ML19339B243
| ML19339B243 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/31/1980 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0578, RTR-NUREG-578 NUDOCS 8011060566 | |
| Download: ML19339B243 (2) | |
Text
U PHILADELPHIA ELECTRIC COMPANY S 23O1 M ARKET STREET P.O. BOX 8699
-'3
OICl 3 PHILADELPHIA. PA.1910T I,,,
swirtos L. DALTROFF n."c70",'.*EU, October }1; 1930....',,ou Re: Docket Nos.: 50-277 50-278
't r. Darrell G.
Eisenhut, Director Division of Licensing U.S.
Nuclear Regulatory Commission Wash _ington, DC 20555
SUBJECT:
Implementation of Category A Lessons Learned Requirements NUREG 0573 Peach Bottom Atomic Power Station
Reference:
(1)
Letter dated January 2, 1980, from 3.
L.
Daltroff, Philadelphia Electric Company, to H.
R.
Denton, NRC (2)
Response to IE Sulletin 80-06 dated June 11, 1980, from S.
L.
Daltroff to 3.
H.
Grier, NRC
Dear Mr. Eisenhut:
This letter provides additional information with respect to a Short Term Lessons Learned requirement identified in reference 1.
Section 2.1.4 of NUREG 0578, requires that the design of control systems for automttic containment isolation valves be such that resetting the isolation signal will not result in the automatic reopening of containment ioslation valves.
In reference 1 (page 3) we reported that the reset logic changes were completed on Unit 3 during an outage which began on December 6,
1979, and that similar modifications would be made on Unit 2 during an outage schedule to begin on, or before, January 1, 1980.
These modifications were implemented as stated except for the Traversing In-Core Probe (TIP) nitrogen purge valves and TIP ball valves which were not included as a result of an oversight during the engineering design of the modification.
The electrical schematics identifying each isolation valve incorporated into the reset logic modification were submitted to the NRC staff during the site audit of all Category "A"
requirements on January 22-23, 1980.
<3 so,1oeo5r/ ele
/
d.
?! r. Darrell G.
Eisenhut Page 2 IE Sulletin 80-06 " Engineered Safety Feature Reset Controls" was issued on March 13, 1980.
This bulletin requested that licensees review drawings of all systems serving safety related functions at the schematic level to determine whether or not upon reset of ESF actuation signal, all associated safety related equipment remains in its emergency mode.
As a result of this review, the TIP valves described above were identified as not remaining in a closed position when a Group II isolation is reset.
The bulletin response dated June 11, 1980, reported this information to the NRC and indicated that existing procedures for the TIP system would be revised to clarify the method used to reset the TIP valves.
Uhen this condition was identi,fied, immediate administrative action was taken, as s t a t'e d in reference 2, to inform the operator that the TIP ball valva control switch must be placed in the " closed" position and the TIP nitrogen purge valve control switch must be placed in the "off" position before resetting a Group II isolation.
Revisions to GP-dB " Resetting of Inboard Half Isolation" and GP 8C " Resetting of Outboard HL1f Isolation" were subsequently revised and issued.
The TIP valves are therefore administratively controlled at this time to ensure that they remain closed following reset of an isolation until a conscious effort is nade to operate the TIP system.
Operation in this manner ensures containment integrity via administrative controls until modifications can be accomplished to the logic system.
It should be recognized that the TIP ball valves are normally maintained in a closed position unless the TIP system is in operation.
When in operation, an individual is constantly manually controlling TIP motion and monitoring system status.
The TIP operating procedures provide direction to place the ball valve switch in "Close" if a Group II isolation occurs.
TIPS are operated approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> each week.
The remainder of the time the TIP machines are off and the ball valves are in a closed position.
In addition to the administrative changes, the engineering necessary to implement a modification to provide the reset logic feature, committed to in reference 1, for the TIP valves was initiated immediately.
Completion of the modification is pending receipt of electrical switches presently on order.
Should you have any questions regarding this matter, please do not hesitate to contact us.
Very truly you,rs, ll' l
,/
9 -
j j' cc: Boyce H.
Grier, NRC
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