United States Nuclear Regulatory Commission - Protecting People and the Environment

Event Notification Report for May 16, 2012

U.S. Nuclear Regulatory Commission
Operations Center

Event Reports For
05/15/2012 - 05/16/2012

** EVENT NUMBERS **


47845 47911 47924

To top of page
Power Reactor Event Number: 47845
Facility: BRAIDWOOD
Region: 3 State: IL
Unit: [1] [ ] [ ]
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: DALE RUSH
HQ OPS Officer: JOHN SHOEMAKER
Notification Date: 04/17/2012
Notification Time: 23:12 [ET]
Event Date: 04/17/2012
Event Time: 21:30 [CDT]
Last Update Date: 05/15/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
HIRONORI PETERSON (R3DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N N 0 Cold Shutdown 0 Cold Shutdown

Event Text

PLANT PROCESS COMPUTER REMOVED FROM SERVICE FOR PLANNED REPLACEMENT

"At 2130 (CDT) on April 17, 2012, the Unit 1 Plant Process Computer (PPC) was removed from service for a planned replacement in the current Unit 1 Refueling Outage. The Unit 1 PPC feeds the Safety Parameter Display System (SPDS) used in the Main Control Room (MCR) and the Technical Support Center (TSC). The Unit 1 PPC also feeds the Emergency Response Data System (ERDS). The Unit 1 and Unit 2 PPCs also feed the Plant Parameter Display System (PPDS) used in the MCR, TSC and Emergency Operations Facility (EOF). Meteorological data will remain available in the MCR but not through ERDS for either Unit 1 or Unit 2. The dose assessment program will remain functional as the Unit 2 Plant Process computer will be capable of providing the necessary data through PPDS to run the program. The dose assessment program is not affected by the Unit 1 PPC being out of service. As compensatory measures, a proceduralized backup method to fax or communicate via a phone circuit applicable data to the NRC, TSC, and EOF exists. There is no impact to the Emergency Notification System (ENS) or Health Physics Network (HPN) communication systems.

"The new Unit 1 PPC is scheduled to be functional on April 21, 2012. However, based on the mode Unit 1 will be in, this will limit the number of points that would provide usable data. The Unit 1 PPC will be tested as mode changes occur. The Unit 1 PPC is planned to be declared functional by Mode 2. A follow-up ENS call will be made once the Unit 1 PPC is declared functional.

"The loss of SPDS and ERDS is a 'major loss of assessment capability' and is reportable under 10CFR50.72(b)(3)(xiii).

"The NRC Senior Resident Inspector and the State of Illinois (through the Illinois Emergency Management Agency Resident Inspector) have been notified of this ENS call."

* * * UPDATE FROM JOE KLEVORN TO JOHN KNOKE AT 1035 EDT ON 05/15/12 * * *

"As of 1035 EDT on May 15, 2012, the Unit 1 PPC is considered operational with respect to the Safety Parameter Display System (SPDS), Plant Parameter Display System (PPDS) and Emergency Response Data System (ERDS). Therefore, a Major Loss of Assessment Capability no longer exists on Unit 1. The EP Manager will contact the NRC Computer Center for Unit 1 to ensure the ERDS data is being satisfactorily sent to the NRC.

"The NRC Resident Inspector and the State of Illinois (through the Illinois Emergency Management Agency Resident Inspector) have been notified of this ENS update."

The R3DO (Patty Pelke) has been notified.

To top of page
!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!
Fuel Cycle Facility Event Number: 47911
Facility: PADUCAH GASEOUS DIFFUSION PLANT
RX Type: URANIUM ENRICHMENT FACILITY
Comments: 2 DEMOCRACY CENTER
                   6903 ROCKLEDGE DRIVE
                   BETHESDA, MD 20817 (301)564-3200
Region: 2
City: PADUCAH State: KY
County: McCRACKEN
License #: GDP-1
Agreement: Y
Docket: 0707001
NRC Notified By: ROD COOK
HQ OPS Officer: HOWIE CROUCH
Notification Date: 05/09/2012
Notification Time: 08:42 [ET]
Event Date: 05/08/2012
Event Time: 16:16 [CDT]
Last Update Date: 05/15/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
76.120(c)(2) - SAFETY EQUIPMENT FAILURE
RESPONSE-BULLETIN
Person (Organization):
SCOTT FREEMAN (R2DO)
LARRY CAMPBELL (NMSS)

Event Text

AUTOCLAVE HIGH PRESSURE ISOLATION SYSTEM FAILURE

"At 1616 CDT, on 05-08-12 the Plant Shift Superintendent (PSS) was notified that C-360 (Toll Transfer & Sampling Building) Autoclave #2 had a failure in the Autoclave High Pressure Isolation System [AHPIS]. [AHPIS] is designed to: 1) prevent a cylinder failure inside the autoclave as a result of overheating; and 2) mitigate releases to the atmosphere from releases inside the autoclave. Autoclave containment is required to be operable per TSR 2.1.3.1 while the autoclave is in TSR modes 3 (containment), 4 (autoclave closed), and 5 (autoclave heating). On 5/08/12 at 1610 CDT an operator noticed water flowing from the autoclave head to shell sealing surface on the #2 autoclave in C-360 while a cylinder was being heated (TSR mode 5 - autoclave heating). The PSS was notified of the loss of containment at 1616 CDT and the [AHPIS] was declared inoperable. The steam cycle was interrupted and the autoclave was placed in a non-applicable TSR mode at 1657 CDT. No release of UF6 occurred due to the failure of the [AHPIS].

"This event is reportable as a 24 hour event in accordance with 10CFR 76.120(c)(2)(i). This is an event in which equipment is disabled or fails to function as designed when: a.) the equipment is required by a TSR to prevent releases, prevent exposures to radiation and radioactive materials exceeding specified limits, mitigate the consequences of an accident, or restore this facility to a pre-established safe condition after an accident; b.) the equipment is required by a TSR to be available and operable and either should have been operating or should have operated on demand; and c.) no redundant equipment is available and operable to perform the required safety function.

"The NRC Senior Resident Inspector has been notified of this event.

"PGDP Assessment and Tracking Report No. ATRC-12-1195; PGDP Event Report No. PAD-2012-02; Responsible Division: Operations"


* * * UPDATE FROM BILLY WALLACE TO DONALD NORWOOD AT 1640 EDT ON 5/9/2012 * * *

After further review the licensee determined that additional reportability criteria were met as described below:

"At 1616 on 05/08/2012, the PSS was notified that C-360 Autoclave #2 had water flowing from the autoclave head to shell sealing surface indicating a potential failure in the Autoclave High Pressure Isolation System (AHPIS) containment, which is relied on as an engineered control in NCSE 042 (SRI 5.5.3). The AHPIS is designed to minimize leaks to atmosphere from the autoclave under maximum pressures resulting from a UF6 release from the cylinder, valve or pigtail in the autoclave. The maximum acceptable leak rate for the autoclaves is 12 SCFM at a minimum test pressure of 90 psig or a 10 psi pressure drop in 1 hour. In order to determine if the AHPIS would have met its safety function, a pressure decay test will be performed. However, the pressure decay test will not be performed within 24 hours of discovery. Therefore, it is conservatively assumed that the leak discovered is greater than 12 SCFM or greater than 10 psi pressure drop in 1 hour; resulting in a 24 hour NCS reportable event. When the leak was noticed, the heat cycle was interrupted and the autoclave placed in a safe configuration. No release of UF6 had occurred in the autoclave when the leak out the autoclave was found.

"This event is reportable as a 24 hour event in accordance with 24-Hr. NRC BL 91-01 Supp. 1. This is a criticality safety event in which violations involving operations that comply with the double contingency principle and do not meet the criteria for a 4-hr report, but still result in a violation of the double contingency principle, such as, events where the double contingency principle is violated but control is immediately reestablished.

"Safety Significance of Events:
--While an NCSA control was not maintained resulting in the potential autoclave leak rate being exceeded, a release of fissile material from a cylinder in the autoclave did not occur and therefore a criticality was not possible.

"Potential Criticality Pathways Involved:
--In order for a criticality to be possible, a cylinder, valve, or pigtail of a fissile cylinder would have to fail and release greater than a safe mass of fissile material into the autoclave and the autoclave containment would have to fail allowing a large release to atmosphere of uranium and settle out in an unfavorable geometry with sufficient moderator present.

"Controlled Parameters:
--The first leg of double contingency is based on mass.

--The first leg of double contingency is based on administrative and design controls to ensure that it is unlikely to have a large release of UF6 from the cylinder, valve or pigtail in the autoclave while healing the cylinder.

--The second leg of double contingency is based on geometry moderation.

"Estimated Amount, Enrichment, Form of Licensed Material:
--No leakage of UF6 occurred.

"Nuclear Criticality Safety Control(s) or Control System(s) and Description of the Failures or Deficiencies:
--The first leg of double contingency is based on mass.

--The first leg of double contingency is based on administrative and design controls to ensure that it is unlikely to have a large release of UF6 from the cylinder, valve or pigtail in the autoclave while heating the cylinder. This control was maintained.

--The second leg of double contingency is based on geometry / moderation.

--Small leaks out of the autoclave to atmosphere are considered normal case and the Autoclave High Pressure Isolation System ensures containment to minimize a significant release to atmosphere if a release occurs in the autoclave during heating. The AHPIS ensures that the maximum leak rate from the autoclave will not exceed 12 SCFM or a maximum acceptable pressure drop of 10 psi in 1 hour. If the containment leak rate is maintained, only a small amount of uranium could leak to atmosphere and the uranium would form in thin layers on surfaces in a geometrically safe configuration. Also there would be insufficient uranium to leak outside of the building; therefore there would not be a sufficient source of moderation. Since this control is assumed to have failed, uranium could leak out of the autoclave to atmosphere if a large release of UF6 occurred in the autoclave and potentially deposit in geometrically unfavorable configurations in areas where sufficient moderators exist. Since the leak rate cannot be confirmed within 24 hours, it is conservatively assumed that the geometry moderation parameter was lost and double contingency was not maintained.

"Corrective Actions To Restore Safety Systems and When Each Was Implemented:
--Perform a pressure decay test on Autoclave #2 according to procedures and if the leak rate is determined to be greater than 12 SCFM or 10 psi in one hour, repair AHPIS prior to heating another cylinder containing uranium.

"The NRC Resident Inspector has been notified of this event.

"PGDP Assessment and Tracking Report No. ATRC-12-1195; PGDP Event Report No. PAD-2012-03; Responsible Division: Operations."

Notified R2DO (Freeman) and NMSS EO (Campbell).


* * * RETRACTION FROM DAVID PETTY TO DONG PARK AT 1403 EDT ON 5/15/2012 * * *

"Subsequent to the above notifications on May 10, 2012, autoclave no. 2 was subjected to a pressure decay test in the as-found condition. The test indicated that the High Pressure Isolation Safety System would have been capable of performing its intended safety function if called upon on May 8, 2012, during the heat cycle subject of the event reports. Thus, the event was not required to be reported under 10CFR 76.120(c)(2)(i) and the notifications may be retracted.

"Subsequent to the above notifications on May 10, 2012, autoclave no. 2 was subjected to a pressure decay test in the as-found condition. The test indicated that the High Pressure Isolation Safety System would have been capable of performing its intended safety function if called upon on May 8, 2012, during the heat cycle subject of the event reports. The pressure drop from the as-found test was less than the maximum allowable pressure drop for the system required for criticality safety. Thus, the event did not meet the criteria to be reported under 24-Hr. NRC BL 91-01 Supp. 1."

The NRC Senior Resident Inspector has been notified of this event. Notified R2DO (Shaeffer) and NMSS EO (Guttmann).

To top of page
Power Reactor Event Number: 47924
Facility: FARLEY
Region: 2 State: AL
Unit: [1] [2] [ ]
RX Type: [1] W-3-LP,[2] W-3-LP
NRC Notified By: STEVE GATES
HQ OPS Officer: MARK ABRAMOVITZ
Notification Date: 05/15/2012
Notification Time: 10:39 [ET]
Event Date: 05/15/2012
Event Time: 07:20 [CDT]
Last Update Date: 05/15/2012
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
SCOTT FREEMAN (R2DO)

Unit SCRAM Code RX CRIT Initial PWR Initial RX Mode Current PWR Current RX Mode
1 N Y 100 Power Operation 100 Power Operation
2 N Y 100 Power Operation 100 Power Operation

Event Text

TECHNICAL SUPPORT CENTER PLANNED MAINTENANCE

"The Farley Nuclear Plant Technical Support Center (TSC) has been rendered non-functional due to a pre-planned and scheduled maintenance period to perform PMs [Preventive Maintenance] on the TSC ventilation system. The TSC ventilation maintenance will be worked with high priority to include around the clock support. Pre-planned compensatory measures are in place in accordance with site procedures to include the conditional relocation of the TSC staff should the Emergency Director deem the TSC to be uninhabitable.

"This report is being generated per Technical Requirements Manual TRM section 13.13.1 condition B for the TSC emergency response facility being out of service for greater than 30 minutes. The projected return to service is on 5/15/12 at 16:30 CDT."

The licensee notified the NRC Resident Inspector.

Page Last Reviewed/Updated Wednesday, May 16, 2012
Wednesday, May 16, 2012