ML19323F698

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DCA Technical Specification Confirmatory Items - Email Commitments
ML19323F698
Person / Time
Site: NuScale
Issue date: 11/19/2019
From: Getachew Tesfaye
NRC/NRR/DNRL/NRLB
To:
Tesfaye G / 415-8013
References
Download: ML19323F698 (16)
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Text

Response to Questions Dated 9/3/19 NuScale Technical Specification Revision 4 Confirmatory Items From: Tesfaye, Getachew Sent: Wednesday, September 04, 2019 10:56 AM To: Norris, Rebecca <RNorris@nuscalepower.com>

Cc: Lee, Samuel <Samuel.Lee@nrc.gov>; Cranston, Greg <Gregory.Cranston@nrc.gov>

Subject:

Updated Discussion Item List NuScale DCA Revision 3.docx

Rebecca, As we discussed yesterday afternoon, I have attached an updated list from the staff.

These discussion items are considered important, but their resolution is not required for the staff to conclude the generic TS satisfy 10 CFR 50.36, and will not hinder the staffs completion of the advanced SER, which will reflect the staffs requested corrections of these items. Therefore, in response to this email, the staff requests that NuScale agree to include in Rev 4 of DCA Parts 2 and 4, changes that correct and resolve these discussion items (and any additional similar items, which NuScale may discover).

Additionally, the staff requests that NuScale post in the electronic reading room (eRR) the marked up affected generic TS and Bases pages showing the proposed changes intended to resolve the discussion items. The staff will discuss with NuScale its questions about the proposed changes as soon as possible after their posting in the eRR in order to quickly reach resolution.

The staff will track the changes, which it finds acceptable and agreed to by NuScale, as confirmatory items, and will verify their incorporation in the DCA following the submission of DCA Rev 4 on the NuScale docket.

Thank you, Getachew

Attachment:

  1. Revision 3 of DCA Part 4 - Discussion Items and Suggested Corrections and Clarifications Actions table NOTE (or NOTES) block should have a blank line between Note block and table --- THIS IS A GLOBAL 1

FORMATTING CORRECTION for conformance to WG Ensure that the Bases for each SR included in the Surveillance Frequency Control Program includes a statement that says 2

the Frequency is controlled in accordance with the Surveillance Frequency Control Program.

3 SR 3.1.2.1 Note, suggest replacing after each fuel loading with after each refueling to be consistent with Frequency SR 3.1.4.1 Note, suggest replacing rods with CRAs 4

SR 3.1.4.2, suggest replacing rod with CRA in both cases 5 3.1.6 Applicability Note - insert is between LCO and not Condition 3.1.7.C - change the CRAs position to the associated CRAs position or 6 the affected CRAs position or the CRAs position 7 B 3.1.8 ASA section, next to last paragraph, second sentence, change CRA to CRAs 8 Required Action 3.3.1.G.1 Note: change Heater to heater Table 3.3.1-1, revise footnote (c) for consistency with footnote (b) phrasing 9

(c) With power below Below the N-2H interlock.

In Rev 3 of DCA part 4, on page B 3.3.1-46, the discussion states the following:

Low ELVS Voltage is determined by measuring two ELVS 480 Vac buses that provide power to the EDSS battery 10 chargers with two sensors per separation group. If both 480 Vac bus voltages are below the setpoint [Table 7.1-3: Reactor Trip Functions, Analytical Limit: 80% of normal ELVS voltage], the following occurs:

1

Response to Questions Dated 9/3/19

  1. Revision 3 of DCA Part 4 - Discussion Items and Suggested Corrections and Clarifications 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> timers started.

If ac voltage is not restored to at least EDSS battery charger B OR C within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> the following will occur:

RTS chassis is de-energized ESFAS chassis is de-energized MWS is de-energized This will generate an ECCS actuation.

FSAR Table 7.1-4, ESFAS Functions, indicates that expiration of the Low ELVS Voltage 24-hour Timer on 2 of 3 [timer]

channels [Analytical Limit: 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s] removes electrical power from the trip valve solenoids of the three RVVs and two RRVs, allowing these five ECCS valves to open.

Explain why MPS Function 3.3.1.24, Low AC Voltage to Low Voltage AC Electrical Distribution System (ELVS) Battery Chargers, does not list ECCS as a supported ESF Logic and Actuation Function in Table 3.3.1-1. Why is this explanation not included in the Subsection B 3.3.1 passage on pages B 3.3.1-46 and B 3.3.1-47? Else, revise Bases to make clear that the timer functionality is required for Function 3.3.1.24 to be operable Table 3.3.1-1, new footnote (b)(i) for Function 20, Low Steam Superheat; A. Change the phrase, or no V-1 interlock (FWIV closed.)

to and V-1 interlock not active (both FWIVs open).

for greater clarity.

B. In accordance with writers guide, renumber new footnote (b)(i) in order of first appearance in the table, as:

(i) With power above the N-2H interlock and V-1 interlock not active (both FWIVs open).

as follows: 1(i) 11 or (i) With V-1 interlock not active (both FWIVs open).

and With footnote (b) still listed, use footnote (i) in combination with footnote (b), as follows: 1(b)(i)

In this syntax, both (b) and (i) must be true; if either is false, then Function 20.a is blocked.

C. Renumber footnotes (i), (j), (k), which have their initial occurance after new footnote (i), as (j), (k), (l)

D. Revise 3.3.1 Bases discussions to clarify that Function 20. Low Steam Superheat initiations of a. RTS, b. DWSI, and c. SSI are enabled when both the N-2H interlock is not active (which is when Thermal Power is above 15% RTP) and the V-1 interlock is not active (which is when both FWIVs indicate open).

2

Response to Questions Dated 9/3/19

  1. Revision 3 of DCA Part 4 - Discussion Items and Suggested Corrections and Clarifications
1. 3.3.1 Actions Table NOTE 2 should refer to SG-specific-steam-related Functions 16, 17, 18, 19, and 20; and NOTE 3 should refer to Function 24---to match revised enumeration stemming from the removal of ECCS actuation on Low RPV Riser Level Function.

These corrections are also needed in all associated discussions in the 3.3.1 Bases which refer to the 3.3.1 Functions by number, such as in the Actions section of Bases on pages B 3.3.1-49 and under Action D.1 on page B 3.3.1-51: for example 3.3.1 Functions 17a, 19a, 20a, 20b, 21a, 21b, 22a should be 3.3.1 Functions 16a, 18a, 19a, 19b, 20a, 20b, 21a Also, as indicated, the DHRS actuation on Functions 19 and 20 (new Function numbers) was removed, but was replaced by SSI actuation--however, with a different Actions Condition. Thus, the Action D.1 Bases should remove references to DHRS actuation in the first sentence. In addition, the list of Functions covered by Action D.1 may be simplified because it now only refers to MPS instrumentation Functions that initiate a reator trip.

2. Under the Bases discussion of 3.3.1 Action D.1, reference to Function 8.b, DHRS actuation on Low Pressurizer Pressure, should be removed because when DHRS was split into DHRS and SSI, DHRS was removed from Function 3.3.1.8.

12

3. Explain why SSI was not added to Function 3.3.1.8, Low Pressurizer Pressure, when DHRS was removed.
4. Explain why CVCSI was removed from Function 3.3.1.8, Low Pressurizer Pressure.
5. Provide specific Chapter 15 references, such as subsection numbers (15.x.y.z) with titles, and sequence of events (SOE) table numbers (Table 15.x-nn) with titles, for which FSAR Chapter 15 analyzed events depend on each of the following MPS Functions (DCA Revision 3 Function enumeration is used). If no such event exists for a listed Function, state the rationale for meeting Criterion 3 and ensure the Functions associated description in the Bases is consistent with that rationale.
a. Function 3.3.1.15, Low Low RCS Flow, to initiate a. RTS and c. DWSI.
b. Function 3.3.1.18, Low Low Main Steam Pressure, to initiate a. RTS, b. DWSI, and c. SSI in MODE 1, and in MODE 2 when capable of CRA withdrawal.
c. Function 3.3.1.21, High Narrow Range Containment Pressure, to initiate c. CVCSI.
d. Function 3.3.1.24, Low AC Voltage to Low Voltage AC Electrical Distribution System (ELVS) Battery Chargers, to initiate a. RTS, b. DHRS, c. CIS, d. CVCSI, e. DWSI, f. PHT, and g. SSI.
e. Function 25, High Under-the-Bioshield Temperature, to initiate a. RTS, b. CIS, c. CVCSI, d. DWSI, and e. SSI.

Referencing instrumentation functions should have same capitalization. Capitalize Actuation and Trip in 3.3.3 Condition phrases:

Condition 3.3.3.A, LTOP Actuation Function Condition 3.3.3.B, Actuation Functions and LTOP Actuation Function 13 Condition 3.3.3.C, ECCS Actuation Function and DHRS Actuation Function Condition 3.3.3.F, Containment Isolation Actuation Function Condition 3.3.3.E, Demineralized Water Supply Isolation Actuation function Condition 3.3.3.F, CVCS Isolation Actuation Function Condition 3.3.3.G, Pressurizer Heater Trip Actuation Function Table 3.3.1-1 Functions 24.c and 25.b have Applicability of MODES 1, 2, and 3. Yet Table 3.3.3-1 Function 3, CIS, which 14 is initiated by these MPS instrument Functions, has applicability of MODES 1 and 2, and also MODE 3 above 200°F wide range RCS hot temperature (T-2 interlock not active). Explain why this inconsistency is specified.

The SR 3.3.1.5, SR 3.3.2.3, and SR 3.3.3.3 Class 1E isolation device Channel Calibration statements should append in 15 accordance with the Setpoint Program (See 16-50)

Required Action 3.4.9.A.2 Completion Time - suggest Prior to entering MODE 4 3 following next refueling outage or SG 16 tube inspection because tube inspection/plugging must be done in MODE 5 17 Condition 3.7.1.A One or more required valves inoperable.

18 5.3.2, remove comma after who From: Norris, Rebecca <RNorris@nuscalepower.com>

Sent: Wednesday, September 04, 2019 7:04 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Cc: Lee, Samuel <Samuel.Lee@nrc.gov>; Cranston, Gregory <Gregory.Cranston@nrc.gov>; Gross, Karl

<kgross@nuscalepower.com>; Melton, Mike <MMelton@nuscalepower.com>

Subject:

[External_Sender] RE: Updated Discussion Item List NuScale DCA Revision 3.docx 3

Response to Questions Dated 9/3/19

Getachew, I am booked solid in the morning, but I was hoping to chat about these items prior to the PM meeting tomorrow. Do you happen to free at 0730 PST? I could even go as early as 0700 if that is when you are available.

Below is a list of NuScale comments with regard to the attached list of suggested edits to DCA Part 4. To be clear, anything listed as Incorporating is still going through our internal review process for DCA Revision 4 and is not finalized - if any issues come up for these in this process, we will let you know as soon as possible. I have highlighted portions where we owe staff further explanation, so it is easier to track.

1. Incorporating
2. Incorporating
3. Evaluating
4. Evaluating
5. Incorporating, CP-1908
6. Evaluating
7. Incorporating
8. Incorporating, CP-1908
9. Likely to incorporate, though not word-for-word to the suggested edit. This is grouped with additional footnote corrections spurred by the email copied below, and will be addressed in CP-1914
10. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> timer is not credited in any safety analyses and does not meet the criteria, so we will likely not be incorporating any change based on this feedback. Please feel free to contact us with any further questions you have on the matter.
11. Likely to incorporate in CP-1914, similar to Item 9
12. Evaluating
13. Incorporating
14. Evaluating
15. Already incorporated in DCA Rev 3, CP-1511 and described in RAI 16-17S1 (ML18355A905)
16. No change expected, but will provide explanation
17. Already incorporated in DCA Rev 3, CP-1441 and described in RAI 16-52 (ML18347A619), pg 19/59 in RAIO-1218-63828
18. Incorporating, CP-1908 Email related to Items 9 and 11, received 8/22/19 12:33PM PST:

There seems to be an issue needing clarification:

Ask NuScale to address the issue of T-3 bypassing SSI actuation on high narrow range containment pressure (Table 3.3.1-1 Function 21.e as numbered in draft Rev 3 of DCA part 4) with RCS WR hot temperature < 350°F (T-3 interlock active), when this Functions applicability of MODE 3 when not PASSIVELY COOLED could apply below 350°F.

I hope this helps, and we will keep you updated.

4

Response to Questions Dated 9/3/19 Rebecca Norris Supervisor, Licensing email: RNorris@nuscalepower.com web: www.nuscalepower.com office: 541-452-7539 cell: 541-602-1260 The contents of this email are intended only for the person to whom it is addressed. If you received it by mistake, please inform me by reply email and then delete the message and any attachments. This email may contain proprietary, confidential and/or privileged material, which doesn't change if it is sent to an unintended recipient. Unless you have my consent, please do not copy, forward, or reveal the contents of this email to anyone.

From: Norris, Rebecca <RNorris@nuscalepower.com>

Sent: Wednesday, September 11, 2019 11:01 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Cc: Lee, Samuel <Samuel.Lee@nrc.gov>; Cranston, Greg <Gregory.Cranston@nrc.gov>; Gross, Karl

<kgross@nuscalepower.com>

Subject:

[External_Sender] RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, Attached is our list of responses to the subject discussion items, including the amended response to item 17.

Please let me know of any comments, and we still intend to upload CPs into the TS eRR folder as they are approved.

Rebecca Norris Supervisor, Licensing email: RNorris@nuscalepower.com web: www.nuscalepower.com office: 541-452-7539 cell: 541-602-1260 The contents of this email are intended only for the person to whom it is addressed. If you received it by mistake, please inform me by reply email and then delete the message and any attachments. This email may contain proprietary, confidential and/or privileged material, which doesn't change if it is sent to an unintended recipient. Unless you have my consent, please do not copy, forward, or reveal the contents of this email to anyone.

Attachment Response to Questions Dated 9/3/19

1. This formatting concern will be addressed in revision 4.
2. This issue will be addressed in revision 4.
3. NuScale is aligning the Note and the Frequency in revision 4 to require performance after each fuel loading. This is conservative because it requires performance after reloading a core, not just after each refueling.

5

Response to Questions Dated 9/3/19

4. These changes will be addressed in revision 4.
5. This change will be addressed in revision 4. The change is also being applied to LCO 3.1.5.
6. An apostrophe was added to CRAs in the Condition of 3.1.7 and an s is being added to CRA in Required Action C.1 of LCO 3.1.7 in revision 4.
7. An s is being added in revision 4 to CRA in the Bases of LCO 3.1.8 as requested.
8. The word heater will no longer be capitalized in Required Action G.1 of LCO 3.3.1 in revision 4.
9. The footnotes of Table 3.3.1-1, 3.3.3-1, and 3.3.4-1 are being reviewed and clarified consistent with the comments received and described below. All footnotes are being re-baselined against the system design as described in the FSAR, safety analyses, and descriptions below. This will also ensure internal consistency, clarity, and conformance with the writers guide. These changes will be incorporated into revision 4.

Modifications to the Notes will result in changes to the Required Actions and Bases associated with LCO 3.3.1, 3.3.3, and 3.3.4 that will also be included in revision 4.

10. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> timer is neither safety-related, nor does it perform a function that is credited in any safety analysis. If conditions warrant, the safety analyses credit ECCS initiation by other signals and do not depend on the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> timer to perform its credited function.

The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> timer provides operational flexibility to allow a controlled shutdown using the decay heat removal system. However this feature is not a part of the primary success path to mitigate a design basis accident or transient. Therefore it is not included in the Technical Specifications. The Bases discussion that includes the timer will be revised in revision 4 to reflect this.

11. These concerns are being considered in conjunction with developing the response to item 9 above.

12.1 These concerns are being considered in conjunction with developing the response to item 9 above.

12.2 These concerns are being considered in conjunction with developing the response to item 9 above.

12.3 The Low Pressurizer Pressure and Low-Low Pressurizer Pressure signals are designed protect RCS subcooled margin for protection against instability events and to detect and mitigate primary system line breaks outside the containment.

Subcooled margin protection is implemented at two limits that result in reactor trip system actuation and demineralized water system isolation. When the RCS hot 6

Response to Questions Dated 9/3/19 temperature is above T-4 the low pressurizer pressure actuation analytical limit is 1720 psia. This protects the RCS subcooled margin for that operating regime.

When operating below the T-4 RCS hot temperature the Low-Low Pressurizer Pressure signal analytical limit of 1600 psia provides similar subcooled margin protection of the RCS.

The lower limit, implemented as the low-low pressurizer pressure signal is credited with mitigating primary system line breaks outside the containment by isolating the CVCS system and the secondary side of the steam generation system.

The safety analyses in FSAR 15.6.2 and 15.6.3 describe the analyses of small line breaks outside the containment and steam generator tube failures that the low-low pressurizer pressure signal mitigates. The subcooled margin protection is illustrated at FSAR Figure 15.0.9 as the two vertical lines on the right side of the figure.

12.4 See 12.3 above.

12.5 [Note that not all Technical Specifications contents are related directly to transients or accidents provided in the Chapter 15 analyses. Other portions of the FSAR include analyses that were considered in the development of the proposed specifications. The information provided refers to locations in the FSAR. This is consistent with 10 CFR 50.36 and precedent provided in the generic standard technical specifications.]

12.5.a RTS and DWS on Low-Low RCS Flow - The Low-Low RCS Flow signal is designed to ensure flow remains measurable and positive during low power startup conditions. The actuation signal supports startup of the NuScale reactor design that depends on an external module heatup system to initiate and ensure natural circulation during heatup to operating conditions. During these startup conditions, if the nonsafety-related module heatup system were to fail, the CVCS could be operating such that colder water is added into the riser over the core, causing a reduced flow condition. This actuation occurs on a decreasing process variable at the low end of detectable RCS flow. A description of the module heatup system and the CVCS design, functions, and operation are provided in FSAR 9.3.4. FSAR section 15.4.6 describes the isolation of demineralized water sources by the MPS prior to loss of a significant portion of the minimum shutdown margin.

12.5.b The Low and Low-Low Main Steam Pressure signals are designed to detect and mitigate secondary system line breaks outside the containment and to protect steam generator inventory and thereby support decay heat removal functionality if needed. The Low Main Steam Pressure setpoint of about 300 psia is too high to permit reactor startup without resulting in actuations including reactor trips. However, the approximately 20 psia Low-Low Pressure setpoint permits startup while continuing to provide the protective measures that the Low Steam Pressure actuations provide. Steam piping failures outside the containment are described and evaluated in FSAR section 15.1.5.

12.5.c CVCSI actuation on High Narrow Range Containment Pressure is described in FSAR 15.6.5, the signal is designed to detect and mitigate RCS or secondary leaks above the allowable limits to protect RCS inventory and ECCS function during these events. CVCS isolation initiates isolation of a portion of the boundary established in response to these postulated events.

7

NuScale Responses to September Tech Spec Questions 12.5.d Function 24, the low AC voltage actuation signal is designed to ensure predictable module protection system (MPS) behavior if degraded voltage conditions exist. The MPS is required to be available to provide credited, predictable response to initiate actions in response to design basis events. This function and its role ensuring the availability and OPERABILITY of the MPS is described in FSAR section 7.1.

12.5.e Function 25, the high under-the-bioshield actuation signal is designed to detect high energy leaks/breaks at the top of reactor module under-the-bioshield to reduce the consequences of HELB on the safety related equipment located on top of the RXM. Postulated high energy line breaks under the bioshield are described in FSAR 3.6.

13. The term actuation will be capitalized in the Conditions of LCO 3.3.3 in revision 4.
14. The Table 3.3.3-1 and Table 3.3.4-1 CIS applicability will be modified to MODES 1, 2, and 3. The Note limiting OPERABILITY requirements to above T-2 will be removed from each table. These concerns are being considered in conjunction with developing the response to item 9 above.
15. These changes were implemented in response to RAI 16-17S1 as shown in the NuScale response (ML18355A905).
16. MODE 3 is the appropriate Completion Time for this Required Action. The SG tubes do not provide any credited safety function in MODES 4 or 5.
17. The word required will be removed from Condition A of LCO 3.7.1 in revision 4.
18. This change will be addressed in Revision 4.

From: Norris, Rebecca <RNorris@nuscalepower.com>

Sent: Friday, September 20, 2019 11:35 AM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Cc: Gross, Karl <kgross@nuscalepower.com>

Subject:

[External_Sender] RE: RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, Attached are NuScales responses to the updated question list. We did intend to upload Change Packages as we approved them, but since they were so inter-related and on the same DCA pages, we were having issues separating them in pdf form, so all 4 CPs will end up being uploaded at the same time. We still intend to use the existing DCA Part 4 Rev 4 Draft eRR, but there is nothing in there yet.

1

NuScale Responses to September Tech Spec Questions We would still be interested in a breakdown of which of these issues the staff considers answered, and which ones you still have questions on, if at all possible. Again, the easiest way would probably be to add a column to the original question spreadsheet, but whichever way is easiest to communicate would be appreciated.

Thank you, and please let me know of any questions on our responses.

Rebecca Norris Supervisor, Licensing email: RNorris@nuscalepower.com web: www.nuscalepower.com office: 541-452-7539 cell: 541-602-1260 The contents of this email are intended only for the person to whom it is addressed. If you received it by mistake, please inform me by reply email and then delete the message and any attachments. This email may contain proprietary, confidential and/or privileged material, which doesn't change if it is sent to an unintended recipient. Unless you have my consent, please do not copy, forward, or reveal the contents of this email to anyone.

From: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Sent: Monday, September 16, 2019 1:20 AM To: Norris, Rebecca <RNorris@nuscalepower.com>

Subject:

RE: RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx Thank you Rebecca.

From: Norris, Rebecca <RNorris@nuscalepower.com>

Sent: Sunday, September 15, 2019 9:28 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Cc: Gross, Karl <kgross@nuscalepower.com>

Subject:

[External_Sender] RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, Because Part 4 touches so many areas, the approval of changes takes a bit longer. As we upload these CPs to the eRR I will make sure to email you a notice with the details.

2

NuScale Responses to September Tech Spec Questions I verified as well, and Craig is correct in that the SR 3.3.1.5, SR 3.3.2.3, and SR 3.3.3.3 statements are not appended with in accordance with the Setpoint Program. Please let me verify with my team as to the cause or reason for lack of inclusion and get back to you soon.

Rebecca Norris Supervisor, Licensing email: RNorris@nuscalepower.com web: www.nuscalepower.com office: 541-452-7539 cell: 541-602-1260 The contents of this email are intended only for the person to whom it is addressed. If you received it by mistake, please inform me by reply email and then delete the message and any attachments. This email may contain proprietary, confidential and/or privileged material, which doesn't change if it is sent to an unintended recipient. Unless you have my consent, please do not copy, forward, or reveal the contents of this email to anyone.

From: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Sent: Friday, September 13, 2019 3:31 AM To: Norris, Rebecca <RNorris@nuscalepower.com>

Subject:

FW: RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Rebecca, Please address staffs request below.

Thank you, Getachew From: Harbuck, Craig Sent: Thursday, September 12, 2019 4:23 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Subject:

RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, In item 15, the referenced supplemental response to 16-17 did not append the phrase in accordance with the Setpoint Program to the SR 3.3.1.5, SR 3.3.2.3, and SR 3.3.3.3 Class 1E isolation device Channel Calibration statements like the Channel Calibration statement of SR 3.3.1.4 does.

The SR 3.3.1.5, SR 3.3.2.3, and SR 3.3.3.3 Class 1E isolation device Channel Calibration statements should append in accordance with the Setpoint Program (See 16-50) 3

NuScale Responses to September Tech Spec Questions These changes were implemented in response to RAI 16-17S1 as shown in the NuScale response (ML18355A905).

I still have no access to draft Rev 4 of DCA in electronic reading room - the electronic reading room location displays no documents Craig From: Tesfaye, Getachew Sent: Thursday, September 12, 2019 1:23 PM To: Harbuck, Craig <Craig.Harbuck@nrc.gov>

Subject:

RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx Communicated to NuScale From: Harbuck, Craig Sent: Thursday, September 12, 2019 1:14 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

Subject:

RE: RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, The provide information is helpful. I have a few more items for NuScale to consider, beginning with item 19 in the attached updated file.

Craig From: Tesfaye, Getachew Sent: Thursday, September 12, 2019 6:19 AM To: Harbuck, Craig <Craig.Harbuck@nrc.gov>; Tjader, Bob <Theodore.Tjader@nrc.gov>

Cc: Cusumano, Victor <Victor.Cusumano@nrc.gov>

Subject:

FW: RE: Updated Discussion Item List NuScale DCA Revision 3.docx From: Norris, Rebecca <RNorris@nuscalepower.com>

Sent: Wednesday, September 11, 2019 11:01 PM To: Tesfaye, Getachew <Getachew.Tesfaye@nrc.gov>

4

NuScale Responses to September Tech Spec Questions Cc: Lee, Samuel <Samuel.Lee@nrc.gov>; Cranston, Greg <Gregory.Cranston@nrc.gov>; Gross, Karl <kgross@nuscalepower.com>

Subject:

[External_Sender] RE: Updated Discussion Item List NuScale DCA Revision 3.docx

Getachew, Attached is our list of responses to the subject discussion items, including the amended response to item 17.

Please let me know of any comments, and we still intend to upload CPs into the TS eRR folder as they are approved.

Rebecca Norris Supervisor, Licensing email: RNorris@nuscalepower.com web: www.nuscalepower.com office: 541-452-7539 cell: 541-602-1260 The contents of this email are intended only for the person to whom it is addressed. If you received it by mistake, please inform me by reply email and then delete the message and any attachments. This email may contain proprietary, confidential and/or privileged material, which doesn't change if it is sent to an unintended recipient. Unless you have my consent, please do not copy, forward, or reveal the contents of this email to anyone.

Attachment Date

  1. NuScale Response Received Submitted Comments/Discussion 1 This formatting concern will be addressed in revision 4. 9/3/19 9/11/19 Submitted 2 This issue will be addressed in revision 4. 9/3/19 9/11/19 Submitted 3 NuScale is aligning the Note and the Frequency in revision 4 to require performance after each fuel 9/3/19 9/11/19 Submitted loading. This is conservative because it requires performance after reloading a core, not just after each refueling.

4 These changes will be addressed in revision 4. 9/3/19 9/11/19 Submitted 5 This change will be addressed in revision 4. The change is also being applied to LCO 3.1.5. 9/3/19 9/11/19 Submitted 5

NuScale Responses to September Tech Spec Questions 6 An apostrophe was added to CRAs in the Condition of 3.1.7 and an s is being added to CRA in 9/3/19 9/11/19 Submitted Required Action C.1 of LCO 3.1.7 in revision 4.

7 An s is being added in revision 4 to CRA in the Bases of LCO 3.1.8 as requested. 9/3/19 9/11/19 Submitted 8 The word heater will no longer be capitalized in Required Action G.1 of LCO 3.3.1 in revision 4. 9/3/19 9/11/19 Submitted 9 The footnotes of Table 3.3.1-1, 3.3.3-1, and 3.3.4-1 are being reviewed and clarified consistent with 9/3/19 9/11/19 Submitted the comments received and described below. All footnotes are being re-baselined against the system design as described in the FSAR, safety analyses, and descriptions below. This will also ensure internal consistency, clarity, and conformance with the writers guide. These changes will be incorporated into revision 4.

Modifications to the Notes will result in changes to the Required Actions and Bases associated with LCO 3.3.1, 3.3.3, and 3.3.4 that will also be included in revision 4.

10 The 24-hour timer is neither safety-related, nor does it perform a function that is credited in any 9/3/19 9/11/19 Submitted safety analysis. If conditions warrant, the safety analyses credit ECCS initiation by other signals and do not depend on the 24-hour timer to perform its credited function.

The 24-hour timer provides operational flexibility to allow a controlled shutdown using the decay heat removal system. However, this feature is not a part of the primary success path to mitigate a design basis accident or transient. Therefore, it is not included in the Technical Specifications. The Bases discussion that includes the timer will be revised in revision 4 to reflect this.

11 These concerns are being considered in conjunction with developing the response to item 9 above. 9/3/19 9/11/19 Submitted 12.1 These concerns are being considered in conjunction with developing the response to item 9 above. 9/3/19 9/11/19 Submitted 12.2 These concerns are being considered in conjunction with developing the response to item 9 above. 9/3/19 9/11/19 Submitted 6

NuScale Responses to September Tech Spec Questions Date

  1. NuScale Response Received Submitted Comments/Discussion 12.3 The Low Pressurizer Pressure and Low-Low Pressurizer Pressure signals are designed protect RCS 9/3/19 9/11/19 Submitted subcooled margin for protection against instability events and to detect and mitigate primary system line breaks outside the containment.

Subcooled margin protection is implemented at two limits that result in reactor trip system actuation and demineralized water system isolation. When the RCS hot temperature is above T-4 the low pressurizer pressure actuation analytical limit is 1720 psia. This protects the RCS subcooled margin for that operating regime.

When operating below the T-4 RCS hot temperature the Low-Low Pressurizer Pressure signal analytical limit of 1600 psia provides similar subcooled margin protection of the RCS.

The lower limit implemented as the low-low pressurizer pressure signal is credited with mitigating primary system line breaks outside the containment by isolating the CVCS system and the secondary side of the steam generation system.

The safety analyses in FSAR 15.6.2 and 15.6.3 describe the analyses of small line breaks outside the containment and steam generator tube failures that the low-low pressurizer pressure signal mitigates. The subcooled margin protection is illustrated at FSAR Figure 15.0.9 as the two vertical lines on the right side of the figure.

12.4 See 12.3 above 9/3/19 9/11/19 Submitted 12.5 [Note that not all Technical Specifications contents are related directly to transients or accidents 9/3/19 9/11/19 Submitted provided in the Chapter 15 analyses. Other portions of the FSAR include analyses that were considered in the development of the proposed specifications. The information provided refers to locations in the FSAR. This is consistent with 10 CFR 50.36 and precedent provided in the generic standard technical specifications.]

12.5.a RTS and DWS on Low-Low RCS Flow - The Low-Low RCS Flow signal is designed to ensure flow 9/3/19 9/11/19 Submitted remains measurable and positive during low power startup conditions. The actuation signal supports startup of the NuScale reactor design that depends on an external module heatup system to initiate and ensure natural circulation during heatup to operating conditions. During these startup conditions, if the nonsafety-related module heatup system were to fail, the CVCS could be operating such that colder water is added into the riser over the core, causing a reduced flow condition. This actuation occurs on a decreasing process variable at the low end of detectable RCS flow. A description of the module heatup system and the CVCS design, functions, and operation are provided in FSAR 9.3.4.

FSAR section 15.4.6 describes the isolation of demineralized water sources by the MPS prior to loss of a significant portion of the minimum shutdown margin.

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NuScale Responses to September Tech Spec Questions Date

  1. NuScale Response Received Submitted Comments/Discussion 12.5.b The Low and Low-Low Main Steam Pressure signals are designed to detect and mitigate secondary 9/3/19 9/11/19 Submitted system line breaks outside the containment and to protect steam generator inventory and thereby support decay heat removal functionality if needed. The Low Main Steam Pressure setpoint of about 300 psia is too high to permit reactor startup without resulting in actuations including reactor trips.

However, the approximately 20 psia Low-Low Pressure setpoint permits startup while continuing to provide the protective measures that the Low Steam Pressure actuations provide. Steam piping failures outside the containment are described and evaluated in FSAR section 15.1.5.

12.5.c CVCSI actuation on High Narrow Range Containment Pressure is described in FSAR 15.6.5, the 9/3/19 9/11/19 Submitted signal is designed to detect and mitigate RCS or secondary leaks above the allowable limits to protect RCS inventory and ECCS function during these events. CVCS isolation initiates isolation of a portion of the boundary established in response to these postulated events.

12.5.d Function 24, the low AC voltage actuation signal is designed to ensure predictable module protection 9/3/19 9/11/19 Submitted system (MPS) behavior if degraded voltage conditions exist. The MPS is required to be available to provide credited, predictable response to initiate actions in response to design basis events. This function and its role ensuring the availability and OPERABILITY of the MPS is described in FSAR section 7.1.

12.5.e Function 25, the high under-the-bioshield actuation signal is designed to detect high energy 9/3/19 9/11/19 Submitted leaks/breaks at the top of reactor module under-the-bioshield to reduce the consequences of HELB on the safety related equipment located on top of the RXM. Postulated high energy line breaks under the bioshield are described in FSAR 3.6.

13 The term actuation will be capitalized in the Conditions of LCO 3.3.3 in revision 9/3/19 9/11/19 Submitted 14 The Table 3.3.3-1 and Table 3.3.4-1 CIS applicability will be modified to MODES 1, 2, and 3. The 9/3/19 9/11/19 Submitted Note limiting OPERABILITY requirements to above T-2 will be removed from each table. These concerns are being considered in conjunction with developing the response to item 9 above.

15 These changes were implemented in response to RAI 16-17S1 as shown in the NuScale response 9/3/19 9/11/19 Supplemental Response (ML18355A905).

The three listed SRs (3.3.1.5, 3.3.2.3, and 3.3.3.3) are not related to LSSS settings as described in the regulatory basis and Technical Specification requirement for the Setpoint Program requirements in specification 5.5.10. For surveillances where the program will be used but that are not within the scope of 10 CFR 50.36(c)(1)(ii)(A) requirements, references to the Setpoint Program are provided in the Bases to indicate such. Based on these requirements, NuScale does not feel it is appropriate to include a statement on the Setpoint Program outside of the Part 4 Bases discussion 16 MODE 3 is the appropriate Completion Time for this Required Action. The SG tubes do not provide 9/3/19 9/11/19 Submitted any credited safety function in MODES 4 or 5.

17 The word required will be removed from Condition A of LCO 3.7.1 in revision 4. 9/3/19 9/11/19 Supplemented after clarification from staff and Submitted 8

NuScale Responses to September Tech Spec Questions Date

  1. NuScale Response Received Submitted Comments/Discussion 18 This change will be addressed in Revision 4. 9/3/19 9/11/19 Submitted 19 This change will be addressed in Revision 4. 9/12/19 20 The wording in FSAR Ch7 is technically accurate, and the proposed clarifications do not materially 9/12/19 change the information, as explained here. The wide range RCS temperature T-5 interlock works in conjunction with the RT-1 interlock as shown in FSAR Figure 7.1-1e to establish an operating bypass of the secondary system isolation on low-low pressurizer pressure, demineralized water system isolation that occurs from any automatic reactor trip signal (see FSAR Figure 7.1-1m), and a chemical volume control system isolation on low-low pressurizer pressure.

21 These statements are to indicate that if future changes to the plant design occur that incorporate 9/12/19 features similar to time constants, the travelers listed will be considered in any required future TS changes.

There are no identified changes to the TS that would result in considering or incorporating changes that are relevant to these travelers at this time.

22 The phrase by use of at least one closed manual or one closed and de-activated automatic valve 9/12/19 will be added to LCO 3.3.1 Required Action F.1 in Revision 4.

23 All Required Actions apply. As described in the responses to 12.5.d and 12.5.e above, Functions 24 9/12/19 and 25 represent protective features that ensure a predictable response to off-normal conditions.

Therefore, the actions are applicable to the safety functions implemented by the MPS. Conditions L and F as applied result in the unit being placed in a passively cooled configuration with the containment isolated.

In this condition the unit will passively transition to a cold, confined status with no further actions required to reach that state. It is somewhat analogous to placing an existing large PWR into cold shutdown to exit operations as the safest configuration available.

However, unlike existing plants that require continued cooling, this NuScale configuration achieves a state with a significantly reduced level of risk as there are no more actions required to maintain the unit in this safe state.

24 The Applicability columns of LCOs 3.3.3 and 3.3.4 for the CIS and SSI are being modified to MODES 9/12/19 1, 2, and 3 with the former footnote removed. This change will be addressed in Revision 4.

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