ML13018A362

Initial Exam 2012-302 Post Exam Comments

ML13018A362
Person / Time
Site:	Oconee
Issue date:	01/15/2013
From:	NRC/RGN-II
To:
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Download: ML13018A362 (7)

Text

Attachment Page 1 of 7 Post Written Exam Comments Question 18 Given the following Unit 1 conditions:

Initial conditions:

• Reactor power = 100%

• 1 SA2/A9 (MS PRESS HIGH/LOW) alarms Current conditions:

• 1A SG pressure = 905 psig increasing

• 1 B SG pressure = 22 psig decreasing

• RCS temperature = 530°F increasing

• The overcooling has been stopped

1) In accordance with Rule5 (MSLB), TBVs will initially be adjusted to maintain (1) constant.

2) The reason for maintaining the above temperature constant is to help prevent (2) .

Which ONE of the following completes the statements above?

A. 1. CETC5

2. pressurizer swell and subsequent RCS re-pressurization B. 1. CETCs

2. tensile stresses in the isolated SG C. 1. Tcolds

2. pressurizer swell and subsequent RCS re-pressurization D. 1. Tcolds

2. tensile stresses in the isolated SG

Attachment Page 2 of 7 Question 18 Answer A Discussion Correct. Rule 5 directs maintaining CETCs constant. This is to reduce Pzr level increase and subsequent RCS re-pressurization.

Answer B Discussion Incorrect. First part is correct. Second part is plausible because SG tensile stresses are a concern after isolating a SG. However it is not the reason for keeping the temperature constant.

Answer C Discussion Incorrect. First part is plausible because Tc is the temperature that is normally used for RCS temperature control. Second part is correct.

Answer D Discussion Incorrect. First part is plausible because Tc is the temperature that is normally used for RCS temperature control. Second part is plausible because SG tensile stresses are a concern after isolating a SG. However it is not the reason for keeping the temperature constant.

Cognitive Level Comprehension Job Level RO QuestionType NEW Development References Student References Provided EAP-EHT EOP Rule 5 Basis for meeting the KA Requires knowledge of the reason an action is taken in Rule 5 as a result of excessive heat transfer.

BWEO5 EK3.2 Excessive Heat Transfer Knowledge of the reasons for the following responses as they apply to the (Excessive HeatTransfer) (CFR: 41.5/41.10,45.6,45.13)

Normal, abnormal and emergency operating procedures associated with (Excessive Heat Transfer).

Attachment Page 3 of 7 Question 18 COMMENT The second part of the question states:

The reason for maintaining the above temperature constant is to help prevent (2)

The candidate answered the question from the position that the above temperature referred to the RCS temperature stated in the stern and that holding this temperature constant was in response to the overcooling not the subsequent RCS heat up.

The Lesson Plan EAP-EHT states on Page 9 of 43:

A rapid overcooling could result in SG damage from tube vibration due to high steam/feed flow as well as thermal shock to the SG and from excessive SG tube tensile loads due to exceeding tube-to-shell AT limits.

As stated in the lesson plan, stopping the overcooling will prevent tensile stresses in the SG.

RECOMMENDATION Accept answers A and B as correct.

DOCUMENTATION Lesson Plan EAP-EHT, Page 9 of 43

Attachment Page 4 of 7 Question 30 Given the following Unit 1 conditions:

Initial conditions:

• Time = 0400

• A transient occurred resulting in a reactor trip from 100% power

• Pzr level = 400 inches stable

• Letdown cannot be established Current conditions:

• Time = 0500

• Forced Cooldown tab in progress

• Pzr level = 400 inches stable

• Pzr temperature = 603°F

• RCS temperature = 581°F

• RCS pressure = 2100 psig decreasing

1) At 0500, RCS pressure will be controlled by adjusting (1) .

2) If NO operator action is taken, RCS pressure will stabilize at no lower than (2) psig.

Which ONE of the following completes the statements above?

A. 1. HPIfIowONLY

2. 1320 B. 1. HPIfI0wONLY

2. 1565 C. 1. HPI flow OR Pzr heaters

2. 1320 D. 1. HPI flow OR Pzr heaters

2. 1565

Attachment Page 5 of 7 Question 30 Answer A Discussion Incorrect. First part is correct. Second part is plausible because it is the saturation pressure for 581 degrees.

Answer B Discussion Correct. The RCS is solid and subcooled. At this time Pzr heaters will not increase RCS pressure. ONLY HPI flow will control pressure (letdown not available). The saturation temperature for 603 degrees is about 1565 psig. Pressure will decease toward this value.

Answer C Discussion Incorrect. First part is plausible because Pzr heaters will normally increase pressure.

Second part is plausible because it is the saturation pressure for 581 degrees.

Answer D Discussion Incorrect. First part is plausible because Pzr heaters will normally increase pressure.

Second part is correct.

Cognitive Level Comprehension Job Level RO QuestionType NEW Development References Student References Provided PNS-PZR R22 EOP FCD Tab Basis for meeting the KA Question requires knowledge of how RCS pressure is controlled when the Pzr is solid.

SYSOO4 K6.26 Chemical and Volume Control System Knowledge of the effect of a loss or malfunction on the following CVCS components:

(CFR: 41 .7 / 45.7) Methods of pressure control of solid plant (PZR relief and water inventory)

Attachment Page 6 of 7 Question 30 COMMENT The second part of the question states:

If NO operator action is taken, RCS pressure will stabilize at no lower than (2)psig.

The basis for the correct answer is that since the RCS is solid and the Pzr is subcooled RCS pressure will decrease toward the saturation pressure for the current Pzr temperature. The saturation pressure for 603°F is 1565 psig.

However the way the question is worded the other answer (1320 psig) is also correct.

RCS pressure will stabilize at no lower than 1320 psig is a true statement.

As worded, 1320 psig is a subset of 1565 psig.

RECOMMENDATION Accept answers A and B as correct.

DOCUMENTATION None

Attachment Page 7 of 7 Post Operating Exam Comments During exam administration, the candidate cue sheet for Admin-239 did not contain information regarding 1 D RPS channel being in Manual bypass. This resulted in the correct answer for Step 7 (one of the Critical Steps) of Admin-239 changing from requiring entry into Tech Spec 3.3.1 (RPS Instrumentation) Condition A to No Tech Spec Entry Required.

As a result, we are requesting that the correct response to Step 7 of Admin-239 be changed to No Tech Spec Entry required.