Upload
lyque
View
217
Download
1
Embed Size (px)
Citation preview
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY
Developing Safeguards for Final Disposal
of Spent Nuclear Fuel in Finland
Olli Okko, Tapani Hack, Marko Hämäläinen, Tapani Honkamaa, Elina Martikka, Mikael Moring
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY
Application for the Final Disposal Facility in Finland,
Safeguards Requirements to be Set Timely
• National decision to start scientific research programme for geological repository
begins 1983 with the site selection of Olkiluoto in 2000 and continuation of
underground site characterisation since 2003.
• Finnish operator Posiva submits the Application for Nuclear Construction licence
for the EPGR Encapsulation Plant and Geological Repository in December 2012.
• Licence conditions (including safeguards requirements) are to be set in 2014
before the construction of the new nuclear facility starts.
• Operating Licence is expected by 2022, safeguards instrumentation and
measures to be in place.
2
Picture from the 2012 application
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 3
Safeguards for Final Disposal of Spent Fuel,
Background Facts
A) The spent fuel elements will be encapsulated, no possibility for re-verification
The encapsulation process shall be under continuous surveillance,
The new subject for accountancy and control is the canister,
C/S is needed confirm the identity and integrity of the canister.
B) The canister will be emplaced in geological media, no access is available
=> C/S is needed to confirm that no undeclared nuclear material is retrieved from the repository !
The canister can be kept under accountancy and continuous surveillance (in the Finnish circumstances) to the final position in the repository, but after the emplacement, the safeguards concept for the underground must be based only on continuous C/S.
As the safe and secure disposal of nuclear fuel is a societal question, the safeguards measures have to adopted accordingly.
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 4
Safeguards Issues for Final Disposal of Spent Fuel
No reverification is possible, i.e.
The repository will not be opened for re-establishment of accountancy data even in case of equipment failure!
The (at least dual) C/S instrumentation has to be robust and reliable during the operational time of the repository to confirm that all nuclear material remain in the geological repository.
In safeguards terminology:
The traditional DIV/PIV is not applicable for a GR !
The “Pure C/S” concept requires NDA + C/S + CoK
Can the IAEA accept this Pure C/S Concept (Stein et al. ESARDA Bulletin 1987) ?
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 5
Pure C/S for Final Disposal of Spent Fuel
ESARDA Bulletin 1987 (Stein et al.) raised a few main questions cited below that are to be solved with up-to-date technology:
Is the pure C/S concept acceptable?
“Since precisely this conception with intensive CIS could be of essential significance
in the case of a direct final repository, a conflict might arise.
The IAEA would have to make considerable cuts and reorientations in their previous
safeguards philosophy in order to solve this issue.”
Termination of safeguards?
”It is not possible from current perspectives to make a decision on the possibility of
monitoring a direct final repository in the postoperational phase or terminating
safeguards.”
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 6
Safeguards for Final Disposal of Spent Fuel
The content of this paper:
Background facts for the new type of facility
No DIV/PIV is applicable for NM in a GR !
- However, discussion on Design Information to be generated, submitted and continuously updated, like the cumulative Physical Inventory.
The “Pure C/S” concept requires NDA + C/S + CoK - NDA – best available techniques, requirement to record what has been disposed of
- C/S – confirmation that everything is disposed of
- CoK – knowledge about the location and content of disposed of material for future generations
Additional safeguards measures: - DIV and CA to visit the underground to verify the design information and to the confirm
the absence of undeclared activities
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 7
Design information for the Geological Repository
at Olkiluoto (STUK- YTO TR 216, 2006)
The pertinent information was submitted
to the IAEA in 2003 when excavation of
the underground premises begun.
National concern is to entrust the IAEA
to verify the impregnate containment at
the safeguards-relevant accuracy.
Verified as built
design information
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 8
Generation of Safeguards Relevant CoK for the
National Licensing of the Finnish Repository
Implementer’s reporting (Safeguards manual for Onkalo):
- Advance notifications about planned activities.
- Generation of up-dated “as built” Design Information.
- Progress and monitoring reports.
- Facilitation of inspections.
- Interaction with all stakeholders.
Authority’s verification ( STUK’s YTV-Guide):
Continuous presence and follow-up:
-Issues related to the long-term safety and safeguards are reviewed in monthly follow-up meetings.
-Safeguards documents are reviewed, verified and archived semi-annually.
- The progress in site understanding is evaluated in semi annual international consultant meetings.
-IAEA/EC tasks:
- Examination and verification of the design information.
- Preparation of safeguards requirements for the disposal process.
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 9
As-Built Design Information Verification in Tunnel
The safety authorities must have credible assurance that the as-built documentation is accurate and correct.
The safety requirement involves an monitoring programme that generates all the information needed also for safeguards documents.
Safeguards inspectors and facility representatives
in the access tunnel to the planned repository.
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 10
Documentation of As-Built Records
Safeguards relevant findings of the national system include the progress in tunnelling is documented on paper in STUK’s archive
- Progress drawings, inspected documents at STUK,
- Laser scanning print-outs, the digital data is stored at the operator to record the quality of the excavation works and to analyse and monitor geological features at the rock walls for safety assessment,
- The as-built tunnelling is reported and archived annually, the lay-outs are updated according to the experience in site specific rock engineering.
- The non-nuclear part of the repository in 2014 in safeguards-relevant scale, the “As-Built Design Information”:
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 11
SSAC Findings on Geological Containment
The scientific research programme generates the information needed for safety assessment and can be used as Open Source information for safeguards conclusions about the integrity of the geological containment.
Safeguards are not expected carry out their own drilling, photogrammetry or geophysics to locate anomalous zones in the bedrock.
Joint use of equipment is been discussed during the site investigations, but the IAEA independency requirement; i.e., the need to authenticate the data and control the maintenance of the equipment has been one of the obstacles.
Geological investigations in the Niche 3 (Posiva WR 2014–35, by N. Koittola):
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 12
Safeguards Measures to be Agreed Legally
Continuous/timely/unannounced institutional presence at the site is
required to verify the as built design information (DIV) and to
conclude the absence of undeclared activities (CA).
Safeguards measures to be focused on the buffer storages and
transport route of spent fuel and segregated from those to be
applied for non-safeguardable part in the repository: disposal of
radioactive materials or infrastructure e.g. office rooms (see Stein
et al., ESARDA Bulletin 12, 1987).
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY
C/S Instruments to be Developed and Tested
on the Canister Transfer and Installation Vehicle
The underground transfers of nuclear fuel should be followed on-line for safety,
security and safeguards purposes to the final position and confirm the identity,
integrity and location of the canister during the transfers (see Fritzell et al.
ESARDA Bulletin, 38, 2008).
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 14
Development of DIV, NDA, C/S and CoK for Final
Disposal of Spent Fuel in Finland, Summary
DIV:
Documentation of the underground rock premises during the operational phase.
Requirement for safeguards relevant accuracy and frequency to be agreed.
After emplacement and backfilling no re-verification is possible.
NDA to be developed:
Best available techniques are needed to verify the content of nuclear material accounted for and disposed of (Honkamaa et. al., at this conference).
No re-measurement can be done!
C/S concept :
The disposal process has be under continuous surveillance and monitoring.
For the encapsulation process a plan is ready (see Park et al., at this conference)
For the disposal process in the repository instrumentation still to be developed
Instruments will be updated with time.
CoK:
Records are to be maintained for an extreme long period of time.
National archiving systems will evolve with time.
Data and information have to be preserved and maintained by authorities.
Societal control of the data and disposal site.
SÄTEILYTURVAKESKUS • STRÅLSÄKERHETSCENTRALEN
RADIATION AND NUCLEAR SAFETY AUTHORITY 15
Developing Safeguards for Final Disposal of Spent
Nuclear Fuel in Finland, Final Remarks
IAEA Bulletin 1/1990 Fattah & Khlebnikov:
“It is necessary for the IAEA to develop safeguards requirements and methodology for geological disposal facilities for spent fuel and to formulate a safeguards policy before such facilities start operating”.
IAEA Symposium 2014:
Progress in 25 years: safeguards policy developed in the 1990ies, integrated
safeguards approaches in the 2000ies, continuous methodology updates etc.
The experience has shown that the requirements and methodology has to developed
and agreed in line with the construction of new facilities.
The principles agreed in the 1980ies are valid and to be implemented with up-to-date
technology as the facility construction begins in the very near future.
The extreme long storage time will remain as the main societal challenge for
archiving data and information, controlling land use plans and implementation of
long-term safeguards.