ML021010403

July 28, 2000, Oyster Creek Nuclear Generating Station, Meeting on Control Room Habitbility

ML021010403
Person / Time
Site:	Oyster Creek
Issue date:	04/10/2002
From:	- No Known Affiliation
To:	Office of Nuclear Reactor Regulation
Tam P
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ML021010536	List: ML021010009 ML021010403
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Download: ML021010403 (18)

Text

Oyster Creek Presentation to NRC Staff July 28, 2000 Control Room Habitability Radiological Consequence Analysis for Control Room Operatorsat Oyster Creek Nuclear GeneratingStation using the Alternate Source Term as an NEI PilotPlant submitted March 31, 199 7 Attachment 2

Agenda Topic Presenter I. Background Radvansky II. Oyster Creek Control Room Radvansky HVAC System Configuration III. Discussion of Analysis Metcalf IV. Summary Busch V. NRC Feedback

Background

Oyster Creek Profile 640 MWe BWR II, Mark I Containment, Commercial Operation-December, 1969 Licensing Issue-Resolution of NUREG 0737 III.D.3.4 Thyroid Dose to CR Operator Key Chronological Events

- 1982-1990 Upgrades to System; Formulation and Acceptance of Current Licensing Basis (CLB)-Whole Body and Skin Dose

- 1996, Mar. NRC Request for Resolution of Thyroid Dose

- 1996, Nov. Accepted as an NEI Pilot Plant for Use of Alternate Source Term in a Licensing Submittal

- 1997, Mar. Submittal Issued to NRC

- 2000, Apr. GPUN Letter Requesting Reactivation of Review; Remobilization of Project I

Oyster Creek Control Room HVAC System Configuration SYSTEM LEGEND KITCHEN & RESTROOM EXHAUST

- EXHAUST SýSUPPLY 7/ /1 41- 41-t1 SYSTEM 'A' 1*1+ 1+

CONTROL LOWER CABLE ROOM SPREADING RM CONTROL ROOM ENVELOPE HVAC SYSTEM DIAGRAMMATIC

Discussion of Analysis

"*Current Submittal Analytical Approach

"*Analytical Model for Oyster Creek AST Application

"*Changes from Current Licensing Basis

"*Dose Results by Type

"*Dose Results by Pathway

"*Atmospheric Dispersion--LER 2000-006 P"7

_/_-

I Current Submittal Analytical Approach

• Pilot Plant Application

• Some Aspects of CLB Retained

- MSIV Leak Rate = f(PDw)

- Occupancy Factors Based on Shifts

- Same X/Qs

- Same Shine Dose

• Steam Line Hold-Up Beyond Outboard MSIVs Not Credited (NRC Request--March 1996 Letter)

• Non-MSIV Bypass Added (NRC Request--March 1996 Letter)

-7 Current Submittal Analytical Approach (Cont)

"* Pilot Plant Status Justification (October 1996)

"* Unique/Interesting Features of Oyster Creek Application

- Credit for Drywell Sprays

- Integrated Containment T/H Analysis

- Significant Potential for No pH Control

- No Control Room Charcoal or Particulate Filters

- Additional Non-MSIV Bypass Pathways

- MSIV Leak Rate = f(PDW)

- No Credit for Deposition Beyond Outboard MSIVs Analytical Model for Oyster Creek AST Application

[M.1* Steamline w/I Open MSIV Drrywell Xspray Steamline w/ Closed MSIVs Xsed Core Other RB Bypass (see Next Overhead) i

-I Torus SGTS Eu..l Reactor Bldg Indicates Filter ESF Leakage (Real or Uliiwa Effective)

LME -

Analytical Model for OC AST Application (Cont)

Other RB Bypass

- Based on "Primary Containment Leakage Rate Testing Program", October 11, 1996

- Lines Which

"*Originate in Primary.Containment

"*Terminate Outside Secondary Containment

"*Not Water-Filled

- Includes: 8" N2 Pathway, 2" N2 Pathway, TIP Purge, Instrument Air, Isolation Condenser Vents, Drywell Spray Test Lines

- Treated in a Manner Similar to Main Steam Lines I

Changes from Current Licensing Basis Aspect Current Licensing Basis Current Submittal Source Term TID-14844 NUREG-1465 Containment Continuous for Pressure Cycled for Activity Removal Sprays* Reduction and Pressure Reduction MSIV Leak = Yes, with UFSAR DW Yes, with Revised (MAAP4) f(PDw) Pressure Pressure Deposition in Hold-Up Only Up to Outboard MSIV Steam Lines*

Pool No Yes (Based on MAAP4 T/H)

Scrubbing*

Occupancy Four Shifts after 24 Hours Five Shifts after 24 Hours Factors Pool pH Not Applicable Revaporization Included

• Additional Overheads I

Containment Sprays

"* MAAP4 Analysis Determines Frequency

"* Consistent with EOPs, Now with SAGs

"* Only Design Flow Credited

"* Drywell Sprays

- STARNAUA Analysis for Removal Rates

"*Realistic Impaction

"*Ignores Hygroscopicity and New Droplet Size Data

- Fall Height Rigorously Considers Obstructions

- Drywell Assumed to Be Well-Mixed

"* Torus Sprays

- SRP 6.5.2 Removal Rates (for Pool Bypass)

Deposition in Steam Lines (and Other RB Bypass Pathways)

"* Steam Lines

- Steam Line with One Open MSIV

• Impaction at Inboard MSIV (DF - 2)

- Steam Line with Closed MSIVs

"*Sedimentation (Well-Mixed) Between MSIVs

"*Calculated with STARNAUA

" Impaction at Inboard MSIV Combined with Sedimentation Removal Rates (i.e., "Lambdas")

"* Other Bypass Pathways

- Sedimentation (Plug-Flow) in Piping within Secondary Containment (Large L/D)

I Pool Scrubbing 0 Treatment Consistent with SRP 6.5.5

• Drywell-to-Torus Flow Commences with Core Debris Relocation (Predicted by MAAP4)

• Approx 50% of Drywell Volume Transferred over 10 Minutes Leading to 40% Purge 0 Pool DF - 2.3 (Approx 50% Pool Bypass) 0 DF Effectively Much Smaller 0 10 Minutes of Return Flow Based on Drywell Spray Operation after Partial Drywell Purge 0 Drywell and Torus Considered Well-Mixed after End of Release Period Dose Results by Type

- Organic Iodine Inhalation Dose 1.33 Rem

- Elemental Iodine Inhalation Dose (w/o Revolatilization) 0.14 Rem

- Dose from Inhalation of Particulates 2.17 Rem

- Revolatilized Iodine Inhalation Dose 0.12 Rem

- External Dose (Activity Inside Control Room) 0.37 Rem

- External Dose (Activity Outside Control Room (i.e., Plume) 0.04 Rem

- External Shine (Containment/Core Spray) 0.60 Rem Total = 4.77 Rem Dose Results by Pathway

- Steam Line with Stuck-Open Outboard MSIV 2.3 5 Rem

- Steam Line with Closed MSIVs 0.56 Rem

- Containment Leakage- 0.21 Rem

- ESF Leakage- 0.35 Rem

- Other (Non-MSIV) Secondary Containment Bypass 0.70 Rem

- Containment and Core Spray Piping Shine 0.60 Rem Total = 4.77 Rem Atmospheric Dispersion - LER 2000-006

"* CLB and 1997 Submittal

- Murphy-Campe

- 1982-83 Meteorological Data

- "A" Control Room Air Intake (Only Intake in 1985)

"* Application of ARCON96

- Ground-Level Release X/Qs Only Recalculated

- Both "A" and "B" Air Intakes Considered

- NRC Draft Guidance Employed

-1995-99 Meteorological Data

• OC Meteorological Program Meets RG 1.23

• Includes Statistical Analysis for Trends