ML17228A983
| ML17228A983 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 01/18/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17228A982 | List: |
| References | |
| NUDOCS 9501240168 | |
| Download: ML17228A983 (8) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 S
T EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATIO RELATED TO AMENDMENT NOS.
131 AND 70 0 FACILITY OPERATING ICENSE NO DPR-67 A D NO. NPF-16 F ORIDA PO E
ST.
DOCKET NOS. 50-335 AND 50-389
- 1. 0 INTRODUCTION By application dated November 2, 1994, the Florida Power
& Light Company (the licensee) requested changes to the St. Lucie Units 1
& 2 Technical Specifications (TS).
The proposed TS changes would clarify the actions required in the event of inoperable equipment associated with the containment'epressurization and cooling systems, and provide consistency between Unit 1; and Unit 2 requirements.
TS 3/4.6.2.1, "Containment Spray System" and 3/4.6.2.3, "Containment Cooling System" would be combined into a single specification 3/4.6.2, "Containment Spray and Cooling Systems."
Fan cooler surveillance requirements would also be affected to the extent that the 31-day surveillance intervals need not be established on a "staggered test basis."
2.0 DISCUSSION AND EVALUATION
- 2. 1 ST.
LUCIE CONTAINMENT HEAT REMOVAL SYSTEMS The safety design requirement for containment heat removal equipment is to be able to cool and depressurize the containment to 50X of its peak accident pressure within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after a Design Basis Accident (DBA) and maintain the containment at that pressure or less for a 30-day period.
This function is provided by the Containment Spray System and the Containment Cooling System.
These systems are required for mitigation of a DBA and are thus classified as Engineered Safety Features (ESFs).
During normal plant operation, the Containment Cooling System serves to maintain the containment temperature below 120'F.
The Containment Spray System is not used during normal operation.
2.1.1 CONTAINMENT SPRAY SYSTEM The function of the Containment Spray System is to provide containment heat removal and iodine removal during accident conditions.
It accomplishes its function through the use of two redundant spray trains.
Each train consists 9501240168 950118 PDR
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of a pump, chemical
- eductor, shutdown heat exchanger, piping, valves, and a
spray header having four nozzle rings and a minimum of 178 nozzles.
On a
containment spray initiation signal (CSIS) the system is initiated with the pumps taking suction from the Refueling Water Tank (RWT).
On a recirculation actuation signal (RAS),
pump suction is automatically switched to the containment sump.
An RAS is generated when the RWT reaches low level.
A Spray Additive System provides NaOH solution to the containment spray fluid via the eductor to ensure a post-accident pH value in the sump between 8.5 and 11.0.
This pH band minimizes the evolution of iodine and the corrosive effects, of chloride.
Cooling water for the heat exchanger is from the Component Cooling Mater System.
Each train of the Containment Spray System is capable of providing SOX of the post accident heat removal requirements and (if the non-redundant chemical addition system is operable) 100X of the iodine removal requirements.
- 2. 1.2 CONTAINMENT COOLING SYSTEM The Containment Cooling System consists of four fan coolers that discharge via back draft dampers into ducts which lead to a ring header.
The cooled air is discharged from the ring header via registers and air outlets to the containment atmosphere in a manner designed to prevent stratification.
During normal operation, three fan coolers are in use with the fans operating at high speed.
Cooling water for the fan coil units is from the Component Cooling Water System.
The fan coolers are arranged in two trains.
Each train of two fan coolers is capable of providing SOX of the post-DBA heat removal requirement.
2.2 PROPOSED TS CHANGES 2.2. I ALLOWABLE OUTAGE TINE CHANGES There are seven degraded conditions for which TS allowable outage times (AOTs) would be affected.
The table (Page
- 6) summarizes the proposed changes for each degraded condition.
The staff evaluated the proposed AOT changes against the criteria of the NUREG-1432 Standard Technical Specifications (STS).
The STS AOTs are based on the systems being designed to the following generic criteria; (a) each spray train is capable of meeting 50X of the total heat removal design requirement and IOOX of the iodine removal design requirement, (b) each fan cooler train is capable of meeting 50X of the total heat removal design requirement and (c) one spray train is capable of iodine removal in accordance with radiological dose consequences analytical calculations.
The licensee's application states that each St. Lucie fan cooler train is capable of satisfying at least 50X of accident heat removal requirements, and that each train of containment spray can satisfy 100X of the iodine removal requirements and 50X of accident heat removal requirements.
The design of the St. Lucie containment heat removal systems are thus consistent with the design requirements upon which the generic STS operability requirements are predicated.
Based on the systems descriptions provided in the Final Safety Analysis Reports, the plant-specific
equipment is similar to that presumed for the generic STS (i.e.,
number of
- pumps, valves, fancoil units, heat exchangers, support
- systems, etc.).
Accordingly, the generic STS completion times, where proposed, are acceptable for St. Lucie.
The STS criteria generally provide a 72-hour AOT for degraded ESF functions for conditions where operable capacity has degraded from 200X to
- 100X, and 7 days for conditions where operable capacity has degraded from 200X to 150X.
A discussion of each affected AOT is provided below.
Note:
"CONDITION" refers to row position in the table.
CONDITION 1, ONE SPRAY TRAIN INOPERABLE (ALL FAN COOLERS OPERABLE),
Ppz~
P 1750 PSIA The licensee proposes to bring the AOTs into consistency for the two units.
The new AOTs would be consistent with STS except that 54 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br /> would be allowed between Mode 3 and Mode 4.
The STS specify 84 hours9.722222e-4 days <br />0.0233 hours <br />1.388889e-4 weeks <br />3.1962e-5 months <br /> from Mode 3 to Mode 5.
However, since the St Lucie facilities do not need chemical additive spray to mitigate a
DBA in Mode 4, a less restrictive 54-hour action to be in Mode 4 is acceptable.
CONDITION 2, ONE SPRAY TRAIN INOPERABLE AND ONE FAN COOLER INOPERABLE, PpzR
> 1750 PS IA The AOT for this condition would be relaxed to appropriately reflect the capacity and redundancy (100X for both cooling and fission product removal) provided by the multiple trains of heat removal equipment that remain operable.
The proposed AOT conforms to the STS requirements.
As noted
- above, the STS criteria are appropriate for St. Lucie.
CONDITION 3 ONE FAN COOLER INOPERABLE PpzR >
1 750 PS IA The differing AOTs for each unit would be brought into consistency with the STS.
As noted
- above, the STS criteria are appropriate for St. Lucie.
~ CONDITION 4, BOTH TRAINS OF FAN COOLERS INOPERABLE (SPRAY OPERABLE),
Pp~
~ 1750 PSIA The AOT would be revised to appropriately reflect the heat and fission product removal capability of the remaining operable spray systems (100X for both cooling and fission product removal).
The change is consistent with the STS.
As noted above, the STS criteria are appropriate for St. Lucie.
CONDITION 5 TWO FAN COOLERS INOPERABLE IN THE SAME TRAIN PpzR
> 1750 PSIA The AOTs for this condition would be relaxed to appropriately reflect the heat removal capability of the remaining operable equipment (150X for containment cooling and 200X for fission product.removal).
The proposed AOTs are the same I
v I
as for condition 3 reflecting the fact that both fan coolers in a train must be operable for the train to be operable.
The change is consistent with the STS and is appropriate fo} St Lucie.
CONDITION.6, ONE FAN COOLER INOPERABLE, Pp~ < 1750 PSIA The proposed change provides an appropriate AOT for a condition in which fission product removal capability is not required and the spray systems will be unavailable.
The change is consistent with the STS and is appropriate for St. Lucie.
CONDITION 7~
TWO FAN COOLERS INOPERABLE IN THE SAME TRAIN Ppz~ < 1750 PSIA
, The proposed AOT, as for condition 5 above, would appropriately reflect the heat removal capability of the remaining operable train and the unavailability of other means of containment heat removal.
The change is consistent with the STS and is appropriate for St. Lucie.
2.2.2 SURVEILLANCE REQUIREMENTS FOR FAN COOLERS TS 4.6.2.3 specifies that the fan coolers be tested at 31-day intervals on a
"staggered test basis."
This means that the 31-day test interval is divided,'nto four equal subintervals with one cooler tested at the beginning of each subinterval.
The reason for staggered testing is to increase the rapidity of detection of common mode failures.
The proposed change would eliminate the stagger feature.
The staff examined the Licensee Event Report (LER) records for the St. Lucie facilities to determine if continued staggered testing was warranted by past operating history.
Of interest were (a) an LER which reported two fan coolers inoperable based on low CCW water flow due to low flow alarm settings (LER 91-004 for Unit 2),
and (b) an LER reporting failure of a fan cooler to start due to dirty breaker contacts (LER 83-008 for Unit 1).
Upon full review of the LERs, the staff determined that the staggered test requirement was not a
factor in the timing of the discovery of the reported failures.
Due to the fan coolers having flow alarms, staggered testing is of minor, if any, benefit.
Since the fan coolers are served by a closed cooling water system, no significant or rapid fouling is expected within the 31-day interval.
- Also, there are other routine actions, such as weekly valve status checks and containment temperature monitoring, that provide additional assurance that fan coolers are operable.
In addition, elimination of staggered testing is consistent with the new STS which no longer specifies that fan cooler tests be on a staggered basis.
Based on the above reasons, the staff concludes that a 31-day test interval for each cooler, independent of the schedules for testing of other coolers, is acceptable.
- 3. 0 TECHNICAL FINDINGS The licensee has proposed TS changes which (a) provide a significant improvement is consistency and format and (b) ensure the availability of sufficient containment heat and fission product removal equipment consistent with the generic staff positions relating to the reliability of these systems.
The proposed changes are therefore acceptable.
4.0
~ETATE CONEELTA ITIN Based upon the written notice of the proposed amendments, the Florida State official had no comments.
5.0 I ONMENT L CONSIDERATION These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The amendments also change surveillance requirements.
The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration and there has been no public comment on such finding (59 FR 63122).
Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
0.0
~OCL ETON The Commission has concluded, based on the considerations discussed
- above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety 'of the public.
Principal Contributor:
M. Long, NRR/DSSA/SCSB Date:
January 18, 1995
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APPL'ICABILITY AFFECTED CURRENT ACTIOH REGUIREHEHT PROPOSED ACTION REQUIREHENT HOOE 1, NODE 2 AND NODE 3 MITH PRESSURIZER PRESSURE 8
1750 PSIA
- l. OHE SPRAY TRAIN INOPERABLE (ALL FOUR FAH COOLERS OPERABLE) 2.
ONE SPRAY TRAIN INOPERABLE AHD OHE FAH COOLER INOPERABLE 3.
ONE FAN COOLER INOPERABLE (BOTH SPRAY TRAINS OPERABLE) 4.
BOTH TRAINS OF FAH COOLERS INOPERABLE (BOTH TRAINS OF CONTAINHEHT UNIT I
~E I OR 2:
RESTORE INOPERABLE SPRAY ADDITIVE SYSTEH MITHIH 72 HOURS OR BE IN NODE 3 MITHIH THE NEXT 6 HOURS IH NODE 3:
RESTORE SPRAY ADDITIVE SYSTEH MITHIN THE HEXT 48 HOURS OR BE IN NODE 4 MITHIH THE FOLLOMIHG 30 HOURS.
UNIT 2 TH HOOE 1
OR 2:
RESTORE INOPERABLE SPRAY SYSTEH MITHIN 72 HOURS OR BE IN AT LEAST H(eE 3 MITHIN THE NEXT 6
HOURS'H H(X)E 3:
RESTORE THE IHOPERABLE SPRAY SYSTEH MITHIH THE NEXT 48 HOURS OR BE IN HOOE 4 IJITHIH THE OM 0
HOUR RESTORE EITHER THE INOPERABLE SPRAY TRAIN OR INOPERABLE FAH COOLER MITHIH 72 HOURS OR BE IN HOT SHUTDOMH lJITHIN THE NEXT 12 HOURS UNIT 1
%FffRE THE FAN COOLER MITHIN 30 DAYS OR BE IH HOOE 4 MITHIN THE NEXT 12 HOURS UHIT 2
~E I OR 2:
RESTORE THE FAH COOLER MITHIN 72 HOURS OR BE IN NODE 3 IJITHIN THE NEXT 6 HOURS IN HOOE 3:
RESTORE THE FAH COOLER MITHIN THE NEXT 48 HOURS OR BE IN HJSE 4 MITHIH THE FOLLOMIHG 30 HOURS.
ENTER LCO 3.0.3 RESTORE INOPERABLE SPRAY TRAIN MITHIH 72 HOURS AHD MITHIH 10 DAYS FROH INITIALDISCOVERY OF FAILURE TO NEET THE LCO OR BE IH NODE 3 MITHIN THE NEXT 6 HOURS AND MODE 4 MITHIH THE FOLLOMING 54 HOURS RESTORE THE FAH COOLER TRAIN MITHIN 7 DAYS AND 'MITHIH 10 DAYS OF DISCOVERY OF FAILURE TO NEET THE LCO, AND RESTORE THE SPRAY TRAIN MITHIN 72 HOURS AHD MITHIN 10 DAYS FROH DISCOVERY OF INITIAL FAILURE TO MEET THE LCO EACH OF THE ABOVE ACTIONS IS TO BE SEPARATELY TRACKED FROH TINE OF DISCOVERY RESTORE FAN COOLER TRAIN TO OPERABILITY lJITHIH 7 DAYS AHD MITHIH 10 DAYS FROH INITIAL DISCOVERY OF FAILURE TO NEET THE LCO OR BE IN NODE 3 'MITHIN THE NEXT 6 HOURS AND IH NODE 4 MITHIH THE FOLLOMING 6 HOURS RESTORE OHE TRAIH lJITHIN 72 HOURS OR BE IH HOOE 3 MITHIN THE HEXT 6 HOURS AHD NODE 4 lJITHIN THE FOLLOMIHG 6 HOURS JHmE 3 MITH PRESSURIZER PRESSURE c
1750 PSIA (NOTE: SPRAY SYSTEHS ARE DEACTIVATED IH THIS CONDITION) 5.
TMO FAH COOLERS INOPERABLE IN THE SANE FAN COOLER TRAIN (BOTH SPRAY TRAINS OPERABLE 6.
ONE FAN COOLER INOPERABLE 7.
TMO FAN COOLERS IHOPERABLE IH THE SANE FAH COOLER TRAIN ENTER LCO 3.0.3 UNIT 1
KKTKE INOPERABLE FAN COOLER MITHIN 30 DAYS OR BE IN HOT SKUTDOMH MITHIN THE NEXT 12 HOURS UNIT 2 HRKRE I OR 2:
RESTORE INOPERABLE FAN COOLER MITHIN 72 HOURS OR BE IN AT LEAST HOT STANDBY 'M!THIN THE HEXT 6 HOURS'N HOOE 3:
RESTORE THE INOPERABLE FAN COOLER MITHIH THE NEXT 48 HOURS OR BE IN COLD SHUTDOMN MITHIH THE FOLLOMING 30 HOURS.
ENTER 3.0.3 RESTORE FAH COOLER TRAIN TO OPERABILITY MITHIN 7 DAYS AND MITHIH 10 DAYS FROH INITIAL DISCOVERY OF FAILURE TO MEET THE LCO OR BE IN NODE 3 MITHIN THE NEXT 6 HOURS AND IH NODE 4 MITHIN THE FOLLOMING 6 HOURS RESTORE THE INOPERABLE FAN COOLER TRAIN MITHIN 72 HOURS OR BE IN HOOE 4 lJITHIN THE NEXT 6 HOURS RESTORE THE INOPERABLE FAH COOLER TRAIN MITHIN 72 HOURS OR BE IN NODE 4 MITHIN THE NEXT 6 HOURS