At D. C. Cook, we will dilute to ARO BOC critical unless we have performed a Subcritical Physics Testing endpoint. In those cases, we have pulled to critical targeting CD at 135 steps. For mid-cycle startups, we pull to critical targeting CD at 135 steps.

From: PWRRM [mailto:pwrrm-bounces@retaqs.com] On Behalf Of Kenneth Pike Sent: Wednesday, November 16, 2016 3:08 PM To: pwrrm@retaqs.com Subject: [EXTERNAL] [Pwrrm] final approach to critical, boron dilute or pull rods?

Do you still position rods and dilute to critical during initial startup after a refueling? On a mid cycle startup do you dilute to critical boron then pull rods to critical or position control rod at estimated critical position and dilute to critical? TVA is interested in what method other plants are using to achieve criticality.

Thanks

Ken Pike (610) 277-8991 x 253