ML19209A641
| ML19209A641 | |
| Person / Time | |
|---|---|
| Site: | 05000514, 05000515, Trojan File:Portland General Electric icon.png |
| Issue date: | 05/18/1979 |
| From: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| To: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| NUDOCS 7910050094 | |
| Download: ML19209A641 (5) | |
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Dear Sir:
IE Bulletin 79-06A, dated April 14, 1979, and its Revision 1, dated April 18, 1979, included 13 items requiring Portland General Electric Company (PGE) action related to the Three Mile Island (THI) accident.
Our responses to the first 12 items were provided in my letters to you dated April 24, 1979 and May 4, 1979.
The following is our response to the final item:
IE Bulletin 79-06A, Rev. 1, Item 13 Propose changes, as required, to those Technical Specifica-tions which must he modified as a result of your implementing the above items and ident!.fy design changes necessary in order to effect long-term resolutions of these items.
PGE Response We have, as outlined in our responses to the remainder of IE Eulletin 79-06A, begun a review of all the information currently available to us concerning the TM1 accident to identify problem areas that suggest the need for changes in the design and operation of the Trojan Nuclear Plant.
This review is an ongoing effort, involving both Plant Staff and Corporate Engineering personnel, that is expected to continue throughout the recovery period at TMI.
We are also following the parallel review efforts of Westinghouse, EPRI, AIF, and EEI, as well as those of the hRC and the ACRS.
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Port!ard Gene d Electric Cenpany R. H. Engelken May 18, 1979 Page 2 Design Changes Based on the information available to date, we have identified a number of design changes at Trojan that can enhance the capability of the Plant for coping with intermediate-range accidents such as occurred at IMI.
The proposed design changes are listed in the attached table.
While most of these changes have resulted from our review of the TMI accident, a'few vere already underway, as noted in the table.
In the course of the TMI review, we have assured that a sufficiently high priority has been given to these items.
The list of design changes currently being pursued should not be regarded as the completion of the PCE review of the TMI accident. As core information becomes available during the TMI recovery, the need for other design or operating procedure changes might become evident. A task force comprised of personnel from the Corporate Engineering, Plant Operations and Licensing Eepartments has been established with the responsi-bility to provide direction for the continuing PCE review of the INI accident.
Technical Specification Changes Technical Specification changes will be associated with some of the proposed design changes in the attached table.
To date, Westinghouse has completed its safety evaluation and proposed Technical Specification changes for the modification of the safety injection initiation logic from coincident low pres-surizer level / low pressure to low pressure only. The results of the internal PCE safety evaluation will be forwarded to the NRC by June 8, 1979 in the form of a License Change Applica-tion (LCA). When the safety evaluations have been completed for the remaining items in the attached table, LCAs will be submitted to the NRC, if appropriate.
In some cases, it may be determined that the proposed changes can be made without Technical Specification changes and NRC approval, in accordance with the provisions of 10 CFR 50.59.
We also recognize the need to complete a thorough review of those sections of the Technical Specifications that involve administrative controls and Plant and Corporate Organization responsibilities from the point of view of dealing with an accident such as that at TMI.
This review will also necessarily address the adequacy of our Radiological Emergency Response Plan (RERP).
We are currently reviewing with the State of Oregon Department of Energy the need for changes to emergency planning in vicu of the iMI experience.
1109 274
Pert!arxlGeneral Electric Company R.11. Engelken
!!ay 18,1979 Page 3 Schedule for Further PGE Action An LCA will be submitted by June 8,1979 regarding the proposed mndification to the safety injection initiation logic. Within 60 days, we will submit a schedule for implementing each of the remaining design changes in the attached table. At that time, we will provide an updated status report and schedule for completing the comprehensive review of appropriate Technical Specification administrative sections and the RERP.
Sincerely, Lb
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C. Goodwin, Jr.
Assistant Vice President Thermal Plant Operation and Maintenance CG/CJP/4sb9A24 Attachment c:
?!r. Lynn Frank, Director State of Oregon Department of Energy 1109 2/5
Sheet 1 of 2 -
DESIGN MODIFICATIONS IN PROGRESS A1 TROJAN AS A RESULT OF THE REVIEW OF THE TMI ACCIDENT Identified TMI Problem Area Proposed Trojan Design Change Description of Trojan Design Change 1.
The stuck open pcuer operated Modify SI initiation logic Replace the present coincident low relief valve amounted to a pres-pressurizer level / low pressure initia-surizer steam-space LOCA.
tion logic with a 2/3 109 pressure only Pressurizer level may not decrease logic.
with decreasing system pressure for a similar event at Trojan.
2.
Highly radioactive water from Containment sump discharge Modify the design provisions for pump-the Containment sump was inadver-ing tiie Containment sump to preclude inadvertent transfer of highly radio-tently transferred to the Auxiliary active water outside of the Containment Building.
(currently controlled by administrative proctdure).
3.
A clear indication of the magni-Increase PERM ranges Increase the upper ranges of the air tude of the release rates to the eject or and Auxiliary building Process Effluent Radiation Monitors. This iten environment was not readily was already underway as a result of available.
past emergency plan exercise reviews.
4.
Resetting of safety injection led Redesign Containment Redenign Containment isolation valves to an inadvertent resetting of the isolation valve response (identified in the response to IE Containment sump discharge valve on resetting Containment Bulletin 79-06A, Item 9) so they do to the open position.
isolation not return to open position upon resetting Containment isolation (currently controlled by administrative procedure).
5.
The capacity of the waste gas Recycle connection from Add provisions to waste gas systeu to C:?
system was such that venting to waste gas system to permit recycle connection from vaste the atmosphere was necessary; Containment gas decay tank to Containment.
'C' a temporary connection had to be psg made from the waste gas decay tank
~se Cys to the Containment to limit these releases.
Shect'2 of,2 DESIGN MODIFICATIO"S IN PROGRESS AT TROJAN AS A RESULT OF THE REVIEW OF THE TMI ACCIDENT Identified TMI Problem Area Proposed Trojan Design Change Description of Trojan Design Change
- 6.
The operability of the AFW system Protective trip for Add low suction pressure protective trip is important for long-term cooling Auxiliary Feedwater (AFW) to AFW pucps to prevent pump damage on following a TMI-type accident.
System pumps.
loss of suction supply before operator action can be completed to restore it.
7.
Same as 6.
Electric motor-driven Install an electric motor-driven AFW pump.
AFU pump.
This non-Category I pump will minimize use of the safety-related AFW pumps during routine plant startup and shutdown.
It will also provide additional backup to the existing diverse and redundant AFW Systems.
This item was already underway. However, it han been assigned a higher priority as a result of the TMI review.
8.
Same as 6.
Status indication of Add system train level inoperable status AFW System manual indication on manual valves in AFW System.
valves.
This will supplement indication already provided for remotely operated valves.
9.
Same as 6.
Independent cooling water Modify AFW pump turbine driver to pro-supply for AFW pump vide cooling water independent of Service turbine driver.
Water System. This modification was in progress prior to the TMI accident and was previously assigned a sufficiently high priority.
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