Blast Study and Blast Radius

[ThePenIsMightier]

What a stupid place to ask. I'm stupid. Etc.
There... Feel better?

So, since the BP Texas City catastrophe happened, there has been a lot more emphasis on building locations, alleged "building" locations and even temporary trailer locations in operating hydrocarbon sites where there is pressure equipment that can explode and catch fire, etc. This is good because many of the fatalities in Texas City could have been prevented if they didn't do dumb shit like set an ATCO trailer at the base of the hydrocracker, and so on.

I'm looking for the legislation that actually governs this sort of thing. Can anyone please just point me in the slightly right direction and I can start chasing down the right path? I'm particularly interested in the USA.

I'm so far only familiar with policies developed by companies like Shell and they are, as usual, based on their HSE fear-mongering nonsense theories and managers who don't know so they default to "well, I'd feel better if..." and they end up renting Blast Resistant Modules and setting them 1km away from anything and complaining why work costs so much.

I want to know what code/law/policy dictates that if you are installing a facility with _______ kJ of stored energy, then you need to have someone with _______ designation do a formal blast study and use that to ensure that workers/Op's are not permanently stationed in a location closer than the ______ psi zone.

Super grateful for any help to acquire some knowledge on this.
Thanks, and sorry this isn't the ideal place to ask!

[JPB]

As far as I know, there is often no legislative requirement. In a safety engineer role I often say to smaller clients that in the end, it is between them and their underwriter. Larger clients like the big integrated O&G players will have their own spacing requirements. In the absence of a regulatory requirement, I default to what I can defend were I called to testify in the event of an incident. This is typically industry best practices, which is a bit of a hodgepodge of NFPA, API, GAPS, etc. standards. The last big safety study I did referenced 6 client specifications, 4 API specs, 3 GAPS specs and 8 NFPA specs. Plus I had to check the EPCs own specs for adherence as well.

[ExtraSlow]

I know how far from the wellhead and flare stack I need to have the sleeping quarters or fuel tanks on a drilling location. Never looked at it for anything else.

[SKR]

I know how far from the wellhead and flare stack I need to have the sleeping quarters or fuel tanks on a drilling location. Never looked at it for anything else.

I had a job in Manitoba where there wasn't enough room to walk between my end of the shack and the flare tank. I don't know what the rules are but I have to think it's more than several inches, even in 3 eyed Manitoba.

Good incentive for me to take accurate mud weights I guess.

[ExtraSlow]

Well, I had to measure out the distance once to the consultants pillow, not to the end of the shack. But that's not how to give everyone the warm fuzzy feelings.

- - - Updated - - -

I was sataifed if they took mud weights at all. It's weird how many people didn't give a fuck.

[jwslam]

Pretty much everything is recommended practice. And every company develops their own risk tolerance. It's really a matter of butting heads with the same topic enough times that FINALLY someone will develop some guidance around it. The document at big blue's biggest facility is only about 4 years old at this point and is still always debated upon and revised / deviated from.

What's included in the document:
-A plot plan of the facility
-Overlay of all the zones created from the blast scenarios, aggregated into a cloud. The clouds include descriptors as to no-go, conditional based on what kind of building / occupancy, and free-for-all
-Who to talk to if you are anywhere near the line, and how to evaluate whether your blast resistant building is sufficient rating

Even with blast radii your calculations can vary so much from using a hole size 2% of pipe diameter vs a standard 1/4" hole...

TLDR for anyone interested on the topic
https://www.aiche.org/sites/default/files/cep/20100318.pdf

CCPS Guidelines for Facility Siting and Layout has a table about limiting exposure between equipment, not really occupied buildings / temp buildings (that operations will always argue is "unoccupied" even though people are there 22/24 hours a day)

Ultimately it's a lot easier to argue these things in a green field state, rather than trying to fix something after it's been laid down...

[FraserB]

All I know is that the supposedly “blast proof” bubble at Scotford seemed a lot flimsier than the permit shacks haha.

[ThePenIsMightier]

All I know is that the supposedly “blast proof” bubble at Scotford seemed a lot flimsier than the permit shacks haha.

LoL at the Scotford "BRS" Blast Resistant Shelters!
Ben der. Done dat.