Core-power and decay-time limits for disabled automatic-actuation of LOFT ECCS
The Emergency Core Cooling System (ECCS) for the LOFT reactor may need to be disabled for modifications or repairs of hardware or instrumentation or for component testing during periods when the reactor system is hot and pressurized, or it may be desirable to enable the ECCS to be disabled without the necessity of cooling down and depressurizing the reactor. A policy involves disabling the automatic-actuation of the LOFT ECCS, but still retaining the manual actuation capability. Disabling of the automatic actuation can be safely utilized, without subjecting the fuel cladding to unacceptable temperatures, when the LOFT power decays to 33 kW; this power level permits a maximum delay of 20 minutes following a LOCA for the manual actuation of ECCS. For the operating power of the L2-2 Experiment, the required decay-periods (with operating periods of 40 and 2000 hours) are about 21 and 389 hours, respectively. With operating periods of 40 and 2000 hours at Core-I full power, the required decay-periods are about 42 and 973 hours, respectively. After these decay periods the automatic actuation of the LOFT ECCS can be disabled assuming a maximum delay of 20 minutes following a LOCA for the manual actuation of ECCS. The automatic and manual lineup of the ECCS may be waived if decay power is less than 11 kW.
- Research Organization:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
- OSTI ID:
- 6354131
- Report Number(s):
- LTR-113-51(Rev.A); RE-A-78-103(Rev.A); TRN: 79-007753
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
LOFT REACTOR
ECCS
AFTER-HEAT
REACTOR PROTECTION SYSTEMS
RESIDUAL POWER
TIME DEPENDENCE
ENGINEERED SAFETY SYSTEMS
NUCLEAR POWER
POWER
PWR TYPE REACTORS
REACTORS
RESEARCH AND TEST REACTORS
TANK TYPE REACTORS
TEST REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS
220900* - Nuclear Reactor Technology- Reactor Safety
220600 - Nuclear Reactor Technology- Research
Test & Experimental Reactors