ML20236F813
| ML20236F813 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/30/1998 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20236F807 | List: |
| References | |
| NUDOCS 9807020356 | |
| Download: ML20236F813 (65) | |
Text
_--___
I Defueled Safety Analysis Report i
Dresden Nuclear Power Station Unit 1 Commonwealth Edison Company J
l f
i June 1998 Revision 0
'I 9907020356 990629 PDR ADOCK 05000010 PDR y
i i
DSAR Defueled Safety Analysis Report (DSAR)
Dresden Nuclear Power Station Unit 1 Commonwealth Edison Company June 1998 TABLE OF CONTENTS Page 1.
INTRODUCTION AND
SUMMARY
................. 1-1 1.1 Introduction..........
1-1 1.2 Licensing and Construction History...
... 1 - 1 1.3 Operating History.............
.... 1-3 2.
SITE CIIARACTERISTICS........
.2-1 3.
FACILITY DESIGN.......
........3-1 3.1 Structures, Systems and Components (SSC)
Important to the Safe Storage of Irradiated Fuel..................
.3-1 3.1.1 Fuel Building........
.........3-1 3.1.2 Irradiated Fuel (Wet Storage)...................
. 3-2 3.1.3 Fuel Storage Pool........
........... 3 -4 3.1.4 Fuel Transfer Pool.....
.... 3-5 3.1.5 Fuel Pool Gates...........
..3-6 3.1.6 Fuel Transfer Tunnel and Fuel Transfer Tube..................................
3-6 3.1.7 Water Level: Fuel Storage Poci and Fuel Transfer Pool......................... 3-7 3.1.7.1 Water Level Indication.................
........... 3-10 3.1.7.2 Emergency Water Makeup...........
...................................3-10 3.1.8 Water Chemistry.............................
......... 3-1 1 3.1.8.1 Fuel Pool Demineralized System......
.... 3-11 3.1.8.2 Corrosion Coupons: Fuel Storage Pool.........
.3-12 3.1.9 Fuel Storage Components.............
........ 3-12 l
3.1.9.1 Channel Storage Racks....
...3-12 3.1.9.2 Fuel Racks...............
........ 3-13 3.1.9.3 Fuel Rack Supports...
............. 3-13 3.1.9.4 Fuel Rack Baskets........
......... 3-14 3.1.10 Ventilation System: Fuel Building.........
.... 3-14 j
3.1.10.1 Supply Fan: Fuel Building................
......................3-15 i
3.1.10.2 Exhaust Fans: Fuel Building.
... 3-15 3.1.11 Radiation Monitors: Fuel Building.
. 3-16 3.1.11.1 Kr-85: Fuel Building............
. 3-16 3.1.11.2 Area Radiation Monitors: Fuel Building...
... 3-16 l
I i
C DSAR i
TABLE OF CONTENTS Page l
3.1.12 Fuel Handling Equipment....................
.................................3-18 l
3.1.12.1 Crane: Fuel B uilding............................................
.3-18 3.1.12.2 Fuel Grapple Crane...............
........3-19 3.1.13 Fuel Preparation Machine...........
............................3-20 3.2 Structures, Systems and Components (SSCs)
Important to Unit 1,2 or 3 Operations,..
.................... 3 -2 1 3.2.I Structures....
........................................................................3-21 l
3.2.1.1 Co ntrol Room............................................................................... 3 -21 3.2.1.2 Chemical Cleaning B uilding............................................................. 3-21 3.2.1.3 Interim Radwaste Storage Facility................................................. 3-21 3.2.2 Systems...........
.............................3-22 3.2.2.1 Emergency L.i ghting.............................................................. 3-22 3.2.2.2 S tan dby Ligh ti n g................................................................................... 3-2 2 3.2.2.3 Control Room Monitoring............................................................ 3-22 3.2.2.4 4KV AC Electrical Distribution System........................................
....3-23 3.2.2.5 480V AC Electrical Distribution System............................................. 3-26 3.2.2.6 120V AC Distribution System........................................................... 3-29 3.2.2.7 125V DC Distribution System............................................................. 3-29 3.2.2.8 Fire Protection System.............
...............................................3-30 3.2.2.9 Environmental Monitoring................
............. 3 -3 5 3.2.2.9.1 Discharge Cs.nal Sample System..................................................... 3-35 3.2.2.9.2 Environmental Monitoring Stations................................................... 3-36 3.2.2.9.3 Unit 1 Chi m n ey............................................................................... 3 -3 6 3.2.2.9.4 Chimney Effluent Monitoring System.............................................. 3-36 3.2.2.9.5 Gaseous M onitorin g System................................................................ 3-3 7 3.2.2.9.6 Ventilation System: Chemical Cleaning Building................................... 3-38 3.2.2.10 General Station Emergency Plan Equipment................................. 3 -3 8 3.2.3 Co mpo n e n t s.................................................................................. 3 -3 8 3.2.3.1 Clean Demineralized Tank............................................................... 3-3 8 3.2.3.2 Contaminated Demineralized Tank.................................................. 3-39 3.2.3.3 Unit I / Unit 2 Service Air Isolation Valve....................................... 3-39 3.3 Balance of Unit 1 Structures, Systems and Components (SSCs)...................... 3-40 3.3.I S tru c t u re s...................................................................................... 3 -4 0 3.3.1.1 Access Control / Administration Buildings.........................................3-40 3.3.1.2 Sphere (Reactor Building).......................................................... 3 -4 0 3.3.1.3 Maintenance Shops......................................................................3-40 l
l 11 1
i 1
L-A
DSAR TABLE OF CONTENTS Page 3.3.1.4 Cribhouse..........
. 3-40 3.3.1.5 Off Gas Building..........
............... 3-40 3.3.1.6 Station Blackout Building............
.3-41 3.3.2 Systems and Components......
...... 3-41 3.3.2.1 Turbine Building Crane.....
....................... 3 -4 1 3.3.2.2 Well Water......................
.3-41 3.3.2.3 Condensate.....................
.................... 3 -4 1 3.3.2.4 Circulating Water..............
.. 3-41 3.3.2.5 Lube Oil..
.. 3-41 3.3.2.6 Power Extraction.........
.. 3-41 3.3.23 Reactor and Auxiliaries.......................
......... 3 -4 2 3.3.2.8 Reactor Enclosure Cooling Water............
......... 3-4 2 3.3.2.9 Service Water.
........ 3-4 2 3.3.2.10 S team S upply...................................
..... 3-42 3.3.2.11 Turbine Building Closed Cooling Water.......................................... 3-42 4.
O P E RA TI O N S..............................................................
......... 4-1 Operation Description......................................
...........4-1 4.1 4.1.1 Control Room Area...
...........................................................4-1 4.1.2 Criticality Prevention........
... 4-1 4.1.3 Chemistry Control......................
.................4-1 4.1.4 Maintenance Activities...............
...................4-1 4.2 S pen t Fuel H an dlin g..................................................................... 4-2 l
4.2.1 Spent Fuel Handling and Transfer.....................................................
..4-2 4.2.2 S pen t Fue l S t orage.................................................................... 4-2 l
5.
RADIATION PROTECTION.............
.......... 5-1 5.1 Liquid Waste Treatment and Retention............................................... 5-1 5.2 S oli d Wast e s.................................................................
.........5-1 5.3 Process and Effluent Monitoring Systems........................................... 5-1 l
5.4 Radiation Protection Program..................................................... 5-1 6.
ACCIDENT. ANALYSIS.........................
....................... 6-1 6.1 Criticality Analysis....................
.......................6-1 6.2 S ource Term Eval uation............................................................. 6-3 6.3 Fuel Pool Drain Down Accident Analysis......................................... 6-4 111
DSAR TABLE OF CONTENTS Page 7.
CONDUCT OF OPERATIONS........................................
.....................7-1 7.1 Comed Organization Structure.................................................7-1 I
7.1.1 ~ Manager of Decommissioning Projects.................................
..............7-1 7.1.2 Unit 1 Decommissioning Plant Manager............................................7-1 7.1.3 Onsite and Technical Support Organization............................................. 7-2 7.2 Decommissioning Procedures.......................................................... 7-2 j
7.2.1 Dresden Station Procedures.................
.......................................7-2 7.2.2 Decommissioning Procedures........
.................................7-2 7.2.3 Preparation and Review of Decommissioning Procedures.........
..................7-3 7.3 Training.......................................................................................7-3 7.3.1 Training of Fuel Handlers..............................................
.................7-3 7.3.2 Training of Plant Staff....
............... 7-4 FIG URES..............
3.1 Fuel Handling System............
......................................3-8 3.2 Fuel Storage Pool & Fuel Transfer Pool................................................ 3-9 3.3 Electrical Distribution System........................................................ 3-24 1
1
)
.IV
(
- 1. Introduction and Summary 1.1.
Introduction The United States Nuclear Regulatory Commission (NRC) approved Revision 3 to the Dresden Unit 1 Decommissioning Program Plan on September 3,1993. Subsequent revisions to the Decommissioning Program Plan were reviewed and approved based on criteria similar to the criteria of Section 50.59 of Title 10 of the Code of Federal Regulations (10 CFR 50.59). In 1998, the Decommissioning Program Plan (DPP) was revised to the current Defueled Safety Analysis Report (DSAR) format contained herein.
Portions of this document refer to the Dresden Units 2 and 3 Updated Final Safety Analysis Report (UFSAR). Dresden Unit I shares the Units 2 and 3 site and surrounding area. Therefore certain information regarding the site characteristics, the local environment, and activities or designs which are applicable to both Dresden Unit 2 and 3, and Dresden Unit 1, are not reiterated in this document. Where appropriate the Unit 2 and 3 UFSAR is referenced herein.
Comed is decommissioning the Dresden Nuclear Power Station Unit 1 by placing the facility in a safe storage condition (SAFSTOR) until Dresden Units 2 & 3 are ready for decommissioning. If an extended operating life program (License Renewal) for Units 2 and 3 is not initiated, all three Dresden units will be decommissioned by removal of radioactive material and dismantlement beginning as early as 2010. The SAFSTOR license DPR-2 Amendment No. 37 for Dresden Unit 1, issued September 3,1993, has an
. expiration date of April 10,2029.
l 1.2.
Licensing and Construction History Dresden Unit I was the first nuclear plant built by private industry. It was a cooperative effort by Commonwealth Edison and a " Nuclear Power Group" (NPG) that included six other electric utilities. General Electric Company designed the plant and offered it at a fixed contract price of $45 million, $15 million of which was contributed by NPG.
l Commonwealth Edison provided the remaining funding, the site, the electrical switchyard and other accessories.13echtel Corporation was the engineer-constructor. The following list provides a chronology of Dresden Unit I licensing and construction history.
i l-1
DSAR Dresden Unit 1 Ucensine and Construction Chronoloey Date Activity March 31,1955 Preliminary Safety Report submitted to the Atomic Energy Commission (AEC).
- May 04,1956 Construction Permit issued.
November 28,1956 Site preparation work begun June,1957 Major construction work begun.
Juue 12,1957 Final Safety Report submitted to the AEC.
- March,1959 Reactor pressure vessel shipped.
September 23,1959 Construction completed.
I October 13,1959 Fuel loading began.
l October 15,1959 First nuclear chain reaction initiated.
{
November 16,1959 Operating License issued.
April 15,1960 First electricity generated.
June 29,1960 Full power operation begun - 180,000 Kilowatts (net).
August 01,1960 Official dedication.
October 12,1960 Commercial operation begun.
- Predecessor of the Nuclear Regulatory Commission (NRC).
l I
l-2 l
4 DSAR 1.3.
Operating History Dresden Unit 1 produced power commercially from 1960 to October 31,1978, generating approximately 15,800,000 Megawatt-hours of electricity.
Dresden Unit I had significant problems associated with control rods and undertook a control rod blade replacement program from November 1960 through March 1961. In April of 1961, criticality testing was conducted with new control blades. On June 2 of 1961, turbine generator operation was resumed. The licensed power of the Unit was increased from 630 MWt to 700 MWt in September of 1962.
The unit had a history of minor steam leaks and erosion in steam piping in the early and mid-1960s. There were also fuel failures during the period of September through December of 1964 and other times which, although not leading to off-gas releases above limits, did cause redistribution of radionuclides from the fuel to other parts of the primary system.
During other outages in the late 1960s, ultrasonic inspections were made on extensive sections of primary piping and welds because of concerns regarding intergranular stress corrosion cracking failun s in some of the smaller 304 stainless steel piping.
Several systems in the plant used admiralty brass (Cu-Ni) heat exchange surfaces, including the Main Condenser. Most of these were taken out of service and replaced with stainlese steel tubing. In the sixth partial refueling, the condenser was re-tubed from admiralty brass to 304L stainless steel. The use of Cu-Ni surfaces did lead to translocation and deposition of corrosion products throughout the operating systems.
' Die use of carbon steel in the Secondary Feedwater System may have also contributed to the elevated corrosion radionuclides levels. These foregoing events led to the need to i
perform a chemical decontamination of the Primary System.
l The Unit was taken off-line on October 31,1978, to backfit it with equipment to meet new federal regulations and to perform a chemical decontamination of major piping systems.
While it was out of service for retrofitting, additional regulations were issued as a result of the March 1979 incident at Three Mile Island. The estimated cost to bring Dresden Unit 1 into compliance with these regulations was more than $300 million.
Commonwealth Edison concluded that the age of the unit and its relatively small size did not warrant the added investment.
In 1984, chemical decontamination of the primary system was performed and 753 curies of Cobalt-60 and 12.4 curies of Cesium-137 were removed. This decontamination was l
l-3
DSAR completed and activities began shortly thereafter to prepare the facility for decommissioning.
Dresden Unit 1 Operatine and Abnormal Event Chronolocy Date Activity August 1960 Ollicial dedication.
October 1960 Commercial operation begun.
i September 1962 Electrical power stretched to 210,000 kilowatts.
December 1962 Achieved 73% annual capacity factor
)
exceeding Edison's best coal plant.
June 1976 World's first test of chemical cleaning on portion of reactor piping (Task K corrosion Test Loop).
' October 1978 Unit shutdown for modification to meet new regulations.
September 1984 Completion of world's first full-scale chemical cleaning of entire primary system.
October 1984 Decision made to decommission unit.
July 1986 NRC issues amendment of License No. DPR-2 to possess-but-not-operate status, Dresden Nuclear Power Station, Unit 1 (Amendment No. 36 to I.icense DPR-2).
July 1992 Unit I areas with the exception of the Fuel Storage Building were devitalized (Security Plan Revision No. 42).
September 1993 NRC authorizes decommissioning of Dresden Unit 1 (Amendment No. 37 to License No. DPR-2).
I January 1994 Sphere piping is challenged by cold temperature extremes, resulting in pipe breaks.
L 1
l l-4
- 2. Site Characteristics Dresden Unit 1 is located on the Dresden Nuclear Power Station site shared with Dresden Units 2 and 3. The site characteristics of Unit I are similar to those associated with Units 2 and 3, as described in the Dresden Units 2 and 3 Updated Final Safety Analysis Reports.
Unit 1 is located in the nonheast quadrant of the site with an intake canal extending west from the Kankakee River and a discharge canal extending north to the Illinois River.
Information descriptive of the Dresden Unit I site regarding the following topics is available in the Dresden Units 2 and 3 Updated Final Safety Analysis Report:
Site Location Site Ownership Exclusion Area Access to the Site Other Activities on the Site Population Distribution Uses of Adjacent Lands and Waters -
.. Other Activities in the Area around the Site with Potential for Effecting Operations Meteorology Hydrology Geology.
l' I
2-1
l q
DSAR j
- 3. Facility Design The Dresden Unit 1 Facility Design is divided into three areas: structures, systems and components important to the safe storage and handling of irradiated fuel, structures, systems, components important to Unit 1,2 or 3 operations and balance of Unit I structures, systems and components.
1 3.1.
Structures, Systems and Components (SSCs)
Important to the Safe Storage and Handling of irradiated Fuel i
i The Unit 1 Fuel Storage Pool, Fuel Transfer Pool, and New Fuel Storage Vault are I
located within the Fuel Storage and Handling Building (commonly referred to as the Fuel Building). The New Fuel Storage Vault is now utilized as an equipment storage area.
The Fuel Building is the only remaining vital (security) area for Unit 1.
l 3.1.1 Fuel Building The Fuel Building, along with systems and components housed within, provides for the safe storage and handling ofirradiated fuel.
The Fuel B0ilding structure performs the following functions:
Provides an enclosure to control of radioactive contamination and radioactive gaseous effluents; Provides a weather resistant enclosure for housing systems and components including the Fuel Storage Pool and Fuel Transfer Pool; 1
Provides structural support for systems and components including the Fuel Building Overhead Crane, and Fuel Grapple Crane; Provides a physical barrier to prevent unauthorized entry.
The Fuel Building is constructed as a single-story structural steel braced-frame with roof trusses on columns, which rest on concrete footings. The Fuel Building has a built-up roof system. Exterior walls consist primarily of reinforced concrete or corrugated cement asbestos siding supported bydeel framing. The Fuel Building is not an airtight structure and is not designed to maintain a negative pressure throughout.
2 The Fuel Building roof was designed for a live load of 25 lbs/ft. A majority of the Fuel 2
Building floor areas were designed for a live load of 600 lbs/ft The design for all beams and girders includes a concentrated load of 3,000 lbs. in addition to live and dead loads.
3-1
DSAR 2
Lateral design loads are 25 lbs/ft for wind and 3.3% (dead load and 1/2 live load) for 2
seismic. All footings are carried to solid rock with a carrying capacity of 25 tons per ft,
l Fuel Building structural steel was designed in accordance with AISC Code 1949. Fuel l
Building concrete was designed to ACI Code 1951. The Uniform Building Code 1955 was used as a general guide, where applicable.
l The Fuel Building structure was designed to support the following cranes and associated loads:
75 ton Fuel Building Overhead Crane (usually called Cyclops crane) with a 10 ton auxiliary hoist.
I ton Fuel Grapple Crane (usually called Grapple crane). The actual load carrying capacity of the current Fuel Grapple Crane is limited to 1/2 ton.
I ton New Fuel Storage Vault Crane.
1 Administrative procedures preclude using the Fuel Building Cranes below a predetermined temperature limit. The administrative temperature limit is above the nil i
ductility transition temperature for the structural steel.
j
)
Ventilation from the Fuel Building exhausts through the Unit I Chimney.
The Fuel Building is maintained as a vital area. Access to the building is controlled by station security procedures.
l Periodic monitoring of the Fuel Building structural integrity is performed through station j
procedures.
The Unit 1 Fuel Building contains personnel and equipment doors. During fuel handling, procedures require: 1) Fuel Building doors to be closed (other thrm for normal personnel egress and ingress),2) Fuel Building ventilation system is to be operable (with a release path to the chimney), and 3) Fuel Building area radiation monitors are to be operable.
These actions will facilitate prompt notification and provide a monitored elevated release path if an accident were to occur.
3.1.2 Irradiated Fuel (Wet Storage)
Nuclear fuel assemblies were the source of power for the Unit 1 Reactor. With the retirement of Dresden Unit 1 in 1984, they are no longer required.
Fuel utilized in previous Unit 1 operations is stored in the following locations:
Unit 1 Fuel Storage Pool 3-2
DSAR l
Unit 1 Fuel Transfer Pool Unit 2 Spent Fuel Storage Pool Unit 3 Spent Fuel Storage Pool Dresden Unit 1 operated for eleven fuel cycles (1,2,3,4,5,6,7,8,9a,9b,10, and 11).
The newest discharged fuel assemblies were placed in the fuel pools following shutdown of the Reactor in October of 1978.
Spent fuel used during previous Unit 1 operations can be stored in the Unit 1 Fuel Storage Pool, Unit 1 Fuel Transfer Pool, Unit 2 Spent Fuel Storage Pool or Unit 3 Spent Fuel Storage Pool.
Unit 2 and Unit 3 Spent Fuel Storage Pools are controlled by Technical Specifications and are described in the UFSAR for these Units.
I' nit 1 Fuel Assemblies remaining at Dresden site were discharged at the end of fuel cycles 6,7,8,9,9b,10 and 11.
Unit 1 Fuel Assemblies in the Unit 2 / 3 Fuel Storage Pools are not channeled. Fuel Assemblies in the Unit 1 Fuel Storage Pool and Fuel Transfer Pool are both channeled and not channeled. Fuel channels were fabricated of Zircalloy 2. Channels were utilized during operations and are not required for the safe storage ofirradiated fuel.
One prototype 8 x 8 fuel assembly design is stored in the Unit 3 Fuel Pool. The 8 x 8 fuel assembly was constructed using Zircalloy 4 cladding material. Active fuel length is approximately 105.34" and overall fuel assembly length is approximately 134.34" prior to irradiation.
Remaining Unit I fuel assemblies, can be generally characterized as a 6 x 6 BWR fuel matrix. Fuel was fabricated with Zircalloy 2 cladding material. Active fuel length is approximately 108" and overall fuel assembly length is approximately 134.35" prior to irradiation. These dimensions vary slightly between designs.
Cross sectional dimensions of Unit I fuel assemblies are just under 4.5" by 4.5" The lower tie plate is composed of two pieces with the lower nozzle being removable. This nozzle contains a machined orifice, which may be of several diameters and designs.
Three fuel vendors fabricated fuel for Unit 1 over its 11 operating cycles:
General Electric cycles 1 - 5.
Gulf United Nuclear cycles 6 - 10.
Exxon cycle 11.
f I
3-3
DSAR The fuel in the early cycles was generally composed of 36 fuel rods except for a few assemblies equipped with an instrument tube to accept in-core nuclear fission chambers.
These instrument tubes are effectively water rods and in later cycles all fuel bundles either had an instrument tube or a water rod in this location. Some assemblies had a poison rod (generally limited to one rod) containing a low concentration of a neutron absorber such as gadolinium.
Two experimental Mixed Oxide (MOX) programs were conducted in Unit 1. One by General Electric involving only 1 pin per bundle in each of four bundles. Later, Gulf United Nuclear ran a program involving 11 bundles of nine MOX pins per bundle. A few of the MOX rods have been shipped to hotcells over the yeers for detailed examination.
A small number of other fuel bundles in storage also had a limited number of fuel rods removed for examination or due to rod failures.
A small amount of Type III-F General Electric fuel had compacted UO powder in place 2
of the more standard ceramic pellets.
Thoria rods were also utilized in limited quantities. These thoria rods have been segregated into a rod basket, hence, no fuel bundles contain thoria rods. Fuel Rod Baskets are approximately the same size as a fuel assembly. The Fuel Rod Baskets are handled and stored in a manner similar to fuel assemblies.
The only remaining accident scenarios of concern for Unit 1 involve the storage of fuel assemblies. Accident analyses documented in Section 6 demonstrate that postulated accidents will not result in off-site dose exposures in excess of 10 CFR 100 or US EPA limits. Additionally,it is shown through analysis that criticality will not occur during normal or postulated upset conditions.
Spent fuel assemblies stored in the Unit 1 Fuel Storage Pool and Fuel Transfer Pool are periodically inspected under the Unit 1 Structural Integrity Monitoring Program. An inventory of the fuel assemblies is performed on a regular basis.
3.1.3 Fuel Storage Pool The Fuel Storage Pool located in the northeast corner of the Fuel Building provides a safe location for the underwater storage of spent fuel. The reinforced concrete pool is 26'-l 1" deep including a curb which rims the top of the floor of the building. The floor of the pool is at the 494'-10" elevation. The pool is 20' wide in the east-west direction and 29' long in the north-south direction. The pool does not have a stainless steel liner typical of later industry designs. The Fuel Storage Pool is equipped with racks for storing spent fuel and auxiliary equipment.
An opening in the structure at the northwest corner of the pool provides an entrance to the Fuel Transfer Pool. Upper and Lower Fuel Pool gates installed in the opening between the two pools are used to limit water loss from the Fuel Storage Pool if the Fuel Transfer 3-4
DSAR Pool is drained for any reason. A penetration installed in the Upper Fuel Pool Gate allows the water level:o equalize between the Fuel Storage Pool and Fuel Transfer Pool.
The Fuel Storage Pool contains water utilized for cooling and shielding spent nuclear fuel. Emergency large volume water makeup for either pool is available from the Fire Protection Water Supply System.
An over flow line is installed at approximately the 520'-2" elevation of the Fuel Storage Pool. Over flow from the Fuel Storage Pool is routed to the Unit 1 Turbine Building Drain Tank.
Unit I fuel has decayed to the point that a cooling system is no longer required.
The IW1 Pool Demineralized System circulates and filters water from the Fuel Storage Pool to maintain water quality.
Piping systems for the Fuel Storage Pool have been modified to preclude the possibility of drain down by siphoning.
The Fuel Storage Pool is periodically inspected under the Unit 1 Structural Integrity Monitoring Program.
Administrative controls have been established to control heavy loads carried over the Fuel Storage Pool.
3.1.4 Fuel Transfer Pool Designed to transfer fuel between the Reactor and the Fuel Building and for the loading of shipping casks, the Fuel Transfer Pool is located in the northwest corner of the Fuel Building. The dimensions of the unlined reinforced concrete pool are 20'-0" in a north-south direction and 25'-6" in an east-west direction. The main floor of the pool is at the 479'-3" elevation which is 4'-6" above the Fuel Transfer Tunnel floor elevation,15'-7" below the Fuel Storage Pool floor elevation, and 42'-6" below the curb which rims the top of the pool above the floor of the building. This main floor of the pool can be used for storing fuel assemblies in Fuel Rack Baskets and other equipment. Up to three Fuel Rack Baskets with fuel can be located in support structures attached to the floor of the Fuel Transfer Pool.
An opening in the concrete structure at the northeast corner of the pool provides an entrance into the Fuel Storage Pool Upper and Lower Fuel Pool Gates (when installed in the opening) limit water loss from the Fuel Storage Pool if the Fuel Transfer Pool is drained for any reason.
The Fuel Transfer Pool contains water utilized for cooling and shielding spent nuclear fuel. Both the sources of makeup water and over flow lines are located in the Fuel 3-5
DSAR Storage Pool. A penetration in the Upper Fuel Pool Gate between the Fuel Storage Pool and Fuel Transfer Pool equalizes the water level between the two pools.
Piping systems for the Fuel Transfer Pool have been modified to preclude the possibility of drain down by siphoning.
The Fuel Transfer Pool is periodically inspected under the Unit 1 Structural Integrity Monitoring Program.
Administrative controls have been established to control heavy loads carried over the Fuel Transfer Pool.
3.1.5 Fuel Pool Gates The Upper and Lower Fuel Pool Gates provide isolation between the Unit 1 Fuel Storage Pool and Fuel Transfer Pool. The gates are primarily constructed of galvanized steel with rubber seals. Each gate is approximately 13'-6" high,4'-7" long and 7 5/8" in width. The gates fit into a channeled opening in the wall separating the Fuel Storage Pool and Fuel Transfer Pool.
When installed, the gates function to limit water loss from the Fuel Storage Pool if the Fuel Transfer Pool is drained for any reason.
To support operation of the Fuel Pool Demineralized System a 6" diameter schedule 40 pipe penetration is located at approximately the 518'-10" elevation of the Upper Fuel Pool Gate. This penetration allows equalization of the water levels in the Fuel Storage Pool and Fuel Transfer Pools for both normal makeup and Fuel Pool Demineralized System operation.
The original design of the gates contain a weir (installed in the upper gate above the normal water level) which serves as an over flow for the Fuel Transfer Pool to the Fuel Storage Pool.
The Fuel Pool gates are periodically inspected under the Unit 1 Structural Integrity Monitoring Program.
3.1.6 Fuel Transfer Tunnel and Fuel Transfer Tube Designed for transporting fuel from the Fuel Building to the Reactor, the reinforced concrete Fuel Transfer Tunnel connected the Fuel Transfer Tube to the Fuel Transfer Pool. The tunnel, which is about 9' wide, is on the south side of the Sphere on the north south centerline. The ledge on both sides of the tunnel supports the rails for the Fuel Rack Basket Carrier. The ledges are about 7'-6" above the floor of the tunnel. The tunnel is about 7'-4" wide below the ledges. The floor of the tunnel is at the 474'-9" elevation, 3-6
DSAR and the ceiling is at the 490'-3" elevation providing 15'-6" floor to ceiling clearance. The tunnel extends from a point 5' north of the center of the Fuel Transfer Tube southward to the Fuel Transfer Pool. The bottom portion of the tunnel including the ledge that supports the rails project into the Fuel Transfer Pool. This design allows the Fuel Rack Basket Carrier to be moved into the Fuel Transfer Pool for unloading or loading Fuel Rack Baskets.
A blind flange constructed of 5/8" thick steel plate has been welded to the bottom of the 42" diameter Fuel Transfer Tube that extends into Fuel Transfer Tunnel. A 1" drain valve is installed on the Fuel Transfer Tubejust above the 502' Sphere floor elevation.
Following installation of the blind flange, the Fuel Transfer Tube was drained to a level below the 502' Sphere floor elevation.
The installation of the welded blind flange and draining of the Fuel Transfer Tube accomplishes the following:
The possibility of draining the Fuel Storage Pool and Fuel Transfer Pool through the Fuel Transfer Tube into the Sphere is eliminated.
The Fuel Transfer Tube has been drained to a level that precludes the potential for future failure due to freezing.
With the above Fuel Transfer Tube modification, the Sphere Fuel Handling System does not require heating during cold weather.
The Fuel Transfer Pool and Fuel Transfer Tube are periodically inspected under the Unit 1 Structural Integrity Monitoring Program. The inspection verifies that leakage past the blind flange is not occurring.
3.1.7 Water Level: Fuel Storage Pool and Fuel Transfer Pool The Fuel Storage Pool and Fuel Transfer Pool contain water utilized for cooling and shielding spent nuclear fuel. The water level in the Fuel Storage Pool is required to be maintained at or above the 512'-10" elevation (18' from the bottom of the pool). A penetration installed in the Upper Fuel Pool Gate, at approximately the 518'-10" elevation, allows the water level to equalize between the Fuel Storage Pool and Fuel Transfer Pool for normal makeup and Fuel Pool Demineralized System operation. The normal water level in the pools is maintained at approximately the 520'-3" elevation. The top of active fuel in the Fuel Storage Pool is at soproximately the.505' elevation. The top of active fuel in the Fuel Transfer Pool is at approxima.ely the 490' elevation. Refer to Fuel Handling System diagram (Figure 3.1) Icr fuel and water level elevations. Under the General Station Emergency Plan, an Emergemy Action Level (EAL) is established i
with Unit 1 Fuel Storage Pool water level less than 18'.
3-7 l
I
lIj]
!i!
4I{jI{il l
!lii
)
L W
B E
4 R
L 1
'0 XW R
L0 A
E*
E -
OH S
T3 U *5 RC A
F 0
~
PA W-F D
7 OE 5
'4 P
v 9
A &
L4 t
A5 PV 4
t M
OC ll Rt TA*
l AP L
O=
~
I E
E BOT Nl FU
- T OOmM
- E E "0 t
TP c
V O
D-TA P
C '0 N
A 3
9 E
9 C
F4
- 9 4
A O
LR L
7 7
TO
- E 4
4 LT rp FS l
t T
E t
G 4
R L
D O
L O
I U
P 3
B T
l, R
E 2
E E
h W
G F
S A
S A
[
l LN B
R O
EA UR L
T W
1 S F1 E
U TL F
4 I E l
N U UF l
l
~
L M*3 EN 4N R
& *8 2
'n F *3 4
O P
m b
Ol G0 TE
- 3 J9 e
eL4 t
- 1
[L s
2 l
y 5
CE 1 S R
3 g R
E j
n O
8 ei O
rl R
gn q
ud 3
a R
iFI IE R
I R
1 A
ic C
u T
E F
MSAB L
EU F
L 6
E 6
P E
N
- 9 7
N TU 2
1 E
5 S
v2 A
L R
ta/
F E
R 6
L E
E L
1 4
5 E
v F
FS
- 5 R
7 4
N 4
0 R
M O
4s*
A 5
0 O
5A6 M
R 3
R 1
T T
l F
L
.P0
- 3 D
fE O5 F
E L
T 01 D
E L
Ll5 t
R MBE L
U 0
E F
h 0
S l
W E
R
]T ti EE5
/
/
u E
my T
B N
U O.
T
/
R E
P hy y
x FS E
nNA 2/
R nT 1
tv1 t1 1 A -
- 0 45v *5 0
.r5
'2 Oi 0
A 5
E l
McE IR l
E i
E I
NW R
IS O
LT
,. _ _ _ _ _ -. ~. _ _ _. _ _ _ _. - - _ _ _ _ _. _ -.
--.-..q e
e tn Q
2 wwwwwwwwwwwwwwwwww
%%%%%%%%C%%%%%%%%%0 e
8 g;
rmtrmo o o o in n o n irrrmrno n., o n n.,, n i 8
i i i i, i, i n, i i i i i i n i, i. i i i n i i i i i i. u i t i i i
,1i i i i i i i i n gs
..., i > 1rrrrrrr
,Tr Tn n. i i r 1rrrrrrrri
,r 1
r hhh h
M Mh
:=
I g*s r
=
=
=
g 4W M O:=h OfM
=d+ik
=k
++#M i
3 #=M M+W++
=
=
= = ===ir +++>+h++'
=
=
=
2 E
s+,+tve+, ++ = =y iv= =v>+=++
==
=
=
.=
d
~
M
~
[
l N*
m,,,,o
,m,mo,,n,m
,o
,a
,o
,,,,,o y
i d$
h
-5
/ e_
)
g8 e
Ee
.Wb:
a ai 9
3us a
a m
==
4 4
c
%)E Ei
=
m m
o C
d r,c
/
c 2
~
T
/
3
=
4 lf N'
l-
~
E
.T
$ d sc I
t E
., 0 EE
\\
l l
l l
DSAR 3.1.7.1.
Water LevelIndication Fuel Storage Pool and Fuel Transfer Pool The Unit 1 Fuel Storage Pool water level is electronically monitored. The instrumentation provides a common annunciator alarm in the Control Room for low water level, high water levels and high temperature. Operating Procedures establish actions to be taken in response to each annunciator alarm.
The high water temperature set point is established to allow for corrective actions to be initiated prior to damaging the Fuel Pool Demineralized System resins.
The low water level set point is established to allow for corrective actions to be initiated i
prior to reaching the Fuel Storage Pool Technical Specification water level of 18' above the top of active fuel (elevation 512'-10").
The high water level set point is established to allow for corrective actions to be initiated prior to overflowing the Fuel Storage Pool curb. The high level alarm set point is above the Fuel Storage Pool overflow line elevation. A high level alarm indicates that the l
overflow line is not functioning properly.
Operating parameters including water level for the Fuel Storage Pool and Fuel Transfer Pool are verified during operator rounds. This is the primary method of monitoring water level.
Area radiation monitors in the Fuel Building would also alarm locally and in the Control Room if the Fuel Storage Pool water level were to significantly decrease.
To identify potential Fuel Storage Pool and Fuel Transfer Pool water leaks,1) water additions to the Fuel Storage Pool are monitored and 2) surrounding ground water tritium levels are monitored.
Routine surveillance ensure operability of the Fuel Pool Level Instrumentation and Fuel Building Area Radiation Monitors.
3.1.7.2.
Emergency Water Makeup Fuel Storage Pool and Fuel Transfer Pool The Dresden Station Fire Protection Water Supply System provides the source of emergency large volume makeup water to the Fuel Storage Pool or Fuel Transfer Pool.
The primary source of makeup water is fire water hose station F-37 in the Fuel Building.
Fire hydrants or other hose stations can also be utilized for makeup on an as needed basis.
3-10
DSAR The Dresden Administrative Technical Requirements and associated surveillance procedures ensure the availability of the Fire Protection Water Supply System for Fuel Storage Pool or Fuel Transfer Pool emergency water makeup.
Emergency Fuel Storage Pool or Fuel Transfer Pool water additions are controlled j
through Operating Procedures.
3.1.8 Water Chemistry Fuel Storage Pool and Fuel Transfer Pool The Fuel Pool Demineralized System is utilized to maintain water chemistry. Corrosion Coupons installed in the Fuel Storage Pool provide a means for monitoring corrosion rates.
3.1.8.1.
Fuel Pool Demineralized System To prevent the growth of micro-organisms and mitigate corrosion of metallic pool structures, quality limits for Fuel Storage Pool water chemistry have been established.
The Fuel Pool Demineralized System is designed to maintain the following Technical Specification water quality limits:
Cl 5.5 ppm.
0 Conductivity 510.0 micrombos per cm at 25 C.
pH: 5.3 to 8.6.
I The Fuel Pool Demineralized System consists of a submersible pump, which takes suction from the Fuel Storage Pool Water is circulated from the Fuel Storage Pool through a valve skid, through up to two demineralized vessels, back through the valve skid, and into the Fuel Storage Pool and/or Fuel Transfer Pool through separate spargers in each pool. The penetration in the Upper Fuel Pool Gate equalizes the water level in the pools regardless of valve configuration during pump operation.
The filter media and ion exchange resins selected for use in the Fuel Pool Demineralized System vary depending on process conditions. The Fuel Storage Pool temperature set point is established to allow for operator actions to be initiated prior to damaging ion exchange resins.
l The Fuel Pool Demineralized System is designed for continuous operation although continuous operation is not required to maintain Fuel Pool water chemistry quality limits.
The system is primarily composed of stainless steel components. The system is designed for flow rates up to 100 gallons per minute and pump operating pressures of up to 150 3-11
DSAR psig. Power for the Fuel Pool Demineralized System is supplied from the 480V Electrical Distribution System.
The Fuel Pool Demineralized System is designed to preclude the possibility of Fuel Storage Pool or Fuel Transfer Pool drain down by siphoning.
Proper operation of the Fuel Pool Demineralized System is verifiea during operator rounds.
Unit 1 Fuel Storage Pool water chemistry is sampled and analyzed periodically.
3.1.8.2.
Corrosion Coupons: Fuel Storage Pool In 1992,27 sets of corrosion coupons were installed in the Fuel Storage Pool to provide a means for measuring corrosion rates. Each coupon set consists of 20 sample coupons, five AISI 1018 carbon steel, five hot dip galvanized, and ten AISI 1018 carbon steel coupons mounted back-to-back (five samples total). A sample set is removed from the l
pool and the amount of corrosion is measured periodically. Corrosion measurements are used as an input to determine corrosion effects on the Fuel Storage Pool Channel Storage Racks. Enough sample sets remain installed to last through the year 2017.
i 3.1.9 Fuel Storage Components The Unit 1 Fuel Storage Pool and Fuel Transfer Pool are being maintained for the safe storage ofirradiated fuel until other onsite or offsite alternatives are available.
Components including Fuel Racks Fuel Rack Supports, Channel Storage Racks and Fuel Rack Baskets are utilized to maintain the safe storage ofirradiated fuel in an underwater l
suberitical configuration.
l l
l l
3.1.9.1.
Channel Storage Racks 1~
The Dresden Unit 1 Fuel Pool is equipped with forty-two Channel Storage Racks. Each rack can be utilized for the underwater suberitical storage of up to sixteen Fuel Assemblies, Rod Baskets, or Channels.
The Channel Storage Racks are a welded fabrication of steel pipes, plates and angles.
After fabrication, the Fuel Racks were hot-dipped galvanized. Cinch anchors and screws secure the Channel Storage Racks to the concrete floor of the Fuel Storage Pool (494'-10" elevation). Stored components rest at a slight incline vertically within the racks. Steel retainers are attached to the top portion of the racks to prevent stored components from tipping.
3-12
DSAR The Channel Storage Rack at location R, Q - 25,32 has been modified. As a result, some of the fuel storage locations within this rack are no longer available for use.
Channel Storage Racks were not designed to current industry seismic requirements. An analysis has been performed which assumes collapse of the racks. The analysis concludes that the physical constraints that exist in the Fuel Storage Pool and the structural integrity of portions of the racks will prevent the fuel assemblies from forming a critical geometry.
The Fuel Storage Pool water chemistry is maintained within Technical Specification limits, in part, to mitigate corrosion of the Channel Storage Racks.
Surveillance procedures are utilized to measure corrosion rates and verify the structural integrity of the Channel Storage Racks.
3.1.9.2.
Fuel Racks Fuel Racks, previously utilized for transferring fuel assemblies in Fuel Transfer Baskets, are now utilized for storing spent fuel. Each Fuel Rack holds up to four fuel assemblies.
Fuel Racks with fuel assemblies will remain suberitical when stored in either Fuel Rack Supports located in the Fuel Storage Pool or Fuel Rack Baskets located in the Fuel Transfer Pool.
Each Fuel Rack consists of a welded fabrication of steel plates, bars and channel. After fabrication, the Fuel Racks were hot-dipped galvanized. Each Feel Rack has nylon rub strips attached to the keeper plate. Fuel assemblies rest vertically within the racks.
Eight Fuel Racks are currently being utilized to store fuel assemblies in two Fuel Rack Baskets located in the Fuel Transfer Pool. Originally, these Fuel Racks contained two elongated holes near the top of each rack to accommodate the Fuel Rack Grapple. These Fuel Racks have been subsequently modified to remove the elongated holes which prevents them from being moved independent of the Fuel Rack Basket.
Surveillance procedures periodically verify the structural integrity of the Fuel Racks and Fuel Rack Baskets, which are in use.
3.1.9.3.
Fuel Rack Supports Three Fuel Rack Supports are mounted on the north wall and floor (494'-10" elevation) of the Fuel Storage Pool. Three supports are provided for the underwater storage of fuel in Fuel Racks. The design and location of the supports permit the insertion and removal of Fuel Racks while remaining underwater. Each support can accommodate one Fuel Rack.
3-13
DSAR Each Fuel Rack Support consists of steel channels, angles, and plates welded to form a "U" shaped frame with mounting brackets. After fabrication, the Fuel Racks Supports i
were hot-dipped galvanized. Cinch anchors and screws are utilized to secure the Fuel Rack Supports to the concrete Fuel Storage Pool structure. The Fuel Rack nests inside the vertical channels and rests on the horizontal channel at the floor.
3.1.9.4.
Fuel Rack Baskets Three Fuel Rack Baskets were originally provided for transporting Fuel Racks and components between the Fuel Building and the Sphere. The Fuel Rack Baskets are designed for the underwater suberitical storage of up to four Fuel Racks with fuel.
l The Fuel Rack Baskets can be stored within structural supports on the floor of the Fuel Transfer Pool (479'-3" elevation). An analysis shows that a Fuel Rack Basket with 16 fuel assemblies can be safely stored along the north wall of the Fuel Storage Pool. For this analysis, the Channel Storage Racks in the Fuel Storage Pool were assumed to be completely loaded with fuel assemblies (672 fuel assemblies).
l A Fuel Rack Basket Carrier can hold one Fuel Rack Basket with Fuel Racks and fuel.
The Fuel Rack Basket Carrier travels on rails within the Fuel Transfer Tunnel.
Each basket is a welded construction of steel plates, rods, angles and channels. After fabrication, the Fuel Rack Baskets were hot-dipped galvanized. Slots in the side plates provide the means for guiding and supporting the Fuel Racks. A hole across the bottom plate allows water to flow through the basket to eliminate floatation. Each Fuel Rack Basket is fitted with an eye hook bail for lifting purposes.
3.1.10 Ventilation System: Fuel Building The Unit I fuel Building Ventilation System is designed and installed to reduce the potential for unmonitored release of radioactive contamination. The Unit 1 Fuel Building is not designed or constructed to maintain a negative pressure throughout. However, the ventilation system is configured with an exhaust flow rate that exceeds the supply fan flow rate.
Controls and indication for the ventilation system are mounted on a local panel within the Fuel Building.
During fuel handling, procedures require: 1) Fuel Building doors to be closed (other than for normal personnel egress and ingress),2) Fuel Building ventilation system is to be operable (with a release path to the chimney), and 3) Fuel Building area radiation monitors are to be operable. These actions will facilitate prompt notification and provide a monitored elevated release path if an accident were to occur.
3-14
Fuel Building ilVAC fans are powered from the 480V AC Electrical Distribution System.
3.1.10.1. Supply Fan: Fuel Building 1
Outside makeup air for the Fuel Building is provided through the Supply Fan, K-129.
The Supply Fan takes suction from an opening in the south wall of the Fuel Building. A motor operated damper opens when the system is operated and closes when the system is shut down.
The Supply Fan is powered from a variable speed motor. The Supply Fan flow rate is approximately 1,500 cubic feet per minute lower than the K-160 Exhaust Fan flow rate.
This flow rate differential is established through ventilation system controls which monitor both the Exhaust Fan and Supply Fan flow rates and adjust the Supply Fan motor speed accordingly. The Supply Fan can not be operated independent of the K-160 Exhaust Fan.
A steam heating coil is in. stalled within the supply ductwork. The steam heating coil is utilized to warm outside air entering the building during cold weather conditions. A temperature sensor located downstream of the heating coil is interlocked with the Supply Fan. The interlock will prevent operation of the Supply Fan below the low temperature set point to prevent the heating coil from freezing.
3.1.10.2. Exhaust Fans: cuel Building Two Exhaust Fans (K-160 and K-131) are provided for the Fuel Building. The Exhaust Fans can be operated independently or in combination.
The K-160 Exhaust Fan provides primary exhaust flow from the Fuel Building. Suction for the Exhaust Fan is provided through a penetration in the ceiling of the Fuel Building.
A motor operated damper opens when the system is operated and closes when the system I
is shut down. The Exhaust Fan is powered by a two-speed electric motor. The Exhaust Fan can produce flow at approximately 4,000 cubic feet per minute (CFM) or 8,000 CFM. The lower flow rate is typically utilized during the winter and the higher flowrate during the summer.
The K-129 Supply Fan is interlocked with the K-160 Exhaust Fan. The interlock prevents the Supply Fan from operating independent of the Exhaust Fan.
i The K-131 Exhaust Fan provides exhaust flow from the Fuel Storage Pool area. The Exhaust Fan is located on a mezzanine within the Unit 1 Fuel Building. Suction for the Exhaust Fan is provided through ductwork, which extends to an inlet plenum located just above the Fuel Storage Pool water level. A motor operated damper opens when the system is operated and closes when the system is shut down. The Exhaust Fan is 3-15
l DSAR powered by an electric motor. The Exhaust Fan can produce approximately 2,000 CFM l
ofairflow.
l l
The K-160 and K-131 Exhaust Fans discharge through a common HEPA filter into the Unit 1 Gaseous Monitoring System ductwork which discharges through the Unit 1 Chimney. Interlocks allow the Fuel Building Exhaust Fans to operate only when a Gaseous Monitoring System Exhaust Fan is operating. These Interlocks ensure that exhaust flows from the Fuel Building are discharged through the Unit 1 Chimney.
3.1.11 Radiation Monitors: Fuel Building The Fuel Building is equipped with a Separate Particulate, lodine and Nobel Gas (SPING) monitor and two Area Radiation Monitors (ARMS).
3.1.11.1. Kr-85 Monitor: Fuel Building The newest discharged spent fuel assemblies were placed in the Fuel Storage Pool and Fuel Transfer Pool following shutdown of the Reactor in October of 1978. As a result of normal radioactive decay, Krypton-85 (Kr-85) is the only radioactive gas of significance remaining within the fuel. A SPING has been installed in the Fuel Building to provide early indications of a Kr-85 release.
The SPING continuously monitors the air within the Fuel Building. The SPING is equipped to provide local and Control Room alarms (Control Room 923-7 Panel).
Radiation levels in excess of the system set point initiates the alarms. A local and Control Room trouble alarm is also provided to notify personnel that the system is not operating properly.
Operating Procedures establish actions to be taken in response to each annunciator alarm.
The SPING is powered from the 120V AC distribution system.
Implementation of Dresden Administrative Technical Requirements and associated surveillance procedures ensure that the SPING is maintained operable.
3.1.11.2. Area Radiation Monitors: Fuel Building The following Area Radiation Monitors (ARMS) are located within the Unit 1 Fuel Building:
Fuel Building ARM (component identification number: 1-1840-102) is mounted on the north wall of the Fuel Building above the Fuel Storage Pool.
3-16
DSAR Fuel Building Trackway ARM (component identification number: 1-1840-103)is l
mounted on the Fuel Building west wall.
l l
The ARMS continuously monitor radiation levels within the Fuel Building. The ARMS 6
have an operating range of 1 mR/hr to 10 mR/hr. This operating range encompasses potential radiological accidents within the building. Each ARM contains a sealed source to maintain radiation level indication above the down scale alarm set point.
Continuous Control Room indication and alarms for the ARMS are provided at the Control Room 901-2 panel. Local alarms are provided at ARM locations in the Fuel Building.
The Fuel Building is utilized to store special nuclear material in the form of spent fuel The set point and location of the Fuel Building Trackway ARM (1-1840-103) provides monitoring for accidental criticality for this special nuclear material storage area.
The Fuel Building ARM (1-1840-102) is positioned in close proximity to the Fuel Storage Pool and Fuel Transfer Pool This ARM would provide an additional indication of a significant Fuel Storage Pool or Fuel Transfer Pool level decrease.
Additionally, the ARMS would provide indications of other activities which could result in higher than normal radiation levels, such as inadvertently removing a fuel assembly or irradiated hardware from the storage pools.
The ARMS are powered from the Control Room 901-2 Panel.
The Fuel Building ARM (1-1840-102) is interlocked to interrupt power to the Fuel Building Crane on high radiation levels.
During fuel handling, procedures require: 1) r'uel Building doors to be closed (other than for normal personnel egress and ingress),2) Fuel Building ventilation system is to be operable (with a release path to the chimney), and 3) Fuel Building area radiation monitors are to be operable. These actions will facilitate prompt notification and provide a monitored elevated release path if an accident were to occur.
Under the Generating Station Emergency Plan the following Emergency Action Level is established:
Unit 1 Fuel Building Area Radiation Monitor greater than or equal to 50 mR/hr.
l (except during controlled evolutions) and Unit 1 Gaseous Monitoring Vent System is not operating.
Surveillance procedures are performed to provide reasonable assurance that the Fuel Building ARMS remain operable. Functional testing of the ARMS can be performed remotely from the Control Room.
3-17 l
DSAR 3.1.12 Fuel Handling Equipment The Fuel Building Crane and Fuel Grapple Crane allow for the handling of fuel and associated fuel casks within the Fuel Building.
3.1.12.1. Crane: Fuel Building The Fuel Building Crane is utilized for moving equipment and components, including heavy loads and shipping casks, within the Fuel Building.
The Crane Bridge spans the Fuel Building in the cast west direction. The crane rails which span the Fuel Building in the north south direction support the Bridge. The crane rails are supported by the Fuel Building structural steel.
l The Fuel Building Crane consists of:
Operating Cab.
Trolley.
Main Iloist.
Auxiliary Hoist.
Bridge.
The Operating Cab mounted below the Trolley contains controls and indication for the operation of the Fuel Building Crane.
The Trolley 3:arries the Operating Cab and all hoisting equipment. The Trolley is powered from a variable speed electric motor. The Trolley has a maximum speed of about 50 feet per minute. The Trolley Brake is released upon application of power to the Trolley Motor. The Trolley carries a set of collectors on each side for picking up power and controlling current from conductors along the bridge beams.
The Main Hoist is powered from a variable speed electric motor. The maximum lifting i
and loviering capacity of the hoist and associated hook is about 75 tons at 5.16 feet per minute. The Main Hoist Brake is released upon application of power to the Main Hoist Motor.
The Auxiliary Hoist is powered from a variable speed electric motor. The maximum lifling and lowering capacity of the hoist and associated hook is about 10 tons at 25.7 feet per minute. The Auxiliary Hoist Brake is released upon application of power to the l
Auxiliary Hoist Motor.
The Bridge is powered from a variable speed electric motor. The Bridge has a maximum
)
speed of about P 2 feet per minute. The Bridge is equipped with a brake. The Bridge carries high bay lighting units for illuminating the work area.
1 3-18 i
j
DSAR The Fuel Building Crane is powered from the 480V AC Electrical Distribution System.
Electrical components within the Fuel Building Crane transform the 480 V AC power into the appropriate AC or DC power voltage required by individual components.
The Fuel Building ARM (1-1840-102) is interlocked to interrupt power to the Fuel Building Crane on high radiation levels.
Operation of the Fuel Building Crane is governed by procedures that describe pre-operation inspection requirements, startup, operation and shutdown.
Administrative procedures preclude using the Fuel Building Cranes below a predetermined temperature limit. The administrative temperature limit is above the nil ductility transition temperature for the structural steel.
l Administrative controls have been established to control the movement of heavy loads by the Fuel Building Crane. The administrative controls are established to preclude damaging spent fuel assemblies stored in the Fuel Storage Pool / Fuel Transfer Pool.
Surveillance are performed on the Fuel Building Crane at regular intervals to ensure that it is maintained in an operable condition.
3.1.12.2. Fuel Grapple Crane 1
The Fuel Grapple Crane is a steel structure that spans the entire fuel building in the east-west direction.
The Unit 1 Fuel Grapple Crane is designed and built for moving the Unit I fuel bundles and charmels within and between the Unit 1 Fuel Storage Pool and the Fuel Transfer Pool. The crane is also used as a work platform for activities over the pools.
The Fuel Grapple Crane consists of positioning and hoisting equipment. The crane has an overhead bridge that travels in a north-south direction, and a single trolley that travels l
across the bridge in an east-west direction. The hoist is mounted to the crane trolley. The fuel hoist capacity is 1000 pounds, however the Unit 1 Grapple Tools are rated at a lower capacity. The lifting system is designed to move Unit I spent fuel assemblies with or without channels. Though designed and built for 1 ton operation hoist lifts are restricted to 500 pounds to achieve a margin of safety for fuel operations.
A stand-up type operator cab is suspended approximately 15 feet below the trolley frame.
All operator controls for positioning and hoisting are located in the grator cab. The refurbished crane includes a solid state load weighing system and new controls.
Interlocks and indications were added to provide safe and reliable operations.
The source of power to the grapple crane is the 480V AC Electrical Distribution System.
3-19
DSAR Approved operation and maintenance procedures are used to maintain and operate the Fuel Grapple Crane.
Administrative procedures preclude using the Fuel Building Grapple Crane below a predetermined temperature limit. The administrative temperature limit is above the nil ductility transition temperature for the structural steel.
3.1.13 Fuel Preparation Machine The Fuel Preparation Machine is utilized to install or remove channels from spent fuel assemblies. These operations are performed under water in the Fuel Transfer Pool. The Fuel Preparation Machine is als, used to physically secure fuel assemblies during visual examination or cleaning.
The Fuel Preparation Machine is permanently mounted on the south wall of the Fuel Transfer Pool. Control levers and a motor are installed above the Fuel Transfer Pool water level. The remainder of the machine is below the water level.
The Fuel Preparation Machine contains a grapple used for moving fuel assemblies. ' A motor functions to lower the grapple assembly through a rack and pinion.
The Fuel Preparation Machine is powered from the 480V AC Electrical Distribution System.
The Fuel Preparation Machine is not normally in service or utilized. Functional testing and maintenance will be performed on the Fuel Preparation Machine ju ior to future use.
l l
l 3-20
DSAR 3.2.
Structures, Systems and Components (SSCs)
Important to Unit 1,2 or 3 Operations 3.2.1 Structures 3.2.1.1.
Control Rocm The west end of the former Unit 1 Control Room has been incorporated into the Station -
Control Room primarily utilized for operation of Units 2/3. The east end of the former Unit 1 Control Room is now part of the administrative support area for Units 1,2 and 3.
Unit 1 instrumentation and controls that are still needed have been relocated to the Station Control Room. Previous Unit 1 Control Room support areas are now utilized to support operatious for Units 1,2 and 3. Operation and design of the Control Room is described in the Dresden Unit 2/3 SAR and associated documents.
3.2.1.2.
Chemical Cleaning Building Located within the Chemical Cleaning Building, the Radwaste Receiving Tanks are contained within a Category I seismic structure. The tanks are contained within a concrete structure designed to contain contaminated liquids which may spill from the tanks during an earthquake. Because the tanks are located within the seismic portion of the facility, they are not considered when calculating the Technical Specification above grade liquid radwaste storage limit (90 curies).
i 3.2.1.3.
Interim Radwaste Storage Facility j
The Interim Radwaste Storage Facility (IRSF) is utilized to handle and store Station low level waste. The operation of the IRSF is described in the Dresden Units 2/3 SAR and associated documents. The IRSF is lccated adjacent to the Chemical Cleaning Facility.
Although physically separated, the IRSF and Chemical Cleaning Facilities share structural walls and some operating systems.
Supply ventilation for the IRSF is provided from the Chemical Cleaning Facility l
Ventilation System. Exhaust ventilation from the IRSF discharges into the Chemical l
Cleaning Building Chimney which is monitored for radioactive release.
l Controls, video display and instrumentation for the IRSF Crane are located within the Chemical Cleaning Facility.
l 3-21
DSAR Electrical power for the IRSF is supplied from the Chemical Cleaning Facility Electrical Distribution System.
3.2.2 Systems 3.2.2.1.
Emergency Lighting Because Reactor operations are no longer conducted for Dresden Unit 1, Emergency Lighting for Safe Shutdown is no longer required.
However, the Unit i 120V AC Power Distribution System continues to provide charging power for nine Unit 2/3 Safe Shutdown emergency lights. Operation and surveillance of these lighting units are described in the Unit 2/3 SAR and associated documents.
3.2.2.2.
Standby Lighting The Unit 2/3 SAR describes standby lighting utilized for operation of Unit 2/3. On the loss of normal power some of the standby lighting units located in the Unit 2/3 Control Room are powered from the Unit 1 125V DC Electrical Distribution System.
Operation and surveillance of these lighting units are described in the Unit 2/3 SAR and associated documents.
3.2.2.3.
Control Room Monitoring Dresden Unit I no longer requires continuous Control Room habitability to assure the safe storage ofirradiated fuel. However certain alanns and indications of facility conditions remain functional in the Unit 2/3 Control Room. A description of the habitability systems associated with the Unit 2 and 3 Control Room is provided in the Dresden Unit 2/3 SAR and associated documents.
Located on Control Room Panels 901-2,923-7, and 901-B1 are controls, recorders and annunciators in operation for some Unit I system components.
Station procedures describe actions to be taken in response to Control Room annunciator alarms.
3-22
DSAR 3.2.2.3.1.
Control Room Panel: Unit 1 Identification number: 901-2 Panel 901-2 is located in the Unit 2/3 Control Room and contains the controls and annunciators for the systems and components remaining in service on Unit I that were originally located in the Unit 1 Main Control Room. Panel 901-2 has control switches for the Unit i Diesel Fire Pump.
Recorders on the 901-2 Panel include the Contaminated Demineralized Waste Storage Tank and Clean Demineralized Water Storage Tank. Meteorological Tower information and Unit 1 Area Radiation Monitor information is recorded on Panel 901-2.
i Alarm annunciators on Panel 901-2 include liigh and Low Level alarms for the Clean and Contaminated Demineralized Water Storage Tanks, Unit 1 Fuel Building Area Radiation Monitors and Unit 1 Fuel Pool Level and Temperature.
1 3.2.2.3.2.
Unit 1 Panel Identification number: 901-B1 Panel 901-B1 is located in the Unit 2/3 Control Room and provides remote metering and control of Transformer 12, Transformer 13, Bus 11, Bus 12 Bus 14, Bus 15, Bus 16 and Bus 17.
Alarm annunciators on Panel 901-B1 include 125V DC System Trouble, Transformer 12, 13,14,15,16 or 17 Trip Indication and 138KV Bus Differential Relay Trouble.
3.2.2.3.3.
SPING Monitor Panel Annunciators for the Unit 1 Chimney Effluent Monitoring System and Fuel Building SPING alarm on Panel 923-7.
3.2.2.4.
4KV AC Electrical Distribution System The Electrical Distribution System for Dresden Unit 1 is shown in diagram format on Figure 3.3.
3-23
J I
]
lll1l i
A 4
C 4
P R
11 1
I>
'l R
S A
T B
U d
B
}
S 3
k D
1 V
l C
k P
T.
I>
R
'I 4
6 y
1 t
R 4
4 i
I>
1 43 b
1 C
C 4
4 S
f' U
C C
B P
P 71 V
I>
0 S
8 4
U 4
B CI' I)l P
I>
}l 0
4 C
C M
I)l 1
6 S
I>
U B
1 5
5 C
1 P
S
)
U 8
B 5
V C
5 0
8 C
C 4
M P
I>
II
)
m l
}
e t
2 I>;
A s
1
_A y
5 A
S S
C
.C S
C C
n M
P o
I>
l P
- 3. i t
3 u E
eb ri I
4 T
r 2
S ut A
U s
6 i
C j
B 3
gi
)
FD P
l, l
l a
1 c
l 2
A 6
i A
r 6
C t
I,,
C P
C ce M
6 E
16 l
C S
P B
I>
l U
B V
6 0
'l C
8 4
C M
I,,
C 5
2 1
7 1
R C
S T
C U
2 B
7 M
1 R
k S
I>
'l 1
V U
T 4
B 7
V C
7 0
P V
1 8
k 4
1,
'l R
8 T.
13 f
B
)
7 CP l>
I A
)
7 C
P l>
II 2 -
A
)
);
C 7
F
- 1 L
4 DSAR The Unit 14KV Power Distribution System is comprised of Transformer 12, Transformer 13,4KV Bus 11 and 4KV Bus 12. The purpose of the Unit 14KV Power Distribution System is to distribute 4KV power to the Unit 1480V Secondary Unit Substations 14,15,16,17, and to the Station Blackout Facility. There are no other loads connected to the Unit 14KV Power Distribution System.
I 3.2.2.4.1.
Transformer 12 The normal source of 4KV power to Unit 1 is Transformer 12. Transformer 12 ratings are 138KV primary voltage,4.16KV secondary voltage, and 10MVA power output. The primary windings of Transformer 12 are connected to the 138KV Yard via overhead lines. The 138KV Yard is described in the Dresden Unit 2/3 SAR and associated documents. The secondary windings of Transformer 12 are connected to Bus 12 through a 2,000 amp bus duct and to Bus 11 through a 1.200 amp bus duct. Transformer 12 is
{
filled with mineral oil to provide electrical insulation and cooling. Local metering of Transformer 12 includes gauges indicating oil level, liquid temperature and gas pressure.
Protective functions for Transformer 12 include trip on overcurrent, differential current, 1
ground fault and undervoltage. Operator control switches to remotely open and close l
circuit breakers on the primary and secondary connections to Transformer 12 are mounted on control panel 901-B1 in the Unit 2/3 Control Room. Visual inspections and l
oil samples are periodically performed on Transformer 12.
I 3.2.2.4.2.
Transforrner 13 l
The backup source of 4KV power to Unit 1 is Transformer 13. Transformer 13 ratings are 34.4KV primary voltage,4.16KV secondary voltage, and 2.5MVA power output.
The primary windings of Transformer 13 are connected to the 34.4KV Yard via overhead lines. The 34.4KV Yard is description in the Dresden Unit 2/3 SAR and associated I
documents. The secondary windings of Transformer 13 are connected to Bus 11 through cables. Transformer 13 is filled with mineral oil to provide electrical insulation and cooling. Protective functions for Transformer 13 include trip on overcurrent, differential current, ground fault and undervoltage. Operator control switches to remotely open and t
close circuit breakers on the primary and secondary connections to Transformer 13 are l
mounted on control panel 901-B1 in the Unit 2 / 3 Control Room. Visual inspections and
)
oil samples are periodically performed on Transformer 13.
l l
\\
q
)
3.2.2.4.3.
Bus 11 j
{
The normal source of 4KV power for Bus 11 is Transformer 12. The backup source of 4KV power is Transformer 13. Bus 11 distributes power to the Station Blackout Facility, and 480V secondary unit substations 14 and 16. Metering of Bus 11 includes volts, amps and watt-hours and are locally mounted at the 4KV switchgear cubicles. Remote 3-25 i
DSAR metering and 4KV switchgear control for Bus 11 is from Panel 901-B1 in the Unit 2 / 3 Control Room. Protective functions for Bus 11 include overcurrent detection and ground fault detection. One alarm associated with Bus 11 is low bus voltage. This alarm is displayed on an annunciator panel on control panel 901-Bl.
Periodic visual inspections are performed on Bus 11.
1 3.2.2.4.4.
Bus 12 The normal source of 4KV power for Bus 12 is Transformer 12. There is no backup source of 4KV power. Bus 12 distributes power to 480V secondary unit substations 15 and 17. Metering of Bus 12 includes volts, amps and watt-hours and is locally mounted at the 4KV switchgear cubicles. Remote metering and 4KV switchgear control for Bus 12 is from Panel 901-B1 in the Unit 2 / 3 Control Room. Protective functions for Bus 12 include trip on overcurrent and ground fault. Periodic visual inspections are performed on Bus 12.
3.2.2.5.
480V AC Electrical Distribution System The Unit 1480V power distribution system is comprised of Primary Unit Substations 118 and 119, and Secondary Unit Substations 14,15,16, and 17. The primary unit substations feed power to Buses 18 and 19 in the Chemical Cleaning Facility. These buses distribute 480V power to motor control centers and IIVAC heating coils. A bus tie circuit breaker can be closed, connecting Buses 18 to 19, to allow maintenance on either primary unit substation without interrupting power to the buses. The secondary unit substations distribute power to 480V motor control centers and 480V panel boards located throughout the Unit I facility. Bus tie circuit breakers can be closed, connecting Buses 14 to 15 and 16 to 17, to allow maintenance on either secondary unit substation transformer without interrupting power to the buses.
3.2.2.5.1.
Transformers 118 and 119 Primary Unit Substation Transformers 118 and 119 have ratings of 34.4KV primary voltage,480V secondary voltage, and 1500 KVA power output. These transformers are filled with silicone oil to provide electrical insulation and cooling. Transformers 118 and i19 are connected to the 34.4KV overhead lines. The secondary windmgs are connected to Buses 18 and 19 through 3,000 amp bus ducts. Local metering of Transformers 118 and 119 includes gauges indicating oil level, liquid temperature and gas pressure. There is no remote metering or control of Transformers 118 and 119. Periodic visual inspections are performed on Transformers 118 and 119.
3-26
DSAR 3.2.2.5.2.
480V Bus 18 The normal source of 480V power for Bus 18 is Transformer 118. The backup source of 480V power is Bus 19 through a bus tie circuit breaker. Bus 18 distributes power to 480V motor control centers and electric heating coils for the Chemical Cleaning Facility HVAC system. Metering of Bus 18 includes volts and amps and is located locally at the bus. Protective functions for Bus 18 include trip on overcurrent and ground fault. No alanns are associated with Bus 18. There are no remotely located operator controls for Bus 18. All switchgear breakers can be manually operated at the bus. Periodic visual inspections are performed on Bus 18.
3.2.2.5.3.
480V Bus 19 The normal source of 480V power for Bus 19 is Transformer 119. The backup source of 480V power is Bus 18 through a bus tie circuit breaker. Bus 19 dist-ibutes power to 480V motor control centers and electric heating coils for the Chemical Cleaning Facility HVAC system. Metering of Bus 19 includes volts and amps and is located locally at 'he bus. Protective functions for Bus 19 include trip on overcurrent and ground fault. No alarms are associated with Bus 19. There are no remotely located operator controls for Bus 19. All switchgear breakers can be manually operated at the bus. Periodic visual inspections are performed on Bus 19.
3.2.2.5.4.
Secondary Unit Substations 14,15,16,17.
Secondary Unit Substation Transformers 14,15,16 and 17 have ratings of 4KV primary voltage,480V secondary voltage, and 750 KVA power output. These transformers are liquid-filled to provide electrical insulation and cooling. Transformers 14 and 16 are connected to Bus 11. The secondary windings are connected to Buses 14 and 16 through copper bus bars. Transformers 15 and 17 are connected to Bus 12. The secondary windings are connected to Buses 15 and 17 through copper bus bars. Local metering of Transformers 14,15,16 and 17 includes gauges indicating liquid level, liquid temperature and gas pressure. There is no remote metering of Transformers 14,15,16 and 17. Alarms associated with Transformers 14,15,16 and 17 monitor the position of the 4KV switchgear breaker feeding the transfonner. When the switchgear breaker is open, an alarm is initiated indicating a transformer trip condition. These alarms are displayed on an annunciator panel on control panel 901-Bl. Periodic visual inspections are performed on Transformers 14,15,16 and 17.
i l
I l
3-27
l DSAR i
3.2.2.5.5.
Buses 14,15,16 and 17 l
The normal sources af 480V power for Buses 14,15,16 and 17 are Transformers 14.15, 16 and 17 respectively. Each bus can be cross-tied for a backup source of 480V power.
l Bus 14 can be cross-tied to Bus 15 and Bus 16 can be cross-tied to Bus 17. Buses 14,15, 16 and 17 distribute power to 480V motor control centers and 480V panel boards.
Metering of Buses 14,15,16 and 17 include volts and amps. These meters are located on Panel 901-B1 in the Unit 2 / 3 Control. Room and locally at the 480V switchgear cubicles.
Protective functions for Buses 14,15,16 and 17 are integral features of each switchgear breaker and include trip on overcurrent. Alarms associated with Buses 14,15,16 and 17 monitor the status of the switchgear breakers feeding motor control centers. When the switchgear breaker is open, an alarm labeled " Power Center Trip" is initiated. This alarm is displayed on an annunciator panel on control panel 901-Bl. Operator controls for Buses 14,15,16 and 17 are mounted on control panel 901-Bl. Switches are provided to open and close the 480V switchgear breakers. Periodic visual inspections are performed on Buses 14,15,16 and 17.
3.2.2.5.6.
480V motor control centers 1
The normal sources of 480V power for 480V motor control centers located in all areas of Unit 1 except the Chemical Cleaning Facility are Buses 14,15,16 and 17. The normal sources of 480V power for 480V motor control centers located in the Chemical Cleaning Facility are Buses 18 and 19. Several motor control centers can be cross-tied to another motor control center for a backup source of 480V power. 480V motor control centers distribute power to various equipment and distribution panels. Metering of 480V motor 1
l control centers in the Chemical Cleaning Facility include amps only. These meters are located on the 480V switchgear breaker cubicles.- There is no metering of all other 480V motor control centers. Protective functions for 480V motor control centers are integral features of each circuit breaker and include trip on overcurrent. There are no alarms i
associated with 480V motor control centers. There are no operator controls for 480V l
motor control centers in the control room. All motor control center breakers can be i
manually operated at the bus. Periodic visual inspections are performed on 480V motor control centers.
l L
l 3.2.2.5.7.
480V panel boards l
- The normal sources of 480V power for 480V panel boards are 480V motor control centers. 480V panel boards distribute power to various equipment. There is no metering C-of 480V panel boards. Protective functions for 480V panel boards are integral features of each circuit breaker and include trip on overcurrent. There are no alarms associated with 480V panel boards. There are no operator controls for 480V panel boards in the control l.
3-28 l
DSAR room. All panel board breakers can be manually operated at the bus. Periodic visual inspections are performed on 480V panel boards.
3.2.2.6.
120V AC Distribution System The Unit 1 120V AC Distribution System is comprised of transformers and distribution panels. The transformers are rated 480V - 208/120V, three phase, and range in power output from 3KVA to 112.5KVA. The power source for the transformers are 480V motor control centers. The distribution panels supply power to the Unit I facility for lights, receptacles, small motors, heat trace cables, and other miscellaneous equipment.
The Unit 1 120V AC Safety System Power Distribution System is retired. The normal sources of power for 120V distribution panels are distribution transformers,480V -
208/120V, powered by 480V motor control centers. 120V distribution panels distribute power to various equipment. There is no metering of 120V distribution panels.
Protective functions for 120V distribution panels are integral features of each circuit breaker and include trip on overcurrent. There are no alarms associated with 120V distribution panels. There are no operator controls for 120V distribution panels in the Unit 2/3 Control Room. All distribution panel breakers can be manually operated at the panel. Periodic visual inspections are performed on 120V distribution panels.
3.2.2.7.
125V DC Distribution System 4
l The Unit 1 125V DC Distribution System is comprised of two motor-generator sets, 125V DC batteries and distribution panels. The motor-generator sets provide normal J
power to 125V DC loads and charging current to the batteries. In the event of a loss of AC power, the batteries will supply power to the 125V DC distribution panels. The purpose of the 125V DC Distribution System is to supply reliable power to critical loads on Unit 2 including the 138KV Switchyard control power and trip power.
3.2.2.7.1.
125V DC Motor-Generator Sets The motor-generator sets are rated 480V input,125V DC output, and power output of 15KW. The power source for the motor-generator sets are 480V motor control centers.
One motor-generator set has the capacity to supply 100% of the demand for 125V DC l
power. The second motor-generator functions as a redundant backup for improved reliability. Normal operation has one motor-generator set running while the other is in standby mode. Metering of the motor-generator sets include an ammeter monitoring the output. Protective functions for the motor-generator sets are provided by the motor control center and 125V DC distribution panel circuit breakers and include trip on overcurrent. There are no alarms associated with the motor-generator sets. A ground detector relay is mounted locally and indicates presence of grounds in the system. There are no operator controls for the motor-generator sets in the control room. A locally mounted rheostat allows manual adjustment of the field excitation. Varying the field 3-29 I
L
DSAR excitation varies the voltage output of the generator. Periodic visual inspections are performed on the motor-generator sets.
3.2.2.7.2.
125V DC Batteries The 125V DC batteries are sized to provide power to critical loads in the event ofloss of l
AC power. Metering of the 125V DC batteries include an ammeter monitoring the l
output. Protective functions for the 125V DC batteries are provided by the distribution panel circuit breakers and include trip on overcurrent. An alarm associated with the 125V DC batteries monitors system voltage and trips on undervoltage. This alarm is displayed on an annunciator panel on control panel 901-B1 in the control room. There are no operator controls for the 125V DC batteries. Periodic visual inspections and discharge tests are performed on the 125V DC batteries.
3.2.2.7.3.
125V DC Distribution Panels There are four 125V DC distribution panels identified as buses. The normal supplies to Bus I and Bus 2 are the motor-generator sets. The backup supply is the battery system.
Bus 3 and Bus 4 are powered by Bus 1 and Bus 2 respectively. Metering of the 125V DC distribution panels include a voltmeter monitoring bus voltage. Protective functions for 125V DC distribution panels are integral features of each circuit breaker and include trip on overcurrent. An alarm is initiated when 125V DC circuit breakers are in an abnormal state. This alarm is displayed on an annunciator panel on control panel 901-B1 in the control room. There are no operator controls for 125V DC distribution panels in the control room. All distribution panel breakers can be manually operated at the bus.
Periodic visual inspections are performed on 125V DC distribution panels.
3.2.2.8.
Fire Protection System Dresden Unit I shares its Fire Protection system and program with Dresden Units 2 and
- 3. The site Fire Protection system and program are described in the Dresden Units 2/3 SAR and associated documents.
3.2.2.8.1.
Fire Protection Water Supply System Dresden Unit I shares a common Fire Protection Water Supply System with Dresden Units 2/3. The description of the Fire Protection Water Supply System applicable to Dresden Units 2/3 is described in the Dresden Units 2/3 SAR and associated documents included by reference. The description contained herein describes the function and interfaces for the original Unit 1 portion of the Fire Protection Water Supply System.
3-30
DSAR I
The Fire Protection Water Supply System supplies fire hydrants, standpipes, hose stations, sprinkler systems and water spray systems located in Dresden Unit 1. The Fire Protection Water Supply System is capable of supplying the anticipated largest single fire flow, including hose stream demands.
The Fire Protection Water Supply System can be supplied from either the Unit 1 Intake Canal or Unit 2/3 Intake Canal. The Unit 2/3 Service Water Pumps and Unit 2/3 Fire Pump take suction from the Unit 2/3 Intake Canal. The Unit 1 Screen Wash Pump and Unit 1 Fire Pump take suction from the Unit 1 Intake Canal. Normal system makeup and pressurization is provided from a connection to the Unit 2/3 Service Water System. The Unit 1 Screenwash system can also be manually started to maintain system pressure. The Unit 2/3 Service Water or Unit 1 Screen Wash Systems can supply small system demands such as system leakage or planned testing. The Unit 1 Fire Pump or Unit 2/3 Fire Pumps are used to supply larger system demands. Either fire pump is capable of supplying the largest single fire flow demand.
The Fire Protection Water Supply System can be utilized to provide makeup to the Unit 2/3 Isolation Condensers.
The Fire Protection Water Supply System is the source of emergency makeup water for the Dresden Unit 1 Fuel Storage Pool and the Fuel Transfer Pool.
The Dresden Administrative Technical Requirements and associated surveillance procedures ensure operability of the Fire Protection Water Supply System and emergency makeup capability for the Unit 1 Fuel Storage Pool and the Fuel Transfer Pool.
3.2.2.8.1.1.
Fire Mains An underground yard Fire Main piping system is provided to supply outside fire hydrants and interior building fire main piping. The yard main is configured in a loop which extends around the Turbine and Reactor Buildings for Units 1,2 and 3. Feed mains connected to the underground loop supply interior building loops or fire systems. The interior piping loop within the Unit 1 Turbine Building can be fed from multiple feed mains connected to the underground yard main piping. The piping loop within the Unit 1 l
Turbine Building feeds a majority of the Unit i standpipes, hose stations, sprinkler systems and water spray systems. The piping loop within the Unit 1 Turbine Building is connected to the piping loop within the Unit 2/3 Turbine Building.
Fire hydrants installed on the yard Fire Main loop provide a means for applying effective j
fire hose lines throughout the plant for use by the fire brigade. Each hydrant outlet is I
provided with hose threads compatible with those used by the local fire departments in the event of the need for outside assistance.
l 3-31
DSAR The piping system is provided with valves to facilitate the isolation of portions of the systems for maintenance or repairs without interrupting the supply to remainder of the system. Control valves on the system are administratively controlled.
Fire protection system piping is not designed as a Seismic Category 1 system.
Fire protection system supply piping is maintained pressurized. This system pressure mitigates the effects of water hammer when a fire pump (s) is started. Makeup pressure from the Unit 2/3 Service Water System or Unit 1 Screen Wash System is below the pressure rating of the system piping. Pressure relief valves are installed on the supply connections from the Unit 2/3 or Unit 1 Fire Pump to prevent exceeding the pressure rating of the Fire Protection Water Supply System piping.
Station procedures are provided for the periodic flushing of the piping systems as well as systematic operation and surveillance of valves and hydrants.
3.2.2.8.2.
Fire Pump Dresden Station maintains two redundant 100% capacity fire pumps. I)resden Unit 1 Fire Pump and Dresden Unit 2/3 Fire Pump.
The Unit 1 Fire Pump is located on the 508'-6" elevation of the Unit 1 Cribhouse. The fire pump draws suction from the Unit 1 Intake Canal. The Unit 1 intake Canal contains a limitless supply of water from the Kankakee River. A strainer is attached to the base of the fire pump to prevent large diameter foreign material from entering the Fire Protection Water Supply System. To prevent zebra mussel infestation of the Fire Protection Water Supply System chemicals are added to the Unit 1 Intake Canal.
The Unit 1 Fire Pump is a vertical turbine type centrifugal pump. The Unit 1 Fire Pump is powered from a diesel engine driver through a right-angle gear drive.
The Unit 1 Fire Pump is capable of supplying the largest anticipated system demand.
During low or shutoff head conditions, a pressure relief valve downstream of the fire pump discharge prevents exceeding the pressure rating of the Fire Protection Water Supply System piping.
Periodic surveillance are performed to ensure operability of the Unit 1 Fire Pump and associated components. The surveillance include an annual capacity test.
3.2.2.8.2.1.
Fire Pump Diesel Engine The Unit 1 Fire Pump is powered from a diesel engine. The diesel engine is supplied from a diesel fuel day tank located adjacent to the engine. Two sets of starting batteries l
3-32 l
\\
l l
)
DSAR are located adjacent to the diesel engine. The heat exchanger installed on the diesel engine is supplied with cooling water from a line downstream of the Sre pump discharge.
The diesel engine intakes air from the Cribbouse. The exhaust line from the engine discharges outside of the Cribhouse. Operation and monitoring of the diesel engine is controlled through a local control panel. The diesel engine will shut down on overspeed.
The Unit 1 Cribhouse is a heated structure. Additionally, the diesel engine has a water jacket heater installed to keep the engine warm.
3.2.2.8.2.1.1.
Diesel Fuel Supply The Fuel Oil System for Unit I remains in service to supply the Unit 1 Fire Pump Diesel Day Tank. Fuel to the Dre pump is supplied via gravity feed from a diesel day tank with an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> fuel supply. The diesel day tank is equipped with a low level alarm.
3.2.2.8.2.2.
Fire Pump Controller Operation of the Fire Pump Diesel Engine is controlled from a local controller located adjacent to the engine in the Unit 1 Cribhouse. The controller is powered from the Unit 1 110V AC Electrical Distribution System.
l The control panel will send a start signal to the engine on low Fire Protection Water Supply System header pressure or power failure.
The Fire Pump can also be started manually at the Controller or from Control Room Panel 901-2.
The Controller provides indication of the following:
Low oil pressure.
High water temperature.
Low fuel level.
Battery failure.
Failure to start.
The Controller provides common trouble alarm in the Contml Room through the Station Fire Alarm Computer. The Fire Protection Water Supply System pressure is recorded independent of the Unit 1 Fire Pump Controller on the Control Room 923-1 panel.
3.2.2.8.3.
Fire Suppression Systems Fire protection services are provided by a pressurized water system serving most areas throughout the buildings and grounds, and portable extinguishers at strategic locations.
i 3-33 u_________---___----__--_--_---_
J
DSAR The site common Fire Protection Water Supply System is interconnected between Units I,2 and 3.
There are no active fire suppression systems within the Sphere. Manual fire protection equipment consists of fire extinguishers that are surveyed on a regular basis.
3.2.2.8.3.1.
Hose Stations and Standpipes Hose stations and standpipes provide manual fire fighting capability for Unit I areas important for Unit 2/3 operations. All hose stations are supplied from the station Fire Protection Water Supply System. Hose stations are equipped with fire hose for use by the station personnel or the Fire Brigade. Standpipes are provided for use by the Station Fire Brigade.
A fire hose station in the Unit 1 Fuel Building is required to be available as an emergency makeup source of water for the fuel storage pool. Six other Unit I hose stations in the Turbine Building, adjacent to Units 2 and 3, and one hose station in the Unit 1 Cribhouse are available for fire fighting purposes. The Turbine Building hose stations would be used to prevent a fire from spreading from Unit I to Units 2/3.
The cribhouse hose station would be used to mitigate fire damage to the Unit 1 Fire Pump and associated equipment.
Station procedures are provided for the periodic surviellance of hose stations and standpipe systems.
3.2.2.8.3.2.
Water Spray and Sprinkler Systems Two water spray systems in the Unit 1 Turbine Building and one sprinkler system in the Cribhouse provide automatic fire fighting capability for Unit I areas important to Unit 2/3 operations. All Unit I sprinkler systems are supplied from the station Fire Protection Water Supply System.
l The Unit 1 West Auxiliary Bay is located on the ground floor (elevation 517'-6") of the Unit 1 Turbine Building. This area contains a large quantity of electrical cables with combustible insulation. The cables are typically arranged in cable trays located below the ceiling elevation. The water spray systems installed in this area provide coverage for the cable trays. The wet pipe water spray systems will mitigate the consequences of a fire in the West Auxiliary Bay from affecting the adjacent Unit 2 Turbine Building and Control
' Room.
The Unit 1 Fire Pump and associated Engine, Batteries, Controller and Diesel Day Tank are located on the 508'-6" elevation of the Unit 1 Cribhouse. A wet pipe sprinkler system is installed at the ceiling elevation of the room containing the Unit 1 Fire Pump and 3-34
__________ _ __J
DSAR associated equipment. The sprinkler system will mitigate consequences of a fire in the l
Unit 1 Fire Pump area.
Station procedures are provided for the periodic surveillance of the sprinkler and water spray systems.
3.2.2.8.4.
Fire Barriers Fire barriers separate the Unit 1 Turbine Building 517'-6" elevation from the adjacent i
Units 2/3 Turbine Building areas. Fire dampers are provided for areas within the Control Room.
Fire barriers are designed and installed to prevent the spread of fire within the plant. The l
Control Room and. Auxiliary Electric Equipment Room are separated from Unit I areas by three-hour fire rated assemblies. Penetrations in these fire barriers have a three-hour fire rating. Structural steel supporting the floor of the Control Room within the Unit 1 Turbine Building has been protected to provide a three-hour fire rating.
Fire dampers are designed and installed to prevent the spread of fire within the plant.
Two fire dampers separating the Control Room from adjacent support rooms are supplied from the Unit 1 Instrument Air System. During a loss of the Instrument Air System the fire dampers fail to the closed position.
Fire rated assemblies required for safe shutdown of Units 2/3 or separating safety-related areas of Units 2/3 are administratively controlled through the DATRs and associated l
surveillance procedures.
3.2.2.9.
Environmental Monitoring Environmental monitoring for Dresden Unit 1 is described and controlled through the Off-Site Dose Calculation Manual (ODCM).
3.2.2.9.1.
Discharge Canal Sample System A Discharge Canal Sample System is provided for the monitoring liquid effluents from Unit 1 Discharge Canal. The system allows for a sample to be taken if a planned discharge from Unit I were to occur. The system consists of a manually operated pump and piping connected to the canal. The sample pump is powered from an overhead electrical line independent of the Unit i Electrical Distribution Systems.
3-35 1
DSAR 3.2.2.9.2.
Environmental Monitoring Stations Envirorunental and meteorological monitoring systems are provided at Dresden Station.
Environs Monitoring Station Number 2 is powered from the Unit 1480V AC Electrical Distribution System.
3.2.2.9.3.
Unit 1 Chimney A reinforced concrete Chimney is located north of the Turbine Building. The Chimney, which is approximately 300 feet tall, provides an elevated release path for gaseous effluents.
Discharge through the Chimney originates from the following sources:
Unit 1 Gaseous Monitoring System with inputs from the Fuel Building and Laundry Ventilation Systems.
Steam Generator Blowdown Tank Vent.
- Sphere Ventilation.
- Turbine Building Ventilation.
- OfTGas System.
- Off Gas Building Ventilation. *
- These system components remain connected to the Chimney, however, are no longer required and have been removed from service.
3.2.2.9.4.
Chimney Effluent Monitoring System The Chimney Effluent Monitoring System consists of Chimney SPING and Chimney Air Sampler.
3.2.2.9.4.1.
Chimney SPING The Chimney SPING provides for continuous monitoring of the Chimney gaseous effluents. Sample lines from the Chimney are connected to the Chimney SPING. The Chimney SPING monitors for noble gases, separate particulate, and iodine. Noble gas counts are shown for all three channels on the recorder located on Panel 923-7 in the 3-36
DSAR Control Room. Annunciators are provided in the Control Room for high nobel gas indications or monitor failure. No automatic control functions are performed by this monitor. The Chimney SPING is powered from the Unit 3 Instrument Bus.
The Offsite Dose Calculation Manual (ODCM) requires the Unit 1 Chimney SPING to be operable at all times. The Chimney SPING may be Out-of-Service (OOS) for calibration and maintenance provided that particulate and iodine samples are taken and analyzed.
Routine surveillance are perfonned to ensure operability of the Chimney SPING.
Operating procedures specify actions to be taken in response to annunciator alarms.
3.2.2.9.4.2.
Chimney Air Sampler The Chimney Air Sampler provides a means for obtaining particulate and iodine samples from the Chimney when the Chimney SPING is out of service. The Chimney Air Sampler consists of a sample line and pump connected to the Chimney. The system is utilized to collect iodine and particulate samples. The backup air sampler is powered from the Unit 1 120V AC Electrical Distribution System.
3.2.2.9.5.
Gaseous Monitoring System The Gaseous Monitoring System was designed to provide a monitor release path for areas having the potential for significant radioactive release. Ventilation exhaust from the Fuel Building, Off Gas Building and Laundry Ventilation System are the only remaining source ofinput into the system.
Two redundant Exhaust Fans are provided for the system (OV1 and OV2). The Exhaust Fans discharge though a ventilation duct into the Chimney. An exhaust fan and control 7
damper provide for a system flowrate of approximately 29,700 cubic feet per minute.
System flow is maintained constant by a flow controller that monitors flow and adjusts the position of the system flow control dampers. This assures that the flow rate remains constant. Because of the low volume of exhaust being discharged into the system through the Fuel Building and Laundry Ventilation System, a majority of the system flow is provided from outside air through the control dampers.
Exhaust fans for the Fuel Building and Laundry Ventilation Systems are interlocked to prevent them from being operated independent of the Gaseous Monitoring System Exhaust Fans.
The Gaseous Monitoring System Exhaust Fans are powered from the Unit 2/3 480V AC Electrical Distribution System. The control switches for the fans are located in the Unit 1 Turbine Building South Auxiliary Bay. A low flow annunciator for the system is provided in the Control Room.
3-37
)
The Gaseous Monitoring System is not required to be operational if the Fuel Building, Off Gas Building, or Laundry Ventilation System are not operating.
Operating procedures specify actions to be taken in response to annunciator alarms.
3.2.2.9.6.
Ventilation System: Chemical Cleaning Building 1
Exhausts from the Chemical Cleaning Building ventilation system are discharged through a IIEPA filter prior to release through a common Chimney shared with the Interim Radwaste Storage Facility.
)
An effluent monitoring system with sample lines and a pump connected to the Chimney provides for radioactive effluent monitoring. Gaseous effluents are continuously sampled -
through a particulate and iodine cartridge. The cartridge is then periodically measured to access the amount of radioactive discharge.
3.2.2.10. General Station Emergency Plan Equipment The Comed Nuclear Generating Stations Emergency Plan (GSEP) describes the
)
organization response to emergency conditions which could occur at Dresden Unit 1.
The Dresden Annex to the GSEP describes events and conditions that could result in activation of the Emergency Plan et the Station. The extended period since Unit I was l
last operated has resulted in a reduction in possible accidents which could result in an emergency declaration.
Two potential emergency conditions remain for Unit 1, either a high radiation level in the Fuel Building, or an unplcuuicd loss oflevel in the spent fuel pools. Some of the sirens 3
utilized to notify personnel of GSEP conditions are powered from the Unit 1480V AC or l
125V DC Electrical Distribution Systems.
l l
Additional details regarding the Station / Unit response to emergency conditions is i
described in the GSEP.
3.2.3 Components t
3.2.3.1.
Clean Domineralizer Tank 4
Clean demineralized water is stored in the Unit 1 Clean Demineralized Water Storage Tank, T-105B. The tank supplies clean demineralized water to a number of Unit 1,2 and 3 functions. The Unit 2/3 Clean Demineralized Water System is described in the Unit 2/3 SAR.
3-38
DSAR The 200,000 gallon capacity tank is located in the yard area south west of the Unit 1 Turbine Building. Space heaters and heat tracing are installed to protect piping connections within a weather-resistant enclosure r.djoining the tank. Manually operated heaters within the tanks are supplied from the Unit 1480V AC Electrical Power Distribution System. The tank is constructed of aluminum and is approximately 35 feet in diameter and 30 feet in height. The tank is open to the atmosphere through a vent.
Tank level information is provided in the Dresden Units 2/3 Control Room as continuous proportional indication with high and low level alarms. Operating procedures specify l
actions to be taken in response to the annunciator alarms. The Clean Demineralized Water Tank is also monitored during operator rounds.
3.2.3.2.
Contaminated Demineralized Tank The Contaminated Demineralized Tank (T-105A) has a capacity of 200,000 gallons and is located in the yard area Southwest of the Unit 1 Turbine Building. Space heaters and heat tracing are installed to protect piping connections within weather resistant enclosures adjoining the tank. Manually operated heaters within the tanks are supplied from the Unit 1480V AC Electrical Power Distribution system. The tank is constructed of aluminum and is approximately 35 feet in diameter and 30 feet in height. The tank is open to the atmosphere through a vent. Tank level information is provided in the Dresden Units 2/3 Control Room as continuous proportional indication with high and low level alamis.
The T-105A tank provides additional storage capability for the Unit 2/3 Contaminated Demineralized Water System. The T-105A tank is connected to the Units 2 and 3 A and B Contaminated Demineralized Water Storage Tanks through a 24 inch diameter line and a cross-tie isolation valve. The Unit 2/3 Contaminated Demineralized Water System is described in the Unit 2/3 SAR and associated documents.
The T-105A tank can be credited as a source of water to achieve Unit 2/3 safe shutdown depending on the Unit 2/3 Contaminated I)emin Tank water volume. The stored volume of the T-105A tank is administratively controlled by the Dresden Administrative Technical Requirements.
3.2.3.3.
Unit 1/ Unit 2 Service Air Isolation Valve A control valve has been installed in the connection between the Unit 1 and Unit 2 Service Air Systems. This control valve automatically closes when Unit 1 Service Air pressure falls to approximately 74 psig, isolating the systems from each other. This prevents an incident in the Unit I air systems from adversely effecting the Unit 2 Service Air system.
3-39
DSAR 3.3.
Balance of Unit 1 Structures, Systems and Components Section 3.3 of the DSAR is provided for completeness only.
Structures, systems and components (SSCs) discussed in this section do not impact nuclear safety, are not required to support the safe storage and handling ofirradiated fuel, and have no impact on the capability of Unit 2/3 to generate electricity and supply it to the grid.
3.3.1 Structures 3.3.1.1.
Access Control / Administration Buildings Entrance to the plant is via the Gatehouse, which is south and slightly west of the Sphere.
This is a station structure shared by Units 1,2 & 3. To the west of the Gate House is the Administration Center. This is a station structure shared by Units 1,2 & 3.
3.3.1.2.
Sphere (Reactor Building)
The Sphere (Reactor Building) is located to the east of the Turbine Building and north of the Fuel Storage Building. The Sphere and associated SSCs are not required to support the permanently shutdown and defueled mode of operation and are not described in the DSAR.
3.3.1.3.
Maintenance Shops The Maintenance Shops are located west of the Fuel Storage Building. These are station structures shared by Units 1,2 & 3.
l 3.3.1.4.
Cribhouse The Cribhouse is located northwest of the Sphere and Turbine Building. This building houses the Unit 1 Fire Pump, Screenwash Pump and associated components. The Unit 1 Circulating Water and Service Water Pumps housed within the Cribhouse are not required to support the permanently shutdown and defueled mode of operation and are not described in the DSAR.
3.3.1.5.
Off Gas Building The Off Gas Building is between the Crib House to the west and the Fuel Oil Storage Tanks to the east. It is directly north of the Sphere. The Off-Gas Building and associated SSCs are not required to support the permanently shutdown and defueled mode of operation and are not described in the DSAR.
i l
I 3-40 i
i u____
l DSAR 3.3.1.6.
Station Blackout Building l
The Unit i 11PCI Building was under construction at the time of Unit I shutdown and l
was not placed in service. This structure is currently utilized as the Unit 2/3 Station Blackout Building.
3.3.2 Systems and Components 3.3.2.1 Turbine Building Crane The Turbine Building Crane is not required to support the permanently shutdown and defueled mode of operation and is not described in the DSAR.
3.3.2.2 Well Water l
The Unit I Well Water System is not required to support the permanently shutdown and defueled mode of operation and is not described in the DSAR.
l 3.3.2.3 Condensate 1
The Condensate System is no longer in operation, is not required to support the l
permanently shutdown and defueled mode of operation, and is not described in the l
DSAR.
l 3.3.2.4 Circulating Water The Circulating Water System is no longer in operation,is not required to support the 1
i permanently shutdarm and defueled mode of operation, and is not described in the I
l DSAR.
1 3.3.2.5 Lube Oil l
The Lube Oil System is no longer in operation, is not required to support the permanently shutdown and defueled mode of operation, and is not described in the DSAR.
3.3.2.6 Power Extraction The Power Extraction System is no longer in operation, is not required to support the permanently shutdown and defueled mode of operation, and is not described in the i
DSAR.
l l
3-41 l
DSAR 3.3.2.7 Reactor and Auxiliaries The Reactor and auxiliaries are no longer in operation, are not required to support the permanently shutdown and defueled mode of operation, and are not described in the DSAR.
3.3.2.8 Reactor Enclosure Cooling Water The Reactor Enclosure Cooling Water System is no longer in operation, is not required to support the permanently shutdown and defueled mode of operation, and is not described in the DSAR.
3.3.2.9 Service Water The Service Water System is no longer in operation, is not required to support the permanently shutdown and defueled mode of operation, and is not described in the DSAR.
3.3.2.10 Steam Supply The Steam Supply System is no longer in operation, is not required to support the permanently shutdown and defueled mode of operation, and is not described in the DSAR.
3.3.2.11 Turbine Bui! ding Closed Cooling Water The Turbine Building Closec' Cooling Water (TBCCW) System is no longer in operation, is not required to support the pennanently shutdown and defueled mode of operation, and is not described in the DSAR.
1-1 l
j 3-42 l
i
i
- 4. Operations 4.1.
Operation Description 4.1.1.1.
Control Room Area The Dresden Unit I facility no longer includes a distinct control room area.
Instrumentation and Controls, including alarms, which remain functional have been incorporated into the Units 2 and 3 Control Room. The Units 2/3 Technical Specifications provide assurance that this area is appropriately staffed. For additional information see the Dresden Units 2 and 3 Updated Final Safety Analysis Report and Technical Specifications.
4.1.2 Criticality Prevention Facility administrative and operating procedures govern the handling and storage of irradiated fuel. These procedures assure that movement of fuel is conducted under the direction of a qualified Unit 1 Supervisor who has a valid PRC licensed senior reactor operators license on Units 2 (3), (SRO) or SRO-L) or a person certified to an approved training program as a Qualified Unit 1 Supervisor. The procedures also assure that fuel is placed and stored only in positions previausly analyzed for this use. Because irritated fuel is in racks of the correct geometry and underwater at all times, criticality will not occur under normal or postulated upset conditions. Criticality analyses for irritated fuel in the Fuel Storage Pool are Scumented in Section 6.0.
4.1.3 Chemistry Control Dresden Unit 1 Technical Specifications define water quality limits applicable to the Fuel Storage Pool. These include limits on Chlorine, conductivity, and pII. The specifications also require the pool water to be sampled and analyzed at least once per 30 days to assure that the limits are met. The bases for the limits are to prevent the growth of micro-organisms and limit concerns about corrosion of metallic pool structures.
Dresden Unit I chemistry controls are implemented by the Dresden Units 2 and 3 chemistry organization. For additional information regarding the qualifications and capabilities of the chemistry organization, see the Dresden Units 2 and 3 Updated Final Safety Analysis Report.
l 4.1.4 Maintenance Activities Comed will continue to implement a program to monitor the performance or condition of systems, structures, and components (SSCs) associated with the storage, control, and 4-1
DSAR 1
maintenance of spent fuel in a safe condition in a manner that provides reasonable assurance that the SSC's are capable of performing their intended function, as required by 10 CFR 50.65.
4.2.
Spent Fuel Handling 4.2.1 Spent Fuel Handling and Transfer Facility administrative and operating procedures govern the handling and storage of irradiated fuel. These procedures assure that movement of fuel is conducted under the direction of a qualified Unit i Supervisor who has a valid NRC licensed senior reactor operators license on Units 2 (3), (SRO) or SRO-L) or a person certified to an approved training program as a Qualified Unit 1 Supervisor.
The Unit i Fuel Building contains personnel and equipment doors. During Fuel Handling, procedures require:
- 1) Fuel Building doors to be closed (other than for normal personnel egress and ingress).
- 2) Fuel Building ventilation system is to be operable (with a release path to the chimney).
- 3) Fuel Building area radiation monitors are to be operable.
These actions will facilitate prompt notification and provide a monitored elevated release path if an accident were to occur.
4.2.2 Spent Fuel Storage 4.2.2.1.
Water Level Dresden Unit I fuel has decayed to the point that a cooling system is no longer required.
Water contained in the Fuel Storage Pool and the Fuel Transfer Pool provides cooling and shielding of the spent nuclear fuel.
Operating parameters for the Fuel Storage Pool and the Fuel Transfer Pool including water level are verified during operator rounds. Additionally, the Fuel Storage Pool water level is electronically monitored in the Control Room.
Operating procedures specify emergency actions to address any unplanned loss of water from the Fuel Storage or Fuel Transfer Pool.
t 4-2
DSAR 4.2.2.2.
Heavy Loads l
To prevent damage to the Fuel Storage Pool, Fuel Transfer Pool or irradiated fuel l
administrative procedures have been established to control heavy loads carried within the l
Fuel Building.
4.2.2.3.
Generation Station Emergency Plan The Generating Station Emergency Plan (GSEP) specifies actions to be taken in the event of radiological accidents.
Under the Generating Station Emergency Plan the following Emergency Action Levels are established:
Unit i Fuel Building Area Radiation Monitor greater than or equal to 50 mR/hr.
(except during controlled evolutions) and Unit 1 Gaseous Monitoring Vent System is not operating.
Unit 1 Fuel Storage Pool water level less than or equal to 18'.
4-3
DSAR o
- 5. Radiation Protection 5.1.
Liquid Waste Treatment and Retention Processing of Unit I radwaste is presently being conducted at the Unit 2/3 Radwaste Facility.
Unit 1 Radwaste System filters and demineralizers are no longer in operation.
Unit 1 Radwaste Systems are now used only to collect and store potentially contaminated water until it can be treated by the Unit 2/3 Radwaste Systems, 5.2.
Solid Wastes Solid wastes generated at Dresden Unit 1 are processed utilizing the procedures and equipment that are associated with Dresden Units 2 and 3. Additional information regarding the way these wastes are handled are described in the Dresden Units 2 and 3 Updated Final Safety Analysis Report.
5.3.
Process and Effluent Monitoring Systems Releases from Dresden Unit I are processed utilizing the procedures and equipment that are associated with Dresden Units 2 and 3. Additional information regarding the way releases are processed is described in the Dresden Units 2 and 3 Updated Final Safety Analysis Report.
Gaseous discharge from the Chemical Cleaning Facility is continuously sampled through a particulate filter and iodine cartridge.
The Dischange Canal Sampler continues to be utilized at Unit 1, as required by the
- Techr.ical Specifications. Changes to this system are not anticipated. Technical Speci'.ications prohibit a planned liquid release from Unit I to the environment.
L.4.
Radiation Protection Program Dresden Station has a Site Radiation Protection Program described in the Dresden Unit 2 and 3 Updated Final Safety Analysis Report. The Radiation Protection Program addresses the following subjects:
Analytical Procedures.
l 5-1
DSAR l
Calibration and Maintenance.
Radiation Protection Design Featurt.s.
l Access Control.
Specifications.
Radiological Surveys.
Equipment, Instrumentation and Facilities.
l Radiation Protection Facilities.
Decontamination and Change Room Facilities.
Laboratories.
Radiation Protection Instrumentation.
l Portable Instrumentation.
I Design Basis.
Description.
Inspection and Testing.
Personnel Protective Equipment.
Procedures.
Control of Personnel Radiation Exposure.
Personnel Dosimetry.
l Personnel Monitoring.
Radioactive Materials Safety.
Policy Considerations.
Management Policy.
Organizational Structure.
Design Considerations.
Operational Considerations.
Collective Dose Assessment.
l l
1 l
5-2 l
l
- 6. Accident Analysis The only structures, systems and components involving nuclear safety for Unit I are the Fuel Storage Pool, Fuel Transfer Pool, Fuel Transfer Tunnel and that portion of the Fuel Transfer Tube which ev.tends into the Fuel Transfer Tunnel. These structures, systems and components are not shared with Units 2 or 3. Postulated accidents involving these structures, systems, and components will not result in off-site dose rates in excess of 10 CFR 100 requirements.
In order to demonstrate the safety of Unit 1 in its current and future SAFSTOR states, accident analyses have been performed. These analyses,in part, provide bases for the configuration of systems, components, and structures, and implementation of administrative and procedural controls.
The remaining accident scenarios of concern involve the fuel stored in the Fuel Storage Pool and Fuel Transfer Pool.
Conservative analyses demonstrate that postulated Fuel Pool accidents will not result in off-site dose exposures in excess of 10 CFR 100 or US EPA limits.
l Because the spent fuel is in racks of the correct geometry (to prevent criticality) and underwater at all times (to provide shielding), criticality will not occur, either during l
normal or postulated upset conditions. This was demonstrated by a 1987 analysis of potential criticality issues.
In 1994, an analysis was performed to determine the radiological consequences of a Unit l
1 Fuel Pool drain down. On-site and off-site dose rates from both direct and sky shine l
radiation were estimated. This calculation assumed that all 683 fuel assemblies were in -
the fuel pool and all fuel bundbs were uncovered.
l In 1989, an analysis provided projections of worst case skin and whole body radiation doses to personnel on-site and at the site boundary due to a spent fuel rupture accident of all 683 fuel assemblies in the Fuel Storage Building with subsequent environmental release. The study showed that the maximum offsite whole body dose from an accidental release of Kr-85 to be below regulatory requirements. Note that no mechanism was identified which could lead to release of significant quantities of Kr-85 or other airborne effluents including tritium.
6.1.
Criticality Analysis 1
In 1987, a criticality analysis was performed to determine the maximum Keff of the Dresden Unit 1 Fuel Storage Pool created by loss of pool cooling water and mechanical failures.
6-1
DSAR The criticality analysis is based on 672 fuel assemblies h>cated in the Fuel Storage Pool.
Fuel assemblies located in the Fuel Transf er Pool were not specifically considered.
The worst case scenario for the fuel pool water loss accident determined that under optimum moderation the Keff for the fuel remains below the maximum value of 0.98 allowed by the NRC Standard Review Plari 9.1.1. The worst case condition considered the fuel pool to be completely drained with spent fuel assemblies in the normal storage positions and in some way an optimum moderation water density (such as a water mist) is introduced.
The worst case scenario for the mechanical failure accident determined that under credible upset scenarios the Keff for the fuel remains below the maximum value of 0.95 allowed by the NRC Standard Review Plan 9.1.2. The worst case condition considered 16 spent fuel assemblies in each storage rack making physical contact without any water space between the assemblies under full pool water conditions.
The following accident conditions were considered in the analysis to bound reasonable credible configurations of fuel assembly rearrangement that could occur in the mechanical failure accident:
The pool water is completely lost but the fuel assemblies are not affected and maintain their original (normal) configuration in the pool.
The pool water is not lost, but the fuel assemblies lose their original configuration to form a new irregular configuration.
The pool water is completely lost, and the spent fuel assemblies lose their original configuration to form a new irregular configuration.
The most limiting mechanical failure condition considered all 16 fuel assemblies in a rack placed in an upright position to form a tight array of 2x8 fuel assemblies with center to center spacing of 4.27 in with a rectangular water cell of 8.0 sq. ft. (24x48 in.).
It is not physically possible to have all the fuel assemblies form tight 26x26 or 4x4 arrays uniformly throughout the pool because physical instability of arrays and obstructions by
]
rack structures and neighboring fuel assemblies during an accident. Therefore they were eliminated from the list of credible accident conditions.
The analysis did not consider any condition in which the fuel assemblies fall on the pool floor because the assemblies are long compared to the structural spacing in the pool. In I
addition, no fuel assembly-drop or heavy object drop accidents were defined because these types of accidents would cause only localized disturbances and are not bounding.
The calculated maximum Keffincluded the effects of fuel channel, dimensional and
)
material tolerances, and pool temperature.
6-2 i
i
DSAR l
f in 1995, the 1987 Criticality Analysis was updated to include the effect of placing a Fuel Rack Basket with 16 fuel assemblies in the northen vacant region of the Fuel Storage Pool. The pool reactivity change due to the presence of the fuel basket was applied to the original analysis for the 672 fuel assemblies located in the Fuel Storage Pool.
The worst case scenario for the fuel pool water loss accident determined that under optimum moderation the Keff of the fuel remained below the maximum value of 0.98 allowed by the NRC Standard Review Plan 9.1.1.
The worst case scenario for the mechanical failure accident determined that under credible upset scenarios the Keff of the fuel remained below the maximum value of 0.95 allowed by the NRC Standard Review Plan 9.1.2.
The maximum Keff for the normal pool and fuel assembly configuration with full pool water was determined to be below the maximum value of 0.90 allowed by Dresden Unit i Technical Specifications.
6.2.
Source Term Evaluation In 1989, radiological consequences of a postulated fuel handling accident in the Fuel Building, resulting in damage to the fuel cladding of 100% of all pins in all 683 fuel assemblies with subsequent release of radioactive material was performed. Three defective fuel pins located in the pool were excluded from the analysis because the Kr-85 gap activity was released at the time the pins became defective. The analysis calculated off-site and on-site accident results. The radiation exposures resulting from this accident represent the upper bounds for any spent fuel accident at Dresden Unit 1.
The accident analysis considers radionuclides remaining in the fuel assemblics.
l liowever, the analysis shows that Kr-85 is the only significant fission gas remaining in i
i the spent fuel assemblies. lience, using the criteria of NRC Regulatory Guide 1.25 the accident analysis is based upon release of the available gap activity, or 30% of total inventory of the Kr-85, to the Fuel Building with a corresponding breech of building integrity and a release to the environment.
1 For the worst case exposure in the Fuel Building the gap fission product activity is assumed to be immediately released into the building causing the maximum possible dose l
rates to personnel.
For the worst case exposure outside of the Fuel Building the gap fission product activity is assumed to be released to the environment, at ground level, through a postulated hole in the Fuel Building exterior wall. The release of the fission products to the environment has a duration of two hours.
l l
l l
6-3
DSAR l
l The analysis shows that the maximum offsite whole body doses at the nearest unrestricted area boundary from an accidental release of Krypton-85 would be sig-nificantly less than the 10 CFR 100 whole body dose limit of 25 Rem in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and the corresponding skin dose equivalent limit of 150 Rem in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The study results also show that the whole body dose to members of the public would be significantly less than the U.S. EPA-Protective Action Guide (PAG) limit of 1 Rem whole body.
6.3.
Fuel Pool Drain Down Accident Analysis I
In 1994, an analysis was performed to determine the radiological consequences of a Unit 1 Fuel Pool drain down. The analysis is based upon 683 fuel assemblies located in the Fuel Building. In the analysis it is conservatively assumed that all of the assemblies are located in the Fuel Storage Pool. Although three fuel rods are also stored in the pool, their contribution to activity is concluded to be negligible. Resultant fuel assembly temperatures, and onsite and offsite dose rates are calculated.
The analysis determined the fuel assembly temperatures for partial and complete Fuel Storage Pool drain down scenarios. For the analysis the ambient building air temperature was conservatively assumed to be 120 F. Under either condition the peak temperatures inside of the fuel pins was determined to be far below the temperature at which fuel cladding is' expected to fail.
Dose rates associate'd with direct and scattered radiation were calculated assuming the complete loss of fuel pool water. Dose rates inside of the Fuel Building were significant.
J The dose rate in the' Unit 2/3 Control Room, including the effects of concrete shielding, was determined to be significantly less than 10 CFR 50 Appendix A GDC 19 limits. The dose rate at the closest point on the site boundary was determined to be significantly less than 10 CFR 100 limits.
I I
Because the fuel temperature following loss of water coverage is much lower than the vaporization temperature of volatile fission products, no significant additional contamination is expected.
1 i
l l
6-4
DSAR f
- 7. Conduct of Operations 7.1.
Comed Organization Structure The Unit 1 Decommissioning Plant Manager reports to a Vice President of the corporation through the Manager of Decommissioning Projects. This ensures high-level management attention is available to commit personnel and resources to properly and safely maintain the plant during the decommissioning phase.
7.1.1 Manager of Decommissioning Projects The Manager of Decommissioning Projects is responsible for decommissioning project activities at Comed Nuclear Stations. Responsibilities include the safe storage of irradiated spent nuclear fuel for permanently shutdown plants; the authority to commit personnel and resources to execute decommissioning activities; reviewing and approving the Post Shutdown Decommissioning Activities Report revisions. proposed license amendments and revised technical specifications; site installation of spent fuel storage casks; cask loading; and long-term maintenance activities.
In addition, the Manager of Decommissioning Projects is responsible for the execution of the Company's Quality Assurance Program, compliance with applicable NRC licenses and governmental regulations, and compliance with appropriate ASME Code requirements.
I 7.1.2 Unit 1 Decommissioning Plant Manager The Unit 1 Decommissioning Plant Manager has overall responsibility for Unit I and has
)
control over Unit I activities necessary for operation and maintenance of structures and systems necessary for the safe storage ofirradiated fuel.
Related responsibilities include:
I Identifying and coordinating project team participants.
i Developing project plans, schedules and budgets.
l Developing project cost estimates.
Ensuring quarterly radiation surveys are performed.
l Ensuring appropriate maintenance and surveillance activities.
I l.
7-1 l
t
1 DSAR i
)
7.1.3 Onsite and Technical Support Organization I
A project team has been assigned responsibility for implementing SAFSTOR for Dresden Unit 1. They are responsible for Project functions including Financial and Planning, Regulatory Assurance, Maintenance and Construction, Operations, Engineering and llealth Physics. Staffing assigned to the Project may vary as required and directed by the Decommissioning Plant Manager.
7.2.
Decommissioning Procedures Dresden Unit I procedures provide guidance for administration, fuel handling operations and maintenance. Dresden Unit i uses the following types and categories of procedures to implement decommissioning.
7.2.1 Dresden Station Procedures l
Dresden Unit I uses Station and Comed procedures for processes that are common to the l
Units (such as Administrative procedures, Fire Protection procedures, Maintenance procedures, Engineering procedures, Safety Evaluation procedures, Operating procedures, Chemistry procedures. Radiation Protection procedures, GSEP procedures, etc.).
I 7.2.2 Decommissioning Procedures Dresden Unit I has also implemented decommissioning procedures, specifically i
applicable to decommissioning activities that differ from Station activities in areas including:
Administrative Controls of Dresden for Decornmissioning Activities.
Maintenance Rule for Deconimissioned Plants per 10 CFR 50.65.
Decommissioning Impact Evaluations per 10 CFR 50.82.
Decommissioning On-Site Review responsibilities and requirements.
Engineering Activities for SAFSTOR Preparation and Configuration Management.
Engineering Activities for Control of Structures. Systems and Components applicable to Safe Storage ofIrradiated Fuel.
l 7-2 1
L__-__-_____________________
i DSAR 7.2.3 Preparation and Review of Decommissioning Procedures 1
Dresden Unit 1 procedures are written, reviewed and authorized in accordance with the requirements of the Comed Quality Assurance Topical Report. The Technical Specifications provide a list ofitems for which written procedures are required to be prepared, approved and implemented.
7.3.
Training 7.3.1 Training of Fuel Handlers Dresden Unit I fuel handlers are qualified under the guidance of an NRC approved certified thel handler training program. The Fuel llandler Initial Training program ensures that Fuel liandlers are adequately trained in the areas of systems, components, and task performances required to fulfill the duties and responsibilities of that position.
Dresden Station provides both initial training and continuing training for Fuel Handlers.
l This training program typically covers the following areas:
Plant systems applicable to Fuel Handling.
. Refueling equipment.
Procedures applicable to Fuel Handling.
The fuel handler tasks that are part of the training program include:
4 L
Performance of fuel movement.
I Inspection / Operation of the Unit 1 Fuel Building Crane (s).
Operation of the Unit i Fuel Handling Tools and Equipment (such as Camera inspection equipment, etc.).
These tasks are incluc j in the fuel handler on the-job-training program. Fuel handlers are supervised by a Qualified Unit 1 Supervisor who has a valid NRC licensed senior reactor operators license on Units 2 (3), SRO or SRO-L or a person certified to an approved training program as a Qualified Unit 1 Supervisor.
1 The Fuel Handler Continuing Training program is required for all Fuel Handlers. This
~
program is designed to provide the Fuel Handler with the necessary knowledge and job l
skills required to continue to perfonn the required duties in a safe and efficient manner l
l 7-3
_-.-_-----_-_________-o
e
,s e
DSAR and to enhance performance. The course content typically includes applicable procedures and industry events.
i 7.3.2 Training for Plant Staff Dresden Station provides training programs that are necessary and prudent for assuring the safety of personnel, preventing the degradation of safety-related systems, structures, and components, and increasing the efficiency of operation through improved human performance. Dresden Unit I staff participates in the Unit 2 and 3 training programs to the extent applicable and appropriate for the assigned position within the Unit 1 j
organization. For example, all personnel assigned to work within the site participate in j
the general training pro <; rams such as Nuclear General Employee Training.
1 Training for Dresden Station personnel is developed using a systematic approach to j
ensure that they receive training appropriate to their positions o. tasks at the station.
Training is normally divided into three types:
Initial training is intended to provide training on safety and job skills
)
commensurate with an individual's position; Retraining, including continuing training, is intended to refresh and reinforce information received during initial training; and Specialized or task-related training is intended to acquaint personnel with information related to complex processes, procedures, and equipment that are not used on a routine basis.
The training needs of non-Dresden Station personnel granted unescorted access to the station are also considered in order to protect them from excessive or unnecessary radiation exposure and to acquaint them with security procedures and various safety concerns. This training is commensurate with the position of the non-Dresden Station personnel.
A detailed description of the training provided to plant staffis provided in the Dresden Units 2 and 3 Updated Final Safety Analysis Report.
j l
l 7-4 u_______