ML19344B379
| ML19344B379 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/26/1976 |
| From: | Abrell G COMMONWEALTH EDISON CO. |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19344B371 | List: |
| References | |
| NUDOCS 8010080734 | |
| Download: ML19344B379 (6) | |
Text
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Common (.. alth'Ei' son I
One First N1sonal Pla:% Chic go. Ilknia Addr;si Riply 12: Post Ofhes Box 767
%o Cl.icago, liknots 60690 S
O May 26, 1976 Mr. Dennis L.
Ziemann, Chief Operating Reactors Branch 2 Division of Operating _ Reactors U.S. Nuclear Regulatory Commission Washington,-D.C.
20555
Subject:
Dresden Station Unit'l High Pressure Coolant Injection (HPCI)
System, NRC Docket No. 50-10 Reference (a) :
K. R. Goller letter to Byron Loc dated August 5,1974, NRC Docket No. 50-10 (b) : ~ G. A. Abrell letter to D.
L. Zicmann dated May 6, 1976, NRC Docket No. 50-10 (c) :
Byron Lee letter to B.
C. Rucche dated October 16, 1975, NRC~ Docket No. 50-10 (d). :
D.
L. Ziemann letter to R.-L.
Bolger dated April 26, 1976, NRC Docket No. 50-10 i,
Dear Mr. Ziemann:
i This letter is in response to Reference (a) requesting a j
progress report every three months starting November 5, 1974.
This j
is Rcport No.
7.-
The submittal of this report was delayed in order to incorporate the results of significant discussions and decisions that were in process as indicated in Reference (b).
Reference ~ (c), which transmitted our HPCI Design-Report, in-dicated that the present core spray system suction pressure would be inadequate 1in the ~ proposed configurai. bn with HPCI.
This condition results-from taking suction from the new HPCI water storage tank which'is at atmospheric pressure rather than from the 110 psig fire
~
water system.. Various~ alternative solutions to this problem were evaluated.
These alternatives included new core spray pumps, suction j
booster pumps,-new safety related fire system, and supplying core spray suction pressure 1from the HPCI pumps.
The last alternative o~"R~RO]DM" 8_01008073y
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- nw;alth Edison Pc. Dennis L.
Ziemann May 26, 1976
~ was considered in several different configurations and was finally rejected because of difficulties reliably controlling the flow and flow changes between HPCI and core spray in the required time.
An alternative has;been selected which appears to be the most' practical, meets all:standardst.is the most economical, and will have the 3 east impact on the HPCI schedule.
The. selected solution is to install diesel drive' booster pumps in a separate building.
These new pumps would take suction from the new HPCI' tank, boost the pressure, and supply the: core spray system with the required suction.
The details of this solution have yet to be designed.
It is obvious.that the de-sign, procurement, and installation of this new core spray suction supply system will have to be completed on a different schedule than the HPCI, schedule, particularly if the HPCI schedule is not to be seriously delayed.
Consequently, the core spray system will have to l
maintain its suction from the fire water system until the new supply system can be installed.
The schedule for installing the new supply system and a proposed design will be transmitted to you as soon as l
the design has reached the point where this is possible.
Completion of the core spray suction from storage will be later than the HPCI.
The. design report indicated that missile protection would be provided for the cable run to the control room and existing power centers running along side the turbine building.
Further design' efforts revealed that a cable run along the planned route and meeting j
?
l all of the present day standards and criteria would be almost impos-i sible to construct because of the existing structures.
This cabic i
run (about 6' x 6' cross-section) to be micsEe protected and seismically I
supported, would cost in excess of $2,000,000 if it could be con-structed without significant modifications to the existing structures.
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Various alternative routes and varying degrecs of compliance with pre-sent day standards were evaluated.
It was decided to route the cable j.
along the ground around the north side of the plant.
Although more detailed engineering will b.e needed to determine how the many existing i
pipes and conduits will be avoided.over part of the route, it appears l
that this' cable run can be constructed to meet-all of the present l
day stand'ards.
It was' decided to upgrade the two 1,000 gallon miesel oil i
l Iday tanks to safety related standards.
It was also found that the diesel generatorcinow proposed by the bidders would utilize more oil l
than the Jay tanks hold and that there is little room to enlarge the day tanks.
In order to. supply a HPCI diesel generator for its re-quired; period of. operation and an emergency diesel generator for seven days at full power, we will have to rely on the 15,000 gallon storage. tank.
We!have, therefore, decided.to make the storage tank W
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May 26, 1976
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..t isafety:relatedoand to utili::e redundant-safety related transfer pumps and pipingibetween the tanks.
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~ The' status of;the;various components of the HPCI system is giveniin Table No.'~l?(attached).
'As can be seen from. Table No. 1,
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- further progress 7was made in the engineering and procurement a's de-scribedlin: the.-De'si,gn Report Lwftich was submitted on October 16, 1975.-
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We have,recently received and are_ preparing answers to the Dresden Unit.1 cmergency' core cooling. system-questions transmitted' 1
by Reference >(d)..These questions are :very. extensive and go well-t beyond the new HPCI. system.
Obviously, those questions cannot be s
answered by May 31, 1976.
It is estimated that all questions will
~be answered by July;15, 1976.
Our Cons.truction Scheduling and Cost Control Department has issued a comprehensive critical path schedule based on input from
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J both the-engineering _and. construction areas.. This schedule indicates
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that the HPCI project will be operational in June 1978.
The schedule Andicates that-the most. critical' items are the (1) nondestructive alsA o
d examination'(NDE), (2) ' oil tanks, (3) diesel generator service water pumps, - and '(4) - HPCI pump motors.
Recent internal procedures require that the NDE,cor. tractor 'be independent.of the working contractors.
c,unsequently, this work was taken out of the c::isting structural and piping,specf.fication and a new specification prepared.
Expediting the. specifi::ation and the possibility of single sourcing the NDE to existirig' contractors-can greatly improv'e - the schedule for NDE.
This 2=
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-approach is being evaluated.
The oil tanks are' delayed because-of 1
1the present requirement to make them safety related.
However, recent
~ discussions with the manufacturer (who has an N - stamp) indicates that they'can.be' delivered sooner than originall.y anticipated.- The diesel generator serviceSwater pumps are;not out-for bids yet, therefore, a de' livery;date'is not-available.
We are considering singic sourcing 1
theserto'a. manufacturer who has a; quality assurance program already approved'by' Commonwealth Edison.
Inf order'to solvefthe;long load timo problem of the HPCI s'
pumps, it(was.'decidedLto buy pumps identical.to:the LaSalle~HPCS-
- pumps iand to buyLthem.through1 General Electric in order to make them interchangeable.with LaSalleis pumps.- The-change in relative schedules,
? code _ change; considerations, and the inability of G.E. to come to terms
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with'the pumpimanufactUrer icd us to abandon that approach.
We have-lsincel (as indicated Ein a previous _ report). issued an unpriced purchase L
f forder=to?Ingersoll-Rand so that they_could get material on order while yhelother details were cbeing;negotinted.
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1976-fir.r Dennis L. - Zicmann :qay26, is now imminent. 'Ingersoll-Rand _ plans to completc the manufacture of the pumps at the.end of August 1977.
Although:this does not moet the required installation schedule, it'is.possible to insert the pumps into the building through openings.in the ceiling without de-
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laying the_ schedule'too seriously.
Because.of.the new'IEEE 323. standard,-Ingersoll-nand does not want to supply the motors with the pumps.
In orderfto properly
- match the motors with the pumps, we plan to single _ source the motors to G.E. who supplied the motors for the identical pumps in the LaSallo HPCS system.
The award of the motors has, however, been delayed be-cause of: problems with our approval of the new quality assurance manual of the RG.E division that producos. these motors.
We are working on ways of solving this problem and hope to still.get some
- kind of reasonable delivery.
I In summary, by expediting, ringle sourcing, and modifying some parts of.the construction sequence, we expect to have the new HPCI system operational by about March, 1978.
Although we have not
~
given' up hope of meeting the December 31, 1977 date, we know that it would be very~ difficult to meet it.
We will continue to exert our best efforts to complete' the s'ystem at the earliest possible time and will advise you of refine-monts in the schedule as they become more firm.
In addition, he are reviewing the decontamination outage schedule.
If an extension to our exemption:from the ECCS criterin appears necessary, we will submit an application at an appropriate date.
One (1) signed original and 39 copics arc provided for your use.
Very truly yours, 0
f G. A.AbrcIl Nuclear I.icensing Administrator
' Boiling Watcr Rcactor Attachment' l
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Tibl6 Nd.' l - ~bredd7,n UnitL1 JIPCI Equipment Status
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i Item Sta tus e
' Structural Work Purchase Requisition written.
Non-Destructive Testing-Specification written.
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Pipi$gand' Installation
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New specification written.
Large Valves
' Purchase awarded.
Small Valves; Purchase awarded and manufacture completed.
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011l Storage' Tank Purchase _ awarded, spec. addend. m being. written.
Pumps' Purchase awarded.
Motors Specification written.
Diesel Generators Bids received and under evaluation.
" Eater Storage Tank Out for bids.
^
Main Control Rdom. Panels Specification written.
' Diesel Gen. Service Water Pumps Did specification ready.
- 011 Day Tanks Purchase awarded, spe. addendum written.
_ Motor Control Centers Bids received and under evaluation.
4 160V Switchgear Dids received and'under evaluation.
-480V Transformers Bids received and under evaluation.
DC' Distribution Panels
_ Specification written and reviewed.
' Batteries Out for" bids.
Cables (600V).
Specificatioh written and reviewed.
- Cables (Skv)
Specification written and' reviewed.
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AITd)16' No'.O 1 (' cont'd ) :
4
- Item Status
- Battery Charge" Out for Bids.
C;bles,( instrumentdtion ) '
Specification written:and reviewed..
. Cable Trays Specification being written.
HVAC Work.
Specification written and' reviewed.
- . Vent Fans.
Out for bids.
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