ML20052B667

Ro:Final Rept Re Possible Loss of self-protection of SNM Ctr.Fuel Bundle May Not Have Decayed Below self-protection Limit as Discrepancies Existed in Readings.Survey Program Improved & Underwater Fuel Surveys Studied

ML20052B667
Person / Time
Site:	05000128
Issue date:	04/12/1982
From:	Rogers D TEXAS A&M UNIV., COLLEGE STATION, TX
To:	Madsen G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-073.71C, 10CFR-73.71C, NUDOCS 8205030429
Download: ML20052B667 (4)

Text

'

( . .

• TEXAS ENGINEERING EXPERIMENT STATION THE TEXAS A&M UNIVERSITY SYSTEM COLLEGE STATION, TEXAS 77843 f'

NUCLEAR SCIENCE CENTER 12 April 1982 713/845-7551 "M@TDtV/g C Mr. G. L. Madsen Office of Inspection and Enforcement ldM ,l  !!

L Region IV _

U.S. Nuclear Regulatory Commission C / 'd '"N /

611 Ryan Plaza, Suite 1000 ,

'OO Arlington, Texas 76012 / / Y-

Subject:

Required Self Protection of Special Nuclear Materia:.J

! m SD 'h -%:,P &.

, rgf t

Dear Mr. Madsen:

g%'a Ad p'*Qf*

/

9, v Enclosed is a final report concerning the possible loss of self p , tion p of special nuclear material at the . Texas A&M Nuclear Science Cente A 9 report is submitted in compliance with 10CFR73.71C and a copy is being sent to the Director of Inspection and Enforcement.

Sincerely,

&w DaleRogers,!,Hanagerof Reactor Operations DR/ym Enclosure 1

820503 0 h 1 - .LD 6hl T

RESEARCH AND DEVELOPMENT FOR MANKIND

Final Repert of Possible Loss of Self Protection of Special Nuclerr haterial s

The Texas A&M University Nuclear Science Center (NSC) is allowed to possess up to 1510 grams of non-self protected special nuclear material. There are currently twenty TRIGA FLIP fuel roda not lacated within the reactor core, and since each contains approximately 120 grams there are eight rods (two bundles) which must be maintained self protected. This report is being made in accordance with 10CFR73.71C to notify the Nuclear Regulatory Commission of the possibility of a brief loss of self protection on a fuel bundle at the NSC.

Fuel Bundle #06 was removed from the reactor core on 17 August 1981 and then monitored for self protection by surveying radiation levels at 18 feet in air. Due- to the uncertainties associated with each measurement several instruments were used, and it should be noted in Table I that large discrepancies existed in the readings. Therefore, to be conservative the lowest value wae always considered. Assuming a linear decay rate based on these lowest readings (Figure I) Bundle #06 was not expected to drop below 100 R/hr at three feet for

.another three weeks. However, a survey performed on March 30, 1982 indicated

-a level of approximately 76 R/hr at three feet.

Corrective Action Due to the scattered data obtained throughout the survey it was not certain that the fuel bundle had actually decayed below the self protection limit. . The bundle was placed in the reactor on April 2,1982 and Region IV was initially.

notified on Monday, April 5, 1982. To avoid a future reoccurrence of this problem a more stringent survey program has been established. Also because of ALARA considerations an effort is being made to establish a method for performing fuel surveys underwater to reduce personnel exposure.

I

l.

TABLE I RADIATION SURVEY RESULTS OF BUNDLE #06 Date Detector R/hr @ 18' R/hr @ 3' 11-}-81 Radector III 5.5 198 Model 2064 SN 582 Radector III 6.5 234 Model 2035 SN 664 12-11-81 Radector III- 5.0 180 Model 2064 SN 582 Radector III 8.0 288 Model 2035 SN 1093 Keithley __

5.99 216 Model 36100 SN 10934 1-4-82 Radector III 4.5 162 Model 2064 SN 582 Radector III 6.9 248 Model 2035 SN 1093 Keithley 4.89 176 Model 36100 SN 10934 Radector III 4.5 162 Model 2035 SN 925 3-30-82 Radector III 2.1 76 Model 2035 SN 1093 Keithley 2.16 78 Model 36100 SN 10934

a .m..-a - . _ .e o 4 _ mu. m... . . _ u.. . - - , -___..m. ....m .ms.. -- _ . . _ . _ _.

• 4 l .

i.

-b '

b{ ; ' {.'  ! -- 'I' -

6 f i.

- :1. '"

j -

J a. .

j; 4 .

j

. n. .r. _m 5

I::. V F. .

. . v. , . ..

.' q .

p j '!'

K.T y

-f !

4 l 222..

c

.:W L ..

.. $,4 .c %

Li

. .w:: t

.i ld

! .1 J,i . . . 9 .j -

/ -l f ..). .! '

[_ 4.

]a n

o -w <

4

. . L _n _ .. 2. _ . ._ . . .. . . . _ .._..c.,_ -* ;___.._ _ . , i._ ; _ . . _ _ . _ _ _

.'j l, .

c , . .,  :

- -l

. #y

- s 2 ,

i 3 x i ~22 44 . d-4 [ t -y . $ . ..

1

'3 -d d ! t :3 i -l i

'- O!

i

i. . -

Ly o -l  :. t l: .g .. .g - ..

Q@. c . . l- ... l

. n. i e t.

t fg g-J ... ww.

O  !

g,.

p, L v av  : , i.

i

w. ..p ,) .  ;- l

g -

- .  :. g ..

l,fm r .. o I. .. e-

- , o. - ,.

c .. m.

. . . ,. b. . . _ . _._

.__.2 . . . _ _ _

_ . _ ,, 0_

] - ..

i ,

1 i j

l . .. l . ._

~q- - 4 _ ._

l l.

. i i

[- - .

r.

s .. g-O

,i O I i I.

p

~

lq n

r  ! '! .l

[ ,

}

j. . 3 ..y li }: .[

i 4,

.j 4

4

. p .. ._

t

_ L _ __ ,

_ga w-

'2 .2 l 3, i r J i . - 1 I l .4 a -Ll r, .

_ ; ::I r l ,

<  : l r

4 w i'

'I  ;

.l j d1 .' ;

l i ~.

f' -j. .l t

.-1 . . .o . _

.q

- o, s- .v. ..g r7 I ,

s j i '[

O

.b 4

Z .

l , l I~ El 1

i

. ~ _ L . ._ . . . L.. .. . . _ __. .; _ ._ , , , . _ _ _ _ , . ,,

i . .

I -

I t .l

' r i j ,-

i i - . .l j-

,09 : . ;l

{ .

i.  !

= -0 24, 4

3 i i i . . , . . . , ,

l 0 m) Q g . C '. O a q O j g  ?

2}  ;

/, ' -

d T. Q o ' M ' 4 4:

-f' ~~ '

< . i-

..b  % , .,

j p j 1- - --9  ! ' !

f m .

.=_

l_m .,

l