Radiation Survey and Waste Inventory Estimation for Decommissioning of Taiwan NPP
Chun-Cheng Lin1*, Wei-Sin Chen1, Jyi-Lan Wuu1, Shu-Jun Chang1
1

Health Physics Division, Institute of Nuclear Energy Research, No. 1000, Wenhua Rd., Jiaan Village, Longtan
District, Taoyuan City 32546, Taiwan (ROC)

Keywords: Radiation survey, radioactive wastes, MARSSIM, Decommissioning.

Abstract
Both radiation survey and waste inventory estimation are parts of the NPP (nuclear power plant) decommissioning
program issues. This paper describes the radiation survey and site investigation methods based on MARSSIM. Waste
inventory estimation for decommissioning is also essential in the whole decommissioning study; it affects D&D
methods, decommissioning cost estimation, packing containers selection and repository design for decommissioning
waste etc. This paper presents the preliminary outcomes of radiation survey and waste inventory estimation fordecommissioning of Chinshan NPP.
1. Introduction
2.1.1 Site Survey and Site Investigation Flowchart
The purpose of the site survey and site investigation
is to define the extent and magnitude of residual
radioactive and hazardous materials within theradiological site. Accurate accounting of allcontaminated materials and structures of the site is aprerequisite for the performance of reasonable cost andschedule estimation for the whole site dismantling anddemolition. Both radiation survey and site investigation
for radiological sites and facilities provide the radiation
information for decommissioning strategy and waste
inventory estimation.
This study presents the whole radiation survey andsite investigation method based on the MARSSIM [1](Multi-Agency Radiation Survey and Site Investigation
Manual) and MARSAME [2] (Multi-Agency Radiation
Survey and Assessment of Materials and Equipment
Manual). The survey and investigation results can also
be used to plan the further decommissioning strategy,
including decontamination techniques, schedules, costs,
waste volume, and health and safety considerations.
In the other hand, the waste inventory estimation isalso an important issue during NPP decommissioning
program, since D&D methods, decommissioning costestimation, packing container selection, repository
design for decommissioning waste etc. would beaffected, hence the waste estimation methodology haveto be determined.[3][4][5][6][7][8]The flowchart for site investigation and survey
package classification is shown in Fig 1. The first stepof site investigation is the historical site assessment(HSA). The purpose of HSA is to collect and evaluate
information about the structures and systems to support
a categorization decision and potential disposition of thematerial and elements (e.g., release or interdiction). The
HSA results allow for the classification of site areas asaffected or unaffected by the operational history, which
can be corresponding to contaminated and noncontaminated. Based on the classification results andmaterial properties, they can further divided into various
survey packages, including A-, B-, C-, D- and R-survey
packages.
A- and B-survey packages respectively represent thecontaminated and non-contaminated structures, which
include the building interiors and exteriors withassociated structures, and the exterior surfaces of plantsystems and components. An example for A-survey
package survey position map is shown in Fig.2. It
indicates the layout of the fifth floor in the sub-mainbuilding in the facility. There are 2 survey units and 59
survey points included in this survey package.
C- and D-survey packages respectively represent thecontaminated and non-contaminated operating systems,
which include interior surfaces of process piping,components, ventilation ductwork, and installed drains
and sumps.

2. Methods and Results
2.1 Radiation Survey

R-survey packages represent the land area andenvironment, which include the facility grounds within
and outside the restricted area, the liquid effluent
pathway, bay, groundwater wells and remote locations
within the site boundaries.

In this section, the site survey and site investigation
flowchart, survey investigation instruments and survey
investigation techniques will be introduced.

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6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan

Each survey package for its survey area shall containthe following elements: preparing a walk down
worksheet, developing specific survey instructions forthat area, and assembling the survey package.
After all the survey package designs are developed,
the further processes will be executed as following: onsite measurement, activation analysis, sampling andlaboratory analysis. Fig. 3 shows the R-survey package
map for the radiological site. The potential
contamination areas include the main building (R00600),
sub-main building (R00700), the laboratory building(R00300) and storage building (R00800); survey
packages will increase in those areas.
Fig. 3. The R-survey package map for the buildings andenvironment area at the site.

2.1.2 Survey Investigation Instruments
The detection types used in this study included onsite measurement detections and laboratory radionuclide
analysis; the detailed information of used devices andinstruments are listed in Table 1. All the detectors andinstruments must be calibrated before use.
Table 1: Survey Investigation Instruments Lists
Fig. 1. The flowchart for survey designs and theclassifications for survey packages.

Detection
Type

Instrument
Type

Instrument modelGeiger

Automess 6112/ 6112B,
THERMO FH40 F2/F4

GM tubeRados RDS-30

On-site measurement(non-contaminatedarea, environment)

NaI

RADEYE PRD,
RADEYE PRD-ER

Laboratory Analysis

HPGe Detector,
Gas-filled Proportional Counter,
Liquid Scintillation Counting Counter,etc.

On-site measurement(contaminated area)

2.2 Waste Inventory Estimation
2.2.1 Decommissioning Strategies and Information

Fig.2. An example for the A-survey package maps. The
symbols are represent to various detection types ( e.g., □ forwall, ◇ for floor, and ○ for equipment)

In general, the decommissioning strategies include
immediate dismantling, deferred dismantling andentombment. The option of entombment is only valid
for emergencies and is not considered a proper
decommissioning strategy.
A waste estimation, that is site-specific, is based onsite radiological and hazardous material characterization
information and further defined engineering data,
including site and plot plans, general arrangement andarchitectural drawings, piping and instrument diagrams,
one-line electrical diagrams, equipment specifications,reference manuals, etc., to provide a basis for thefacilities,systemsandstructures
requiringdecontamination and dismantling.

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6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan

Data collection also includes the site-specificinventory of systems and structures, local labor
requirements for skilled labor and management andlocal consumables and materials.

Table 2：Classification determined by long-lived
radionuclides
Radionuclide

Activity Concentration

14C0.30 TBq/m3

142.2.2 Classifications of Radioactive Waste

3C in activated metal

3.0 TBq/m59

3

Ni in activated metal

The first step before waste estimation is to define theclassifications by radioactivity, such as HLW (highlevel waste), SNF (spent nuclear fuel), TRU(transuranic waste), ILW (intermediate level waste),
LLW (low level waste), FRW (free released waste), EW(exempt waste) and VLLW (very low level waste).
It has to be noticed that the LLW includes four
subcategories (i.e. A, B, C and GTCC) only by NRC’srequirement.
SNF is regard as operational waste in common, thus
is not considered in the decommissioning wasteestimation.
And the second step is to confirm the origins ofradioactive waste that was from surface contamination,activation of materials or water processing streams.

8.1 TBq/m

94

3

Nb in activated metal

0.0074 TBq/m

99

3

Tc

0.11 TBq/m

129

3ITRU (Alpha emitting
transuranic nuclides withhalf-life greater than 5 years)
241

0.0030 TBq/m
3.7 kBq/g
130 kBq/g

Pu
242740 kBq/g

Cm

Table 3：Classification determined by short-lived
radionuclides
3Radionuclide

2.2.3 Classification of Low-level Waste (LLW)

Total of all nuclides
with less than 5year half-life

Determination of the classification of radioactive
waste involves two considerations. One is the longlived radionuclides;
theotheris shorter-lived
radionuclides (and their shorter-lived precursors).
Taiwan refers the waste classification regulation tothe NRC 10CFR61.55 for developing the classificationof LLW.
Table 2 and 3 are to classify the LLW. If theconcentration does not exceed 0.1 times the value inTable 2, the waste is Class A. If the concentration
exceeds 0.1 times the value in Table 2 but does notexceed the value in Table 2, the waste is Class C.
If the concentration does not exceed the value inColumn 1 of Table 3, the waste is Class A. If theconcentration exceeds the value in Column 1 of Table 3,
but does not exceed the value in Column 2 of Table 3,
the waste is Class B. If the concentration exceeds thevalue in Column 2 of Table 3, but does not exceed thevalue in Column 3 of Table 3, the waste is Class C.
If the concentration exceeds the value in Table 2 orthe concentration exceeds the value in Column 3 ofTable 3, the waste is Class GTCC (Greater Than ClassC)

3

H60

Co63

NiActivity Concentration (TBq/m )Column 1

Column 2

Column 3

26

Note*

Note*

1.5

Note*

Note*

26

Note*

Note*

0.13

2.6

26

1.3

26

260

0.0015

5.6

260

0.037

1.6

170

63

Ni in activatedmetal90

Sr137

Cs

Note*：There are no limits established for these radionuclides inClass B or C wastes. Practical considerations such as the effects ofexternal radiation and internal heat generation on transportation,
handling, and disposal will limit the concentrations for these wastes.
These wastes shall be Class B unless the concentrations of othernuclides in Table 3 determine the waste to the Class C independent ofthese nuclides.

2.2.4 Low-level Waste (LLW) Inventory Estimation
It can be summarized the above information of
decommissioning waste in two templates, material andradiological inventories, respectively. The accurate
estimation of the waste quantities and activities to begenerated during the dismantling operations and of theassociated radiological burden requires a thorough andcomprehensive inventory of all the plant systemcomponents and structures which are subject topotential radioactive contamination. There are the LLW
inventory estimation of Chinshan NPP shown in Fig.5,
Fig.6 and Fig.7.

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6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan[2] Multi-Agency Radiation Survey and Assessment ofMaterials and Equipment manual. Nuclear Regulatory
Commission NUREG-1575, Supp. 1, EnvironmentalProtection Agency EPA 402-R-09-001, Department ofEnergy DOE/ES-0004, January 2009.
[3] A. Anunti, H. Larsson, M. Edelborg, Decommissioning
study of Forsmark NPP, SKB, 2013.
[4] M. Edelborg, Decommissioning Planning for Forsmark
and Oskarshamn NPPs, WEC Sweden, NKS seminar,
2010.
[5] T. Hansson, T. Norberg, A. Knutsson, P. Fors, C.
Sandebert, Ringhals Site Study- An assessment of thedecommissioning cost for the Ringhals site, SKB, 2013.
[6] TLG Services, Inc., Decommissioning cost analysis for theVermont Yankee nuclear power station, 2012.
[7] TLG Services, Inc., Decommissioning cost analysis for theOyster Creek nuclear power station, 2004.
[8] TLG Services, Inc., Decommissioning cost analysis for theMillstone power station Unit 1, 1999.

Fig. 5. LLW Inventory Estimation of Chinshan NPP Category (Activated, Contaminated, Metal, Concrete & Other).

Fig. 6. LLW Inventory Estimation of Chinshan NPP Classification (A, B, C & GTCC).

Fig. 7. LLW Inventory Estimation of Chinshan NPP - theweight and activity percentage of waste classification.

3. Conclusions
This study presents the whole radiation survey andsite investigation methods based on the MARSSIM. Onsite measurement and laboratory analysis are practiced
with the survey methods and designs.
Radiation survey and site investigation can provide
the radiation information for decommissioning planningand waste inventory estimation. These studies introduce
the methodology of waste inventory estimation,
including material and radioactivity, and demonstrate
the preliminary outcomes of Chinshan NPP.
REFERENCES[1]

Multi-Agency Radiation Survey and Site
Investigation Manual (Revision 1). Nuclear
Regulatory Commission NUREG-1575 Rev. 1,
Environmental Protection Agency EPA 402-R-97016 Rev. 1, Department of Energy DOE EH-0624
Rev. 1, August 2002.

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6th East Asia Forum on Radwaste Management Conference
November 27-29, 2017, Osaka, Japan