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cAIOCKET FILE SEP 2 81980 ASB READING PCheck Docket Hos:
50-343 and 50-364 ME'10RA?IDUM FOR: Robert L. Tedesco, Assistant Director for Licensing, DCL FROM:
Thomas M. Novak, Assistant Director, for Operating Reactors, DOL FROM:
Paul S. Check, Assistant Director for Plant Systens, DSI SUdJECT:
FARLEY tlUCLEAR PLANT UNITS 1 & 2 - SAFETY EVALUATI0tl REPORT - ASB's INPUT ON THE IMPLEMENTATION OF REC 0mENDATI0 tis FOR THE AUXILIARY FEED',lATER SYSTEMS
~ provides the Auxiliary Systems Granch (AS3) Safety Evaluation Report (SER) input for the Farley Nuclear Plant, Units 1 and 2 Auxiliary Feedwater System (AFilS) reliability evaluation.
In a letter dated October 13, 1979, the NRC forwarded to Alaoama Power Company our requirements regarding tne Unit 1 AP.iS. These requirenents are identified in NUREG-CCll,
" Generic Evaluation of Feedwater Transients and Small Break Loss of Coolant A7.idents In Nestinghouse-Designed OperatioU Plants." Alabana Power Company provided responses in letters dated Novencer 20,1979, May 27,1300, April 1, 1960, and July 16, 1900.
In an April 17, 1980 conference call with Alabana Power Company, the licensee made comitments to document the similarity of the Auxiliary Feddwater System for Units 1 and 2.
In an April 21, 1980 letter the licensee docunented the similarity and verified that the designs were essentially identical. The re-fore, our Safety Evaluation Report applies equally to both units.
For Farley Unit 2 the enclosure is Auxiliary Systens Branch's input to SER Supolement No. 5 which resolves Task Action Plan II.E.1.1 which is a requirenent for a full power license. The enclosure also resolves Task Action Plan Item II.E.1.1 for Farley Uni t 1.
Recorrendations GS-7 and GL-5 (automatic initiation) and additional short tern recorrendation No. 3 (flow indication) are currently being evaluated lsy tne Instrumentation and Control Systens 3 ranch, and our Safety Evaluatsio input will De provided at a later date.
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ENCLOSURE FARLEY NUCLEAR PLANT, UNITS 1 & 2 IMPLEMENTATIONS OF RECOMMENDATIONS FOR AUXILIARY FEED'JATER SYSTEMS I.
Introduction and Background The Three Mile Island Unit 2 (TMI-2) accident and subsequent investigations and studies highlighted the importance of the Auxiliary Feedwater System (AF45) in the mitigation of transients and accidents. As Part of our assessment of the TMI-2 accident and related implications for operating plants, we evaluated the AF4 systems for all operating and near-term operating license plants having nuclear steam supply systems (NSSS) designed by 'destinghouse (NUREG-0611) or Combustion Engineering (NUREG-0635). Our evaluations of these system designs are contained in the NUREGs along with our recommendations for each plant and the concerns which led to each recomendation. The objectives of the evalua-tion were to:
(1) identify necessary changes in AF4 system design or related procedures in order to assure the safe operation of these plants, and (2) to identify other system characteristics of the AF4 systems which, on a long term basis, may require system modifications. To accomplish these objectives we:
(1) Reviewed plant specific AFJ system designs in light of current regulatory requirements (SRP) and, (2) Assessed the relative reliability of the various AF4 systems under various loss of feedwater transients (one of which was the initiating event of TMI-2) and other postulated failure conditions by determining the cotential for AFJ system failure due to comon causes, single point vulnerabilities, and human error.
_2-
'de concluded that the implementation of the recommendations identified during this review will considerably improve the reliability of the AFW Systems for each,Jerating plant.
The following plant specific recommendations did not apply to this plant:
GS-1, GS-2, GS-3, GS-8, GL-1, GL-2 and GL-4.
The basis for these recommendations can be found in Appendix III of NUREG-0611, and the
- .ystem description which detemined the basis for not applying these recommendations can be found in Appendix X of NUREG-0611.
II.
Implementation of Our Recomendations A.
Short Term Recommendations 1.
Recomendation GS-4
" Emergency procedures for transferring to alternate sources of AP1 supply should be available to the plant operators. These procedures should include criteria to infom the operator wnen, and in what order, the transfer to alternate water sources should take place. The following cases should be covered by the procedures:
- The case in which tne primary water supply is not initially available. The procedures for this case should include any operator actions required to protect the AP4 system pumos against self-damage before water flow is initiated; and,
- The case in wnich the primary water supp'y is being depleted.
The procedure for this case should previde for transfer to the alternate water sources prior to draining of the primary water sucoly."
In response to this recormendation (November 20, 1979 letter) the licensee has developed and implemented procedures that include criteria to inform the coerator when to transfer to the alternate source and include actions required to protect the auxiliary feed-water system pumps against self-damage before water flow is initiated.
Based on the licensee's implementation of these procedures we conclude that the licensee's response to this recomendation is acceptable pending verification by the Division of Inspection and Enforcement.
2.
_ Recommendation GS The as-built plant should be capable of pro-viding the required ARi flow for at least two hours from one AFW pump train independent of any alternating current power source. If manual AR4 system initiation or flow control is required following a complete loss of alternating current power, emergency procedures should be established for manually initiating and controlling the system under these conditions. Since the water for cooling of the lube oil for the turbine-driven pump bearings may be dependent on alternating current power, design or procedural changes shall be made to eliminate this dependency as soon as practicable. Until this is done, the emergency procedures should provide for an individual to be stationed at the turoine-driven pump in the event of the loss of all alternating current power to monitor pump bearing and/or lobe oil temperatures.
If necessary, this operator would operate the turbine-driven pump in an on-off-mode until alternating current power is restored. Adequate lighting powered by direct current power sources and comunications at local stations should also be provided if manual initiation and control a +5e AFW system is needed.
(See Recommendation GL-3 for the longer-tenn resolution of this concern.)
. The licensee in its letter dated November 20, 1979, stated that a licensing basis for the AFW system (Farley 1) was that the turbine driven pump be capable of one hour of operation independent of all AC power. The steam admission valves require both DC power and an operable air supply for the valves to open and allow turbine opera-tion. These valves are provided with air reservoirs of sufficient capacity to open the valves and allow turbine operation. Although the licensing basis was one hour of turbine operation, two hour turbine operation was used as the c-iginal design basis.
In our letter dated April 8,1980, we requested the licensee to perfom appropriate periodic testing to demonstrate that the air reservoirs meet the minimum requirements (2 '1ours) since the air reservoirs are relied on to perform a safety function following a loss of air or a loss of all AC power.
If the air reservoirs cannot meet the two hour requirement, we required that the licensee establish emergency procedures for manually initiating and controlling the system independent of any AC power source. The licensee in its letter dated May 27, 1980, agreed to perform periodic testing of the air reservoirs and to establish appropriate emergency procedures if the reservoirs do not meet the two hour requirement.
Based on the licensee's omitment to perform periodic tests to demonstrate two hour capability of the air reservoir system and its further commitment to establish emergency procedures if the two hour requirement cannot be met we conclude that the licensee's response to this recommendation is acceptable.
. 3.
Recommendation GS The licensee should confim flow path availability of an AFA system flow train that has been out of service to perform periodic testing or maintenance as follows:
- Procedures should be implemented to require an operator to determine that the APA system valves are properly aligned and a second operator to independently verify that the valves are properly aligned.
- The licensee should propose Technical Specifications to assure that prior to plant startup following an extended cold shutdown, a flow test would be perfomed to verify the nomal flow path from the primary AFA system water source to the steam generators. The flow test should be conducted with AP4 system valves in their nomal alignment.
The licensee in letters dated November 20, 1979, and May 27, 1980, stated that administrative controls have been implemented and written into appropriate plant procedures or directives which require that after maintenance which could affect valve alignment or after a refueling outage a system valve lineup verification will be perfomed by a second individual who holds a reactor operator's license.
The licensee, by letter dated November 20, 1979, also committed to revise his technical specification to require that a flow test be performed to verify that each AFA pump will deliver flow to each steam generator following an extended cold shutdown.
. The licensee's response meets the requirements of this recommendation and is, therefore, acceptable.
B.
Additional Short Term Recommendations 1.
Recommendation - The licensee should provide redundant level indica-tions and low level alarms in the control room for the AFd system primary water supply to allow the operator to anticipate the need to make up water or transfer to an alternate water supply and prevent a low pump suction pressure condition from occurring. The low level alarm setpoint should allow at least 20 minutes for operator action, assuming that the largest capacity APW pump is operating.
In response to tnis recommendation by letters dated November 20, 1979, and May 27, 1980, the licensee has committed to install redundant safety grade (Class IE) instrumentation and power supplies. Based on the licensee's commitment to install a redundant safety grade conden-sate storage tank level indication system we conclude that the response is acceptable.
2.
Reconrendation (This recommendation has been revised from the oricinal recommendation in NUREG-0611) - The licensee should perfom a 48-hour endurance test on all AFd system pumps, if such a test or continuous period of operation has not been accomplished to date. Following the 48-hour pump run, the pumps should be shut down and cooled down and then restarted and run for one hour. Test acceptance criteria should include demonstrating that the pumps remain within design limits with
. respect to bearing / bearing oil temperatures and vibration and that pump room ambient conditions (temperature, humidity) do not exceed environmental qualification limits for safety-related equipment in the room.
In letters dated May 27, 1980, (Farley 1) and July 16,1980, (Farley
- 2) the licensee provided the results of the endurance tests for both the motor driven and turbine driven pumps. The results included:
(a) a description of the test method and how the tests were instru-mented, (b) a description of how the test conditions compared to design operating conditions, (c) plots of bearing or bearing oil temperatures vs. time for each bearing demonstrating that limits were not exceeded, (d) plots of pump room ambient temperature and humidity vs. time, and (e) a statement confiming that the pump vibration did not exceed allowable limits during the tests.
We have reviewed the test method and test results and conclude that no design limits were exceeded during the 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> tests. We, there-fore, conclude that the licensee has met this recommendation, and the AF4 pumps are acceptable for long term operation.
4.
Recommendation - Licensees with plants which require local manual realignment of valves to conduct periodic tests on one AFW system train and which have only cne remaining AP4 train available for operation, should propose Technical Specifications to provide that
. a dedicated individual who is in communication with the control room be stationed at the manual valves. Upon instruction from the control room, this operator would re-align the valves in the AFW system train from the test mode to its operational alignment.
In a letter dated November 20, 1979, the licensee stated that this recommendation does not apply to the Farley design.
Since two pumps are always available during testing of either train and since local realignment of valves is not necessary during periodic tests, we agree with the licensee that this recommendation is not applicable to the Farley Nuclear Plant.
C.
Lona Term Recommendations 1.
Recommendation GL At least one AFW system pump and its associated flow path and essential instrumentation should automatically initiate ARi system flow and be capable of being operated indeoendently of any alternating current power source for at least two hours. Conversion
.cf direct current power to alternating current is acceptable.
As indicated in the evaluation of GS-5 above, the Farley AFW system turbine driven pump is designed to be automatically initiated and controlled for at least two hours independent of any AC power.
The licensee's commitment to perform periodic tests to demonstrate that the two hour requirement is met meets the requirement for the short and long term aspect of this recommendation. We, therefore, conclude that the licensee's response to this recommendation is acceptable.
9-D.
Recommendation " Basis for Auxiliary Fecdwater System Flow Requirements _"_
As a result of recent staff reviews of operating plant Auxiliary Feedwater Systems (AP45), the staff concluded that the design bases and criteria provided by licensees for establishing AF'45 requirements for flow to the steam generator (s) to assure adequate renoval of reactor decay heat are not well defined or documented.
'de required that the licensee provide AFWS flow design bases infonnation as applicable to the design basis transients and accident conditions for the Farley plant.
By letter dated April 1,1980, the licensee provided responses to titis recommendation. These responses included results of analyses where 'neces-sary to show that sufficient AFW flow could be delivered by the Farley AFW system design to meet the minimum heat removal requirements following any design basis transient or accident and assuming the worst case single active failure. These analyses also bounded the heat removal requirements following a complete loss of all AC power assuming the turbine driven AF4 pump is available since it operates independently of AC power. We have reviewed the licensee's responses and the results of their analyses which show that the minimum required flow can be met by one 350 gpm motor driven pump and that the maximum allowable flow of 880 gpm following a steam line rupture will not be exceeded based on the AF4 system design.
Based on our review we conclude that the Farley AF4 system design meets the minimum flow requirements and, therefore, the licensee's response to this recommendation is acceptable.