ML17174A289
| ML17174A289 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, Zion  |
| Issue date: | 12/14/1979 |
| From: | Peoples D COMMONWEALTH EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0578 NUDOCS 7912270469 | |
| Download: ML17174A289 (8) | |
Text
e
!)_. Commonwe. Edison One First National Plaza. Ch.icago, Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690 December 144 1919 Mr. Darrell G. Eisenhut, Acting Director Division of Operating Reactors U.S. Nuclear Regulatory Commission Washington, D.C. 20555
Subject:
References (a) :
( b) :
( c) :
( d) :
( e) :
( f) :
Dear Mr. Eisenhut:
Dresden Station Units 1, 2 and 3 Quad Cities Station Units 1 and 2 Zion Station Units 1 and 2 Additional Response to NRC Lessons Learned Recommendations 2.l.7a and 2.l.7b NRC Docket Nos. 50-10/237/246, 50-254/265, and 50-295/304.
October 18, 1979 letter from C. Reed to D. G. E isenhut.
November 21, 1979 letter from C. Reed to H. R. Denton.
November 30, 1979 letter from C. Reed to H. R. Denton.
December 3, 1979 letter from D. L. Peoples to H. R. Denton.
September 13, 1979 letter from D. G. Eisenhut to all operating reactors October 30, 1979 letter from H. R. Denton to all operating reactors.
References (a) through (d) contain Commonwealth Edison Company's commitments to meet the near term requirements of the Lessons Learned and Emergency Preparedness Task Force as outlined in Reference (e) and supplemented in Reference (f).
A December 10, 1979 phone conversation with members of your staff indicated the. need for additional information with regard to our response to Lessons Learned Recommendations 2.l.7a and 2.l.7b, "AFW System Automatic Initiation" and "AFW System Flow Indication,.qo3' to Steam Generator". to this letter contains the S
requested information.
This information is applicable only toA" ill ul):
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Mr. Darrell G. Eisenhut e
Commonwealth Edison NRC Docket Nos. 50-10/237/246, 50-254/265, and 50-295/304 2 -
December 14, 1979 Zion Station as Dresden and Quad Cities Stations do not have auxiliary feedwater systems.
One (1) signed original and seventy-nine (79) copies of this transmittal are provided for your use.
However, one complete set of the associated drawings supporting the responses in Attach-ment 1 are being transmitted under separate cover to Mr. P. R.
Matthews of your staff.
Very truly yours,
/I.if(~
.. #. D. L. Pe~pQ.,. _,,.,_
D~ector of Nuclear Licensing WFN:rap Attachment
- -lo ATTACHMENT 1 NRC Dock~os. 50-10/237/246, 50-254/265, and 50-295/304 COMMONWEALTH EDISON COMPANY RESPONSE TO NRC STAFF'S REQUEST FOR ADDITIONAL INFORMATION ON LESSONS LEARNED RECOMMENDATIONS 2.l.7a and 2.l.7b
The following information and.list of drawings should demonstrate conformance to the referenced criteria:
- 1.
2.l.7a Auto-Initiation of Auxiliary Feedwater
- Criterion 1 "The design shall provide for the automatic initiation of the Auxiliary Feedwater System."
Response
Refer to FSAR Sections 6.7.2 and 14.1.9 and Westinghouse Drawing No. 5653D30 Sheets 1, 5, 7, 8 and 15 (copies sent under separate cover).
Criterion 2 "The automatic initiation signals and circuits shall be designed so that a single failure will not result in the loss of Auxiliary Feed-water System function."
Response
Refer to FSAR Sections 7.5.1 and 7.5.2, response to FSAR Question 7.24, and Westinghouse, Drawing No. 5653D30 Sheet 15 (copies sent under separate cover).
Criterion 3 "Testability of the initiating signals and circuits shall be a feature of the design."
Response
As stated in Reference (a) and as described in Zion FSAR Section 6.7.2, the auxiliary feedwater system at the Zion Station is automatically initiat~d by the following:
- low-low steam generator level
- loss of off-site power
- safety injection signal Provisions have been incorporated into the design of the auxiliary feedwater system's initiation signals and circuits such that tests may be performed to demonstrate and verify initiation of the auxiliary feedwater system from any of these conditions.
The test of the auxiliary feedwater initiation signals and circuits at the Zion Station is ac-complished in (2) two phases.
The first phase is the Safeguard Logic's Test during which the logi relays and circuits of the auxiliary feedwater system are tested for operability.
This test is performed independently for each train.
These Safeguards Logic Tests are performed monthly.
(Reference FSAR Section 7.5 page 7.5~7 "Engineered Safety Features Logic Testing".)
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The second phase is the Safeguards Equipment Actuation Test.
During this test simulated actuation signals for low-low steam generator level, loss of offsite power, and safety injection are applied through the test circuits and operation of the respective auxiliary feedwater pump is verified.
Actuation tests for low-low steam generator level and* loss of*offsite power are conducted mont~ly.
The actuation test for safety injection is performed quarterly.
Cri~erion 4 "The initiating signals and circuits shall be powered from the emergency buses."
Response
Refer to response to FSAR Question 7.24, FSAR Section 6.7, Section 8.5, ~nd S&L Drawing Nos. 22E-l-4240, 22E-l-4483, and 22E-l-4484 (copies sent under separate cover)
- Criterion 5 "Manual capability to initiate the auxiliary feedwater system from the control room shall be retained and shall be implemented so that a single failure in the manual circuits will not result in the loss of system function."
Response
Criterion 6
Response
Refer to FSAR Section 6.7 and Westinghouse Drawing No. 5653D30 Sheet 15 (copies sent under separate cover) *
"The a-c motor-driven pumps and valves in the auxiliary feedwater system shall be included in the automatic actuation (simultaneous and/or sequential) of the loads onto the emergency buses."
Refer to FSAR Section 8.4.3 (Table 8.4-2) and S&L Drawings 22E-l-4000B, 22E-l-4000C, 22E-l-4000H, J, P, Q, AH, AJ, AM, AN, 22E-l-4000AP, AT, AU, AW, AX, (copies sent under separate cover).
- Criterion 7 "The automatic initiating signals and circuits shall be designed so that their failure will not result in the loss of manual capability
Response
to initiate the AFWS from the controJ. r<uorn."
Refer to FSAR Section 6.7, response to FSAR Question 7.24,Westinghouse Drawing No. 5653D30 Sheet 15 (copies sent under separate cover).
Clarifications 1 through 5 (From Reference (f), October 30, 1979 H. R. Denton letter)
- 1.
Provide automatic/manual initiation of AFWS.
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- 2.
Testability of the initiating signals and circuits is required.
- 3.
Initiating signals and circuits shall be powered from the emergency buses.
- 4.
Necessary pumps and valves shall be included in the.automatic sequence of the loads to the emergency buses.
Verify that the addition of these loads does not compromise the emergency diesel generating capacity.
- 5.
Failur~ in the automatic circuits shall not result in the loss of manual capability to initiate the AFWS from the control room.
Response
covered by responses to Criteria 1 through 7 above.
Clarification 6 "a.
For those designs where instrument air is needed for operation, the electric power supply require-ment should be capable of being manually connected to emergency power sources."
Response
FSAR Section 6.7.2 states that the Auxiliary Feedwater System control is accomplished by means of an air operated control valve.
The motor driven air compressors are capable of being manually connected to emergency power sources (Diesel-Generators).
Refer to FSAR 8.4.3 (Table 8.4-2).
As a further precaution, should the air supply to the valves fail, motor operated valves can be utilized for control.
- 2.
2.l.7b Auxiliary Feed Flow Indication Criterion 1
Response
"Saf~ty-grade indication of auxiliary feed-water flow to each steam generator shall be provided in th~ control room."
Four flow indicators for Auxiliary Feedwater flow to each steam generator are provided on the control room panel 1CB12.
The flow transmitters are environmentally and seismically qualified.
The indicators are not seismically qualified and therefore, that portion of the circuit is not considered to be safety grade.
Refer to S&L Drawing No. 22E-l-4863 (copies sent under separate cover).
Criterion 2 "The auxiliary feedwater flow instrument channels shall be powered from the emergency buses consistent with satisfying the emergency power diversity requirements of the auxiliary feedwater system set forth in Auxiliary
Response
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Systems Branch Technical Position 10-1 of the Standard Review Plan, Section 10.4.9."
The Auxiliary Feedwater flow instrument channels are powered from 120V AC instrument distribution cabinet #114 which is powered from 7.SkVA inverter #114 (uninterruptible power source).
Refer to FSAR Section 8.5 and S&L Drawing Nos.
22E-l-4484 and 22E-l-4863 (copies sent under separate cover)..
Clarification A-1 (From Reference (f), October 30, 1979 H. R.
Denton letter)
"Auxiliary feedwater flow indication to each steam generator shall satisfy the single failure criterion."
Response
As stated in Reference (a), the auxiliary feedwater flow to each steam generator is indicated in the Zion control room and in addition, each steam generator level is indicated on three narrow range and one wide range gauge in the control room.
Clarification A-2 "Testability of the auxiliary feedwater flow indication channel~ shall be a feature of the design."
Response
The design of the auxiliary feedwater flow indication channels is such that testability is a feature.
The feedwater flow indications to each steam generator are tested and calibrated during each refueling outage.
The three narrow range steam generator level indication channels are tested and calibrated during each refueling outage.
Tne wide range steam generator level indication channels are tested and calibrated every (4) four years.
Clarification A-3 "Auxiliary feedwater flow instrument channels shall be powered from the vital instrument buses."
Response
Covered by response to Criterion 2 above.
Clarification B-1 "Safety-Grade (Long-Term)
Auxiliary feedwater flow indication to each steam generator Shall satisfy safety-grade requirements."
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Response
Refer to our response to Criterion 1 above.
Clarification C-1 "For the Short-Term the flow indication channels should by themselves satisfy the single failure criterion for each steam generator.
As a fall-back position, one auxiliary feedwater flow channel may be backed up by a steam generator level channel."
Response
Refer to response to Clarification A-1 above.
Refer to S&L Drawing Nos. 22E-l-4863 and 22E-l-4793 Page FW3 (copies sent under separate cover)
- Clarification C-2 "Each auxiliary feed water channel should provide an indication of feed flow with an accuracy on the order of + 10%."
Response
Each Auxiliary Feedwater channel does provide an indication of feed flow with an accuracy on the order of + 10%.