ML19296B540
| ML19296B540 | |
| Person / Time | |
|---|---|
| Site: | 07002623 |
| Issue date: | 01/11/1980 |
| From: | Donohew J Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19296B538 | List: |
| References | |
| NUDOCS 8002210019 | |
| Download: ML19296B540 (14) | |
Text
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Uff!IED STATES OF A" ERICA fiUCLEAR REGULATORY C0"/11SS10ft BEFORE THE ATOMIC SAFETY Af D LICEriSIflG BOARD In the Matter of
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DUKE POWER COMPAfiY (Amendment to Materials Licease Docket fio. 70-2623 Sf!M-1773 for Oconee fluclear Station Spent Fuel Transportation and Storage at McGuire fluclear Station)
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AFFIDAVIT OF DR. JACK fl. 00fiOHEW I, Dr. Jack fi. Donohew, being duly sworn, do depose and state:
1.
I am employed by the Environmental Evaluation Branch, Division Operating Reactors, U.S. fluclear Regulatory Commission.
I do dose calculations for environmental evaluations of operating nuclear power plants. My work includes analysis of spent fuel modifications and the dose impacts that could occur from damage to spent fuel assemblies caused by such things as spent fuel car ks falling into spent fuel pools resulting in damage to spent tuel assemblies.
2.
My professional qualifications were briefly described at Tr. 4434.
A more complete description of my professional qualifications are attached to this Affidavit.
3.
This Affidavit addresses questions concerning doses caused by rupture of Oconee spent fuel assemblies of at least 270 days in age while stored at the McGuire spent fuel pool.
It also addresses doses caused by rupture of McGuire spent fuel assemblies of a minimum of 40 days in age stored in the McGuire spent fuel pool. The cause of the rupture of spent fuel assemblies bIh 8002210 8
is postulated to be from the falling of a 25-ton truck cask into the spent fuel assenblies stored in the McGuire spent fuel pool. This affidavit does not address occupational dose. That subject will be addressed by another Staff individual.
Background and Analysis
===1.
Background===
I was contacted on September 11, 1979, and asked to provide testimony as a witness at the McGuire/0conee hearing with respect to questions concerning radiation dose from the postulated rupture of Oconee spent fuel assemblies of at least 270 days in age proposed to be stored in the McGuire spent fuel pool. At that time, I was not familiar with the proposed licensing action to transport and store Oconee spent fuel of at least 270 days in age in the McGuire spent fuel pool. Nor was I completely familiar with the review that had been previously conducted relative to opera-tion of the McGuire spent fuel pool as part of the operation of McGuire, Units 1 and 2.
I understand that the applit tion for licenses authorizing the operation of McGuire, Units 1 and 2 is now pending before the Commission.
I was told, however, that the topic raised by the Licensing Board's questions had not been addressed by either the NRC Staff, or the Applicant, Duke Power Company. The reason was that administrative controls would be implemented that would prevent the postulated accident of a 25-ton truck cask falling into the McGuire spent fuel pool from occurring.
The hypothetical situation I was asked to evaluate was described to me as follows: A 25-ton truck cask would fall into the McGuire spent fuel pool 6nto spent nuclear fuel
assemblies.
I was asked to evaluate the consequences of this postulated situation relative to 10 CFR Part 100 req 0irements.
My professional opinion given at the hearing on September 12,.,19 in response to questions about the postulated circumstances was necessarily general (Tr. 4432-47).
My conclusions were based on a general description of facts given to me that day.
Thus, my views were necessarily, based on my training and experience as an expert,in the subject area involved.
I did no detailed calculations to support my professional opinion due to the time constraints imposed.
In my opinion, however, none were necessary given the fact that the Oconee spent fuel involved in the postulated accident would be at least 270 days in age.
Following the hearing, however, I was asked to do a more detailed analysis to support my conclusions given at the September 12, 1979 hearing. Accordingly, the following analysis supports my conclusions given at the hearing, and responds to the Licensing Board's Order of October 31,1979 which, in pertinent part, states:
"***However, regarding the question about consequences of a cask drop into the fuel storage pool, the Board notes that replies to its questions about criticality and radioactive emissions to the public were in the nature of summary statements (Tr. 4439-47). The Board therefore requests that the parties supplement these answers with numerical analysis, and include the additional question of radioactive exposure of operating employees."l/
if Order Concerning CESG's Petition to Compel Discovery (October 31,1979).
4 II. Discussion 1.
Board Question Provide a numerical analysis of the potential dose consequences to the public from a twenty-five (25) ton shipping cask falling into the McGuire spent fuel pool and damaging spent fuel that is in the spent fuel pool. /
2.
Assumptions Tables 1 and 2 enclosed list the assumptions for the calculations of the potential consequences of damaging Oconee spent fuel or McGuire spent fuel in the McGuire pool. The number of Oconee spent fubl assumed damaged is conservatively estimated to be the total storage capacity (500 fuel assem-blies) of the McGuire pool. The number of McGuire spent fuel conservatively assumed damaged is conservatively estimated to be the latest refueling (65 assemblies = 40 days) and several earlier refuelings (age = 1 year) sufficient to fill the pool. Forty days, equivalent to the amount of time it takes to refuel a reactor, is the minimum age for McGuire spent fuel. My understand-ing is that transfer of Oconee fuel into the McGuire spent fuel pool will not be permitted during reactor refueling.
The assumed age of 270 days for Oconee spent fuel is the youngest age for the Oconee spent fuel proposed to be transferred to the McGuire pool. All the spent fuel damaged was assumed to have the maximum peaking factor in Regulatory Guide 1.25 for a single fuel assembly.
- / As I pointed out earlier in this affidavit, occupational dose calculations relative to the postulated circumstances will be submitted by another Staff member.
. 3.
Calculations Figures 1 and 2 show the two-hour potential consequences at the Exclusion Area Boundary from damage to a single Oconee fuel assembly and a single McGuire fuel assembly, respectively, in the McGuire spent fuel pool.
Table 1 lists the potential consequences for damaging 500 Oconee fuel assemblies in the McGuire pool. Table 2 lists the potential consequences for damaging spent fuel assemblies from a refueling (65 assemblies, age = 40 days) of the McGuire reactor.
Use of the 65 assemblies discharged from a McGuire refueling repre-sents the lowest aged McGuire spent fuel in the pool. The potential conse-quences at the Low Population Zone (LPZ) are lower than those of the Exclusion Area Boundary, because of the greater distance from the radiation source; therefore, calculations for the LPZ are unnecessary.
The potential consequences given in Tables 1, 2 and 3 are the product of the potential consequences of damaging a single assembly (figure 1 or figure 2) and the number of fuel assemblies damaged.
The longterm potential thyroid exposure to the public from damaging an Oconee fuel assembly or a McGuire fuel assembly is 6.3 x 10-6 rem and 9.7 x 10-6 rem, respectively, at the McGuire Exclusion Area Boundary.
4.
Conclusions The potential consequences to the public of damaging 500 Oconee spent fuel assemblies at the McGuire pool is a very small fraction of the exposure guide-
.- lines of 10 CFR Part 100. The potential consequences are less than 1 mrem thyroid and 1 rem whole body.
The potential consequences of damaging McGuire fuel at the McGuire pool is well within the exposure guidelines of 10 CFR Part 100. This conclusion is based on the use of the youngest McGuire spent fuel for the latest refueling, aged at least 40 days. Any additional McGuire spent fuel in the pool which might be damaged would be from earlier refuelings. This McGuire spent fuel would have aged more than one year; thus, calculation of doses for the 40 day old McGuire fuel envelope doses that could result from damaged McGuire fuel aged more than one year.
Table 3 lists the potential consequences of damaging 500 McGuire fuel assemblies which have aged c.t least one year.
The thyroid potential con-sequences are insignificant compared to the value given in Table 2 for damaging spent fuel 40 days old from the latest McGuire refueling. This analysis conservatively assumed that the youngest McGuire spent fuel would not be restricted from the area where a shipping cask falling i. to the McGuire pool would damage spent fuel.
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9-Table 1 ASSUMPT10iiS FOR AliD POTEliTIAL C0i;SEQUE;.CES OF THE POSTULATED FUEL HA11DLIllG ACCIDEl4TS AT THE EXCLUSION AREA BOUNDARY FOR itGUIRE Assumptions:
Guidance in Regulatory Guide 1.25 Power Level 2620 Mwt (0conee)
Fuel Exposure Time 3 years Peaking Factor
- 1.65 Equivalent humber of Assemblies Damaged 500 (0conee) llumber of Assemblies in Core 177 (0conee)
Charcoal Filters elemental iodine 90%
methyl iodine 70%
Decay Time Before Moving Fuel 270 days 0-2 hours x/q Value, Exclusion Area Boundary (release) Elevated 9.5 X 10-4 sec/m3 Doses, Rem Thyroid Whole Body Exclusion Area Boundary (EAB)
Consequences from Accidents 0.0032 0.71 Maximum value for single assembly.
Table 2 ASSUMPTIONS FOR AND POTENTIAL CONSEQUENCES OF THE POSTULATED FUEL HANDLING ACCIDENTS AT THE_ EXCLUSION AREA BOUNDARY FOR McGUIRE Assumptions:
Guidance in Regulatory Guide 1.25 Power Level 3565 Mat (McGuire)
Fuel Exposure Time 3 years Peaking Factor
- 1.65 Equivalent Number of Assemblies Damaged 65 (McGuire Refueling)
Number of Assemblies in Core 157 (McGuire)
Charcoal Filters elemental iodine 90%
methyl iodine 70%
Decay time before moving fuel 40 days 0-2 hours x/q Value, Exclusion Area 3
Boundary (release) Elevated 9.5 X 10-4 sec/m Doses, Rem Thyroid Whole Body Exclusion Area Boundary (EAB)
Consequences from Accidents 144 0.825
- Maximum value for single assembly.
- 11 _
Table 3 ASSUMPTIONS FOR AND POTENTIAL CONSEQUENCES OF THE POSTULATED FUEL HANDLING ACCIDENTS AT THE EXCLUSION AREA BOUNDARY FOR McGuire Assumptions:
Guidance in Regulatory Guide 1.25 Power Level 3565 Mwt (McGuire)
Fuel Exposure Time 3 years Peaking Factor
- 1.65 Equivalent Number of Assemblies Damaged 500 (McGuire)
Number of Assemblies in Core 157(McGuire)
Charcoal Filters elemental iodine 90&
methyl iodine 70%
Decay time before moving fuel 365 days 0-2 hours x/q Value, Exclusion Area Boundary (release) Elevated 9.5 X 10-4 sec/m3 Doses, Rem Thyroid Whole Body Exclusion Area Boundary (EAB)
Consequences from Accidents 0.0049 0.7 Maximum value for single assembly.
. I hereby certify that the above statements are true and correct to the best of my knowledge and belief.
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-f DrOJack fl. Donohew b.
Subscribed and sworn to before me this ll7f day of deuunny.1980.
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