{Title of Document}: A Review of the Criteria Related to Seismic Design Spectrum for Selected Nuclear Facilities {Author(s)} John M. Nichols

{Corresponding (first) author}: John M {Revision Number} 37 {Submission date for review 1}: {Submission of revised document}: {Paper File Name} C:\Documents and Settings\nicholsj\My Documents\Word\Papers\Paper031W\paper031.doc {Proposed Publisher} ASCE {Number of pages} 10 {Aims} 1. To review the spectra developed by Newmark and Hall in 1978 as a result of

the additional information gained since that time. 2. To look at the Nuclear Explosions to see if the 1-2 Hz range develops pulses. 3. To use tripart charts 4. To use the Hanford Facilities as an example. 5. The consider the equation for the Bandwidth developed by Newmark and

Hall and consider whether it {Target audience}: Practicing Engineers in the field, who are not necessarily familiar

with Fast Fourier transforms or large intraplate earthquakes or the theory of pulses in earthquakes. Limited seismological knowledge.1

{Outline of Papers Data and Results} 1. 2. 3. 4.

1 Footnotes guide the reviewer to understand the intent of the authors.

A Review of the Criteria Related to Seismic Design

Spectrum for Selected Nuclear Facilities

J.M. Nichols2

ABSTRACT

Newmark and Hall established the Criteria related to the Seismic Design of Selected

Nuclear Facilities in 1978. This paper reviews the seismic design spectrum for

selected nuclear facilities with specific reference to the 0.5 to 2 Hz range of

frequencies. Data used to support this review and any suggested changes to the

Newmark and Hall standard are based on findings from recent large intraplate events

in Canada and India, synthetic data on the New Madrid seismic zone, the Russian data

on seismic traces for nuclear explosions and from recent studies on pulse loadings.

The results show the bandwidth limitation used by Newmark, whilst valid for a range

of earthquakes is too restrictive for earthquakes that contain pulse loadings. The key

element of the analysis is in the use of the Fast Fourier Transform, the mathematics of

odd functions, and the Fourier series specific to earthquake traces containing 1 to 2

Hz pulses to review and adjust the bandwidth limitation. These findings are

considered valid for intraplate areas including the central and eastern United States

and will affect the design spectrum for some buildings.

2 Curtin

INTRODUCTION

The relevant section for the

LITERATURE REVIEW

This literature review outlines the development of the seismic standards in the last

half century and presents a summary of some of the critical earthquake data that has

been used to establish these standards. NRC (2002) has control of the Nuclear Power

Industry within the legal requirement of the US Government regulations (10 CFR).

The United States government3 has been developing facilities within the North

American continental region that use or process nuclear materials since WW2. These

facilities are scattered throughout the lower 48 states within interplate and intraplate

regional areas.

We are using the example of the recent development at the Hanford Nuclear Site to

illustrate the changes in these standards that have occurred in the fifty years. The

Department of Energy4 (DOE) controls the Hanford site in the Cascade mountain

region of Washington State that contains nuclear facilities including a power plant.

The site has a radioactive liquid waste storage facility that dates from 1944. A

planned waste vitrification plant (WVP) will provide the DOE with a method to treat

the liquid waste. The treated solid waste output can then be placed in to a long-term

storage unit. These WVP facilities are vulnerable to damage in a seismic event

(Newmark and Hall, 1978; DOE 1999).

3 There is debate between American and British English as to whether government is plural or singular. I have used the preferred American (Murphy, 1994). 4 The style of the paper uses a reader-centered format. Each section is broken into paragraphs with a topic sentence for each paragraph and a continuity thread from the general to the specific for each section. We try to reach a conclusion in the Literature Review as to why this paper is required. The style derives from the Manual {.} used extensively in Australian Universities.

The site-design criteria report for the Hanford WVP has provided a summary of the

seismic design methods used from 1944 to the present in the development of nuclear

facilities such as power plants (DOE 1999; 10 CFR). These methods can be placed in

the context of the 20th Century development of engineering seismology. The earliest

method has been dated from Sanos use in 1916 of the equivalent shear load for

building design5. Richter has summarized the available knowledge on engineering

seismology up till 1958 within a world-wide framework. As part of this text, Richter

has provided a table of estimated acceleration with frequency for design purposes

(Table 1). The shaded numerals represent the most common data for moderately

strong ground motions. (Richter, 1958, 25). These two historical points provide a

guide as to the rate of development of seismic design standards in the first half of the

last century. They illustrate the level of development of the standards during the early

design stages for the facilities on the Hanford site.

Table 1 Richters 1958 Estimated Design Seismic Acceleration

Amplitude of Surface Movement (mm) Acceleration a (g)0.001 0.01 0.1 1.0 10 100 1000

1 500 160 50 16 5 1.6 0.5 0.1 160 50 16 5 1.6 0.5 0.16 0.01 50 16 5 1.6 0.5 0.16 0.05

Gubbins6(.) records the introduction of the world seismic network in the late 1950s

to the early 1970s that occurred during the development of a number of the facilities

at the Hanford site. A significant increase did occur in the number of stations and the

5 Umemura details the work of Sano (1916) presenting the concepts of seismic coefficients for lateral force design in aseismic design and then states that Naito subsequently used this material in designing buildings in the Kanto of Japan. These buildings withstood the great Kanto 1923 earthquake. There exists anecdotal evidence that the use of lateral force provisions were developed by several researchers in the early 1900s. 6 Gubbins, D., (1992), Seismology and Plate Tectonics, (Cambridge: Cambridge UP), 2nd ed, 276.

quality of the equipment that has been recording the movements of the earth surface

since the time of the Cold War. The principal need for this new equipment has been to

measure the seismic traces that were generated from nuclear blasts. This data was not

as freely available as the early seismic information that had been available to Richter.

Kim and Richards (2001) have summarized the recently released secret data from the

Russian seismic data collection site at Borovoye. This data has provided digital

signals for about 68 per cent of all known nuclear explosions that provides a wealth of

data that is now available for signal processing and analysis of pulse loads. In the field

of signal processing, Cooley and Tukey in the mid 1960s developed the discrete Fast

Fourier Transform (DFFT) which has provided an alternate method to examine the

frequency spectra for a time signal (Brigham, 1974)7. Newmark and Hall (1978) have

established the earthquake spectra (termed NH1978S) used for nuclear facilities but

did not use the DFFT method relying on a rigorous mathematical analysis of seismic

data. This analysis has been explained by Chopra ().

Newmark and Hall (????) studied the impact of pulses on the design spectra and

earthquake traces. They had been using the El Centro and the Eureka earthquakes as

examples in the analysis. NH1978S earthquake spectra can be compared to the DFFT

of the 1940 El Centro earthquake(-) and the 1954 Eureka earthquake (+) and Richter

estimates of a design earthquake using a tri-part chart8 (Figure 1).

Two spectra are plotted from the Newmark and Hall results. Spectra NH1978Sa has a

peak ground acceleration of 0.16g and Spectra NH1978Sb has a peak ground

acceleration of 0.32 g. These two spectra correspond to the equivalent peak ground

acceleration from the El Centro and Eureka earthquakes used by Newmark and Hall

in their 1978 analysis. These spectra demonstrate the spectrum amplification factors 7 Brigham outlines the development in the mid sixties by Cooley and Tukey of their FFT algorithm. 8 The original tri-part chart used by Newmark in terms of frequency has been used in this paper.

developed by Newmark and Hall (1978, Table 2 and 3.) are observable in the DFFT

of the acceleration signals. The plotted results in Figure 1 have demonstrated that the

NH1978Sb spectrum bounds the DFFT of the El Centro earthquake for all frequencies

greater than 0.5 Hz. The NH1978Sa spectrum bounds the El Centro earthquake for

frequencies greater than 2 Hz. The Eureka earthquake DFFT shows a broad band of

acceleration at the 0.2 g level from 0.3 to 3 Hz as observed by Newmark and Hall

(????. Figure 2.49). The SDOF operator that was used by Newmark and Hall ()

mirrors the

Richter (1958) has considered that the constant velocity segment of the spectra (the

band width limitation constraint applies to the constant velocity segment) occurs from

1.6 to 5 Hz. Newmark and Hall (1978) have considered that the constant velocity

segment ranged from 0.3 to 2 Hz. Hall (2002) has stated that the earthquake data from

their research supported the inequality

22 331 vadv

0.001

0.01

0.1

1

10

0.1 1 10 100

Frequency (Hz)

Vel

ocity

(m/s)

1g1m

Newmark Fig 50.32 g0.16g

NMZS MCE

Richter 1958

Chopra ( , 225) has explained the derivation of the band width limitation that was

established by Newmark and Hall in 1978 as:

26vad = (2)

Equations (1) and (2) have been expressed in terms of energy units from Newtonian

physics. The peak to peak amplitude is 2a for a Fourier component of the harmonic

waves that result corresponds the limit of 1 in equation (1). The limit of 33 to 35 was

physically observed by Newmark and Hall.

Figure 2 Phase Angle for the El Centro Earthquake

00.5

1

1.5

2

0 0.5 1 1.5 2 2.5

Frequency (Hz)

Phas

e A

ngle

(PI u

nits

)

This figure uses the tri-part chart to present the acceleration, velocity and the

displacement for a given frequency, which are related by the law of differentiation.

The velocity ( v ) component for a harmonic wave has a 2 phase angle difference to

the accleration ( a ) and displacement ( d ) components. Newmark and Hall (1978, 25)

presented an estimated power band for their earthquakes that can be expressed as an

inequality using velocity as the dependent variable:

22 61 vadv

domain the resulting pattern from a harmonic pulse loading decaying with time,

which has been termed the Kim Rule of odd integers (KROI.). This rule states that the

harmonic pulse will decay generating odd multiple harmonic waves. So a 1 Hz pulse

generates a 3, 5, 7, 9, 11 pulse set. The amplitude of each harmonic pulse decreases

with increasing pulse frequency.

Johnson and Kantor () summarize the issue of seismicity in intraplate regions,

confirming the comments by Richter (1958, .) on historically seismically quiet

regions...

The Newmark and Hall spectra in Figure 1 whebn compared to the El Centro

earthquake FFT provides insight into the decisions that they made in developing the

1978 Spectra for the NRC. Hall (2001)9 outlined the basis for the selecting an

assumption of a constant velocity segment of the spectra. We conclude that this

constant velocity assumption for the spectra provides a reasonable match to the data

for earthquake motion at distance, however recent intraplate earthquake and nuclear

explosion data suggest that it was a non-conservative assumption for a range of

subsequently measured ground motions.

Newmark and Hall (.) investigated pulse loadings related to nuclear explosions.

Their work shows the resulting apparent constant velocity segment from some

earthquake events, but their work demonstrates the effect of single pulses and

multiple pulses on design spectra. Cueste and Aschheim (200?) investigated pulse

loading for determining R factors for the design of inelastic structures. These

investigators concluded that the quadratic pulse provided the closest match to a

9 Hall, W.?., (2001) in a personal conversation with the first author indicated that J.A Blume had suggested an alternative spectra, but this Blume variant to the 1978 Spectra was not used by Newmark and Hall.

series of earthquake traces, except for the 1985 Mexico City earthquake. A synthetic

earthquake trace based on the Cueste and Aschheim algorithm

LITERATURE REVIEW

DOE (1999). Review of Seismic Design Criteria used at Selected DOE Hanford Site

Nuclear Facilities and at the DOE Waste Vitrification Plant. Richmond, WA,

Office of Radiological, Nuclear, and Process Safety Regulation of the TWRS

Privatization Contractor: 58.