ML17341A392

Proposed Tech Spec Page 3.12-1 Adding Footnote to Change Period for Decay of Region 10 Fuel in Unit 3 Reactor from 120 to 95 Days.Safety Analysis & Bases & Background Encl

ML17341A392
Person / Time
Site:	Turkey Point
Issue date:	07/23/1981
From:	FLORIDA POWER & LIGHT CO.
To:
Shared Package
ML17341A391	List: ML17341A390 ML17341A392
References
NUDOCS 8107310152
Download: ML17341A392 (8)

Text

3.12 CASK HANDLING Applies to limitations during cask handling.

Objecti ve: To minimize the possibility of an accident during cask handling operations that would affect the health and safety of the publ i c.

Ouring cask handling operations:

(1) The spent fuel cask shall not be moved into the spent fuel pit until all the spent fuel in the pit has decayed for a minimum of one thousand (1,000) hours.

(2) Only a single element cask may be moved into the spent fuel pit.

(3) A fuel assembly shall not be removed from the spent fuel pit in a shipping cask until it has decayed for a minimum of one hundred twenty (120) days.+

• The Region 10 fuel which was in the Unit 3 reactor during the period of April 19, 1981 thru April 24, 1981 may be removed from the Unit 3 spent fuel pit in a shipping cask after a minimum decay period of ninety five (95) days.

3. 12-1. 7-23-81 81073i0152 Si0723 PDR ADQCK 05000250 P PDR

BACKGROUND & BASES

1) The assemblies Florida Power and Light proposes to move were in a'.critical reactor for ~674 hours, some 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of this at a power level of 3%. This will have resulted in a very small accumulation of transuranic products.

2) Referring to the enclosed table of Important Fission Products, it is evident that the gases of greatest concern ( Iodine and Xenon) will have undergone more than 7 half-life decays by the 95th day of cooling. Seven half-lives will of course reduce the initial quantity by >99%.

3) In consideration of Items 1 and 2, it is felt that the requirements of 10 CFR 100 are met as referenced in the Technical Specification Bases.

4) Health Physics estimates show that a minimum of 4 Man-Rem and possibly upwards of 7 Man-Rem will be saved if the fuel can be moved in conjunction with the current transfer.

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II Re: Turkey Point Units 3 & 4 Docket Nos. 50-250, 50-251 Fuel Assemblv Decav Time SAFETY ANALYSIS: FUEL SHIPMENT 120 DAYS I. With respect to an accident previousl'y evaluated in the FSAR:

,1 The probability of occurrence or consequences of an accident or malfunction of equipment important to safety previously evaluated

. in the FSAR is not increased.

II. With respect to the possibility of an accident of a different type than analyzed in the FSAR:

All plant parameters will be maintained within Technical Specification V.imits- (with the exception of 3.12). No conditions will be set up to create the possibility of an accident that has not been previously .

analyzed and submitted in licensing correspondence.

III. Within respect to the margin of safety as defined in the basis for any technical Specification:

This test requires that all Technical Specification Limits (aside from 3.12) be maintained. Thus, the margin of safety as discussed in Technical Specifications will not be decreased.

7-23-81

CORE DECAY HEAT CALCULATION tf f-5.2.2P 'f ) ' '

Po Where: Decay Heat w/same units as P, Reactor Operating Power l'- Po=

T.= Cooling Time in days To Operating Time in days P

22

= 6.1.10

-3 (87 3)

~

87 '1

~

P = 0 e 387'10 HW = .387 KWT (Total core) *2 Conservative 1% power = .01'2200 = 22 K4 T

Conservative 3 operating days No problem with cask requirement of < 2.5 kw per ~assembl

• l Calculation performed 87 days after startup.

• 2 Based on model using all fresh fuel for ease of calculation since no fuel of higher burnup (exposure) will be moved.

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IMPORTANT FISSION PRODUCTS AND HALF LIVES ISOTOPE a/z 7 HALF LIVES I- 131 8.05 days ~ 56 I- 132 2.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> I- 133 20.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> I 134 52 minutes I- 135 6.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> XE-131m 11.8 days ~ 82.6 XE-133 5.3 days 37 XE-133m 2.3 days XE-135 9.1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> XE-135m 15.6 minutes XE-138 17.5 minutes CS-138 32. 2'inutes CS-134 2.05 years CS-137 30 years SR-89 n 53 days SR-90 27. 7 years

100 NUCLEAR REACTOR ENGI YEERIXG [2.184 2.184. The rate of emission of beta and gamma energy is often called the several open decay heat poIoer, since the decay'energy appears in the form of heat. If this after shutdoIvn:

power is expressed in watts, by using the conversion factor I ~lev 1.6 X 10 " rate of energy Te wat~c ($ 1.45), and is represented by P, it folloivs that power. It will IO-'or P 't'(r To)~ o r~'], very rapidly in

-- - ~-Po 6.1 X 10 (2.o6) expected, the rI ..

where P and Po can be expressed in any convenient, but identical, units, since 4rradiation timI )

the ratio is dimensionless.. In equation (2.56), r To is the time in days after 2.186. Althm:;

shutdoim, i.e., the cooling period. For long irradiation periods () about 1 (or the equivale year) and short cooling times (( about 10 days), the approximate equation generatIon nI rI" ever, a somewhs (2.o6) can be simplified by neglecting the second term in the brackets. The rate of release of. the decay energy is then dependent only on the cooling time, r To, for short coolnlg and not on the operating time. P 2.185. The results of equation (2.56) can be represented in graphical form, Po O.I[(r T as in Fig. 2.29. This gives the ratio of the beta and gamma decay heat power to the reactor operating power (P/Po) as a function of time after shutdown where aH times ur accurate within o for the heat proc resulting, from rI 2.187. SoInc v:.

calculated from i-Io o rAsLn 2.1" 1otOAY IO-3 Operating Time l <

IOOO 1 meek......."

30 da)w.-- ~ . ~ ~ ~

IOO 1 year....-. " ~ ~

60 Infinite...... " I

~

Io sec after shutdoI~

as ItLtge as o per cooled by liquid heat m the e'en reactors, boiling 3 (0 IO-o noted, too, from 0 20 40  : 60 80 IOO I20 decay power fra, COOLING TIME Ir-roI, DAYS shutdown times FIO. 2.29. Decay power as function of time after shutdown diKereuccs becu>>.

7-.23-81