ML20206R929
| ML20206R929 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 09/12/1986 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8609190256 | |
| Download: ML20206R929 (5) | |
Text
Northem States Power Company 414 Nicollet Mall Manneapohs, Minnesota 55401 Telephone (612) 330-5500 September 12, 1986 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Additional Information to Support the License Amendment Request dated February 21, 1986 The attached information is being provided in response to NRC Staff requests for additional information related to the Change in Operating License Expiration Date License Amendment Request dated February 21, 1986.
Please contact us if you have further questions concerning this submittal.
b w-David Musolf Manager - Nuclear Support Services DMM/EFE/efe c: Regional Administrator-III, NRC NRR Project Manager, NRC Resident Inspector, NRC MPCA Attn:
F W Ferman G Charnoff Attachment hO 8609190256 860912 PDR ADOCK 05000282 II P
1 j
~
t Prairie-Island Nuclear Generating Plant'
. Northern Stateg?ower Company Additional Information.to. Support the~
License-Amendment Request dated February 21~. 1986
-~
- 1.. Prcvide a projection of occupational radiation exposure expected for the'
' Prairie. Island Units for the period of _ extension.(2008-2015).
Identify projected outage ' years and doses for each unit.
Response
The annual' dose received ~at Prairie Island for each of'the last five years is summarized below. The average annual dose for that period is approximately 255 person-rem per year. Dose rates and maintenance are -
. expected to increase' in the future by approximately 104;and 204 respectively,. however we ' expect modifications such as the post-TMI upgrades to ' decrease so that the overall dose attributed to modification projects _ will drop by '254.
We anticipate that increased use of robotics
- in maintenance and use of longer fuel cycles will.also. reduce the annual dose. Fuel sipping will continue to be: performed as needed to keep the reactor coolant activity as low as reasonably achievable.
Overall we. expect the Prairie Island annual dose to. increase by about.
104.-to approximately 280 person-rem per year for the period of. 2008 to-2015.
The total dose for this period is estimated to be 1960 person-rem.
~ Year Total Dose (person-rem)
No. of Refueling Outages 1981 314 2-
- 1982' 212 2
1983 219 2
1984 136
-1 1985 393-2*
- Ten-year ASME Code Inspection Outages for each unit.
- 2. Provide the most recent available low population zone (LPZ) census data for the Prairie Island Units.
Indicate the most recent population projections for the LPZ for the year 2015. -Indicate the nearest population centers with over 25,000 population in the vicinity of the l'
plant (e.g. South St. Paul, 26 miles NW of the ~ site) in accordance with the latest census (1980) and any recent projections 6f such (e.g. 2015).
Response
4 L
The_ Prairie Island Updated Safety Analysis Report (USAR) defines the LPZ for Prairie Island as 1.5 miles. However, population data is only
- available ' for even mile distances around the plant. The 1980 estimated 0-2 mile population is 431 (USAR, Table 2.2-1) and the projected 0-2 mile population for the year 2015 is 708, based on the 1970 to 1980
. population increase.
1
--++vg e 1e twy-y9--
,e.+r-t v---t1=->
reme-
+e-,%.-
yv + v e
==r----r-r e mve-ve9=- -wv - - +---erw *--m
~* y d4 pir e w w w - e-r e e r m + y e -ir mem-r ~ t-+e s e e e esw -w +ve et w p -we +,
3+- We n -r v s v -a g ww+ -,
r e-+
k
^
~
gq
~
' Based on 1980 Census Bureau-Document PC80-1-A25, the following.
~
population ~ centers with a population greater 'than 25,000 are within 50 miles of' Prairie Island:
Population Center Loca' tion SMSA*.
2015**'
L
-Minneapolis /St Paul 30 mi NW-2,113,533.
2,700,000 Rochester 41 mi S 92,006' 130,000
'
- Standard Metropolitan St'atistical Area (includes some area.outside 50 mile radius).
- Projection based on Census Bureau 1970-1980 increase.
- 3. Identify specific land use changes which have affected offsite dose calculations, particularly those for ingestion' pathways for child thyroid (e.g. dairy cow in the NW sector).
Provide a summary of the results of any such revised calculations.
Response
There have been no land use changes which. have significantly affected offsite dose calculations.
Results of the 1985 offsite dose calculations 'for the critical receptor and highest milk receptor are provided below.
This 1985 data is typical of the. dose assessments from each year. of plant operation, and is expected to be-typical'of plant operation thru 2015.
Critical Receptor for 1985:
Sector: SSE Distance: 0.6 Miles Pathway: Ground, Inhalation, Vegetable Age' Group: Child Thyroid' Dose: 0.554 mrem Highest Milk Receptor for 1985:
Sector: SSE Distance: 2.2 Miles Pathway: Ground, Milk, Inhalation Age Group: Infant
' Thyroid Dose: 0.2 mrem 2
+,
s
'.b
- 4. Provide a general comparison'of the radiological impacts on man as
' assessed in the FES with those actually experienced during plant operations.
Response-l The -following table is a summary of the most recent Prairie Island offsite radiation dose assessment which covers the period of January 1 through December 31, 1985. These annual doses are'substantially lower
.than those reported in the FES.
10 CFR Part 50. Appendix I Gaseous Releases Guideline Per Unit Per Year
' Maximum Site Boundary 0.023' 20 Gamma Air Dose (mrad)
Maximum _ Site Boundary 0.072 40 Beta Air Dose (arad)*
Total Maximum Offsite 0.56 30 Dose to Any Organ (arem)
Offshore Location
.(mrem, 7 days / year)
Whole Body 0.0002 10 Organ 0.0003-30 Liquid Releases Total Maximum Offsite 0.003 6
Whole Body Dose-(arem)
Total Maximum Offsite 0.036 20 Organ Dose (arem)*
- 5. Clarify the FES statements on the disposition of spent fuel and solid radioactive waste (e.g. spent; fuel will not be shipped to West Valley).
Response
The Prairie Island spent fuel storage pool has been reracked to maximum capacity, but will not provide adequate storage to the end of current licensed operation.
The rod consolidation process is being explored and a demonstration program is being developed. Rod consolidation would provide for operation out to 2010 with full core discharge capability.
If a Federal repository is not available by then, other methods of onsite storage,~ such as dry cask storage, would be employed.
3
.c f
1 : ';
e-Approximately 10 radwaste shipments are presently made per year from '
Prairie-Island. -We anticipate that the number of radwaste shipments should stay on the order of 10 to'20 shipments.per year.
- 6. Provide 'more specific information on modifications to the plant which have affected the offsite or occupational dose either favorably or-
~
unfavorably.
-Response:
Many modifications have been made to the plant to reduce effluents, reduce radwaste shipments, and reduce personnel exposure. Maj or. changes include the installation of a charcoal-filter in the containment purge system and the addition of a charcoal filter to the liquid radwaste system..These modifications have reduced' effluents, occupational exposure, 'and the number of radwaste shipments. A portable super compactor has also been purchased which will reduce radwaste shipment volumes even further,
- 7. Provide a discussion of the Prairie Island ALARA Program.
Response
The changes described in the response to Item 6 are examples of the
-Prairie Island ALARA program at work. Prairie Island has.an effective ALARA program that receives management support. Annual occupational exposures are among the lowest in the industry. The-application of ALARA at Prairie Island. includes. ALARA reviews of modifications, detailed radiation protection procedures that are designed to keep exposures ALARA, and consideration of ALARA in operations and maintenance procedures, s.
4 L__