ML20137G243
| ML20137G243 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 08/19/1985 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20137G237 | List: |
| References | |
| TAC-59579, TAC-59580, NUDOCS 8508270247 | |
| Download: ML20137G243 (5) | |
Text
-
Attachment I 3/4.5 EMERGENCY CORE COOLING SYSTEMS 3/4.5.1 ACCUMULATORS COLD LEG INJECTION LIMITING CONDITION FOR OPERATION 3.5.1.1 Each cold leg injection accumulator shall be OPERABLE with:
a.
The isolation valve open, b.
A contained borated water volume of between 8022 and 8256 gallons c.
A boron concentration of between 1900 and 2100 ppm, d.
A nitrogen cover pressure of between 430 and 484 psig, and e.
A water level and pressure channel OPERABLE.
APPLICABILITY:
MODES 1, 2, and 3*.
ACTION:
a.
With one accumulator inoperable, except as a result of a closed isolation valve or boron concentration less than 1900 ppm, re-l store the inoperable accumulator to OPERABLE status within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
b.
With one accumulator ' inoperable due to the isolation valve being closed, either immediately open the isolation valve or be in at least H0T STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
c.
With one accumulator inoperable due to boron concentration less than 1900 ppm and:
- 1) the volume weighted average boron concentration of the three limiting accumulators greater than 1900 ppm, restore the inoperable accumulator to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the low boron determination or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
- 2) the volume weighted average baron concentration of the three limiting accumulators less than 1900 ppm, restore the in-operable accumulator to OPERABLE status or return the volume weighted average boron concentration of the three limiting
" Pressurizer pressure above 1000 psig.
McGUIRE - UNITS 1 and 2 3/4 5-1 Amendment No.
(Unit 1)
Amendment No.
(Unit 2) 85n9270247 850819 PDR ADOCK 05000369 P
EMERGENCY CORE COOLING SYSTEMS LIMITING CONDITION FOR OPERATION ACTION: (cont'd) accumulators to greater than 1900 ppm and enter ACTION c.1 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> of the low boron determination or be in H0T STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce pressurizer pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
SURVEILLANCE REQUIREMENTS 4.5.1.1.1 Each cold leg injection accumulator shall be demonstrated OPERABLE:
a.
At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by:
- 1) Verifying the contained borated water volume and nitrogen cover pressure in the tanks, and
- 2) Verifying that each cold leg injection accumulator isolation valve is open.
b.
At least once per 31 days and within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after each solution volume increase of greater than or equal to 1% of tank volume not resulting from normal makeup by verifying the boron l
concentration of the accumulator solution; c.
At least once per 31 days when the RCS pressure is above 2000 psig by verifying that power to the isolation valve operator is disconnected by removal of the breaker from the circuit; and d.
At least once per 18 months by verifying that each accumulator isolation valve opens automatically under each of the following conditions:
- 1) When an actual or a simulated RCS pressure signal exceeds the P-11 (Pressurizer Pressure Block of Safety Injection) l
- Setpoint,
- 2) Upon receipt of a Safety Injection test signal.
4.5.1.1.2 Each cold leg injection accumulator water level and pressure channel shall be demonstrated OPERABLE:
a.
At least once per 31 days by the performance of an ANALOG CHANNEL OPERATIONAL TEST, and b.
At least once per 18 months by the performance of a CHANNEL CALIBRATION.
McGUIRE - UNITS 1 and 2 3/4 5-2 Amendment No. (Unit 1)
Amendment No. (Unit 2) l
Attachment II TECHNICAL JUSTIFICATION AND SAFETY ANALYSIS The specifications associated with Cold Leg Injection Accumulators are intended to ensure that a sufficient volume of borated water will be imme-diately forced into the core through each of the cold legs in the event the reactor coolant system (RCS) pressure falls below the pressure of the accu-mulators. This surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures. The limits placed upon accumulator volumes, and pressures ensure the assumptions used in the safety analyses are satisfied.
Boron concentration limits help to provide reasonable assurance that the reactor will remain subcritical following the LOCA event.
The existing specification requires each Cold Leg injection Accumulator to maintain conditions consistent with safety analyses assumptions including boron concentrations within the range of 1900-2100 ppm. The proposed revision to the required action statement maintains the overall volume and baron delivery requirements but allows for a more flexible schedule to restore a single accumulator to operable status. The assurance of satisfying volume and boron delivery requirements is provided by calcu-lating the average volume and volume weighted averaged boron concentration of the three limiting accumulators. The limiting accumulators are defined as the combination of three accumulators which delivers the minimum volume weighted average boron concentration. The accumulator which would provide the maximum boron delivery is not accounted for due to the assumption that the voluna from that accumulator passes directly out of the break in the RCS piping.
The allowance of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore the inoperable accumulator if the volume weighted average ot the three limiting accumulators is greater than 1900 ppm is deemed appropriate since safety analyses assumptions remain satisfied but the low concentration h1 a single accumulator is indicative of a possible problem and therefore investigation and corrective action is the prudent response. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowance maintains the existing require-ment to restore the inoperable accumulator but does not unnecessarily initiate operator actions in the attempt to avoid more severe action statement procc-dures.
The benefit of the revision is thus a less hurried atmosphere for operator actions allowing for a well planned response to the inoperable accumulator and a reduction in the number of unnecessary plant mode changes while maintaining plant conditions which satisfy safety analyses assumptions'.
The action statement related to conditions in which the volume weighted average boron concentration of the three limiting accumulators is less than 1900 ppm allows 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to either restore the inoperable accumulator to operable status or return the volume weighted average boron concentration of the three limiting accumulators to greater than 1900 ppm and continue appropriate actions per the previously discussed action statement. The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance reflects the fact that a slight deficiency in boron con-centration in a single accumulator is a less severe condition than devia-tions in the volume or cover pressure parameters since the cold leg accumulators serve primarily as a cere cooling mechanism. The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowance suf ficiently minimizes the probability of a LOCA event concurrently
(
i
with the volume weighted average boron concentration of the three limiting accumulators being less than 1900 ppm and also provides a reduction in the number of plant mode changes associated with the severe action statements of the existing specification.
Reactivity control via normal control sys-tems, the operabic* cold leg accumulators, and the refueling water storage tank also help to minimize concerns related to increasing the allowable time an accumulator may be inoperable due to low boron concentration from I hour to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> prior to initiating a plant operating mode reduction.
Considering the frequency of slight deficiencies in singic accumulator boron concentrations at McGuire and the associated increase in forced mode changes, inspection of the accumulator specification was necessary due to the increased likelihood of an unplanned plant transient resulting from action statement requireme nt s. The development of the volume weighted average boron concen-tration of the three limiting accumulators aspect of the proposed specifica-tion adequately ensures the validity of the safety analyses and provides a reasonable time period to address the minor deviations in boron concentration of the inoperable accumulator. The increased time period (6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />) for opera-tion with a single accumulator inoperable and the volume weighted average boron concentration of the three limiting accumulators less than 1900 ppm is reasonable considering the probability of a LOCA concurrent with this condition and the availability of other means of reactivity control.
The proposed change to surveillance requirement 4.5.1.1.1.b is to specify the volume increase to require boron verification is from a source other than normal makeup. Normal makeup is taken f rom the refueling water storage tank which is required by Technical Specification 3.5.5 to have a concentration of between 2000 and 2100 ppm of boron, thus no dilution of boron concentration can occur as a result of normal makeup, therefore verification of the boron concentration after normal makeup is unnecessary.
Attachment III ANALYSIS OF SIGNIFICANT HAZARDS CONSIDERATION Pursuant to the requirements of 10CFR50.91, this analysis provides a determination that the proposed amendment of the Technical Specification does not involve any significant hazards consideration, as defined by 10CFR50.92.
The proposed change of Technical Specification 3/4.5.1.1 is intended to improve the reliability and availability of McGuire.
The cold leg accumulators are to ensure that a large volume of borated water is injected into the RCS in the event of a LOCA and serve no other function.
No hardware changes will be made to affect the probability of an accident, and the volume of borated water to be delivered to the core is unaffected.
The proposed amendment would not:
1)
Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2)
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3)
Involve a significant reduction in a margin of safety.
Based upon the preceding analysis, Duke Power Company concludes that the proposed amendments do not involve a significant hazards consideration.
F 9