ML20153B938
| ML20153B938 | |
| Person / Time | |
|---|---|
| Site: | University of Michigan |
| Issue date: | 09/18/1998 |
| From: | Jun Lee MICHIGAN, UNIV. OF, ANN ARBOR, MI |
| To: | Micheals T Office of Nuclear Reactor Regulation |
| References | |
| TAC-M99366, NUDOCS 9809230291 | |
| Download: ML20153B938 (4) | |
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Slb' MiCHicAN MEMORIAL-PHOENIX PROJECT Q
PHOENIX MEMORIAL LABORATORY FORD NUCLEAR REACTOR ANN ARBOR, MICHIGAN 48109-2100 cm. a $. o-t September 18,1998 Mr. Theodore Michaels Non-Power Reactors and Decommissioning Project Directarate Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, DC 20555
SUBJECT:
Self-Contained Breathing Apparatus - Changes to Ford Nuclear Reactor Emergency Plan: Revision 16
REFERENCE:
Your Letter dated January 27,1998 TAC No. M99366
Dear Mr. Michaels:
The purpose of this letter is to inform you of changes regarding self-contained breathing a aparatuses (SCBA's) at the University of Michigan's Ford Nuclear Reactor. These c1anges do not decrease the effectiveness of the Emergency Plan under Part 50.54(q).
In 1996 questions were raised by U of M Occupational Safety and Environmental Health (OSEH) personnel regarding the fitness of the SCBA's that we had on site at that time.
The main concern was that these SCB A's were well over twenty years old and could no longer be maintained satisfactorily.
We realized that no review was made to evaluate the continued need for SCBA's at FNR prior to our facility being relicensed in 1985, with a new supporting Safety Analysis Report (SAR). We have therefore performed a review, based on our SAR and facility
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operations, keeping in mind changes and modifications made to the facility since 1985, with respect to emergency planning. The enclosed review has been approved by our Safety Review Committee and Radiation Safety Officer. OSEH also concurs with this review.
The conclusion of this review is that SCBA's are not required at FNR, but that air purifying respirators are desirable for at least our on-call supervisors.
Sincerely, M.
J n C. Lee
. Interim Director Enclosure c
9909230291 980918 POR ADOCK 05000002 F
PDR Phone:(734) 764-6213 Fax: (734) 763-7863 www.umich.edu/~mmpp/
a Review on the Use of Self-Contained Breathing Apparatus at the Ford Nuclear Reactor There are four basic types of credible respiratory hazards at FNR: radioactive materials, hazardous chemicals, fires and explosions.
1.' Maximum Credible Accident at FNR from the Safety Analysis Report:
Radioactive Material Release Potential FNR's SAR addresses a wide range of credible accidents. These include excess reactivity additions, abnormal loss of coolant events, and failed experiments.
For an excess reactivity addition of 1.6 % AK/K, attributed to one experiment or a group of experiments, the SAR conclusion is that no portion of the fuel lattice would melt. FNR Tech Specs ensure that the actual limit on experiment reactivity is a smaller maximum value of 1.2 % AK/K. There would be no release of fission products from the reactor due to an excess reactivity addition.
For an abnormal loss of coolant situation, the SAR concludes that there would be no core damage. There would be no release of fission products from the reactor due to the abnormal loss of coolant. The only hazard would be increased radiation levels due to the decrease in pool water shielding.
For a failed experiment, the only concern is airborne radioactivity in the FNR building air from the experiment itself. There would be no fission product release from the reactor due to a failed experiment.
Experiments have limits on their total amount of radioactivity such that, if any experiment should fail, reactor operators could diagnose the problem, perform a reactor shutdown and complete a building evacuation without exceeding any occupational dose limits. The limits on experiments, as analyzed in our Safety Analysis Report, are based upon the assumption that it would take reactor operators 6 minutes to diagnose the problem, perform a reactor shutdown and complete a building evacuation. It is also assumed that all the radioactivity from any failed experiment would become airborne in 1/4 of the pool floor air volume. These limits and assumptions determine the maximum concentration possible.
This maximum concentration is compared to the derived air concentration (DAC) in Appendix B to 10 CFR 20, Table 1, Column 3 value. Exposure to the maximum airborne concentration from a failed experiment for 6 minutes would not exceed the 2000 DAC-hour occupational dose limit.
Experiments with single encapsulation are limited to 1/10 of the total potential activity in the experiment review process. Experiments with double encapsulation are allowed the
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full amount of total potential activity during experiment review, because the double barrier significantly decreases the probability of experiment failure.
Assuming an experiment failure with the release of a significant amount of airborne activity, operators would receive alarms from the radiation monitoring system (which includes area monitors, gaseous activity monitors, and air particulate monitors). Six minutes is an adequate amount of time for the operators to evaluate the situation, shut down the reactor, and evacuate the reactor building.
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Conclusions:==
There are no credible reactor accidents which would damage the fuel or cladding. Therefore the reactor is not a possible source of significant airborne radioactivity. Experiments are assumed to possibly fail, so their design, contents and Page 1 of 3
l irradiation conditions are limited to ensure that the maximum airborne radioactivity that might be released would not cause any individuals in the reactor building to exceed occupational dose limits even in the worst case scenario.
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- 2. Chemical Respiratory Hazards at FNR The inventory oflaboratory or industrial chemicals at FNR is extremely limited. Alcohol solvents such as ethanol and methanol are used in limited quantities (4 liter bottles or smaller). The alcohol solvents do not pose a significant respiratory hazard. A spill can be easily handled by exiting the immediate area.
Three helium and two neon gas cylinders are situated on the pool floor. These noble gases are used for reactor experiments, and do not pose a significant respiratory hazard. The pool floor area is also well-ventilated.
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Liquid nitrogen is used to cool various laboratory radiation detectors throughout the facility. The liquid nitrogen is a potential asphyxiant, but the quantities used (less than 30 liters) and adequate room ventilation preclude a respiratory hazard, even upon complete release.
l Flammables in various parts of the facility are stored in limited quantities and kept in i
flammable storage cabinets. They represent no significant respiratory hazard.
The secondary coolant system's chemistry controls use Alkine A and Sodium Hypochlorite (industrial bleach) as the additives for pH stabilization, corrosion prevention, and moss /
mildew prevention. Alkine A is only a mild irritant per its MSDS sheet. Industrial bleach is a strong irritant, and any spill, by its noxiousness, would drive nearby persons to seek fresh air. Cleanup can be handled by persons using NIOSH approved resairators, under the supervision of OSEH. The secondary coolant system is non-safety re; ated, so there would be no impact on reactor safety or the ability to safely shut down the reactor.
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Conclusion:==
There are no chemicals in use at FNR that represent a significant respiratory hazard or a reactor safety hazard.
- 3. Fire Hazards at FNR FNR is designed with reinforced concrete and masonry walls. Floor and ceiling tiles are fire retardant. Vulnerable areas are protected by sprinkler systems. Flammable, are kept in flammable storage lockers when not being used. Reactor operators are instructed not to attempt to fight any fire that is "more than minor," i.e. more than a fire in a trash receptacle that can be handled with one portable extinguisher For any fire more than minor, the operators shut down and secure the reactor and evacuate the reactor building.
The City of Ann Arbor's Fire Department responds to all fire alarms from our facility.
- 4. Explosion Hazards There are no explosion hazarc' A FNR of even the slichtest significance. For experiments, technical specifications requir. ut: (1) explosive m % ials shall not be placed in the reactor pool; and (2) neutron radiography of explosives aall be conducted with the explosives contained in a blast proof irradiation container, a prototype of which has been successfully tested and demonstrated not to fail by detonation of at least twice the amount of explosive to be tested.
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- 5. Historical Perspective Normal reactor operations have not in the past required and do not now require the use of respirators. There has been no need to use respiratory protection to respond to any accident at FNR.
- 6. Overall Conclusion There are no significant hazards or accident scenarios that would require the use of respiratory protection equipment in order to combat or control a situation which would affect reactor safety. Due to the uncertainties associated with emergency planning, it is prudent practice to maintain some respiratory protection equipment available for use.
Air purifying respirators are adequate for dealing with lesser respiratory hazards. Air purifying respirators are not adequate for two situations: atmospheres that are oxygen-deficient, and atmospheres that are immediately dangerous to life and health (IDLH). Self-contained breathing apparatuses are required for these two types of atmospheres. There i
are no hazards at FNR that could lead to either an oxygen-deficient or an IDLH atmosphere. Therefore air purifying respirators are adequate for FNR, and SCBA's are not needed.
The U of M's OSEH group operates a Respiratory Protection Program which meets the following regulations:
- 1. Respiratory Protection Standard (29 CFR 1910.134, Michigan ).
- 2. Respiratory Protection and Controls to Restrict Internal Exposure in Restricted '
Areas (10 CFR 20 Subpart H).
i All licensed reactor operators and lead operators receive a pulmonary function test as a part of their periodic physical exams. The pulmonary function test is required prior to the fit test for respirator usage. Fit testing and issuance of air purifying respirators are performed by U of M's OSEH group. Currently, our on-call supervisors are all fit-tested for respirator usage and have been issued their own personal air purifying respirator with cartridges.
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