ML20086Q533
| ML20086Q533 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 12/20/1991 |
| From: | UNION ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20086Q530 | List: |
| References | |
| NUDOCS 9112300243 | |
| Download: ML20086Q533 (11) | |
Text
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ULNRC-2539
. ATTACHMENT 1 j
TECHNICAL SPECIFICATION CHANGES n
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EACly arETY FEATUPES ACTUATIDH SYSTEM INSTRi m lATION TRIP SETPOINTS
.E TOTAL SENSOR JtilP ALLOWABLE s
FUNCTIONAL UNIT ALLOWANCE (TA)
Z ERROR (5)
SLTDOiNT VALUE g
Z 8.
Loss of Power (Continued) b.
-Grid Degraded 0.'18
- 0. S3 0
fo7A7 Y lo7.s7.i O.3g y Voltage
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w/119s delay w/11.9 1 11.6s delay s.
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Control Room Isolation a.
Manual Initiation N.A.
N.A.
N.A.
M.A.
M.A.
Y b.
Automatic Actuation N.A.
N.A.
M.A.
6 N.A.
N.A.
Y Logic and Actuation C*,
Raiays (55PS) c.
Automa*.ic Actuation Logic and Actuation Relays (BOP ESFAS)
H.A.
H.A.
M.A.
H.A.
H.A.
d.
Phase "A" Isolation See Item 3.a. above for all Phase "A' Isoietion Trip 5etpoints and Allowable
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Values.
- 10. Solid-State Load Siquencer H.A.
H.A.
N.A.
M.A.
M.A.
- 11. Engineered Safety a
fri features Actuation Systes Interlocks
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P-11 H.A.
H.A.
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Reactor Trip. P-4 H.A.
N.A.
N.A.
N.A.
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ULNRC-2 5 39 -
J ATTACHMENT 2 SAFET'l EVALUATION 9
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ULNRC-2539 Page 1 of 3 SAFETY EVALUATION This amendment application requests a revision to T4chnical Spetification Table 3.3-4, Functional Unit 8.b, to revise the trip setpoint, the allowable value, total allowance, sensor error, and "Z"-value of the "4 kV Undervoltage - Grid Degraded Voltage" protection function to agree with the required design values.
This amendment is necessary to comply with BTP-PSB-1 (Reference 1) which requires that " [t]he selection of undervoltage setpoints shall be determined from an analysis of the voltage requirements of the Class-1E loads at all onsite system distribution levels.
The revised degraded voltage setpoint is based en a new load flow analysis consistent with the NRC-approved methocology described in Reference 2 and meets the requirements of BTP-PSB-1.
The setpoint tolerances are in accordance with ISA Standard 67.04-1982 (Reference 3) as endorsed by Regulatory Guide 1.105 (Reference 4) and identified in Information Notice 91-29 (Reference 5).
The grid degraded voltage protection function assures that all safety-related equipment have adequate voltage to operate.
If the sensed voltage on a safety-related Class IE 4.16 kV AC bus is less than the setpoint, then the offsite AC supply is removed and the emergency diesel generator-is aligned ~to provide adequate voltage to the equipment.
Also, the closer the degraded voltage setpoint is to the normal operating: voltage, the_ greater-the chance for inadvertent tripe.
An upper limit on the degraded bus voltage setpoint provents inadvertent shedding of the busses and starting of the emergency diesel generators to supply the load.
During early 1991,-Union Electric Company conducted an Electrical Distribution System Functional Assessment -("EDSFA")- of the Callaway Nuclear Plant ("Callaway").
During the EDSFA, Union-Electric discovered that the existing Technical Specification degraded voltage setpoint for Callaway was noC revised as a tasult of a 1984 load flow analysis.
A summary of the undervoltage protection analyses ' for the SNUPPS Plants performed in-1984 is described in Reference 2.:
Union Electric has determined that the value currently allowed by Technical Specifications-is bounded by the safety analysis.. This amendment restores margin between the safety analysis and the Technical Specification setpoints.
The revised setpoint is calculated by the original-Architect-Engineer.of the Callaway F Int using' load data provided by Union Electric.
The-safety-related Class 1E distribution system is modelled from the 4.16 kV AC buses to.the 480 V motor control centers.
The voltage at the 4.16 kV bus is lowered until L
any one niotor control center reaches its low voltage limit to.
ULNRC-3539 Page 2 of 3 adequately power required components.
This value of voltage on the 4.16 kV bus corresponds to the desired degraded voltage setpoint.
The amendment to Technical Specification Table 3.3-4 does not involve an unreviewed safety question because operation of the Callaway Plant with the revised setpoint would not:
1.
ILcrease the probability of occurrence or consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report.
The revised setpoint restores margin to meet the requirements of BTP PSB-1.
No other probabilities, acc'ident initiators or assumptions are affected.
The consequences of accidents previously evaluated are not-changed.
No changes to equipment operations are made that increase energy levels of either potential, kinetic, chemical or-nuclear energies.
2.
Create the possibility for an accident or malfunction of.a different type than any previously evaluated in the safety analysis report.
No new accidents are created by the revised setpoint.
No new equipment is added.- No new modes of operation or means of control are made.
The probability of a malfunction of equipment important to safety is reduced since the revised setpoint rescores margin to ensure adequate voltage exists for equipment to operate. - The consequences of malfunctions-of equipment important to safety'are-not. changed.
No changes to equipment operations are made that increase potential kinetic, chemical, or nuclear energy. levels.
No new malfunctions are created.- No new controlling-modes or
.equiprant operations are created.
3.
Reduce the margin of safety aL defined in theLbasis.for any technical specification.
The. revised.setpoint restores margin to meet.the requirements of BTP PSB-1.
No-other margins of safety are-affected.
Given the above discussions, as well as those presented in the Significant Hazards Consideration,;the revised setpoint does not adversely affect or endanger the health or safety;of the general public or involve a significant. safety hazard.
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i ULNkC-2539 Page 3 of 3 Refergnggs 1)
U.S. Nuclear Regulatory Commission Branch Technical Position
("BTP") PSB-1,
" Adequacy of Station Electric Distribution System Voltages,"
Rev.
O, July 1981 i
2)
SLNRC 84-0011, " Power Systems Branch Review Grid i
Undervoltage, " January 31, 1984 3)
Instrument Society.of America Standard 67.04-1982, 4
"Setpoints for Nuclear Safety-Related Instrumentation used in Nuclear Power Plants" 4)
Regulatory Guide-1.105 Revision 2-1986, " Instrument Setpoints for Safety-Related Systems" l
5)
.?mC Information Notice No. 91-29, " Deficiencies Identified During Electrical Distribution System Functional i
Inspections,"' April 15, 1991 1
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ATTACHMENT 3 SIGNIFICANT HAZARDS ~ EVALUATION t
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ULNRC-2539 Page 1 of 2 SIGNIFICANT HAM @j EVALUATION I
This amendment application requests a revision to Technical Specification Table 3.3-4, Functional Unit 8,b, to revise the trip setpoint, the allowaole value, total allowance, sensor error, and "Z"-value of the "4 kV Undervoltage - Grid Degraded Voltage" protection function to agree with tne required design values.
This amendment is necessary to comply with USNRC Branch Technical Position ("BTP") PSB 1,
" Adequacy of Station Electric Distribution System Voltages," which requires that "[t]he selection of undervoltage.
. setpoints shall be determined from an analysis of the voltage requirements of the Class 1E loads at all onsite system distribution levels..
The grid degraded voltage protection function. assures that all safety-related equipment have adequate voltage to operate.
The revised degraded voltage setpoint is based on a new load flow analysis consistent with NRC-approved methodology and meets the requirements of BTP PSB-1.
The setpoint tolerances are in accordance with Instrument Scciety of America Standard 67.04-1982, "Setpoints for Nuclear Safety-Related Instrumentation Used in Nuclear Power Plants," as endorsed by USNRC Regulatory Guide 1.105, " Instrument Setpoints for Safety-Related Systems."
The amendment to Technical Specification Table 3.3-4 does not involve a significant hazard consideration because operation of.
the Callaway Plant with the revised setpoint would not:
1.
Inv.)1ve a significant increase in the probability or consequences of an accident previously evaluated.
The change restores margin to meet the requirements of_BTP PSB-1.
Ik) other probabilities, accident initiators, or assumptions are affected.
The consequences of accidents previously evaluated are not changed.
No changes to equipment operations are made that increase energy levels of either potential, kinetic,-chemical or nuclear energies.
2.
Create the possibility of a new or differentLkind of accident from any previously evaluated.
No new accidents are created by the revised setpoint.
No new equipment is~added.-_No new modes of operation or means of control are made.
The probability of a malfunctionuof j
equipment important to safety is reduced since the_ revised setpoint restores the original margin to ensure adequate voltage exists for_ equipment-to operate.
The consequences of malfunctions of. equipment important to safety are not changed.
No changes to equipment operations are made that increase potential, kinetic, chemical, or nuclear energy levels. <No new malfunctions are created.
No new controlling _ modes or equipment operations are created.
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ULNRC-2539 Page 2 of 2 3,
Involve a significant reduction in a margin of safety.
The revised setpoint restores margin to meet the requirements of BTP PSB-1.
No other margins of safety'are affected.
As discussed above, the revised setpoint does not. involve a significant increase in the probability or consequences of an i
accident previously evaluated, create the possibility of a new or different kind of accident from any previously evaluated, or result in a significant reduction in a margin of safety.
Therefore, it has been determined that the amendment does not involve a significant hazards consideration.
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ULKRC-2539 f
ATTACHMENT 4 ENVIRONMENTAL CONSIDERATION 1
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4 ULNRC 2539 Page 1 of 1 ENVIRONMENTAL CONSIDERA"10E This amendment application requests a revis ion to Technical Specification Table 3.3-4, Functional Unit 8.b, to revise the trip setpoint, allowable value, total allowance, sensor error, and "Z"-value of the "4 kV Undervoltage - Grid Degraded Voltage" protection function to agree with the required design values.
This amendment is necessary to comply with USNRC Branch Technical Position ("BTP") PSB-1, " Adequacy of Station Electric Distribution System Voltages,." which requires that " [t] he selection of undervoltage.
setpoints shall be determined from an analysis of the voltage requirements of the Class 1E loads at all onsite system distribution levels.
The grid degraded voltage protection function assures that all safety-related equipment will have adequate voltage to operate.
If the sensed voltage on a safety-related Class 1E 4.16 kV AC bus is less than the setpoint, then the offsite AC supply is removed and the emergency diesel generator is aligned to provide adequate voltage to the equipment.
The proposed amendment involves changes with respect to the use of facility components located within the restricted area ae defined in 10 CFR 20, and changes a surveillance requirement.
Union Electric has determined that the proposed amendment does not involve:
1)
A significant hazard consideration, as discussed in of this amendrant application; 2)
A significant change in the types or significant increase in the amounts of any effluents that may be released offsite; 3)
A significant increase in individual or cumulative occupational radiation exposure.
Accordingly the proposed amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 (c) (9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.