip channels are required to be OPERABLE when operating in MODES 1, 2, and 3. In MODES 4 and 5 the function is fulfilled. Four channels NuScale B 3.3.1-30 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

Loss of condenser vacuum;

Loss of nonemergency AC power to the station auxiliaries;

Closure of a MSIV; and

Inadvertent operation of the DHRS.

The High Main Steam Pressure trip causes the reactor trip breakers to open and the DHRS, DWSI, and Pressurizer Heater Trip to actuate.

Four High Main Steam Pressure reactor trip and DWSI channels measuring pressure on each steam line are required to be OPERABLE when operating in MODE 1 and MODE 2 when capable of CRA withdrawal. In MODE 2 with no capability of withdrawing any CRA, and in MODES 3, 4, and 5 the reactor will remain subcritical.

Four Main Steam Pressure DHRS channels are required to be OPERABLE in MODES 1 and 2, and MODE 3 without PASSIVE COOLING in operation. In MODE 3 with PASSIVE COOLING in operation, sufficient cooling for decay heat loads is met. In MODES 4 and 5 the reactor is subcritical and passively cooled.

Four Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODES 2 and 3 with the pressurizer heater trip breakers closed. In MODES 2 and 3 with the pressurizer heater trip breakers open and in MODES 4 and 5 this function is fulfilled.

The High Main Steam Pressure DHRS and Pressurizer Heater Trip channels are automatically bypassed when containment water level is above the L-1 interlock and the RTBs are open. 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 Main Steam Pressure - Reactor Trip, Demineralized Water System Isolation, Decay Heat Removal System Actuation, and Pressurizer Heater Trip The Low Main Steam Pressure trip provides protection for:

Increase in steam flow; NuScale B 3.3.1-32 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

The Low Low Main Steam Pressure trip causes the reactor trip breakers to open and the DHRS, DWSI, and Pressurizer Heater Breaker Trip to actuate.

Four Low Low Main Steam Pressure reactor trip and DWSI channels measuring pressure on each steam line are required to be OPERABLE when operating in MODE 1 and MODE 2 when capable of CRA withdrawal. In MODE 2 with no capability of withdrawing any CRA and in MODES 3, 4, and 5 the reactor is subcritical.

Four Low Low Main Steam Pressure DHRS Trip channels are required to be OPERABLE when operating in MODES 1 and 2.

Protection from low main steam pressure is not required in MODES 3, 4, and 5.

Four Low Low Main Steam Pressure Pressurizer Heater Breaker Trip channels are required to be OPERABLE in MODE 1 and MODE 2 when pressurizer heater breakers are closed. In MODE 2 with pressurizer heater trip breakers open and in MODES 3, 4, and 5 the function is fulfilled.

The Low Low Main Steam Pressure DHRS channels are automatically bypassed when water level is above the L-1 interlock and the RTBs are open. 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.

7. Steam Superheat Steam Superheat is determined by MPS SFM processing of main steam temperature and pressure data. Steam pressure sensors are shared between the High and Low Main Steam Pressure trips and are used as input to the High and Low Steam Superheat trips. Four steam temperature sensors are located on each steam pipe upstream of the MSIVs. Each channel of superheat receives two steam generator pressure inputs and two steam temperature inputs (one pressure and one temperature signal from each steam line). The degree of superheat is found by determining the saturation temperature (TSAT) at the measured main steam pressure (PSTM), and subtracting this value from the measured main steam temperature (TSTM). The main steam saturation temperature is found via a simple steam table lookup function using the measured steam pressure value.

TSH = TSTM - TSAT(PSTM)

NuScale B 3.3.1-34 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

PASSIVE COOLING in operation, sufficient cooling for decay heat loads is met. In MODES 4 and 5 the reactor is subcritical and passively cooled.

Four Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODES 2 and 3 with the pressurizer heater trip breakers closed. In MODES 2 and 3 with the pressurizer heater trip breakers open and in MODES 4 and 5 this function is fulfilled.

Four High Containment Pressure CVCSI and CIS channels are required to be OPERABLE when operating in MODES 1 and 2, and MODE 3 with RCS temperature above the T-3 interlock. In MODE 3 with RCS temperature is below the T-3 interlock, and in MODES 4 and 5 the containment pressure is allowed to exceed this setpoint and is expected, isolation is not required.

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.

The High Containment Pressure Containment Isolation, DHRS, Pressurizer Heater Trip, and CVCSI actuations are automatically bypassed when RCS temperature is below the T-3 interlock. The High Containment Pressure DHRS and Pressurizer Heater Trip actuation is also automatically bypassed when containment water level is above the L-1 interlock.

9. Containment Water Level Containment Water Level is measured by 4 sensors (one per separation group) located in the containment vessel. The level is measured by a radar instrument which will run the entire distance of the measurement, from the containment head to an elevation below 45 ft.

a. High Containment Water Level - Emergency Core Cooling System Actuation The High Containment Water Level trip provides protection for LOCA events.

The High Containment Water Level trip signal causes ECCS actuation. Four ECCS High Containment Water Level trip NuScale B 3.3.1-37 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

This will generate an ECCS actuation.

Eight (4/bus) Low ELVS Voltage DWSI and reactor trip channels are required to be OPERABLE when operating in MODE 1 and MODES 2 and 3 when capable of CRA withdrawal. In MODES 2 and 3 with no capability of withdrawing any CRA and in MODES 4 and 5 the reactor is subcritical.

Eight (4/bus) Low ELVS Voltage Containment Isolation channels are required to be OPERABLE when operating in MODES 1, 2, and 3. In MODES 4 and 5 the functions are fulfilled.

Eight (4/bus) Low ELVS Voltage DHRS channels are required to be OPERABLE in MODES 1 and 2, and MODE 3 without PASSIVE COOLING in operation. In MODE 3 with PASSIVE COOLING in operation, sufficient cooling for decay heat loads is met. In MODES 4 and 5 the reactor is subcritical and passively cooled.

Eight (4/bus) Low ELVS Voltage Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODE 2 with the pressurizer heater trip breakers closed. In MODES 2 with the pressurizer heater trip breakers open and in MODES 3, 4, and 5 this function is fulfilled.

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

12. Under-the-Bioshield Temperature Temperature under the bioshield is measured by 4 sensors (one per separation group) mounted on the pool wall outside containment.

a. High Under-the-Bioshield Temperature - Reactor Trip, Demineralized Water System Isolation, Containment Isolation, Decay Heat Removal System Actuation, and Pressurizer Heater Trip An undetected small main steam line break under the bioshield would expose the equipment to sustained elevated temperatures challenging the safety-related functions of the MSIVs and DHR valves. The High Temperature Under-the-Bioshield trip provides protection for the safety-related equipment that would be exposed to these harsh temperature conditions.

NuScale B 3.3.1-40 Draft Revision 3.0

Module Protection System Instrumentation B 3.3.1 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

Four High Under-the-Bioshield Temperature reactor trip and DWSI channels are required to be OPERABLE when operating in MODE 1 and in MODES 2 and 3 when capable of CRA withdrawal. In MODES 2 and 3 with no capability of withdrawing any CRA and in MODES 4 and 5 the reactor is subcritical.

Four High Under-the-Bioshield Temperature DHRS and Containment Isolation channels are required to be OPERABLE when operating in MODES 1, 2, and 3. In MODES 4 and 5 these functions are fulfilled.

Four High Under-the-Bioshield Temperature Pressurizer Heater Trip channels are required to be OPERABLE when operating in MODE 1 and in MODE 2 with the pressurizer heater trip breakers closed. In MODES 2 with the pressurizer heater trip breakers open and in MODES 3, 4, and 5 this 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.

ACTIONS The most common causes of channel inoperability are outright failure of a sensor or MPS SFM module sufficient to exceed the tolerance allowed by the unit-specific setpoint analysis as specified by the SP. Typically, sensor drift is found to be small and results in a delay of actuation rather than a total loss of capability to actuate within the allowed tolerance around the NTSP. This determination is of the channel's actual trip setting generally made during the performance of a CHANNEL CALIBRATION when the process sensor output signal is measured and verified to be within specification. If any as-found measured value is outside the as-found tolerance band, then the channel is inoperable, and corrective action is required. The unit must enter the Condition for the particular MPS Functions affected. The channel as-found condition will be entered into the Corrective Action Program for further evaluation and to determine the required maintenance to return the channel to OPERABLE status.

When more than two channels of an MPS Function are inoperable, the affected MPS Function is lost and the unit is outside the assumptions of the applicable safety analyses. This condition is addressed for all MPS Functions by the second condition statement C (One or more Functions with three or more channels inoperable).

NuScale B 3.3.1-41 Draft Revision 3.0

ESFAS Logic and Actuation B 3.3.3 B 3.3 INSTRUMENTATION B 3.3.3 Engineered Safety Features Actuation System (ESFAS) Logic and Actuation BASES BACKGROUND The ESFAS portion of the Module Protection System (MPS) protects against violating the core fuel design limits, ensures reactor coolant pressure boundary integrity during anticipated operational occurrences (AOOs) and postulated accidents, and ensures acceptable consequences during accidents by initiating necessary safety systems.

Details of the design and operation of the entire MPS are provided in the Bases for LCO 3.3.1, Module Protection System (MPS) Instrumentation.

Setpoints are specified in the [owner-controlled requirements manual]. As noted there, the MPS transmits trip determination data to both divisions of the ESFAS scheduling and voting modules (SVMs). Redundant data from all four separation groups is received by each division of the ESFAS SVMs.

LCO 3.3.3 addresses only the logic and actuation portions of the MPS that perform the ESFAS functions. The scope of this LCO begins at the inputs to the SVMs and extends through the actuating contacts on the actuated components. This LCO also includes the pressurizer heater trip breakers. Component OPERABILITY and surveillance requirements are provided in the system LCOs and by programmatic requirements identified in Chapter 5, Administrative Controls.

LCO 3.3.1, Module Protection System (MPS) Instrumentation, and LCO 3.3.2, "Reactor Trip System (RTS) Logic and Actuation," provide requirements on the other portions of the MPS that automatically initiate the Functions described in Table 3.3.1-1.

The ESFAS logic and actuation consists of:

1. Emergency Core Cooling System (ECCS) actuation;

2. Decay Heat Removal System (DHRS) actuation;

3. Containment Isolation System (CIS) actuation;

4. Demineralized Water Supply Isolation (DWSI) actuation;

5. Chemical and Volume Control System Isolation (CVCSI) actuation;

6. Pressurizer Heater Trip (PHT); and

7. Low Temperature Overpressure Protection (LTOP) actuation.

NuScale B 3.3.3-1 Draft Revision 3.0

ESFAS Logic and Actuation B 3.3.3 BASES APPLICABLE SAFETY ANALYSES, LCO, and APPLICABILITY (continued)

5. CVCSI Actuation The CVCSI is designed to mitigate postulated events that result from overfilling the reactor coolant system. It also mitigates primary system high energy line breaks postulated to occur outside of the containment. The actuation is required to be OPERABLE in MODES 1, 2, and 3. In MODES 4 and 5 the CVCS is physically isolated from the module and therefore cannot affect the boron concentration and reactivity in the reactor nor can it overfill the RCS.

6. Pressurizer Heater Trip The PHT is designed to protect the pressurizer heaters from uncovering, overheating, and potentially compromising the RCS pressure boundary. The PHT is required to be OPERABLE when the pressurizer heaters are, or may be energized. The trip is required to be OPERABLE in MODE 1, and in MODES 2 and 3 if a pressurizer heaterPHT breaker is closed. In MODES 4 and 5 the power supply to the pressurizer heaters are physically isolated from the module and therefore cannot be energized.

7. LTOP Actuation The LTOP is designed to protect the reactor vessel integrity from postulated overpressure events that occur below the nil ductility transition (NDT) temperature below which the fracture toughness of the reactor vessel is reduced. Therefore the system must be OPERABLE in MODE 3 if the reactor coolant is below the NDT as specified in the PTLR and established as the LTOP enable temperature, the T-1 interlock. Alternatively, the function is satisfied if two RVVs are open. In MODES 1 and 2, the reactor vessel temperature is above the NDT temperature and the reactor safety valves provide overpressure protection. In MODE 4 the RVVs are de-energized and open which prevents pressurization of the reactor vessel. In MODE 5 the reactor coolant system is in open contact with the ultimate heat sink and cannot be pressurized.

The ESFAS logic and actuation satisfies Criterion 3 of 10 CFR 50.36(c)(2)(ii).

Operability requirements for manual ESFAS actuation are described in LCO 3.3.4.

NuScale B 3.3.3-4 Draft Revision 3.0

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

SR 3.3.3.2 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 ESF 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.

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."

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 administrative 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 3.3.3-10 Draft Revision 3.0

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

SR 3.3.3.3 SR 3.3.3.3 is the performance of a CHANNEL CALIBRATION of the Class 1E isolation devices, as described in SR 3.3.1.4.

A note provides an allowance for the SR so that it does not need to be met for class 1E isolation devices that have isolated the 1E circuits from the non-1E power. This allowance permits continued operation when an isolation device that may not be able to satisfy the requirements of the SR but that has already performed its safety function.

Class 1E isolation devices ensure that electrical power to the associated MPS circuitry and logic will not adversely affect the ability of the system to perform its safety functions. The devices de-energize and isolate the MPS components if such a condition is detected. This surveillance verifies the setpoints and functions of the isolation devices including associated alarms and indications by performing a CHANNEL CALIBRATION of required Class 1E isolation devices. The overcurrent and undervoltage setpoints of the Class 1E isolation devices are established and controlled in accordance with the Setpoint Program.

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

SR 3.3.3.4 SR 3.3.3.4 verifies the pressurizer heater trip breaker (PHTB) actuates to the open position on an actual or simulated trip signal on each pressurizer heater breakerPHTB. This test verifies OPERABILITY by actuation of the end devices. The pressurizer heater breakerPHTB test verifies the under voltage trip mechanism opens the breaker. A Note is provided indicating that the SR does not need to be met for pressurizer heater trip breakers that are open or closed under administrative control. This allowance permits continued operation when a trippressurizer heater breaker may not be able to satisfy the requirements of the SR but is already open or can be quickly opened by administrative means. When a pressurizer heater trip breaker is open it has performed its safety function. This is acceptable because of 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

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-79

72. In Revision 2 of DCA part 2, FSAR Tier 2, Section 5.2, page 5.2-24 states, Maintaining acceptable containment leakage detection performance using the containment pressure monitoring and CES condensate monitoring systems is dependent on maintaining containment pressure below the vapor pressure for the lowest internal containment wall temperature. For conservatism, the minimum containment wall temperature is assumed to be equal to the reactor pool bulk temperature. Figure 5.2-3 provides a containment pressure saturation curve as a function of reactor pool bulk temperature with an adjustment to account for containment pressure instrumentation uncertainty. When containment pressure is in the Not Acceptable region of Figure 5.2-3, condensation may exist inside the containment thus impacting the accuracy of the containment pressure monitoring and CES condensate monitoring systems.

(i) Based on this discussion, the applicant is requested to confirm that the CNV pressure vs.

CNV inner wall temperature limit curve of FSAR Figure 5.2-3 defines the CNV pressure above which CES condensate channels and CES inlet pressure channels are insufficiently accurate and therefore inoperable.

(ii) The applicant is requested to consider adding a Surveillance to Subsection 3.4.7 that verifies CNV pressure is within limits with a Frequency of 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

(iii) The staff observes that the Bases for Subsection 3.4.7 does not discuss the relationship between CES performance, as indicated by CNV pressure (and CNV wall temperature), and operability of the CES RCS leakage detection methods (CES condensate channels and CES inlet pressure channels). The applicant is requested to revise Subsection B 3.4.7 by including a NuScale Nonproprietary

discussion of the dependency of these RCS leakage detection methods on CNV narrow range pressure (and CNV inner wall temperature assumed to match UHS temperature), and whether the gaseous radioactivity monitor channel operability is affected by CNV pressure.

NuScale Response:

(i) The pressure-temperature curve provided in FSAR Tier 2, Figure 5.2-3 illustrates the acceptable operating region that ensures the Containment Evacuation System (CES) condensate and pressure channels will detect and provide representative values for primary leakage. OPERABILITY of the CES condensate and pressure channels requires the combination of pool temperature and containment pressure to lie within the region labeled Acceptable on the figure. This is described in more detail in FSAR Tier 2, section 5.2.5.

(ii) There is no need for an additional Surveillance Requirement because the definition of OPERABILITY will require that the pressure and temperature of the containment vessel remain within the Acceptable region of FSAR Tier 2, Figure 5.2-3 when the CES channels are required to be OPERABLE. The bases of SR 3.7.4.1 and 3.7.4.2 have been modified to explicitly include the instruments used to ensure the containment is operating within the acceptable region. Plant procedures required by specification 5.4.1 will incorporate this check.

LCO 3.5.3, Ultimate Heat Sink (UHS), requires pool temperature be monitored and maintained within limits. The minimum acceptable temperature is 65 ºF, which corresponds to a limit of approximately 0.2 psia on Figure 5.2-3.

Normal containment operating conditions are described in FSAR Tier 2, Table 6.2-1, Containment Design and Operating Parameters. As described there, the normal containment pressure will be less than 0.1 psia. (Note that many analyses conservatively assume containment operating pressures greater than this; however, those values are chosen to delay actuation or otherwise introduce conservatisms and improve confidence in the associated safety determination.)

UHS pool temperature and containment pressure are continuously monitored and available to the plant operators responsible for ensuring the OPERABILITY of the CES condensate and pressure monitoring channels for compliance with the technical specifications. Plant procedures will require appropriate actions be initiated if these variables are not within limits during operations. Plant procedures are required by technical specification 5.4.1, and will be prepared in accordance with COL Item 13.5-2.

NuScale Nonproprietary

A new surveillance to verify that the indication and alarm are not present would provide no additional assurance of OPERABILITY.

(iii) The bases of LCO 3.4.7 have been modified by including a discussion of the dependency of these RCS leakage detection methods on containment vessel pressure and UHS pool temperature.

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

RCS Leakage Detection Instrumentation B 3.4.7 B 3.4 REACTOR COOLANT SYSTEM (RCS)

B 3.4.7 RCS Leakage Detection Instrumentation BASES BACKGROUND GDC 30 of Appendix A to 10 CFR 50 (Ref. 1) requires means for detecting, and, to the extent practical, identifying the source of RCS LEAKAGE. Regulatory Guide 1.45 (Ref. 2) describes acceptable methods for selecting LEAKAGE detection systems.

LEAKAGE detection systems must have the capability to detect significant reactor coolant pressure boundary (RCPB) degradation as soon after occurrence as practical to minimize the potential for propagation to a gross failure. Thus, an early indication or warning signal is necessary to permit proper evaluation of all unidentified LEAKAGE.

Industry practice has shown that leakage of 0.5 gpm can be readily detected in contained volumes by monitoring changes in water level. The containment evacuation system (CES) sample vessel is used to collect and quantify water vapor that is from the containment that may be indicative of RCS LEAKAGE. The sample vessel is instrumented to alarm for increases in the normal flow rates to the vessel. This system sensitivity is acceptable for detecting unexpected increases in condensate that may indicate unidentified LEAKAGE.

Containment pressure is also used as an indicator to detect RCS LEAKAGE. The containment pressure monitoring is performed by CES inlet pressure instrumentation and provides indication in the main control room. The minimum pressure accuracy of the containment pressure monitoring instrumentation can detect a pressure change corresponding to a leak rate of < 1 gpm in 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months and a minimum detectable leak rate of

< 0.05 gpm.

OPERABILITY of the CES condensate collection and inlet pressure monitoring instrument channels requires the containment atmosphere to be maintained within a pressure-temperature range that prevents atmospheric saturation conditions from existing. These conditions ensure that leakage into the containment will result in vaporization of the water and changes in the measured containment pressure. Conditions are maintained by continuously ensuring that the containment pressure does not approach the saturation pressure of water that could be present in the containment. The pressure limit is conservatively chosen and based on the ultimate heat sink pool water temperature. A description of the acceptable operating region is provided in FSAR Section 5.2 (Ref. 3).

NuScale B 3.4.7-1 Draft Revision 3.0

RCS Leakage Detection Instrumentation B 3.4.7 BASES BACKGROUND (continued)

The reactor coolant contains radioactivity that, when released, can be detected by radiation monitoring instrumentation in the CES gas discharage line. Reactor coolant radioactivity can therefore be used for leak detection. The CES system has a gaseous effluent monitor to detect isotopes that provide indication of LEAKAGE.

In addition to meeting the OPERABILITY requirements, the monitoring instrumentation is typically set to provide the most sensitive response without causing an excessive number of spurious alarms.

APPLICABLE The need to evaluate the severity of an alarm or an indication is SAFETY important to the operators, and the ability to compare and verify ANALYSES with indications from other systems is necessary. The system response times and sensitivities are described in FSAR Sections 5.2, 3.6, 5.2, and 11.5 (Refs. 3, 4, and 5).

The safety significance of RCS LEAKAGE varies widely depending on its source, rate, and duration. Therefore, detecting and monitoring RCS LEAKAGE into the containment area is necessary. Separating the identified LEAKAGE from the unidentified LEAKAGE provides quantitative information to the operators, to take corrective action should a leak occur.

RCS LEAKAGE detection instrumentation satisfies Criterion 1 of 10 CFR 50.36(c)(2)(ii).

LCO One method of protecting against large RCS LEAKAGE derives from the ability of instruments to rapidly detect extremely small leaks that indicate a possible RCPB degradation. This LCO requires instruments of diverse monitoring principles to be OPERABLE to provide a high degree of confidence that small leaks are detected in time to allow actions to place the unit in a safe condition.

The LCO is satisfied when monitors of diverse measurement means are available. Thus, the CES sample vessel level monitors, in combination with CES inlet pressure channels and a CES gas discharge radioactivity monitor, provides five channels of leakage detection using three diverse methods. The specification requires two of the three diverse methods to be OPERABLE. CES inlet pressure monitoring is performed by two redundant, seismically qualified pressure instruments.

NuScale B 3.4.7-2 Draft Revision 3.0

RCS Leakage Detection Instrumentation B 3.4.7 BASES ACTIONS (continued)

C.1 and C.2 If the Required Action cannot be met within the required Completion Time or if all required leakage detection methods are inoperable, the unit must be brought to a MODE in which the requirement does not apply. To achieve this status, the unit must be brought to at least MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 3 with RCS hot temperature <200°F within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months . This action will place the RCS in a low pressure state which reduces the likelihood of leakage and crack propagation. The allowed Completion Times are reasonable, based on operating requirements and normal cooling capabilities, to reach the required unit conditions from full power conditions in an orderly manner.

SURVEILLANCE SR 3.4.7.1, SR 3.4.7.2, and SR 3.4.7.3 REQUIREMENTS These SRs require the performance of a CHANNEL CHECK for each of the required RCS leakage detection instrumentation channels. The check gives reasonable confidence that the channel is operating properly. The CHANNEL CHECK of the CES condensate and inlet pressure channels includes instrumentation used to assure the containment is operating within the acceptable pressure-temperature region necessary for instrument OPERABILITY. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

SR 3.4.7.4 and SR 3.4.7.5 These SRs require the performance of a COT on the CES gaseous radioactivity monitor and each required CES condensate channel when they are required to be OPERABLE. The test ensures that the monitor or channel can perform its function in the desired manner. A successful test may be performed by the verification of the change of state of an output of the channel. This is acceptable because all of the other required channel outputs are verified by the CHANNEL CALIBRATION. The test verifies the alarm setpoint and relative accuracy of the instrument string when applicable. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

NuScale B 3.4.7-5 Draft Revision 3.0

RCS Leakage Detection Instrumentation B 3.4.7 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.4.7.6, SR 3.4.7.7, and SR 3.4.7.8 These SRs require the performance of a CHANNEL CALIBRATION for each of the required RCS leakage detection instrumentation channels.

The calibration verifies the accuracy of the instrument string. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. 10 CFR 50, Appendix A, Section IV, GDC 30.

2. Regulatory Guide 1.45, May 2008, U.S. Nuclear Regulatory Commission.

3. FSAR Section 5.2, Integrity of the Reactor Coolant Boundary.

34. FSAR Section 3.6, Protection against Dynamic Effects Associated with Postulated Rupture of Piping.

4. FSAR Section 5.2, Integrity of the Reactor Coolant Boundary.

5. FSAR Section 11.5, Process and Effluent Radiation Monitoring Instrumentation and Sampling.

NuScale B 3.4.7-6 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-80

73. A response is not required because the applicant stated in an email dated November 12, 2018, to follow up the November 6, 2018, public meeting conference call, that it would address this item in Part 2, Item 10 of a supplemental response to RAI 197-9051, Question 16-28, and in Revision 3 of DCA part 4. In Revision 2 of DCA part 4, Notes that say "...may be unisolated intermittently under administrative controls." are listed below. The applicant is requested to consider whether all the "(s)" on the word "path(s)" or "heater(s)" can be changed to "s" as an improvement over the STS. The "(s)" actually means "one or more" and that is clearly implied by using "paths" and "heaters."

LCO 3.1.9 Required Action B.1 Note: "[Dilution source] Flow path(s) [in the CVCS makeup line] may be unisolated intermittently under administrative controls."

73.2 LCO 3.3.1 Required Action F.1 Note: "CVCS flow path(s) may be unisolated intermittently under administrative controls."

LCO 3.3.3 Required Action E.1 Note: "Flow path(s) [from the demineralized water storage tank to the RCS] may be unisolated intermittently under administrative controls."

LCO 3.3.3 Required Action F.1 Note: "[CVCS charging and letdown] Flow path(s) may be unisolated intermittently under administrative controls."

LCO 3.3.3 Required Action G.1 Note: "[Pressurizer] Heater(s) may be energized intermittently under manual controls."

LCO 3.3.4 Required Action E.1 Note: "Flow path(s) [from the demineralized water storage tank to the RCS] may be unisolated intermittently under administrative controls."

LCO 3.3.4 Required Action F.1 Note: "Flow paths [from CVCS to the RCS] may be unisolated intermittently under administrative controls."

LCO 3.3.4 Required Action G.1 Note: "[Pressurizer] Heater(s) may be energized intermittently under administrative controls."

NuScale Nonproprietary

LCO 3.4.6 Actions table Note 1: "CVCS flow path(s) may be unisolated intermittently under administrative controls."

LCO 3.6.2 Actions table Note 1: "Penetration flow path(s) may be unisolated intermittently under administrative controls."

LCO 3.7.1 Actions table Note 2: "Main steam line flow path(s) may be unisolated intermittently under administrative controls."

LCO 3.7.2 Actions table Note 2: "Feedwater flow path(s) may be unisolated intermittently under administrative controls."

NuScale Response:

The use of "(s)" has been changed in locations previously provided in responses to RAI, however NuScale does not have a design-specific reason to make additional, general editorial deviations from standard technical specifications (STS) form. No additional changes are being implemented "as an improvement over the STS."

Impact on DCA:

There are no impacts to the DCA as a result of this response.

NuScale Nonproprietary

Boron Dilution Control 3.1.9 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME B. Required Action and B.1 --------------NOTE------------

associated Completion Flow path(s) may be Time not met. unisolated intermittently under administrative OR controls.

Two CVCS demineralized water Isolate dilution source flow 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months isolation valves paths in the CVCS inoperable. makeup line by use of at least one closed manual or OR one closed and de-activated automatic Boric Acid supply boron valve.

concentration not within limits.

OR CVCS makeup pump demineralized water flow path not configured to ensure maximum flowrate is within limits.

NuScale 3.1.9-2 Draft Revision 3.0

MPS Instrumentation 3.3.1 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME D. As required by Required D.1 Open reactor trip breakers. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and referenced in Table 3.3.1-1.

E. As required by Required E.1 Reduce THERMAL POWER 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and to below the N-2L interlock.

referenced in Table 3.3.1-1.

F. As required by Required F.1 --------------NOTE----------------

Action C.1 and CVCS flow path(s) may be referenced in unisolated intermittently Table 3.3.1-1. under administrative controls.

Isolate the CVCS flow to the 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Reactor Coolant System (RCS).

G. As required by Required G.1 Open pressurizer heater 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and breakers.

referenced in Table 3.3.1-1.

H. As required by Required H.1 Isolate demineralized water 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Action C.1 and flow path to RCS.

referenced in Table 3.3.1-1.

I. As required by Required I.1 Be in MODE 2. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action C.1 and referenced in AND Table 3.3.1-1.

I.2 Be in MODE 3 and 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months PASSIVELY COOLED.

NuScale 3.3.1-2 Draft Revision 3.0

MPS Instrumentation 3.3.1 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY SR 3.3.1.4 -------------------------------NOTE-----------------------------

Neutron detectors are excluded from the CHANNEL CALIBRATION.

Perform CHANNEL CALIBRATION on each In accordance with required channel listed in Table 3.3.1-1. the Surveillance Frequency Control Program SR 3.3.1.5 -------------------------------NOTE----------------------------- In accordance with Not required to be met for Class 1E isolation the Surveillance devices that have isolated 1E circuits from non-1E Frequency Control power. Program.

Verify associated Class 1E isolation devices are OPERABLE.

NuScale 3.3.1-6 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 ACTIONS (continued)

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

Action B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.3-1. under administrative controls.

OR --------------------------------------

Both divisions of Isolate the flow path from 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Demineralized Water the demineralized water Supply Isolation storage tank to the reactor actuation function coolant systemIsolate inoperable. dilution source flow paths in the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

F. As required by Required F.1 ----------------NOTE--------------

Action B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.3-1. under administrative controls.

OR --------------------------------------

Both divisions of CVCS Isolate theCVCS charging 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Isolation actuation and letdown flow paths from function inoperable. the CVCS to the Reactor Coolant System by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.3-3 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 controls.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Both divisions of Pressurizer Heater Open pressurizer heater de-energization function breakers.De energize 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 time is within limits. the Surveillance Frequency Control Program NuScale 3.3.3-4 Draft Revision 3.0

ESFAS Logic and Actuation 3.3.3 Table 3.3.3-1 (page 1 of 1)

ESFAS Logic and Actuation Functions APPLICABLE MODES OR OTHER ACTUATION SPECIFIED REQUIRED FUNCTION CONDITIONS DIVISIONS CONDITIONS

1. Emergency Core 1, 2, 3(a) 2 C Cooling System (ECCS)

2. Decay Heat 1, 2, 3(a) 2 C Removal System (DHRS)

3. Containment 1, 2, 3(b) 2 D Isolation System (CIS)

4. Demineralized 1, 2, 3 2 E Water Supply Isolation (DWSI)

5. CVCS Isolation 1, 2, 3 2 F (CVCSI)

6. Pressurizer Heater 1, 2(c), 3(c) 2 G Trip

7. Low Temperature 3(d) 2 A Overpressure Protection (LTOP)

(a) Not PASSIVELY COOLED.

(b) With any RCS temperature above the T-2 interlock.

(c) Not required when Pressurizer Heater trip breakers are open and deactivated.With pressurizer heater trip breakers closed.

(d) With wide range RCS cold temperature below the LTOP enable temperature specified in the PTLR (T-1 interlock) and more than one reactor vent valve closed.

NuScale 3.3.3-6 Draft Revision 3.0

Manual Actuation Functions 3.3.4 ACTIONS (continued)

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

Action A.1 or B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.4-1. under administrative controls.

Isolate the flow path from the 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months demineralized water storage tank to the Reactor Coolant SystemIsolate dilution source flow paths in the CVCS makeup line by use of at least one closed manual or one closed and de-activated automatic valve.

F. As required by Required F.1 ---------------NOTE--------------

Action A.1 or B.1 and Flow path(s) may be referenced in unisolated intermittently Table 3.3.4-1. under administrative controls.

Isolate the flow paths from 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months the CVCS to the Reactor Coolant System by use of at least one closed manual or one closed and de-activated automatic valve.

NuScale 3.3.4-2 Draft Revision 3.0

Manual Actuation Functions 3.3.4 ACTIONS (continued)

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

Action A.1 or B.1 and Heater(s) may be referenced in energizedPressurizer heater Table 3.3.4-1. breakers may be closed intermittently under administrative controls.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months De energize affected pressurizer heaters.Open pressurizer heater breakers.

H. As required by Required H.1 Open two reactor vent Immediately Action A.1 or B.1 and valves.

referenced in Table 3.3.4-1.

I. As required by Required I.1 Be in MODE 2. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months Action A.1 or B.1 and Referenced in AND Table 3.3.4 1.

I.2 Be in MODE 3 with RCS 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months temperature below the T-2 interlock.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.3.4.1 Perform actuation device operational test. In accordance with the Surveillance Frequency Control Program NuScale 3.3.4-3 Draft Revision 3.0

Manual Actuation Functions 3.3.4 Table 3.3.4-1 (page 1 of 1)

Manual Actuation Functions APPLICABLE MODES MANUALLY OR OTHER ACTUATED SPECIFIED REQUIRED FUNCTION CONDITIONS DIVISIONS CONDITIONS

1. Reactor Trip 1, 2(a), 3(a) 2 C System

2. Emergency Core 1, 2, 3(b) 2 D Cooling System

3. Decay Heat 1, 2, 3(b) 2 D Removal System

4. Containment 1, 2, 3(c) 2 I Isolation System

5. Demineralized 1, 2, 3 2 E Water Supply Isolation

6. CVCS Isolation 1, 2, 3 2 F System

7. Pressurizer Heater 1, 2(d), 3(d) 2 G Trip

8. Low Temperature 3(e) 2 H Overpressure Protection (a) When capable of CRA withdrawal.

(b) When not PASSIVELY COOLED.

(c) With any RCS temperature above the T-2 interlock.

(d) Not required when pressurizer heater trip breakers are open and deactivated.With pressurizer heater trip breakers closed.

(e) With wide range RCS cold temperature below the LTOP enable temperature specified in the PTLR (T-1 interlock) and more than one reactor vent valve closed.

NuScale 3.3.4-4 Draft Revision 3.0

Chemical and Volume Control System Isolation Valves 3.4.6 3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.6 Chemical and Volume Control System (CVCS) Isolation Valves LCO 3.4.6 Each of the following CVCS line flow path isolation valves shall be OPERABLE:

a. RCS Injection Isolation Valves,

b. RCS Discharge Isolation Valves,

c. Pressurizer Spray Isolation Valves, and

d. RPV High Point Degasification Isolation Valves.

APPLICABILITY: MODES 1, 2, and 3.

ACTIONS

NOTES------------------------------------------------------------

1. CVCS flow path(s) may be unisolated intermittently under administrative controls.

2. Separate Condition entry is allowed for each flow path.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or more CVCS flow A.1 Isolate the affected CVCS 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months paths with one CVCS flow path by use of at least valve inoperable. one closed and de-activated automatic valve, closed manual valve, or blind flange.

AND NuScale 3.4.6-1 Draft Revision 3.0

Containment Isolation Valves 3.6.2 3.6 CONTAINMENT SYSTEMS 3.6.2 Containment Isolation Valves LCO 3.6.2 Each containment isolation valve shall be OPERABLE.

APPLICABILTY: MODES 1 and 2, MODE 3 with RCS hot temperature 200ºF.

ACTIONS

NOTES-----------------------------------------------------------

1. Penetration flow path(s) may be unisolated intermittently under administrative controls.

2. Separate Condition entry is allowed for each penetration flow path.

3. Enter applicable Conditions and Required Actions for systems made inoperable by containment isolation valves.

4. Enter applicable Conditions and Required Actions of LCO 3.6.1, Containment, when isolation valve leakage results in exceeding the overall containment leakage rate acceptance criteria.

CONDITION REQUIRED ACTION COMPLETION TIME A. -----------NOTE------------ A.1 Isolate the affected 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Only applicable to penetration flow path by use penetration flow paths of at least one closed and with two containment de-activated automatic isolation valves. valve, closed manual valve,

blind flange, or check valve with flow through the valve One or more penetration secured.

flow paths with one containment isolation AND valve inoperable.

NuScale 3.6.2-1 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 ---------------------------------NOTE------------------------------ In accordance with Not required to be met for automatic containment the INSERVICE isolation valves that are closed to comply with TESTING ACTIONS, that are open under administrative PROGRAM controls.

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

SR 3.6.2.4 ---------------------------------NOTE------------------------------ In accordance with Not required to be met for automatic containment the Surveillance isolation valves that are closed to comply with Frequency Control ACTIONS, that are open under administrative Program controls.

Verify each automatic containment isolation valve that is not locked, sealed, or otherwise secured in position, actuates to the isolation position on an actual or simulated actuation signal except for valves that are open under administrative controls.

NuScale 3.6.2-3 Draft Revision 3.0

MSIVs 3.7.1 3.7 PLANT SYSTEMS 3.7.1 Main Steam Isolation Valves (MSIVs)

LCO 3.7.1 Two MSIVs and two MSIV bypass valves per steam line shall be OPERABLE.

APPLICABILITY: MODES 1 and 2, MODES 3 and not PASSIVELY COOLED.

ACTIONS

NOTES-----------------------------------------------------------

1. Separate Condition entry is allowed for each inoperable valve.

2. Main steam line flow path(s) may be unisolated intermittently under administrative controls.

CONDITION REQUIRED ACTION COMPLETION TIME A. -----------NOTE------------ A.1 Isolate the affected main 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Separate Condition steam line flow path by use entry is allowed for of at least one closed and each inoperable valve. de-activated automatic

valve, closed manual valve, or blind flange.

One or more required MSIV valves inoperable. AND A.2 --------------NOTES--------------

1. Isolation in high radiation areas may be verified by use of administrative means.

2. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of administrative means.

Verify the affected main Once per 7 days steam line flow path is isolated.

NuScale 3.7.1-1 Draft Revision 3.0

Feedwater Isolation 3.7.2 3.7 PLANT SYSTEMS 3.7.2 Feedwater Isolation LCO 3.7.2 One Feedwater Isolation Valve (FWIV) and one Feedwater Regulation Valve (FWRV) for each steam generator shall be OPERABLE.

APPLICABILITY: MODES 1 and 2, MODES 3 and not PASSIVELY COOLED.

ACTIONS

NOTES------------------------------------------------------------

1. Separate Condition entry is allowed for each inoperable valve.

2. Feedwater flow path(s) may be unisolated intermittently under administrative controls.

CONDITION REQUIRED ACTION COMPLETION TIME A. One or two FWIVs A.1 Isolate the affected FWIV 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months inoperable. flow path by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange.

AND A.2 --------------NOTES--------------

1. Isolation in high radiation areas may be verified by use of administrative means.

2. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of administrative means.

Verify FWIV path isolated. Once per 7 days NuScale 3.7.2-1 Draft Revision 3.0

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

When an interlock or permissive is not supporting the associated Function's OPERABILITY at the existing plant conditions, the affected Function's channels must be declared inoperable and appropriate ACTIONS taken.

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

SR 3.3.1.5 A note provides an allowance for the SR so that it does not need to be met for class 1E isolation devices that have isolated the 1E circuits from the non-1E power. This allowance permits continued operation when an isolation device that may not be able to satisfy the requirements of the SR but that has already performed its safety function.

Class 1E isolation devices ensure that electrical power to the associated MPS circuitry and logic will not adversely affect the ability of the system to perform its safety functions. The devices de-energize and isolate the MPS components if such a condition is detected. This surveillance verifies the setpoints and functions of the isolation devices including associated alarms and indications.

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

REFERENCES 1. Regulatory Guide 1.105, Revision 3, Setpoints for Safety-Related Instrumentation.

2. 10 CFR 50, Appendix A, GDC 21.

3. 10 CFR 50.34.

4. FSAR, Chapter 7, "Instrumentation and Controls."

5. FSAR, Chapter 14, "Initial Test Program and ITAAC."

6. 10 CFR 50.49.

7. TR-0606-49121, Rev. 0, NuScale Instrument Setpoint Methodology.

8. IEEE Standard 603-1991.

9. FSAR, Chapter 15, "Transient and Accident Analyses."

NuScale B 3.3.1-52 Draft Revision 3.0

Containment Isolation Valves B 3.6.2 BASES SURVEILLANCE REQUIREMENTS (continued)

SR 3.6.2.3 Verifying that the isolation 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. Isolation 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. A Note is provided indicating that the surveillance requirement is not required to be met for automatic containment isolation valves that were closed to comply with ACTIONS, but are open under administrative controls.

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.

A Note is provided indicating that the surveillance requirement is not required to be met for automatic containment isolation valves that were closed to comply with ACTIONS, but are open under administrative controls.

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

NuScale B 3.6.2-7 Draft Revision 3.0

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-81

74. In Revision 2 of DCA part 4, Subsections 3.4.6 and 3.6.2. The applicant is requested to explain how the operability of the eight CVCS containment isolation valves specified by LCO 3.4.6 differs from the operability of these valves specified by LCO 3.6.2. In particular, the CVCS isolation valves are required in Mode 3 with RCS hot temperature < 200°F by LCO 3.4.6. Does this imply that below 200°F, the eight CVCS isolation valves do not need to meet SR 3.6.2.2 and SR 3.6.2.5 (verify combined leakage rate of all containment bypass leakage paths is 0.6 La when pressurized Pa)?

Can meeting SR 3.6.2.1 (verify required valves accumulator [nitrogen] pressures) or meeting SR 3.4.6.1 (verify required valves accumulator [nitrogen] pressures) be credited as meeting the other? Should each of these two SRs include a Note that permits this?

Can meeting SR 3.6.2.3 (verify isolation time of each containment isolation valve) or meeting SR 3.4.6.2 (verify isolation time of each automatic power operated CVCS valve) be credited as meeting the other? Should each of these two SRs include a Note that permits this?

Can meeting SR 3.6.2.4 (verify each automatic containment isolation valve ... actuates to the isolation position on an actual or simulated actuation signal) or meeting SR 3.4.6.3 (verify each automatic CVCS valve ... actuates to the isolation position on an actual or simulated actuation signal) be credited as meeting the other? Should each of these two SRs include a Note that permits this?

NuScale Nonproprietary

NuScale Response:

The MODES of applicability are slightly different in that LCO 3.4.6 applies in MODES 1, 2, and 3, while 3.6.2 applies in MODES 1, 2, and MODE 3 when the reactor coolant system (RCS) is below 200 °F. The functional requirements of the valves are slightly different in that LCO 3.4.6 actuation is via the chemical and volume control system isolation (CVCSI) actuation function in accordance with LCO 3.3.3. The valve actuation required by LCO 3.6.2 is via the containment isolation system actuation function (CIS) in accordance with 3.3.3. Logic or actuation failures can be postulated that would affect one actuation function and not the other, in which case Conditions associated only with that function would be entered.

In accordance with SR 3.0.1, SRs must be met during the MODES or other specified Conditions in the applicability of individual LCOs. Based on this, SR 3.6.2.4 does not apply for actuation from the CIS function when the RCS is below 200 °F. SR 3.6.2.2 applies to manual valves and blind flanges and therefore it does not apply to these valves.

Surveillance tests are often written to accomplish multiple test objectives across multiple specifications. The accumulator pressure tests, actuation time tests, and actuation logic tests may be written to accomplish the alternative corresponding test objective. They may also be performed separately for operational or design reasons. For example the actuation tests may be written to verify the functionality of the CVCSI actuation function distinctly from the CIS actuation function even though in this case the same isolation valves are actuated.

Notes indicating cross reference are not required and could unnecessarily restrict future surveillance test procedures and their maintenance. Addition of the Notes would provide no value to the SRs.

Impact on DCA:

There are no impacts to the DCA as a result of this response.

NuScale Nonproprietary

Response to Request for Additional Information Docket No.52-048 eRAI No.: 9634 Date of RAI Issue: 11/29/2018 NRC Question No.: 16-60-82

75. In Revision 2 of DCA part 4, Subsection B 3.6.2, Actions section. The applicant is requested to Correct the Bases for Action B.1. The first paragraph ends with the phrase "...with two condition isolation valves" but should say ""...with two containment isolation valves."

Revise the Bases discussions of the Notes for Condition A and Condition B, which state, "Only applicable to penetration flow paths with two containment isolation valves." The staff suggests that Subsection B 3.6.2 state the containment penetrations that are for a closed system or that have just one active containment isolation valve; and the LCOs that govern the containment isolation function operability of such penetration flow paths.

NuScale Response:

The typographical error at the end of the first paragraph of the bases for Condition B Actions has been corrected.

The NuScale containment design is much simpler than existing PWRs. The containment system includes two containment isolation valves on all lines except for the secondary feedwater and steam generator lines where the secondary system inside the containment and reactor vessel form the second barrier to release of radioactive material. Those valves are addressed in LCO 3.7.1, Main Steam Isolation Valves, and LCO 3.7.2, Feedwater Isolation. There are no other closed loop systems without two containment isolation valves in the NuScale design. See FSAR Tier 2, section 6.2, Containment Systems for additional information.

While this is different from existing PWRs, the NuScale bases are written to clarify the intent and applicability of the technical specifications for the plant operators and staff. Those individuals NuScale Nonproprietary

will be trained and familiar with the simplified containment design. They will also be familiar with the requirements of LCOs 3.7.1 and 3.7.2. The additional information recommended by the staff for inclusion would provide no additional value to the plant staff. Based on this, no additional changes to the bases are proposed.

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

Containment Isolation Valves B 3.6.2 BASES ACTIONS (continued)

B.1 Condition B has been modified by a note indicating that this Condition is only applicable to those penetration flow paths with two containmentdition isolation valves.

With two containment isolation valves in one or more penetration flow paths inoperable, the affected penetration flow path must be isolated within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . The method of isolation must include the use of at least one isolation device that cannot be adversely affected by a single active failure. Isolation devices that meet this criterion are a closed and de-activated automatic valve, a closed manual valve, or a blind flange. The 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Completion Time is consistent with the ACTIONS of LCO 3.6.1. In the event the affected penetration is isolated in accordance with Required Action B.1, the affected penetration must be verified to be isolated on a periodic basis per Required Action A.2, which remains in effect. This periodic verification is necessary to assure leak tightness of containment and that penetrations requiring isolation following an accident are isolated. The Completion Time of once per 31 days for verifying each affected penetration flow path is isolated is appropriate considering the fact that the devices are operated under administrative controls and the probability of the misalignment is low.

C.1 and C.2 If the Required Actions and associated Completion Times are not met, the unit must be brought to a MODE or condition in which the LCO does not apply. To achieve this status, the unit must be brought to at least MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and MODE 3 with RCS hot temperature < 200ºF within 48 hours5.555556e-4 days 0.0133 hours 7.936508e-5 weeks 1.8264e-5 months .

Completion Times are established considering the likelihood of an event that would require CIS actuation. They also provide adequate time to reach the required unit condition from full power conditions in an orderly manner.

NuScale B 3.6.2-5 Draft Revision 3.0

ML19056A587

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REFERENCES:

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