ML20245J461
| ML20245J461 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 08/08/1989 |
| From: | NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20245J409 | List: |
| References | |
| NUDOCS 8908180041 | |
| Download: ML20245J461 (2) | |
Text
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-LIMITI'NG' CONDITION FOR OPERATION 1
Li 3' 5 CORE AND CONTAINMENT COOLING SYSTEMS
'G.
'1.
The ultimate' heat sink shall be OPERABLE with an ' average water
_ temperature of less than or equal to 75'F'at the Unit 1 intake structure,' except when the reactor is in COLD SHUTDOWN OR REFUEL CONDITION.
2.
If the requirements of 3.5.G.I cannot be met, an orderly shutdown of the reactor shall be initiated and the reactor-shall be in the COLD SHUTDOWN or REFUEL CONDITION WITHIN 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
4.5 CORE AND CONTAINMENT COOLING SYSTEMS G.'
Surveillance of the Ultimate Heat Sink shall be performed as follows:
1.
At least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying the average water temperature at the Unit I intake structure to be within limits.
2.
At least once per 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> by verifying the water temperature at the Unit I structure to be within limits when the average water temperature exceeds 70*F.
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Millstone Unit I 3/4 5-10 j
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3.5 CORE AND CONTAINMENT COOLING SYSTEMS BASES A ' potential draining. of the' reactor vessel would allow this water to enter into the torus and after approximately 270,000 gallons accumulated
'(needed to meet minimum NPSH requirements for the-LPCI and/or CS pumps) the l
torus would be able to serve as a common suction header. This would allow a closed loop operation of the LPCI or CS pumps after a realignment of these systems to the torus rather than.the condensate storage tank is made.
During the time the vessel is open and CRD maintenance or fuel removal and replacement is underway the electrical sources of power will be: two onsite emergency power sources (gas turbine and a diesel generator) and i.
one offsite power, or two sources of offsite power and one onsite emergency power source.
The single failure criterion is met by the utilization of two independent low pressure core cooling subsystems and the availability-of the three independent power supplies at all times.
With the worst single failure, loss of transfer bus number 7, a redundant LPCI or CS subsystem would still be available for service.
G.
Ultimate Heat Sink The limitations on the ultimate heat sink temperature ensures that
' sufficient cooling capacity is available to either 1) provide normal cooldown of the facility, or 2) to mitigate the effects of accident conditions within acceptable limits.
Millstone Unit 1 B3/4 5-5 I
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