ML20082K394

Amend 107 to License NPF-49,revising TSs to Clarify Definition of Core Alterations Change Verbiage in Lcd Addressing Refueling Operations

ML20082K394
Person / Time
Site:	Millstone
Issue date:	04/12/1995
From:	Mckee P Office of Nuclear Reactor Regulation
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ML20082K397	List: ML20082K394
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NUDOCS 9504190267
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I o-pARfCp Ag UNITED STATES NUCLEAR REGULATORY COMMISSION E

f WASHINGTON, D.C. 20565-0001

%,..... p NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.

DOCKET NO. 50-423 MILLSTONE NUCLEAR POWER STATION. UNIT NO. 3 l

AMENDMENT TO FACILITY OPERATING LICENSE I

Amendment No. 107 i

License No. NPF-49 1.

The Nuclear Regulatory Conaission (the Comission) has found that:

A.

The application for amendment by Northeast Nuclear Energy Company, et al. (the licensee)1 dated September 30, 1994, as supplemented February 13, 1995, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Comission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

9504190267 950412 PDR ADOCK 05000423 p

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2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-49 is hereby

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amended to read as follows:

(2)

Technical Specifications

.The Technical Specifications contained in Appendix A, as revised through Amendment No.107

, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto are j

hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

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This license amendment is effective as of the date of its issuance, to be implemented within 30 days of issuance.

i FOR THE NUCLEAR REGULATORY COMMISSION

/

Phillip F. McKee, Director j

Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation 4

Attachment:

Changes to the Technical l

Specifications i

i Date of Issuance:

April 12, 1995 i

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j ATTACHMENT TO LICENSE AMENDMENT NO.107 l

FACILITY OPERATING LICENSE NO. NPF-49 DOCKET NO. 50-423 Replace the following pages of the Appendix A Technical Specifications with j

the attached pages. The revised pages are identified by amendment number and contain vertical lines indicating the areas of change.

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Remove Insert

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4 XV XV 1-2 1-2 1

3/4 9-2 3/4 9-2 3/4 9-8 3/4 9-8 3/4 9-9 3/4 9-9 j

B 3/4 9-2 B 3/4 9-2 thru 3/4 9-7 8 3/4 9-3 8 3/4 9-8 3

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,o INDEX l

l BASES SECTION EME l

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 l

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 DISTRIBUTION B 3/4 8-1 3/4.8.4 ELECTRICAL EQUIPMENT PROTECTIVE DEVICES.........

B 3/4 8-3 i

3/4.9 REFUELING OPERATIONS l

3/4.9.1 BORON CONCENTRATION...................

B 3/4 9-1 l

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 l

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 B3/49-7 3/4.9.10 and 3/4.9.11 WATER LEVEL - REACTOR VESSEL AND STORAGE POOL B 3/4 9-8 3/4.9.12 FUEL BUILDING EXHAUST FILTER SYSTEM...........

B 3/4 9-8 l

3/4.9.13 SPENT FUEL POOL - 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 xy Amendment No. pp, pp.107 0290

DEFINITIONS CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY shall exist when:

a.

All penetrations recuired to be closed during accident conditions I

l are either:

1)

Capable of being t 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 fl anges, 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 t.he requirements of Specification 3.6.1.3, d.

The containment leakage rates are within the limits of Specification 3.6.1.2, and The sealing mechanism associated with each penetration (e.g., welds, e.

j 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.

1 CORE ALTERATIONS l

l 1.9 CORE ALTERATIONS shall be the movement of any fuel, sources, reactivity i

control components, or other components affecting reactivity within the reactor i

vessel with the vessel head removed and fuel in the vessel. Suspension of CORE ALTERATIONS shall not preclude completion of movement of a component to a safe position.

DOSE EOUIVALENT 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, 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."

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 l

l energies per disintegration (MeV/d) for the radionuclides in the sample.

MILLSTONE - UNIT 3 1-2 Amendment No. jfp.107 0284

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REFUELING OPERATIONS 3/4.9.2 INSTRUNENTATION LIMITING COMITION FOR OPERATION i

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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 j

containment and control room.

APPLICABILITY:

MODE 6.

ACTION:

4 a.

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

positive reactivity changes.

j b.

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

determine the boron concentration of the Reactor Coolant System at I

j 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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i S9RVEILLANCE REQUIREMENTS i

4.9.2 Each Source Range Neutron Flux Nonitor shall be demonstrated OPERABLE by performance of:

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a.

A CHANNEL CHECK including audible counts at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, i

j b.

An ANALOG CHANNEL OPERATIONAL TEST within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> prior to the initial start of CORE ALIERATIONS, and j

c.

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

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NILLSTONE - UNIT 3 3/4 9-2 Amendment No.107 l

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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:

l With no RHR loop OPERABLE or in operation, suspend all operations involving a 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 l

4.9.8.1 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 l

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, l

provided no operations are permitted that could cause dilution of the RCS baron l

concentration.

MILLSTONE - UNIT 3 3/4 9-8 Amendment No.10) 0298

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i REFUELING OPERATIONS LOW WATER LEVEL LINITING CONDITION FOR OPERATION 3.9.8.2 Two independent residual heat removal (RHR) loops shall be OPERABLE, and at least one RHR loop shall be in operation.*

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 OPJRABLE, 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 contair. ment 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 REQUIRENENTS 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 concentration.

NILLSTONE - UNIT 3 3/4 9-9 Amendment No.107 0295

REFUELING OPERATIONS BASES i

j 3/4.9.6 REFUELING MACHINE i

The OPERABILITY requirements for the refueling machine ensure that:

(1) refueling machines will be used for movement of drive rods and fuel assem-i blies, (2) each crane has sufficient load capacity to lift a drive rod or fuel j

assembly, and (3) the core internals and reactor vessel are protected from excessive lifting force in the event they are inadvertently engaged during i

j lifting operations.

j 3/4.9.7 CRANE TRAVEL - SPENT FUEL STORAGE AREAS l

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 4

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 l

assembly, and (2) any possible distortion of fuel in the storage racks will not j

result in a critical array. This assumption is consistent with the activity j

release assumed in the safety analyses.

1 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 i

j stratification. Heat is removed from the RCS by circulating reactor coolant i

4 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 i

j decay heat removal is manually accomplished from the control room. The heat removal is manually accomplished from the control room. The heat removal rate is adjusted b exchanger (s) y controlling the flow of reactor coolant through the RHR heat and the bypass. Mixing of the reactor coolant is maintained by j

this continuous circulation of reactor coolant through the RHR system.

j APPLICABLE SAFETY ANALYSES i

l If the reactor coolant temperature is not maintained below 200*F, boiling of the 1

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 i

reduction in boron concentration in the coolant due to boron plating out on i

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.

l One train of the RHR system is required to be operational in MODE 6, with the-i water level 2 23 ft above the top of the reactor vessel flange to prevent this i

challenge. The LCO does permit deenergizing the RHR pump for short durations, 1

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i NILLSTONE - UNIT 3 B 3/4 9-2 Amendment No.107 oasi t

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3/4.9.8.1 HIGH WATER LEVEL (continued) 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 l

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 LCO 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 CONDITION 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 an maintain the water in the reactor vessel below 140*F as required during the REFUELING MODE, and (2) sufficient coolant circulation is maintained through the core to 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.

The LCO is modified by a note that allows the required operating RHR loop to be i

removed from service for up to I hour per 8-hour period. This permits l

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 f

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

water in the refueling cavity.

i ACTIONS l

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

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.

t MILLSTONE - UNIT 3 8 3/4 9-3 Amendment No.107 l

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3/4.9.8.1 HIGH WATER LEVEL (continued) i Reduced boron conc ~entrations can occur by the addition of water with lower boron concentration that contained in the RCS. Therefore, actions that result in an i

j unplanned boron dilution shall be suspended immediately.

l If RHR loop requirements are not met, actions shall be taken immediately to I

suspend loading of irradiated fuel assemblies.in the core. With no forced circulation cocling, decay heat removal from the core occurs by natural 3

convection to the heat sink provided by the water above the core. A minimus j

refueling water. level of 23 ft above the reactor vessel flange provides an j

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 i

j condition.

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If RHR loop requirements are not met, actions shall be initiated and continued i

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, l

corrective actions shall be initiated immediately, i

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If RHR loop requirements are not met, all containment penetrations providing i

j 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 j

exists for the coolant to boil and release radioactive gas to the containment i

j atmosphere. Closing containment penetrations that are open to the outside atmosphere ensures dose limits are not exceeded.

i 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 i

the coolant boiling in that time, i

j surveillance Reauirement This Surveillance demonstrates that the RHR loop is in operation and circulating i

reactor coolant.

The flow rate is determined by the flow rate necessary to

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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, j

considering the flow, temperature, pump control, and alarm indications available j

to the operator in the control room for monitoring the RHR system.

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1 MILLSTONE - UNIT 3 8 3/4 9-4 Amendment No.107 l

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f, BASES 3-3/4.9.8.2 LOW WATER LEVEL BACKGROUND I

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'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 i

mixing of borated coolant, and to prevent boron stratification. Heat is removed i

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-3 RHR System for normal cooldown decay heat removal is manually accomplished from -

l 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 l

of the reactor coolant is maintained by this continuous circulation of reactor i

j coolant through the RHR system.

APPLICABLE SAFETY ANALYSES If the reactor coolant temperature is not maintained below 200'F, boiling of the i

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 j

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.

j LIMITING CONDITION FOR OPERATION 1

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; 4

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Mixing of borated coolant to minimize the possibility of criticality; and e

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Indication of reactor cooling temperature.

I 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 i

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.

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MILLSTONE - UNIT 3 8 3/4 9-5 Amendment No.107 q

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BASES 3/4.9.8.2 LOW WATER LEVEL (continued)

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 LCO 3.9.8.1, " Residual Removal (RHR) AND Coolant Circulation-High Water Level."

i ACTIONS 1

If less that the required number of RHR loops are OPERABLE, actions shall a.

be immediately %itiated and continued until the RHR loop is restored to OPERABLE status ind to operation, or until 2 23 ft of water level is

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established above 1.ini reactor vessel flange. When the water level is j

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 i

operation. An immediate Completion Time is necessary for an operator to initiate corrective action.

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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.

1 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.

i MILLSTONE - UNIT 3 8 3/4 9-6 Amendment No.107 0287 J,.

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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 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. 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 i

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.

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l NILLSTONE - UNIT 3 B 3/4 9-7 Amendment No.107 0287

REFUELING OPERATIONS natFC l

3/4.9.10 and 3/4.9.11 WATER 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 limitat' ions 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 i

moisture on the adsorbers and HEPA filters.

The OPERABILITY of this system and the resulting iodine removal capacity are consisfent with the assumptions of the safety analyses.

ANSI N510-1980 will be used as a procedural guide J

for surveillance testing.

3/4.9.13 SPENT FUEL POOL - 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 POOL - STORAGE PATTERN The limitations of this specification ensure that the reactivity conditions of the Region I storage racks and spent fuel pool k,n 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 control for fuel assemblies in l

adjacent and diagonal locations of the STORAGE PATTERN.

STORAGE PATTERN for the Region I storage - racks will be established and expanded from the walls of the spent fuel pool per Fir;ure 3.9-2 to ensure dracition and control of the Region I/ Region ~lf" boundary and minimize the number of boundaries where a fuel misplacement incident can occur.

MILLSTONE - UNIT 3 B 3/4 9-8 Amendment No. M,107 0287

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