ML20039B343
| ML20039B343 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 12/17/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8112220556 | |
| Download: ML20039B343 (3) | |
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SOUTH CAROLINA ELECTRIC a gas COMPANY POST OFFICE BOX 764 CotuMeiA, Souin CAROLINA 29218 T.c.Niewots.Jn.
Decerter 17, 1981 Vice Patsiotar ano G.oup Execurwa NUCLEAn Openations Mr. Harold R. Dmton, Director Office of Nuclear Peactor Begulaticn U. S. Nuclear Regulatory Ocnnissicn Washingtcn, D. C.
20555
Subject:
V. C. Sumer Nuclear Staticn Docket No. 50/395 Technical Specificatim Radiation &nitoring h
Dear Mr. Dmtm:
his letter presets the TE&G positicn cn a request
'diangNY cyg the Technical Specificaticns for Virgil C. Sumer Nuclear;Statk'21ISSJs -
2
%e specificaticn of interest is 3.11.2.1 relating to gaseous..,
efflum ts. In particular it relates to an stry in Table 4.11,-2 ~ '
,D refereced by surveillance requirem mt 4.11.2.1.2.
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%e 1ast etry in this table specifies an LLD of
-6 1 x 10
/4 ci/ml for the cxntinuous noble gas mcnitors which N. _._ -'
observe releases from the main plant vent and the reactor building 6
purge. We are suggesting a change to 2 x 10
/4 ci/ml (for Kr-85) as described in our FSAR (Pgs.11.4-8 to 11.4-10). %e specific guidance for 'his surveillance requiremmt is fomd in Regulatory c
Guide 1.21 Appmdix A, secticn A.1.C., which states that the smsitivity of gross radioactivity measuremmts should be sufficient to permit measuremmt of a_ small fraction of the activity which would result in m annual air dose of 10 millirads due to gama radiaticm at or beycnd the site bomdary.
te following site specific informaticn cm be used to show conpliance with this guide.
'Ibtal Postulated noble gas released from the plant = 3100 ci/yr (Final Ehvircnmmtal Statemmt (FES) Table 4.5)
Postulated Noble gas ganma dose = 0.23 mrem /yr (FES Table 4.9)
Postualted Noble gas Beta dose = 0.57 mrem /yr h
(FES Table 4.9) lO 11 g2g[ob k
A
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Mr. Harold R. Deitcn Page two December 17, 1981 So, the postulated release at the Virgil C. Sumer Nuclear Statial to give a 10 mrem /yr gama dose to the maximally exposed individual is s
1.34 x 10 ci/yr
'Ihe typical main plant v nt flw is 175,388 CEM (FSAR Fig. 9.4-9)
A proposed increase of 30% to this rate will not change the ccnclusicns reached below.
'Ihe average ccncentraticn in a release that would lead to an 10 mren dose is givcn by the ratio of yearly release and yearly _tgtalflow. 'Ihe average crncestraticn =-
52 x 10
/4 i/ml. A similar calculaticn for beta dose gives
-6 42 x 10 ja.ci/ml.
-6 Our installed instrummtaticn is smsitive to 2 x 10 17,7 which is approximately 1/20th of these <xncestraticns. It could thus detect 1/20th of the maximum allcmed dose if the release persisted for an mtire year or 1/7300th if it lasted for ole day. Since most releases will probably conn frcm the reactor purge which has a maximum flow of cnly 20,000 CFM. 'Jhe detecticn fracticn will actually be evm smaller _tp indicated by the atave calculaticns.
Clearly, a LLD of 2 x 10 p ci/ml (for Kr-85) will allow us to detect small fracticns (less than 10%-25%) of the regulatory limit found in Regulatory Guide 1.21.
We can see no justificaticn to cause us to replace our existing ntnitors with those that ccnform to the ncn site specific Standard Radiological ff el cal 6
Specificaticns nominal value of 1 x 10 A ci/ml. 'Ihis emclusicn is in exact agreemmt with the positicn taket by the NBC staff cn pages 11-20 and 11-23 of the Safety Evaluaticn Report.
SCE&G ccnsiders this adequate justificaticn for our present design and requests your inimdiate attmticn be givet to this matter.
Sincerely, u
T. C. Ni Is, Jr.
N:'IC4:tdh
.Ya Mr. Harold R. Dentm Page three Decenber 17,-1981 i
cc:
V. C. Sumer G. H. Fischer T. C. Nichols, Jr.
H.'N. Cyrus J. C. Rioff D. A. Naunm W. A. Williams, Jr.
R. B. Clary O. S. Bradham A.' R. Kocn M. N. Browne B. A. Bursey J. L. Skolds J. B. Knotts, Jr.
H. E. Yoccm H. T. Babb M. B. Miitaker NPCF File l
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