Coping with Abnormal Events at a LFTR

USPWR_SRO
Posts: 489
Joined: Apr 24, 2008 4:54 am
Location: Columbia, SC

Coping with Abnormal Events at a LFTR

Post by USPWR_SRO » May 22, 2009 7:37 pm

In several threads thoughts about how a LFTR would cope with plant emergencies of various types have been discussed.

Just to provide some food for thought here is a list of many of the things a PWR is designed and operating crews are trained to prepare for:

Code: Select all

INSIDE PLANT LOCAL AREA EVACUATION
SHUTDOWN FROM OUTSIDE THE CONTROL ROOM 
EARTHQUAKE               	
OFFSITE POWER SYSTEM DISTURBANCES         	
LOSS OF INSTRUMENT CONTROL SYSTEM AIR      	
REACTOR COOLANT PUMP SEAL FAILURE           	
LOSS OF SUPPORT SYSTEM COOLING 	
SEVERE WEATHER 	
CONDENSER SALT LEAK 	
LOSS OF CONDENSER VACUUM	
EMERGENCY BORATION/INADVERTANT DILUTION OR BORATION
MISALIGNED OR IMMOVABLE CONTROL ROD	
REACTOR COOLANT LEAK	
LOSS OF SHUTDOWN COOLING	
RECOVERY FROM INADVERTANT ENGINEERED SAFTY FEATURE ACTUATION		
REACTOR PROTECTION SYSTEM FAILURE
LOSS OF VITAL AC INSTRUMENT POWER 	
LOSS OF NON-VITAL AC INSTRUMENT POWER	
FUEL HANDLING ACCIDENTS
LOSS OF SPENT FUEL POOL LEVEL OR COOLING
FIRE	
LOSS OF CONTROL ROOM ANNUNCIATORS	
FEEDWATER CONTROL SYSTEM MALFUNCTION	
OPERATOR ACTIONS DURING SECURITY EVENTS	
LOSS OF POWER TO AN AC BUS	
PRESSURIZER PRESSURE OR LEVEL MALFUNCTION	
RAPID DOWN POWER	
Obviously some of these would not apply, others not mentioned would apply to an LFTR, for example LOSS OF POWER TO PRIMARY SALT LOOP HEATING or maybe LOSS OF FORCED COOLING TO CORE DUMP VALVE, or LOSS OF RESIDUAL HEAT REMOVAL TO GAS DECAY TANKS. I changed some names for clarity and to eliminate acronyms.

I would think about this list with the idea of being able to reply to any problem on it from a LFTR perspective. The NRC and other regulatory authorities will have a mindset based on these (semi) standard set of operational problems. We should be able to anticipate many questions.

User avatar
Kirk Sorensen
Posts: 4152
Joined: Nov 30, 2006 3:30 pm
Location: Alabama
Contact:

Re: Coping with Abnormal Events at a LFTR

Post by Kirk Sorensen » May 22, 2009 7:53 pm

What's a condenser salt leak?

USPWR_SRO
Posts: 489
Joined: Apr 24, 2008 4:54 am
Location: Columbia, SC

Re: Coping with Abnormal Events at a LFTR

Post by USPWR_SRO » May 23, 2009 1:37 am

When a main condenser that is cooled by seawater or even river water develops a leak in a condenser tube, the saltwater side is sucked in and contaminates the condensate and feedwater of the steam plant. That sodium is then concentrated in the Steam Generator secondary side, greatly accelerating u-tube corrosion leading to u-tube thinning or even failure.

rgvandewalker
Posts: 379
Joined: Dec 14, 2006 1:01 pm

Re: Coping with Abnormal Events at a LFTR

Post by rgvandewalker » Jun 15, 2009 12:55 am

Cool. There's several basically different types of things. There's

1. Environment, human, political, control, heat engine and generator emergencies, which will all be similar, and

2. Nuclear kernel emergencies, which might have similar categories, but different equipment and responses.

If so, then maybe these type 1 items will be very similar:

CONDENSER SALT LEAK    
EARTHQUAKE                  
FIRE   
INSIDE PLANT LOCAL AREA EVACUATION
LOSS OF CONDENSER VACUUM   
LOSS OF CONTROL ROOM ANNUNCIATORS   
LOSS OF INSTRUMENT CONTROL SYSTEM AIR         
LOSS OF NON-VITAL AC INSTRUMENT POWER   
LOSS OF POWER TO AN AC BUS   
LOSS OF VITAL AC INSTRUMENT POWER    
OFFSITE POWER SYSTEM DISTURBANCES            
OPERATOR ACTIONS DURING SECURITY EVENTS   
PRESSURIZER PRESSURE OR LEVEL MALFUNCTION   
SEVERE WEATHER    
SHUTDOWN FROM OUTSIDE THE CONTROL ROOM 

And these will be different. I think they further subdivide into
non-LFTR:
FEEDWATER CONTROL SYSTEM MALFUNCTION 
LOSS OF SHUTDOWN COOLING
MISALIGNED OR IMMOVABLE CONTROL ROD

and LFTR problems:
EMERGENCY BORATION/INADVERTANT DILUTION OR BORATION (clean the salt? By distillation?)
FUEL HANDLING ACCIDENTS (The fuel is solid 233UF, probably in pellets. Scrape solidified leaked fuel & carrier salt? Sweep it up? From a stainless steel floor?)
LOSS OF SPENT FUEL POOL LEVEL OR COOLING (Add water, check for leaks, use double-walled pools.)
LOSS OF SUPPORT SYSTEM COOLING  (? What's this?)
RAPID DOWN POWER  (Stop the fuel pumps, let doppler broadening halt power.)
REACTOR COOLANT LEAK (Ouch. No clue. Depends on design.)
REACTOR COOLANT PUMP SEAL FAILURE (Likewise)          
REACTOR PROTECTION SYSTEM FAILURE (? What's this?)
RECOVERY FROM INADVERTANT ENGINEERED SAFTY FEATURE ACTUATION (?)

Post Reply