E-3 (SGTR)

Question 1

E-3

What are the major action catagories in E-3, include order?

Answer 1

• identify and isolate ruptured S/G
• C/D (establish subcooling)
• Depressurize (restore RCS inventory)
• Terminate SI (stop primary-> secondary lkg)

Question 2

E-3

If both MD AFW pumps are OOS and only steam supply available to TDAFW is from a ruptured S/G, will you use contaminated water to run the TDAFW pump?

If you have a faulted, ruptured S/G what L _s/g will you try and maintain for affected S/G?

Answer 2

YES, it would be worse to not have a heat sink than to have an unmonitored release

None, you do not feed a faulted S/G (even if it is ruptured)

Question 3

E-3

What level do you maintain for a ruptured S/G?

Why?

Answer 3

• L _s/g > 15%
• promote thermal stratification, in later steps when RCS is cooled, if steam touches exposed tubes
• steam can condense, lowering P _s/g
• Causing break flow to worsen/ recomence

Question 4

E-3

Once you commence depressurizing to stop the breakflow in SGTR, what is the “Depressurization Termination Criteria”?

Answer 4

• P_rcs < P _{s/g (ruptured)}

AND

• L_pzr > 12%

OR

• Lpzr > 74%

OR

• RCS subcooling < 20 deg F

Question 5

E-3

Upon completing E-3 what are the three procedures, order of preference and advantages/ disadvantages to each that you can transition into for Post SGTR c/d?

Answer 5

• E-3.1, c/d using backfill (preferred)
  
  • slow, dilutes RCS but minimizes radiological release
• E-3.2, c/d using blowdown
  
  • slow, craps up secondary but minimizes radiological release and does not dilute RCS
• E-3.3, c/d using stm dmp
  
  • radiological release and may cause water hammer but is fast (consider if low fw supply)

Question 6

E-3

If the RCPs are not running and you commence a cooldown and depressurization…..

What CSFST may be invalid?

What do you do if you recieve this indication?

Answer 6

T_c for the ruptured loop may give you a false red or magenta path

disregard T_c indication untill C/D, depress, and terminate SI is complete