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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Acknowledgements: US Chemical Safety Board for excerpts more…
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