ML18052A367
| ML18052A367 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/25/1986 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML18052A366 | List: |
| References | |
| NUDOCS 8604020133 | |
| Download: ML18052A367 (5) | |
Text
3.7 ELECTRICAL SYSTEMS Applicability
- --------------App-11-e-s- *to*- t*h-e- availaDili-t)r--o-f e1-ect-r-1ca1*-power -for-the- -o-perat-1ng-.. of-- --- -- -----*----~ ---
plant components.
Objective To define those conditions*6f electrical power availability necessary to provide for safe reactor operation and the continuing availability of engineered safety features.
3.7.1 Specifications
- The primary coolant system shall not be heated or maintained at temperatures above 325°F if the following electrical systems are not operable:
- a. Station power transformer 1-2 (2400 V).
- b. Start-up transformer 1-2 (2400 V).
c; 2400 V engineered safeguards buses lC and lD.
- d. 480 V distribution buses 11 and 12.
- e. 480 V distribution buses 19 and 20.
- f. MCC numbers 1, 2, 25 and 26.
- g. MCC numbers *7, 8, 21, 22, 23 and 2~.
- h. 125 V d-c buses DlO and D20.
- i. Four preferred a-c buses YlO, Y20, Y30 and Y40.
- j. Two station batteries and the d-c systems including at least one
.battery charger on ~ach bus.
- k. Both diesel generators, with a minimum of 2500 gallons of fuel in each day tank and. a minimum of 16, 000 gallons of fuel in the underground sto~ag~ tank.
- 1. Switchyard battery and the d-c system with one battery charger.
m.. 240 V a-c power panels No 1 and 2; and their associated Air Blast Circuit Breaker (ABCB) _distr~bution sy~tems, wJ1ich are. located in the switchyard.
- n. 2400 V bus lE.
( 8604020133 860325 'I PDR ADOCK 05000255 I t P. PDR.
r ---
3-41 Proposed TSP0386-0046-NL04
3.7 ELECTRICAL SYSTEMS (Contd)
, 3.7.2 With the Primary Coolant System at a temperature greater than 325°F, the requirements of Specification 3.7.1 may be modified to permit one of the following c~nditions to exist. If any of the provisions of
- - -* -- * - -------those exceptions-are- :vio-lated ,- the reactor. sh*all oe placeo--in- a -lioY shutdown condition within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. If the violation is not corrected within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the reactor shall be placed in a* cold shutdown condition within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- a. Station power transformer 1-2 (2400 V). may be inoperable for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the operability of both diesel generators is demonstrated im,mediately.
- b. Start-up transformers 1~2 (2400 V) may be inoperable for up to
. 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the operability of both diesel generators is demonstrated immediately. Continued operation beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is permissible provided that a report is sent to the NRC immediately with an outline of the plans for prompt restoration of the start-up transformer and the additional precautions to be taken while the transformer is out of service, and continue operating until notified differently by the NRC.
- c. 2400 V engineered safeguards bus lC or lD may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the operability of the diesel generator associated with the operable bus is demonstrated immediately and there.are no inoperable engineered safety feature componen~s.
associated with the operable bus.
- d. 480 V distribution bus 11 or 12 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safety feature components associated with the operable bus.
- e. 480 V distribution bus 19 or 20 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safety feature components associated with the operable bus.
- f. MCC 1 and 25 or 2 and 26 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safety feature components associated with the operable trio of MCC's.
- g. MCC 7, 21 and 23 or 8, 22 and 24 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are no inoperable safety feature components associated with the operable trio of MCC.
. h. 125 V d-c bus DlO or D20 may be inoperable for up to 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided there are-no inoperable aafety feature components associated with the operable bus and adequate portable emergency lighting i~ _available during the inoperabiHty of the D20 _bus~
- i. One of the four pref erred a-c buses may be inoperable for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> provided the reactor protection and engineered safety feature systems supplied by the remaining three buses are all operable.
3-42 Proposed TSP0386-0046-NL04
3.7 ELECTRICAL SYSTEMS (Contd)
- j. One of the station batteries may be inoperable for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, providirig both batt~ry chargers on the affected bus are in operation.
k~ One of the diesel generators may be inoperable for up to 7 days (total for both) during any 30-day period, provided the other diesel is started to verify operability, shutdown and the controls are left in the automatic mode, and there are no inoperable engineered safety feature components associated with the operable diesel generator.
- 1. 240 V a-c power panel No 1 or power panel No 2 may be inoperable provided that the associated ABCBs are maintained operable by other means *. If the ABCBs. are.not maintained operable, either power panel may be inoperable for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided that the associated ABCBs are in the "open" position.
- m. The switchyard battery may be inoperable for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided both battery chargers are operable.
- n. The 2400 V bus lE may be inoperable up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
- o. The switchyard 125 V d-c power panel No 1 .or power panel No 2 may be inoperable provided the associated ABCBs .are maintained operable by other means. If the *ABCBs are riot maintained operable, either power panel may be inoperable for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided that the associated ABCBs are in the "open" position.
- p. The contents of the underground fuel oil. storage tank may be between 16 1 000 gallons and 10,000 gallons for. 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
- q. Both fuel oil transfer pumps may be inoperable for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.
Basis The electrical system equipment .is arranged.so that no single contingency can inactivate enough safeguards equipment to jeopardize the plant safety. *The 480 V equipment is arranged on four buses. The 2400 V equipment is supplied from two buses.
The normal source of auxiliary power with the plant at power is from the station pow~r transformers being fed from the main.generator with standby power from the start-up tran~f 9rmer and emergency power from.
either.one of two diesel* generators. To supplement the standby power source, a spare 345 -2.4/4.16 kV 25 MVA transformer is installed and can 21 connected in place of a start-up transformer within
- 3 days. ( There are two emergency power sources on site which do not require outside. power or use of the start-up transformer. Upon*loss of normal and standby power sources, the 2400 V buses are energized from the diesel generators. Bus load shedding, transfer to the diesel generator and ~~Jkup of critical loads are carried out automatically.
- 3-43 Proposed TSP0386-0046-NL04
3.7 ELECTRICAL SYSTEMS (Contd)
When the turbine generator is out of service ~or an extended period, the generator can be isolated by the removal of links in the bus between the generator and the main transformer, allowing the main transfory~r-and--the station power traiisformers to-be_:_r_eturnea- to-service.
- _ * -
The two 4160 V buses et~~ provide power for two primary coolant pumps and a condensate pump. Operation of the plant could continue if one of these buses were not ~vailable ~s long as power level, et~,
were in accordance wi~h Sections 2 and 3.1.2 of these specifications.
The design of the electrical system has been carried out with reliability as a prime consideration. Station power is provided frpm three independent- sources. The outage of any two sources will not cause interruption of service to the station power supply 2400 V or below, down to and including 125 V d-c supply.
Equipment served by the engineered safeguards buses is arranged so that loss of an entire(~ys does not compromise safety of the plant .
l during DBA conditions. For example, if 2400 V bus lD is lost, two service water pumps, one containment spray pump and three containment air cooler recirculation fans are lost. This leaves two containment spray pumps, one containment air cooler recirculation fan and one service water pump, which is more than sufficient to control containment pressure below-the-design value during the-DBA.
The requirements for MCC No. 1, 2, 7, 8, 21, 22, 23, 24, .25, and 26 as well as the 480*V distributions buses 11, 12, 19 and 20 will assure
-availability of safety equipment.such -as charging pumps, boric acid pumps and safety injection valves. The 125 V d-c buses DlO and 020 are required for critical instrument and control operations.
The required minimum fuel oil availability of 2500 gallons in each diesel's day tank is considered adequate since approximately 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> running time (worst case loading) is available before transfer to fuel
- oil from the storage tank is mandatory. The fuel oil transfer pumps are used for transferring fuel oil from the storage tank to the day tanks. In addition, a connection is available outside the diesel rooms to pump oil directly into the day tanks from an oil tanker
- truck. The 16,000 gallons in the storage tank in addition to the day tank will provide a diesel opera~5~n under required loading conditions for a minimum period of 6 days. It is considered incredible not to be able to secure fuel oil from one of sever~l sources within a radius of 70.miles in less than three days under the worst of weather conditions. One battery charger on each battery shall be operating so that the batteries will always be at full charge in anticipation.of loss-of-ac power incident. This insures that adequate d-c power will_
be available for starting the emergency generato~s a~d-~ther emergency uses. _Each battery has two battery chargers available ra.ted at 200 amperes each._ Except for the first minute following a DBA, the capacity of the two battery chargers will handle all required loads.
The second battery continues to be available in the event of a DBA to pick up the load from its half of the installed engineered 3-44 Proposed TSP0386-0046-NL04
- ~ .
- 3.7 ELECTRICAL SYSTEMS
- (Contd) safeguards. ( 6 ) ~ Each of the reactor protective system channels and the engineered safeguards instrumentation channels is supplied by one of
-the -prefe-rred: a-c-- buses.-~ The--r-emoval-of- one -of **the- *preferred-a.~*c* _:
buses is per~itted as*the 2-of-4 logic can be cha~d to a 2-of-3 or l-of-2 logic without compromising reactor safety. .
Reliable switchyard operation requires the availability*of the d-c system in the switchyard for breaker controls and the 240 V a-c system for air compressor operation. The power and air requirements are small, however, and readily adaptable to temporary hookup to alternate power panels or air compressors, so continued operation without the time limitations is permitted provided the affected Air Blast Circuit Breakers (ABCBs) can be restored to operability through such temporary hookups. .In all such situations, restoration to normal conditions shall be accomplished as soon as practicable.
The 2400 V bus lE is required to assure avallability of the pressurize~ heaters.
T.o attain a high degree of reliability for starting and assuming load,
.the diesel generators are started to prove operability and shutdown with the controls left in the automatic "start" position.
References (1) FSAR, Section 8.1.2.
(2) FSAR Update, Section 8.1.
(3) FSAR, Section 8.3.2 and 8.4.
(4) FSAR, Section 8.3.1 .
. (5) FSAR, Section 8.4.1.3.
(6) FSAR, Section.8.4.2.
(7) FSAR, Section 8.3.5.
3-45 Proposed TSP0386-0046-NL04 .