ML20133K762
| ML20133K762 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 06/29/1996 |
| From: | Querio R COMMONWEALTH EDISON CO. |
| To: | Miller H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 9701210335 | |
| Download: ML20133K762 (10) | |
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Commonwealth Edison Company
- Lasalle Generating Station 3
2601 North 21st Road Marseilles. IL 61.44 l-9'5" TelKl%.W 4>'61 1
June 29,1996 Regional Administrator, Region III U. S. Nuclear Regulatory Commission c'"-
801 Warrenville Road Lisle, Illinois 60532-4351
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Subject:
LaSalle Station Units 1 and 2 Request For Regional Notification of Enforcement Discretion to Facility Operating License NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374
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Dear Mr. Miller,
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The purpose of this letter is to confirm the results of a teleconference that took place between Commonwealth Edison (Comed) and the NRC Staff, at 1610 hours0.0186 days <br />0.447 hours <br />0.00266 weeks <br />6.12605e-4 months <br /> on June 29, 1996, in which Comed requested a Regional Notification of Enforcement Discretion from Technical Specification Limiting Condition for Operation (LCO) 3.03. ' Unit l'is presently in Mode 3, HOT SHUTDOWN, and Unit 2 is in Mode 3, HOT SHUTDOWN. This*LCO period will expire at 0615 hours0.00712 days <br />0.171 hours <br />0.00102 weeks <br />2.340075e-4 months <br />. CDT on June 30,1996 for Unit I and 1215,' June 30, 1996 for Unit 2. Comed requests that the allowed time for Unit I and Unit 2 to remain in the HOT SHUTDOWN condition be extended on a one time basis, from 0615 hours0.00712 days <br />0.171 hours <br />0.00102 weeks <br />2.340075e-4 months <br /> CDT on June 30,1996 to 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br />. CDT on July 9,1996. The basis for this request is' provided in the enclosed attachment.
If the above request for Enforcement Discretion is not granted, LaSalle County Station Unit I will be placed in Mode 4, COLD SHUTDOWN by 0615 hours0.00712 days <br />0.171 hours <br />0.00102 weeks <br />2.340075e-4 months <br /> CDT on June 30, 1996 and Unit 2 will be placed in Mode 4, COLD SHUTDOWN by 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br /> CDT on June 30,1996.
If there are any questions or comments concerni,ng this letter, please refer them to me at (815) 357-6761, extension 3600.
I 9701210335 960629 PDR ADOCK 05000373 d,
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Respectfully,
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. Querio Site Vice President LaSalle County Station cc:
Document Control Desk H. J. Miller, NRC Region HI Administrator
.c P. G. Brochman, NRC Senior Resident Inspector - LaSalle D. M. Skay, Project Manager - NRR - LaSalle F. Niziolek, Office of Nuclear Facility Safety - IDNS
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i ATTACHMENT REQUEST FOR ENFORCEMENT DISCRETION LASALLE COUNTY STATION UNITS 1 AND 2 June 29,1996
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TECHNICAL SPECIFICATION OR LICENSING C'ONDITION THAT WILL BE l
VIOLATED.
At 0615 a.m. CST on June 30,1996, LaSalle County Station Unit 1 Technical Specification Limiting Condition For Operation (LCO) 3.0.3 will require that Unit I be in the Cold Shutdown Condition.
At 1215 p.m. CST on June 30,1996, LaSalle C ty Station Unit 2 Technical Specification Limiting Condition For Operation (LCO) 3.0.3 will require that Unit 2 be in the Cold Shutdown Condition.
Tech Spec 3.0.3 specifies that when a Limiting Condition for Operation is not met, except as provided in the associated ACTION requirements, within I hour action shall be initiated to place the unit in an OPERATIONAL CONDITION in which the Specification does not apply by placing it, as applicable, in:
1.
At least STARTUP within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
At least IiOT SHUTDOWN within the following 6 houni, and 2.
3.
At least COLD SHUTDOWN within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
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1 The action to place the unit in COLD SHUTDOWN with the subsequent 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time limit is the portion of Technical Specification 3.0.3 which will be violated.
2.
EVENTS DESCRIPTION..
On Wednesday (6/19) afternoon shift, and again on Monday (6/24) day shift, a condition occurred that resulted in elevated Service Water (WS) Strainer differential pressure on all three non-essential Service Water Strainers. On both occasions pressure differential (dP) reached approximately 6 pounds per square inch difference (psid) on the Ul WS Strainer which was in a continuous backwash condition, and greater than 8 psid on the U0 and U2 WS Strainers. The dP on the U0 and U2 WS Strainers was excessive enough to prevent their respective baskets to rotate to fac.'litate strainer backwashes. On both occasions, Service Water header pressure reductions were observed.
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Just prior to the 6/24 occurrence, the OB Diesel Fire Pump (DFP) experienced a high temperature condition during surveillance testing. It is suspected that the condition causing the WS Strainer high dP also caused some fouling of the DFP Heat Exchanger M
On June 28,1996, while conducting' inspections in the Service Tunnel, large blocks of 1
material were discovered on the floor of the Service Water Tunnel which invalidated the i
Operability Evaluation that was currently in place. That evaluation assumed that all the -
material would float at the top of the Service Water Tunnel. A decision was then made 1
to declare the Safety Related Service Water systems inoperable and to take the j
commensurate actions outlined in Technical Specifications..
POTENTIAL CAURRR..
Material used to fill the cracks in the Lake Screen House basement floor and walls i
entered the Service Water Tunnel and caused the non-essential Service Water Strainer plugging and resulted in high strainer dP.
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THE NEED FOR PROMPT ACTION 4
i U1 and U2 Safety Related and Non-Safety Related Diesel Fire Pumps have been declared inoperable. To return them m operability the Service Water Tunnel foreign material i
i needs to be removed and the Safety and Non-safety Service Water system including diesel fire pumps will be inspected and cleaned i
j 3.
EVALUATION OF SAFETY SIGNIFICANCE OF PROPOSAL TO I
REMAIN IN HOT SHUTDOWN i
i This document will evaluate the Safety significance and potential consequences for the proposed course of action. The proposed course of action is to maintain both Unit I and
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2 in Hot Shutdown condition (OC3) for an extended period, to allow cleanup of foreign i
material from the service water tunnel.
1 The Unit I and Unit 2 Reactors will be maintained in Hot Shutdown (Operating j
Condition 3). By maintaining Unit I and Unit 2 in Hot Shutdown, the station car; me i
non-service water methods to maintain the reactors in a safe and stable condition.
- l. e While in Hot Shutdown, the units will be maintained adminstratively between 200 and i
250 psig reactor pressure. Decay heat will be removed to the Main Condensers, which are cooled by Cire Water and as such, are not subject to Service Water Strainer plugging.
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Further, by maintaining Hot Shutdown on Unit I and 2, the reactor water pressure will be maintained within the capability of 1) Condensate / Condensate Booster, and 2) Low 4
i Pressure Emergency Core Cooling and Low Pressure Core Spray pumps.
j LaSalle Station has alternate shutdown cooling methods available which are predicated i
upon the availability of Non-Essential Service Water. These alternate sources are of j
limited capacity, and as such, are not available at the present time. In the event that the first contingincy would be challenged or would fail, the second contingency would be to.
implement this alternate shutdown cooling system methodology using approved station l
procedures LOP-CD-10 and LOP-RT-13. This plan assumes that nonesential service
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water remains available.
RCIC and HPCS remain available as a final contingency option to maintain Hot l
Shutdown Reactor Pressure and water level. The pressure of 200 to 250 psig is sufficient for RCIC operation, and would not present a challenge to High Pressure Core Spray Operation.
The High Pressure Core Spray System will remain available. The station has performed calculations in the event that the Diesel Generator Cooling Water Supply should become unavailable, and has determined that a 10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> window exists before equipment area temperatures will reach critical values. Contingency plans have been formed and will be in place to provide an emergency source of cooling water to assure that control of Reactor Pressure will be maintained.
Station Emergency procedures (Emergency Operating procedures) exist for further contingencies. These procedures detail symptom based actions for Reactor pressure and i
Level controls. While it is not anticipated that such procedures will be required, they remain available for unforeseen circumstances.
EVALUATION OF LOSS OF EITHER OR BOTH NON-ESSENTIAL AND/OR ESSENTIAL SERVICE WATER.
LaSalle Station has established contingency plans to correct such casualties. These include plans to restore station air, Reactor Pressure Vessel Inventory control, Decay Heat Removal, and Fire protection.
These plans include the addition of two temporary fire truck pumpers provided by local
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fire departments. These units are capable of providing 2000 gpm at 150 psig to the units, and have been connected to plant systems.
Additional station procedures (LOA-ZZ-10) exist to further combat a loss of service water and restore non-essential services. These procedures will be implemented to assure that the station will remain in a safe configuration.
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i EVALUATION OF A LOSS OF OFFSITE POWER WHILE UNITS ARE IN HOT SHUTDOWN CONDITIONS.
i In the event of a loss of offsite power (LOOP), station Diesel generators are expected to i
start as designed. Contingency plans are in place to provide backup cooling water to the systems in the event that the normal cooling water supply should be compromised while the diesel generators are in operation.
t Station blackout procedure LOA-AP-101/201 addresses actions to take in the event of a j
l Connection to two independent Class IE supplies will be maintained through the Unit 1 l
and Unit 2 Station Aux Transformers, which reduces the probability of the occurrence of a LOOP to lowlevels.
From Probable Risk Assessment, minimizing the use of Residual Heat Removal Service l
Water Pumps during this situation, while staying in Hot Shutdown (OC 3) will result in i
minimized use of essential and non essential service water. As a result, the probability of j
core melt is reduced by staying in Hot Shutdown condition, rather than moving to Cold j
Shutdown condition, as the propagation of the foreign materials is controlled until the foreign materials can be removed from station piping and water supplies.
CONCLUSIONS
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l At this time, the proper course of action will be to maintain both Unit I and Unit 2 in Hot i
Shutdown condition. This will allow the station time to clean the foreign material from j
the Service Water Tunnel, while maintaining an adequate margin of safety to protect the j
health and safety of the public.
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Once this material has been removed from the Service Water Tunnel, it will be appropriate and proper for the station to picce Unit I and 2 in Cold Shutdown, or return Unit I and 2 to operation following appropriate review.
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EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION 1'
Commonwealth Edison has evaluated the proposed request for enforcement discretion and determined that it does not represent a significant hazards consideration. Based on the criteria for defining a significant hazards consideration established in 10CFR 50.92,
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Operation of LaSalle County Station Units I and 2 in accordance with the proposed request will not:
Involve a significant increase in the probability or consequences of an accident a.
previously evaluated because:
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.4 The proposed change to remain in HOT SHUTDOWN allows an additional method of decay heat removal (i.e. steaming to the main condenser) to remain available and allows for decay heat removal without placing the normal RHR shutdown cooling system in operation. Remaining in hot shutdown does not 1
increase the amount of decay heat generated and only slightly increase in the amount of sensible heat which would remain in the reactor coolant system compared to that occurring in cold shutdown conditions. Remaining in this j
condition allows the entire decay heat load to be removed with a system (circulating water) which is independent of the affected water tunnel.
Compensatory Action will be established to mitigate loss ofmain condenser.
Therefore the removal of decay heat in~HOf SHUTDOWN is preferred over returning to cold shutdown. The proposed changes'do not involve a significant l
increase in the probability or consequences of an accident previously evaluated.
b.
Create the possibility of a new or different kind of accident from any previously j
evaluated because The proposed changes do not create the possibility for an accident or malfunction j
of a different type than previously evaluated in the UFSAR. In the HOT SHUTDOWN condition, removal of decay heat can be areomplished, primary l
and secondary containment will remain in effect. All control rods are inserted
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There is no change made to system design conditions therefore there is not a 1
possibility of a different accident or malfunction type than previously evaluated.
i Involve a significant reduction in the margin of safety because:
c.
The proposed changes do not reduce the margin of safety as defined in the basis i
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for any Technical Specification. The Basis for Specification 3.0.3 states that the specification delineates the time limits for placing the unit in a safe shutdown condition when plant operation cannot be maintained within the limits for safe operation defined by the LCO and actions. The plant will be maintained in a safe shutdown condition during the period of time requested by the proposed change.
The 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> specified is the normal time for an orderly shutdown, however in i
this case it is shown that remaining in hot shutdown provides equivalent safe j
operation based on the condition of the units.
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ENVIRONMENTAL ASSESSMENT LaSalle County Station has evaluated the enforcement discretion against the criteria for identification oflicensing and regulatory actions requiring environmental assessment in accordance with 10CFR51.20. It has been determined that the proposed changes meet the criteria for a categorical exclusion as provided under 10CFR51.22(c)(9). This conclusion has been determined because the changes requested do not pose significant hazards considerations or do not involve a significant increase in'the amounts, and no l
significant changes in the types, of any effluents that may be released offsite.
Additionally, this request does not involve a significant increase in the individual or cumulative occupational radiation exposure.
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6.
PROPOSED COMPENSATORY ACTIONS
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Desired Confinuration Maintain Hot Shutdown (200 - 250 PSIG)
Reasons:
Minimizes Essential Service Water (CSCS) Pump Runs Reactor Core Isolation Cooling (RCIC) available Press allows for low pressure ECCS Injection Main Condenser Available As Heat Sink Main Steam Line Drains Condensate / Condensate Booster as Makeup
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Alternate Decay Heat Removal LOP-CD-10 (use of Main Condenser at higher flow rate)
LOP-RT-13 (use of Reactor Water Cleanup System) -
Limitations:
LOP-CD 4.5 Days Away (U2)
LOP-RT 17 Days Away (U2)
RCIC Pressure Control Mode:
Limitations:
Would add heat to Suppression Pool Limited Availability (10 hrs. w/o providing alternate room cooling)
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Non-Essential / (And/Or) Fe=ential Service Water Plunnina RPV Inventory Control-e RCIC Available for (10 hrs. w/o providing alternate room cooling)
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LPCS/LPCI/HPCS (limited w/o providing alternate room cooling) j 1 I Decay Heat Removal:
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RCIC 10 Hrs Based on area cooling
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.LPCI/LPCS Injection with SRV Return To Supp. Poolm (SRV Sta Air backed up by bottle banks) j a
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Fire Protection:
Pumpers (2000 GPMI50 PSIG)
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3rd Pumper Avail. (1000 GPM150 PSIG)
Diesel Fire Pumps (DFPs)(Admin OOS) 0A - First OB -Extreme Emergency I
h Heightened Level of Awareness Regarding Potential Plugging of Essential and Non-Essential Service Water Strainers.
Loss Of Non F===ati=1 (And/Or) Fa==ntial Service Water With A Ems Of Off-Site Power I
o Bounding case would include loss of Offsite Power w/o Service WNer Loss Risk ofLoss.of Off Site. Power tobe minimized by work restrictions (i.e.
switchyard.acpeas control,,. Operators' heightened level of awareness, Work Control review of scheduled maintenance activities)
Restore cooling te 0, l A, 2A Diesel Generatorss through alternate means
-RPVInventory Control RCIC (10 hrs. w/o providing alternate room cooling)
Oos Trainino/Awaranaes
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Leads established at the plant and simulator Develop Training for OPS Crews to Cover 3 Scenarios Desired Configuration Essential /Non-Essential Service Water Plugging 2 above and loss of Offsite Power Develop Comprehensive Briefing Material for on-shift crews.
7.
The ten day duration of the relief request is based on the length of time, that we currently l
estimate, will be required to clean and inspect the Service Water Tunnel as well as, the safety related, non-safety related service water systems, and Fire Protection Systems.
8.
This request for a Notification of Enforcement Discretion has been reviewed and i
approved by LaSalle senior management, as well as Onsite Review in accordance with LaSalle Station procedures.
9.
This request satisifies NOED criterion 2 for an operating plant given in NRC Administrative Letter 95-05, " Revision to Staff Guidance for Implementing NRC Policy on Notices of Enforcement Discretion, dated November 7,1995. The basis for this is provided in section 3 above.
10.
This is a one time request. Therefore a follow-up license amendment is not required.
11.
There are cunently no line-item improvements to the Technical Specifications nor Improved Technical Specifications that provide for relief from the COLD SHUT DOWN i
LCO requirements of Technical Specification 3.0.3.
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