ML20137F979
| ML20137F979 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 03/27/1997 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20137F924 | List: |
| References | |
| NUDOCS 9704010279 | |
| Download: ML20137F979 (6) | |
Text
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' EMERGENCY CORE COOLING SYSTEMS
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8 SURVEILLANCE REQUIREMENTS (Continued) 1 2.
A visual inspection of the safety injection system sump and verifying that the subsystem suction inlets are not restricted l
by debris and that the sump components (trash racks, screens, l
j etc.) show no evidence of structural distress or corrosion.
i 3.
Verifying that a minimum total of 97.5 cubic feet of solid b
trisodium phosphate dodecahydrate (TSP) is contained within the l
TSP storage baskets.
I j
4.
Verifying that when a representative sample of 4 t 0.01 grams 1
i of TSP from a TSP storage basket is submerged, without agitation, in 4
- 0.1 liters of 120 + 10 'F water borated within RWSP boron concentration limits, the pH of the mixed solution is raised to greater than or equal to 7 within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
4 e.
At least once per 18 months, during shutdown, by:
1.
Verifying that each automatic valve in the flow path actuates to its correct position on SIAS and RAS test signals.
2.
Verifying that each of the following pamps start automatically upon receipt of a safety injection actuation test signal:
a.
High pressure safety injection pump.
b.
Low pressure safety injection pump.
3.
Verifying that on a recirculation actuation test signal, the low pressure safety injection pumps stop, the safety injection system sump isolation valves open.
f.
By verifying that each of the following pumps equired to be OPERABLE performs as indicated on recirculation flow when tested pursuant to Specification 4.0.5:
1.
High pressure safety injection pump differential pressure greater than or equal to 1429 psid.
2.
Low pressure safety injection pump discharge pressure greater than or equal to 177 psig.
9704010279 970327 PDR ADOCK 05000382 P
PDR WATERFORD - UNIT 3 3/4 5-5 AMENDMENT NO. 64
i i
EMERGENCY CORE COOLING SYSTEMS
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i BASES
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i i
ECCS SUBSYSTEMS (Continued)
With the RCS temperature below 350*F, one OPERABLE ECCS subsystem is
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acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the limited core cooling requirements.
1 The trisodium phosphate dodecahydrate (TSP) stored in dissolving baskets i.
located in the containment basement is provided to minimize the possibility of corrosion cracking of certain metal components during operation of the ECCS
]
following a LOCA.
The TSP provides this protection by dissolving in the sump water and causing its final pH to be raised to greater than or equal to 7.0.
The Surveillance Requirements provided to ensure OPERABILITY of each component ensure that at a minimum, the assumptions'used in the safety analyses are met and that subsystem OPERABILITY is maintained.
Surveillance Requirements for throttle valve position stops and flow balance testing pro-vide assurance that proper ECCS flows will be maintained in the event of a LOCA. Maintenanca of proper. flow resistance and pressure drop in the piping system to each injection point is necessary to:
(1) prevent total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration, (2) provide the proper flow split between injection points in accordance with the assumptions used in the ECCS-LOCA analyses, and (3) provide an acceptable level of total ECCS flow to all injection points equal to or above that assumed in the ECCS-LOCA analyses. The requirement to dissolve a representative sample of TSP in a sample of water borated within RWSP boron concentration limits provides assurance that the stored TSP will dissolve in borated water at the postulated post-LOCA temperatures.
The requirement to verify the minimum pump discharge pressure on recircula-tion flow ensures that the pump performance curve has not degraded below that used to show that the pump exceeds the design flow condition assumed in the safety analysis and is consistent with the requirements of ASME Section XI.
3/4.5.4 REFUELING WATER STORAGE POOL (RWSP)
The OPERABILITY of the refueling water storage pool (RWSP) as part of the ECCS also ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA. The limits on RWSP minimum volume and boron concentration ensure that (1) sufficient water is available within containment to permit recirculation cooling flow to the core, and (2) the reactor will remain subcritical in the cold condition following mixing of the RWSP and the RCS water volumes with all CEAs inserted except for the most reactive control assembly. These assumptions are consistent with the i
LOCA analyses.
WATERFORD - UNIT 3 8 3/4 5-2
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i NPF-38-191 ATTACHMENT B
EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) i
- 2. A visualinspection of the safety injection system sump and verifying that the subsystem suction inlets are not restricted by debris and that the sump components (trash racks, screens, etc.) show no evidence of structural distress or corrosion, 1
- 3. Verifying that a minimum total of 380 cubic feet of granular trisodium phosphate l
4 dodecahydrate (TSP) is contained within the TSP storage baskets.
- 4. Verifying that when a representative sample of 13.07 i 0.03 grams of TSP from a TSP storage basket is submerged, without agitation, in 4 i 0.1 liters of 120 i 10 F water borated to 3011 i 30 ppm, the pH of the mixed solution is raised to greater than or equal to 7 within 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />.
- e. At least once per 18 months, during shutdown, by:
- 1. Verifying that each automatic valve in the flow path actuates to its correct position on SIAS and RAS test signals.
- 2. Verifying that each of the following pumps start automatically upon receipt of a safety injection actuation test signal 1
- a. High pressure safety injection pump.
- b. Low pressure safety injection pump.
- 3. Verifying that on a recirculation actuation test signal, the low pressure safety injection pumps stop, the safety injection system sump isolation valves open.
- f. By verifying that each of the following pumps required to be OPERABLE performs as indicated on recirculation flow when tested pursuant to Specification 4.0.5:
- 1. High pressure safety injection pump differential pressure greater than or equal to 1429 psid.
- 2. Low pressure safety injection pump discharge pressure greater than or equal to 177 psig.
WATERFORD - UNIT 3 3/4 5-5 AMENDMENT NO 64
l j
s s
' EMERGENCY CORE COOLING SYSTEMS l
BASES l
4
).
l ECCS SUBSYSTEMS (Continued) i l
With the RCS temperature below 350*F, one OPERABLE ECCS subsystem is
)
acceptable without single failure consideration on the basis of the stable reactivity condition of l
the reactor and the limited core cooling requirements.
The trisodium phosphate dodecahydrate (TSP) stored in dissolving baskets located in the containment basement is provided to minimize the possibility of corrosion cracking of i
certain metal components during operation of the ECCS following a LOCA. The TSP provides j'
this protection by dissolving in the sump water and causing its final pH to be raised to greater than or equal to 7.0. The requirement to dissolve a representative sample of TSP in a sample 4
of water borated to be representative of post-LOCA sump conditions provides assurance that j
the stored TSP will dissolve in borated water at the postulated post-LOCA temperatures. A boron concentration of 3011 ppm boron is postulated to be representative of the highest post-LOCA sump boron concentration based on the assumptions used in calculation EC-S96-013.
[
The RWSP, SITS, and RCS maximum boron concentrations assumed are conservative estimates of future anticipated boron concentrations. The assumed maximum boron concentrations for the RWSP and SITS are greater than those currently allowed in i
. Technical Specifications in order to bound futura expected increases in required boron j
concentrations because of longer fuel cycles and higher energy fuel designs. Post-LOCA sump pH will remain between 7.0 and 8.1 for the maximum (3011 ppm) and minimum (1504 i
ppm) boron concentrations calculated using the maximum and minimum post-LOCA sump '
4 volumes and conservctively assumed maximum and minimum source boron concentrations.
j The Surveillance Requirements provided to ensure OPERABILITY of each component l
ensure that at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is maintained. Surveillance Requirements for throttle valve position stops and flow balance testing provide assurance that proper ECCS flows will be maintc:r;ad in j-the event of a LOCA. Maintenance of proper flow resistance and pressure drop in the piping j
system to each injection point is necessary to: (1) prevent total pump flow from exceeding runout conditions when the system is in its minimum resistance configuration, (2) provide the proper flow split between injection points in accordance with the assumptions used in the ECCS-LOCA analyses, and (3) provide an acceptable level of total ECCS flow to allinjection points equal to or above that assumed in the ECCS-LOCA analyses.
l The requirement to verify the minimum pump discharge pressure on recirculation flow ensures that the pump performance curve has not degraded below that used to show that the pump exceeds the design flow condition assumed in the safety analysis and is consistent with the requirements of ASME Section XI.
WATERFORD - UNIT 3 8 3/4 5-2
EMERGENCY CORE COOLING SYSTEMS l
BASES 3/4.5.4 REFUELING WATER STORAGE POOL (RWSP) l k
The OPERABILITY of the refueling water storage pool (RWSP) as part of the ECCS i
also ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA. The limits on RWSP minimum volume and boron concentration ensure that (1) sufficient water is available within containment to permit recirculation cooling flow to j
the core, and (2) the reactor will remain subcritical in the cold condition following mixing of the j
RWSP and the RCS water volumes with all CEAs inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA analyses.
I The contained water volume limit includes an allowance for water not usable because i
of pool discharge line location or other physical characteristics.
i The lower limit on contained water volume, the specific boron concentration and the physical size (approximately 600,000 gallons) of the RWSP also ensure a pH value of between J
7.0 and 11.0 for the eclution recirculated within containment after a LOCA. This pH band minimizes the evet at of iodine and minimizes the effect of chloride and caustic stress
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corrosion on mechanical systems and components.
1 The maximum limit on the RWSP temperature ensures that the assumptions used in the containment pressure analysis under design base accident conditions remain valid and 4
avoids the possibility of containment overpressure. The minimum limit on the RWSP i
i temperature is required to prevent freezing and/or boron precipitation in the RWSP.
4 a
WATERFORD - UNIT 3 8 3/4 5-3