ML20199C992
| ML20199C992 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 01/12/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20199C996 | List: |
| References | |
| NUDOCS 9901190253 | |
| Download: ML20199C992 (4) | |
Text
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3/LB.
El FCTRICAL POWER SYSTEMS BASES 3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURCES AND DISTRIBUTION (Continued)
The operability requirements for the AAC DG are specified in the Technical Requirements Manual. In addition, to be considered OPERABLE to support the founeen day action statement the AAC DG must be capable of providing power to the affected bus (i.e., connectable to the bus with the associated breakers and control power available). If the AAC DG becomes inoperable during g
the 14 day action statement, the OPERABILITY of the remaining EDGs does not need to be demonstrated since the AAC DG was designed and purchased according to specifications which adequately ensure that common cause failure is not likely.
The ACTION requirements specified in Modes 5 and 6 address the condition where sufficient power is unavailable to recover from postulated events (i.e., fuel handling accident).
Implementation of the ACTION requirements shall not preclude completion of actions to establish a safe conservative plant condition. Completion of the requirements will prevent the occurrence of l
postulated events for which mitigating actions would be required.
The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be maintained in the shutdown or refueling condition for extended time periods,2) sufficient.
instrumentation and control capability is available for monitoring and maintaining the unit status, and 3) sufficient power is available for systems necessary to recover from postulated events in.
these MODES, e.g., the control room emergency ventilation system fans during a fuel handling accident.
The Surveillance Requirements for demonstrating the OPERABILITY of the diesel generators are in accordance with the recommendations of Regulatory Guide 1.9 " Selection of Diesel Generator Set Capacity for Standby Power Supplies," March 10,1971, and 1.108 " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants" Revision 1 August 1977, as modified by Amendment No. 83 issued August 22,1986.
-The testing of the largest post-accident load rejection in Surveillance Requirement (SR)-
a 4.8.1.1.2.d.2, for demonstrating the OPERABILITY of the EDGs,is in accordance with the testing recommendations of Regulatory Guide 1.9, Revision 1, Section C.5.
The EDG testing in SRs 4.8.1.1.2.c,4.8.1.1.2.d.5,4.8.1.1.2.d.11.b), and 4.8.1.1.2.e separate the start requirements for voltage and frequency from the steady state limits. The 10-second start requires the EDG to meet the minimum values for voltage and frequency. The EDG's voltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state NORTH ANNA - UNIT 1, B 3/4 8-2 Amendment No. 2^2,2 :4, 216 9901190253 990112 PDR ADOCK 05000338 P
a...
3/4.8 ELECTRICAL POWER SYSTEMS BASES i
3/4.8.1 and 3/4.8.2 A.C. and D.C. POWER SOURCES AND DISTRIBUTION (Continued) frequency. The steady state voltage and frequency limits are not required to be maintained during the 10-second start requirement. Following the fast start of the EDG, the time to reach steady state voltage and frequency is periodically monitored in the performance tests. The tests can be used to l'
identify degradation of the governor and voltage regulator performance. The EDG is unloaded in l,
some portions of these surveillance tests and short-term variations in voltage and frequency, outside the steady state limits may occur in this condition. The safety analyses assume the long-l.I term steady state electrical power requirements for voltage and frequency to the ECCS equipment i
is 4160i 420 volts and 60 i0.5 Hz.
l l
In lieu of actual accident loading demonstration during the performance of SRs 4.8.1.1.2.d.4 and 4.8.1.1.2.d.6, the EDGs are allowed to supply the required loads by a combination of evolutions. This testing may include a series o.. sequential, overlapping, or total steps so that the entire connection and loading sequence is verified. This method of testing adequately verifies the capability of each EDG system to energize the emergency bus and supply the power necessary for the required safety equipment to mitigate analyzed events.
The Surveillance Requirements for demonstrating the OPERABILITY of the Emergency Diesel Generator batteries and the Station batteries are based on the recommendations of Regulatory Guide 1.129, " Maintenance, Testing and Replacement of Large Lead Storage Batteries for Nuclear Power Plants," February 1978, and IEEE Std. 450-1980, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Large Lead Storage Batteries for Generating Stations and Substations," as modified by Amendment No. 97 issued March 25,1988.
1 i
f I
NORTH ANNA - UNIT 1 B 3/4 8-3 Amendment No.
216
s,*,
3/4.8 ELECTRICAL POWER SYSTEMS BASES during the 14 day action statement, the OPERABILITY of the remaining EDGs does not need to be demonstrated since the AAC DG was designed and purchased according to specifications which adequately ensure that common cause failure is not likely.
The ACTION requirements specified in Modes 5 and 6 address the condition where j
sufficient power is unavailable to recover from postulated events (i.e., fuel handling accident).
Implementatic,n of the ACTION requirements shall not preclude completion of actions to establish a safe conservative plant condition'. Completion of the requirements will prevent the occurrence of postulated events for which mitigating actions would be required.
The OPERABILITY of the minimum specified A.C. and D.C. power sources and associated distribution systems during shutdown and refueling ensures that 1) the facility can be maintained in the shutdown or refueling condition for extended time periods,2) sufficient instrumentation and control capability is available for monitoring and maintaining the unit status, and 3) sufficient power is available for systems necessary to recover from postulated events in these MODES, e.g., a fuel handling accident.
The Surveillance Requirements for demonstrating the OPERABILITY of the Emergency Diesel Generators are in accordance with the recommendations of Regulatory Guide 1.9 " Selection of Diesel Generator Set Capacity for Standby Power Supplies," March 10,1971, and 1.108
" Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants" Revision 1, August 1977, as modified by Amendment No. 48 issued August 22, 1986.
The testing of the largest post-accident load rejection in Surveillance Requirement (SR) 4.8.1.1.2.d.2, for demonstrating the OPERABILITY of the EDGs,is in accordance with the testing recommendations of Regulatory Guide 1.9, Revision 1, Section C.S.
y The EDG testing in SRs 4.8.1.1.2.c,4.8.1.1.2.d.5,4.8.1.1.2.d.11.b), and 4.8.1.1.2.e separate the L
start requirements for voltage and frequency from the steady state limits. The 10-second start l
requires the EDG to meet the minimum values for voltage and frequency. The EDG's veltage must exceed the 95% value of rated voltage in order for the output breaker to automatically close. The minimum frequency requirement is based on the safety analyses assumption for steady state l ~ ~ ~
frequency. The steady state voltage and frequency limits are not required to be maintained during the 10-second start requirement. Following the fast start of the EDG, the time to reach steady state voltage and frequency is periodically monitored in the performance tests. The tests can be used to identify degradation of the governor and voltage regulator performance. The EDG is unloaded in
}
some portions of these surveillance tests and short-term variations in voltage and frequency,
{
outside the steady state limits may occur in this condition. The safety analyses assume the long-i NORTH ANNA - UNIT 2 B 3/4 8-2 Amendment No.138,1S4,195,197
_ _ _ ___ ~ _ _ _.. - _ _ _ _._. _ _ _ _ =. _.._. _ _ _ _ _
3/4.8 ELECTRICA.L POWER SYSTEMS BASES term steady state electrical power requirements for voltage and frequency to the ECCS equipment is 4160 t 420 volts and 60 0.5 Hz.
In lieu of actual accident loading demonstration during the performance of SRs 4.8.1.1.2.d.4 and 4.8.I.l.2.d.6, the EDGs are allowed to supply the required loads by a combination y
of evolutions. This testing may include a series of sequential, overlapping, or total steps so that the entire connection and loading sequence is verified. This method of testing adequately verifies the capability of each EDG system to energize the emergency bus and supply the power necessary for 9
_ the required safety equipment to mitigate analyzed events.
The Surveillance Requirements for demonstrating the OPERABILITY of the Emergency Diesel Generator batteries and the Station batteries are based on the recommendations of Regulatory Guide 1.129," Maintenance, Testing and Replacement of Large Lead Storage Batteries for Nuclear Power Plants," Febmary 1978, and IEEE Std 450-1980,"IEEE Recommended Practice for Maintenance, Testing, and Replacement of Large Lead Storage Batteries for Generating Stations and Substations," as modified by Amendment No. 84 issued March 25,1988.
Containment electrical penetration and penetration conductors are protected by either de-energizing circuits not required during reactor operation or by demonstrating the OPERABILITY of primary and backup overcurrent protection circuit breakers during period surveillance.
The surveillance frequency applicable to molded case circuit breakers and/or buses provides assurance of breaker and/or fuse reliability by testing at least one representative sample
- of each manufacturer's brand of circuit breaker and/or fuse. Each manufacturer's molded case circuit breakers and/or fuses'are grouped into representative samples which are then tested on a rotating basis to ensure that all breakers and/or fuses are tested. If a wide variety exists within any manufacturer's brand of molded case ;ircuit breakers and/or fuses, it is necessary to divide that manufacturer's breakers and/or fuses i nto groups and treat each group as a separate type of breaker or fuse for surveillance purposes.
The OPERABILITY of the motor-operated vain thermal and overload protection and/or bypass devices ensures that these devices will not prevent safety-related valves from performing 4
their function. The Surveillance Requirements for demonstrating the OPERABILITY of these devices are in accordance with Regulatory Guide 1.106," Thermal Overload Protection for Electric 3
Motors on Motor-Operated Valves," Revision 1, March 1977.
~ NORTH ANNA - UNIT 2 B 3/4 8-3 Amendment No. +95,197
.