ML20115H981
| ML20115H981 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 10/20/1992 |
| From: | Shields J COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0519, RTR-NUREG-519 GL-89-10, NUDOCS 9210270412 | |
| Download: ML20115H981 (2) | |
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/ 1400 Opus Piece Downers Grove, Illinois 60516 October 20,1992 Dr. Thomas E. Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Document Control Desk
Subject:
LaSalle County Station Units 1 and 2 Deletion of the Steam Condensing Mode of the Residual Heat Removal (RHR) System NBC QncheWoL50 3Z3mtL50 314
References:
(a)
D.J. Chrzanowski (CECO) letter to Dr. Murley, dated September 5,1991; Commonwealth Edison Response to Request for Additional Information (RAI) for Generic Letter 8910 Supplement 3 (b)
R.J. Barrett letter to T.J. Kovach, dated April 16,1992; Response to Generic Letter 8910, Supplement 3:
"Consideratbn of the Results of NRC Sponsored Tests of Motor-Operated Valves" Unit 2 Technical Specification License Condition 2.C(15 (i),
High/ Low Pressure Interface Between Reactor Core Iso)lation (c)
Cooling (RCIC) and Residual Heat Removal (RHR)
(d)
C.W. Schroeder (CECO) latter to H.R. Denton (USNRC), dated March 1,1984; Fire Protection System Analysis of RCIC/RHR High/ Low Pressure Interface (e)
NUREG 0519 Supplement 8, Safety Evaluation Report related to the operation of LaSalle County Station, Units 1 and 2, dated March 1984
Dear Dr. Murley:
The Residual Heat Removal (RHR) system on both Units at LaSalle County Station is designed to operate in a number of different modes, one of which is the steam condensing mode. This system configuration is designed to be usad when the primary system is isolated from the main condenser. Steam at reactor p)ressure and temperature is routed through the Reactor Core Isolation Cooling (RCIC steam supply line to the RHR heat exchanger. The resultant condensate is then returned to either l
the RCIC pump suction or to the suppression pool. This mode of operation is further described in UFSAR sections 5.4,6.3 and 5.4.7.2.2.3, and shown on Piping and l
Instrumentation Drawings M-101 sheet 1 and M 96 sheet 4 for Unit 1, and M 147 sheet l
1 and M 142 sheet 4 for Unit 2.
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9210270412 921020
-PDR ADOCK 05000373 00[ p, P
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L I
e 2-When In the steam condensIr.g mode, the RCIC outboard motor-operated valve 1E51-F004/2E51 F064 is open. However, dunng design reviews in response to Generic Letter 8910 Su >plement 3, Consideration of the Results of NRC Sponsored Tosts of Motor-Operatec Va ves, it was determined that the valves would be incapeble of closing during a line break scenario coincident with a degraded voltage condition.
As a result, valves 1E51-F064 and 2E51 F064 were taken out of service in the closed position. These valves are considered non deficient while out of service closed, ss shown in Attachment 1 to reference (a). In order for the valve 9 to be considered non deficierit while in the steam condensing mode, valve replacement, actuator replacement, and gear change / closing time extension would be required. With valves 1E51 F004 or 2E51 F064 open in Operating Conditbn 4 for alternate shutoown cooling, eng: hat the valves were operable and non deficient.nooring calculations determined t Utilization of the steam condensing mode of RHR in Operating Conditions 1,2, or 3 is not used at LaSalle due to concerns on potential water hammer and subsequent 1
equipment damage. Attemale methods of decay heat rernoval exist and we routinely used. Commonwealth Edison (CECO) has performed a Safety Evaluation in accordance wah 10CFR50.50, which documented the acceptability of deleting steam condensing as a mode of RHR while in Operating Conditions 1,2, or 3. The UFSAR and station procedures will be revised to reflect the results of this Safety Evaluation, j
As LaSalle has decided not to uso the steam condensing rnode of RHR, vcives 1(2)E51 F004 will be kept administratively closed with power removed when in Operating Conditions 1,2, or 3. These valves may be opened in Operating Condition 4 for alternate shutdown cooling. With these administrative controls in alace, valves 1E51 F0u4 and 2E51 FOG 4 are considered non-deficient in a!! operat ng modes. No additional actions are necessary to restore design margin, and 17e proposed changes listed for these valves in Attachment 1 of reference (a) (valve replacement, actuator replacement, and gear change / time extension) will not be performed.
At the present time, valves 2E12 F087A and 1E12 F087A ue kept closed administratively to comply with the reference (c) License Condition. As discussed in reference (d), valves 1E12 F087A/B (2E12-F087A/B), along with valves 1E51 F064 (2E51 F064) and 1E12-F052A/B (2E12 F052A/B) are the higli/ low pressure interface valves between RCIC and RHR. On Unit 2, a warm up line containing valve 2E51 F091 bypasses valve 2E51 F064, and is also en interface valve. The reference (e) SER stated that License Condition 2.C(15)(1) was satisfied once power was administratively removed from one of the interface valves. The RCIC outboard isolation valve will be kept administratively closed with power removed when in Operating Conditions 1,2, and 3. The administrative closure of 1E51-F064 and both 2E51-F064 and 2E51-F091 will now satisfy the License Condition, and the administrativa controls may be removed from valves 1E12 F087A and 2E12 F087A.
The UFSAR and station procedures will be revised to reflect this transfer.
Please direct any questions to this office.
- Sincerely, k
0 Ann Shields Nuclear Licensing Administrator cc:
A.E. Davis, Regional Administrator - Rlll B.L. Siegel, Project Manager NRR D.L. Hills, Senior Resident inspector Office of F.eactor Safety IDNS ZNLD/2229
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