Text

Proposed Tech Specs Re Main Steam Line Isolation Valves
	ML20085L190
Person / Time
Site:	Millstone
Issue date:	06/20/1995
From:	; NORTHEAST NUCLEAR ENERGY CO.
To:	;
Shared Package
ML20085L189	List: B15241, Application for Amend to License NPF-49,relocating Requirements of Spec 3.6.6 for Main Steam Line Isolation Valves (Msivs) to Spec 3.7.1.5, Msivs; ML20085L190;
References
	NUDOCS 9506280353
	Download: ML20085L190 (22)
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k Docket No. 50-423 i B15241 l li l

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Attachment 1 !

i Millstone Nuclear Power Station, Unit No. 3 I Proposed Revision to Technical Specifications [

Main Steam Line Isolation Valves (

Marked-up Pages :

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June 1995 9506280353 950620 PDR ADDCK 05000423 P PDR

, g May 26,1995 BASES

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SECTION P. AGE TABLEB3/4.4-1 REACTOR VESSEL FRACTURE TOUGHNESS PROPERTIES . . B 3/4 4-9 FIGURE B 3/4.4-1 FAST NEUTRON FLUENCE (E>1MeV) AS A FUNCTION OF FULL POWER SERVICE LIFE . . . . . . . . . . . . . . . . . B 3/4 4-10 3/4.4.10 STRUCTURAL INTEGRITY . . . . . . . . . . . . . . . . . . B 3/4 4-15 3/4.4.11 REACTOR COOLANT SYSTEM VENTS . . . . . . . . . . . . . . B 3/4 4-15 i

F4. 5 EMERGENCY CORE COOLING SYSTEMS 3/4.5.1 ACCUMULATcRS . . . . . . . . . . . . . . . . . . . . . . B 3/4 5-1 3/4.5.2 and3/4.5.3 ECCS SUBSYSTEMS . . . . . . . . . . . . . . . B 3/4 5-1 3/4.5.4 REFUELING WATER STORAGE TANK . . . . . . . . . . . . . . B 3/4 5-2 3/4.5.5 pH TRIS 0DIUM PH0SPHATE STORAGE BASKETS . . . . . . . . . B 3/4 5-3 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT . . . . . . . . . . . . . . . . . . . B 3/4 6-1 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS . . . . . . . . . . B 3/4 6-2 3/4.6.3 CONTAINMENT ISOLATION VALVES . . . . . . . . . . . . . .,B 3/4 6-3 3/4.6.4 COMBUSTIBLE GAS CONTROL . . . . . . . . . . . . . . . . . B 3/4 6-3 3/4.6.5 SUBATMOSPHERIC PRESSURE CONTROL SYSTEM . . . . . . . . . B 3/4 6-3b 3/4.6.6 SECONDARY CONTAINMENT . . . . . . ... . . . . . . . . . . B 3/4 6-4 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE . . . . . . . . . . . . . . . . . . . . . . B 3/4 7-1 3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION . . . . . B 3/4 7 8 i

3/4.7.3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM . . . . . . B 3/4 747 3/4.7.4 SERVICE WATER SYSTEM ..................B3/47-(T 3/4.7.5 ULTIMATE HEAT SINK . . . . . . . . . . . . . . . . . . . B 3/4 7-D #6 3/4.7.6 FLOOD PROTECTION . . . . . . . . . . . . . . . . . . . . B 3/4 7- h 6 3/4.7.7 CONTROL ROOM EMERGENCY VENTILATION SYSTEM . . . . . . . . B 3/4 7 M 3/4.7.B CONTROL ROOM ENVELOPE PRESSURIZATION SYSTEM . . . . . .

3/4.7.9 AUXILIARY BUILDING FILTER SYSTEM . . . . . . . . . . . . B 3/4 7-@r 3 3/4.7.10 SNUBBERS . . . . . . . . . . . . . . . . .'. . . . . . . B 3/4 7 h 3 RILLSTONE - l#11T 3 xiv Amendment No. pp. 77,115 esis

- April 12,1995

. EST,X BASES

{

SECTION PEE ,

3/4.7.11 SEALED SOURCE CONTAMINATION . . . .. ...... .... B 3/4 7 3/4.7.12 DELETED 3/4.7.13 DELETED 3/4.7.14 AREA TEMPERATURE MONITORING . . . . . . . . . . . . . . . B 3/4 7 .

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 POWER DISTRIBUTION . .. . . .. ........ B 3/4 8-1 ,

3/4.8.4 ELECTRICAL EQUIPMENT PROTECTIVE DEVICES . . . . . . . . . B3/48-3 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 COMUNICATIONS ..................... 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 _. . . . . . B3/49-2 .

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 ...................... 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 POOL - REACTIVITY . . . . . ......... B 3/4 9-8 3/4.9.14 SPENT FUEL POOL - STORAGE PATTERN . . . . . . . . . . . . B 3/4 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 NILLSTONE - WIT 3 xy Amendment No. pp, pp, Jpp, 107 meo

[ CONTa1NMENT SYSTEMS P

. 2/4.6.3 CONTAfMMENT ISOLATION VALVE 5 LIMITING CONDITION FOR OPERATION n

1 3.6.3 The containment isolation valves shall be OPERABLE with isolation times l 1ess than or equal to the required isolation times. J l

l APPtitABILITY: MODES 1, 2, 3, and 4.

E,U2$:

With one or more of the isolation valve (s) inoperable, maintain at least one isolation valve OPERABLE in each affected penetration that is open and: :

a. Restore the inoperable valve (s) to OPERABLE status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , or

b. Isolate each affected penetration within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by use of at least one deactivated automatic valve secured in the isolation position, or

c. Isolate each affected penetration within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by use of at least one closed manual valve or blind flange; or

d. Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following M hours.

SURVE!LLANCE REQUIRENENTS 4.6.3.1 Each isolation valve shall be demonstrated OPERABLhier to returning the valve to service after maintenance, repair, or replacement work I

L is performed on the valve or its associated actuator, control, or power circuit by performance of a cycling test and verification of isolation time. 1 1

4.6.3.2 Each isolation valve shall be demonstrated OPERABLE during the COLD 5HUTDOWN or REFUELING MDDE at least once per 28 months by:

a. Verifying that on a Phase 'A' Isolation test signal, each Phase 'A" isolation valve actuates to its isolation position,

b. Verifying that on a Phase '8' Isolation test signal, each Phase "B" isolation valve actuates to its isolation position, and

c. Verifying that on a Containment High Radiatit,n test signal, each purge supply and exhaust isolation valve actuates to its isolation position.

4.6.3.3 The isolation time of each power operated or automatic valve shall be determined to be within its limit when tested pursuant to Specification 4.0.5. 1 Ns W '

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The provisions of3 5pecification 4.or+ are not applicable for spin steam line isolation valves w y % ".00

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. PLANT SYSTEMS January 10, 1995 IRAIN STEAM LINE ISOLATION VALVES E LIMITING CONDITION FOR OPERATION 3.7.1.5 Each main steam line isolation valve (MSIV) shall be OPERABLE.

APPLICABILITY: MODE [1,l2,3,and41 aw e4 M ava c\ose 4 D N 3/ awA + excap

ACTION: o.w d cle gehtvalre 4 .

MODE 1:

With one MSIV inoperable Fut opein POWER OPERATION may continue provided the inoperable vaive is restored to OPERABLE status withinp t 8 --Ohours; otherwise be in L HOT 51Anumi w unin sne neu 6 nuurs miu1 on nui snuipuun witnin Ine following 6 hourM rooDE 2. va\%0

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With one(MSIbynoper le,subsequentherationinMODE2),or3,or4may proceed provided the isolation valv@t= =untunen closed / Otherwise, be ,

J in HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in D SHUTDOWN wi g *the** L M#*

following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months . 5e. pava +4. c4wd;4m En le cittaw

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SURVEILLANCE REQUIREMENTS , 4.7.1.5.1 Each MSIV shall be demonstrated OPERABLE by verifying full closure within 10 seconds in Modes 1, 2, and 3 when tested pursuant to Specification i 4.0.5. The provis ons of Specification 4.0.4 are not applicable for entry into l MODE 3. ,, , ,, ,,q g ..,. sim wk&e d sch.,4 m a t S**l' 4.7.1.5.2 Each MSIV shall be demonstrated OPERABLE by verifying full closure within 120 seconds.in Mode 4 when tested pursuant to Specification 4.0.5. The l provisions of Speci ication 4.0.4 are not applicable for entry into MODE 4.

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M!gL5 TONE-UNIT 3 3/4 7-9 AmendmentNo.(J.77.///

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PLANT SYSTEMS JAN 31 1986 BASES' 3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES pg h'

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The 0P5 ABILITY of the main steam line isolatiorry ves ensures that no more than one steam generator will blow down in the event of a steam line rupture. This restriction is required to: (1) minimize the positive reac-tivity effects of the Reactor Coolant System cooldown associated with the blowdown, and (2) limit the pressure rise within containment in the event the steam line rupture occurs within containment. The OPERABILITY of the main steam isolation valves within the closure times of the Surveillance Require-ments are consistent with the assumptions used in the safety analyses. y L _

3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION The limitation on steam generator pressure and temperature ensures that l the pressure-induced stresses in the steam generators do not exceed the maximum allowable fracture toughness stress limits. The limitations of 70*F and 200 psig are based on a steam generator RTNDT of 60'F and are sufficient to prevent brittle fracture 3/4.7.3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM l

' The OPERABILITY of the Reactor Plant Component Cooling Water System ensures :

that sufficient cooling capacity is available for continuedThe operation of safety-redundant cooling related equipment during normal and accident conditions.

capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety analyses.

i 3/4.7.4 SERVICE WATER SYSTEM The OPERABILITY of the Service Water System ensures that sufficient cooling capacity is available for continued operation of safety-related equip-ment during normal and accident conditions. The redundant cooling capacity of ,

this system, assuming a single failure, is con'sistent with the assumptions used in the safety analyses.

3/4.7.5 ULTIMATE HEAT SINK J The limitation on the ultimate heat sink temperature ensures that cooling water at less than the design temperature limit is available to either: f I

(1) provide normal cooldown of the facility or (2) mitigate the effects of accident conditions within acceptable limits.

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MILLSTONE - UNIT 3 B 3/4 7-3 CM7

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3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES BACKGROUND The main steam line isolation valves (MSIVs) isolate steam flow from the -

secondary side of the steam generators following a high energy line break ;

(HELB). MSIV closure terminates flow from the unaffected (intact) steam i generators. i One MSIV, is located in each main steam line outside, but close to, !

containment. The MSIVs are downstream from the main steam safety valves l (MSSVs) and auxiliary feedwater (AFW) pump turbine steam supply, to prevent MSSV and AFW isolation from the steam generators by MSIV closure. Closing the MSIVs isolates each steam generator from the others, and isolates the turbine,

. Steam Bypass System, and other auxiliary steam supplies from the steam i generators. j The MSIVs close on a main steam isolation signal generated by low steam j generator pressure, high containment pressure, or steam line pressure negative i rate (high). The MSIVs fail closed on loss of control or actuation power. ;

Each MSIV has an MSIV bypass valve. Although these bypass valves are normally closed, they receive the same emergency closure signal as do their associated MSIVs. The MSIVs may also be actuated manually.

A description of the MSIVs is found in the FSAR, Section 10.3.

APPLICABLE SAFETY ANALYSIS (

The design basis of the MSIVs is established by.the containment analysis for the large steam line break (SLB) inside containment, discussed in the FSAR, 1 Section 6.2. It is also affected by the accident analysis of the SLB events !

presented in the FSAR, Section 15.I.5. The design precludes the blowdown of more than one steam generator, assuming a single active component failure (e.g., the failure of one MSIV to close on demand).

The limiting temperature case for the containment analysis is the SLB inside containment, with a loss of offsite power following turbine trip, and failure of the MSIV on the affected steam generator to_close. At hot zero power, the steam generator inventory and temperature are at their maximum, maximizing the analyzed mass and energy release to the containment. Due to reverse flow and failure of the MSIV to close, the additional mass and energy in the steam headers downstream from the other MSIV contribute to the total release. With the most reactive rod cluster control assembly assumed stuck in the fully withdrawn position, there is an increased possibility that the core will become critical and return to power. The reactor is ultimately shut down by the boric acid injection delivered by the Emergency Core Cooling System.

The accident analysis compares several different SLB events against different acceptance criteria. The large SLB outside containment upstream of the MSIVs is limiting for offsite dose, although a break in this short section of main !

steam header has a very low probability. The large SLB upstream of the MSIV

Page 2 of 4 Insert A to Pace B 3/4 7-3 L.

at hot zero power is the limiting case for a post trip return to power. The analysis . includes scenarios -with offsite -power available and with a loss of -

offsite power following turbine trip. With offsite power available, the reactor coolant pumps continue to circulate coolant through the steam generators, maximizing the Reactor Coolant System cooldown. . With a loss of -

offsite power, the response of mitigating systems ' is. delayed. Significant single failures considered include failure of an MSIV to close.

The MSIVs serve only a safety function and remain open during power operation.

These valves operate under the following situations:

j

a. An HELB inside containment. In order to maximize the mass and energy I release into containment, the analysis assumes that the MSIV in the affected steam generator remains open. For this accident scenario, steam is discharged into containment from all steam generators until the remaining MSIVs close. After MSIV closure, steam is discharged into containment only from the affected steam generator and from the residual steam in the main steam header downstream of the closed MSIVs in the unaffected loops. Closure of the MSIVs isolates the break from the unaffected steam generators.

b. A break outside of containment and upstream from the MSIVs is not a containment pressurization concern. The uncontrolled blowdown of more than one steam generator must be prevented to limit -the potential for uncontrolled RCS cooldown and positive reactivity addition. Closure of the MSIVs isolates the break and limits the blowdown to a single steam generator.

c. A break downstream of the MSIVs will be isolated by the closure of the MSIVs.

d. Following a steam generator tube rupture, closure of the MSIVs isolates the ruptured steam generator from the intact steam generators. In addition to minimizing radiological releases, this enables the operator to maintain the pressure of the steara generator with the ruptured tube below the MSSV setpoints, a necessary step toward isolating the flow through the rupture.

e. The MSIVs are also utilized during other events, such as a feedwater line break. This event is less limiting so far as MSIV OPERABILITY is concerned.

J LCD This LCO requires that four MSIVs in the steam lines be OPERABLE. The MSIVs are considered OPERABLE when the isolation times are within limits, and they close on an isolation actuation signal.

This LCO provides assurance that the MSIVs will perform their design safety function to mitigate the consequences of accidents that could result in offsite exposures comparable to the IOCFRIOD li;its or the NRC Staff approved I licensing basis.

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I APPLICABILITY The MSIVs must be OPERABLE in MODE I and in MODES 2 and 3, except when closed and deactivated when there is significant mass and energy in the RCS and steam generators. When the MSIVs are closed, they are already performing the safety function.

In MODE 4, even though steam generator energy is low, the MSIVs must be operable in MODE 4 except when closed and deactivated.

I In MODE 5 or 6, the steam generators do not contain much energy because their temperature is below the boiling point of water; therefore, the MSIVs are not required for isolation of potential high energy secondary system pipe breaks ,

in these MODES. 1 ACTIONS MODE 1 With one MSIV inoperable in MODE 1, action must be taken to restore OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Some repairs to the MSIV can be made with the unit hot. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is reasonable, considering the low probability of an accident occurring during this time period that would require a closure of the MSIVs.

The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is greater than that normally allowed for i containment isolation valves because the MSIVs are valves that isolate a l closed system penetrating containment. These valves differ from other containment isolation valves in that the closed system provides a passive barrier for containment isolation. ,

If the MSIY cannot be restored to OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months , the plant must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . The Completion !

Times are reasonable, based on operating experience, to reach MODE 2 and to j close the MSIVs in an orderly manner and without challenging plant systems. !

i MODES 2. 3. and 4 )

.. k Since the MSIVs are required to be OPERABLE in MODES 2, 3, and 4, the inoperable MSIVs may either be restored to OPERABLE status or closed. When closed, the MSIVs are already in the position required by the assumptions in the safety analysis.

The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is consistent with that allowed in Mode 1.

For inoperable MSIVs that cannot be restored to OPERABLE status within the specified Completion Time, but are closed, the inoperable MSIVs must be verified on a periodic basis to be closed. This is necessary to ensure that the assumptions in the safety analysis remain valid. The 7 day verification time is reasonable, based on engineering judgment, in view of MSIV status i

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_ _ _ _ _ _ _ _ _ _ _ _ _.____________.______.____.______________._____._________.._J

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- indications available in the control room, and other administrative controls,

.to ensure that these valves are in the closed position.

If the-MSIVs cannot be restored to OPERABLE status or are not closed within

.the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed at least in MODE 3'within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 5 within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months . The allowed Completion Times are reasonable, based on operating experience, to reach the ,

required unit conditions from MODE 2 conditions in _ an orderly manner and

- without challenging unit systems. The Action Statement is modified by a note ,

indicating that separate condition entry is allowed for each MSIV. l SURVEILLANCE REQUIREMENTS 4.7.1.5.1 This surveillance verifies that MSIV closure time is less than l

10 seconds on an actual or simulated actuation signal in MODES 1, 2, and 3_ !

when tested pursuant to Specification 4.0.5. The MSIV closure time is assumed i in the accident analyses. This surveillance is normally performed upon returning the plant to operation following a refueling outage. The test.is conducted in MODE 3 with the plant at suitable (appropriate) conditions (e.g., ;

pressure and temperature). This surveillance requirement is modified by an exception which allows a delay of testing. until MODE 3, to establish .

conditions consistent with ' those under which the acceptance. criterion was :

. generated . This exception to Specification 4.0.4 would also allow the MSIVs :

to be cycled to demonstrate post repair OPERABILITY. . Action requirements shall not apply until OPERABILITY has been verified. In addition, if the closure time of the MSIV is less than 10 seconds when verified in accordance :

with Specification 4.7.1.5.2, the OPERABILITY demonstration of the MSIV in -

MODES 1, 2, or 3 is not required per Specification 4.7.1.5.1. ,

4.7.1.5.2 This surveillance verifies that MSIV closure time is less than ;

120 seconds in P,0DE 4 when tested pursuant to Specification 4.0.5. This MSIV !

closure time is assumed in the analyses. This surveillance is normally ,

performed upon returning the plant to operation following'a refueling outage. '

The test is conducted in MODE 4 with the plant at. suitable (appropriate) l conditions (e.g., pressure and temperature . This surveillance requirement is ;

modified by an exception which allows a ) delay of testing until MODE 4, to i establish conditions consistent with those under which the acceptance !

criterion was generated. This exception to Specification 4.0.4 would also allow the MSIVs to be cycled to demonstrate post repair OPERABILITY. Action ;

requirements shall not apply until OPERABILITY has been verified.

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Docket No. 50-423 1 B15241 )

l Attachment 2 l -

1-l- Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Main Steam Line Isolation Valves Retyped Pages L'

i June 1995 )

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. _ _ ._ _ _ _ _ _ _ _ _ _ _ _ _________________.__________________a

p CONTAIMENT SYSTEMS

. 3/4.6.3 CONTAIMENT ISOLATION VALVES ;

LIMITIM C0EITION FOR OPERATION h

3.6.3 The containment isolation valves shall be OPERABLE

with isolation times l :

less than or equal to the required isolation times.

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

ACTION:

With one or more of the isolation valve (s) inoperable, maintain at least one isolation valve OPERABLE in each affected penetration that is open and:

a. Restore the inoperable valve (s) to OPERABLE status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months , or i

b. Isolate each affected penetration within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by use of at least one deactivated automatic valve secured in the isolation position, or i

c. Isolate each affected penetration within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by use of at least one closed manual valve or blind flange; or

d. Be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

SURVEILLANCE REQUIREMENTS ,

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4.6.3.1 Each isolation valve shall be demonstrated OPERABLE prior to '

returning the valve to service after maintenance, repair, or replacement work is performed on the valve or its associated actuator, control, or power circuit by performance of a cycling test and verification of isolation time.

4.6.3.2 Each isolation valve shall be demonstrated OPERABLE during the COLD SHUTDOWN or REFUELING MODE at least once per 18 months by:

a. Verifying that on a Phase "A" Isolation test signal, each Phase "A" isolation valve actuates to its isolation position,

b. Verifying that on a Phase "B" Isolation test signal, each Phase "B" isolation valve actuates to its isolation position, and

c. Verifying that on a Containment High Radiation test signal, each purge supply and exhaust isolation valve actuates to its isolation position.

4.6.3.3 The isolation time of each power-operated or automatic valve shall be determined to be within its limit when tested pursuant to Specification 4.0.5.

The provisions of this Specification are not applicable for main steam line isolation '

valves. However, provisions of Specification 3.7.1.5 are applicable for main steam line isolation valves.

MILLSTONE - UNIT 3 3/4 6-15 Amendment No. 77, J/, 77, om 19,

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PLANT SYSTEMS

[

. MAIN STEAM LINE ISOLATION VALVES LIMITING CONDITION FOR OPERATION 3.7.1.5 Each main steam line isolation valve (MSIV) shall be OPERABLE.

APPLICABILITY: MODE 1 MODES 2, 3, and 4, except when all MSIVs are closed and deactivated.

ACTION:

MODE 1:

With one MSIV inoperable, POWER OPERATION may continue provided the inoperable valve is restored to OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ; otherwise be in MODE 2 within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months MODES 2, 3, and 4:

With one or more MSIVs inoperable, subsequent operation in MODE 2, or 3, or 4 may proceed provided the inoperable isolation valve (s) are closed in 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months and verified closed once per 7 days. Otherwise, be in HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months . Separate condition entry is allowed for each MSIV.

SURVEILLANCE REQUIREMENTS 4.7.1.5.1 Each MSIV shall be demonstrated OPERABLE

by verifying full closure within 10 seconds on an actual or simulated actuation signal in MODES 1, 2, and 3 when tested pursuant to Specification 4.0.5. The provisions of Specification 4.0.4 are not applicable for entry into MODE 3.

4.7.1.5.2 Each MSIV shall be demonstrated OPERABLE by verifying full closure within 120 seconds on an actual or simulated actuation signal in MODE 4 when tested pursuant to Specification 4.0.5. The provisions of Specification 4.0.4 are not applicable for entry into MODE 4.

If the closure time of the MSIV is less than 10 seconds when verified in accordance with Specification 4.7.1.5.2, then the operability demonstration of the MSIV in MODES 1, 2, or 3 is not required per Specification 4.7.1.5.1.

MIjLSTONE-UNIT 3 3/4 7-9 Amendment No. JJ 77 JPJ,

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3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES BACKGROUND The main steam line isolation valves (MSIVs) isolate steam flow from the secondary side of the steam generators following a high energy line break (HELB), MSIV closure terminates flow from the unaffected (intact) steam generators.

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One MSIV is located in each main steam line outside, but close to, containment. The MSIVs are downstream from the main steam safety valves (MSSVs) and auxiliary feedwater (AFW) pump turbine steam supply, to prevent MSSV and AFW isolation from the steam generators by MSIV closure. Closing the MSIVs isolates each steam generator from the others, and isolates the turbine, Steam Bypass System, and other auxiliary steam supplies from the steam generators.

The MSIVs close on a main steam isolation signal generated by low steam generator pressure, high containment pressure, or steam line pressure negative rate (high). The MSIVs fail closed on loss of control or actuation power.

Each MSIV has an MSIV bypass valve. Although these bypass valves are normally closed, they receive the same emergency closure signal as do their associated MSIVs. The MSIVs may also be actuated manually.

A description of the MSIVs is found in the FSAR, Section 10.3.

APPLICABLE SAFETY ANALYSIS The design basis of the MSIVs is established by the containment analysis for the large steam line break (SLB) inside containment, discussed in the FSAR, Section 6.2. It is also affected by the accident analysis of the SLB events presented in the FSAR, Section 15.1.5. The design precludes the blowdown of more than one steam generator, assuming a single active component failure (e.g., the failure of one HSIV to close on demand).

The limiting temperature case for the containment analysis is the SLB inside containment, with a loss of offsite power following turbine trip, and failure of the MSIV on the affected steam generator to close. At hot zero power, the steam generator inventory and temperature are at their maximum, maximizing the analyzed mass and energy release to the containment. Due to reverse flow and failure of .the MSIV to close, the additional mass and energy in the steam headers downstream from the other MSIV contribute to the total release. With the most reactive rod cluster control assembly assumed stuck in the fully withdrawn position, there is an increased possibility that the core will become critical and return to power. The reactor is ultimately shut down by the boric acid injection delivered by the Emergency Core Cooling System.

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l 3/4.7.1.5' MAIN STEAM LINE ISOLATION VALVES fcontinued) l The accident ' analysis _ compares several different SLB events against different i acceptance criteria. The large SLB outside containment upstream of the MSIVs :

is limiting for offsite dose, although a break in this short section of main- :

steam header'has a very low probability. The large SLB upstream of the MSIV !

at hot zero power.is the limiting case for a post trip return to power. The i analysis includes scenarios with offsite power available and with a loss of !

offsite power following turbine trip. With offsite power available, the reactor coolant pumps continue to circulate coolant through the steam .;

generators, maximizing the Reactor Coolant System cooldown. With a loss of ;

offsite power, the response of mitigating systems is delayed. Significant ;

single failures considered include failure of an MSIV to close.

i The MSIVs serve only a safety function and remain open during power operation.

These valves operate under the following situations:

a. An HELB inside containment. In order to maximize the mass and energy release into containment, the analysis assumes that the MSIV in the affected steam generator remains open. For this accident scenario, steam ,

is discharged into containment from all steam generators until the remaining MSIVs close. After MSIV closure, steam is discharged into.

containment only from the affected steam generator and from the residual steam in the main steam header downstream of the closed MSIVs in the unaffected loops. Closure of the.MSIVs isolates the break from the unaffected steam generators.

b. A break outside of containment and upstream from the MSIVs is not a containment pressurization concern. The uncontrolled blowdown of more than one steam generator must be prevented to limit the potential for uncontrolled RCS cooldown and positive reactivity addition. Closure of the MSIVs isolates the break and limits the blowdown to a single steam generator.

c. A break downstream of the MSIVs will be isolated by the closure of the MSIVs. ,

d. .

Following a steam generator tube rupture, closure of the MSIVs isolates the ruptured steam generator from the intact steam generators. In addition to minimizing radiological releases, this enables the operator to maintain the pressure of the steam generator with the ruptured tube below the MSSV setpoints, a necessary step toward isolating the flow through the rupture.

e. ' The MSIVs are also utilized during other events,'such as a feedwater line break. This event is less limiting so far as MSIV OPERABILITY is concerned.

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3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES fcontinued)

LCO. ;

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' This.LC0 requires that four MSIVs in the steam lines be OPERABLE. The MSIVs- l are considered OPERABLE when the isolation times are within limits, and they 1

- close on an isolation actuation signal. 1 i

This LCO provides assurance that the MSIVs will perform their design safety i function to mitigate the consequences of accidents that could result in l offsite' exposures comparable to the 10CFR100 limits or the NRC Staff approved !

licensing basis, j i

APPLICABILITY ,

i The MSIVs must be OPERABLE in MODE I and in MODES 2 and 3, except when closed .

' and deactivated when there is significant mass and energy in the RCS and steam !

generators. When the MSIVs are closed, they are already performing the safety !

function.

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In. MODE 4, even though steam generator energy is low, the MSIVs must be ;

operable in MODE 4 except when closed and deactivated. l 1

In MODE 5 or 6, the' steam generators do not contain much energy because their ;

temperature is below tha boiling point of water; therefore, the MSIVs are not i required for isolation of potential high energy secondary system pipe breaks .

in these MODES. i M

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MODE 1 With one MSIV inoperable in MODE 1, action must' be taken to restore OPERABLE !

status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Some repairs to the MSIV can be made'with the unit ;

hot. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is reasonable,,considering the low ;

probability of an' accident occurring during this time period that would require a closure of the MSIVs.

The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is greater than that normally allowed for ;

containment isolation valves because the MSIVs are valves that isolate a closed system penetrating containment. These valves differ from other -

containment isolation valves in that the closed system provides a' passive :

barrier for containment isolation. -

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- MILLSTONE - UNIT 3 B 3/4 7-5 Amendment No. !

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3/4.7.1.5 MAIN STEAM LINE ISOLATION VALVES fcontinued)

If the MSIV cannot be restored to OPERABLE status within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ,: the plant '

must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in MODE 2 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . The Completion Times are reasonable, based on operating experience, to reach MODE 2 and to j close the MSIVs in an orderly manner and without challenging plant systems. j i

MODES 2. 3. and 4 .!

l Since the MSIVs are required to be OPERABLE in MODES 2, 3, and 4, the ;

inoperable MSIVs may either be restored to OPERABLE status or closed. When j closed, the MSIVs are already in the position required by the assumptions in i

.the safety analysis. l The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Completion Time is consistent with that allowed in Mode 1. l For inoperable MSIVs that cannot be restored to OPERABLE status within the !

specified Completion Time, but are closed, the inoperable MSIVs must be j verified on a periodic basis to be closed. This-is necessary to ensure that ;

the assumptions in the safety analysis remain valid. The 7 day verification !

time is reasonable, based on engineering judgment, in view of MSIV status l indications available in the control room, and other administrative controls, l to ensure that these valves are in the closed position. i t i i If the MSIVs cannot be restored to' OPERABLE status or are not. closed within l the associated Completion Time, the unit must be placed in a MODE in which the j LCO does not apply. To achieve-this status, the unit must be placed at least ;

in MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , and in MODE 5 within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .- The allowed ;

Completion Times are reasonable, based on operating experience, to reach the l

. required unit conditions from MODE 2 conditions in an orderly manner and ;

without challenging unit systems. The Action Statement is modified by a note !

indicating that separate condition entry is allowed for cach MSIV. !

t SURVEILLANCE REQUIREMENTS j l

4.7.1.5.1 This surveillance verifies that MSIV closure time is less than [

10 seconds on an actual or simulated actuation signal in MODES 1, 2, and 3 i when tested pursuant to Specification 4.0.5. The MSIV closure time is assumed ;

in the accident analyses. This surveillance is normally performed upon !

returning the plant to operation following a refueling outage. The test is ;

conducted in MODE 3 with the plant at suitable (appropriate) conditions (e.g., ;

,. pressure and temperature). This surveillance requirement is modified by an !

exception which allows a delay of testing until MODE 3, to establish conditions consistent with those under which the acceptance criterion was generated. This exception to Specification 4.0.4 would also allow the MSIVs MILLSTOME - LNtIT 3 B 3/4 7-6 Amendment No. j

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BASES SURVEILLANCE REQUIREMENTS (continued) to be cycled to demonstrate post repair OPERABILITY. Action requirements shall not apply until OPERABILITY has been verified. In addition, if the closure time of the MSIV is less than 10 seconds when verified in accordance with Specification 4.7.1.5.2, the OPERABILITY demonstration of the MSIV in MODES 1, 2, or 3 is not required per Specification 4.7.1.5.1.

4.7.1.5.2 This surveillance verifies that MSIV closure time is less than 120 seconds in MODE 4 when tested pursuant to Specification 4.0.5. This MSIV closure time is assumed in the analyses. This surveillance is normally performed upon returning the plant to operation following a refueling outage.

The test is conducted in MODE 4 with the plant at suitable (appropriate) conditions (e.g., pressure and temperature). This surveillance requirement is modified by an exception which allows a delay of testing until MODE 4, to establish conditions consistent with those under which the acceptance criterion was generated. This exception to Specification 4.0.4 would also allow the MSIVs to be cycled to demonstrate post repair OPERABILITY. Action requirements shall not apply until OPERABILITY has been verified.

3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION The limitation on steam generator pressure and temperature ensures that the pressure-induced stresses in the steam generators do not exceed the maximum allowable fracture toughness stress limits. The limitations of 70*F and 200 psig are based on a steam generator RTuor of 60*F and are sufficient to prevent brittle fracture.

3/4.7.3 REACTOR PLANT COMPONENT COOLING WATER SYSTEM The OPERABILITY of the Reactor Plant Component Cooling Water System ensures that sufficient cooling capacity is available for continued operation of safety-related equipment during normal and accident conditions. The redundant cooling capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety analyses. .

3/4.7.4 SERVICE WATER SYSTEM i

The OPERABILITY of the Service Water System ensures that sufficient l cooling capacity is available for continued operation of safety-related equip-l ment during normal and accident conditions. The redundant cooling capacity of this system, assuming a single failure, is consistent with the assumptions used in the safety analyses.

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3/4.7.5' ULTIMATE HEAT SINK LThe limitation on the ultimate !. eat sink temperature ensures that cooling.

' water.at less than the design temperature limit is available to either:

(1) provide normal cooldown of the facility or (2) mitigate the. effects of-accident' conditions within acceptable limits. ]

The limitation on maximum temperature is based on providing a 30-day cooling l water supply to safety-related equipment without exceeding its design basis ;

temperature and-is consistent with the recommendations of Regulatory Guide 1.27, !

" Ultimate Heat Sink for Nuclear Plants," March 1974. l 3/4.7.6 FLOOD PROTECTION The limitation on flood protection ensures that the service water pump .

cubicle watertight doors will be closed before the water level reaches the ;

critical elevation of 14.5 feet Mean Sea Level. Elevation 14.5 feet MSL is )

the level at which external flood waters could enter the service water pump l cubicle. ;

3/4.7.7 CONTROL ROOM EMERGENCY VENTILATION SYSTEM !

The OPERABILITY of the Control Room Emergency Ventilation System ensures 'l that: (1) the ' ambient' air temperature does not exceed the. allowable temperature l for continuous-duty rating for the equipment and instrumentation cooled by this !

system, and (2) the control room will remain habitable for operations personnel '

during and following all credible accident conditions. 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'0PERABILITY of this system in conjunction with control room design provisions is based on limiting the radiation exposure to personnel occupying the control room to 5 rems or less whole body, or its equivalent for l the duration of the accident. This limitation is consistent with the )

requirements of General Design Criterion 19 of Appendix A,10 CFR Part 50. i ANSI N510-1980 will be used as a procedural guide for surveillance testing. l 3/4.7.8 CONTROL ROOM ENVELOPE PRESSURIZATION SYSTEM The OPERABILITY of the two independent Control Room Envelope Pressurization l Systems ensures that: (1) breathable air is supplied to the control room, l instrumentation rack room, and computer room, and (2) a positive pressure is !

maintained within the control room envelope during control building isolation.

Each system will provide air to the control room for I hour following an initia-tion of a control building isolation signal at which time, the Control Room Emergency Ventilation System would be started.

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

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3/4.7.9 AUXILIARY' BUILDING FILTER SYSTEM The OPERABILITY of the Auxiliary Building Filter System ensures that radioactive materials leaking from the equipment within the charging pump, component cooling water pump and heat exchanger areas following a LOCA are filtered prior to reaching the environment. The charging pump / reactor plant component cooling water pump ventilation' system must- be operational to ensure operability of the auxiliary building filter system and the supplementary leak collection and release system. 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 operation of this system and the resultant effect on offsite dosage calculations was assumed in the safety analyses. ANSI N510-1980 will be used as a procedural gu % for surveillance testing.

3/4.7.10 SNUBBERS All snubbers are required OPERABLE to ensure that the structural integrity of the Reactor Coolant System and all other safety-related systems is main-tained during and following a seismic or other event initiating dynamic. loads. j For the purpose of declaring the affected system OPERABLE with the inoperable ,

L snubber (s), an engineering evaluation may be' performed, in accordance with Section 50.59 of 10 CFR Part 50.

Snubbers are classified and grouped by design and manufacturer but not by size. Snubbers of the same manufacturer but having different internal mechanisms are classified as different types. For example, mechanical ' snubbers utilizing the same design features of the 2-kip, 10-kip and 100-kip capacity- ,

manufactured by Company "A" are of the same type. The same design mechanical i snubbers manufactured by Company "B" for the purposes of this Technical Specification would be of a different type, as would hydraulic snubbers from -

either manufacturer-.

A list of individual snubbers with detailed information of snubber location and size and of system affected shall be available at the plant in accordance with Section 50.71(c) of 10 CFR Part 50. The accessibility of each snubber shall be determined and approved by the Plant Operations Review Committee. The determination shall be based upon the existing radiation levels and the expected time to perform a visual inspection in each snubber location as well .

as other factors associated with accessibility during plant operations (e.g., j temperature, atmosphere, location, etc.), and the recommendations o~f Regulatory i Guides 8.8 and 8.10. The addition or deletion of any hydraulic or mechanical ;

snubber shall be made in accordance with Section 50.59 of 10 CFR Part 50. ;

The visual inspection frequency is based upon maintaining a constant i level of snubber protection to each safety-related system during an earthquake or severe transient. Therefore, the required inspection interval varies inversely with the observed snubber failures on a given system and is determined by the number of inoperable snubbers found during an inspection of each system.

-In order to establish the inspection frequency for each type of snubber on a B 3/4 7-9 Amendment U ,

M.=ILLSTONE - UNIT 3

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3/4.7.10 SNUBBERS (Continued) safety-related system, it was assumed that the frequency of snubber failures and initiating events is constant with time and that the failure of any snubber 1 on that sytten could cause the system to be unprotected and to result in failure j

'during an assumed initiating event. Inspections performed before that interval i has elapsed may be used as a new reference point to determine the next J inspection. However, the results of such early inspections performed before ;

the original required time interval has elapsed (nominal time less 25%) may not ;

be used to lengthen the required inspection interval. Any ir.spection whose .i results require a shorter inspection interval will override the previous j schedule. l The acceptance criteria are to be used in the visual inspection to 4 determine OPERABILITY of the snubbers. For example, if a fluid port of a ';

hydraulic snubber is found to be uncovered, the snubber shall be declared inoperable and shall not be determined OPERABLE via functional testing.

l To provide assurance of snubber functional reliability, one of three ;

functional testing methods is used with the stated acceptance criteria: l

1. Functionally test 10% of a type of snubber with an additional 5% i tested for each functional testing failure, or

2. Functionally test a sample size and determine sample acceptance or rejection using Figure 4.7-1, or

3. Functionally test a representative sample size and determine sample acceptance _or rejection using the stated equation.

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t Figure 4.7-1 was developed using "Wald's Sequential Probability Ratio '

Plan" as described in " Quality Control and Industrial Statistics" by Acheson J. Duncan.

Permanent or other exemptions from the surveillance program for individual !

snubbers may be granted by the Commission if a justifiable basis for_ exemption i is presented and, if applicable, snubber life destructive testing was performed i

.to qualify the snubbers for the applicable design conditions at either the com- !

pletion of their fabrication or at a subsequent date. Snubbers so exempted !

shall be listed in the list of individual snubbers indicating the extent of the !

exemptions.-

The service life of a snubber is established via manufacturer input and ,

information through consideration of the snubber service conditions _and '

associated installation and maintenance records (newly installed snubbers, seal replaced, spring replaced, in high radiation area, in high temperature area, etc.). The requirement to monitor the snubber service life is included to ensure that the snubbers periodically undergo a performance evaluation in view i of their age and operating conditions. These records will provide statistical !

bases for future consideration of snubber service life. l l

l MILLSTONE - UNIT 3 8 3/4 7-10 Amendment # , l

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e BASES 3/4.7.11 SEALED SOURCE CONTAMINATION The limitations on removable contamination for sources requiring leak I testing, including alpha emitters, is based on 10 CFR 70.39(a)(3) limits for plutonium. This limitation will ensure that leakage from Byproduct, Source, and Special Nuclear Material sources will not exceed allowable intake values.

Sealed sources are classified into three groups according to their use, with Surveillance Requirements commensurate with the probability of damage to a source in that group. Those sources which are frequently handled are required to be tested more often than those which are not. Sealed sources which are continuously enclosed within a shielded mechanism (i.e., sealed sources within !

radiation monitoring or boron measuring devices) are considered to be stored and need not be tested unless they are removed from the shielded mechanism.

3/4.7.14 AREA TEMPERATURE MONITORING The area temperature limitations ensure that safety-related equipment will not be subjected to temperatures in excess of their environmental qualification temperatures. Exposure to excessive temperatures may degrade equipment and can cause a loss of its OPERABILITY. The temperature limits include an allowance for instrument error of 12.2*F. 3 i

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MILLSTONE - UNIT 3 8 3/4 7-11 Amendment No. pp, pp. Jpp, 0399

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