ML20054L168

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ML20054L168
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Site: FitzPatrick Constellation icon.png
Issue date: 04/01/1982
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POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
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PROC-820401, NUDOCS 8207070217
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ENCLOSURE 3 ficat Transfer Lesson Plan 8207070217 820701 PDR ADOCK 05000333 P PDR

April s l, '1982 Revt 1 A. Heat Transfer B. References ,

1. Elementary Engineering Thermodynamics, Volume three, NED0 - 10806, General Electric Company, May 1973
2. NEDM - 20140, Fuel Densification Effects on General Electric Boiling Water Reactor
3. NEDO - 10958, General Electric Thermal Analysis Basis (GETAB) s C. Objectives,_

~

1. Understand all methods of heat transfer.
2. Be able to discuss thermal limits and how calculated.
3. Know definitions of various terms.

A. Be able to sketch various graphs' pertaining to heat transfer.

1 D. Intr 7 duction to Heat Transfer -

Heat transfer maybe defined as the transfer of energy by means of a temperature difference. It should be noted that the direction of energy flow is always from the reg'on of high temperature to the region of icwer temperature. There are three modes of heat transfer: (1) conduction (2) convection (3) radiation.

1. Conduction I
a. Definition - transfer of energy due to the transfer of kinetic eneray between the molecules of a substance. See fioure 1
b. Fundamental principles of conduction heat transfer:

(1) There must be a temperature (internal energy) gradient in order for heat to be transfer ed through a material.

(2) The amount of ' Aa* transferred will depend upon the thickness of the materie:

(3) The amount af heat transferred will obviously be heavily deoendent on the type of material .

(4) The total amount of heat transferred is also dependent on the total area throuah which it is to be transferred.

(1;

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A i

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Using these principles, it is possible to construct a word  :

, equation, then a mathematical equation which qualitatively i describes conduction heat transfer.  !

TJ._ Heat Transfer iiate = area x temperature gradient i
- material thickness 4

To make the above expression an equation requires a constant of proportionality. The constant we will use will be a number de-

_' scribing the relative abilities of various materials to conduct  ;

heat. The constant is called thermal conductivity.

i Hea t Transfer Rate = thermal conductivity x area x temperature gradient

, material thickness i

In mathematical terms:

  • g=KA(T)-T) 2 or KA ( AT) x x g = Rate of heat transfer (BTU /hr)

K = Thermal conductivity (BTU /hr - ft - F) 2 A = Area (ft ) 3 T1 = Higher temperature ( F)

{ T2 = Lower temperature ( F) a X = Material thickness (ft)

The following is a list of materials and their yalues for rela-tive heat transfer capability:

Ma terial Thermal _ Conductivity (BTU /hr - ft OF)

Air 0.014 Stainless Steel 12 Copper 220 Iron 38 0

{ Staturated Steam (600 F) 0.11 (2)

c. Conduction is the method by which the heat moves out of the fuel, through the gap, the clad and through the film of stagnant water which coats the clad. This stagnant film is important. It exists because water has a viscosity. Viscosity is a property of liouids which is normally a consideration of lubricants. Kerosene has no viscosity and things like molasses and grease have high viscosity.

flo matter how fast water. flows through the core there will be a thin film of water coating the clad. Heat passes through this film by conduction. When heat moves through materials by conduction, the heat energy passes from molecule to molecule. It travels about the way the bucket brigade got water from the well to the burning barn in the old western movies. It was passed along.

Some molecules are better at passing the heat than others. (See Section D.1.b) UO2 is bad. 00g is a ceramic material much like the fire brick used to insulate boiler furnaces. To push the heat out of the fuel, takes an extremely high temperature difference. The fuel center temperature is above 30000F while its surface which k" away is <10000F.

The gap between the fuel and the clad _is not a good conductor. That is why helium is introduced into the fuel rod during manufacturing in place of air, to help the gap conduct heat. Hydrogen, which is used in the main generator vould be better, but it absorbs neutrons.

The size of the gap affects the heat conduction. The bigger the gap, the worse the conduction and the narrower the gap, the better.

This effect will be important in a later discussion on Average Planar Linear Heat Generation Rate (aPLAGR).

The clad itself is a very good heat conductor and it takes very little temperature difference from the inside to the outside of the clad to get the heat to flow through it.

The water film is not a good conductor, but it's not bad either.

The heat would flow better if the film wasn't there, but, as you will see, core must be taken when working with this film. A water film is a much better conductor than a steam film.

Once the heat has been conducted through this stagnant water film, it is transferred to the flowing water by convection.

2. Convection
a. Definition - transfer of heat between a fluid and a surface by the circulation or mixing of the fluid.

i (3)

i t

b. In figure 2, a fluid is flowing over a heated wall surface. Note '

the very thin layer of fluid immediately next to the wall surface. .

This layer is called the " stagnant film" and is characterized by  ;

several slowly moving layers of fluid only several molecules thick.  :

Heat is transferred across this stagnant film by a process similar ,

to conduction, only a slight difference between the two because  !

there is some mechanical motion of the layer. The heat energy is  !

carried away from the surface by two mechanisms: 1. The physical  ;

collision of molecules of fluid and wall material, thereby trans- '

ferring heat energy in a manner identical to conduction, and 2. The i mechanical movement of molecules away from the surface and out into l the i vid where they give up their stored energy to other fluid .

molecules.  !

In mathematical terms:

g=K f A (Ts -T) f ,

j X f

g = Total heat transfer rate (BTU /hr)

K f = Thermal conductivity of the stagnant film (BTU /hr - ft 0F) 2 A = Total area (ft ) ,

T = Surface temperature (UF) s Tf = Fluid, temperature ( F)

X7 = Stagnant film thickness (ft) e
c. When the water is able to move, its ability to transfer heat is greatly improved. This is because there are many more water molecules available in a flowing system to oick up the heat from the surface of the stagnant water film.

If the recirculation pumps aren't running, as power begins to increase from zero, heat is transferred to the stagnant water between the fuel rods.

l (4)

-. _ _ _, _ _ _ _ = _ . , . - _ - , . - - . _

As the water heats, it expands and becomes less dense. When this happens, the weight, or really the downward force exerted by gravity on the water in the core becomes less than the downward gravitional force on the slightly cooler water in the downcomer area and in the jet pumps. The water in the jet pumps will be pulled downward by gravity, forcing the water in the core upward. This flow is called Natural Circulation, and is responsible for the relationship between power and flow at low power. Of all the water molecules flowing in the system only 10% strike the surface of the fuel rods and pick up enouch heat to make steam. This 10% then moves back into the main stream and raises the average bulk temperature of the fluid to saturation temperature just by their presence without transferring much heat to the surrounding medium. For example: there are 10 water molecules at 500, I molecule strikes the surface of the fuel rod increasing its temperature to 1000F. The average temperature of the 10 molecules is now 55 F but 9 molecules are at 500F and 1 is at 1000F. By convecting the average temperature of the molecules has been raised from 500F to 550F.

Up to a point, as more water flows through the core, more convective heat transfer occurs.

The term used when the recirculation pumps are running is forced convection. Forced convection allows better convective heat trans-fer. This results in more power from a smaller core, and that means ,

a cost savings.

3. Radiation [

, a. Definition - Electromagnetic radiation emitted by a body as a result of its temperature, 'or, the transmission of heat in the form of radiant energy or wave motion, from one body to another across and

  • intervening space.
b. The following is characteristic of radiation heat transfer:

(1) Reauires high emitting surface temperature (2) Is undesirable in a BWR.

(3) Could occur in a dry vessel following a LOCA.

c. You can feel heat radiation on your skin when you put your hand say, on the bottom of a hot clothes iron, a hot pioe, etc. Many times the heat radiation has saved you from burnina your hand when you were about to touch somethina that you didn't think was hot. You know that if you can " feel-the-radiation," you probably will be burned if you touch that object. Conduction and convection are better and more effective methods of transferring heat than radiation.

(5)

4. Heat Flux Heat will flow in all directions through anything as long as there is a a temperature difference. It will even flow in all directions through
nothing. '
through an Since area. it flows in all directions, we can talk about it flowing To " handle" it properly an arga is used. BTU /hr - ft or W/cm2 are units of heat flux. The ftd or cm represent the area through which the heat is flowing. This area is measured perpendicular to the heat flow direction. In the BWR core, this is normally f t2 or cm2 of clad area.

BTU /hr and watts are units of power. (3.4 BTU /hr = 1 watt). . Power is the ra te-o f-doi ng-work. Heat flux is the thermal power flowing through a unit i area.

a. There are two formulas used for calculating heat flux: ,

i . ,

Conduction - 0/A = K (T7-T) 2 X  ;

i Convection-h/A=Kf (T s -T) f X

f I

1

b. For convection heat flux it is very difficult to determine the actual .

film thickness. The actual value of Xf will vary with the rate of fluid I flow, the fluid viscosity, the heat flux, the type of surface and whether  !"

the fluid is liquid or boilino. It is cultomary in heat transfer to combine the termsfK /Xf and call this fraction the " film heat transfer coefficient" (h f) (BTU /hr - ft2 0F). The basic equation for convection [

heat transfer then becomes:

r (BTU -T ) (heat flux from surface to fluid) hr- f t' 9) h/A-hf (T s f <

(BTV) h=h fA (T 3- T ) f(total heat transfer rate from surface to fluid)

The value of hf , as stated previously, is d pendent on a complex set of fluid variables, and if required in solvin problems, will be given.  ;

5. Heat Transfer in Heat Exchangers (Ficure 3)

A heat exchancer is basically a mechanical arrangement in which two fluids are allowed to flow but are physically separated by metal. The hotter fluid l gives up its energy to the colder fluid via conduction and convection modes of heat transfer through the metal boundary.

l i

.-.m , ,,-.-----m- - . - . - - - - - - - - - - - - - - - - . - + - - - - - - . -- ---

Overall heat transfer rate equation from one fluid to another:

q=UA(AT) flote: (AT) is an average temperature difference and "U", a new term, is the "overall heat transfer coefficient" (BTU /hr - f t2 _ op ), ,

Heat energy absorbed or given up by a fluid as it flows through a heat exchanger equals:

fluid " fluid Cp fluid (T g -T g) i hfluid = Rate of heat energy absorbed or given up by i fluid as it flows ,

through a heat exchanger (BTU /hr) . t m

fluid = Fluid flow rate (1b/hr) ,

Cp fluid = Specific heat of the fluid (BTU /lb UF)

T = outlet temperature of the fluid (OF) '

out Tin = inlet temperature of the fluid ( F)

The two phase fluid equation is:

fluid - n (h out -hin) flote: "h" is enthalpy in BTU /lb l E. Boiling Heat Transfer (Figure 4A and 4B) ,

r

1. Definition - Boiling is the evaporation of a liquid to vapor occuring within the body of the liquid by the mechanism of bubble formation.

i I

(7) 1 2

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1

2. Continuing the discussion of heating water by convection (per D.2.C) in the core, assume that it has just reached 2120F. It begins to boil in that stagnant water film which is incontact with the clad. At the mole-cular level, the clad isn't smooth. A microphotograph of the clad shows large peaks and valleys on its surface (Figure 5).

The water in the valleys is surrounded by a lot of metal surface so it gets more than the average amount of heat transferred to it. It's the first to boil .

These peaks and valley's in the clad where the bubbles first form are called " sites of nucleation". If you ever looked down into an aluminum pot when it is just beginning to boil, you may have noticed these sites of nucleation.

As more and more heat pours into the area of the bubble, it gets bigger and bigger. Eventually the bubble gets big enough so that bouyant forces will make it move upward. If bouyant force doesn't do it, it will eventually get larger in diameter than the thickness of the stagnant film and _the flowing water will pull it away from the clad. Water fills in behind the bubble and helps accelerate it outward, away from the clad.

3. . Nucleate Boiling (Figure 6A and 68)

This bubble type of boiling is called Nucleate Boilino. The bubbles do many things which can be discussed later, but here, the most important thing they do is to break up the stagnant water film by shooting through it from the clad surface to the flowing water. This is a big helo to heat trans fer. Nucleate boiling heat transfer can be ten times as efficient as non-boiling heat transfer in moving the heat from the clad to the bulk of the coolant flowing in the channel.

There is two types of nucleate boiling:

a. Subcooled nucleate boiling.
b. Bulk (saturation) nucleate boiling As a steam bubble is formed, it moves away from the wall. If the bulk of the water is at less than saturation temperature, the bubble will then cool and condense. This is called sub-cooled nucleate boiling, because the bulk of the water is sub-cooled below the saturation temperature. If the bulk of the water is at saturation temperature, the steam bubble will not cool and condense as it moves aw',y. It will remain as a steam bubble mixed in the bulk of the water. This process is commonly called bulk boiling.
4. Film Boiling As we increase heat flux, more and more bubbles form until many of the spaces on the clad are covered with bubbles. Although the bubbles are moving away frcm the surface, time wise, it apnears that vapor is on the surface more and more of the tire. The higher the heat flux, the more the heat transfer rechanism deteriorates towards s team t,lanketina. . The enset of this phencrenon is called onset of transiticn boiling (OTB) and signals the end of nucleate boiling and the enset of heat transfer deterioration.

(O

As the heat flux continue: to increase, bubbles continue to form at a~ faster and faster rate. Finally, in one portion the clad, bubbles will form so fast that the liquid cannot displace the bubbles and they combine to form a " bubble" or " vapor" blanketed region on the surface. This is a highly unstable condition. The bubbles may move away from the surface allowing liquid to again wet the surface or the bubble blanket may spread until the surface is vapor blanketed.

If the heat flux is increased further, the partial vapor blanket would spread over the entire surface of the clad. We would then find a thin i layer of steam everywhere on the surface.

If we allowed film boiling to take place in the reactor core, the metal of the fuel rods might have melted or have been deformed or cracked. Radio-activity would then leak from the damaged rod into the coolant with rather severe ramifications. D"B, transition boiling and complete film boiling are never permitted in an operating reactor under ordinary or transient conditions.

  • l F. Boiling Water Reactor Thermal Analysis Since the first responsibility of the reactor operator is to protect the core, it becomes necessary for the operator to be conversant in the terminology and have a basic understanding of core thermal hydraulics. The following is a discussion of some of the terms.
1. Quality Ouality (X) = Weicht of the vapor Weight of the vapor + weight of liquid Current BWR's have a core exit quality of about 10%. A good " picture" of the mixture at the core outlet can be obtained by analogy. Shake a bottle of  ;

carbonated soft drink and then take your thumb off the top. The mixture in I the bottle neck would be similar to the core e. it mixture.

2. Void Fraction Void Fraction = Vacor Volume (for some length of fuel channel) I Channel Volune The coolant is in bulk boiling for a substantial length of the core, this means ,

that some fraction of the coolant volume is vapor and some fraction is liquid.

Obviously, as the coolant gets higher in the core more and more of the coolant

volume will be vapor or voids.
3. Slip Ratio (Figure 7)  ;

Slip Ratio = Vacor Velocity L1culo veloci ty I >

1

I Common sense tells us that in the coolant channels the lighter vapor is going to rise (flow) faster than the more dense liquid. What this amounts to is that a pound of liquid at the core inlet will arrive at the core exit as a vapor - liquid mixture over a period of time.

The vapor portion will arrive at the exit before the liquid. It therefore use the term slip ratio. From the figure it can be seen that for a slip ratio of one, the value of void fraction for 10% quality is about 70%.

4. Summa ry Figure 8 is an instructive plot of source curves of important coolant and fuel bundle temperatures versus flowpath lenoth up the core,
a. Line #1 - coolant energy (enthalpy) increase. Miximum energy increase occurs at the point of maximum heat flux.
b. Line #2 - fuel rod center line temperature. Temperature center line  ::

> temperature of fuel surface. Nucleate boiling transfer heat best: heat is transferred to the coolant better so

  • temperature center line stays lower.

h/A=kf el (Tcenter line -Tfuel surface) fuel

c. Line #3 - fuel rod surface temperature. Rise initially due to film AT required to accomodate the heat flux. Fuel rod tempera- e ture levels off when nucleate boiling starts. Heat flux is j greater and AT is about constant; excellant heat transfer of [

nucleate boiling decreases X and increases K film

  • film

-T j

h/A=Kfilm (Tsurf liouid)

X fj)g

! d. Line #4 - coolant temperature; increases as heat is added until temp-l erature reaches Tsat and begins to bulk boil. Temperature stays constant to core exit.

1 e

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e. Line #5 - h/A; ideal heat flux plotted from core bottom to top; maximum heat flux at midpoint.

For an even better perspective of the effects of different modes of heat transfer, Figure 9 shows heat transfer for a single fuel rod in a bundle.

Three conditions shown:

(1) Nucleate boiling with a low heat flux.

(2) Nucleate boiling with a high heat flux.

(3) Film boiling with a larger heat flux (heat transfer mode is film boiling).

G. Heat Generation

1. Linear Heat Generation Rate (Figure 10)

If the w/cm valve could be summed for each square centimeter of the clad in one linear foot of fuel rod, the total would be the so-called linear heat generation rate or LHGR. This number is normally stated in kilowatts per fqot. For Fitzpatrick, an average rod would have a heat flux of 35 w/cm c for the A foot of fuel rod '

would have roughly 170 cmfx7 . Sofuel the at full power.

average LHGR would be about 5.9' kw/ft. Sit ce the 8x8 fuel is smaller in diameter, it would have a smaller 2

LHGR for the same (35 w/cm ) heat flux. The relationship between heat fl0x and tHGR depends on the fuel rod diameter.

LHGR is monitored by the process computer to limit the plastic deformation of the cladding to less than 1%.

The LHGR necessary to cause 1% strain varies from 25 kw/ft at the beginning-of-life to 20.5 kw/ft at the end-of-life (40,000 mwd /T). This is because the fuel becomes more brittle at E0L due to exposure to flux and temperature.

The maximum LHGR allowed for 8x8 fuel is 13.4 kw/ft.

The process computer can then calculate MFLPD:

MFLPD = LHGR actual = and is <1.0 LHGR limit '

2. Average Planar Linear Heat Generation Rate (APLHGR)

This limit comes frcm the LOCA analysis. During part of the LOCA, the water level inside the shroud drops quite low. The fuel is temporarily without coolant. U0p is a poor heat conductor. It takes 7 seconds for the heat of fission to be conducted out of the fuel. Therefore, it is (l')

__ - . _ . _ , . _ _ , ,. ..r ~ v.., , ,.

1 the heat in " storage" in the fuel that is of concern. Even though the reactor has scrammed, the fuel is still hot. The heat content of the fuel fI (or fuel enthalpy) is measured in calories / gram, (which is the metric equivalent of BTU /lb) and though it won't be near its design maximum value of 280 cal /gm, it'll still be high when the clad " dries out".

The stored heat will go toward the clad. With no coolant, the only way the clad has to get rid of the heat is to transfer it by radiation which is the worst 0

form of heat transfer. The maximum allowable clad temperature is 2200 F.

The rods near the center of the bundle will "see" only other fuel rods in all directions. They will try to radiate their heat to other hot rods whicn are also radiating.

What is important under dryout conditions is not what the peak heat flux is, but what is the highest averaae. A high peak in a low average lo-cation is better than a low peak in a high average location.

The heat transferred from the clad can't be controlled but the heat content t of the fuel can be. The amount of heat stored in the fuel is a direct result of the operating kw/ft existing in the fuel just before the scram.

This is measured on a horizontal plane thrcugh each fuel. node and is named the average planar LHGR. A better definition of APLGHR would be "the sum of the LHGR's for all of the fuel rods in c bundle at a specified node divided by the number of fuel rods in the bundle." The maximum incore value of all the APLHGR's is the MAPLHGR. MAPLHGR is measured in kw/ft.

So the definition for MAPLHGR would be "the limiting (maximum) value for APLHGR that exists anywhere in the core'.' These limits are used to prevent fuel clad temperature from reaching 22000F during a LOCA.

Figure 11 is a typical plot of FMPLHGR as a ~ function of exposure. Generally the curve shows a decrease in the allowable kw/ft at the beginning of the cycle. This is caused by the same thing that makes the MLHGR limit vary axially, fuel densification.

As che fuel densifies it not only shrinks axially, but radially. This increases the gap between the fuel pellet and the inside of the clad which, in turn, will d? crease the heat transfer out of the fuel. To compensate for that, the fuel temperature will increase. The increased fuel tempera-ture means more heat stored in the fuel and that leads to a hiaher clad temperature during a LOCA. So the allowable kw/ft is decreased to compensate for the pellet shrinkage.

As exposure continues, cracks develop in the pellec. These are vertical cracks which run from the surface of the pellet to its center. As power is increased and decreased, the cracks will rachet open and eventually will bring the pellet into contact with the clad. This increases the fuels ability to transfer heat so the NAPLHGR limit increases because less heat can be stored in the fuel. As you will see in the PCIOMR section, this pellet growth does have scne disadvantages.

(12)

l In some early fuel, the limit is reduced at high exposure because of in-creased fission gas pressure. That is shown in the figure as a dotted line. The increased gas pressure adds to the stress on the clad during 4

dry out and would cause failure at elevated temperatures, so the limit is reduced. This only applies to old 7x7 fuel which was designed before the MAPLHGR limit came into existance. In newer fuel, sufficient gas plenum i space is provided, so the limit will continue to increase with exposure.

Here again, the limit is a variable.

The process computer calculates a ratio called MAPRAT.

5 MAPRAT = MAPLHGR and is < 1.0 MAPLHGR limit i

Note: See Appendix A i

H. Peaking Factors i 3 1. Nodes A node is a 6" cube of fuel, surrounded by a channel whose ter 2nd bottom

! are at control rod notch positions. Twenty-four nodes 'i a vertical stack make up the active fuel portion of a fuel bundle. 50 h abundle power is just the sum of the individual powers calculated for the nodes of the bundle.

The total of all the bundle powers will equal the core thermal power cal-culated by a heat balance.

If the average core power (determined by heat balance) and the number of bundles in the core are known, the average bundle power raybe determined:

Average Core Power Number of Bundles - Average Bundle Power

2. Radial Relative Peaking Factor (RPF) 4 RPF = The ratio of the power produced by any given bundle in the core to i core average bundle power.

t j

i RFP = Bundle Power of Interest Average Bundle Power i

I (12)

- -~

3. Axial Peaking Factor ( APF)

The APF for any fuel bundle can be determined once its nodal powers are known. The average nodal power is simply the bundle power divided by 24, the number of nodes in the bundle. The APF is then determined by

! dividing the peak nodal power by the average. '

APF = Power in node and bundle of interest Average nodal power of that bundle 1

4. Local Peaking Factor (LPF)

The LPF for a node varies with void fraction, exposure, control rod posi-tion and xenon distribution. It's so complicated that the process computer calculation will only calculate it for equilibrium xenon and can't tell you ,

t which fuel rod in the node is the peak rod. For this reason core must be l taken in using computer information, particularly during a scram recovery when the xenon distribution is changing. Therefore :

LPF = Particular rod power at a node and bundle of interest Average rod power at the node and bundle of interest l

5. Total Peaking Factor (TPF)

Obviously, the total peaking factor (TPF) is found by multiplying RPF x I APF x LPF for any aiven node. Therefore:

i TPF = (RPF x APF x LPF) i I. Critical Power L i

2

1. The Concept of Critical Power Back in the pre-reactor days the term " Departure from Nucleate Boiling" or
DNB was the phrase used to describe the chance from nucleate to film boiling. This was the term transferred to the early reactors as were 1

terms like a " dollars worth of reactivity". They have fallen into disuse

, except in those plant which were conceived in those early days. Mos t 4

PWR's still use the term DNB; the BWR's don't.

i From the early days of the BWR, it was recocnized that the concept of DNB didn' t fit. The reason for this was that the water flowing in a PWR was for below the boiling point. The term subcooled is used to indicate the conditions reouired a much higher temperature difference from the clad to [

l the bulk water that that required in the BWR. The early PWR data was  :

! plotted on a plane of heat versus the temperature difference between the clad surface and the bulk water. Values of 1000F were not uncommon in normal power operation.

1 (la)

For the same heat flux, the BWR was running less than 200 F due to the better heat transfer in boiling. The data plotted on the heat flux -

1 temperature difference plane also had a bad scatter to it.

For These reasons, GE searched for a better set of coordinates for its heat transfer data. Initially, GE plotted heat flux vs quality, but the data also had bad scatter to it. The search for something better continued.

The "something better" came, in the early sixties, from some work done

, at a university in Italy. The Italians plotted their data on a plane of quality vs boiling length. This took much of the scatter out of the data.

The quality vs. boiling length concept was adopted to the BWR and resulted in the concept of " critical power" - CP. Exceeding critical power in a fuel bundle could result in excessive clad temperatures. The critical power in a BWR occurs when a fuel bundle reaches the onset of transition  :

boiling (OTB) somewhere along its length. Transition boiling is not stable film boiling and the clad can stand transition boiling for a long time, but to be conservative, OTB is to be avoided.

This is done by limiting the critical power ratio (CPR), where CPR is defined as:

Critical Bundle Power Actual Bundle Power The lowest in core ratio of all bundles is the minimum critical power ratio or MCPR. As long as the value of MCPR is kept above a mimimum value of somewhere between 1.2 and 1.4 during normal operation, there is rio analyzed transient which will cause any of the fuel to reach OTB, and  ;

certainly none which will cause clad temperatures in excess of 22000F. -

j 2. Determining CP and TPR j The calculations of CP and CPR are fairly simple once the peaking factors have been calculated. The value of CP depends on three things provided the reactor is not being operated far from its normal range of conditions.

l They are: bundle flow, inlet subcooling, and the location and magnitude j of the axial power peak in the bundle.

Figure 12 is the starting point. A value called CP ase b can be determined from bundle flow. The relationship between CP ase h and CP is expressed by the equation:

CP = CPbase

  • K s
  • K a l Where: K is a factor used to correct CF ase for changes in the inlet sub-cooling. SK is a factor used to correct her the location of the axial peak.

a l

1 (H)

-_ - _- _ ~ , - - . -_

,m. _ . . _ , . - , _ _ . _ - _ - . _ - - _ - _ _ . . , . - _ . - , ~ . . . . . . . . _ - . _ _ _ - - _ _ _ _ - _ _

The amount of inlet subcooling can be calculated by a heat balance '

process which includes mixing the heat flows of the streams comino from the moisture separators and the feedwater and adding the recirc pump work. Once that is determined, the value of K is determined from a simple, pre-calculated equation of the form:s ,

K = 1 + (DHS - 25) / 100f (w)

DHS is the inlet subcooling in BTU /lb i

f (w) = 0.09, if DHS is 25 BTU /lb or less, and  !

f (w) = 2.6 x 10-6 w + 0.125, if DHS is ' greater than 25 BTU /lb. Here, i w is core flow in Ib/hr. l l'

i-

The effect of changing the subcooling is significant. As subcooling  !

l increases, colder water ~ enters the core. This will pull the power J peak toward the bottom of the core, but it will also tend to shorten i the boiling length. A lower peak will help and shorter boiling length ,

F won't. Overall, the result is an increase in CP as subcooling increases ,

at the fixed bundle flow used to determine CP base

  • The other variable not reflected in bundle flow is the location of the axial peak. A bottom peak is assumed, but CP varies with the size of the peak so, as shown in Figure 13, the axial pealing factor must be calculated first. The axial peaking factor is calculated by dividing the peak nodal power in the bundle by the average nodal power in that bundle.

j The only other requirement to using the KA curve is the definition of a double peak. Both peaks have to be atleast 15". higher than the valley between them. If they are, use the center peak curve.

CP can now be calculated; CPR is determined by dividing CP by the actual bundle power.

CPR = Critical Bundle Powar Actual Bundle Power

3. MCPR
a. Critical Quality (X )

c 1

(1) Definition - the quality of the coolant which exists when trans-

! ition boiling is expected to occur.

I l

u (16)

i (2) X depends on:

c (a ) Coolant mass flux (1b/hr - f t )

(b) System pressure (c) Boiling length (LB) - axial distance in the channel between initiation of bulk boiling and the point X c is attained.

(d) Heated length (distance over which heat production occurs).

(e) Thermal diameter = (4) (total flow area around the rods)

Total Rod Perimeter (f) Additional parameter (RT - characterize the local peaking pattern with respect to the most limiting rods and takes into account the details of flow and enthalpy distribution within the bundle.

b. GEXL Correlation (Figure 14)

J (1) Correlates X cand L from b experimental data.

(2) The longer the L the greater the bundle average steam quality may be reaching i

c' i c. CPR (1) CPR = Critical bundle power Bundle power of interest (2) CPR = 1.0 when transition boiling occurs.

(3) Thermal limits require CPR >1.07 (4) CPR for a bundle depends on:

(a) Coolant flow l

(i) Increasing flow causes critical power to increase.

(ii) Coolant is further away from transition boiling.

(iii) Operations is allowed with lower CPR's at high power (flow) than at low power (flow).

4 (iv) MCPR (operational) = K 7MCPR (rated) i i

(I7)

(b) Bundle average quality.

(i) Increasing Inlet subcooling will increase critical power.

(a) Cooler inlet water requires more energy (heat) to be added to the water to cause transition boiling.

(b) Subcooling is determined by the temperature of the inlet feedwater. The operator has little control of this parameter.

l (ii) Increasing reactor pressure will cause critical power to decrease. l (a) As pressure increases, enthalp.y (BTU /lb) de-creases. A pound of coolant must acouire less energy to reach transition boiling. -

(b) Also, the Lb decreases, so the bundle is closer to a critical quality for a given power level.

4. CPRRAT When the initial analysis for transient values of CPR was done, the worst case accident became the turbine trip without bypass, with the scram being initiated by stop valve closure.

However, a complication occurred in the handling of the result of a rapid increae in recirculation flow such as would occur if the pump controls should suddenly call for full speed from the pumps when they were running at a lower speed. For all other transients, a limiting, fixed value of CPR could be established. For coeration at low flow, the lines of Figure 15 are used to compensate for the flow increase transient.

Figure 15 is a plot of core flow vs. a factor called K f. The way Kf is determined depends on where the mechanical stops on the scoop tube positioner are set. At FitzPatrick they are set at ? . Should the recirc system be operating in master manual, the lower line on the fiaure is used aiia in master auto (if Dermitted to be used), the unper line. The master manual lines are less conservative. When the single failure criteria is applied while the recirc oumps are in r. aster manual, the MCPR safety limit will not be violated.

( '. : '

l l

Once a value for Kr has been determined, it can be used to vary the flow CPR1imit equals kf x Tech CPR)jNR.

Spec value found That isin exactly Tech Specs.

what the computer does. Then it compares 1 bk. limit to the value of CPR it calculated for the bundle and calls the ratio CPRRAT, or C

CPRRAT = 7ie CPR limit As long as all values of CPRRAT are less than one, you're ok.

The process computer can also use this k f value when calculating MFLCPR:

MFLCPR = (MCPR) (Kf ) and is <1.0 MCPR Actual See table I for summary.

'J. Thermal Limits

1. Purpose - a. Thermal limits are developed to prevent transition boiling during normal operation and transients,
b. Minimize the number of fuel element failures during the lifetime.

of the core.

2. Thermal limits that protect the fuel are divided into three groups (conditions):
a. Thermal limit that protects the fuel clad during normal operation. Prevents film boiling and limits fuel clad temperature.
b. Thermal limit that protects the fuel during a DBA (LOCA). This limits the KW/ft so no damage occurs provided that ECCS come on to recover the fuel,
c. Thermal 1imit that protects the fuel from melt down (5000 F), therefore prevent clad rupture.
3. Three thermal limit parameters are of concern:
a. MCPR
b. APLHGR
c. LHGR All of these were discussed in previous sections.

K. PCIOMR As stated before, as exposure increases, at high power, more and more of the pellets will contact the inside of the clad. At low power (below 8 kw/f t) the pellets aren't generally in contact with the clad, and those that are, aren't (19)

pushing outward with any great force. As power is increased above the 8 kw/f t threshold, the pellets will exert more and more force on the clad, particularly along the sharp edges of the crack that was responsible for the pellet growth.

1 If the pellet has contacted the clad, and power is increased rapidly, the force exerted on the clad by the pellet will be high and the clad will crack length wise at the pellet - clad contacted points. If the rate of loading is kept low, the clad will give or creap and as it moves away from the pellet, the force decreases and the clad won't crack.

A simple analogy to this is kids' toy called " silly putty". If you pull it fast, it snaps, but if you pull it slowly it will stretch a long way.

The clad is a little tougher than silly putty. Once it has been stret'hed,c it will stay that way for a long time, even if the pellet power is decreased and the pellet is no longer pressing on the clad. Eventua,lly, if the pellet doesn't contact the clad for a long time (about 2000 MWD /t), the clad will shrink back to its old shape. -

i The operator will run a TIP trace and use this to determine nodal powers in that area. As long as the final node power is below the curve, power may be changed up or down at any rate. If the final nodal power will be above the curve, then the rate of power increase is limited to .12 kw/ft-hr. In actual practice, the pratical rate-of-loading is somewhere around 5-8 ?"We per hour depending on plant size. Once the oower increase has stopped, it must be held for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> or more to allow the clad to complete its stretch.

This is called soaking.

After the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> soak, the APLHGR values for all the nodes are recorded by the process computer. Nodal powers can then be changed at any rate as long as the final nodal power is below the pre-recorded envelope of ApLHGR powers.

The actual application of the laws during startup is stringent and time con-suming. Rod withdrawal is difficult because with certain rod notches the I

power can be shot through the threshold at very high rates. You will need the guidance of the reactor engineer during rod withdrawal.

Once the envelope is established after the soak, it is good for approximately i 40 to 60 days at full power. It can be extended by operating the node at the ,

maximum APLHGR value that the node has attained for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Every-time this is done, the exoosure counter on the node (which is the computer) can be reset to zero. If the time at pre-conditioning power is allowed to exceed the 1000 or 1500 MWD /t, then the pre-conditioned value returns to 8 KW/ft.

l Preconditioning is done:

i-

1. Anytime the threshold power or power envelope is exceeded.

! 2. Before each thousand t'WD/ Ton if envelope not maintained croperly.

3. Anytime preconditioning evelope needs to be generated or extended.

1 (20)

L. Fuel Enthalpy

1. What is fuel enthalpy?

As indicated earlier, in the discussion of MAPLHGR, the heat content of the fuel is the fuel enthalpy and is neasured in calories / gram.

2. What is the importance of fuel enthalpy?

In normal operation even the high power density fuel will have a fuel enthalpy well below 100 cal /gm. Should a power spike occur such as from a rod drop accident and the fuel enthalpy spikes to 170 cal /gm, the fuel pellets would swell to the point where the clad could crack due to pressure put on it by the fuel. If the power spike should peak enough to result in fuel enthalpies of 425 cal /gm, not only would the clad rupture, but the fuel would be red hot and literally explode into finely divided particles and disperse into the coolant. When the red hot particles hit the coolant, the coolant would flash to steam and set up a pressure shock wave which could knock nozzles of the reactor pressure vessel.

This must be avoided The Rod Worth Minimizer and Rod Sequence Control System are used to limit the worth of control rods such that a rod drop accident will not result in an excessive high fuel enthalpy. ,

i e

4 (21)

TABLE

SUMMARY

MFLPD MAPRAT MFLCPR Item Local Fuel pin Average fuel oin Total fuel Measured power in node power in node bundle power Limiting 1" plastic Clad temperature Boiling Condition strain on clad of 22000 Transition Cause of Fuel pellet Decay heat and Loss of Nucleate boiling [

Failure expansion stored* heat following around clad

. LOCA

~

Failure Fuel clad cracking Gross cladding fail- Fuel clad cracking'due to.

Mode due to stress ure due to lack of lack of cooling cooling Value <1.0 <1.0 <1.0 j

I 1

(22) ,

LHGR APID APLHGR The following is a discussion of the terns LHGR (Linear Heat Generation Rate) and APLHGR (Average Planar Linear Heat Generation Rate). Although the computer technique and the technique used below may differ, the end result (LHGR and APLHGR) are physically equivalent. ,

if the average core power (determined by heat balance) and the number of bundles in the core are known, the average bundle power may be determined.

Average Core Power = Average Bundle Power Number of Bundles Applying the RPF (Radial Peaking Factor), the following results are obtained:

Average Bundle Power X RPF Total oower of bundle of interest 1 Total power of average fuel bundle

= Total Power of Bundle of Interest Dividing the Total Power of the Bundle of Interest by the number of nodes in that bundle, the average nodal power of that bundle is obtained.

Total Power of Bundle of Interc-t = Average Nodal Power of that Bundle ~

number of nodes Applying the APF (Axial Peaking Factor)

Averace Nodal Power of that Bundle X APF Power in node of interest 1 Avg Nodal Pwr of that bundle

= Power generated in Node of Interest Now, knowing the number of fuel generating rods in that node, the following is obtained:

Power cenerated in Node of Interest = Average Rod Power at a given node Number of rods generating power Since a node is a plane of a fuel bundle 6" high and the power that is generated in a rod during this 6" travel is the LHGR, the term that has just been calculated (AVERAGE ROD POWER AT A GIVEN N0DE) is the AVERAGE PLANAR LINEAR HEAT' GENERATION RATE.

This avg rod power at a given node determines the arount of stored energy (decay heat) that is present when the reactor is shutdown. Since all Emercency Core Cooling Systems (ECCS) have a maximum heat renoval capability, there nust be a limit on the APLHGR. The entire node (all rods) does not have to be considered 'n this calculation

, because the peak gladding temperature followinc a loss of coolant a;cident will vary by less than + 20 F across a fuel assembly due to rod to rod powe distribution.

This calculation for APLHGR is performed for every node in the core. The maximum APLHGR which is calculated from all the nodes is known as the MAPLHGR.

The APLGHR are compared to the technical specification limit to ensure that the operation of the plant is within the heat removal capabilities of the ECCS. .

Having determined the AVERAGE R00 POWER AT A GIVErlf40DE FOR A PARTICULAR ,

BUNDLE, the following results are obtained by applying the LPF (Local Peaking Fa ctor) .

Aj.a_ Rod Pwr at a civen node particular Bundle (radial Location) X 1  ;

LPF (Particular rod power at a civen node & bundle) = LHGP~

Avg. Rod Pwr at a given tiode & Bundle F

Particular rod power at a given node & bundles. , j The particular rod described here is the " hottest" i.e., the rod that is  :,

generating the nost power in the 6" or node travel. The term that has just been computed is known as LHGR.

LHGR - That amount of heat produced for a given segment of a rod usually 6".

Once again, this calculation is perforned for every node in the core. In this case we are not looking for stored energy, we are looking for the rod that has the -

highest possibility of having the fuel pellet perforate the cladding. It is found in the rod that is producing the highest power per unit length (LHGR). Therefore, when all nodal calculations are completed these LHGR's are checked against technical ,l specification limits to ensure there is no condition that exists that could cause j pellet to clad interaction. ,

i As stated before, this calculation of APLHGR & LHGR is not how the computer technique is accomplished; however, the end results are physically equivalent.

l l

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INSIDE OUTOIDE Se: tion of a P.'ane Wall FIGURE 1

ST.%GP( A'4T FitJ.4

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, { !l FLUID 2 yg . fluid ONE TEMPERATURE I o >

T2 - TUBE INNER SURFACE TEMPERATURE y fj T'3 i [ T3 = TUBE OUTER SURFACE TEMPERATURE l *d l

TUBE / i g! T4 - FLUID TWO TEMPERATURE

$ / WALL ' lI Xg - FLulO ONE FILM THICKNESS '

d

$ XW = TUBE WALL THICKNESS HEAT * , i

$ X2 = TU8E WALL THICKNESS U  !

- e' .Xg M-XW+ X2 M-Heat Transfer Mechanism for a Typica1Her E> changer i

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FIGURE 3 i

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AT (TSURFACE - TLiousol Plot of Heat Flux vs Temperature The regi ons of heat transfer are described by the method of heat transfer as follows:

Region I - characterized by conduction and convection heat transfer

- No boiling Region ll - characteri2ed by nucleate boiling ,

Region lli - transition region - characterized by partial film boiling - unstable region Region IV - Film boiling region - continuous vapor b!anket - radiation heat transfer i

e 4

FIGURE 4A

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io _ . _ . _ . . . . . . . . _ . . . ---. . .___..._

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j SLIP R ATIO = 2 a

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SLIP R ATIO = 3 w o.4 5

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g l I I 1 l l 1 I l 0 to 20 30 40 50 60 70 30 90 100 STE AM OU ALITY l%)

Plot of Sl;p Ratio as a Parameter of Quality and Void frxtion i

I l

1 I

FIGURE 7 i

-. y , .- .. - - . -

w-+ - -

- _ - --.,.,y-. _ - , - - - , y, r

COOLANT E N TH A LFY e

FUEL ROD CENTERLINE 2 T E P tPE R A TUR E

  • g 3 FUEL ROO SURF ACE g T E f.tPE R AT1J R E
  • p b

[ COOLANTT EF.tPE R ATURE U

  • I NUCLEATE I BOILING 2 AT FUEL
  • ROD

= -

AL w

AT FILM V BULK BOILING b O/A N - _  %

- s

/ \

/ N j *

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CORE TOP

~~

CCRE CHANNEL L EP.CTH >

BO T10M Plot of Coolant and Fuel Bandie Temperature es flon Path L ength FIGURE 8

Ottoo - o o UO2 c a 0.5500 - o 5 s g 0 2

r. < .a 2 o 2 a a <

0.53:0 - d 'f f f ,j 0.4500 -

04000 -

0 3500 -

0.3000 01500 -

02o0c -  ! b -

f 0.1500 - i 0.500 -

y sQ  ;

0.0 -

Effects of Heat Transfer t.fodes for a Single Fuel Rod i

i I

FIGURE 9

rustral5E II ADsOACTIVE ItELE A:iE FilOM Tale PLAtJ f Wail:4N LIMITS g 1

1 I

\( l 2 e me unit FtsLL Cl AlsDat4G GilO55 Ct ADutt4G  ! F.J2L CL AOD6t.G t.tL Cn Arnhu Cat ACKir4G DUE F Attull[ UtlE TO 10 illGil SlitE SS LACK OF COOL ING f CatACKINI. DuL TO !

e LACK OF COOLat.G l l i 1 1  !

e L

4:a ut.t of" DECAY est AT L005 OF tauCLE A f ai FUL 1. rt t t E T l E M r A t4580tl At40 STOstto all AT 1:0 Lir4G Af 40uND -

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40 50 60 70 80 90 100 110 120 130 140 150 BUNDLE COOLANT FLG1,11(x 10 lbm/hr)

CRITICAL POLLER VERSUS BUNDLE FLOW ,11I011 ENltIClatENT hifMDIES n -.

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m

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ENCLOSURE 4 Fluid Flow Statics and Dynamics Lesson Plan i

i

)

I t

i . _ . . _

1. LESSON TITLE: FLUID FLOW STATICS & DYNAMICS .

!!. PURPOSE: To review the various factors that act on fluid at rest and the properties of fluids in motion.

III. PRESENTATION:

A. Units - Discuss

1. Pound-Mass (lbm)
2. Pound-Force (lbr)
3. Acceleration of Gravity (g)
4. Proportionality Constant ( 1 )

gc -

B. Define - Fluid C. Discuss the following properties:

1. Density (4)
2. Specific Volume (v) .
3. Specific Gravity (SG)
4. Pressure (P)

D. State Pascal's Law, relate to core spray & central rod drive.

E. Define - Buoyancy, Archimedes' Principle o

B =s f Vb9 F= B-W F. Discuss pressure - height relationship G. Discuss:

1. Mass Flow Rate (m)
2. Volume Flow Rate (VFR) i m =joAV VFR = AV
3. Mass conservation - use examples with mass & volume flow rates.

H. Discuss Bernoulli's equation and its use.

g Z1

+

V1 2 + P1 = c Z2 _'ig2 _ + P2 9c 2Cc /0 9c 2Cc /0 Use etc.:ple, t

1. Define
1. Dynamic Pressure
2. Static Pressure
3. Total Pressure

=

PT P + /DV2 29c Use example.

J. Fluid Friction

1. Define :
a. Fluid Friction
b. Viscosity K. Reynold's Number & Types of Flow Discuss Reynold's numbers and their relation to laminar & turbulent flow.

L. Head Loss 4

Discuss head loss using Reynold's equation.

M. Discuss water hammer & pressure effect on piping.

P = / cpV h

ph

= Pressure above initial system pressure.

N. Discuss net positive suction head and effect of system parameters on same.

i i

1 i

, - ~ , , _ ,_ _ - - _ _ . , . _ _ . _ _ _ . . , , _ . , _ _ _ - , _ , . _ . _ , , _ . - - - - _ . - - - - - - - . - - , . _ . - - - .

l 1

i ENCLOSURE 5 Elementary Thermodynamics Lesson Plan

I. LESSON TITLE: ELEMEtiTARY THERM 0DYriAMICS II. PURPOSE: To help the student to understand conversion of thermal energy to useful work.

III. PRESEtiTATI0rl:

A. Thermodynamic Properties

1. Define - llorking substance
2. Define - Thermodynamic Property B. Temperature
1. Define - Temperature
2. Temperature Scales
a. Fahrenheit
b. Rankine
c. Centigrade
d. Kelvin
3. Temperature Conversion
a. R=UF + 460 Do Conversion U
b. K=UC + 273 Calculations
c. F = 9/5 UC + 32 C. Pressure
1. Define pressure
2. Discuss the following:
a. Gage pressure
b. Absolute pressure
c. Differential pressure
d. Vacuum
e. Backpressure
3. Show relation between:
a. FT (H 2O)
b. IN. (H 2O)
c. I ti . (Hg)
d. Atmospheric pressure D. Specific Volume and Density
1. Define specific volume
2. Define density

r E. Work and Energy

{

1. Define Work - wk = Fxd  :
2. Define Energy i
a. Potential - PE
b. Kinetic - KE
c. Internal - Potential and Kinetic F. First Law of Thermodynamics Energy is conserved; it can be neither created nor destroyed.

Energy In - Energy Out + Energy Accumulated I

Q=W + AE 7

Where: Q = Heat Transferred to System (BTU) ,

W = Work Done by System (ft-lbf) ,

aE = Change in System Energy (BTU)

J = Joule's Constant = 778 ft-lbr/ BTU

G. Power J

! 1. Define Power l 2. Normally expressed in:

a. Horsepower
b. Watts H. General Energy Equation l

Apply the law of conservation of energy to turbine, pump and boiler processes and show relationship of energy into process, work obtained from process, and energy leaving process.

The following restraints are placed on the process and the working substance:

1. The working substance is entering and leaving the process at the same rate implying the ' weight of the working sub-
stance with the process does not vary with time.
2. Properties of the working substance at point of interest do not vary with time.
3. Rates at which thermal energy (as heat) and/ur work enter or leave the process do not vary with time.

T 1

l

. - , , --e. - , a., - .-- - - . - _ . , . . , , . . , , , , ~ . , , . - - _ . - - , - - . . - - -

J. Elementary Cycles and the Second Law of Thermodynamics

1. Define Thermodynamic Cycle (A recurring series of thermodynamic processes used for the transformation of energy to produce a useful effect)
2. Elements of a Thermodynamic Cycle
a. A Working Substance to act as a vehicle for trans-porting energy between processes in the cycle:
b. A Source or'High Temperature Energy Reservoir to supply energy to the working substance;
c. An Engine to convert the thermal energy of the working substance to useful mechanical work; and t
d. A Sink or Low Temperature Energy Reservoir to  ;

absorb thermal energy from the working substance. j

e. A Pump to move the working substance from the low temperature to the high temperature reservoir.
3. Discuss Typical BWR Cycle
4. Discuss Second Law of Thermodynamics Carnot - It is impossible for any engine in any type of cycle, to convert all of the thermal energy supplied to it into mechanical work.
5. Define Thermal Efficiency ( n th) i Thermal Eff. ( nth) = Work Output
  • Thermal Energy Input .

= WK Net X 100'.'

J x qin

6. Properties of Steam and Steam Power Cycles
a. Define: Saturated Liquid Saturated Vapor '

Subcooled Liquid Super Heated Vapor Latent Heat of Vaporization l'

b. Define Entropy
c. Discuss Basic Steam Cycle using T-5, H-S Diagrams

ENCLOSURE 6 Requalification Training Report

" Mitigating Reactor Core Damage" L

F l

l t

f i

1 A"NUAL RE0UALIFICATION 1981 l

Training Conducted Week of: 4-19-81 4-26-81 .

( 5-03-81 i 5-17-81  ;

5-24-81 t 6-21-81 i i

I. Training Objective l To assure licensed and non-licensed operator personnel remain competent to operate the plant in a safe, reliable and efficient manner, particu-

! larly under emergency or abnormal conditions. .

To provide shift technical advisors and operating personnel from plant

{ manager through the operations chain to the non-licensed operators the i knowledge necessary to recognize conditions that could or have resulted

, in core damage and to mitigate the consequences of such accidents. i i .

II. References and Aids A. References

1. General Physics lesson Plans, Mitigating Reactor Core Damage l
2. General Electric NED0-24708A ,
3. BWR Owners Group, Emergency Procedure Guidelines
I 4. Lesson Plans
a. ECCS Intigrated Response
b. Automatic Depressurization System
c. HPCI
d. RHR
e. CS
5. Technical Specifications B. Aids
1. Overhead Projector
2. Board i 3. Transparencies III. Description of Training Structured classroom discussion complemented by instructor's remarks that encompassed the following:

A. Three Mile Island Incident

, 1. The first 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of TMI-2 Accident

2. Accident Data and its Applicability to Light Water Reactors l B. Core Cooling '<echanics a-

- - + - - - - -

,--.c---,,-g- ,, -y ---- -- ~~ -+ + - - , , - w--- - - -~ , ~ . , - --~~m- ~ m- ~r - - -m--- m---w-

1. BBR Thermal - Hydraulics-
2. Critical Power and Linear Heat Generation Rate

. 3. ECCS Systems ,

( ,

4. Natural Circulation in a BWR C. Potentially Damaging Operating Conditions
1. Loss of Feedwater Events ,
2. Small Break LOCA ,

1

~

D. Recognizing Core Damage / Critical Plant Parameters l

1. Fission Product Release '
2. Isotopic Analysis
3. Hydrogen Production
4. Vital Instrumentation E. Hydrogen Hazards During Severe Accidents i
1. Hydrogen Sources
2. Hazardous Concentrations
3. Control and Measurement of Hydrogen and Oxygen F. Neutron Monitoring / Core Recriticallity
1. Neutron Monitoring
2. SLCS , i G. Radiation Hazards / Radiation Monitoring

{

1. Emergency Planning
2. High Radiation Areas
3. Radiation Monitoring System -
4. Radiation Detector behavior in High Radiation Fields H. BWR Lessons Learned j IV. Evaluation of Training Upon completion of training an exam was administered by the instructor.

l I s l l

i

-l a /

i Enclosure 7 Selected Course Schedules (Replacement License Training) i l

1

4 -

SUBJECT:

HEAT TRANSFER DATE- 2/1/82 DATE- 2/2/82 DATE- 2/3/82 DATE- 2/4/82 DATE- 2/5/82 Thermodynamics and Heat Exchanger and Boiling Heat Transfer Thermodynamic Limits Effects on MCPR Fluid Flow Steam Cycle Power Distrubtion in Boilina Lenath Safety Limits Reactor Core Final Exam .

Critical Quality Fuel Densification

1. LHGR Transition Boiling LUNCH LUNCH LUNCH LUNCH LUNCH Heat & Heat Transfer Heat Balance 2. APLHGR Critical Power PCIOMR
1. Definitions Heat Transfer in a 3. Peakino CPR Review BWR Factors
2. Mechanisms MCPR
1. Definitions TRAINING SCHEDULE s

SUBJECT:

TRANSIENT AND ACCIDENT ANALYSIS DATE- 2/8/82 DATE- 2/9/82 DATE- 2/10/82 DATE- 2/11/82 DATE- 2/12/82 Heat Transfer Pressure Increase Loss of Feedwater Small Break Accident SP's, A0P's, E0P's Events Flow Comprehensive Exam LUNCH LUNCH LUNCH LUNCH LUNCH Introduction to Loss of Coolant Flow Core Flow Increase LOCA Introduction to ECCS Transient and and ECCS Integrated Accident Analysis 1. Pressure Req. Fail Core Flow Decrease

Response

2. 50RV
3. Loss Aux. PWR Nod. Temp. Decrease Positive Addition

_ . . . . . . _ _ _ _ _ _ _ l TRAINING SCHEDULE

'a

SUBJECT:

MITIGATING CORE DAMAGE DATE- 2/15/82 DATE- 2/16/82 DATE- 2/17/82 DATE- 2/18/82 DATE- 2/19/82 Holiday Core Cooling Hydrooen Hazards Recognizing Core Sunna ry Mechanics During Severe Damage (continued)

Accidents A

M LUNCH LUNCH LUNCH LUNCH LUNCH lioliday Monitoring Critical Recognizing Core Radiation liazards and Quiz (Continued) Parameters During Damage Radiation Monitor Accident Conditions Response Transient and i Accident Analysis P and Mitigating Core M Damaae I

TRAINING SCHEDULE t 4

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