ML20210D160
| ML20210D160 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 09/09/1986 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20210D088 | List: |
| References | |
| NUDOCS 8609190067 | |
| Download: ML20210D160 (9) | |
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INSERT FOR 4.3.3.12.1(d) AND 4.9.2.1.1(d)
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(d) At least once per 18 months the BDMS shall be demonstrated OPERABLE by:
(1) Verifying that each cutomatic valve actuated by the BDMS moves to its correct position upon receipt of a trip signal, and (2) Verifying each reactor aakeup water pump stops, as designed, upon receipt of a trip signal.
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8609190067 860909 PDR ADOCK 05000413 P
PDR a
INSTRUMENTATION 3/4.3.3.12 BORON DILUTI(El MITIGATION SYSTEM LIMITING CONDITION POR OPERATION As a minimum, two trains of the Baron Dilution Mitigation System 4
3.3.3.12 chall be OPERABLE and operating with Shutdown Margin Alarm Ratios set at less than or equal to 4 times the standy-state count rate.
APPLICABILITY; MODES 3, 4. AND 5 (UNIT 1 ONLT)
ACTION:
With one train of the Boron Dilution Mitigation System inoperable (a) or not operating, restore the inoperable train to OPERABLE status within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, or suspend all operations involving positive reactivity changes (1) and verify that valve NY-230 is closed and secured within the next hour, or verify two Source Range Neutron Plux Monitors are OPERABLE (2) with Alara Setpoints less than or equal to one-half decade above the steady-state count rate and verify that the 2
combined flowrate from both Reactor Makeup Water Pumps is less than or equal to 200 gym (Mode 3) or 80 gym (Mode 4 or 4
- 5) within the next hour.
With both trains of the Boron Dilution Mitigation System (b) inoperable or not operating, restore the inoperable trains to OPERAELE status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, or suspend all operations involving positive reactivity changes 3
(1) and verify that valve NV-230 is closed and secured within the next hour, or verify two Source Range Neutron Plux Monitors are OPERABLE (2) with Alar:s Setpcints less than or equal to one-half decade above the steady-state count rate and verify that the combined flow rate from both Reactor Makeup Water Pumps is less than or equal to 200 gym (Mode 3) or 80 gym (Mode 4 or
- 5) within the next hour.
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(c) The provisions of Specification 3.0.4 are not applicable.
SURVEILLANCE REQUIREMENTS Each train of the Baron Dilution Mitigation System shall be 4.3.3.12.1 demonstrated OPERABLE by performance of:
(a) A CHANNEL CHECK at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
CATAWEA - UNITS 1 & 2 3/4 3-92a
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i SURVEILLANCE REQUIREMENTS (CONTINUED)
(b) An ANALOG CHANNEL OPERATIONAL TEST prior tc startup if not performed in previous 7 days, and (c) An ANALOG CHANNEL OPERATIONAL TEST at least once per 31 days.
4.3.3.12.2 If using the Source Range Neutron Fluz Monitors to mest the requirements of Technical Specification 3.3.3.12, (a) The monthly surveillance requirements of Table 4.3-1 for the Source Range Neutron Flux Monitors shall' include verification that the Alarm Setpoint is less than or equal to one-half decade (square root of 10) above the steady-state count rate.
(b) The combined flow rate from bott. Reactor Makeup Water Punps shall be verified as less than or equal to 200 gym (Mode 3) or 80 gpm (Mode 4 or 5) at least once per 31 days.
4 CATAWBA - 1: NITS 1 & 2 3/4 3-92b
REFUELING OPERATIONS 3/4.9.2 INSTRUMENTATION LIMITING CONDITION FOR OPERATION 3.9.2.1 As a minimum, two trains of the Boron Dilution Mitigation System shall be OPERABLE and operating with Shutdown Margin Alarm Ratios set at less than or equal to 4 times the steady-state count race, each with continuous indication in the control room.
AFFLICABILITY: MODE 6 (UNIT 1 ONLY)
ACTION:
(a) With one or both trains of the Boron Dilution Mitigation System inoperable or not operating, (1) immediately suspend all operations involving CORE ALTERATIONS or positive reactivity changes, or verify that two Source Range Neutron Flux Monitors are (2)
OPERABLE and operating with Alarm Setpoints less than or equal to one-half decade (square root of 10) above the G
steady-state count rate, each with continuous visual N
indication in the control room and one with audible y
indication in the containment and control room within the R
next hour.
With both trains of the Boron Dilution Mitigation System (b) inoperable or not operating and one of the Source Range Neutron Flux Monitors inoperable or not operating immediately suspend all operations involving core ALTERATIONS or positive reactivity h
changes.
With both trains of the Boron Dilution Mitigation System (c) inoperable or not operating and both of the Source Range Neutron k
Flux Monitors inoperable or not operating, determine the boron concentration of the Reactor Coolant System at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
SURVEILLANCE REQUIREMENTS Each train of the Boron Dilution Mitigation System shall be 4.9.2.1.1 demonstrated OPERABLE by performance of:
(a) A CHANNEL CHECK at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, An ANALOG CHANNEL OPERATIONAL TEST within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> prior to the (b) initial start of CORE ALTERATIONS and An ANALOG CHANNEL OPERATIONAL TEST at least once per 31 days, (c)
CATAWBA - UNITS 1 & 2 3/4 9-la
CNS 7.6.23.3.14 Multiple Setpoints Annunciator alarms are initiated at the 5 inch water level'in the doghouse while trip outputs are initiated at the 11 inch setpoint.
7.6.23.3.15 Completion of Protection Action Once it is Initiated Once initiated the doghouse water level instrumentation and controls continue to perform their safety function until the condition requiring its operation has been eliminated.
7.6.23.3.16 Manual Initiation There is no system level manual initiation associated with doghouse water level monitoring.
7.6.23.3.17 Access to Setpoint Adjustments, Calibration, and Test Points Access to setpoint adjustments, calibration, and test points for the safety-related instrumentation and controls associated with doghouse level monitoring are controlled by administrative and security measures.
7.6.23.3.18 Identification of Protective Action The safety-related instrumentation and controls associated with doghouse level monitoring are train related and do not include protection channels as defined in IEEE 279-1971.
7.6.23.3.19 Information Read-Out Information read-outs are provided in the control room to allow confirmation of system safety functions.
7.6.23.3.20 System Repair The doghouse water level instrumentation and controls are designed to facilitate the replacement, repair, or adjustment of malfunctioning instruments and controls.
7.6.23.3.21 Identification The safety-related instrumentation and control equipment associated with doghouse level monitoring is physically identified as described in Section 7.1.2.3.
7.6.24 BORON DILUTION MITIGATION SYSTEM 7.6.24.1 Description The shutdown margin monitor portion of the Boron Dilution Mitigation System (BOMS) measures the count rate from a neutron counting instrument.
It performs a statistical time average of the neutron count rate and displays 7.6-72
CNS this average if in the source range (from 0.1 counts per second (cps) to 10,000 cps).
It also provides an alarm output to indicate a decrease in reactor shutdown margin when the count rate increases by an amount determined by the preset alarm ratio.
The shutdown monitor alarm setpoint is continu-ously recalculated and automatically reduced as the reactor is shutdown and the neutron flux is reduced. When the neutron count rate achieves a steady value and then eventually increases, the alarm setpoint remains at its lowest value unless it is manually reset. An alarm will occur when the time averaged neutron count rate increases due to a reactivity addition to a value determined by the preset alarm setpoint. The response time for the alarm depends on the initial count rate and the rate of change of neutron flux.
The preset alarm ratio is chosen to ensure an early alarm will occur during an inadvertent boron dilution event.
Analysis of inadvertent boron dilution events is discussed in Section 15.4.6.
There are two redundant alarm channels.
In addition to providing an alarm on the main control beards, an alarm in either channel will automatically:
- 1) Close the respective train-related valve, NV188A or NV189B, in the charging pump suction line from the volume control, tank (see Figure 9.3.4-2) thereby isolating the pumps from sources of water for boron dilution; and
- 2) Stcp both reactor makeup water pumps (see figure 9.3.5-7) to provide added assurance that unborated water is not introduced into dilution pathways; and 3) Open the respective train-related valve, NV252A or NV253B, (see Figure 9.3.4-8) in order to align the refueling water storage tank (a source of borated water) with the charging pumps.
7.6.24.2 Design Bases The Boron Dilution Mitigation System is designed to protect the reactor from an inadvertent criticality by automatically stopping the flow of unborated water.
7.6.24.3 Analysis The requirements'of IEEE 279-1971 are written for protection systems as defined in Section 1 of that standard; therefore, those requirements are not directly applicable to these controls.
However, a discussion of the extent to which the design of this system meets the appropriate portions of IEEE 279, Section 4, is provided below.
7.6.24.3.1 General Functional Requirement The BDMS functions reliably and automatically to prevent inadvertent recriticality due to 'coron dilution.
The BDMS will also provide an alarm to indicate increasing count rate from any cause that might lead to inadvertent criticality.
7.6.24.3.2 Single Failure Criterion Controls for the BDMS are designed such that a single failure can not prevent prcper action at the system level.
The single failure criterion is met by assuring physical and electrical separation between the redundant trains.
7.6-73
CNS 7.6.24.3.3 Quality of Components The quality assurance program under which the components of this system are qualified is described in Chapter 17.0.
This program includes appropriate requirements for design review, procurement, inspection, and testing to ensure that system components are of a quality consistent with minimum maintenance requirements and low failure rates.
7.6.24.3.4 Equipment Qualification Qualification of this electrical equipment is discussed in Reference 1.
7.6.24.3.5 Channel Integrity The redundant trains of safety-related controls for the BDMS are designed to assure system functional. capability.
7.6.24.3.6 Channel Independence The safety-related instrumentation and controls for the BDMS are physically separated and electrically isolated as discussed in Section 8.3.1.4.
7.6.24.3.7 Control and Protection System Interaction The safety-related instrumentation and controls of the BDMS are train related and do not include protection channels as defined in IEEE 279-1971.
7.6.24.3.8 Derivation of System Inputs The inputs to the BDMS are derived from direct measurements of neutron flux (excore).
7.6.24.3.9 Capability for Test, Calibration, and Sensor Checks The BDMS safety-related instrumentation and controls are designed to facilitate testing and calibration as required by the Technical Specifications.
7.6.24.3.10 Channel Bypass or Removal From Operation The safety-related instrumentation and controls of the BDMS are train related and do not include protection channels as defined in IEEE 279-1971.
System redundancy is reduced when the BDMS is tested; however, testing requires only a short period during the modes of operation when the BDMS is operational.
7.6.24.3.11 Operating Bypasses The BDMS instrumentation and controls do not employ operating bypasses in their initiating logic.
7.6-74
CNS 7.6.24.3.12 Indication of Bypass Indication is provided in the main control room when either train of the BDMS has been made inoperable at the system level.
7.6.24.3.13.
Access to Means for Bypassing Access to the controls and equipment that could be manipulated to make the BDMS inoperable is controlled by administrative and security measures.
7.6.24.3.14 Multiple Setpoints Multiple setpoints are not required for the Boron Dilution Mitigation System.
7.6.24.3.15 Completion of Protection Action Once it is Initiated Once initiated the Boron Dilution Mitigation System will actuate the pumps and valves described in Section 7.6.24.1 to their safe position.
Any repositioning must be done manually by the operator.
7.6.24.3.16 Manual Initiation The valves and pumps described in Section 7.6.24.1 can be manually operated from the control room.
7.6.24.3.17 Access to Setpoint Adjustments, Calibration, and Test Points Access to setpoint adjustments, calibration, and test points is controlled by administrative and security measures.
7.6.24.3.18 Identification of Protective Action The safety-related instrumentation and controls of the BDMS are train related and do not include protection channels as defined in IEEE 279-1971.
7.6.24.3.19 Information Read-Out Indication of the status of the Boron Dilution Mitigation System is provided on safety grade displays in the control room.
Control room annunciators alarm actuation of the BDMS and (on separate windows) loss of power to the BDMs.
7.6.24.3.20 System Repair The BDMS is designed to facilitate the replacement, repair, or adjustment of malfunctioning instruments and controls.
7.6.24.3.21 Identification The BDMS safety-related instrumentation and control equipment is physically identified as described in Section 7.1.2.3.
7.6-75 l
CNS REFERENCES FOR SECTION 7.6 1.
Gaama-Metrics, " Qualification Test Report for the RCS Series Neutron Flux Monitoring System", June 1983 (Propietary)
J 7.6-76
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