ML20133H547
| ML20133H547 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 07/26/1985 |
| From: | Fiedler P GENERAL PUBLIC UTILITIES CORP. |
| To: | Zwolinski J Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0661, RTR-NUREG-0737, RTR-NUREG-0783, RTR-NUREG-661, RTR-NUREG-737, RTR-NUREG-783, TASK-02-03.B, TASK-02-03.B1, TASK-02-03.C, TASK-03-04.A, TASK-03-10.A, TASK-05-05, TASK-2-3.B, TASK-2-3.B1, TASK-2-3.C, TASK-2-4.A, TASK-3-10.A, TASK-3-4.A, TASK-5-5, TASK-RR 1866F, IEB-79-14, IEB-80-11, NUDOCS 8508090388 | |
| Download: ML20133H547 (7) | |
Text
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f GPU Nuclear Corporation NOOIMI 100 Interpace Parkway Parsippany.New Jersey 07054 1149 (201)263-6500 TELEX 136 482 Writer's Direct Dial Number:
July 26,1985 Mr. John A. Zwolinski, Chief Operating Reactors Branch No. 5 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Zwolinski:
Subject:
Oyster Creek Nuclear Generating Station Docket No. 50-219 Cycle 11 Refueling Outage We have recently completed the preliminary planning for work to be conducted at Oyster Creek through the next refueling outage. The purpose of this letter is to review with you the results of that planning and to seek concurrence from the Staff on the proposed deferment of some regulatory items.
During your visit to our office in April, we discussed with you and Mr. Donohew some very preliminary results of the outage planning efforts for Oyster Creek.
As our planning has now evolved, Oyster Creek will be shut down for a mini outage in approximately October of 1985 at which time Environmental Qualification work to comply with 10CFR50.49 will be completed as well as certain followup actions relating to Bulletin 79-14.
Inspections and other preliminary work preparation for the major refueling outage will also be completed at this time.
The refueling outage is now scheduled for a mid-April, 1986 start.
In developing the refueling outage plan, we reviewed the total backlog of proposed plant modifications and major maintenance items. The development of the outage plan shows large blocks of work which we feel are of high priority. This includes completion of all Appendix R Fire Protection modifications, which is the largest single plant modification project; a series of activities to enhance the ability of the plant to be less susceptible to IGSCC (weld IHSI treatment); substantial work in the Control Room including computer hardware installation; and a number of other modifications throughout the plant.
As the planning developed for the refueling outage, it became apparent the total proposed work scope was exceeding prudent manageability guidelines and would drive the planned outage duration to unacceptable limits, probably
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GPU Nuclear Corporation is a subsidiary of General Pubhc Utilities Corporation
Mr. John A. Zwolinski,. Chief Page Two exceeding nine months. The Company has spent several months, including extensive reviews by senior management, in assessing this work scope growth in outage planning.
It has been concluded, for a number of reasons identified below, that the work scope must be restrained.
In considering restraint of work scope, we have generally placed highest priority on issues providing maximum safety and operability return, providing maximum assurance of minimizing future IGSCC pipe cracking, and reducing worker radiation exposure on a number of other major activities. Even so, the preliminary outage plan contemplates an outage length from potentially six to nine months long, a peak craft work force of 550 personnel, a total contractor work force of approximately 800 and a projected total man rem exposure estimate of about 850. The planned work still consists of 30 total modification projects and a maintenance effort of over 3,000 individual items, including 110 major activities. Even with the proposed restraint in work scope, the next refueling outage for Oyster Creek is the second longest outage planned for the station, exceeded only by the refueling outage just completed.
We believe the proposed next refueling cycle work scope limitation will enhance our ability to manage the planned work through improved job supervision, minimize what might otherwise be unsafe congestion in the Control Rocm, Drywell and the 480V Switchgear Room and allow us to improve control of radiation exposure. There still remains an inherent risk of work scope growth during the outage because of a large number of detail inspections to be undertaken (recirculation loop piping, isolation condenser piping, reactor internals, reactor feedwater nozzles, etc.) which have the potential for requiring corrective action.
To contain work scope and improve manageability, we are requesting deferment of several regulatory related modifications and are suggesting that these modifications be completed in the following operating cycle or refueling outage. to this letter contains a listing of those modifications which we believe can be deferred until the following operating or refueling cycle. Our assessment of these eight items is that no significant safety risk is involved.
In one case, i.e., item one of the attachment, the deferment request is caused by substantial technical difficulties and resultant schedule slippage being experienced by our software vendor.
We believe prudent technical arguments exist for the permanent cancellation of other modifications. Attachment 2 to this letter identifies those regulatory items which we believe scope adjustments or cancellations are technically justified. For those items reflecting scope adjustment, we intend to accomplish the revised scope during the next refueling outage.
In many cases preliminary discussions have already occurred with your Staff on these items, and we are preparing technical submittals to further support the reasonableness for cancellation. These submittals will be forwarded to you beginning very shortly and extending over the next two to three months.
In the event we cannot come to final resolution with the Staff on the issues of cancellation, we would propose deferinent until the following refueling outage to allow our outage planning to stabilize.
Mr. John Zwolinski, Chief Page Three Experience gained during the cycle 10 refueling outage indicates that a phased approach for certain modifications and a complete deferral of others is necessary to allow proper control of total work scope and resources. The planning activities outlined in this letter is a first step to utilize and develop the integrated living schedule concept for future Oyster Creek modification work.
Your concurrence with our proposed deferments in Attachment I would be appreciated. As outage planning for Oyster Creek continues, we will advise you promptly of any further requested changes should such change become necessary.
If you should have any questions concerning this correspondence and the attachments, please contact Mr. M. W. Laggart, Manager, BWR Licensing at (201) 299-2341.
Very truly yours, l
g aA A er Vice President and Director Oyster Creek RFW/al/05600 ATT cc:
Dr. Thomas E. Murley, Administrator Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa.
19406 NRC Resident Inspector Oyster Creek Nuclear Generating Station Forked River, N.J.
08731 J. Donohew U.S. Nuclear Regulatory Conmission 7920 Norfolk Avenue Bethesda, Md.
20014
i Attachment I Items for Deferment 1.
Safety Parameter Display System Software (NUREG 0737 Supplement 1)
The Safety Parameter Display System (SPDS) hardware is scheduled to be installed during the Cycle 11 refueling outage. Although SPDS hardware installation is expected to be completed during the outage, delays in delivery of vendor-provided hardware and software preclude making SPDS fully operational until during the operating cycle after the outage.
2.
Isolation Condenser Makeup Pump As a result of SEP Topics II-3.8, II-3.B.1, II-3.C, and III-4.A, GPUN committed to provide a protected means from a protected water supply to supply makeup to the Isolation Condenser shells for decay heat removal in the event flooding conditions or tornado missiles render the normal makeup sources inoperable. Makeup is currently provided by the Condensate Transfer System with the Fire Protection Water System as the normal backup.
In addition, the Demineralized Water System can be utilized to provide makeup via a temporary hose interconnection. The reliability afforded by one primary and two backup makeup sources makes it unlikely that all of these sources would be rendered inoperable. The protected makeup method will be provided during operating Cycle 11 subsequent to the refueling outage and deferral is requested.
3.
Intake Canal Level Instrumentation An automatic water level instrument with remote readout was scheduled for installation during the Cycle 11 refueling outage. This modification is in response to SEP Topics II-3.B, 11-3.B.1 and II-3.C per IPSAR Section 4.1.
We propose to defer this installation until operating Cycle 11 subsequent to the refueling outage.
Intake canal level is monitored at least once per eight hour shift and this inspection practice is formalized in the shift turnover procedure.
The above inspection is adequate until installation of the level instrument is complete.
In addition, the dramatic weather conditions which cause extremes in intake canal water level would provide an obvious indication to surveil the intake water level closely.
4.
Masonry Walls (IE Bulletin 80-11)
A partial deferment is requested for all walls that do not require the plant to be shut down to be accomplished. For all walls requiring plant shutdown, installation will be completed during the Cycle 11 refueling outage.
It is our intent to complete the modifications during operating Cycle ll; however, if unanticipated operational safety concerns inhibit some aspect of the modifications, they will be completed during the Cycle 12 refueling outage.
The wall failure consequence analysis previously submitted by GPUN letters dated March 14 and May ll, 1984 has shown that wall failures will not jeopardize the safe shutdown of the facility.
This deferment does not apply to required submittals that will be provided on the agreed upon schedule.
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" 5.
Torus Attached Piping Supports The objectives of the Mark 1 Containment Long Term Program were to establish conservative design basis loads that are appropriate for the anticipated life of the plant and to restore the originally intended design safety margins for the containment system.
The current design margins for torus attached piping have been found to be adequate to ensure system integrity for all loading conditions, even though they do not fully _ meet the original design margins.
The Long Term Program identified piping supports and reinforcing saddles which are to be added and existing supports which are to be modified to increase the design safety margins. Piping system support modifications requiring a shutdown will be accomplished during the Cycle 11 refueling outage.
Due to work load considerations, the remaining piping support modifications will be installed during the operating cycle s'Jbsequent to the Cycle 11 refueling outage; however, if unanticipated operational safety concerns inhibit some aspect of the modifications, they will be completed during the Cycle 12 refueling outage. By Order dated January 19, 1982, Torus Attached Piping modifications are currently required to be completed prior to startup from the Cycle 11 refueling outage. As discussed above, we request that a portion of these modifications be deferred to the following operating cycle.
6.
Torus Bulk Temperature Indication (Mark 1 Program - NUREG 0661/0783)
NRC Order dated January 19, 1982 requires Torus bulk temperature indication in accordance with Mark 1 Program requirements to be provideo prior to startup from the Cycle 11 refueling outage.
In addition, we committed to meet Regulatory Guide 1.97 Torus Bulk Temperature requirements during the Cycle 11 refueling outage. He propose to defer the upgrade of Torus temperature indication until the Cycle 12 refueling outage. Currently, Torus bulk water temperature is monitored by four (4) thermocouples situated in pairs diametrically opposed.
7.
SEP Topic III-10.A. Thermal-Overload Protection for Motors of Motor-Operated Valves (MOV)
The methodology previously submitted to evaluate the adequacy of the setpoints for unbypassed thermal overloads (TOL) was based on the then prevalent practice at OCNGS of setting the torque switches.
This practice was based on restricting the valve seating current to within 120 to 2007. of rated motor full load current.
However, by the end of 1984, GPUN had implemented and completed a new approach on the MOV torque switch settings.
This approach is based on the Motor-Operated Valve Analysis and Test System (MOVATS) method of valve testing, wherein a valve's actual thrust output is recorded.
The acceptable setting for a torque switch is the one which produces a thrust greater than the minimum required thrust for the valve's safety function. As a result, a new methodology was developed to reflect this change.
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The newly developed methodology is based on M0V motor winding thermal limits. This information is obtained from the motor characteristic curves supplied by the valve vendor. GPUN has requested this information and is waiting for the supplier to comply.
It was also revealed that in order to install some of the new TOL heaters, the ESF valve circuits have to be de-energized thus requiring a plant shutdown. However, the majority of the new TOL heaters can be installed without plant shutdown. Therefore, approximately 70% of the modifications required will be accomplished during the next operating cycle (Cycle 11) and the remainder will be accomplished during the Cycle 12 refueling outage.
8.
Airborne Particulate and Gaseous Radioactivity Monitors (SEP Topic V-5)
As indicated in section 4.16.1 of the Integrated Plant Safety Assessment Report (NUREG 0822, January 1983), GPUN committed to identify system modifications necessary to make the airborne particulate and gaseous radioactivity monitors operational.
In a subsequent meeting and telephone conversation with the SEP Branch staff, we communicated our intent to complete the modifications during the upcoming Cycle 11 refueling outage. The evaluation of the system has revealed numerous problem areas requiring extensive redesign, modification or replacement.
We are assessing various alternatives in order to arrive at a workable
' engineered' system. Considering the extent of remaining design work and projected delivery times for equipment procurement we currently anticipate completion of installation and startup testing during the Cycle 12 refueling outage and request deferral until that time.
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Items for Cancellation or Scope Change 1.
Feedwater Nozzle Internal Inspection (NUREG 0619) - Scope Change - We would perform the external UT inspection of the feedwater nozzles next refueling outage, however, we would not plan on proceeding with internal PT inspections. We believe the external UT inspection will substantiate lack of significant nozzle cracking.
2.
Containment Vent and Purge Valve Replacement (NUREG 0737) - Cancellation 3.
Containment Isolation Signals to Vent and Purge Valves on Containment High Radiation (NUREG 0737) - Cancellation 4.
Isolation Condenser High Point Vents (10CFR50.44) - Cancellation 5.
Recirculation Loop Interlock (NUREG 0737) - Scope Change - The recirculation loop interlock had been planned at a fully automatic interlock so that the operator could not isola +a the five recirculation loops. We proposed to proceed with the modifice 'on at the next refueling outage, but the design is being modified toward optrator alarm interaction rather than being totally automatic.
6.
Torus Thermal Mixing (Mark 1 Program - NUREG 0661) - Cancellation l
7.
Torus Local Temperature Indication (Mark 1 Program - NUREG 0661/0783) -
Cancellation - Based on endorsement of BWR Owner's Group position 4
contained in GE Report NE00-30832.
8.
Drywell Temperature Monitoring and Instrument Air Transmitters - Part of Reg. Guide 1.97 - Cancellation - (Items A.6 and 0.25 of Table 3 GPUN letter dated June 13, 1984 - Reg. Guide 1.97 response)
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