ML20108E718
| ML20108E718 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/07/1996 |
| From: | DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20108E302 | List: |
| References | |
| NUDOCS 9605130130 | |
| Download: ML20108E718 (3) | |
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Ak
- v NPF-73 INDEX
, s BASES SECTION PAGE 3/4.4.5 STEAM GENERATORS B 3/4 4-2 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE.
B 3/4 4-4 3/4.4.7 CHEMISTRY.
B 3/4 4-5 1
3/4.4.8 SPECIFIC ACTIVITY B 3/4 4-5 d
3/4.4.9 PRESSURE / TEMPERATURE LIMITS B 3/4 4-6 l
l 3/4.4.10 STRUCTURAL INTEGRITY.
B 3/4 4-15 3/4.4.11 REACTOR COOLANT SYSTEM RELIEF VALVES.
B 3/4 4-16 4
j 3/4.4.12 REACTOR COOLANT SYSTEM HEAD VENTS B 3/4 4-16 3/4.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l 3/4.5.1 ACCUMULATORS.
B 3/4 5-1 3/4.5.2 AND 3/4.5.3 ECCS SUBSYSTEMS B 3/4 5-1 i
l 3/4.5.4 SEAL INJECTION FLOW.
B 3/4 5-2
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i 3/4.6 CONTAINMENT SYSTEMS l
3/4.6.1 PRIMARY CONTAINMENT.
B 3/4 6-1 1
3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS.
B 3/4 6-10 t
I 3/4.6.3 CONTAINMENT ISOLATION VALVES.
B 3/4 6-11 l
3/4.6.4 COMBUSTIBLE GAS CONTROL.
B 3/4 6-11 3/4.7 PLANT SYSTEMS 3/4.7.1 TURBINE CYCLE.
B 3/4 7-1 3/4.7.2 STEAM GENERATOR PRESSURE / TEMPERATURE LIMITATION B 3/4 7-3 3/4.7.3 PRIMARY COMPONENT COOLING WATER SYSTEM.
B 3/4 7-3 Revised by NRC letter BEAVER VALLEY - UNIT 2 XI dated May 7, 1996 9605130130 960507 DR ADOCK 05000412 PDR
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NPF-73 CONTAINMENT SYSTEMS BASES 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS 3/4.6.2.1 and 3/4.6.2.2 CONTAINMENT OUENCH AND RECIRCULATION SPRAY SYSTEMS The OPERABILITY of the containment spray systems ensures that containment depressurizetion and subsequent return to subatmospheric pressure will occur in the event of a LOCA.
The pressure reduction and resultant termination of containment leakage are consistent with the assumptions used in the accident analyses.
The recirculation spray system consists of four 50 percent capacity subsystems each composed of a spray pump, associated heat exchanger and flow path.
All recirculation spray pumps and motors are located outside containment and supply flow to two 360' recirculation spray ring headers located in containment.
One spray ring is supplied by the "A" train subsystem containing recirculation spray pump 2RSS-P21A and the "B"
train subsystem containing recirculation spray pump 2RSS-P21D with the other spray ring being supplied by the "A"
train subsystem containing recirculation spray pump 2RSS-P21C and the "B"
train subsystem containing recirculation spray pump 2RSS-P21B.
When the water in the refueling water storage tank has reached a predetermined extreme low level, the C and D subsystems are automatically switched to the cold leg recirculation 1
mode of emergency core cooling system operation.
Verifying that each recirculation spray system pump's developed head at the flow test point is greater than or equal to the required developed head ensures that recirculation spray system pump performance has not degraded during the cycle.
The term " required developed head" refers to the value that is assumed in the Containment Integrity Safety Analysis for the recirculation spray pump's developed head at a specific flow point.
This value for the required developed head at a flow point is defined as the Minimum Operating Point (MOP) in the Inservice Testing Program.
Flow and differential head are normal test parameters of centrifugal pump performance required by Section XI of the ASME Code.
Since the recirculation spray system pumps cannot be tested with flow through the spray headers, they are tested on bypass flow.
This test confirms one point on the pump design curve and is indicative of overall performance.
Such inservice tests confirm component OPERABILITY, trend performance, and detect incipient failures by indicating abnormal performance.
i Revised by NRC letter BEAVER VALLEY - UNIT 2 B 3/4 6-10 dated Maf 7, 1996
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fg NPF-73 CONTAINMENT SYSTEMS 4
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BASES i
I 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS (Continued) i l
3/4.6.2.3 CHEMICAL ADDITION SYSTEM f
The OPERABILITY of the chemical addition system ensures that 1
sufficient NaOH is added to the containment spray in the event of a LOCA.
The limits on NaOH minimum volume and concentration, ensure j
that 1) the iodine removal efficiency of the spray water is maintained because of the increase in pH value, and 2) corrosion effects on. components within containment are minimized.
These assumptions are consistent with the iodine removal efficiency j
assumed in the accident analyses, i
3/4.6.3 CONTAINMENT ISOLATION VALVES The OPERABILITY of the containment isolation valves ensures l
that the containment atmosphere will be isolated from the outside i
environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment.
Containment isolation within the time limits specified ensures that i
the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for both a LOCA l
and major secondary system breaks.
The opening of locked or sealed closed containment isolation valves on an intermittent basis under administrative control includes the following considerations:
(1) stationing an operator, who is in constant communication with the control room, at the valve i
controls, (2) instructing this operator to close these valves in an j
accident situation, and (3) assuring that environmental conditions j
will not preclude access to close the valves and that this action i
will prevent the release of radioactivity outside the containment.
3/4.6.4 COMBUSTIBLE GAS CONTROL j
The OPERABILITY of the equipment and systems required for the detection and control of hydrogen gas ensures tha', this equipment will be available to maintain the hydrogen concentration within containment below its flammable limit during post-LOCA conditions.
l Either recombiner unit is capable of controlling the expected hydrogen generation associated with 1) zirconium-water reactions, i
- 2) radiolytic decomposition of water, and 3) corrosion of metals j
within containment.
These hydrogen control systems are consistent with the recommendations of Regulatory Guide 1.7,
" Control of j
Combustible Gas Concentrations in Containment Following a LOCA."
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j Revised by NRC letter i
BEAVER VALLEY - UNIT 2 B 3/4 6-11 dated May 7,1996 i
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