Speaker: Mr. Satoshi Sato
(Director and Vice-President of Master Power Associates Co., Ltd.,
and former General Electric nuclear power plant engineer)
|The Photo of 82nd CNIC Public Research Meeting|
The Nuclear Regulation Authority (NRA) accepted public comments on its new safety standards for nuclear power reactors during the 30 days from 11 April to 10 May.1 To stimulate the interest of citizens in this public comment opportunity, CNIC invited Mr. Satoshi Sato, a former nuclear power plant engineer who is very well versed in the details of global nuclear power plant safety standards, to give a commentary on the new draft safety standards at a public research meeting on 26 April.2 Below is a report on the talk given by Mr. Sato.
1. A short deliberation period on a wide-ranging topic
In February this year (2013), the NRA solicited public comments on the Draft Framework for Safety Standards (design criteria, severe accident countermeasures, and earthquake/tsunami countermeasures), allowing three weeks for comments. In fact, these documents were nothing more than a rehash of the General Criteria prepared by the US Nuclear Regulatory Commission (NRC) in 1967. The period allowed for public comments for the General Criteria was two months.
This time, the NRA has set a period of 30 days for comments on the Draft Safety Standards, 27 documents consisting of over 3,000 pages, based on one part of the NRA Draft Framework for Safety Standards. Included in these are the regulations for research reactors such as the fast breeder reactor Monju.
Management capabilities at Fukushima Daiichi Nuclear Power Station have been deteriorating on a daily basis, leading to a situation where the management has even been made to look like a fool by a rat.3 Does the NRA truly have the time to deal with safety standards for Monju and reprocessing in a situation like this? The NRA should be aware of the concerns about nuclear power that are spreading among the citizens of this country.
In spite of this, the regulations relating to research reactors have been prepared at the same time as those for commercial nuclear power plants. It can only be thought that the NRA is attempting to dilute the public comments. I feel very strongly the differences in safety culture between Japan and the West.
2. The limits of safety standards and safety culture
Safety standards are one part of the regulatory infrastructure, and even if reactors pass the reviews and inspections these do not necessarily guarantee their safety.
The safety review of nuclear power plants should not consist only of the screening of documents; an onsite inspection is also absolutely necessary. The NRC, for example, carries out reviews in its Maryland headquarters, and inspections are carried out on a continual basis by the inspector based at each nuclear power plant and each regional inspector. It is not the case at all that inspections are over after just one visit to a power plant.
Also, in the case of the US regulatory system, there are firstly laws and regulations, the details of which are indicated in regulatory guidelines, in which civil criteria and notifications are referred to. Nevertheless, however meticulous the regulatory structure may be, there are always a large number of loopholes.
It is therefore extremely important to build up a safety culture where those involved make a positive and collective effort to block off the loopholes.
3. The erosion of defense in depth
The basis of the safety functions of nuclear reactors are the three functions of shutting down (the nuclear reaction), cooling (the nuclear reactor) and containing (radioactive material).
Nuclear power plants are built so that in the event of a LOCA (Loss Of Coolant Accident) a large number of safety devices, such as the ECCS (Emergency Core Cooling System) operate automatically to secure these three safety functions (defense in depth). Therefore, at first glance, it appears that nuclear power plants can be operated safely.
In Japan’s nuclear industry, however, the fact is that defense in depth and safety culture have continually been pushed into the background.
For instance, since the 1970s the industry has been plagued with the problem of the “stress corrosion cracking”4 of nuclear reactor piping. Naturally, this has also occurred in Japan, but the nuclear industry has not publicized this fact, and has replaced the cracked pipes and so on under the name of preventive maintenance.
In addition, although as a general rule defense in depth is demanded “in principle,” there are many cases where exceptions are allowed. Despite the suppression pool having an extremely important function for safety, once it is damaged, it cannot be replaced. The high pressure system of the ECCS is supplied with water from the condensate storage tank, but there is only one of these tanks. There is also only one fuel tank for the diesel engines.
4. Five angles for the safety regulations
Under previous safety evaluation guidelines, loss of external power supply, deterioration of the containment vessel, damage to the nuclear reactor building and so on were thought to be impossible from an engineering point of view and were therefore excluded from consideration. However, all the accidents that were thought to be impossible happened at Fukushima Daiichi Nuclear Power Station. Further, according to Site Evaluation Application Criteria, even if such accidents were to occur, it was thought that the amount of radioactive material released would be within a certain permissible limit and would be within the confines of the nuclear power plant site, but at Fukushima 10,000 times the assumed amount of radioactive material was released. This indicates that Site Evaluation Application Criteria and the safety evaluation guidelines are mistaken and should be reviewed.
Having workers take part in emergency operations under conditions that involve exposure to high levels of radiation is a breach of the Constitution and the Labor Standards Act. Despite this, everything is permitted since it is an emergency. In order to have people take part in emergency operations, informed consent and voluntarism are indispensible.
In the case of fire prevention, the nuclear power plant’s fire fighting team is only supposed to carry out initial fire fighting activities until the local fire department arrives, but as there are many hazards in nuclear power plants it should be the power plant’s fire fighting team, which is familiar with the site, that handles all emergencies rather than an external fire department.
In Seismic Design, in the four serious earthquakes that have occurred in Japan since 2005, tremors exceeding the standard earthquake have occurred five times. I think that the lack of an intention to change this lax earthquake resistance policy should be seen as a problem. The earthquake resistance strength is also dealt with only at the analytical level, but this is inadequate since we cannot know what is happening inside components with a complex structure, such as electronic equipment, simply by analysis; experiments should actually be carried out and earthquake-proof models accredited.
What ought to be the greatest source of trust at a nuclear power plant is the power company’s own safety culture. Up to now, however, the power companies have shown the most enthusiasm for whittling away safety standards. Thus it is necessary to build up a culture of safety.
Nuclear power plants began with Eisenhower’s “Atoms for Peace” speech. At present, however, we are rushing forward in a very dangerous direction. The next generation will face great torment if regulations are not strengthened.
The NRA began work in September 2012. The legal basis for its foundation, the Act for the Establishment of the Nuclear Regulatory Authority, stipulates that the various safety standards for nuclear power plants shall be established by July 2013. On this basis, the NRA has been working quickly since last year to formulate the safety standards. At the 11th NRA meeting on 19 July 2013, the draft safety standards, slightly amended on the basis of the public comments, were approved and it was decided that the new safety standards would be enforced from 8 July. As Mr. Sato pointed out in his talk, the formulated safety standards have many problems which have not been resolved even having passed through the public comments process.
In this section I would like to point out the problems of the safety standards by focusing on two points. One is the problem of the screening and assessment system and the other is a problem of the procedure for formulating the safety standards.
The first problem, that of the assessment system, is an extremely important one. In the case of the assessment system for restarting the nuclear power plants that are now shut down, the power companies make an application to the effect that they are carrying out safety measures based on the safety standards, which is then assessed by the Secretariat of the NRA and approved by the NRA Commission.
The new safety standards do not contain any criteria in the form of certain standards that have to be met. It is left to the power companies to consider what kind of protection measures to formulate and to take countermeasures. The NRA Secretariat then confirms whether or not the protection measures will be able to fully cope with the risks laid out in the safety measures, and this is finally approved by the NRA Commission. It is thought that a “safety culture” will be built up within the power companies through this process.
However, the vast majority of the staff of the NRA Secretariat have simply shifted across from the former Nuclear and Industrial Safety Agency (NISA) – just those people who have been pointed out as being “regulatory captives” in the past. It is these people, who have made scant effort to look back at the Fukushima Daiichi Nuclear Power Station accident, who will screen the documentation submitted by the power companies and carry out the onsite inspections, and it is these power companies who are now choking in red ink due to the current heavy reliance on thermal power generation, desperately screaming that all will be fine if only the nuclear power plants could be operated, and yet who at present have not a shred of “safety culture.”
With no clear regulatory criteria, power companies lacking in safety culture, and a staff of “regulatory captives” who have simply shifted sideways and are continuing to carry out regulation, can we have confidence safety will be guaranteed? It is extremely doubtful.
The second point concerns the procedure of the formulation of the safety standards. During the period when the safety standards were being formulated there was absolutely no explanation to citizens, and although the opinions of the power companies were sought, those of other knowledgeable people who are critical of nuclear power were not. In addition, while opportunities to submit public comments were implemented twice, the submission periods were short and the opinions sent in were hardly reflected in the formulation process at all.
Nuclear power plants are extremely complex systems that make comprehensive use of a wide range of skills and knowledge. Yet despite the fact that after the experience of March 11, 2011 three accident inquiry commissions, the National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission, the Japanese Government Investigation Committee on the Accident at the Fukushima Nuclear Power Stations, and the (private) Independent Investigation Commission on the Fukushima Nuclear Accident, all pointed out that there were great flaws in the existing regulatory procedures, the formulation of the new safety standards, which according to the NRA Commissioner Toyoshi Fuketa “would normally take five years,” were completed in a mere ten months and almost entirely by interested parties. This is a huge problem.
Given the large number of criticisms of the safety standards, even if there is a statutory limit on the formation of the standards, should the law be amended to allow careful and thorough consideration of their formulation?
As the new safety standards are enforced, the power companies submitted their applications for restarting nuclear power plants. Applications for 12 nuclear power plants have already been handed in: Hokkaido Electric Power Company’s Tomari Nuclear Power Station Unit 1-3, Kansai Electric Power Company’s Ohi Nuclear Power Station Unit 3 and 4, Takahama Nuclear Power Station Unit 3 and 4, Shikoku Electric Power Company’s Ikata Nuclear Power Station Unit 3, as well as Kyushu Electric Power Company’s Genkai Nuclear Power Station Unit 3 and 4, Sendai Nuclear Power Station Unit 1 and 2.
A staff of 80 in three teams in the NRA Secretariat will screen the applications, a process which is expected to take at least six months.
(Hajime Matsukubo, CNIC)
3: Nuke Info Tokyo 154 News Watch
4: Stress Corrosion Cracking is the cracking induced from the combined influence of stress and a corrosive environment.