ML17193A025
| ML17193A025 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 08/12/1980 |
| From: | Crutchfield D Office of Nuclear Reactor Regulation |
| To: | Peoples D COMMONWEALTH EDISON CO. |
| References | |
| TASK-05-11.A, TASK-5-11.A, TASK-RR NUDOCS 8009120279 | |
| Download: ML17193A025 (7) | |
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~ NRC PDR
- HSmith LPDR Project Manager TE~A-
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GELD
- NSIC.
- OI&E (3)
,-**.- :'iAud*µ*s'r= *: 1 2 1980.. NRR Reacli ng ACRS' (.16)
- Docket Np.
50~237*
- DEi senhut
- TNovak
- JOl shi nsk i RTed~sco.*
Mr. o. *L()uis Peoples 01recto.r ;of Nuclear Li.censtng *-"*
Commonwealth Edfson Co~any * ~
Post Office Box 767.* *
- ___
- SEP. TF
~ SEP Pf v
- Chicago, Illinois* 60690 *
Dear Mr. Peoples:
RE:
SEP TOPIC V--11.A~,' 11REQUIREMENTS.FOR IS_OLATION OF HIGH AND LOW PRESSURE.
SYSTEMS 11 (DRESDEN._UNlT Z).
-~riclosed is a copy-or our eyaluation of* Systemat-1c*Evaluation Program Topic V-11.A, 11Requiremerits*for l~Qlation of. ~1gh -and Low.Pressure Systems!! *.
This assessment"co!Jl)ares *your facility, as described tn Dock.et No. 237, with the criteria currently used by the* regul~tory staff for licensing new fac111ties.
Please inform_ us 1f your as;~uiJt facility differs from the licensing basi_s assumed in our a$sessment w1.thin 30 days of *receipt of th1s letter.. -
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Thi_s evaluation ~ill be a* basic input* :to-the *1ntegrated *safety assessment for your faciHty*unless you-identi'fy changes needed.to refle~ the' as-buflt conditions at your f~cf11ty. This "top1c assessment may be _revised in* the.
future *if your fac111t,y ~esign.1~{ch_anged... or if NRC criteria relat-1ng to this topic are modif1ed before the :1r:itegr~ted as$essment is co~'leted~
.. *.. *.;*l~4µj
- Den*n1s-M.- Crutchfield, Chief
Enclosure:
Coi:rpleted SEP
. Topic v~ 11. J,\\.
cc w/enclosure:
~ee next page
.. -. -~erat1ng Reactors Branch 115
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- __ *. _ofv1 s:1~~ :Qf.Qpe~a~1_n~ Rea~tors
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SURNAME
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NRC FORM 318 (9-76) 'NRCM 0240
. vu.'s. GOVERNMENT PRINTiNG OFFICE: 1979--289-36.9
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Docket No. 50-237 Mr. D. Louis Peoples Director of Nuclear Licensing Co111110nwealth Edison Coflllany Post Office Box 767 Chicago, Illinois 60690
Dear Mr. Peoples:
August 12, 1980 RE:
SEP TOPIC V-11.A, "REQUIREMENTS FOR ISOLATION OF HIGH AND LOW PRESSURE SYSTEMS" (DRESDEN UNIT 2)
Enclosed is a copy of our evaluation of Systematic Evaluation Program Topic V-11.A, "Requirements for Isolation of High and Low Pressure Systems".
This assessment colJllares your facility, as described in Docket No. 50-237, with the criteria currently used by the regulatory staff for licensing new facilities. Please inform us if your as-built facility differs from the licensing basis assumed in our assessment within 30 days of receipt of this letter.
This evaluation will be a basic input to the integrated safety assessment for your facility unless you identify changes needed to reflect the as-built conditions at your facility. This topic assessment may be revised in the.
future if your facility design is changed or if NRC criteria relating to this topic are modified before the integrated assessment iS*COfll>leted.
Enclosure:
Corrp 1 eted SEP Topic V-11. A cc w/enclosure:
See next page Sincerely,
/7 J I tt
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t-U.tfi;;_ r; *t a.t,Jl;h'-"'
Dennis M. Crutchfield, Chief Operating Reactors 'Branch US Division of Operating Reactors
Mr. D. Louis Peoples cc w/enclosure:
Isham, Lincoln & Beale Counselors at Law One First National Plaza, 42nd Floor Chicago, Illinois 60603 Mr. B. B. Stephenson Plant Superintendent Dresden Nuclear Power Station Rural Route #1 Morris, Illinois 60450 Natural Resources Defense Council 917 15th Street, N. W.
Washington, D. c. 20005 U. S. Nuclear Regulatory Conmission Resident Inspectors Office Dresden Station RR fl Morris, Illinois 60450 Susan N. Sekuler Assistant Attorney General Environmental Control Division 188 w. Randolph Street Suite 2315 Chicago, Illinois 60601 Morris Public Library 604 Liberty Street Morris, Illinois 60451 Chai nnan Board of Supervisors of Grundy County Grundy County Courthouse Morris, Illinois 6045fr
.e August 12, 1980 Department of Public Health ATTN:
Chief, Division of Nuclear Safety 535 West Jefferson Springfield, Illinois 62761 Director, Technical Assessment Division Office of Radiation Programs
{AW-459)
- u. s. Environmental Protection Agency Crystal Mall 112 Arlington, Virginia 20460
- u. s. Environmental Protection Agency Federal Activities Branch Region V Office ATTN:
EIS COORDINATOR 230 South Dearborn Street Chicago, Illinois 60604 Resident Inspector Dresden Nuclear Power Station c/o U. S. NRC Rura 1 Route #1 Morris, Illinois 60450
I
~
SEP TECHNICAL EVALUATION REPO~
REQUIREMENTS FOR ISOLATION OF HIGH AND LOW PRESSURE SYSTEMS SEP TOPIC V-ll.A
.DRESDEN NUCLEAR STATION UNIT 2
1.0 INTRODUCTION
The pur?OSe of t~is review is to determine if the electrical, instrumentation, and control (EI&C) features used to isolate systecs with a lower pressure rating than the reactor coolant primary system are in compliance with current licensing requirements as outlined in SEP Topic V-llA.
Current guidance for isolation of high and low pres-sure systems is contained in 3ranch Technical Position (BTP) EICSB-3,.
BTP RSB-5-1, and the Stancard Review Plant (SRP), Section 6.3
- 2.0 CRITERB.
2.1 Residual F.eat Removal (~) Systems.
Isolation requirements for RHR systeClS contained in 3!? ~SB-5-1 are:
(1)
The suction side oust be provided with the following is6lition features:
CaY Two power-operaied valves in series with posi-tion indicated in :he control room.
(b)
The valves must ~1ave independent and diverse interlocks to prevent opening if-the reactor coolant system (aCS) pressure is above the
. design pressure of the RHR system.
(c)
The valves must have independent and diverse interlocks to ensu=e at least one valve ~loses upon an increase in RCS pressure above the design pressure of the RHR system.
(2)
The discharg~ side =ust be provided with one of the following features:
(a)*
(b)
The valves, position indicators, and interlocks described in (l)(a) through (l)(c) above.
O~e or =ore check valves in series with a nor=ally-closed po~er-operated valve which has 1
*--*- ----------------------- -**-~---****- - -- --* -* ----------*-------------**---*--*-*-
I
.s pcsition indicated in the c.rol room.
If this valve is csed for an Emergency Core Cooli~g System (ECCS)-function, the valve ~ust open C?On receipt of a safety injection signal (SIS) *hen RCS pressure has decreased below
~~~~ system design pressure.
(c)
Three ~heck valves in series.
(d)
Two check valves in series, provided that both
~ay be periodically checked for leak tightness and are checked at least annually.
2.2 E~ergency Core Cooling System.
Isolation requirements for ECCS are contained in S:u> 6.3.
Isolation of ECCS to prevent overpres-surization must ~eet one of the following features:
(1)
One or ~ore che~k valves in series with a nor.:lally-closed ::iotor-operated valve (MOV) which is to be opened upon receipt of a SIS when RCS pressure is less than the ECCS design pressure (2)
Three check valves in series (3)
Two check va bes in series, provided that both may be periodically checked for leak tightness and are checked at least annually.
2.3 Other Syste::is.
All other low pressure systems interfacing with the RCS must ~eet the following isolation require~ents from BTP EICSB-3:
(1 )' At least t;.;o valves in series must be provided to isolate the system when RCS pressure is above the system desisn pressure and valve position sho:.ild be provided in the control room * *
(2)
For syste::is with t"Jo ~OVs, each MOV should have independent and diverse interlocks to prevent opening u...~til RCS pressure is below the system design pressure and ihould automatically ~lose when RCS press:.ire increases above system design pressure (3) _For syste=s *ith one check valve and a MOV, the MOV should be i:iterlocked to prevent opening if RCS pressure is a~qve syste~ design pressure and should autocatically close ~~enever RCS pressure exceeds system cesign p~essure
- 2
3.o orscussroAn EVALGAtION The-re are three syste~ at Dresden 2, with direct interface to the RCS pressure boundary, ~hich have a design pressure rating for all or part of the syste:n *.;hlch is' loi."er than the RCS design pressure.
These system~ are the Reactor ~ater Clean-Up (RWCU) system, Low Pressure Coolant Injection (LPCI) system, and Core Spray (CS) system.
3.1 Reactor Water Clean-Up System.
The RWCU system ta~es suction on the RCS, cools the water by circulation through regenerative and non-regenerative heat exchangers, and lowers the water pressure by the use of a pressure control valve.
After passing through the low pres-sure filter and clean-up portions of the system, the water is pumped at high pressure through the regenerative heat exchanger and back to the reactor via the feed line.
The suction side of the system has ~hree
~otor-operated isolation valves, an inboard valve, a pump suction valve, and a pump bypass valve.
Isolation on the discharge side is provided by a MOV and three check..,,.a lves.
The MOVs cannot open if the pressure in the low pressure portions of the system is higher than its designed pressure.
T:.1ey will a.uto=atically close on high RWCU system tempera-ture, low flow, high RWCU systec pressure, low reactor level, high dtywcll pressure, or loss of control power.
However, the interlocks for these valves all use the sa~e sensors and relays.
Each MOV has position indication in the control room.
Isolation provisions of the R~CU system do not meet the current licensing criteria since the interlocks for the isolation valves are not independent as required by BTP EICSB-3.
3.2 Low Pressure Coolant Injection System. *The LPCI system takes suction on the suppression pool (or condensate storage tank) and dis-charges into the reactor vessel.
The discharge of each loop has two nor:naliy-closed MOVs which cannot be opened unless a LPCI system initi-ation signal is present and the ~CS pressure is below the design pres-sure of the system.
The ~alves ~ill automatically close if either the LPCI ~ysteo signal or RCS ?ressure increases above the L?CI system 3
design pressure. Each *1a1:.-e has position indic.on in the control
,,. *,
- room.
The L?CI system is in cc:ifor.nance with isolation provisions of current lice:ising requi=e=ents.
3.3 Core Spray Syste~. T:ie CS system consists of two loops taking_suction on the SUp?ression pool and discharging into the reactor vesse 1 through two l10Vs. C:ne no~lly open, the other normally closed)
. and a testable {air-opera:ed) cbeck valve per loop.
All three valve positions are indicated iu the control room.
The normally-closed MOV will only open upon a CS system initiation signal when RCS pressure has decreased below CS system desig-:i pressure.
The MOV will automatically close upon clearing the initiation signal or increasing RCS pressure above CS 'system design pressure.
Therefore, the CS system meets the isolation criteria of cur=ent licensing requirements.
4.0 SUMM.ARY Dresden 2 has three systet:.S.with lower design pressure ratings than the RCS which are di=ectly connected to the RCS.
The LPCI and CS systems meet. current lice~sing criteria contained in SRP 6.3 for isola-tion of high and tow pressure systems.
The RWCU system is not in com-pliance with BTP EICSB-3 since the isolation valve interlocks are not independent.
5.O REFERENCES
- 1.
NUREG-075/087, Branch Technical Positions EICSB-3, RSB-5-1; Stan-dard Review Plan 6.3.
- 2.
D.resden 2 Piping a~d Instrumentation Drawings M-27, M-29, M-30, and M-177.
- 3.
Dresden 2 Electrical Drawi~g~ 12E2509A, 12E2509B, 12E2440 1 12El441, and 12.E 1431.
4