Fluent Essays

Write a 2  page essay describing how business decision support systems have evolved over the past several decades as computer and data capabilities have grown.  The rubric for this assignment can be viewed when clicking on the assignment link. Surname 1 Name: Instructor: Course: Date: Safety in the Nuclear Industry QUESTION 1A Ref. Control Type of control Rank A Each batch of enriched uranium must not exceed a net uranium-235 mass of 600g. PASSIVE ENGINEERED SAFETY FEATURE-It is universally accepted that nuclear energy is responsible for approximately 15\% of the global electricity (Mario, et al 1260). In this case, so many nations are in the process of introducing nuclear energy or grow their overall nuclear energy .Additionally, ever since the beginning of the 1980s, it known that the application of passive engineered safety features or rather those systems whose overall operation takes full advantage of convention and gravity natural forces, can either directly or indirectly play a very crucial role in making the economics of nuclear energy more simplified and potentially improve the dynamics of nuclear power plant designs. For instance the Conference that revolved around the Safety of 1 Surname 2 Nuclear Power that was basically convened in the year 1991 argued that the employment of passive safety measures is very effective and desirable in realizing simplification and improving performance reliability of the effective and essential safety functions and for this case, it should be used wherever necessary B The uranium-235 concentration in the dissolver must be monitored by regular sampling and must not be allowed to exceed 10 gU235/litre. ACTIVE ENGINEERED “SAFETY MECHANISM”- One major difference between active engineered safety mechanism and passive safety feature is the fact that active safety depends on a computer automated intervention or an operator whereas on the other hand, passive safety mechanisms depends basically on natural selection or rather the laws of nature in ensuring that the reactor adjusts automatically on adverse events in a very effective manner (Mario, et al 1260). Additionally, this systems mechanisms are activated automatically in response to any accident or safety concern or any related abnormal event .besides, in a nuclear reactor, such mechanism are activated with 3 Surname 3 the help of a human operator, mechanically or automatically with the help of a computer driven systems. C The total quantity of liquor in the dissolver must be monitored and automatically controlled as not to exceed a maximum of 10 litres. ACTIVE ENGINEERED “SAFETY MECHANISM”- Active engineered systems mechanisms are basically the system mechanisms that employ the active understanding of the nuclear dissolver vessel in ensuring that the nuclear reactor is working in a more effective way (Mario, et al 1260). In other words, this system mechanism takes into consideration the nuclear stability control systems, traction control systems. 4 D The dissolver vessel should be designed to be safe by diameter for all possible uranium enrichments and concentrations. Operational controls “operating instructions”- In the implementation of safety in the nuclear reactor dissolver, consideration should also be given to the type and quality of information provided by each operational indicator. In other words, it is accepted that there is a direct relationship when it comes to the safety and the indicator 7 E The dissolver vessel should be fitted with Operational controls “operating instructions”- , indicators are operational indicators should not be 5 Surname 4 fixed neutron poisons so that criticality safety will be ensured for all possible uranium enrichments and concentrations. susceptible to any kind of manipulation and the indicators should not be expressed in quantitative terms accepted as unambiguous F Batches of gadolinium should be added to each batch of uranium to ensure that the dissolver product will be safe under all possible conditions. Passive engineered-safety feature”- Some new passive engineered designs fundamentally utilize natural selection basically as a technique of eliminating core power in normal nuclear energy operations. However, the employment of passive engineered systems help in the elimination of costs that revolve around maintenance, operation, installation of active features that need several pumps with redundant and independent electric power supplies. On the contrary, taking into account the weak driving forces associated with this kind of safety features based on natural circulation, analysis methods and careful designs must be used so as to see to it that the passive engineered safety measures focus only on their intended purpose. For instance, for thermal insulation purposes, the size and the type 2 Surname 5 of the insulation used in the reactor will be basically be predominantly reflective metallic. besides, any other fibrous insulation methods employed in the nuclear energy reactor should be basically be conformance with the nuclear reactors’ RG 1.36 as far as the leachable concentration of enriched uranium oxide in nitric acid. Passive nuclear safety is universally accepted as a nuclear reactor feature that does not need any operator to shut it down in case of an emergency which in most cases results from overheating due to loss of coolant flow or loss of coolant. One reason why this safety feature is important in enriched uranium oxide in nitric acid nuclear creator is based on the fact that their basic physics law tend to slow rather than increasing because of their tendency to rely ion engineering of components. Therefore, given the nature of its operation in the dissolver vessel, then it is one of the best safety measures. G The dissolver vessel should be designed Operational controls “Operating Instructions”-in this case, the nuclear reactor organization needs to set up 6 Surname 6 with a maximum volume of 10 litres. appropriate arrangements that will see to it that the nuclear reaction minimizes the risks to health and safety. Hence the volume of the nuclear reactor should as well be conducted based on the quality assurance of the organization and the dissolver vessel quality. QUESTION 1B Table 1b (Question 1b) Ref. Control Type of control Rank A Only paint tins with a gross mass of less than 10kg may be admitted to the store. PASSIVE ENGINEERED SAFETY FEATURE- When this remotely actuated makeup safety feature is implemented effectively, it will ensure the adequacy of uranium bearing sludge. Storage and in the process, it will help in the protection of the safety and human health in case of any accident conditions. Besides, if this storage safety feature is demonstrated to be reliable, it is universally accepted that it will ensure that the decomposition coolant reactor is just below the normal weight of 1 Surname 7 the uranium bearing sludge that can be supported effectively by the nuclear reactor. B Operators must ensure that the edge to edge separation between paint tins in the store is not less than 60cm. Active engineered “safety mechanism”-this safety mechanism is very approximate because in this case, it is assumed that the maximum gradients for each recovered sludge, each wall and the reactor floor occur simultaneously. Apparently as a result of their differing strengths then then will basically heat up and decompose at different rates. Moreover, another reason is because there are doubts about the extent to which the nuclear decomposer structure will be capable of resisting the thrusts generated by the recovered sludge and the steel liner. In this case, the estimated thickness measurers at a number of cross-sections are an evidence of the strength of the recovered sludge, the comprehensive strength of the decomposition sludge and the sections dimensions. 3 C Paint tins must not be stacked on top of each other. OPERATIONAL CONTROLS “operation measures”-stacking tins on top of each other may cause adverse conditions as far as changes and modifications in properties that may result from loss of material. In other words, the operational 5 Surname 8 effectiveness when it comes to storage of recovered sludge depends on the uniqueness of its content and therefore, it should not be ambiguous in any state.in some case, protective steel are embedded in the spaces between the stacks as well as the equipment situated inside the nuclear reactor container. D A grid of 60cm squares must be marked on the floor area of the store. Each grid square may hold only a single paint tin, which must be placed at the centre of the square. Operational controls (Control measures) - this is a control measure that will ensure that the recovered sludge is arranged in a very organized manner. In this case, the nuclear reactor will be able to detect the nature of human error during operations. 6 E A wooden framework will be provided to provide a series of defined storage locations for the paint tins awaiting assay. Paint tins may only be Passive engineered “safety feature”-Employment of a wooden framework will ensure that the recovered sludge decompose through natural selection or the forces of gravity. In this case, The framework or rather the containment design will ensure that the nuclear reactor decomposition curb the uncontrolled release of sludge and radioactivity 4 Surname 9 stored in these designated locations. to the neighbouring environment hence to some extent, it acts as a safety feature to human health. F The paint tins to be used must have a volume of 10 litres. Operations control “Control measures”-because the primary purpose of the tins is to basically control the adverse effects of the recovered sludge due to pressure differences, therefore, it is obvious that since the pressure in the nuclear reactor coolant is very high, the volume or rather the capacity of the tins should as well be very high (Herrero, and Otero 1237). Therefore, the 10 litre tins should be very helpful in controlling any cases of flooding because of sludge overflows. 2 Question 2 A very good nuclear health and safety culture is universally accepted to possess the following attributes: First, whenever there is any possible adverse case, Quality, and safety are given priority over cost and schedule (David J., et al 233). In other words, any potential errors and near misses whenever they occur are basically viewed as an issue of concern that can be as well be taken to be a learning experience that can later generate benefits to the nuclear plant. In simple terms, individuals are therefore encouraged to report, identify and correct any form of imperfections so as to ensure that any individual attached to the nuclear plant to avert any future problems (Mariscal, Herrero, and Otero 1237). Moreover, every change that occur in the nuclear Commented [U1]: *What are the 3 key safety characteristics unique to the nuclear industry that need to be managed? This part was not answered. Please introduce the 3 key safety characteristics unique to the nuclear industry? And then show how they’re managed. What stated in the Draft is NOT unique to the Nuclear industry and is applicable in any process industry? Please rectify. Looked at functionally, the three basic safety functions in a nuclear reactor are: •to control reactivity, •to cool the fuel and •to contain radioactive substances. See Ref/http://www.world-nuclear.org/information- library/safety-and-security/safety-of-plants/safety-of- nuclear-power-reactors.aspx Surname 10 plant, every safety assessment and every plant meeting should be considered as an opportunity to learn, reinforce and tech the preceding principles and attributes (David. et al 255). Besides, this can only be realized if the nuclear reactor plant management prevent isolationism or individualism and in the process, help in the establishment of a learning organization. Second, the nuclear plant activities should be carried out based on the energy plant procedures. In other words, if any individual has any doubts as far as the procedure is concerned, the plant evolution is stopped by ensuring that the nuclear reactor plant is returned is to its initial stable and safe condition.in such circumstances, the procedures are changed and evaluated if need be before moving to the next stage (Mariscal, `Herrero, and Otero 1237). Besides, if problems are identified, the root cause of the devastating effect is the root cause and in the process establishing the best solutions without necessarily being diverted by who contributed or identified the devastating effect or who contributed to the challenging problem. In such instances, the primary goal is to see what is right and not basically who is right. Third, the main primary objective of supervisory management revolves around the fact that each nuclear plant task is performed in a very effective manner the first time (Alberto and Ketokivi 66). Additionally, the management or the supervisory should be able to accept full responsibility for each and every happening and the success of each work and be involved in the work in every possible manner that will ensure that the work is successfully (Herrero, and Otero 1237). Moreover, the supervisors should as well establish policies and practices that convey an overall nuclear plant’s attitude of individual trust and in the process, set up measures that can be able to foster teamwork at each and every organizations level and in the process, reinforce positive working attitude towards safety and health (Mario, et al 1260). Surname 11 Furthermore, feedback should be solicited from each and every organization personnel to assist in establishing impediments, concerns and any opportunities to improve on the level of organizational safety. In simple terms, this is achieved whenever the management encourages and reinforces a collective behavior that reinforces and leads the plant staff to identify any potential problems fully and promptly. Therefore, the nuclear plant as an organization possesses an obligation and a commitment to improve the safety and health continuously and in the process, help in managing any form of change effectively. QUESTION 3 ALARP is universally accepted as an aspect of reducing the level of risks in such a way that it is very practically low (As Low As Reasonably Practicable). Additionally, the operator in practice must be in a position to portray through supported and reasoned arguments that in the operation, there are no any other options that can be adopted reasonably tom curb the risk level to a much lower level (Knut 235). Reasonably practicable in this case is used to represent a much narrower terminology as compared to physically possible. In other words this can be assumed that the amount of risk is weighed upon the placement of the sacrifices involved in curbing the risk whether it is time, trouble, or money. If there will be any gross disproportion between the two scales the risk being found to be insignificant then the defendants is able to discharge the onus on the two calculated options (Prasad, Cole and Haase). Any safety case is supposed to show how its operator will be able to meet the regulatory provisions requirements that are very relevant to the control of any adverse effects including risks top health and safety of its personnel at the facility (Alan, et al 453). Most of the legal regulations are embedded in the terminology or rather the phrase that revolve around curbing the risk level to ALARP. In this case, it is accepted that the operator must work hard to prove via Surname 12 supported and reasoned arguments that indeed there are no any other measures or techniques that can practically be employed to make the risks to be as low as possible further (Prasad, 213). Additionally, the phrase reasonably practicable is very significant to the health and safety of any nuclear energy regime (Barnard, et al 265). In other words, it gives room to the operator to establish goals to ensure their own safety rather than depending and following blindly prescriptive requirements. Besides, such conditions also allow the nuclear plant to either accept or reject any arrangements of the operator as far as safety is concerned. Furthermore, this act of flexibility in any nuclear plant can be very beneficial but it can at times be very challenging because it basically needs individuals to practice judgment with respect to how they will be able to curb any potential risks (Barnard, et al 270). One striking aspect in this case is the fact that a decision can be reached upon evaluation of any existing good practice. However, in case the nuclear plant incurs a complex situation, it is accepted that it can be very challenging to make a decision based on good practice alone. For example, in case the nuclear plant has embraced a new technology, then it can be very challenging to make a decision following previous good practice hence leaving room for other decision-making techniques to be employed in informing the judgment. The safety case for any nuclear plant must possess a detailed description of the legal formal assessment of safety that is worked on by the operator. In such instance, the regulations of the FSA should identify all potential adverse happenings that might cause a major accident. Besides, the FSA should also identify control measures and technical measures that are important in reducing any potential risks to a level that can be classified to be ALARP. In other words, ALARP can basically be classified, as a very reasonable way that any nuclear plant can approach any adverse effects or potential problems since it acknowledges that there is no organization that Surname 13 can realize 100\% absolute safety which makes an essential part of legislative goal setting. Moreover, the adopted control measures in ALARP for any primary adverse event can be taken to collectively eliminate the risk to a level that can be deemed to be ALARP. Thus basically implies that, it is only the inclusion of sufficient level of related risk information will some nuclear plants be able to make the right decision as far as the appropriate safety and health measure is concerned. When it comes to legacy facilities, the extent of reasonable practicability revolves around whether the potential risks that are anticipated can be reduced based on previous good practice. In this case, the risk assessment is performed by taking into consideration some of the previous held legal principles and good practice that entailed very low sacrifices. In this case, the higher the original level of risks in question, the more extensive is the effort involved in showing that the employment of the good practice will help curb the risk to ALARP. On the other hand, for new facilities, a selection between multiple fields is encouraged at any stage including the design stage that revolve around making a decision as far as the design concepts are concerned. However, in such instances, it is accepted that anew installation has no potential of producing risk or a problem that is much extensive than the already existing good practice cannot handle for comparable functions. In other words, in case of anew project, it is wise for the operators to take into consideration the risks and adverse conditions that are involved over the whole project life cycle. Therefore, the reasonable risk applicability should therefore be determined based on the assumptions of this baseline hence ensuring that the risk reduction technique that is chosen is very ALARP. Question 4 Commented [U2]: Question 4 part (a): No answer was found for this part of the question [Describe the principal reactions within a reactor core ]!! please consider adding an appropriate answer to this part of the question?? DISCRIB WHAT REACTIONS (EXOTHERMIC REACTIONS) TAKE PLACE INSIDE THE REACTOR CORE? THEN, PRESENT THE SHIELDING MEASURES FOR THE PROCESS. Surname 14 Radiation protection is universally accepted as a science of protecting the environment from the adverse influence and implications of ionizing radiation. Additionally, it is a very extensive issue not only in nuclear energy plants but as well as in medical centers and industries. Some of the ways in which individuals are protected from ionizing radiation ids through. First, reducing the time because the a level of radiation an individual is exposed to basically depends on the time that the individual are directly exposed to the radiation source hence this can be curbed by reducing the exposure time (Barnard, et al 268). Second, by reducing the distance such that if an individual is very near the source of radiation then they are believed to be very vulnerable as compared to if they are very far (Herrero, and Otero 1237). Third is shielding such that if the source of radiation is very intensive such that distance and time cannot deal with it, shielding is found to be very efficient. In this case, shielding is made up of concrete, water, or lead barriers. In case of gamma radiation, it is accepted that depleted uranium can be employed as a potential shield protection but is found to be inadequate when it comes to shielding of neutron radiation. The primary source of nuclear radiation in nuclear plants is the nuclear reactor core and the nuclear reactor itself (Barnard, et al 268). Hence in such instances, the nuclear shielding employed is biological shielding. Additionally, radiation shields are employed in this case in reducing neutrons or gamma rays on the reactor vessels. In so doing, this shielding protects the reactor vessels alongside its internal parts from intensive heat caused by gamma ray absorption using thermal shields. A strange gamma and neutron radiation is sometimes employed in protecting the reactor vessel most especially when it comes to PWR nuclear power plants. Additionally, structural materials that involve reactor internals and pressure vessels are destroyed by fast neutrons (Herrero, and Otero 1237). One sure thing is the fact that fast neutrons are responsible in Surname 15 establishment of structural defects that result into embrittlement of material that are embedded in the pressure vessel. In this case, in order tom reduce the neutron flux level that occurs at the vessel level, the core loading strategy can undergo some modifications (Barnard, et al 268). To curb this issue, out-in fuel loading technique fresh fuel assemblies are employed and placed at the core periphery. In nuclear plants, one challenging aspect is to shield neutrons and gamma rays owing to the fact that the ranges of charged particles like alpha-particles and beta-particles as far as matter is concerned are basically very short. 4b) determination of photon flux Given mass= 70kg Projected area= 0.7m2 Depth=0.20m Linear energy absorption coefficient = 7 m-1 Given the fact that the SI diode thickness is 20 microns, energy is 7 Kev, diode current 1.0 and assuming the thickness of Al filter =0.20 microns surface area or rather the distance travelled is 0.20 mm, the calculated photon flux is 9.131933045233797 multiplied by 10^12 photons per second. 4c) Shielding to decrease outside radiation hazard is performed when increasing distance or decreasing the time is not possible. The material to be used in shielding depends on the kind of energy and type of radiation. Particles of Alpha are shielded easily. Thin pieces of papers are enough to stop the alpha particles; hence alpha particles present no outside radiation hazard. Particles of beta are more penetrating as compared to alpha particles. The shields for beta are made of brass, aluminum, plastic, or any other materials that possess low atomic number. Commented [U3]: Please provide the reference of this equation Commented [U4]: Explain the results determined and state what does the calculated value mean in this context. Please rectify Surname 16 Material Linear energy absorption coefficient (cm2/g) Density (g/cm3) Linear energy abs. coeff. (m-1) Water 4.942E-02 1.000E+00 4.94 Concrete 4.557E-02 2.300E+00 1.978 Lead 4.606E-02 1.135E+01 4.058 Iron 4.265E-02 7.874E+00 0.542 Glass 4.447E-02 2.230E+00 1.994 C2) the best material to help reduce the implication of gamma is lead because it has a lower density and very high absorption rate. Besides, since the linear energy absorption coefficient is bigger compared to other materials, lead is much better.. 4d) Control Principle Description Commented [U5]: Relate and refer the determined answer to the concept of ALARP by including a connection statement between the result found and ALARP concept. And consider what so called Cost Benefit Analysis and economical decision making? is lead available and economical? Surname 17 Reduce exposure time the radiation amount which an individual accumulates depends on the time they stay in the field of radiation To reduce an individual’s dose, it is advisable to restrict the time of exposure in the area.in other words, how long an individual stays in a radiation area is computed based on limit/dose rate. Reduce the exposure distance The amount of gamma radiation an individual is exposed to depends on the proximity to the gamma radiation source. The intensity of gamma radiation decreases as the distance between the gamma radiation source and an i9ndividual decreases. Lead shielding Shielding is a more effective technique when employed in areas where time and distance are not able to Lead is a very common and effective shielding material because it is inexpensive, it possesses a very high density, and it is very cheap to work with. However, the intensity and the amount of shielding employed is believed to depend on the level and the amount of photon energy Surname 18 reduce the gamma radiation exposure. Employment of a half value layer Shows how best a material is able to reduce the intensity of radiation half as low as its original intensity. The higher the thickness of a material is able to reduce the radiation exposure, the more effective it is as far as reducing the halfway radiation exposure reduction is concerned (Barnard, et al 268). Surname 19 Works Cited Barnard, S., et al. The first gamma-H2AX bio dosimetry intercomparison exercises of the w2434developing European biodosimetry network RENEB. Radiation protection dosimetry 164.3 (2015): 265-270. Birnbach, David J., et al. A framework for patient safety: A defense nuclear industry-based high-reliability model. Joint Commission Journal on Quality and Patient Safety 39 (2013): 233-240. Hernansanz, Alberto, and Mikko Ketokivi. Getting to the Core of Matter: The Outsourcing Hazard in the Nuclear Industry. Academy of Management Proceedings. Vol. 2013. No. 1. Academy of Management, 2013. Mariscal, M. A., S. García Herrero, and A. Toca Otero. Assessing safety culture in the Spanish nuclear industry through the use of working groups. Safety science 50.5 (2012): 1237- 1246. Martin, Alan, et al. An Introduction to Radiation Protection 6E. CRC Press, 2012. Martínez‐Córcoles, Mario, et al. Strengthening Safety Compliance in Nuclear Power Operations: A Role‐Based Approach. Risk Analysis 34.7 (2014): 1257-1269. Prasad, K. N. Rationale for using multiple antioxidants in protecting humans against low doses of ionizing radiation. The British journal of radiology (2014). Prasad, K. N., W. C. Cole, and G. M. Haase. Radiation protection in humans: extending the concept of as low as reasonably achievable (ALARA) from dose to biological damage. The British Journal of Radiology (2014). Surname 20 Ringen, Knut. Optimal Safety and Health Management of Construction Activities: Evidence from the US Nuclear Power Industry. 30th International Congress on Occupational Health (March 18-23, 2012). Icoh, 2012. Schneider, Mycle, and Antony Froggatt. World nuclear industry status report 2013. (2013). Evaporators Understand the process of evaporation and why evaporators are used Understand hazards of evaporator systems “To lose or cause to lose liquid by vaporization, leaving a more concentrated residue”  Reduce volumes for storage (HA evaporation) ◦ Reprocessing raffinate volumes are reduced by about 50 -100 times reducing the storage volume required  Product concentration ◦ Without evaporation, the downstream processes would become inefficient Simple and robust with no moving parts and min maintenance  Poker  Thermosyphon  Kettle Feeding Hot Vapour discharge Disentrainment Recirculation of liquor Heating Steam  Reduces boiling temperature and therefore reduces corrosion  Improving temperature driving force  Keeps the size of the evaporator down  To avoid runaway reactions (Reaction rate)  Reduce volatile ruthenium Evaporator Bump Over Click Here to view video  Movie file (mpeg) energetic event caused by a sudden conversion of superheat in a liquor to a vapour, which in turn carries liquor with it. Cause: The Application of vacuum to a liquid, where the temperature of the liquid before the vacuum is applied (or increased) is greater than the boiling point of the liquid at that applied vacuum. The liquid becomes superheated relative to its boiling point at that reduced pressure. • Loss of vacuum without loss of steam heating followed by re- instatement of vacuum • Loss of vacuum with loss of steam (but not radiogenic heat) followed by re-instatement of vacuum • Air in-bleed control valve fails shut • Temporary loss of cooling water to the condenser without tripping the vacuum raising ejectors 0 0.2 0.4 0.6 0.8 1 1.2 0 20 40 60 80 100 120 Temp C B ar a Partial loss of vacuum Continue heating Vacuum reinstated BUMP OVER !! Do not apply a vacuum to a liquid where the temperature of the liquid before the vacuum is applied (or increased) is greater than the boiling point of the liquid at that applied vacuum  Minimise loss of vacuum events  Trip the steam heating on loss of vacuum  Trip vacuum raising ejectors on loss of vacuum  Minimise hot/self heating solids build up (suspend/wash out)  Cool contents of evaporator to a temperature that is lower than that before the loss of vacuum, then reinstate the vacuum Loss of cooling capacity due to failed components This is only of concern if the evaporator contents are self heating The heat load of the evaporator contents will be limited to ensure sufficient cooling capacity is available Loss of / or low cooling water flow to the evaporator condenser This will result in loss of vacuum to the condenser and subsequent evaporator pressurisation It is normal to trip the steam heating and / or the vacuum raising ejectors on low cooling water flow to the condenser If cooling water is restored to the condenser without having tripped the steam heating, then bump / boil over may result Activity Breakthrough  Due to failure of a heating / cooling component  Pressure cascade reversal. Due to steam collapse in the heating component resulting in the pressure in the evaporator being greater than that in the heating component  Protection is by Automatic Isolation System (AIS). On detection of activity in the steam condensate (or cooling water) returns an automatic isolation valve will close preventing radioactivity migration Hydrogen Build-up from radiolysis Solvent Nitrate Reactions Reaction of nitric acid with solvent at elevated temperature reaction is self accelerating and can result in evaporator pressurisation due to high non-condensables Avoided by ensuring solvent cannot be fed to an evaporator that contains nitric acid Low density trip in feed tank, controls on upstream plants (steam distillation) and limits on evaporator temperature  Ammonium Nitrate decomposition • Thermal decomposition giving non condensables. This can also result in evaporator pressurisation • Limit Ammonium Nitrate concentrations and evaporator temperature  Evaporator pressurisation must be avoided since it can force active liquor out of the controlled area. ��MSc Process Safety and Loss Prevention� �Safety in Nuclear Operations� (Module CPE6014)��Waste Processing Learning Objectives: What is evaporation? Why evaporation? Evaporator types Thermosyphon Highly active kettle evaporator Why Reduced Pressure? Hazards – Boil Over Slide Number 10 “Bump Over” Evaporator Bump Over: Cause Bump Over: Cause Evaporator Bump Over: Prevention Preventative Measures Other Hazards Other Hazards Other Hazards: Other Hazards Slide Number 20 TUTORIAL QUESTIONS – THURSDAY 15th MAY 2014 COMPLETE SOLUTIONS TO THE TUTORIAL QUESTIONS SET ARE BELOW. 1. A beam of photons is partially attenuated in passing through a brick wall, which is thick. If the linear absorption coefficient is and the incident photon flux is calculate the energy deposition rate in Watts for each of wall. Energy deposition rate ( ) is To find the change in photon flux We can use the linear absorption equation And therefore ( ) Putting these back into the energy deposition rate equation gives ( ) ( ) ( ) ⁄ To put into appropriate units ⁄ 2. i) If a person has a mass of and presents a total area of , calculate the maximum permissible incident radiation intensity for photons if the allowed dose rate is ⁄ . Data: Average absorption length for humans Human linear absorption coefficient We know the energy deposition rate equation ( ) However, we need the equation in terms of incident radiation intensity ( ) We are given the energy deposition rate in terms of allowed dose rate ⁄ To convert to appropriate units ⁄ Knowing the mass of a person is and the total area is we can find the energy deposition rate ⁄ Putting this back into the rearranged equation we get ( ) ( ) ⁄ ii) If the above photon flux is present on the outside of the 1.5 m thick concrete shielding of a reactor core, calculate the photon flux at the inside of the shield if the linear absorption coefficient of concrete is . We know the linear absorption equation However, what was previously the incident radiation intensity is now the latter radiation intensity so we need to rearrange the above equation in terms of incident radiation intensity Putting in the values ⁄ 3. A concrete wall thick reduces the intensity of a parallel beam of rays to an intensity . What is the total thickness of a concrete wall required to reduce the beam to 1\% of ? Data: Absorption coefficient of concrete First of all we calculate the thickness of a concrete wall required to reduce the beam from to 1\% of . We know the linear absorption equation Rearranging into terms of and exchanging for ( ⁄ ) Knowing that ( ) We now need to add this value to the original thickness of a concrete wall required to reduce the beam from to . 4. A fuelled fast reactor contains of and has a maximum output of 600 MW (thermal). Calcualte the doubling time in years Data: Breeding ratio ( ) Energy release per fission ( ) Fission cross-section ( ) Absorption cross-section ( ) We know that the doubling time equation is ( ) Using Avagadros Constant we can find ⁄ , , , and are all given in the question. To calculate ⁄ ⁄ Putting all the values back into the original equation ( ) ( )( )( ) ( )( )( ) Converting to appropriate units 5. Fissile is to be used in combination with fertile in a breeding programme in which the atom ratio of is 0.15. Determine the minimum breeding ratio for the process to ensure full consumption of the . We know the equation for the breeding ratio We also know that in this combination we have And in this ratio we have is in terms of mass and we have the atom ratio. However, because the molar masses of these two isotopes are very close we can make the assumption that the atom ratio is the same as the mass ratio and thus 6. Fissile is to be used in combination with fertile in a breeding programme which consumes all of the . If the breeding ratio is 0.92, calculate the mass ratio in which the two elements should be combined. We use the same equation as in question 5 However, we now have the breeding ratio and are required to calculate the mass ratio We know that in this combination of isotopes we have If we take the mass of to be 1 we can find the mass ratio of thorium 0.087