ML20198B742

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Proposed Tech Specs Changing Wording of Primary Containment Integrity Definition to State That Manual PCIVs Which Are Required to Be Closed During Accident Conditions May Be Opened Intermittently Under ACs
ML20198B742
Person / Time
Site: Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date: 12/11/1998
From:
VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20198B739 List:
References
NUDOCS 9812210099
Download: ML20198B742 (11)
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Text

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ATTACHMENT 3 Vermont Yankee Nuclear Power Station Proposed Technical Specification Change No. 210:

Intermittent Opening of Primary Containment Isolation Valves Marked-up Version of the Current Technical Specifications and Bases l

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December 1998 l

9812210099 901211 PDR P

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VYNPS 1.0 DEPINITI'ONS K. Operable - A system, subsystem, train, component or device shall be operable or have operability when it is capable of performing hs specified function (s). Implicit in this definition shall be the assumption that all necessary attendant instrumentation., controls, normal and emergency electrical power sources, cooling or seal water, lubrication or other auxiliary equipment that are required for the oystem, subsystem, train, component or device to perform its function (s) are also capable of performing their related support function (s).

L. Operatino - Operating means that a system or component is performing its intended functions in its required manner.

M. Operatino Cycle - Interval between the end of one refueling outage and the end of the next subsequent refueling outage.

N. Primary Containment Intecrity - Primary containment integrity means that the drywell and pressure suppression chamber are intact and all of the following conditions are satisfiad:

1. All manual containment isolation valves on lines connecting to the reactor coolant system or containment which ars nor r 5 rad ho open durina accident- <2nditions are closed j S uc.L vah,as maj b e, _ opened Me d.%%eJN un d er Ed.M_Ms%M =.se. c.edM s. ~
2. AC leasL one coor an eacn'alfloCK 1s Closed anQ Sealeu.
3. All automatic containment isolation velves are operable or deactivated in the isolated position.
4. All blind flanges and manways are closed.

O. Protective Instrumentation Definitions

1. Instrument Channel - An instrument channel means an arrangement of a sensor and auxiliary equipment required to generate and transmit to a trip system a single trip signal related to the plant parameter monitored by that instrument channel.
2. Trio System - A trip system means an arrangement of instrument channel trip signals and auxiliary equipment required to initiate action to accomplish a protective trip function. A trip system may require one or more instrument channel trip signals related to one or more plant parameters in order to initiate trip system action. Initiation of protective action may require the tripping of a single trip system or the coincident tripping of two trip systems.
3. Protective Action - An action initiated by thi protection system when a limit is reached. A protective action can be at a channel or system level.
4. Protective Function - A system protective Tetion which results from the protective action of the channels monitoring a
particular plant condition.

l P. Rated Neutron Flux - Rated neutron flux is the neutron flux that corresponds to a steady state power level of 1593 thermal megawatts.

Q. Rated Thermal Power - Rated thermal power means a steady state power level of 1593 thermal megawatts.

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Amendment.No. H , M , 83 2

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VYNPS BASES: 3.7 (Cont'd) j

, In' conjunction with the Mark I containment Long-Term Program, a plant f i unique analysis was performed (see Vermont Yankee let ter, dated  ;

April 27, 1984, transmitting Teledyne Engineering Services Company

)I Reports, TR-5319-1, Revision 2, dated November 30, 1983 and  !

j TR-5319-2, Revision 0) which demonstrated that all strusses in the k .s suppression chamber structure, including shell, externa.1 supports, 1 . vent system, internal structures, and attached piping neet the

't' j structural acceptance criteria of NUREG-0661. The maintenance of a N

O%TI drywell-suppression chamber differential pressure of 1.7 psid and a

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Y'$ suppression chamber water level corresponding to a downcomer f I d w y

submergence range of 4.29 to 4.54 ft, will assure the incegrity of the suppression chamber when subjected to post-LOCA suppression pool j; 4 hydrodynamic forces. ,

MP %k4fs Using a 50'F rise (Section 5.2.4 FSAR) in the suppression chamber

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A water temperature and a minimum water volume of 68,000 ft3, the 170*F g temperatura which is used for complete condensation would be approached only if the suppression pool temperature is 120*F prior to k the DBA-LoCA. Maintaining a pool temperature of 1000F will assure i

I h {\ that the 170*F limit is not approached.

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't I 4) %'b , ( Experimental data indicate that excessive steam condensing loads can be avoided if the peak temperature of the suppression pool is kk2%

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s ' k maintained below 1600F during any period of relief valve operation with sonic conditions at the discharge exit. Specifications have

'j h-been placed on the envelope of reactor operating conditions so that g hg C.q the reactor can be depressurized in a timely manner to avoid the A g is }, g regime of potentially high suppression chamber loadings.

Ig gh b , k I I In addition to the limits on temperature of the suppression chamber  !

'*I pool water, operating procedures define the action to be taken in the g i event a relief valve inadvertently opens or sticks open. This action N

j N would includes (1) use of all available means to close the valve,

}s }* (2) initiate suppression pool water cooling heat exchangers, f

" s 1Q 4 (3) initiate reactor shutdown, and (4) if other relief valves are (S s used to depressurize the reactor, their discharge shall be separated M*o-M 5 from that of the stuck-open relief valve to assure mixing and A s( - uniformity of energy insertion to the pool.

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Double isolation valves are provided on lines which penetrate the ty 3

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.R primary containment and open to the free space of the containment.

,4 g Closure of one of the valves in each line would be sufficient to

  • t e { j maintain the integrity of the pressure suppression system. Au to:. *-

-9 4 initiation is required to minimite the potential leakage paths f 7 the containment in the event of a loss-of-coolant accident. Details k'N

} of the isolation valves are discussed ir Section 5.2 of the FSAR.

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  • k The purpose of the vacuum relief valves is te equalize the pressure between the drywell and suppression chamber and suppression chamber h9 4  % and reactor building so that the structural integrity of the f R[ "

containment is maintained.

g Technical Specification 3.7.A.9.c is based on the assumption that the h g 'f,4, g g

operability testing of the pressure suppression chamber-reactor building vacuum breaker,- when required, will normally be perfonned

( g i,sg during the came four hour testing interval as the pressure Ng V }qg suppressicr ::h' amber-drywell vacuum breakers in a order to minimize

, g ,i operation with <1.7 psi, differential pressure.

IN $ b Amendment No. % , GG, Be, Ltr dtd 7 'l/85 164

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ATTACHMENT 4 Vermont Yankee Nuclear Power Station Proposed Technical Specification Change No. 210:

Intermittent Opening of Primary 1 Containment Isolation Valves t

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Retyped Technical Specifications 4 and Bases Pages l

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i i i V 1 I l Decemher 1998
  • l VYEPS '

1.0 DEFINITIONS a

1.0 DEFINITIONS The succeeding frequently used terms are explicitly defined so that a uniform interpretation of the specifications may be achieved.

A. Reportable Occurrence - The equivalent of a reportable event which shall be any of the conditions specified in Section 50.73 to 10CFR Part 50.

B. Alteration of the Reactor Core - The act of moving any component affecting reactivity within the reactor vessel in the region above the core support plate, below the upper grid and within the shroud. Normal movement of control rods or neutron detectors, or the replacement of neutron detectors is not defined as a core alteration.

C. Hot Standby - Hot standby means operation with the reactor critical and the main steam line isolation valves closed.

D. Immedtate - Immediate means that the required action will be initiated as soon as practicable considering the safe operation of the unit and the importance of the e required action.

1 E. Instrument Calibration - An instrument calibration means the adjustment of an instrument signal output so that it corresponds, within acceptable range and accuracy, to a known value(s) of the parameter which the instrument monitors.

Calibration shall encompass the entire instrument including actuation, alarm, or trip. Response time as specified is not part of the routine instrument calibration but will be checked once per operating cycle.

F. Instrument Check - An instrument check is qualitative determination of acceptable operability by observation of instrument behavior during operation. This determination shall include, where possible, comparison of the instrument with other independent instruments measuring the same variable.

G. Instrument Functional Test - An instrument functional test shall be:

1. Analog channels - the injection of a cignal into the channel as close to the sensor as practicable to verify operability including alarm and/or trip functions.
2. Listable channels - the injection of a signal into the sensor to verify the operability including alarm and/or trip functions.

H. Log System Functional Test - A logic system functional test means a test of all

. relays and contacts of a logic circuit from sensor to activated device to insure all components are operable per design intent. Where posrible, action will go to completion, i.e., pumps will be started and valves op2ned.

I. Minimum Critical Power Ratio - The minimum critical power ratio is defined as the ratio of that power in a fuel assembly which is calculated to cause some point in that assembly to experience boiling transition as calculated by application of the appropriate NRC-approved critical power correlation to the actual assembly operating power.

J. Mode - The reactor mode is that which is established by the mode-selector-switch.

Amendment No. 44, 44, 46, 444, 137 1

I VYNPS 1.0 ,

DEFINITIONS K. Operable - A system, subsystem, train, component or device shall be operable or have operability when it is capable of performing its specified function (s). Implicit in this definition shall be the assumption that all n.cessary attendant instrumentation, controls, normal and emergency electrical power sources, cooling or seal water, lubrication or other auxiliary equipment that are required for the system, subsystem, train, component or device to perform its function (s) are also capable of performing their related support function (s).

h. Operating - Operating means that a system or component is performing its intended functions in its required manner. _

H. Operating Cycle - Interval between the end of one refueling outage and the end of the next subsequent refueling outage.

N. Primary Containment Integrity - Primary containment integrity means that the drywell and pressure suppression chamber are intact and all of the following conditions are satisfied:

1. All manual containment isolation valves on lines connecting to the reactor coolant system or containment, which are not required to be open durtng accident conditions, are closed. Such valves may be opened intermittently under administrative controls.
2. At least one door in each airlock is closed and sealed.
3. All automatic containment isolation valves are operable or deactivated in the isolated position.
4. All blind flanges and manways are closed.

O. Protective Instrumentation Definitions

1. Instrument Channel - An instrument channel means an arrangement of a sensor and auxiliary equipment required to generate and transmit to a trip system a single trip signal related to the plant parameter monitored by that instrument channel.
2. Trip System - A trip system means an arrangement of instrument channel trip signals and auxiliary equipment required to initiate action to accompitsh a protective trip function. A trip system may require one or more instrument channel trip signals related to one or more plant parameters in order to initiate trip system action. Initiation of protective action may require the tripping of a single trip system or the coincident tripping of two trip systems.
3. Protectiv . Action - 7m action initiated by the protection system when a limit is reached. A protective action can be at a channel or system level.

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4. Protective Function - A system protective action which results from the I protective action of the channels monitoring a particular plant condition. i l

i 1 P. Rated Neutron Flux - Rated neutron flux is the neutron flux that corresponds to a  !

steady state power level of 1593 thermal megawatts. l Q. Rated Thermal Power - Rated thermal power means a steady state power level of I 1593 thermal megawatts.

Amendment No. 4, M, M 2 )

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1 VYNPS l

t 1.0 DEFINITIONS l

R. Reactor Power Operation - Reaccor power operation is any operation with the mode I switch in the "Startup/ Hot Standby" or "Run" position with the reactor critical and above 1% rated thermal power.

1. Startup/ Hot Standby Mode - In this mode the low turbine condenst volume trip is bypassed when condenser vacuum is less than 12 inches Hg and both turbine stop valves and bypass valves are closed; the low pressure and the 10 percent closure I main steamline isolation valve closure trips are bypassed; the reactor l protection system is energized with IRM neutron monitoring system trips and l control rod withdrawal interlocks in service and APRM neutron monitoring system operable. I
2. Run Mode - In this mode the reactor system pressure is equal to or greater than 800 psig and the reactor protection system is energized with APRM protection and RBM interlocks in service.

S. Reactor Vessel Pressure - Unless otherwise indicated, reactor vessel pressures listed in the Technical Specifications are those measured by the reactor vessel steam space detector.

T. Refueling Outage - Refueling outage is the period of time between the shutdown of the unit prior to a refueling and the startup of the plant subsequent to that refueling. For the purpose of designating frequency of testing and surveillance, a refueling outage shall mean a regularly scheduled refueling outage; however, where such outages occur within 8 months of the completion of the previous refueling outag., the required surveillance testing need not ba performed until the next regularly scheduled outage.

U. Secondary Containment Integrity - Secondary containment integrity means that the reactor building is intact and the following conditions are met:

1. At least one door in each access opening is closed.
2. The standby gas treatment system is operable.
3. All reactor building automatic ventilation system isolation valves are operable or are secured in the isolated position.

V. Shutdown - The reactor is s shutdown condition when the reactor mode switch is in the shutdown mode position and no core alterations are being performed. When the mode switch is placed in the shutdoen position a reactor scram is initiated, power to the control rod drives is removed, and the reactor protection system trip systems are de-energized.

1. Hot Shutdown means conditions as above with reactor coolant temperature greater that 212*F.
2. Cold shutdown means conditions as above with reactor coolant temperature equal to or less than 212*F.
3. Shutdown means conditions as above such that the effective multiplication factor (Kere) of the core shall be less than 0.99.

I Amendment No M , 84 3

t VYNPS 1.0 DEFINITIONS W. Sid21sted* Automatic Actuation - Simulated automatic actuation means applying a simulated signal to the sensor to actuate circuit in question.  !

X. Transition Boiling - Transition boiling means the boiling regime between nucleate and film boiling. Transition boiling is the regime in which both nucleate and film boiling occur

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intermittently with neither type being completely stable.  ;

Y. Surveillance Frequency - Unless otherwise stated in these specifications, periodic surveillance tests, checks, calibrations, and examinations shall be performed within the specified surveillance intervals. These intervals may be adjusted plus 25%. The i operating cycle interval is considered to be 18 months and the tolerance stated above is applicable.

Z. Surveillance Interval - The surveillance interval is the calendar time between surveillance tests, checks, calibrations, and examinations to be performed upon an instrument or component when it is required to be operable. These tests unless otherwise stated in these specifications may be waived when the instrument, component, or system is not required to be operable, but these tests shall be performed on the instrument, l component, or system prior to being required to be operable. j AA. Vital Fire Suppression Water System - The vital fire suppression water system is that part of the fire suppression system which protects those instruments, components, and systems required to perform a safe shutdown of the reactor. The vital fire suppression system includes the water supply, pumps, and distribution piping with associated sectionalizing valves, which provide immediate coverage of the Reactor Building, Control Room Building, and Diesel Generator Rooms.

BB. Source Check - The qualitative assessment of channel response when the channel sensor is exposed to a radioactive source.

CC. Dose Equivalent I-131 - The dose equivalent I-131 shall be that concentration of I-131 (microcurie / gram) which alone would produce the same thyroid dose as the quantity and isotopic mixture of I-131, I-132, I-133, I-134 and I-135 actually present. The thyroid dose conversion factors used for this calculation shall be those listed in NRC Regulatory Guide 1.109, Revision 1, October 1977.

DD. Solidification - Solidification shall be the conversion of wet wastes into a form that meets shipping and burial ground requirements. Suitable forms include dewatered resins and fiJter s1.udges.

l EE. Deleted TF. Site Boundary - The site boundary is shown in Figure 2.2-5 in the FSAR.

GG. Deleted HH. Deleted Amend.unt ho. M, M, 44, M, M, M4, M4, 151 4

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.; VYMPS l

1.0 DEFINITIONS II. bff*e$ite Do'se Ca lculation Manual (ODCM) - A manual containing the current methodology and parameters used ;n the calculation of off-site doses due to radioactive gaseous and liquid effluents, in the calculation of gaseous and liquid effluent monitoring alarm / trip

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i setpoints, and in the conduction of the environmental radiological monitoring program.

JJ. Process Control Progratm (PCP) - A process control program shall contain the sampling, 1 analysis, tests, and determinations by which wet radioactive waste from liquid systems is ]

l, assured to be converted to a form suitable for off-site disposal. J l  !

i KK.. Gaseous Radwaste Treatment System - The Augmented Off-Gas System (AOG) is the gaseous ]

i radwaste treatment system which has been designed and installed to reduce radioactive gaseous effluents by collecting primary coolant system off-gases from the primary system and providing for delay or holdup for the purpose of reducing the total radioactivity prior.to release to the environment.

LL. . Ventilation Exhaust Treatment System - The Radwaste Building and AOG Building ventilation l 1

-HEPA filters are ventilation exhaust treatment systems which have been designed and l . installed to reduce radioactive material in particulate form in gaseous effluents by f passing ventilation air through HEPA filters for the purpose of removing radioactive

. particula,tes from the gaseous exhaust stream prior to release to the environment.  ;

j. Engineered safety feature atmospheric cleanup systems, such as the Standby Gas Treatment l (SBGT) System; are'not considered to be ventilation exhaust treatment system components.

l MM. Vent'/ Purging - Vent / Purging is the controlled process of discharging air or gas from the i

! primary containment to control. temperature, pressure, humidity, concentratior. or other i

!-  : operating conditions. >

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1 NN. Core Operating Limits Report - The Core Operating Limits Report is the unit-specific

! document that provides core operating limits for the current operating reload cycle. 4

j. These cycle-specific core operating limits shall be determined for each reload cycle in I accordance with Specification 6.7.A.4. Plant operation within these operating limits is ,

addressed in individual specifications.

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r. ' Amendment No. 84, 116 i:

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. i l: 1 l VYNPS I

b BAS ES'-: ' 3.t'(Cont'd)

In conjunction with the Mark I Containment Long-Term Program, a plant I unique analysis was performed (see Vermont Yankee letter, dated April 27, 1984, transmitting Teledyne Engineering Services Company l Reports, TR-5319-1, Revision 2, dated November 30, 1983 and  ;

TR-5319-2, Revision 0) which demonstrated that all stresses in the I suppression chamber structure, including shell, external supports, j vent system, internal structures, and attached piping meet the structural acceptance criteria of NUREG-0661. The maintenance of a drywell-suppression chamber differential pressure of 1.7 psid and a suppression chamber water level corresponding to a downcomer submergence range of 4.29 to 4.54 ft. will assure the integrity of the suppression chamber when subjected to post-LOCA suppression pool

-hydrodynamic forces. l l

Using a 50*F rise (Section 5.2.4 FSAR) in the suppression chamber

, nater temperature and a mit imum water volume of 68,000 ft', the -170*F temperature which is used for complete condensation would be approached only if the suppression pool temperature is 120*F prior to the DBA-LOCA. . Maintaining a pool temperature of 100*F will assure l that the 170*F limit is not approached.

Experimental' data inoicate that excessive steam condensing loads can be avoided !.f the peak temperature of the suppression pool is maintained below 160*F during any period of relief valve operation

.with sonic conditions at the discharge exit. Specifications have been placed on the envelope of reactor operating conditions so that the reactor can be depressurized in a timely manner to avoid the  !

regime of potentially high suppression chamber loadings.

In addition to the limits on temperature of the suppression chamber pool water, operating procedores define the action to be taken in the event a relief valve inadvertently opens or sticks open. This action would include: (1) use of all available means to close the valve,

'(2) initiate suppression pool water cooling heat exchangers, (3) initiate reactor shutdown, and (4) if other relief valves are used to depressurize the reactor, their discharge shall be separated from that of the stuck-open relief valve to assure mixing and uniformity of energy insertion to the pool.

Doubla isolation valves are provided on lines which penetrate the primary containment and open to the free space of the containment.

Closure of one of the valves in each line would be sufficient to maintain the integrity of the pressure suppression system. Automatic initiation is required to minimize the potential leakage paths from the containment in the event of a loss-of-coolant accident. Details of the isolation valves are discussed in Section 5,,2 of the FSAR.

Manual primary containment isolation valves that are required to be closed by the definition of Primary Containment Integrity may be opened intermittently under administrative controls. These controls consist of stationing a dedicated operator, with whom Control Room communication is immediately available, in the immediate vicinity of

'the valve controls. In this way, the penetration can be rapidly isolated when a need for primary containment isolation is indicated.

Amendment No.- 16, 60,.44, L&r dtd '/1/96- 164

O VYNPS

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The~ purpose of the vacuum relief valves is to equalize the pressure between the drywell and suppression chamber and suppression chamber and reactor building so that the structural integrity of the containment is maintained.

Technical Specification 3.7.A.9.c is based on the assumption that the operability testing of the pressure suppression chamber-reactor building vacuum breaker, when required, will normally be performed during the same four hour testing interval as the pressure suppression chamber-dry.rell vacuum breakers in order to minimize  ;

operation with <l.7 psi, differential pressure.

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Amendment No. 44, 60, &&, her dtd '/1/95 164a

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