CNL-19-077, Application to Modify Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 Technical Specifications 3.6.15, Shield Building, (WBN-TS-19-10)

Application to Modify Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 Technical Specifications 3.6.15, Shield Building, (WBN-TS-19-10)

ML19340B773
Person / Time
Site:	Watts Bar
Issue date:	12/06/2019
From:	Polickoski J Tennessee Valley Authority
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CNL-19-077
Download: ML19340B773 (48)

Text

Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 CNL-19-077 December 6, 2019 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 License Nos. NPF-90 and NPF-96 NRC Docket Nos. 50-390 and 50-391

Subject:

Application to Modify Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 Technical Specifications 3.6.15, Shield Building," (WBN-TS-19-10)

References:

1. TVA Letter to NRC, CNL-16-147, Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 - Non-Voluntary License Amendment Request to Modify and Clarify Technical Specification 3.6.15, Shield Building, Condition B Note (WBN-TS-16-17), dated March 6, 2017 (ML17065A301)

2. NRC letter to TVA, Watts Bar Nuclear Plant - NRC Integrated Inspection Report 05000390/2016001, 05000391/2016001, dated April 7, 2016 (ML16098A323)

3. NRC electronic mail to TVA, Watts Bar Acceptance Review Draft Supplemental Information Request - LAR to Revise Technical Specification 3.6.15 Shield Building (CAC Nos. MF9393 and MF9394),

dated April 19, 2017 (ML17170A172)

4. TVA Letter to NRC, CNL-17-060, Withdrawal of Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 - Non-Voluntary License Amendment Request to Modify and Clarify Technical Specification 3.6.15, Shield Building, Condition B Note (WBN-TS-16-17), dated May 10, 2017 (ML17131A206)

5. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Withdrawal of Requested Licensing Action RE: License Amendment to Clarify Shield Building Technical Specification (CAC Nos. MF9393 and MF 9394),

dated June 22, 2017 (ML17111A701)

In accordance with the provisions of Title 10 of the Code of Federal Regulations (10 CFR)

Part 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 the

U.S. Nuclear Regulatory Commission CNL-19-077 Page 2 December 6, 2019 Technical Specifications (TS) for the Watts Bar Nuclear Plant (WBN) Units 1 and 2. The proposed license amendment request (LAR) revises WBN Units 1 and 2 TS 3.6.15, Shield Building, to delete the existing Condition B and to revise the acceptance criteria for annulus pressure in WBN Units 1 and 2 Surveillance Requirement (SR) 3.6.15.1 from equal to or more negative than -5 inch water gauge (w.g.) to equal to or more negative than -1 inch w.g.

In Reference 1, TVA submitted a non-voluntary LAR to revise the Note in WBN Units 1 and 2 TS 3.6.15 Condition B to address a nonconservative TS that was identified by the Nuclear Regulatory Commission (NRC) in Reference 2. During the acceptance review of this request, NRC issued a draft request for supplemental information (Reference 3) questioning the current licensing basis for the TS 3.6.15 Condition B Note and requesting TVA to provide administrative controls and analyses to support the one-hour duration in the TS 3.6.15 Condition B Note. NRC provided further clarification during a conference call on April 28, 2017.

TVA determined that it was not possible to supplement the request within the required 13 working days following the conference call with NRC on April 28, 2017. Therefore, in Reference 4, TVA withdrew the request submitted in Reference 1. NRC acknowledged this withdrawal in Reference 5, but stated that if TVA resubmits this request, then TVA needs to address the issues documented by NRC in Reference 3.

Accordingly, TVA is submitting the enclosed voluntary LAR, which resolves the NRC concerns by deleting the existing WBN Units 1 and 2 TS 3.6.15, Condition B, thereby aligning the WBN Units 1 and 2 TS 3.6.15 Conditions with the Westinghouse Standard TS in NUREG-1431, Revision 4.

The enclosure provides a description of the proposed changes, technical evaluation of the proposed changes, regulatory evaluation, and a discussion of environmental considerations.

Attachments 1, 2, 3, and 4 to the enclosure provide the existing WBN Units 1 and 2 TS and Bases pages marked-up to show the proposed changes. Attachments 5 and 6 to the enclosure provide the existing WBN Units 1 and 2 TS pages retyped to show the proposed changes. Changes to the existing TS Bases are provided for information only and will be implemented under the Technical Specification Bases Control Program. Attachment 7 to the enclosure provides a history of WBN Units 1 and 2 TS 3.6.15, Condition B.

TVA determined that there are no significant hazards considerations associated with the proposed change and that the TS change qualifies 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 the enclosure to the Tennessee Department of Environment and Conservation.

TVA requests NRC approval of the proposed license amendment within one year from the date of this submittal and implementation within 30 days from the date of approval.

There are no new regulatory commitments associated with this submittal. Please address any questions regarding this request to Kimberly D. Hulvey, Fleet Licensing Manager, at (423) 751-3275.

U.S. Nuclear Regulatory Commission CNL-19-077 Page 3 December 6, 2019 I declare under penalty of perjury that the foregoing is true and correct. Executed on this 6th day of December 2019.

Respectfully, James T. Polickoski 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:

Application to Modify Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 Technical Specifications 3.6.15, Shield Building," (WBN-TS-19-10)

CONTENTS 1.0

SUMMARY

DESCRIPTION ............................................................................................. 2 2.0 DETAILED DESCRIPTION.............................................................................................. 2 2.1 Background.................................................................................................................. 2 2.2 Description of the Proposed Changes .......................................................................... 2 2.3 Reason for the Proposed Changes .............................................................................. 3

3.0 TECHNICAL EVALUATION

............................................................................................. 4 3.1 System Description ...................................................................................................... 4 3.1.1 Shield Building ...................................................................................................... 4 3.1.2 Containment ......................................................................................................... 4 3.1.3 Emergency Gas Treatment System (EGTS) ......................................................... 5 3.2 Technical Analysis ....................................................................................................... 5 3.2.1 Proposed Change to SR 3.6.15.1 ......................................................................... 5 3.2.2 Proposed Deletion of TS 3.6.15, Condition B .......................................................14

4.0 REGULATORY EVALUATION

.......................................................................................16 4.1 Applicable Regulatory Requirements/Criteria ..............................................................16 4.2 Precedent ...................................................................................................................17 4.3 Significant Hazards Consideration ..............................................................................17 4.4 Conclusions ................................................................................................................19

5.0 ENVIRONMENTAL CONSIDERATION

..........................................................................19

6.0 REFERENCES

...............................................................................................................20 ATTACHMENTS

1. Proposed TS Changes Mark-Ups for WBN Unit 1

2. Proposed TS Changes Mark-Ups for WBN Unit 2

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

4. Proposed TS Bases Page Changes (Mark-Ups) for WBN Unit 2 (For Information Only)

5. Proposed TS Changes (Final Typed) for WBN Unit 1

6. Proposed TS Changes (Final Typed) for WBN Unit 2

7. History of WBN Units 1 and 2 TS 3.6.15, Condition B CNL-19-077 E1 of 20

Enclosure 1.0

SUMMARY

DESCRIPTION Pursuant to 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 requesting a license amendment to amend the Facility Operating Licenses (OLs) NPF-90 and NPF-96 for the Watts Bar Nuclear Plant (WBN) Units 1 and 2, respectively. The proposed license amendment deletes WBN Units 1 and 2 Technical Specification (TS) 3.6.15, "Shield Building," Condition B, and revises the annulus pressure in WBN Units 1 and 2 TS 3.6.15 Surveillance Requirement (SR) 3.6.15.1 as described in Section 2.0 of this enclosure.

2.0 DETAILED DESCRIPTION

2.1 BACKGROUND

In Reference 1, TVA submitted a non-voluntary license amendment request (LAR) to revise the Note in WBN Units 1 and 2 TS 3.6.15 Condition B to address a nonconservative TS that was identified by the Nuclear Regulatory Commission (NRC) in Reference 2. As noted in Reference 3, NRC determined that the Note in WBN Units 1 and 2 TS 3.6.15 Condition B could allow grace from the annulus pressure requirement for ventilating operations for an unlimited amount of time. During the acceptance review of Reference 1, NRC issued a draft request for supplemental information (Reference 4) questioning the current licensing basis for the TS 3.6.15 Condition B Note, and requesting TVA to provide administrative controls and analyses to support the one-hour duration in the TS 3.6.15 Condition B Note. NRC provided further clarification during a conference call on April 28, 2017.

TVA determined that it was not possible to supplement the request within the required 13 working days following the conference call with NRC on April 28, 2017. Therefore, in Reference 5, TVA withdrew the request submitted in Reference 1. NRC acknowledged this withdrawal in Reference 6, but stated that if TVA resubmits this request, then TVA needs to address the issues documented by NRC in Reference 4.

2.2 DESCRIPTION

OF THE PROPOSED CHANGES The proposed change deletes Condition B in WBN Units 1 and 2 TS 3.6.15 in its entirety, including the following expired information in the Note to WBN Unit 1 TS 3.6.15, Condition B:

or while Penetration 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building dome is open until annulus pressure is restored.*

• 1. The combined opening time of Penetrations 1-EQH-271-0010 or 1-EQH-271-0011 is limited to a total time of five hours a day, six days a week during Cycle 7 operation.

2. Penetrations 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building Dome may not be opened if in Action Conditions LCO 3.6.9A or 3.8.1B.

3. Upon opening Penetration 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building Dome, both EGTS control loops shall be placed in the CNL-19-077 E2 of 20

Enclosure A-Auto Stand-by position and returned to normal position following closure of penetration.

The above note was approved by the NRC in WBN Unit 1 TS Amendment 59 and was only applicable during WBN Unit 1 Cycle 7. Therefore, the above note is no longer applicable.

The proposed change revises WBN Units 1 and 2 SR 3.6.15.1 to revise the annulus pressure from equal to or more negative than -5 inch water gauge (w.g.) to equal to or more negative than -1 inch w.g.

Attachments 1, 2, 3, and 4 to this enclosure provide the existing WBN Units 1 and 2 TS and Bases pages marked-up to show the proposed changes. Attachments 5 and 6 to this enclosure provide the existing WBN Units 1 and 2 TS pages retyped to show the proposed changes. Changes to the existing TS Bases are provided for information only and will be implemented under the Technical Specification Bases Control Program.

2.3 REASON FOR THE PROPOSED CHANGES The reason for the proposed license amendment is as follows:

1. Resolve the non-conservatism in the Note to WBN Units 1 and 2 TS 3.6.15 Condition B as discussed in Section 2.1 of this enclosure.

2. Resolve NRC concerns regarding the Note to TS 3.6.15 Condition B during the acceptance review for the previous submittal of this LAR as discussed in Section 2.1 of this enclosure. Specifically, this LAR addresses the following three issues documented by NRC in Reference 6.

As noted above, the NRC identified that your application did not provide technical information in sufficient detail to enable staff to complete its review.

Therefore, if you decide to resubmit the request, it must include the following information:

• A proposed change to TS 3.6.15 that is consistent with the NRC-approved design basis as reflected in the UFSAR Section 15.5.3, Environmental Consequences of a LOCA analysis, or

• Explain how the dose reference values of 10 CFR 100 and the dose criterion of GDC 19 of 10 CFR 50 Appendix A are met using the proposed administrative controls. Provide the results of this analysis, the inputs, assumptions, methodology and technical basis for the analysis, and,

• Explain what administrative controls will be used to ensure that the integrity of the pressure boundaries can be restored so that the LOCA analysis results meet the dose reference values in 10 CFR 100 and the dose criterion in GDC 19, and in what document(s) they are located.

Regarding the first bullet of item 2 above, as discussed in Section 3.2.1 of this enclosure, the change to SR 3.6.15.1 for the annulus pressure is bounded by the current analysis described in the WBN dual-unit updated final safety analysis report (UFSAR) in that, as noted in UFSAR section 15.5.3, the dose analysis conservatively assumes the annulus is at atmospheric pressure at event CNL-19-077 E3 of 20

Enclosure initiation. The current design basis also supports the deletion of TS 3.6.15, Condition B as noted in Section 3.2.2 of this enclosure.

Regarding the second and third bullets of item 2, the administrative controls were in reference to the Note in Condition B to TS 3.6.15 that allowed the annulus pressure requirement to not be met for certain activities. With the deletion of Condition B to TS 3.6.15, the proposed changes will no longer contain the Note; therefore, no administrative controls are necessary. Furthermore, as discussed in Section 3.2.1 of this enclosure, the proposed change to the annulus pressure requirement in SR 3.6.15.1 continues to assure that the loss of coolant accident (LOCA) analysis results meet the dose reference values in 10 CFR 100 and the dose criterion in 10 CFR 50 Appendix A, General Design Criterion (GDC) 19.

The proposed change to delete TS 3.6.15, Condition B, also results in alignment of the Conditions in WBN Units 1 and 2 TS 3.6.15 with the Westinghouse Standard TS (STS) 3.6.8, Shield Building (Dual and Ice Condenser), in NUREG 1431, Revision 4. STS 3.6.8 is applicable to WBN in that the WBN containment design includes an ice condenser and a separate reinforced concrete Shield Building that surrounds the steel containment vessel. The WBN Shield Building also ensures proper operation of the emergency gas treatment system (EGTS) and limits the radioactive leakage from the containment to those paths and leakage rates assumed in the accident analysis.

3.0 TECHNICAL EVALUATION

3.1 SYSTEM DESCRIPTION A description of the relevant systems and structures is presented below as background for evaluation of the proposed changes.

3.1.1 Shield Building The Shield Building is a reinforced concrete cylinder structure surrounding the steel containment structure. An annulus space exists between the steel containment vessel and the inside of the Shield Building. The Shield Building is supported by a circular base slab and covered at the top with a spherical dome. It is designed to provide the following:

1. radiation shielding from accident conditions

2. radiation shielding from parts of the Reactor Coolant System (RCS) during operation

3. protection of the steel containment vessel from adverse atmospheric conditions and external missiles propelled by tornado winds The Shield Building for each unit is located adjacent to the Auxiliary Building.

3.1.2 Containment The containment is a low-leakage, freestanding steel pressure vessel surrounded by the reinforced concrete Shield Building. Containment piping penetration assemblies provide for the passage of process, service, sampling, and instrumentation pipelines into the containment vessel while maintaining containment integrity.

CNL-19-077 E4 of 20

Enclosure The inner steel containment and its penetrations establish the boundary of the containment, limiting the leakage of fission product radioactivity from the containment to the environment. The design basis for the containment is that the containment must withstand the pressures and temperatures of the limiting design basis accident (DBA) without exceeding the design leakage rates.

3.1.3 EGTS The EGTS establishes a negative pressure in the annulus between the Shield Building and the steel containment vessel. Filters in the system control the release of radioactive contaminants to the environment.

The design bases for the EGTS are:

1. to keep the air pressure within each Shield Building annulus below atmospheric pressure at all times in which the integrity of that particular containment is required

2. to reduce the concentration of radioactive nuclides in the annulus air that is released to the environs during a LOCA in either reactor unit to levels sufficiently low to keep the site boundary and low population zone (LPZ) dose below the 10 CFR 100 values

3. to withstand the safe shutdown earthquake

4. to provide for initial and periodic testing of the system capability to function as designed The negative pressure control setpoint chosen for post-accident operation is low enough that leakage across the boundary is into the annulus from both the primary containment and areas adjacent to the Shield Building. Appropriate selection of the annulus negative pressure level also overcomes the pressure differentials produced by wind and temperature effects.

The EGTS consists of two separate and redundant trains. Each train includes a heater, a prefilter, moisture separators, a high efficiency particulate air (HEPA) filter, an activated charcoal adsorber section for removal of radioiodines, and a fan. Ductwork, valves, dampers, and instrumentation also form part of the system. The moisture separators function to reduce the moisture content of the airstream. A second bank of HEPA filters follows the adsorber section to collect carbon fines and provide backup in case of failure of the main HEPA filter bank. The system initiates and maintains a negative air pressure in the Shield Building by means of filtered exhaust ventilation of the Shield Building following receipt of a safety injection signal.

3.2 TECHNICAL ANALYSIS

3.2.1 Proposed Change to SR 3.6.15.1 As noted in NUREG-1431, Revision 4, Westinghouse STS 3.6.8, Shield Building (Dual and Ice Condenser), SR 3.6.8.1, the value for the annulus pressure requirement is bracketed, meaning it is a plant-specific value. The current value of -5 inch w.g. in WBN Units 1 and 2 SR 3.6.15.1 is the same as that in the initial WBN Units 1 and 2 TS.

This value was in the original analysis of offsite and control room doses due to a large break LOCA (LBLOCA) for WBN Unit 1.

CNL-19-077 E5 of 20

Enclosure The current LBLOCA analysis of record for WBN, documented in section 15.5.3 of the WBN dual-unit UFSAR, assumes the annulus is initially at atmospheric conditions. This is the same initial condition used to support the licensing of WBN Unit 2 and was described in WBN Unit 2 FSAR Amendment 107 (Reference 7). The results of the LOCA analysis in WBN Unit 2 FSAR Amendment 107 were also reflected in NUREG-0847 Supplemental Safety Evaluation Report (SSER) 25 (Reference 8).

The value proposed for WBN Units 1 and 2 SR 3.6.15.1 of -1 inch w.g. accounts for the following:

• As stated in Branch Technical Position (BTP) 6-3, a positive pressure with regard to secondary containment structures is defined as any pressure greater than

-0.25 inch w.g., to conservatively account for wind loads and the uncertainty in pressure measurements.

• Information Notice (IN) 88-76 documents a phenomenon where the pressure inside the secondary containment is not maintained at higher elevations due to temperature induced differential pressure effects. WBN pressure sensors for the Shield Building are located at elevation 783 while the upper elevation of the Shield Building is at elevation 879.04. As noted in the ASHRAE Handbook of Fundamentals, the differential pressure caused by stack effect inside of the Shield Building must also be considered, based on the instrument elevation.

Based on these considerations, a calculated value of -0.63 inch w.g. at the elevation of the pressure sensors ensures the pressure at any elevation in the annulus is equal to or more negative than -0.25 inch w.g. To provide conservatism and added margin, the value of -1 inch w.g. is proposed for SR 3.6.15.1.

Given that the current LBLOCA analysis of record for WBN assumes the annulus is initially at atmospheric conditions, then a value of -1 inch w.g. ensures that the annulus is maintained at a negative pressure and is bounded by the current LBLOCA analysis.

Parameters and Consequences for Current LBLOCA Analysis of Record The parameters used in the current LBLOCA analysis are provided in Tables 3.2.1-1 through 3.2.1-8 of this enclosure. Two cases are considered:

• One case analyzes a single failure such that one whole train of the EGTS fails from the beginning of the accident.

• The second case analyzes a single failure in the controls of the EGTS such that one set of EGTS dampers is assumed to be in the full exhaust position (pressure control operator [PCO] failure case).

The WBN LBLOCA radiological consequences for the Control Room (CR), two-hour Exclusion Area Boundary (EAB), and 30-day Low Population Zone (LPZ) shown in Tables 3.2.1-9 and 3.2.1-10 of this enclosure are below the 10 CFR Part 100 and 10 CFR Part 50 Appendix A GDC 19 regulatory limits. Therefore, the proposed value of

-1 inch w.g. is acceptable because it is bounded by the current licensing basis analysis, which assumes the annulus is at atmospheric conditions.

The results presented in Table 3.2.1-10 also account for the future application of Tritium Producing Burnable Absorbing Rods (TPBARs) for WBN Unit 2 in accordance with References 9 and 10.

CNL-19-077 E6 of 20

Enclosure Table 3.2.1-1: Parameters used in the LBLOCA Analysis Parameter Value Primary containment free volume 1.27E+06 cubic feet (ft3)

Shield Building annulus free volume 3.75E+05 ft3 Primary containment deck (air return) fan flow rate 40,000 cubic feet per minute (cfm)

Number of containment deck air return fans operating 1 of 2 Fractions of core inventory available for release Noble gases 100 percent (%)

Iodines 25%

Tritium 100%

Initial iodine composition in containment Elemental 91%

Organic 4%

Particulate 5%

Primary containment leak rates 0-24 hour (hr) 0.25% per day 1-30 days 0.125% per day Percent of primary containment leakage to Auxiliary Building 25%

Auxiliary Building Gas Treatment System (ABGTS) filter efficiencies elemental iodine 99%

methyl iodine 99%

particulate iodine 99%

Delay time of activity in Auxiliary Building before ABGTS operation None Delay time before filtration credit is taken for the ABGTS 4 minutes Mean holdup time in Auxiliary Building after initial 4 minutes 0.3 hr ABGTS flow rate 9000 cfm Leakage from the Auxiliary Building to ABGTS HVAC 27.88 cfm downstream of the filters Leakage from ABGTS HVAC into Auxiliary Building 8.87 cfm Leakage from Auxiliary Building into EGTS HVAC 10.7 cfm downstream of the filters Leakage from Auxiliary Building to environment from single 9900 cfm failure of ABGTS (from 30 minutes to 34 minutes post-LOCA)

Percent of primary containment leakage to annulus 75%

Percent of annulus free volume available for mixing of 50%

recirculated activity CNL-19-077 E7 of 20

Enclosure Table 3.2.1-1: Parameters used in the LBLOCA Analysis Parameter Value Emergency gas treatment system filter efficiencies elemental iodine 99%

methyl iodine 99%

particulate iodine 99%

EGTS total flow 3600 cfm/train Initial annulus pressure atmospheric Annulus inleakage 250 cfm at -1.45 w.g.

Emergency Core Cooling System (ECCS) leakage 3760 cubic outside containment centimeter (cc)/hr Sump volume 9.63E+04 ft3 Core inventory of iodine released to the sump 50%

Core inventory of tritium released to the sump 97%

Iodine partition factor for ECCS leakage 10 Table 3.2.1-2: Ice Condenser Elemental and Particulate Removal Efficiency Time Interval Post-LOCA (Hours) Removal Efficiency 0.0 to 0.156 0.96 0.156 to 0.267 0.76 0.267 to 0.323 0.73 0.323 to 0.489 0.71 0.489 to 0.615 0.60 0.615 to 0.768 0.58 0.768 to 0.824 0.40 0.824 to 720 0.0 CNL-19-077 E8 of 20

Enclosure Table 3.2.1-3: EGTS Flow Rates for Failure of a Single EGTS Train Case (WBN Units 1 and 2)

Time Interval Time Interval Recirculation Rate Exhaust Rate cubic feet seconds sec hrs hrs cfm per hour cfm cfh (sec)

(cfh) 0 30 0.0000 0.0083 0.00E+00 0.00E+00 0.00E+00 0.00E+00 30 39 0.0083 0.0108 3.60E+03 2.16E+05 0.00E+00 0.00E+00 39 40 0.0108 0.0111 3.29E+03 1.97E+05 3.13E+02 1.88E+04 40 41 0.0111 0.0114 2.35E+03 1.41E+05 1.25E+03 7.49E+04 41 42 0.0114 0.0117 1.30E+03 7.83E+04 2.30E+03 1.38E+05 42 43 0.0117 0.0119 3.63E+02 2.18E+04 3.24E+03 1.94E+05 43 190 0.0119 0.0528 0.00E+00 0.00E+00 3.60E+03 2.16E+05 190 191 0.0528 0.0531 5.37E+02 3.22E+04 3.06E+03 1.84E+05 191 192 0.0531 0.0533 7.33E+02 4.40E+04 2.87E+03 1.72E+05 192 193 0.0533 0.0536 7.35E+02 4.41E+04 2.86E+03 1.72E+05 193 194 0.0536 0.0539 7.38E+02 4.43E+04 2.86E+03 1.72E+05 194 199 0.0539 0.0553 7.45E+02 4.47E+04 2.85E+03 1.71E+05 199 207 0.0553 0.0575 7.64E+02 4.58E+04 2.84E+03 1.70E+05 207 215 0.0575 0.0597 7.91E+02 4.74E+04 2.81E+03 1.69E+05 215 225 0.0597 0.0625 8.25E+02 4.95E+04 2.77E+03 1.66E+05 225 245 0.0625 0.0681 8.93E+02 5.36E+04 2.71E+03 1.62E+05 245 265 0.0681 0.0736 9.93E+02 5.96E+04 2.61E+03 1.56E+05 265 285 0.0736 0.0792 1.10E+03 6.61E+04 2.50E+03 1.50E+05 285 305 0.0792 0.0847 1.22E+03 7.30E+04 2.38E+03 1.43E+05 305 446 0.0847 0.1239 1.66E+03 9.98E+04 1.94E+03 1.16E+05 446 601 0.1239 0.1669 2.36E+03 1.41E+05 1.24E+03 7.46E+04 601 602 0.1669 0.1672 2.66E+03 1.60E+05 9.39E+02 5.63E+04 602 1700 0.1672 0.4722 3.60E+03 2.16E+05 0.00E+00 0.00E+00 1700 1701 0.4722 0.4725 3.51E+03 2.10E+05 9.19E+01 5.51E+03 1701 1702 0.4725 0.4728 3.42E+03 2.05E+05 1.77E+02 1.06E+04 1702 1703 0.4728 0.4731 3.41E+03 2.05E+05 1.89E+02 1.14E+04 1703 1704 0.4731 0.4733 3.41E+03 2.05E+05 1.91E+02 1.15E+04 1704 1705 0.4733 0.4736 3.41E+03 2.04E+05 1.92E+02 1.15E+04 1705 1706 0.4736 0.4739 3.41E+03 2.04E+05 1.92E+02 1.15E+04 1706 1855 0.4739 0.5153 3.40E+03 2.04E+05 2.05E+02 1.23E+04 1855 2100 0.5153 0.5833 3.37E+03 2.02E+05 2.28E+02 1.37E+04 2100 30 days 0.5833 30 days 3.35E+03 2.01E+05 2.50E+02 1.50E+04 CNL-19-077 E9 of 20

Enclosure Table 3.2.1-4: WBN Unit 1 EGTS Flow Rates for PCO Failure Case Time Interval Time Interval Recirculation Rate Exhaust Rate sec sec hr hr cfm cfh cfm cfh 0 30 0 0.0083 0 0 0 0 30 39 0.0083 0.0108 7200 4.32E+05 0 0 39 40 0.0108 0.0111 6573 3.94E+05 627 3.76E+04 40 41 0.0111 0.0114 4705 2.82E+05 2495 1.50E+05 41 42 0.0114 0.0117 2610 1.57E+05 4590 2.75E+05 42 43 0.0117 0.0119 725 4.35E+04 6475 3.88E+05 43 71 0.0119 0.0197 0 0 7200 4.32E+05 71 80 0.0197 0.0222 0 0 7200 4.32E+05 80 81 0.0222 0.0225 1568 9.41E+04 5632 3.38E+05 81 82 0.0225 0.0228 4222 2.53E+05 2978 1.79E+05 82 102 0.0228 0.0283 4064 2.44E+05 3136 1.88E+05 102 132 0.0283 0.0367 3816 2.29E+05 3384 2.03E+05 132 165 0.0367 0.0458 3659 2.20E+05 3541 2.12E+05 165 169 0.0458 0.0469 3619 2.17E+05 3581 2.15E+05 169 210 0.0469 0.0583 3659 2.20E+05 3541 2.12E+05 210 307 0.0583 0.0853 3950 2.37E+05 3250 1.95E+05 307 498 0.0853 0.1383 4701 2.82E+05 2499 1.50E+05 498 602 0.1383 0.1672 5386 3.23E+05 1814 1.09E+05 602 603 0.1672 0.1675 5568 3.34E+05 1632 9.79E+04 603 850 0.1675 0.2361 4597 2.76E+05 1534 9.20E+04 850 1100 0.2361 0.3056 4694 2.82E+05 1437 8.62E+04 1100 1350 0.3056 0.375 4791 2.87E+05 1340 8.04E+04 1350 1600 0.375 0.4444 4888 2.93E+05 1243 7.46E+04 1600 1850 0.4444 0.5139 4985 2.99E+05 1146 6.88E+04 1850 2100 0.5139 0.5833 5082 3.05E+05 1049 6.29E+04 2100 3600 0.5833 1.0 5174 3.10E+05 957 5.74E+04 3600 30 days 1.0 30 days 3584 2.15E+05 694 4.16E+04 CNL-19-077 E10 of 20

Enclosure Table 3.2.1-5: WBN Unit 2 EGTS Flow Rates for PCO Failure Case Time Interval Time Interval Recirculation Rate Exhaust Rate sec sec hrs hrs cfm cfh cfm cfh 0 30 0 0.0083 0.00E+00 0.00E+00 0.00E+00 0.00E+00 30 39 0.0083 0.0108 7.20E+03 4.32E+05 0.00E+00 0.00E+00 39 40 0.0108 0.0111 6.57E+03 3.94E+05 6.27E+02 3.76E+04 40 41 0.0111 0.0114 4.70E+03 2.82E+05 2.50E+03 1.50E+05 41 42 0.0114 0.0117 2.61E+03 1.57E+05 4.59E+03 2.75E+05 42 43 0.0117 0.0119 7.25E+02 4.35E+04 6.47E+03 3.88E+05 43 71 0.0119 0.0197 0.00E+00 0.00E+00 7.20E+03 4.32E+05 71 78 0.0197 0.0217 0.00E+00 0.00E+00 7.20E+03 4.32E+05 78 79 0.0217 0.0219 1.06E+03 6.37E+04 6.14E+03 3.68E+05 79 80 0.0219 0.0222 4.78E+03 2.87E+05 2.43E+03 1.46E+05 80 102 0.0222 0.0283 4.34E+03 2.60E+05 2.86E+03 1.72E+05 102 132 0.0283 0.0367 4.19E+03 2.51E+05 3.01E+03 1.81E+05 132 165 0.0367 0.0458 3.92E+03 2.35E+05 3.28E+03 1.97E+05 165 170 0.0458 0.0472 3.76E+03 2.26E+05 3.44E+03 2.06E+05 170 210 0.0472 0.0583 3.72E+03 2.23E+05 3.48E+03 2.09E+05 210 307 0.0583 0.0853 3.76E+03 2.26E+05 3.44E+03 2.06E+05 307 498 0.0853 0.1383 4.05E+03 2.43E+05 3.15E+03 1.89E+05 498 602 0.1383 0.1672 4.80E+03 2.88E+05 2.40E+03 1.44E+05 602 603 0.1672 0.1675 5.23E+03 3.14E+05 1.97E+03 1.18E+05 603 850 0.1675 0.2361 5.14E+03 3.08E+05 1.43E+03 8.59E+04 850 1100 0.2361 0.3056 5.24E+03 3.14E+05 1.33E+03 7.99E+04 1100 1350 0.3056 0.375 5.34E+03 3.20E+05 1.23E+03 7.39E+04 1350 1600 0.375 0.4444 5.44E+03 3.26E+05 1.13E+03 6.79E+04 1600 1850 0.4444 0.5139 5.54E+03 3.32E+05 1.03E+03 6.19E+04 1850 2100 0.5139 0.5833 5.64E+03 3.38E+05 9.32E+02 5.59E+04 2100 3600 0.5833 1.0 5.74E+03 3.44E+05 8.32E+02 4.99E+04 3600 30 days 1.0 30 days 3.46E+03 2.07E+05 6.04E+02 3.62E+04 CNL-19-077 E11 of 20

Enclosure Table 3.2.1-6: Core Inventory Nuclide Inventory (Ci)

Kr-83m 1.23E+07 Kr-85m 2.69E+07 Kr-85 8.81E+05 Kr-87 5.23E+07 Kr-88 7.38E+07 Kr-89 9.10E+07 Xe-131m 9.54E+05 Xe-133m 5.80E+06 Xe-133 1.88E+08 Xe-135m 3.59E+07 Xe-135 4.96E+07 Xe-138 1.59E+08 I-131 9.01E+07 I-132 1.31E+08 I-133 1.88E+08 I-134 2.08E+08 I-135 1.76E+08 H-3 2.68E+07 Table 3.2.1-7: Control Room Parameters Parameter Value Volume 257,198 ft3 Makeup/pressurization flow 711 cfm Recirculation Flow 2889 cfm Unfiltered Intake 51 cfm Filter Efficiency First Pass 95%

Second Pass 70%

Occupancy Factors 0-24 hours 100%

1-4 days 60%

4-30 days 40%

Table 3.2.1-8: Atmospheric Dispersion Factors (sec/m3)

Time Period EAB LPZ CR 0-2 hr 6.382E-04 1.784E-04 1.09E-03 2-8 hr ------ 8.835E-05 9.44E-04 8-24 hr ------ 6.217E-05 1.56E-04 1-4 days ------ 2.900E-05 1.16E-04 4-30 days ------ 9.811E-06 9.59E-05 CNL-19-077 E12 of 20

Enclosure Table 3.2.1-9: WBN Unit 1 Dose Consequences from an LBLOCA Single Train EGTS Case EAB and LPZ CR Regulatory Dose (rem) CR 2 Hour EAB 30 Day LPZ Regulatory Limit Limit Whole Body 8.87E-01 5 2.07E+00 1.89E+00 25 Beta 7.49E+00 30 1.14E+00 2.26E+00 300 Thyroid 3.62E+00 30 3.87E+01 1.38E+01 300 PCO Control Failure Case EAB and LPZ CR Regulatory Dose (rem) CR 2 Hour EAB 30 Day LPZ Regulatory Limit Limit Whole Body 1.10E+00 5 2.50E+00 2.37E+00 25 Beta 9.36E+00 30 1.43E+00 2.66E+00 300 Thyroid 3.11E+00 30 3.03E+01 1.20E+01 300 Table 3.2.1-10: WBN Unit 2 Dose Consequences from an LBLOCA Single Train EGTS Case EAB and LPZ CR Regulatory Dose (rem) CR 2 Hour EAB 30 Day LPZ Regulatory Limit Limit Whole Body 8.87E-01 5 2.07E+00 1.89E+00 25 Beta 7.49E+00 30 1.14E+00 2.26E+00 300 Thyroid 3.62E+00 30 3.87E+01 1.38E+01 300 PCO Control Failure Case EAB and LPZ CR Regulatory Dose (rem) CR 2 Hour EAB 30 Day LPZ Regulatory Limit Limit Whole Body 1.07E+00 5 2.42E+00 2.30E+00 25 Beta 9.10E+00 30 1.38E+00 2.61E+00 300 Thyroid 3.09E+00 30 3.03E+01 1.19E+01 300 CNL-19-077 E13 of 20

Enclosure 3.2.2 Proposed Deletion of TS 3.6.15, Condition B Deletion of Note to TS 3.6.15 Condition B Routine activities that cause interaction with the WBN Shield Building annulus during normal operation (e.g., venting operations, required annulus entries, Auxiliary Building isolations) do not result in annulus differential pressure being equal to or less negative than -1 inch w.g. A review of annulus differential pressure readings during a 12-month period is provided in Figures 3.2.2-1 and 3.2.2-2.

Figure 3.2.2-1 WBN Unit 1 Annulus Differential Pressure (inches w.g.)

CNL-19-077 E14 of 20

Enclosure Figure 3.2.2-2 WBN Unit 2 Annulus Differential Pressure (inches w.g.)

Figures 3.2.2-1 and 3.2.2-2 indicate that the routine annulus entries during normal operation in this 12-month period caused the WBN Unit 1 annulus differential pressure to drop to a level no less negative than -5.45 inch w.g., and the WBN Unit 2 annulus differential pressure to drop to a level no less negative than -4.0 inch w.g.

The approximate six-week period where there was a significant decrease in the differential pressure corresponds to refueling outages. The remaining spikes where there was a significant decrease in the differential pressure are attributed to instrument calibrations, repair period for a damaged penetration seal, and to momentary indication change of unknown origin on a single pressure transmitter.

Therefore, with the change to the annulus differential pressure requirement as discussed in Section 3.2.1 of this enclosure, the note in Condition B is no longer needed and can be deleted.

CNL-19-077 E15 of 20

Enclosure Deletion of TS 3.6.15 Condition B TS 3.6.15 Condition B currently requires an eight-hour completion time for required actions if the annulus pressure requirement in SR 3.6.15.1 is not met. This eight-hour completion time is in contrast to the 24-hour completion time established in Condition A regarding other aspects of Shield Building operability such as closure of each access opening (SR 3.6.15.2), structural integrity (SR 3.6.15.3), and annulus inleakage (SR 3.6.15.4).

However, a failure to meet the requirements of SR 3.6.15.2, SR 3.6.15.3, and SR 3.6.15.4 would have a greater impact on the ability of the EGTS to drawdown the annulus and maintain a negative pressure. This is because a failure to meet the initial annulus pressure would have impact only in the first few minutes of an event, as the initial annulus pressure only determines how long it takes the EGTS to drawdown the annulus and thus how long the annulus will be at a positive pressure. It does not impact the ability of the EGTS to drawdown the annulus or maintain a negative pressure.

Conversely, a failure to meet the other surveillance requirements has a direct impact on the ability of the EGTS to drawdown the annulus and maintain a negative pressure.

Therefore, the impact of not meeting the assumed annulus initial pressure is no more significant than the other aspects that determine Shield Building operability. Thus, the existing Condition A is adequate for setting the completion time for all aspects of Shield Building operability and Condition B can be deleted.

History of WBN Units 1 and 2 TS 3.6.15, Condition B Attachment 7 to this enclosure provides a history of WBN Units 1 and 2 TS 3.6.15, Condition B. As shown in Attachment 7, TS 3.6.15, Condition B was originally intended for the EGTS TS and is not consistent with the Westinghouse STS.

4.0 REGULATORY EVALUATION

4.1 APPLICABLE REGULATORY REQUIREMENTS/CRITERIA 10 CFR 50.36, Technical Specifications, requires that the TS include limiting conditions for operation, which are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the TS until the condition can be met.

10 CFR 100, Reactor Site Criteria establishes an exclusion area, a low population zone, and population center distance with respect to an individual whole body and total radiation dose.

GDC 16, Containment design, requires that reactor containment and associated systems be provided to establish an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment and to assure that the containment design conditions important to safety are not exceeded for as long as postulated accident conditions require.

CNL-19-077 E16 of 20

Enclosure GDC 19, Control room, requires that a control room shall be provided from which actions can be taken to operate the nuclear power unit safely under normal conditions and to maintain it in a safe condition under accident conditions, including loss-of-coolant accidents. Adequate radiation protection shall be provided to permit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of five rem whole body, or its equivalent to any part of the body, for the duration of the accident. Equipment at appropriate locations outside the control room shall be provided (1) with a design capability for prompt hot shutdown of the reactor, including necessary instrumentation and controls to maintain the unit in a safe condition during hot shutdown, and (2) with a potential capability for subsequent cold shutdown of the reactor through the use of suitable procedures.

GDC 60, Control of releases of radioactive materials to the environment, requires that the nuclear power unit design include means to control suitably the release of radioactive materials in gaseous and liquid effluents and to handle radioactive solid wastes produced during normal reactor operation, including anticipated operational occurrences.

Conclusion The Shield Building boundary integrity ensures that the release of radioactive materials from the primary containment would be restricted to those leakage paths and associated leakage rates assumed in the safety analyses. This restriction, in conjunction with operation of the Shield Building limits the site boundary radiation doses to within the regulatory limits of 10 CFR 100 and GDC 19 during accident conditions. The proposed changes do not affect the ability of the Shield Building to perform its intended function as they are bounded by the current licensing basis.

4.2 PRECEDENT There are no applicable regulatory precedents regarding the changes proposed in this license amendment request. However, the proposed change to delete the current TS 3.6.15, Condition B in its entirety is consistent with the Westinghouse STS in NUREG-1431, Revision 4.

4.3 SIGNIFICANT HAZARDS CONSIDERATION Tennessee Valley Authority (TVA) proposes to delete the existing Watts Bar Nuclear (WBN) Units 1 and 2 Technical Specification (TS) 3.6.15, Shield Building, Condition B.

The proposed change is based, in part, on a revision to the existing annulus pressure requirement in WBN Units 1 and 2 Surveillance Requirement (SR) 3.6.15.1 from equal to or more negative than -5 inch water gauge (w.g.) to equal to or more negative than -1 inch w.g. The revision to the annulus pressure in SR 3.6.15.1 is bounded by accident analyses in the WBN dual-unit Updated Final Safety Analysis Report (UFSAR). The proposed changes also aligns the WBN Units 1 and 2 TS 3.6.15 Conditions with NUREG-1431, Standard Technical Specifications - Westinghouse Plants, Revision 4.

CNL-19-077 E17 of 20

Enclosure TVA has evaluated whether or not a significant hazards consideration is involved with the proposed amendment(s) 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 consequences of an accident previously evaluated?

Response: No.

The proposed changes do not require physical changes to plant systems, structures, or components. The Shield Building is a passive accident mitigating feature. As such, the Shield Building is not associated with a potential accident-initiating mechanism. The revised plant-specific value for the Shield Building Annulus differential pressure requirement provided in SR 3.6.15.1 ensures the initial conditions assumed in the safety analysis remain bounding. Therefore, the changes do not affect accident or transient initiation or consequences.

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

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

Response: No.

The proposed changes do not introduce new or different accidents to be postulated and subsequently evaluated, and no changes are being made to the plant that would introduce any new accident causal mechanisms. This license amendment request does not affect any plant systems that are potential accident initiators; nor does it have any significantly adverse effect on any accident mitigating systems.

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

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

Response: No.

The proposed changes do not alter the permanent plant design, nor does it change the assumptions contained in the safety analyses. Margin of safety is related to the ability of the fission product barriers to perform their design functions during and following accident conditions. These barriers include the fuel cladding, the reactor coolant system, and the containment system. The performance of these barriers is not degraded by the proposed changes, as the annulus pressure requirement ensures the initial condition in the safety analysis remains bounding. Surveillance Requirements 3.6.15.2, 3.6.15.3, and 3.6.15.4 ensure EGTS can perform its design function. Therefore, the change in the annulus pressure requirement does not affect the ability of EGTS to perform its safety function.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

CNL-19-077 E18 of 20

Enclosure Based on the above, TVA concludes 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 CONCLUSION

S 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 Commissions 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 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-19-077 E19 of 20

Enclosure

6.0 REFERENCES

1. TVA Letter to NRC, CNL-16-147, Watts Bar Nuclear Plant (WBN) Unit 1 and Unit 2 -

Non-Voluntary License Amendment Request to Modify and Clarify Technical Specification 3.6.15, Shield Building, Condition B Note (WBN-TS-16-17), dated March 6, 2017 (ML17065A301)

2. NRC letter to TVA, Watts Bar Nuclear Plant - NRC Integrated Inspection Report 05000390/2016001, 05000391/2016001, dated April 7, 2016 (ML16098A323)

3. Letter from NRC to TVA, Watts Bar Nuclear Plant - NRC Integrated Inspection Report 05000390, 05000391/2015004 and 07201048/2015002, dated February 12, 2016 (ML16043A214)

4. NRC electronic mail to TVA, Watts Bar Acceptance Review Draft Supplemental Information Request - LAR to Revise Technical Specification 3.6.15 Shield Building (CAC Nos. MF9393 and MF9394), dated April 19, 2017 (ML17170A172)

5. TVA Letter to NRC, CNL-17-060, Withdrawal of Watts Bar Nuclear Plant (WBN)

Unit 1 and Unit 2 - Non-Voluntary License Amendment Request to Modify and Clarify Technical Specification 3.6.15, Shield Building, Condition B Note (WBN-TS-16-17),

dated May 10, 2017 (ML17131A206)

6. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Withdrawal of Requested Licensing Action RE: License Amendment to Clarify Shield Building Technical Specification (CAC Nos. MF9393 and MF 9394), dated June 22, 2017 (ML17111A701)

7. TVA Letter to NRC, Watts Bar Nuclear Plant (WBN) - Unit 2 - Final Safety Analysis Report (FSAR), Amendment 107, dated November 17, 2011 (ML121780190) and FSAR Chapter 15 Accident Analyses (ML12178A210)

8. NUREG-0847, Supplement 25, Safety Evaluation Report Related to the Operation of Watts Bar Nuclear Plant, Unit 2, dated December 2011 (ML12011A024)

9. NRC letter to TVA, Watts Bar Nuclear Plant, Units 1 and 2 - Issuance of Amendment Regarding Revision to Watts Bar Nuclear Plant, Unit 2, Technical Specification 4.2.1, Fuel Assemblies, and Watts Bar Nuclear Plant, Units 1 and 2, Technical Specifications Related to Fuel Storage (EPID L-2017-LLA-0427), dated May 22, 2019 (ML18347B330)

10. TVA Letter to NRC, CNL-17-144, Application to Revise Watts Bar Unit 2 Technical Specification 4.2.1, Fuel Assemblies, and Watts Bar Units 1 and 2 Technical Specifications Related to Fuel Storage (WBN-TS-17-028), dated December 20, 2017 (ML17354B282)

CNL-19-077 E20 of 20

Enclosure Attachment 1 Proposed TS Changes (Mark-Ups) for WBN Unit 1 CNL-19-077

Shield Building 3.6.15 3.6 CONTAINMENT SYSTEMS 3.6.15 Shield Building LCO 3.6.15 The Shield Building shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Shield Building inoperable. A.1 Restore Shield Building to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> OPERABLE status.

B. ------------NOTE------------------ B.1 Restore annulus pressure 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Annulus pressure requirement within limits.

is not applicable during venting operations, required annulus entries, or Auxiliary Building isolations not exceeding 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in duration or while Penetration 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building dome is open until annulus pressure is restored.*

Annulus pressure not within limits.

CB. Required Action and CB.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 not met. AND CB.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 />

• 1. The combined opening time of Penetrations 1-EQH-271-0010 or 1-EQH-271-0011 is limited to a total time of five hours a day, six days a week during Cycle 7 operation.

2. Penetrations 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building Dome may not be opened if in Action Conditions LCO 3.6.9A or 3.8.1B.

3. Upon opening Penetration 1-EQH-271-0010 or 1-EQH-271-0011 in the Shield Building Dome, both EGTS control loops shall be placed in the A-Auto Stand-by position and returned to normal position following closure of penetration.

Watts Bar-Unit 1 3.6-40 Amendment 59, XX

Shield Building 3.6.15 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.15.1 Verify annulus negative pressure is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> equal to or more negative than -51 inches water gauge with respect to the atmosphere.

SR 3.6.15.2 Verify the door in each access opening is closed, 31 days except when the access opening is being used for normal transient entry and exit.

SR 3.6.15.3 Verify shield building structural integrity by During performing a visual inspection of the exposed interior shutdown for and exterior surfaces of the Shield Building. SR 3.6.1.1 Type A tests SR 3.6.15.4 Verify each Emergency Gas Treatment System train 18 months on a with final flow 3600 and 4400 cfm produces an STAGGERED TEST annulus pressure equal to or more negative than BASIS

-0.61 inch water gauge at elevation 783 with respect to the atmosphere and with an inleakage of 250 cfm.

Watts Bar-Unit 1 3.6-41 Amendment XX

Enclosure Attachment 2 Proposed TS Changes (Mark-Ups) for WBN Unit 2 CNL-19-077

Shield Building 3.6.15 3.6 CONTAINMENT SYSTEMS 3.6.15 Shield Building LCO 3.6.15 The shield building shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Shield building inoperable. A.1 Restore shield building to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> OPERABLE status.

B. ------------NOTE---------------- B.1 Restore annulus pressure 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Annulus pressure within limits.

requirement is not applicable during ventilating operations, required annulus entries, or Auxiliary Building isolations not exceeding 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in duration.

Annulus pressure not within limits.

C.B. Required Action and CB.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 not met. AND CB.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 /> Watts Bar - Unit 2 A

3.6-35 Amendment XX

Shield Building 3.6.15 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.15.1 Verify annulus negative pressure is equal to or more 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> negative than -51 inches water gauge with respect to the atmosphere.

SR 3.6.15.2 Verify the door in each access opening is closed, 31 days except when the access opening is being used for normal transient entry and exit.

SR 3.6.15.3 Verify shield building structural integrity by During shutdown for performing a visual inspection of the exposed interior SR 3.6.1.1 Type A and exterior surfaces of the Shield Building. tests SR 3.6.15.4 Verify each Emergency Gas Treatment System train 18 months on a with final flow 3600 cfm and 4400 cfm produces STAGGERED TEST an annulus pressure equal to or more negative BASIS than - 0.61 inch water gauge at elevation 783 with respect to the atmosphere and with an inleakage of 250 cfm.

Watts Bar - Unit 2 A

3.6-36 Amendment XX

Enclosure Attachment 3 Proposed TS Bases Changes (Mark-Ups) for WBN Unit 1 (For Information Only)

CNL-19-077

Shield Building B 3.6.15 BASES ACTIONS A.1 In the event shield building OPERABILITY is not maintained, shield building OPERABILITY must be restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Twenty-four hours is a reasonable Completion Time considering the limited leakage design of containment and the low probability of a Design Basis Accident occurring during this time period.

B.1 The Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is based on engineering judgment. The normal alignment for both EGTS control loops is the A-Auto position. With both EGTS control loops in A-Auto, both trains will function upon initiation of a Containment Isolation Phase A (CIA) signal. In the event of a LOCA, the annulus vacuum control system isolates and both trains of the EGTS pressure control loops will be placed in service to maintain the required negative pressure. If annulus vacuum is lost during normal operations, the A-Auto position is unaffected by the loss of vacuum. This operational configuration is acceptable because the accident dose analysis conservatively assumes the annulus is at atmospheric pressure at event initiation.

(Ref. 3)

A Note has been provided which makes the requirement to maintain the annulus pressure within limits not Note: applicable for a maximum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> during: Ventilating operations, Required The highlighted text on annulus entries, or Auxiliary Building isolations. Ventilating operations include this page and the containment venting, the Reactor Building Purge Ventilating System alternate following page was containment pressure relief function, and testing of the Emergency Gas incorporated as part of Treatment system. In addition to Note makes the requirement to maintain the Amendment 59. This annulus pressure within limits not applicable while Penetration 1-EQH-271-0010 amendment also added a or 1-EQH-271-0011 in the Shield Building dome is open until annulus pressure is series of notes to restored. Allowing one of the Shield Building dome penetrations to be open is Technical Specification based on provisions being in place to close it within fifteen minutes of LOCA 3.6.15. As stated in initiation. Limiting the time for opening either of the penetrations to a combined NRCs Safety Evaluation total of five hours a day, six days a week keeps the amount of time the Shield for Amendment 59 Building is inoperable to approximately 60 percent of the eight hour completion (NRCs letter dated time for LCO B.

January 6, 2006), these During controls werenormal only plant operation, the Annulus is maintained at a negative pressure equal to or more negative applicable until WBN than -5 inches water gauge (wg) by the Annulus Vacuum Control subsystem Unit 1 entered Mode 5 at (non-safety related) of the Emergency Gas Treatment System (EGTS). One train the start of the Cycle 7 (loop) of the Annulus Vacuum Control subsystem is operating (controls in A-Auto) refueling outage. The and one train is in standby (controls in A-Auto Stand-by).

highlighted text in this BasesOpening Shield section and theBuilding dome Penetration 1-EQH-271-0010 or 1-EQH-271-0011 during Modes 1-4 will notes in Technical result in the Annulus pressure becoming more positive than the -5 inches wg Specification 3.6.15 will be required by Technical Specification 3.6.15. When the Annulus pressure becomes deleted via a future more positive than -0.812 inches wg, the EGTS control system perceives that the amendment to the loop in A-Auto (i.e., the operating train) has failed. Control of Annulus pressure is Technical Specifications. then transferred to the loop in A-Auto Stand-by (i.e., the train in standby). Since the loop originally controlling Annulus pressure is (continued)

Watts Bar-Unit 1 B 3.6-97 Revision 15, 29, 101, 129 Amendment XX

Shield Building B 3.6.15 BASES ACTIONS B.1 (continued) perceived to have failed, only one control loop (the controller originally in A-Auto Stand-by) remains functional. If a single failure of the remaining control loop were to occur, this would result in both control loops failing and would render the safety-related portion of EGTS inoperable. To prevent this situation, operator action will be taken to place both EGTS control loops in the A-Auto Stand-by position when the annulus differential pressure is more positive than a -5 inches wg. If EGTS is subsequently initiated in this configuration, both trains of EGTS will start. Absent a single failure, one EGTS control loop train will manually be returned to the A-Auto position when the Annulus differential pressure becomes more negative than -0.812 inches wg. In addition, the remaining EGTS control loop train will be turned off, then immediately placed in the A-Auto Stand-by position (i.e., the associated isolation valves shall be closed by means of the MCR hand switch).

This action is in the design and is necessary to restore the EGTS to the normal operational configuration and to prevent excess EGTS exhaust and Annulus in-leakage.

Additional assurance is administratively provided of support system operability by restricting the opening of Penetration 1-EQH-271-0010 or 1-EQH-271-0011 if in Actions for LCO 3.6.9.A EGTS, or 3.8.1.B, AC Sources - Operating. If a hatch is opened and one of the above systems becomes inoperable, the hatch will be closed.

CB.1 and CB.2 If the shield building cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to 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 to 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.

SURVEILLANCE SR 3.6.15.1 REQUIREMENTS Verifying that shield building annulus negative pressure is within limit (equal to or more negative than -5 inches water gauge, value does not account for instrument error, Ref. 2) ensures that operation remains within the limit assumed in the large break loss of coolant accident dose containmentanalysis (Ref. 6). Based on consideration of Branch Technical Position (BTP) 6-3 and Information Notice (IN) 88-76, a value of -0.63 inch w.g. at the elevation of the pressure sensors has been established (value does not account for instrument error, Ref. 2 and Ref. 3). To provide conservatism and added margin, the value of -1 inch w.g. was chosen.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Frequency of this SR was developed considering operating experience related to shield building annulus pressure variations and pressure instrument drift during the applicable MODES.

SR 3.6.15.2 Maintaining shield building OPERABILITY requires maintaining each door in the access opening closed, except when the access opening is being used for normal transient entry and exit. The 31 day Frequency of this SR is based on Watts Bar-Unit 1 B 3.6-98 Revision 15, 29, 101, 129 Amendment XX

Shield Building B 3.6.15 BASES engineering judgment and is considered adequate in view of the other indications of door status that are available to the operator.

Watts Bar-Unit 1 B 3.6-99 Revision 15, 29, 101, 129 Amendment XX

Shield Building B 3.6.15 BASES SURVEILLANCE SR 3.6.15.3 REQUIREMENTS (continued) This SR would give advance indication of gross deterioration of the concrete structural integrity of the shield building. The Frequency of this SR is the same as that of SR 3.6.1.1. The verification is done during shutdown.

SR 3.6.15.4 The EGTS is required to maintain a pressure equal to or more negative than

-0.50 inches of water gauge ("wg) in the annulus at an elevation equivalent to the top of the Auxiliary Building. At elevations higher than the Auxiliary Building, the EGTS is required to maintain a pressure equal to or more negative than -0.25 "wg. The low pressure sense line for the pressure controller is located in the annulus at elevation 783. By verifying that the annulus pressure is equal to or more negative than -0.61 "wg at elevation 783, the annulus pressurization requirements stated above are met. The ability of a EGTS train with final flow 3600 and 4400 cfm to produce the required negative pressure during the test operation provides assurance that the building is adequately sealed. The negative pressure prevents leakage from the building, since outside air will be drawn in by the low pressure at a maximum rate 250 cfm. The 18 month Frequency on a STAGGERED TEST BASIS is consistent with Regulatory Guide 1.52 (Ref. 1) guidance for functional testing.

REFERENCES 1. Regulatory Guide 1.52, Revision 2, "Design, Testing and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmospheric Cleanup System Air Filtration and Adsorption Units of Light-Water Cooled Nuclear Power Plants."

2. Watts Bar Drawing 1-47W605-242, "Electrical Tech Spec Compliance Tables."

3. TVA Calculation EPMMMA121889, Temperature Induced Differential Pressure Effects in Reactor Building and Aux. Bldg. Secondary Containment, Revision 008DCN 52216-A, Elimination of A-AUTO STANDBY Hand Switch Position for EGTS Pressure Control Loops.

4. WBN UFSAR Section 6.2.3.2.2, Emergency Gas Treatment System (EGTS).

5. WBN UFSAR Section 9.4.6, Reactor Building Purge Ventilating System (RBPVS).

6. TVA Calculation TIRPS197, Offsite Doses Due to a Regulatory Guide 1.4 Loss of Coolant Accident, Revision 023 Watts Bar-Unit 1 B 3.6-100 Revision 15, 29, 101, 129 Amendment XX

Enclosure Attachment 4 Proposed TS Bases Changes (Mark-Ups) for WBN Unit 2 (For Information Only)

CNL-19-077

Shield Building B 3.6.15 BASES (continued)

APPLICABILITY Maintaining shield building OPERABILITY prevents leakage of radioactive material from the shield building. Radioactive material may enter the shield building from the containment following a DBA. Therefore, shield building OPERABILITY is required in MODES 1, 2, 3, and 4 when DBAs could release radioactive material to the containment atmosphere.

In MODES 5 and 6, the probability and consequences of these events are low due to the Reactor Coolant System temperature and pressure APPLICABILITY limitations in these MODES. Therefore, shield building OPERABILITY is (continued) not required in MODE 5 or 6.

ACTIONS A.1 In the event shield building OPERABILITY is not maintained, shield building OPERABILITY must be restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is a reasonable Completion Time considering the limited leakage design of containment and the low probability of a Design Basis Accident occurring during this time period.

CB.1 and CB.2 If the shield building cannot be restored to OPERABLE status within the required Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to 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 to 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.

B.1 The Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> is based on engineering judgment. The normal alignment for both EGTS control loops is the A-Auto position.

With both EGTS control loops in A-Auto, both trains will function upon initiation of a Containment Isolation Phase A (CIA) signal. In the event of a LOCA, the annulus vacuum control system isolates and both trains of the EGTS pressure control loops will be placed in service to maintain the required negative pressure. If annulus vacuum is lost during normal operations, the A-Auto position is unaffected by the loss of vacuum. This operational configuration is acceptable because the accident dose analysis conservatively assumes the annulus is at atmospheric pressure at event initiation.

A Note has been provided which makes the requirement to maintain the (continued)

Watts Bar - Unit 2 B 3.6-89 Revision 4 Amendment XX

Shield Building B 3.6.15 BASES (continued) annulus pressure within limits not applicable for a maximum of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> during; Ventilating operations, Required annulus entries, or Auxiliary Building isolations. Ventilating operations include containment venting, the Reactor Building Purge Ventilating System alternate containment pressure relief function, and testing of the Emergency Gas Treatment system.

(continued)

Watts Bar - Unit 2 B 3.6-90 Revision 4 Amendment XX

Shield Building B 3.6.15 BASES SURVEILLANCE SR 3.6.15.1 REQUIREMENTS Verifying that shield building annulus negative pressure is within limit (equal to or more negative than -5 inches water gauge; value does not account for instrument error) ensures that operation remains within the limit assumed in the large break loss of coolant accident dose containmentanalysis (Ref. 5). Based on consideration of Branch Technical Position (BTP) 6-3 and Information Notice (IN) 88-76, a value of -0.63 inch w.g. at the elevation of the pressure sensors has been established (value does not account for instrument error, Ref. 4 and Ref.

6). To provide conservatism and added margin, the value of -1 inch w.g.

was chosen. The 12-hour Frequency of this SR was developed considering operating experience related to shield building annulus pressure variations and pressure instrument drift during the applicable MODES.

SR 3.6.15.2 Maintaining shield building OPERABILITY requires maintaining each door in the access opening closed, except when the access opening is being used for normal transient entry and exit. The 31-day Frequency of this SR is based on engineering judgment and is considered adequate in view of the other indications of door status that is available to the operator.

SR 3.6.15.3 This SR would give advance indication of gross deterioration of the concrete structural integrity of the shield building. The Frequency of this SR is the same as that of SR 3.6.1.1. The verification is done during shutdown.

(continued)

Watts Bar - Unit 2 Amendment B 3.6-91 Amendment XX

Shield Building B 3.6.15 BASES SURVEILLANCE SR 3.6.15.4 REQUIREMENTS (continued) The EGTS is required to maintain a pressure equal to or more negative than -0.50 inches water gauge (" wg) in the annulus at an elevation equivalent to the top of the Auxiliary Building. At elevations higher than the Auxiliary Building, the EGTS is required to maintain a pressure equal to or more negative than -0.25" wg. The low pressure sense line for the pressure controller is located in the annulus at elevation 783. By verifying that the annulus pressure is equal to or more negative than -0.61" wg at elevation 783, the annulus pressurization requirements stated above are met. The ability of a EGTS train with final flow 3600 cfm and 4400 cfm to produce the required negative pressure during the test operation provides assurance that the building is adequately sealed. The negative pressure prevents leakage from the building, since outside air will be drawn in by the low pressure at a maximum rate 250 cfm. The 18 month Frequency on a STAGGERED TEST BASIS is consistent with Regulatory Guide 1.52 (Ref. 1) guidance for functional testing.

REFERENCES 1. Regulatory Guide 1.52, Revision 2, Design, Testing and Maintenance Criteria for Post Accident Engineered-Safety-Feature Atmospheric Cleanup System Air Filtration and Adsorption Units of Light-Water Cooled Nuclear Power Plants.

2. WBN UFSAR Section 6.2.3.2.2, Emergency Gas Treatment System (EGTS).

3. WBN UFSAR Section 9.4.6, Reactor Building Purge Ventilating System (RBPVS).

4. TVA Calculation EPMMMA121889, Temperature Induced Differential Pressure Effects in Reactor Building and Aux. Bldg.

Secondary Containment, Revision 008

5. TVA Calculation TIRPS197, Offsite Doses Due to a Regulatory Guide 1.4 Loss of Coolant Accident, Revision 023

6. Watts Bar Drawing 2-47W605-242, "Electrical Tech Spec Compliance Tables."

Watts Bar - Unit 2 B 3.6-92 Revision 4 Amendment XX

Enclosure Attachment 5 Proposed TS Changes (Final Typed) for WBN Unit 1 CNL-19-077

Shield Building 3.6.15 3.6 CONTAINMENT SYSTEMS 3.6.15 Shield Building LCO 3.6.15 The Shield Building shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Shield Building inoperable. A.1 Restore Shield Building to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 not met. AND 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 /> Watts Bar-Unit 1 3.6-40 Amendment 59, XX

Shield Building 3.6.15 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.15.1 Verify annulus negative pressure is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> equal to or more negative than -1 inches water gauge with respect to the atmosphere.

SR 3.6.15.2 Verify the door in each access opening is closed, 31 days except when the access opening is being used for normal transient entry and exit.

SR 3.6.15.3 Verify shield building structural integrity by performing During a visual inspection of the exposed interior and shutdown for exterior surfaces of the Shield Building. SR 3.6.1.1 Type A tests SR 3.6.15.4 Verify each Emergency Gas Treatment System train 18 months on a with final flow 3600 and 4400 cfm produces an STAGGERED TEST annulus pressure equal to or more negative than BASIS

-0.61 inch water gauge at elevation 783 with respect to the atmosphere and with an inleakage of 250 cfm.

Watts Bar-Unit 1 3.6-41 Amendment XX

Enclosure Attachment 6 Proposed TS Changes (Final Typed) for WBN Unit 2 CNL-19-077

Shield Building 3.6.15 3.6 CONTAINMENT SYSTEMS 3.6.15 Shield Building LCO 3.6.15 The shield building shall be OPERABLE.

APPLICABILITY: MODES 1, 2, 3, and 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. Shield building inoperable. A.1 Restore shield building to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> 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 not met. AND 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 /> Watts Bar - Unit 2 A

3.6-35 Amendment XX

Shield Building 3.6.15 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.6.15.1 Verify annulus negative pressure is equal to or more 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> negative than -1 inches water gauge with respect to the atmosphere.

SR 3.6.15.2 Verify the door in each access opening is closed, 31 days except when the access opening is being used for normal transient entry and exit.

SR 3.6.15.3 Verify shield building structural integrity by During shutdown for performing a visual inspection of the exposed interior SR 3.6.1.1 Type A and exterior surfaces of the Shield Building. tests SR 3.6.15.4 Verify each Emergency Gas Treatment System train 18 months on a with final flow 3600 cfm and 4400 cfm produces STAGGERED TEST an annulus pressure equal to or more negative BASIS than - 0.61 inch water gauge at elevation 783 with respect to the atmosphere and with an inleakage of 250 cfm.

Watts Bar - Unit 2 A

3.6-36 Amendment XX

Enclosure Attachment 7 History of WBN Units 1 and 2 TS 3.6.15, Condition B A document review of the historical development and evolution of the WBN TS, prior to issuance of WBN Unit 1 Operating License, provided the following historical basis regarding the current TS 3.6.15, Condition B.

NRC transmitted the final draft TS for WBN Unit 1 on February 15, 1985 (Reference 1). The NRC transmittal letter stated:

These Technical Specifications were developed utilizing the Westinghouse Standard Technical Specifications (W-STS), Revision 4, as a basis. They reflect plant-specific design requirements, new regulatory requirements issued since the development of the W-STS Revision 4, and operating experience from other recently licensed W plants.

The W-STS document discussed above is NUREG-0452, Revision 4 (Reference 2). A review of Reference 2 did not identify or provide a basis for the WBN current TS 3.6.15, Condition B.

Reference 2 did not include TS 3.6.15, Shield Building, but it did include TS 3.6.8.2, Shield Building Integrity, which did not address the current TS 3.6.15 Condition B.

In Reference 1, TS 3.6.1.8, Emergency Gas Treatment System included an Action b. that stated:

b. With the annulus pressure more positive than minus 5.0 inches Water Gauge with respect to the Mechanical Equipment Room, restore the annular pressure to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

This is the first time that text similar to the current TS 3.6.15, Condition B appears in the proposed WBN TS, though it was associated with the EGTS, not the Shield Building.

On February 19, 1985, TVA submitted proposed revisions to the WBN Unit 1 draft TS, which included TS 3.6.1.8, Emergency Gas Treatment System (Reference 3). The revisions were based on discussions and meetings with NRC, and the previously NRC transmitted draft TS (Reference 1).

In Reference 3, TVA added the following hand-written requirement to TS 3.6.1.8:

b. With the annulus pressure - 5.0 inches water gauge with respect to the mechanical equipment room, restore the annulus pressure to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The hand-written text is the same as that provided by NRC in Reference 1. At the time, TS 3.6.15, Shield Building was not a part of Reference 2. It is surmised that TVA coincidentally added the hand-written requirement b, based on discussions and meetings with NRC, as NRC was issuing the revised text for TS 3.6.1.8 (Reference 1). However, no meeting minutes or other documentation could be found to support this conclusion.

CNL-19-077 Att 7-1 of 3

Enclosure In a letter to NRC dated March 24, 1985 (Reference 4), TVA stated:

During a February 6, 1985 meeting held to discuss various issues regarding the Watts Bar draft technical specifications, NRC representatives indicated that Watts Bar technical specification 3.6.1.8, Emergency Gas Treatment System, should be revised to incorporate requirements for annulus pressure limitations.

Reference 4 further states:

By letter dated February 19, 1985, TVA submitted proposed revisions to technical specification 3.6.1.8 which corresponded to the revisions made by NRC, except for the incorporation of a footnote which exempted the pressure limit requirements during venting operations, required annulus entries, and Auxiliary Building isolations.

Thus, Reference 4 provides confirmation that NRC added requirement b. as Action b. to TS 3.6.1.8, with the exception of the aformentioned footnote.

On April 15, 1985, NRC issued replacement pages for the WBN Unit 1 final draft TS, which included the revised pages for TS 3.6.1.8 including Action b. (Reference 5).

On April 17, 1990 (Reference 6), TVA issued the proposed draft TS for WBN Unit 1 based on the Restructured Standard Technical Specifications (RSTS). It should be noted that the RSTS formed the basis for and evolved into NUREG-1431. Based on the RSTS, the Action b. that was previously included in TS 3.6.1.8, Emergency Gas Treatment System, was now in the similarly titled, but re-numbered TS 3.6.5, Emergency Gas Treatment System (EGTS).

Subsequently, on August 27, 1992, TVA revised and updated the draft TS (Reference 7) to be in accordance with the latest draft of NUREG-1431, Standard Technical Specifications -

Westinghouse Plants, Revision 0. This new draft revision of the TS now included TS 3.6.15, Shield Building, but did not include the current TS 3.6.15, Condition B. As noted in the Justification Key Section of Reference 7:

Based on Watts Bar Comments to the Phase I mark-up it was determined that verifying that the shield building annulus pressure is within limits was to be remain in the EGTS Section 3.6.9) -- therefore it was removed from Section 3.6.15.

As noted above, Reference 7 renumbered TS 3.6.5, Emergency Gas Treatment System (EGTS) to TS 3.6.9 and included the current Condition B (along with the Note) that is currently in WBN Unit 1 and Unit 2 TS 3.6.15, Shield Building.

On April 2, 1993 (Reference 8), NRC transmitted the proof and review version of the WBN Unit 1 TS for TVAs review and comment. It should be noted that the current Condition B and Condition B Note for TS 3.6.15 were added at this time. The Condition B that was previously in TS 3.6.9, Emergency Gas Treatment (EGTS), was deleted and moved to TS 3.6.15. There was no explanation for the revisions. However, the NRC letter did state, The staff held several technical meetings with your staff during the period December 1992 through March 1993 to address various issues related to the TS. Such efforts culminated in the enclosures attached to this letter.

TVA provided comments to NRC for the proof and review version of the WBN Unit 1 TS on April 30, 1993 (Reference 9). TVA made minor comments related to the TS 3.6.15 SRs, but there were no comments with regard to Condition B.

CNL-19-077 Att 7-2 of 3

Enclosure The WBN Unit 1 operating license was issued on February 7, 1996 (Reference 10). Condition B for TS 3.6.15, except for a minor clarification to the Condition B Note, has not been revised since the operating license was issued. The minor clarification to the TS 3.6.15, Condition B Note was to address specifically added penetrations in the Shield Building dome in support of the 2006 stream generator replacement project (SGRP) (Reference 11).

The WBN Unit 2 OL was issued on October 22, 2015 (Reference 12). With the exception of the WBN Unit 1 minor clarification associated with the 2006 SGRP, TS 3.6.15, Condition B Note is the same for WBN Unit 2.

In summary, the current WBN TS 3.6.15, Condition B was originally included in TS 3.6.1.8, Emergency Gas Treatment System, relocated in the similarly titled, but re-numbered TS 3.6.5, Emergency Gas Treatment System (EGTS), relocated to the re-numbered TS 3.6.9, Emergency Gas Treatment System (EGTS),and finally deleted from TS 3.6.9 and relocated to TS 3.6.15, Shield Building. Therefore, TS 3.6.15, Condition B was initially considered to be a part of the EGTS and not the Shield Building. In either case, Condition B is not consistent with NUREG-0452 or subsequent NUREG-1431.

REFERENCES

1. NRC letter to TVA, Final Draft Technical Specifications for the Watts Bar Nuclear Plant, Unit 1, dated February 15, 1985 (ML073511912)

2. NUREG-0452, Standard Technical Specifications for Pressurized Water Reactors, Revision 4, dated November 15, 1979 (ML102590431)

3. TVA letter to NRC (no subject), dated February 19, 1985 (ML073511909)

4. TVA letter to NRC (no subject), dated March 24, 1985 (ML073511914)

5. NRC letter to TVA, Final Draft Technical Specifications for the Watts Bar Nuclear Plant, Unit 1, dated April 15, 1985 (ML072890489)

6. TVA letter to NRC, Watts Bar Nuclear Plant (WBN) Unit 1 - Proposed Technical Specifications (TS), dated April 17, 1990 (ML073520334)

7. TVA letter to NRC, Watts Bar Nuclear Plant (WBN) Unit 1 - Proposed Technical Specifications (TS), dated August 27, 1992 (ML073200281)

8. NRC letter to TVA, Watts Bar Unit 1 - Proof and Review Version of Technical Specification (TAC M76742), dated April 2, 1993 (ML073230276)

9. TVA letter to NRC, Watts Bar Nuclear Plant (WBN) Unit 1 - Comments on the Proof and Review Technical Specifications, dated April 30, 1993 (ML073200325)

10. NRC letter to TVA, Issuance of Facility Operating License No. NPF-90, Watts Bar Nuclear Plant, Unit 1 (TAC M94025), dated February 7, 1996 (ML080290360)

11. NRC letter to TVA, Watts Bar Nuclear Plant, Unit 1 - Issuance of Amendment Regarding Temporary Use of Penetrations in Shield Building Dome During Modes 1-4 (TAC No. MC6569), dated January 6, 2006 (ML060050378)

12. NRC letter to TVA, Issuance of Facility Operating License No. NPF-96, Watts Bar Nuclear Plant Unit 2, dated October 22, 2015 (ML15251A587)

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