ML14184A604
| ML14184A604 | |
| Person / Time | |
|---|---|
| Site: | Brunswick, Robinson, 05000000 |
| Issue date: | 05/22/1984 |
| From: | Vassallo D Office of Nuclear Reactor Regulation |
| To: | Utley E Carolina Power & Light Co |
| References | |
| NUDOCS 8406040040 | |
| Download: ML14184A604 (9) | |
Text
May 22,.1984 Docket Nos. 50-261/325/324 Mr. E. E. Utley Executive Vice President Carolina Power & Light Company Post Office Box 1551 Raleigh, North Carolina 27062
Dear Mr. Utley:
SUBJECT:
SCALING FACTORS FOR IRRADIATED COMPONENTS Re:
Brunswick Units 1 and 2 and H. B. Robinson Unit 2 We are reviewing the February 2, 1984 letter from S. R. Zimmerman, Carolina Power & Light Company (CP&L), to D. G. Eisenhut, DL, in which CP&L provided information on the methods it intends to use to obtain scaling factors for two waste streams - oil and irradiated components - at the H. B. Robinson Steam Electric Plant, Unit No. 2 and at the Brunswick Steam Electric Plant, Units 1 and 2.
We have completed our evaluation of the method CP&L intends to use to obtain scaling factors for the waste oil presently solidified and stored at the Robinson plant. We understand from members of the CP&L staff that CP&L has revised its plans and will obtain scaling factors for other contaminated oil at the above plants in accordance with the NRC Low-Level Waste Licensing Branch technical position on waste classification.
Therefore, CP&L will no longer need our approval of the method proposed in the February 2, 1984 letter for obtaining scaling factors for waste oil.
We have reviewed the method proposed by the February 2, 1984 letter for obtaining scaling factors for irradiated components. We find the proposed approach to be appropriate, i.e., measuring gamma dose rate from components to determine the activity concentration of Co-60 and determining the activity concentrations of other nuclides using scaling factors determined from the results of activation calculations for a reference BWR or PWR.
However, the details of the proposed method are not -acceptable in their present form.
[84.60646Q4QC 840522 PDR ADOCK 05000261
. PDR
Mr. E. E. Utley
- 2 We have developed the enclosed initial draft guidance which we believe would help CP&L in considering possible amendments to its proposed methods for obtaining scaling factors for irradiated components. Please review the guidance and respond with your comments as to how the guidance will affect your methods as proposed in your February 2, 1984 letter.
Sincerely, Original signed by/
Domenic B. Vassallo, Chief Operating Reactors Branch #2 Division of Licensing
Enclosure:
As stated cc w/enclosure:
See next page DISTRIBUTION Docket Files NRC PDR Local PDR ORB#2 Reading ORB#1 Reading DEisenhut OELD SNorris MGrotenhuis SMacKay GRequa ELJordan JNGrace ACRS (10)
Gray File DL:RBDj DL:0 B 2 1
D ORB#2 SNoris:ajs MGrotenhuis SMacK qua DVassallo 05/lj/84 05/ /84 05/ /
/84 05/ik(84
Mr. E. E. Utley Carolina Power & Light Company Brunswick Steam Electric Plant, Units 1 and 2 cc:
Richard E. Jones, Esquire James P. O'Reilly Carolina.Power & Light Company Regional Administrator 336 Fayetteville Street Region II Office Raleigh, North Carolina 27602 U. S. Nuclear Regulatory Commission 101 Marietta Street, Suite 3100 George F. Trowbridge, Esquire Atlanta, Georgia 30303 Shaw, Pittman, Potts and Trowbridge 1800 M Street, N. W.
Dayne H. Brown, Chief Washington, D. C. 20036 Radiation Protection Branch Division of Facility Services Mr. Charles R. Dietz Department of Human Resources Plant Manager Post Office Box 12200 Post Office Box 458 Raleigh, North Carolina 27605 Southport, North Carolina 28461 Mr. Franky Thomas, Chairman Board of Commissioners Post Office Box 249 Bolivia, North Carolina 28422 Mrs. Chrys Baggett State Clearinghouse Budget and Management 116 West Jones Street Raleigh, North Carolina 27603 U. S. Environmental Protection Agency Region IV Office Regional Radiation Representative 345 Courtland Street, N. W.
Atlanta, Georgia 30308 Resident Inspector U. S. Nuclear Regulatory Commission Star Route 1 Post Office Box 208 Southport, North Carolina 28461
Mr. E. E. Utley H. B. Robinson Steam Electric Carolina Power and Light Company Plant 2 cc:
G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, DC 20036 Regional Radiation Representative EPA Regiona IV 345 Courtland Street, N.E.
Atlanta, GA 30308 Mr. McCuen Morrell, Chairman Darlington County Board of Supervisors County Courthouse Darlington, South Carolina 29535 State Clearinghouse Division of Policy Development 116 West Jones Street Raleigh, North Carolina 27603 Attorney General Department of Justice Justice Building Raleigh, North Carolina 27602 U.S. Nuclear Regulatory Commission Resident Inspector's Office H. B. Robinson Steam Electric Plant Route 5, Box 413 Hartsville, South Carolina 29550 James P. O'Reilly Regional Administrator -
Region II U.S. Nuclear Regulatory Commission Sutie 2900 101 Marietta Street Atlanta, GA 30303 Mr. R. Morgan General Manager H. B. Robinson Steam Electric Plant Post Office Box 790 Hartsville, South Carolina 29550
INITIAL DRAFT GUIDANCE FOR OBTAINING SCALING FACTORS FOR IRRADIATED REACTOR COMPONENTS I. DETERMINE ACTIVITY CONCENTRATION OF COBALT-60 The dose rate should be measured and the activity concentration of Co-60 calculated assuming all of the measured dose is due to Co-60.
Where components have been accumulated over a period of years, a pseudo-activity concentration of Co-60 at the beginning of the accumulation period should be calculated based on the assumption that~all of the irradiated components were accumulated at that time.
II. DETERMINE COMPOSITION OF COMPONENTS Relative to Cobalt Vendor supplied certifications of component composition may be used.
To the extent that certifications are not available, sampling and chemical analysis should be used to determine component composition relative to cobalt.
Otherwise, conservative values of component composition must be used for cobalt, iron, nickel, niobium, thorium, uranium, molybdenum, barium, lithium, and tellurium,-as determined from analysis of data in Reference (3)
(Tables 4.7*, 4.9 and 4.10) and other sources, to determine the component
- Note:
Conservative values for type 304L stainless steel based on Table 4.7 of Reference (3),
which would be expected on the average to be exceeded no more than approximately 0.1% of the time are as follows:
= 400;
-L 50 L 4;
= 3; Co
'Co
'Co
'Co Th U
Mo B
0.06, -
0.03
= 30 Ba
-=
6 Co
'Co
'Co
'Co
-2 composition relative to cobalt. Typical or average values of component composition relative to cobalt may be used for the other elements based on Reference (3) (Tables 4.8 and 4.11) and other sources.
III.
DETERMINE ACTIVITY CONCENTRATIONS OF OTHER NUCLIDES Activity concentrations of nuclides other~than Co-60 should be determined based on the pseudo-activity concentration of Co-60 determined in I. above and on the results of the activation calculations reported in Reference (3).
The reported results are based on the average compositions of target elements given in Reference (3).
The results are reported for the core axial midplane for a reference PWR and for a reference BWR after a 40 year operating history at a 75% duty factor.
Activity concentrations relative to Co-60 activity concentrations should be determined from the tabulated results in Reference (3) for the apprdpriate reactor type (BWR or PWR) and component function (shroud, core barrel, thermal pads, vessel cladding, pressure vessel walls) and corrections made to adjust the results to the compositions determined in II.
above.
Where the component functions are not determined, or where there is a mix of components with different functions, the most conservative values should be used.
Where the irradiation of the components is less than 15 effective full-power years (EFPYs) of reactor operation, the Fe-55 activity concentration should be adjusted to account for its higher buildup rate, compared to Co-60 during
-3 this time using Figure 1 or as follows:
for 0-5 EFPYs multiply by 2; for 5-10 EFPYs multiply by 1.5; for 10-15 EFPYs multiply by 1.25.
Similarly, for EFPYs less than 25 years, the activity concentrations of the nuclides with significantly lower buildup rates compared to Co-60 (C-14, Ni-59, Ni-63, Nb-94, Tc-99, 1-129) may be adjusted using Figure 1 or as follows:
for 0-5 EFPYs multiply by 0.3; for 5-10 EFPYs multiply by 0.45; for 10-156 EFPYs multiply by 0.67; for 15-20 EFPYs multiply by 0.8; for 20-25 EFPYs multiply by 0.9.
Where the activity concentration of Fe-55 is based on the pseudo-activity concentration of Co-60, the Fe-55 activity concentration may be adjusted to account for decay of Fe-55 over the entire accumulation period.
REFERENCES (1) Smith, R. I., Konzek, G. J., and Kennedy, W. E., Jr., 1978. "Technology, Safety and Costs of Decommissioning a Reference Pressurized Water Reactor Power Station," NUREG/CR-0130.
(2) Oak, H. D., Holter, G. M., Kennedy, W. E., Jr., and Konzek, G. J., 1980.
"Technology, Safety and Costs of Decommissioning a Reference Boiling Water Reactor Power Station," NUREG/CR-0672.
(3) Evans, J. C., et al. 1984. "Long-Lived Activation Products in Reactor Materials," NUREG/CR-3274.
1.0 55 Fe 0.9 0.8
-CORE SHROUD160Co,
- ~0.
-~
CORE BARREL 0.7 S0.64
< 0.5
_6Ni'-
94I 2
Nb 0.4 59.14 0.3
-NI.
C 0
0.2 0.1 0
0 4
8 12 16 20 2'
28 32 EFFECTIVE FULL POWER YEARS (EFPY)
F~c2LI.