ML16161A803
| ML16161A803 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/11/1987 |
| From: | Conlon T, Fillion P, Hunt M, Miller W, Taylor P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16161A799 | List: |
| References | |
| 50-269-87-02-NP, 50-269-87-2-NP, 50-270-87-02, 50-270-87-2, 50-287-87-02, 50-287-87-2, NUDOCS 8704300479 | |
| Download: ML16161A803 (20) | |
See also: IR 05000269/1987002
Text
od
NUCLEAR REGULATORY COMMISSION
REGIONI
101 MARIETTA STREET. N W.. SUITE 2900
ATLANTA, GEORGIA 30323
Report Nos.:
50-269/87-02, 50-270/87-02, and 50-287/87-02
Licensee: Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.: 50-269, 50-270, and 50-287
License Nos.:
Facility Name: Oconee 1, 2, and 3
.
Inspection Conducted:
Jan uary 26-30 1987
Inspector: L4
7
//
.//._
W. H. Miller, Jr.
Date Signed
on
f -Sgned
PDate
Signed
Accompanying Personn :
D. J. Kubicki, NRC/NRR-PWR B
Approved by:
,7C
.E
on, Cief, Pant Systems Section
Dateigned
Engineering Branch
Division of Reactor Safety
SUMARY
Scope:
This special announced inspection was in the areas of fire protection,
standby shutdown facility (SSF)
and related features required to meet 10 CFR 50,
Appendix R, Sections III.G, III.J, III.L and 111.0.
Results:
One violation was identified -
Inadequate Appendix R Circuit Analysis,
paragraph 5.a(1) and 5.c(3).
No deviations were identified.
8704300479 870422
ADOCK 05000269
0
DETAILS
1. Persons Contacted
Licensee Employees
- H. D. Brandes, Analytical Engineer
S. R. Christopher, Analytical Engineer
G. D. Chronister, Technical Specialist
- T. Coutu, Operations Engineer
- T. Curtis, Integrated Scheduling Group
E. G. Frampton, Supervising Design Engineer
- P. F. Guill, Licensing Engineer
- C. Harlin, Compliance engineer
T. Hathcock, Technical Specialist
L. T. Harkinson, Design Engineer
- J. R. Hendricts, Principle Engineer
- E. L. Hyland, Design Engineer
- W. G. Itin, Safety Supervisor
T. W. King, Fire Protection Specialist
B. Loftis, I&E Engineer
- J. T. McIntosh, Superintendent Station Services
S. P. Neshict, Design Engineer
- T. Owen, Maintenance
- K. W. Sandel, Design Engineer
- D. Sweigart, Superintendent Operations
- H. Tilson, I&E Specialist
- M. S. Tuckman, Station Manager
- N. Watson, Mechanical Maintenance Engineer
Other licensee employees contacted included craftsmen, engineers,
technicians,
operators,
mechanics,
security office members
and office
personnel.
NRC Resident Inspectors
- J. C. Bryant
- L. D. Wert
- Attended exit interview
2.
Exit Interview
The inspection scope and findings were summarized on January 30, 1987, with
those persons indicated in paragraph above.
The inspector described the
areas inspected and discussed in detail the inspection findings.
No dis
senting comments were received from the licensee.
The following new items
were identified during this inspection:
-
Violation 269, 270, 287/87-02-01, Inadequate Appendix R Circuit Analy
sis, paragraph 5.a.(1) and 5.c.
2
-
Unresolved Item 269, 270, 287/87-02-02, Determine the Acceptability of
the SSF Dedicated Submersible Pump as Related to an Appendix R Repair,
paragraph 5.b.
-
Unresolved Item 269, 270, 287/87-02-03, Adequacy of Spurious Actuation
Event Evaluation Following Control Room Evacuation, paragraph 5.c.2.
-
Unresolved Item 269, 270, 278/87-02-04,
NRR Resolution to Appendix R
Exemptions, paragraphs 5.a.2. and 8.
-
Inspector Followup Item 269,
270,
287/87-02-05,
Review Licensee's
Part 21 Reevaluation on Ruskin .Fire Dampers, paragraph 9.
-
Unresolved Item 269,
270,
287/87-02-06,
Inadequate Fire Detection
Coverage to Meet Requirements of Appendix R, III.G.3, paragraph 5.a.3.
-
Inspector Followup Item 269/87-02-7, Sprinkler Protection Required for
Instrument Calibration Room in Area 300, paragraph 5.a.3.
3. Licensee Action on Previous Enforcement Matters
This subject was not addressed in the inspection.
0
4.
Unresolved Items
Unresolved items are matters about which more information is required to
determine whether they are acceptable or may involve violations or devia
tions.
Four unresolved items identified during this inspection are dis
cussed in paragraphs 5.a(3), 5.b, 5.c.2, and 8. .
5.
Compliance with 10 CFR 50 Appendix R Sections III.G ana III.L
An inspection was conducted to determine if the fire protection features
provided for structures, systems and components important to safe shutdown
at Oconee were in compliance with Appendix R, Sections III.G and III.L.
Since the Oconee Nuclear Station utilizes the dedicated shutdown system
approach, the scope of this inspection determined if the fire protection
features provided were capable of maintaining either the dedicated SSF or
one train of normal plant hot shutdown systems free from fire damage.
The
fire protection features for the normal plant safe shutdown systems for
which the dedicated shutdown capabilities had been provided were also
reviewed to determine if these features were capable of limiting potential
fire damage to these components.
The resolution of the turbine building
flooding and physical security requirements were not evaluated.
The original Oconee plant design did not subdivide the plant into multiple
fire areas to separate redundant shutdown components nor were redundant
shutdown train cables separated to meet the current separation requirements
of Appendix R Sections III.G. The plant was basically one large fire area.
To meet these separation requirements, Duke designed the SSF to provide an
alternate and independent method of achieving and maintaining hot shutdown
3
for one or more units for a period of approximately three days.
Damage
control and repair operations are required to bring the plant to cold
shutdown.
The principle components of the SSF include:
a detached seismically de
signed structure called the Standby Shutdown Facility (SSF),
SSF reactor
coolant makeup system, auxiliary service water pump, and a totally indepen
dent power source from an SSF diesel- generator and associated electrical
components.
The SSF contains a small control room from which the SSF
components can be operated on monitored.
If the normal reactor coolant
makeup system is lost, the coolant system volume is to be maintained by a
26 gpm motor driven makeup pump, installed in each reactor building, which
takes suction from the fuel transfer tube and spent fuel pool of the affect
ed unit. If the normal and routine emergency feedwater system is lost, the
secondary volume makeup is to be maintained by an SSF auxiliary service
water pump (motor driven) powered by the SSF power system.
This pump is
located in the SSF structure and takes suction from the condenser circulat
ing water piping for Unit 2.
All electrical power and control cables are either located in the SSF or are
routed from the SSF to the reactor building via the west penetration room in
each unit, except the SSF cables to reactor coolant letdown valve HP-4.
Refer to paragraph 5.a.(1) for details on this item.
The west penetration
rooms are separated from the remainder of the plant by walls, floors and
ceilings having a fire resistant rating equivalent to three-hours.
a. Safe Shutdown Capabilities
In order to ensure safe shutdown capabilities, where cables or equip
ment of redundant trains of systems necessary to achieve and maintain
hot standby conditions are located within the same fire area outside
the primary containment Appendix R,Section III.G.2 requires that one
train of hot standby systems be maintained free of fire damage by one
of the following means:
-
Separation of cables and equipment and associated nonsafety
circuits of redundant trains by a fire barrier having a three-hour
rating;
-
Separation of cables and equipment and associated non-safety
circuits of redundant trains by a horizontal distance of more than
20 feet with no intervening combustibles or fire hazards.
In
addition, fire detectors and an automatic fire suppression system
shall be installed in the fire area; or,
-
Enclosure of cable and equipment and associated non-safety cir
cuits of one redundant train in a fire barrier having a one-hour
rating.
In addition, fire detectors and an automatic fire sup
pression system shall be installed in the fire area.
4
Where the protection of systems whose function is required for hot
standby does not satisfy the above requirements of Section III.G.2,
alternative or dedicated shutdown capabilities independent of cables,
systems or components in the area,
room or zone under consideration
shall be provided in accordance with Appendix R,Section III.G.3 and
III.L.
In addition,Section III.G.3 requires that fire detection and
fixed suppression be installed in the area,
room or zone under
consideration.
On the basis of the above Appendix R .criteria, the inspectors made an
audit of cabling and components associated with the dedicated SSF to
determine the adequacy of the separation afforded to the SSF with
respect to plant areas containing both redundant trains of normal
essential hot standby systems.
In addition, the inspectors made an
audit of the fire protection features afforded for those plant areas
which contain both redundant trains and normal essential plant systems
required to achieve and maintain safe shutdown conditions.
(1) Separation of SSF from Normal Plant Shutdown Systems Outside
Containment
The inspectors reviewed the licensee's "Appendix R Cable Routing
Evaluation" which was provided to NRC Region II on September 22,
1986. This evaluation indicated that all of the SSF cables were
routed from SSF building to the Reactor Building via the west
penetration room for each unit. These west penetration rooms are
separated from the east penetration rooms and the remainder of the
plant by walls, floors and ceilings having a fire resistant rating
equivalent to three-hours. Thus, the SSF cables were designed to
be separated from the cables or component of at least one of the
normal plant shutdown trains.
The east penetration room contains
one normal shutdown train and the west penetration room contains
one normal shutdown train plus the SSF shutdown cables.
To verify
that the licensee's cables evaluation was correct, drawings which
indicated the cable routes for the following samples of the SSF
and the redundant or compliment devices of the normal essential
shutdown components for all three units were reviewed:
SSF
Compliment
Function
Device
Device
Pressurizer Level
LT-72
LT-4P1
Steam Generator "A" Level
LT-66
LT-7P
Steam Generator "B" Level
LT-67
LT-7P
Reactor Coolant Makeup
SSF
RC Makeup Pump
Pump
5
Emergency
SSF Auxiliary
Emergency Turbine
Driven Feedwater
Pump
Pumps
Pressurizer Heater
Group B
Groups A & C-K
Bank 2
A walkdown of the SSF cables also was made and the SSF cables
within the Unit 1 west penetration were inspected.
Only the
Unit 1 east and west penetration rooms were inspected due to the
high radiation levels in these areas.
Based on this review, it
appeared that the above SSF cables were adequately separated from
the normal shutdown cables.
However, during this review it was
noted that the SSF cabling to the motor operator for reactor
coolant letdown valve HP-4, was located in both the east and west
penetration rooms of each unit. The cabling to the motor operator
for the redundant valve HP-3 was located within the west penetra
tion room. Valves HP-3 and 4 are the control valves on the outlet
side of letdown coolers "A" and "B",
respectively, and can be
controlled from either the main control room or the SSF.
In the
event of an Appendix R design type fire within the east penetra
tion room of any unit, if valve HP-4 is open it could not be
closed.
This could result in the lost of the reactor coolant
system volume. The lost through the letdown system would exceed
the makeup capacity of the 26 gpm SSF reactor coolant makeup pump
provided for each unit.
The east penetration rooms are provided
with a fire detection system but are not provided with an automat
ic fire suppression system to reduce the fire damage potential
within the area.
This improper cable separation is identified as
an example of Violation 269,
270,
287/87-02-01,
Inadequate
Appendix R Circuit Analysis.
The Duke design did not require the cable for the motor operator
to valve HP-4 to be either enclosed within a three-hour barrier or
relocated.
This was apparently due to design's impression that
letdown Cooler A was the cooler normally in use and that valve
HP-4 was normally closed.
However,
in actual practice both
coolers are used intermittently.
(2) Cable Separation Inside Containment
Duke, by letter, dated November 11, 1983, requested an exemption
from the Appendix R Section III.G.2 separation requirements for
redundant shutdown equipment,
components and cabling located
within the reactor buildings.
This exemption is currently being
reviewed by NRC/NRR.
Therefore, the equipment and cable separa-
6
tion provided for the redundant shutdown trains within the reactor
building was not reviewed during this inspection pending comple
tion of NRC/NRR's evaluation of this exemption request.
The
exemption for the reactor building is an example of Unresolved
Item 269,
270,
287/87-02-04,
NRR's Resolution to Appendix R
Exemptions.
(3) Fire Protection of Normal Safe Shutdown Capabilities (Appendix R
Section III.G.3)
An inspection was made to determine if the fire protection fea
tures provided for various areas of the plant containing the
normal plant safe shutdown components and cabling met the require
ments of Appendix R Section III.G.3.
Section III.G.3 requires
automatic fire detection and a fixed fire suppression system to be
installed in plant areas for which alternative or dedicated
shutdown capabilities have been provided.
NRC's Generic Letter
(GL)
86-10, Question 3.4.4 stipulates that where fire detection
and suppression systems have not been installed throughout a fire
area, justification must be provided and documented.
NRC/NRR
staff reviewers have reviewed the licensee's fire hazard analysis,
inspected various plant areas and concluded that there'are appar
ently no unmitigated fire hazards which warrant the installation
of additional fire suppression systems.
However, in the penetra
tion rooms, in concealed spaces above suspended ceiling containing
cable raceways in the auxiliary building and in storage areas in
the auxiliary building, adequate fire detection systems are not
provided.
This identified
as Unresolved
Item 269,
270,
287/87-02-06, Inadequate Fire Detection Coverage to Meet Require
ments of Appendix R Section III.G.3,
pendinq resolution by
NRC /NRP.
During the plant tour it was noted that on elevation 796' of the
auxiliary building, an instrument calibration work area has been
constructed adjacent to Room 303 in Unit 1.
This work area had
been provided with a suspended ceiling which obstructed the
ceiling level sprinkler system.
The licensee has committed to
either:
-
Remove the suspended ceiling over the work area;
-
Extend the sprinkler system below the ceiling; or
-
Install an approved "drop-out" type suspended ceiling.
Pending implementation of one of these options, this item is
identified as Inspector Followup Item (IFI) 269/87-02-07, Sprin
kler Protection Required for Instrument Calibration Room in
Area 300.
j..
7
b. Standby Shutdown Facility (SSF)
The SSF for this site consists of a structure containing a diesel
generator, and Auxiliary Service Water (ASW) pump and additional pumps
instrumentation needed to support operation of the facility during an
Appendix R fire, a flood or a security intrusion.
The facility is to
be placed in operation in the event tof an Appendix R fire which causes
an evacuation or lost of plant control from the control rooms for
Unit 1, 2, and 3. This inspection was devoted to plant conditions
created by an Appendix R fire.
The cooling water for the diesel generator, HVAC and supply for the ASW
pump is taken from the Unit 2 condenser cooling water (CCW)
intake
piping.
To meet long term operation commitments the CCW intake piping
must remain full.
This will provide adequate water for cooling the
diesel engine, and ASW to each of the three units steam generators for
However, in the event of an Appendix R fire, it is
assumed that incoming power is lost for the duration of the event.
With the lost of all off-site power including the Keowee underground
feed, the only power available for operation of equipment is from the
SSF diesel generator. 'Upon
lost of off-site power, the CCW pumps are
inoperative and only a natural siphon will keep the CCW intake piping
full.
Several conditions could occur within three to four hours should
the natural siphon be lost.
1. The SSF water supply could become overheated due to the recircula
tion of diesel cooling water.
2. The SSF ASW pump could experience runout as the primary loop
temperature decreases.
3. Service water for the SSF systems could lose flow due to air
collection at the common suction high point.
4. Other conditions related to design basis events and security
events could cause the conditions described in 1, 2, and 3.
To ensure that there will be adequate cooling water in the Unit 2 CCW
intake piping, the licensee has designed a portable SSF-Dedicated
Submersible Pump for installation within 31 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br />.
The pump is de
signed to be submerged in the intake canal within 3j hours after the
SSF is placed in operation. The pump is powered from the SSF diesel
generator through temporarily installed cables and the submersible pump
discharge is connected to the CCW high point vent for refilling of the
CCW intake piping.
The procedure for this pump installation is dis
cussea at the end of this section.
The licensee must begin installation of this pump immediately upon the
-
decision to man the SSF to bring the unit(s) to hot shutdown. Since it
is assumed all off-site power is not available for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />
8
(Appendix R,Section III.G) the CCW pumps would be inoperative, thus
creating possible conditions to cause the natural siphon in the intake
piping to be lost.
The licensee has stated that the installation of the SSF dedicated
submersible pump is not considered an Appendix R fire damage repair.
The installation of this pump will require further review by the NRC to
determine if the actions required within the first 3j hours meet the
definition of repairs as stated in Section III.G.1 of Appendix R. This
required action is identified as Unresolved Item (269, 270, 287/87-02),
Determine the Acceptablility of the SSF Dedicated Submersible Pump as
Related to an Appendix R Repair.
It should be noted that the Oconee Standby Shutdown Facility was
declared inoperative on October 15,
1986,
and remained inoperative
until December 14, 1986.
During this period, it was determined that
the fire conditions listed earlier in this paragraph could occur should
operation of the SSF be required and the Unit 2 CCW flow be interrupted
or lost.
During this time that the SSF was inoperative, several
modifications were made to correct unsatisfactory operational condi
tions.
An alternate path for the diesel service (cooling) water to
divert the heated water from the Unit 2 CCW intake piping was estab
lished.
An air eductor was installed using ASW pump discharge to pull
a vacuum at the ASW pump suction high point.
The third modification
was the addition of a dedicated submersible pump to make up the water
that is removed from the CCW intake piping by the diverting of the
diesel generator cooling water and the makeup water pumped to the steam
generator secondary side by the ASW pump.
While these modifications correct potential SSF operational problems,
the importance of the installation of the dedicated submersible pump
within 31 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br /> is stressed during training on the loss of the CCW
system. Additionally, there is no means to determine from the SSF if
siphon flow exists in the CCW intake water piping during SSF operation.
The licensee developed two special procedures for the installation of
the dedicated submersible pump. These are identified as follows:
-
MP/O/B/1300/59, Pump Submersible Emergency SSF Water Supply
Installation
-
IP/O/B/375/03, Procedure to Provide Power for SSF Submersible
Pump
These procedures detail the necessary actions required to move the
submersible pump assembly to the intake structure, install the neces
sary electrical cabling, and connect the discharge hoses in order to
restore the water level in the CCW intake piping.
The inspector
examined the designated equipment and the proposed routing for moving
the pump and installing the electrical cables.
Close coordination of
the various required activities should be maintained to insure that the
0~~
9
task is completed within the time frame requirements. The task appears
possible if the above actions are observed.
c. Associated Circuits
An inspection was conducted of associated circuits as defined in
GL 81-12, dated February 20, 1981, Supplement to GL 81-12 and Oconee's
letter of March 18, 1981 to the NRC. This portion of the inspection
was based on the associated circuit portion of the Oconee Fire Protec
tion Plant/Safety Evaluation Report (FPP/SER), dated April 23, 1983.
For the associated circuit inspection, it should be noted that Oconee
has a SSF which is a dedicated and independent system that can be used
to achieve hot shutdown.
The three areas of concern affiliated with associated circuits as
defined in the above referenced GL are:
-
A common power source (common bus) where the shutdown equipment
and the power source is not electrically protected from the
circuit of concern by coordinated breakers,
fuses, or similar
devices; or
-
A connection to circuits of equipment whose spurious operation
(spurious signal) would adversely affect the shutdown capability;
or
-
A common enclosure with the shutdown cables, and
Type (1) are not electrically protected by circuit breakers, fuses
or similar devices, or
Type (2)
will allow propagation of the fire into the enclosure.
(1) Associated Circuits by Common Power Supply (Common Bus)
Circuits and cables associated by common power supply are non-safe
shutdown cables whose fire-induced failure will cause the loss of a
power source (buss, distribution panel, or MCC) that is necessary to
support safe shutdown. This problem could exist for power, control or
instrumentation circuits.
The problem of associated circuits of
concern by common power supply is resolved by ensuring adequate elec
trical coordination between the safe shutdown power source supply
breaker and the component feeder breakers or fuses.
Coordination of overcurrent devices on the normal plant buses was
reviewed by the inspectors.
The overcurrent protective devices were
applied according to good engineering practice and NRC concerns about
the possibility of fire induced faults causing loss of shutdown capa
bility were resolved.
10
Specifically, coordination was checked on the following buses:
-
4160 Volt buses:
BlT, B2T
-
4160 Volt buses:
B11, B21, 812, 822, B13, B23
-
4160 Volt buses:
1TE, 1TC, lTD, 2TE, 2TC, 2TD, 3TE, 3TC, 3TD
-
600 Volt buses:
1X8, 2X8, 3X8
-
Motor control centers:
1XS1, 1XS2, 1XS3, 2XS1, 2XS2, 2XS3, 3XS1,
3XS2, 3SX3
-
208/120 Volt power panels:
1SKL, 2SKL, 3SKL, 1SKJ, 2SKJ, 3SKJ,
1SKK, 2SKK, 3SKK
-
125 Volt DC distribution center:
iDCA, 1DCB, 2DCA, 2DCB, 3DCA,
3DCB
(2) Isolation Switches and Double Fusing
For valves that are controlled from both the main control panel and the
SSF panel,
there is interconnecting wiring between the two panels and
field devices.
Therefore,
these circuits must be designed with
isolation switches and double (parallel) fuses. The inspector reviewed
the elementary diagrams for valves controlled from the SSF and found
that they meet the NRC requirements with respect to isolation switches
and double fuses.
(3) Associated Circuits Causing Spurious Operation
Circuits associated because of spurious operation are those that can,
by fire-induced failures cause safe shutdown equipment or nonsafe
shutdown equipment to maloperate in a way that defeats the function of
safe shutdown systems or equipment. Examples include the uncontrolled
opening or closing of valves, or of circuit breakers,
due to
fire-induced damage to nonsafe shutdown instrument and control circuits
that affect the control circuit interlocks of the safe shutdown
components.
The reactor inspector reviewed the licensee's analysis of
possible fire-induced spurious signals and open circuits that could
defeat the safe shutdown systems. Special attention was focused on the
following piping and valves:
Piping
Valves
RC letdown
HP-1, HP-2, HP-3, HP-4 and HP-5
RCP seal injection
HP-20, HP-21
return
Core decay head removal
supply
Alternate decay heat
removal line
Pressurizer PORV block
RC-4
valve
Pressurizer steam sample
RC-5
Pressurizer water sample
RC-6
RCS venting
RC-155 through RC-160
In reviewing the licensee's analysis, it
was determined that fire in
the turbine auxiliary building area could damage the power cables to
reactor coolant (RC)
letdown motor operator valve (MOV)
HP-4, which is
on the outlet line of letdown Cooler B. Thus, a fire propagating to
the east penetration room could disable the ability to close valve HP-4
providing a flow path that would negate the makeup pump capability of
the SSF RC makeup pump.
Additional review revealed that the cables for MOV's LP-1 and LP-2
(located in the decay heat removal line from the RC hot leg) were
located in the same fire area (west penetration room).
A fire in this
area could cause the spurious opening of these valves while the RC
pressure is above 350 PSI which would exceed the design capability of
the low pressure piping downstream of these valves.
The inspectors were advised that the analysis of spurious operation of
the letdown valve (HP-4)
and decay heat removal valves (LP-1 and LP-2)
under the conditions identified had not been considered.
The licensee was advised that the two conditions identified appeared to
be
a violation which
was identified as Violation 269,
270,
287/87-02-01, Inadequate Appendix R Circuit Analysis. The licensee took
the following corrective actions to remedy the condition cited. The RC
letdown cooler "B" was valved out (isolated) by closing valve HP-2 and
de-energizing it
(opening the power feed breaker).
This was done on
all three units. The spurious operation of valves LP-1 and LP-2 in the
decay heat removal system was controlled -by opening the feeder breaker
to LP-1 in each unit.
These actions appear to be appropriate for the
conditions identified. The impact on the overall unit operation should
be evaluated to insure that Technical Specifications (TS)/operating
conditions have been satisfied.
These actions should be identified in
appropriate procedures.
(4)
The Common Enclosure Concern
The common enclosure concern is found when redundant trains are routed
together with a non-safety circuit which crosses from one raceway or
enclosure to another, and the non-safety circuit is not electrically
protected or fire can destroy both redundant trains due to inadequate
fire protection means.
The common enclosure concern at Oconee was not a concern in that the
SSF cables were separate from the plant redundant cables and their
associated non-safety-related cables.
Therefore, this item was not
inspected.
d. Dedicated Shutdown Capability
A safety evaluation report was issued in a letter, dated April 28,
1983, documenting NRR review of the licensee dedicated shutdown system
and its conformance to 10 CFR 50, Appendix R, Section III.G.3 and
III.L.
The Oconee dedicated shutdown system is identified as the SSF
and provides an independent means to achieve and maintain the reactor
coolant system in hot shutdown conditions for one or all three units.
The SSF is placed into operation if
a fire results in the installed
normal
and emergency plant systems becoming inoperable.
A masonry
structure located adjacent to and outside the plant, houses the major
equipment and controls for safe shutdown.
The SSF consist of an
emergency diesel generator, starting batteries and supporting auxiliary
systems, (i.e., lube oil, cooling water, air conditioning).
Normal AC
power supply is via 4160 volt from plant switchgear B2T-4.
Either
separate source of power is capable of supplying SSF electrical loads.
The SSF has a control room and panels for monitoring and controlling
primary and secondary volumes for each unit.
pressure control and pressurizer level can be maintained by manual
control of a bank of pressurizer heaters and letdown flow from the
plant to the spent fuel pool at the SSF control room.
Makeup water to the reactor coolant system and sealing water to the
reactor coolant pumps
(RCP)
seals is provided by a 26 gpm positive
displacement makeup pump. Each unit has it own pump and take a suction
from its own unit spent fuel pool.
The makeup pump discharges to the
RCP seal injection line.
Steam generator volume control is accom
plished using the SSF auxiliary service water pump (ASW) which gets its
water supply from the condenser circulating water system. Decay heat
removal is accomplished using mainsteam code safety valves.
The inspector reviewed operating personnel training, shift staffing and
the use of plant procedures as these activities relate to safe shutdown
and the use of the systems associated with the SSF to achieve this
goal.
These areas were also reviewed to determine if the requirements
of Appendix R,Section III.L for placing the units in hot shutdown
13
conditions and subsequently cooling the plant to cold shutdown
conditions can be accomplished.
(1) Shift Staffing
The inspectors held discussions with operating engineers,
and
operations
personnel
and
reviewed Operation Management
Procedure 1-2,
Rules of Practice.
This procedure defines the
shift staffing requirements for different plant operating condi
tions and exceeds the minimum shift crew that is identified in
Technical Specifications, Table 6.1.1.
The inspectors conducted a walkthrough of OP/O/A/1600/11, Standby
Shutdown Facility Emergency Operation. The walkthrough started in
the Unit 1 and 2 Control Room where a fire was postulated to have
occurred and required abandoning the shared control room and
manning the SSF for both Units.- A loss of off-site power was also
postulated.
The inspectors teamed up with those plant operators
that are necessary to place the SSF into operation and observed
the procedures step to accomplish placing the units in hot shut
down.
Based on the assignment of operators to place the SSF into
operations and the additional operatihg personnel available, shift
staffing appears to be adequate.
(2) Operating Procedures
The inspector reviewed the below listed procedures which places
the SSF equipment and systems in a standby status.
The basic
purpose of these procedures is to provide a normal lineup for SSF
mechanical and electrical systems. These procedures also fill and
vent the RCS makeup system and steam generator makeup system.
Precautions and operating system limits are provided for each
procedure.
No items of concern were identified with the following
procedures:
-
OP/O/A/1600/08, SSF Reactor Coolant Makeup System
-
OP/O/A/1600/09, SSF Auxiliary Service Water System
-
OP/O/A/1600/10, Operation of the SSF Diesel Generator
The inspectors reviewed AP/1/A/1700/08, Loss of Control Room and
OP/O/A/1600/11,
SSF
Emergency Operations to verify that the
procedures identifies the systems to accomplish the performance
goals identified in Appendix R,Section III.L for takina a Unit or
Units to hot shutdown conditions.
Dedicated systems necessary to
accomplish the performance goals have been incorporated into these
procedures.
The inspectors examined the process variables used to monitor
system performance while achieving and maintaining hot shutdown
14
conditions.
The direct reading instrumentation within the SSF
exceeds the minimum monitoring capability identified in IE
Notice 84-09 or approval has been received from NRR for exemption
such as source range indication and steam generator pressure
indication.
The walkthrough of OP/O/A/1600/11 was also conducted to verify
that:
-
communications between various stations are adequate and
-
radio sets, flash lights, procedures, keys and other supplies
are readily available for use
-
identification plate on valves, and instrumentation agree with
those called for in the procedure steps
-
steps of the procedure are clear and can be accomplished
-
equipment and valves can be operated
The principle procedures used to subsequently cooldown the unit(s)
and achieve cold shutdown conditions within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> were re
viewed. OP/0/A/1102/24, Operational Guidelines Following Fire in
Auxiliary Building, Turbine Building or Vital Area.
The main
purpose of this procedure is to assess the damage to those plant
systems which will be used to maintain subcritical conditions in
the reactor during cooldown,
systems for maintaining reactor
coolant inventory and remove decay heat. This procedure restores
system valve alignment, electrical power source as necessary in
preparation for their operation.
Once system operational status is restored then OP/O/A/1102/25,
Cold Shutdown Following a Fire, can be used to lower RCS tempera
ture and pressure sufficiently to establish the Low Pressure
Injection system operations.
Final cold shutdown is achieved
using this system.
During the review of the operating procedures, it was noted that
procedure OP/O/A/1600/11 requires the operators to close the
mainsteam boundary line valves prior to leaving the control room.
This does not conform to GL 86-10, Question 3.8.4, which states
that the only manual action in the control room prior to evacua
tion is usually limited to reactor trip unless assurance is
provided that subsequent spurious actuations will not result from
a postulated "Appendix R Fire".
The licensee, stated in a letter
to the NRC,
dated September 20,
1982, that hot shorts or spurious
actuation due to fire within the first 10 minutes of the event are
not part of the design basis.
During this time interval, the
plant would be in the transition from normal plant systems to the
15
SSF components. Apparently no evaluation has been made to justify
the assumption that the mainsteam boundary line valves would
remain closed to maintain secondary side volume.
This item is
being referred to NRR for further evaluation and is identified as
Unresolved Item 269,
270, 287/87-02-03, Adequacy of Spurious
Actuation Events Evaluation Following Control
Room Evacuation,
pending NRR resolution.
(3) Damage Control Measures
10 CFR 50, Appendix R, requires that nuclear stations maintain the
ability to repair major fire damage and be in the cold shutdown
within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
The licensee has developed guidelines that
described the organization, resources and procedures needed to
meet this requirement. These guidelines identify the responsibi
lities of various personnel in determining the inoperable equip
ment, repairs required, repair priorities and repair evaluations.
Also, these guidelines define manpower, call out of personnel and
manpower qualification.
The repair support equipment and repair
materials required are identified as part of these guidelines.
The following repair procedures were reviewed:
MP/O/A/3009/12,
Emergency Plan for Replacement of HPI,
LPI,
LPSW Motors Following a Fire in Turbine
Building or Auxiliary Building
MP/0/A/1300/20,
Pump Ingersol Rand - High Pressure Injection
Removal AND Replacement of Pump AND Motor
MP/O/A/1300/40,
Pumps - Alignment and Coupling to Motor
MP/0/A/2000/3,
ONS and Keowee Hydro Station Motor Inspection
and Maintenance
IP/0/A/3010/08,
Fire Damage Control Procedure
The replacement equipment (motors, switchgear, control stations,
electrical cables) and the necessary special tools were examined
at the designated storage locations.
The proposed routes for
moving equipment into place and installing replacement power and
control cables were reviewed and found to be satisfactory.
All
proposed actions appeared feasible but will require close coordi
nation of equipment and man power control.
(4)
Review of SSF Surveillance Procedures
The inspectors reviewed the following procedures and verified that
the inspections and tests required by the Draft Technical Specifi
cations on the SSF components,
submitted to the NRC by letter,
dated July 26, 1985, had been incorporated into the procedures:
16
PT/0/A/600/20,
SSF Instrumentation (Weekly)
PT/O/A/600/21,
SSF Diesel Generator Operation
(Monthly)
PT/O/A/600/23,
SSF Fuel Oil Inventory (Monthly)
PT/(1, 2 & 3)/A/0150/
Operational Valve Functional Test
22A
(Quarterly)
PT/(1, 2 & 3)/A/0150/22B,
Shutdown Valve Functional Test
(Refueling Outage)
PT/(1, 2 & 3)/A/0400/
SSF Reactor Coolant Makeup
07,
Pump Performance Test (Quarterly)
PT/(1, 2 & 3)/A/0400/05,
SSF Auxiliary Service Water
Performance Test (Quarterly)
PT/O/A/0400/04,
5SF Diesel Engine Service Water
Performance Test (Quarterly)
PT/O/A/0400/06,
5SF HVAC Service Water Pump
Performance Test (Quarterly)
PT/0/A/0400/03,
Diesel Engine Fuel Oil Transfer
Performance Test (Quarterly)
PT/0/A/0400/11,
SSF Diesel Generator Performance
Test (Quarterly)
PT/(1, 2 & 3)/A/'50/22C,
Refueling Valve Functional Test
(Refueling Outage)
MP/0/A/5050/32,
5SF Diesel Annual Preventive Mainte
nance (Annual)
IP/0/A/370/(1A,
1B & IC),
Reactor Coolant Makeup Pump Instru
mentation (Refueling Outage)
IP/0/A/370/(2A, 2B, & 2C),
Reactor Coolant System Instrumen
tation (Refueling Outage)
IP/0/A/375/1A,
5SF Auxiliary Service Water Pump
Instrumentation (Annual)
,P/0/A/380/5,
SSF Diesel Generator Fuel Oil Tanks
(Annual)
IP/O/A/385/1A,
SSF 125V DCBatteries (Daily)
17
IP/O/A/385/1B,
SSF 125V DC Battery Capacity Test
(Monthly)
IP/O/A/385/1D,
SSF 125V DC Battery Monthly Surveil
lance (Monthly)
CP/O/B/4002/18,
Chemistry Procedure for Sampling SSF
Fuel Oil Tanks (Day Tank - Monthly
and Underground Tank - 60,Days)
(5) Operating Personnel Training
The inspectors held discussions with Senior Training Instructors
to determine what training is being provided concerning the
operations of the SSF.
It was determined that personnel who are
receiving training in this area included senior reactor operators
(SRO),
reactor operators
(RO)
and nuclear equipment operators
(NEO).
The licensee has scheduled classroom study, system walk
down qualifications concerning SSF systems.
In addition, SSF
operating'procedures are reviewed as part of the on-going operator
requalification programs.
The inspectors reviewed the licensee's
lesson 'plans,
system walkthrough qualification standards and
training schedules and found these documents to be well organized,
detailed and comprehensive.
The operations department also
conducts training as outlined in Operation Management
Procedure 3-1, Operations Training.
This procedure requires that
training be provided with respect to significant operational
experiences,
major changes to existing operating guidelines,
procedures or equipment.
Training packages are put together in
the aforementioned areas and sign-off that the material has been
reviewed by operators is provided.
The inspectors reviewed
training packages recently aiven on the SSF capability and found
them to be comprehensive.
6. Compliance with 10 CFR 50, Appendix R, Section 111.0, Oil Collection System
Appendix R,Section III.0 requires the reactor coolant pumps to be equipped
with an oil collection system if the containment is not inerted during
normal operations.
The system is required to be designed, engineered and
installed such that failure will not lead to fire during normal or design
basis accident condititions, and that the system will withstand the safe
shutdown earthquake.
All leakage from potential pressurized and unpres
surized leakage sites is to be collected and drained to a vented closed
container that can hold the entire lube oil system inventory.
The drain
pipe is required to be sized to accommodate the largest potential oil leak.
The tank vent requires a flame arrestor if the flash-point characteristics
of the oil presents the hazard of fire flash-back.
An inspection of the Oconee reactor coolant pump oil collection systems was
made during an inspection conducted on September 30 - October 4, 1985 and as
documented by Report Nos.
269, 270, 287/85-34, the collection systems were
18
found to meet the Appendix R requirements.
However, the systems within
Unit 3 was found to be in need of minor maintenance.
Subsequently, the
licensee has issued procedure MP/0/A/3009/09, Motor Reactor Coolant Pump
Preventative Maintenance, which requires that during a refueling outage the
oil collection system will be subjected to a routine preventative mainte
nance program and the drain tank will be verified to be empty before unit
startup. This should assure that the systems will be properly maintained.
Within the area inspected, no violations or deviations were identified.
7. Compliance with 10 CFR 50, Appendix R, Section III.3, Emergency Lighting
Appendix R,Section III.J., requires emergency lighting units with at least
an eight-hour battery power supply to be provided in all areas needed for
operation of safe shutdown equipment and operation of safe shutdown equip
ment and in access and egress routes thereto.
A total of approximately 47 eight-hour battery powered emergency lighting
units have been installed in plant areas needed for operation of shutdown
equipment and components and in the access and egress routes to these areas.
The number of lighting units is low at Oconee due to the SSF and NRC/NRR
previously approved emergency lighting exemptions.
However, the installa
tion and arrangement of a random sample of the installed lighting units were
reviewed by the inspectors and found to meet Appendix R Section III.J.
The emergency lighting units are inspected monthly to verify operability of
the units and to check the battery supply and position of the lamp heads.
Annually, a sample of four lights are operated for eight-hours to verify
that the units will operate for the required time.
These tests and inspec
tions are conducted using surveillance procedure IP/0/B/3000/20,
PM of Self
Contained Battery Packs on Emergency Lights.
This procedure .was reviewed
and found to include all of the required inspection and test requirements.
Within the areas examined, no violations or deviations were identified.
8. Licensee Identified Items
During the licensee's Appendix R evaluation several deviations from the
Appendix R requirements were identified.
Exemption requests with justifi
cations have been sent to the NRC/NRR on these items. These exemptions, as
listed below, will remain outstanding pending NRR resolution:
-
Separation of SSF cables from other electrical cables within the Cask
Decon Rooms,
-
Separation of shutdown cables inside reactor buildinc,
-
Fire barrier separation between east and west penetration rooms,
-
Cork insulation in the seismic gap of fire barriers.
19
This is identified as Inspector Followup Item (269,
270, 287/87-02-04),
Resolution to Appendix R Exemptions.
9. Part 21 Issue - Closure of Fire Dampers Under Airflow Conditions
By letter dated November 6, 1984, Ruskin, a manufacturer and distributor of
fire dampers, notified the industry that under certain airflow conditions,
fire dampers installed in ventilation openings would not close.
The licensee's position on the potential problem is that in the event of a
fire, the fire brigade would ascertain if fire spread had occurred through
these dampers and would take action to assure that fire damage would be
minimized.
The NRC/NRR staff's position is that the successful functioning of fire
dampers, such as in the wall separating the penetration rooms, is necessary
to assure that one division of shutdown systems is free of fire damage.
In
addition, fire brigade size is insufficient to permit timely discovery of
fire spread through nonfunctional dampers.
The licensee is to reassess their evaluation to this problem.
This is
identified as Inspector Followup Item (269,
270, 287/87-02-05), Review of
Licensee's Part 21 Reevaluation on Ruskin Fire Dampers, and will be reviewed
during a subsequent NRC inspection.
10.
Inspector Followup Item
(Closed) IFI 269, 270, 287/85-34-01, Procedures to be Provided for Periodic
Preventative Maintenance of the Reactor Coolant Pump Motor Lube Oil Collec
tion System and Verification that Oil Collection System Drain Tanks are
Empty.
These items have been included in Procedure MP/O/A/3009/09,
Motor
Reactor Coolant Pump - PM. This item is closed.