Lessons from Har­vey

Chemical Industry Digest - - Chemingineering -

Like­li­hood of mon­ster hur­ri­canes like Har­vey and Irma need to be ratch­eted up by one or even two lev­els. This will al­ter our risk per­cep­tion com­pletely and will call for new safe­guards and dis­as­ter man­age­ment plans.

Last month hur­ri­cane Har­vey smashed into Texas, the re­fin­ing and petro­chem­i­cal cap­i­tal of the world. What fol­lowed was may­hem as hun­dreds of tonnes of toxic chem­i­cals, in­clud­ing car­cino­gens, spilled and were re­leased into the at­mos­phere. De­spite ad­vanced warn­ing, the in­dus­try was caught nap­ping in its pre­pared­ness to han­dle the emergency.

As our planet warms up ir­re­vo­ca­bly, hur­ri­canes and ty­phoons are likely to be­come more fre­quent and in­tense. Sa­has­rana­man ex­am­ines lessons the in­dus­try can learn from Har­vey. In­dus­try needs a rad­i­cal re­think on risk as­sess­ment, in­ven­tory and plant sit­ing in order to re­build the trust with the com­mu­nity at large.

Hur­ri­cane Har­vey is on course to join the du­bi­ous list of dis­as­ters - headed by Bhopal, Flixbourough and Seveso - in the Chem­i­cal In­dus­try. Not only did the cat­e­gory 4 hur­ri­cane crip­ple the re­fin­ing and petro­chem­i­cal hub of the world in Texas, but it also led to un­prece­dented spillage and re­lease of toxic and car­cino­genic chem­i­cals into the at­mos­phere. Ac­cord­ing to a re­port in New York Times, more than 2000 ad­di­tional tonnes of chem­i­cals were re­leased from 46 in­dus­trial fa­cil­i­ties dur­ing the week Aug 23- Aug 30. In ad­di­tion, 14 sites hold­ing toxic wastes were in­un­dated. It is not that Har­vey ar­rived unan­nounced. It was known for a week and its lethal potential was as­sessed at least 48 hours be­fore it struck Texas. Yet the chem­i­cal plants in ar­guably the most in­dus­tri­ally ad­vanced coun­try of the globe were caught nap­ping and their re­sponses turned out woe­fully in­ad­e­quate. How did this hap­pen? A sil­ver lin­ing of every ac­ci­dent is that it man­dates us to raise the bar for safe prac­tices. But for Flixbourough we would not be hav­ing Ha­zop; Re­spon­si­ble Care emerged out of Bhopal’s grave­yard. So, what do we learn from Har­vey? I can quickly think of fol­low­ing three lessons.

Re­vis­it­ing risk as­sess­ment

Hur­ri­canes like Ka­t­rina, Har­vey and Irma can no longer be con­sid­ered as “acts of God” or Black Swan events. They are now the new nor­mal and risk ma­tri­ces need to be re­con­structed. Weather ex­perts believe that hur­ri­canes will get more fre­quent and more pow­er­ful as a fall­out of global warm­ing. Chem­i­cal In­dus­try needs to have plans in place to deal with them. Math­e­mat­i­cally speak­ing, risk is a prod­uct of sever­ity and like­li­hood. Like­li­hood of mon­ster hur­ri­canes like Har­vey and Irma need to be ratch­eted up by one or even two lev­els. This will al­ter our risk per­cep­tion com­pletely and will call for new safe­guards and dis­as­ter man­age­ment plans.

Ha­zop is an­other risk man­age­ment tool that needs a se­ri­ous re­think. While a lot of at­ten­tion gets lav­ished on the In­side Bat­tery Limit (ISBL) plant dur­ing Ha­zop study, the Out­side Bat­tery Limit (OSBL) plant gets a short shrift. It is the OSBL that has the big­gest foot print, usu­ally sev­eral mul­ti­ples of the ISBL. Again, it is the OSBL that holds most of the in­ven­tory in the plant. OSBL comes across as a poor unglam­orous cousin of ISBL dur­ing de­sign, en­gi­neer­ing, per­son­nel train­ing, op­er­a­tion and main­te­nance of a process plant. Even in ed­u­ca­tion cur­ric­ula it hardly gets the im­por­tance it de­serves. This ap­proach and at­ti­tude

In­ven­tory re­duc­tion not only brings down the oper­at­ing ex­penses sig­nif­i­cantly, but is a gi­ant step to­wards im­prov­ing plant safety. Rea­sons for sit­ing re­finer­ies on the coast are ob­vi­ous. But they are sit­ting ducks for hur­ri­canes. And if hur­ri­canes and ty­phoons are likely to be more fre­quent we need a rad­i­cal re­think.

needs to change.

Plants, es­pe­cially those on sea coasts, can be asked to redo Ha­zops con­sid­er­ing flood­ing and power out­age as a cause. The worst cred­i­ble con­se­quence and safe­guards for this sce­nario should be placed in pub­lic do­main. This will go a long way to im­prove the trust and con­fi­dence of the larger com­mu­nity around the plant.

Re­vis­it­ing plant in­ven­tory

Many chem­i­cal plants, es­pe­cially those built in the last mil­len­nium, carry far too much in­ven­tory. This ex­cess bag­gage harks back to the pre-com­puter and pre-In­ter­net era when sup­ply chain man­age­ment prac­tices, as we know them to­day, were not preva­lent. On­line pro­cure­ment now has done away with time con­sum­ing pa­per­work and ap­provals. RFID track­ing of ship­ment has re­duced un­cer­tain­ties. Logistics plan­ning, op­ti­mised ship­ping meth­ods and routes, syn­ergy with sup­pli­ers etc helps the in­dus­try to prune down the in­ven­tory. In­ven­tory re­duc­tion not only brings down the oper­at­ing ex­penses sig­nif­i­cantly, but is a gi­ant step to­wards im­prov­ing plant safety.

Con­sider what hap­pened dur­ing Har­vey. Nearly half a mil­lion gal­lons of gaso­line spilled out from just two tanks owned by one of the largest pipe­line op­er­a­tors. The ex­act cause of the leak is still un­der in­ves­ti­ga­tion. The pound­ing rain­fall also re­port­edly sank float­ing roofs of at least a dozen large stor­age tanks lead­ing to leaks. At least two dozen stor­age tanks hold­ing var­i­ous re­fin­ery ma­te­ri­als have col­lapsed spew­ing out car­cino­genic aro­mat­ics – Ben­zene, Toluene and Xy­lene. API stan­dards man­date that float­ing roofs should be de­signed to with­stand a rain­fall of 250 mm in 24 hours. Har­vey brought more than dou­ble that rain. Per­haps on hind­sight, we need to re­design and strengthen float­ing roof tanks for a higher rate of rain­fall. It will most cer­tainly add to the cost, but would be a small price to pay for pro­tect­ing the en­vi­ron­ment. In­creased fre­quency of in­spec­tion, main­te­nance and struc­tural au­dit of large stor­age tanks should also help. Clearly stor­age tanks bore the brunt of the storm surge. The dam­age would have been less with re­duced in­ven­tory.

It must be men­tioned here that some re­finer­ies were able to in­crease the lev­els in their stor­age tanks dur­ing the build-up to Har­vey. This made the tanks less buoy­ant and less vul­ner­a­ble to float­ing when the water swamped the tank farm.

Re­vis­it­ing plant sit­ing

Rea­sons for sit­ing re­finer­ies on the coast are ob­vi­ous. But they are sit­ting ducks for hur­ri­canes. And if hur­ri­canes and ty­phoons are likely to be more fre­quent we need a rad­i­cal re­think. New re­finer­ies, not that many new ones are likely to be built, should be lo­cated in­land. Ex­ist­ing re­finer­ies should con­sider erect­ing mul­ti­ple bar­ri­ers to avoid loss of con­tain­ment.

One of the most hor­rific ac­ci­dents in the af­ter­math of Har­vey was the fire and ex­plo­sion in a per­ox­ides plant. Per­ox­ides are very un­sta­ble com­pounds and need to be stored un­der re­frig­er­a­tion. When the hur­ri­cane knocked out main power sup­ply to the plant, the backup gen­er­a­tors failed to start be­cause they were sub­merged in water. Lo­cat­ing the gen­er­a­tors at grade level was clearly a bad idea. But it ap­pears bad only on hind­sight. The com­pany had re­frig­er­ated trucks to move out the per­ox­ides to a safer in­land location. But by the time they de­cided to act, the roads were over­whelmed with water. The ac­ci­dent could have been to­tally avoided had the backup gen­er­a­tors been lo­cated at a height be­yond rea­son­able ac­cess of flood waters.

Post Script

Seis­mic zones are taken into ac­count while de­sign­ing struc­tures in a chem­i­cal plant. Now that hur­ri­canes are ex­pected to be­come even more fre­quent than killer earth­quakes, we need an im­proved sys­tem and re­sponse in place from de­sign tech­niques to dis­as­ter man­age­ment. Iron­i­cally, the re­sponse to Har­vey was ham­pered by in­dus­tries tak­ing shel­ter un­der the figleaf of an anti-ter­ror­ism act, un­der which they were not ob­li­gated to dis­close to au­thor­i­ties the na­ture and quan­tity of chem­i­cals they stored in their premises.

K Sa­has­rana­man In­de­pen­dent Con­sul­tant - Process En­gi­neer­ing, En­ergy, Util­i­ties and Safety

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