ML21278A293

2 to Updated Final Safety Analysis Report, Chapter 14, Section 14.22, Waste Gas Incident

ML21278A293
Person / Time
Site:	Calvert Cliffs
Issue date:	09/07/2021
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
Shared Package
ML21278A102	List: ML21257A249 ML21257A253 ML21257A254 ML21257A255 ML21257A256 ML21257A258 ML21257A259 ML21257A260 ML21257A261 ML21257A262 ML21257A263 ML21257A264 ML21257A265 ML21257A267 ML21257A268 ML21257A269 ML21257A278 ML21257A281 ML21257A282 ML21257A283 ML21257A284 ML21257A285 ML21257A286 ML21257A287 ML21257A288 ML21257A289 ML21257A298 ML21257A299 ML21257A300 ML21257A301 ML21257A302 ML21257A303 ML21257A304 ML21257A305 ML21257A306 ML21278A106 ML21278A107 ML21278A108 ML21278A109 ML21278A110 ML21278A111 ML21278A112 ML21278A113 ML21278A114 ML21278A115 ML21278A116 ML21278A117 ML21278A118 ML21278A122 ML21278A123 ... further results
References
NEI 99-04
Download: ML21278A293 (1)

Text

CALVERT CLIFFS UFSAR 14.22-1 Rev. 51 14.22 WASTE GAS INCIDENT 14.22.1 GENERAL The most limiting waste gas incident is defined as an unexpected and uncontrolled release to the atmosphere of the radioactive xenon and krypton fission gases that are stored in one waste gas decay tank.

As the components of the waste gas system are subjected to pressures no greater than 150 psig, a failure is certainly not likely. However, a rupture of a waste gas decay tank is analyzed to define the limit of the hazard that could result from any malfunction in the radioactive waste gas system.

14.22.2 METHOD OF ANALYSIS It is assumed that the maximum activity in any one waste gas decay tank would occur shortly after a heatup and subsequent reactor startup from a cold shutdown condition of one unit near the end of a 24-month operating cycle. It is further assumed that this unit has been operating for an extended period with 1% defective VAP fuel and that all of the coolant is let down and the noble gases from one RCS volume are stored in one tank. On this basis the noble gas activity in the tank, neglecting decay after letdown, is as follows:

Isotope Activity, curies (Reference 1)

Kr 85m 672 Kr 85 7,637 Kr 87 393 Kr 88 1,242 Xe 131m 1,749 Xe 133 106,943 Xe 135 4,325 Xe 138 188 The activity is assumed to be released into the Auxiliary Building with the ventilation system discharging into the turbulent wake of the plant buildings. Therefore, the 0-2 hour meteorological model described in Chapter 2 is applicable. Doses were computed using the dose conversion factors and methodology described in ICRP-30.

14.22.3 RESULTS For this incident the whole body immersion dose at the nearest exclusion zone boundary is 0.182 REM, using Chi/Q = 1.3x10-4 sec/m3.

14.

22.4 CONCLUSION

S In the unlikely event of rupture of a gas decay tank resulting in a release of the maximum stored gaseous activity from one RCS volume, the dose at the nearest exclusion zone boundary is a factor of approximately 100 less than the 10 CFR Part 100 dose guideline value. Therefore, a waste gas incident does not represent undue hazard to the public health and safety.

This event is not affected by the transition to Advanced CE-14 HTP fuel.

14.

22.5 REFERENCES

1.

J.R. Massari, RC Waste Processing System Incident and Waste Gas Incident Dose Analysis, CA05994, October 18, 2002