ML20077H232
| ML20077H232 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/26/1983 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| FVY-83-79, NUDOCS 8308090681 | |
| Download: ML20077H232 (4) | |
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g.. e VERMONT YANKEE NUCLEAR POWER CORPORATION 2.C.2.1 FVY 83-79 RD 5. Box 169, Ferry Road, Brattleboro, VT 05301
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g ENGINEERING OFFICE 1671 WORCESTER ROAD FRAMINGHAM, MASSACHUSETTS 01701 TELEPHONE 617-872-8103 July 26,1983 U. S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention:
Mr. Thomas T. Martin, Director Division of Engineering & Technical Programs
Reference:
a) License No. DPR-28 (Docket No. 50-271)
Dear Mr. Martin:
This letter is written in response to a telephone request directed to a member of the Vermont Yankee plant staff made by John White on July 15,1983, regarding the potential for transuranics at Vermont Yankee.
The telephone call was made as a result of an inspection conducted by your Mr. McBride.
During that inspection, he reviewed data gener-ated by SAI, Inc., on samples taken at Vermont Yankee in support of'an NRC project to help with the implementation of 10 CFR 61. After re-viewing the data, Mr. McBride felt that if the Co60-to-transuranics ratios found in the SAI data were applied to air samples at the plant, there may be a problem with personnel exposures and environmental releases.
plant personnel and were analyzed for gross 8-4,ples were taken by As a result of that concern, some smear sam Co60 and gross a.
The l
initial gross a values reported to John White indicated the presence of alpha activity in the samples. At that time, Mr. White was informed that the results were preliminary and, in fact, that there were known problems with the alpha counter.
Subsequent analyses have proven those j
initial results were completely invalid.
We believe there is no significant environmental release of trans-uranics at Vermont Yankee because of the results of routine stack sample analyses. All stack samples are analyzed for gross a and gama l
isotopics routinely. Data from the last three (3) quarters was analyzed.
Quarterl Quarterly Ave. Co 0 conc. y(pCi/cc)
Gross a conc. (pCi/cc) 6 3rd Qtr.1982 3.25 x 10-13 2.12 x 10-16 16 4th Qtr.1982 2.5 x 10-13 1.83 x 1016 1st Qtr.1983 1.13 x 10-12 2.18 x 10-J)")
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VERMONT YANKEE NUCLEAR POWER CORPORATION U. S. Nuclear Regulatory Commission July 26, 1983 Page 2 gng the gross a data and the ratio of transuranic alpha emitters to Pu from the SAI data, the concentration of transuranics emitted from the plant stack is shown to be a small percentage of the applic-abge168hourMPC. Additionally, a comparison was made between the Co 0 (analyzed monthly) and gross a (analyzed quarterly) with the fol-lowing results.
The gross alpha remained constant at about 2 x 10-16 pci/cc for the 3rd and 4th quarters of 1982 and the 1st quarter of 1983. Although 60 evels remained constant for.the 3rd and 4th quarters of 1982 and l
Co the first two months of 1983 at m3 x 10-13 pCi/cc, they jumped by a factor of 10 in March 1983, the first month of the refueling outage.
This made the 1st quarter 1983 Cobo average higher by a factor of 4.
60 The fact that the Co increased and the gross a did not, strongly implies that there is no correlation between Coou and transuranics in air samples.
The smear samples taken and analyzed by plant personnel were re-analyzed once the problems with the gross a counter were corrected.
to Pu 41 ratio is The table of results is attached.
Note that the Co60 2
very dependent on the sensitivity of the gross a counter; thus, the most valid results are from the two samples where positive alpha re-sults are indicated. All other values are minimum values. These re-sults imply that, assuming one believes there is a correlation between Co60 and Pu291,1f Co60 is controlled to within its MPC, the Pu241 levels will be adequately controlled with no resultant personnel expo-sure problem.
Additionally, based on previous evaluations of the data by VY per-sonnel and outside consultants, we question the validity of some of the SAI data. Accordingly, additional samples have been sent to SAI and Teledyne Isotopes, Inc.
Because of the concerns expressed by your Mr. White and Mr. McBride, we have requested both vendors to expedite the analyses of those samples. We have also requested Teledyne Iso-tones to analyze' the comgosite of 2nd quarter 1983 stack filters for Pu M, Pu239, Pu240, Pu291 All of this data should be available by October 1,1983. We will continue our follow-up in this area in our preparation for implementation of 10 CFR 61 in December 1983.
Because of the information provided above, we are of the opinion that no transuranic problem exists at Vermont Yankee.
o VERMONT YANKEE NUCLEAR POWER CORPORATION U. S. Nuclear Regulatory Comission July 26, 1983 Page 3 We trust this information addresses the concerns expressed by Mr. White and Mr. McBride. Should you need additional information, please contact us.
Very truly yours, h
Y
[j Warren P. M rphy Vice President & ManagVof Operations GDW/jh f
VERMONT YANKEE SMEAR SAMPLE DATA 60 Location B,d Activity Alpha Activity Co Ratio Ratio 60 60 24I DPM(a )
DPM (D)
DPM Co to Gr a Co to PU Cask Room #1 9,500
< 0. 4 5417
> 13542
> 282 Cask Room #2 35,700-
< 0. 4 16250
> 40626
> 846 RCU Phase Separator #1 9,200
< 0. 4 2930
> 7325^
>152 RCU Phase Separator #2 12,000
< 0. 4 3174.6
> 7936
>l65 Cond Phase Separator #1 360,000.
< 0.4 190476
> 476190
> 9920(it)
Cond Phase Separator #2 439,000 0.6 255317 425528*-
8865(*Ar)
Lip of Dryer / Separator Pit #1 165,000
< 0.4 145854
> 36462
> 759 Lip of Dryer / Separator Pit #2 44,000
< 0.4 39516
> 98790
> 2058 Lip of Spent Fuel Pit #1 108,000 0.5 89910 179820*
3746(*)
Lip of Spent Fuel Pit #2 71,000
< 0.4 47508'
>118770
> 2474 A recount of smears on Beta counter showed insignificant change
- only these ratios should be. considered since these are the only samples with positive alpha indications above minimum sensitivity.
it these smears were taken in the same area as the original smears sent to SAI.
O to see these levels, the NMC proportional counter chamber was cleaned, the center wire replaced, a new voltage platggu run, a new 20 minute background run, a 20 minute background alpha check done on a 2 pCi Co source with no change, alpha efficienty verified at 50%, and each sample counted for 20 minutes.