ML16154A702
| ML16154A702 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/18/1995 |
| From: | Casto C, Moore R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A703 | List: |
| References | |
| 50-269-95-19, 50-270-95-19, 50-287-95-19, NUDOCS 9511140285 | |
| Download: ML16154A702 (7) | |
See also: IR 05000269/1995019
Text
REGo
UNITED STATES
o
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report Nos.:
50-269/95-19, 50-270/95-19 and 50-287/95-19
Licensee: Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.:
50-269, 50-270, and 50-287
License Nos.:
and DPR-55
Facility Name:
Oconee Nuclear Station Units 1, 2 and 3
Inspection Conducted: October 9-13, 1995
Inspector:
R.'\\e~rdD
te Signed
Approved by:
/ 4
1--/0
C. Casto, Chief,
Date Signed
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
This routine, unannounced inspection was conducted in the area of engineering
(IP 37550). The inspection reviewed the design base documentation for the
Keowee hydroelectric generators' mechanical support systems to verify that the
design information was consistent with industry standards and that the
systems' safety functions were adequately identified and verified.
Additionally reviewed were the licensee's actions to resolve a system
reliability issue from the 1992 Loss-of-Offsite Power (LOOP) event.
Results:
In the areas inspected, violations or deviations were not identified.
The licensee's design documentation for the Keowee mechanical systems was
consistent with industry standards. The systems' safety functions were
identified and appropriate calculations and testing were developed to verify
these functions.
9511140285 951018
ADOCK 05000269
Enclosure
GPDR
2
The modification to the Keowee 600 VAC power logic improved the reliability of
the governor oil system and the hydroelectric generators. Overall, the
licensee's actions demonstrated an increased understanding of the Keowee
mechanical systems' operating and design characteristics since the 1992 LOOP
event.
0
Enclosure
REPORT DETAILS
1 .
Persons Contacted
Licensee Employees
- E. Burchfield, Regulatory Compliance Manager
M. Bailey, Regulatory Compliance
- D. Coyle, Mechanical Systems Engineering Manager
- J. Davis, Engineering Manager
B. Foster, Safety Assurance Manager
- C. Little, Electrical Engineer
- K. Louvin, Mechanical System Engineer
R. McCoy, Seismic Qualification Utilities Group Senior Engineer
F. Moss, Seismic Qualification Utilities Group Senior Engineer
- B. Peele, Station Manager
- R. Severance, Mechanical Systems Engineer
- J. Smith, Regulatory Compliance
Other licensee employees contacted during this inspection included
craftsmen, engineers, technicians and administrative personnel.
NRC Employees
P. Harmon, Senior Resident Inspector
L. Keller, Resident Inspector
- N. Salgado, Resident Inspector
- Attended exit interview
Acronyms and abbreviations are identified in paragraph 8.
2.
Background
The Keowee Hydroelectric Station provides the emergency AC power source
for the Oconee Nuclear Station. There are two hydroelectric generators
with independent support systems. The hydro station was not originally
under the Duke Power Nuclear Generation Department management;
therefore, documentation and programmatic controls to ensure Keowee met
nuclear industry standards were not fully implemented. Audit and
inspection activities over several years indicated that aspects of the
design, operation, and maintenance merited improvement. An October,
1992, Loss of Offsite Power event demonstrated that there was inadequate
understanding of Keowee operation and design.
The Power Upgrade Project was initiated in September, 1994, to bring the
Keowee design, operations and maintenance activities to nuclear
standards. An element of the project was to develop design basis
documentation (DBD) for the Keowee hydroelectric generator mechanical
systems, upgrade and control drawings, and develop calculations and
testing to verify the design function of these systems. The DBDs
provided a basis to improve the licensee's understanding of systems'
Enclosure
2
operating characteristics and design. This inspection reviewed the
licensee's mechanical systems DBDs, drawings, and calculations to
determine if they were consistent with nuclear industry standards.
These standards were established by Regulatory Guide (RG) 1.64, Quality
Assurance Requirements for the Design of Nuclear Power Plants, and
American National Standards Institute (ANSI) N45.2.11 - 1974, Quality
Assurance Requirements for the Design of Nuclear Power Plants.
3.
Keowee Design Base Document
The inspector reviewed the Keowee mechanical DBD to verify that the
systems' design functions and parameters were identified and that
appropriate calculations and testing were referenced to verify the
design functions. The following design basis specifications encompassed
the Keowee mechanical DBD:
OSS-0254.00-00-1043, Design Basis Specification for the Keowee
Turbine Guide Bearing Oil (GBO) System, dated May 24, 1995
OSS-0254.00-00-1044, Design Basis Specification for the Keowee
Governor Air (AG) System, May 24, 1995
OSS-0254.00-00-1044, Design Basis Specification for the Keowee
Governor Oil (OG) System, May 24, 1995
OSS-0254.00-00-1044, Design Basis Specification for the Keowee
Turbine Generator Cooling Water (WL),System, May 24, 1995
OSS-0254.00-00-1044, Design Basis Specification for the Keowee
Turbine Sump Pump (TS) System, May 24, 1995
OSS-0254.00-00-1044, Design Basis Specification for the Keowee Air
Circuit Breaker (ACB) Air System, in draft.
Section 20, System Design Bases, of the specifications stated the safety
function of the systems. The safety related design function of the GBO
system was to maintain a level in the turbine guide bearing upper oil
reservoir to assure lubrication for the turbine shaft guide bearings.
The AG system pressurized the governor oil pressure tank for positioning
the water inlet gates to the water turbine for blackstart of the hydro
electric generator. The OG system controlled the generator output by
positioning of the inlet gates during operation. The WL system removed
heat from the generator air coolers and oil coolers. The TS system .
prevented flooding in the turbine wheel pit sump due to gland leak-off.
The ACB air system provided compressed air for operation of the
generator breaker. The inspector concluded that the safety function of
the Keowee mechanical systems was adequately specified in the DBD.
Enclosure
3
Section 40 or Appendix A, Testing/Calculation Matrix, of the
specifications individually listed the design requirements and
supporting calculation, procedure, or justification. Unsupported design
requirements were identified by a Problem Investigation Program (PIP)
report to track resolution of the design requirement justification. An
example of an undefined design requirement parameter was the minimum
pressure of the governor oil pressure tank at the initiation of a design
base event. This was tracked by PIP 4-095-0673. Additionally, the
test/calculation matrix referenced the test procedure which would
provide routine verification of system equipment performance. The
implementation of the Inservice Testing and Inspection Program (IST/ISI)
for the Keowee mechanical systems was scheduled for November 1, 1995.
The licensee was implementing instrumentation modifications to
facilitate IST/ISI testing. The inspector concluded that the DBD
provided adequate verification of the systems' design requirements.
Design parameters were adequately identified and addressed.
4.
Calculations and Drawings
The inspector reviewed the calculations and drawings which supported the
DBD to verify that all assumptions had been verified, the design
documents were consistent with industry standards, and the drawings were
consistent with the installed configuration. Calculations were
developed in accordance with Engineering Directive Manual procedure EDM
101, Engineering Calculations/Analysis, revision 4. The following
calculations were reviewed:
KC 1-2-2014, High Pressure Oil (HPO) System Analysis, dated
May 25, 1995
KC 1-2-2003, Turbine Sump Pump Flow, May 24, 1995
KC 1-2-2005, Turbine Generator Cooling Water Analysis,
May 17, 1995
1-2-2015, Turbine Guide Bearing Oil System Analysis, May 26, 1995
1-2-2009, WL System Water Hammer Evaluation, May 31, 1995
KC 1-2-2012, Governor Safety System Safety Relief Valve Sizing,
May 31, 1995
KC 1-2-2013, Governor Air System Recovery Time, May 30, 1995
KC 1-2-2018, ACB Air System Recovery Time, May 31, 1995
KC 1-2-2019, Keowee Mechanical Systems Single Failure Analysis,
June 1, 1995.
Enclosure
4
The inspector concluded that the calculations were generally well
documented. There were no unverified assumptions and the conclusions
adequately supported the design base function capabilities which were
addressed. Configuration sketches supporting system flow analysis were
accurate. Industry standards related to design inputs, design
verification, and design document control were appropriately
implemented.
The following drawings were reviewed and field verified:
KFD-1O1A-1.1, Flow Diagram of Turbine Generator Guide Bearing Oil
System, revision 2
KFD-106A-3.0, Flow Diagram of Lube Oil System, revision 0
KFD 100A-1.1, Flow Diagram of turbine Generator cooling Water
System, revision 3
KFD 104A-1.1, Flow Diagram of Governor Air System, revision 5
KFD 105A-1.1, Flow Diagram of Governor Oil System, revision 3
KFD 102A-1.1, Flow Diagram of Turbine Sump Pump System,
revision 2.
The drawings were consistent with the installed equipment configuration
and clearly designated the portion of the systems which were safety
related. This was defined on the drawings as Duke Piping Class F.
Additionally, the drawings were designated as QA Condition 1 documents.
The inspector concluded that the drawings were accurate and drawing
control was consistent with industry standards regarding design
documentation.
5.
Equipment Seismic Qualification
The inspector-reviewed the seismic qualification basis for the
mechanical systems. Qualification of this equipment was provided by the
licensee's implementation of the Seismic Qualification Utility Group
(SQUG) methodology. This methodology incorporated the Generic
Implementation Procedure (GIP)-2, Seismic Verification of Nuclear Plant
Equipment, dated February, 1992. The seismic capability of most of the
equipment was established by the SQUG reviews. The inspector reviewed
the screening evaluation work sheets for critical switches and relays in
the mechanical systems which would impact the emergency start or
operation of the hydroelectric generators. These included the oil level
switches for the HPO and GBO systems and the Generator Carbon Dioxide
(CO2) Release Pressure Switches. These switches and associated relays
could not be qualified by the criteria of GIP-2 and were identified as
outliers as required by the licensee's NRC approved SQUG program. A
minor modification (OE 7258) and PIP 5-094-1755 were initiated to
Enclosure
5
replace the C02 switches. The resolution of the SQUG outliers will be
submitted to the NRC at the completion of the licensee's implementation
of this program in 1996. The inspector concluded that the licensee had
appropriately addressed the Keowee mechanical equipment seismic.
qualification with the SQUG program.
6.
Governor Oil System Reliability
The inspector reviewed the licensee's actions to resolve a reliability
issue identified during the 1992 LOOP event. During the event the power
supply to the governor oil pumps became a critical issue in the
operation of the hydroelectric generators. At that time operator action
was required to align a power source to the pumps as a result of a
transient experienced by the Keowee Station 600 VAC auxiliaries which
powered the pumps. A modification, NSM ON-52930, was installed in
September, 1993, to address this issue. The modification provided power
seeking relays in the auxiliaries' 600 VAC power logic'to permit
automatic auxiliary power swap over for the pump load centers. An
additional proposal under review was the installation of a DC powered
pump. This required further review of the impact on the Keowee
batteries. The inspector concluded that the power logic modification
improved the reliability of the Keowee hydroelectric generators
7.
Exit Meeting
The inspection scope and results were summarized on October 12, 1995,
with those individuals indicated in paragraph 1. The inspector
described the areas inspected and discussed in detail the inspection
findings. There were no dissenting comments received from the licensee.
Proprietary information is not contained in this report.
8.
Acronyms and Abbreviations
Alternating Current
ACB
Air Circuit Breaker
AG
Governor Air
ANSI
American Nuclear Standards Institute
Design Bases Documentation
Direct Current
GBO
Turbine Guide Bearing Oil
HPO
High Pressure Oil
IST/ISI
Inservice Testing/Inservice Inspection
Loss-of-Offsite-Power
Governor Oil
Problem Investigation Program
Seismic Qualification Utilities Group
TS
Turbine Sump
WL
Turbine Generator Cooling Water
EnDCosure