ML20134G852

Proposed Tech Specs,Adding Surveillance Requirements for fast-acting Dampers in Standby Gas Treatment Sys Installed During Recent Refueling Outage

ML20134G852
Person / Time
Site:	Hatch
Issue date:	08/20/1985
From:	GEORGIA POWER CO.
To:
Shared Package
ML20134G841	List: ML20134G838 ML20134G852
References
TAC-59543, TAC-59544, NUDOCS 8508280113
Download: ML20134G852 (15)

Text

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Georgialbwer A Attachment 4 NRC DOCKET 50-366 OPERATING LICENSE NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNIT 2 PURGE AND VENT MODIFICATIONS Instructions for Incorporating Changed Pages into the Technical Specifications The - proposed chan to the Technical Specifications (Appendix A to the Operating License) gewould be incorporated as follows:

Remove - Page Insert Page Unit 1 3.7-10a 3. 7-10a 3.7-10b 3.7-11 3.7-11 3.7-11 a 3.7-11 a 3.7-34 3.7-34 3.7-34a 3.7-34a 3.7-34b Unit 2 3/4 6-2 3/4 6-2*

3/4 6-46 3/4 6-46 3/4 6-47 3/4 6-47 3/4 9-10 3/4 9-10 3/4 9-10a 3/4 9-10a B 3/4 6-6 B 3/4 6-6*

B 3/4 6-7

• Unchanged from our letter of June 15, 1983 8508290113 850820 PDR ADOCK 05000321 P PDR

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3.7.A.7 Primary Containment 4.7.A.7 Primary Containment Purge System Purge System

a. 'When primary containment is a. In addition to the requirements required, all drywell and of Specification 4.7.D, each suppression chamber 18 inch purge drywell and suppression chamber supply and exhaust isolation 18 inch purge supply and valves shall be operable and in exhaust isolation valve shall the fully closed position except be verified to be closed at when required for inerting, de- least monthly.

inerting, or pressure control.

b. Each refueling outage each

b. Each drywell and suppression drywell and suppression chamber chamber 18 inch purge supply and 18 inch purge supply and exhaust isolation valve shall have exhaust isolation valve with a a leakage rate as specified in resilient material seat shall 4.7.A.2. be demonstrated operable by having its valve seat replaced

c. The drywell and suppression and verifying that the leakage chamber 18 inch excess flow rate is within its limit.

isolation dampers shall be operable at all times when the c. At least once per 2 years the Unit 1 primary containment dampers will be visually integrity is required and the 18 inspected and cycled to verify inch isolation valve (s) to the the dampers have no damage drywell or suppression chamber are which renders them incapable of open. performing their design function.

If these requirements cannot be met, close the drywell and suppression chamber 18 inch purge supply and exhaust isolation valve (s) or otherwise isolate the penetration (s) within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or fulfill the requirements of Specification 3.7.A.8.

8. Shutdown Requirements If Specification 3.7.A cannot be met, an orderly shutdown shall be initiated and the reactor shall be brought to Hot Shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and shall be in the Cold Shutdown condition within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3. 7-10a

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8. Standby Gas Treatment System 8. Standby Gas Treatnent System

1. Operability Recuirements 1. Surveillance When System Operable 1.a A minimum of three (2 of 2 in Unit l 1 and 1 of 2 in Unit 2) of the four At least once per operating cycle, not independent standby gas treatment to exceed 18 months, the following system trains shall be operable at conditions shall be demonstrated:

all times when Unit 1 secondary containment integrity is recuired, a. Pressure drop across the combined HEPA filters and charcoal absorber With one of the Unit I standby gas bank is less than 6 inches of treatment systems inoperable, for water at the system design flow any reason, Unit I reactor rate (+10% -0%).

operation and fuel handling and/or handling of casks in the vicinity b. . Operability of inlet heater at of the spent fuel pools is rated power when tested in permissible for a period of seven accordance with ANSI N510-1975.

(7) days provided that all active components in the remaining c. Air distribution is uniform within operable standby gas treatment 20% across the filter train when systems in each unit (minimum of 1 tested in accordance with in Unit 1 and 1 in Unit 2) shall be N510-1975.

demonstrated to be operable within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, and daily thereafter.

3.7-10b

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B, Standby-Gas" Treatment System B.l Standby Gas Treatment System J

1.: Operability Requirements (Cont'd) .l. Surveillance When System Operable

. . (Cont'd) e If the inoperable Unit 1 standby gas .

? treatment system.is.not made fully d. Automatic initiation of each train of operable within the seven (7) day the Unit 1 and Unit 2 standby gas period, the Unit 1 reactor shall be treatment systems.

shutdown and placed in the cold shutdown condition within the next.36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> and e. Manual operability of the bypass

' Unit 1 or Unit'2 fuel handling- .

valve for filter cooling.

. operations shall be terminated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

. Unit 1: reactor operation and Unit 1 or Unit.2 fuel handling shall not.be allowed if both of the Unit 1 standby gas treatment systems are inoperable or

1f both.of the Unit 2 standby gas treatment systems are inoperable except as allowed by 3.7.B.I.b.

1.b .With both Unit 2 SGTS inoperable for surveillance of the Unit 2 primary.

containment excess flow isolation

dampers, Unit ~1 reactor operation is-

' permissible for a period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

if the following conditions are' met:

(1) Maintain at least 1/4" H 02 vacuum

'in Unit I secondary containment by using normal ventilation and Unit 1 SGTS as necessary:

L(2)AssureoperabilityofbothUnit1 SGTS filter trains L(3) Assure Unit 2 SGTS valves to-refueling floor cannot be opened

(4) Allow no fuel movement in Units i 1 or 2 '

~(5) Unit 2secondarycontainment integrity is intact except for Unit 2 SGTS operability requirements.

l.c If the requirements of 3.7.B.l.b cannot be met, an orderly shutdown shall be initiated and the reactor shall be brought to Hot Shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and shall be in Cold Shutdown within- the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3.7-11 l

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3,7.B.2 Performance Reauirements .2. Filter Testing

a. The results of the in-place DOP and a. The tests and analysis shall be halogenated hydro-carbon tests at performed at least once per design flows on HEPA filters and operatlng cycle, not to exceed 18 charcoal absorber banks shall show months, or after every 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> of 99% DOP removal and 99% halogenated system operation, or following

' hydrocarbon removal when tested in painting, fire or chemical release accordance with ANSI N510-1975. in any ventilation zone communicating with the system.

b. -The results of laboratory carbon sample analysis shall show 90% of b. DOP testing shall be performed radioactive methyl iodine removal after each complete or partial when tested in accordance with replacement of the HEPA filter bank ROT-M16-lT (800C, 95% R.H.).. or after any structural maintenance on the system housing

c. Fans shall be shown to operate within +10% -0% design flow when c. Halogentated hydrocarbon testing tested in accordance with ANSI shall be performed after each N510-1975. complete or partial replacement of the charcoal absorber bank or after any structural maintenance on the-system housing.

d. Each circuit shall be operated with the heaters on at least 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> every month.

3.7-11a

CONTAINMENT SYSTEMS BASES FOR LIMITING CONDITION FOR OPERATION

.3.7.A.7 Primary Containment Purge System The purge system is designed to perform two basic functions:

pressure control and inert /de-inert the primary containment. Under normal operations the purge system is used to maintain containment pressure less than two psig. Post LOCA, the purge system, through the 2 inch bypass lines, is also used to reduce containment pressure. The 18 inch lines are the primary means of reducing the oxygen concentration inside containment before long term power operations to less than 4% in accordance with Technical Specification 3.7.A.5. Conversely, it is also the path for restoring oxygen concentration to life sustaining levels before drywell entry. The system is hard-piped to the Standby Gas Treatment System; therefore, any entrained radioactivity will be reduced before being t eleased to the environment through the main stack.

The use of the drywell and suppression chamber purge lines is not limited since the 18" valves will close during a LOCA or steam line break accident and therefore the site boundary dose guideline of 10 CFR Part 100 would not be exceed in the event of an accident during purging operations. The design of the 18" purge supply and exhaust isolation valves meets the requirements of Branch Technical position CBS 6-4, " Containment Purging During Normal Plant Operations.

Replacement of the 18" valve resilient seats on a cyclic basis will allow the opportunity for repair before gross leakage failure develops. The 0.60 La leakage limit shall not be exceeded when the leakage rates determined by the leakage integrity tests of these valves are added to the previously determined total for all valves and penetrations subject to the B and C tests.

Surveillance testing of the excess flow isolation dampers is recommended by the vendor to verify that the blades pivot freely and no other damage is evident. Industry practice does not require testing for closure under simulated flow conditions for " tornado" type dampers.

3.7.A.8 Shutdown Requirements l Bases for shutdown requirements are discussed above in conjunction with the individual requirements for primary containment integrity.

B. Standby Gas Treatment System The standby gas treatment systems are designed to filter and exhaust the Unit 1 secondary containment atmosphere to the off-gas stack during secondary containment isolation conditions, with a minimum release of radioactive materials from these areas to the environs.

3.7-34

CONTAIPMENT SYSTEMS BASES FOR t.IMITING C0tOITION FOR OPERATION B. Standby Cas Treatment System (Continued)

The Unit 1 standby gas treatment system fans are designed to automatically start upon receipt of a high radiation signal from either the Unit 1 or Unit 2 refueling floor ventilation exhaust duct monitors or the thit I reactor building ventilation exhaust duct monitors, or upon receipt of a signal from the Unit 1 primary containment isolation system. The Unit 2 standby gas treatment system fans are designed to automatically start, to assist the Unit I fans to exhaust the Unit 1 secondary containment atmosphere upon receipt of a high radiation signal from either the thit 1 or Unit 2 refueling floor ventilation exhaust duct monitors or the thit 1 ,

reactor building ventilation exhaust duct monitors, or upon receipt of a signal from the thit 1 primary containment isolation system. In addition, the systems may also be started manually, from the Main Control Room.

In the case of the Unit 1 standby gas treatment system, upon receipt of any of the isolation signals, both fans start, isolation dampers open and each fan draws air from the isolated Unit 1 Secondary containment.

In the case of the thit 2 standby gas treatment system, upon receipt of an isolation signal from the Unit 1 primary containment isolation system, reactor building ventilation exhaust duct monitors, or the Unit 1 or Unit 2 refueling floor ventilation exhaust duct monitors, both fans start, fan supply and discharge dampers open, and the fans draw air from the isolated thit 1 secondary containment.

OMe the SGTS systems have been initiated automatically may place any one of the Unit I and Unit 2 trains in the, the operator standby mode provided the remaining train in each unit is operable. Should a failure occur in the remaining operating trains, resulting in air flow reduction below a preset value, the standby systems will restart automatically.

As a minimum for operation, one of the two thit 1 standby gas treatment trains and one of the two Unit 2 standby gas treatment trains is recuired to achieve the design differential pressure, given the design building infiltration rate. Once this design differential pressure is achieved, any leakage past the secondary containment boundary shall be inleakage.

A detailed discussion of the standby gas treatment systems may be found in Section 5.3.3.3 of the Unit 1 FSAR, and in Section 6.2.3 of the Unit 2 FSAR.

Any one of the four filter trains has sufficient adsorption capacity to provide for cleanup of the Unit 1 secondary containment atmosphere following containment isolation. Any one of the four available 3.7-34a

CONTAINMENT SYSTEMS BASES FOR LIMITING CONDITION FOR OPERATION B. Standby Gas Treatment System (Continued) standby gas treatment trains may be considered an installed spare.

Therefore, .with one of the standby gas treatment trains in each unit inoperable, there is no immediate threat to the Unit I containment system performance, and reactor operation or fuel handling operations may continue while repairs are being made. Should either or both of the remaining standby gas treatment trains be found to be inoperable, the Unit 1 plant should be placed in a condition that does not require a standby gas treatment system.

.n exception can be taken for a brief period to both trains of Unit 2 SGTS being available when Unit 2 is in Cold Shutdown and Unit 1 is operating. This exemption is based on the low probability of the occurrence of a DBA LOCA on Unit I during the brief period that Unit 2 SGTS remained inoperable. In addition, Unit 2 SGTS would be in a condition such that it could be restored quickly to assist in the mitigation of the LOCA, if required.

Inspection of the excess flow isolation dampers will not affect Unit 1 SGTS availability, if the Unit I refueling floor equipment hatch cover is not in place, since the Unit 1 SGTS flow path during drawdown comes from the Unit 1 refueling floor or reactor building which is one common air volume in Unit 1. If the damper is removed during SGTS drawdown demand, the suction will remain from this same common air volume.

High efficiency particulate air (HEPA) filters are installed before the charcoal adsorbers to prevent clogging of the iodine adsorbers.

The charcoal adsorbers are installed to reduce the potential release of radioiodine to the environment. Bypass leakage for the charcoal adsorbers and particulate removal efficiency for HEPA filters are determined by halogenated hydrocarbon and D0P respectively. The laboratory carbon sample test results indicate a radioactive methyl iodide removal efficiency for expected accident conditions.

Operation of the fans significantly different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers. If the performances are as specified, the calculated doses would be less than the guidelines stated in 10 CFR 100 for the accident analyzed.

3.7.C. Secondary Containment The secondary containment is designed to minimize any ground level release of radioactive materials which might result from a serious accident. The refueling area of the reactor buildir.g includes the Unit 1 and Unit 2 refueling floor volumes. Therefo*e, the reacter l building provides secondary containment during Unit I reactor operation when the drywell is sealed and in service; snd provides primary containment when the Unit 1 and/or Unit 2 reactor 1: thut h n and its respective drydell is open, as during refueling.

3.7-24b

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CONTAINMENT SYSTEMS PRIMARY CONTAINMENT PURGE SYSTEM LIMITING CONDITION FOR OPERATION 3.6.6.5.1 The drywell and suppression chamber 18 inch purge supply and exhaust isolation valves shall be OPERABLE with:

a.. Each valve closed except for purge system operation for inerting, deinerting and pressure control.

b. A leakage rate such that the provisions of Specification 3.6.1.2 are met.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2 and 3.

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ACTION:

a. With an 18 inch drywell and suppression chamber purge supply and/or exhaust isolation valve (s) inoperable or open for other than inerting, deinerting or pressure control, close the open 18 inch valve (s) or otherwise isolate the penetration (s) within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.6.6.5.1 The primary containment purge system shall be demonstrated OPERABLE:

a. In addition to the requirements of Specification 3.6.3, at least once per 31 days, when not PURGING and VENTING, by verifying that each 18 inch drywell and suppression chamber valve is closed.

b. At least once per 18 months by replacing the valve seat of each 18 inch drywell and suppression chamber purge supply and e:,haust isolation valve having a resilient material seat and verifying that the leakage rate is within its limit.

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CONTAINMENT SYSTEMS PRIMARY CONTAINMENT PURGE SYSlEM LIMITING CONDITION FOR OPERATION 3.6.6.5.2 The drywell and suppression chamber 18 inch fast acting excess flow isolation dampers shall be OPERABLE.

APPLICABILITY: OPERATIONAL CONDITIONS 1, 2, and 3.

ACTION:

a. With an 18 inch drywell and suppression chamber excess flow isolation damper inoperable, close the open 18 inch valves drywell and suppression chamber purge supply and exhaust isolation valves or otherwise isolate the penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in at least H0T SHUTOOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTOOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.6.6.5.2 The primary containment purge system excess flow isolation dampers shall be demonstrated capable of performing their design function by:

a. At least once per operating cycle, the dampers will be visually inspected and cycled to verify the dampers have no damage which renders them incapable of performing their design function.

HATCH - UNIT 2 3/4 6-47 I

' REFUELING OPERATIONS STANDBY GAS TREATMENT SYSTEM i . LIMITING' CONDITION FOR'0PERATION 3.9.5.3 Two Hatch-Unit 2 independent standby gas treatment subsystems and two Hatch-Unit 1 independent standby gas treatment subsystems shall be

' 0PERABLE.

i -APPLICABILITY: CONDITIONS 5 and *.

ACTION:

a. With one of the above required standby gas treatment subsystems inoperable, restore the inoperable subsystem to OPERABLE status within 30 days, or:

1. Suspend all irradiated fuel and spent fuel shipping cask handling in the Hatch - Unit I secondary containment, and

2. In CONDITION 5, suspend Hatch - Unit 2 CORE ALTERATIONS and operations-that could reduce the SHUTDOWN MARGIN.

l l b. With two or more of the above required standby gas treatment subsystems inoperable:

1. Suspend all irradiated fuel and spent fuel shipping cask handling in the Hatch - Unit I secondary containment, and

2. 'In CONDITION 5, suspend Hatch - Unit 2 CORE ALTERATIONS and operations that could reduce the SHUTDOWN MARGIN.

c. Both Unit 2 independent trains of standby gas treatment may be inoperable for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> during Unit I reactor operation for surveillance a of the Unit 2 primary containment excess flow isolation dampers if the following conditions are met:

1. Using Unit- 1 standby gas treatment system and normal ventilation, maintain at least 1/4" H 02 vacuum in Unit I secondary containment

2. Assure operability of both Unit 1 SGTS filter trains

3. Assure Unit 2 SGTS valves to the refueling floor cannot be opened

4. Allow no fuel movement in Units 1 or 2

• When irradiated fuel or the spent fuel shipping cask is being handled in the Hatch - Unit I secondary containment.

HATCH - UNIT 2 3/4 9-10

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1 REFUELING OPERATIONS LIMITING C0tOITION FOR OPERATION (Continued)

5. Unit 2 secondary containment integrity is intact except for Unit 2 standby gas treatment system cperability recuirements If any of the above conditions cannot be met, an orderly shutdown shall be initiated and the reactor shall be brought to Hot Shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and shall be in Cold Shotdown within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

d. The provisions of Specification 3.0.3 are not applicable. g SURVEILLANCE REQUIREMENTS _

4.9.5.3.1 Each of the above reouired Hatch - Unit 2 standby gas treatment subsystems shall be demonstrated OPERABLE per Specification 4.6.6.1.1.

4.9.5.3.2 Each of the above recuired Hatch, - Unit I standby gas treatment subsystems shall be demonstrated OPERABLE per Hatch - Unit 1 Technical Specifications.

HATCH - UNIT 2 3/4 9-10a

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. o CONTAITNEtE SYSTEMS BASES CONTAIlMEtE A'H10 SPHERE COtEROL (Continued)

The OPERABILITY of the systems required for the detection and control of hydrogen gas ensures that these systems will be available to maintain the hydrogen concentration within containment below its flammable limit during post-IOCA cpmditions Either recombiner is capable of controlling the expected hydrogen generation associated with: (1) zirconium-water reactions, (2) radiolytic decomposition of water, and (3) corrosion of metals within containment. The hydrogen mixing system is provided to ensure adequate mixing of the containment atmosphere following a IOCA. This mixing.

action will prevent localized accumulations of hydrogen from exceeding the flammable limit , ,

The requirement for the primary containment atmosphere oxygen concentration to be less than 4% by volume is being added for fire protection considerations. This is being done in lieu of the installation of sprinkler for the recirculation pumps inside the drywell.

3.6.6.5 PRIMARY C0tEAI?NENP PURGE SYSTEM The primary containment purge system is designed to perform two basic functions: pressure control and inert /de-inert the primary containment.

Under normal operations the purge system is used to maintain containment pressure less than two psig. Post IOCA, the purge system, through the 2 inch bypass lines, is also used to reduce containment pressure. The 18 inch lines are the primary means of reducing the oxygen concentration inside containment before long term power operations to less than 4% in accordance with Technical Specification 3.6.6.4. Conversely, it is also the path for restoring oxygen concentration to life sustaining levels before drywell entry. The system is hard-piped to the Standby Gas Treatment System; therefore, any entrained radioactivity will be reduced before being released to the environment through the main stack.

'Ihe use of the drywell and suppression chamber purge lines is not limited since the 18" valves will close during a IOCA or steam line break accident and therefore the site boundary dose guideline of 10 CETI Part 100 would not be exceeded in the event of an accident during purging operations. The design of the 18" purge supply and exhaust isolation valves meets the requirements of Branch Technical Position CSB 6-4, " Containment Purging During Normal Plant Operations."

Replacement of the 18" valve resilient seats on a cyclic basis will allow the opportunity for repair before gross leakage failure develops. 'The 0.60 La leakage limit shall not be exceeded when the leakage rates determined by' the leakage integrity tests of these valves are added to the previously determined total for all valves ard ponetrations subject to Type B and C tests.

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1 CONTAIPNENT SYSTEMS

, BASES PR MARY CONTAIPNENT PURGE SYSTEM (Continued) ,

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An exception can be taken for a brief period to both trains of Unit 1.

!, SGTS being available when Unit 1 is in Cold Shutdown and Unit 2 is S operating.- This exemption is based on the low probability of the occurrence of a DBA LOCA on.U' n it 2 during the brief period that thit 1 SGTS remained inoperabic , In addition, Unit 1 SGTS would be in a condition such that it could be restored ouickly to assist in the mitigation of the LOCA, if reouired. ',

An exception can be taken for a brief period to both trains of Unit 2 SGTS . being available when Unit 2 is in Cold Shutdown and Unit 1 is operating. This er. emotion is based on the low probability lof the occurrence

< of a 'DBA LOCA on Unit I during the brief period that Unit 2 SGTS remained inoperable.. In addition,. thit 2 SGTS would be in a condition such that it i could be restored ouickly to assist in the mitigation of the LOCA, if l- ,reouired.

Surveillance testing of the excess flow isolation dampers is recommended

! by the vendor to verify that the blades pivot freely and no other damage is evident. Industry practice, does not recuire testing for closure under simulated flow conditions for " tornado" type dampers, s ,

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