ML19343D108
| ML19343D108 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 03/27/1981 |
| From: | Crouse R TOLEDO EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| I-193, IEB-80-06, IEB-80-6, NUDOCS 8104090454 | |
| Download: ML19343D108 (5) | |
Text
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TOLEDO
%mm EDISON Docket No. 50-346 RcHAAC E CWM${
License No. NPF-3 DE I419,259 5221 Serial No. 1-193 g
March 27, 1981 s
- h R [/Sg7A 944 Mr. James G. Keppler Z
Regional Director, Region III Office of Inspection and Enforcement E
Y U. S. Nuclear Regulatory Commission 799 Roosevelt Road
/
g Glen Ellyn, Illinois 60137 N
Dear Mr. Keppler:
This letter revises our previous response to IE Bulletin No. 80-06 submitted January 9, 1981 (Serial No. 1-183).
The attached response addresses the Engineered Safety Feature (ESF) and other Safety Related Systems reset controls as they relate to Davis-Besse Nuclear Power Station Unit No. 1.
Very truly yours, ff RPC/RFP: lab cc:
DB-1 NRC Resident Inspector Mr.
D. Garner, D.O.L., USNRC NRC Office of Inspection and Enforcement Division of Reactors Operations Inspection Washington, D.C.
20555
- APR 3y 8104o,9o454 Q
THE TOLEDO EDISON COMPANY EDISON PLAZA 300 MADISON AVENUE TOLEDO. OH!O 43652
' Docket No. 50-346 Lic:nsa No. NPF-3 Serial No. 1-193 March 27, 1981 ATTACHMENT 1 NRC IE BULLETIN 80-06 RESPONSE (REVISED)
Item 1:
Review the drawings for all systems serving safety related functions at the schematic level to determine whether or not upon the reset of an ESF actuation signal, all associated safety related equipment remains in its emergency mode.
Response
After re-reviewing at the schematic / elementary level all safety related components affected by the Safety Features Actuation System (SEAS) and the Reactor Protection System (RPS), we have confirmed that a reset alone will not auto-matically remove any component from the required safety position.
Another safety related system is the Steam and Feedwater Rupture Control '3ystem (SFRCS).
The SFRCS is an automatic self-resetting system t hose purpose is to ensure an adequate feedwater supply to th; NSSS steam generator to remove reactor decay heat during periods when the normal feedwater supply and/or electrical power supply to the essential-auxiliaries is not available.
In the event of a main feed-water line rupture, the SFRCS will align the auxiliary feedwater system to the unaffected steam generator. This-is accomplished by suitably controlling the steam inlet valves and discharge valves. associated with the auxiliary feedvater pumps (see FSAR Section.7.4.1.3).
If.the rupture condition for the affected steam generator is isolated, the system will automatically realign both auxiliary feed pumps to their respective steam generators.
Item 2:
Verify the actual installed instrumentation and controls'at-the facility are consistent with the schematics reviewed in item 1 above by conducting a test to demonstrate that all equipment remains in its emergency mode upon removal of the actuating signal and/or manual resetting of the various isolating or actuation signals.
Provide a schedule for the performance of the testing in your response to this Bulletin.
Response
Following is a description of the tests performed on the systems serving safety related functions (SFAS, SFRCS and RPS).
The SFAS has two actuation channels.
Both channels have been tested and verified for all the fans, pumps and the emergency diesel generator.
For the high pressure injection (HPI) pump, the decay heat (DH) pump and the containment spray (CS) pump, REVISED the breakers were tested and verified.
The rest of the pumps,
' fans and the emergency diesel generator were actually run and verified.
REVISED
Docket.Na. 50-346 Licensa No. NPF-3 Sarial No. 1-193 Pbrch 27, 1981 page 2
~
i' Most all SFAS valves for both the channels were tested and the results confirmed our findings of Item 1 for those valves tested. The main steam isolation valves and the atmospheric vent valves were tested by way of monitoring their solenoids-(energization and degeneration) and the results confirmed our REVISED findings of Item 1.
These valves were not actually cycled for lack of' steam in the operation mode when these valves were tested. The following valves could, however, not be tested for the reasons as given:
1.
DH2733 (due to the test set-up,' cycling this valve could have unnecessarily added water from Borated Water Storage Tank to the Reactor Coolant System).
2.
DH2734 (the test set-up required this valve to be open for providing suction to the decay heat pump 1-2 which was actually started).
3.
DH13B, DH14B (the decay heat removal train contain-ing these valves was in service and therefore these valves could not be cycled).
Corresponding valves on the other channel were tested.
The valves in Items 1, 2 and 3 above which were not tested will be tested within 60 days of the date of this letter.
REVISED There are four conditions which can trip the SFRCS; i.e.,
low main steam line pressure, low steam generator level, differential pressure between the main feedwater line and the steam generator and the loss of all four reactor coolant pumps. The first three input trips isolate the steam generators in each case. The fourth input trip does.not isolate the steam generators.
The last three input trips also start the two auxiliary feedwater pumps (AFP) on their respective steam generators.
The first input trip starts both AFP's on the unaffected steam generator (the steam generator with a low steam pressure is defined as the affected steam generator).
During the testing of SFRCS, all the associated valves with the system were tested as follows:
For a trip of SFRCS, all the associated valves except the atmospheric vent valves (ICSilA and ICSilB) were placed in the non-safety position before the trip.
During the-per-formance of the SFRCS test, it was verified that all valves move to their safety position and stay there on a SFRCS REVISED trip and remain there on a trip reset except FW779 and FW780. These two valves cycle open and clo'se continuously instead of closing and remaining closed. This cycling occurs only when the valve control switches are in the "0 PEN" position coincident with an SFRCS trip' signal.
REVISED
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Dockst No. 50-346 LLicense-No.-NPF-3
= Serial ~No. 1-193 b
March 27, 1981:
page.3
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The logic (relays)'which activates the atmospheric vent valves J
was tested for the SFRCS trip. -For these-two valves, the relays which deenergize their solenoids (to close the valves) are actuated in an identical-manner; i.e., deenergized by SFAS and SFRCS. These valves were tested for SFAS as. described.
earlier.
During the' actual reactor _ trips in the past, it-has been shown that on-resetting of the RPS,the associated control rod drive, breakers do not automatically close.
Item 3:
If any safety related equipment:does not remain in its' emergency mode upon reset of an ESF signal at your facility, describe proposed system modification, design change, or other corrective action planned to resolve ~the' problem.
Responsc:
The.tes, results as described in Item 2 indicate that in the.
SFAS all safety related equipment tested remains in its emergency mode upon reset of the ESF trip signal.
For RPS also, the safety _related. equipment remains in its emergency. mode;upon reset of Reactor Trip Signal.
In case of SFRCS, the controls of the two feedwater valves (FW779 and FW780) will be corrected by second refueling outage, presently scheduled for spring 1982.. In the meantime, the station procedures have been revised so that the: valves control switches cannot be left in the "0 PEN" position.
REVISED
SUBMITTAL FOR THE DAVIS-BESSE NUCLEAR POWER STATION UNIT 1 FACILITY OPERATING LICENSE NPF-3 IN RESPONSE TO A 10 CFR 50.54(f)
-REQUEST DATED MARCH 13, 1980-4 This response is filed in'accordance with 10 CFR 50.54(f) relating to Mr. James G..Keppler's letter of March 13, 1980. This deals with engineered safety features reset controls and revises the previous response submitted on January 9, 1981.
l By n _c -
Vice President, Nuclear Sworn to and subscribed before me the 27th of March, 1981.
l l
Nota (y Public JUDITH HIRSCH NotyyPublic, Wood County Ohio My Commission Expires June 30,1982 4
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