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JAEA Reports

Review of incident involving reactor pressure vessel head degradation at U.S. PWR

Watanabe, Norio

JAERI-Review 2004-015, 144 Pages, 2004/07

JAERI-Review-2004-015.pdf:25.58MB

In March 6, 2002, significant degradation to the reactor vessel head material adjacent to a control rod drive nozzle was discovered at a U. S. pressurized water reactor (PWR), Davis Besse. Based on the documents issued by the U.S. Nuclear Regulatory Commission (USNRC) and the licensee, this report provides a brief description on circumstances related to discovery of the reactor vessel head degradation, and describes the degraded condition and causes, the USNRC's responses to this event and so on. In attachments, given are the contents of the generic communications (Bulletins, Generic Letters and Information Notices) issued by the USNRC for the events involving boric acid corrosion and degradation of reactor coolant pressure boundary components and the summary of the investigation reports issued by the USNRC's lessons-learned task force.

JAEA Reports

Behavior of carbon-14 in the Tokai reprocessing plant

; ; ; Omori, Eiichi

JNC TN8410 2001-021, 33 Pages, 2001/09

JNC-TN8410-2001-021.pdf:4.37MB

Carbon-14 released from the nuclear facilities is an important radionuclide for the safety assessment, because it tends to accumulate in environment through food chain and has as a significant impact to personal dose. Carbon-14 has been monitored routinely as one of the main gaseous radionuclides exhausted from the Tokai Reprocessing Plant (TRP) since OCtober of 1991. Furthermore, behavior of carbon-14 in TRP has been investigated through the reprocessing operation and the literature survey. This report describes the result of investigation about the behavior of carbon-14 in TRP as followings. (1)Only a very small amount of carbon-14 in the fuel was liberated into the shear off-gas and most of it was liberated into the dissolver of-gass. Part of the carbon-14 was trapped at the caustic scrubber installed in the of-gas treatment process, and untrapped carbon-14 was released into the environment from the main stack. Amount of carbon-14 released from the main stack was about 4.16.5GBq every ton of uranium reprocessed. (2)Carbon-14 trapped at the caustic scrubbers installed in the dissolver off-gas and in the vessel off-gas treatment process is transferred to the low active waste vessel. Amount of carbon-14 transferred to the low active waste vessel was about 5.4 9.6GBq every ton of uranium reprocessed. (3)The total amount of carbon-14 input to TRP was summed up to about 11.915.5 GBq every ton of uranium reprocessed considering the released amount from the main stack and the trapped amount in the off-gas treatment devices. The amount of nitrogen impurity in the initial fuel was calculated about 1522ppm of uranium metal based on the measured carbon-14. (4)The solution in the low active waste vesselis concentrated at the evaporator.Most of the carbon-14 in the solution was transferred into concentrated solution. (5)Tokai vitrification Demonstration Facility (TVF) started to operate in 1994. Since then, carbon-14 has been measured in the ...

JAEA Reports

ATR Data Base 「Fugen」 Design/R&D/Characteristics[Pressure Tube Assembly]

PNC TJ1409 97-023, 19 Pages, 1997/03

PNC-TJ1409-97-023.pdf:0.55MB

None

JAEA Reports

ATR Data base 「Fugen」design/ R&D / characteristics [Safety Analysis]

PNC TJ1409 97-022, 53 Pages, 1997/03

PNC-TJ1409-97-022.pdf:1.18MB

1 Reflection of R&D Results, Design and Operation Experiences All knowledge obtain in the project, such as R&D results, design, operation experiences and so on, are tbe reflected to following items. 1) Improvement of safety and reliability in plant eration 2) Design modification of the plant 3) Design of the next plant 2 Basic Sndpoint for Data Base Composition "Design/R&D/Plant Performance Data Base" will be mposed ad shown in the following, so that the Data Base could be utilized for reflecng them to the above items and for improving the above items, effectively and efficitly. (1) United Data Bases of Design and R&D "Design/R&D/Plant Performance Data Ba" will be composed by uniting design data base and R&D data base, considering that t R&D of the project is mainly made in order to establish the design engineering and chnical basis, such as design policy, design criteria, design conditions, alloable dign limits, design verification, etc. (2) Addition of Initial Plant Performa

JAEA Reports

ATR Data base 「Fugen」 design/ R&D /characteristics [Thermal/Hydraulic]

PNC TJ1409 97-021, 27 Pages, 1997/03

PNC-TJ1409-97-021.pdf:0.59MB

1 Reflection of R&D Results, Design and Operation Experiences All knowledge obtain in the project, such as R&D results, design, operation experiences and so on, are tbe reflected to following items. 1) Improvement of safety and reliability in plant eration 2) Design modification of the plant 3) Design of the next plant 2 Basic Sndpoint for Data Base Composition "Design/R&D/Plant Performance Data Base" will be mposed ad shown in the following, so that the Data Base could be utilized for reflecng them to the above items and for improving the above items, effectively and efficitly. (1) United Data Bases of Design and R&D "Design/R&D/Plant Performance Data Ba" will be composed by uniting design data base and R&D data base, considering that t R&D of the project is mainly made in order to establish the design engineering and chnical basis, such as design policy, design criteria, design conditions, alloable dign limits, design verification, etc. (2) Addition of Initial Plant Performa

JAEA Reports

ATR Date Bese 「Fugen」 Design/R&D/Characteristics[Nuclear]

PNC TJ1409 97-020, 29 Pages, 1997/03

PNC-TJ1409-97-020.pdf:0.67MB

1 Reflection of R&D Results, Design and Operation Experiences All knowledge obtain in the project, such as R&D results, design, operation experiences and so on, are tbe reflected to following items. 1) Improvement of safety and reliability in plant eration 2) Design modification of the plant 3) Design of the next plant 2 Basic Sndpoint for Data Base Composition "Design/R&D/Plant Performance Data Base" will be mposed ad shown in the following, so that the Data Base could be utilized for reflecng them to the above items and for improving the above items, effectively and efficitly. (1) United Data Bases of Design and R&D "Design/R&D/Plant Performance Data Ba" will be composed by uniting design data base and R&D data base, considering that t R&D of the project is mainly made in order to establish the design engineering and chnical basis, such as design policy, design criteria, design conditions, alloabledesignlimits, design verification, etc. (2) Addition of Initial Plant Performa

JAEA Reports