ML20042F109
| ML20042F109 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 05/01/1990 |
| From: | OMAHA PUBLIC POWER DISTRICT |
| To: | |
| Shared Package | |
| ML20042F102 | List: |
| References | |
| NUDOCS 9005070229 | |
| Download: ML20042F109 (13) | |
Text
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9005070229 900501 PDR ADOCK 05000285 P
2.0 LIMITING CONDITIONS FOR,0PERATION 2.2 Chemical and Volume Control System -
Anolicability Applies to the operational status of the chemical and volume control system.
Ob.iective To define those conditions of the chemical and volume control system necessary to assure safe reactor operation.
Soecifications (1).When fuel is in the reactor and the reactor is subcritical, there l
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shall be at least one flow path to the core for boric acid injection.
This flow path may be from the SIRW tank, with at least 10,000 gals, available at refueling. boron concentration or from a BAST which meets the requirements of Figure 2-11 for a SIRW tank boron concentration at the technical specification limit.
(2) The reactor shall not be made critical unless all the following minimum requirements are met:
a.
At least two charging pumps shall be operable, b.
One boric acid transfer pump shall be operable, c.
The minimum volume of borated water contained in the> boric acid storage tank (s) (BAST) is dependent on the BAST and SIRW tank boron concentrations. The minimum requiredovolume curve is i
shown in Figure 2-11'.-
Depending on the -flow paths available,.
this volume of borated water can be either the.combinedLvolume
.of the two BASTS, or can be contained in a specific BAST. _The
' BAST.is defined as the tank,. gravity feed valve, ^ pump' and' associated piping. The ambient temperature of the boric acid tank solution CH-11A-and CH-118 shall meet the temperature requirements of Figure 2-12.
d.
System piping-and valves shall be operable such:that one:of the following four conditions will be satisfied.
If piping or' valves become inoperable and a condition change is required, six (6) hours are allowed when changing from one condition listed below to another condition listed below.
In the event that the condition ~ change cannot be completed within the six (6)' hours l-allowed, the unit shall be placed in at least-HOT SHUTDOWN within six (6) hours,'in-at least suberitical and <300*F within the next six (6)' hours and-in at-least~ COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> unless corrective measures are completed.
2-17
2.0 LIMITING COGITIONS FOR OPERATION f,
2.2 Chemical andWume Control System (Continued)-
l dl.
The required BAST volume of Figure 2-11 can be combined between CH-11A and CH 11B when both tanks are operable, d2.
When LCV-218-3 is inoperable or the SIRW tank volume is below Technical Specification 2.2(1) minimum, then each BAST must-be operable and contain the required volume of Figure 2-11 corresponding to the requirements' of the SIRW tank Technical Specification boron concentration.
d3. When BAST CH-118 is inoperable, then BAST CH-11A must be operable and contain the required volume of Figure 2-11 and LCV-218-3 must be operable.=
d4. When BAST CH-llA is-inoperable, then BAST CH-11B must be -
operable and contain-the required volume of Figure 2-11 and '
i LCV-218-3 must be operable.
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Level instruments on the inservice BAST shall be operable.
e.
(3) Modification of Minimum Requirements During power operation, the minimum requirements may be modified to allow any one of the following conditions to exist at any one time.
If the system is not restored to meet the minimum requirements within the-time period specified, the reactor shall be placed in the hot shutdown condition in 4-hours and in the cold shutdown condition within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, a.
One of the operable charging pumps may be removed from service provided two charging-pumps are operable within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, i
b.
Both boric acid pumps may be out of service for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided l
that both BASTS meet the requirements of Figure-2-11.
One level instrument channel on each inservice concentrated. boric c.
acid tank may be out of service for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, d.
One BAST may be removed from service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided that either of the conditions of 2.2(2)d3 or 2.2(2)d4 above is met.
Basis The chemical and volume control (bystem provides. control of the reactor coolant system boron inventory.
This is normally accomplished by using any one of the three charging pumps in series with one of the two boric acid pumps. An alternate method of boration will be to use.the charging pumps directly from the SIRW storage tank. A third method will be to depressurize and use the safety injection pumps.
There are two sources of borated water available for injection through three different paths.
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2.0 LIMITING CONDITIONS ER0PERAllQH 2.2 Chemical and Volume Ntrol System (Continued)
(1) The boric acid' pumps can deliver the BAST contents (2.5 4.5 weight
'o percent concentration of boric acid) to the charging pumps. The tanks are located above the charging pumps so that the boric acid will flow by gravity without being pumped.
(2) The safety injection pumps-can take suction from the-SIRW tank which maintains a boric acid concentration greater than the required
'i refueling concentration.
(3) The charging pumps can take their suctions-by gravity from either the boric acid tanks or the SIRW tank.
Each concentrated boric acid tank containing 2.5-4.5 weight percent boric acid has sufficient boron to bring the plant to a cold shutdown condition.
Boric acid pumps are each of sufficient capacity to feed all three charging pumps at their maximum capacity.
The concentrated boric acid storage tank is sized for 2.5-4.5 weight aercent boric acid solution and is capelele of storing solution up to 4.5 weig1t percent solution. AllL components of the system are capable of maintaining 4.5 weight percent solution. The elevation of the concentrated boric-acid
-tank is sufficiently above the charging pump suction.so-as'to provide l
adequate gravity flow to the charging pumps.
Figure 2-12 contains a 10*F bias to account for temperature measurement uncertainty. An-administrative procedure to monitor the temperature of;the BASTS and boric-acid-system piping in the Auxiliary Building ensures that the temperature requirements of Figure 2-12-are met.
Should the system temperature be unacceptable for-operation at the-current boric acid-concentration, immediate steps will be taken to reduce the boric acid concentration or raise the temperature of the system such that the concentration is within the acceptable range of Figure 2-12.
The SIRW tank contents are sufficient to borate the reactor coolant in order to reach cold shutdown at any time during core life.
The limits on component operability and the time periods for inoperability i
were selected on the basis of the redundancy indicated above and engineering judgment.
4 References (1) USAR; Section 9.2 l
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- 3.9 4.1 4.3 4.5 STORED BAST CONC (WT P. BORIC ACID)
+ 2000 PDM
- 2150 PPM
- 2300 PPM IN SIRWI IN SiRWT IN S[RWT
-lN SIRWT-lN SIRWT FORT CALHOUN MIN BAST LEVEL vs STORED BAST CONCENTRATION OMAHA PUBLIC POWER DISTRICT FIGURE FORT CALHOUN STATION-UNIT 1 2-11 I
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30 40 50 60 70 80 90 100 110 120 130 140 TEMPERATURE (DEGREES F) 4.
I BORIC ACID SOLUBluTY IN WATER OMAHA PUBUC POWER DISTRICT FIGURE FORT CALHOUN STATION. UNIT 1 2 12' t
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'IABIE 3-2 (continued)
MDIDEM N RR <wn-m. NIFATIQ35 AND irami OF
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DIGINEERED SAFEIY rzmures. DEFIMPENIATION AND_.CulmRS Surveillance 01annel Description Function-Freauency Surveillance Method 14.
(continued) b.
calibrate R
b.
Phown pressure arti differential pressure applied to pressure arxi level sensors.
15.
Boric Acid Tank level a.
Oleck D
a.
Cbnpare two indications.
I b.
Test R
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Punp tank below low-level alarm point to verify switch operation.
c.
Calibrate-R c.
Phown differential pressure applied to level' sensors. ' At least three points in indicator.
rarge will be cbtained-high, afMie of-rarupt, ard low (near alarm set-point).
5 16.
Boric Acid Tank Tenperature a.
Oieck D
a.
Inlication Observe temperature devices for M twdirgs.
17 Steam Generator Low Pressure a.-
Oieck S
a.
Signal-(SGIS)
Ompare'four ir4a.2d. pressure inlications.
b.
Test-M(2) b.
'Sim11ated signal.
c.
Calibrate-R c.
Ynown pressure applied'to sensors to verify trip points, logic operation, block permissive, auto reset ard valve closures.
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Basis for No Sionificant Hazards Considerations The proposed change to Section 2.2, Chemical and Volume Control System will revise Technical Specifications 2.2(1),2.2(2)c,2.2(2)d,2.2(2)e,_2.2(2)f,
'2.2(3)c, 2.2(3)d, 2.2(3)e, 2.2(3)f, and Table 3-2, add Figure 2-11, and 2 and amend the basis, reference and Table of Contents.
The Specifications define:
(1) the volume and concentration of boric acid to be maintained in the SIRW tank and BAST for cooldown of the plant; and (2) and flow paths from the BAST to the reactor coolant system during the various modes of plant operation.
Technical Specification Section 2.2(1) has been modified to reduce the chance of a mistake in interpretation. The phrase "and the reactor is subcritical" has been added to specify to which mode (s) of o)eration this item applies.
The-10,000 gallon SIRW tank requirement indicates tie equivalent volume of borated water necessary to mitigate an inadvertant dilution incident or to provide make-up for a spillage.
In the past no minimum volume had been specified which has allowed for operator interpretation of the requirement.
Section2.2(2)d2 also provides guidance for minimum volume requirements.
Technical Specification Section 2.2(2)c and 2.2(2)d specify the minimum tank levels and system flow paths to ensure that an adequate source of boric acid is available to provide a 4.0% delta k/k shutdown margin during a plant cooldown.
The flow path available will determine if the required volume of borated water can be either the combined volume of the two BASTS, or can be contained in a specific BAST. The most conservative cooldown requirements have been utilized.
in the determination of the minimum BAST level along with application of appropriate biases and uncertainties for level indication, vortex generation, and auxiliary spray usage.
Single failure requirements with operator action i
have been identified to ensure the ability of the boric acid system to aerform i
its safety function of plant cooldown.- Credit is not taken in any of tie safety analyses including the LOCA analysis for concentrated boric acid injection to mitigate an accident or anticipated operational occurrence.
l Technical Specification Section 2.2(2)e is deleted las heat tracing of the boric acid system is no longer required to prevent precipitation of boric acid from solution. The reduction of the concentration range.to_be maintained in one or j
both BASTS is specified in Figure 2-11.
The new Figure 2-11 will represent the 1
minimum required volume at a given concentration of boric acid to be maintained.
The proposed change will allow this volume to be maintained as a combined volume in either or both of the BASTS.
The concentration is in the range of approximately 2.5 to 4.5 weight percent boric acid.. Figure 2-11 incorporates five curves which represent the minimum boric acid volume required from BASTS for a given SIRW tank concentration.
In order to verify the minimum ambient temperature in the Auxiliary Building is sufficient to prevent boric acid precipitation an administrative procedure to monitor the. temperature in the inservice BAST (s) and boric acid system piping will be implemented.
The temperature values will be verified with Figure 2-12 to ensure operation at an acceptable boric acid concentration.
Immediate actions will be required by operators should the concentration be identified as unacceptable.
Sufficient operators actions will ensure that the boric acid system remains operable at all times. Operation at an' unacceptable concentration will potentially restrict the ability to inject boron into the reactor coolant system, but not prohibit the ability due to the line size and the acid concentration.
Technical Specification Section 2.2(3)c -and 2.2(3)d are deleted since they specify the minimum system configuration requirements fcr the equipment during operation. - The-system flow paths have been established in Section 2.2(2)d to ensure sufficient boric acid is available for injection to the RCS.
The proposed change will require that both the gravity feed.and the toric acid transfer pumps are operable.- There is one gravity feed path and one boric acid pump path from each BAST.
If the combined volume of boric acid required is contained as a combined volume between the two BASTS, then the proposed change will required both gravity feed paths and both boric acid transfer pump paths be operable.
If the minimum boric acid requirements are being satisfied by one BAST, then the proposed change will allow one BAST to be out of service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> based on standard technical specifications duration.
Technical Specification Section 2.2(3)e is deleted as it specifies the minimum heat tracing operability. The reduction of the concentration range to be maintained in one or both BASTS is specified in Figure 2-11. The new Figure 2-11 will represent the minimum required volume at a given concentration of boric acid to be maintained.
The proposed change will allow this volume to be maintained as a combined volume in either or both of the BASTS. The concentration is in the range of approximately 2.5 to 4.5 weight percent boric acid.
Figure 2-11 incorporates five curves which re) resent the minimum boric acid volume required from BASTS for a given SIRW tan( concentration.
Technical Specification Section 2.2(3)f has been changed to 2.2(3)c for consistency in numbering for the section.
Technical Specification 2.2(3)d has been added to specify a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> duration for one of the BASTS to be removed from service.
This time-period is consistent with the standard technical specifications utilized by other Combustion Engineering Plants.
Figure 2-11 specifies the minimum required boric acid tank volume as a function of concentration to maintain the shutdown margin of 4.0% delta k/k at all times i
during a cooldown to 210*F. To set the minimum BAST volume corresponding to the various BAST and SIRW tank concentrations a parametric analysis was completed to calculate the required boric acid concentration to maintain the 4.0% delta k/k shutdown margin for various BAST and SIRW tank levels versus RCS temperature, i
Figure 2-12 specifies the acceptable boric acid coricentration for system-temperature to ensure the solubility of the boric acid in water. The curve is derived from the US Borax & Chemical Corporation Technical Data Sheet for boric acid solubility in water. A 10*F bias has been added to the US Borax l
temperature value to account for temperature measurement uncertainty and to i
provide for additional solubility margin.
This is consistent with the proposed changes described above.
.The basis of Technical Specification Section 2.2 has been amended to reflect the proposed change as described in-the justification and discussion evaluation. This is consistent with the proposed changes described'above.
The reference "FSAR, Section 9.2" has been changed to "USAR, Section 9.2" as the FSAR has been replaced by the USAR. This is an administrative change and does not have any impact on the Technical Spocification.
Table 3-2 has been changed to specify the surveillance requirements necessary to validate the temperature and level basis for Technical Specification Section 2.2.
The BAST temperature will be monitored as well as the boric acid system piping temperatures to ensure that the solubility requirements of Technical
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Specification Figure 2-12 are maintained. The piping temperatures will be-verified in accordance with an administrative procedure (s) and will be terminated, with NRC concurrence, when a sufficient temperature database has been established. The level will be verified by use of two indications, one of which may be a sight glass.
The proposed amendment to the Technical Specification does not involve' a significant hazards consideration because the operation of the Fort Calhoun Station in accordance with this amendment would not:
(1)
Inulve a significant-increase-in the probability of occurrence or consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report. The boric acid system is not utilized in the safety analysis report to mitigate the consequences of an accident ~or malfunction.
From the standpoint of reactivity control, the BAST and SIRW tank concentrations ensure that a minimum of 4.0% shutdown margin is maintained during a cooldown from hot standby to cold shutdown as described in the safe shutdown scenario described below.
The plant is in hot standby and has been held at hot zero power conditions with the most reactive rod stuck in the full out position for 23.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> following a power reduction from 100% to 0%.
(The-Xenon )eak after shutdown will have decayed back to the 100% power equiliarium Xenon level.
Further Xenon decay will add positive reactivity to the core during the plant cooldown).
No credit was taken for the negative reactivity effects of the. Xenon concentration peak following the power reduction.
At 23.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> offsite power is lost and the plant goes into natural circulation. All non-safety grade plant equipment and components are lost. During the natural circulation cooldown the RCS average temperature. initially rises 25'F due to decay heat in the core. The initial temperature at the start of the cooldown is 557'F.
1 Approximately 0.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> later, at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the operators commence a j
cooldown to cold shutdown (210'F).
The proposed volume and flow path' requirements will ensure that the plant can-be brought to cold r
L shutdown conditions assuming letdown is unavailable, in conjunction with the loss of offsite power, and assuming the limiting single failure. Therefore, the proposed change does not. increase the probability or consequences of an accident or malfunction of equipment important to safety.
(2) Create the possibility for an accident or malfunction of a new or different type than previously evaluated in the safety analysis report.
The proposed change does not physically alter the configuration of the plant and no new or different mode of operation L
has been implemented.
Therefore, the possibility of an accident or-malfunction of a new or different type than any previously evaluated in the safety analysis report.
l (3)
Involve a significant reduction in the margin of safety as defined in the basis for any Technical Specification'.
The proposed change i
maintains the basis of the safety analysis.
In addition, the more restrictive requirements of boron flow paths effectively ensure that the plant can be brought to cold shutdown in the limiting safe t
l shutdown scenario. Therefore, the margin of safety as defined in the basis for the Technical Specification is not reduwd.
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Based on the above considerations,-OPPD does not believe that this amendment involves a significant hazards consideration as defined by 10CFR50.92 and the r
proposed changes will not result in a condition which significantly alters the impact of the station on the en=ironment.
Thus, the proposed changes meet the eligibility criteria for. categorical exclusion set forth in 10CFR51.22(e)(9) and pursuant to 10CFR51.22(b) no environrnental impact or environmental assessment need be prepared.
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TECHNICAL SPECIFICATIONS - FIGURES l
' TABLE OF CONTENTS PAGE WHICH' FIGURE DESCRIPTION FIGURE FOLLOWS l 1-1 TMLP Safety Limits 4 Pump Operations..........
1-3 1 Axial Power Distribution LSSS for 4 Pump Operation...
1-3 1-3 TMLP.LSSS 4 Pump Operation................
1-3 l
2-1A RCS Press-Temp Limits Heatup....
2-6 l
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2-1B RCS Press-Temp Limits.Cooldown......'.......
2-6' l-I 2-3 Predicted Radiation Induced NDTT Shift.........
2-6
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2-11 MIN BAST Level vs Stored BAST Concentration......
2-19
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2-12 Boric Acid Solubility in Water...............
2-19 l
2-10 Spent Fuel Pool Region 2 Storage Criteria.......
2-38
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2-4 PDIL..........................
2-53 1
2-5 Allowable Peak Linear Heat Rate vs Burnup.......
2-53 l
2-6 LC0 for Excore Monitoring of LHR............
2-53' I
2-7 LCO for DMB Monitoring..................
2-53~
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2-8 Flux Peaking Augmentation Factors...........
2-53 l
2-9 FT,F T R X Y and Core Power Limitations..........
2-53_
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1 viii Amendment No. JJE-o j
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