ML21264A164
| ML21264A164 | |
| Person / Time | |
|---|---|
| Issue date: | 09/21/2021 |
| From: | Thomas Wellock Office of Public Affairs |
| To: | |
| References | |
| Download: ML21264A164 (1) | |
Text
D efen se in D ep th : A War fo r Sa fe t y
One hundr e d ye a r s a g o t he Fr e nc h a nd G e r ma n a r mie s of World War I devis ed a new defens ive s t rat eg y called de fe ns e in de pt h. I t s a im w a s t o pr e ve nt a n e ne my br e a kt hr oug h of a n a r my s fr ont line w it h a de e p system of int e r c onne c t e d t r e nc h line s a nd s t r ong point s. Popula r iz e d in a ll it s de s pe r a t ion a nd g r is ly e ffe c t ive ne s s in films s uc h a s All Quie t on t he We s t e r n Fr ont, de fe ns e in de pt h ha s be c ome t he N R C s offic ia l me t a phor in t he ba t t le t o pr ot e c t t he public fr om radia t ion ha z a r ds. I t is t he ke y c onc e pt g ove r ning nuc le a r s a fe t y in us ing mult iple s t r a t e g ie s in s a fe t y-s ys t e m de s ig n, ope r a t ions, a nd e me r g e nc y pr oc e dur e s a nd pla nning.
T he N R C s us e of t he t e r m ha s r oot s in t he M a nha t t a n Pr oje c t of Wor ld Wa r I I. M ilit a r y me t a phor s s e e me d pa r t ic ula r ly a pt for t hos e c ha r g e d w it h e ns ur ing t he s a fe t y of t he e a r ly plut onium pr oduc t ion r e a c t or s a t H a nfor d, Wa s hing t on. T he y w or r ie d a bout t he pot e nt ia l for a r e a c t or c a t a s t r ophe fr om a r a dia t ion r elea s e of explos ive violenc e. T h eir s olut ion wa s t o er ec t mult iple lines of defens e of t r a ine d ope r a t or s a nd e me r g e nc y pe r s onne l, c a r e fully s e a le d fue l r ods, s hie lding w a lls, ba c kup c ooling a nd pow e r s ys t e ms, a nd e ve n a ba c kup t o t he ba c kup s hut dow n s ys t e m a fina l s olut ion s o dr a s t ic tha t it w ould de s t r oy t he r e a c t or t o s a ve t he ope r a t or s live s. Fit t ing ly, it s monike r de r ive d fr om a not he r milit a r y t er m t he la s t dit c h s a fe t y de vic e.
Aft er t he wa r, t he lines of defens e in rea ct or s a fet y were ca t eg oriz ed int o funct ions by At omic Ener g y Commission safety committees:
- Fea t ures t ha t ma de a rea ct or inherent ly s a fe;
- St a t ic, or phys ic a l, ba r r ie r s, s uc h a s c ont a inme nt building s, w e r e t o ha lt t he e s c a pe of r a dia t ion; a nd
- A c t ive s ys t e ms t o s hut dow n a nd c ool t he r e a c t or in t he c a s e of unus ua l c ondit ions.
While t he A E C s s a fe t y a ppr oa c h be c a me mor e c ohe r e nt, t he r e w a s no c ons e ns us a mong e x pe r t s ove r t he r e la t ive impor t a nc e of e a c h c a t e g or y. Some e x pe r t s foc us e d mos t ly on a de s ig n s phys ic a l ba r r ie r s,
while ot hers g ave weig ht t o all t hree cat eg or ie s a nd inc lude d r e a c t or ope r a t ion t oo.
Ove r t ime, de fe ns e in de pt h r e pla c e d t he s c a t t e r e d c onc e pt of line s of de fe ns e. I t s fir s t us e a ppe a r s t o ha ve be e n in 1 9 5 8 t o de s c r ibe s a fe t y de s ig n in t he plut onium e x t r a c t ion pr oc e s s e s a t H a nfor d. I n a 1965 let t e r t o C ong r e s s, A E C C ha ir ma n G le nn Se a bor g a pplie d t he t e r m t o c ivilia n r e a c t or s a fe t y a s a n a c c ide nt pr e ve nt ion a nd mit ig a t ing s t r a t e g y.I t pr ovide d, he w r ot e, mult iple s a fe g ua r ds a g a ins t t he oc c ur r e nc e of a s e r ious a c c ide nt, a nd for c ont a inme nt of fiss ion pr oduc t r e le a s e. T he t e r m s t uc k.
B ut t he s t or y c ont inue s. T he Offic e of N uc le a r R e g ula t or y R e s e a r c h ha s publis he d a report on t he his t or y of de fe ns e in de pth up t o t he pr e s e nt, w hic h c ove r s t he t e r m s a pplic a t ion t o t he w hole nuc le a r fue l c yc le. I t s a fa s c ina t ing look a t how t his be dr oc k s a fe t y c onc e pt ha s e volve d unde r t he influe nc e of e ve nt s a nd ne w know le dg e.
B y T hom a s We lloc k, NR C H is t or ia n