A VTT Fukushima Daiichi Unit 3 (1F3) method for estimation of liquids and consequences of releases (MELCOR) model was modified to simulate the Fukushima Daiichi Unit 2 (1F2) accident. Five simulations were performed using different modeling approaches. The model 1F2 v1 includes only the basic modifications to reproduce the 1F2 accident. The model 1F2 v2 includes the same modifications used in 1F2 v1 plus the wet well (WW) improvement. In the 1F2 v3 model, the reactor core isolation cooling (RCIC) system logic was modified to avoid the use of tabular functions for the mass flow inlet and outlet. Because of this analysis, it is concluded that there is a strong dependency on parameters that still have many uncertainties, such as the RCIC two-phase flow operation, the alternative water injection, the suppression pool (SP) behavior, the rupture disk behavior and the containment failure modes, which affect the final state of the reactor core.

References

References
1.
Government-TEPCO
,
2011
, “Report of Japanese Government to the IAEA Ministerial Conference on Nuclear Safety—The Accident at TEPCO’s Fukushima Nuclear Power Stations,” Government of Japan, Tokyo, Japan,
Report
https://japan.kantei.go.jp/kan/topics/201106/iaea_houkokusho_e.html.
2.
INPO
,
2011
, “Special Report on the Nuclear Accident at the Fukushima Daiichi Nuclear Power Station,” Institute of Nuclear Power Operations, Atlanta, GA, Report No.
INPO 11-005
https://www.nei.org/Master-Document-Folder/Backgrounders/Reports-And-Studies/Special-Report-on-the-Nuclear-Accident-at-the-Fuku.
3.
TEPCO
,
2011
, “Fukushima Nuclear Accident Analysis Report (Interim Report),” Tokyo Electric Power Company, Inc., Tokyo, Japan,
Report
.http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/111202e14.pdf
4.
TEPCO
,
2012
, “Fukushima Nuclear Accident Analysis Report,” Tokyo Electric Power Company, Inc., Tokyo, Japan,
Report
.http://www.tepco.co.jp/en/press/corp-com/release/betu12_e/images/120620e0104.pdf
5.
SNL
,
2012
, “Fukushima Daiichi Accident Study (Status as of April 2012),” Sandia National Laboratory, Albuquerque, NM, Report No.
SAND2012-6173
https://energypubs.sandia.gov/publications/fukushima-daiichi-accident-study.
6.
EPRI
,
2013
, “Fukushima Technical Evaluation Phase 1—MAAP5 Analysis,” Electric Power Research Institute, Palo Alto, CA, Report No.
1025750
https://www.epri.com/#/pages/product/1025750/.
7.
Sevón
,
T.
,
2013
, “MELCOR Modeling of Fukushima Unit 2 Accident,” 22nd International Conference on Nuclear Energy for New Europe (
NENE
), Sept. 9–12.http://www.nss.si/proc/nene2013/pdf/NENE2013_404.pdf
8.
Fontanet
,
J.
,
López
,
C.
,
Fernández
,
E.
, and
Herranz
,
L. E.
,
2013
, “CIEMAT Contribution to the BSAF Project: Analysis of the Fukushima Unit 2 Accident With MELCOR,”
39th Annual Meeting of Spanish Nuclear Society
, Tarragona, Spain, Sept. 25–27.https://inis.iaea.org/search/search.aspx?orig_q=RN:45046301
9.
Takahashi
,
A.
,
Marco
,
P.
,
Hideo
,
M.
,
Hiroaki
,
S.
, and
Masanori
,
N.
,
2014
, “Accident Analysis of Fukushima Daiichi Nuclear Power Plant Unit 2 by the SAMPSON Severe Accident Code,”
ASME
Paper No. ICONE22-30670.
10.
Takahashi
,
A.
,
Pellegrini
,
M.
,
Mizouchi
,
H.
,
Suzuki
,
H.
, and
Naitoh
,
M.
,
2015
, “Simulation Analysis on Accident at Fukushima Daiichi Nuclear Power Plant Unit 2 by SAMPSON Code,” Chiba, Japan, May 17–20, Paper No. ICONE23-1517.
11.
Sevón
,
T.
,
2015
, “
A MELCOR Model of Fukushima Daiichi Unit 3 Accident
,”
Nucl. Eng. Des.
,
284
, pp.
80
90
.
12.
SNL,
2010
, “SOARCA Project. Best Modeling Practices,” Sandia National Laboratories, Albuquerque, NM, Report No. NUREG/CR-7008.
13.
SNL
,
2012
, “State-of-the-Art Reactor Consequence Analyses Project. Volume 1: Peach Bottom Integrated Analysis,” Sandia National Laboratories, Albuquerque, NM, Report No.
NUREG/CR-7110
.https://www.nrc.gov/reading-rm/doc-collections/nuregs/contract/cr7110/v1/
14.
Herranz
,
L. E.
,
Fontanet
,
J.
,
Fernández
,
E.
, and
López
,
C.
,
2014
, “Influence of the Nodalization on Major Thermal-Hydraulic Variables Governing Mark-I Containment Response to an SBO Sequence: Plant Assessment,” Reunión Anual de la Sociedad Nuclear Española, Valencia, Spain.
15.
TEPCO
,
2012
, “Information Portal for the Fukushima Daiichi Accident Analysis and Decommissioning Activities,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, https://fdada.info/
16.
NRC
,
1975
, “Reactor Safety Study,” U.S. Nuclear Regulatory Commission, Washington, DC, Report No.
WASH-1400
https://www.nrc.gov/docs/ML1622/ML16225A002.pdf.
17.
ORNL
,
1982
, “BWR Containment Failure Analysis During Degraded-Core Accidents,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No.
CONF-820609--55
https://inis.iaea.org/search/search.aspx?orig_q=RN:14724001.
18.
ORNL
,
1983
, “BWR 4/Mark I Accident Sequences Assessment,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No.
NUREG/CR-2825
https://inis.iaea.org/search/search.aspx?orig_q=RN:14761438.
19.
Hirao, K.
,
Zama, T.
,
Goto, M.
,
Naruse, Y.
,
Saito, K.
,
Suzuki, T.
, and
Sugino, H.
,
1993
, “
High-Temperature Leak-Characteristics of PCV Hatch Flange Gasket
,”
Nucl. Eng. Des.
,
145
(3), pp.
375
386
.
20.
TEPCO
,
2013
, “Plant Specifications of the Unit 2,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, https://fdada.info/en/home2/accident2/specification2/
21.
TEPCO
,
2011
, “Fukushima Daiichi Nuclear Power Station Response After the Earthquake,” Tokyo Electric Power Company, Inc., Tokyo, Japan,
Report
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110618e15.pdf.
22.
TEPCO
,
2011
, “Unit 2 Operator Task Handover Journal,” Tokyo Electric Power Company, Inc., Tokyo, Japan, Report No. NM-51-4 1F-F1-001.
23.
TEPCO
,
2013
, “Diagram of RCIC Quencher in Unit 2,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, https://fdada.info/en/home2/accident2/specification2/
24.
Terry Corporation Engineering
,
1973
, “Water Injection Test. Solid Wheel Turbine,” Terry Corporation Engineering, Tustin, CA.
25.
TEPCO
,
2013
, “Amount of Water Injection Assumed in MAAP Analysis for Unit-2,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, http://www.tepco.co.jp/en/press/corp-com/release/betu14_e/images/140806e0115.pdf
26.
TEPCO
,
2013
, “Examination Into Water Injection by Fire Engines,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, http://www.tepco.co.jp/en/press/corp-com/release/2013/12/index-e.html
27.
Darley & Co.
,
2011
, “PUMP MODEL 2BE10YDN-N Curve No. C544,” Darley & Co., Itasca, IL, accessed Feb. 9, 2018, http://www.darley.com/library/pump-performance-curves
28.
Shaukats
,
S.
,
Jackson
,
J.
, and
Thatcher
,
D.
,
1991
, “Regulatory Analysis for Generic Issue 23: Reactor Coolant Pump Seal Failure,” U.S. Nuclear Regulatory Commission, Washington, DC, Report No.
NUREG-1401
https://inis.iaea.org/search/search.aspx?orig_q=RN:35066272.
29.
B. O. Group
,
1981
, “BWR Owner’s Group Evaluation of NUREG-0737 Item K3.25—Effect of Loss of Alternating Current Power on Pump Seals,” B. O. Group.
30.
TEPCO
,
2012
, “MAAP Code-Based Analysis of the Development of the Events at the Fukushima Daiichi Nuclear Power Station,” Tokyo Electric Power Company, Inc., Tokyo, Japan,
Report
https://inis.iaea.org/search/search.aspx?orig_q=RN:47033063.
31.
Cook
,
D. H.
,
1984
, “Calculation of Thermal Mixing for the BWR Mark I Containment Pressure Suppression Pool,” 12th Water Reactor Safety Meeting, Gaithersburg, MD, Oct. 22–26, Report No.
CONF-8410142--10
http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/16/058/16058304.pdf.
32.
Rand
,
D.
, and
Turbine
,
S.
,
2015
, “
Motor and Generator D
,”
Terry Nuclear Drive Turbines
,
Dresser Rand
, Houston, TX.
33.
TEPCO
,
2013
, “Attachment 2-2. Containment Vessel Pressure Behaviors at Unit-2,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, http://www.tepco.co.jp/en/press/corp-com/release/betu13_e/images/131213e0114.pdf
34.
TEPCO
,
2013
, “Attachment 2-1. Reactor Pressure Behaviors at Unit-2,” Tokyo Electric Power Company, Inc., Tokyo, Japan, accessed Feb. 9, 2018, 2015, http://www.tepco.co.jp/en/press/corp-com/release/betu14_e/images/140806e0113.pdf
You do not currently have access to this content.