ML19296A193
| ML19296A193 | |
| Person / Time | |
|---|---|
| Site: | 05000128 |
| Issue date: | 02/06/1979 |
| From: | Berg R TEXAS A&M UNIV., COLLEGE STATION, TX |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7902130176 | |
| Download: ML19296A193 (15) | |
Text
{{#Wiki_filter:. Texas A&M University College Station, Texas 77843 713/845 1811 Office of University Research 6 February 1979 Director of Iluclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Ref: Docket Number 50-128 License R-83 Dear Sir-It is proposed to make a change to the Technical Specifications for the Nuclear Science Center Reactor (NSCR) of Texas A6M University. The September 1978 inspection of the NSCR by Region IV of the Office of Inspection and Enforce-ment resulted in a request that radiography of explosive material in excess of the limits specified in the Technical Specifications of 3.6.c be terminated until further review by the Commission. At the time of the inspection, explosives had been radiographed in a neutron radiography facility that was constructed external to the reactor pool. By NRC letter dated June 23, 1971 radiography of explosives in research and testing reactor facilities is considered an unreviewed safety question. This letter was discussed over the phone with your personnel and it was their conclusion that a change to the Technical Specifications was not necessary for radiography of explosives in an experimental facility external to the reactor pool structure. Since this view is no longer held we are submitting this request for a change. The proposed change and safety evaluation which is attached has been reviewed and approved by our Reactor Safety Board. For your information we have enclosed a copy of the approved SOP's governing use of the neutron radiography facility. Since the inspection by I & E we have lost income by having to turn away radiography business. Since income is critical to us we request that this a mendmen t receive prompt review. Your cooperation and assistance in con-sidering this Technical Specification change is sincerely appreciated. Very truly yours, c Q(( \=: n--~ Robert R. Berg, Chairman Reactor Safety Board Texas AEM University ( Enclosures : Safety Analysis for Amendment No. 7 to License R-83 S0P IV-F Neutron Radiography Beam Port No. 4 CC: Dr. John D. Randall, Director, NSC T Mr. Harry E. Whitmore, Associate Director, TEES Yl 3 7902136/76
\
Texas Af,M University Nuclear Science Center Safety Analysis for Amendment No. 7 to License R-83 February , 1979 College Station, Texas
Introluction It is proposed to modify the Technical Specifications to Facility License No. R-83 to permit the radiography of up to five pounds of explosive uaterials in a radiography f acility associated with the Nuclear Science Center ^:wtor. Specification Change It is proposed that Section J. o . c r'd as follow? 3.6 Limitations on Experiments
- c. Explosive raterials in quantities greater than 5 pounds shall not be allowed within the reactor building. Irradiation of explosive materials shall be restricted as follows:
(1) Explosive materials in quantities greater than 25 milli-grama shall not be irradiated in the reactor pool. Ex-plosive materials in quantities less than 25 milli-grams may be irradiated provided the pressure produced upon detonation of the explosive has been c21culated and/ or experimentally demonstrated to be less than the design pressure of the container. (2) Explosive caterials in quantities greater than 25 milli-grams shall be restricted from the upper research level, demineralizer room, cooling equipment room and the interior of the pool containment structure. (3) Explosive materials in quantities greater than 5 pounds shall not be irradiated in experimental facilities. (4) Cumulative exposures for explosive materials in quantities greater than 25 milligrams shall not exceed 10 12 n/cm 2 fgp neutrons or 25 roentgen for gamma exposures. bases C. This specification is intended to prevent damage to the reactor or reactor safety systems resulting from failure of an experiment involving explosive naterials.
- 1. This specification is intended to prevent damage to the reactor core and safety related reactor components located within the reactor pool in the event of failure of an experiment involving the irradiation of explosive materials. Limited quantities of less than 25 milligrams and proper containment of such experiments provide the required safety for in pool irradiation.
- 2. This specification is intended to prevent damage to vital equip-ment by restricting the quantity and location of explosive materials within the reactor building. Explosives in quantitiec exceeding 25 milligrams are restricted from areas containing the reactor bridge, reactor console, pool water coolant and purification systems and reactor safety related equipment.
(1)
- 3. The f ailure of an experiment involving the irradiation of up to S lbs of explosive material in an experimental facility located external to the reactcr pool structure will not result in damage to the r eactor or the reactor pool containment structure.
- 4. This specification is intended to prevent any increase in the sensitivity of explosive materials due to radiation damage during exposures .
Safety Analysis The proposed changes to Specification 3.6.c are intended to provide for the radiography of explosive materials within the beam port 4 facility. Located en the north side of the lower research level, the facility consicts of a concrete block structure installed adjacent to the pool shield wall to contain and shield a thermal neutron L ar extracted from beam port 4 (see figure 1). The cave structure is designed for remote positioning of samples with the beam port in operation. A hydraulic operated shield door is raised to shield the neutron beam during ;oading of a sample, then lowered for the exposure. Since the specification restricts explosive materials from areas where the reactor safety systems would be endangered, the most serious accident involves the detonation of a charge while it is being radiographed. The beam port is exposed at this time and its rupture could result in loss of pool water. The analysis will therefore center on predicting the pressure developed on the weakest part of the beam port. Emperical studies are available concerning the prediction of peak pressures within a vented or unvented structure. 1,2 The quantities involved in this calculation are the ratio of the amount of explosive (W, in pounds equivalent TNT) to the volume of the containment structure (V, in ft 3) and the vent area through which the pressure may be released. For a more conservative analysis the vent area wi]i be assumed to be zero, i.e., the entire blast is contained within the radiograph, facility. This ignores two open door ways with a combined surface area of 2' Jt*. The quantity of explosive will be considered to be the maximum of 5 pounds allowed in the facility. For a containment volume of 270 ft (see 3 figure 1), W 5 lb 7= 270 ft' ' 3 From figure 2 the peak pressure (Pqg) is 100 psi. Using the conservative assumption that this maximum pressure will be transmitted through shields and collimators, the force exerted upon the end of the beam port is, 100 psi x A BP
= 2000 lb g.
(A BP
=
the cross sectional area of the beam port). (2)
The rupture strength of the beam port is determined by the fillet weld between the beam tube and end plate (see figure 3). The area of the shear plane is, A = ni (D - t ) where, t = weld thickness = .25 in d = t ube 0. D . = 6. 7 5 in A = n (0.25) (6.75 - .25)
= 5.1 in 2 Gince the yield strength is 20,000 pai for 6061 alwalnum, RS = 5.1 (20,000) = 100,000 lb Applying a safety factor of 4, RS = 100,000 = 25,000 lb f
4 A comparison of the peak blast pressure developed 2500 lbg , with the rupture strength of the beam port extensicn, 25,000 lb reveals a wide margin of safety. Inaddition,theentireanalysishasbe,enbasedonsomevery conservative assumptions;
- 1. 27 square feet of vent areas were ignored.
T. Collimators and shielding present which would serve to dampen the blast were ignored.
- 3. A maximum of 5 pounds of explosive naterials within the facility was considered. Nornal quantities will be substantially less than this limit.
- 4. A safety tactor of 4 was used in calculating the rupture strength of the beam port extension.
In conclusion, the analysis indicates there will not be a rupture of the beam port for detonation of a 5 pound explosive charge during radiography. liawever, should a rupture occur there is no unreviewed safety question presented, since the analysis for the loss of pool water has already been performed in Amendment II to the Safety Analysis Report. Thus, radiography of explosive materials within the specifications set fcrth presents no danger to the general public. References
- 1. Kingery , C . M. , Schumacher , R. N . , and Ewing, W. O. , Jr . (1975), "In-ternal Pressures from Explosions in Suppressive Structures", BRL Interim Memorandum Report No. 403, Aberdeen Proving Ground, Maryland, June 1975.
(3)
- 2. Sewell, R. G. S. and Kinney G. I' . (1974), " Internal Explosions in Vented and Unvented Char.bers", Minutes of 14th Explosives Safety Seminar.
h.;w Orleans, 8-10 Nover.ber 1973, Department of "efense Explosives Safety Board, pp. 87-98.
- 3. Biker, W. E., (1978), " Inter nal Blast Loading", A Short Course on Explosion llazards Evaluation, Southwest Research Institute, pp. 3-16 to 3-34.
(4)
n CONTAINMENT VOLUME SCALE: I" = 4'-O CAVE SURY b1Nx< s
-m.x
/ h 99 Axxxxxxxxxxxxxxw+
_ = g 4 N ( /x- '
-,.--senwen N
xxgxxxxxxxxxxxxxy 4
- s. q .- .
s _ _ _ _
-- - y%g %
. mm -
h .
; - m - e noco g
39 FIGURE I . BEAM PORT 4 , NEUTRON RADIOGRAPHY FACILITY O
---{z1
.!= d .- h2-4Ml=e . F : r 72 :_=h h =- ;IT.F.! + -: = I *
- 2. 2 . . -
I . J.- :1. _ .r::: g .: n : -3: :: M.t.u
-- - 2.; ; 8
-{It _1 :rils 2
-4 .= . E - F= : :iC T3 --
t -- 4
-I'.T .,I T j T .r- -
fi: =ii .--.ay.:
- b:F. :-- 1 .:_y m
T n_ ., . 4.r _-:rlm.. y =a
..:p
=
y -gg-r_ y g a :: . yr. og g? T- ._J :.- .% ,4 y : s- *j: t-
.u =1. =m } . i- - =g
=T m
. . x--- ca
.n .m Tm
- -ln- -.: y;p;- -_- _" j - --%..
,j . ,a _
.p
.m.---
.%. f - 2. 3 4+
- i"!- 7
--93 I d.-
. - -m: ._-121.1 ---
- --- :. - 1. ; =.: . 13. h ' 1} n- r r : r-- :
c'. 8 : j ..- ::r .3 rr t -- r
- -11
-- r.-
-- 2
- --:r 2- .2 =_y=.1=_ =-1. .1, j-
- . r : -- 4 :: y:-=:.;.,z@
L_.bg - . ..:. p . c 3 - .1 - L. . k. . r. . --
=-.. :. .-
. -. -- r:
r: ._ n
;a.1_. 31. . 3. = n -. .-- - _- - y-p _- :=
u ._ _ .m 34 . q-. - _
- t - - - ..mit:-
"--~m 1_ _ . - ~. 21= . . : C ;- y5 -
r' -
--f I-- c ni-J _. -* :{ - -
_[';- 3. = L _Lc_L
. 1._- t . _ g- .--*r.qr . .-_- J:. -.r-$ . _c. _ __
.__ .c'.:n_
_J - _-*].,,
=n__na h- e.-
2
.:ch:.=l_u
_ _ . .f.....y---
.1. _. ... -.-_ -.. - -
-d & a..
_1,. _..
._p._. _ - _. _ -
.. T.
+ _ .. __ -.. _}__. ._
. y _.
4 : Q, m -y
-_.,.-_-_.._4...--,-e
- . . ... ,,_4
.44..
p .- - .- ._ - w O w -- 7-lytm r - rrn r w m., y. .C.. m ... m. ~ . p. -
- *t., q m-v. - W.,,
1 Mi. m-1 ./, 7'h I C..pW t .,TP.clabr d i
~
~. -. " e u1 --~'r ~i '~
n ,Jj -a- = - -
+ + . -l
s g TWf.7 .n _.?1? 1 M=.-~3: ) - . ! --
- p. ~ _ M h s:r- -L'.;
^ ; ,-'i- ]7 4 i -N i 4- ) =" , :
t i i m:1 W .-4=1 ' E-'s+ : 'djj S 3^
' MMS h 1lS _ i ntl'Ki i [-E- r5~ % i- M W:'
.. p--y :. ; J. r -b i-- ; -- - q y.-
- : : k-,-. r. 1'y.} __
y.31.g, ;_=i
; e :-
- n . h =_E ... . . .f- ;4:_ - +h... . - - - - . .
m:p yhp - - r a u- ,a;h- m=~j d.E,N.- ,.- 7_1 ;;;.. j.gn a g 4y. 1*2.{ntT 9 L =p-p=e i.. W jF]: .4 [2 1. --
= :- i 1: 2 _; ._
- y. _ d = req _L_
, 4 q c. =
- 1. . _i f.1 aj ' - J y t; L~ -
4.g _q . _.il?- M skzH . , T& U2} : -! _+= IH i' LEY
- _ L ,s . h
-= &- b f1b.g i.-' f - Hn~==~~"jir.' Sa= =
'^ = -
^ E d =~ E :-'4 + . V O nf =h : S_:T.-T=E EL- N ;h~E :*:-- lG .
_b^.:= ^--
= -^~15~
=_g- -j .$. L ' i.
d= sA E --E - = [_ii&t '---N-N]-.32.% . = = V-3 E's-::WE_- ? N k 4 :&siln -.q '-].:5 3=
-y--. g _ zg g - ., - , - . . - - , - . . -
- m. - - - . -. p- - ~z
- 1_. % - O 3_..--~r;M + e T dz 7 .,2. : . ;- = Cr T _I . : t= 1 ; . ;'. re T-T r ?"
- , . .M.. _ct.cf -. _.
w L'-~ -!- . __ _T _ _ _p._.,
}r .__.._..-4..
__ ___4 Un
._} _, __. y
.- _._4_....t..
7,+__,
- _ , _ _r __.-p- % _.
_34 "., . . e --- - b_al- - -- F I.... N M
- p. rw ... *% -t-. ",'l--, E
~
2m r-- : E _,.r,,. _r
- L .L IMI:-.4 O mg 1-4. ; m'Jy ',4--4vf, -sa. . . bv ., .
~}
. Kl- sg j.^ h.fm. f. .
4 r a,-,-- _ * ' { -[- ' __ _' . ' ' ' " t-- -. O. __3 s
' r_A g
_,___ 93
- p .. t -y. an:: L_._..g g . 3 . p y .4 T- .. i t ?_: _. y -
.Qs- --: u
.: -i 2. 2. . J.@. =_,> .a._ h. *- .a: : 4 4.- h. .
. . p. a. . .. ._-3. w._ -- . _a.
j n p. 4 -v. .. ;sy - - - . - -
. -7 ,
e-4 b-i i-Q'] ;'iiE5 -fi @h iG _.. - <C r.-,-- .. . . - -.
-..~ . _ _ . _ . . . . _ - ,-- a .
---q i - %- .__.27.=f.h _.t c_ _ _ m M f.T)]-hl_4 .].m'. z ,-lj=__"..
.. b^
m-- :- g y Hu m
= =- _- gf,r .ty.g' .q . . . _, .2._
7 i! [ gTJMr-; 5_. c-a mile a ETr_5,- _, -- f _y . T TT u 42 y T
':e.a.. T _
I Z P. _=WWI5$Y WY$$_OW ?{- $ %Ei $ :$ &;--.aV.t ' N.. ?$. Wh1$3 Y
+- r p- <z
.. e. -- r m = -p4 n. =--_i.
.pc .
4m.cp- : . l..; n_ u=.i := : .:c-.,.w=. g _ .::2= . . __ g 21 - . w- 4 -- i : - . . -
.,.=.:..-
po NSIShW.?:.$ 5 ?YE 1 .-: _7- ib?N _~ ~5 . 5 5'-[-i' kh{h - _._r5 Y @ $_W.5-D N N
. _ _ , _ , _ . . . . _ . . _ _._.m._ o
-.rr. r;- -:...Q._
. . _ ._.4._,,._._7-,._- ._._ r,-- d_~-]- 7 , ._.r. g- __._j. ___2_ . . ,._?____-
3.__,. r .. . . ,_.__._- a m 7, , _,.]. ._p.... .
~., q . . u Nw 3_ . 4_ -
y.. 7
+..- - .. _ _.._
, . _ _ _wi y
,77_ .A + .
9 4_
+ - .. - _ - .,_
- p. ..p.. ,._- . , , . - , ,
to & pga . ..s y
~
.. s.{+4 y~
;,3 aT gg ,
y, gs _ T 'ff- ,.m y t y . -- - , .. TD, r ' 5w sq e4 t*
-..1 .. ..:
'T 'I M i~ W.
D,i',, ,
' ~
, Ag,q +TpriggT _ _+ y q ., r. +, 4._g , j. i t,ti +n, N
- i. i e1b %- ,-d .i.:.%i.: t-i .f 4 ' cl = EL9i; ' % i : 1 -. '- d #d [
W--l=' t-E#.i=-!Jiii' M D]. h@g . g , ; M
'e? -M- -4bliE M 4 h t i E M -k.F;-i;-bs1#M iMdW
- 1. 7..r. -. =. . 2i. i J.i_=.=.i=_ _m : =_ _.P.
wi.t u_w__ t _E_f. i_n_.u.:._E:.=. _::.;_E L%r : T-1 e. ..E_. 5_. - I._.E ti: I
%}
g~ - d M_2-4j
- w. 3 _4d g: ?d.i
-4::m
- . . .M M.n=.
-w r. %s h.v_..W.=L, v Mne- mj w@s;t.3 +M d =q.u@--ba Ntzf_M@.= 1 d C ~~~-
j;*
--s - e_ ._.=.:--0_.==-
s,
@3 3
T_- 1-J -i. - er:2
- _.:+ _ i.HT:-q=.=d
,. = = g- -
q- =_ Ef+y. _j -.4=_:- n, isc ].pk_:.p:
-- -.;.:_==_=- .
_w. - i :- c
= U W M = 2 -}C W E =-1 5.h .L__ g % =#E-ti
=lEEdikM=E _._ _ ._ W%- i - M._,. ,- i_=_. . _ . M =Eli =i N .
@l -}
C _.- ._!__ __4_ _n . ,4_. ::- ,J 1.i- . m- "_ u~,s. ) I
" ~'
- ,4 T-'
-' ~~-'
k i i! '
--d -T'-- Tb 1 4-
[Y T iO C 9 N N O V N C 4 N C) ,g (A r-d O O O O H e-4 e-e e -4 r--e R U m c=t -- Q. Cd- - Q0
' SHEAR PLANE SHEAR AREA = 5.1 sq. In.
i Al. FILLET WELD
- y. THICK END Ft. ATE s e/
F i SECIFICATIONS:
, AL- 6061 -T6 O',
l I.D. = 6 " O.D. = 6 3 /4 " REF. DETAIL- A
'D g . -
t ,4-1 l _ 6 T 2'- Bh' FIGURE 3. NSCR NEUTRON RADIOGRAPHY BEAM PORT EXTENSION
yg*o Form 112 Nuclear Science Center 1-73 STANDARD OPERATING PROCEDURES Prepared by Subject Section Page J PT Neutron Radiography Beam Fort No. 4 IV-F 1
- 1. Ceneral This procedure pertains to the use of the neutron radiography facility including the beam port #4 area, darkroom and laboratory #3.
- 2. Description of Neutron Radiography Facility The facility is located on the lower research level as shown in Figure IV-F-1. A concrete block structure is located adjacent to the pool shield wall to con;ain and shield a thermal neutron beam extracted from beam port No. 4 (see figure IV-F-2).
The cave structure is designed for remote positioning of camples with the beam port in operation. A hydraulic chutter at the beam port exit may be raised to shield the neutron beam between exposures. bab 3 and the cark room are located on the lower research level and are insediately accessible from the sample loading area. The darkroom is available for loading and unloading cassettes and film processing caly. Laboratory 3 is designated as a sample storage area where cabinets are available for the safe storage of samples for neutron radiography.
- 3. Personnel Control Personnel control for the radiography facility is maintained via "C-2" entry devices which alarm in the reactor control room upon entry and provide a flashing red light signal visible to the person entering.
- a. The following areas, shown in Figure (IV-F-1), are controlled by the "C-2" entry devices. The " Inner / Outer" switch on the Reactor Console switches between the inner and outer control areas so that one of these circuits is always active. The "C-2" and scram circuit switch on the shield door is always active.
(1) Inner Controlled Area The sample preparation room is designated as the inner control area. The "C-2" device controlling this area is locateu on the' access door. This circuit is normally deactivated during beam port operation. (2) Outer Control Area The outer control area includes the entire lower research level. The "C-2" devices are located on the down ramp door and the stairwell door. This circuit is normally activated only during beam port operation. (3) Radiography Cave The "C-2" entry device on the cave entry door is designed to cause a scram if the reactor is near the radiography reflector and the door is opened. The bridge rail stop, which restricts moving the reactor any closer than 18 inches from the reflector, must be in place for reactor operation when the cave entry door is open. The keys to the bridge rail stop and the cave entry door are to be kept on a single key ring and personnel entering the cave will maintain possession of the key ring while in the cave.
- b. The keys to the Radiography Facility will be issued by the SR0 only.
- c. When leaving the radiography facility, the experimenter will lock the door and return the keys to the SRO. If the experimenter has any special instructions concerning his experiment , he will relay this information to the SRO at this time.
Approved: ( d- , l /~v7 k g Director, NSC Chairman, RSB / Date
~
u . d. l I l i,\ I I l
\ l S
\ l
\
\ N
\ L O x O r I T
@/
s R R T E N
$ /
/
/
A C
\ O ET ', O C L
\
\ M RI R
/
/ "2 E E / -
y N P C N I
/
s -
' L O
1!ii1 ,i R T
~ ,
a_ N _ O
' _ C
_ q _ '
, _ _ ' L E
_ ' N
'\
~ _ - N
~ _
- O
~
l l l i i' S _ - R
- E
- P u
L -
- '[p O L
- @ s' 4 m / R T
NR E V E
- O E L C ET
, H
' RI M C Y ER R
/ R TE A T U P E
, N L O S EO E R R
' E T
- VN R
/ AO E CC W
/ S O
' S L f E
/ \
\ C C I Q \
\
\ A F
, \ D -
/
/
/
@ \
E S Z
/ L J
' \ L T O H G E R R T IL U N G O G I C N F
" NI 2 R A
C W
@$}}