ML20031F035
| ML20031F035 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 08/31/1981 |
| From: | Decker Q EG&G, INC. |
| To: | Shemanski P Office of Nuclear Reactor Regulation |
| References | |
| CON-FIN-A-6429 EGG-EA-5516, NUDOCS 8110190082 | |
| Download: ML20031F035 (18) | |
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i EGG-EA-5516 l
AUGUST 1981
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l TECHNICAL SPECIFICATIONS FOR REDUNDANT DECAY HEAT vo
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REMOVAL CAPABILITY, ARKANSAS NUCLEAR ONE, UNIT N0. 2 g
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y.3 This is an informal report intended for use as a preliminary or working document i
Prepared for the U.S. Nuclear Regulatory Commission Under DOE Contract No. DE-AC07-761001570 0
g g g g idaho FIN No. A6429 yD 8110190082 810831 PDR RES I.
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FORM EG1G-398 (Rev. I179)
INTERIM REPORT Accession No.
EGG-EA-5516 Report No.
Contract Program or Project
Title:
Selected Operating Reactor Issues Programs (III)
Subject of this Document:
Technical Specifications for Redundant Decay Heat Removal Capability, Arkansas Nuclear One, Unit No. 2 Type of Document:
Technical Evaluation Report Author (s):
NlC 20S08FC1 anC "001DIC8 Q. R. Decker SSIStance 36p0F:
D:ta of Document:
August 1981 R sponsible NRC Individual and NRC Office or Division:
Paul C. Shemanski, Division of Licensing Tnis document was prepared primarily for preliminary orinternat use. it has not received full review and approval. Since there may be substantive changes, this document should not be considered final.
EG&G Idaho, Inc.
Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C.
Under DOE Contract No. DE-AC07 76 f D01570 NRC FIN No.
A6429 INTERIM REPORT
0455J TECHNICAL SPECIFICATIONS FOR REDUNDANT DECAY HEAT REMOVAL CAPABILITY ARr'ANSAS NUCLEAR ONE, UNIT NO. 2 Docket No. 50-368 August 1981 Q. R. Decker Reliability and Statistics Branch Engineering Analysis Division EG&G Idaho, Inc.
NRC Research anc Tecinica' Assis':ance Report TAC No. 42107 him m ei re nmipum i a m i
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4 ABSTRACT In response to D. G. Eisenhut letter dated June 11, 1980, Arkansas Power & Light Co. submitted " Proposed Revisions to Technical Specifications" for the Arkansas Nuclear One, Unit No. 2.
These proposed revisions would provide for redundancy in decay heat removal capability in all modes of operation.
After review of the proposed revisions, it is concluded that existing and proposed technical specifications assure redundant decay heat remov61 capability in all operating modes except for. hot standby (mode 3).
FOREWORD This report is supplied as part of the." Selected Operating Reactor Issues Program (III)" being conducted for the U.S. Nuclear Regulatory Commission, Office of Nucletr Reactor Regulation, Division of Licensing, by
. c-EG&G Idaho, Inc., Reliability and Statistics Cranch.
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The U.S. Nuclear Regulatory Commission funded the work under the
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authorization, B&R.20,19 01 06, FIN No. A6429.
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4 CONTENTS l.G INTRODUCTION......................................................
1
'2.0 REVIEW CRITERIA...................................................
1 3.0 DISCUSSIONS AND EVALUATION........................................
2 3.1 Startup and Power Operations.................................
'2 3.2 Hot Standby..................................................
2 3.3 Shutdown.....................................................
3 s
3.4 Refueling....................................................
4
4.0 CONCLUSION
S.......................................................
4
5.0 REFERENCES
4 APPENDIX A--NRC MODEL TECHNICAL SPECIFICATI0h5.........................
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i TECHNICAL EVALUATION REPORT TECHNICAL SPECIFICATIONS FOR REDUNDANT DECAY HEAT REMOVAL CAPABILITY ARKANSAS NUCLEAR ONE, UNIT NO. 2 1 '
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1.0 INTRODUCTION
A number of events have occurred at operating PWR facilities where decay heat removal capability has been seriously degraded due to inade-quateadministrativecontrolsduringshutdownmodesofgperation. One of these events, described in IE Information Notice 80-20, occurred at the Davis-Besse, Unit No. 1 plant on April 19, 1980.
In IE Bulletin 80-122 dated May 9,1980, licensees were requested to inuediately implement admin-istrative controls'which would ensure that proper rraans are available to provide redundant methods of decay. heat removal. While the function of the bulletin was to effect immedia 2 action with regard to this problem, the NRC considered it necessary thht ai. amendment of each license be made to provide for permanent long term assurance that_ redundancy in decay heat removal capability will be maintained.
By letter date June 11, 1980,3 all PWR licensees were requested to propose Technicsi Specification (TS) changes that provide for redundancy in decay heat removel capability in all modes of operation; use the NRC model TS which provide an acceptable solu-tion of the concern and include an appropriate safety analysis as a basis; and submit toe proposed TS with the basis by-October 11, 1980.
Arkansas Power & Light Co. (AP&L) submitted proposed revisions for decay heat removal to their TS for Arkansas Nuclear Ore, Unit 2 (ANO-2), on October 31, 1980.4 2.0 REVIEW CRITER,A 1
The review criteria for this task are contained in the June 11, 1980 letter from the NRC to all PWR licensees. The HRC provided the model tech-nical specifications (MTS)5 which identify the normal required redundant coolant system ano the required actions when redundant systems are not available for a typical four loop plant (Appendix A).
The general review i
criteria are:
1.
Two independent mrthods for decay heat removal are required in the plant TS for each operating mode.
2.
Periodic surveillance requirements should insure the operability of the systems.
The specific sections of the Combustion Engineering Standard Technical Specifications 5 that apply to this task are as follows:
3/4.4 Reactor Coolant System
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-3/4.4.1 Reactor Coolant System and' Coolant Circulation l'
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Startup and Power Opecation (modes 1 & 2) 3.4.1.1 Limiting Conditions for Operation 4.4.1.1 Surveillance Requirement Hot Stanaby (mode 3) 3.4.1.2 Limiting Conditions for Operation 4.4.1.2.1 Surveillance Requirement 4.4.1.2.2 Surveillance Requirenent Shutdown (modes 4 & 5) 3.4.1.3 Limiting Conditions for Operation 4.4.1.3.1 Surveillance Requirenent 4.4.i.3.2 Surveillance Requirement 4.4.1.3.3 Surveillance Requirement 4.4.1.3.4 Surveillance Requirement Refueling Operations _(c.de 6) 3.5.8.1 9 Condition for Operation 3.9.8.2 Li.ocing Condition for Operation 4.9.8.1 Sur eillance Requirement 4.9.8.2 Sur.eillance Requirement 3.0 DISCUSSION AND EVALUATION Arkansas Nuclear Une, Unit 2, is a two coolant loop Combustion Engi-neering (CE) PWR plant.
Due to plant design the proposed TS for this plant vary f rom the NRC model developed from Westinghouse stancard TS.
The following discussion takes into account the differences between the two different plant technical specifications.
3.1 Startup and Power Operation--Modes 1 and 2 The proposed TS require that both reactor coolant loops and coolant pumps are to be operational.
If these conditions are not met, the reactor is to be in Hot Stanaby (Mode 3) within 1!nour. The proposea TS require verification that the required reactor coolant loops are in operation at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
The above describec proposea TS are in agreement with the MTS since two coolant loops are required and the periodic surveillance assures the operability of the systems.
3.2 Hot Stanaby--Mode 3 The proposed TS require two coolant loops and at least one associatec coolant pump for each loop shall be operable and at least one of the coolant I
i 2
loops shall be in operation during this operating mode.a There are nu proposed requirements for operation or operability of as:cciated steam gen-erators. Section-3.1.1.26 of existing approved plant TS require only one steam generator to be operable during the hot standby mode. The pr oposed.
TS require the plant to be in Hot Shutdown (Mode 4 & 5) in 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> it the two coolant loops are not operable and cannot.be restored to operable status in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, suspend all operations involving a redaction in boron concen-tration in the coolant system and initiate corrective action to return the coolant loop to operation. Proposed TS require verification that at least I
one coolant pump is operable once per 7 days and at least one cooling loop 4,
is in operation at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
i The proposed and existing plant TS are 'n agreenent with the MTS; except that the MTS require at least two steau generators to be operable during this operating mode.
The proposed and existing TS surveillance
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requirements are in agreement with the MTS requirements.
l 3.3 Shutdown--Modes 4 & Sb l
The proposed TS satisfy the requirements for the shutdown modes by i
having(at least two coolant loops operable; either the two reactor coolant loops including at least one of their associated coolant pumps and their associatedsteamgenerators)orthetwoshutdowncoolingloops.c The TS also require one of the above loops to be in operation.
If this criteria is not met and immediate corrective action does not restore the loop (s) to operable or operational status, the reactor is to be in Cold Shutdown within 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br /> and reduction of boron concentration operations are to be suspended.
l a.
All reactor coolant pumps maj be de-energized for up to I hour provideo i
(1) no operations are permitted that would cause dilution of the reactor coolant system boron concentration, and (2) core outlet temperature is maintained at least 100F below saturation temperature, b.
A reactor coolant pump shall not be started with one or more of the RCS j '
cold leg temperatures less than or equal to 2750F unless:
(1) the pressuriter water volume is less than 600 cubic feet or (2) the secondary-water temperature of each steam generator is less than 430F (310F when measured by a surface contact instrument) above each of the RCS. cold leg temperatures.
l c.
The normal or emergency power source may be inoperable in MODE S.
d.
All reactor coolant pumps and shutdown cooling pumps may be de-energized for up to I hour provided: '(1) no operations are permitteo that would cause dilution of the reactor. coolant svstem boron 3
cuncentration, and (2) core outlet temperature is liaintained at least iOOF below saturation temperature.
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The requirements for this mode of operation 'are met by requiring two coolant loops and associated pumps to be operable with one of the two oper-ating. Operation and operability of the loops is required to be verified periodically.
3.4 Refueling--Modej AP&L did not propose new technical specification) for all water levels (per MTS 3.9.8.1 and 4.9.8.1) as existing approved TSD meet the require-ments of the MTS.
However they did' provide proposed TS for the low water level.
In the low water level mode, (<23 feet water above the reactor pres-sure vessel tlange) if either of the shutdown cooling loops are determined inoperable, the proposed TS require that immediate corrective action be initiated to return the required cooling loop (s) to operable sta+us.
The proposed TS for the low water level agree with the MTS; requiring at least two cooling loops be operable and surveillance to assure their operability.
6 include provisions Section_3.8 of Arkansas Nuclear One, Unit 2, TS requiring redundant heat removal capability for all water levels. This satisfies the requirements of the NCR.
4.0 CONCLUSION
The AP&L proposed and existing TS do not meet the MTS redunaancy requirements during the ANU-2 hot standby mode; since, the TS do not require two steam generators to be operable. The ANO-2 proposed ano existing TS satisfy the redundancy and' surveillance requirments in all other operating modes.and provide redundancy with respect to single failure considerations..
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5.0 REFERENCES
1.
NRC IE Information Notice 80-20, May 8, 1980.
2.
NRC IE Bulletin 80-12, May 9, 1980.
l 3.
NRC Letter, D. G. Eisenhut, To.All Operating Pressurized Water Reactors (PWR's), dated June 11, 1980.
4.
AP&L Letter, W. Cavanaugh to C, D. G. Eisenhut, dated October 31, 1980.
L 5.
Standard Technic 61 Specifications f or Combustion Engineering' Pre. cur-ized Water Reactors, NUREG-0212, Rev.-1, Fall 1980.
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Arkansas Nuclear One, Unit 2, License Applicatf-:, FSAR,-Volume VIII.
'(Arkansas Power & Light Co., Little Rock, Arkansas) 1974.
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APPENDIX A MODEL TECHNICAL SPECIFICATIONS FOR REDUNDANT DECAY HEAT REMOVAL FOR ALL PRESSURIZEP WATER REACTORS (PWR's) l O
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3/4.4 REACTOR COULANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION STARTUP AND POWER OPERATION LIMITlNG CONDITION FOR OPERATION 3.4.1.1 All reactor coolant loops shall be in operation.
APPLICABILITY: MODES 1 and 2.*
ACTION:
With less than the above required reactor coolant loops in operation, be in at least HOT STANDBY within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.
SURVEILLANCE REQUIREMENT 4.4.1..
The above required reactor coolant loops shall be verified to be in operation and circulating reactor coolant at least ance per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
See Special Test Exception 3.10.4.
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l REACTOR COOLANT SYSTEM HOT STANDBY LIMITING CONDITION FOR OPERATION 3.4.1.2 a.
At least two of the reactor coolant loops listed below shall be OPERABLE:
1.
Reactor Coolant Loop (A) and its associated steam generator and reactor coolant pump, l
2.
Reactor Coolant Loop (B) and its associated steam generator and reactor coolant pump, 3.
Reactor Coolant Loop (C) and its associated steam generatcr and reactor coolant pump, 4.
Reactor Coolant Loop (D) ano its associated steam generator and reactor coolant pump.
b.
At least one of the above coolant loops shall be in operation.*
APPLICABILITY: MODE 3 ACTION:
a.
With less than tne above required reactor coolant loops OPERABLE, restore the recuired loops to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
All reactor coolant pumps may be de-energized for up to 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> provided (1) no operations are permitted that would cause dilution of tha reactor coolant system baron concentration,'and (2) core outlet temperature is e
maintained at ' east 100F below saturation temperatree.
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REACTOR LOOLANT SYSTEM b.
With no reactor coolant loop in operation, suspend all operations involvi:3 a reduction in boron concentiation of the Reactor Coolant System and immediately initiate corrective action to return the required coolant loop to operation.
,'dVEILLANCE REQUIREMENT 5L 4.4.1.2.1 At least the above required reactor coolant pumps, if not in operatica, shall be determined to be OPERABLE once per 7 aays by verifying correct breaker alignments and indicated power availability.
4.4.1.2.2 At least one cooling loop shall be verified to be in operation and circulating reactor coolant at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
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REACTOR COOLANT SYSTEM SHUTOOWN LIMITING CONDITION FOR OPERATION 3.4.1.3 a.
At 1. cst two of the coolant loops listed below shall be OPERABLE:
1.
Reactor Coolant Loop (A) and its associatea steam gen-erator and reactor coolant pump,*
2.
Reactor Coolant Loop (B) and its associated steam gen-erator and reactor coolant pump,*
3.
Reactor Coolant Loop (C) and its associated steam gen-er: tor and reactor coolant pump,*
4.
Reactor Coolant Loop (D) and its associated stean, gen-erator and reactor coolant pump,*
5.
Residual Heat Removal Loop (A),**
6.
Residual Heat Removal Loop (B).**
b.
At least one of the ab ve coolant loops shall be in operation.***
A reactor cool'.t pump shall not be started with one or more of the RCS cold leg tempe otures less than or equal to (275)0F unless 1) f.:.e pressurizer water volume is les: than cuoic feet or 2) the secondary water temperature of each steam generator is less than
'F above each of the RCS cold leg temperatures.
The normal or emergency power source may be 'noperable in MODE 5.
All reactor coola.t pumps and decay heat removal pumps may be ce-energized for up to I hour provided 1) no operations are permitleo that would cause dilution of the reactor coolant system boron concentration, and
- 2) core outlet temperature is maintained at least 100F below saturation temperature.
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REACTOR COOLANT SYSTEM APPLICABILITY: MODES 4 and 5.
ACTION:
a.
With less than the above required loops OPERABLE, immediately initiate corrective action to return the required loops to OPEkAblE status as soon as possible; be in COLD SHUT 00nh within 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />.
b.
With no coolant loop in operation, suspend all operations involving a reduction in boron concentration of the Reactor Coolant System and innediately initiate corrective action to return the required coolant loop to operation.
SURVEILLANCE REQUIREMENT 4.4.1.3.1 The requirea residual heat removal loop (S) shall be determinea OPERABLE per Specification 4.0.5.
4.4.1.3.2 The required reactor coolant pump (s), if not in operation, snall be aetermined to be OPERABLE once per 7 days by verifying correct breaker alignments ana inaicated power availability.
4.4.1.3.3 The required steam generator (s) shall be determined OPERABLE by verifying seconaary side level to be greater than or equal to (
)% at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
4.4.1.3.4 At least one coolant loop shall be verified to be in operation and circulating reactor coolant at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
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REFUEllhG OPERATIONS 3/4.9.8 RESIUUAL HEAT REMOVAL AND COOLANT CIRCULATION ALL WATER LEVELS LIMITING CONDITION FOR UPERATION 3.9.8.1 At least one residual heat removal (RHR) loop shall be in operation.
APPLICABILITY: MODE 6
>CTION:
a.
With less than one residual heat removal loop in operation, except as provided in b. below, suspend all operations involving an increase in the reactor decav heat load or a reauction in boron concentration of the Reactor Coolant System.
Close all containment penetrations provioinc direct access from the con-tainmeri atmosphere to the outside atmosphere within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, b.
The residual heat removal loop may be removed from operation for up to I hour per 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> period during the performance of CORE ALTERATIONS in the vicinity of the reactor pressure vessel (iot) legs.
c.
The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENT 4.9.8.1 At least one residual heat removal loop shall be verified to be in operation and circulating reactor coolant at a flow rate of greater than or equal to (2800) gpm at least once per 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
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REFUELING OPERATIONS LOW WATER LEVEL LIMITlhG CONDITION FOR OPERATION 3.9.8.2 Two indepenaent Residual Heat Removal (RHR) loops snall be OPERABLE.*
APPLICABILITY: MODE 6 when '.he water level above the top of the irraciated fuel assemblies seated within the reactor pressure vessel is less than 23 feet.
ACTION:
a.
With less than the renuired RHR loops OPERABLE. inneciately initiate corrective action to return the requirea RHR loops to OPERABLE status as soon as possible.
b.
The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIRLMENT 4.9.8.2 The required Residual Heat Removal loops shall be determined OPERABLE per Specification 4.0.5.
The nonnal or emergency power source may be inoperable for each HHR loop.
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3/4.4 REACTOR C09LANT SYSTEM BASES 3/4.4.1 REACTOR COULANT LOOPS nWO COOLANT CIRCULATION The plant is designed to operate with all reactor coolant loops in operation, and maintain DNBR above 1.30 during all normal operations and anticipated transients.
In MODES 1 and 2 with one reactor coolant loop not I
in operation this specification requires _that the plant be in at least HOT STANDBY within I hour.
In MODE 3, a single reactor coolant loop provides sufficient heat removal capability for removing decay heat; however, single failure con-siderations require that-two loops be OPERABLE.
In MODES 4 ana 5, a single rt or coolant loop or RHR loop provides sufficient heat removal capability for removing decay heat; but single i
failure considerations require that at least two loops be OPERABLE. Thus, if the reactor coolant loops are not OPERABLE, this specification requires i
The operation of one Reactor Coolant Pump or one RhR pump provioes adequate flow to ensure mixing, prevent stratification and produce gradua' reactivity changes during boron concentration reductions in the Reactor Coolant System.
The reactivity change rate associated with boron reduction will, therefore, be within the capability of operator recognition ano control.
l The restrictions on starting a Reactor Coolant Pump with one or more l
RCS cold legs less than or equal to (275)0F are provided to prevent RCS pressure transients, caused by energy additions from the secondary system, l
which could exceed the limits of Appendix G to 10 CFR Part 50. The RCS i
will be protected against overpressure transients and will not exceed the I
limits of Appendix G by either (1) restricting the water volume in the pressurizer and thereby providing a volume for the primary coolant to expand into, or (2) by restricting starting of the RCPs to when the secon-dary water temperature of each steam generator is less than (
)0F above each of the RCS cold leg temperatures.
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REFUELING OPERATIONS BASES 3/4.9.8 RESIDUAL HEAT REMOVAL AND COULANT CIRCULATION The requirement that at least one residual heat removal (RHR) loop be in operation ensures that (1) sufficient cooling capacity is available to remove decay heat and maintain the water in the reactor pressure vessel below 140 F as required during the REFUELING MODE, and (2) sufficieri cool-ant circulation is maintained through the reactor core to minimize the effect of a boron dilution incident and prevent boron stratification.
The requirement to have two RHR loops UPERABLE when there is less than 23 feet of water above the core ensures that a single failure of the oper-ating RHR loo? will not result in a complete loss of residual heat removal capability. Witn the reactor vessel head removed ano 23 feet of water above the core, a large heat sink is available for core cooling.
Inus, in the event of a failure of the operating RHR loop, adequate time is provided to initiate emergency procedures to cool the core.
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