ML20079A091
| ML20079A091 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 12/21/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20079A095 | List: |
| References | |
| NUDOCS 9412300146 | |
| Download: ML20079A091 (3) | |
Text
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4 QUAD-CITIES j
DPR-29 Explode two of six charges or two of
.i four charges manufactured in the same batch using the permanent system l
wiring to verify proper function.
Then install the untested charges in i
the explosion valves.
Domineralized water shall be injected via a test connection into the reactor explosion valves)t are not c except not checke recirculation tes
- l Test that the setting of the system pressure reli'ef valves is between 1455 and 1545 psig.
3.
Disassemble and inspect one explosion i
valve so that it can be established i
that the valve is not clogged.
Both valves shall be inspected in the course of two operating cycles.
B.
Operation with Inoperable Components B.
Operation with Inoperable Components From and after the date that a When a com!nt component shal$erable, i
redundant component is made or found onent becomes ino its redund be to be inoperable, Specification 3.4.A 1
shall be considered fulfilled and demonstrated to be operable continued operation permitted provided immediately and daily thereafter.
4 that the component is returned to an eperable condition within 7 days.
C.
Liquid Poison Tank-Boron Concentration C.
Liquid Poison Tank-Boron Concentration
!i The liquid poison tank shall contain a boron bearing solution of at least 14 The availability of the proper boron-i wei ht percent, but not more than 16.5 bearing solution shall be verified by crei h percent sodium pentaborate performance of the following tests:
dec h drate at all times when the stand liquid control s requir d to be operable.ystem is The i'
available volume and temperature of i
the sodium pentaborate solution shall i
be greater than or equal to the limits specified by Figures 3.4-1 and 3.4-2.
i 3.4/4.4-2 Amendment No. 151 i
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9412300146 941221 PDR ADOCK 05000254 P
QUAD-CITIES opa-as 3.4 LIMITING CONDITION FOR OPERATION BASES l
l A.
The design objective of the standby liquid control system is to provide i
the capability of bringing the reactor free full power to e cold, i
l xenon-free shutdown assum' ne that none of the witufrawn control rods cam 1
be inserted. To meet this objective, the liquid control system is desigmod to inject a quantity of boron which produces a concentration of no less i
than 600 ppe of boron in the reactor core in less than 100 minutes with l
j
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imperfect mixing. A boron concentration of 400 pps in the reactor care is required to bring the reactor from full power to a 35 Ak or more subcritical condition considering the hot to cold reactivity swing, menom poisoning and an additional margin in the reactor core for imperfect mixing of the chemical solution in the reactor water. A normal quantity of 3:54 gallons of solution having a 145 sodium pentaborate concentration is l
required to meet this shutdown requirement. An additional volume of j
solution is contained below the pump suction and is not available for injection. Other equivalent com>1 nations of increased concentration and i
reduced volume are also acceptable provided they have considered required temperatures and net positive suction head.
For a required pumping rate of 40 gpa 'a minimus' of 3254 gallons of at least 14 WT percent solution at s 110 F will be inserted in less than 100 l
g i
i minutes. This insertion rate of boron solution will override the rate of reactivity insertion due to cooldown of the reactor following the menon peak.
Two pump operation will enable faster reactor shutdown for ATVS events. The minimum gross volume required in the storage tank is i
dependent on solution temperature (to assure adequate not positive suction j
head). The monthly pump minimum flowrate test shall require a minimum flowrate of 40 gps. This requirement, combined with the solution concentration requirement of at least 14 WT percent, will demonstrate that the Standby Liquid Control System meets the requirements of 10 CFR 50.62.
Boron concentration, solution temperature, and volume are checked on a frequency to assure a high reliability of operation of the system should it ever be required. Experience with pump operability indicates that monthly testing is adequate to detect if failures have occurred.
The only pra-tical time to test the standby liquid control system is during a refueling outage and by initiation from local stations.
Components of the system are checked periodically as described above and make a functional test of the entire system on a frequency of less than once during each refueling outage unnecessary. A test of explosive charges from one manufacturing batch is made to assure that the charges are satisfactory. A continual check of the firin j
provided by pilot lights in the control room.g circuit continuity is l
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j 3.4/4.4-4 Amendment No. 151
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i b,
p QUAD-CITIES DpR-2g P
l l
B.
Only one of the two standby liquid control pumping circuits is needed for i
proper operation of the system.
If one pumping c'rcuit is found to be i
i inoperable, there is no immediate threat to shutdown capability, and reactor i
operation may continue while repairs are being made. Assurance that the i
remaining system will perform its intended function and that the reliability j
of the system is good is obtained by demonstrating operation of the pump in the operable circuit at least once daily. A reliability analysis indicates l
that the plant can be operated safety in this mannec for 7 days.
l The Standby Liquid Control System is operated by a five position control switch (SYS 1&2, SYS 1 0FF, SYS 2, and SYS 241).
positions are for opera, ting cycle surveillance testing.The single pump operation This testing demonstrates the capability of firing the explosive trigger assemblies. Also during this testing, sodium pentaborate is circulated from the storage tank, through one. suction line, through a pump, and back into the storage tank.
This is done separately for each system demonstrating that both suction lines are not plugged. The two pump operation positions will be used for the injection of the sodium pentaborate into the vessel during an ATWS event.
{
By using the two pump operation position, the Standby Liquid Control System will j
be meeting the requirements of 10 CFR 50.62 (Requirements for reduction of i
risk from ATWS events for light-water-cooled nuclear power plants).
4 C.
the saturation temperature is 73*F.For the maximum solution concentration o The solution shall be kept at least 10 F above the saturant temperature to guard against boron precipitation.
The 100F margin is included in Figure 3.4-2. Temperature and liquid level alarms for -
the system are annunciated in the control room.
Figure 3.4-1 provides 4
i additional requirements for minimum tank volume based on solution temperature and concentration to ensure adequate net positive suction head exists for one or two pump operation.
Pump operability is checked on a frequency to assure a high reliability of operation of the system should it ever be required.
Once the solution has been made up, boron concentration will not vary unless more boron or more water is added. Level indication and alarm indicate j
whether the solution volume has changed, which might indicate a possible i
solution concentration change. Considering these factors, the test intarval l
has been established.
D.
Periodic tests to demonstrate two-pump flow capability are not feasible in the present system configuration and are unnecessary because the flow path i
integrity can be determined from the test of a single pump.
Initial two-pump test data correlation with single-pump test data verified the capability of the piping to support two-pump flow.
periodic single-pump test data is compared to the required flow rate and to the prev 1ous test data to identify any significant degradation.
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3,4/4,4 5 Amendment No.151
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