ML20010F320
| ML20010F320 | |
| Person / Time | |
|---|---|
| Site: | Washington State University, Palo Verde |
| Issue date: | 08/28/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Van Brunt E ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| Shared Package | |
| ML20010F296 | List: |
| References | |
| NUDOCS 8109100030 | |
| Download: ML20010F320 (2) | |
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1 August 28, 1981 i
Docket Nos. 50-528, 50-529, 50-530 Arizona Public Service Company P. O. Box 21666 Phoenix, Arizona 85036 Attention: Mr. E. E. Van Brunt, Jr.
Vice President, Nuclear Projects i
Gentlemen:
i The enclosed IE Infomation Notice contains 5 items of infomation that generally-l have impact on areas nomally under the responsibility of a facility's health physics group. To promote efficiency, these several items have been grouped together and are being given a broad distribution.
Consequently, some of the topics may not be applicable to your facility's health physics program. With
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this multiple-item approach, we believe valuable infomation and suggested guidance can periodically be provided to licensees. We intend to reserve the traditional " single-item" Infomation Notice / Circular vehicle for health physics 4
matters requiring more immediate licensee attention. However, we feel the new approach will give NRC a more flexible tool to comunicate with licensees on general infomazion related to health physics.
The following provides a brief sumary of each item and addresses licensee applicability:
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Part 1: Use of Recirculating-Mode (Closed-Circuit) Self-Contained Breathing l
Apparatus (Rebreathers), provides an upgraded protection factor and t
upgraded guidelines for use of the BioPak-60P self-contained breathing apparatus-rebreather(SCBA-R). This part is applicable to all licensees i
who currently possess this device, or are contemplating its purchase.
Part 2: Use of the Chemical "DOP." provides interim guidance in the use of the chemical di-sec, octyl phthalate (D0P), in light of the results of
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the recent National Cancer Institute /Natic.lal Toxicology Program carcino-l genesis bioassay tests of DOP. This part is applicable to all licensees who use D0P, either in quantitative respirator fit testing, or for l
high-efficiency particulate air (HEPA) filter testing.
Part 3: Placement of Personnel Monitoring Devices for External Radiation Exposure, describes a rituation in which inappropriate placement of personnel nonitaring devices resulted in the underestimating of the i
radiation dose received by workers.
This part is applicable to all
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-licensees who may encounter non-unifom fields of radiation.
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Arizona Public Service Co pany Part 4: Personnel Entry into Inerted Containment, describes a recent personnel entry into a nitrogen-inerted boiling water reactor (BUR) containment. Although the event described occurred at a BWR, this part I
provides guidance to help. improve worker safety for those licensees whose facilities may have nonradiological airborne nazard _ areas.
This l
part is applicable to licensees who may have cause to enter toxic or oxygen-deficient atnospheres such as unventilated tanks and voids, or areas affected by oxygen displacement fire suppression systems.
Part 5: Evaluation of Instrunent Characteristics Uhen Using Portable Raciation Survey Instruments, provides a discussion of various radio-logical and nonradiological characteristics that should be considered in the routine calibration and use of portable radiation survey instncents.
This part is applicable to all licensees who use portable survey instru-ments.
The guidance contained in this notice includes those items that the NRC staff believes should be considered.
The guidance is not a substitute for NRC regulations and license requirements and, therefore, compliance is not
. required. No written response to this infonnation notice is required.
If you have any questions related to the provided guidance, please contact this office.
Sincerely, Uriginal signe3 By R. H. Engeken R. H. Engelken Director
Enclosures:
IE Information Notice No. 81-26, Part 1: Use of Recirculating-Mode (Closed-Circuit) Self-Contained Breathing Apparatus (Rebreathers)
Part 2: Use of the Chemical "DOP" i
Part 3: Placement of Personnel Monitoring Devices for External Radiation Exposure Part 4: Personnel Entry into Inerted Containment Part 5:
Evalration of Instrument Characteristics When using Portable Radiation Survey Inst. aments cc w/ enclosures:
F. U. Hartley, APS G. C. Andognini, APS i
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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C. 20555 August 28, 1981
~ IE INFORMATION NOTICE NO. 81-26: COMPILATION OF HEALTH PHYSICS RELATED INFORMATION ITEMS Part 1: Use of Recirculating-Mode (Closed-Circuit) Self-Contained Breathing Apparatus (Rebreathers)
Part 2:
Use of the Chemical "D0P" Part 3:
Placemar.t of Personnel Monitoring Devices for External Radiation Exposure Part 4: Personnel Entry into-Inerted Containt.ent Part 5:
Evaluation of Instrument Characteristics When Using Portable Radiation Survey Instruments 0
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IM 81-26, Part 1 August 28, 1981 c
Page 1 of 3
- IE INFORMATION NOTICE NO. 26, PAF.T 1: USE OF RECIRCULATING-MODE (CLOSED-CIRCUIT) SELF-CONTAINED BREATHING APPARATUS (REBREATHERS)
Description of Circumstances:
This notice updates infomation in IE Information Notice No. 80-19 issued on May 6,1980 that informed licensees of a National Institute for Occupational Safety and Health (NIOSH) "stop-sales-and-recall" order of the BioPak-60P (60P) recirculating-mode (closed-circuit) self-contained breathing app &ratus -
(rebreathers) identified as SCBA-R.
It also provides updated guidelines for the use of SCBA-R.
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NIOSH rescinded its.stop-sales-and-recall order (NIOSH Users Notice of July 11, 1980) after the original problem was satisfactorily resolved.
The Los Alamos National Laboratory (LANL)- has retested the equipment, as approved
- since the rescinding of the recall, to assure that recommendations on use are based on the perfomance of devices tested and certified by NIOSH.
Discussion:
Current regulatory guidance (Regulatory Guide 8.15, " Acceptable Practices for Respiratory Protection") recognizes only a " demand" mode of operation for rebreathers (i.e., a mode in which there is some negative pressure in the l
facepiece during at least part of the breathing cycle).
The protection factor pemitted for such devices with full facepieces is 50.
The recently developed 60P rebreather operates in the positive-pressure mode (i.e., pressure in the facep;ece remains positive throughout the breathing i
cycle).
This device has been issued NIOSH test and certification number l
TC-13F-85.
Therefore, under the provisions of 10 CFR 20.103 and Regulatory l
Guide 8.15, Section C, NRC licensees may make allowances for the use of the l
60P in estimating exposures of individuals to airborne radioactive materials.
However, the NIOSH certification tests do not differentiate this new class l
of positive-pressure rebreathers from the demand-mode reSreathers, and no quantitative information on efficacy (protection factors) is orovided.
Guidance:
The Los Alamos National Laboratory has tested the new devices as part of its ongoing program for NRC. LANL has developed sufficient information for NRC l
to provide authorization for the use of these rehreathers with an assigned i
protection factor of 5,000.
In addition to the existing regulatory position presented in Re5Jlatory Guide 8.15, the following guidance pertains to the
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use of positive-pressure rebreathers and should be followed by licensees who use the rebreathers. Some of the discussion deals specifice'ly with the 60P rebreather that, at present, is the only available NIOSti tested-and-certified l
device of-this type.
IN 81-26, Part 1 August 28, 19.81 Page 2 of 3 1.
For work in which very high protection factors are required, the positive-pressure (pressure-demand), open-circuit, self-contained breathing apparatus (SCBA) is still-the apparatus of choice, unless the advantage of increased working time provided by a positive-pressure rebreather is necessary.
The
' nominal "30-minute" open-circuit SCBA will provide air for only 15 or 20 minutes under fairly heavy working conditions. A recent report presents data indicating i. hat, under very heavy working rates, standard air cylinders can be exhausted in as little as 10 minutes (L. G. Myhre, et al., " Physio-logical Limits of Firefighters," ESL-TR-79-06, Final Report, Air Force School of Aerospace Medicine, October 1977-January 1979).
The 60P, which was tested at LANL under moderate working rotes, provided at least a full 60 minutes of service; it also weighs less.than most open-circuit SCBA.
However, all rebreathers have an inherent problem; should contaminants enter the system, such as through a temporary facepiece leak, they would generally circulate through the breathing bags and be breathed repeatedly.
Open-circuit devices, on the cther hand, clear themselves of contaminants much more quickly because breath is exhaled to atmosphere and clean air is supplied with each inhalation.
2.
Perceptible outward leakage of air from i*BA-R at any time is unacceptable because service life will be reduced to only a few minutes.
The rebreather makeup air supply comes from a small bottle of oxygen that will.be quickly exhausted if the facial seal of the mask is not maintained. Wearers of positive-pressure SCBA-R have to be trained to immediately leave the area,
where the respirator is required if such outward leakage is detected.
1 3.
It is important that each person who is to use the rebreather be quantita-tively fit tested. To the extent that the test hood or chamber will allow, many different body and head movements should be included in these tests to simulate actual work movements while protection factors are measured.
A satisfactory fit is provided when a protection factor of at least 5,000 is achieved (no more than 0.02% leakage).
These devices, when well-fitted, can provide protection factors of 20,000 or greater.
Therefore, a factor of less than 5,000 indicates an unacceptably poor fit for the situations in which such equipment is designed for use.
There is also the practical consideration that many licensees use quantitative fit test equipment (e.g., with sodium chloride aerosol) that cannot generally measure protection factors much greater than 5,000.
The rsk supplied with the 60P is manufactured by AGA (Swedish Company) and comes in only one size.
It is a relatively wide mask that will stay well sealed to the face for pood protection for those usert who have wider faces. People with narrow faces, particularly those with narrow and short faces, might be unable to c hieve a satisfactory fit (i.e., a fit with a protection factor of at least 5,00C'.
4.
Spec.ial training is essential for Nople who will use rebreathers.
The operation of rebreathers is very ditferent from that of open-circuit SCBA with which many workers are familiar. Training should include, in addition to the usual infonnation on the construction and operation.of the unit,
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IN 81-26, Part 1 i
August 28, 1981 i
Page 3 of 3 hands-on refilling of the carbon-dioxide-removing sorbent and replacement of the oxygen supply bottle (even though maintenance will not be perfomed by the wearer). Training should also include instruction in the function of the anti-anoxia valve (the wearer will experience difficulty in exhaling as a warning that the oxygen supply is shut off).
Trainees should wear the unit while exercising (e.g., jogging, calisthenics, simulated work movements) to learn of any restrictions experienced in breathing or-in movement. They should use the unit to end-of-service air supply to become familiar with the behavior of the unit as it runs down and to recognize the end-of-service whistle that sounds for only a brief time.
Training should be sufficiently extensive for wearers to be thoroughly familiar with and confident in the use of the apparatus.
5.
An anti-fogging solution should be applied to the facepiece lens before each use since there is much more fogging in rebreathers than in open-circuit equipment. Some of the first samples of anti-fogging solution supplied to LANL by Biomarine Industries were defective.
!icensees who have purchased this solution should check with the manufacturer about the need for replace-ment chemicals. Part of the training should prepare wearers to expect more
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fogging tnan they have experienced with open-circuit apparatus.
6.
The manufacturer of the BioPak-60P has alerted purchasers of the equipment to attach a special accessory hood (the "BioShield") to the 60P when it is used in fire fighting. The hood consists of a flexible " Beta Glass" covering that stretch-fits around the visor and covers-the head, facemask, and hoses to the wearer's shoulders. The purpose of the nood is to keep flames or falling embers from igniting combustible materials (such as hair) that might be close to a leak of concentrated oxygen from the equipment (e.g., out of the facepiece). NIOSH certification permits the use of this accessory hood. Licensees who use the 60P for firefighting, or near open flames or falling sparks or embers, should also use this special fire-resistant accessory hood to prevent serious or.'atal burns that could result from an oxygen-fed fire.
This IE Information Notice is provided to notify licensees of the authorized use of the BioPak-60P and the interim regulatory positions. When Regulatory Guide 8.15, " Acceptable Programs for Respiratory Protection," is revised, the revision will reflect NIOSH certifical. ion and LANL testing of rebreathers.
In the interim, NRC Inspectors will use the specific guidance provided above in addition to the regulatory positions given in Regulatory Guide 8.15 for evaluating t'te acceptability of licensee respiratory protection programs.
No written response to this infomation notice is required.
If you need additional infomation with regard to this matter, please contact the appropriate NRC regional office, e
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IN 81-26, Part 2 August 28, 1981 Page 1 of 3 IE INFORMATION NOTICE NO. 81-26, PART 2: USE OF THE CHEMICAL "D0P"
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Introduction:==
This information notice contains preliminary information dealing with the potential toxicity of the chemical di-sec, octyl phthalate (DOP) as shown by animal ~ testing conducted by the National Cancer Institute / National Toxicology Program (NTP).
Further guidance will be issued when more definitive infonnation is developed-about D0P and its applications and use.
Background:
00P, also-called di(2-ethylhexyl) phthalate (DEHP), is used in many facilities, including those of sore NRC licensees, for quality assurance testing and in-place testing of high-efficiency particulate air (HEPA) filters and for recommended quantitative facepiece fit testing of respirators.
D0P is also a plasticizer commonly added to give flexibility to polymers (e.g.,
polyvinyl chloride). As such, it is used in natural and synthetic rubbers lacquers, cellulose compounds, and as a pump fluid for oil-diffusion pumps.
Because it is produced and used in very large amounts (almost 400 million pounds in the United States in 1977), exposure of the general population to products containing D0P is widespread.
The U.S. Food and Drug Administration (FDA) approved DOP for use in polymers in food-contact items, and it is used in vinyl tubing to transfer blood, intravenous fluids, and milk. DOP has been found in blood stored in vinyl bags and transferred through vinyl tubing (up to 66 mg/l of blood and 250 mg/l in bagged plasma).
It has been found in the tissues of patients transfused with blood or blood products stored in flexible polyvinyl chloride containers.
D0P has also been found in neo-natal tissues after umbilical.catheterization. Children whc are given multiple transfusions of blood to treat serious blood diseases might, in a year, receive as much as 1500 mg (about 28 mg/kg) of DOP.
Hazard Assessments:
D0P has, until recently, been considered to be a substance of low toxicity by all routes of intake.
The recommended time-weighted avuage threshold limit value (TLV) for the work environment that is adopted by the Occupational S;fety and Health Administration (OSHA) is 5 mg/m3 in air--the same as that for certain nuisance dusts.
However, the National Cancer Institute / National Toxicology Program recently conducted carcinogenesis bioassay tests on D0P/DEHP. One strain of mouse and one strain of rat in a lifetime feeding study were fed relatively large amounts of 00P (3,000 to 12,000 ppm) in dosed feed.
No inhalation study was perfonned.
A draft NTP report of this study, which has been reviewed and approved with slight changes by the NTP Peer-Review Panel of Experts, finds that D0P is
~ carcinogenic in B6C3F1 mice and in F344 rats (hepatocellular carcinomas in mice and hepatocellular carcinomas and neoplastic nodules in female rats). The report makes no determination of risk to humans.
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IN 81-26, Part 2 August 2, 1981 Page 2 of 3 Current Considerations:
The National Institute for Occupational Safety and Health (NIOSH) has not yet issued final revised new recommendations on the suitability of DOP for various uses. However, on April 30, 1981, NIOSH issued for comment a draft special report on DEHP toxicity.
The draft report recommends corn oil as the best alternative from a toxicological viewpoint, for the time being, as a sub-situte aerosol for quantitative facepiece fitting of respirators.
Final recommendations are expected within a few months.
The Los Alamos National Laboratory (LANL) is investigating potential substitutes for D0P (in quantitative fit testing) for both NRC and the Department of Energy (DOE). LANL has successfully used di-2 (ethylhexyl) sebacate (DEHS, "Octoil-S")
as a substitute test agent that seems to be of acceptably low toxicity according to current data. The draft NIOSH report also examines the suitability of DEHS as a substitute for D0P in generating quantitative fit test aerosols.
The report does not rule out such use of DEHS at this time, but it indicates that more toxicity tests are needed before NIOSH can make a more definitive recommendation on such use of DEHS.
Manufacturers of quantitative fit test equipment have recomended the use of corn oil as an interim substitute test agent for D0P. A satisfactory test aerosol can be generated from corn oil for making the measurements. There may be some disadvantages,'however, in odor (described as that of french fries or popcorn) from oxidation of the oil, potential for mold growth on test chamber exit-air filters, and housekeeping problems from the need for more frequent and more difficult cleaning.
Guidance:
A forthcoming final NTP report may find that DOP/DEHP is a weak carcinogen in two strains of mice and rats as indicated by feeding studies.
D0P is present in many products in comon use, and human exposures to it are widespread.
NIOSH and OSHA have not yet had time to fully evaluate and make recommendations on the health significance of exposures to and uses of DCP. Until such infor-mation is available, the following interim guidance is suggested for licensees:
1.
For quantitative respirator fit testing, even though human exposures are very small during these tests, it would be prudent, at least for now, to discontinue the use of D0P and to sdstitute an available, less potentially hazardous test agent for these tests Corn oil, as recommended by the test equipment manufacturers, is acceptable for this use.
Licensees should check with manufacturers for detailed instructions on the use of corn oil and on how to avoid or minimize potential problems with odor, mold growth, and cleaning. Di-2 (ethylhexyl) sebacate ("Octoil-S") may also be used if mandacturers deem it compatible with the operation of their equipment.
2.
. For quality assurance or in-place testing of HEPA filters, D0P may be used where required. However, emissions of DOP from generating and test equipment should be controlled by containment and ventilation to avoid unnecessary exposures of personnel.
Exposures of personnel to DOP should be individually assessed and minimized by well-planned work practices.
Respiratory protective equipment should be used if necessary.
J IN 81-26, Part 2 August 28, 1981 Page 3 of 3
.. Several different agencies are continuing to' clarify and resolve the questions -
that arise with respect to the use of D0P.. Licensees'will be further informed
' as more definite information is developed about D0P, suitable substitutes, or
. recommendations on permissible applications and use.
No wr'itten response to this information notice is required.
If you have any questions regarding this matter, please contact the appropriate NRC Regional
- 0ffice.
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IN 81-26, Part 3 August 28, 1981 Page 1 of 3 I
IE INFORMATION NOTICE NO. 81-26, PART 3: -PLACEMENT'0F PERSONNEL MONITORING DEVICES FOR EXTERNAL RADIATION EXPOSURE Descriptior. of Circumstances:
A recent inspection at a nuclear power plant revealed a situation in which 1,nappropriate' placement of personnel monitoring devices resulted in under-estimating the radiation dose received by the worke'rs.
In this. case, the heads.
and lenses of the workers' eyes were exposed to about 50% more radiation than was measured by their chest-worn film badges and self-reading pocket dosimeters.
Such a nonuniform radiation field resulted during repair work in a steam generator when the principal source of radiation came from overhead.
Conservative re-evaluation by the licensee of the dose received by these individuals revealed that sixty-six workers may have exceeded their 3 rem per calendar quarter exposure limit specificed in 10 CFR 20.101.
On a regular basis, NRC inspectors observe other situations where sufficient attention has not been given to the placement of personnel dosimeters. Many of these involve situations where significant extremity (hand) exposure occurs and extremity dosimeters are not supplied to workers by the licensee.
In marty cases, the licensee has not made the necessary surveys and/or calculations to adequately evaluate the need to supply extremity dosimeters to the workers.
In other cases, the evaluations may have been conducted, but no evaluation records are available.
Discussion:
It is fairly standard practice to wear personnel dosimeters on the trunk, most frequently at the chest or waist position.
This is acceptable practice when workers are exposed to relatively unifonn fields of radiation. However, it is important to evaluate all nonstandard and unusual situations, particularly where high dose rates are possible, to determine if trunk-worn dosimeters are appropriate.
In the majority of the cases, the dose limit of interest is the one that' applies to the whole body, head and trunk, active blood-forming organs, lenses of eyes, and gonads. Since the same limit applies to all of these body locations, the potential dose to each should be considered. The objective should be to place the dosimeter in a position where it will measure the highest dose to the areas of interest.
i Therefore, if the principal source of radiation is overhead, the dosimeter should probably be placed on the head.
If the principal source of radiation is from underfoot, the appropriate lochtion for the dosimeter might be on the lower leg just above the ankle, since long bones of the lower 1.eg contain active blood-forming marrow.
If a worker is sitting on or straddling the source of radiation, the dosimeter should be positioned to record the radiation dose to the gonaG.
If the source of radiation is predominantly behind the workers, the dosimeter should be worn on the back rather than on the front of the body.
To be explicit, the dosimeter should be worn at the location of highest entry dose.
The other situation that occurs regularly is significantly higher exposure to the hands, forearms, feet, or ankles. These situations occur most frequently during direct-handling or manipulation of radioactive items or while working
l IN 81-26, Part 3 August 28, 1981 Page 2'of 2 a
from behind a partial. shield.
In many of these cases,.NRC regulations would require wearing dosimeters.to record what might be termed the "whole body dose" and dosimeters to record the dose to the extremities.
NRC Regulation 10 CFR 20.202 requires that an appropriate personnel monitoring device be worn if an individual receives or is likely to receive a dose in a calendar quarter in excess of 25% of the values specified in paragraph (a) of 10 CFR 20.101. Thus, a "whole body badge" is required if 300 mrem per quarter is likely to be-received by those portions of the body with a limit of 1.25 rem per quarter.
In addition, an extremity badge is required if an extremity is likely to receive about 4.7 rem in a quarter.
Dosimetry for the only other limit, skin of whole body, is normally accommodated by the beta capability of'most personnel dosimeters.
All of.he discussions above apply to situations in which the NRC regulations require that dosimeters be worn by radiation workers.
There are many cases when an employer may choose to supply dosimeters to workers above and beyond the NRC requirements. This may be done for administrative, informatior, gathering, or other purposes.
In some special situations, a worker may be seen wearing several dosimeters. Such conservative safety practices are encouraged.
Some discussion of requirements for radiation surveys and evaluations may be in order. Because 10 CFR Part 20 requires each licensee to supply personnel dosimeters to workers under certain conditions, there is the companion require-ment that the licensee make such surveys and evaluations necessary to comply with that requirement. For example, if significant hand exposure is likely to occur and a licensee chooses not to supply extremity dosimeters, the potential dose to the hands must have been evaluated by instrument surveys, calculations, or by other means to support the psition that extremity monitoring is not required. Records of such surveys and evaluations must be maintained for inspection.
l Guidance:
No written response to this notice is required. Licensees should review their radiation survey and evaluation practices to ensure personnel monioring require-ments are met. Special attention should be given to nonuniform radiation fields.
If you require additional information regarding this subject, please contact the appropriate NRC Regional Office.
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l IN 81-26, Part 4 August 28, 1981 Page 1 of 3 IE INFORMATION NOTICE N0. 81-26, PART 4: PERSONNEL ENTRY INTO INERTED CONTAINMENT
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Introduction:==
The information provided below deals with personnel safety issues that are outside the scope of the NRC's nuclear safety requirements; as such no action or response to this infomation notice is required.
However, this infomation notice provides useful infomation that will be helpful to licensees in their efforts to maintain safe working conditions for their employees.
Description of Circumstances:
On February 24, 1981, a boiling water reactor (BWR) licensee dispatched three workers, who were fitted with self-contained breathing apparatus (SCBA), into the primary containment.(drywell) with the reactor at 30% power and the drywell fully nitrogen-inerted to approximately 3% oxygen by volume.
The purpose of this drywell entry was to detemine the source of unidentified, primary system leakage into the drywell.
An inerted drywell constitutes an atmosphere immediately dangerous to life and health (IDLH). Personnel safety provisions for the February 24 entry included verbally restricting the areas where the personnel should travel in the contain-ment; providing two other persons with SCBA equipment on standby ouside the containment airlock for rescue, if necessary; and preparing for ventilating the containment if a problem arose.
The entry lasted 7 minutes and the plant page system was used occasionally to verify the status of the work party.
Upon completion of the activity, the work party left the containment with no reported problems. Licensee management reportedly authorized the entry for the purpose of maintaining the plant at power, rather than shutting down.
Discussion:
Had an individual's air supply failed while in the inerted drywell, the planned deinerting in the event of a problem would not have prevented severe personnel injury. Unprotected exposure to an atmosphere containing less than 6% oxygen by volume causes spasmodic breathing, convulsive movements, and death in minutes.
In atmosphere with oxygen content in the 8-12% by volume range, unconsciousness can be immediate and without warning upon loss of air supply (3CBA failure).
Title 29, Code of Federal Regulations, Part 1910.34 provides certain regulatory requirements for the safe use of respirators in aangerous atmospheres.
It states, in part, "Comunications (visual, voice or signal line) shall be main-tained between both or all individuals present...," e.g., for this situation the working party in the drywell and the rescue party outside the containment airlock. Given the,gistics of the situation and ava iable communications equipment, the use of signal line or voice communications was physically impossible. The licensee used the plant pager system intennittently, and thus communications were not maintained on a continual basis.
Discussion with the licensee management revealed a lack of awareness of the above-cited Title 29 requirement.
Other airborne-toxic / oxygen-deficient areas can exist at nuclear power plants.
Some cxamples include unventilated tanks or voids; inerted primary components l
l IN 81-26. Part'4 August 28, 1981 Page 2 of 3 such as steam generators or portions of primary loop piping; areas affected by oxygen displacement fire suppression systems; confined spaces affected by decaying marine growth, such as? circulating water cooling systems; and areas affected by leakage of chlorination systems or accidental mixing of caustic and acid chemicals for makeup water treatment.
Subatmospheric containments can constitute oxygen-deficient areas, to varying degrees, depending on the containment air pressure. At sea level, for example, if the containment air pressure is 11.1 lb/in.2, then the partial pressure of oxygen is approximately 420 mm of mercury; 30 CFR 11 defines an oxygen-ceficient atmosphere as "...an atmosphere which contains an oxygen partial pressure of less than 148 millimeters of mercury (19.5 percent by volume at sea level)."
Another potential nonradiologicci hazard can exist for personnel making BWR drywell entries.
In some earlier designed plants, the primary safety valves discharge directly to the drywell atmosphere.
In the event of safety valve activation, personnel could be severely injured or killed.
Guidance:
IDLH areas, such as an inerted BWR drywell, should not be entered.
In fully inerted areas, assuming SCBA failure, physical-incapacitation occurs 'n secsnds and-death occurs in minutes.
If entry into inerted areas is required under certain extreme emergency conditions and timely deinerting is not passible, then carefully planned and controlled personnel entries can be accomplished.
Even after purging and ventilating, a deinerted area can present a personnel hazard.
Pockets of the inerting gas can remain in localized low-lying areas of the space. Before the deinerted area is opened for unrestricted worker access, a thorough sampling inspection should be perfonned by personnel equipped with SCBA.
Licensees should establish and maintain a nonradiological airborne hazards control program. Basic elements of such a safety program should include the following:
1.
Identification of potential hazard areas 2.
Quantification of the hazard potential 3.
Procedural controls to implement safe work practices commensurate with identified hazards 4.
Worker training program Such a nonradiological hazards control program could be an extension of the
. licensee's respiratory protection rrogram established to satisfy the requirements of 10 CFR 20.103.
NUREG-0041, " Manual of Respiratory Protection Against Airborne Radioactive Materials," contains a summary of the OSHA regulations-in the non-radiological airborne hazards area (Chapter 3), and provides a discussion of the ovaluation and classification of' respiratory hazards (Chapter 4). Another useful reference document for improving worker safety in nonradiological hazards areas is the DHEW (NIOSH) Publication No.86-106, " Criteria for a Recont, ended i
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IN 81-26, Part 4 August 28, 1981 Page 3 of 3
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Standard... Working in Confined Spaces," December, 1979.
This document is available for purchase from the Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402.
As discussed above, no specific actions or reports are required.
If you have any questions regarding this matter, please contact the appropriate NRC Regional-
.0ffice..
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'IN 81-26, Part 5.
August 28, 1981 Page 1~of 2
.!E INFORMATIN NOTICE NO. 81-26, PART 5:
EVALUATION OF INSTRUMENT CHARACTERISTICS-WHEN USING PORTABLE RADIATION SURVEY'
- INSTPUMENTS i
L Descr'iption of Circumsta'nces:
The Barnwell, South Carolina, radia.:tive waste burial site recently received a shipment of. radioactive waste that exceeded the radia'; ion ~ levels specified by the U.S. Department of Transportation (DOTh The power reactor licensee responsible for the shipment concluded that the error resulted from the use of
.a portable' radiation survey instrument in an orientation other than that-for.
I which it was designed. ANSI N323-1978, "Radiatifon Protection Instrumentation l
Test and Calibration," defines-geotropism as a change in instrument response with a change in instrument orientation as a result of gravitational ~ effectr.
ANSI N323-1978 discusses this phenomenon as well'as other nonradiological and' radiological characteristics that should be considered in the routine calibration and use of portable radiation survey instri,ments.
Strictly speaking, geotropism is the result of gravitational forces on the instrument. Almost invariably, this results from the effects of gravity a the moving parts of conventional meter movements.
For example, if an instrument is calibrated in an upright orientation, a change in response may be experienced i.f the instrument is used on its side with the earth's. gravity assisting (or. resisting) the movement of the meter needle or other meter move-ment parts. Additional geotropic effects can also be introduced if. instruments 4
i are not zerced in the crientation in which the measurementtill be made.
Geotropic effects are nonnally not present in those' instruments with digital-4 readouts, since there are no moving meter parts.
Another instrument characteristic that is influanced.by orientation is tenned i
" angular dependence.".This effect may be observed when a change of instrument i
response is noted or when there is a change in the direction fron. which the l.
radiation enters the detector.
It is easy to visualize this effect in an instrument with the detector mounted internally 'but on one side of the f
instrument case.
Thus, a measurement made with the side of the instrument j-where the. detector is located closest to the source' may be considerably higher than if the instrument is oriented so the radiation enters from the side o
i farthest from the detector. Some of this effect results from the distance (geometry)effectandsomema f the instrument between
.the source and the detector (y result ' rom other parts oEven greater shielding effect-n shielding effect).
ic is observed on moet instruments if the radiation enters from the'back. Angular dependence may also be observed in-instruments with cylindrical detectors..either ionization or GM type. That is, a different response may-be obtained when the
.long axis of the detector is pointed at the source than when it is oriented at right' angles to the source.
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' Guidance:
--Improper orientation of radiation survey instruments during calibration or
'u'se. can cause errors in radiation measurements. All NRC licensees should
[f verify that personnel' calibrating or using radiation survey instruments are aware'of this phenomenon and that controis are established to ensure that
{
. instruments are properly oriented during calibration and use.
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IN 81-26, Part 5
-August 28, 1981 Page 2 of 2
-No written _ response to this infonnation. notice is required.
If you require additional infonnation regarding this matter. contact the appropriate NRC Regional Office..
Attachment:
Recently issued IE Information Notices-4 l
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Attachment IN 81-27 August 28, 1981 RECENTLY ISSUED IE INFORMATION NOTICES-Information Date of-Notice No.
Subject Issue Issued to 81-25 Open Equalizing' Valve 8/21/81 All power reactor of Differential Pressure facilities with an' Transmitter Causes Reactor OL or CP Scram and Loss of Redundant Safety Signals.
81-24 Auxiliary Feed P;.tip 8/5/81 All power reactor.
Turbine Bearing Failures-facilities with an OL'or CP 81-23 Fuel Assembly Damaged 8/4/81 All power reactor due to Improper Positioning facilities with an of Handling Equipment OL or CP 81-22 Section 235 and 236 7/31/81 All power research Amendments to the reactor, fuel Atomic Energy Act fabrication and of 1954 reprocessing, and spent fuel storage licensees and' applicants 81-21 Potential Loss of Direct 7/21/81 All power reactor Access to Ultimate Heat Sink facilities-with an OL or CP 81-20 Test Failures of Electrical 7/13/81 All power reactor Penetration Assemblies facilities with an OL or CP 81-19 Lost Parts in Primary 7/6/81 All power reactor Coolant System facilities with an OL or CP 81-18 Excessive Radiation 6/23/81 Specified licensees Exposures to the Fingers of holding byproduct Three Individuals Incurred licenses During Cleaning and uj e p
Testing of Radioactive Sealed Sources at a Sealed-Source Manufacturing Facility OL = Operating Licenses
-CP.= Construction Permits
f SINS Ho.: 6835
' Accession
"-8107230026 1-26 UNITED STATES NUCLEAR REGULATORY COMMISSION 4
0FFICE Of INSPECTION AND ENFORCEMENT
- WASHINGTON, _ D.C. 20555 -
August.28, 1981.
IE INFORMATION NOTICE NO. 81-26: COMPILATION OF-HEALTH PHYSICS RELATED INFORMATI6t1 ITEMS Part it Use of Recirculating-Mode (Closed-Circuit) -Self-Contained Breathing Apparatus (Rebreathers)
Part 2: Use of the Chemical "DOP" Part 3:
Placement of Personnel Monitoring Devices for External Rad.iation Exposurc
. art 4:
Personnel. Entry. into Inerted Containment Part 5:
Evaluation of Instrument Characteristics When Using Portable Radiation Survey Instruments i
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