ML15097A269

301 Post Exam Comments

ML15097A269
Person / Time
Site:	Saint Lucie
Issue date:	04/07/2015
From:	NRC/RGN-II
To:	Florida Power & Light Co
References
50-335/15-301, 50-389/15-301 50-335/OL-15, 50-389/OL-15
Download: ML15097A269 (7)

Text

Attachment I - St. Lucie NRC Examination Facility Comments Question 32 Unit 2 is performing a cooldown per 2-GOP-305, Reactor Plant Cooldown Hot-Standby To Cold Shutdown, for a refueling outage with the following conditions:

Time: 11:30

• RCS pressure is 1750 psia

• RCS temperature is 504°F

• 2A & 2B S/Cs are 740 psia Time: 11:32

• 2A Steam Line ruptures outside Containment and just upstream of the MSIV

• RCS pressure is 1630 psia and rapidly lowering

• SG pressures are 580 psia and rapidly lowering Which ONE of the following states:

1) What ESFAS actuation(s) must be MANUALLY actuated?

2) Which procedure will be implemented to mitigate the event?

A. 1) BOTH MSIS, and SIAS.

2) 2-EOP-05, ESDE.

B. 1) ONLY SIAS.

2) 2-EOP-05, ESDE.

C. 1) BOTH MSIS, and SIAS.

2) 2-ONP-01 .01 Plant Condition 1 Steam Generator Heat Removal LTOP Not in Effect.

D. 1) ONLY SIAS.

2) 2-ONP-01 .01 Plant Condition 1 Steam Generator Heat Removal LTOP Not in Effect.

Answer Key: D

References:

2-GOP-305, Reactor Plant Cooldown, Hot Standby to Cold Shutdown ESFAS system description, 0711401 Main Steam system description, 0711304 Applicant question with proctor response for Q.#32 (copy)

Attachment I - St. Lucie NRC Examination Facility Comments Comment: The proper answer to question should be answer selection C.

The applicant should assume, from the given conditions that at time 11:30, based on plant conditions and the procedure in use, that SIAS has been blocked and MSIS is not blocked due to being above the block permissive setpoint (700 psia).

At time 11:32, given plant conditions are as follows:

• RCS pressure is 1630 psia and rapidly lowering

• SG pressures are 580 psia and rapidly lowering Based on this information, RCS pressure is below the SIAS actuation setpoint of 1736 psia decreasing and SC pressures are below the MSIS actuation setpoint of 600 psia decreasing.

Since SIAS is blocked at the time of the event, the operators must manually actuate SIAS.

Given that SC pressures (plural) are 580 psia and rapidly lowering, this means that MSIS did NOT automatically actuate as designed at 600 psia. If it had actuated, then only the faulted steam generator pressure (2A) would continue to lower and the intact SC pressure (2B) would stabilize since the main steam line break was upstream of the 2A SG MSIV (refer to attached drawing).

Since MSIS did not actuate automatically as designed at 600 psia, the operators must manually actuate MSIS in addition to SIAS.

FPL Utility Position: Based on the above discussion, change correct answer to C instead of D.

2

Q-Z REVISION NO.: PROCEDURE TITLE: PAGE:

49 REACTOR PLANT 000LDOWN HOT STANDBY TO COLD

},

SHUTDOWN 16 of 91 PROCEDURE NO.:

2-GOP-305 ST. LUCIE UNIT 2 .INinAL 4.3 RCS 1750-1800 PSIA; Temperature Greater Than 505°F (continued)

NOTE Administrative maximum cooldown rate for Pressurizer is 75°F I hr down to 120°F. (Section 7.1.3, Management Directive 12)

CAUTION With less than 4 RCPs in OPERATION, RCS depressurization to less than 1800 psia should be started as soon as possible to minimizes differential pressure across seal of idle RCP(s) while NO means of seal cooling exists.

(Section 7.1.3, Management Directive 9)

9. LOWER RCS pressure between 1750 and 1800 psia, while maintaining RCS temperature greater than 500°F.

(Section 7.1.3, Management Directive 7)

10. PLOT Pressurizer cooldown on Attachment 13, Reactor Coolant Cooldown System Curve.

11. RECORD Pressurizer cooldown on Attachment 11, Pressurizer Cool down.

NOTE

• Setpoint for SIAS Block permissive is 1836 psia S / G pressure.

• BLOCK keyswitchspnng returns to normal (left) position.

_4> 12. WHEN Annunciator R-8, SIAS CHANNEL A I B ACTUATION BLOCK PERMISSIVE alarms, THEN BLOCK SIAS as follows:

A. VERIFY Annunciator R-8, SIAS CHANNEL A I B ACTUATION BLOCK PERMISSIVE, is IN ALARM.

B. BLOCK CHANNEL A SIAS as follows:

(1) VERIFY amber light above SIAS BLOCK CHANNEL A keyswitch is ON.

(2) Momentarily PLACE SIAS BLOCK CHANNEL A keyswitch in BLOCK position. (Key 99)

REVISION NO.: PROCEDURE TITLE: PAGE:

49 REACTOR PLANT 000LDOWN HOT STANDBY TO COLD SHUTDOWN 21 of 91 PROCEDURE NO.:

2-GOP-305 ST. LUCIE UNIT 2 INI14AL 4.4 Preparation for RCS Cooldown (continued)

5. (continued)

F. ENSURE hose installed at V07166, routed to floor drain.

Person notified:___________________ Time:

4.5 Commencing RCS Cooldown NOTE Cooldown for refueling outage will typically require a Chemistry hold up to six hours prior to commencement of cooldown less than 500°F.

1. IF an RCS cooldown has NOT yet been started, THEN START RCS cooldown per Section 4.3, Step 3.

2. REDUCE ROS temperature and pressure tising Attachment 13, Reactor Coolant Cooldown System Curve.

NOTE

• Setpoint for MSIS Block permissive is 685 psia S I G pressure which corresponds to an RCS temperature of 503°F.

• MSIS Block keyswitch spring returns to normal (left) position.

3. WHEN the fOllowing annunciators are IN ALARM, THEN BLOCK MSIS:

• P-18, MSIS CHANNEL A ACTUATION BLOCK PERMISSIVE

• P-20, MSIS CHANNEL B ACTUATION BLOCK PERMISSIVE A. BLOCK MSIS CHANNEL A as follows: (Key 21)

(1) VERIFY amber light above MSIS BLOCK CHANNEL A keyswitch is ON.

(2) Momentarily PLACE MSIS BLOCK CHANNEL A keyswitch to BLOCK position.

(3) VERIFY red light above MSIS BLOCK CHANNEL A keyswitch is ON.

IV

PSLOPS 0711401, Rev. 19 Page 34 of 58 FOR TRAINING USE ONLY SYSTEM DATA ESFAS DATA TABLE SIGNAL PARAMETER APPROXIMATE DESIGN BASES SETPOINT EVENT UNIT1 UNIT2 C SIAS LQ_Pzr-P.ressure-- _jOO psia 1736 psia LOCA HI Cntmt Pressure 5.0 psig 3.5psig CIS HI Cntmt Pressure 5.0 psig 3.5 psig LOCA

[CIAS] SIAS Actuation HI Cntmt Radiation 10 R/hr 10 R/hr (Refueling) 90 mr/hr 90 mr/hr MS,I L S/G Pressure 600 psia 600 psia Stm Line Break

[HI Cntrnt Pressure] NiA 3.5psig L- J CSAS HI Cntmt Pressure 10 psig 5.4 psig LOCA with SIAS Actuation w/SIAS w/SIAS Stm Line break RAS LO RWT Level 4 ft. 6 ft. LOCA DSS* HI Pzr Pressure 2450 psia 2450 psia ATWS total loss of FW with No RPS trip NOTE: The AFAS-1 and AFAS-2 signals are considered by the FSAR and Technical Specification to be part of the ESFAS. For instructional purposes, due to the difference in flowpath and operational design, they are taught in the AFAS/Auxiliary Feedwater Lesson Text.

Loss of power to safety related buses is addressed in the ESFAS Technical Specifications, but is addressed instructionally in Main Power Distribution text.

The DSS is not an ESFAS signal, but is functionally identical to other ESFAS signals.

Since the DSS equipment is located in the ESFAS cabinets, it is described in this text.

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