Home Unfiltered air inleakage analysis of the control room envelope of Kuosheng nuclear power plant
Article
Licensed
Unlicensed Requires Authentication

Unfiltered air inleakage analysis of the control room envelope of Kuosheng nuclear power plant

  • Yu-Ching Tsai ORCID logo EMAIL logo and Chun-Wei Yang
Published/Copyright: August 24, 2023
Become an author with De Gruyter Brill

Abstract

The control room envelope (CRE) of a nuclear power plant is quite important during all kinds of the accidents. Only with the guaranteed habitability of the CRE, the operators can shut down the reactor safely during an accident with the release of hazardous chemicals or radioactive gases. In this study, Kuosheng nuclear power plant (NPP) in Taiwan had performed the inleakage test by using tracer gas technique, and six cases with different heating, ventilation and air conditioning system (HVAC) lineups were tested in this study. The test results showed that the unfiltered inleakage rate for the pressurization modes ranged from 0.063 m3/s to 0.098 m3/s and were all within the acceptance criteria of 0.212 m3/s. For the isolation modes, the unfiltered inleakage rate ranged from 0.240 m3/s to 0.321 m3/s and were still within the acceptance criteria of 0.944 m3/s. The test result provided useful information to improve the vulnerability of the CRE. It also showed that a decrease in the positive differential pressure of the CRE relative to its surroundings did not inevitably increase the unfiltered inleakage rate of the CRE if the critical boundary, such as the negative differential portions of the ventilation system, were still well sealed.


Corresponding author: Yu-Ching Tsai, Associate Researcher of Institute of Nuclear Energy Research, No. 1000 Wenhua Rd. Jiaan Village, Longtan Township, Taoyuan City 32546, Taiwan, E-mail:

Funding source: Institute of Nuclear Energy Research

Award Identifier / Grant number: Unassigned

Acknowledgments

The completion of this study relies on the massive on-site testing works that were performed excellently by Standard Testing & Engineering Inc., and the coordination and investigation works directed by the project leader of Institute of Nuclear Energy Research, Dr. Yi-Kuang Chan. We appreciate their contributions on this study.

  1. Research ethics: Not applicable.

  2. Author contributions: The authors have has accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Competing interests: The authors state no conflict of interest.

  4. Research funding: None declared.

  5. Data availability: Not applicable.

Nomenclature

A

the air exchange rate across the boundary

C 0

the initial concentration of tracer gas within CRE

C 1

the concentration within CRE measured at time t1

C 2

the concentration within CRE measured at time t2

C D

the concentration of tracer gas downstream of the injection point

C I

the concentration of injection tracer gas

C U

the concentration of tracer gas upstream of the injection point

C(t)

the concentration of tracer gas within CRE

CRE

control room envelope

CRHS

control room habitability system

HVAC

heating, ventilation and air conditioning system

P

point of pressure measurement

ΔP

differential pressure

Q(t)

the volumetric airflow rate across the CRE or total inleakage rate

Q makeup

makeup air flow rate

Q unfiltered

unfiltered air inleakage rate

S(t)

the volumetric flow rate of tracer gas injection

t

time

Tr

the sampling points of tracer gas concentration

U1

unit 1 of Kuosheng nuclear power plant (NPP)

U2

unit 2 of Kuosheng NPP

V

the volume of the CRE

References

Adams, D.A. (1998). Critical review: historical persepective and evolution of commercial nuclear utility control room vehtilation systems. In: 25th DOE/NRC nuclear air cleaning and treatment conference, Minneapolis, USA.Search in Google Scholar

ANS (1985). Safety criteria for HVAC systems located outside primary containment. American Nuclear Society, Illinois, ANS, 59.2-1985.Search in Google Scholar

ASTM (2000). Standard test method for determining air change in a single zone by means of a tracer gas dilution (E-741-00). American Society for Testing and Materials, Philadelphia.Search in Google Scholar

ASTM (2011). Standard test method for volumetric and mass flow rate measurement using tracer gas dilution (E2029-11). American Society for Testing and Materials, Philadelphia.Search in Google Scholar

Chang, L., Zhang, X., and Cai, Y. (2016). Experimental determination of air inleakage to pressurized main control room caused by personnel entering. Build. Environ. 99: 142–148, https://doi.org/10.1016/j.buildenv.2016.01.027.Search in Google Scholar

Grot, K.R. and Lagus, P.L. (2012). Tracer gas inleakage testing - what have we learned in twenty years. In: 32nd nuclear air cleaning conference, Denver, USA.Search in Google Scholar

Lagus, P.L. (2004). Air inleakage measurements in high equilibrium time control room envelopes. In: 28th nuclear air cleaning and treatment conference, Escondido, USA.Search in Google Scholar

Lagus, P.L. and Carlson, J.A. (2010). The effect of boundary breech on measured inleakage. In: 31th nuclear air cleaning conference, Charlotte, USA.Search in Google Scholar

Lagus, P.L., Grot, K.R., Carlyle, J.W., Helly, P.J., and Fleming, K.M. (2018). High equilibrium time CREEVS inleakage measurements. In: 35th international nuclear air cleaning conference, Charleston, USA.Search in Google Scholar

McGallian, B.L. and Adams, D.A. (1998). Control room envelope reconstitution. In: 25th DOE/NRC nuclear air cleaning and treatment conference, Minneapolis, USA.Search in Google Scholar

Nuclear Energy Institute (2003a). Methodology for development of emergency action levels. NEI 99-01. Nuclear Energy Institute, Washington, D.C.Search in Google Scholar

Nuclear Energy Institute (2003b). Control room habitability assessment guidance (revision 1). NEI 99-03. Nuclear Energy Institute, Washington, D.C.Search in Google Scholar

Robert, R. and Campbell, P.E. (2002). US control room habitability testing summary and lessons learned. In: 27th nuclear air cleaning and treatment conference, Nashville, USA.Search in Google Scholar

Schultz, S.P., Burley, R.H.Jr., and Taylor, C.B. (2002). Utility views on control room habitability analysis and testing. In: 27th nuclear air cleaning and treatment conference, Nashville, USA.Search in Google Scholar

Song, D.S., Lee, J.B., Ha, S.J., and Huh, S.C. (2015). Assessment of control room habitability and unfiltered air inleakage test of the OPR 1000 NPP. J. Nucl. Sci. Technol. 52: 905–911, https://doi.org/10.1080/00223131.2014.995145.Search in Google Scholar

STDTE (2020). CRE inleakage test for Kuosheng NPS – final report. TQ20-SR-012. Standard Testing & Engineering Inc., Daejeon, Republic of Korea, pp. 11–30.Search in Google Scholar

Tsai, C.M. and Yuen, Y.R. (2016). The analysis of allowable unfiltered inleakage rate of Kuosheng nuclear power plant. CRE-KS-REP-001-R2. Institute of Nuclear Energy Research, Taoyuan, Taiwan.Search in Google Scholar

USNRC (1971). General design criteria 19 for nuclear power plants. Appendix A to Part 50. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (1980a). NRC action plan developed as a result of the TMI-2 accident. NUREG-0660. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (1980b). Clarification of TMI action plan requirements. NUREG-0737. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (1980c). Standard review plan. NUREG-0800. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (2003a). Generic letter 2003-01 control room habitability. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (2003b). Demonstrating control room envelope integrity at nuclear power reactors. Regulatory guide 1.197 Rev.0, 2003b. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (2006). Control room habitability (revision 3), TSTF-448. U.S. Nuclear Regulatory Commission, Washington, D.C.Search in Google Scholar

USNRC (2007). Control room habitability at light-water nuclear power reactors. Regulatory guide 1.196 (rev. 1). U.S. Nuclear Regulatory Commission, Washington, D. C.Search in Google Scholar

USNRC (2008). Control room habitability program guide. U.S. Nuclear Regulatory Commission, Washington, D.C., NHUG-G-001.Search in Google Scholar

Received: 2023-06-15
Published Online: 2023-08-24
Published in Print: 2023-10-26

© 2023 Walter de Gruyter GmbH, Berlin/Boston

Downloaded on 28.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/kern-2023-0044/html?lang=en
Scroll to top button