ML20126H925
| ML20126H925 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 12/30/1992 |
| From: | Hopkins J Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-M84153, NUDOCS 9301050358 | |
| Download: ML20126H925 (17) | |
Text
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Decernber 30, 1992 Docket No. 50-346 i
LICLNSEE:
10LEDO EDISON COMP /4Y FAClll1Y:
DAVIS-BESSE HUCLEAR POWlR STA110N, UNil 1 SUBJEC1:
SUMMARY
Of MEE11NG ll[LD ON DECEMB(R 15, 1992 10 Di$ CUSS A PROPOSED AL1ERNAllVE 10 SfAS IN MODE 6 (TAC NO. M84153)
On December 15, 1992, NRC staff members met at Rockville, Maryland, with employees of Toledo Edison Company (TE) to discuss a proposed amendment that would allow an alternative to the safety features actuation system (SfAS) in Mode 6 (refueling) for the Davis-Hesse Nuclear Power Station, Unit 1.
A list of attendees is included as enclosure 1.
The handouts used at the meeting are included as enclosure 2.
The current operation of the containment purge system in Mode 6 including SLAS i
isolation and the pronosed alternate method of system isolation in Mode 6 in l
accordance with the posed license amendment dated July 28, 1992 were discussed.
TE stateo 5 tt the consequences of the fuel handling accident remain acceptable and in fact do not change as a result of this proposal.
The.
NRC staff had the following two questions at the close of the meeting.
What is the power supply for the noble gas monitor RE505207 What was the amount of containment purge system operation in Mode 6 during the last refueling outage?
TE stated that it would obtain that information for the staff.
OllIGINAI, SIGNED BY l
Jon B. Ilopkins, Sr. Project Manager Project Directorate 111 Division of Reactor Projects Ill/lV/V Office of Nuclear Reactor Regulation i
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Enclosures:
Docket file OGC As stated NRC & local PDRs EJordan PD3-3 Reading JMinns cc w/ enclosure:
1Murley/FHiraglia BMarcus See next page JPartlow ACRS(10)
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DATE a /3 o/92 l'L / W/92 53 M ly/yO/92 OfflCIAL HLCORD DOCUMENT NAME:
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W ASHIN010N. D. C. 20t46 y*****,1 Deconber 30, 1992 Docket No. 50-346 LICENSEE:
TOLEDO EDISON COMPANY FACILITY:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1
SUBJECT:
SUMMARY
OF HEETING HELD ON DECEMBER 15, 1992 10 DISCUSS A PROPOSED ALTERNATIVE TO SFAS IN H0DE 6 (TAC NO. H84153)
On December 15, 1992, NRC staff members met at Rockville, Maryland, with employees of Toledo Edison Company (TE) to discuss a proposed amendment that would allow an alternative to the safety features actuation system (SFAS) in Mode 6 (refueling) for the Davis-Besse Nuclear Power Station, Unit 1.
A list of attendees is included as enclosure 1.
The handouts used at the meeting are included as enclosure 2.
The current operation of the containment purge system in Mode 6 including SFAS isolation and the proposed alternate method of system isolation in Mode 6 in accordance with the proposed license amendment dated July 28, 1992 were discussed.
TE stated that the consequences of the fuel handling accident remain acceptable and in fact do not change as a result of this proposal. The NRC staff had the following two questions at the close of the meeting.
What is the power supply for the noble gas monitor RE505207 What was the amount of containment purge system operation in Mode 6 during the last refueling outage?
1E stated that it would obtain that information for the staff.
31 $ f
./, Project Directorate 111-3 on B. Hopkins, Sr. Project Manager Division of Reactor Projects Ill/IV/V Office of Nuclear Reactor Regulation-
Enclosures:
As stated cc w/ enclosure:
See.next page 9
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Davis-Besse Nuclear Power Station Toledo Edison Company Unit No. 1 Cc:
Mary E. O'Reilly Centerior Energy Corporation Radiological Health Program 300 Madison Avenue Ohio Department of Health Toledo, Ohio 43652 Post Office Box 118 Columbus, Ohio 43266-0149 Mr. Robert W. Schrauder Attorney General Manager, Nuclear Licensing Department of Attorney Toledo Edison Company General 300 Madison Avenue 30 East Broad Street Toledo, Ohio 43652 Columbus, Ohio 43215 Mr. James W. Harris, Director Gerald Charnoff, Esq.
Division of Power Generation Shaw, Pittman, Potts Ohio Department of Industrial Regulations and Trowbridge P. O. Box 825 2300 N Street, N.W.
Columbus, Ohio 43216 Washington, D.C.
20037 Regional Administrator, Region III Ohio Environmental Protection Agency U.S. Nuclear Regulatory Commission DERR--Compliance Unit 799 Roosevelt Road ATTN:
2ack A. Clayton Glen Ellyn, Illinois 60137 P. O. Box 1049 Columbus, Ohio 43266-0149 Mr. Robert B. Borsum Babcock & Wilcox President, Board of Ottawa Nuclear Power Generation Division County Commissioners 1700 Rockville Pike, Suite 525 Port Clinton, Ohio 43452 Rockville, MD 20852
. Resident Inspector State of Ohio V. S. Nuclear Regulatory Commission Public Utilities Commission 5503 N. State Rnute 2 180 East Broad Street Oak Harbor, Ohio 43449 Columbus, Ohio 43266-0573 Mr. Murray R. Edelman Mr. James R. Williams Executive Vice President -
State Liaison to the NRC Power Generation Adjutant General's Department Centerior Service Company Office of Emergency Management Agency 6200 Oak Tree Boulevard 2825 West Granville Road Independence, Ohio 44101 Columbus, Ohio 43235-2712 Mr. Donald C. Shelton, Vice President Nuclear - Davis-Besse Centerior Service Company c/o Toledo Edison Company 300 Madison Avenue Toledo, Ohio 43652 l
ATTENDEES December 15, 1992 IB!if.
DEattlIA110!i J. Hopkins NRC D. Wuokko TE J. Wood TE J. Minns NRC B. Marcus NRC C. Rupp TE A. Zarkesh TL
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-,,,,,9 Toledo Edison / NRC Meeting on Revising Technical Specification Requirements for Safety Features Actuation System During Refueling Outages NRC Headquarters Rockville,.MD December 15,1992 1
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4-(n a - - -,,,,,3 AGENDA Purpose of Meeting Safety Features Actuation System Design Safety Analysis Report Present System Operation Refueling Technical Specification Requirements Alternate System Operation Proposed Technical Specification Changes
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PURPOSE Present Davis-Besse's proposal to modify the Safety Features Actuation System (SFAS) refueling outage TS requirements. An alternative to SFAS would be provided to mitigate releases from the refueling design basis accident (fuel handling accident).
Change would:
- Allow removal of SFAS frc,m service during refueling outages and maintenance to be performed more easily.
- Provide an option that would not relocate SFAS Area Radiation Monitors into containment with resulting wear and tear.
- Reduce potential for inadvertent SFAS actuations during refueling outages.
- Increase flexibility in outage activity scheduling.
- Provide an alternate means to SFAS for restricting the accidental release of radioactivity..
- Retain present SFAS refueling outage TS requirement as an alternate method.
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-m m.m15 SFAS DESIGN
- Safety Features Actuation Syatem (SFAS)
- Design Basis: Prevent or limit fission product and energy release from the core, Isolate the containment vessel, and initiate the engineered safety features equipment.
- Four independent and redundant sensor channels
- Diverse Inputr, Monitoring: Containment radiation levels containment vessel pressure reactor coolant pressure borated water storage tank level
- Sensor channals are coupled to fourindependent and redundant logic channels which actuate (on a two-out-of-four basis) two independent and redundant component trains
- Sensors, logic and relays de-energize to trip 4
CENTE SAFETY ANALYSIS REPOR'
- Refueling Design Basis Accident: Fuel Handling Accident inside Containment
- SAR Section 15.4.7.3 Addresses Radiological Consequences of Fuel Handling Accident inside Containment:
- Does not credit containment isolation
- Does not credit any fi!tration prior to release to atmosphere
- Potential doses are well within guideline values of 10CFR Part 100:
DAVIS-BESSE DOSE PART 100 EXCLUSION AREA LPZ BOUNDARY BOUNDARY Thyroid (rem) 300 44.7 2.33 Whole Body (rem) 25 0.17 8.86 x 10'3 5
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PRESENT SYSTEM OPERATION
{ Refer to Drawing)
- Four SFAS Area Radiation Monitors are relocated from containment annulus to inside containment vessel during refueling outages to maximize sensitivity for a fuel handling accident.
- To Purge in Mode 6 (During Core Alterations or Fuel Movement)
- Containment Purge Supply and Exhaust Fans are started.
- Containment isolation Valves (CIVs) CV5005, CV5006, CV5007 and CV5008 are opened.
- Supply air passes through two volume control dampers (CV5062 and CV5013)
- Purge air passes through HEPA filter and charcoal filter to station vent.
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PRESENT SYSTEM OPERATION (Refer to Drawing)
- In Event of High Airborne Radiation inside Containment (During Core Alterations or Fuel Movement):
- Detected by GFAS area radiation monitors
- Purge supply and exhaust fans shutdown in response to SFAS signal closing associated dampers
- CIVs CV5005, CV5006, CV5007 and CV5008 close by SFAS signal
- Emergency Ventilation System (EVS) started by SFAS signal
- Bypass Damper (CV5061) to the EVS opens on high radiation level detected by RE5052 l
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REFUELING SFAS TS REQUIREMENTS
- TS 3/4.3.2; SFAS instrumentation Requires SFAS high containment radiation instrumentation for containment isolation and manual actuation to be operable during core alterations or movement of irradiated fuel within containment (to meet TS 3/4.9.4 requirements).
- TS 3/4.9.4, Refueling Operations - Containment Penetrations Requires closure of containment purge and exhaust isolation valves during core alterations or movement of irradiated fuel within containment upon an isolation signal.
- TS 3/4.9.9, Refueling Operations - Containment Purge and Exhaust isolation System Requires containment purge and exhaust isolation system closure capability on SFAS high containment radiation signal.
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ALTERNATE SYSTEM OPERATION (Refer to Drawing)
- Utilize existing Containment Purge and Exhaust System Noble Gas Monitor RE5052C (Located in the Containment Purge Exhaust Fan Suction)
- RE5052C is required by Offsite Dose Calculation Manual
- Shiftly channel check performed
- Monthly source check performed
- Quarterly functional test performed (including stopping of supply and exhaust fans and closure or opening of dampers) e in Event of High Airborne Radiation, the Following l
Occurs Automatically:
- Purge supply and exhaust fans shutdown
- Outside air intake volume control damper (CV5003A) and purge supply fan discharge volume control damper'(CV50038) close
- Volume control damper upstream of the purge air exhaust filter
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(CV5062) and the purge exhaust fan discharge volume control-damper (CV5013) close-
- Volume control damper in bypass duct to EVS (CV5061) opens. EVS filter inlet dampers (CV5024 and CV5025) remain closed until EVS fans are started manually from control room.
- Additional Control Room Actions Can Be Taken:
- Shut containment purge and exhaust isolation valves from control room i
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"""l3%w DAv40 ESSE NUCLEAR NR ET ATCH PROPOSED TS CHANGES TS 3/4.3.2, SFAS Instrumentation Add use of Containment Purge and Exhaust System Noble Gas Monitor (RE5052C) as an altemative to SFAS to meet TS 3/4.9.4 requirements TS 3/4.9.4, Refueling Operations -
Containment Penetrations Revise Limiting Condition for Operation and Surveillance Requirements to allow use of either the SFAS or Monitor 5052C in restricting release of radioactivity
- TS 3/4.9.9, Refueling Operations - Containment-Purge and Exhaust isolation System Relocate requirements to TS 3/4.9.4 to eliminate duplication.
Change requirement for SFAS -initiated Containment Purge and Exhaust isolation System consistent with TS 3/4.3.2 and 3/4.9.4 changes.
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Safety Features Actuation System level 1 Start EVS Containment Vessel Purge and Sample Valve Isolation Level 2 l
Start HPl l
Start Containment Air Cooler at Low speed l
Start Component Cooling Water Pumps Close Containment Vacuum Relief Valves Start Corvice Water Open Containment Spray isolation Valve Start EDG lsolate Containment Level 3 Start Decay Heat / Low Pressure injection Pumps and line valves up Other misc. Isolations Level 4 Start Containment Spray More misc Isolations Level 5 Indication of need to transfer suction from BWST to Emergency Sump
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i Safety Features Actuation System
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Five different actuationsi Level 1 Containment radiation _twice background
. Reactor coolant pressure. low (1650 psig)
Containment vessel pressure high (18.4 pala)
Level 2 Reactor coolant pressure low (1650 psig)
Containment vessel pressure high (18.4 psla)
Level 3 --
Reactor coolant pressure low-low'(450 psig)
Containment vessel pressure high (18.4 psla)
Level 4 Containment pressure high-high (38.4 psla) level 5 7
_BWST levellow (8 ft) g m
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RCS Pressure Contonment Preme 2/4 Logic g
Containment Rodiation CH 1 Ch 1 i
BWST Level Actuation Channel 1
RCS Pressure to W nt R es e T-2/4 Logic Containment Rodiation CH 3 Ch 3 BWST Level i
RCS Pressure Containment Pressure loput 2/4 iC Buttering Containment Rodiction CH 2 Ch BWST Level Actuation Channel 2
RCS Pressure 9jn j 2/4 logic Containment Press tt g
Containment Radiation CH 4 Ch 4 BWST Level t-