ML21053A038
| ML21053A038 | |
| Person / Time | |
|---|---|
| Site: | National Bureau of Standards Reactor |
| Issue date: | 12/11/2020 |
| From: | Dimeo R US Dept of Commerce, National Institute of Standards & Technology (NIST) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| Torres P | |
| Shared Package | |
| ML21053A037 | List: |
| References | |
| Download: ML21053A038 (2) | |
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UNITEDSTATESDEPARTMENT OFCOMMERCE InJ National Institute ofStandards andTechnology b,@,f Gaithersburg, Maryland 20899-e December 11, 2020 Document Control Desk U.S.Nuclear Regulatory Commission Washington, DC 20555-0001
Subject:
Request for license amendment andadjustment oftritium effluent values for newD2cold source under 10 CFR 20.1302(2)(c)
Ref:Docket 50-184, TR-5Facility License Sirs/Madams:
TheNISTCenter forNeutron Research (NCNR) Test Reactor(NBSR) isintheprocess ofdesigning andbuilding aliquid deuterium cold source toreplacethecurrent liquid hydrogen source.
NRCreviewed theoriginal liquidhydrogen cold source andconcluded inaletter ofMay17,1993, that nounreviewed safety question existed andthat itcould beimplemented under 10CFR50.59.
Analyses ofthe proposed liquid deuteriumcold source
- showthat, similar totheoriginal liquid hydrogen cold
- source, there isnocredible scenario that could affect the reactor.
- However, pursuant to10CFR50.59(c)(2)(viii),
a license amendment isrequested for anewmethod ofevaluation toadequately evaluate thetritium dosefromahypothetical release ofgaseous deuterium.
In10CFR20,Appendix B,alicensee isinstructed totreat effluent concentrations of HTorT2(and, byinference, DT)gasasequivalent totritiated water.Appendix B
incorrectly states that HTandT2oxidizes inairandinthebodytoHTO."The International Committee onRadiation Protection, inICRP-66 states that only about 0.01%oftheHTisabsorbed andconverted toHTO.Thus, inaccordance with10CFR 20.1302(2)(c),
theNCNRisrequesting thecommission approve theuseofactual chemical characteristics ofgaseous DTinusing theICRP-66 gaseous tritium dose conversion factor inlieu ofthe10CFR20Appendix Binstruction totreat astritiated water.
Astheattached analysis
- shows, proper useofICRPvalues forgaseous DTwill result inpublic doses wellbelow 10CFR20limits andiseasily bounded bythe maximumhypothetical accident calculated doses.
- However, asthis isachange inanalysis methodology asdefined by10CFR50.59(c)(2)(viii),
theNCNRisalso requesting a
license amendment tousethis analysis inChapter 11oftheUFSAR.
Asisthecaseforthe current cold
- source, there appear tobenopotential adverse effects on the reactor, sonotechnical specifications need tobechanged.
Respectfully, o
Robert Dimeo Director Ideclare under penalty of perjury thattheforegoing istrueandcorrect.
Executed onDecember 11,2020 Attachments:
Tritium evaluation memo Statement ofNoSignificant Hazards