Information Notice 2004-19, Problems Associated with Back-up Power Supplies to Emergency Response Facilities and Equipment
| ML042730010 | |
| Person / Time | |
|---|---|
| Issue date: | 11/04/2004 |
| From: | Hiland P NRC/NRR/DIPM/IROB |
| To: | |
| Fleming J NSIR/DPR/EPD 415-1587 | |
| References | |
| TAC MC4467 IN-04-019 | |
| Download: ML042730010 (6) | |
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C. 20555 November 4, 2004 NRC INFORMATION NOTICE 2004-19: PROBLEMS ASSOCIATED WITH BACK-UP
POWER SUPPLIES TO EMERGENCY
RESPONSE FACILITIES AND EQUIPMENT
ADDRESSEES
All holders of operating licenses for nuclear power reactors, except those who have
permanently ceased operations and have certified that fuel has been permanently removed
from the reactor vessel.
PURPOSE
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert
addressees to problems with back-up power supplies for emergency response facilities (ERFs)
and equipment. Emergency response equipment and ERFs need to be functional in the event
of an emergency. It is expected that recipients will review the information for applicability to
their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no
specific action or written response is required.
BACKGROUND
The ERF and emergency response equipment requirements must meet the following standard
of Title 10 of the Code of Federal Regulations (CFR), Part 50, Paragraph 47(b)(8):
Adequate emergency facilities and equipment to support the emergency response are
provided and maintained.
Requirements are also found in Section IV.E Emergency Facilities and Equipment of
Appendix E to 10 CFR Part 50:
Adequate provisions shall be made and described for emergency facilities and
equipment, including:
A licensee onsite technical support center (TSC) and a licensee near-site emergency
operations facility from which effective direction can be given and effective control can
be exercised during an emergency.
DESCRIPTION OF CIRCUMSTANCES
AND
DISCUSSION
TSC Emergency Diesel Generator Switch Misalignment
On June 14, 2004, as a result of a loss of offsite power (LOOP) event at Palo Verde Nuclear
Generating Station, electrical power was lost to the TSC. The TSC diesel generator started as
designed, but subsequently tripped due to high engine temperature. During troubleshooting, it
was determined that the engine operating switch was in idle. With the switch in idle, the diesel
generator started on loss of electrical power to the TSC, but did not come up to proper voltage
and frequency and did not reenergize the TSC electrical distribution panel. As a result, the
engine radiator cooling fan did not start; therefore, the engine overheated and tripped on high
temperature.
The licensee determined that the engine operating switch was apparently left in the idle position
following post-maintenance testing of the engine-starting system performed on June 8, 2004.
After corrective maintenance was performed on one battery terminal and connector, the team
leader allowed the electricians to test the engine starting system without a working copy of the
test procedure in the field, since this test was routinely performed by the electricians. After the
diesel generator was successfully started, the engine operating switch was moved from run to
idle to allow the engine to run at a slower speed and cool down before being secured. A follow- up NRC inspection determined that the failure to have a working copy of the test procedure at
the engine during this post-maintenance testing and failure to use the restoration guidance
contained in the test procedure contributed directly to the failure to restore the TSC diesel
generator to its normal standby condition. The NRC inspection also determined that the diesel
generator failure contributed to a delay in staffing the TSC because the responding members of
the emergency response organization were moved to an alternate TSC. This issue was
documented in NRC Inspection Report 05000528/2004012; 05000529/2004012;
05000530/2004012. (ADAMS# ML042020061)
Procedural Changes Modifying the Effectiveness of the Emergency Operations Facility (EOF)
On June 25, 2001, the NRC resident inspector at the Cooper Nuclear Station observed the
licensees response to an alert declaration due to a fire affecting the station startup transformer.
During the event, the inspector noted that the EOF had no alternating current (AC) power. The
normal power supply to the EOF was deenergized when the startup transformer isolated
following an electrical component failure. As a result, the EOF had limited communication
abilities and emergency battery powered lighting.
Although a back-up power supply existed for the EOF, it was only allowed to supply power to
necessary equipment when the plant was operating in Mode 4, cold shutdown or Mode 5, refueling. In operating Modes 1, 2, and 3, power operations, startup, and hot shutdown, respectfully, the back-up power supply was allowed to power only communication equipment
due to electrical loading restrictions on the switchgear. The NRC resident inspector determined
that this restriction significantly compromised the ability of the emergency operations facility to
adequately function following a loss of normal power in Modes 1, 2, and 3. In 1986, the licensee performed a design change to increase the reliability of the EOF and
provide a back-up source of power during a loss of offsite power event. This design change
originally placed no restrictions on using the back-up power supply to the EOF for any operating
mode. On September 14, 1991, the licensee revised a system operating procedure which
restricted the back-up power source to supply only the emergency operations facility
communication system when operating in Modes 1, 2, and 3, due to power limitations on the
electrical switchgear. This issue was documented in NRC Inspection Report 50-298/01-09.
(ADAMS# ML043070372)
Failure to Maintain the TSC Batteries
On December 11, 2003, the NRC completed an inspection at the Indian Point Nuclear
Generating Station, Unit 2. While reviewing condition reports, the inspection team noted that, during the quarterly surveillance tests performed on October 21, 2003, one cell in each of the
two TSC battery banks did not meet the acceptance criteria specified in the test procedures.
Although the cells were marginally out of specification, the team determined that the licensee
did not take prompt corrective actions either to return the two cells to within specifications or to
evaluate the impact of the out of specification conditions on the functionality of the battery
banks. Although the TSC battery banks performed as designed during the northeastern grid
blackout on August 14, 2003 (August 14 event), the team determined that the degraded cells
had the potential to adversely affect the facilities and equipment required to support emergency
response. This issue was documented in NRC Inspection Report 05000247/2004003.
(ADAMS# ML040360248)
Miscellaneous Failures During the August 14 Event
During the August 14 event, the TSC back-up diesel generator at Indian Point Unit 2 failed to
automatically start and subsequent operator actions to manually start and load the diesel failed.
The Unit 2 TSC diesel generator failed to function due to electrical loading in excess of its
design capacity. This condition was initially identified in February 2000 and was not resolved in
a timely manner. Observations by the licensee during emergency planning training revealed a
potential for the TSC back-up diesel generator to be overloaded. Also, a review by the licensee
of the electrical power distribution drawings showed a potential existed for the TSC back-up
diesel generator to be overloaded under some conditions. Long-term corrective actions for this
diesel were postponed. The Unit 2 TSC and Operational Support Center remained without a
back-up AC electrical power supply until September 15, 2003, when a temporary alteration was
installed and satisfactorily tested.
Additionally during the August 14 event, the Indian Point Unit 3 TSC back-up diesel generator
started and then tripped while being loaded and was unavailable for the duration of the
blackout. The Unit 3 TSC diesel generator failed to function due to a malfunctioning overspeed
controller. The diesel generator was repaired and restored to service on September 16, 2003.
During a refueling outage, on April 18, 2003, the Unit 3 TSC back-up diesel generator was
tested under simulated blackout conditions and tripped while being loaded. Subsequently, a licensee system engineer initiated a work order to replace a suspected faulty overspeed trip
module. Seven hours later, the Unit 3 TSC diesel was retested in an unloaded condition and
declared operable. The work order to replace the TSC diesel generator overspeed trip module
was postponed by the licensees maintenance planning organization until November 2003, based upon a determination that the diesel problem was not an operability concern.
During an inspection at Indian Point Units 2 and 3, following the August 14 event, an NRC team
identified that the licensee did not have a preventive maintenance program in place to ensure
the continued functionality of the numerous Un-Interruptible Power Supplies (UPSs) in the EOF
which provide back-up power to emergency response equipment. By design, there is no
electrical back-up power supply to the EOF. Instead, the EOF has a number of UPSs which
provide short-term battery back-up power to dedicated ERF communications and data
transmission systems. During the August 14 event, the UPSs failed or functioned at only a
fraction of their design capacity.
The failures of the Unit 2 and 3 TSC back-up diesel generators and the EOF UPSs were
documented in NRC Inspection Report 05000247/2003013 and 05000286/2003010. (ADAMS#
CONCLUSION
Problems with back-up power supplies and equipment have the potential to impact the ability of
ERFs to support a prompt and effective response to an emergency. The occurrence of these
types of problems can be reduced by following restoration procedures after testing and
maintenance, promptly resolving deficiencies identified during testing and maintenance, and
reviewing design changes for impact on the operability of ERF back-up power supplies.
CONTACT
This information notice requires no specific action or written response. Please direct any
questions about information in this notice to the technical contact listed below or the appropriate
Office of Nuclear Reactor Regulation project managers.
/RA/
Patrick L. Hiland, Chief
Reactor Operations Branch
Division of Inspection Program Management
Office of Nuclear Reactor Regulation
Technical Contact:
Jason L. Flemming
(301) 415-5787 E-mail: jlf2@nrc.gov
Attachment: List of Recently Issued NRC Information Notices licensee system engineer initiated a work order to replace a suspected faulty overspeed trip
module. Seven hours later, the TSC diesel was retested in an unloaded condition and declared
operable. The work order to replace the TSC diesel generator overspeed trip module was
postponed by the licensees maintenance planning organization until November 2003, based
upon a determination that the diesel problem was not an operability concern.
Failure of EOF Uninterruptible Power Supplies (UPSs)
During an inspection at Indian Point Units 2 and 3, following the August 14 event, an NRC team
identified that the licensee did not have a preventive maintenance program in place to ensure
the continued functionality of the numerous UPSs in the EOF which provide back-up power to
emergency response equipment. By design, there is no electrical back-up power supply to the
EOF. Instead, the EOF has a number of UPSs which provide short-term battery back-up power
to dedicated ERF communications and data transmission systems. During the August 14 event, the UPSs failed or functioned at only a fraction of their design capacity.
The failures of the Unit 2 and 3 TSC back-up diesel generators and the EOF UPSs were
documented in NRC Inspection Report 05000247/2003013 and 05000286/2003010. (ADAMS#
CONCLUSION
Problems with back-up power supplies and equipment have the potential to impact the ability of
ERFs to support a prompt and effective response to an emergency. The occurrence of these
types of problems can be reduced by following restoration procedures after testing and
maintenance, promptly resolving deficiencies identified during testing and maintenance, and
reviewing design changes for impact on the operability of ERF back-up power supplies.
CONTACT
This information notice requires no specific action or written response. Please direct any
questions about information in this notice to the technical contact listed below or the appropriate
Office of Nuclear Reactor Regulation project managers.
/RA/
Patrick L. Hiland, Chief
Reactor Operations Branch
Division of Inspection Program Management
Office of Nuclear Reactor Regulation
Technical Contact:
Jason L. Flemming
(301) 415-5787 E-mail: jlf2@nrc.gov
Attachment: List of Recently Issued NRC Information Notices
DISTRIBUTION: ADAMS IN File
ADAMS ACCESSION #: ML042730010
DOCUMENT NAME: E:\Filenet\ML042730010.wpd
OFFICE DPR:EPD:NSIR TECH EDITOR EMCB EPD:DPR:NSIR D:EPD:DPR:NSIR
NAME JLFlemming PKleene SLRosenberg EWWeiss NLMamish
DATE 10/06/2004 09/23/2004 10/17/2004 10/08/2004 10/12/2004 OFFICE DPR:NSIR OES:IROB:DIPM A:SC:OES:IROB:DIPM A:C:IROB:DIPM
NAME EJLeeds CDPetrone ACMcMurtray PLHiland
DATE 10/14/2004 10/18/2004 11/03/2004 11/04/2004 / /2004 OFFICIAL RECORD COPY
Attachment 1 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
_____________________________________________________________________________________
Information Date of
Notice No. Subject Issuance Issued to
_____________________________________________________________________________________
2004-18 Recent Safety-related Event at 10/26/2004 All licensees authorized to
Panoramic Wet-source- possess and use sealed sources
storage Irradiator in panoramic wet-source-storage
irradiators, and irradiator vendors.
2004-17 Loose Part Detection and 08/25/2004 All holders of operating licenses
Computerized Eddy Current for pressurized-water reactors
Data Analysis in Steam (PWRs), except those who have
Generators permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor.
2004-16 Tube Leakage Due to a 08/03/2004 All holders of operating licenses
Fabrication Flaw in a for pressurized-water reactors
Replacement Steam Generator (PWRs), except those who have
permanently ceased operations
and have certified that fuel has
been permanently removed from
the reactor.
2004-15 Dual-Unit Scram at Peach 07/22/2004 All holders of operating licenses
Bottom Units 2 and 3 for nuclear power reactors except
those who have permanently
ceased operation and have
certified that fuel has been
permanently removed from the
reactor vessel.
2004-14 Use of less than Optimal 07/19/2004 All licensees authorized to
Bounding Assumptions in possess a critical mass of special
Criticality Safety Analysis at nuclear material.
Fuel Cycle Facilities
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