Nuclear Projects

Project Title	Client	Industry	Date	Duration	Project Summary
Common Cause Failure Methods Research	HM Nuclear Installations Inspectorate	Nuclear	1992	4 months	Working on behalf of HM Nuclear Installations Inspectorate, PMSC Limited investigated the distinction between "direct" and "indirect" Common Cause Failure system defences. PMSC developed methods to allow a ranking of these defences, in terms of their effect in reducing the likelihood of CCFs. The checklist consisted of specific questions which were raised on a system in a way in which the levels of CCF defence present could be readily identified and assessed. The ranking exercise was undertaken using a series of paired comparisons to judge the comparative weight of influence of each defence. Examples of the direct defences considered were redundancy, diversity, separation and segregation, whilst the indirect defences considered were defences such as reliability analysis. The culmination of this research was to produce a framework and checklist for the purposes of CCF auditing.
AECL (JC)	AECL	Nuclear	1995/96	12 man months	PMSC Limited placed a safety consultant on attachment with Atomic Energy of Canada Limited to assist them with their safety and licensing assessment work load associated with the various facilities at Deep River and Chalk River Nuclear Laboratories in Canada. The nature of the work was to perform safety studies such as HAZOP's, FTA and other risk assessment on the AECL plant
Peer Reviews (THORP)	HM Nuclear Installations Inspectorate	Nuclear	1993	6 months	Working directly for the Health & Safety Executive Nuclear Installations Inspectorate, PMSC Limited assisted with the peer review of the various THORP safety case submissions. The reviews concentrated on the feed pond, the dissolvers and the various HAZANs performed in support of the safety case. In total, some 30 HAZANs were reviewed for a variety of fault scenarios. In each case, the fault tree analysis was independently verified using the Isograph fault tree construction and analysis TGR code. Examples of the types of scenarios reviewed were as follows: Potential criticalities Dropped objects Impacts Contamination problems Aerial discharge Technical notes were prepared on behalf of HM NII to assist their decision-making process and allow them to consider the overall view on safety.
Common Cause Failure Study (Wylfa Power Station)	HM Nuclear Installations Inspectorate	Nuclear	1992	3 months	PMSC Limited acted as the co-ordinating consultants for the Health & Safety Executive in a CCF in PSA comparisons study. PMSC's remit was firstly to help organise the competitive bidding process and produce the required technical specifications for the work; and secondly to produce a summary report for the project, comparing and contrasting the methods and results from the study. The study comprised three consultants applying various CCF predictive methods to three pre-selected systems at the Wylfa Magnox Power Station in Anglesey. The CCF methods applied were as follows: CCF cut-off method Modified partial Beta Factor method Partial Beta Factor method Multiple Greek letter method The pre-selected systems were the Tertiary Feedwater System, Electrical Overlay System and the Reactor Ancillary Cooling Water System. At the time of the study, the EOLS was only in the design concept stage. The TFWS was present but not yet commissioned, whilst the RACWS was fully operational. Hence, a cross-section of arrangements was analysed. In order to facilitate the CCF analysis, the consultants selected for this study also constructed fault trees for each of the systems in order to compare the random contributions to those from CCFs.
Heysham 2 Buffer Store Extension Cooling System	Nuclear Electric (Barnwood)	Nuclear	1993	2 months	Working directly for Nuclear Electric, PMSC Limited was appointed as the independent verification consultant for the reliability analysis of the cooling system (performed by SRC), and the reliability analysis of the electrical supplies to the essential service boards (performed by NNC). PMSC's role was to co-ordinate and interface the two studies. To facilitate this work, PMSC recreated the fault tree analysis on its in-house fault tree package (TGR Ver. 4), and performed independent calculations to check the analysis. As a result of PMSC Limited's co-ordination role, several recommendations were made to both NNC and SRC via Nuclear Electric to help interface the studies more smoothly, to achieve a consistent basis for the study. Post-Project Note It is understood that recommendations from this project resulted in projects 006 and 011 (both on Heysham) being awarded to PMSC Limited.
Reliability Analysis of the C & I for Heysham II CO₂ Plant	Nuclear Electric (Barnwood) - Now British Energy	Nuclear	1994	2 1/2 months	Working directly for Nuclear Electric, PMSC Limited performed a parts count reliability analysis on the C&I design for the Heysham 2 CO2 Plant. This work involved a review of the control and instrumentation diagrams for the following areas: Auxiliary boiler control Package boiler control LP/HP transfer pumps PSU/Vaporiser control valve The reliability predictions utilised Military Standard 217E Notice 1, and IEEE 500 as the baseline data sources. However, for some of the power pack units vendor service data was used. This work formed part of the design substantiation for the case for onload refuelling for Heysham 2.
Secondment of PMSC Personnel - HAZOP / Safety Support to AECL	Atomic Energy of Canada Limited	Nuclear	1994	12 months	Working directly for AECL, PM Safety Consultants Limited provided ongoing technical support to the Canadian Nuclear Research programme. Specifically, PMSC Limited personnel assisted on the HAZOPs and safety submissions for the MAPLEX project and various other reprocessing facilities at the Deep River site in Ontario, Canada. In addition, PMSC personnel also performed reliability and maintainability calculations as part of the reliability centred maintenance strategy being adopted and implemented by AECL. PMSC's work was carried out under the management supervision of the Regulatory Services division, and was for submission to the Atomic Energy Control Board, the Canadian regulatory body. Unfortunately, due to the nature of the work, additional details are confidential and cannot be disclosed.
EQE / PMSC Joint Bid to SNL	EQE	Nuclear	1994	2 weeks	Bid cancelled therefore project did not proceed.
Heysham II CO₂Cooling System	Nuclear Electric (Barnwood) - Now British Energy	Nuclear	1994	5 months	PM Safety Consultants Limited was appointed by Nuclear Electric as the reliability consultant for this project. The CO₂cooling system was undergoing design modification to support the case for provision of cooling to the fuelling machine for onload refuelling of the reactor. This system was required to meet specified design targets, and the reliability model developed for the project was instrumental in the decision-making process. The model was developed from the system schematics, and the failure rate data used was from PMSC's in-house sources, supplemented by site-specific data wherever possible. The fault tree analysis was constructed and analysed utilising the Isograph TGR (Ver. 4) software.
CCF Assessors Guidebook	HM Nuclear Installations Inspectorate	Nuclear	1994	3 months	Working directly for the HSE Nuclear Installations Inspectorate, PMSC Limited assisted with the preparation of a CCF Assessors Guidebook. The work required the review of ten selected CCF methods as indicated below: Beta Factor Method Partial Beta Factor Method Enhanced Partial Beta Factor Method Extended Partial Beta Factor Method Rolls Royce Beta Factor Method CCF Cut-Off Method Multiple Greek Letter Method Dependent Failure Probability DFP Method C Factor Method Binomial Failure Rate Model In each case, the guidebook presented a description of the method, and its data requirements. Furthermore, a critique of each method was presented in order to identify the pros and cons of each method.
Safety Analysis for SNL Dry Store Vaults & Storage Tubes	GEC Alstom Engineering Systems Limited	Nuclear	1994	6 months	Working directly with GEC ESL, PMSC Limited personnel undertook detailed safety analysis for the Scottish Nuclear Dry Store proposed for both Torness and Hunterston. Specifically, PMSC personnel undertook detailed event tree construction and analysis for Work Area 6, vaults and storage tubes. The event tree analysis required consideration of the following aspects: Identification of bounding fuel damage sites. Identification, description and quantification of event tree nodes. Scoping out the requirements for the radiological consequence analysis. Interpretation of the frequency and consequence results in terms of dose band information and expenditure of the dose band budget. The culmination of this work was the preparation of the detailed System Design Substantiation document for submission to HM Nuclear Installations Inspectorate. Post-Project Note The Dry Store project was cancelled by the client (Scottish Nuclear) on 28th February 1995, in favour of reprocessing at THORP.
Preparation of Safety Case Documentation for SNL Dry Store	Thompsons Nuclear Engineering Limited	Nuclear	1994	2 months	Working directly with TNE at Wolverhampton, PMSC Limited personnel prepared the detailed System Design Substantiation documents which underpinned the production of the safety case for the fuel drying machine and associated interlocks for the SNL Dry Store. Post-Project Note The Dry Store project was cancelled by the client (Scottish Nuclear) on 28th February 1995, in favour of reprocessing at THORP.
AECL (KB)	AECL	Nuclear	1995/96	12 man months	PMSC Limited placed a safety consultant on attachment with Atomic Energy of Canada Limited to assist them with their safety and licensing assessment work load associated with the various facilities at Deep River and Chalk River Nuclear Laboratories in Canada. The nature of the work was to perform safety studies such as HAZOP's, FTA and other risk assessment on the AECL plant.
AECL (Secondment AL)	AECL	Nuclear	June/July 1995	12 months (Early Termination of AL Contract 3months) replacement provided)	Nuclear Safety Work on behalf of AECL, Deep River
Review of the Schedule of Initiating Events for 14 & 15 Docks at Devonport	HM Nuclear Installations Inspectorate	Nuclear	1998	6 months	Working directly for HM NII, PMSC Limited conducted a detailed technical peer review of the schedule of initiating fault frequency submissions for both 14 and 15 Dock at the Devonport naval base. This project was part of PMSC's ongoing technical support to HM NII on safety case matters at Devonport.
Assessment of the Risk of Failure to Shutdown of the NRU Reactor	Atomic Energy of Canada Limited	Nuclear	1998/1999	12 months	The assessment formed part of the NRU Reactor Safety Evaluation project undertaken by AECL. PM Safety ConsultaNTS Limited seconded an engineer to AECL to assist in the assessment and the production of a report. The assessment was part of a justification case for the adequacy of a single fast-acting shutdown system in the NRU reactor. The justification case was a requirement of the Atomic Energy Control Board (AECB), in order to permit continued operation of the NRU reactor beyond the year 2000. Major tasks included: Completion of Initiating Failure Event Frequency Analysis Completion of Common Cause Failure Analysis Completion of Hazard Vulnerability Study Completion of First Trip System and Shutdown System Fault Tree Analysis (minor revisions) Completion of Second Trip System Fault Tree Analysis (description only) Completion of Event Tree Analysis Completion of Report Response to Review Comments Post Project Note The project was cancelled by AECL in May 1999, 8 months into the project.
Support for 14/15 Dock Safety Case Assessment	Health & Safety Executive	Nuclear	1999/2000	3 months	PMSC Limited assisted HM NII in the technical review of safety case documents for 14 and 15 docks at Devonport naval dockyards in Plymouth. This contract was part of the ongoing support being provided by PMSC Limited to the NII.
Reliability of 9 Dock Overside Services	Health & Safety Executive	Nuclear	2000	3 months	PMSC Limited assisted HM NII in the technical review of safety case documents (PCSR stage) for the Overside Services for 9 dock at Devonport naval dockyard in Plymouth. This contract was part of the ongoing support provided by PMSC to the NII. Additionally, the Overside Services contribution to the 9 dock Probabilistic Safety Assessment (PSA) was reviewed and improvements proposed.
Independent PSA of 9 Dock Overside Services	HM NII	Nuclear	2001	6 months	PM Safety Consultants Limited have complied an independent PSA model for the provision of overside cooling water services for facilities at Devenport Dockyard. Further details are classified.
Secondment of PMSC Personnel	AECL	Nuclear	22-Apr-02	12 Months	Working directly for AECL, PM Safety Consultants limited provided ongoing technical support to the Canadian Nuclear Research programme. Specifically, our secondee has been providing licensing support in 3 project areas for the Waste Remediation Division researching the acceptance criteria from similar plants. 1) Upgrade the existing processing plant 2) and 3) are to build new facilities and make historic waste safe. Furthermore, PMSC aided the revision of the ' Site Characteristics Document ' which contains details of site description and an assessment of external hazards to the site.