ML19344B372
| ML19344B372 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/08/1977 |
| From: | Abel J COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML19344B371 | List: |
| References | |
| NUDOCS 8010080724 | |
| Download: ML19344B372 (12) | |
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ATTACHMENT 01 STATE OFLILLINOIS
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COUNTY OF COOKj
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AIFIDA1IT l
4 I, JAMES S. ABEL, being firsi duly sworn on oath, depose and state that the-following is.true to the best of my knowledge ~and belief:-
1 1.
I hold a degree in Engineering from Rose-Huhnan Institute of Technology and am currently employed as a Section Engineer in the Station Nuclear Engineering Department of Commonwealth Edison Company with responsibility for supervising engineering efforts in connection with each of Commonwealth Edison's boiling water reactors, including Dresden Unit 1.
These responsibilities require familiarity 4
with the upgrading of the Dresden Unit 1 emergency core cooling systems and the development of analysis.of conformance with applicable performance! criteria as well as otl.er design aspects of the Unit.
2.
Existing. plant equignent -has been shown by analysis
(" Plant As.Is" 10 CFR 50.46 Appendix K analysis dated July, 1975) to be i
capabla of complying with current regulations applicable to emergency 4
-core cooling system' performance.
This existing equipment is incor-porated in the-.following systems: ' core spray, post incident, emergency.
-condenser and primary reactor (feedwater.
The core. spray system is designed to! provide sufficient spray coolant flow when reactor 1
pressure is low.
The post incident system provides long term core i
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~(2) l coolant! flow and containment heat removal..'For postulated loss of coolant accidents without. coincidental loss of reactor pressure the emergency condenser will-reduce reactor pressure to allow full core.
spray flow.
The.feedwater system provides core cooling flow when the 1
reactor pressure;is high, and.this addition of cold feedwater supple-
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mentsithe' emergency condenser in reducing reactor pressure.
The core i
spray system, post incident system'and emergency condenser are designed to operate on off. site power.or the existing on site power systems.
The feedwater system will operate'only on normal auxiliary power or off site power.
3.
The high pressure coolant injection (HPCI) system and the new essential service (ES) diesel generators are being designed and installed as required by the August 5, 1974 order of the NRC.
The existing plant equipment has been shown by analysis
(" Plant As Is" 10 CFR 50.46 Appendix K analysis dated July, 1975) to be capable of complying with current regulations applicable to emergency core cooling system performance except that these-existing systems (except for core spray) were designed to original plant standards and do not completely conform with the redundancy requirements underlying 10 CFR 50.46.
Dresden Unit 1 has-only sne on site diesel generator and does not' meet the failure criterion requirement that the ECCS short term and long term functions be-invulnerable to a single failure which h
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- -disables = on-site power-assuming off ! site power is' not available.
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As discussed in-Item 2.Lof'this^ Affidavit, for postulated loss of U
coolant;acciden'5, the reactor primary feedwater system will provide-
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- sufficient.high pressure coolant flow.
This feedwater system tras not designedfor' constructed'as-a safeguar'd system- ; herefore, it
' 'does not contain ccanpletely redundant components and controls and it i
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'is not supplied from'an on site power source.
The HPCI system'and-the new ES diesel'. generators are designed to meet the currently j;
applicable' standards and to provide redundant active components.
These modifications are now expected.to cost $15,000,000 and to be l
completed by December 31, 1978.
When completed, the ECCS will, i
in our opinion, fully comply with 10 CFR 50.46, Appendix K and the underlying requirements.
4 '.
The HPCI. system for Dresden Unit 1 will serve the same function as similar systems in use in BWR s and 4's.
Th'e system as. proposed will deliver a sufficient quantity of water to rapidly
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depressurize the; primary system to a low pressure which allows operation of the core spray system.
This supplementary depressurization and coolant injection-is provided for postulated small and intermediate
-primary piping system breaks which'could result in exceeding fuel temperature criteria. prior..to sufficient depressurization through the break ~to-allow core spray operation. -Although the existing primary n
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-feedwater pumps and emergency condenser are essentially capable of-
' handling this problem, they are not specifically designed to meet single failureEcriteria,. seismic, and. quality assurance-standards.
5.- ' The proposed _ HPCI system has two redundant and independent divisions'for all active components.- Each' division includes an t
electric motor driven-pump which is capable of delivering.100 percent of.the required flow.
Each pump motor will be supplied by a devoted i
diesel generator.
Each division contains its own valving, instru-i mentation, and control.
The two HPCI pumps take suction from a large seismically designed water storage tank.
In addition, two new i
ES diesel generators (500 KW or greater) and associated equipment I
will be installed to provide two (2) independent sources of-on site
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power-for other emergency core cooling systems.
The equipment is being designed and built in accordance with the applicable present 1
day safety relkted standards.
The system is described in detail in the Dresden Unit 1 ECCS Design Report dated October 17, 1975, which was submitted to the Nuclear Regulatory Commission (NRC), and updated by letter dated-May 31, 1977, remains applicable.
-6.
In: response to an NRC. question, we transmitted to the NRC by. letter' dated-March 25, 1975, what-we projected was a reasonable scheduleLfor completion of the HPCI. system.
This schedule indicated' that-the system could be-operational on September 2,_1978. ~ In
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_responseLthe NRCfstaff urged'that every effort be made to meet an v
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. earlier _date.- Consequently, in'our June 18, 1975 request for an-exemption we indicated that the earliest possible-HPCI system operational date was December 31, 1977.
This schedule required paying a premium, exchanging equipment with our LaSalle units, expediting, or buying equipment f (like the long lead time HFCI motor driven pumps) before completing the ECCS analysis and design.
We - followed this approach, but have not been completely successful.
We planned to buy the main HPCI motor driven pumps from Ingersoll-Rand (IR) through General Electric (GE) to make them interchangeable with LaSalle.
After several months of review, this arrangement was i
rejected because IR and GE could not agree on commercial terms, the LaSalle schedule changed, and quality assurance / code revision required updating.
We then contracted directly with IR for the HPCI motor 4
driven pumps, but had to procure the motors separately to conform with the new IEEE standard.
This resulted in delaying HPCI pump motor orders to the extent that they are a controlling item on the new project schedule.
7.
As the design progressed in more detail, it became apparent that several important changes and/or additions were needed which Lwould delay the project.
The building size had to be increased to
-accommodate all of the equipment.
Th'is required relocating the HPCI building. a greater distance from the containment sphere.
The duct run for the: power, control, and instrumentation cables that was to
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(l (6) run along the turbine building could not be built to the present day
. seismic and' tornado protection standards without rebuilding the existing structures.
The design was changed to inelude a fully qualified duct run that runs along the ground around the north side of the station.
This new duct run will cost about $1,500,000 and is still in the
_ process of design.
The NRC brder dated-June 23, 1976, required a reactor protection system (RPS) modification which will utilize a major portion of the existing spare sphere penetrations.
This resulted in procuring and installing additional electrical penetrations for the HPCI system.
8.
Slightly radioactively contaminated soil, which was discovered during excavation for the HPCI building, c ased us to undertake additional core borings, evaluations, soil removal and disposal.
The discovery of the contaminated soil and the unusually harsh 1976/1977 winter, which were beyond our expectation and control, together resulted in a 3 to 6 month delay in the construction of the'HPCI building.
9.
The building is now expected to be completed by March of j
1978. ' The equipment deliveries which at this time are controlling the schedule are the HPCI pump motors, the service water and fuel oil transfer pumps, and the specialty. fire protection equipment.
The HPCI motor,:the service water and the oil transfer pumps are expected to be delivered-in June of;1978.
The fire-protection CO2 unit is
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(7) expected'to be delivered in August of 1978.
Equipment insta. cation,
- system. tie-ins, and pre-operational testing are expected to be completed by-December 31, 1978.
This is the earliest reasonably possible operational date for the HPCI' system taking into account the' difficulties discussed above.and includes the modifications to-improve the emergency on-site power source.
10.
Ccxamonwealth Edison has submitted quarterly progress reports that have kept the NRC staff informed throughout the project of the current progress, problems, and schedule.
The quarterly progress reports submitted since'the exemption was granted are i
attached.
'As' evidenced by these reports, much of the HPCI equipment has been awarded.
As of the present time, we have spent over
$2,500,000, committed an additional $5,000,000, and estimate that the total cost of the'HPCI project vill be $15,000,000.
To achieve the earliest possible' completion dato, we have accepted the risk of
-proceeding without NRC approval of the system design report submitted
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in Octoben, 1975.
In'a further effort to achieve the earliest possible operational date,.we are using our Construction Scheduling & Cost 4
i i Control ~ (CS6CC). Department to aid in scheduling our activities,
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' identifying the critical' items, and h eping track of the progress
'of the' job.,This is'one of the few projects other than major. generating unitiadditions using.these! techniques.
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During the'~ period before the new HPCI system and the additional ES. dies il generators become operational, conformance with the. performance ob',ectives of 10 CFR 50.46 will be achieved through the use of the existing systems-(feedwater pumps, core spray, emer-gency condenser, and the 500 KW diesel generator) and by operating within the Maximum Average Planar Linear Heat Generation Rate (MAPLHGR)' limits determined by the 10 CFR 50 Appendix K analysis 2
(Plant As Is).
By letter to Mr. Rusche (NRC) dated July 31, 1975, Commonwealth Edison transmitted to the NRC the results of the emergency
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core cooling analysis (Plant As Is) performed in accordance with' 10 CFR 50 Appendix K and a proposed Technical Specification change incorporating the MAPLHGR limits corresponding to the Appendix K
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i analysis.
The analysis demonstrated that Dresden Unit 1 with the i
existing equignent is capable of meeting the performance objectives
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of 10 CFR 50.46 if operated within the proposed MAPLHGR limits.
We have implemented the' proposed' Technical Specification and will continue to, follow it.
We will likewise calculate, submit to the NRC, and operate within the limits of MAPLHGR curves for any additional
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fuel types that may be' loaded into the core during the extension period.
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l12.- The; existing l feedwater system (3 ' primary feedwater pumps)
- along with the emergency condenser will provide the functions of the
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new HPCI system until the'HPCI system is operational.
Additional
- surveill'ncef s required by the Technical Specification to provide.
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Ladded assurance.of the : operability of the primary feedwater pumps.
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An augmented in service inspection program has been developed and implemented at'Dresden Unit 1 to provide added assurance against the unlikely event of a primary system piping rupture.
This inspection-program is, to the extent practicable, in accordance with ASME Boiler and Pressure Vessel Code,Section XI, except that the frequency of inspection for primary system piping i
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l has been increased.
The inspection program is described in the Dresden Unit 1 Technical Specifications.
Dresden Unit 1 has a unique design feature which provides easy and routine personnel access to l
the primary containment, making the detection of leaks through personnsi observation and monitoring unusually feasible.
Additionally, the leak detection systems. installed at Dresden Unit 1 have been designed and demonstrated to be capable of detecting leakage from insignificant cracks in piping.within the primary system boundary during operation.
This leak detection capability provides further l
l assurance that in the-extremely unlikely event a crack should occur i
it will be detected and repaired before a break of significant size could develop.
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14.-
Due to other difficulties, the new waste treatment facility l
will not be ready for the chemical cleaning of Dresden Unit 1 until about the fall'of 1978.- During a planned fall, 1978 refuel'ing outage,
.the tie -in and testina of tha HPCI system will be accomplished along L
with the chemical cleaning of the primary system.
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(10) 15.
To further assure the health and safety of the public, Conamonwealth Edison Company expects to complete by December 31,.'.077, the following actions to improve the reliability of the existing emergency core cooling systems during the extension period:
a.
Electrically disable feedwater valve MO 130 in the full open position to prevent a failure of this. valve from rendering the feedwater system inoperable, b.
Modify the abnormal operating procedures to instruct the operator to-check the feedwater control valve position during a LOCA and to open bypass valve MO 50 if the control valve has failed.
- c. -Install.and utilize a 345/138 KV transformer to connect the Dresden Unit 1 138 KV system with the Dresden Units 2 and 3 345 KV system.
This enhances the reliability of the off site
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. power-supply to Dresden Unit 1.
d.
Remove the plastic face from each of the drum level switches.
This will qualify these switches to perform their ECCS function in a LOCA environment.
e.
Review the sphere high pressure and drum level sensors, i
switches, and' cables which initiate the ECCS to determine that they can function in_a'LOCA environment and make modifications as necessary.
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During the Summer, 1977 refueling, a leak test of the primary coolant boundary will be performed in accordance wiuh the applicable edition of the ASME Boiler and Pressure Vessel
. Code,Section XI.
This test will provide further assurance of the high degree of integrity of tha primary coolant boundary piping.
t g.
To augment the highly reliable off site power and the existing on site diesel generator, a backup diesel generator will be available at the plant site by December 31, 1977.
This diesel generator will provide a redundant source of on site power for long term cooling functions.
To meet this schedule, we must install a commercial grade diesel generator using a design without NRC review.
This diesel generator will be replaced by the new essential service diesel generators described in Item 5. of this Affidavit.
h.
The-fire protection system will be modified such that long term cooling can be accomplished without relying on portions of its underground piping.
This modification involves providing fittings in the fire protection systom piping near the core spray and post incident pumps and in the cribhouse.
These fittings will provide a-means to connect piping or hose between theifire protection system pumps and the emergency core cooling i
systems in.the event the. permanent connection via the underground piping system is unavailable.
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considering our 17-years of safe operating.cxperience with Dresden Unit 1, the extremely low probability of a LOCA occurring simultaneously with a loss of all off site power, the capabilities of'the existing core spray system as augmented by the primary feed-water system and emergency condenser,-the existing diesel generator, the in service inspection and leak detection capability, the Technical Specification operating limitations on MAPLHGR, and the favorable results of the Appendix K analysis, an extension of the exemption for Dresden Unit 1, does not jeopardize public health and safety.
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JAMES S. ABEL F
thisYgdandsworntobeforeme Subscr day of.
Oubl,, 1977.
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