At Comanche Peak the initial startup after a refueling is a dilution to critical with all rods out. The objective is to terminate the dilution such that after mixing there is about 50 pcm of excess reactivity that is zeroed out by insertion of our lead control bank. This sets us up for low power physics testing.
Each reactor startup after the initial is a rodded startup. We establish a boron concentration to achieve criticality with the lead control bank 100 steps withdrawn from the bottom. We withdraw control rods 50 steps or less and monitor the approach to critical after each rod withdrawal.
Matthew R. Weeks Luminant Matthew.Weeks@luminant.commailto:Matthew.Weeks@luminant.com office 254-897-5183, fax 254-897-6780 cell 817-975-2051, home 817-249-4559
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From: PWRRM [mailto:pwrrm-bounces@retaqs.com] On Behalf Of Kenneth Pike Sent: Wednesday, November 16, 2016 2:08 PM To: pwrrm@retaqs.com Subject: [Pwrrm] final approach to critical, boron dilute or pull rods?
EXTERNAL EMAIL
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
