Decommissioning waste

Calcium-41 Ca-41 is produced by neutron activation of natural Ca-40. It has been found to exceed the GQ by a factor of 2 in both graphite fuel struts and desiccant from HNA (3 streams). The reported desiccant value is an upper limit probably based on trace contamination by graphite dust. In decommissioning wastes, activation of the concrete bioshield would also be expected to produce Ca-41 but these wastes streams are regarded as low level wastes in the NIREX inventory and hence GQ values do not apply. Measurements of Ca-41 can be obtained after chemical separation of Ca, which is done routinely for Ca-45 measurements. After any Ca-45 (t 14 =163 days) has decayed away, it can be measured by liquid scintillation counting. Procurement of direct standards from NPL would be required. In fresh samples, if the Ca-45 has been measured, then the Ca-41 could be estimated by comparison of activation... 

A. King, Ph.D. Thesis, Analysis of Long-Lived Radionuclides in Decommissioning Waste, Loughborough University, PhD Summary, BNFL NSTS/GEN/EAN/0237/03, February 2004. 

The remaining 273 potentially relevant radionuclides are subjected to a methodology which considers UK waste streams from commercial reactor fuel and decommissioning waste from final site clearance (SC), in addition to UK safety relevant situations for transport, repository operations and post-closure safety cases. This eliminates 161... 

E. Wamecke, in Conditioning of Radioactive Operational Decommissioning Wastes, KONTEC 97, 1997. 

Alder, J. C. 1989. Preliminary studies of packaging and disposal of decommissioning waste in Switzerland. AmcZ. Technol. 86(2) 197-206. Bostic, W. D., J. L. Shoemaker, P. E. Osborne, and B. Evans-Brown. 1989. Treatment and disposal options for a heavy metals waste containing soluble technetium-99. ACS Symp. Ser., Volume Date 1989, 422 345-67 cited in Chem. Abstr. CA 113(20) 179992b. 

Comments from EDF on required complements to the regulations can be found in the reports on Operational Waste and Decommissioning Waste for issues connected to these topics. Since the Consortium was informed by NTSC that a contract had been agreed with Argonne National Laboratory (USA) for the latter to provide advice on required complements to Kazakhstan regulation, further foreseen developments on this issue were dropped to avoid duplication. 

Waste Storage Capacity - Provision should be made In the site layout for a waste storage facility (which may not be constructed until just prior to decommissioning If It Is Intended only for decommissioning wastes) to provide temporary storage space so that accumulated waste will neither slow down decommissioning nor be stored In areas which may pose exposure hazards. 

ANS (1983) Nuclear safety criteria for the design of stationary PWR plants , ANSI/ANS 51.1. Bayliss, C. and Langley, K. (2003) Nuclear Decommissioning, Waste Management and Environmental Site Remediation. Elsevier. 

Kiichler, L., Auler, I., Gunther, H. Further development and operation of an automatic large-scale activity measurement facility for low-level decommissioning waste. Proc. CEC 3. Internat. Conf on Decommissioning of Nuclear Installations, Luxembourg 1994, p. 271-281... 

A short decommissioning period with no decommissioning waste left on the site, achieved by a completely replaceable system design. 

Ideally, samples presented for gamma spectrometry would be homogeneous. Unfortunately, in the real world samples are often far from homogeneous, much less representative. A 100 g sample of a decommissioning waste submitted... 

Decommissioning wastes contain a lot of wastes which can be utilised as resources. In order to reduce the influence on the environment, the effective re-use of these wastes is also very important. Various organisations are now performing the research work on this issue. 

In this system, the funds for dismantling are induded, but disposal costs for decommissioning wastes are not. The method for estimation of disposal cost shoxdd be established in accordance with the above establishment of regulatory system for disposal, and the disposal costs are to be reflected to the reserve fund system in future. 

TABLE 2. DECOMMISSIONING WASTES AND SITUATION OF REGULATORY ARRANGEMENTS... 

M T CROSS, MI WAREING, C. DIXON Decommissioning Waste Management (North) Group,... 

This paper will describe the nature and characteristics of GCR decommissioning wastes which are intended for disposal in a UK repository The Nirex Waste Package Specifications and the key technical issues, which have been identified when considering GCR decomrmssiomng waste against the performance requirements within the specifications, are discussed... 

This paper describes the key technical issues within the Nirex Waste Package Specifications which have been found to be of significance when considering GCR decommissioning waste against the performance requirements for safe transport and disposal. 

The vast majority of GCR decommissioning wastes should meet the requirements for disposal as defined by Nirex waste package specifications, if appropriately packaged. Of all the specifications, those relating to the wasteform are of particular interest from a GCR decommissioning view point and a number of wasteform issues have now been addressed by Nirex and are described in the following section. 

Assessments have been carried out by Nirex in support of GCR decommissioning packa ng proposals. Issues requhiiig consideration with respect to performance under storage and disposal conditions have arisen due to the chemical composition of GCR components, their radionuclide content or their potential to release energy under normal or accident conditions. This section addresses some of the issues considered for various materials and components of GCR decommissioning wastes. 

The first comprehensive series of calculations for estimating the activity inventories of decommissioning waste of the Finnish nuclear reactors were carried out in 1988-1989 at the Nuclear Engineering Laboratory (YDI) of the Technical Research Centre of Finland (VTT)... 

The compositions of the bioshield materials were analyzed at the same time [3]. A few complementary studies have been performed later [4,5]. The activity inventories are taken into account in dose rate and radiation protection calculations and in safety assessments of the final disposal of the decommissioning waste, which are either already going on or will be started in the near future. 

ANTTILA, M., WASASTJERNA, F., VIENO, T., Activity inventory of the activated decommissioning waste in the Loviisa nuclear power plant. Nuclear Waste Commission of Finnish Power Companies, Report YJT-89-02 (1989). 

Depending on radioactivity levels the disintegrated internals will be transported either in core material transport casks to CLAB for intermediate storage or transferred to shielded waste transportation containers for final disposal in SFR (Final repository for operational and decommissioning waste). 

In part 1 of the Study it was established that the final storage for reactor wastes, SFRl, and its later enlargement for decommissioning wastes might be suitable for the RPV s without internals providing the transports down to the storage area could... 

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