RA-19-2019, Brunswick 2019-301 Post-Exam Comments

Brunswick 2019-301 Post-Exam Comments

ML19032A163
Person / Time
Site:	Brunswick
Issue date:	01/30/2019
From:	Gideon W R Division of Reactor Safety II
To:	Catherine Haney NRC/RGN-II
References
RA-19-2019 IR 2018301
Download: ML19032A163 (8)

Text

Facility Comment on the Tech Spec determination for Scenario 2 Event 2.

The answer key stated to declare the control rod inoperable IAW TS 3.1.3

. This is not correct based on the following (follows the IDO format):

Entry Condition Control rod drifting in to 00.

From Tech Spec bases for LCO 3.1.3:

The OPERABILITY of an individual control rod is based on a combination of factors, primarily, the scram insertion times, the control rod coupling integrity, and the ability to determine the control rod position.

Accumulator OPERABILITY is addressed by LCO 3.1.5. The associated scram accumulator status for a control rod only affects the scram insertion times; therefore, an inoperable accumulator does not immediately require declaring a control rod inoperable. Although not all control rods are required to be OPERABLE to satisfy the intended reactivity control requirements, strict control over the number and distribution of inoperable control rods is required to satisfy the assumptions of the DBA and transient analyses.

There is no mission time applicable for the control rod system.

Surveillance requirements for control rod per TS 3.1.3 are:

Determine the position of each control rod Insert each withdrawn control rod at least one notch Verify each control rod scram time from fully withdrawn to notch position Verify each control rod does not go to the withdrawn overtravel position.

Basis for Reasonable Expectation of Operability With a control rod drifting in to position 00 no technical specification surveillance requirements are adversely impacted for the control rod.

In this scenario the control rod was latched at position 00 and was performing its required function.

Also, there were no indications of abnormally elevated temperatures on the control rod drive (i.e. CRD Hydraulic Temperature High alarm was not received) so scram times would not be adversely affected.

Subsequent actions required by plant procedures to isolate and disarm the control rod would render the control rod inoperable, however, these actions were not completed in the observed scenarios. Therefore, given the identified condition of the control rod drifting in to 00 the control rod remains operable.