ML20236N032

From kanterella
Jump to navigation Jump to search
Affidavit of D Bridenbaugh Re Ground Acceleration at Site Near Hosgri Fault.Related Correspondence
ML20236N032
Person / Time
Site: Diablo Canyon  Pacific Gas & Electric icon.png
Issue date: 09/08/1976
From: Bridenbaugh D
AFFILIATION NOT ASSIGNED
To:
Shared Package
ML20236J368 List: ... further results
References
FOIA-87-214 OL, NUDOCS 8708110345
Download: ML20236N032 (7)
v • d • e


Text

'

? -

4

[% <

s q Q+

RELATED C01ULESPONDENCE '. g{[6 Y UNITED STATES OF AMERICA .

0I 1 NUCLEAR REGULATORY COMMISSION Y' #

BEFORE THE ATOMIC SAFETY AND LICENSING BOARD y ,

b In the Matter of ) ]

Docket Nos. 5 O.

PACIFIC GAS AND ELECTRIC. COMPANY 50-323 0.L.

)

(Diablo Canyon Nuclear Power Plant, ) '

Units Nos. 1 and 2) ) ]

l l

AFFIDAVIT OF DALE BRIDENBAUGH

(

Dale Bridenbaugh deposes and says under oath as follows:

1 i

I

1. I am a ; graduate engineer thoroughly familiar with operating problems of nuclear generating plants including operating difficulties that could lead to nuclear reactor accidents. I received my B.S. in Mechanical Engineering from the South Dakota School of Mines and Technology in 1953. For the past twenty-two years, until February,1976, I worked as an engineer with General Electric on all aspects of power generation equipment design, manufacture and operations. During
  • the last ten of those twenty-two years, I worked in management positions in the area of operations of nuclear power plants and i solutions to operational problems of those plants. My most recent position at General Electric was Manager - Performance Evaluation and Improvement. My responsibilities in that position includes evaluation of the operations of all General Electric -

designed nuclear power plants in the world. A complete list of

)

r, ,- b p -

G708110345 870729 y

J PDR FOIA CONNOR87-214 .PDR . _ _ _ _ - _ _ _ - - -

my training, experience and qualifications as a nuclear power plant engineer accompanies this affidavit as Attachment 1.

l

2. Based upon my experience as a nuclear plant operations engineer and the intimate familiarity with nuclear power plant f

l operating problems and component capabilities that experience i

l has given me, it is my opinion that a ground acceleration of l .759 at the Diablo Canyon plant site that the nearby Hosgri l fault can produce could credibly cause serious reactor accidents at'the Diablo Canyon power plant. Such an accident would release significant quantities of radionuclides into the atmosphere, resulting in significant adverse impacts on the environment.

3. Seismic events provide a difficult aspect of nuclear power plant design verification. The current Diablo Canyon seismic evaluation is a prime example of the problem imposed by attempting to design to withstand forces that are impossible ,

to fully model and predict, and,which cannot be tested in a full scale, integrated system mode.

4. Diablo Canyon was originally given a design basis of 0.4g ground acceleration. The current seismology indicates that a ground acceleration of at least 0.75g at the plant site is credible. This changed level of knowledge regarding seismicity at the Diablo Canyon site places in serious doubt the capabilities of the structures and components of the generating plant, including ,

the control systems, to withstand'a major credible seismic event

. *'s

.' without breakage or malfunction resulting in a serious reactor accident causing substantial harm to the environment and' human f health. .

5. Current desigr. standards call for multi-frequency, multi-axis, testing or suitable seismic analysis of major components, particularly those in the safety systems. The purpose-of such testing'is to consider transient loads due to the seismic events and to find the simultaneous effect of the loads from different frequencies and different directions of excitation. Experience has shown that the results of a seismic test of a major reactor 4

component are generally quite different from analytical results and often difficult to reconcile. Plants may be designed to less severe decign basis carthquake criteria, and~the modeling of the structures may be less sophist'icated than new information would require. The result is lower calculated excitation at some locations where safety-related equipment is mounted.

l l

6. The risk that a plant may experience earthquake loads much greater than the original design criteria may be due to any of several causes: (1) inadequate modeling, (2) the effect of combined loads compared to single frequency tests, and (3) design l

criteria changes.after the design basis is set. The discovery of the previou' sly unknown Hosgri fault near Diablo Canyon gives rise to the probability that the design is inadequate. Such inadequacies could result in serious accidents if major. earth-quakes were to occur. The following is a list of typical accident 4

i u_ . _ _ .

~'c'enarios s that could result from an earthquake at Diablo Canyon.

Many other credible accident scenarios could be developed.

.I. Loss Of Coolant Accidents (LOCA)

' Loss of coolant accidents are events that must be considered in the standard design

  • basis. However, inadequate '

l se'ismic design may have a serious effect on plant performance during a LOCA for several reasons:

(a) First, gross movement of the structures and/or components may result in multiple / simultaneous ruptures which exceed the brsak size considered as the paximum )

l credible in the design basis.

l (b) Gross movement of the pressure vessel or of the I steam generators may result in ruptures that are not I

l considered credible under normal circumstances; i.e., a rupture of the vessel.

1 (c) Major seismic events will almost surely be accompanied by loss of off-site power, and may result in loss of on-site emergency power if the seismic basis i is inadequate. This will result in the "one-in-a-billion' consequences specified in the Reactor Safety Study.

II. Loss of Control Function All reactor safety systems are designed to withstand events as specified in IEEE-279, "the single failure criteria." Loss of control of critical systems can result in serious power transients and/or inability of safety systems to provide critical core cooling as designed.

Such failures could result in serious core damage and/or meltdown.

l

I I

III. Gross Structure / Component Failure i

Many accident sequences not evaluated in the normal review process could result from seismic events exceeding the. general' design basis. All such accident sequences '

1 would. result in major core melting and release of substantial quantities of radioactive materials. A few to consider are:

(a) Containment system failure, resulting in j uncontrolled release of materials for any LOCA.

l (b) Failure of reactor vessel internals.

Such i

failures would include movement of fuel, interfering with control rod insertion, failure of ECCS components and/or water supply, f ailure of core barrel support i 1

structure resulting in a large reactivity addition transient, etc. .

(c) Gross failure of steam generator internals resulting in a LOCA coupled'with loss of containment function.

(d) Gross structural failure of control areas. Gross {

l damage to the plant buildings could make personnel access to both the normal and to the remote shutdown control areas impossible or highly hazardous. Such loss of control could lead to a complete core. meltdown.

IV. Spent Fuel and Waste Storage Accidents Inadequate seismic design could lead to serious l 1

releases of radioactive material from the radioactive material 1 storage areas. This problem will be particularly acute since no spent fuel reprocessing facilities are likely to

[

1

l .

j

~

be in operation for the next 6-8 years. This unavailability of reprocessing facilities will increase .the on-site inventory of stored fuel and its attendant risk. Credible j seismic event-induced accidents of fuel storage areas 4 l

' include: .

(a) Failure of spent fuel storage racks collapsing, l j resulting in an uncontrolled criticality.

(b) Structural damage to the storage pool. Such *

)

1 structural damage could result in leakage of the j water and radioactive material to the environs. A gross failure could result in complete loss o water and fuel melting. I (c) l' Seismic events occurring during fuel handling. i i

These earthquakes could result in dropping of the  ;

shipping cask, failure of bridges and highways during i

fuel transportation, etc. This type of accident  !

could also cau'se the release of radioactive waste. i,

7. Most of the plant, including structures, components, systems, and procedures, was designed, manufactured, and constructed to a now-inadequate seismic basis. It is therefore imperative that i all the above events, in addition to the normally considered t accidents, be given a thorough evaluation before nuclear operation t I

is permitted.

' Changes must be completed before operation to insure the protection of the environment and the health and I l

i 1

l

safety of the public.

JaALLat Dale Bridenbaugh'

[ '

i Subscribed and sworn to before me this 7 d'ay of September, 1976.

wounini.. nun .n....neus.n..nrn.in..n.nu..

j t

E MAURE:N STURGEON  ?! .

/:-7p a 1,*. n < t f'ef s. t y w 5 Nouun , vs s - ..a F

""N'#^' N

  • 5

/ Notary Publi E g SANI A CL A!<A C.;UWl Y p

( 5 Mr Comndssion le><en February 9,1980 M Estiusstsasso H u n s : n s tun u s i e sis s s e n s sis u s u s s s 0' My Commission Expires (SEAL)

G

- l

\

i l

r e l

l 1 l

dhe

-- - - - - - - - - - - - - _ - - - - _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Retrieved from "https://kanterella.com/w/index.php?title=ML20236N032&oldid=3176049"