The purpose of risk assessment

This entry is part 4 of 8 in the series Risk Assess­ment

I’m often asked what seems like a pret­ty sim­ple ques­tion: “Why do we need to do a risk assess­ment?” There are a lot of good rea­sons to do risk assess­ments, but ulti­mate­ly, the pur­pose of risk assess­ment is best summed up in this quo­ta­tion:

Risk assess­ments, except in the sim­plest of cir­cum­stances, are not designed for mak­ing judge­ments, but to illu­mi­nate them.”

Richard Wil­son and E. A. C. Crouch, Sci­ence, Vol­ume 236, 1987, pp.267

What did TEPCO know about Fukushima before 11-Mar-11?

This entry is part 5 of 8 in the series Risk Assess­ment

I recent­ly had a col­league point out an inter­est­ing paper pub­lished in the “Bul­letin of the Atom­ic Sci­en­tists” about the lev­el of knowl­edge that exist­ed between the start of con­struc­tion of the Fukushi­ma Dai­ichi nuclear plant and the dev­as­tat­ing tsuna­mi of 11-Mar-11. If you are inter­est­ed in know­ing more, I high­ly rec­om­mend this paper. The full text is avail­able for free. There is a pret­ty good dis­cus­sion on this arti­cle on slash­dot as well if you are inter­est­ed.

Fukushima: The myth of safety, the reality of geoscience

My first arti­cle in this series dealt with the dis­as­ter at Fukushi­ma as a fail­ure of risk assess­ment, but clear­ly it is more than that. This is a pol­i­cy, reg­u­la­to­ry and polit­i­cal fail­ure, and risk assess­ment is only one part of the dis­cus­sion. Going back to my orig­i­nal premise, the arti­cle pub­lished in the Bul­letin points out that there was sound sci­en­tif­ic data avail­able to sup­port a risk assess­ment had it been used. The prob­lem of course was that the data, and repeat­ed warn­ings from geo­sci­en­tists, were ignored in favour of the busi­ness goals that TEPCO and the Japan­ese gov­ern­ment had.

I am not anti-nuclear. I believe that nuclear pow­er is nec­es­sary to allow us wean our­selves off of coal and petro­chem­i­cal fueled gen­er­a­tion and to pro­vide us with the time need­ed to get oth­er renew­able sources of ener­gy on-stream. I am also of the opin­ion that the fourth gen­er­a­tion reac­tor designs that are avail­able now should be built. These reac­tors are capa­ble of using the high­ly radioac­tive ‘waste’ from the third gen­er­a­tion reac­tors and reduc­ing it to a byprod­uct with a short half-life and rel­a­tive­ly low radioac­tiv­i­ty. These designs pro­vide the capa­bil­i­ty to stretch our nuclear fuel sup­plies by as much as 1000 x accord­ing to some authors, and to elim­i­nate poten­tial stock­piles of weapons-grade mate­r­i­al. These ben­e­fits alone should be enough to get them built.

Whether nuclear pow­er will remain a part of our future past the end of my life­time I can­not pre­dict. I do know that ener­gy will always be need­ed as long as humans walk this plan­et. Safe, renew­able sources must be devel­oped to allow us to build a sus­tain­able future.

How Risk Assessment Fails—Again. This time at DuPont.

This entry is part 6 of 8 in the series Risk Assess­ment

A recent report released by the US Chem­i­cal Safe­ty Board (CSB) looks at a series of acci­dents that occurred over a 33-hour peri­od on Jan­u­ary 22 and 23, 2010 at the DuPont Corporation’s Belle, West Vir­ginia, chem­i­cal man­u­fac­tur­ing plant.

A num­ber of sig­nif­i­cant fail­ures occurred, but I want to focus on one pas­sage from the press release that is telling, par­tic­u­lar­ly con­sid­er­ing that DuPont is seen as a class leader when it comes to work­er safe­ty. I would encour­age you to read the entire release. You can also have a look at the DuPont inves­ti­ga­tion details on the CSB site. CSB also pro­duced a video dis­cussing the inves­ti­ga­tion.

From the press release:

Inter­nal DuPont doc­u­ments released with the CSB report indi­cate that in the 1980’s, com­pa­ny offi­cials con­sid­ered increas­ing the safe­ty of the area of the plant where phos­gene is han­dled by enclos­ing the area and vent­ing the enclo­sure through  a scrub­ber sys­tem to destroy any tox­ic phos­gene gas before it entered the atmos­phere. The analy­sis con­clud­ed that an enclo­sure was the safest option for both work­ers and the pub­lic.  How­ev­er, the doc­u­ments indi­cate the com­pa­ny was con­cerned with con­tain­ing costs and decid­ed not to make the safe­ty improve­ments. A DuPont employ­ee  wrote in 1988,  “It may be that in the present cir­cum­stances the busi­ness can afford $2 mil­lion for an enclo­sure; how­ev­er, in the long run can we afford to take such action which has such a small impact on safe­ty and yet sets a prece­dent for all high­ly tox­ic mate­r­i­al activities.[sic]”

The need for an enclo­sure was reit­er­at­ed in a 2004 process haz­ard analy­sis con­duct­ed by DuPont, but four exten­sions were grant­ed by DuPont man­age­ment between 2004 and 2009, and at the time of the Jan­u­ary 2010 release, no safe­ty enclo­sure or scrub­ber sys­tem had been con­struct­ed. CSB inves­ti­ga­tors con­clud­ed that an enclo­sure, scrub­ber sys­tem, and rou­tine require­ment for pro­tec­tive breath­ing equip­ment before per­son­nel entered the enclo­sure would have pre­vent­ed any per­son­nel expo­sures or injuries.”

The high­light­ed pas­sage above shows one of the key fail­ure modes in risk assess­ment: fail­ure to act on the results. So what’s the point of con­duct­ing risk assess­ments if they are going to be ignored? In a pre­sen­ta­tion in 2010, a col­league of mine made this state­ment:

The risk assess­ment process is intend­ed to be used as a deci­sion mak­ing tool that will help to pro­tect work­ers.” — Tom Doyle, 2010

This is a fun­da­men­tal truth. The risk assess­ment paper­work can­not pro­tect a work­er from a haz­ard, only action based on the report can do that.

When deci­sion mak­ers receive the results from a risk assess­ment process and choose to ignore it, or as the press release stat­ed, “…exten­sions were grant­ed by DuPont man­age­ment…”, man­age­ment is mak­ing a fun­da­men­tal­ly flawed deci­sion. The risk assess­ment process inten­tion­al­ly expos­es the haz­ards in the scope of the analy­sis, and explic­it­ly ana­lyzes the prob­a­ble sever­i­ty of injury and occur­rence. Once the analy­sis is com­plete, choos­ing to ignore the results, pre­sum­ing that there is no evi­dence that the results are incor­rect, amounts to neg­li­gence in my opin­ion.

Does this mean that we should not con­duct risk assess­ments? Absolute­ly not! In the West­ern world, we are oblig­at­ed to pro­tect the safe­ty of work­ers, includ­ing our col­leagues and employ­ees, as well as any­one else that may inten­tion­al­ly or unin­ten­tion­al­ly be exposed to the haz­ards cre­at­ed by our activ­i­ties. We are moral­ly and eth­i­cal­ly, as well as legal­ly, oblig­at­ed.

Used cor­rect­ly, risk assess­ment in any of its many forms pro­vides a pow­er­ful tool to pro­tect peo­ple. Like any oth­er pow­er­ful tool, it also takes sig­nif­i­cant courage and skill to use cor­rect­ly. Default­ing to the cost argu­ment alone, as it appears that DuPont did in this case, results in the type of fatal fail­ures seen in this trag­ic series of events.

Spe­cial thanks to my col­league Bryan Hay­ward, the Safe­ty Engi­neer­ing Net­work Group on LinkedIn, and SafTEng.net.

What is your expe­ri­ence with imple­ment­ing risk assess­ment? Have you expe­ri­enced this kind of result in your work? Share your expe­ri­ences by com­ment­ing on this post!

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