ML19294B630
| ML19294B630 | |
| Person / Time | |
|---|---|
| Site: | 07002623 |
| Issue date: | 02/11/1980 |
| From: | Hager S CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | |
| Shared Package | |
| ML19294B626 | List: |
| References | |
| NUDOCS 8003050172 | |
| Download: ML19294B630 (7) | |
Text
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s BEFORE THE ATOMIC SAFETY AND LICENSING BOARD s.
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DUKE POWER COMPANY
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Docket No.
70-2623 (Amendment to Materials License
)
SNM-1773 for Oconee Nuclear
)
Station Spent Fuel Transportation
)
and Storage at McGuire Nuclear
)
Station)
)
AFFIDAVIT OF S.
B.
HAGER S.
B. Hager, Chief Engineer, Civil and Environmental Division, Design Engineering Department, Duke Power Company, having been duly sworn, hereby states as follows:
By Order of October 31, 1979, the Atomic Safety and Licensing Board
(" Board") requested that all parties provide numerical analyses of the consequences of a cask drop onto Oconee spent fuel stored in the McGuire fuel storage pool with respect to (1) the effects of resulting radioactive releases on the general public and plant operating personnel, and (2) the potential for achieving criticality in the pool.
Responding to the Board's request, I have directed that analyses of the situation be performed and based on conservative assump-tions conclude that (1) the maximum number of fuel assemblies damaged by such an incident would be 226, (2) radiological emissions resulting from such damage would not exceed the site 8003050 \\
2.
boundary criteria as specified in 10 CFR Part 100 for the general public or relevant exposure criteria for operating personnel as specified in Criterion 19 of 10 CFR Part 50, and (3) criticality would not be achieved.E!
Specific elements of the analyses follow:
A.
Structural Consequences of the Hypothetical Cask Drop Into the McGuire Spent Fuel Pool The calculations in this section were performed to determine the number of fuel assemblies which could be damaged by such an event.
This result was used to determine the resulting exposure and criticality consequences.
1.
Methodology The fuel storage cask was modeled as a free falling mass that impacts on the fuel storage racks.
The kinetic energy of the falling cask was converted into strain energy in the fuel racks.
2.
Assumptions _and Definiticns The following assumptions and definitions were utilized in the calculation:
(a)
" Damage" to a fuel assembly is defined as:
(1)
Contact between the fuel cask and the fuel storege rack holding the fuel assembly; and (2)
Flexure of the storage rack containing the fuel assembly.
1/
It is still my position that administrative controls as outlined in my testimony would preclude a cask from being in a position to fall into the spent fuel pool, and, even if in such a position, there would be insuf ficient energy to cause a falling cask to go beyound the cask pit and enter the spent fuel pool (Tr. 4332-33, 4345 and Applicant's Exhibit 28).
3.
(b)
The cask used is a mcdel NAC-1 truck cask.
(c)
The hypothetical cask drop is initiated by tipping the cask from a vertical position over the edge of the spent fuel pool wall.
(d)
The structural strength of the fuel assemblies is not considered in resisting the impact of the cask.
(e)
Fuel racks contacted by the falling cask fail by crushing of their ends and buckling of their unsupported lengths.
(f)
Buckled racks deflect outward and contact adjacent racks, loading them in flexure.
3.
Results A parametric study was performed using various impact positions.
The number of fuel assemblies damaged are:
Case Assemblies Damaged (a)
Cask impacts racks in horizontal position 211 (b)
Cask impacts racks in vertical position and falls to horizontal position.
226 (c)
Cask impacts in horizontal position and adjacent racks do not deflect.
126 It was concluded that the maximum number of* fuel assemblies damaged by dropping an NAC-1 cask into the McGuire fuel pool is 226.
B.
Radiological Consequences of the Hypothetical Cask Drop Into the McGuire Spent Fuel Pool 1.
Methodology The methods for determinir site boundary doses and
4.
operating personnel doses are described in Section C.3 of Regu-latory Guide 1.25 and Chapter 15A of the McGuire FSAR, respectively.
t 2.
Assumptions I
(a)
The number of fuel assemblies damaged and thus releasing radioactive material is 226 (see Section A above).
(b)
One batch of damaged Oconee assemblies is 270 days old, and all other batches are decayed according to annual refueling (i.e.,
360 days, 450 days, and 635 days).
(c)
All other assumptions used in determining the level of radioactivity releases are described in Section C.1 of Regulatory Guide 1.25.
To account for batch discharge from the core instead of the maximum fuel assembly discussed in Regulatory Guide 1.25, a radial peaking factor of 1.0 is used.
Atmospheric diffusion factors are obtained from Table 2.3.4-2 of the McGuire FSAR.
3.
Results The table below shows that the dose limits of 10 CFR Part 100, and General Design Criterion 19 of 10 CFR 50 are not exceeded.
(a)
Site boundary-2 hour dose --
calculated dose limit (10 CFR Part 100) thyroid 0
rem 300 rem whole body 9.9 rem 25 rem (b)
Control Room 1 day dose --
calculated dose limit (10 CFR Part 50) thyroid 0
rem 30 rem whole body 0.4 rem 5 rem
5.
C.
Criticality Analysis of the Hypothetical CDsk Drop Into the McGuIre Spent Fuel Pool 1.
Methodology Criticality calcuations were performed using the KENO computer code:
a multi-group Monte Carlo criticality program widely used in the nuclear industry.
The Monte Carlo method uses neutron transport theory to trace the paths of individual neutrons collision by collision until they are lost by absorption or leakage.
The outcome of each collision is determined by probability distribution functions generated from neutron cross-section data.
The criticality value ( eff) is then estimated by the statistical analysis of a large number of neutron batches and the value stated for the 99% confidence level.
Duke benchmarked Keno against critical experiments published by Battelle Laboratories and Oak Ridge National Laboratory to insure the Code's accuracy and conservatism.
Two classes of incidents were analyzed:
(a) criticality assuming massive damage to 226 assemblies (See Section A above), and (b) criti-cality assuming 226 fuel assembly racks were pushed together (worst case-situation).
2.
Assumptions (a)
Boron content in pool is the lowest allowed (2000 ppm).,
(b)
Pool water temperature is conservatively low, 68 F
(120' F is normal).
(c)
Assembly enrichment is the maximum of any assembly now in the Oconee pool (1.2%).
6.
(d)
Each assembly is modeled as containing expected quantities of pl'2tonium.
However, neutron absorption by fission product poisons were conservatively neglected.
3.
Results (a)
Case 1 (massive damage to 226 assemblies) keff = 0.45; (b)
Case 2 (fuel racks of 226 assemblies pushed together) koff = 0.95.
b S. B. Hager r
Subscribed and sworn to before me this
// 96 day of Feb ruary, 1980 0%,s &
wt Notary Public My Commission expires: 3, ~ )..s ?.
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UNITED STATES OF AMERICA
'M g56N y d NUCLUAR REGULATORY COMMISSION 2
BEFORE THE COMMISSION 5
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In the Matter of
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DUKE POWER COMPANY
)
Docket No. 70-2623
)
(Amendment to Materials License
)
SNM-1773 for Oconee Nuclear
)
Station Spent Fuel Transportation
)
and Storage at McGuire Nuclear
)
Station)
)
CERTIFICATE OF SERVICE I hereby certify that copies of " Affidavit of S.
B. Hager,"
dated February 11, 1980, in the above-captioned matter have been served upon the following by deposit in the United States mail this 12th day of February, 1980:
Mr. Jesse L.
Riley Chairman, Atomic Safety and President Licensing Board Panel Carolina Environmental Study Group U. S. Nuclear Regulatory 854 Henley Place Commission Charlotte, N.
C.
28207 Washington, D.
C.
20555 Edward G. Ketchen, Esq.
Chairman, Atomic Safety and Counsel for NRC Regulatory Staff Licensing Appeal Board Office of the Executive Legal U. S. Nuclear Regulatory Director Commission U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Washington, D. C.
20555 Mr. Chase R. Stephens Richard P. Wilson, Esq.
Docketing and Service Section Assistant Attorney General Office of the Secretary State of South Carolina U. S. Nuclear Regulatory 2600 Bull Street Commission Columbia, S. C.
29201 Washington, D. C.
20555 David S. Fleischaker, Esq.
Natural Resources Defense Council 1735 Eye Street, N.W.
Suite 709 Washington, D.
C.
20006 J. Michael McGarry, III., Esq.
g Debevoise & Liberman
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1200 17th Street, N.W.
Washington, D.
C.
20036 William L.'P6rteY
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