ML20003A310
| ML20003A310 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 01/21/1981 |
| From: | Hukill H METROPOLITAN EDISON CO. |
| To: | Collins P Office of Nuclear Reactor Regulation |
| References | |
| L1L-018, L1L-18, LIL-18, NUDOCS 8102030470 | |
| Download: ML20003A310 (7) | |
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l Metropolitan Edison Company Post Office Box 480 g
Middletown, Pennsylvania 17057 717 944-4041 Writer's Direct Dial Nurnber January 2L 1981 L1L 018 Of fice of Nuclear Reactor Regulation Division of Human Factors Safety Operator Licensing Branch Attn:
Mr. Paul F. Collins, Chief U. S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. DPR-289 Mitigating Core Damage Training Program In conjunction with our commitment to describe our training program for Mitigating Core Damage prior to our restart examination, please find enclosed our proposed training program. For your information, this material is being developed for us by Mr. Paul Bemis of Chem Nuclear, Inc., and he will present a pilot course on the subject during the week of March 16, 1981.
Sincerely, H'.
D.
uxill Director, TMI-l HDH:SLN:1ma Enclosures l
l cc:
L. Barrett H. Silver l
R. W. Reid c
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h5 Aetropolitan Ed: son Company is a Member of the General Public Utitttes System
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ADVANCED HEAT TRANSFER, FLUID FL0tl, THERMODYNAMICS / MITIGATION OF CORE DAMAGE I.
CORE THERNRL HYDRAULICS 1.
Heat Transfer fundamentals a.
Modes b.
Heat generation in the fuel rod c.
Temperature in fuel rod 2.
Boiling Heat Transfer a.
Axial flux distribution and coolant enthalpy along the coolant channel b.
Axial temperature profiles c.
Temperature difference between clad surface and moderator as a function of height 3.
Heat Transfer Curve a.
Definitions of each section b.
DNBR c.
Analysis of DNB curve 4.
Decay Heat Theory 5.
Results of DNB commencing at various times followi.ng a Rx trip.
6.
Power distribution and fuel densification 7.
Hot channel factors a.
Definitions b.
Determination c.
Tech Spec Relationships 8.
Vessel Heat Up and Cool Down Effects II.-
CORE COOLING 11ECHAtlICS 1.
Alternate methods of core cooling 2.
Hot leg vs. cold leg injection 3.
Core spray, core cooling effects 4.
The mechanics of natural circulation 5.
Heat removal paths including heat sinks 6.
Steam vs. water cooling 7.
Effects of boron precipatation 8.
Quenching effects on fuel cladding III. POTENTIAL DAf1AGIllG OPERATING CONDITIONS 1.
Loss of offsite power while one onsite power train is out of service.
2.
Extended station blackout 3.
Stuck open PZR safety valve 4.
Loss of normal heat sink following reactor / turbine trip 5.
Loss of DC control power to a 4160v ESF bus 6.
Address damage thresholds such as: clad and fuel melt temperatures, boiling in the core, time-dependent. effects and core material deformation criteria 7.
Operating under saturated conditions 8.
Pressurizer empties and refills 9.
Steam generator tube ruptures
- 10. Over pressurization accidents
- 11. Buildup of non-condensables in pressurizer and condenser IV.
GAS / STEAM BINDING AFFECTING CORE COOLING 1.
Natural circulation 2.
Sources of gas / steam vapor during accident conditions 3.
Symptoms and effects of gas / steam binding in the vessel / generator tube -
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E areas and recommended corrective actions.
4.
Symptoms and effects of gas / steam binding on coolant pump operation.
5.
Possible effects of introducing nitrogen into the primary system during small break LOCA V.
RECOGNIZING CORE DAMAGE 1.
Use of excore neutron detectors for determining coolant levels.
2.
Use of core thermocouples; range needed for adequate use and alternate methods when underranged; readouts and recorders.
3.
Plant Computer capabilities for data acquisition, including time in and out of limits and alarm setpoints.
4.
Use of incore (movable and fixed) neutron detectors for determining peak core temperatures.
5.
Review of existing " post accident" critical parameter instrumentation capabilities.
DAIMGE VERIFICATI0tl METHODS:
6.
Use of any installed " failed fuel" detector or similar systems.
7.
Use of installed radiation monitoring systems to assess extent of damage as well as radiation / contamination levels.
8.
Isotopic analysis, threshold for high probability that some clad failure has occurred.
9.
Isotopic analysis indicating clad damage, fuel pellet deformation, and fuel in the coolant from severe clad damage.
- 10. Use of thermocouples for locating blocked flow channels.
VI.
M0tlITORING CRITICAL PARAMETERS DURIllG ACCIDEllT CONDITIO!1S, NON-NUCLEAR INSTRUt!ENTATI-1.
Temperature Measuring Instruments (RTD's and Thermocouples) a.
Theory of Operation 3
b.
Environmental Effects c.
Input to Control and Protection Systems 2.
Pressure tieasuring Instruments a.
Theory of Operation b.
Environmental Effects c.
Input to Control and Protection Systems 3.
Flow Instruments a.
Theory of Operation b.
Environmental Effects c.
Input to Control and Protection Systems 4.
Level Instruments a.
Theory of Operation b.
Environmental Effects c.
Input to Control and Protection Systems 5.
The use and capability of the plant computer in monitoring and analyzing critical parameters.
VII. GAS HAZARDS DURING SEVERE ACCIDENTS 1.
Hazardous concentrations and characteristics of hydrogen explosions 3.
Hydrogen / oxygen concentration measuring equipment and alternate means during containment isolation 4.
Hydrogen recombiners or other means of limiting-buildup in containment 5.
Primary system gas venting 6.
Radioactive gas accumulation in containment following a break in the primary system.
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VIII. CRITERIA FOR OPERATION AND COOLING MODE SELECTION 1.
Optimum core flow rate with severdy damaged fuel cladding 2.
Criteria for coolant pump operation 3.
Consideration for indication of flow channel blockage and core hot spots.
4.
Effectiveness and disadvantages of " feed and bleed" method of core cooling.
5.
Considerations prior to using normal shutdown cooling mode.
6.
Importance of maintaining the containment isolated.
7.
Corrosion effects on equipment within containment including expected time to failure in the case of submerged equipment.
8.
Brief review of emergency procedure use to address the unexpected condition for which no procedure cxists.
IX.
RADIATION HAZARDS AND MONITOR RESPONSE 1.
Actuation of Radiological Emergency Plan 2.
Identification of plant areas normally used that may become high radiation areas.
3.
Primary coolant and containment atmosphere sampling procedures 4.
Anticipated response from radiation monitors within containment.
5.
Method of determining radiation levels by direct measurement of detector output signal.
6.
Methods for reading radiation levels exterior to containment and calculating interior values.
7.
Radiation monitor failure modes X.
THERMAL EFFECTS ON STEAM GENERATORS 1.
Materials and thermal coefficients of expansion 2.
Tube denting p'roblems 3.
"DNB" curve applied to the steam generator
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4.
tlater hammer problems 5.
Themal shock problems 1
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