ML19326B971
| ML19326B971 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/23/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19326B967 | List: |
| References | |
| NUDOCS 8004180675 | |
| Download: ML19326B971 (3) | |
Text
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5) steam mass released to environs = 2.84 x 10 1bs.
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6) primary coolant released to secodary (34 minutes) = 8.7 x 1041bs.
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- 7) minimum primary to secondary iodine equilibrium activity ratio =
20 to I (for 1 gpm leakage).
- 8) specific I-131 dose equivalent activity = 3.5 uCi/gm (Primary)
= 0.17 uCi/gm (Secondary).
9) gross specific activity in primary = 72/E pCi/gm.
10)
X/Q = 7.0 x 10~4 sec/m at limiting point beyond site boundary 3
of 1046 meters for 30 m release height - equivalent to ground level release due to topography including building wake effect for 5 percentile meteorology.
11) total gross radioactivity in primary coolant released to secondary coolant released to environs.
12) ten percent of the combined radioiodine activity from primary activity in secondary coolant and secondary activity present in steam mass (released to environs) assumed released to environs.
The whole body dose resulting from immersion in the cloud containing the rolcased activity would include both gamma and beta radiation.
The gamma dose is dependent on the finite size and configuration of the cloud.
- However, the analysis employed the simple model of the semi-infinite cloud, which gives 2
an upper limit to the potential gamma dose.
The semi-infinite cloud model is applicable to the beta dose, because of the short range of beta radiation in air. The resulting whole body dose was determined to be less than 0.5 Rem for this accident.
The thyroid dose from t*3 steam generator tube rupture accident has been analyzed assuming a tube rupture at full load and loss of offsite power at the time of the reactor trip, which results in steam release through the relief valves in the period before the faulty steam generator is isolated and primary system pressure is reduced.
The limiting iodine activities for the primary and secondary systems are used in the initial conditions.
One-tenth of the iodine contained in the liquid which is converted to steam and passed through the relief valves is assumed to reach the site boundary.
The resulting thyroid dose from the combined primary and secondary iodine activity released to the environs was determined to be 1.5 Rem for this accident.
The limit for secondary iodine activity is consistent with the limits on primary system iodine activity and primary-to-secondary leakage of Igpm.
If the activity should exceed the specified limits following a power transient, the major concern would be whether additional fuel defects had developed bringing
_the total to above expected levels.
From thc. observed removal of excess activity by decay and cleanup, it should be apparent whether activity is returning to a level 1elow the specification licit.
Appropriate action to be taken to bring the activity within specification include one or more of the following:
gradual decrease in power to a lower base power, increase in 1etdown flow rate, and venting of the makeup tank gases to the waste gas decay tanks.
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6.
If c control rod in the regulating or sxial power shaping groups is declared inoperabic per Specification 4.7.1.2, operation above 60 percent of the thermal power allowable for the reactor coolant pump combination may continue provided the rods in the group are y
positioned such that the rod that was declared inoperable is main-Q tained within allowable group average position limits of Specifica-tion 4.7.1.2 and the withdrawal limits of Specification 3.5.2.5.3.
3.5.2.3 The worth of a singic inserted control rod shall not exceed 0.65%.sk/k at rated power or 1.0'sak/k at hot zero power except for physics testing when the requirements of Specification 3.1.8 shall apply.
'3.5.2.4 Quadrant tilt:
0 1.
Execpt for physics tests, if quadrr.nt tilt exceeds 4*5, power shall bc _ reduced iricediately to below the power Icyc1 cutoff (sec Figures 3.5.2-1A and 3.5.2-1B).
Morcover, the power Icyc1 cutoff value shall be reduced 2's for cach 1% tilt in excess of 4's tilt.
For 1 css than 4 pump operation, thorn.a1 power shall be reduced 2*5 of the thermal power allowabic for the rcactor coolant pump combin-ation for each it tilt in excess of 44.
2.
h'ithin a period of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the quadrant power tilt shall be reduced to less than 4t, except for physics tests, or the following adjust-ments in setpoints and limits shall be made:
a.
The protection system maximum allowabic setpoints (Figure
]
2.3-2) shall be reduced 2% ir. power for cach l'5 tilt.
I b.
The control rod group withdrawal limits (Figures 3.5.2-1A and 3.5.2-1B) shall be reduced 2'. in power for cach 1% tilt in excess of 44.
c.
The operational imbalance limits (Figurc 3.5.2-3) hall be reduced 2% in power for cach 1*6 tilt in excess of it.
3.
If quadrant tilt is in excess of 25**,
except for physics tests or diagnostic testing, the reactor will be placed in the hot shutdom condition.
Dingnostic testing during power. operation with a quad-rant power tilt is permitted provided the thermal power allowable for the reactor coolant pump-combination is restricted as stated in 3.5.2.4.1 above.
4.
Quadrant tilt shall be menitored on a minimum frequency of once every two hours during power operation above 15'4 of rated power.
3.5.2.5 Control red positions:
1.
Technical Specification 3.1.3.5 (safety rod withdrawal) does not prohibit the exercising of individual safety rods as required by Tabic 4.1-2 or apply to inoperable safety rod limits in Technical Specification 3.5.2.2.
2.
Operating rod group overlap. shall be 25'4 +5 between two sequential groups, except for physics tests.
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L (2) A radiochemical analysis shall consist of the quantitative measurement of the activity for each radionuclide which is identified in the primary h.'
coolant 15 minutes after the primary system is sampled.
The activities for the individual isctopes shall be used in ti e determination of E.
A l
radiochemical analysis and calculation of E and iodine isotopic activity shall be performed if the measured gross activity changes by more than 10 pCi/gm from the previous measured level.
The gamma energy per disinte-gration for those radioisotopes determined to be present shall be as given in " Table of Isotcpes" (1967) and beta energy per disintegration shall be as given in USNRDL-TR-802 (Part II) or other references using the e
equivalent values for the radioisotopes.
(3)
In addition to the weekly measurement, the radioiodine concentration shall be determined if the measured gross radioactivity concentration changes by more than 10 pCi/gm from the previous measured 1cvel.
(4)
Iodine isotopic activities shall be weighted to give I-131 dose equivalent activity.
(5)
In addition to the weekly measurement, the radioiodine concentration shall be determined if there are indications that the primary to secondary coolant leakage rate has increased by a factor of 2.
(6)
Whenever the steady state radiciodine or gross radioactivity concentration 2
of prior operation is greater than 1 percent but less than 10 percent of Specification 3.1.4.1, a sample of reactor coolant shall be taken within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of any reactor criticality and analyzed for radioactive iodines of I-131 through I-135 and gross radioactivity as well as the coolant sample and. analyses requirea by the above.
Whenever the steady state radioiodine or gross radioactivity concentration of prior operation is greater than 10 percent of Specification 3.1.4.1, a sample of reactor coolant shall be taken prior to any reactor criticality and analy:cd for radioactive iodines of I-131 through I-135 and gross radioactivity as well as the coolant sample and analyses required by above.
(7)
Not required when plant is in the cold shutdown condition or refueling shutdown condition.
(8) 02 analysis is not required when plant is.in the cold shutdown co'ndition or refueling shutdown condition.
(9) Required only when fuel is in the pool and prior to transferring fuel to the pool.
(10)
Not required when not generating steam in the steam generators.
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