This is very helpful Tom. Thanks for your excellent detail memory! So it sounds like the issue you're recalling may exist for various PWR plant designs. In situations where fuel failure has been relatively high, you can see dose rates on those in-yard tanks going above 2.5 mrem/hr. The RWST and the SIRW are analogous tanks holding large quantities of refueling water.
The specific tanks I was wondering about, though, are the holdup tanks used to store what is left after being processed through the plant's cleanup systems, especially demineralizers and filters. In Combustion plants, these are referred to simply as the Holdup Tanks. Together with the Reactor Makeup Water Tanks, they represent the main stored activity outside of the plant buildings. So the Holdup Tanks would have less radioactivity than any of the reactor water storage tanks. Does anyone have experience of elevated doses for these Holdup Tanks? Tim I donât know if you are interested in Westinghouse plants but I was the RPM at Trojan for 25 years including the years with significant failed fuel. Our Refueling Water Storage tank which held reactor and refueling canal water was located outside adjacent to the spent fuel and containment buildings. We had hot spots on contact with the bottom flange of the tank of over 100 mr/hr and general areas (@30 cm) of 30 mr/hr. We had to build a structure around the base of the tank for security purposes and we had the structure sized to keep the dose rates outside the structure below 5 mr/hr. Later we had to use rope barriers to demarcate the 2 mr/hr area. I worked at Palisades way back in the 70âs and seem to remember similar results for the SIRW tank (that is a long time ago to try to recall) Regards Tom Meek, CHP (semiretired) From: Tim Lloyd [mailto:[email protected]] Sent: Thursday, June 2, 2016 8:33 AM To: [email protected] Subject: [powernet] Dose Rates on In-Yard Holdup Tanks I have a question for operators of CE plants. Does anyone have experience of high dose rates on holdup tanks located in the yard outside the plant building? If not, do you have a feel for the types of dose rates that are typical on these storage tanks? Best regards, Tim Lloyd Timothy M. Lloyd, P.E. Principal Engineer, Nuclear Operations and Radiation Analysis Westinghouse Electric Company Products: Spent Fuel Radiation Analysis ; Radiation Engineering & Analysis 236 Glenwood Avenue Santa Cruz, CA 95060 +1 831 227-8453 (office/mobile) [email protected] <mailto:[email protected]> On June 13, 2016 3:26:49 PM EDT, Tim Lloyd <[email protected]> wrote: >---------------------------- Original Message >---------------------------- >Subject: RE: [powernet] Dose Rates on In-Yard Holdup Tanks >From: "Tim Lloyd" <[email protected]> >Date: Mon, 13 June, 2016 11:57 am >To: [email protected] >Cc: "Tom gmail" <[email protected]> >-------------------------------------------------------------------------- > >This is very helpful Tom. Thanks for your excellent detail memory! > >So it sounds like the issue you're recalling may exist for various PWR >plant designs. In situations where fuel failure has been relatively >high, >you can see dose rates on those in-yard tanks going above 2.5 mrem/hr. >The >RWST and the SIRW are analogous tanks holding large quantities of >refueling water. > >The specific tanks I was wondering about, though, are the holdup tanks >used to store what is left after being processed through the plant's >cleanup systems, especially demineralizers and filters. In Combustion >plants, these are referred to simply as the Holdup Tanks. Together with >the Reactor Makeup Water Tanks, they represent the main stored activity >outside of the plant buildings. > >So the Holdup Tanks would have less radioactivity than any of the >reactor >water storage tanks. > >Does anyone have experience of elevated doses for these Holdup Tanks? > > Tim > >> I donât know if you are interested in Westinghouse plants but I was >the >> RPM at Trojan for 25 years including the years with significant >failed >> fuel. Our Refueling Water Storage tank which held reactor and >refueling >> canal water was located outside adjacent to the spent fuel and >containment >> buildings. We had hot spots on contact with the bottom flange of the >tank >> of over 100 mr/hr and general areas (@30 cm) of 30 mr/hr. We had to >build >> a structure around the base of the tank for security purposes and we >had >> the structure sized to keep the dose rates outside the structure >below 5 >> mr/hr. Later we had to use rope barriers to demarcate the 2 mr/hr >area. >> >> I worked at Palisades way back in the 70âs and seem to remember >similar >> results for the SIRW tank (that is a long time ago to try to recall) >> >> Regards >> >> Tom Meek, CHP (semiretired) >> >> >> >> From: Tim Lloyd [mailto:[email protected]] >> Sent: Thursday, June 2, 2016 8:33 AM >> To: [email protected] >> Subject: [powernet] Dose Rates on In-Yard Holdup Tanks >> >> >> >> >> I have a question for operators of CE plants. >> >> Does anyone have experience of high dose rates on holdup tanks >located in >> the yard outside the plant building? If not, do you have a feel for >the >> types of dose rates that are typical on these storage tanks? >> >> Best regards, >> >> >> Tim Lloyd >> >> Timothy M. Lloyd, P.E. >> Principal Engineer, Nuclear Operations and Radiation Analysis >> Westinghouse Electric Company >> Products: Spent Fuel Radiation Analysis ; Radiation Engineering & >Analysis >> 236 Glenwood Avenue >> Santa Cruz, CA 95060 >> +1 831 227-8453 (office/mobile) >> [email protected] <mailto:[email protected]> >> >> >> >> -- - Tim Sent from my phone. Please excuse my brevity.
