ML19321B114
| ML19321B114 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 06/16/1980 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Kay J YANKEE ATOMIC ELECTRIC CO. |
| References | |
| TASK-10, TASK-RR NUDOCS 8007280008 | |
| Download: ML19321B114 (7) | |
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UNITED STATES g
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June 16, 1980 Docket No. 50-29 1
i Mr. James A. Kay Senior Engineer - Licensing Yankee Atomic Electric Cogany 25 Research Drive Westborough, Massachusetts 01581
Dear Mr. Kay:
RE: MRC REQUIREENTS FOR AUXILIARY FF.EDWATER (AFW) SYSTEM AT YANKEE R0WE We have revietrd your submittal dated Decerrber 21, 1979, in response to the subject requirements, identified in our letter dated November 9,1979.
The staff positions in the enclosure to this letter indicate the status of our review of your responses to our requirements.- The encicsure also identifies the additional information needed to coglete our review of item C.1, "AWF System AC Power Dependency GL-3".
As indicated in the enclosure, items D.1, " Protection Against Internally and Externally Generated Missiles", and D.2, " Automatic Initiation and Termination of AFW Flow to Steam Generators", will be evaluated under the Systematic Evaluation Program (SEP) and will be addressed in a separate safety evaluation report to be issued by the SEP.
You are requested, within 30 days from receipt of this letter, to submit the needed information concerning item C.1, and to indicate your intentions with respect to meeting the requirements identified in the enclosure in staff position C.3.
Sincerely,
- 0. dw Gus C. Lainas Assistant Director for Safety Assessment
/, Division of Licensing
Enclosure:
As stated cc w/ enclosure:
See next page 18007280006
La Mr. Janes A. Kay June 16, 1980 cc w/ enclosure:
Mr. James E. Tribble, President Yankee Atomic Electric Company 25 Research Drive Westborough, Massachusetts 01581 Greenfield Connunity College 1 College Drive Greenfield, Massachusetts 01301 Chairman Board of Selectmen Town of Rowe Rowe, Massach:.setts 01367 Energy Facilities Siting Council 14th Floor One Ashburton Place Boston, Massachusetts 02108 Director, Technical Assessment Division Office of Radiation Programs (AW-459)
U. S. Environmental Protection Agency Crystal Mall #2 Arlington, Virginia 20460 U. S. Environmental Protection Agency Region I Office ATTN: EIS C0ORDINATOR JFK Federal Building Boston, Massachusetts 02203
L-i STAFF POSITIONS AUXILIARY FEEDWATER SYSTEM RELIABILITY EVALUATION f
YANKEE R0WE DOCKET N0. 50-29 A.
Short Tenn Generic Recommendations 1.
Reconsnendation GS-2 The licensee's response is acceptable. Prese.cly, all single valves or i
nultiple valves in series in the flow path which could interrupt the AFW flow are maintained in locked open position. These valves are verified every 15 days to be locked open by existing operating procedure.
In addition, the technical specifications require that the position.of all AFW valves in this flow path that are not locked, sealed or otherwise secured in position be verified at 15 day intervals. The licensee has submitted a proposed change to these technical specifications to require that each valve in the flow path which could interrupt all AW ils be locked open and that the position of all valves be verified eury 15 dcys.
2.
Recommendation GS-4 The response is acceptable. The licensee indicates that the existing operating procedures have been revised to include the transfer of AFW suction to its alternate water sources.
3.
Reconsnendation GS-5 The licensee's response is acceptable. The AFW system at Yankee Rowe is capable of providing adequate flow for at least two hours following f
a couplete loss of AC power. The system is manually started and control-led using the existing operating procedures. The AFW punp bearings do not require external cooling water and pung sealing water is provided by gravity flow from the Demine..aed Water Storage Tank (DWST).
Emergency lighting and a plant consnunication system are provided at the pump and at the control valve station. Emergency lighting is battery powered and the consnunication system can be powered from the vital bus.
4.
Recommendation GS-6 The licensee's response is acceptable. The operating procedures presently used at Yankee Rowe require operational testing following maintenance and verification of valve line-up following system testing. The operating procedures have been modified to require a second operator to verify independently that the valves are properly aligned. The licensee has submitted a proposed revision to the technical specification requiring that prior to startup from cold shutdown the AFW flow path will be verified both by valve line-up and by flow testing.
4 I
, i 5.
Recommendation - Cycling of Manual Valves The licensee's response is acceptable. The operating procedures have been changed to require a quarterly exercise of the normally closed valves in the connection bat.reen the charging pumps, safety injectio..
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punps and the AFW system.
B.
Additional Short Term Reconsnendations i
1.
Primary AFW Source Low Level Alarm The licensee's response is acceptable. Yankee Rowe has one pneumatic level instrumentation loop for the primary water supply. An additional electronic level instrument loop with indication on the main control board indicated by a pressure switch will be instdled in the pneumatic level loop. Each low level annunciator setpoirc will permit the operator at least 20 minutes to change over to an alternate source of water.
2.
AFW Pump Endurance Test The licensee indicated that an endurance test will be performed during the 1980 refueling outage. We will require that an endurance test be conducted for each AFW pump in accordance with the attached revised l
Additional Short Term Reconmendation No. 2.
Note that the test require-ment has been reduced from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The licensee informed us that the required AFW pump endurance test has been conpleted and that the requested test information will be submitted.
3.
Dedicated Crqator for Local Manual Realignment of Valves Tha licensee's response is acceptable. The operation off the AFW system does not require manual realignment of valves to conduct periodic tests.
The initiation of AFW would simply require opening the AFW to the main feedwater isolation valves and throttling the recirculation valve. A dedicated operator is already provided and is in continuous connunicatinq with the control room when the AFW pump is running.
C.
Long Term Recommendations 1.
AFW System AC Power Dependency GL-3 The licensee's response is incouplete. The present AFW pump at Yankee Rowe is a bladed turbine driven reciprocating positive displacement punp.
It was not designed for sudden starts. Normal starting procedure has the pump recirculation line open. Thus the pump is started manually i
and brought up to speed without ioad. The load is gradually applied by opening the flow control valve and slowly closing the recirculating valve.
I A dedicated AFW system operator has been provided for this purpose. The 1
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. operator has approximately one hour's time to perform the manual actions since the steam generator at Yankee Rowe has relatively long dry-out times.
In addition, the licensee has proposed to provide two additional motor driven AFW pumps which can be started remotely from the control room as well as started locally for all events when AC is available. These pumps and associated equipment will be installed at the first refueling outage following pump delivery. We require that the licensee provide drawings indicating the locations of the motor driven AFW punps and the associated piping arrangement.
In the event of loss of AC power to operate the electric criven AFW pumps, the operator will have ample time to start the steam driven emergency boiler feed pump. Existing procedures for starting this pump will be used if the electric driven pumps are not available in the event of loss of AC power.
2.
The licensee's response is acceptable. Refer to Item C.1 above.
3.
Postulated High Energy Line Break The licensee's response is acceptable. However, we will require the licensee to revise the plant operating procedures to include the operation of the charging pumps or safety injection pumps in the event that the normal AFW system flots path is not available.
4.
Impact of Containment Isolation Signal on Steam Supply Line to AFW Turbine The licensee's response is acceptable. The air operated trip valve in the steam header which supplies steam to the turbine driven pump will not be tripped on a Safety Injection Actuation Signal (SIAS).
5.
Emergency Power Supply to the Charging Pumps The licensee's e esponse is acceptable. The charging pumps can be manually operated from the emergency bus.
D.
Additional Long Term Concerns 1.
Protection Against Internally and Externally Generated Missiles 2.
Automatic Initiating & Termination of AFW Flow to Steam Generator The Yankee Rowe plant is within the scope of the Systemtic Evaluation Program (SEP). The additional long term concerns stated above will be evaluated by the SEP. The SEP will issue a separate Safety Evaluation Report in this regard.
Attachment:
As stated L
r ATTACHMENT Revision tc Recot:mer.dation No,'2 of " Additional Short Ter:-
Recommendetions" Regarding Auxiliary Feedwater Pump Endurance Test The licenses should perform an endurance test on all AA: system. pumps. The test should continue for at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after achieving the following I
test conditions:
- pump / driver operating at rated speed and
- pump developing rated discharge pressure and flow or some higher pressure at a reduced flow but not exceeding the pump vendor's maximum permitted discharge pressure value for a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> test
- Fo; turbine drivers, steam temperature should be as close to normal operating steam temperature as practicable but in no case should the temperature be less than 400*F.
1 Following the 48-hour pump rui, the pumps should be shut down and allowed to cool down until pump tamperatures reduce to within 20'F of their values at the start of the 48-hour test and at least 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> have elapsed.#
Following the cool down, the pumps should be restarted and run for one j
hour. Test acceptance criteria should include demonstrating that the pumps ret.ain within design limits with respect to bec.-ing/ bearing oil tempera-tures and vibration and that ambient pump room conditions (temperature, humidity) do not exceed environmental qualification limits for safety-i.
1 i'
related equipment'in the room.
The Itcensee'should provide a sumary of the conditions and results of the tests. The susrLey should include the fonowing: 1) A 5-ief descrip-ic-of the test mothed (incTuding flow schematic diepram) and how the test h
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L 2-was instrumented (i.e., where and how bearing tesperatures were measured).
2)'A discussion of how the test conditions (pump flow, head, speed and steam temperature) compara to design operating conditfor.s. 3) Plots of bearing / bearing oil temperature vs. time for each be ring of each a
AFW pump / driver demonstrating that temperature design limits were not exceeded. 4) A plot of pump room ambient temperature and humidity vs,.
time demonstrating that the pump room ambient conditions do not exceed environmental qualification limits for safety-related equipment in the roca. 5) A statement confirming that the pump vibration did not exceed allowable limits during tests.
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