Joseph: Please see V. C. Summer’s responses below.

 

Bill Bell

Reactor Engineering

V. C. Summer Station

803-345-4389

 

From: pwrrm-bounces@retaqs.com [mailto:pwrrm-bounces@retaqs.com] On Behalf Of WILLETT, JOSEPH E
Sent: Tuesday, February 06, 2007 3:05 PM
To: respvr@retaqs.com; pwrrm@retaqs.com
Subject: [Pwrrm] Secondary Calorimetric Feedback Needed (PWR) – Heat Balance(BWR)

 

To All,

I apologize, this is a repeat Request, but the HIT Team I’m working on needs more specific information regarding secondary calorimetric calculations. I could use a reply by February 15th.

       

Fort Calhoun Station is currently experiencing 3-5 MWth swings (peak-to-peak) in a one hour period to on our secondary calorimetric calculation. This last outage we replaced both S/Gs and refurbished our FW regulation valves.  Prior to this outage our swings were normally 1 MW over 4 hour period. We attempt to keep power at a corporate goal of 1498 MWth (1500 MWth is our rated power level). We do not see these swings on the NI or Delta-T power indications that follow the secondary calorimetric swings.

We have not implemented Appendix K using ultrasonic flow measurement for Main feedwater as of yet.

Our Question(s)

1) What are other plants goals/expectations for maintaining power level? (=/- MW or goal);                      -How easy is it to maintain?

 

-Is there a band within which you operate? What is it? Is it maintained?

                                                                                                There is no specific band established.  The attached OAP-100.06 specifies the maximum allowable power levels and durations.

-What procedure or guidance is provided to your operators?

                                                                                                OAP-100.06, Section 10

-Can I get a copy of the procedure?

                                                                                                Yes, it is attached to this email.

2) How is your secondary calculation performed?  (Averaging Inputs, Instantaneous values, combination)

-Is it a module or program on your plant computer or is it an off-line routine?

                                                                                                                        We use a computer program running constantly on the plant computer.

-What is the frequency of the calculations utilized? (1 sec, 1 minute, 10 minutes 30 minutes, etc…)?

                                                                                                                        The plant computer executes the program once a second.

-What is the frequency of the scan rate for input parameters utilized? (1 sec, 1 minute, 10 minutes 30 minutes, etc…)? Does it vary by parameter? Are they averaged, and for how long? (30 seconds, 60 seconds, etc...)

                                                                                                                        The scan rate for all of the calorimetric inputs (pressures, flows, temperatures) is once a second.

-What is there BASIS for the calculation? Is there supporting documentation? What is it?

                                                                                                                        The FSAR specifies that a feedwater flow rate based calculation will be used for complying with the plant license.

-What frequency do the operators control to? (2 minute average, 10 minute average, 30 minute average, etc….)

                                                                                                                        As discussed in the attached OAP-100.06 the operators control to an 8 hour average power level.

 

3) Are your temperature and flow transmitters set specifically for this calculation? (dampening or bias settings)

                                                All of the instruments that feed the calorimetric calculation are calibrated every 18 months and op tested once a quarter.  They do not employ any special dampening.

4) Are any of your control loops (Feedwater) used in the secondary calorimetric calculation?

                                                Yes,  Feedwater flow rate and steam pressure instrumentation also provide protection and control functions.

5) Have you had any issues related to power swings or related to your secondary calorimetric?

                                                Yes, a continuing problem we have here are feed flow spikes in our A loop.  We have been investigating the cause of this problem but have not yet found the cause.

6) Who has ownership/control of your program/logic? System Engineering, Design Engineering, Operations, Reactor Engineering or some other department?

                                                Reactor Engineering owns the calorimetric program.

J. E. Willett

----------------------------------------------------

Joseph E. Willett, P.E.      

Principal Reactor Engineer-Fuel

Nuclear Operations Division

 E-mail: jwillett@oppd.com

  Omaha Public Power District           Phone:  (402) 533-7213

  P.O. Box 99                           Pager:   (402) 561-3899

  Ft. Calhoun, NE  68023-0390   FAX:      (402) 533-6747

  Mail Station: FC-1-1 Plant

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