Monticello is currently experiencing a small instrument nitrogen leak into the drywell. The leak is requiring us to vent the drywell frequently to control pressure. Monticello currently requires any drywell venting to be released to the stack via standby gas treatment. The repetitive nature of the evolution is stressing the standby gas treatment system, presenting a potential risk to the availability/operability of the system. Therefore, Monticello is considering a change to the ODCM to allow primary containment venting without requiring standby gas treatment. The path we are considering would be through containment sampling systems to the plenum and out the building vent; flow rate of approximately 5 scfm with little or no dose consequence. Does your plant require the use of standby gas treatment for all venting operations? Have you encountered a situation where you have vented or purged without the use of standby gas treatment? Would it be possible to get the contact information for the subject expert at your station? Some folks here are suggesting we may have inerted the drywell at startup without standby gas in service in the past. Please send your response to: Scott Quiggle at [email protected]<mailto:[email protected]> Or call 763-271-5174 Thanks for your time and assistance. SQ
Glenn Mathiasen, CHP Xcel Energy | Responsible By Nature Principal Health Physicist 2807 West County Road 75, Monticello, MN 55362 P: 763.295.1384 F: 763.295.1225 E: [email protected]<mailto:[email protected]> ________________________________________________ XCELENERGY.COM Please consider the environment before printing this email.
