ML051300259

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Presentation Slides on Proposed Manual Action Rule Impact on Peach Bottom Preliminary Comments - Presentation to NRC Staff
ML051300259
Person / Time
Site: Peach Bottom  Constellation icon.png
Issue date: 04/27/2005
From:
Exelon Generation Co, Exelon Nuclear
To:
NRC/FSME
Diec D, NRR/DRIP/RPRP, 415-2834
Shared Package
ML051300222 List:
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Download: ML051300259 (29)
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Proposed Manual Action Rule Impact on Peach Bottom Preliminary Comments Presentation to NRC Staff April 27, 2005

Purpose

  • The purpose of this presentation is to provide insights on the impact of the proposed Appendix R Manual Action Rulemaking on a specific plant.
  • This plant is an older BWR-4/Mark-1 that uses a post-fire shutdown methodology similar to most BWR plants, but is bounding for decay heat and containment response.

Agenda

  • Provide overview of existing PBAPS manual actions
  • Provide details on the impact the proposed rule would have on PBAPS

Overview - Licensing Always Been Included in the PBAPS FSSD Analysis

- July 1983 Meeting and September 1983 Submittal

  • Associated circuits that have a separation from the fire area less than that required by Section III.G.2 of Appendix R and have a connection to circuits of equipment whose spurious operation could adversely affect the shutdown capability have been adequately resolved by appropriate action pre-or post-fire.
  • This analysis assumes that any manual capability credited as part of the safe shutdown system for the purposes of this review, will be based on verification that, at a minimum, sufficient numbers of operating shift personnel will be available to fight the fire and perform the necessary operator actions.
  • The only requirements is that sufficient time must be available to restore the affected safe shutdown system function prior to the occurrence of an unrecoverable plant condition. For this analysis, a time-line/manpower concept is utilized to establish that sufficient time is available for restoration of the safe shutdown system function. The resulting time-line diagram shows the number of personnel involved in performing each safe shutdown function and the time required to perform those functions. The time-line diagram demonstrates that sufficient time and personnel are available to perform the safe shutdown functions.

Overview - Licensing

- Fire Protection Program Document (UFSAR) - 1986

  • Per GL 86-10 guidance, gathers all related FP information into a single volume of the UFSAR. Describes FSSD methods including manual actions. Provides listing of manual actions

- 1989 Submittal on MHIF and manual actions

  • Response to URI on MHIF and Manual Actions

- Safety Evaluation Report 1993

- August 1995 Submittal (G.L. 92-08 Response)

- T-Lag Meeting 1997

  • Explained manual actions are used

- T-Lag Order

  • Required completion of actions docketed in 1997 T-Lag meeting.

=

Background===

  • Previously Approved

- Industry Definition of Current Licensing Basis based on NRC Definition (LIC-100, 10CFR54.3, GL 91-18)

  • Docketed Correspondence
  • Information contained in letters that are referenced in SERs
  • Orders, License Conditions, Bulletin & Generic Letter responses.

- Appendix R implementation encompassed all of these

  • Resolution of enforcement actions (URIs, Violations, LERs)

- Typically documented via inspection reports.

- Not limited to information explicitly stated in a Safety Evaluation Report

Overview - Risk

  • Risk Impact of Manual Actions

- Required to be addressed in IPEEE (GL 88-20 Supplement 4, NUREG-1407)

- Addressed in Peach Bottom IPEEE Submittal

- Evaluated by NRC (NUREG/CR-4550, NUREG-1742, section 3.4.8.1)

- Re-evaluated in current PBAPS Fire PRA

  • 1 dominant scenario per unit
  • Remaining MA scenarios < 2.8E-7

Feasibility

  • Timelines and staffing requirements

- Part of original FSSD design basis calculations

- Certain actions field tested during PBAPS extended shutdown

- 2002 Manual Action Feasibility Study

  • Comprehensive Review of FSSD Manual Actions

- NRC inspection team reviewed during 2003 Fire Protection Triennial

  • Found manual actions feasible with no safety concerns

Types of Actions

  • Trip/Open Breakers
  • Close Breakers
  • Operate Handswitches

- Restore power to battery chargers

- Establish Lighting for Alt. SSD Panel

  • Operate Valves

- Manually operate

- Operate at MCC

  • Pull Control Power Fuses

Feasibility

- Most manual actions are similar to tasks operators perform on a frequent basis.

- Pre-engineered to be as simple as possible

- Most tasks can be accomplished without entering the affected fire area.

  • Operators know plant layout and can often take alternate routes to reach the same location.

- Many post-fire safe shutdown tasks are similar to tasks performed for both normal and shutdowns addressed by other EOPs and AOPs.

Specific Concerns

  • Time Margin for Manual Actions

- Current Design basis actions are based on assumed all-encompassing fire at T=0

  • Creates perception issue
  • Sequencing & timing taken on inflated importance

- For realistic fire scenarios

  • Most manual actions are not required
  • Sequence & timing less important
  • Operators will have advance warning of fire conditions since T never really equals 0

Specific Concerns

  • Dose

- NUREG-0737 - GDC-19 dose limits are applicable to emergency actions, not 10CFR20.

- 10CFR20 sets occupational limits, annual accounting & bookkeeping.

  • Accounting and bookkeeping cant be managed in emergency situation, creates a distraction
  • Not reasonable to maintain dose balance in reserve for post-fire actions, nor is it currently required for other non-fire post-accident conditions.

Typical Generic Actions

  • Appendix R assumptions (ex., GL 86-10 guidance) non-mechanistically force us to assume many initiators.
  • These same initiators already have generic manual actions as part of their response, regardless of the cause.
  • Due to the design of Rx protection systems, no amount of fire barriers/encapsulation can completely prevent these initiators from occurring in a fire.

Typical Generic Actions

  • Chapter 15 Accidents & Transients typically allow manual actions, 10 minutes after event initiation.

- Only exception is that actions to protect Tech Spec Safety Limits for Chapter 15 Accidents & Transients must be automatic (GL 91-18)

  • Common (BWR/PWR)

- LOOP - Verify DG operation, including local observation and adjustment

- LOOP or 4kv transfer - Verify transfer, re-set power supplies & chargers, verify system alignments

- LO Inst Air - Reposition critical valves by hand or manually align backup supply to critical valves

- Any Event - Manage unit dependencies to support the accident unit (plant specific)

Typical Generic Actions

- Transient - Inhibit ADS

- SORV - Remove fuses

- LOFW - Maximize CRD flow (manual valve)

- Cont Isolation - Re-open instrument valves. Restore instrument nitrogen to valves in containment.

- LO RCP Seal Cooling - manually restore cooling and/or trip RCPs

- LOFW - manually initiate turbine-driven EFW

- ES Actuation - Reset actuation, return systems to standby

- Depressurization/Cooldown - Periodically Block ESAS

Impact of Proposed Rule

  • Detection and Automatic Suppression In Fire Area Requiring the Manual Action

- Existing Detection and Suppression provided to meet specific hazards (BTP 9.5-1) and regulatory requirements (App. R).

- Existing exemptions in some areas for lack of detection (III.F) or lack of suppression (III.G.2.b, III.G.2.c) based on hazards analysis.

  • Will these exemptions still be valid? Revision reqd?

Impact of Proposed Rule

  • Most fire areas are large with multiple zones and rooms.

- Suppression often limited to an zone/room with a specific hazard and is not area wide.

- Further subdivision of fire areas into smaller areas would require additional FSSD analysis and upgrade of barriers.

Impact of Proposed Rule

  • Primary impact was lack of full area automatic suppression systems.

- 13 out of 47 fire areas affected

- 168 rooms/zones affected within these 13 fire areas.

Impact of Proposed Rule

  • Exemption Justification

- Low combustible loading in most zones

  • Typical combustibles in the areas are not prone to fast spreading fires.

- Spatial and physical separation between rooms/zones within fire area

  • Typically, damage to a specific part of the fire area results in the need for manual actions.
  • Existing barriers while not credited for App. R will slow fire growth and limit exposure.

Impact of Proposed Rule

  • Unintended Consequences

- New suppression systems will create hazards to some equipment.

- Flooding design basis impacted

- Gridlock future changes to FP program

  • Significantly limit what changes could be made under Standard FP Licensing Condition w/o prior NRC approval (contrary to Commission policies on burden reduction for requirements marginal to safety, GL 86-10, GL 88-12).

Impact of Proposed Rule

  • $67 Million - Cost Estimate for sprinklers

- Excludes Turbine deck, Refuel floor, Feedwater heater rooms, Stair towers

- Additional factors to consider (not in $ est.)

  • Dose - Significant dose during installation and future testing.
  • Drainage - Many areas do not have floor drains (or the drains covered for Rad/Environmental reasons).
  • Plant Equipment - Impact of sprinkler flow and pipe breaks would have to be addressed.
  • Impact on capacity of existing fire protection water supply system.

Impact of Proposed Rule

  • Fire Area Example

- Turbine Building (Fire Area 50)

  • Large fire area encompassing both U2 & U3 areas.
  • 143,000 ft2 already provided with automatic sprinkler protection.

- Lube oil rooms, moisture separators, condenser pits, common areas, 13kV Switchgear areas, feed pump rooms, railroad bay and hatch area.

Impact of Proposed Rule

  • Turbine Building (Fire Area 50)

- 87,000 ft2 not proposed to have automatic suppression (exemption required)

  • Pipe tunnels, ventilation equipment area, feedwater heater rooms, turbine deck (turbine bearings and underskirt area have sprinklers)
  • Cost for sprinklers if required would exceed $26 million

- 57,000 ft2 could need sprinkler protection under proposed rule (exemption would be submitted)

  • Areas do not present FSSD hazards
  • Areas not required to have suppression under prior NRC rules or guidelines.
  • Cost for sprinkler installation would exceed $17 million

Impact of Proposed Rule

  • RadWaste Building (Fire Area 2)

- Large multistory building between two reactor buildings, common fire area

  • Suppression systems in HPCI pump rooms and in old baling and drumming room
  • 45,000 ft2 would need sprinkler protection under the proposed rule

- Projected cost would exceed $13 million

Impact of Proposed Rule

  • Radwaste Building (Fire Area 2)

- Exemption Request would be submitted

  • Low combustible loading throughout building (except where suppression is provided)
  • Building is well compartmentalized primarily for radiation considerations
  • Many high dose rooms

Impact of Proposed Rule

  • Training

- Increase in training requirements in FSSD procedures will impact the training organization.

  • Training cycle already full.
  • FSSD procedures are covered on two year cycle but not in detail required by the proposed rule.
  • Training is already performed, however proposed rule will result in 94 unique training events per operator.

- Result will be less training time to spend on other more risk significant events.

- Train on the same action, for multiple fire areas?

Impact of Proposed Rule

  • Procedures

- Written using a template

  • Format provides consistent and easy to understand guidance for the operator.

- Human factors reviews.

  • Operator feedback
  • 1 procedure per fire area per unit
  • Each action is in a separate tear-out

Summary

  • Improvement in Safety Does Not Support Proposed Rule Given the Cost of Compliance

- Cost of additional automatic suppression systems could exceed $70 million at PBAPS

- Training burden may impact plant safety since less time will be available for other even more risk relevant training.

- Ignores 25 years of precedent on manual actions at PBAPS

- Significant burden developing exemptions

- PBAPS Triennial inspection found all actions feasible

Conclusion

  • The results from NRC fire protection inspections to date indicate that there is insufficient evidence that the generic use of these manual actions poses a safety concern. - Reg Analysis 12/2004
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