ML20086T406
| ML20086T406 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 02/28/1984 |
| From: | CAROLINA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML20086T404 | List: |
| References | |
| NUDOCS 8403060302 | |
| Download: ML20086T406 (2) | |
Text
3/4.1 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made suberitical' from all operating conditions, 2) the reactivity transients associated with postulated accident conditions are controllable within acceptable limits, and 3) the reactor will be maintained sufficiently suberitical to preclude inadvertent criticality in the shutdown condition.
Since core reactivity values will vary through core life as a function of f uel depletion and poison burnup, the demonstration of SHUTDOWN MARGIN will be performed in the cold xenon-free condition and shall show the core to be suberitical by at least R + 0.38% delta k/k. The value of R in units of
% delta k/k is the dif ference between the calculated value of maximum core reactivity during the operating cycle and the calculated beginning-of-life core reactivity.
The value of R must be positive or zero and must be determined f or each fuel loading cycle.
Satisfaction of this limitation can be best demonstrated at the time of fuel loading, but the margin must be determined anytime a control rod is incapable of insertion.
This reactivity characteristic has been a basic assumption in the analysis of plant performance and can best be demonstrated at the time of fuel loading, but'the margin must also be determined anytime a control rod is incapable of i nse rtion.
3/4.1.2 REACTIVITY ANOMALIES Since the SHUTDOWN MARGIN requirement f or the reactor is small, a careful check on actual conditions to the predicted conditions is necessary, and the changes in reactivity can be inferred f rom these comparisons. of rod patterns.
Since the comparisons are easily done, frequent checks are not an impositirn on normal operations. A 1% change is larger _ than is expected f or normal operation so a change of this magnitude should be thoroughly e va lu ated.
A change ao large as 1% would not exceed the design conditions of the reactor and is on the safe side of the postulated transients.
"During the firtt startup following CORD ALTERATIONS" implies that the specificd surveillance should be performed upon the initial attainment of a high equilibriun power level, preferably of at least 90% of RATED THERMAL POWER, during the unit startup.
3/4.1.3 CONTROL RODS
,The specifications of this section ensure that 1) the minimum SHUTDOWN MARUIN is maintained, 2) the control-rod insertion times are consistent with those used in the' accident analysis, and 3) the 0403060302 840228 PDft ADOCK 05000324 p
PDR BRUNSWICK - UNIT 1 B 3/4 1-1 Amendment No.
7
.I 3/4.1 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made suberitical from all operating conditions, 2) the reactivity transients associated with postulated accident conditions are controllable within acceptable limits, and 3) the reactor will be maintained sufficiently suberitical to preclude inadvertent criticality in the shutdown condition.
Since core reactivity values will vary through core life as a function of fuel depletion and poison burnup, the demonstration of SilUTDOWN MARGIN will be performed in the cold xenon-free condition and shall show the core to be suberitical by at least R + 0.38% delta k/k. The value of R in units of
% delta k/k is the difference between the calculated value of maximum core reactivity during the operating cycle and the calculated beginning-of-life core reactivity. The value of R must be positive or zero and must be determined f or each fuel loading cycle.
Satisfaction of this limitation can be best demonstrated at the time of fuel loading, but the margin must be determined anytime a control rod is incapable of insertion.
This reactivity characteristic has been a basic assumption in the analysis of plant performance and can best be demonstrated at the time of fuel loading, but the margin must also be determined anytime a control rod is incapable of insertion.
3/4.1.2 REACTIVITY ANOMALIES Since the 311UTDOWN !!ARGIN requirement f or the reactor is small, a careful check on actual conditions to the predicted conditions is necessary, and the changes in reactivity can be inferred f rom these comparisons of rod patterns.
Since the comparisons are easily done, frequent checks are not an imposition on normal operations. A 1% change is larger than is expected for normal operation so a change of this magnitude should be thoroughly e va lu at ed.
A change as large as 1% would not exceed the design conditions of the reactor and is on the safe side of the postulated transteats.
"During the first startup f ollowing CORE ALTERATIONS" implies that the specified surveillance should be perforned upon the initial attainment of a high equilibrium power level, preferably of at least 90% of RATED THERMAL POWER, during the unit startup.
3/ 4.1. 3 CONTROL RODS The specifications of this section ensure that 1) the minimum S!!UTDOWN MARGIN is maintained, 2) the control rod insertion times are consistent with those used in the accidert analysis, and 3) the l
1 BRUNSWICK - UNIT 2 B 3/4 1-1 Amendment No.