Information Notice 1986-70, Potential Failure of All Emergency Diesel Generators: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
 
(One intermediate revision by the same user not shown)
Line 3: Line 3:
| issue date = 08/18/1986
| issue date = 08/18/1986
| title = Potential Failure of All Emergency Diesel Generators
| title = Potential Failure of All Emergency Diesel Generators
| author name = Jordan E L
| author name = Jordan E
| author affiliation = NRC/IE
| author affiliation = NRC/IE
| addressee name =  
| addressee name =  
Line 14: Line 14:
| page count = 6
| page count = 6
}}
}}
{{#Wiki_filter:SSINS No.: 6835 IN 86-70 UNITED STATES NUCLEAR REGULATORY
{{#Wiki_filter:SSINS No.: 6835 IN 86-70
                                  UNITED STATES


COMMISSION
NUCLEAR REGULATORY COMMISSION


OFFICE OF INSPECTION
OFFICE OF INSPECTION AND ENFORCEMENT


===AND ENFORCEMENT===
WASHINGTON, D.C. 20555 August 18, 1986 IE INFORMATION NOTICE NO. 86-70:  POTENTIAL FAILURE OF ALL EMERGENCY
WASHINGTON, D.C. 20555 August 18, 1986 IE INFORMATION


NOTICE NO. 86-70: POTENTIAL
DIESEL GENERATORS
 
===FAILURE OF ALL EMERGENCY DIESEL GENERATORS===


==Addressees==
==Addressees==
:
:
All nuclear power reactor facilities
All nuclear power reactor facilities holding an operating license or a
 
holding an operating
 
license or a construction


permit.
construction permit.


==Purpose==
==Purpose==
: This notice informs recipients
:
This notice informs recipients of multiple design deficiencies in a vital ac


of multiple design deficiencies
power system that could potentially result in the loss of all emergency diesel


in a vital ac power system that could potentially
generators (EDGs). It is expected that recipients will review the information


result in the loss of all emergency
for applicability to their facilities and consider actions, if appropriate, to


diesel generators (EDGs). It is expected that recipients
preclude a similar problem occurring at their facilities. However, suggestions


will review the information
contained in this information notice do not constitute NRC requirements; there- fore, no specific action or written response is required.


for applicability
==Description of Circumstances==
 
:
to their facilities
On June 10, 1986, in accordance with 10 CFR Part 21, Florida Power & Light
 
and consider actions, if appropriate, to preclude a similar problem occurring


at their facilities.
(FP&L) reported the results of a failure modes and effects analysis (FMEA).


===However, suggestions===
This analysis identified multiple design deficiencies in the Turkey Point
contained


in this information
Units 3 and 4 vital ac power system that could potentially result in the loss


notice do not constitute
of both EDGs due to overloading. In addition, one deficiency was identified


NRC requirements;
that could result in the loss of all ac power to Unit 4. Turkey Point Units 3 and 4 share two EDGs. Simplified diagrams of part of the Turkey Point 3 & 4 electrical distribution system are provided as Figures 1 and 2.
there-fore, no specific action or written response is required.Description


of Circumstances:
One design deficiency involved a "swing bus." As shown on Figure 1, 480 volt
On June 10, 1986, in accordance


with 10 CFR Part 21, Florida Power & Light (FP&L) reported the results of a failure modes and effects analysis (FMEA).This analysis identified
MCC "D" is normally supplied from EDG "B" but will shift its power supply to


multiple design deficiencies
EDG "A" if needed. MCC "D" also feeds a non-safety stub bus through a single


in the Turkey Point Units 3 and 4 vital ac power system that could potentially
circuit breaker. This breaker is normally opened by the 48 load sequencer to


result in the loss of both EDGs due to overloading.
isolate the non-safety loads from MCC "D" when the 48 4160V bus is loaded on


In addition, one deficiency
EDG "B". A single failure in that circuit breaker would leave the non-safety


was identified
loads connected to MCC "D". During safety injection for one unit, the addi- tional non-safety loads could overload EDG "B", possibly resulting in a trip


that could result in the loss of all ac power to Unit 4. Turkey Point Units 3 and 4 share two EDGs. Simplified
of this EDG. MCC "D" would then transfer its power supply and could overload


diagrams of part of the Turkey Point 3 & 4 electrical
EDG "A" as well.


distribution
8608130578


system are provided as Figures 1 and 2.One design deficiency
IN 86-70
                                                            August 18, 1986 In addition to the above design deficiency, five deficiencies in the EDG load


involved a "swing bus." As shown on Figure 1, 480 volt MCC "D" is normally supplied from EDG "B" but will shift its power supply to EDG "A" if needed. MCC "D" also feeds a non-safety
evaluation were found, each of which could contribute to an overloading of both


stub bus through a single circuit breaker. This breaker is normally opened by the 48 load sequencer
EDGs. Both EDGs could be overloaded in the event of a safety injection on one


to isolate the non-safety
unit and a loss of offsite power to both units. In some cases this could occur


loads from MCC "D" when the 48 4160V bus is loaded on EDG "B". A single failure in that circuit breaker would leave the non-safety
without a single failure. These deficiencies are as follows:
0    The post-TMI Emergency Operating Procedures require an additional charging


loads connected
pump and high head safety injection pump in the 1-30 minute and 30-60
      minute EDG load interval, respectively.


to MCC "D". During safety injection
o    In the event of a single failure of one EDG, actual testing of component


for one unit, the addi-tional non-safety
cooling water and intake cooling water showed that pump loads (KW) were


loads could overload EDG "B", possibly resulting
higher than expected. Under this condition, the cooling water pumps provide


in a trip of this EDG. MCC "D" would then transfer its power supply and could overload EDG "A" as well.8608130578 IN 86-70 August 18, 1986 In addition to the above design deficiency, five deficiencies
flow to parallel hydraulic trains. Since the flow resistance is lower, the pump flow rate is greater and the pump motor horsepower would increase.


in the EDG load evaluation
This in turn may increase the load on the EDG to an unacceptable value.


were found, each of which could contribute
o    Recent environmental qualification evaluations per 10 CFR 50.49 assumed


to an overloading
that the emergency containment coolers operate longer than previously


of both EDGs. Both EDGs could be overloaded
assumed.


in the event of a safety injection
0    Load center transformer losses had not been accounted for in prior EDG


on one unit and a loss of offsite power to both units. In some cases this could occur without a single failure. These deficiencies
load evaluations.


are as follows: 0 The post-TMI Emergency
o    Some nonsafety loads that are auto-start enabled when the safety injection


Operating
signal is reset could result in EDG overloading. These loads would not


Procedures
always immediately start, but would auto-start when their start setpoints


require an additional
were reached after the reset.


charging pump and high head safety injection
In addition to the overloading deficiencies above, a design deficiency.was found


pump in the 1-30 minute and 30-60 minute EDG load interval, respectively.
that could result in the loss of one EDG, and at the same time could result in


o In the event of a single failure of one EDG, actual testing of component cooling water and intake cooling water showed that pump loads (KW) were higher than expected.
the loss of all ac power to Unit 4 as mentioned earlier. In the event of a


Under this condition, the cooling water pumps provide flow to parallel hydraulic
single failure of the 4A battery or the 4A load sequencer subsequent to a loss


trains. Since the flow resistance
of off-site power, the 4A 4160V bus shown in Figure 2 would be prevented from


is lower, the pump flow rate is greater and the pump motor horsepower
automatically loading onto the "A" EDG. It would also prevent the transfer of


would increase.This in turn may increase the load on the EDG to an unacceptable
the 4A MCC swing bus from 4A load center to 4B load center. The "B" EDG has a


value.o Recent environmental
self-contained supply of fuel oil that lasts about one hour. After that time, fuel must be gravity supplied by the day tank via a solenoid operated valve.


qualification
However, this valve is powered from MCC 4A. Therefore, the above mentioned


evaluations
single failure would also cause the loss of the "B" EDG and the loss of all ac


per 10 CFR 50.49 assumed that the emergency
power to Unit 4. The Unit 3 3B 4160V bus would also be deenergized, along with


containment
three of the four high head safety injection pumps and the control room


coolers operate longer than previously
air-conditioning.
 
assumed.0 Load center transformer
 
losses had not been accounted
 
for in prior EDG load evaluations.
 
o Some nonsafety
 
loads that are auto-start
 
enabled when the safety injection signal is reset could result in EDG overloading.
 
These loads would not always immediately
 
start, but would auto-start
 
when their start setpoints were reached after the reset.In addition to the overloading
 
deficiencies
 
above, a design deficiency.
 
was found that could result in the loss of one EDG, and at the same time could result in the loss of all ac power to Unit 4 as mentioned
 
earlier. In the event of a single failure of the 4A battery or the 4A load sequencer
 
subsequent
 
to a loss of off-site power, the 4A 4160V bus shown in Figure 2 would be prevented
 
from automatically
 
loading onto the "A" EDG. It would also prevent the transfer of the 4A MCC swing bus from 4A load center to 4B load center. The "B" EDG has a self-contained
 
supply of fuel oil that lasts about one hour. After that time, fuel must be gravity supplied by the day tank via a solenoid operated valve.However, this valve is powered from MCC 4A. Therefore, the above mentioned single failure would also cause the loss of the "B" EDG and the loss of all ac power to Unit 4. The Unit 3 3B 4160V bus would also be deenergized, along with three of the four high head safety injection
 
pumps and the control room air-conditioning.


Discussion:
Discussion:
The single failure vulnerability
The single failure vulnerability of the non-safety stub bus discussed above may
 
of the non-safety
 
stub bus discussed
 
above may have been evaluated


during the licensing
have been evaluated during the licensing review and the loads on the EDGs found


review and the loads on the EDGs found to be low enough so that failure of the stub bus breaker would not overload the diesel. Subsequent
to be low enough so that failure of the stub bus breaker would not overload the


to initial operation, however, additional
diesel. Subsequent to initial operation, however, additional loads have been


loads have been
IN 86-70
                                                            August 18, 1986 added on the diesels. Prior to November, 1985, there was the potential for


IN 86-70 August 18, 1986 added on the diesels. Prior to November, 1985, there was the potential
loading the EDGs to 3544 kw in the 1-30 minute period and 3451 in the 30-60
minute period following a LOCA in one unit with a loss of offsite power in both


for loading the EDGs to 3544 kw in the 1-30 minute period and 3451 in the 30-60 minute period following
units. These load levels exceed the highest FSAR value (1/2 hour exceptional


a LOCA in one unit with a loss of offsite power in both units. These load levels exceed the highest FSAR value (1/2 hour exceptional
rating) of 3050 Kw by a substantial margin. With the EDGs overloaded, the


rating) of 3050 Kw by a substantial
potential exists that safety-related loads would not start or would not operate


margin. With the EDGs overloaded, the potential
at design ratings. Under these conditions, the EDG engines could stall and


exists that safety-related
damage to the generator and/or engine could occur. There are no test data


loads would not start or would not operate at design ratings. Under these conditions, the EDG engines could stall and damage to the generator
available to demonstrate that the EDGs could accept the above load levels.


and/or engine could occur. There are no test data available
As an interim solution to the above design deficiencies, FP&L disabled the


to demonstrate
automatic transfer between EDGs and established a dedicated operator to take


that the EDGs could accept the above load levels.As an interim solution to the above design deficiencies, FP&L disabled the automatic
corrective action (i.e., manipulate appropriate breakers) as necessary. The


transfer between EDGs and established
licensee has now modified EDG loads, loading sequences and plant procedures.


a dedicated
This example illustrates the importance of reviewing EDG load limits under all


operator to take corrective
possible operating configurations for a range of design basis accident condi- tions. FP&L, through an FMEA, system testing, and evaluation of EDG load limits, found design deficiencies that may have prevented one or both EDG's from


action (i.e., manipulate
performing their required function.


appropriate
No specific action or written response is required by this information notice.


breakers)
If you have any questions about this matter, please contact the Regional
as necessary.


The licensee has now modified EDG loads, loading sequences
Administrator of the appropriate regional office or this office.


and plant procedures.
Jordan, Director


This example illustrates
Divisi  of Emergency Preparedness


the importance
and Engineering Response


of reviewing
Office of Inspection and Enforcement


EDG load limits under all possible operating
Technical Contacts:  Henry Bailey, IE


configurations
(301) 492-9006 Joseph Giitter, IE


for a range of design basis accident condi-tions. FP&L, through an FMEA, system testing, and evaluation
(301) 492-9001 Attachments:
1. Figures 1 and 2, Turkey Point - Units 3 & 4*
2. List of Recently Issued IE Information Notices


of EDG load limits, found design deficiencies
Attachment 1 IN 86-70
                                                                  August 18, 1986 FIGURE 1 TURKEY POINT - UNITS 3 E 4 EDG "B"
    I)
                      LOAD CENTERS


that may have prevented
h


one or both EDG's from performing
*
      480V 4C                                      3D 480V


their required function.No specific action or written response is required by this information
N.C.


notice.If you have any questions
N.C.


about this matter, please contact the Regional Administrator
480V            MCC      D                            NON-SAFETY


of the appropriate
SAFETY


regional office or this office.Jordan, Director Divisi of Emergency
UNIT 3                UNIT 4
'Simplified Diagram of Portion of Electrical Distribution System.


===Preparedness===
Attachment 1 IN 86-70
and Engineering
                                          FIGURE 2                            August 18, 1986 TURKEY POINT - UNITS 3 & 4*
                                          If


Response Office of Inspection
EDG "'A"  /-\ 4160V 3A                                            3B 4160V      EDG 'B"
                4160V 4A                                          4B 4160V


and Enforcement
4A          3S


Technical
I)
                                      I          Cl38            4B


Contacts:
Si          Si            Si            Si
Henry Bailey, IE (301) 492-9006 Joseph Giitter, IE (301) 492-9001 Attachments:
1. Figures 1 and 2, Turkey Point -Units 3 & 4*2. List of Recently Issued IE Information


Notices
LOAD CENTERS


Attachment
480V 4A                                        4D 480V


1 IN 86-70 August 18, 1986 FIGURE 1 TURKEY POINT -UNITS 3 E 4 EDG "B" I)LOAD CENTERS 480V 4C 3D 480V* h N.C.N.C.480V MCC D NON-SAFETY
N.O.


SAFETY UNIT 3 UNIT 4'Simplified
N.O.


Diagram of Portion of Electrical
480V                                                  NON-SAFETY


Distribution
SAFETY


System.
"B1 EDG


Attachment
AUXILIARIES


1 IN 86-70 August 18, 1986 FIGURE 2 TURKEY POINT -UNITS If 3 & 4*EDG "'A"/-\ 4160V 3A 3B 4160V EDG 'B" 4160V 4A 4B 4160V I)I 3S Si Cl 38 Si 4A Si 4B Si LOAD CENTERS 480V 4A 4D 480V N.O.N.O.480V NON-SAFETY
'Simplified Diagram of Portion of Electrical Distribution System.


SAFETY"B1 EDG AUXILIARIES
Attachment 2 IN 86-70
                                                            August 18, 1986 LIST OF RECENTLY ISSUED


'Simplified
IE INFORMATION NOTICES


Diagram of Portion of Electrical
Information                                  Date of


Distribution
Notice No.    Subject                        Issue    Issued to


System.
86-69          Scram Solenoid Pilot Valve    8/18/86  All BWR facilities


Attachment
(SSPV) Rebuild Kit Problems            holding an OL or CP


2 IN 86-70 August 18, 1986 LIST OF RECENTLY ISSUED IE INFORMATION
86-68          Stuck Control Rod              8/15/86  All BWR facilities


NOTICES Information
holding an OL or CP


Date of Notice No. Subject Issue Issued to 86-69 86-68 86-67 86-66 86-65 Scram Solenoid Pilot Valve 8/18/86 (SSPV) Rebuild Kit Problems Stuck Control Rod 8/15/86 Portable Moisture/Density
86-67         Portable Moisture/Density      8/15/86 All NRC licensees


8/15/86 Gauges: Recent Incidents -And Common Violations
Gauges: Recent Incidents -And           authorized to possess, Common Violations Of Require-          use, transport, and


Of Require-ments For Use, Transportation, And Storage Potential
ments For Use, Transportation,         store sealed sources


For Failure Of 8/15/86 Replacement
And Storage


AC Coils Supplied By The Westinghouse
86-66          Potential For Failure Of      8/15/86  All power reactor


Electric Corporation
Replacement AC Coils Supplied          facilities holding


===For Use In Class lE Motor Starters And Contractors===
By The Westinghouse Electric            an OL or CP
Malfunctions


Of ITT Barton 8/14/86 Model 580 Series Switches During Requalification
Corporation For Use In Class


Testing Deficiencies
lE Motor Starters And


In Upgrade 8/14/86 Programs For Plant Emergency Operating
Contractors


Procedures
86-65          Malfunctions Of ITT Barton    8/14/86  All power reactor


Loss Of Safety Injection
Model 580 Series Switches              facilities holding


8/6/86 Capability
During Requalification Testing          an OL or CP


Potential
86-64          Deficiencies In Upgrade        8/14/86  All power reactor


Problems In West- 7/31/86 inghouse Molded Case Circuit Breakers Equipped With A Shunt Trip Failure Of Auxiliary
Programs For Plant Emergency            facilities holding


Feed- 7/28/86 water Manual Isolated Valve All BWR facilities
Operating Procedures                    an OL or CP


holding an OL or CP All BWR holding All NRC licensees authorized
86-63          Loss Of Safety Injection      8/6/86    All PWR facilities


to possess, use, transport, and store sealed sources All power reactor facilities
Capability                              holding an OL or CP


holding an OL or CP All power reactor facilities
86-62          Potential Problems In West-    7/31/86  All power reactor


holding an OL or CP All power reactor facilities
inghouse Molded Case Circuit            facilities holding


holding an OL or CP All PWR facilities
Breakers Equipped With A                an OL or CP


holding an OL or CP All power reactor facilities
Shunt Trip


holding an OL or CP All power reactor facilities
86-61          Failure Of Auxiliary Feed-      7/28/86  All power reactor


holding a CP facilities
water Manual Isolated Valve              facilities holding


an OL or CP 86-64 86-63 86-62 86-61 OL = OperatinG
a CP


License CP = Construction
OL = OperatinG License


Permit}}
CP = Construction Permit}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 03:02, 24 November 2019

Potential Failure of All Emergency Diesel Generators
ML031250102
Person / Time
Site: Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Skagit, Marble Hill
Issue date: 08/18/1986
From: Jordan E
NRC/IE
To:
References
IN-86-070, NUDOCS 8608130578
Download: ML031250102 (6)
v • d • e


SSINS No.: 6835 IN 86-70

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF INSPECTION AND ENFORCEMENT

WASHINGTON, D.C. 20555 August 18, 1986 IE INFORMATION NOTICE NO. 86-70: POTENTIAL FAILURE OF ALL EMERGENCY

DIESEL GENERATORS

Addressees

All nuclear power reactor facilities holding an operating license or a

construction permit.

Purpose

This notice informs recipients of multiple design deficiencies in a vital ac

power system that could potentially result in the loss of all emergency diesel

generators (EDGs). It is expected that recipients will review the information

for applicability to their facilities and consider actions, if appropriate, to

preclude a similar problem occurring at their facilities. However, suggestions

contained in this information notice do not constitute NRC requirements; there- fore, no specific action or written response is required.

Description of Circumstances

On June 10, 1986, in accordance with 10 CFR Part 21, Florida Power & Light

(FP&L) reported the results of a failure modes and effects analysis (FMEA).

This analysis identified multiple design deficiencies in the Turkey Point

Units 3 and 4 vital ac power system that could potentially result in the loss

of both EDGs due to overloading. In addition, one deficiency was identified

that could result in the loss of all ac power to Unit 4. Turkey Point Units 3 and 4 share two EDGs. Simplified diagrams of part of the Turkey Point 3 & 4 electrical distribution system are provided as Figures 1 and 2.

One design deficiency involved a "swing bus." As shown on Figure 1, 480 volt

MCC "D" is normally supplied from EDG "B" but will shift its power supply to

EDG "A" if needed. MCC "D" also feeds a non-safety stub bus through a single

circuit breaker. This breaker is normally opened by the 48 load sequencer to

isolate the non-safety loads from MCC "D" when the 48 4160V bus is loaded on

EDG "B". A single failure in that circuit breaker would leave the non-safety

loads connected to MCC "D". During safety injection for one unit, the addi- tional non-safety loads could overload EDG "B", possibly resulting in a trip

of this EDG. MCC "D" would then transfer its power supply and could overload

EDG "A" as well.

8608130578

IN 86-70

August 18, 1986 In addition to the above design deficiency, five deficiencies in the EDG load

evaluation were found, each of which could contribute to an overloading of both

EDGs. Both EDGs could be overloaded in the event of a safety injection on one

unit and a loss of offsite power to both units. In some cases this could occur

without a single failure. These deficiencies are as follows:

0 The post-TMI Emergency Operating Procedures require an additional charging

pump and high head safety injection pump in the 1-30 minute and 30-60

minute EDG load interval, respectively.

o In the event of a single failure of one EDG, actual testing of component

cooling water and intake cooling water showed that pump loads (KW) were

higher than expected. Under this condition, the cooling water pumps provide

flow to parallel hydraulic trains. Since the flow resistance is lower, the pump flow rate is greater and the pump motor horsepower would increase.

This in turn may increase the load on the EDG to an unacceptable value.

o Recent environmental qualification evaluations per 10 CFR 50.49 assumed

that the emergency containment coolers operate longer than previously

assumed.

0 Load center transformer losses had not been accounted for in prior EDG

load evaluations.

o Some nonsafety loads that are auto-start enabled when the safety injection

signal is reset could result in EDG overloading. These loads would not

always immediately start, but would auto-start when their start setpoints

were reached after the reset.

In addition to the overloading deficiencies above, a design deficiency.was found

that could result in the loss of one EDG, and at the same time could result in

the loss of all ac power to Unit 4 as mentioned earlier. In the event of a

single failure of the 4A battery or the 4A load sequencer subsequent to a loss

of off-site power, the 4A 4160V bus shown in Figure 2 would be prevented from

automatically loading onto the "A" EDG. It would also prevent the transfer of

the 4A MCC swing bus from 4A load center to 4B load center. The "B" EDG has a

self-contained supply of fuel oil that lasts about one hour. After that time, fuel must be gravity supplied by the day tank via a solenoid operated valve.

However, this valve is powered from MCC 4A. Therefore, the above mentioned

single failure would also cause the loss of the "B" EDG and the loss of all ac

power to Unit 4. The Unit 3 3B 4160V bus would also be deenergized, along with

three of the four high head safety injection pumps and the control room

air-conditioning.

Discussion:

The single failure vulnerability of the non-safety stub bus discussed above may

have been evaluated during the licensing review and the loads on the EDGs found

to be low enough so that failure of the stub bus breaker would not overload the

diesel. Subsequent to initial operation, however, additional loads have been

IN 86-70

August 18, 1986 added on the diesels. Prior to November, 1985, there was the potential for

loading the EDGs to 3544 kw in the 1-30 minute period and 3451 in the 30-60

minute period following a LOCA in one unit with a loss of offsite power in both

units. These load levels exceed the highest FSAR value (1/2 hour exceptional

rating) of 3050 Kw by a substantial margin. With the EDGs overloaded, the

potential exists that safety-related loads would not start or would not operate

at design ratings. Under these conditions, the EDG engines could stall and

damage to the generator and/or engine could occur. There are no test data

available to demonstrate that the EDGs could accept the above load levels.

As an interim solution to the above design deficiencies, FP&L disabled the

automatic transfer between EDGs and established a dedicated operator to take

corrective action (i.e., manipulate appropriate breakers) as necessary. The

licensee has now modified EDG loads, loading sequences and plant procedures.

This example illustrates the importance of reviewing EDG load limits under all

possible operating configurations for a range of design basis accident condi- tions. FP&L, through an FMEA, system testing, and evaluation of EDG load limits, found design deficiencies that may have prevented one or both EDG's from

performing their required function.

No specific action or written response is required by this information notice.

If you have any questions about this matter, please contact the Regional

Administrator of the appropriate regional office or this office.

Jordan, Director

Divisi of Emergency Preparedness

and Engineering Response

Office of Inspection and Enforcement

Technical Contacts: Henry Bailey, IE

(301) 492-9006 Joseph Giitter, IE

(301) 492-9001 Attachments:

1. Figures 1 and 2, Turkey Point - Units 3 & 4*

2. List of Recently Issued IE Information Notices

Attachment 1 IN 86-70

August 18, 1986 FIGURE 1 TURKEY POINT - UNITS 3 E 4 EDG "B"

I)

LOAD CENTERS

h

480V 4C 3D 480V

N.C.

N.C.

480V MCC D NON-SAFETY

SAFETY

UNIT 3 UNIT 4

'Simplified Diagram of Portion of Electrical Distribution System.

Attachment 1 IN 86-70

FIGURE 2 August 18, 1986 TURKEY POINT - UNITS 3 & 4*

If

EDG "'A" /-\ 4160V 3A 3B 4160V EDG 'B"

4160V 4A 4B 4160V

4A 3S

I)

I Cl38 4B

Si Si Si Si

LOAD CENTERS

480V 4A 4D 480V

N.O.

N.O.

480V NON-SAFETY

SAFETY

"B1 EDG

AUXILIARIES

'Simplified Diagram of Portion of Electrical Distribution System.

Attachment 2 IN 86-70

August 18, 1986 LIST OF RECENTLY ISSUED

IE INFORMATION NOTICES

Information Date of

Notice No. Subject Issue Issued to

86-69 Scram Solenoid Pilot Valve 8/18/86 All BWR facilities

(SSPV) Rebuild Kit Problems holding an OL or CP

86-68 Stuck Control Rod 8/15/86 All BWR facilities

holding an OL or CP

86-67 Portable Moisture/Density 8/15/86 All NRC licensees

Gauges: Recent Incidents -And authorized to possess, Common Violations Of Require- use, transport, and

ments For Use, Transportation, store sealed sources

And Storage

86-66 Potential For Failure Of 8/15/86 All power reactor

Replacement AC Coils Supplied facilities holding

By The Westinghouse Electric an OL or CP

Corporation For Use In Class

lE Motor Starters And

Contractors

86-65 Malfunctions Of ITT Barton 8/14/86 All power reactor

Model 580 Series Switches facilities holding

During Requalification Testing an OL or CP

86-64 Deficiencies In Upgrade 8/14/86 All power reactor

Programs For Plant Emergency facilities holding

Operating Procedures an OL or CP

86-63 Loss Of Safety Injection 8/6/86 All PWR facilities

Capability holding an OL or CP

86-62 Potential Problems In West- 7/31/86 All power reactor

inghouse Molded Case Circuit facilities holding

Breakers Equipped With A an OL or CP

Shunt Trip

86-61 Failure Of Auxiliary Feed- 7/28/86 All power reactor

water Manual Isolated Valve facilities holding

a CP

OL = OperatinG License

CP = Construction Permit


Retrieved from "https://kanterella.com/w/index.php?title=Information_Notice_1986-70,_Potential_Failure_of_All_Emergency_Diesel_Generators&oldid=2200050"