ML20095J161
| ML20095J161 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 12/19/1995 |
| From: | HOUSTON LIGHTING & POWER CO. |
| To: | |
| Shared Package | |
| ML20095J158 | List: |
| References | |
| NUDOCS 9512260338 | |
| Download: ML20095J161 (5) | |
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ATTACHMENT 2 i
MARKED UP PAGES FOR PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS i
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4 9512260338 951219 PDR ADOCK 05000498 P
3/4.10 SPECIAL TEST EXCEPTIONS 3/4.10.8 DIESEL OPERABILITY EXCEPTION - MODES 1. 2. 3 & 4 LIMITING CONDITION FOR OPERATION (LCO) 1 3.10.8 The requirements of Specifica;.on 3/4.7.4 and LCOs supported by this Specification may 'be suspended for 7 days / train / cycle AND Specification 3/4.8.1.1 may be suspended for 21 days / train / cycle provided:
The requirements for two (2) of the onsite power sources specified in Specification a.
3.8.1.1.b AND the two (2) supporting ECW loops specified in Specification 3.7.4 are OPERABLE; b.
The circuits required by Specification 3.8.1.1.a are OPERABLE; c.
The equipment specified in ACTION 3.8.1.1.d is OPERABLE; i
d.
The circuit between the 138 kV offsite transmission network, via the Emergency Transformer, and the onsite Class IE Distribution System shall be functional and available; e.
The technical support center diesel generator and the positive displacement pump are functional and available; f.
Planned maintenance on the equipment specified in ACTION 3.8.1.1.d is suspended; 4
l APPLICABILITY: MODES 1, 2, 3, and 4.
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1 DIESEL OPERABILITY EXCEPTION - MODES 1. 2. 3 & 4 LIMITING CONDITION FOR OPERATION (LCO)
ACTION:
With any specified condition (s) not met, then restore the specified condition (s) a.
within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or place the unit in the following MODE, as applicable,:
1.
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 />, 2.
At least HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and 3.
At least COLD SHUTDOWN within the next 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
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With any specified condition (s) not met, then exit this Special Test Exception and enter the appropriate Technical Specification Action Statement.
SURVEILLANCE REQUIREMENTS 4.10.8.1 Perform Surveillance Requirements 4.8.1.1.1.a for the Standby and Auxiliary Transformers at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
4.10.8.2 Verify Emergency Transformer breaker alignment correct and indicated power available at least once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.
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l F4.10 SPECI AL TEST EXCEPTIONS BASES 3/4.10.8 DIESEL OPERABILITY EXCEPTION - MODES 1. 2. 3 & 4 This Special Test Exception (STE) permits an essential cooling water loop to be inoperable for a cumulative 7 days per train per fuel cycle and a standby diesel generator to be inoperable for a cumulative 21 days per train per fuel cycle. In both cases, it is intended that if the essential cooling water is inoperable, the associated standby diesel generator is also inoperable. This exception is to be used for planned maintenance and testing only if all of the necessary compensatory actions are in place.
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If any condition of the LCO is not met during the time a standby diesel generator and/or the essential cooling water is inoperable under this special test exception, a maximum of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> would be permitted to restore the condition before a plant shutdown or exiting the special test exception is required. In addition, a risk assessment must be performed in accordance with the South Texas l
Project Configuration Risk Management Program (CRMP). Based on the results of the assessment, the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> allowed outage time may be further restricted. The intention of this action is to allow a component in one of the other two trains to be inoperable for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, if the risk assessment l
determines 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is acceptable, during this special test exception. If unable to return the l
inoperable equipment to operable status within the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time limit or if the time limit determined by the risk assessment is shorter, actions must be taken in accordance with the STE and the CRMP.
The CRMP specifies the process for assessing and monitoring changes in core damage probability or large early release probability while in certain planned and unplanned maintenance configurations. Large Early Release Probability (LERP) is defined as a large (>3") and early containment failure or bypass that possess a significant potential for short term health impact. Early containment failure includes failures occurring before or within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> of reactor vessel breach and before the effective implementation of the off-site emergency response and protective actions.
Generally, the CRMP process is initiated once a planned maintenance schedule has been approved for a selected period of time (typically one work week). The planned maintenance schedule is evaluated to identify the plant configurations that result from the scheduled work activities. A risk profile for the selected time period is then generated by quantifying the PSA for each identified plant configuration. Risk thresholds are used to determine when management / supervisory oversight or compensatory actions are warranted.
3/4.10 SP"ECI AL TEST EXCEPTIONS BASES 3/4.10.8 DIESEL OPERABILITY EXCEPTION - MODES 1. 2. 3 & 4 The purpose of this exception is to allow pre-planned testing and maintenance of the standby diesel generator and the essential cooling water and to allow credit for the performance of surveillances prescribed in SR 4.8.1.1.2 while in Modes 1,2,3 and 4. The STE is not intended to be a
used as a means to start planned outage maintenance prior to the start of the planned outage. As much as is practical, the plant should be maintained in a steady state condition for the duration of the STE. Time permitting, evolutions, including mode changes, should be evaluated in accordance with the CRMP.
a The emergency transfonner will be administratively dedicated to the ESF bus with the inoperable standby diesel generator. This means that the breaker alignment will enable the 4
emergency transformer to supply power to the affected bus if a loss of offsite power were to occur.
It is also intended to allow the use of the emergency transformer to supply any ESF bus during a 2
loss of offsite power if the Shift Supervisor determines this is necessary. No pre-planned maintenance will be performed on the technical support center diesel, the positive displacement pump or the emergency transformer during the use of this STE. In addition the Shift Supervisor will j
control all work that is performed in the switchyard in accordance with established station procedures, i
i The analytical basis for the STE is a combination of deterministic and probabilistic methods.
From a deterministic, design basis perspective, STP maintains the capability to mitigate most design i
basis events with one of its three ESF trains. This is a condition that is conservatively postulated to result from an accident while the STE is in effect with a loss of off-site power and a subsequent failure of one of the remaining ESF diesel generators and assumed failure of the emergency transformer.
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Since maintenance and testing activities are explicitly included in the PSA analysis, it is
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possible to determine the impact of equipment outages on the probability of core damage or radiological release events for those systems and components within the scope of the PSA.
Generally, the impact of unavailable equipment is seen as a reduction in the defense-in-depth which l
causes an increase in probability of core damage or radiological release. The time and duration of planned equipment outages can be assessed and incorporated into the PSA analysis. The incremental risk associated with the STE has been determined to be small, which is attributable to the s
redundancy and capability of the STP design as noted above. 'Ihe CRMP provides the process for contmiling plant configurations to keep the risk acceptably small.
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SOUTH TEXAS - UNITS 1 & 2 B 3/410-3 Unit 1 - Amendment No.
Unit 2 - Amendment No.
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