Equipment Qualification of Accident Monitoring Equipment for Severe Accidents

Transcription

1 Equipment Qualification of Accident Monitoring Equipment for Severe Accidents James F. Gleason, P.E. November 2018

2 Fukushima Lessons Learned SA License Requirements IEEE / RG 1.97 SAMG Qualification of Enhanced SA Instrumentation

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6 EA : HARDENED CONTAINMENT VENTS Instrumentation RG 1.97 Accident Monitoring 10 CFR Combustible Gas Control: Hydrogen IEEE Accident Monitoring Type C and Type F Severe Accident RG 1.7 Combustible Gas Control 10 CFR 50.34(f)(2)(xix): Monitoring after Fuel Damage 10 CFR Part 50, GDC 13, 19 and 64 Accident Monitoring EA Spent Fuel Pool Monitoring

7 19 Fuel Damage Severe Accidents 5 since 1979 TMI Chernobyl Fukushima 1 Fukushima 2 Fukushima to 1978

8 SA Event Summary

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10 SAMG Needs for ESAI to Provide Fast and Accurate Information to the Operators because SA events are very fast

11 DBA SA EQ Pedigree Average 0 100% Average 0 0% Fukushima SA exceeded EQ Temperature by >300 F, Pressure > 70 PSI. SA= 640 F, 120 psig. The need for Qualified instrumentation does not stop just because there is fuel damage. The SA focus changes to protecting Containment Integrity. Nuclear Plant Operators need instrumentation qualified for Severe Accidents

12 Fukushima Time line TMI Lessons Learned added in 1981: 10CFR50.44 Hydrogen Oxygen Monitoring Gas Sampling During Severe Accidents (SA)* 0 Hour SA Starts Coolant flow stops nuclear fuel overheats 4 Hours Hydrogen generated from Zirconium water reaction 5.5 Hours Core materials accumulate in lower vessel head 14 Hours Reactor breached Lower Head Melt Failure MCCI 30 Hours MCCI is 1.5 meters into concrete Hydrogen Gas Sampling Off Hydrogen Gas Sampling Off Hydrogen Gas Sampling Off Hydrogen Gas Sampling Off Hydrogen Gas Sampling Off Readings = 0 Readings = 0 Readings = 0 Readings = 0 Readings = 0 *Gas Sampling not possible due to breaching containment at worst possible conditions of Severe Accidents (SA)

13 Comparison of Enhanced SA Instrumentation to Gas Sampling During Severe Accidents (SA) Goal: more information to Plant Operators ESAI on Hydrogen, O2, T, P ESAI on Hydrogen, O2, T, P ESAI on Hydrogen, O2, T, P ESAI on Hydrogen, O2, T, P ESAI on Hydrogen, O2, T, P Readings 10 / second Readings 144,000 Readings 198,000 Readings 504,000 Readings 1,080,000 0 Hour SA Starts Coolant flow stops nuclear fuel overheats 4 Hours Hydrogen generated from Zirconium water reaction 5.5 Hours Core materials accumulate in lower vessel head 14 Hours Reactor breached Lower Head Melt Failure MCCI 30 Hours MCCI is 1.5 meters into concrete Hydrogen Gas Sampling Off Readings = 0 Hydrogen Gas Sampling Off Readings = 0 Hydrogen Gas Sampling Off Readings = 0 Hydrogen Gas Sampling Off Readings = 0 Hydrogen Gas Sampling Off Readings = 0

14 New Severe accident: design extension conditions during which fuel damage has occurred. 4.3 Type C variables potential for breach or the actual breach of fission product barriers (e.g., fuel cladding, reactor coolant system pressure boundary, and containment pressure boundary). New 4.6 Type F variables indicate fuel damage and the effects of fuel damage. parameters needed to execute the severe accident mitigation guidelines (SAMGs) and/or variables needed to mitigate those accidents postulated in a plants severe accident analysis.

15 Sensors

16 Clark Testing Seismic - Six (6) SCHOTT Glass-to-metal seal EPA - 3 each Simultaneously Tested - 2 each Instrumentation, Power and Coax Circuits

17 Kinectrics LOCA SA Temperature SA Pressure - Six (6) SCHOTT Glass-to-metal seal EPA Simultaneously Tested - 2 each Instrumentation, Power and Coax Circuits

18 NTS - Huntsville Performance Aging Radiation - Sandia Seismic SA GLS HMU/HMUC Rockbestos Special Cable Firewall III/Firewall III SCHOTT Connectors with Raychem SCHOTT Glass-to-metal seal EPA

19 Applicability of Accident Monitoring Instrumentation Applies to Design Basis Applies to Beyond Design Basis Accident (BDBA), which is also known as Severe Accident (SA). When did nuclear plant licenses change to require BDBA qualification on some equipment? What NRC regulation requires BDBA qualification? What equipment currently requires BDBA qualification? What is changing to require BDA qualification on more equipment?

20 50.44 Combustible gas control for nuclear power reactors: 1981 (4) Monitoring. (i) Equipment must be provided for monitoring oxygen in containments that use an inerted atmosphere for combustible gas control. Equipment for monitoring oxygen must be functional, reliable, and capable of continuously measuring the concentration of oxygen in the containment atmosphere following a significant beyond design-basis accident for combustible gas control and accident management, including emergency planning. (ii) Equipment must be provided for monitoring hydrogen in the containment. Equipment for monitoring hydrogen must be functional, reliable, and capable of continuously measuring the concentration of hydrogen in the containment atmosphere following a significant beyond design-basis accident for accident management, including emergency planning.

21 50.44 Combustible gas control for nuclear power reactors (c) Requirements for future water-cooled reactor applicants and licensees. The requirements in this paragraph apply to all watercooled reactor construction permits or operating licenses under this part, and to all water-cooled reactor design approvals, design certifications, combined licenses or manufacturing licenses under part 52* of this chapter, any of which are issued after October 16, (1) Mixed atmosphere. All containments must have a capability for ensuring a mixed atmosphere during design-basis and significant beyond design-basis accidents. *Part 52: AP1000, ESBWR, SMR

22 Revision to RG 1.97 Accident Monitoring The staff is issuing Revision 5 of RG 1.97 to endorse IEEE Std Criteria for Accident Monitoring Instrumentation for Nuclear Power Plants, with exceptions and clarifications Licensees and applicants that have committed to an earlier revision of RG 1.97 may voluntarily add Type F variables, that is, those variables to be monitored while managing a severe accident: The ranges of instrumentation should include appropriate margins Instrumentation used to implement EOPs must fulfill accuracy requirements derived from the plant design basis. Monitor the direct effects of fuel damage (e.g. combustible gases concentration, radiation, pressure, or temperature).

23 No New Regulations Required

24 GLSEQ Combustible Gas Control Seminar Outline Historical Regulations and Link to TMI Accident 10 CFR Combustible gas control for nuclear power reactors. Reg Guide 1.7 CONTROL OF COMBUSTIBLE GAS CONCENTRATIONS IN CONTAINMENT Fukushima Accidents Advanced I&C R&D EA : HARDENED CONTAINMENT VENTS Instrumentation NRC and ACRS Resolution or was it? Changes to Standards : Type F Variables IEEE IEC ED1 / IEEE 497 Reg Guide 1.97 R5 EQ for SA GLSEQ Severe Accident Instrumentation Line (IS-SAIL ) Type C and Type F 24

25 Thank You! Jim Gleason Phone