United States Nuclear Regulatory Commission - Protecting People and the Environment
Home > NRC Library > Document Collections > Reports Associated With Events > Event Notification Reports > 2001

Event Notification Report for July 30, 2001

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           07/27/2001 - 07/30/2001

                              ** EVENT NUMBERS **

38139  

!!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED  !!!!!!!
+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   38139       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PILGRIM                  REGION:  1  |NOTIFICATION DATE: 07/13/2001|
|    UNIT:  [1] [] []                 STATE:  MA |NOTIFICATION TIME: 14:52[EDT]|
|   RXTYPE: [1] GE-3                             |EVENT DATE:        07/13/2001|
+------------------------------------------------+EVENT TIME:        08:55[EDT]|
| NRC NOTIFIED BY:  JOHN MacDONALD               |LAST UPDATE DATE:  07/27/2001|
|  HQ OPS OFFICER:  STEVE SANDIN                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |ANTHONY DIMITRIADIS  R1      |
|10 CFR SECTION:                                 |                             |
|AINA 50.72(b)(3)(v)(A)   POT UNABLE TO SAFE SD  |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     N          Y       100      Power Operation  |100      Power Operation  |
|                                                   |                          |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| APRM FLOW-BIASED SCRAM SETPOINTS SET NONCONSERVATIVELY                       |
|                                                                              |
| "On July 13, 2001 at 0855 hrs, with the reactor at 100% core thermal power,  |
| Pilgrim Station determined the Average Power Range Monitoring (APRM) system  |
| flow-biased reactor scram setpoints were non-conservative and potentially    |
| exceeded Core Operating Limit Report (COLR) analyses. Programmed Flow        |
| Control Trip Reference (FCTR) cards establish the APRM flow-biased scram     |
| setpoints. The FCTR cards are a plant enhancement in response to the BWR     |
| stability issue. During core flow mapping for FCTR card calibration in       |
| accordance with station procedure (9.17.1), it was determined by reactor     |
| engineering personnel that the input setting for the FCTR card DIP switches  |
| was non-conservative. In response to this event, the APRMs were declared     |
| inoperable and Technical Specification 3.1 and the Actions of Table 3.1.1    |
| were initiated. TS Table 3.1.1 requires that reactor trip capability for the |
| given trip function be restored within 1 hour or initiate insertion of       |
| operable control rods and complete insertion of all operable control rods    |
| within 4 hours. However, Instrumentation and Controls personnel completed    |
| FCTR card DIP switch adjustments in accordance with station procedure        |
| (3.M.2-5.4.s) within approximately 45 minutes. All APRM RPS functions were   |
| declared operable at 0946 hours and TS 3.1 was exited. The reactor remained  |
| at 100% core thermal power throughout the event and there were no plant      |
| transients as a result of the event.                                         |
|                                                                              |
| "The cause of the event appears to [be] a lack of administrative controls to |
| ensure the FCTR card flow mapping be performed when steady-state 100% core   |
| thermal power is achieved following refueling outages or significant power   |
| maneuvers."                                                                  |
|                                                                              |
| The licensee informed the NRC resident inspector and will inform the         |
| Commonwealth of Massachusetts.                                               |
|                                                                              |
| * * * UPDATE AT 1221EDT ON 7/27/01 FROM OLSON TO S. SANDIN * * *             |
|                                                                              |
| The licensee is retracting this report based on the following:               |
|                                                                              |
| "Pilgrim Station retracts a report made to the NRC Operations Center on July |
| 13, 2001 at 1500 hours.  The Event Number was 38139.  The report was made    |
| pursuant to 10 CFR 50.72(b)(3)(v)(A) when it was determined the Average      |
| Power Range Monitoring (APRM) system flow-biased reactor scram setpoints     |
| were set non-conservatively.                                                 |
|                                                                              |
| "Subsequent testing has determined that the setpoints were set               |
| conservatively and that the APRM flow-biased reactor scram was operable.     |
| Therefore, no situation existed which was reportable pursuant 10 CFR         |
| 50.72(b)(3)(v)(A).                                                           |
|                                                                              |
| "The NRC resident inspector has been informed of this retraction."           |
| Notified R1DO(White).                                                        |
+------------------------------------------------------------------------------+