ML19221B147
| ML19221B147 | |
| Person / Time | |
|---|---|
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-15.7.1, NUREG-75-87, NUREG-75-87-15.7.1, SRP-15.07.01, NUDOCS 7907120524 | |
| Download: ML19221B147 (2) | |
Text
NU R E G-75 /087 p e "Ec
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y O4 U.S. NUCLEAR REGULATORY COMMISSION N[hh) STANDARD REVIEW PLAN
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OFFICE OF NUCLEAR REACTOR REGULATION SECTION 15:7.1 WASTE GAS SYSlEM FAILURE LEV!P: RESPONSIBILITIES Primary - Accident An31ysis Branch ( AAB)
Secondary - Efflut.nt Trestrent Systens Branch (ETSB)
Site Analysis Branch (SAB) 1.
AREAS OF REVIEW 1.
The radiolegical coasequences of an unexpected and uncentrolled release to the etno-sphere of radioactive fission gases that are stored or transferred in the wastr gas systen are reviewed to determine compliance with dose criteria.
2.
The applicant's ;afety analysis report (SAR) is reviewed to see that there a e tech-nical specifications to limit to an appropriate level the activity which col.id be released, assuning the failure of any active component in the wasta gas sy?:en.
(The ETSB reviews the w3ste gas systen desfgn on SRP 11.3.)
s II.
ACrEPTANCE CRITERI A Failure of waste gas systems that comply with the current staff oosition on s3ismic and quality group design requirements shou d result in doses well within the guilea ire values l
of 10 CFR Part 100 using conservative calculational assumptions. Systens w',ose f ailure would result in exposures approaching or exceeding the guideline values of 10 CFR Part 100 should have a technical specification liniting the amount of activity in ene system. The technical specification should linit the activity in wiste gas system con,)onents such that any single failure of a co por:ent will not result in a whole body doc,e a; the nearest exclusion area toundary in excess of 0.5 ren.
For older plants, where it is proposed to modify the waste gas systen', systens which do not meet the current seismic requirements should have a technical specification such that '_he two-hour whole body dose at the nearest exclusion area boundary, in the event of a sy'. tem failure is less than 5 ren using conservative calculational assuscions.
s III.
REVIEW PROCEDURES The reviewer selects and emphasizes aspects of the areas covered by this review pl3n as may be appropriate for a particular case. The judgment on areae, to be qiven attentic'i and 7907120fMI USNRC STANDARD REVIEW PLAN Stendeed rev ew pfene see p,epeeed for the guidance of the O*fice of Nucieer Reactor Regoletion statt eeer sneible for the review of applic stions to construct and s
operote nwcieet power piente These documents see enede eve sobie to the puba6c as poet of the Come,,eeson s polec y to enform the nacteer mdustry end the 9
general pub:sc of reguistory procedueos and poiscies Standeed review plane are not evbeettutes f or e,goletory gwndee ce the Comm.saion e reguistione end cornpnence witn them se not toqu6 red The stenderd review plan sectione are beve/
- ievie on 2 of the Stendeed f ormet and Content o l Safety Anotyees Reporte for howciese Power Plante Not eJi sort +one of the Stendeed Format have e cure **po
. rev'ew pien Pubose d stands.d rev+eo piene will be revised pe *odecativ ee approprieve to accommodate co omente end to reflect new ln f ormation and emperient.e e
Come. ente end suggestions for senprovement WH be co. sidere( end should be sent to the U S Nucleet Regulatory Commission Office of Nuc lear Reector Regwia#*an. WeeMngton O C 20b66 t
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emphasis in the review is based on an inspection of the r.aterial presented to see whether it is similar to that recently reviewed en other plants and whether items of special safety significance are involved.
If the current sta f f positions on qualit, and seismic design provisions are corplied wit h, the probability of failure of passive corponents is sufficiently Icw that the censequences ray be compared with the exposure guidelines of 19 CFR Part 100. Conservative calculational assurptions, similar to those used in analyzing other design basis accidents, should be used.
(See, f or exan ple, Standard Review Plan 15.6.5.)
The reviewer obtains 3ssistance from the ETSB as necessary to account for special character-istics of the waste gas system. The appropriate X/Q values are obtained fron the SAB.
The radiologicdl consequences are then corputed using a digital computer code (Ref. 2).
At the oper ating license stage, the reviewer verifies that a technical specification has been provided to limit the waste gas inver: tories in components such that single active failures of components, such as the lif ting 3nd sticking of a relief valve, will result in small exposures when the consequences are conservatively calculated. Unless otherwise demnstrated, all the inventory of a pressurized tank (and r. orc' ally interconnected tanks if these would not be Ntomatically isolated) is assumed to be released on lifting and sticking of a relief valve. If charcoal is present, a slow evolution of gas ray be assured for the fra: tion of gas shown not to be reledsed during the tank depressurization.
IV.
EVALUATION FINDINGS The reviewer verifies that sufficient inforration has been provided and the review and calculations support conclusions of the follcaing type, to be included in the staf f's safety evaluation report:
Potential failures of the waste gas syste": have been reviewed and the computed doses have been found to be well within the guideline value of 10 CFR Part 100.
Technical Specification linits have (will ce) set to li qit potential doses from sirqle failuces of active components to small fractions of the 10 CFR Part 100 guideliens.'
V.
REFERENCES 1.
10 CFR Part 100, "R actor Sito Criteria."
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Cornuter codes are currently under developnent. Docu';entation will De published as a NU?EG report.
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