ML20151L832
| ML20151L832 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 07/28/1988 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20151L838 | List: |
| References | |
| NUDOCS 8808040157 | |
| Download: ML20151L832 (4) | |
Text
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CONTAINMENT SYSTEMS BASES i
DRWELL AND CONTADMENT PURGE SYSTEM (Continued)
Leakage integrity tests with a maximum allowable leakage rate for purge supply and exhaust isolation valves will provide early indication of resilient material seal degradation and will allow the opportunity for repair before gross leakage failure develops.
The 0.60 L, leakage limit shall not be exceeded when the leakage rates determined by the leakage integrity tests of these valves are added to the previously determined total for all valves and penetrations subject to Type 8 and C tests.
3/4.6.1.9 FEEDWATER LEAKAGE CONTROL SYSTEM The OPERABILITY of the feedwater leakage control system is required to meet the restrictions on overall containment leak rate assumed in the accident analyses.
3/4.6.2 DRWELL 3/4.6.2.1 DRWELL INTEGRITY Drywell integrity ensures that the steam released for the full spectrum of drywell pipe breaks is condensed inside the primary containment either by the suppression pool or by containment spray.
By utilizing the suppression pool as a heat sink, energy released to the containment is minimized and the severity of the transient is reduced.
3/4.6.2.2 DRWELL BYPASS LEAKAGE The limitation on drywell bypass leakage rate is based on having contain-ment spray OPERABLE.
It ensures that the maximum leakage which could bypass the suppression pool during an accident would not result in the containment exceeding its design pressure of 15.0 psig.
The integrated drywell leakage value is limited to 10% of the design drywell leakage rate.
The limiting case accident is a very small reactor coolant system break which will not automatically result in a reactor depressurization. The long term differential pressure created between the drywell and containment will result in a significant pressure buildup in the containment due to this bypass leakage.
3/4.6.2.3 DRWELL AIR LOCK o
The limitations on closure for the drywell air lock is required to meet caiS the restrictions on DRWELL INTEGRITY and the drywell leakage rate given in R8-Specifications 3.6.2.1 and 3.6.2.2.
The specification makes allowances for go the fact that there may be long periods of time when the air lock will be in c3o a closed and secured position during reactor operation.
Only one closed door w
in the air lock is required to maintain the integrity of the drywell.
SS The air supply to the drywell air lock and seal system is the service and instrument air system.
This system consists of two 100% capacity air compressors per unit and can be cross-connected.
This system is redundant and e'tremely x
' gg reliable and provides system pressure indication in the control room.
PERRY - UNIT 1 B 3/4 6-3
CONTAINMENT SYSTEMS
~
BASES 3/4.6.2.4 DRYWFLL STRUCTURAL INTEGRITY This limitation ensures that the structural integrity of the drywell will be maintained comparable to the original design specification for the life of the unit. A visual inspection in conjunction with Type A leakage tests is sufficient to demonstrate this capability.
3/4.6.2.5 DRYWELL INTERNAL PRESSURE The limitations on drywell-to-containment differential pressure ensure that the drywell peak calculated pressure of 21.8 psig does not exceed the design pressure of 30.0 psig and that the containment peak pressure of 11.31 psig does not exceed the design pressure of 15.0 psig during LOCA conditions. The maximum external drywell pressure differential is limited to +0.5 psid, well below the 2.4 psid at which suppression pool water will be forced over the weir wall and into the drywell. The limit of 2.0 psid for initial positive drywell to contain-ment pressure will limit the drywell pressure to 21.8 psig which is less than the design pressure and is consistent with the safety analysis.
)
i 3/4.6.2.6 DRYWELL AVERAGE AIR TEMPERATURE
]
i The drywell average temperature is an input parameter to the containment /
l drywell response analyses as the result of a DBA-LOCA.
Furthermore, the drywell average temperature is important in drywell equipment qualification considerations.
1 3/4.6.3 DEPRESSURIZATION SYSTEMS The specifications of this section ensure that the drywell and containment i
pressure will not exceed the design pressure of 30 psig and 15 psig, respectively, during primary system blowdown from full operating pressure.
The suppression pool water volume must absorb the associated decay and structural sensible heat released during a reactor blowdown from 1045 psig.
Using conservative parameter inputs, the maximum calculated containment pressure during and following a design basis accident is below the containment design pressure of 15 psig.
Similarly the drywell pressure remains below the design pressure of 30 psig.
The maximum and minimum water volumes for the suppression pool are 118,548 cubic feet and 115,612 cubic feet, respectively, These values include the water volume of the containment pool, horizontal vents, and weir annulus.
Testing in the Mark III Pressure Suppression Test Facility and analysis have assured that the suppression pool temperature will not rise above 185 F for the full range of break sizes.
Should it be necessary to make the suppression pool inoperable, this shall only be done as specified in Specification 3.5.3.
Experimental data indicates that effective steam condensation without excessive load on the containment pool walls will occur with a quencher device and pool temperature below 200'F during relief valve operation.
Specifications have been placed on the envelope of reactor operating conditions to assure the bulk pool temperature does not rise above 185'F in compliance with the contain-ment structural design criteria.
PERRY - UNIT 1 B 3/4 6-4 Amendment No. 14
. CONTAINMENT SYSTEMS DRYWELL AVERAGE AIR TEMPERATURE LIMITING CONDITION FOR OPERATION 3.6.2.6 Drywell average air temperature shall not exceed 145 F.
l APPLICABILITY: OPERATIONAL CONDITIONS 1, 2 and 3.
ACTION:
With the drywell average air temperature greater than 145'F, reduce the l
average air temperature to within the limit within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.6.2.6 The drywell average air temperature shall be the arithmetical average
- of the temperatures at the following elevations # and shall be determined to be within the limit at least once per 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s:
Elevation Azimuth a.
653'-8" 315*, 220, 135*, 34*
b.
634'-0" - 640'-0" 340, 308, 215*, 145,
30*, 20*
c.
604'-6" - 609'-8" 310*, 308*, 253*, 212*,
150*, 140*, 80
- At least one reading from each elevation for an arithmetical average.
- The temperature at each elevation shall be the arithmetical average of the temperatures obtained from all available instruments at that elevation.
PERRY - UNIT 1 3/4 6-21 Amendment No. 6,14
CONTAINMENT SYSTEMS 3/4.6.3 DEPRESSURIZATION SYSTEMS SUPPRESSION P0OL
- l LIMITING CONDITION FOR OPERATION 3 6.3.1 The suppression pool shall be OPERABLE with the pool water:
a.
Volume between 115,612 ft3 and 118,548 ft3 equivalent to a lavel between 18'0" and 18'6", and a b.
Maximum average temperature of 90'F except that the maximum average temperature may be pennitted to increase to:
1.
105*F during testing which adds heat to the suppression pool.
2.
110 F with THERMAL POWER less than or equal to 1% of RATED THERMAL POWER.
3.
120'F with the main steam line isolation valves closed following a scram.
APPLICABILITY: OPERATIONAL CONDITIONS 1, 2 and 3.
ACTION:
a.
With the suppression pool water level ou' side the above limits, restore the water level to within the 11. its within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or be in at least HOT SHUTDOWN within the next 12 1ours and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, b.
With the suppression pool average water temperature greater than 90 F, restore the average temperature to less than or equal to 90*F within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, except, as permitted above:
1.
With the suppression pool average water temperature greater than 105*F during testing which adds heat to the suppression pool, stop all testing which adds heat to the suppression pool and restore the averege temperature to less than 90*F within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
2.
With the suppression pool average water temperature greater than:
a) 90'F for more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and THERMAL POWER greater than 1% of RATED THERMAL POWER, be in at least H0T SHUTDOWN within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
b) 110*F, place the reactor mode switch in the Shutdown position and operate at least one residual heat removal loop in the suppression pool cooling mode.
PERRY - UNIT 1 3/4 6-22