D. C. Cook response:
Uncertainties are accounted for in the accident analysis. We should operate the plant at a nominal 100% power. However...
Our Ops procedure for at-power operation states that the one-hour average thermal power must not exceed 100%. It further states that if thermal power exceeds 100%, then a number of actions must take place, including initiating a condition report per our CAP. The management expectation concerning this second requirement is that it is triggered if the ten-minute average exceeds 100%. The pain incumbent with such a condition report has motivated our operators to drive the plant such that the ten-minute average remains below 100%. This is exacerbated by our feedwater control systems that tend to oscillate more than they did in years past. The end result is that we operate near 99.7%.
David Goff Reactor Engineer Donald C. Cook Nuclear Plant 269-465-5901 x1465
Adina K Lafrance adina.k.lafrance@dom.com Sent by: pwrrm@retaqs.com 01/21/2010 08:42 AM Please respond to PWR Reactivity Management pwrrm@retaqs.com
To "RETAQS (pwrrm@retaqs.com)" pwrrm@retaqs.com cc
Subject [Pwrrm] Measured power and uncertanties
Surry is trying to answer a question this morning regarding power level indications and uncertainties.
We are stating that within a certain confidence level, that the calorimetric calculation will produce a reactor power output (at RTP) from 98.8 to 101.2% with the rightly calibrated process instrumentation in the calorimetric program (App K). Half the time the operating power will be above 100%, half the time it will be below 100%. The opposing opinion is that if we have a 1.2% RTP uncertainty that we operate at or below 98.8% so as to not exceed RTP. The uncertainties in question relate to the plant computer-none of the redundant indications indicate higher than RTP (most notably delta Ts). It is also noted that we were told that no other site operates the way we are with regard to uncertainties.
Can you please tell us how your site operates with regard to uncertainties and your RTP?
Thank you in advance.
Adina LaFrance
The significant problems we face cannot be solved at the same level of thinking we were at when we created them. -Albert Einstein
Nuclear Analysis & Fuel Reactor Engineer Surry Power Station Email: Adina.K.LaFrance@Dom.com Phone: 757-365-2658 Pager #: 4290
---------------------------------------------------------------- This e-mail message and all attachments transmitted with it from the Nuclear Generation Group of American Electric Power are for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.