ML19317E898
| ML19317E898 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/15/1974 |
| From: | US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19317E894 | List: |
| References | |
| NUDOCS 8001070698 | |
| Download: ML19317E898 (2) | |
Text
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'3.2, HIGH f 15UI C INJECTION AND C11C ICAL /( 'T103 SYSTDIS f;., v % O i..
Applienbility
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' Applies to 'the high pressure injection and the chemical addition systems.
Objective To_ provide for adequate boration under all operating conditions to assure ability to bring the reactor to a cold shutdown condition.
Specification The' reactor shall not be critical unless the following conditions are met:
3.2.1 Two high pressure injection pumps per unit are oper'ble except as specified in 3.3.
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_One source _!per__unijt[of_ concent. rayed _ soluble boric acid in addition to 3.2.2 the borateNtorage tank _is_,av_ailable and operable.
This can be ei t'ner :
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1 a.
The boric acid mix tank centaining at least 74 inches (450 3
ft )of 10,600 ppm b'ros as boric acid solution,at a temperature o
of at least 10*F above the crystallization temperature.
System piping and valves necessar) to establish a flow path from the l
tank to the;high pressure injection systeYsfiali a1so be operable
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and shall have at 1 cast the same temperature requirement as the
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boric' acid mix tank.
One associated boric acid pump shall be operable.
If the daily average air temperature in the. vicinity of this tank and associated flow path piping is less than 85*F, at
~1 east one channel of heat tracing shall be in operation for this
' tank and piping.
-r b.
Thefconcentrated boric acid storage _tanklcontaining.at 1_e a_ s t, 26 inches (550 f t ). of dfypa_ baron as boric acid solution 3
with a temperature of at least 10*F above the crystallization temperature.
System piping and valves necessary to establish a flow path from the tank' to the high pressure injection system shall be operable a'6d shall l'ii/c 'tbE san'e temperatur'e requirement'
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as the concentrated boric ~ acid storage. tank.
One associated boric acid pump shall be operable. If the daily average air temperature in the vicinity of this tank is less than 70*F, at least one channel of heat tracing shall be in operation for this tank and associated piping!
Bases The high pressure-injection system and chemical addition system provide control of the reactor coolant system boron ccccentration. (1) This is normally accomplished by using any_ of the. three high pressure injection pumps in series with a boric acid pump associated with either the boric acid mix-tank or t'ac concentrated boric acid storage teck.
An alternate.cthed of j
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3.2-1 6
8001070 h
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btration will'be nac of the high presnure injection pumps taking suction directly from the horated water storage tank. (2)
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The quantity of boric acid in storage from any of the 3 above mentioned sources is sufficient to borate the cenctor coolant system to a 1% sub-critical margin in the cold-condition at the end of core life.
The maximum required is the equivalent of 396 ft3 of 10,600 ppm boron as boric acid
- solution. A minimum of 450 ft3 of 10,600 ppm' boron as boric acid solution in the boric acid mix tank, a minimum of 550 ft3 of 8,700 ppm boron as boric acid solution in the concentrated boric acid storage tankc J)a_minicun.of, o
_350,000 gallons of 1800 ppm., boron,_as boric acid, solution in:the borated,uate,r, storaj e tank (3,).vi1 Q atisfy the requiremen,ts.
The-specification assures that at least tuo of these suppli_es are available whenever the reactor is critical so that a single failure will not prevent boration to a cold condition.,
The required amount of boric acid can be added in several ways.
The quickesc method allows for the necessary boron addition in less than one hour. The
- slowest method (using 'one 10 gpm pump taking suction from the boric acid storage _ tank) would require approximate'ly 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> to inject enoug.h_ boron to kee tt h aetor 1% suberitical with xenon in the core. As xenon decays out, more boron would have to be added. Therefore, in order to account for xenon decay, the 10 gpm pump would pump for something less than 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.
At this i
time, the reactor coolant system would be at a temperature of approxicately 175*F and the core would be more than'1% subcritical.
The, concentration of boron in the boric acid mix tank and concentrated boric acid storage tank may be higher than the concentration which would crystallize y
at ambient conditions.
For this reason and to assure a flou of boric acid is available when needed, these tanks and their associated piping will be kept 10*F above the crystallization temperature for the concen'tration present. Once in the.h!-h pressure inject' ion system, the concentrate is sufficiently well mixed
- and diluted so that normal system temperatures assure boric acid solubility-.
c The boric acid mix tank concentration of 10'600 ppm boron corresponds to a
' precipitation temperature of 80*F, and the concentrated boric dcid storage tank concentration of'8700 ppm corresponds to a precipitation temperature of 68'F.
It is expected that the surface temperatures of these tanks and associated piping will be 10*F above the precipitation temperatures.
If the
- air temperature should approach a precipitation temperature, at least one channel of heat' tracing in service assures that heat losses to the atmosphere will'be made up to maintain this 10*F margin.
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REFERENCES (1) FSAR, Section 9.1; 9.2 (2) -FSAR Figure 6.2
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3.2-2 s
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