ML20141L879

Amend 101 to License DPR-21,revising TS on Allowed Outage Times for Protective Instrumentation & for RB Access Control

ML20141L879
Person / Time
Site:	Millstone
Issue date:	05/28/1997
From:	Mckee P NRC (Affiliation Not Assigned)
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Shared Package
ML20141L878	List: ML20141L876 ML20141L879 ML20141L882
References
NUDOCS 9706030089
Download: ML20141L879 (17)

Text

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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20656 4001 4 ,o 9*****

l NORTHEAST NUCLEAR ENERGY COMPANY DOCKET NO. 50-245 MILLSTONE NUCLEAR POWER STATION. UNIT 1 AMEN 0 MENT TO FACILITY OPERATING LICENSE Amendment No.101 License No. DPR-21

1. The Nuclear Regulatory Commission (the Commission) has found that:

A. The application for amendment by Northeast Nuclear Energy Company (the licensee) dated March 6, 1997, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended 1 (the Act), and the Commission's rules and regulations set forth i in 10 CFR Chapter I; I B. The facility will operate in conformity with the application, the  ;

provisions of the Act, and the rules and regulations of the  !

Commission; 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. ,

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9706030099 970528 PDR ADOCK 05000245 p PDR

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, l and paragraph 2.C.(2) of Facility Operating License No. DPR-21 is hereby amended to read as follows:

(2) Technical Soecifications The Technical Specifications contained in Appendix A, as revised through Amendment No.101, are hereby incorporated in the license. The licensee shall operate the facility in accordance ,

with the Technical Specifications.

3. This license amendment is effective as of the date of. issuance, to be implemented within 90 days of issuance.

• FOR THE NUCLEAR REGULATORY COMMISSION 1

k' Phillip F.*McKee Deputy Director for Licensing Special Projects Office Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: May 28, 1997 I

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ATTACHMENT TO LICENSE AMENDMENT NO.101

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FACILITY OPERATING LICENSE NO. DPR-21

_ , DOCKET NO. 50-245 Replace the following pages of the Appendix A, Technical Specifications, with the attached pages. The revised pages are identified by amendment number and l contain vertical lines indicating the areas of changa 1

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., Remove ' Insert 3/4 1-4 3/4 1-4 3/4 2-2 3/4 2-2 3/4 2-6 3/4 2-6 3/4 2-8 3/4 2-8 l 3/4 2-12 3/4 2-12 i 3/4 7-13 3/4 7-13 B 3/4 1-2 B 3/4 1-2 B 3/4 1-2a*

B 3/4 2-1 B 3/4 2-1 l B 3/4 2-la* '

B 3/4 2-5 B 3/4 2-5 B 3/4 7-6 8 3/4 7-6 B 3/4 7-6a B 3/4 7-9a B 3/4 7-9a

• overflow page - no change i

TABLE 3.1.1 (Continued)

REACTOR PROTECTION SYSTEM (SCRAM) INSTRUMENTATION REQUIREMENTS i ox  ;

30 t

n Minimum Number l 8 of Operable Modes in which Function

• Inst. Channels Trip Function Trip Level Setting Must Be Onerable

Action * ,

5: per Trip (1) REFUEL / STARTUP/ MOT

System SHUTDOWN (8,11) STANDBY RUN

2 Turbine Condenser Low 2 23 in. Hg. Vacuum X (3) X (3) X A or C '

Vacuum i 4 (6) Main Steam 11ne Isolation i 10f, Valve Closure X (3) , X (3) X A or C Valve Closure 2 Turbine Control Valve See Section 2.1.2 F X (4) X (4) X (4) A or C R

Fast Closure

• 2 Turbine Stop Valve s 10f, Valve Closure X (4) X (4) X (4) A or C

& Notes: 1. A channel may be placed in an inoperable status for up to two hours g during periods of required surveillance without placing the Trip System a in the tripped condition provided the associated Trip Function maintains

, trip capability. Otherwise, there shall be two operable or tripped trip

.o systems for each function. _

y 2. Pemissible to bypass, with control rod block, for reactor protection P system reset in REFUEL and SHUTDOWN positions of the reactor mode switch.

w 3. Bypassed when reactor pressure is < 600 psig.

P 4. Bypassed when first stage turbine pressure is less than that which

. w corresponds to 507, rated reactor thermal power.

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TABLE 3.2.1 INSTRUMENTATION THAT INITIATES PRIMARY CONTAllMENT ISOLATION FUNCTIONS E Minimum Number of i

l Operable Instrument Channels Per Trip l e

System (1) Instruments Trio Level Settino Action (3) i y 2 Reactor Low Water 2 127 inches above top of active fuel A 2 Reactor Low Low Water 79 (+4-0) inches above top of active fuel A

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2 (4) High Drywell Pressure 1 2 psig -

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2 (2) (5) High Flow Main Steamline i 120% of rated steam flow B  !

2 of 4 in each of High Temperature Main 2 subchannels Steamline Tunnel 1 200*F B i 2 Low Pressure Main 2 825 psig B Steamlines , i 2 High Flow Isolation 164 inches 1 trip setting (water differential C Condenser Line on steam line) 2 150 inches.

44 inches 1 trip setting (water differential i

, on water side) 2 35 inches.

s t (1) A channel may be placed in an inoperable status for up to two hours during periods of required 7

surveillance without placing the Trip System in the tripped condition provided the associated function maintains trip capability. Otherwise, whenever primary containment integrity is required, there shall be two operable or tripped trip systems for each function, except for low pressure main steamline which only need be available in the RUN position.

(2) Per each steamline.  :

(3) Action: If the first column cannot be met for one of the trip systems, that trip system shall be tripped.

g If the first column cannot be met for both trip systems, the appropriate actions listed below shall be taken:

l- A. Initiate an orderly shutdown and have reactor in cold shutdown condition in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. l' 3 B. Initiate an orderly load reduction and have reactor in HOT STANDBY within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

• C. Close isolation valves in isolation cendenser system.

. (4) May be bypassed when necessary by closing the manual instrument isolation valve for PS-1621, A through i g D, during purging for containment inerting or deinerting.

(5) Minimum number of operable instrument channels per trip system requirement does not have to be met for a q

steamline if both containment isolation valves in the line are closed.  !

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TABLE 3.2.2 (Continued)

7. INSTRUNENTATION THAT INITIATES AM CONTROLS THE EMERGENCY CORE C00 LIM SYSTDIS I

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! N NOTE: ,

1) A channel may be pl:ced in an inoperable status for up to two hours during periods of required surveillance without placing the Trip System in the tripped condition provided the associated Trip Function maintains trip capability. Otherwise, if the first column cannot be met for one of the trip systems, that system shall be tripped. If the first column cannot be met for both trip systems, iimmediately initiate an orderly shutdown to cold conditions.

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t TABLE 3.2.3 (Continued)-

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= INSTRUMENTATION THAT INITIATES R00 SLOCK

1. 9 I E

E Notes-3 '

(1) A channel may be placed in an inoperable status for up to two hours during periods of required surveillance without placing the Trip System in the tripped condition provided the associated

• function maintains trip capability. Otherwise, for the STARTUP/ HOT STAND 8Y and RUN positions of the t i Reactor Mode Selector Switch, there shall be two operable or tripped trip systems for each function  !

except the scram discharge volume - water level high and the SRM rod blocks; IRM downscale are not operable in the RUN position and APRM downscale need not be operable in the STARTUP/ HOT STAND 8Y mode. '

If the first column cannot be met for one of the two trip systems, tils l condition may exist for up to seven days provided that during that time the operable system is functionally tested immediately and i daily thereafter; if this condition lasts longer than seven days, the system shall be tripped. If  ;

the first column cannot be met for both trip systems, the systems shall be tripped.  !

(2) W is the recirculation flow required to achieve rated core flow expressed in percent.

$ (3) IRM downscale may be bypassed when it is on its lowest range.

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f, (4) This function may be bypassed when the count rate is 2100 cps or when all IRM range switches are above t Position 2. '

i (5) One of these trips may be bypassed. The SRM function may be bypassed, in the higher IRM ranges, when the IRM upscale rod block is operable.

(6) The trip may be bypassed when the reactor power is $30% of rated. A RBM channel will be considered inoperable if there are less than half the total number of normal inputs from any LPRM level.

(7) There must be a total of at least four (4) operable or operating APRM channels.

(8) For the STARTUP/ HOT STANDBY and RUN positions of the Reactor Mode Selector Switch, there shall be one (I) g scram discharge volume - water level high instrument per instrument volume tank required to be operable. If  !

g either of the instruments become inoperable, a rod block shall be initiated within one hour.

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2 l- LIMITING COMITION FOR OPERATION l 3.2' PROTECTIVE INSTRUNENTATION C.2. The m'inimum number of operable instrument channels specified in l l Table 3.2.3 for the Rod Block Nonitor may be reduced by one for i

maintenance and/or testing for periods not in excess of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in I i

any 30-day period.

I j D. Air E1 actor Off-Gas System 1

1 1. Except as specified in 3.2.D.2 below, both air ejector off-gas l j system radiation monitors shall be operable during reactor power j 3 operation. The trip settings for the monitors shall be set at a l l value not to exceed the equivalent of the instantaneous stack i release limit specified in Specification 3.8. The time delay l setting for closure of the steam jet-air ejector off-gas isolation

! valve shall not exceed 15 minutes.

l l 2. One air ejector off-gas system radiation monitor may be placed in an inoperable status for up to two hours during periods of required i surveillance without placing the Trip System in the tripped condition. l

! Otherwise, from and after the date that one of the two air ejector l 1 off-gas system radiation monitors is made or found to be inoperable, i reactor power operation is permissible only during the succeeding 24 i hours, provided the inoperable monitor is tripped, urless such system i l 1s sooner made operable. I 3

I E. Reactor Buildino Ventilation Isolation. Steam Tunnel Ventilation j Isolation and Standby Gas Treatment System Initiation l 1. Except as specified in 3.2.E.2 below, two rezctor building ventilation duct radiation monitors, two refueling floor radiation monitors and two steam tunnel ventilation radiation monitors shall be operable whenever secondary containment integrity is required.

. 2. One of the two reactor building ventilation duct radiation monitors, i one of the.two refueling floor radiation monitors, and one of the two

steam tunnel ventilation radiation monitors may be ino>erable for 24 i hrs. If it is not restored to service in this time, tie reactor

building ventilation system and steam tunnel ventilation system shall ,

l be isolated and the standby gas treatment operated until repairs are j

complete or until secondary containment integrity is not required. l i -

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j. 3. The radiation monitors shall be set to trip as follows:

! a. Ventilation duct - 11 mr/hr.

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b. Refueling floor - 100 mr/hr.

i c. Steam tunnel ventilation - 50 mr/hr.

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Ni11 stone Unit 1 3/4 2-12 Amendment No. J. JJ. pp, pp. 101

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LIMITING CONDITION FOR OPERNION 3.7 CONTAINMENT SYSTEMS C. Secondary Containment i 1. Secondary containment integrity, as defined in S'ection 1, shall be OPERABLE:

a. When moving the fuel cask, irradiated fuel or other loads in containment which have the potential for causing a significant release of fission products.

b. When performing CORE ALTERATIONS or operations with a potential for draining the reactor vessel when the vessel contains irradiated fuel.

4 l c. When in RUN,,STARTUP/ HOT STANDBY or HOT SHUTDOWN.

2. If the above cannot be met:

\ a. immediately suspend the activities listed in 3.7.C.I.a and j

3.7.C.I.b; and l

b. when in RUN, STARTUP/ HOT STANDBY, or HOT SHUTDOWN, restore f

secondary containment to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or establish, within the succeeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, conditions where secondary containment integrity is not required.

i SURVEILLANCE REQUIREMENTS 4.7 CONTAINMENT SYSTEMS C. Secondary Containment

1. Secondary containment surveillance shall be performed as indicated below:

a. A secondary containment capability test shall be conducted after isolating the reactor building and placing either standby gas treatment system filter train in operation. Such tests

. shall demonstrate the capability of the secondary containment

to maintain a 1/4 inch of water vacuum with a filter train flow rate of not more than 1100 scfs. Secondary containment capability shall be demonstrated at three or more points within '

the containment prior to fuel movement and may be demonstrated

up to 10 days prior to fuel movement. Secondary containment capability need not be demonstrated more than once per operat-ing cycle unless damage or modifications to the secondary containment have violated the integrity of the pressure retaining boundary of that structure.

b. At least once a month, verify at least one door in each secondary containment access opening is closed.

Millstone Unit 1 3/47-13 Amendment No. J, g , # ,101 0289

a j 3.1 REACTOR PROTECTION SYSTEN RASES l

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l The reactor protection system automatically initiates a r: actor scram to: 3 j 1. preserve the integrity of the fuel cladding; j 2. preserve the integrity of the primary system barrier; and l

3. minimize the energy which must be absorbed, and prevent criticality j following a loss of coolnd :ident.

! .These specifications provid' che limiting conditions for operation i necessary to preserve the abi1 Q of the system to tolerate single failures and j still perform its intended function even during periods when instrument

channels may be out of service because of maintenance. When necessary, one

channel may be made inoperable for brief intervals to conduct required l , functional tests and calibrations. Entry into associated action statements may be delayed for up to two hours provided the associated trip function maintains j trip capability. A two-hour allowance for testing is judged acceptable based

} upon:

! I l a. Remaining capability to trip. Testing of ore sensor does not render

the trip system inoperable, but rather, simply increases the single  :

i failure vulnerability of one trip function in one channel. l

Inoperabilities affecting diverse trip functions would require  !

j multiple failures.  !

! b. Diversity of sensors available to provide the trip signals.

l Surveillance testing is not performed on multiple variables' sensors simultaneously; so other trip functions either remain operable or were previously' declared inoperable and placed on a tripped condition.

! c. Low likelihood of an event requiring the initiation of a scram during j this time frame.

i d. Reasonable test interval. The two-hour test duration provides a

! reasonable amount of time for testing without placing undo time j constraints on personnel.

2 i e. Two-hour time interval is consistent with GE BWR Technical

! Specification (NUREG-0123).

1 l f. Two hours represents one-half of the required action completion time j (four hours) associated with an inoperable RPS trip function.

i If it is discovered that an instrument channel cannot meet the surveillance

{: requirement, the instrument channel shall be declared inoperable.

The reactor protection system is of the dual channel type. Ref.

! Section 7.2 of the UFSAR. The system is made up of two independent logic i channels, each having two subchannels of trfpping devices. Each subchannel j has an input from at least one independent sensor monitoring each of the critical parameters.

l NILLSTONE UNIT 1 B 3/4 1-2 Amendment No. 75, 101

,a 0290 i

! 3.1 REACTOR PROTECTION SYSTEM 4

.' BASES i

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The outputs of the subchannels are combined in a 1 out of 2 logic; i.e.,

an input signal on either one or both of the subchannels will cause a trip j system trip. The outputs of the trip systems are arranged so that a trip on

both channels is required to produce a reactor scram.

l This system meets the requirements of the proposed IEEE Star.dard for j Nuclear Power Plant Protection Systems issued September 13, 1966. The system

has a reliability greater than that of a 2 out of 3 system and somewhat less

than that of a 1 out of 2 system.

l With the exception of the Average Power Range Monitor (APRM), Intermediata i Range Monitor (IRM) channels, Main Steam Isolation Valve Closure, and Turbine Stop Valve Closure, each subchannel has one instrument channel. When the

! minimum condition for operation on the number of operable instrument channels

! per untripped protection logic channel is met or if it cannot be met and the

affected protection trip system is placed in a tripped condition, the

! effectiveness of the protection system is preserved; i.e., the system can tolerate a single failure and still perform its intended function of scramming the reactor. Three APRM instrument channels are provided for each protection trip system.

l APRMs #1 and #3 operate contacts in a logic subchannel and APRMs #2 and j #3 operate contacts in the other logic subchannel.

APRMs #4, #5 and #6 are arranged similarly in the other protection trip

! system. Each protection trip system has one more APRM than is necessary to j meet the minimum number required per channel. This allows the bypassing of

, one APRM per protection trip system for maintenance, testing or calibration.

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l MILLSTONE UNIT 1 8 3/4 1-2a Amendment No. JJ,101 0290

3.2. PROTECTIVE INSTRUNENTATION BASES l

l In addition to reactor protection instrumentation which initiaties a reactor scram, protective instrumentation has been provided which initiates action to mitigate the consequences of accidents which are beyond the operator's ability to control or terminates operator errors before they result in serious consequences. This set of specifications provides the limiting conditions of operation for the primary system isolation function, initiation of the emergency core cooling system, control rod block, and standby gas treatment systems. The objectives of the specifications are to assure the effectiveness of the protective instrumentation, when required, by preserving l its capability to tolerate a signal failure of any component of such systems l even during periods when portions of such systems are out of service for l maintenance. When necessary, one channel may be made inoperable for brief l intervals to conduct required functional tests and calibrations and to 1

prescribe the trip settings. required to assure adequate performance. Entry l

into associated action statements may be delayed for up to two hours provided the associated actuation function maintains actuation capability. A two-hour j allowance for testing is judged acceptable based upon:

a. Remaining capability to actuate. Testing of one sensor does not render the actuation system inoperable, but rather, simply increases the single failure vulnerability of one actuation function in one channel.

b. Low likelihood of an event requiring the actuation of a primary containment isolation or an Emergency Core Cooling System. '

c. Reasonable test interval. The two-hour test duration provides a reasonable amount of time for testing without placing undo time constraints on personnel.

If it is discovered that an instrument channel cannot meet the surveillance requirement, the instrument channel shall be declared inoperable.

Isolation valves are installed in those lines that penetrate the primary containment and must be isolated during a loss of coolant accident so that the radiation dose limits are not exceeded during an accident condition. Actua-tion of these valves is initiated by protective instrumentation shown in Table 3.2.1 which senses the conditions for which isolation is required. Such instrumentation must be available whenever primary containment integrity is required. The objective is to isolate the primary containment so that the guideline values of 10 CFR 100 are not exceeded during an accident.

The instrumentation which initiates primary system isolation is connected in a dual bus arrangement. Thus, the discussion given in the bases for Specification 3.1 is applicable here.

l NILLSTONE UNIT 1 B 3/4 2-1 Amendment No. JJ,101 l 0291

i 3.2 PROTECTIVE IRSTRUMENTATION

,' BASES The low reactor water level instrumentation is set to trip when reactor water level is 127 inches above the top of the active fuel. This trip initi-ates closure of Group 2 and 3 primary containment isolation valves but does not trip the recirculation pumps. Ref. Section 7.3 and Figure 7.3-6 of the UFSAR. For a trip setting of 127 inches above the top of the active fuel and a 60-second valve closure time, the valves will be closed before core uncovery occurs even for the maximum break in the line; and therefore, the setting is adequate.

The low low reactor water level instrumentation is set to trip when reactor water level is 79 inches above the top of the active fuel. This trip initiates closure of Groups 1 and 5 primary containment isolation valves, Ref.

Section 7.3 and Figure 7.3-6 of the UFSAR, activates the ECC subsystems, starts the emergency diesel generator and the gas turbine generator, and trips the recirculation pumps. This trip setting level was chosen to be high enough i to prevent spurious operation but low enough to initiate ECCS operation and l primary system isolation so that post accident cooling can be effectively l accomplished and the guideline values of 10 CFR 100 will not be violated.

For the complete circumferential break of a 28-inch recirculation line and with the trip setting given above, ECCS initiation and l

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1 l l l gLSTONEUNIT1 B 3/4 2-la Amendment No. JJ,101

3.2 PROTECTIVE IlttTRLSIENTATION RASES Two air ejector off-gas monitors are provided and when their trip point is reached, cause an isolation of the air ejector off-gas line. Isolation is initiated when both instruments reach their high trip point or one has an upscale trip and the other a downscale trip. There is a 15-minute delay before the air ejector off-gas isolation valve is closed. This delay is accounted for by the 30-minute holdup time of the off-gas before it is released to the stack.

Both instruments are required for trip but the instruments are so designed that any instrument failure gives a downscale trip. The trip settings of the instruments are set so that any instrument failure gives a downscale trip. The trip iettings of the instruments are set so that the instantaneous stack release rate limit given in Specification 3.8 is not exceeded.

Entry into associated action statements may be delayed for up to two hours. A two-hour allowance for testing is judged acceptable based upon:

! a. Low likelihood of an event requiring the isolation of the air

ejector off-gas system, r

j b. Reasonable test interval. The two-hour test duration provides a reasonable amount of time for testing without placing undo time constraints on personnel.

If it is discovered that an instrument channel cannot meet the surveillance requirement, the instrument channel shall be declared inoperable.

Three sets of two radiation monitors provide signals to initiate isolation of the reactor building and steam tunnel ventilation and operation of the standby gas treatment system when these systems are aligned for automatic actuation. Additionally, these monitors-provide indication of radiological conditions for the areas they monitor and alarm in the event of abnormal conditions. One set of monitors is located adjacent to the reactor building ventilation exhaust duct, one set is located in the vicinity of the fuel pool, and the other set is located adjacent to the steam tunnel ventila-tion exhaust duct. A high level trip on any one of the six monitors or two downscale trips on any one set of monitors will provide signals to the standby gas treatment system initiation and normal ventilation isolation logics. Trip settings of 100 mr/hr on the fuel pool monitor, 11 mr/hr on the ventilation duct monitor, and 50 mr/hr on the steam tunnel ventilation monitor are based on initiating normal ventilation isolation and standby gas treatment system operation when a gross release of radioactive material exists.

MILLSTONE UNIT 1 0392 83/42-5 Amendment No. # , pp. 101 i

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3.7 CONTAllglEAT SYSTEMS na m  !

a radioactive methyl iodide removal efficiency of at least 95 percent for expected accident conditions. If the efficiencies of the HEPA filters and charcoal adsorbers are as specified, the resulting doses will be less than the lo CFR 100 guidelines for the accidents analyzed. Operation of the fans signify different from the design flow will change the removal efficiency of the HEPA filters and charcoal adsorbers.

s Only one of the two standby gas treatment trains is needed to clean up the reactor building atmosphere upon containment isolation. If one train is found to be inoperable, there is no immediate threat to the containment system performance, and reactor operation or refueling operation may continue while repairs are being made. During RUN, STARTUP/H0T STANDBY and H0T SHUTDOWN, OPERABILITY of the standby gas treatment system is required.

Standby gas treatment iystem OPERABILITY is also required during COLD SHUTDOWN or REFUELING when situations exist where a significant release of fission products can be postulated, such as moving the fuel cask, irradiated fuel or other loads in containment; or when performing CORE ALTERATIONS or operations with a potential for draining the reactor vessel when the vessel contains irradiated fuel. During a REFUELING OUTAGE, when reactor coolant temperature is less than or equal to 212' F and secondary ccntainment integrity is' required, two off-site power sources (345 kV or 23 kV and one emergency power source would provide an adequate and reliable sourc)e of power and allow diesel or gas turbine preventative maintenance. Likewise, one source of offsite power (345 kV or 23 kV) and two emergency power sources provide an adequate and reliable source of power.

C. Secondary Containment The secondary containment is designed to minimize any ground level release of radioactive materials which might result from a. serious accident. The reactor building provides secondary containment during reactor operation, when the drywell is sealed and in service; the reactor building provides primary containment when the reactor.is shutdown and the drywell is open, as during refueling. Because the secondary containment is an integral part of the complete containment system, secondary containment integrity is required at all times that primary containment is required. Secondary containment integrity is also required when activities having the potential of significant fission products release, such as movement of the fuel cask, irradiated fuel, or other loads in containment are performed. Administrative controls ensure that loads moved in containment, which may result in significant release of fission products, are evaluated to determine if secondary containment is required.

If secondary containment is inoperable in RUN, STARTUP/ HOT STANDBY or HOT SHUTDOWN, it must be restored to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> time provides a period of time to correct the problem that is commensurate with the importance of maintaining secondary containment integrity in RUN, STARTUP/ HOT STANDBY or HOT SHUTDOWN. This time period also ensures that the probability of an accident (requiring secondary containment OPERABILITY) occurring during periods where secondary containment is inoperable is minimal. If secondary containment cannot be restored to OPERABLE status MILLSTONE UNIT 1 B 3/4 7-6 Amendment No. F , 5 ,101 0277

t l- 3.7 CONTAIMENT SYSTEMS macre within the required time, the plant must be brought to a condition in which the LC0 does not apply. An additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> are allowed to achieve this condition. The allowed times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

D. Primary Containment Isolation Valves Double isolation valves are provided on lines penetrating the primary containment. Closure of one of the valves in each line would be sufficient to maintain the integrity of the pressure suppression system.

Automatic initiation is required to minimize the potential leakage paths from the containment in the event of a loss of coolant accident.

MILLSTONE UNIT 1 B 3/4 7-6a Amendment No. F 101 0277

. i 4.7 CONTAllmOff SYSTEMS

) RASE 5 l

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! B. Standhv Cas Treat = ant System and l

C. Secondary Containment

! Pressure drop across the combined .4 EPA filters and charcoal adsorbers of j

less than 7 inches of water, at the system design flow rate, will i indicate that the filters and adsorbers are not clogged by excessive

! amounts of foreign matter. Heater capability, pressure drop should be

, deterinined at least once per operating cycle to show system performance capability. i i

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' Verifying that seconda'ry containment access doors are closed ensures that l

the infiltration of outside air of such a magnitude as to prevent  !

i maintaining the desired negative pressure does not occur. Maintaining l

secondary containment OPERABILITY, in accordance with the defirition for i SECONDARY CONTAINMENT INTEGRITY, requires verifying at least one door in j

! each access opening is closed. The access openings covered by i

Surveillance Requirement 4.7.C.I.b are the normal and emergency double-door accesses on Reactor Building elevation 14' 5" and the railroad track '

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l bay access doors. The monthly frequency for the surveillance requirement is considered adequate in view of the other indications of door status j that are available.

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a MILLSTONE UNIT 1 5 3/4 7-9a Amendment No. pp. 77,101 0294 3

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