Text

Issuance of Amendments (TAC Nos. M85972 and M85973) (TS 92-08)
	ML18087A136
Person / Time
Site:	Sequoyah
Issue date:	11/26/1993
From:	Labarge D; Division of Operating Reactor Licensing
To:	Medford M; Tennessee Valley Authority
	Hon A
References
	TAC M85972, TAC M85973
	Download: ML18087A136 (39)
	v • d • e

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O.C. 20666-0001 EQUOYAH NUCLEAR i fi*. *..

SITE LICENSING STA: i November 26, 1993 DEC 03 '93 Docket Nos. 50-327 and 50-328 Tennessee Valley Authority ATTN: Dr. Mark O. Medford, Vice President Technical Support 38 Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

Dear Dr. Medford:

SUBJECT:

ISSUANCE OF AMENDMENTS (TAC NOS. M85972 AND M85973)

The Co11111ission has issued the enclosed Amendment No. 172 to Facility Operating License No. DPR-77 and Amendment No. 163 to Facility Operating License No. DPR-79 for the Sequoyah Nuclear Plant, Units 1 and 2, respectively. These*

amendments are in response to your application dated March 10, 1993.

The amendments incorporate the technical specification changes necessary to reduce the boric acid concentration in the boric acid tanks from 12 percent to between 3.5 and 4.0 percent.

A copy of the Safety Evaluation is also enclosed. Notice of Issuance will be included in the Co11111ission's biweekly Federal Register notice.

Sincerely, fl~~

David E. LaBarge, Sr. Project Manager Project Directorate 11-4 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

Enclosures:

1. Amendment No. 172 to License No. DPR-77

2. Amendment No. 163 to License No. DPR-79

3. Safety Evaluation cc w/enclosures:

See next page

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I SEQUOYAH NUCLEAR PLANT Tennessee Valley Authority ATTN: Dr. Mark 0. Medford cc:

Mr. Craven Crowell, Chairman TVA Representative Tennessee Valley Authority Tennessee Valley Authority ET 12A 11921 Rockville Pike 400 West Summit Hill Drive Suite 402 Knoxville, TN 37902 Rockville, MD 20852 Mr. W. H. Kennoy, Director General Counsel Tennessee Valley Authority Tennessee Valley Authority ET 12A ET UH 400 West Sununit Hill Drive 400 West Sununit Hill Drive Knoxville, TN 37902 Knoxville, TN 37902 Mr. Johnny H. Hayes, Director Mr. Michael H. Mobley, Director Tennessee Valley Authority Division of Radiological Health ET 12A 3rd Floor, L and C Annex 400 West Sununit Hill Drive 401 Church Street Knoxville, TN 37902 Nashville, TN 37243-1532 Mr. Robert Fenech County Judge Site Vice President Hamilton County Courthouse Sequoyah Nuclear Plant Chattanooga, TN 37402 Tennessee Valley Authority P.O. Box 2000 Regional Administrator Soddy, Daisy, TN 37379 U.S. Nuclear Regulatory Conmission Region II Mr. R. M. Eytchison, Vice President 101 Marietta Street, NW., Suite 2900 Nuclear Operations Atlanta, GA 30323 Tennessee Valley Authority 3B Lookout Place Mr. William E. Holland 1101 Market Street Senior Resident Inspector Chattanooga, TN 37402-2801 Sequoyah Nuclear Plant U.S. Nuclear Regulatory Co11111ission Mr. B. S. Schofield, Manager 2600 Igou Ferry Road Nuclear Licensing and Regulatory Affairs Soddy Daisy, TN 37379 Tennessee Valley Authority 46 Blue Ridge Mr. D. E. Nunn, Vice President 1101 Market Street Tennessee Valley Authority Chattanooga, TN 37402-2801 3B Lookout Place 1101 Market Street

Mr. Ralph H. Shell Chattanooga, TN 37402-2801 Site Licensing Manager Sequoyah Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Soddy Daisy, TN 37379

UNITED STATES NUCLEAR REGULATORY COMMI SSION WASHINGTON. O.C. 2CJ666.0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-327 SEQUOYAH NUCLEAR PLANT, UNIT I AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 172 License No. DPR-77 I. The Nuclear Regulatory Commission (the Commission) has fo~nd that:

A. The application for amendment by Tennessee Valley Authority (the licensee) dated March 10, 1993, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act),

and the Commission's rules and regulations set forth in 10 CFR Chapter I;

8. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activiti es authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activiti es will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfie d.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.{2) of Facility Operating License No. DPR-77 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 172, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance, to be implemented no later than the end of the Unit 2 Cycle 6 refueling outage that is scheduled to begin in April 1994.

~~~~ORY.COMMISSION Frederick J. Hebdon, Director r

Attachment:

Project Directorate 11-4 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation Changes to the Technical Specifications Date of Issuance: November 26, 1993

r' ATTACHMENT TO LICENSE AMENDMENT NO. 172 FACILITY OPERATING LICENSE NO. DPR-77 DOCKET NO. 50-327 Revise the Appendix A Technical Specifications by removing the pages identified below and inserting the enclosed pages. The revised pages are identified by the captioned amendment number and contain marginal lines indicating the area of change.

REMOVE INSERT 3/4 1-1 3/4 1-1 3/4 1-3 3/4 1-3 3/4 1-7 3/4 1-7 3/4 1-8 3/4 1-8 3/4 1-11 3/4 1-11

3/4 1-lla 3/4 1-12 3/4 1-12 3/4 1-13 3/4 1-13

3/4 l-13a 3/4 9-1 3/4 9-1 3/4 10-1 3/4 10-1 83/4 1-2 83/4 1-2 83/4 1-3 83/4 1-3

83/4 l-3a

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3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORATION CONTR9l SHUTDOWN MARGIN - Ta~ Greater Than 2oo*F LIMITING CONDITION FOR OPERATION 3.1.1.1 The SHUTDOWN MARGIN shall be greater than or equal to 1.6% delta k/k for 4 loop operation.

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

ACTION:

With the SHUTDOWN MARGIN less than 1.6% delta k/k, immediately initiate and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.1.1 The SHUTDOWN MARGIN shall be determined to be greater than or equal to 1.6% delta k/k:

r a. Within one hour after detection of an inoperable control rod(s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the rod(s) is inoperable.

If the inoperable control rod is immovable or untrippable, the above required SHUTDOWN MARGIN shall be verified acceptable with an increased allowance for the withdrawn worth of the immovable or untrippable control rod(s).

b. When in MODE 1 or MODE 2 with ~ff greater than or equal to 1.0, at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying that control bank withdrawal is within the limits of Specification 3.1.3.6.

c. When in MODE 2 with ~ff less than 1.0, within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months prior to achieving reactor criticality by verifying that the predicted critical control rod position is within the limits of Specification 3.1.3.6.

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See Special Test Exception 3.10.1 SEQUOYAH - UNIT 1 3/4 1-1 Amendment No. 172

r REACTIVITY CONTROL SYSTEMS SHUTDOWN MARG IN - Tavg Less Than or Equal to 200' F LIMITING CONDITION FOR OPERATION 3.1.1.2 The SHUTDOWN MARGIN shall be greater than or equal to 1.0% delta k/k.

APPLICABILITY: MODE 5.

ACTION:

With the SHUTDOWN MARGIN less than 1.0% delta k/k, immediately initiate and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.2 The SHUTDOWN MARGIN shall be determined to be greater than or equal to 1.0% delta k/k:

a. Within one hour after detection of an inoperable control rod{s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the rod{s) is inoperable.

r If the inoperable control rod is immovable or untrippable, the SHUTDOWN MARGIN shall be verified acceptable with an increased allowance for the withdrawn worth of the immovable or untrippable control rod{s).

b. At least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months by consideration of the following factors:

1. Reactor coolant system boron concentration,

2. Control rod position,

3. Reactor coolant system average temperature,

4. Fuel burnup based on gross thermal energy generation,

5. Xenon concentration, and

6. Samarium concentration.

SEQUOYAH - UNIT 1 3/4 1-3 Amendment No. 12, 172

REACTIVITY CONTROL SYSTEMS

~ 3/4.1.2 BORATION SYSTEMS FLOW PATHS - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.1 As a minimum, one of the following boron injection flow paths shall be OPERABLE:

a. A flow path from the boric acid tank via a boric acid transfer pump and charging pump to the Reactor Coolant System if only the boric acid storage tank in Specification 3.1.2.Sa is OPERABLE, or

b. The flow path from the refueling water storage tank via a charging pump to the Reactor Coolant System if only the refueling water storage tank in Specification 3.1.2.Sb is OPERABLE.

APPLICABILITY: MODES 4, 5 and 6.

ACTION:

MODE 4 - With none of the above flow paths OPERABLE, suspend all operations involving CORE ALTERATIONS or positive reactivity changes and restore one flow path as soon as possible.

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MODES 5 - With none of the above flow paths OPERABLE, suspend all operations and 6 involving CORE ALTERATIONS or positive reactivity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.1 At least one of the above required flow paths shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying that the temperature of the areas containing flow path components from the boric acid tanks to the blending tee is greater than or equal to 63.F when it is a required water source.

b. Whenever the area temperature(s) is(are) less than 63.F and the boric acid tank is a required water source, the solution temperature in the flow path components from the boric acid tank must be measured to be greater than or equal to 63.F within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereafter until the area temperature(s) has(have) returned to greater than or equal to 63.F.

c. At least once per 31 days by verifying that each valve (manual, power operated or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

SEQUOYAH - UNIT 1 3/4 1-7 Amendment No. 157, 172

J REACTIVITY CONTROL SYSTEMS r FLOW PATHS - OPERATING -

LIMITING CONDITION FOR OPERATION 3.1.2.2 At least two of the following three boron injection flow paths shall be OPERABLE:

a. The flow path from the boric acid tanks via a boric acid transfer pump and a charging pump to the Reactor Coolant System.

b. Two flow paths from the refueling water storage tank via charging pumps to the Reactor Coolant System.

APPLICABILITY: MODES 1, 2, and 3.

ACTION:

With only one of the above required boron injection flow paths to the Reactor Coolant System OPERABLE, restore at least two boron injection flow paths to the Reactor Coolant System to OPERABLE status within 72 hours or be in at least HOT STANDBY and borated to a SHUTDOWN MARGIN.equivalent to at least 1% delta k/k at 2oo*F within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ; restore at least two flow paths to OPERABLE status within the next 7 days or be in HOT SHUTDOWN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

r SURVEILLANCE REQUIREMENTS 4.1.2.2 At least two of the above required flow paths shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying that the temperature of the areas containing flow path components from the boric acid tanks to the blending tee is greater than or equal to 63.F when it is a required water source.

b. Whenever the area temperature(s) is(are) less than 63.F and the boric acid tank is a required water source, the solution temperature in the

flow path components from the boric acid tank must be measured to be greater than or equal to 63.F within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereafter until the area tempe.rature(s) has (have) returned to greater than or equal to 63.F.

c. At least once per 31 days by verifying that each valve (manual, power operated or automatic) in the flow path that is not locked, sealed, or otherwise secured in pas it ion, is in its _correct position.

d. At least once per 18 months during shutdown by verifying that each automatic valve in the flow path actuates to its correct position on a safety injection test signal.

e. At least once per 18 months by verifying that the flow path required by Specification 3.l.2.2a delivers at least 35 gpm to the Reactor Coolant System.

SEQUOYAH - UNIT I 3/4 1-8 Amendment No. 12, 157, 172

REACTIVITY CONTROL SYSTEMS

~ BORATED WATER SOURCES .-SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.5 As a minimum, one of the following borated water sources shall be OPERABLE:

a. A boric acid storage system with:

1. A minimum contained borated water volume of 5000 gallons,

2. Between 6120 and 6990 ppm of boron, and

3. .A ~inimum solution temperature of 63.F.

b. The refueling water storage tank with:

1. A minimum contained borated water vo~ume of 55,000 g~lons,

2. A minimum boron concentration of 2500 ppm, and

3. A minimum solution temperature of 60.F.

APPLICABILITY: MODES 4, 5 and 6.

ACTION:

With no borated water source OPERABLE, suspend all operations involving CORE ALTERATIONS or positive reactivity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.5 The above required borated water source shall be demonstrated OPERABLE:

a. For the boric acid storage system, when it is the source of borated water by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the boric acid storage tank solution temperature is greater than or equal to 63.F at least once per 7 days by verifying the area temperature to be greater than or equal to 63.F, or SEQUOYAH - UNIT 1 3/4 1-11 Amendment No. 140, *172

I REACTIVITY CONTROL SYSTEMS

~ SURVEILLANCE REQUIREMEtR"S (Continued}

4. Whenever the boric acid tank area temperature is less than 63.F and the boric acid storage system being used as the source of borated water, within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereafter, verify the boric acid tank solution temperature to be greater than or equal to 63.F until the boric acid tank area temperature has returned to greater than or equal to 63.F.

b. For the refueling water storage tank by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the solution temperature at least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months while in Mode 4 or while in Modes 5 or 6 when it is the source of borated water.

SEQUOYAH - UNIT 1 3/4 1-lla Amendment No. 140, 172 l

REACTIVITY CONTROL SYSTEMS BORATED WATER SOURCES GPERATING LIMITING CONDITION FOR OPERATION 3.1.2.6 As a minimum, the following borated water source{s) shall be OPERABLE as required by Specification 3.1.2.2:

a. A boric acid storage system with:

1. A contained volume of borated water in accordance with Figure 3.1.2.6,

2. A boron concentration in accordance with Figure 3.1.2.6, and

3. A minimum solution temperature of 63.F.

b. The refueling water storage tank with:

1. A contained borated water volume of between 370,000 and 375,000 gallons,

2. Between 2500 and 2700 ppm of boron,

3. A minimum solution temperature of 60.F, and

4. A maximum solution temperature of 105.F.

APPLICABILITY: MODES 1, 2, and 3.

ACTION:

a. With the boric acid storage system inoperable and being used as one of the above required borated water sources, restore the storage system to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and borated to a SHUTDOWN MARGIN equivalent to at least 1% delta k/k at 2oo*F; restore the boric acid storage system to OPERABLE status within the next 7 days or be in HOT SHUTDOWN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

b. With the refueling water storage tank inoperable, restore the tank to OPERABLE status within one hour or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

SEQUOYAH - UNIT 1 3/4 1-12 Amendment No. 140, 172

REACTIVITY CONTROL SYSTEMS

~ SURVEILLANCE REQUIREMENTS 4.1.2.6 Each borated water source shall be demonstrated OPERABLE:

a. For the boric acid storage system, when it is the source of borated water by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the boric acid storage tank solution temperature is greater than or equal to 63.F at least once per 7 days by veri-fying the area temperature to be greater than or equal to 63.F, or

4. Whenever the boric acid tank area temperature is less than 63.F and the boric acid storage system being used as the source of borated water, w.ithin 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every.24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereafter, verify the boric acid tank solution temperature to be greater than or equal to 63.F until the boric acid tank area temperature has returned to greater than or equal to 63.F.

b. For the refueling water storage tank by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the solution temperature at least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ..

SEQUOYAH - UNIT 1 3/4 1-13 Amendment No. 172

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BORIC ACID TANK REQUIRED VOLUME vs. BORIC ACID TANK CONCENTRATION 9,500

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CMinin um) (f\ 'axiniu m) 6,500 6,200 6,400 6,600 6,800 7 ,000 CONCENTRATION - ppm BORON FIGURE 3.1.2. 6 SEQUOYAH - UNIT 1 3/4 l-13a Amendment No .. 172

3/4.9 REFUELING OPERAIIONS r 3/4.9.1 BORON CONCENTRATION LIMITING CONDITION FOR OPERATION 3.9.l With the reactor vessel head closure bolts less than fully tensioned or with the head removed, the boron concentration of all filled portions of the Reactor Coolant System and the refueling canal shall be maintained uniform and sufficient to ensure that the more restrictive of the following reactivity conditions is met:

a. Either a Keff of 0.95 or less, which includes a 1% delta k/k conservative allowance for uncertainties, or

b. A boron concentration of greater than or equal to 2000 ppm, which includes a SO ppm conservative allowance for uncertainties.

APPLICABILITY: MODE 6*

ACTION:

With the requirements of the above specification not satisfied, immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes and initiate* and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or its equiva-lent until Keff is reduced to less than or equal to 0.95 or the boron concen-tration is rest~red to greater than or equal to 2000 ppm, whichever is the more restrictive. The provisions of Specification 3.0.3 are not applicable.

SURVEILLANCE REQUIREMENTS 4.9.1.1 The more restrictive of the above two reactivity conditions shall be determined prior to:

a. Removing or unbolting the reactor vessel head, and

b. Withdrawal of any full length control rod in excess of 3 feet from its fully inserted position within the reactor pressure vessel.

4.9.1.2 The boron concentration of the reactor coolant system and the refueling canal shall be determined by chemical analysis at least once per 72

hours. *

The reactor shall be maintained in MODE 6 whenever fuel is in the reactor vessel with the vessel head closure bolts less than fully tensioned or with the head removed.

SEQUOYAH - UNIT 1 3/4 9-1 Amendment No. 12, 144, 172

3/4.10 SPECIAL TEST EXCEPTIONS 3/4.10.l SHUTDOWN MARGIN LIMITING CONDITION FOR OPERATION 3.10.l The SHUTDOWN MARGIN requirement of Specification 3.1.1.1 may be suspended for measurement of control rod worth and shutdown margin provided reactivity equivalent to at least the highest estimated control rod worth is available for trip insertion from OPERABLE control rod(s).

APPLICABILITY: MODE 2.

ACTION:

a. With any full length control rod not fully inserted and with less than the above reactivity equivalent available for trip insertion, immediately ini-tiate and continue boration at greater than or equal to 35 gpm of a solu-tion containing greater than or equal to 6120 ppm boron or its equivalent until the SHUTDOWN MARGIN required by Specification 3.1.1.1 is restored.

b. With all full length control rods inserted and the reactor subcritical by less than the above reactivity equivalent, immediately initiate and con-tinue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or its equivalent until the SHUTDOWN MARGIN required by Specification 3.1.1.1 is restored. 1 SURVEILLANCE REQUIREMENTS 4.10.1.1 The position of each full length rod either partially or fully withdrawn shall be determined at least once per 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

4.10.1.2 Each full length rod not fully inserted shall be demonstrated capable of full insertion when tripped from at least 50% withdrawn position within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to reducing the SHUTDOWN MARGIN to less than the limits of Specification 3.1.1.1.

SEQUOYAH - UNIT 1 3/4 10-1 Amendment No. 12, 172

REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1.4 MINIMUM TEMPERATURE FOR CRITICALITY This specification ensures that the reactor will not be made critical with the Reactor Coolant System average temperature less than 541°F. This limita-tion is required to ensure 1) the moderator temperature coefficient. is within its analyzed temperature range, 2) the protective instrumentation is within its normal operating range, 3) the P-12 interlock is above its setpoint, 4) the pressurizer is capable of being in a OPERABLE status with a steam bubble, and

5) the reactor pressure vessel is above its minimum RTNoT temperature.

3/4.1.2 BORATION SYSTEMS The boron injection system ensures that negative reactivity control is available during each mode of facility operation. The components required to perform this function include 1) borated water sources, 2) charging pumps, 3) separate flow paths, 4) boric acid transfer pumps, and 5) an emergency power .*

supply from OPERABLE di ese 1 generators. * **

With the RCS average temperature above 350°F, a minimum of two boron injection flow paths are required to *ensure single functional capability in the event an assumed failure renders one of the flow paths inoperable. The boration capability of either flow path is sufficient to provide a SHUTDOWN MARGIN from expected operating conditions of 1.6% delta k/k after xenon decay and cooldown to 200°F. The maximum expected boration capability requirement occurs at near EOL from full power peak xenon conditions and requires SEQUOYAH - UNIT 1 B 3/4 1-2 Amendment No. 155,157,171, 172

REACTIVITY CONTROL SYSTEMS BASES

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borated water from a boric acid tank in accordance with TS Figure 3.1.2.6, and additional makeup from either: (1) the common boric acid tank and/or batching, or {2} a minimum of 26,000 gallons of 2500 ppm borated water from the refueling water storage tank. With the refueling water storage tank as the only borated water source, a minimum of 57,000 gallons of 2500 ppm borated water is required.

The boric acid tanks, pumps, valves, and piping contain a boric acid solu-tion concentration of between 3.5% and 4.0% by weight. To ensure that the boric acid remains in solution, the air temperature is monitored in strategic loca-tions. By ensuring the air temperature remains at 63.F or above, a s*F margin is provided to ensure the boron will not precipitate out. To provide operational flexibility, if the area temperature should fall below the required value, the solution temperature (as determined by the pipe or tank wall temperature) will be monitored at an increased frequency to compensate for the lack of solution temperature alarm in the main control room.

With the RCS temperature below 350.F, one injection system is acceptable without single failure consideration on the basis of the staole reactivity condi-tion of the reactor and the additional restrictions prohibiting CORE ALTERATIONS and positive reactivity change in the ev~nt the single injection system becomes inoperable.

The boron capability required below Jso*F, is sufficient to provide a SHUTDOWN MARGIN of 1.6% delta k/k after xenon decay and cooldown from 350.F to

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2oo*F, and a SHUTDOWN MARGIN of 1% delta k/k after xenon decay and cooldown from 2oo*F to 140.F. This condition requires either 5000 gallons of 6120 ppm borated water from the boric acid storage tanks or 13,400 gallons of 2500 ppm borated water from the refueling water storage tank.

The contained water volume limits include allowance for water not available because of discharge line location and other physical characteristics . The 55,000 gallon limit in the refueling water storage tank for Modes 4, 5, and 6 is based upon 22,182 gallons that is undetectable due to lower tap location, 19,197 gallons for instrument error, 13,400 gallons required for shutdown margin, and an additional 221 gallons due to rounding up.

The limits on contained water volume and boron concentration of the RWST also ensure a pH value of between 7.5 and 9.5 for the solution recirculated within containment after a LOCA. This pH band minimizes *the evolution of iodine and minimizes the effect of chloride and caustic stress corrosion on mechanical systems and components.

The OPERABILITY of one boron injection system during REFUELING ensures that this system is available for reactivity control while in MODE 6.

3/4.1.3 MOVABLE CONTROL ASSEMBLIES The specifications of this section ensure that (1) acceptable power distri-bution limits are maintained, (2) the minimum SHUTDOWN MARGIN is maintained, and (3) limit the potential effects of rod misalignment on associated accident anal-yses. OPERABILITY of the control rod position indicators is required to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits.

SEQUOYAH - UNIT 1 B 3/4 1-3 Amendment No. 140, 157, 172

UNITED STATES NUCLEAR *REGULATORY COMMISSION WASHINGTON, D.C. 20666-0001 r

TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-328 SEQUOYAH NUCLEAR PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 163 License No. DPR-79

1. The Nuclear Regulatory Commission {the Commission} has found that:

A. The application for amendment by Tennessee Valley Authority (the licensee} dated March 10, 199~, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act},

and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i} that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii} that such activities will be conducted in compliance with the Conunission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied. *

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment and paragraph 2.C.(2) of Facility Operating License No. DPR-79 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 163, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance, to be implemented no later than the end of the Unit 2 Cycle 6 refueling outage that is scheduled to begin in April 1994.

~~~TOR~ COMMISSION Frederick J. Hebdon, Director Project Directorate 11-4 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: November 26, 1993

r ATTACHMENT TO LICENSE AMENDMENT NO. 163 FACILITY OPERATING LICENSE NO. DPR-79 DOCKET NO. 50-328 Revise the Appendix A Technical Specifications by removing the pages identified below and inserting the enclosed pages. The revised pages are identified by the captioned amendment number and contain marginal lines indicating the area of change.

REMOVE INSERT 3/4 1-1 3/4 1-1 3/4 1-3 3/4 1-3 3/4 1-7 3/4 1-7 3/4 1-8 3/4 1-8 3/4 1-11 3/4 1-11

3/4 I-Ila 3/4 1-12 3/4 1-12 3/4 1-13 3/4 1-13

3/4 l-13a 3/4 9-1 3/4 9-1 3/4 10-1 3/4 10-1 r

83/4 1-2 83/4 1-2 83/4 1-3 83/4 1-3

83/4 l-3a r

314.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORATION CONTROL SHUTDOWN MARGIN - T~

9 >200.F LIMITING CONDITION FOR OPERATION 3.1.1.1 The SHUTDOWN MARGIN shall be greater than or equal to 1.6% delta k/k for 4 loop operation.

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

ACTION:

With the SHUTDOWN MARGIN less than 1.6% delta k/k, immediately initiate and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.1.1 The SHUTDOWN MARGIN shall be determined to be greater than or equal to 1.6% delta k/k:

a. Within one hour after detection of an inoperable control rod(s) and

~ at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafte r while the rod(s) is inoperable.

~*

If the inoperable control rod is immovable or untrippable, the above required SHUTDOWN MARGIN shall be verified acceptable with an increased allowance for the withdrawn worth of the immovable or untrippable control rod(s).

b. When in MODE 1 or MODE 2 with Kett greater than or equal to 1.0, at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying that control bank withdrawal is within the limits of Specification 3.1.3.6.

c. When in MODE 2 with ~ff less than 1.0, within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months prior to achieving reactor criticali ty by verifying that the predicted critical control rod position is within the limits of Specification 3.1.3.6.

See Special Test Exception 3.10.1 SEQUOYAH - UNIT 2 3/4 1-1 Amendment No. 163

REACTIVITY CONTROL SYSTEMS SHUTDOWN MARGIN - Ta~ L-ess Than or Equal to 2oo*F LIMITING CONDITION FOR OPERATION 3.1.1.2 The SHUTDOWN MARGIN shall be greater than or equal to 1.0% delta k/k.

APPLICABILITY: MODE 5.

ACTION:

With the SHUTDOWN MARGIN less than 1.0% delta k/k, immediately initiate and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.2 The SHUTDOWN MARGIN shall be determined to be greater than or equal to 1.0% delta k/k: *

a. Within one hour after detection of an inoperable control rod(s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the rod(s) is inoperable.

If the inoperable control rod is immovable or untrippable, the SHUTDOWN MARGIN shall be verified acceptable with an increased allowance for the withdrawn worth of the immovable or untrippable control rod(s).

b. At least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months by consideration of the following factors:

1. Reactor coolant system boron concentration,

2. Control rod position,

3. Reactor coolant system average temperature,

4. Fuel burnup based on gross thermal energy generation,

5. Xenon concentration, and

6. Samarium concentration.

SEQUOYAH - UNIT 2 3/4 1-3 Amendment No. 163

REACTIVITY CONTROL SYSTEMS 3/4.1.2 BORATION SYSTEMS FLOW PATHS - SHUTDOWN

'LIMITING CONDITION FOR OPERATION 3.1.2.1 As a minimum, one of the following boron injection flow paths shall be OPERABLE:

a. A flow path from the boric acid tank via a boric acid transfe r pump and charging pump to the Reactor Coolant System if the boric acid storage tank in Specification 3.1.2.Sa is OPERABLE, or

b. The flow path from the refueling water storage tank via a charging pump to the Reactor Coolant System if the refueling water storage tank in Specification 3.1.2.Sb is OPERABLE.

APPLICABILITY: MODES 4, 5 and 6.

ACTION:

MODE 4 - With none of the above flow paths OPERABLE, suspend all operations involving CORE ALTERATIONS or positive reactiv ity changes and restore one flow path as soon as possible.

r MODES 5 - With none of the above flow paths OPERABLE, suspend all operations and 6 involving CORE ALTERATIONS or positive reactiv ity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.1 At least one of the above required flow paths shall be demonstrated OPERABLE:

a. At least once per 7 days by verifying that the temperature of the areas containing flow path components from the boric acid tanks to the blending tee is greater than or equal to 63.F when it is a required water source.

b. Whenever the area temperature(s) is(are) less than 63.F and the boric acid tank is a required water source, the solution temperature in the flow path components from the boric acid tank must be measured to be greater than or equal to 63.F within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereaf ter until the area temperature(s) has(have) returned to greater than or equal to 63.F.

c. At least once per 31 days by verifying that each valve (manual, power operated or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

SEQUOYAH - UNIT 2 3/4 1-7 Amendment No. 147, 163

REACTIVITY CONTROL SYSTEMS FLOW PATHS - OPERATING-LIMITING CONDITION FOR OPERATION 3.1.2.2 At least two of the following three boron injection flow paths shall be OPERABLE:

a. The flow path from the boric acid tanks via a boric acid. transfer pump and a charging pump to the Reactor Coolant System.

b. Two flow paths from the refueling water storage tank via charging pumps to the Reactor Coolant System.

APPLICABILITY: MODES 1, 2, and 3.

ACTION:

With only one of the above required boron injection flow paths to the Reactor .

Coo 1ant System OPERABLE, restore at 1east two boron i hject ion fl ow patti's *to the*

Reactor Coolant System to OPERABLE status within 72 hours or be in at least HOT STANDBY and borated to a SHUTDOWN MARGIN equivalent to at least 1% delta k/k at 2oo*F within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ; restore at least two flow paths to OPERABLE status within the next 7 days or be in HOT SHUTDOWN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months ;

(!""" SURVEILLANCE REQUIREMENTS 4.1.2.2 At least two of the above required flow paths shall be demonstrated

oPERABLE:

a. At least once per 7 days by verifying that the temperature of the areas containing flow path components from the boric acid tanks to the blending tee is greater than or equal to 63.F when it is a required water source.

b. Whenever the area temperature(s) is(are) less than 63.F and the boric acid tank is a required water source, the solution temperature in the flow path components from the boric acid tank must be measured to be greater than or equal to 63.F within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereafter until the area temperature(s) has(have) returned to greater than or equal to 63.F.

c. At least once per 31 days by verifying that each valve (manual, power operated or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.

d. At least once per 18 months during shutdown by verifying that each automatic valve in the flow path actuates to its correct position on a safety injection test signal.

~ e. At least once per 18 months by verifying that the flow path required

\. by Specification 3.l.2.2a delivers at least 35 gpm to the Reactor Coolant System.

SEQUOYAH - UNIT 2 3/4 1-8 Amendment No. 147, 163

REACTIVITY CONTROL SYSTEMS BORATED WATER SOURCES --SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.5 As a minimum, one of the following borated water sources shall be OPERABLE:

a. A boric acid storage system with:

1. A minimum contained borated water volume of 5000 gallons,

2. Between 6120 and 6990 ppm of boron, and

3. A minimum solution temperature of 63.F.

b. The refueling water storage tank with:

1. A minimum contained borated water volume of 55,000 gallons,

2. A minimum boron concentration of 2500 ppm, and

3. A minimum solution temperature of 60.F.

APPLICABILITY: MODES 4, 5 and 6.

~ ACTION:

With no borated water source OPERABLE, suspend all operations involving CORE ALTERATIONS or positive reactivity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.5 The above required borated water source shall be demonstrated OPERABLE:

a. For the boric acid storage system, when it is the source of borated water by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the boric acid storage tank solution temperature is greater than or equal to 63°F at least once per 7 days by verifying the area temperature to be greater than or equal to 63.F, or SEQUOYAH - UNIT 2 3/4 1-11 Amendment No. 131, 163

REACTIVITY CONTROL SYSTEMS r

SURVEILLANCE REOUIREMEtffS {Continued)

4. Whenever the boric acid tank area temperature is less than 63.F and the boric acid storage system being used as the source of borated water, within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months therea fter, verify the boric acid tank solution temperature to be greater than or equal to 63.F until the boric acid tank area temperature has returned to greater than or equal to 63.F.

b. For the refueling water storage tank by:

I. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the solution temperature at least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months while in Mode 4 or while in Modes 5 or 6 when it is the source of borated water.

r SEQUOYAH - UNIT 2 3/4 I-Ila Amendment No. 163

REACTIVITY CONTROL SYSTEMS BORATED WATER SOURCES GPERATING LIMITING CONDITION FOR OPERATION 3.1.2.6 As a minimum, the following borated water source(s) shall be OPERABLE as required by Specification 3.1.2.2:

a. A boric acid storage system with:

1. A contained volume of borated water in accordance with Figure 3.1.2.6 ,

2. A boron concentration in accordance with Figure 3.1.2.6 , and

3. A minimum solution temperature of 63.F.

b. The refueling water storage tank with:

1. A contained borated water volume of between 370,000 and 375,000 gallons,

2. Between 2500 and 2700 ppm of boron,

3. A minimum solution temperature of 60.F, and

4. A maximum solution temperature of ios*F.

APPLICABILITY: MODES 1, 2, and 3.

J ACTION:

a. With the boric acid storage system inoperable and being used as one of the above required borated water sources, restore the storage system to OPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and borated to a SHUTDOWN MARGIN equivalent to at least 1% delta k/k at 2oo*F; restore the boric acid storage system to OPERABLE status within the next 7 days or be in HOT SHUTDOWN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

b. With the refueling water storage tank inoperable, restore the tank to OPERABLE status within one hour or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

SEQUOYAH - UNIT 2 3/4 1-12 Amendment No. 131, 163

REACTIVITY CONTROL SYSTEMS

~ SURVEILLANCE REQUIREMENTS 4.1.2.6 Each borated water source shall be demonstrated OPERABLE:

a. For the boric acid storage system, when it is the source of borated water by:

1. Verifying the boron concentration at least once per 7 days,

2. Verifying the borated water volume at least once per 7 days, and

3. Verifying the boric acid storage tank solution temperature is greater than or equal to 63.F at least once per 7 days by veri-fying the area temperature to be greater than or equal to 63.F, or

4. Whenever the boric acid tank area temperature is less than 63.F and the boric acid storage system being used *a.~ the source of borated water, within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months thereaf ter, verify the boric acid tank solution temperature to be greater than or equal to 63.F until the boric acid tank area temperature *

has returned to greater than or equal to 63.F.

b. For the refueling water storage tank by:

r 1.

2.

Verifying the boron concentra~ion at least once per 7 days, Verifying the borated water volume at least once per 7 days, and

3. Verifying the solution temperature at least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ..

SEQUOYAH - UNIT 2 3/4 1-13 Amendment No.163

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<Minin uml (~ laxiniu m) 6,500 6,200 6,400 6,600 6,800 7 ,000 CONCENTRATION - ppm BORON FIGURE 3.1.2.6 Amendment No. 163 SEQUOYAH - UNIT 2 3/4 1-13a

3/4.9 REFUELING OPERAIIONS 3/4.9.1 BORON CONCENTRATION LIMITING CONDITION FOR OPERATION 3.9.l With the reactor vessel head closure bolts less than fully tensioned with the head removed, the boron concentration of all filled portions of theor Reactor Coolant System and the refueling canal shall be maintained.uniform and sufficie nt to ensure that the more restrict ive of the following reactiv ity conditions is met:

a. Either a Kett of 0.95 or less, which includes a 1% delta k/k conservative allowance for uncertainties, or

b. A boron concentration of greater than or equal to 2000 ppm, which includes a 50 ppm conservative allowance for uncerta inties.

APPLICABILITY: MODE 6*

ACTION:

With the requirements of the above specification not satisfie d, immediately suspend all operations involving CORE ALTERATIONS or positive reactiv ity changes and initiate and continue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or its equiva-lent until Keff is reduced to less than or equal to 0.95 or the boron concen-tration is restored to greater than or equal to 2000 ppm, whichever is the more restrict ive. The provisions of Specification 3.0.3 are not applicable.

SURVEILLANCE REQUIREMENTS 4.9.1.1 The more restrict ive of the above two reactiv ity conditions shall be determined prior to:

a. Removing or unbolting the reactor vessel head, and

b. Withdrawal of any full length control rod in excess of 3 feet from its fully inserted position within the reactor pressure vessel.

~ *The reactor shall be maintained in MODE 6 whenever fuel is in the reactor

~'

vessel with the vessel head closure bolts less than fully tensioned or with the head removed.

SEQUOYAH - UNIT 2 3/4 9-1 Amendment No. 104, 163

3/4.10 SPECIAL TEST EXCEPTIONS r .

. 3/4.10.l SHUTDOWN MARGJN LIMITING CONDITION FOR OPERATION 3.10.1 The SHUTDOWN MARGIN requirement of Specification 3.1.1.1 may be suspended for measurement of control rod worth and shutdown margin provided reactivity equivalent to at least the highest estimated control ro9 worth is available for trip insertion from OPERABLE control rod(s).

APPLICABILITY: MODE 2.

ACTION:

a. With any full length control rod not fully inserted and with less than the above reactivity equivalent available for trip insertion, immediately ini-tiate and continue boration at greater than or equal to 35 gpm of a solu-tion containing greater than or equal to 6120 ppm boron or its equivalent until the SHUTDOWN MARGIN required by Specification 3.1.1 .. l* is restored.

b. *with all full length control rods inserted and the reactor subcritical by less than the above reactivity equivalent, immediately initiate and con-tinue boration at greater than or equal to 35 gpm of a solution containing greater than or equal to 6120 ppm boron or its equivalent until the SHUTDOWN MARGIN required by Specification 3.1.1.1 is restored.

SURVEILLANCE REQUIREMENTS 4.10.1.1 The position of each full length rod either partially or fully withdrawn shall be determined at least once per 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months .

4.10.1.2 Each full length rod not fully inserted shall be demonstrated capable of full insertion when tripped from at least 50% withdrawn position within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months prior to reducing the SHUTDOWN MARGIN to less than the limits of Specification 3.1.1.1.

~

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SEQUOYAH - UNIT 2 3/4 10-1 Amendment No. 163

.. REACTIVITY CONTROL SYSTEMS

("""' ~BA~S~ES--=------------------=-==---=-------------------------=---=--=-

3/4. 1. 1. 4 MINIMUM TEMPERATURE FOR CRITICALITY This specification ensures that the reactor will not be made critical with the Reactor Coolant System average temperature less than 541°F. This limita-tion is required to ensure 1) the moderator temperature coefficient is within it analyzed temperature range, 2) the protective instrumentation is within its normal operating range, 3) the P-12 interlock is above its setpoint, 4) the pressurizer is capable of being in a OPERABLE status with a steam bubble, and

5) the reactor pressure vessel is above its minimum RTNDT temperature.

3/4.1.2 BORATION SYSTEMS The boron injection system ensures that negative reactivity control is available during each mode of facility operation. The components required to perform this function include 1) borated water sources, 2) charging pumps, 3)

.separate flow paths, 4) boric acid transfer pumps, and 5) an emergency power supply from OPERABLE diesel generators.

With the RCS average temperature above 350°F, a minimum of two boron injection flow paths are required to ensure single functional capability in the event an assumed failure renders one of the flow paths inoperable. The boration capability of either flow path is sufficient to

~

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SEQUOYAH - UNIT 2 B 3/4 1-2 Amendment No. 147, 146, 161, 163

REACTIVITY CONTROL SYSTEMS BASES BOBATION SYSTEMS (Continued) provide a SHUTDOWN MARGIN from expected operating conditions of 1.6% delta k/k after xenon decay and cooldown to 200°F. The maximum expected boration capa-bility requirement occurs at near EOL from full power peak xenon ~onditions and requires borated water from a boric acid tank in accordance with TS Figure 3.1.2.6, and additional makeup from either: (1) the conunon boric acid tank and/or batching, or (2) a minimum of 26,000 gallons of 2500 ppm borated water from the refueling water storage tank. With the refueling water storage tank as the only borated water source, a minimum of 57,000 gallons of 2500 ppm borated water is required.

The boric acid tanks, pumps, valves, and piping contain a boric acid solu-tion concentration of between 3.5% and 4.0% by weight. To ensure that the boric acid remains in solution, the air temperature is monitored in strategic locations. By ensuring the air temperature remains at 63°F or above, a 5°F margin is provided to ensure the boron will not precipitate out. To provide

operational flexibility, if the area temperature should fall below the required value, the solution temperature (as determined by the* pipe or tank wall tem-perature) will be monitored at an increased frequency to compensate for the lack of solution temperature alarm in the main control room.

With the RCS temperature below 350°F, one injection system is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the additional restrictions prohibiting CORE ALTERATIONS and positive reactivity changes in the event the single injection system becomes inoperable.

The boron capability required below 350°F is sufficient to provide a SHUTDOWN MARGIN of 1.6% delta k/k after xenon decay and cooldown from 350°F to 200°F, and a SHUTDOWN MARGIN of 1% delta k/k after xenon decay and cooldown from 200°F to 140°F. This condition requires either 5000 gallons of 6120 ppm borated water from the boric acid storage tanks or 13,400 gallons of 2500 ppm borated water from the refueling water storage tank.

The contained water volume limits include allowance for water not avail-able because of discharge line location and other physical characteristics.

The 55,000 gallon limit in the refueling water storage tank for Modes 4, 5, and 6 is based upon 22,182 gallons that is undetectable due to lower tap location,

. I 19,197 gallons for instrument error, 13,400 gallons required for shutdown margin, and an additional 221 gallons due to rounding up.

The limits on contained water volume and boron concentration of the RWST also ensure a pH value of between 7.5 and 9.5 for the solution recirculated within containment after a LOCA. This pH band minimizes the evolution of iodine and minimizes the effect of chloride and caustic stress corrosion on mechanical systems and components.

The OPERABILITY of one boron injection system during REFUELING ensures that this system is available for reactivity control while in MODE 6.

SEQUOYAH - UNIT 2 B 3/4 1-3 Amendment No. 131, 147, 163

.. REACTIVITY CONTROL SYSTEMS

~ BASES (Continued) 3/4.1.3 MOVABLE CONTROL ASSEMBLIES The specifications of this section ensure that (1) acceptable power dis-tribution limits are maintained, (2) the minimum SHUTDOWN MARGIN is maintained, and (3) limit the potential effects of rod misalignment on associated accident analyses. OPERABILITY of the control rod position indicators is required to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits.

SEQUOYAH - UNIT 2 B 3/4 l-3a Amendment No. 163 I

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.' f ~. ~ NUCLEAR REGULATORY COMMISSION

~ ,! WASHINGTON, D.C. 20566-0001 ENCLOSURE 3

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 172 TO FACILITY OPERATING LICENSE NO. DPR-77 AND AMENDMENT NO. 163 TO FACILITY OPERATING LICENSE NO. DPR-79 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-327 AND 50-328

1.0 INTRODUCTION

By letter dated March 10, 1993, Tennessee Valley Authority, licensee for Sequoyah Units I and 2, proposed revisions to the Technical Specifications **.

(TS) .for Units I and 2. These revisions support the licensee's plans to reduce the boron concentration requirements for the 3 boric acid tanks (BATs) which serve Units 1 and 2. With a reduced concentration, the need to heat trace the BATs and the piping and valves in the boric acid makeup system (BAMS) to keep the boric acid in solution can be eliminated. The normally anticipated ambient temperatures in the auxiliary building where this r equipment is located would be sufficiently high to prevent boric acid precipitation and deposits. To provide a technical basis for the proposed changes, the licensee's submittal included Combustion Engineering Company Report CEN-602, Rev. 2, titled "Boric Acid Concentration Reduction Effort Technical Bases and Operational Analysis."

The current minimum boron concentration required for each of the BATs is 20,000 ppm (or approximately 12 percent by weight). To keep boric acid in solution at this concentration, heating networks must maintain the BATs and BAMs piping and valves at a temperature above 145°F. This concentration and the current minimum BAT borated water volume of 2175 gallons are based on the ability to borate the reactor coolant system (RCS) to the required cold shutdown concentration through a feed and bleed process. Prior to commencing cooldown, the RCS is borated to a concentration required to provida a shutdown margin of 1 percent delta k/k at 200°F. In addition, the BAMS must provide blended makeup to compensate for the coolant contraction that occurs during cooldown. RCS boron concentration is maintained constant during the cooldown process.

The proposed reduction in boron concentration for the BATs is obtained through a basic. change in methodology for carrying out the boration and cooldown operations. Rather than achieving the required boration prior to cooldown, boration is accomplished concurrently with cooldown as part of normal inventory makeup needed to compensate for coolant contraction. Using the refueling water storage tank (RWST) to supplement the BATs for makeup, the r minimum required boric acid concentration in the BATs can be reduced from approximately 12 weight percent to between 3.5 and 4.0 weight percent. To compensate for the reduced concentration, the minimum borated water volume in

r the BATs and RWST, and the minimum required delivery volume flow rate, must be increased accordingly.

2.0 EVALUATION To demonstrate the acceptab ility of the proposed reduction in BAT boron concentration, the licensee has performed calculations for specific cooldown scenarios. These calculations determine the minimum RCS boron concentration necessary to maintain the required shutdown margin for each temperature during cooldown, and the expected boron delivery from the BATs and RWST to the RCS at any time during cooldown. Maintenance of shutdown margin is assured throughout the cooldown, provided that the actual amount of boron supplied to the RCS using makeup always maintains RCS boron concentration above the minimum value required.

The reactivit y balance performed takes into account the positive reactivit y addition of moderator cooldown, as well as the positive reactivit y addition of xenon decay. Conservative core physics assumptions were made to bound the reactivit y effects of any cooldown scenario which may occur at any point in the fuel cycle, and to maximize boron demand. In the revised analysis, the bounding scenario for determining boration requirements corresponds to a cooldown at near end-of-li fe {EOL) with xenon at its post-trip peak. {Note that in the current FSAR, the bounding scenario corresponds to EOL with equilibrium xenon). Conservative assumptions employed included the following:

an initial RCS boron concentration of zero; the most negative TS limit for moderator temperature coefficie nt; EOL inverse boron worth; the most reactive rod stuck in full out position; conservatively low initial temperature for cooldown; hot standby conditions held for 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to allow peak xenon level to be reached, and; a low cooldown rate {10 F/hr) to allow for significa nt xenon decay during cooldown.

By performing a boron mass balance, the actual boron concentrations in the RCS at various temperatures during a cooldown were determined. Normal coolant shrinkage resulting from the decreasing temperatures was calc~lated and borated water {from either the BATs or the RWST) was assumed delivered to the RCS to compensate for this shrinkage. Pressurizer level was assumed to be constant. With makeup water of known boron content, the accumulated boron in the RCS and the RCS boron concentration was determined for each temperature.

In the cooldown scenario from hot standby {Mode 3) to cold shutdown {Mode 5},

the borated makeup water source is .switched from the BATs to the RWST at some point during the process. Thus, the BAT minimum concentration and volume requirements are determined such that the RCS boron concentration is first raised to a level wherein subsequent makeup supplied solely by the RWST {at a lower concentration of 2500 ppm) is adequate to maintain the required safe shutdown margin. For cooldown from cold shutdown {200°F) to the refueling temperature {assumed at 135°F), the calculation was performed for two scenarios: using only the BATs as a source of makeup, and using only the RWST as a source of makeup. Various conservative assumptions were employed in these calculati ons concerning system volumes, makeup source temperatures, RCS leakage, letdown, and boron mixing in the RCS, in order to provide a conservative estimate of boron delivery to the RCS.

Based on our review, we find the licensee has adequately demonstrated that the calculated RCS boron concentration at each temperature exceeds the minimum required to maintain the required shutdown margins for each of the cooldown scenarios presented. Additionally, the calculations provide an adequate basis for determining minimum concentration and volume requirements for the BATs.

For the accidents and transient s addressed in Chapter 15 of the FSAR, no credit is taken for concentrated boric acid addition from the BATs to the RCS for the purpose of controlling reactivit y. The only boron source given such credit is the lower concentration RWST. The only safety function associated with the boric acid contained in the BATs is maintenance of post-operation shutdown margin. The proposed reduction in BAT concentration, therefore, will not adversely impact the consequences of events such as boron dilution, a steam line break, and overcooling.

In the event the required shutdown margin is lost, current TS require commencement of boration at greater than or equal to 10 gpm using a solution of at least 20,000 ppm boron. With the proposed reduction in BAT concentration, a corresponding increase in delivery volume flow rate to 35 gpm will be required to ensure equivalent recovery capability. The licensee has proposed a modification to the boric acid piping to accommodate this revised delivery rate.

To support the planned reduction in BAT boron concentration, changes to the current TS have been proposed by the licensee. The revised values of BAT boron concentration, delivery volume flow rate, and BAT volume replace the current values in the following TS: 3.1.1.1, 3.1.1.2, 3.1.2.5.a (l,2),

3.1.2.6, 3.9.1, 3.10.1, and surveillance requirement 4.1.2.2.d . Fig. 3.1.2.6 has been added to define new BAT operability requirements for volume and concentration over the 3.5 to 4 percent concentration range. TS 3.1.2.5.b has been revised to reflect the increase in the required boric acid solution volume in the RWST. Additionally, Mode 4 applicab ility has been removed from TS 3.1.2.6 and added to 3.1.2.5 to provide consistency with 3.1.2.1 and 3.1.2.2. This proposed change also required changing the Action Statement for TS 3.1.2.6 from COLD SHUTDOWN (Mode 4) to HOT SHUTDOWN (Mode 3) to provide consistency with the applicab ility change. The licensee' s analysis supports the relocation of Mode 4 by demonstrating that adequate boration capability exists to maintain the required shutdown margin for cooldown below Mode 4.

Elimination of the heat tracing networks for the BATs and BAMS piping and valves (no longer required at the reduced BAT boron concentration) has resulted in revisions to the TS operability and surveillance requirements in Sections 3.1.2.5.a , 4.1.2.1, 4.1.2.2, 4.1.2.5, and 4.1.2.6. The current TS require that operability of at least one boron flowpath from the BATs be demonstrated at least once every 7 days by verifying that the temperature of the heat traced portions of the path is greater than 145°F. The solubilit y temperature at the new maximum specified BAT boron concentration of 4 weight percent is S8°F. With a S°F margin added to this value, the revised surveillance requirements specify that the temperature of the areas housing r the boration flowpaths and components be verified greater than 63°F at least once every 7 days. These areas will be continuously monitored, and a control room alarm that annunciates whenever area temperature falls below 63°F, will be installed .

r The licensee has assessed the impact of the proposed changes on Appendix R requirements and found that these changes do not affect the plant's ability to reach hot standby and cold shutdown. In addition, related changes to Bases Section 3/4.1.2 were proposed to support the proposed TS changes.

Based on staff review and evaluation of the planned reduction in BAT boron concentration, the associated elimination of boric acid flowpath heat tracing, the resulting revisions to the TS, and the analytical bases to support these actions, as described in the licensee's March 10, 1993 submittal, we find that adequate boration capabili.ty will continue to be provided to ensure that required shutdown margins are maintained during all modes of operation.

Therefore, the TS changes proposed in support of these modifications are acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Tennessee State official was notified of the proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR r .

Part 20 and to surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 28058). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

5.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that: (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 amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: H. Abelson Dated: November 26, 1993

ML18087A136

Contents

Text

Dear Dr. Medford:

SUBJECT:

Enclosures:

Attachment:

Attachment:

1.0 INTRODUCTION

3.0 STATE CONSULTATION

4.0 ENVIRONMENTAL CONSIDERATION

5.0 CONCLUSION

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ML18087A136

Text

Dear Dr. Medford:

SUBJECT:

Enclosures:

Attachment:

Attachment:

1.0 INTRODUCTION

3.0 STATE CONSULTATION

4.0 ENVIRONMENTAL CONSIDERATION

5.0 CONCLUSION

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