ML19254E932

Affidavit of JB Read on 790913 Re Recent A6 Aircraft Crash Experience.Crash Rate Was Conservative.Aircraft Hazards Need to Be Considered as Basis for Design

ML19254E932
Person / Time
Site:	Skagit
Issue date:	09/13/1979
From:	Read J J AFFILIATION NOT ASSIGNED
To:
Shared Package
ML19254E927	List: ML19254E932
References
NUDOCS 7911050075
Download: ML19254E932 (3)

Text

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UNITED STATES OF !."Er,ICA NUCLEAR REGULATORY COMMISSION BEFCRE THE ATCMIC SAFETY AT cICENSI!S BOARD In the Matter of

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PUGET SOUND POWER & LIGHT COMPA?.Y, , ) Occket Mos. STN 50-522 ET AL. ) STN 50-523

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(Skagit Duclear Power Project, )

Units 1 and 2) )

RECENT A6 AIRCRAFT CRASH EXPERIENCE AFFIDAVIT GF JACCUES B. J. READ I, Jacquen 8. J. Read, being duly sworn do depose and state that:

In a previous affidavit, dated July 15, 1976, I stated that 10-4 per hour was an appropriately conservative crash rate to assume .applic,ble to A6 .

aircraf t to be operated en low level training routes fron. Whidbey Island Naval Air Station. This rate was developed for use in Standard Review Plan

.,Section 3.5.1.6 and was calculated from an analysis of 2136 United States Navy (USN),' Marine Corps (USMC) and Air Force world-wide :ccibents- during.

theperiod19$3to1973ofwhit.n56accidentsinvolvedtheA6aircraftor variationY thereof. After examining the low-level training routes from Whidbey Island Naval Air Station and their proximity to the proposed Skagit site, it was my opinion t:at this crash rate was an appropriately conserva-tive one to assume in the Skagit aircraft risk analysis.

To determine whether th,, crash rate is still appropriate in light of more recent experience, I requested that the Department of the Navy Naval Safety Center compile and release A6 crash rates for more recent years, and have

]tiined from them the data set forth below.

1268 293 300R ORGINAL hh 7911050

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_2-CALE'iDAR A6 CPASHES A6 CRASHES ' DOSS INFLIGHT UNCERTAINTY YEAR PACIFIC-U.S. WORLD-WIDE CRASH PATE ESTIPATE

-(Yl'0 ) 4 (fiiN) 1968 3 10 1.11 hour1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> ) .35 hour4.050926e-4 days <br />0.00972 hours <br />5.787037e-5 weeks <br />1.33175e-5 months <br />'3 1969 2 10 .98 .31 1970 -

2 9 .97 .32 1971 2 10 .f9 .31 1972 1 10 .84 .27 1973 4 6 .62 .25 1974 0 2 .20 .11 1975 0 5 .46 .21 -

1976 3 5 45 .20 1977 0 4 .35 .18 1978 0 9 .69 .23 11-year total 17 80 .69 .08

- The second column contains the number- of destroyed A6 aircraf t from accidents _

occurring wthin operational range (circa 1000 miles) of Whidbey Island. The Navy indicated that it could not provide information relative to the number ~of accidents involving A6 aircraft from Whidbey Island since the Naval Safety Centerdoe[notmaintaindata'toreadilyidentifythepointoforiginofflights-

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or the use of'l' w21evel-o routes. 'The' fourth' column contains the gross in-flight

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rate, i.e., all A6 crashes not involving landing and take-offs divided oy total hours aloft. The last column contains a Poisson estimator of the standard deviation of' the rate. This uncertainty estimata indicates that the decline . ,_

in crash rate in the more recent years is statistically significant, whereas the smaller increase during 1978 is not.

The gross in-flight accident rate is predominated by accidents which occur during simulated combat conditions, for example, simulated bombing runs at the Boardman, Cregon Navy Weapons System Trair.ing Facility. These accidents have occurred during siraulated assaults upon targets and the associated aporoaches and recoveries thich involve high speed and acceleraticn activities.

Accordingly, it is conservative to use the gross in-flight accident rate to 1268 294 300RORSNAL

describe flights in low level

• raining routes such as those that exist near the proposed Skagit site which (:3,not involve simulated combat conditions.

The magnitude of this conservatism is discussed for the A6 aircraft in Section 4 of the report " Aircraft Considerations, Pre-application Site Review by the Jirectorste of Licensing, U. S. Atomic Energy Commission, in the Matter of Portland General Electric Company, Boardman Nuclear Plant, Boardman, Oregon, Project No. 485," dated October 12, 197? (a copy has been previously supplied to SCANP)

Based on the foregoing data for the A6 aircraft for the years 19c8-73, it is my opinion that a crash rate of 10- per huur is an appropriately conservative assumption to be used in a risk analysis of the aircraft hazard at the Skagit site. These data refitct that the gross in-flight crash. rate during the 11- -

year period is 6.9 x 10-5 per hour and that there is a statistically significant decrease in this crash rate in more- recent years. Accordingly, the Staff -

still concludes, based on more recent data, that aircraft hazaris at the

-proposed'SkagitsitearesufficientlylowthattheyneednotIeconsidered --

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as a basis for design.

di,o-., 0 uy4  ; .t ,

Jacques o. J. Keaa

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i Subscribed and sworn to before me -

this/3~" day of September 1979

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// l.

Notary Pub 1ic My Ccamission Evp;res: )- , /, ' ' 2 1268 295 P00R ORGINAL

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