ML20211N156
| ML20211N156 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 10/08/1996 |
| From: | CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML20211N021 | List: |
| References | |
| NUDOCS 9710160037 | |
| Download: ML20211N156 (11) | |
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ATTACHMENT 1 '
l CONSUMERS ENERGY COMPANY BIG ROCK POINT PLANT L --
DCCKET 50 155 ANNUAL REPORT - MODIFICATIONS 9710160037 971000 "
NUCLEAR REGULATORY COMMISSIDN BIG ROCK POINT PLANT ANNUAL REPORT - ATTACHMENT 1
>SC 966022 1
Replace Resin Sluice Pipes and Add Resin Disposal Tank Level Switches SC 96 022 re> laced a portion of the buried concrete enclosed resin sluice lines from tie cleanup, condensate and radwaste demineralizers with above ground piping in a welded steel trough. The trough is shielded with concrete on the sides and steel is used on the top. High level alarms were also added to the resin disposal tank as a means to alert the operators to the potential 40r tank overflow.
Safety Analysis Summary The safety evcluation concluded that the change in location of the resin sluice lines and the addition of tank level instrumentation did not constitute an unreviewed safety question. Even though the UFHSR did not address actual piping location or tank level control, the UFHSR was updated to reflect the modi fication.
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l NUCLEAR REGULATORY COMMISSION BIG ROCK POINT PLANT ANNUAL REPORT - ATTACHMENT 1 50 97 011 Spent fuel Pool Heat Exchanger (HX 68) Leak Repair Spent fuel pool heat exchanger HX 6B developed a leak from the tube side (spent fuel pool water) to the shell side (rcactor cooling water side). An engineering evaluation determined that a maximum of 17 tubes could be plugged to repair the leaking heat exchanger without impacting the heat removal rate required during postulated design basis acciden .;.
Safety Analysis Summary The safety evaluation conclurted that the prosedure changes did not constitute an unreviewed safety question. The heat exchanger is classified as "not important to safety" and "not safety related". The proposed change to the heat exchanger design duty does not impact the assumed heat reinoval rate of 0 Btu /hr during postulated design basis accidents.
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t ATTACHMENT 2 CONSUMERS ENERGY COMPANY BIG ROCK POINT PLANT DOCKET 50 155 ANNUAL REPORT - MISCELLANEOUS CliANGES l
4 NUCLEAR REGULATORY COMMISSION BIG ROCK POINT PLANT ANNUAL REPORT ATTACHMENT 2 TechrHeal Spaification Change Addition of a 100 SCFH Air Compressor to the Service and Instrument Air System.
Facility Change FC 648C added a new 100 standard cubic feet per minute (scfm) air compressor to the service air portion of the Service and Instrument Air System. This addition allowed the instrument air portion to be completely isolated from the service air portion of the Service and Instrument Air System. Isolation of instrument air from service air increases instrument air's wailable capacity by eliminating service air demands from the three (3) existing 70 scfm air compressors. Utilizing the existing piping configuration and cross connect, both the new and the existing air compressors are capable of supporting the Service and Instrument Air System as determined necessary by the Operations Department. Air quality was uncL p 3d by the addition of the ne' air compressor regardless of how the air compressors u" placed into operation. The new air compressor has similar design characteristics as the existing air compressors and the instrument air piping is essentially unchanged.
Safety Analysis Summary The safety evaluation concluded that the addition of a fourth air compressor to the facility and splitting the Instrument Air System from the Service Air System did not constitute an unreviewed safety question. The proposed change did not:
- 1) Involve a significant increase in the probability or consequences of an accident previously evaluated.
Utilizing the existing piping configuration, both the new and the existing air compressors are capable of supporting either portion of the Service and Instrument Air System. The addition of the fourth air compressor decreased the probability of an accident previously evaluated, because capacity is being added to the system.
The consequences of an accident previously evaluated was not affected by the addition of a fourth air compressor. The service and Instrument Air System performs the non-safety related function of providing compressed air for service use and moisture free compressed instrument air for control air demands. The instrument air portion is designed so that its operation is required for plant reliability, not plant nuclear safety. Safety-related equipment supplied by instrument air is designed to fail in its safe condition upon loss of instrument air or. safety related equipment (and nonsafety-related equipment determined to be important to safety) required to operate subsequent to instrument air failure is supplied by backup nitrogen accumulators.
- 2) Create the possibility of a new or different kind of accident from any accident previously evaluated.
The operation of the equi > ment in the Service and Instrument Air System is essentially unchanged. Tle new air compressor is a similar design (nonlubricated), providing additional air volume at a quality comparable to
NUCLEAR REGULATORY COMMISSION BIG
- ROCK POINT PLANT ANNUAL REPORT - ATTACliMENT 2
.the three existing air compressors. Therefore, the possibility of an accident of a different kind than any previously evaluated has not been created.
- 3) Involve a significant reduction in a margin of safety The Technical Specification did not specify a margin of safety for the operation of the Service and Instrument Air System, other than specifying that
" service and instrument air shall be supplied by three, nonlubricated air compressors, each rated at 70 scfm. Instrument air shall also pass through a dryer". Addition of a fourth air compressor increased the available capacity.
thus increasing the margin of safety. Therefore, adding the statement "and one, nonlubricated air compressor rated at 100 scfm" to Technical Specification 4.2.9. did not reduce the margin of safety.
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NUCLEAR REGULATORY COMMISSION BIG
- ROCK POINT PLAN 1 ANNUAL REPORT - ATTACHMENT 2
. Procedure TR 84: Emergency Diesel Generator Inspection and Repair Steps were added to TR-84 to incorporate new inspections resulting from l condition reports. Service water piping and the rack solenoid will now be ins)ected for zebra mussels and biofouling. Notes have been added to remind worters of the "Right to Know" program. In addition, the acceptable generator voltage range when loaded vith the electric fire pump was revised to reflect a recent engineering analysis performed to document operability. Several editorial changes were also made to improve the " useability" of the procedure.
Safety Analysis Summary The safety evaluation concluded that the procedure changes did not constitute an unreviewed safety question.
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NUCLEAR REGULATORY COMMISSION BIG' ROCK POINT PLANT ANNUAL REPORT - ATTACHMENT 2
. Procedure 0.VAS 1, Cold / Warm Weather Checklists i
The Alternate Shutdown (ASD) Building ventilation / exhaust fan is operated continuously all year. Due to excessive heat loss during the cold weather months. fan operation was reduced to 10 minutes each day during the cold l weather months. The fan is then returned to continuous operation during the warm weather months. 0-VAS-1 was revised to control this evolution.
Safety Analysis Summary The safety evaluation concluded that the procedure changes did not constitute an unreviewed safety question. During the colder months, 10 minute operation of the fan will completely turnover the air in the ASD building battery room, preventing the hydrogen concentration from exceeding 1%.
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NUCLEAR REGULATORY COMMISSION i BIG ROCK POINT PLANT l ANNUAL REPORT ATTACHMENT 2
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. Procedure 50P 21, Circulating Water System - 1 SDP 21 was revised to incorporate the use of " sawdust" in troubleshooting and temporary repairs of the main condenser. Prior to use, the following requirements must be met:
- 1. Evaluate the effects of sawdust on the operability of the Emergency Diesel Generator
- 2. Obtain the necessary permits from the Michigan Department of natural Resources.
- 3. Develop an approved plant procedure for the use of sawdust to temporarily stop main condenser tube leakage.
Safety Analysis Summary The safety evaluation concluded that the 3rocedure changes did not constitute an unreviewed safety question, Based on tie recent condensate demineralizer resin replacement criteria, adequate ion exchange capacity existed to shutdown the plant without taking any credit for using sawdust. The plant philosophy regarding the need to address several concerns relative to future sawdusting was proceduralized.
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! i NUCLEAR REGULATORY COMMISSION BIG ROCK POINT PLANT ANNUAL REPORT - ATTACHMENT 2
.S0P 30 Control Rod Drive System S0P 30 was revised to allow the o>erators ta ) lace the jog bypass switch in the run position to allow the wit 1drawal of t10se control rods that are on 00 and cannot be withdrawn with this switch in the jog position.
Safety Analysis Summary The safety evaluation concluded that the procedure changes did not constitute an unreviewed safety question. The accident that is analyzed in the UFHSR is the *mispositioned control rod moved out to notch 23". Only one rod will be moved at a time, and a secona control room operator verifies that the correct rod is selected and only moved one notch. The consequences of more than one notch out of sequence is bounded by the analysis.
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NUCLEAR REGULATORY COMMISSION B10 ROCK POINT PLANT ANNUAL REPORT - ATTACHMENT 2
.50P 38, Safety System 50P 38 was revised to further reduce the potential for a loss of coolant from the scram dump tank when resetting the safety system. The scram dump tank isolation hand switch HS 4S6 is placed to close prior to resetting the safety system. When the scram outlet valves are verified closed. HS-4S6 is placed to
, open. which allcws the scram dump tank to drain.
Safety Analysis Summary The safety evaluation concluded that the procedure changes did not constitute an unreviewed safety question. Administrative controls will provide assurance that the scram dump tank vent and drain valves will be open prior to repositioning the mode switch.
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