ML20073J859

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Proposed Tech Specs,Revising Definition of Core Alterations, Section 3/4.9.2 Re Refueling Operations,Instrumentation & Sections 3/4.9.8.1 & 3/4.9.8.2 Re RHR & Coolant Circulation, High Water Level & Low Water Level
ML20073J859
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Site: Millstone Dominion icon.png
Issue date: 09/30/1994
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NORTHEAST NUCLEAR ENERGY CO.
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ML20073J854 List:
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NUDOCS 9410070163
Download: ML20073J859 (28)
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Docket No. 50-423 B14987 Attachment 1 Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Core Alterations Definition and Refueling Operations Marked-Up Pages September 1994 l

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DR 0070I63 94c930 ADOCK 0500o423 POR

03/24/94 INDEX '

. BASES SECTION PAGE 3/4.7.11 SEALED SOURCE CONTAMINATION .............. B 3/4 7-6 3/4.7.12 DELETED 3/4.7.13 DELETED 3/4.7.14 AREA TEMPERATURE MONITORING . . . . . . .<. . . . . . . . B 3/4 7-8 3/4.8 ELECTRICAL POWER SYSTEMS '

3/4.8.1,3/4.8.2,and3/4.8.3 A.C. SOURCES, D.C. SOURCES, AND ONSITE POWLR DISTRIBUTION ............... B 3/4 8-1 3/4.8.4 ELECTRICAL EQUIPMENT PROTECTIVE DEVICES . . . . . . . . . B 3/4 8-3 3/4.9 REFUELING OPERATIONS 3/4.9.1 BORON CONCENTRATION . . . . . . . . . . . . . . . . . . . B 3/4 9-1 3/4.9.2 INSTRUMENTATION . . . . . . . . . . . . . . . . . . . . . B 3/4 9-1 3/4.9.3 DECAY TIME ....................... B 3/4 9-1 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS . . . . . . . . . . . . B 3/4 9-1 3/4.9.S COMMUNICATIONS ..................... B 3/4 9-1 3/4.9.6 REFUELING MACHINE . . . . . . . . . . . . . . . . . . . . B 3/4 9-2 3/4.9.7 CRANE TRAVEL - SPENT FUEL STORAGE AREAS . . . . . . . . . B 3/4 9-2 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION . . . . . . B 3/4 9-2 3/4.9.9 CONTAINMENT PURGE AND EXHAUST ISOLATION SYSTEM .....

B 3/4 9-@7 3/4.9.10 and 3/4.9.11 WATER LEVEL - REACTOR VESSEL AND STORAGE POOL ...................... B3/49-N 3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM . . . . . . . . . . . B 3/49-@ $ i 3/4.9.13 SPENT FUEL POOL - REACTIVITY .............. B3/49-@6 1 3/4.9.14 SPENT FUEL POOL - STORAGE PATTERN . . . . . . . . . . . . B34/9-0)9 i 3/4.10 SPECIAL TEST EXCEPTIONS /

/

3/4.10.1 SHUTDOWN MARGIN . . . . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.2 GROUP HEIGHT, INSERTION, AND POWER DISTRIBUTION LIMITS

. B 3/4 10-1 3/4.10.3 PHYSICS TESTS . . . . . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.4 REACTOR COOLANT LOOPS . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.5 POSITION INDICATION SYSTEM - SHUTDOWN . . . . . . . . . . B 3/4 10-1 F

MILLSTONE - UNIT 3 xv AmendmentNo.Jf,[9',

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December 19, 1988 q

DEFINITIONS 3 ,

CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY shall exist when:

1

a. All penetrations required to be closed during accident conditions  ;

are either:

(

1) Capable of being closed by an OPERABLE containment automatic isolation valve system, or operator action during periods when containment isolation valves may be opened under administrative control per Specification 4.6.1.la.
2) Closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed positions.
b. All equipment hatches are closed and sealed, O
c. Each air lock is in compliance with the requirements of Specification 3.6.1.3,
d. The containment leakage rates are within the limits of Specification 3.6.1.2, and
e. The sealing mechanism associated with each penetration (e.g., welds, bellows, or 0-rings) is OPERABLE.

CONTROLLED LEAKAGE 1.8 CONTROLLED LEAKAGE shall be that seal water flow supplied to the reactor coolant pump seals.

ICORE ALTERATIONS j 'D elCIC 1.9 CORE ALTERATIONS shall be the movement or manipulation of any component NHh}in the reactor pressure vessel with the vessel head removed and f kthe vessel. Suspension of CORE ALTERATIONS shall not preclude completion of jmovementofacomponenttoasafeconservativeposition. H DOSE E0VIVALENT I-131 I.10 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,

" Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I."

T - AVERAGE DISINTEGRATION ENERGY 1.11 I shall be the average (weighted in proportion to the concentration of ,c df ..

each radionuclide in the sample) of the sum of the average beta and gamma energies per disintegration (MeV/d) for the radionuclides in the sample.

MILLSTONE - UNIT 3 1-2 Amendment No.

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REFUELING OPERATIONS g 3 y jgg 3/4.9.2 INSTRUMENTATION LIMITING CONDITION FOR OPERATION 3.9.2 OIs a min o Source Range Neutron Flux Monitors shall be OPERABLE, ac with continuous visual indication in the control room and one with audible in ication in the containment and control room.

APPLICABILITY: MODE 6.

ACTION:

a. With one of the above required monitors inoperable or not operating, immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes.
b. With both of the above required monitors inoperable or not operating, determine the boron concentration of the Reactor Coolant System at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.9.2 Each Source Range Neutron Flux Monitor shall te demonstrated OPERABLE by performance of: ., jJ n a a p e. i m ti u A n

a. A CHANNEL CHECK at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, W
4. An ANALOGJEANh0PERATIONAt-TEST wii.hin 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> prior to-the initial 4-start-of-CORED tTERATIONS, and %

b[ An ANALOG CHANNEL OPERATIONAL TEST at least once per 7 days.

MILLSTONE - UNIT 3 3/4 9-2

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REFUELING OPERATIONS 0 1 I306 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION ,'

HIGH WATER LEVEL ,

LIMITING CONDITION FOR OPERATION ,

3.9.8.1 At least one residual heat removal (RHR) loop shall be OPERABLE and in operation."

APPLICABILITY: MODE 6, when the water level above the top of the reactor vessel flange is greater than or equal to 23 feet.

ACTION:

With no RHR loop OPERABLE or in operation, suspend all operations involving e 4-: ::: '- the re::ter d="my h*=+ !c:d er a reduction in boron concentration oT the Reactor Coolant Systemfand immediately initiate corrective action to return the required RHR loop to OPERABLE and operating status as soon as possible. Close all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

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SURVEILLANCE REQUIREMENTS 4.9.8.1 At least one RHR loop shall be verified in operation and circulating l reactor coolant at a flow rate of greater than or equal to 2800 gpm at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

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  • The deri gRHR loop may the perfere:nt: Ofbe removed CC"E from operation ALTERAiiCRS 4a for up to I hour per 8-hour period ,

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s MILLSTONE - UNIT 3 3/4 9-8 r;7(f

REFUELING OPERATIONS LOW WATER LEVEL M 31 }S86 LIMITING CONDITION FOR OPERATION 7

3.9.8.2 Two independent residual heat removal (RHR) loops shall be OPERABLE, and at least one RHR loop shall be in operation.O C t APPLICABILITY: MODE 6, when the water level above the top of the reactor vessel flange is less than 23 feet.

ACTION:

a. With less than the required RHR loops OPERABLE, immediately initiate corrective action to return the required RHR loops to OPERABLE status, or to establish greater than or equal to 23 feet of water above the reactor vessel flange, as soon as possible.
b. With no RHR loop in operation, suspend all operations involving a reduction in boron concentration of the Reactor Coolant System and immediately initiate corrective action to return the required RHR loop to operation. Close all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.9.8.2 At least one RHR loop shall be verified in operation and circulating reactor coolant at a flow rate of greater than or equal to 2800 gpm at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

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Prior to initial criticality, the RHR loop may be removed from operation for I up to I hour per 8-hour period during the performance of CORE ALTERATIONS in e vicinity of the reattor vessel hot legs. d f

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-1. h a r p g SAmy p 6ud , 9 N A okd h o o p ewkm s cm P en nw \ wA -bd cad ca e hWbc n ci; h RLS MILLSTONE - UNIT 3 3/4 9-9 " " " ' " '" '

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January 31, 1986 RE:UE LING 0 E R A~ ~ ONS ,

BASES 3/4.9.6 REFUEL]N3 MACHINE The OPERABILITY requirements for the refueling machine ensure that:

(3) refueling machines will be used for movement of drive rods and fuel assem- 1 blies, (2) each crane has sufficient lead capacity to lift a drive rod or fuel assem0ly, anc (3) the core internals and reactor vessel are protected from excessive lifting force in the event they are inadvertently engaged during lifting operations.

3/a 9.7 CRANE TRAVEL - SPENT FUEL STORAGE AREAS The restriction on movement of loacs in excess of the nominal weight of a fuel anc control rod assembly and associated handling tool over other fuel assentlies in the storage pool ensures that in the event this load is droppec:

(1) the activity release will be limitec to that contained in a single fuel assemtly, and (2) any possible Thisdistortion of fuelconsistent assum; tier,is in the storage racks with the will not activity result in a critical array.

release assamed in the safety analyses.

3/4 9 5 REEL.LHEATREMbvALAN: COOLANT CIRCULATION Def ek av'd he+ 8' The requirement that at les> L woe-resittuaWE is<;vslm (LT) IUcMe-frr ope-ation ensures that: (1) sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor vessel below 140*F as requirec curing the REFUELING MODE, anc (2) sufficient coolant circulation is maintainec through the core to minimi2e the ef fect of a boron dilution incident and prevent b0ron stratification.

The reovirement to have two RHR lo::s OPERABLE when there is less than 23 feet of wate- above the reactor vessel flange ensures that a single failure of the operating RHR loop will not result in a complete loss of residual heat removal capability. With the reactor vessel head removed and at least 23 feet of water above the reactor pressure vessel flange, a large heat sink is avail-able for core cooling. Thus, in the event of a failure of the operating R H D. loop, acequate time is provided to initiate emergency procedures to cool )

he core. .

3/4.9.9 CONTAINHENT PURGE AND ExHAU$i 150LAT10N SYSTEM i

The OPERASILITY of this system ensures that the containment vent and purge penetrations will be automatically isolatee upon detection of highThe OPERAB radiation levels within the containment.

required to restrict the release of radioactive saterial from the containment atm: sphere to the environment.

h MILLSTONE - UN:i 3 B 3/a 9-2

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1$f BASES D E ET [

I 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION 3/4.9.8.1 HIGH WATER LEVEL BACKGROUND The purpose of the Residual Heat Removal (RHR) System in MCDE 6 is to remove decay heat and sensible heat from the Reactor Coolant System (RCS), as required by GDC 34, to provide mixing of borated coolant and to prevent boron stratification. Heat is removed from the RCS by circulating reactor coolant through the RHR heat exchanger (s), where the heat is transferred to the Reactor Plant Component Cooling Water System. The coolant is then returned to the RCS via the RCS cold leg (s). Operation of the RHR system for normal cooldown or decay heat removal is manually accomplished from the control room.

The heat removal rate is adjusted by controlling the flow of reactor coolant through the RHR heat exchanger (s) and the bypass. Mixing of the reactor coolant is maintained by this continuous circulation of reactor coolant through the RHR system.

APPLICABLE SAFETY ANALYSES If the reactor coolant temperature is not maintained below 200*F, boiling of the reactor coolant could result. This could lead to a loss of coolant in the reactor vessel. Additionally, boiling of the reactor coolant could lead to a reduction in boron concentration in the coolant due to boron plating out on components near the areas of the boiling activity. The loss of reactor coolant and the reduction of boron concentration in the reactor coolant would eventually challenge the integrity of the fuel cladding, which is a fission

,roduct barrier. One train of the RHR system is required to be operational in n

MODE 6, with the water level 2 23 ft above the top of the reactor vessel flange to prevent this challenge. The LC0 does permit deenergizing the RHR pump for short durations, under the conditions that the boron concentration is not diluted. This conditional deenergizing of the RHR pump does not result in a challenge to the fission product barrier.

APPLICABILITY One RHR loop must be OPERABLE and in operation in MODE 6, with the water level 2 23 ft above the top of the reactor vessel flange, to provide decay heat removal. The 23 ft water level was selected because it corresponds to the 23 ft requirement established for fuel movement in LC0 3.9.10, " Water Level -

Reactor Vessel." Requirements for the RHR system in other MODES are covered by LCOs in Section 3.4, Reactor Coolant System (RCS), and Section 3.5, Emergency Core Cooling Systems (ECCS). RHR loop requirements in MODE 6 with the water level < 23 ft are located in LCO 3.9.8.2, " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level."

LIMITING CONDITIONS FOR OPERATION The requirement that at least one RHR loop be in operation ensures that:

(1) sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor vessel below 140*F as required during the REFUELING MILLSTONE - UNIT 3 B3/49-p Amendment No.

BASES 3 d E.st.T Nd 3/4.9.8.1 HIGJ1 WATER LEVEL (continued)

MODE, and (2) sufficient coolant circulation is maintained through the core to minimize the effect of a boron dilution incident and prevent stratification.

p op m g R w h p s W k e p q.de M ~5 An OPERABLE RHR loop includes an RHR pump, a heat exchanger hvalves, piping, instruments and r.ontrols to ensure an OPERABLE flow path,(nd' ;o determ1B> the low-end temperature. The flow path starts in one of the RCS hot legs and is roturned to the RCS cold legs.

The LC0 is modified by a note that allows the required operating RHR loop to be removed from service for up to I hour per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period. This permits operations such as core mapping or alterations in the vicinity of the reactor vessel hot leg nozzles and RCS to RHR isolation valve testing. During this I hour period, decay heat is removed by natural connection to the large mass of water in the refueling cavity.

ACTIONS RHR loop requirements are met by having one RHR loop OPERABLE and in operations, except as permitted in the Note to the LC0.

If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform boron concentrations. Reduced boron concentrations cannot occur by the addition of water with a lower boron concentration than that contained in the RCS because all of unborated water sources are isolated.

Reduced boron concentrations can occur by the addition of water with lower boron concentration than that contained in the RCS. Therefore, actions that result in an unplanned baron dilution shall be suspended immediately. 1 If RHR loop requirements are not met, actions shall be taken immediately to suspend loading of irradiated fuel assemblies in the core. With no forced circulation cooling, decay heat removal from the core occurs by natural convection to the heat sink provided by the water above the core. A minimum refueling water level of 23 ft above the reactor vessel flange provides an ,

adequate available heat sink. Suspending any operation that would increase i decay heat load, such as loading a fuel assembly, is a prudent action under  !

this condition.

If RHR loop requirements are not met, actions shall be initiated and continued in order to satisfy RHR loop requirements. With the unit in MODE 6 and the refueling water level ;t 23 ft above the top of the reactor vessel fl ange, corrective actions shall be initiated immediately.

If RHR loop requirements are not met, all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere must ,

be closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. With the RHR loop requirements not met, the '

potential exists for the coolant to boil and release radioactive gas to the containment atmosphere. Closing containment penetrations that are open to the outside atmosphere ensures dose limits are not exceeded.

1 MILLSTONE - UNIT 3 B3/49-f'4 Amendment No. t i

AA AEst 7 [' JQ (

BASES 3/4.9.8.1 HIGH WATER LEVEL (continued)

The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is reasonable, based on the low probability of the coolant boiling in that time.

(SURVETRAffCE RE0VIREMlRTSC Surveillance Reauirement (4.9.R.P This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. The frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient, considering the fl ow, temperature, pump control, and alarm indications available to the operator in the control room for monitoring the RHR system.

MILLSTONE - UNIT 3 B3/49-W Amendment No.

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BASES

  1. D $(

3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION 3/4.9.8.2 LOW WATER LEVEL BACKGROUND The purpose of the RHR System in MODE 6 is to remove decay heat and sensible heat from the Reactor Coolant System (RCS), as required by GDC 34, to provide mixing of borated coolant, and to prevent baron stratification. Heat is removed from the RCS by circulating reactor coolant through the RHR heat exchangers where the heat is transferred to the Component Cooling Water System. The coolant is then returned to the RCS via the RCS cold leg (s).

Operation of the RHR System for normal cooldown decay heat removal is manually accomplished from the control room. The heat removal rate is adjusted by controlling the flow of reactor coolant through the RHR heat exchanger (s) and the bypass lines. Mixing of the reactor coolant is maintained by this continuous circulation of reactor coolant through the RHR System.

APPLICABLE SAFETY ANALYSES If the reactor coolant temperature is not maintained below 200*F, boiling of the reactor coolant could result. This could lead to a loss of coolant in the reactor vessel. Additionally, boiling of the reactor coolant could lead to a reduction in boron concentration in the coolant due to the boron plating out on components near the areas of the boiling activity. The loss of reactor coolant and the reduction of baron concentration in the reactor coolant will eventually challenge the integrity of the fuel cladding, which is a fission product barrier. Two trains of the RHR System are required to be OPERABLE, and one train in operation, in order to prevent this challenge.

Limitina Conditions for Operations In MODE 6, with the wai,er level < 23 ft above the top of the reactor vessel flange, both RHR loops must be OPERABLE. Additionally, one loop of RHR must be in operation in order to provide:

a. Removal of decay heat;
b. Mixing of borated coolant to minimize the possibility of criticality; and
c. Indication of reactor cooling temperature.

The requirement to have two RHR loops OPERABLE when there is less than 23 feet of water above the reactor vessel flange ensures that a single failure of the operating RHR loop will not result in a complete loss of residual heat removal capability. With the reactor vessel head removed and at least 23 feet of water above the reactor pressure vessel flange, a large heat sink is available for core cooling. Thus, in the event of a failure of the operating RHR loop, adequate time is provided to initiate emergency procedure to cool the core.

MILLSTONE - UNIT 3 B 3/4 9-7, Amendment No.  ;

BASES

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3/4.9.8.2 LOW WATER LEVEL (continued) g y g p.,

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An OPERABLE RHR loop consists of an RHR pump, exchanger,\

piping, instruments, and controls to ensure an OPERABLE flow pathh([0CEN_

tie earinTn the low end temperature. The flow path starts in one of the RCS hot egs and is returned to the RCS cold legs.

APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to provide decay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.5, Emergency Core Cooling Systems (ECCS). RHR loop requirements in MODE 6 with the water level 2 23 ft are located in LC0 3.9.8.I, " Residual Heat Removal (RHR) and Coolant Circulation-High Water Level."

ACTIONS a. If less than the required number of RHR loops are OPERABLE, actions shall be immediately initiated and continued until the RHR loop is restored to OPERABLE status and to operation, or until 2 23 ft of water level is established above the reactor vessel fl ange. When the water level is 2 23 ft above the reactor vessel flange, the Applicability changes to that of LCO 3.9.8.1, and only one RHR loop is required to be OPERABLE and in operation. An immediate Completion Time is necessary for an operator to initiate corrective actions.

b. If no RHR loop is in operation, there will be no forced circulation to provide mixing to establish uniform boron concentrations. Reduced boron concentration cannot occur by the addition of water with a low boron concentration than that contained in the RCS, because all of the unborated water sources are isolated.

i If no RHR loop is in operation, actions shall be initiated immediately, and continued, to restore one RHR loop to operation.

Since the unit is in Actions 'a' and 'b' concurrently, the restoration of two OPERABLE RHR loops and one operating RHR loop should be accomplished expeditiously. -

If no RHR loop is in operation, all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere must be closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. With the RHR loop requirements not met, the potential exists for the coolant to boil and release radioactive gas to the containment atmosphere. Closing containment penetrations that are open to the outside atmosphere ensures that dose limits are not exceeded. ,

The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is reasonable, based on the low probability of the coolant boiling in that time. ,

t MILLSTONE - UNIT 3 83/49-jV Amendment No.

BASES dVRVEftrANCFRE0VIREMENTW - 7/3 92t Low W A

  • FA LEV E L be..k w d ) .

Surveillance Recuirement/4 M.M h "

This Surveillance demonstrates that one RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and boron stratification in the core. In addition, during operation of the RHR loop with the water level in the vicinity of the reactor vessel nozzles, the RHR pump suction requirements must be met.

s The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient, considering the flow, temperature, pump control, and alarm indications available to the operator for monitoring the RHR System in the control room. .

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MILLSTONE - UNIT 3 B 3/4 9-6 Amendment No.

l August 29, 1989 REFUELING OPERATIONS BASES 3/4.9.10 and 3/4.9.11 WsTER LEVEL - REACTOR VESSEL and STORAGE POOL The restrictions on minimum water level ensure that sufficient water depth is available to remove 99*. of the assumed 10". iodine gap activity released from the rupture of an irradiated fuel assembly. The minimum water depth is consistent with the assumptions of the safety analysis.

3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM The limitations on the Fuel N iding Exhaust Filter System ensure that all radioactive material released frw. an irradiated fuel assembly will be filtered through the HEPA filters and charcoal adsorber prior to discharge to the atmosphere. Operation of the system with the heaters operating for at least 10 continuous hours in a 31-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA filters. The OPERABILITY of this system and the resulting iodine removal capacity are r.onsistent with the assumptions of the safety analyses. ANSI N510-1980 will be used as a procedural guide for surveillance testing.

3/4.9.13 SPENT FUEL POOL - REACTIVITY H >

The limitations described by figure 3.9-1 ensure that the reactivity of {

fuel assemblies introduced into Region 11 are conservatively within the )

assurptions of the safety analysis.

Administrative controls have been developed and instituted to verify that the enrichment and burn-up limits of Figure 3.9-1 have been maintained for the fuel assembly.

3/4.9.14 SPENT FUEL POOL - STORAGE PATTERN The limitations of this specification ensure that the reactivity conditions of the Region I storage racks and spent fuel pool k,ff wiH remain less than or equal to 0.95.

The Cell Blocking Devices in the 4th location of the Region I storage racks are designed to prevent inadvertent placement and/or storage of fuel assemblies in the blocked locations. The blocked locatirn remains empty to provide the flux trap to maintain reactivity control for fuel assemblies in adjacent and diagonal locations of the STOPAGE PATTERN.

STORAGE PATTERN for the Region I storage racks will be established and expanded from the walls of the spent fuel pool per Figure 3.9-2 to ensure definition and control of the Region I/ Region 11 boundary and minimize the number of boundaries where a fuel misplacement incident can occur.

MILLSTONE - UNIT 3 B3/49,-/g AmendmentNo.[f'

4 Docket No. 50-423 B14987 Attachment 2 Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Core Alterations Definition and Refueling Operations Retyped Pages September 1994

j INDEX BASES SECTION EAGE 3/4.7.11 SEALED SOURCE CONTAMINATION .............. B 3/4 7-6 3/4.7.12 DELETED 3/4.7.13 DELETED 3/4.7.14 AREA TEMPERATURE MONITORING . . . . . . . . . . . . . . . B 3/4 7-8 3/4.8 ELECTRICAL POWER SYSTEMS 3/4.8.1, 3/4.8.2, and 3/4.8.3 A.C. SOURCES, D.C. SOURCES, AND ONSITE POWER DISTRIB'JTION ............... B 3/4 8-1 3/4.8.4 ELECTRICAL EQUIPMENT PROTECTIVE DEVICES . . . . . . . . . B 3/4 8-3 3/4.9 REFUELING OPERATIONS 3/4.9.1 BORON CONCENTRATION . . . . . . . . . . . . . . . . . . . B 3/4 9-1 3/4.9.2 INSTRUMENTATION . . . . . . . . . . . . . . . . . . . . B 3/4 9-1 3/4.9.3 DECAY TIME ....................... B 3/4 9-1 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS ............ B 3/4 9-1 3/4.9.5 COMMUNICATIONS ..................... B 3/4 9-1 3/4.9.6 REFUELING MACHINE . . . . . . . . . . . . . . . . . . . . B 3/4 9-2 3/4.9.7 CRANE TRAVEL - SPENT FUEL STORAGE AREAS ......... B 3/4 9-2 3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION , . . . . . B 3/4 9-2 3/4.9.9 CONTAINMENT PURGE AND EXHAUST ISOLATION SYSTEM ..... B 3/4 9-7 3/4.9.10 and 3/4.9.11 WATER LEVEL - REACTOR VESSEL AND STORAGE P0OL ...................... B 3/4 9-8 3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM . . . . . . . . . . . B 3/4 9-8 3/4.9.13 SPENT FUEL P0OL - REACTIVITY .............. B 3/4 9-8 3/4.9.14 SPENT FUEL POOL - STORAGE PATTERN . . . . . . . . . . . . B 34/ 9-8 3/4.10 SPECIAL TEST EXCEPTIONS 3/4.10.1 SHUTDOWN MARGIN . . . . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.2 GROUP HEIGHT, INSERTION, AND POWER DISTRIBUTION LIMITS . B 3/4 10-1 3/4.10.3 PHYSICS TESTS . . . . . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.4 REACTOR COOLANT LOOPS . . . . . . . . . . . . . . . . . . B 3/4 10-1 3/4.10.5 POSITION INDICATION SYSTEM - SHUTDOWN . . . . . . . . . . B 3/4 10-1 MILLSTONE - UNIT 3 xv Amendment No. Ef, 77, 0290 l

DEFINITIONS CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY shall exist when:

a. All penetrations required to be closed during accident conditions are either:
1) Capable of being closed by an OPERABLE containment automatic isolation valve system, or operator action during periods when containment isolation valves may be opened under administrative control per Specification 4.6.1.la.
2) Closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed positions.
b. All equipment hatches are closed and sealed,
c. Each air lock is in compliance with the requirements of Specification 3.6.1.3,
d. The containment leakage rates are within the limits of Specification 3.6.1.2, and
e. The sealing mechanism associated with each penetration (e.g., welds, bellows, or 0-rings) is OPERABLE.

CONTROLLED LEAKAGE 1.8 CONTROLLED LEAKAGE shall be that seal water flow supplied to the reactor '

coolant pump seals.

CORE ALTERATIONS 1.9 CORE ALTERATIONS shall be the movement of any fuel, sources, reactivity control components, or other components affecting reactivity within the reactor vessel with the vessel head removed and fuel in the vessel. Suspension of CORE ALTERATIONS sha'i not preclude completion of movement of a component to a safe position.

DOSE E0VIVALENT I-131 1.10 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, 1-134, 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,

" Calculation of Annual Doses to Man from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix I."

E - AVERAGE DISINTEGRATION ENERGY 1.11 E shall be the average (weighted in proportion to the concentration of each radionuclide in the sample) of the sum of the average beta and gamma energies per disintegration (MeV/d) for the radionuclides in the sample.

MILLSTONE - UNIT 3 1-2 Amendment No. 77, 0284

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I REFUELING OPERATIONS 3/4.9.2 INSTRUNENTATION LINITING CONDITION FOR OPERATION 3.9.2 Two Source Range Neutron Flux Monitors shall be OPERABLE, with continuous visual indication in the control room and one with audible indication in the containment and control room.

APPLICABILITY: MODE 6.

ACTION:

a. With one of the above required monitors inoperable or not operating, immediately suspend all operations involving CORE ALTERATIONS or  !

positive reactivity changes.

b. With both of the above required monitors inoperable or not operating, ,

determine the boron concentration of the Reactor Coolant System at  :

least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

SURVEILLANCE REQUIRENENTS i

4.9.2 Each Source Range Neutron Flux Monitor shall be demonstrated OPERABLE by performance of -

a. A CHANNEL CHECK including audible indication at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and
b. An ANALOG CHANNEL OPERATIONAL TEST at least once per 7 days. >

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MILLSTONE - UNIT 3 3/4 9-2 Amendment No.

0285

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REFUELING OPERATIONS  ;

3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION HIGH WATER LEVEL LIMITING CONDITION FOR OPERATION 3.9.8.1 At least one residual heat removal (RHR) loop shall be OPERABLE and in operation.*

APPLICABILITY: MODE 6, when the water level above the top of the reactor vessel flange is greater than or equal to 23 feet.

ACTION:

With no RHR loop OPERABLE or in operation, suspend all operations involving a l reduction in boron concentration of the Reactor Coolant System and suspend loading irradiated fuel assemblies in the core and immediately initiate corrective action to return the required RHR loop to OPERABLE and operating status as soon as possible. Close all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.9.8.1 At least one RHR loop shall be verified in operation and circulating l reactor coolant at a flow rate of greater than or equal to 2800 gpm at least i once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. j I

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  • The RHR loop may be removed from operation for up to I hour per 8-hour period, provided no operations are permitted that could cause diiution of the RCS boron concentration.

MILLSTONE - UNIT 3 3/4 9-8 Amendment No.

0200

REFUELING OPERATIONS  !

LOW WATER LEVEL ,

i LINITING CONDITION FOR OPERATION l

l 3.9.8.2 Two independent residual heat removal (RHR) loops shall be OPERABLE, and  :

at least one RHR loop shall be in operation.* i APPLICABILITY: MODE 6, when the water level above the top of the reactor [

vessel flange is less than 23 feet.  :

ACTION: l

a. With less than the required RHR loops OPERABLE, immediately initiate  !

corrective action to return the required RHR loops to OPERABLE i status, or to establish greater than or equal to 23 feet of water i above the reactor vessel flange, as soon as possible.  !

b. With no RHR loop in operation, suspend all operations involving a l reduction in boron concentration of the Reactor Coolant System and f immediately initiate corrective action to return the required RHR  !

loop to operation. Close all containment penetrations providing i direct access from the containment atmosphere to the outside  !

atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. l l

i SURVEILLANCE REQUIREMENTS j .

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4.9.8.2 At least one RHR loop shall be verified in operation and circulating reactor coolant at a flow rate of greater than or equal to 2800 gpm at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

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  • The RHR loop may be removed from operation for up to I hour per 8-hour period, provided no operations are permitted that could cause dilution of the RCS boron l concentration.

l HILLSTONE - UNIT 3 3/4 9-9 Amendment No. I c2se l

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REFUELING OPERATIONS  !

BASES 3/4.9.6 REFVELING MACHINE i The OPERABILD. requirements for the refueling machine ensure that:

(1) refueling machines will be used for movement of drive rods and fuel assem- .

blies, (2) each crane has sufficient load capacity to lift a drive rod or fuel assembly, and (3) the core internals and reactor vessel are protected from excessive lifting force in the event they are inadvertently engaged during  :

lifting operations.

3/4.9.7 CRANE TRAVEL - SPENT FVEL STORAGE AREAS The restriction on movement of loads in ' excess of the nominal weight of a fuel and control rod assembly and associated handling tool over other fuel  :

assemblies in the storage pool ensures that in the event this load is dropped:

(1) the activity release will be limited to that contained in a single fuel assembly, and (2) any possible distortion of fuel in the storage racks will not  :

result in a critical array. This assumption is consistent with the activity release assumed in the safety analyses.  !

3/4.9.8 RESIDUAL HEAT REMOVAL AND COOLANT CIRCULATION 3/4.9.8.1 HIGH WATER LEVEL BACKGROUND  :

The purpose of the Residual Heat Removal (RHR) System in MODE 6 is to remove  !

decay heat and sensible heat from the Reactor Coolant System (RCS), as required by GDC 34, to provide mixing of borated coolant and to prevent boron stratification. Heat is removed from the RCS by circulating reactor coolant i through the RHR heat exchanger (s), where the heat is transferred to.the Reactor l Plant Component Cooling Water System. The coolant is then returned to the RCS I via the RCS cold leg (s). Operation of the RHR system for normal cooldown or I decay heat removal is manually accomplished from the control room. The heat 'I removal is manually accomplished from the control room. The heat removal rate is adjusted by controlling the flow of reactor coolant through the RHR heat exchanger (s) and the bypass. Mixing of the reactor coolant is maintained by this continuous circulation of reactor coolant through the RHR system.

APPLICABLE SAFETY ANALYSES J

If the reacter coolant temperature is not maintained below 200*F, boiling of the reactor coolant could result. This could lead to a loss of coolant in the reactor vessel. Additionally, boiling of the reactor coolant could lead to a reduction in baron concentration in the coolant due to boron plating out on components near the areas of the boiling activity. The loss of reactor coolant and the reduction of boron concentration in the reactor coolant would eventually challenge the integrity of the fuel cladding, which is fission product barrier.

One train of the RHR system is required to be operational in MODE 6, with the water level 2 23 ft above the top of the reactor vessel flange to prevent this challenge. The LC0 does permit deenergizing the RHR pump for short durations, MILLSTONE - UNIT 3 B 3/4 9-2 Amendment No.

0287 I

BASES 3/4.9.8.1 HIGH WATER LEVEL (continued)-

under the conditions that the boron concentration is not diluted. This l conditional deenergizing of the RHR pump does not result in a challenge to the fission product barrier.

APPLICABILITY ,

One RHR loop must be OPERABLE and in operation in MODE 6, with the water level 2 23 ft above the top of the reactor vessel flange, to provide decay heat -

removal. The 23 ft level was selected because it corresponds to the 23 ft requirement established for fuel movement in LC0 3.9.10, " Water Level - Reactor Vessel." Requirements for the RHR system in other MODES are covered by LCOs in ,

Section 3.4, Reactor Coolant System (RCS), and Section 3.5, Emergency Core  ;

Cooling Systems (ECCS). RHR loop requirements in MODE 6 with the water level

< 23 ft are located in LC0 3.9.8.2, " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level."

J.IMITING CONDITION FOR OPERATION l

The requirement + .t at least one RHR loop be in operation ensures that:

(1) sufficient iing capacity is available to remove decay heat an maintain ,

the water in the ? actor vessel below 140'F as required during the REFUELING MODE, and (2) su. 3cient coolant circulation is maintained through the core to i minimize the effect of a boron dilution incident and prevent stratification.

An OPERABLE RHR loop includes an RHR pump, a heat exchanger, valves, piping, instruments and controls to ensure an OPERABLE flow path. An operating RHR flow path should be capable of determining the low-end temperature. The flow path starts in one of the RCS hot legs and is returned to the RCS cold legs. i The LC0 is modified by a note that allows the required operating RHR loop to be removed from service for up to I hour per 8-hour period. This permits operations such as core mapping or alterations in the vicinity of the reactor  ;

vessel hot leg nozzle and RCS to RHR isolation valve testing. During this ,

1-hour period, decay heat is removed by natural connection to the large mass of ,

water in the refueling cavity. .

ACTIONS RHR loop requirements are met by having one RHR loop OPERABLE and in operations,  !

except as permitted in the Note to the LCO.  ;

t If RHR loop requirements are not met, there will be no forced circulation to provide mixing to establish uniform baron concentrations. Reduced boron  :

concentrations cannot occur by the addition of water with a lower boron concentration than that contained in the RCS because all of unborated water sources are isolated.

l MILLSTONE - UNIT 3 B 3/4 9-3 Amendment No.  !

0287 l

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BASES 3/4.9.8.1 HIGH WATER LEVEL (continuedl I

Reduced boron concentrations can occur by the addition of water with lower boron '

concentration that contained in the RCS. Therefore, actions that result in an unplanned boron dilution shall be suspended immediately. j If RHR loop requirements are not met, actions shall be taken immediately to suspend loading of irradiated fuel assemblies in the core. With no forced '

circulation cooling, decay heat removal from the core occurs by natural ,

convection to the heat sink provided by the water above the core. A minimum refueling water level of 23 ft above the reactor vessel flange provides an adequate available heat sink. Suspending any operation that would increase  ;

decay heat load, such as loading a fuel assembly, is a prudent action under this ,

condition. '

i' If RHR loop requirements are not met, actions shall be initiated and continued in order to satisfy RHR loop requirements. With the unit in MODE 6 and the refueling water level 2 23 ft above the top of the reactor vessel flange, corrective actions shall be initiated immediately. '

If RHR loop requirements are not met, all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere must be closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. With the RHR loop requirements not met, the potential erists for the coolant to boil and release radioactive. gas to the containment '

atmosphere. Closing containment penetrations that are open to the outside  :

atmosphere ensures dose limits are not exceeded. '

The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is reasonable, based on the low probability of l the coolant boiling in that time.

t Surveillance Reauirement l This Surveillance demonstrates that the RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to ,

provide sufficient decay heat removal capability and to prevent thermal and  !

boron stratification in the core. The frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient,  !

considering the flow, temperature, pump control, and alarm indications available i to the operator in the control room for monitoring the RHR system.  !

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MILLSTONE - UNIT 3 8 3/4 9-4 Amendment No. I 0287

BASES 3/4.9.8.2 LOW WATER LEVEL BACKGROUND The purpose of the RHR System in MODE 6 is to remove decay heat and sensible heat from the Reactor Coolant System (RCS), as 6 equired by GDC 34, to provide mixing of borated coolant, and to prevent boron stratification. Heat is removed from the RCS by circulating reactor coolant through the RHR heat exchangers where the heat is transferred to the Component Cooling Water System. The coolant is then returned to the RCS via the RCS cold leg (s). Operation of the RHR System for normal cooldown decay heat removal is manually accomplished from the control room. The heat removal rate is adjusted by controlling the flow of reactor coolant through the RHR heat exchanger (s) and the bypass lines. Mixing of the reactor coolant is maintained by this continuous circulation of reactor coolant through the RHR system.

APPLICABLE SAFETY ANALYSES If the reactor coolant temperature is not maintained below 200*F, boiling of the reactor coolant could result. This could lead to a loss of coolant in the reactor vessel. Additionally, boiling of the reactor coolant could lead to a reduction in boron concentration in the coolant due to the boron plating out on components near the areas of the boiling activity. The loss of reactor coolant and the reduction of boron concentration in the reactor coolant will eventually challenge the integrity of the fuel cladding, which is a fission product barrier. Two trains of the RHR System are required to be OPERABLE, and one train in operation, in order to prevent this challenge.

LIMITING CONDITION FOR OPERATION In MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, both RHR loops must be OPERABLE. Additionally, one loop of RHR must be in operation in order to provide:

a. Removal of decay heat;
b. Mixing of borated coolant to minimize the possibility of criticality; and
c. Indication of reactor cooling temperature.

The requirement to have two RHR loops OPERABLE when there is less than 23 feet of water above the reactor vessel flange ensures that a single failure of the operating RHR loop will not result in a complete loss of residual beat removal capability. With the reactor vessel head removed and at least 23 feet of water above the reactor pressure vessel flange, a large heat sink is available for core cooling. Thus, in the event of a failure of the operating RHR loop, adequate time is provided to initiate emergency procedure to cool the core.

MILLSTONE - UNIT 3 8 3/4 9-5 Amendment No.

0287

I BASES 3/4.9.8.2 LOW WATER LEVEL (continued) l' An OPERABLE RHR loop consists of an RHR pump, a heat exchanger, valves, piping, instruments, and controls to ensure an OPERABLE flow path. An operating RHR flow path should be capable of determining the low end temperature. The flow path starts in one of the RCS hot legs and is returned to the RCS cold legs.

APPLICABILITY Two RHR loops are required to be OPERABLE, and one RHR loop must be in operation in MODE 6, with the water level < 23 ft above the top of the reactor vessel flange, to provide decay heat removal. Requirements for the RHR System in other MODES are covered by LCOs in Section 3.5, Emergency Core Cooling Systems (ECCS).

RHR loop requirements in MODE 6 with the water level 2 23 ft are located in LC0 3.9.8.1, " Residual Removal (RHR) AND Coolant Circulation-High Water Level."

ACTIONS

a. If less that the required number of RHR loops are OPERABLE, actions shall be immediately initiated and continued until the RHR loop is restored to l OPERABLE status and to operation, or until 2 23 ft of water level is established above the reactor vessel flange. When the water level is 2 23 ft above the reactor vessel flange, the Applicability changes to that of LC0 3.9.8.1, and only one RHR loop is required to be OPERABLE and in operation. An immediate Completion Time is necessary for an operator to l initiate correct've action.
b. If no RHR loop is in operation. there will be no forced circulation to provide mixing to establish uniform boron concentrations. Reduced boron concentrations cannot occur by the addition of water with a low boron concentration than that contained in the RCS, because all of the unborated water sources are isolated.

If no RHR loop is in operation, actions shall be initiated immediately, and continued, to restore one RHR loop to operation. Since the unit is in Actions

'a' and 'b' concurrently, the restoration of two OPERABLE RHR loops and one operating RHR loop should be accomplished expeditiously.

If no RHR loop is in operation, all containment penetrations providing direct access from the containment atmosphere to the outside atmosphere must be closed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. With the RHR loop requirements not met, the potential exists for the coolant to boil and release radioactive gas to the containment atmosphere. Closing containment penetrations that are open to the outside atmosphere ensures that dose limits are not exceeded.

The Completion Time of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is reasonable, based on the low probability of the coolant boiling in that time.

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l MILLSTONE - UNIT 3 B 3/4 9-6 Amendment No.  ;

0287

BASES ,

V Jh-thz L" WMGlhEkCr*hmil Surveillance Reauirement This Surveillance demonstrates that one RHR loop is in operation and circulating reactor coolant. The flow rate is determined by the flow rate necessary to provide sufficient decay heat removal capability and to prevent thermal and i boron stratification in the core. In addition, during operation of the RHR loop l with the water level in the vicinity of the reactor vessel nozzles, the RHR pump I suction requirements must be met. The Frequency of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is sufficient,  !

considering the flow, temperature, pump control, and alarm indications available to the operator for monitoring the RHR System in the control room.

3/4.9.9 CONTAINMENT PURGE AND EXHAUST ISOLATION SYSTEM The OPERABILITY of this system ensures that the containment vent and purge penetrations will be automatically isolated upon detection of high radiation levels within the containment. The OPERABILITY of this system is required to restrict the release of radioactive material from the containment atmosphere to the environment. I c

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MILLSTONE - UNIT 3 8 3/4 9-7 Amendment No.

0287

REFUELING OPERATIONS RASFR 3/4.9.10 and 3/4.9.11 WATER LEVEL - REACTOR VESSEL and STORAGE P00L -

The restrictions on minimum water level ensure that sufficient water depth is available to remove 99% of the assumed 10% iodine gap activity released from the rupture of an irradiated fuel assembly. The minimum water depth is consistent with the assumptions of the safety analysis.

3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM The limitations on the Fuel Building Exhaust Filter System ensure that all radioactive material released from an irradiated fuel assembly will be filtered through the HEPA filters and charcoal adsorber prior to discharge to the atmosphere. Operation of the system with the heaters operating for at least 10 continuous hours in a 31-day period is sufficient to reduce the buildup of moisture on the adsorbers and HEPA filters. The OPERABILITY of this system and the resulting iodine removal capacity are consistent with the assumptions '

of the safety analyses. ANSI N510-1980 will be used as a procedural guide for surveillance testing.

3/4.9.13 SPENT FUEL P00L - REACTIVITY The limitations described by Figure 3.9-1 ensure that the reactivity of fuel assemblies introduced into Region II are conservatively within the assumptions of the safety analysis.

Administrative controls have been developed and instituted to verify that the enrichment and burn-up limits of Figure 3.9-1 have been maintained for the fuel assembly.

3/4.9.14 SPENT FUEL P00L - STORAGE PATTERN The limitations of this specification ensure that the reactivity conditions of the Region I storage racks and spent fuel pool k,,, will remain less than or equal to 0.95.

  • The Cell Blocking Devices in the 4th location of the Region I storage racks are designed to prevent inadvertent placement and/or storage of fuel assemblies in the blocked locations. The blocked location remains empty to provide the flux trap to maintain reactivity cc7 trol for fuel assemblies in adjacent and diagonal locations of the STORAGE PATTERN. ,

STORAGE PATTERN for the Region I storage racks will be established and l expanded from the walls of the spent fuel pool per Figure 3.9-2 to ensure definition and control of the Region I/ Region II boundary and minimize the .

number of boundaries where a fuel misplacement incident can occur.

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l HILLSTONE - UNIT 3 B 3/4 9-8 Amendment No. 77, ,

0287

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