Ken,
Callaway conducts periodic measurements of B-10 content in applicable tanks and adjusts minimum Boron concentration limits accordingly. An example from the site procedure is quoted below.
Jim McInvale
Operating limits and control bands are set to compensate for depletion of B-10 due to use of
recycled boric acid. The lower operating limit, 2030 ppm, compensates for a potential B-10
level in the RWST of 19.6%, making it equivalent to 19.9 atom %. Yearly analyses of B-10
in the RWST will be performed to verify and track the changes in B-10 level. This new
operating limit is more conservative than the T/S requirement of 2000 ppm B.
________________________________
From: pwrrm@retaqs.com [mailto:pwrrm@retaqs.com] On Behalf Of Kenneth R Pike Sent: Wednesday, July 08, 2009 9:16 AM To: pwrrm@retaqs.com Subject: [Pwrrm] RCS B10 depletion impact on Boron Inj Safety Systems?
In developing a B10 depletion lesson recently I discovered a concern that I have not seen raised before. Does your Safety Analysis for your boron injection or S/D systems (Accumulators, Boron Injection Tank or RWST) consider anything less than nominal B10 abundance (19.9 a/o) in the boron ppm requirement? If the analysis assumes nominal B10 and there is some B10 depletion then the negative reactivity assumed could be more than that actually available (non-conservative) upon injection. Is this accounted for in some fashion?
Thanks in advance
Ken Pike
Retaqs, Inc.
610.277.8991 x 253
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