All of the advanced nuclear energy countries first adopted pools for storage, due to the high content of residual heat and radioactivity when the spent nuclear fuel first leaves the reactor. After the spent nuclear fuel has cooled for some time, it was moved to dry storage facilities, where residual heat was removed by cooling through natural air convection, and no cooling water circulation power was required. Since some of the spent nuclear fuel of Chinshan and Second Nuclear Power Plants have already been placed in pools to cool for a long time, Taipower referred to the practices of advanced nuclear energy countries and planned to move the spent nuclear fuel that has been sufficiently cooled to dry storage facilities for storage.

Spent nuclear fuel produced during the electricity generation operations of nuclear power plants contains uranium and plutonium, but they must be reprocessing before they can be extracted and used to make atomic bombs. It is impossible for Taipower to extract plutonium for use in making atomic bombs under the inspection and supervision of the International Atomic Energy Agency.

1. The dry storage facility for spent nuclear fuel at Japan’s Fukushima Daiichi Nuclear Power Plant had been operating since 1995 until present, and had a designed storage capacity of 20 metal casks. Currently, it has 9 sets of 408 bundles of spent nuclear fuel stored. The facility was reconstructed from existing workshops, and dry storage was carried out by natural air convection.
2. After a magnitude 9.0 earthquake struck the northeast coast of Japan on March 11th, 2011, a tsunami with a maximum height of 15 m was triggered off, causing spent nuclear fuel pools of three nuclear reactors at the Fukushima Daiichi Nuclear Power Plant to lose cooling power due to power loss, resulting in the occurrence of a serious nuclear disaster.
3. According to a report by the Nuclear Emergency Response Headquarters, Japan, on March 18th, 2011, after the dry storage facility for spent nuclear fuel of the Fukushima Daiichi Nuclear Power Plant was inspected, it was confirmed that there was no abnormality after the strong earthquake and tsunami attack. Compared to wet storage in the form of spent nuclear fuel pools, dry storage is safer.

In accordance with the “Key Points on Compensation from Nuclear Power Generation Back-end Operating Funds for Radioactive Waste Storage and Before the Completion of the Decommissioning of Nuclear Power Plants,” the targets of compensation include special municipalities, counties, townships, county-administered cities, and districts in which the radioactive waste storage facilities are located, as well as neighboring townships, county-administered cities, and districts. The site location division is as follows:

1. Governments of special municipalities and counties of site location: The government of the special municipality of site location of Chinshan, Second, and Fourth Nuclear Power Plants is the New Taipei City Government; that of the Third Nuclear Power Plant is the Pingtung County Government; and that of the Lanyu Storage Site for low-level nuclear waste is the Taitung County Government.
2. Public offices of townships (county-administered cities and districts) of site location: The public office of the township (county-administered cities and districts) of site location of Chinshan Nuclear Power Plant is Shimen District Office; that of the Second Nuclear Power Plant is Wanli District Office; that of the Third Nuclear Power Plant is Hengchun Township Office; that of the Fourth Nuclear Power Plant is Gongliao District Office; and that of the Lanyu Storage Site for low-level nuclear waste is Lanyu Township Office.
3. Public offices of neighboring townships (county-administered cities and districts): The public office of the neighboring township (including county-administered cities and districts) of Chinshan Nuclear Power Plant is Jinshan District Office; that of the Second Nuclear Power Plant is Jinshan District Office; that of the Third Nuclear Power Plant is Manzhou Township Office, Checheng Township Office, and Mudan Township Office; that of the Fourth Nuclear Power Plant is Shuangxi District Office; and there is no neighboring township (county-administered cities and districts) public office for the Lanyu Storage Site for low-level nuclear waste.
4. The compensation amount for spent nuclear fuel dry storage facilities is shown in the following table:

According to regulations, the use of compensation funds must be included in the annual budgets and accounts of district offices. Taipower fully respects local decisions. As for the scope of application, the uses must meet the requirements of Article 6 of the “Key Points on Compensation from Nuclear Power Generation Back-end Operating Funds for Radioactive Waste Storage and Before the Completion of the Decommissioning of Nuclear Power Plants,” including the following:

(1) planning, construction, maintenance, and operations of local public infrastructure;

(2) subsidies related to residents’ cooperation with energy saving and carbon reduction measures; and

(3) other matters approved via budgetary procedures that facilitate the construction of radioactive waste storage facilities.

As long as they are included in budgetary and accounting procedures, they can be implemented after they have been reviewed and approved by the representative offices of public opinion. For example, the current electricity subsidy is directly disbursed to residents.

Pursuant to Article 56 of the Additional Protocols (the first additional protocols appended in 1977) to the Geneva Conventions signed in August 1949, it is clearly stipulated that aggressors should avoid construction works or installations with potential for danger (such as dykes and nuclear power plants, whether they are for civic or military use) during battle, or other military targets located at or near the location of such works or installations. Therefore, nuclear power plants are facilities under special protections against attack as required by international conventions.
The dry storage facilities for spent nuclear fuel of the First and Second Nuclear Power Plants are located within the sites of the nuclear power plants, respectively, and are protected by the Geneva Conventions. They are facilities under special protections against attack. Also, in terms of air defense for nuclear power plants, missile interception can be implemented within the scope of national air defense in Taiwan, which provides air safety guarantees for facilities within nuclear power plants, but this information belongs to confidential documents concerning homeland security, and Taipower cannot obtain and publish them externally.
In addition, the Sandia National Laboratories of the United States have made conservative assumptions and conducted research and analysis by subjecting concrete casks to more than 30 times of anti-tank fire attack. The results showed that it will not cause the release of radioactive materials into the environment.
In summary of the above, the dry storage facilities for spent nuclear fuel of Chinshan and Second Nuclear Power Plants are protected by the Geneva Conventions, and are facilities under special protections against attack. In addition, under conservative assumptions, subjecting concrete casks to more than 30 times of anti-tank military attack also will not cause the release of radioactive materials into the environment.

The dry storage facility safety analysis report by Taipower has taken into consideration the fact that the air inlet of the concrete casks may be partially blocked due to factors such as wind-blown debris, animal nesting, or waste matter. Therefore, air filters have been installed to reduce blockages in the air inlet, which can speed up the removal of blockages outside the concrete cask.
If ants build nests in the air passage, this will block the air passage, reduce air convection, and increase the temperature at the air outlet. The situation of blockage can be learned from monitoring the air outlet temperature of the concrete cask, or from operators or other regular inspection activities. Each air outlet of each concrete cask at the dry storage facility of Chinshan Nuclear Power Plant is equipped with a temperature monitor. The measurement signals are connected to the monitoring center, and the monitored data are regularly reviewed by specialized personnel daily. The temperature monitoring system is also installed with an alarm. In the event that the temperature of the air outlet and inlet (environmental temperature difference) exceed specified limits, the alarm will be sounded. In the even that any abnormality is found, it will be immediately handled on the spot at the storage site, so as to ensure that the vents of the storage casks are unobstructed.
In the event that Taipower personnel discover ant nests, they can remove them with tools such as water hoses, or manually, and the cleaning process will be accompanied by radiation protection personnel. The radiation intensity is first measured before the work of cleaning out the ant nests. Appropriate measures to prevent ants from nesting again will also be taken, such as spraying insecticides regularly.

1. According to statistics of the Atomic Energy Council, Taiwan, as of the end of December 2018, 24 countries around the world have set up dry storage facilities, including the United States, Canada, and Germany. There are currently 131 dry storage facilities in use, and another 9 are under construction, or waiting to begin operations. This shows that dry storage is already widely used and mature as a spent fuel storage technology in the international arena.

2. The first dry storage facility in the United States is located in Surry Power Station in Virginia. It has been 30 years since it began operations in 1986, and the United States Nuclear Regulatory Commission has approved the facility to operate until 2046, which shows that dry storage is safe and reliable.

3. The design of dry storage facilities of Chinshan and Second Nuclear Power Plants is based on the concrete cask storage system approved by the United States Nuclear Regulatory Commission, with improved safety standards, so as to accommodate the relevant environmental assessment commitments, in which the effective dose rate per person at site boundaries must not exceed 0.05 mSv per year, which is one-fifth of the 0.25 mSv per year stipulated by current regulations in Taiwan. According to the safety analysis report of the dry storage facilities for spent nuclear fuel of Chinshan and Second Nuclear Power Plants submitted by Taipower to the Atomic Energy Council, Taiwan, the design of the storage facility ensures positive safety margins for the structure, heat transfer, shielding, criticality, sealing, or radiation protection of the facility in the event of abnormality, accidents, or hypothetical natural disasters, all of which meet the relevant regulatory requirements of the facility. The sealed canister can maintain structural integrity without the risk of external release of radioactive materials, and can ensure the quality of the environment and public health.

1. The CLI-01-22 regulation issued by the United States Nuclear Regulatory Commission stipulates that the threshold probability of a credible accident in a dry storage facility is 10^-6, that is, an accident with a probability of occurrence of less than 10^-6 is not a credible accident in the facility, and the licensee does not need to perform analysis for whether the facility can withstand the accident.
2. Chinshan and Second Nuclear Power Plants are located within a restricted area, with the restricted radius being 3.7 km (2 nautical miles), and various aircraft are not allowed to enter the restricted area at any time. In addition, Songshan Airport and Taoyuan International Airport, which are closest to the dry storage sites of Chinshan and Second Nuclear Power Plants and have the most frequent take-offs and landings, must have fewer take-offs and landings than the permitted frequency stipulated in the NUREG-0800 regulation. Therefore, in accordance with the requirements of the NUREG-1567 and NUREG-0800 regulations for the evaluation of the probability of aircraft impact at the location of dry storage facilities, they have complied with requirements stipulating that the probability of an aircraft impact event leading to an external radiation dose exceeding 10 CFR Part 100 should be less than 10^-7 times per year.
3. According to the above-mentioned regulations of the United States Nuclear Regulatory Commission, the construction of dry storage facilities for spent nuclear fuel of Chinshan and Second Nuclear Power Plants does not require aircraft impact event analysis to be conducted. However, in order to allow the public to understand the safety of dry storage facilities for spent nuclear fuel, Taipower collected the following evaluation reports from the United States for illustration. For reasons concerning homeland security, the US does not provide the details of analysis to the public, and provides only the general analysis results.
4. Electric Power Research Institute (EPRI), United States: Assuming that a Boeing 767-400 passenger aircraft hits the middle and upper end of the surface of a concrete cask, analysis results showed that although the phenomenon of concrete shattering is shown at the point of impact, only dents are created in the sealed canister filled with nuclear fuel inside of the concrete cask, and no cracks are made, so the radioactive material will not be released into the environment.
5. NAC International, United States: Assuming that a Boeing 747 passenger aircraft hits a concrete cask, analysis results showed when the cask slides or is overturned, this will not cause the welding of the sealing lid of the sealed canister to fail, and no radioactive material will be released.
6. United States Nuclear Regulatory Commission: According to the analysis data of the Indian Point Energy Center, the Nuclear Regulatory Commission evaluated the hypothetical situation in which an F-16 fighter plane hits section B of a concrete cask. The evaluation results showed that no radioactive material will be released.

According to regulations and geological conditions, dry storage facilities will not become final disposal sites:

(1) According to Article 27 of the “Enforcement Rules for the Nuclear Materials and Radioactive Waste Management Act,” “the validity period of an operation license … is up to 40 years for treatment facilities or storage facilities of radioactive waste.”

(2) In the relevant dry storage environmental assessment documents of Chinshan and Second Nuclear Power Plants, Taipower has promised that the designed lifespan of the medium-term storage facility is 40 years, and that the medium-term storage facility will not be converted into a final disposal site.

(3) According to the “Regulations on the Final Disposal of High Level Radioactive Waste and Safety Management of the Facilities,” highly radioactive waste must be placed 300 m to 1,000 m underground and in an appropriate geological environment, which is completely different from the geological conditions of dry storage facilities on land surface. Also, the safety requirements for dry storage facilities and final disposal sites stipulated by the regulations are different, so dry storage facilities will not become final disposal sites.

The designed lifespan of the dry storage systems of Chinshan and Second Nuclear Power Plants is 50 years. During the operation period of the dry storage facilities, Taipower has monitored the durability and anti-corrosion capability of the 304/304L stainless steel material used in the sealed canister material (including the heat-affected zone of the welding bead) over a long time, and will install each cask with environmental test strips made of the same material as the sealed canister, so as to monitor the long-term corrosion resistance of the material and ensure the long-term safety of the sealed canister. In addition, during the operation period, the Atomic Energy Council, Taiwan, must randomly dispatch personnel to inspect the safety of dry storage facilities. Also, Taipower must regularly submit reports on operation, radiation protection, environmental radiation monitoring, and situations of abnormality or emergency to the Atomic Energy Council, and the Atomic Energy Council must also publish the relevant reports.

1. The back-end fund is managed by a trustworthy management committee: Since the fiscal year 1999, the back-end fund has been restructured into a non-profit fund under the charge of the Ministry of Economic Affairs, Taiwan. The Ministry of Economic Affairs has invited various relevant agencies (and institutions) as well as scholars and experts to form a “back-end fund management committee” to ensure the public credibility of the budgeting, management, and use of back-end funds.
2. The total back-end operating cost is estimated to be approximately NT$335.3 billion (based on currency value in 2008): The estimation for the total back-end operating cost is based on 6 nuclear power units operating for 40 years, and high- and low-level radioactive waste being disposed within Taiwan. As of the end of October 2019, the accumulated net value of the back-end fund was NT$333.505 billion. The predetermined overhead rate of nuclear power generation in previous years fell between NT$0.14 and NT$0.18, compared with NT$0.17 in 2012, which is considered to be in the middle-to-high level compared with the predetermined overhead rates of other major nuclear energy countries. Considering the scale of nuclear power generation in various countries and the scope of use of budgeted expenses, there is no situation of underestimation for the total back-end operating cost of Taipower.
3. Re-evaluation of total back-end operating cost to ensure that back-end funds are sufficient to support needs: Every five years, or in the event of major changes in technology, regulations, and scale of nuclear power generation, the reassessment of total back-end operating cost can ensure that back-end funds are sufficient to meet the needs of back-end operations (including dry storage of spent nuclear fuel).

1. According to the data published by the Soil and Water Conservation Bureau of the Council of Agriculture, Taiwan, following a nationwide on-site survey in March 2005, although there are two streams in the upper reaches of Ganhua Creek at risk of mudflows and landslides, the slope slant drops sharply to about 2° to 4° near the confluence at the mouth of the creek. If mudflows and landslides occur in the upstream, settlement and accumulation will occur in this area. The distance between the stream sections at risk of debris flow and accumulation and the scope of area for entering Chinshan Nuclear Power Plant is about 5 km, so the dry storage site will not be affected by debris flow disasters in the upstream. However, in order to maintain the safety of this facility, if improper land use that may cause potential harm in the lower reaches of Ganhua Creek is found in the upper reaches in the future, Taipower will reinforce its work of monitoring and inspection.
2. Assuming that the worst case scenario of concrete casks being buried under debris flow, that is, the air inlet and outlet of the concrete casks become completely blocked, Taipower has established the “Contingency Plan for Dry Storage Facility for Spent Nuclear Fuel of Chinshan Nuclear Power Plant.” In this plan, contingency measures are proposed for various accident scenarios, and can ensure that air inlets are completely cleared of debris within 85 hours of complete blockage, without causing the temperature of the concrete cask to rise and radiation to be released. The plan has been approved for future reference by the Atomic Energy Council, Taiwan, on August 17th, 2011 (Letter No. 1000002140).

Regarding the emergency response evacuation plan in Wanli District, the New Taipei City Government has released the “Public Protection Contingency Plan for New Taipei City Nuclear Accident-Prone Area” in the Nuclear Safety Section on the New Taipei City Disaster Prevention Info Website (www.dsc.ntpc.gov.tw/DPRI2/), last updated on April 11th, 2014. In the plan, the evacuation assembly points, protection stations, shelters, and evacuation routes of various areas are specified. Whether new evaluation paths need to be established shall be determined based on the overall consideration of local governments.

During site selection for the Second Nuclear Power Plant, the geological conditions of faults, earthquakes, and volcanoes have already been fully taken into consideration. Over the decades of operation of the power plant, Taipower has also actively monitored and investigated the activities of Tatun Volcano Group, in ways such as the following:

• From 1996 to 2001, the American Systems Corporation was commissioned to study the possibility of volcanic activity in the Tatun Volcano Group.
• In 2010, the Geological Society Located in Taipei was commissioned to study the four occasions of felt earthquakes that occurred in Jinshan District on October 20th, 2009, as well as the correlations between the earthquake mechanism, Shanchiao Fault, and the Tatun volcanoes.
• A study of the seismic safety evaluation report of the Second Nuclear Power Plant in 2011 noted the following: Assuming that the Dinghuoxiu Mountain and Nanzi Mountain of Tatun Volcano Group—which are closest to power plant—erupt, the lava will flow into the Pacific Ocean via the Masu Creek and Yuantan Creek, respectively, instead of flowing to the Second Nuclear Power Plant.

In addition, the Ministry of Science and Technology and other institutions have set up the Tatun Volcano Observation Station and included an inclinometer, which can detect the occurrence of any change in the crustal uplift. Even if the Tatun volcanoes erupt, the lava will flow into the Pacific Ocean via the Masu Creek and Yuantan Creek, respectively, instead of flowing to the Second Nuclear Power Plant. Also, the Second Nuclear Power Plant is still some distance away from the Tatun volcanoes, so any impact should be minimal. However, Taipower has remained cautious. If the air outlets of dry storage facilities are completely blocked by volcanic ash or finer volcanic dust, in accordance with the requirements of the safety analysis report on the dry storage facility for spent nuclear fuel of the Second Nuclear Power Plant, the air outlets shall be cleared of obstructing debris within the time limit (100 hours), so as to maintain the natural convection function of the facility.

Example cases in which open-air dry storage facilities are set up near densely populated areas are as follows:

1. The José Cabrera Nuclear Power Station in Spain has an open-air dry storage facility located in Almonacid de Zorita, about 70 km from the capital of Madrid, which has a population of 3,273,049 people (as of 2010) and a population density of about 5,403 people per square kilometer.
2. The Wolseong Nuclear Power Plant in South Korea has an open-air dry storage facility located in Gyeongju, North Gyeongsang Province, about 30 km from the city center of Gyeongju, which has a population of 30,000 people (as of 2012) and a population density of about 216 people per square kilometer. In addition, the Wolseong Nuclear Power Plant is approximately 25 km from Ulsan Metropolitan City, which has a population of 1,135,494 people (as of 2011) and a population density of approximately 1,030 people per square kilometer.

The design of the storage facility has taken the needs of daily maintenance and emergency response into consideration. Therefore, a buffer operation area has been reserved on the mountain side of the facility, with an area of ​​about 40 m × 15 m. This buffer operation area can be used for daily maintenance, transportation and storage operations, and accident contingency, so there is sufficient space for contingency use. In addition, analysis and evaluation of various natural disasters and hypothetical accidents have been conducted for the facility, including the following: earthquakes, typhoons, floods, lightning strikes, fires, explosions, as well as concrete casks overturning, falling, suffering impact, and air inlet blockage. An “accident contingency plan” was also drafted, submitted for review to the Atomic Energy Council, Taiwan, and approved by the council in October 2012 for use as future reference.

The adjacent slopes at the site of this project have been further strengthened and reinforced, through structures such as grid beam ground anchors, micropiles, and retaining piles, covering an elevation of about 55 m. In addition, monitoring instruments are set up in multiple spots, so as to observe the stability of the slope over the long term, so that a situation in which debris flow from adjacent slopes buries the concrete casks at the facility is unlikely to occur. It is conservatively assumed that in the event of a debris flow burying concrete casks, according to the established response procedures of Taipower, the debris can be completely removed within 85 hours. The relevant response procedures are as follows: depending on the actual situation of burying, the debris blockage in the air inlet or outlet of the concrete casks can be removed using tools such as large or small excavators, cleaning vehicles, and water pipes, or manually.

Over the last 40 years, spent nuclear fuel has been successfully transported more than 3,000 times in the United States, and the mileage of road, rail, and barge transport has reached 1.7 million miles. Also, there are tens of thousands of records of successful transportation outside the United States, so it can be said that experience and technology in transporting spent nuclear fuel are mature and secure.

The transportation of spent nuclear fuel from dry storage facilities to final disposal sites should comply with laws and regulations such as the “Nuclear Materials and Radioactive Waste Management Act,” “Rules for Safe Transportation of Radioactive Materials,” and “Regulations for the Nuclear Fuels Operational Safety Management.” Information analysis and transportation route planning should be conducted, and the transportation plan should be implemented after approval by the competent authority. The preliminary planning process is as follows:

1. Loading container and transportation equipment:

In order to ensure the safe and smooth of spent nuclear fuel by land and sea transportation, it is necessary to choose suitable loading containers and transport equipment, and special equipment tailored for special needs should be used, such as transport casks, transport vehicles, transport ships, cranes, and lifting equipment. The relevant vehicles must have obtained operating licenses approved by the relevant competent authorities.

2. Land transport routes and shipping:

The relevant routes must be first evaluated, and peak hours during the daytime with busy crowds and traffic should be avoided, so as to facilitate control over the situation and increase the safety of transportation. The members of the transportation team should comprise nuclear fuel professionals. The vehicles of the transportation team should be driven by professional drivers with good driving skills and prior training in radiation protection. The team of vehicles should be directed by an experienced captain who can cope with various situations of emergency. The relevant vehicles and transport ships for sea travel must be manufactured in dimensions suited for transporting spent nuclear fuel.

3. Road bearing capacity:

In order to ensure the safety of transportation operations, analysis and investigation of the transportation routes must be carried out in advance, including the following: (1) collecting relevant data and on-site investigation: topographic surveys, and survey of culverts and bridges; and (2) on-site detection and testing: detection operations such as ground penetrating radar detection and seismic refraction detection.

Comprehensive safety assessment: including road alignment, pavement bearing capacity, analysis of relevant structures such as culverts, roadside ditches, and retaining walls, slope stability analysis, and bridge inspection.

Based on the results of the transportation route investigation and evaluation, the appropriate heavy vehicle types and transportation routes suited for the conditions of the location should be planned, with overall consideration for the construction period and feasibility of road improvement construction works in relation to the characteristics of the heavy vehicles, before developing a preliminary method for improvement construction works.

4. Pier/port investigation and evaluation:

In future, before spent nuclear fuel is transported out of the plant, it is necessary to first conduct investigation and evaluation for the construction of a new specialized pier or the expansion of existing ports and piers, and construction works must be completed.

5. Connection between dry storage and final disposal site:

In future, when the spent nuclear fuel is to be transported from a dry storage facility to a final disposal site for spent nuclear fuel, the sealed canister containing the spent nuclear fuel may be removed from the concrete cask and placed in a metal transport cask (note: as opposed to removing the TSC, VCC, and AOS as a whole), before being transported to the final disposal site for disposal. After the spent nuclear fuel arrives at the final disposal site, it will first be sent to the reception and processing site for safety inspection and serial number registration, before being sent to the encapsulation plant. The spent nuclear fuel will then be transferred from the sealed canister into the disposal tank and sealed. Finally, the disposal tanks are transported from the land surface to an underground disposal tunnel via a shaft.

The material of the sealed canister shell of the dry storage facility is 304L stainless steel of 15.9 mm in thickness, with excellent heat resistance, durability, and corrosion resistance. Based on test results of the American Society for Metals, it is conservatively estimated that the cumulative depth of local pitting corrosion over 50 years will be about 0.094 mm, which does not affect the structural integrity of the sealed canister.

Taipower adopts temperature control to reduce residual stress during its process of welding sealed canister for dry storage. After welding, radiographic inspection is performed to ensure welding quality and prevent stress corrosion. In addition, as the temperature of sealed canisters in dry storage is higher than the surrounding temperature, coupled with natural air convection, it is not easy for salt content to deliquesce, which can prevent the corrosion effect of chloride ions.

Taipower has a complete monitoring plan for dry storage facilities. In addition to automated monitoring equipment, it also has regular inspection conducted by specialized personnel. For further monitoring, a test piece of the same material used in the sealed canister welding is placed at the air inlet of the concrete cask, through which the integrity of the sealed canister can be ensured via regular inspection.

The crane on the fifth level of the reactor building of Chinshan Nuclear Power Plant has been upgraded to prevent malfunction due to single component failure, in compliance with the relevant regulations NUREG-0554 and NUREG-0612 of the United States Nuclear Regulatory Commission. After the crane is upgraded, in the event of an earthquake, the crane can safely suspend the hanging load in the building without resulting in a fall, and the crane will not lose its ability to suspend the load even if a single component fails.

In the event of an earthquake during the hoisting process, the vibration primarily comes from the workshop structure, which in turn affects the crane. Since the cask and crane are connected by soft steel cables, during an earthquake, the horizontal displacement of the upper part of the crane is small, and the cask itself is under inertia, so the horizontal force will not be conveyed to the cask via the steel cable, and the cask will remain in place. Therefore, an earthquake will not cause a pendulum effect in the cask. Even if a single component fails, the crane will not lose its ability to suspend the cask.

Before the crane is manufactured in the factory, it must pass various material inspections, as well as component and overall functional tests, and all records must be kept. After the crane equipment is delivered to Cinshan Nuclear Power Plant for assembly, various functional tests will also have been performed, including the no load test, full load test, and rated load test. The test content includes all electrical instrument control, mechanical, and structural components of the crane, and records of test results are also kept.

Finally, in accordance with the relevant provisions of the “Regulations for Safety Inspection of Hazardous Machines and Equipment,” an application for inspection was made to the North Inspection Office, Ministry of Labor, Taiwan. The inspection and testing were also conducted in accordance with the aforementioned regulations, and the certificates of inspection have been obtained from the relevant inspection authority.

In addition, in order to keep the functions of the crane in good order, and prevent the deterioration of the machine (and components) due to factors such as environment and time, thereby affecting the safety of the equipment, Chinshan Nuclear Power Plant has implemented automatic inspection forms to be completed every 18 months, every year, every month, and every day (before operation), in accordance with the provisions of the “Labor Safety and Health Organization Management, and Automatic Inspection Methods,” which entails item-by-item inspections conducted according to the inspection period to confirm the safety of the crane.

Under the multiple safety measures taken for crane in the reactor building of Chinshan Nuclear Power Plant, including comprehensive safety design considerations, strict compliance with government laws and regulations, acceptance of government supervision, and implementation of maintenance and automatic protection inspections, the crane is certain to continue good performance with zero error, zero failures, and zero accidents.

After the spent nuclear fuel is packed in a sealed canister, it should be covered with shielding lid of about 18 cm in thickness before being lifted out from the cooling pool (spent nuclear fuel pool). The drainage operation for the sealed canister is performed via a pressurization method supplemented by a water pump. After drainage, a vacuum drying system is installed on the sealed canister. The drying operation is completed when the pressure in the canister is less than 3 torr (mmHg). The function of the vacuum drying system used in the dry storage facility for spent nuclear fuel of Chinshan Nuclear Power Plant has been verified in the overall functional test and approved by the competent authority.

The sealed canister in the dry storage facility for spent nuclear fuel of Chinshan Nuclear Power Plant has multiple protective shieldings. After being evacuated and filled with inert gas, it is sealed and stored by double welding (hydrogen concentration monitoring and argon flushing are conducted during the entire process of welding). The canister is then placed in the concrete cask and cooled by natural convection, so the spent nuclear fuel will not overheat nor be in contact with water during storage, and there will be no possibility of a hydrogen explosion. Therefore, a hydrogen explosion in the sealed canister in the dry storage facility for spent nuclear fuel of Chinshan Nuclear Power Plant due to reaction with zirconium and water under high temperature is not possible.

Overseas dry storage facilities are used to store spent nuclear fuel that have cracks of less than 1 mm in the sheath, while Taipower stores spent nuclear fuel that is without damage. The details are as follows:

Taipower’s dry storage facility for spent nuclear fuel of Chinshan Nuclear Power Plant is required to submit a “safety analysis report” and other related documents to the competent authority, that is, the Atomic Energy Council, Taiwan, in accordance with the “Nuclear Materials and Radioactive Waste Management Act,” in order to apply for a “construction license.” In particular, the “Fuel Integrity Evaluation and Inspection Plan" and “Spent Nuclear Fuel Sipping Test Sampling Plan” were formulated for storing spent nuclear fuel, which were approved in September 2009 after strict professional review by the Atomic Energy Council. On this basis, Taipower also handles the integrity evaluation and inspection of spent nuclear fuel waiting to be stored in dry storage facilities.

According to ISG-1 Revision 2 of the United States Nuclear Regulatory Commission, highly damaged spent nuclear fuel with cracks greater than 1 mm in the fuel sheath is not suited for direct storage in dry storage facilities. If the operation records show that the coolant in the reactor is free of heavy metal isotopes, it can be determined that the fuel has no major damage, and can proceed directly to dry storage. For the crack in the sheath of spent nuclear fuel with major damage to be greater than 1 mm, this can be determined based on the operation records, and no other inspection method is required.

Taipower selects spent nuclear fuel that is completely without damage for dry storage based on operation records. According to ISG-1 Revision 2 of the United States Nuclear Regulatory Commission, there is no need to conduct inspection with regard to the “deterioration in fuel sheath material and situation in which the fuel sheath is about to be damaged,” but in order to strengthen confidence in the project, Taipower conducted additional sampled sipping testing, with reference to the inspection plan for verification of non-damage in nuclear-grade commodities, provided by EPRI-7218 of the Electric Power Research Institute, United States.

In addition, Taipower learned the spent nuclear fuel integrity verification method of the Vermont Yankee Nuclear Power Plant in the United States via inquiry to the United States Institute of Nuclear Power Operations (INPO), which is as follows: Before loading the spent nuclear fuel into the dry storage system, the reactor operation records are reviewed to verify the integrity of the spent nuclear fuel. A sipping test is performed only for the spent nuclear fuel whose integrity cannot be verified by operation records. In contrast, Taipower has adopted a more conservative inspection method for testing nuclear fuel integrity than that of the United States, which is as follows: Select the spent nuclear fuel that is completely without damage based on operation records, and carry out sampled sipping test.

In order to further reinforce dry storage safety, and respond to high concerns from the public regarding the safety of nuclear waste, Taipower has performed sipping tests on the 112 bundles of spent nuclear fuel in two earlier groups that have undergone thermal testing and are waiting to be stored, so as to prove the validity of integrity testing on current batches of spent nuclear fuel, thereby increasing public confidence in nuclear safety.

Taipower has completed simulation testing of spent nuclear fuel retrieval operations in January 2013, and confirmed the feasibility of the retrieval operation and the ability to perform the operation. It has also drafted the results of the simulation test into the “Test Result Report for Experimental Simulation of Retrieval” and submitted it to the Atomic Energy Council, Taiwan, which approved the content of the report on September 14th, 2013, after review.