Radiation level

For this kind of case, a modification of the dilution method is being developed. Instead of using an external fixed-geometry measurement chamber, a suitable part of the process, e.g. a stretch of pipe, is used. A radiation detector is mounted on the outside of the pipe, and a tracer emitting sufficiently hard gamma radiation is used. As sufficient mixing can be achieved by injecting upstream the separator the radiation level found will be strictly proportional to the concentration and thus inversely proportional to the true flow rate. 

Fig. 23. Nuclear radiation level gauge, using an Ohmart-type ceU stack.

Table 2. Corrosion Products Contributing to PWR Shutdown Radiation Levels ...

Whereas addition of hydrogen to feedwater helps solve the O2 or ECP problem, other complications develop. An increase in shutdown radiation levels and up to a fivefold increase in operating steam plant radiation levels result from the increased volatiUty of the short-Hved radioactive product nitrogen-16, N, (7.1 s half-life) formed from the coolant passing through the core. Without H2 addition, the in the fluid leaving the reactor core is in the form of nitric acid, HNO with H2 addition, the forms ammonia, NH, which is more volatile than HNO, and thus is carried over with the steam going to the turbine. 

Water chemistry is important to the safe and reflable operation of a nuclear power plant. Improper conditions can lead to equipment and material failures which ia turn can lead to lengthy unscheduled shutdown periods for maintenance (qv) and repair operations. Water chemistry can also have an impact on the radiation levels duriag both power operations and shutdown periods. These affect the abiUty of personnel to perform plant functions. 

Exposure is minimized by ehoiee of souree, by duration of exposure, by distanee from souree (at 1 m die radiation level is redueed almost 10-fold), and by shielding. The greater die mass per unit area of shield material die greater die shielding effieieney. Whereas a- and (3-partieles pose few problems (die former ean be absorbed by, e.g., paper and die latter by 1 em Perspex) y- and X-rays are not eompletely absorbed by shield material but attenuated exponentially sueh dial radiation emerging from die shield is given by ... 

Table 15.5 Radiation levels for a road consignment of radioactive material under exclusive use ...

The radiation level for a consignment transported under exclusive use by a vehicle shall not exceed ... 

Table 6. Maximum permissible flare radiation levels for personnel.

The ground flare shall not exceed radiation level of 500 BTU/hr ft at third persons of the radius of 500 ft, excluding solar radiation. 

Flare radiation level calculations are to be based on the worst case wind velocity, a design wind velocity of 40 Kph and a maximum of 100 Kph. Vendor shall provide radiation plots for each case. 

Answer The automobile death rate is about lE-7/passenger mile. If 25,000 people evacuate 20 miles, this is 5E5 passenger miles, hence, the risk is 5E5 IE-7 = 0.05 deaths. The radiation exposure is 2.5E4 5E-4 48 = 600 person-rem. Using information from problem 4, the estimated deaths from radiation is 600 lE-4 = 0.06. About the same. The risk from radiation may be over estimated because the radiation level was measured close to the plant on the other hand, the traffic fatality estimate may be high because of police presence and slow driving. 

Wooden sticks affected by radiation from the fireball permitted an estimate of the radiation levels emitted. It was thus established that the emissive power of the LPG cloud was approximately 180 kW/m (16 BTU/s/ft ). 

TABLE 6.7. Relationship of Death from Radiation Burns to Radiation Level and Duration... 

I Estimate the thermal impact. The thermal impact of a fireball on humans is a function of both the radiation received and the fireball duration. The impact can be estimated from Figure 9.1. In this case, the fireball duration is estimated to be about 10 seconds, while the estimated radiation is presented in Table 9.1. Based on these data the impact to unprotected humans can be estimated and is shown in Table 9.2. Note that while there is a difference of about 15% in the radiation levels estimated from the two models, the estimated impact on humans is essentially the same. 

Recommended Design Flare Radiation Levels Including Solar Radiation... 

Design values for radiation levels usually used [62] ... 

Refer to Table 7-32 and select the condition for radiation level, K, and ground distance, R, from stack. 

Spectral Gamma Ray Log. This log makes use of a very efficient tool that records the individual response to the different radioactive minerals. These minerals include potassium-40 and the elements in the uranium family as well as those in the thorium family. The GR spectrum emitted by each element is made up of easily identifiable lines. As the result of the Compton effect, the counter records a continuous spectrum. The presence of potassium, uranium and thorium can be quantitatively evaluated only with the help of a computer that calculates in real time the amounts present. The counter consists of a crystal optically coupled to a photomultiplier. The radiation level is measured in several energy windows. 

How many disintegrations per second occur in a basement that is 40 X 40 X 10 feet if the radiation level from radon is the allowed 4 X 10 12 Ci/L ... 

Use the result of Example and assume that the radiation level from Pu is no longer a hazard when 99% of it has decayed. How long will this take ... 

Exposure to low doses of radiation causes no short-term damage but makes the body more susceptible to cancers. In particular, people who have been exposed to increased radiation levels have a much higher incidence of leukemia than the general population has. Marie Curie, the discoverer of radium, eventually died of leukemia brought on by exposure to radiation in the course of her experiments. Medical researchers estimate that about 10% of all cancers are caused by exposure to high-energy radiation. 

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