ML20151H714
| ML20151H714 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 07/20/1988 |
| From: | ARKANSAS POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20151H710 | List: |
| References | |
| NUDOCS 8808020013 | |
| Download: ML20151H714 (2) | |
Text
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t 3.1.6 Leakage i
Specification 3.1.6.1 If the total reactor coolant leakage rate exceeds 10 gpm, the reactor shall be shutdown within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection:
1 3.1.6.2 If unidentified reactor coolant leakage (exceeding normal evaporative losses) exceeds 1 gpm or if any reactor coolant i
leakage is evaluated as unsafe, the reactor shall be shutdown l
within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
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3.1.6.3.a If it is determined that any reactor coolant leakage exists j
through a non-isolable fault in a reactor coolant system t
strength boundary (such as the reactor vessel, piping, valve body, etc., except steam generator tubes), the reactor shall be shutdown and a cooldown to the cold shutdown condition
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shall be initiated within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of detection.
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3.1.6.3 b If the total leakage through the tubes of both steam f
generators equals or exceeds 1.0 gpm, a reactor shutdown shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and the reactor shall be in the cold shutdown condition within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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3.1.6.4 If reactor shutdown is required by Specification 3.1.6.1, 1
3.1.6.2, or 3.1.6.3, the rate of cooldown and the conditions of shutdown shall be determined by the safety evaluation for
- i each case and reported as required by Specification 6.12.3.
't 3.1.6.5 Action to evaluate the safety implication of reactor coolant t
leakage shall be initiated within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of detection.
The i
nature, as well as the magnitude of the leak, shall be i.
considered in this evaluation.
The safety evaluation shall
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assure that the exposure of offsite personnel to radiation is within the guidelines of 10CFR20.
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3.1.6.6 If reactor shutdown is required by Specification
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3.1.6.1, 3.1.6.2, or 3.1.6.3, the reactor shall not be restarted until the leak is repaired or until the prob'iem is l
otherwise corrected.
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m 3.1.6.7 When the reactor is at power operation, three reactor oES coolant leak detection systems of different operating J poo.
principles shall be in operation.
One of these systems is sensitive to radioactivity and consists of a radioactive gas
, @oc detector and an air particulate activity detector.
Both of i
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these instruments may be out-of-service simultaneously for a
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g, period of no more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided two other means are 8g available to detect leakage and reactor building air samples a
are taken and analyzed in the laboratory at least once per
- g4 shift; otherwise, be in at least Hot Standby within the next c) l O$
6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
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3.1.6.8 Loss of reactor coolant through reactor coolant i
r, ump seals and system valves to connecting r,ystems which i
i Amendment No. 5/
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b.
Total reactor coolant system leakage rate is periodically determined by comparing indications of re_ actor power, reactor coolant temperature, pressurizer water level and reactor coolant makeup tank level over a time interval.
All of these. indications are recorded.
Since the pressurizer level is maintained essentially constant by the pressurizer level controller, any coolant leakage is replaced by coolant from the reactor coolant makeup tank resulting in a tank level decrease! The reactor l
coolant makeup tank capacity is 31 gallons per inch of height and i
each graduation on the level recorder represents 2 inches of tank height.
This inventory monitoring method is capable of detecting changes on the order of 62 gallons.
A 1 gpm leak.would therefore be detectable within approximately 1.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />..
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As described above, in addition to direct obse~ ttion, the means of detecting reactor coolant leakage are based v., different l
principles, i.e., activity, sump level and reactor coolant 4i inventory measurements.
Two systems of different principles provide, therefore, diversified ways of detecting leakage to the I
reactor building.
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The reactor building gaseous monitor is sensitive to low leak rates if expected values of failed fuel exist.
The rates of reactor coolant leakage to which the instrument is sensitive are discussed in FSAR Section 4.2.3.8.
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i The upper limit of 30 gpm is based on the contingency of a hypothetical loss of all AC power.
A 30 gpm loss of water in conjunction with a i
hypothetical loss of all AC power and subsequent cooldown of the reactor coolant system by the atmospheric dump system and steam driven emergency feedwater pump would require more than 60 minutes to empty the pressurizer from the combined effect of system leakage and contraction.
This will be ample time to restore both electrical power to the station and makeup flow i
to the reactor coolant system.
l The steam generator tube leakage limit (i.e., primary to secondary leakage l
limit) in Specification 3.1.6.3 is intended to assure timely shutdown of the plant for appropriate corrective action before rupture of the steam generator i
tubes occurs under normal operating or postulated accident conditions.
These limits also serve to provide added assurance that the dosage contribution l
from tube leakage will be limited to a small fraction of 10CFR100 limits for i
a design basis steam generator tube rupture or main steam line break event.
References j
l FSAR Section 4.2.3.8 l
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j Amendment No. 2I 29 l
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