ML20084Q934
| ML20084Q934 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 06/05/1995 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20084Q927 | List: |
| References | |
| NUDOCS 9506090127 | |
| Download: ML20084Q934 (5) | |
Text
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ATTACHMENT 2 UMERICK GENERATING STATION UNITS 1 AND 2 DOCKET NOS. 50-352 50-353 UCENSE NOS. NPF-39 j
NPF-85 TECHNICAL SPECIFICATIONS CHANGE REQUEST NO. 94-49-0 LIST OF AFFECTED PAGES UNIT 1 1JNIT 2 3/4 1-20 3/4 1-20 B 3/41-4 B 3/41-4 9506090127 950605 ADOCK0500g2 DR
REACTIVITY CONTROL SYSTEMS SURVEILLANCE RE0VIREMENTS (Continued) b.
At least once per 31 days by:
1.
Verifying the continuity of the explosive charge.
2.
Determining by chemical analysis and calculation
- that the i
available weight of sodium pentaborate is greater than or equal to 3754 lbs; the concentration of sodium pentaborate in i
solution is less than or equal to 13.8% and within the limits of Figure 3.1.5-1 and; the following equation is satisfied:
C E
0 21 13% wt.
29 atcm %
86 gpm L
where C - Sodium pentaborate solution (% by weight)
Q - Two pump flowrate, as determined per surveillance requirement 4.1.5.c.
E = Boron 10 enrichment (atom % Boron 10) 3.
Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not lock'ed, sealed, or otherwise secured in position, is in its correct position.
c.
Demonstrating that, when tested pursuant to Specification 4.0.5, the requirement of the ATWS equation (4.1.5.b.2) is met at a pressure of greater than or equal to 1190 psig.
d.
At least once per 24 months during shutdown by:
1.
Initiating at least one of the standby liquid control system loops, including an explosive valve, and verifying that a flow path from the pumps to the reactor pressure vessel is available by pumping demineralized water into the reactor vessel.
The replacement charge for the explosive valve shall be from the same manufactured batch as the one fired or from another batch which has been certified by having one of the batch success-i fully fired. All injection loops shall be tested in 3 operating cycles.
2.
Verify all heat-traced piping between storage tank and pump suction is unblocked.**
i e.
Prior to addition of Boron to storage tank verify sodium pentaborate enrichment to be added is 1 29 atom % Boron 10.
- This test shall also be performed anytime water or boron is added to the solu-tion or when the solution temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after water or boron addition or solution temperature is restored.
- This test shall also be performed whenever suction piping temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after solution temperature is restored.
LIMERICK - UNIT 1 3/4 1-20
l l
REACTIVfTY CONTROL SYSTEMS BASES 3/4.1.5 STANDBY LIOVID CONTROL SYSTEM The standby, liquid control system provides a backup capability for bringing the reactor from full power to a cold, Xenon-free shutdown, assuming that the eithdrawn control rods remain fixed in the rated power pattern. To meet this objective it is necessary to inject a quantity of boron which produces a concen-tration of 660 ppm in the reactor core and other piping systems connected to the reactor vessel.
To allow for potential leakage and improper mixing, this concentrat. ion is increased by 25%. The required concentration is achieved by having available a minimum quantity of 3,160 gallons of sodium pentaborate solution containing a minimum of 3,754 lbs of sodium pentaborate having the requisite B 10 atom % enrichment of 29% as determined from Reference 5.
This quantity of solution is a net amount which is above the pump suction shutoff level setpoint thus allowing for the portion which cannot be injected.
The required delivery rate is determined in accordance with 10CFR50.62, and accounts for variable conditions associated with pump flow, solution concentration and boron enrichment. The pumping rate provides a negative reactivity insertion rate over the permissible solution volume range, which adequately compensates for the positive reactivity effects due to elimination of steam voids, increased water density from hot to cold, reduced doppler effect in uranium, reduced neutron leakage from boiling to cold, decreased control rod worth as the moderator cools, and xenon decay. The temperature requirement ensures that the sodium pentaborate always remains in solution.
With redundant pumps and explosive injection valves and with a highly reliable control rod scram system, operation of the reactor is permitted to continue for short periods of time with the system inoperable or for longer periods of time with one of the redundant components inoperable.
The SLCS system consists of three separate and independent pumps and explosive valves.
Two of the separate and independent pumps and explosive valves are required to meet the minimum requirements of this technical specification and, where applicable, sati.sfy the single failure criterion.
The SLCS must have an equivalent control capacity of 86 gpm of 13% weight sodium pentaborate in order to satisfy 10 CFR 50.62 (Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants). As part of the ARTS /MELLL program the ATWS analysis was updated to reflect the new rod line. As a result of this it was determined that the Boron 10 enrichment was required to be increased to 29% to prevent exceeding a suppression pool temperature of 190*F. This equivalency requirement is fulfilled by having a system which satisfies the equation given in 4.1.5.b.2.
The upper limit concentration of 13.8% has been established as a reasonable limit to prevent precipitation of sodium pentaborate in the event of a loss of tank heating, which allow the solution to cool.
l LIMERICK - UNIT 1 B 3/4 1-4
.. REACTIVITY CONTROL SYSTEMS SURVEILLANCE RE0UIREMENTS (Continued) b.
At least once per 31 days by:
1.
Verifying the continuity of the explosive charge.
2.
Determining by chemical analysis and calculation
- that the available weight of sodium pentaborate is greater than or equal to 3754 lbs; the concentration of sodium pentaborate in solution is less than or equal to 13.8% and within the limits of Figure 3.1.5-1 and; the following equation is satisfied:
C E
O DI 13% wt.
29 atom %
86 gpm l
l where C - Sodium pentaborate solution (% by weight)
I Q - Two pump flowrate, as determined per surveillance requirement 4.1.5.c.
E - Boron 10 enrichment (atom % Boron 10) 3.
Verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position.
}
c.
Demonstrating that, when tested pursuant to Specification 4.0.5, the requirement of the ATWS equation (4.1.5.b.2) is met at a pressure of greater than or equal to 1230 25 psig.
d.
At least once per 24 months during shutdown by:
1.
Initiating at least one of the standby liquid control system loops, including an explosive valve, and verifying that a flow path from the pumps to the reactor pressure vessel is available by pumping demineralized water into the reactor vessel.
The replacement charge for the explosive valve shall be from the same manufactured batch as the one fired or from another batch which has been certified by having one of the batch success-fully fired. All injection loops shall be tested in 3 operating cycles.
2.
Verify all heat-treated piping between storage tank and pump suction is unblocked.**
e.
Prior to addition of Boron to storage tank verify sodium pentaborate enrichment to be added is 2 29 atom % Boron 10.
oThis test shall also be performed anytime water or boron is added to the solu-tion or when the solution temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after water or boron addition or solution temperature is restored, coThis test shall also be performed whenever suction piping temperature drops below the limits of Figure 3.1.5-1 for the most recent concentration analysis, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after solution temperature is restored.
LIMERICK - UNIT 2 3/4 1-20
. REACTIVITY CONTROL SYSTEMS BASES 3/4.1.5 STANDBY LI0VID CONTROL SYSTEM The standby liquid control system provides a backup capability for bringing 1
the reactor from full power to a cold, Xenon-free shutdown, assuming that the eithdrawn control rods remain fixed in the rated power pattern. To meet this objective it is necessary to inject a quantity of boron which produces a concen-tration of 660 ppm in the reactor core and other piping systems connected to the reactor vessel. To allow for potential leakage and improper mixing, this con-centration,is increased by 25%. The required concentration is achieved by having available a minimum quantity of 3,160 gallons of sodium pentaborate solution containing a minimum of 3,754 lbs of sodium pentaborate having the requisite B 10 atom % enrichment of 29% as determined from Reference 5.
This quantity of solution is a net amount which is above the pump suction shutoff level setpoint thus allowing for the portion which cannot be injected.
The required delivery rate is determined in accordance with 10CFR50.62, and accounts for variable conditions associated with pump flow, solution concentration and baron enrichment.
The pumping rate provides a negative reactivity insertion rate over the permissible solution volume range, which adequately compensates for the positive reactivity effects due to elimination of steam voids, increased water density from hot to cold, reduced doppler effect in uranium, reduced neutron leakage from boiling to cold, decreased control rod worth as the moderator cools, and xenon decay. The temperature requirement ensures that the sodium pentaborate always remains in solution.
With redundant pumps and explosive injection valves and with a highly reliable control rod scram system, operation of the reactor is permitted to continue for short periods of time with the system inoperable or for longer periods of time with one of the redundant components inoperable.
The SLCS system consists of three separate and independent pumps and explosive valves.
Two of the separate and independent pumps and explosive valves are required to meet the minimum requirements of this technical specification and, where applicable, satisfy the single failure criterion.
The SLCS must have an equivalent control capacity of 86 gpm of 13% weight sodium pentaborate in order to satisfy 10 CFR 50.62 (Requirements for reduction of risk from anticipated transients without scram (ATWS) events for light-water-cooled nuclear power plants).
As part of the ARTS /MELLL program the ATWS analysis was updated to reflect the new rod line.
As a result of this it was determined that the Boron 10 enrichment was required to be increased to 29% to prevent exceeding a suppression pool temperature of 190*F.
This equivalency requirement is fulfilled by having a system which satisfies the equation given in 4.1.5.b.2.
The upper limit concentration of 13.8% has been established as a reasonable limit to prevent precipitation of sodium pentaborate in the event of a loss of tank heating, which allow the solution to cool.
LIMERICK - UNIT 2 8 3/4 1-4