ML20148H844
| ML20148H844 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 09/09/1963 |
| From: | Bryan R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML20148H841 | List: |
| References | |
| NUDOCS 8011190777 | |
| Download: ML20148H844 (2) | |
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O 10.'ITED STATES AT0"IC ENERGY COM"ISSION
!!A2ARDS N ALYSIS DY Tile RESEAPCil W!D PnWER REACTOR SAFETY BRANCil DIVISION OF LICENSIN6 AND REn1LATION IN TifE "ATTER OF YANKEE ATOMIC ELECTRIC COMPANY -
PROPOSED CIANCE NO. 32 DOCKET NO. 50-29 Introduction c:g Parsuant to the provisions of Section 50.59 of the Connission's regulations, Yankee Atonic Electric Conpany, by Proposed Change No. 32 dated " arch 19, 1963, and supplenent thereto dated August 23, 1963, requested authorization to install a vent line which will provide a
=m neans of establishing a continuous, controlled flow from the vapor phase portion of the reactor pressurizer to the low pressure surge tank. The installation and use of such a line would pernit the renoval of non-condensible gases which could accunulate in the pressurizer and inter-fere with the proper operation of the pressurizer.
Discussion Decent operation of the Yankee reactor in conjunction with boric acid tests revealed the presence of oxygen in the main coolant systen during fressuri:er level changes.
This indicated that oxygen had been accumulat-int in the ressurizer during. these tests.
In order to rer.ove such non-condensibic gases which may accunu) ate in the pressurizer during future operations, Yankee has proposed that a vent line be installed which would discharge up to approximately 40 lbs, of gas per hour from the pressurizer.
This line ':ould include a filter, a pressure reducing orifice and a a
nanually operated needic valve.
Along with the Proposed Change, Yankee submitted a drawing which shows the arrangenent of the conponents of this vent line.
The vent line would discharge to the low pressure surge tank through
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the same piping as the pressurizer relief valves.
h'c do not believe that use of the vent line during normal operation represents a significant a
change in snfety, The one iten which we do believe involves a safety question is the proposal that remotely actuated valves not be nrovided in the vent line.
"esolution of this question involves a consideration n
of the consequences of continued flow through the vent line during credible accident situati us.
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If the prinary systen becane hirhly contaninated with radioactive fission products, personnel night iot he able to close a nnaually operated vent line valve due to conditions of high radiation levcis or a steam atrosphere in the containnent.
To prevent such a situation from occurring, Yanisce plans to install a radiation conitor which vill provide the reactor operator with a continuous indication of the activity Icvc1 in the nrinary coolant systen.
If high Icvels of radioactivity should be experienced, the operater could denrossurize the prinary syster to linit the discharre of radioactive notorials through the nrossu:e vent line.
'opresentatives of Yankee have stated that such depressurization could be perforned within 20 hours2.314815e-4 days <br />0.00556 hours <br />3.306878e-5 weeks <br />7.61e-6 months <br />, and before note than a fraction of a "cr cent of the radioactive isotopes present in the prinary syster could Icah to the lou pressure surre tank.
In view of the fact t' tat the low pressure surge tank is in a shicided con artnent and is protected fron rupturing due to overnressure by a rupture disc discharging back into the containnent huilding, we do not believe hat the ten-orarily uncontrolled Icahage of scall amounts of fission nroduct activity to the low *ressure surge tant would represent a significant hazard.
Conclusion Based on our review, we ave concluded that the Proposed Change does not present significant hazards considerations not described or innlicit i-the hazards sunnary report and that there is reasonahic assurance that the Scalth and safety of the public ill not 5c endangered,
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"#,c rt 'i. Drynn, Chief
'es eare' r, Power ca ctor Sa fety E ranc'1 Division of 1.icensinp r, 'Mrulation
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