ML20140A017
| ML20140A017 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 05/19/2020 |
| From: | Tursa M Portland General Electric Co |
| To: | William Allen Office of Nuclear Material Safety and Safeguards |
| Allen W | |
| References | |
| RG-1.091 | |
| Download: ML20140A017 (1) | |
Text
1 Allen, William From:
Mark Tursa <Mark.Tursa@pgn.com>
Sent:
Friday, May 15, 2020 8:11 PM To:
Allen, William Cc:
Jim VanLooven; Kim Lehman
Subject:
[External_Sender] Trojan hazards analysis - RG 1.91 criteria
- Chris,
DuringourrecentcallIcommittedtodiscussingRegulatoryGuide1.91withSargentLundyasitappliestotheTrojan ISFSIhazardanalysispreparedbySargent&LundyandrecentlysubmittedinLCA7208.Thespecificquestionwas whetherthehazardprobabilitiesformultiplechemicalsshouldbecombined.
Regulatoryguide1.91,Revision2,pages5and6discussesamethodforevaluatingwhethertheprobabilityofahazardis acceptablylow.Themethodologydescribeddiscussestheevaluationofriskonapersubstancebasis.RegulatoryGuide 1.91,Revision2specificallystatesthatifagivensubstanceisshippedbymultipletransportationmodes,theriskfromall modesshouldbesummed.Thereisnoindicationthattheriskfromallchemicalhazardsshouldbesummed.
PriorguidanceinRegulatoryGuide1.91,Revision1,page1.912clearlystatesthattheacceptancecriterionappliesto Equation(2),whichcalculatestheexposureforanindividualsubstance.Revision1alsostatesthattheriskfrommultiple transportationmodesshouldbesummedforagivenchemical,butdoesnotindicateallchemicalsshouldbesummed.
Basedontheavailableregulatoryguidance,ourinterpretationoftheacceptancecriterionisthatallhazardsourcesfor anindividualchemical(tank,pipeline,barge,train,etc.)combinedare<106events/year.
Pleaseletmeknowifyouhaveanyquestionsonthisinformation.
Thankyou.
Mark