Here are the Callaway numbers for the past 4 years.

-108

-48

-57

178

-90

45

-194

-80

-127

150

-20

60

If we are using design data from a Nuclear Design Report and post Xenon concentrations are different than that assumed in the developing NDR data, there is some impact on the error. Accuracy of Boron sample results has probably been one of the biggest contributors to errors. When we use 3-D models depleted to actual conditions, the results are not a lot better than NDR data (due to partly model biases.)

Going way back to AOA days, we had some huge errors that turned out to be our first evidence of the phenomenon.

Jim McInvale

________________________________

From: pwrrm-bounces@retaqs.com [mailto:pwrrm-bounces@retaqs.com] On Behalf Of John.F.Helfenberger@dom.com Sent: Wednesday, October 17, 2007 2:48 PM To: pwrrm@retaqs.com Subject: [Pwrrm] Actual vs. Predicted ECP values

What do the other sites typically have for pcm differences in ECP actual vs. predicted? Kewaunee recently had a MOL startup and we were about 175 pcm out from predicted, which is well within our procedural acceptance criteria of +/-400 pcm. On the previous 2 startups at BOL, we were within 25 pcm of predicted. What are typical values seen by other plants?

John Helfenberger, Lead Reactor Engineer Kewaunee Power Station Phone: 920-388-8294 Dominion Tie-line: 8-691-8294 Pager: 920-704-4471

________________________________

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