CNL-23-015, Expedited Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-22-08)

Expedited Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-22-08)

ML23058A447
Person / Time
Site:	Watts Bar
Issue date:	02/27/2023
From:	Hulvey K Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation, Document Control Desk
References
CNL-23-015
Download: ML23058A447 (1)

Text

1101 Market Street, Chattanooga, Tennessee 37402

CNL-23-015

February 27, 2023

10 CFR 50.90

ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001

Watts Bar Nuclear Plant, Units 1 and 2 Facility Operating Licenses Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391

Subject:

Expedited Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-22-08)

References:

1. TVA letter to NRC, CNL-20-012, Application to Modify the Watts Bar Nuclear Plant Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-18-16), dated May 19, 2020 (ML20140A342)

2. TVA letter to NRC, CNL-20-091, Response to Request for Additional Information Regarding Application to Modify the Watts Bar Nuclear Plant Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-18-16) (EPID L-2020-LLA-0114),

dated December 16, 2020 (ML20351A424)

3. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Issuance of Amendment Nos. 145 and 51 for One-Time Change to Technical Specification 3.7.11 to Extend the Completion Time for Main Control Room Chiller Modifications (EPID L-2020-LLA-0114), dated May 5, 2021 (ML21078A484)

In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR) 50.90, "Application for amendment of license, construction permit, or early site permit," Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN), Units 1 and 2, respectively.

U.S. Nuclear Regulatory Commission CNL-23-015 Page 2 February 27, 2023

In References 1 and 2, TVA submitted a request for an amendment to revise WBN Units 1 and 2 Technical Specification (TS) 3.7.11 "Control Room Emergency Air Temperature Control System (CREATCS)," to add a one-time change of a footnote to the Completion Time for Required Action A.1 to allow one CREATCS train to be inoperable for up to 60 days while performing modifications to the CREATCS chillers. The proposed amendment also added a one-time change of a footnote to the Completion Time for Required Action E.1 to allow delayed entry into TS Limiting Condition for Operation (LCO) 3.0.3 for up to four days in the event that both CREATCS trains are inoperable during the modifications to the CREATCS chillers. The proposed changes were in support of modifications to the WBN Units 1 and 2 Main Control Room (MCR) CREATCS chillers. In Reference 3, the Nuclear Regulatory Commission (NRC) approved References 1 and 2.

As noted in the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, the timeframe for performing the modifications to the WBN Units 1 and 2 MCR CREATCS chillers is from May 1, 2022, to May 1, 2023.

However, due to delays in the vendor delivery of the MCR CREATCS chillers, which were beyond the control of TVA, the timeframe of the above footnotes is being revised to begin no earlier than July 1, 2023, and end no later than December 31, 2024. The remaining provisions of the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1 are unchanged.

The enclosure to this submittal provides a description and technical evaluation of the proposed change, a regulatory evaluation, and a discussion of environmental considerations. Attachment 1 to the enclosure provides the existing WBN Units 1 and 2 TS pages marked up to show the proposed changes. Attachment 2 to the enclosure provides the existing WBN Units 1 and 2 TS pages retyped to show the proposed changes. to the enclosure provides the existing WBN Units 1 and 2 TS Bases pages marked up to show the proposed changes. Changes to the existing TS Bases are provided for information only and will be implemented under the TS Bases Control Program.

TVA has determined that there are no significant hazards considerations associated with the proposed changes and that the TS changes qualify for a categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). In accordance with 10 CFR 50.91(b)(1), TVA is sending a copy of this letter and enclosure to the Tennessee State Department of Environment and Conservation.

TVA requests approval of the proposed license amendment on an expedited basis by June 15, 2023, with implementation within 15 days of issuance of the amendment. As noted above, TVA is unable to currently meet the current timeframe for performing the modifications to the WBN Units 1 and 2 MCR CREATCS chillers in the current date range of May 1, 2022, to May 1, 2023, primarily due to delays in the vendor delivery of the MCR CREATCS chillers. TVA has been working with the vendor to establish a firm schedule for completing the MCR Chiller replacement activity. Based on vendor input, a revised schedule was developed on January 25, 2023, which, as shown in the enclosure to this submittal, shows the start date for the B MCR chiller replacement commencing in July 2023.

U.S. Nuclear Regulatory Commission CNL-23-015 Page 3 February 27, 2023

There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to slrymer@tva.gov.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 27th day of February 2023.

Respectfully,

Digitally signed by Edmondson, Carla Date: 2023.02.27 17:22:53 -05'00' Kimberly D. Hulvey Director, Nuclear Regulatory Affairs

Enclosure:

Evaluation of Proposed Change

cc (Enclosure):

NRC Regional Administrator - Region II NRC Senior Resident Inspector - Watts Bar Nuclear Plant NRC Project Manager - Watts Bar Nuclear Plant Director, Division of Radiological Health - Tennessee State Department of Environment and Conservation

Enclosure

Evaluation of Proposed Change

Subject:

Expedited Application to Modify the Watts Bar Nuclear Plant, Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-22-08)

Table of Contents Contents 1.0

SUMMARY

DESCRIPTION........................................................................................ 1 2.0 DETAILED DESCRIPTION........................................................................................ 1 2.1 Description of the Proposed Change.......................................................................... 1 2.2 Reason for the Proposed Change.............................................................................. 3

3.0 TECHNICAL EVALUATION

....................................................................................... 3 3.1 System Description.................................................................................................... 3 3.2 MCR Temporary Chilled Water Equipment Description.............................................. 3 3.3 Compensatory Measures........................................................................................... 8 3.4 Conclusion.................................................................................................................. 8

4.0 REGULATORY EVALUATION

................................................................................... 8 4.1 Applicable Regulatory Requirements and Criteria...................................................... 8 4.2 Precedent................................................................................................................... 9 4.3 No Significant Hazards Considerations Analysis........................................................ 9 4.4 Conclusions.............................................................................................................. 10

5.0 ENVIRONMENTAL CONSIDERATION

.................................................................... 10

6.0 REFERENCES

......................................................................................................... 11

Attachments

1. Proposed TS Changes (Mark-Ups) for WBN Units 1 and 2

2. Proposed TS Changes (Final Typed) for WBN Units 1 and 2

3. Proposed TS Bases Page Changes (Mark-Ups) for WBN Units 1 and 2 (For Information Only)

CNL-23-015 Enclosure

1.0

SUMMARY

DESCRIPTION

In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR) 50.90, "Application for amendment of license, construction permit, or early site permit," Tennessee Valley Authority (TVA) is submitting a request for an amendment to Facility Operating License Nos. NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN), Units 1 and 2, respectively.

In References 1 and 2, TVA submitted a request for an amendment to revise WBN Units 1 and 2 Technical Specification (TS) 3.7.11 "Control Room Emergency Air Temperature Control System (CREATCS)," to add a one-time change of a footnote to the Completion Time for Required Action A.1 to allow one CREATCS train to be inoperable for up to 60 days while performing modifications to the CREATCS chillers. The proposed amendment also added a one-time change of a footnote to the Completion Time for Required Action E.1 to allow delayed entry into TS Limiting Condition for Operation (LCO) 3.0.3 for up to 4 days in the event that both CREATCS trains are inoperable during the modifications to the CREATCS chillers. The proposed changes were in support of modifications to the WBN Units 1 and 2 Main Control Room (MCR) CREATCS chillers. In Reference 3, the Nuclear Regulatory Commission (NRC) approved References 1 and 2.

As noted in the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, the timeframe for performing the modifications to the WBN Units 1 and 2 MCR CREATCS chillers is from May 1, 2022, to May 1, 2023.

However, due to delays in the vendor delivery of the MCR CREATCS chillers, which were beyond the control of TVA, the timeframe of the above footnotes is being revised to begin no earlier than July 1, 2023, and end no later than December 31, 2024. The remaining provisions of the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1 are unchanged.

2.0 DETAILED DESCRIPTION

2.1 Description of the Proposed Change

The footnote to the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Action A.1 currently states:

An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than May 1, 2022, and ending no later than May 1, 2023, provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

CNL-23-015 E1 of 12 Enclosure

Similarly, the footnote to the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Action E.1 currently states:

An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than May 1, 2022, and ending no later than May 1, 2023, provided compensatory measures are implemented as described in TVA letter CNL 20-012, dated May 19, 2020.

This license amendment request (LAR) proposes the following changes to the above footnotes to WBN Units 1 and 2 TS 3.7.11 (changes are shown in bold italics).

The footnote to the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Action A.1 is being revised to state:

An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 31, 2024, provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

The footnote to the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Action E.1 is being revised to state:

An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 31, 2024, provided compensatory measures are implemented as described in TVA letter CNL 20-012, dated May 19, 2020.

Attachment 1 to the enclosure provides the existing WBN Units 1 and 2 TS pages marked up to show the proposed changes. Attachment 2 to the enclosure provides the existing WBN Units 1 and 2 TS pages retyped to show the proposed changes.

Attachment 3 to the enclosure provides the existing WBN Units 1 and 2 TS Bases pages marked up to show the proposed changes. Changes to the existing TS Bases are provided for information only and will be implemented under the TS Bases Control Program.

CNL-23-015 E2 of 12 Enclosure

2.2 Reason for the Proposed Change

Due to unforeseen supplier chain issues, TVA is unable to meet the current end date of May 1, 2023, for the MCR chiller replacement as required by the existing footnotes to the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1. As shown in Table 1, the new MCR chillers have not yet been received and are not scheduled to be installed until the third quarter 2023. TVA has received confirmation from the supplier vendor that they can currently meet the below delivery dates for the MCR chillers. The proposed completion date of December 31, 2024, as discussed in Section 2.1 of this enclosure, provides a margin for any potential further schedule delays and also minimizes the risks from any further potential vendor delays.

Table 1 Revised WBN MCR Chiller Replacement Timeline Activity Date U1R18 Outage 4/14/2023 - 5/13/2023 Qualification of MCR Chillers 4/28/2023 New MCR B Chiller at WBN 5/3/2023 New MCR A Chiller at WBN 5/9/2023 Replace existing MCR B chiller 7/17/2023 - 8/24/2023 U2R5 Outage 11/3/2023 - 12/2/2023 Replace existing MCR A chiller 1/29/2024 - 3/24/2024 U1R19 Outage 11/1/2024 - 12/13/2024

3.0 TECHNICAL EVALUATION

3.1 System Description

See Section 3.1 to Reference 1 and the TVA response to EMIB-RAI-1 in Reference 2.

3.2 MCR Temporary Chilled Water Equipment Description

See Section 3.1 to Reference 1, the TVA response to EMIB-RAI-1 in Reference 2, and Reference 4.

Differences between the currently planned MCR temporary chiller equipment description and the MCR temporary chiller equipment description in Section 3.1 to Reference 1 and the NRC Regulatory Audit Summary (Reference 4) are provided in Tables 2 and 3, respectively. Also, a revised Figure 1 provides an update to Figure 1 from Reference 1 regarding the Temporary Non-Safety Related Chiller System. There are no changes to the MCR temporary chiller equipment description in Reference 2.

CNL-23-015 E3 of 12 Enclosure

Table 2

Item Description in LAR Currently Planned Reason for Significance No. (Reference 1) Installation Change

1. Page E6 of 24, Permanent To allow more This new paragraph 1 describes, modifications have efficient (less configuration is The chilled water piping installed branch time) transition functionally inlet and outlet to the AHU connections on the between the equivalent to is removed and replaced air handling unit temporary and the with temporary piping for (AHU) inlet and permanent configuration the temporary chiller outlet piping, chillers which described in system. eliminating the need will be Reference 1 to remove the piping advantageous and is expected at the AHUs. Each during the post to benefit the branch connection (a modification project by tee in the piping) test (PMT) reducing the includes an isolation window. time in the TS valve and blind Required Action flange. The new Completion branch connection Time.

piping, valve and blind flange meet the design requirements of the piping system.

The installation of the branch connections does not adversely impact the conclusions of the moderate energy line break flooding study.

When the temporary cooling equipment is to be removed, the isolation valve is closed and the blind flange is installed.

CNL-23-015 E4 of 12 Enclosure

Table 2

Item Description in LAR Currently Planned Reason for Significance No. (Reference 1) Installation Change

2. Page E6 of 24, Section 3.2 The temporary chiller The temporary These items describes major equipment installation may have chiller were included and includes Chilled water as many as three installation for Pump. pumps. Additionally, includes completeness one major multiple pumps of information.

equipment item that to meet was not included in necessary the Reference 1 hydraulic description is a conditions. The transfer switch, to temporary allow transfer chiller between plant power installation and the diesel includes a generator (DG) for transfer switch.

the temporary chiller.

3. Page E6 of 24, The DG referred to in Clarification on Both the rented Section 3.2.1 refers to a Reference 1 (a the rating of the Aggreko 320kW DG. Section 3.2.4 rented Aggreko Aggreko DG equipment and also refers to the 320kW chiller) is rated at and also to the Carrier/CAT DG. 320kW at 50Hz. The include equipment have rating of the currently reference to the adequate planned DG is CAT generator electrical and 300kW at 60Hz, which the site cooling capacity which is adequate for has purchased, to meet the the temporary/rented along with a requirements Aggreko chiller Carrier chiller. for the equipment. A temporary Caterpillar (CAT) chiller system.

generator and Carrier chiller have also been purchased by the site to reduce reliance on rented equipment. The ratings (tons and kW) of the CAT/Carrier equipment exceed the ratings of the rented Aggreko equipment.

CNL-23-015 E5 of 12 Enclosure

Table 2

Item Description in LAR Currently Planned Reason for Significance No. (Reference 1) Installation Change

4. Page E6 of 24, Permanent branch To allow a more This new Section 3.2.1, second connections have efficient (less configuration is paragraph states, been added to the time) transition functionally Connection to the AHU AHU piping. between the equivalent to coils will be made by Therefore, it is more temporary and the isolating the chilled water accurate to state permanent configuration piping, removing the flex "Connection to the chillers, which described in hoses between the AHU AHU coils is made will be Reference 1 coils and the chilled water via permanent advantageous and is expected piping and then connecting flanged branch during the PMT to benefit the the temporary chilled water connections with an window. project by supply and return hoses to isolation valve, reducing the the AHU coils using which were added as time in the TS existing flange part of the chiller Required Action connections. replacement project Completion subsequent to the Time.

submittal of Reference 1.

5. Page E7 of 24, Hose sizes used in Final Larger hose Section 3.2.2 refers to the temporary chilled configuration to sizes meet 2.5 inch () diameter water system are of meet hydraulic hydraulic supply and return hoses. various sizes (3, 4 requirements. requirements and 6). and offer less resistance compared to smaller hose sizes.

6. Page E7 of 24, As noted in Provide Both locations Section 3.2.3 states, The Reference 4, "The flexibility in are a similar equipment associated with two potential chiller locations distance (hose the temporary chiller locations with and align run). Both system will be located in respect to assumed Reference 1 locations are the yard west of the plant north are with also sufficiently Auxiliary Building and in (a) due west of the Reference 4. distant from the the Control Building Auxiliary Building or plant air (Elevation 729.0 feet). (b) northwest of the intakes, which Unit 1 Containment." were reviewed by the NRC in Reference 4.

CNL-23-015 E6 of 12 Enclosure

Table 2

Item Description in LAR Currently Planned Reason for Significance No. (Reference 1) Installation Change

7. Page E7 of 24, This statement is Clarification. Clarification.

Section 3.2.3 states, the intended to mean as temporary chiller system required. The design will be protected from package states that if freezing. the chiller is deployed during winter months, steps should be taken to avoid freezing (e.g.,

draining lines when not in use, use of heat tape and insulation).

CNL-23-015 E7 of 12 Enclosure

Table 3

Item Description in NRC Audit Currently Planned Reason for Significance No. Report (Reference 4) Installation Change

1. Page 4 of 7 of the Audit Permanent branch To allow more This new Report states, Connection connections have efficient (less configuration is to the AHU coils will be been added to the time) transition functionally made by isolating the plant AHU piping; between the equivalent to chilled water piping, therefore, a current temporary and the removing the flex hoses statement would be, permanent configuration between the AHU coils and "Connection to the chillers which described in the permanent plant chilled AHU coils is made will be Reference 1 water piping, and then via permanent advantageous and is expected connecting the temporary flanged branch during the PMT to benefit the chilled water supply and connections with an window. project by return hoses to the AHU isolation valve, which reducing the coils using the existing were added as part time in the TS flange connections. of the chiller Required Action replacement project Completion subsequent to the Time.

submittal of the LAR."

2. Page 5 of 7 of the Audit The CAT DG has a To reflect the The run time for Report states, The 300-gallon tank, capacity of the the CAT DG is temporary chiller skid which provides a CAT DG which longer than the diesel generator (DG) fuel 24-hour run time. would be used run time for the oil tanks capacity provides with the Carrier Aggreko DG, a 12-hour run time for the chiller. which is chiller skid without fuel oil conservative to replenishment, which what is allows the licensee time for described in the replenishing measures. Audit Report.

3.3 Compensatory Measures

The compensatory measures listed in References 1 and 3 remain unchanged.

3.4 Conclusion

The proposed revision to the footnotes in the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, is administrative in nature to reflect the revision to the scheduled completion time for the modification activities planned for the upgrade of the MCR chillers.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements and Criteria

See Section 4.1 to Reference 1.

CNL-23-015 E8 of 12 Enclosure

4.2 Precedent

As noted in Section 1.0 to this enclosure, in Reference 3, the NRC approved References 1 and 2, which added the current footnotes to the Completion Time for Required Actions A.1 and E.1. The proposed change revises the start date for these footnotes from May 1, 2022, to July 1, 2023, and the expiration date from May 1, 2023, until December 31, 2024.

4.3 No Significant Hazards Considerations Analysis

TVA is requesting an amendment to Facility Operating Licenses NPF-90 and NPF-96 for the WBN Units 1 and 2, respectively. As noted in the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, the timeframe for performing the modifications to the WBN Units 1 and 2 MCR CREATCS chillers is from May 1, 2022, to May 1, 2023. However, due to delays in the vendor delivery of the MCR CREATCS chillers, which were beyond the control of TVA, the timeframe of the above footnotes is being revised to begin no earlier than July 1, 2023, and end no later than December 31, 2024. The remaining provisions of the footnotes to the Completion Times for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1 are unchanged.

TVA evaluated whether or not a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of Amendment," as discussed below:

1. Does the proposed amendment involve a significant increase in the probability or consequence of an accident previously evaluated?

Response: No.

The proposed revision to the footnotes in the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, is administrative in nature to reflect the revision to the scheduled completion time for the modification activities planned for the upgrade of the MCR chillers. The compensatory measures listed in References 1 and 3 remain unchanged.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the proposed change create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No.

The proposed revision to the footnotes in the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, is administrative in nature to reflect the revision to the scheduled completion time for the modification activities planned for the upgrade of the MCR chillers. The compensatory measures listed in References 1 and 3 remain unchanged.

Therefore, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.

CNL-23-015 E9 of 12 Enclosure

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed revision to the footnotes in the Completion Time for WBN Units 1 and 2 TS 3.7.11, Required Actions A.1 and E.1, is administrative in nature to reflect the revision to the scheduled completion time for the modification activities planned for the upgrade of the MCR chillers. The compensatory measures listed in References 1 and 3 remain unchanged.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Based on the above, it is concluded that the proposed amendment does not involve a significant hazards consideration under the standards set forth in 10 CFR 50.92(c),

and accordingly, a finding of no significant hazards consideration is justified.

4.4 Conclusions

In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 ENVIRONMENTAL CONSIDERATION

A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement. However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or significant increase in the amounts of any radioactive effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b),

no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

CNL-23-015 E10 of 12 Enclosure

6.0 REFERENCES

1. TVA letter to NRC, CNL-20-012, Application to Modify the Watts Bar Nuclear Plant Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-18-16), dated May 19, 2020 (ML20140A342)

2. TVA letter to NRC, CNL-20-091, Response to Request for Additional Information Regarding Application to Modify the Watts Bar Nuclear Plant Unit 1 and Unit 2 Technical Specifications for Main Control Room Chiller Completion Time Extension (WBN-TS-18-16) (EPID L-2020-LLA-0114), dated December 16, 2020 (ML20351A424)

3. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Issuance of Amendment Nos. 145 and 51 for One-Time Change to Technical Specification 3.7.11 to Extend the Completion Time for Main Control Room Chiller Modifications (EPID L-2020-LLA-0114),

dated May 5, 2021 (ML21078A484)

4. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Regulatory Audit Summary Related to Request to Technical Specification 3.7.11, Control Room Emergency Air Temperature Control System (CREATCS) (EPID L-2020-LLA-0114), dated January 26, 2021 (ML21012A084)

CNL-23-015 E11 of 12 Enclosure

Revised Figure 1 Temporary Non-Safety Related Chiller System

CNL-23-015 E12 of 12 Enclosure

Attachment 1

Proposed TS Changes (Mark-Ups) for WBN Units 1 and 2

CNL-23-015 CREATCS 3.7.11

3.7 PLANT SYSTEMS

3.7.11 Control Room Emergency Air Temperature Control System (CREATCS)

LCO 3.7.11 Two CREATCS trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, 4, 5, and 6, During movement of irradiated fuel assemblies.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One CREATCS train A.1 Restore CREATCS train to 30days

• inoperable. OPERABLE status.

B. Required Action and associated B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time of Condition A not met in MODE 1, 2, 3, or 4. AND

B.2 Be in MODE 5. 36hours

C. Required Action and associated C.1 Place OPERABLE CREATCS Immediately Completion Time of Condition A train in operation.

not met in MODE 5 or 6, or during movement of irradiated OR fuel assemblies.

C.2 Suspend movement of irradiated Immediately fuel assemblies.

(continued)

• An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than JulyMay 1, 202 23, and ending no later than DecemberMay 31, 20234, provided compensatory measures are implemented as described in TVA letter CNL 012, dated May 19, 2020.

Watts Bar-Unit 1 3.7-25 Amendment 35, 85, 112, 145,

CREATCS 3.7.11

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

D. Two CREATCS trains D.1 Suspend movement of Immediately inoperable in MODE 5 or 6, or irradiated fuel assemblies.

during movement of irradiated fuel assemblies.

E. Two CREATCS trains E.1 Enter LCO 3.0.3. Immediately**

inoperable in MODE 1, 2, 3, or 4.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY

SR 3.7.11.1 Verify each CREATCS train has the capability to remove In accordance with the assumed heat load. the Surveillance Frequency Control Program

• • An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 202 23, and ending no later than December May 3 1, 20234, provided compensatory measures are implemented as described in TVA letter CNL 012, dated May 19, 2020.

Watts Bar-Unit 1 3.7-26 Amendment 35, 132, 145,

CREATCS 3.7.11

3.7 PLANT SYSTEMS

3.7.11 Control Room Emergency Air Temperature Control System (CREATCS)

LCO 3.7.11 Two CREATCS trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, 4, 5, and 6, During movement of irradiated fuel assemblies.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One CREATCS train A.1 Restore CREATCS train 30 days*

inoperable. to OPERABLE status.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A not met AND in MODE 1, 2, 3, or 4. B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />

C. Required Action and C.1 Place OPERABLE Immediately associated Completion CREATCS train in Time of Condition A not met operation.

in MODE 5 or 6, or during movement of irradiated fuel OR assemblies. C.2 Suspend movement of Immediately

irradiated fuel assemblies.

D. Two CREATCS trains D.1 Suspend movement of Immediately inoperable in MODE 5 or 6, irradiated fuel assemblies or during movement of irradiated fuel assemblies.

• An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 31, 20234, provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

Watts Bar - Unit 2 3.7-24 Amendment 51,

CREATCS 3.7.11

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

E. Two CREATCS trains E.1 Enter LCO 3.0.3. Immediately**

inoperable in MODE 1, 2, 3, or 4.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY SR 3.7.11.1 Verify each CREATCS train has the capability to remove the assumed heat load. In accordance with the Surveillance Frequency Control Program

• • An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 31, 20234,

provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

Watts Bar - Unit 2 3.7-25 Amendment 36, 51,

Enclosure

Attachment 2

Proposed TS Changes (Final Typed) for WBN Units 1 and 2

CNL-23-015 CREATCS 3.7.11

3.7 PLANT SYSTEMS

3.7.11 Control Room Emergency Air Temperature Control System (CREATCS)

LCO 3.7.11 Two CREATCS trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, 4, 5, and 6, During movement of irradiated fuel assemblies.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One CREATCS train A.1 Restore CREATCS train to 30days

• inoperable. OPERABLE status.

B. Required Action and associated B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time of Condition A not met in MODE 1, 2, 3, or 4. AND

B.2 Be in MODE 5. 36hours

C. Required Action and associated C.1 Place OPERABLE CREATCS Immediately Completion Time of Condition A train in operation.

not met in MODE 5 or 6, or during movement of irradiated OR fuel assemblies.

C.2 Suspend movement of irradiated Immediately fuel assemblies.

(continued)

• An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 31, 2024, provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 202 0.

Watts Bar-Unit 1 3.7-25 Amendment 35, 85, 112, 145,

CREATCS 3.7.11

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

D. Two CREATCS trains D.1 Suspend movement of Immediately inoperable in MODE 5 or 6, or irradiated fuel assemblies.

during movement of irradiated fuel assemblies.

E. Two CREATCS trains E.1 Enter LCO 3.0.3. Immediately**

inoperable in MODE 1, 2, 3, or 4.

SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY

SR 3.7.11.1 Verify each CREATCS train has the capability to remove In accordance with the assumed heat load. the Surveillance Frequency Control Program

• • An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 31, 2024, provided compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

Watts Bar-Unit 1 3.7-26 Amendment 35, 132, 145,

CREATCS 3.7.11

3.7 PLANT SYSTEMS

3.7.11 Control Room Emergency Air Temperature Control System (CREATCS)

LCO 3.7.11 Two CREATCS trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, 4, 5, and 6, During movement of irradiated fuel assemblies.

ACTIONS

CONDITION REQUIRED ACTION COMPLETION TIME

A. One CREATCS train A.1 Restore CREATCS train 30 days*

inoperable. to OPERABLE status.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time of Condition A not met AND in MODE 1, 2, 3, or 4. B.2 Be in MODE 5. 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />

C. Required Action and C.1 Place OPERABLE Immediately associated Completion CREATCS train in Time of Condition A not met operation.

in MODE 5 or 6, or during movement of irradiated fuel OR assemblies. C.2 Suspend movement of Immediately

irradiated fuel assemblies.

D. Two CREATCS trains D.1 Suspend movement of Immediately inoperable in MODE 5 or 6, irradiated fuel assemblies or during movement of irradiated fuel assemblies.

• An allowance is permitted for one CREATCS train to be inoperable for up to 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 3 1, 2024, provided compensatory measures are implemented as described in TVA letter CNL-20- 012, dated May 19, 2020.

Watts Bar - Unit 2 3.7-24 Amendment 51,

CREATCS 3.7.11

ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME

E. Two CREATCS trains E.1 Enter LCO 3.0.3. Immediately**

inoperable in MODE 1, 2, 3, or 4.

SURVEILLANCE REQUIREMENTS

SURVEILLANCE FREQUENCY SR 3.7.11.1 Verify each CREATCS train has the capability to remove the assumed heat load. In accordance with the Surveillance Frequency Control Program

• • An allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July 1, 2023, and ending no later than December 31, 2024, provided compensatory measures are implemented as described in TVA letter CNL-20- 012, dated May 19, 2020.

Watts Bar - Unit 2 3.7-25 Amendment 36, 51,

Enclosure

Attachment 3

Proposed TS Bases Page Changes (Mark-Ups) for WBN Units 1 and 2 (For Information Only)

CNL-23-015 CREATCS B 3.7.11

BASES

ACTIONS A1 (continued)

(continued)

The Completion Time is modified by a footnote that states an allowance is permitted for one CREATCS train to be inoperable for 60days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 3 1, 20234,

provided the following co mpensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

• A temporary, non-safety related chiller system with a temporary DG to provide power to the temporary chiller system will be installed and operated as described in the LAR.

• Instructions for operation of the temporary cooling equipment will be provided.

• During replacement of the CREATCS chillers, TVA will employ a graded approach to defense-in-depth and protected equipment strategies based on the operating status of the affected unit. The risk of the activity will be assessed and managed, including the use of physical barriers as needed.

Additionally, TVA procedures preclude work on or near protected equipment and limit access to the area to emergency situations and non-intrusive monitoring of running equipment per operator rounds.

• During replacement of the CREATCS chillers, no elective maintenance will be performed on TS related support equipment for the Operable CREATCS chiller except for any required TS SRs.

B.1 and B.2

In MODE 1, 2, 3, or 4, if the inoperable CREATCS train cannot be restored to OPERABLE status within the required Completion Time, the plant must be placed in a MODE that minimizes the risk. To achieve this status, the plant must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.

The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

C.1 and C.2

In MODE 5 or 6, or during movement of irradiated fuel, if the inoperable CREATCS train cannot be restored to OPERABLE status within the required Completion Time, the OPERABLE CREATCS train must be placed in operation immediately. This action ensures that the remaining train is OPERABLE, that no failures preventing automatic actuation will occur, and that active failures will be readily detected.

(continued)

Watts Bar-Unit 1 B 3.7-53 Revision 45, 172 Amendment 35, 145,

CREATCS B 3.7.11

BASES

ACTIONS C.1 and C.2 (continued)

(continued)

An alternative to Required Action C.1 is to immediately suspend activities that present a potential for releasing radioactivity that might require isolation of the control room. This places the unit in a condition that minimizes accident risk.

This does not preclude the movement of fuel to a safe position.

D.1

In MODE 5 or 6, or during movement of irradiated fuel assemblies, with two CREATCS trains inoperable, action must be taken immediately to suspend activities that could result in a release of radioactivity that might require isolation of the control room. This places the unit in a condition that minimizes risk. This does not preclude the movement of fuel to a safe position.

E.1

If both CREATCS trains are inoperable in MODE 1, 2, 3, or 4 the CREATCS may not be capable of performing its intended function. Therefore, LCO 3.0.3 must be entered immediately. The Completion Time is modified by a footnote that states an allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 3 1, 20234,

provided the following compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

• A temporary, non-safety related chiller system with a temporary DG to provide power to the temporary chiller system will be installed and operated as described in the LAR.

• Instructions for operation of the temporary cooling equipment will be provided.

• During replacement of the CREATCS chillers, TVA will employ a graded approach to defense-in-depth and protected equipment strategies based on the operating status of the affected unit. The risk of the activity will be assessed and managed, including the use of physical barriers as needed.

Additionally, TVA procedures preclude work on or near protected equipment and limit access to the area to emergency situations and non-intrusive monitoring of running equipment per operator rounds.

(continued)

Watts Bar-Unit 1 B 3.7-54 Revision 45, 172 Amendment 35, 145,

CREATCS B 3.7.11

BASES

ACTIONS E1 (continued)

(continued)

• During replacement of the CREATCS chillers, no elective maintenance will be performed on TS related support equipment for the Operable CREATCS chiller except for any required TS SRs.

The purpose of the footnote is to ensure the MCR temperature is being controlled. The specified temperature limit of 9 0°F is above the normal operating temperature of the MCR (approximately 75°F), providing operational flexibility when implementing the mitigating actions. This temperature does not impact the operability of equipment or habitability of the MCR. The limit of 90°F maintains margin below the lowest specification for the MCR equipment cabinets of 104°F.

Subsequent to immediate MCR temperature verification, the one-hour frequency is adequate given the indications available in the MCR. Main control room temperature data is measured and displayed from readily available equipment in the MCR and operators will have awareness of temperature trending relative to the 90°F limit.

SURVEILLANCE SR 3.7.11.1 REQUIREMENTS This SR verifies that the heat removal capability of the system is sufficient to remove the heat load assumed in the sizing calculations in the control room.

This SR consists of a combination of testing and calculations. This is accomplished by verifying that the system has not degraded. The only measurable parameters that could degrade undetected during normal operation are the system air flow and chilled water flow rate. Verification of these two flow rates will provide assurance that the heat removal capacity of the system is still adequate. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

REFERENCES 1. Watts Bar FSAR, Section 9.4.1, "Control Room Area Ventilation System."

2. Watts Bar FSAR, Section 3.7.3.18, Seismic Qualification of Main Control Room Suspended Ceiling and Air Delivery Components.

3. NRC Safety Evaluation dated February 12, 2004, for License Amendment 50.

(continued)

Watts Bar-Unit 1 B 3.7-54a Revision 64, 162, 172 Amendment 50, 132, 145,

CREATCS B 3.7.11

BASES

ACTIONS A1 (continued)

(continued)

The Completion Time is modified by a footnote that states an allowance is permitted for one CREATCS train to be inoperable for 60 days. This TS provision is only authorized for one entry per train during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 31, 20234, provided the following compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

• A temporary, non-safety related chiller system with a temporary DG to provide power to the temporary chiller system will be installed and operated as described in the LAR.

• Instructions for operation of the temporary cooling equipment will be provided.

• During replacement of the CREATCS chillers, TVA will employ a graded approach to defense-in-depth and protected equipment strategies based on the operating status of the affected unit. The risk of the activity will be assessed and managed, including the use of physical barriers as needed. Additionally, TVA procedures preclude work on or near protected equipment and limit access to the area to emergency situations and non-intrusive monitoring of running equipment per operator rounds.

• During replacement of the CREATCS chillers, no elective maintenance will be performed on TS related support equipment for the Operable CREATCS chiller except for any required TS SRs.

B.1 and B.2

In MODE 1, 2, 3, or 4, if the inoperable CREATCS train cannot be restored to OPERABLE status within the required Completion Time, the plant must be placed in a MODE that minimizes the risk. To achieve this status, the plant must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

(continued)

Watts Bar - Unit 2 B 3.7-61 Revision 47 Amendment 51,

CREATCS B 3.7.11

BASES

ACTIONS C.1 and C.2 (continued)

In MODE 5 or 6, or during movement of irradiated fuel, if the inoperable CREATCS train cannot be restored to OPERABLE status within the required Completion Time, the OPERABLE CREATCS train must be placed in operation immediately. This action ensures that the remaining train is OPERABLE, that no failures preventing automatic actuation will occur, and that active failures will be readily detected.

An alternative to Required Action C.1 is to immediately suspend activities that present a potential for releasing radioactivity that might require isolation of the control room. This places the unit in a condition that minimizes accident risk. This does not preclude the movement of fuel to a safe position.

D.1

In MODE 5 or 6, or during movement of irradiated fuel assemblies, with two CREATCS trains inoperable, action must be taken immediately to suspend activities that could result in a release of radioactivity that might require isolation of the control room. This places the unit in a condition that minimizes risk. This does not preclude the movement of fuel to a safe position.

E.1

If both CREATCS trains are inoperable in MODE 1, 2, 3, or 4, the CREATCS may not be capable of performing its intended function.

Therefore, LCO 3.0.3 must be entered immediately. The Completion Time is modified by a footnote that states an allowance to monitor the main control room temperature every hour and verify the main control room temperature is less than or equal to 90°F is permitted for up to four days in lieu of the immediate entry into LCO 3.0.3. If the main control room temperature exceeds 90°F, or the duration without a train of CREATCS being OPERABLE exceeds four days, immediate entry into LCO 3.0.3 is required. This provision is only applicable during modification activities planned for the upgrade of the main control room chillers beginning no earlier than July May 1, 20223, and ending no later than December May 31, 20234, provided the following compensatory measures are implemented as described in TVA letter CNL-20-012, dated May 19, 2020.

Watts Bar - Unit 2 B 3.7-62 Revision 34. 47 Amendment 36, 51,

CREATCS B 3.7.11

BASES

ACTIONS E.1 (continued)

(continued)

• A temporary, non-safety related chiller system with a temporary DG to provide power to the temporary chiller system will be installed and operated as described in the LAR.

• Instructions for operation of the temporary cooling equipment will be provided.

• During replacement of the CREATCS chillers, TVA will employ a graded approach to defense-in-depth and protected equipment strategies based on the operating status of the affected unit. The risk of the activity will be assessed and managed, including the use of physical barriers as needed. Additionally, TVA procedures preclude work on or near protected equipment and limit access to the area to emergency situations and non-intrusive monitoring of running equipment per operator rounds.

During replacement of the CREATCS chillers, no elective maintenance will be performed on TS related support equipment for the Operable CREATCS chiller except for any required TS SRs.

The purpose of the footnote is to ensure the MCR temperature is being controlled. The specified temperature limit of 90°F is above the normal operating temperature of the MCR (approximately 75°F), providing operational flexibility when implementing the mitigating actions. This temperature does not impact the operability of equipment or habitability of the MCR. The limit of 90°F maintains margin below the lowest specification for the MCR equipment cabinets of 104°F. Subsequent to immediate MCR temperature verification, the one-hour frequency is adequate given the indications available in the MCR. Main control room temperature data is measured and displayed from readily available equipment in the MCR and operastors will have awareness of temperature trending relative to the 90°F limit.

SURVEILLANCE SR 3.7.11.1 REQUIREMENTS This SR verifies that the heat removal capability of the system is sufficient to remove the heat load assumed in the sizing calculations in the control room. This SR consists of a combination of testing and calculations. This is accomplished by verifying that the system has not degraded. The only measurable parameters that could degrade undetected during normal operation are the system air flow and chilled water flow rate. Verification of these two flow rates will provide assurance that the heat removal capacity of the system is still adequate. The Surveillance Frequency is controlled under the Surveillance Frequency Control Program.

Watts Bar - Unit 2 B 3.7-62a Revision 34. 47 Amendment 36, 51,