ML15146A008

Reactor Operator and Senior Reactor Operator Examination Results

ML15146A008
Person / Time
Site:	Palo Verde
Issue date:	04/24/2015
From:	Mcghee M Arizona Public Service Co
To:	Chris Steely Operations Branch IV
References
Download: ML15146A008 (7)

Text

1 ID: Q44311 Points: 1.00 Given the following conditions:

Unit 1 is operating at 100% power (1) What is the predicted effect on the RCS if a Purification ion exchanger that has been isolated for 5 days is placed in service without performing any pre-service flushes?

(2) What actions should be taken to offset the reactivity change?

A. (1) RCS temperature will rise (2) RCS dilution B. (1) RCS temperature will rise (2) RCS boration C. (1) RCS temperature will lower (2) RCS dilution D. (1) RCS temperature will lower (2) RCS boration Answer: D Correct answer was changed to C.

After reviewing the as given conditions with Operations and Training personnel the following determinations have been made: Even though an isolated and cooled down IX placed in service would have an affinity to absorb boron the over-riding effect would be the 10-15 ppm RCS dilution that would had occurred over those 5 days due to fuel depletion. Therefore placing the IX back in service without pre-service flushes would have caused a small boration and subsequent lowering of RCS temperature. To maintain 100% reactor power and RCS T-cold on program the operators would dilute to offset the negative reactivity and raise RCS T-cold to the program value.

OPTRNG_EXAM Page: 1 of 1 21 May 2015