ML20049A443
| ML20049A443 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 02/13/1981 |
| From: | Delgeorge L COMMONWEALTH EDISON CO. |
| To: | Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| LOD-81-40-22, NUDOCS 8102180446 | |
| Download: ML20049A443 (7) | |
Text
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Commonwealth Edison One First National Ptaza, Chicago. Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690 l
February 13, 1981 1
1 Mr. B.J. Youngblood, Chief Licensing Branch 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Subject:
LaSalle County Station Unit 1 & 2, Revised Response to Question 4111.86, NRC Docket Nos. 50-373/374 LOD 81-40-22 Reference (a) L.O. DelGeorge letter to B.J. Youngblood, (LOD 81-40-16) dated February 10, 1981.
Dear Mr. Youngblood:
Attached is a proposed revision to Q111.86 which is submitted to refine the selection of valves subject to reactor coolant pressure boundary leak testing.
This revision is intended to resolve questions raised by the NRC Staff and supplement the information previously submitted in Amendment 54 of the FSAR and that submitted in Reference (a).
In the event you have any questions in this regard, please direct them to this office.
Very truly ycurs,
.4 L.O. Delgeorge Nuclear Licensing Administrator Attachment cc: NRC Resident inspector-LSCS g
8102180 d h
LSCS-FSAR h ugnse to 0111._86 1.
The folicwing 13 a list of those valves which perfor.n a pressure isolation function between the Reactor Coolant Syntom (RCS) and a low pressure system:
Valve System Number Servica FSAR Figuro LPCS E21-F006*
LPCS Injection 6.3-5, 7.3-9 E21-F005' LPCS Injection 5.3-5, 7.3-9 HPCS E22-y005=
EPCS Injection 6.3-1, 7.3-3 C22-F004" HPCS Injection 6.3-1, 7,3-3 RER E12 -F 041A, B,
LPCI Injaction S.4-13, 7.3-11 CA E12-F042A,B, LPCI Injec tion 5.4-13, 7.3-11 Ch E12-F050A,D*
Shutdown Cooling 5.4-13, 7.3-11 naturn E12-F053n,n*
Shutdown Cooling 5.4-13, 7.3-11 Return Shutdown Cooling 5,4-13, 7.3-11 E12-F009 Suction E12-7003 Shutdown Cooling 5.4-13, 7.3.11 Suction RCIC E51-F066A RCIC Head Spray 5,4-9 E51-7065*
RCIC Head Spray 5.4-9
- These valves form a pressure isolation barrier which consists of a check valve in sorine with a motor-operated valve.
The chJch valve is provided with a small (2-inch or smaller) bypasa valve to permit performance testing the check valve.
The aactions of piping on the outboard side of the motor-operated valves are provided with a; safety-relief valve capable of handling the maximum postulated leakage flow through the by:; ass valves around the inboard check valves.
Therefor 3, the potential for over-pressurination by leakago through the bypass valves has been adequately addressed in the original design, and, nead not be considered f urther.
LECS-FSAR 2
The additional leakage tests required by the NRC to meet this now criteria will be performed at the nornal operating pressure of the RCS.
This will be a separate test from the Appendix J, Type C tests.
Therefore, no information on the methods of extrapolating fram the low pressure Type C testing to this test need be supplied.
3.
A maximum of one gpm will be the established acceptance criteria for each valve subject to thin speciaI leak test, in agreement with the stated URC criteria.
- 4.. Although the suggested mode of shutdown prior to entering Mode 2 for performing this test appears to be reasonable, CNCo does not ces the need to restrict their operational flexibility, by connitting to a spooific time for executing
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thin test.
The leak testing will normally be performed during shutdovn; however, it may be more desirable to perform thess tests as the unit is brought down to cold shutdown or during the outage,, rather than when the unit in being restarted.
Since no experience in performing these newly definad' tests is available, the determination of the exact time sequence in the refueling outage when they are to be performed should l
r'emain open so the impact on outage critical, path can be minim 1:ed, The testing interval of once per refueling outage vill be implemented, but it should be noted that this will not average out to a year 19 interval since LSCS is designed for i
nn eighteen month refueling cycle, l
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LSCS-FSAR 5.
The pressure isolation barriers which consist of check valves lu naries with motor-operated valves -)
(C have been identified by an asterisk in the lint provided in part 1 of thin responce All of these check valves are furnished with position indication which reads out in the main control room.
Therefore, the disc poaltion on the check valves can be determined at any time, and the dwtermination of the existence of a high pressure on the downstream side (upatream side of the ancond valvo in series) as a result of an unseated valve diso can be made on this basis.
In addition, prescure test connections are installed on the outboard side of containment between the inhoard check valve and the second valve in series (outboard ~ inblation valve).
These tent connections were originally Installed Ln order to perform the Type c leakage test.
Prior to per-forming these survelliance testa during shutdown, tha test connections are fitted with a pressure gauge to detect any high pressure between the valves.
This same procedure will be utilized in the performance of this new leakage test to ensure pernonnel safety.
I.SCS-FSAR The RPC5, LPCS, RMR/LPC3, RCIO Head Spray and 19E/ Shutdown Cooling Return and !utR Shutdown Cooling Euc tion linee arc all monitored for RCS leakage into to the oystem by pressure cwitches located in the pump discharge linea (or suction lines for shutdown cooling suction and RCIC) outside the primary contal.nment.
These switch 4es activate a high pressure alarm in the main control room when the line pressure er.ceeds >
its normal high valua.
All enese lines are.provided with safety-relief valves which relieve any overpressure leaking from the RCS through the outboard isolation by discharging to the suppression pool.
The auction sides of the ECCS pumps aretalso provided with thermal relief valves,which relieve any overpressurization that leaks back through ths. check valves in the pump discharge line.
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If any of the leakages thrcugh the RCS boundary valves were significant, tht= R1"/ wator level imbalance, as well as the suppression pool level increase, resulting from the safety-relief valve idischarge would provide the plant operators with additional indication that a problem had developed.
It should also be noted, that the piping between the i.nboard valve and outhpard isolation valve is designed for full RCS design conditions or greater in all cases listed in Item 1.
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LSC5-FSAR In the cases of the HFCS injection line and the RCIC head spray lines, Lhe design precouras of theso lines uset or exceed the RCS design pressure on the outboard cide of the outboard isolation valve.
Therefore, overpressurization
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of thega lines would not be possLule.
To get to a point in these systems where RCS leakage would present an over-preasurication problem, the leakage of other system Valves, 1
such as the pump discharge check valves, vould also havs to be postulated, This additionalleakage, couplod with the poaulated leakages already assumad to occur through both RCS boundary pressure isolation valves, does not appear to be a plausible event.
Dased on the design provisione described in the preceding paragraphs, it.is felt that suf ficient justification has been provided to preclude the need to perform this leakage test each time the valve is moved from its fully closed position.
This leak testing will be performe& only af ter maintonacce to the valve effecting the pressure retaining capability is perforned or at the regular interval of each i
refueling outage.
Testing these valves each time they are moved from the fully closed position would not be i
practicable, especially in the case of the ' inboard check These valves are required by the tr4chnical specifi-valves.
l cations to be e:tercised periodically during full power to
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4 LSCS-PSAR ensure their operability, and there are no provisions that would parmit leak testing Lbese valves during full power op+ra tiori.
Thus, exception is taken to the portion of Attachment A to this question :that. requires leah testing when the valve is x;ved from its fully closed position.
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