ML20028G797

Proposed Tech Specs Re Spent Fuel Pool Rerack

ML20028G797
Person / Time
Site:	Crystal River
Issue date:	08/23/1990
From:	FLORIDA POWER CORP.
To:
Shared Package
ML20028G796	List: ML20028G795 ML20028G797
References
NUDOCS 9009040174
Download: ML20028G797 (6)

Text

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Pag 2 7 of 10 ,f ATTACHMENT l l

2.5.2 Model Superposition 14ethod The modal superoositinn method elves a time history solution of l-the resnonse of an arbitrary structure to known nodal force or tround '

acceleration time histories. The structurir may include linear and nonlinear elements. The four types of nonlinear elements allowed, are 3 The uncoupled model eovations are i SilFM, SilFM, STIF2R and STIF42. ,

integrated analytically.

l 2.5.2.1 Model Suoerposition tiethod Theory l The equation of motion for a structure is: l (M) (5) + (C (2.5.2 1) g ) di + (Kg ) (X) = (F(t))

where (M)

• Pass matrix  ;

(C) = damping matrix t

(Kt ) = stiffness matrix (F(t))

• nodal force or inertial force due to ground acceleration The damping matrix (Cg) and the stiffness matrix (Kt ) in Eq.

(2.5.2.1) are time dependent. This is due to the presence of nonlinear  ;

elements in the structure. Let (Ct ) = (C) + (Cy) and (Kg ) = (K) + [K ,) (2.5.2-2)

(C) and IK) are time independent matrices consisting of the following:

1. damping and stif fness matrices of linear elements.

REY.R 2/10/82 2'b*II 9009040174 900823 PDR ADOCK 05000302 P PDC

.., Page 8 of 10 l

. i

2. dampino and stiffness matrices due to the initfel state of

)

the nonlinear elements. \

t (Cnt) and (Kn*,) are time deoendent matrices producedThe by chanoes I in the state of the nonlinear elements from their orteinal state. i substitution of (e. (2.5.2 2) into to. (2.5.2-1) nives:  ;

(M) (5) + (C) (k) + (K) (1) * (F(t)) -[C,,) (k) - (K,,) (X)

(2.5.2-3) a (F ( t)) + (F ,,(X,0.W where ,

(2.5.2 4)

(F (X,i,t))

• nonlinear force = -(C 1 (i) - (K ) {XI Melrovitch,1967 (pp. 390-394), assumes that the dampino matrix, (C), can be reduced to a diagonal form by means of modal transformation.

be the naturs1 circular frecuency for the ith mode and ($) be the 1.et Wt matrix of modes, nomalized with respect to the mass matrix, associated with the eteenvalue problem:

r 0

(2.5.2 5)

' (4) (f) + (K) (X)

The coupled system of ecuations (2.5.2-3) is uncoupled by the linear transfomation (2.5.2-6)

(1) = (n) (c)

I Eq. (2.5.2 6) is substituted where (q) is a modal displacement vector.

in Eq.

(2.5.2 2) and the resulting equation is premultiplied by ($3T, These operations give the following uncoupled modal equations:

RE) R 2/10/82 2.5-12 l

L - - . - _ _ _ _ . _ _ _ _

- - Page 9 of 10 V

(')

d + D 2w ( *) (k) + N kl (Q) ii i

= (o[(F(t)) + [4[(F n.(X,k,t)) (2.5.2-7) ,

= (0) + {0n t.I where (a) = modal displacement vector w

g

= eicenvalue (i.e., the circular frequency) of the ith mode E

t

= model danpino for the ith node (Q) = generalized linear force vector

=

(+3T F(t)

(Ont)

= generalized, nonlinear force vector

=

(of(Fnt(X.X,t))

The ith nodal equation is:

V .. .

2 (2'5'2*8) 49 + ?>q ',j oj + 94qj*Q4+O n f,4 The yeneralized linear force, Qj, is due to the applied forces, in WECAN, during each time step, only linear variation of the

.spolied forcing function is allowed. So, the ceneralized linear force, Og, is represented as:

0 =C 3 +C (t-t ), t1<t<tg + t.t g

(2.5.2-9) 2j where l g =Ol g and Oi ltg + At 'O!i t g '[

0 *

. 2 ct  !

4 V

REV.R 2/10/82 2.5-13

Pty;) 10 of 10 ,

i 6

The generalized nonlinear force, Onty.is due to the nonlinear elements This force is represented by the first tere of the in the structure.  :

Taylor series (2.6.2 10)

=C (t t ), tg<t<t1 + at 0

q 3{ + C 4j 3 where C =Qnt l 3{ g *)  !

3

~0 nt Ont4 l g\

t 3 t3 - at C

4{=

e 4

REY.T 7/1/84 2.5-14

ENCLOSURE 2 Page 1 of 2 CRYSTAL RIVER RACKS FPC RESPONSES TO INFORNAL NRC QUESTIONS The dose budget for Radiation Work Permit (RWP) 90 0144 for specific rack removal activities for the "B' spent fuel pool was determined using man hour estimates provided by the contractor and dose rates typically encountered in these work areas. This estimate was generated prior to commencement of the work in accordance with Crystal River Unit 3 Administrative Instruction (AI)-1600, "ALARA i' Program Manual."

Assumptions Nade in Generation of This Dose Budoett  ;

1. The effective dose rate experienced for activities above the surface of the spent fuel pool will be 1 mrem /hr.

2. Equipment staging, setup, and removal performed in various areas of the Radiation Control Area (RCA) do not result in any appreciable dose.

3. Absence of any problems which could significantly increase project man hours.

The man hour figures supplied by the contractor for each rack are multiplied by the number of racks to be removed. No prov;sions are mada in the budget for any contingencies.

4. Dose rates from removed racks do not significantly increase General Area dose rates in the area of the spent fuel pool. (Removed racks are shipped on a timely basis and do not accumulate in or near the work area.)

5. Activities associated with installation of new high density fuel racks and their dose estimates are as follows:

! a. Refuel Floor Support Work (existing RWP) l l 0 Preparatory Activities:

l Equipment staging 64 man-hours negligible dose Equipment setup 64 man-hours negligible dose o Rack Removal Sequence:

Detorque/ remove anchor 150 man hours 0.100 man-rem nuts (25 man-hr/ rack at 1 mR/hr). Six racks will be removed from spent fuel pool "B".

Decontaminate, paint, 1,440 man hours 1.500 man-rem I

and prepare racks for l shipping (240 man-hr/ rack at I mR/hr).

ENCLOSURE 2 Page 2 of 2 o Pool Cleanup Activities:

Pool cleanup, etc. 128 man hours 0.100 man-rem at 1 mR/hr o Rack Installation:

New high density racks 2,560 man hours negligible dose installed, excluding diving work. A total of 8 racks will be installed.

(320manhr/ rack) o Acceptance Testing:

(8 man hr/ rack 64 man hours 0.050 man rem at 1 mR/hr)

b. Diving Operations * -0.250 man rem (RWPtobewritten)

c. Handling and Processing of Vacuum Filters * -1.500 man-rem (RWP to be written)

TOTAL

• 3.500 man-rem

• The estimated dose budgets for these activities are based on available information.

Measures Utilized to Minimize Personnel Exposqtti

1. Health Physics Technician / worker review of NRC Information Notice 90-33 related to sources of unexpected exposures associated with spent fuel pool work activities.

2. Use of remote tooling to remove nuts from existing rack retainer bolts.

3. High pressure water decontamination of existing racks underwater prior to removal to reduce dose rates from surface contamination.

4. Strippable paint will be applied to the old racks to "fix" contamination in pla 9 to eliminate potential for skin exposures from hot particles.

5. Shipping of old racks intact. On-site cutting or other volume reduction techniques which may receive significant dose are not being performed.

6. Use of portable lead ' shielding racks to minimize dose rates from racks removed and stored on the 164 ft, elevation.

7. Cleanup of the spent fuel pool floor after rack removal to minimize diver dose rates from accumulated material there.

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