ML20070C183
| ML20070C183 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 12/06/1982 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20070C174 | List: |
| References | |
| 5525N, NUDOCS 8212140072 | |
| Download: ML20070C183 (3) | |
Text
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Attachment LaSalle County Station Unit 1 License Change Request NPF -11/ 82 -lE
Subject:
Single Loop Recirculation Operation
References:
(a):
LaSalle County Statian FSAR Appendix G dated April, 1978 (b):
LaSalle County Station FSAR Attachment 6.B dated May, 1980 (c):
LaSalle County Station SER, NUREG 0519, Section 4.4.2 dated Ma rch,1981 (d):
LaSalle County Station Technical Specifications, Section 3/4.4.1.1, Recirculation Loops (e):
LaSalle County Station Technical Specifications, Section 3/4.10.4, Special Test Exception for Recirculation Loops (f):
Dresden Nuclear Power Station Unit (2),
OPR-19, License Amendment 63, dated 6/30/81
Background
Discussions on possible single loop operation were initiated when Reference (a) was submitted.
Substantial additional information was provided to the NRC in Reference (b).
When Reference (c) was prepared, it apparently only considered the material in Reference (a) and did not address the information that had been provided in Reference (b).
As a result of this, the Technical Specifjestions Reference (d) and special test exception Reference (e) were promulgated by the NRC.
The information that has been presented in Reference (b) has since been used as a model for analyses done to support similar change requests fos Dresden and Quad Cities Stations.
Reference (f) is an example of an r.mendment that the NRC has issued for Dresden Unit 2, based on infcrmation submitted similar to that in Reference (b).
Re ference (b) indicates that RPT Response Time is 140 msec, not the 190 msec assumed in the transient analysis.
The 190 msec is incorporated NPF-ll Appendix A and resulted in a 0.01 MCPR penalty.
The analysis for single loop operations is not affected by the 140 to 190 msec change because the MCPR penalty has already been inco rpo ra t ed.
8212140072 821206 5525N hDRADOCK 050003
4 Discussion As a result of the loss of offsite power test, LaSalle County Station Unit I had a brief outage.
During preparations to restart Unit 1, it was discovered that the recirculation loop A discharge valve could not be fully opened.
Additional investigation and review with the valve manufacturer has revealed no further in fo rma tio n.
Resolution of the problem with the valve appears to require valve disassembly.
Because this valve can not be isolated from the reactor vessel, either core unload or installation of jet pump plugs appear to be required.
In order to either unload the core or proceed with operations that have the potential for draining the reactor vessel, secondary containment is required.
Currently, secondary containment at LaSalle County Station is configured in accordance with Appendix N to the FSAR, which excludes the refuel floor.
This was done to allow the completion of construction on Unit 2.
There remains approximately two weeks of invessel construction work on Unit 2 which must be completed before Unit 1 secondary containment can be realigned to allow the refuel floor to be part of Unit 1 serendary containment.
Finally, the Technical Specifications (Reference (d)) currently require that the Unit be in at least hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> if only one recirculation loop is in operation.
Commonwealth Edison does have additional testing to be done at LaSalle County Station.
This testing includes the Safety Relie f Valve test program which is expected to last from 10 days to three weeks.
In addition, there is single loop operation testing which can be conducted at this time as a part of Test Condition 3.
Therefore, to avoid unnecessary loss of testing and generation, it is requested that the NRC complete their review of the information submitted in May, 1980 ( Re ference (b) ) and grant the a ttached proposed license condition.
Conclusion Commonwealth Edison finds no unreviewed safety questions in this License Change Request.
This license change has been prepared based upon similar license changes previously granted by the NRC at Dresden and Quad Cities Stations.
Although the analyses justify operation a t higher power levels, it is our understanding that the NRC currently will not grant single loop operation at greater than 50% power.
Therefore, the change requested is for 50% operation.
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PROPO SED 12/6/8 2 License Condition License No. NPF-11 1
2.C. (34) Provisions to allow operation with one recirculation loop-out of service:
In lieu of the requirement of Technical Specification 3.4.1.1 LCO and action a and Specification 3/4.4.1.3, the unit may be operated with one -recirculation loop out o f service provided all of the following provisions are me t:
l (a)
The steady state thermal power. level will not exceed 50%
o f raced.
(b)
The Minimum Critical Power Ratio (MCPR) Safety Limit will t
be increased by 0.01 ( T.S. 2.1. 2).
(c)
The MCPR Limiting Condition for Operation (LCO) will be increased by 0.01.
( T. S. 3. 2. 3).
(d)
The Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) limits will be multiplied by a reduction factor o f 0. 8 7.
(T.S. 3.2.1)
(e)
The APRM Scram and Rod Block Setpoints and the SBM Setpoints shall be reduced by 5.3% to read as follows:
T.S. 2. 2.1 ( Tabl e 2. 2.1-1) :
S 10.66W+ 45.7 ( Trip setpoint)
S6 0.66W+ 48.7 (Allowable value)
T.S.3.2.2:
SS( 0.6 6W+ 4 5. 7 T*
SRB $ (0.66W+ 36.7)T*
T.S. 3. 3. 6 ( Tabl e 3. 3.6-2) :
APRM Upscalef 0.66W+ 36.7 ( Trip Setpoint)'
Sr 0.66W+ 39.7 ( Allowable Valve)
RBM Upscale 6 0.66W+ 34.7 ( Trip Setpoint) 1 0.66W+ 37.7 ( Allowable Value)
- T is defined in T.S.
3.2.2.
(f)
APRM flux noise will be measured once per shif t and the recirculation loop flow will be reduced if the flux noise averaged over 1/2 hour exceeds 5% peak to peak, as measured on the APRM chart recorder.
(g)
The core plate delta p noise will be measured once per shif t and the recirculation loop flow will be reduced if the noise exceeds 1 psi peak to peak.
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