ML20244A765

Determines That EPICOR-II Does Require Amend to TMI-2 Ol. Draft Statements Encl

ML20244A765
Person / Time
Site:	Three Mile Island
Issue date:	09/27/1979
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	Hendrie J NRC COMMISSION (OCM)
Shared Package
ML20244A768	List: ML20244A765 ML20246E389 ML20246E395 ML20246E400 ML20246E406
References
FOIA-89-88 NUDOCS 7910220127
Download: ML20244A765 (5)

Text

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MEMORANDUM FOR: Chairman Hendrie Commissioner Gilinsky a -,

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l Commissioner' Kennedy Commissioner Bradford Commissioner Ahearne

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. THRU: Executive Director forNdit$tiF' FROM: Harold R. Denton, Director Office of Nuclear Reactor Regulation l

SUBJECT:

DETERMINATION THAT EPICOR-11 DOES REQUIRE AN AMENDMENT TO THE TM1-2 OPERATING LICENSE Over the past weeks, members of the NRR and ELD staff have reviewed the EPICOR-II system proposed for use at THI-2 to decontaminate intermediate-level water resulting from the March 28 accident. Based on our review, which has been guided by tne provisions of 10 CFR 550.59, we have concluded that an amendment to the TM1-2 operating license is required.

The first question to be considered is whether the proposed activity involves a change in the facility or procedures described in the licensee's Safety Analysis Report (SAR) per 10 CFR 650.59(a)(1). We have determined that, although the SAR describes a liquid radwaste treatment system, EPICOR-Il represents a sufficient modification of this system and pertinent procedures to be considered a change in the SAR. This is because incident to installation and use of EPICOR-II, building, construction and component installation was performed, new operations procedures were developed, and the operators were put through a training program. Thus, it is necessary to address the remaining aspects of_10 CFR 650.59.

Changes to the f acility or procedures described in an SAR may be made by a licensee without NRC approval, i.e., without a license amendment, provided that such changes do not involve a change to the Technical Specifications of the f acility's operating license, or an unreviewed safety question,10 CFR 550.59(a)(1). With respect to EPICOR-II, the present Technical Specifications.

for TMI-2 contain one provision bearing on liquid radwaste treatment which would require a change to accomodate EPICOR-11; namely, all principal points which could be release paths of radioactive gaseous effluents have identified monitors and surveillance requirements to comply with CDC 64. Since the EPICOR-Il system as erected in an existing building separate from the Auxiliary Building, it was A rovided with a separate ventilation system. This ventilation system was provide with an effluent monitor since the ventilation exhaust is a potential release O(f point for radioactive gaseous effluents. Other than this somewhat generic

[ specification in which all release point monitors are listed, all other pertinent 0 Technical Specifications relate to effluent limitations and would remain h unchanged. The staff does not believe that any other Technical Specifications

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- O O An unreviewed safety question is. deemed to be involved

• (i) if the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased; or (ii) ,

if a possibility for an accident or malfunction of a different type' than any evaluated previously in the safety analysis' report my be created; or (jii) if the margin of safety as defined in the basis for any technical specification is reduced." 10 CFR 550.59(a)(2).

Each of the foregoing considerations is addressed in turn:

1. The Probability .of Occurrence of an Accident or Malfunction of Equipment In the SAR, the rupture of the shim bleed tank in the auxiliary

~ building containing radioactive liquid is assumed tc occur. This is the bounding accident involving a release of liquid radioactivity from the existing TMI-2 liquid radwaste system. The contents -of the shim bleed tank are assumed to reach the ground water after migration through the soil and then the public through water transport pathway.

No specific senario is given as the cause of the rupture.

In the case of EPICOR-11, a similar type accident would involve the rupture of the tanks in this system which are essentially storage tanks for processed water (i .e., water that has already passed through the prefilter, cation demineralized and polishing desineralizer).

The activity of the water in the EPICOR-II storage. tanks will be substantially less than that in a shim-bleed tank because the clean-up process will achieve much higher decontamination factors.

However, since .the building housing the EPICOR-II storage tanks is not provided with a steel liner, these tanks can be assumed to rupture and their contents reach the ground water, similar to the

-assumptions in the SAR for shim bleed tank rupture. Thus, the probability of this accident is essentially the same for EPICOR-II as it is for the accident analyzed in the SAR, though the consequences cf -the accident for EPICOR-II would be lower since only processed water would be involved.

To preclude some of the more comon radwaste accidents, e.g., over-flowing of tanks, uncontrolled leakage from pumps and flanges, and insufficient processing, a number of design features have been incorporated into the design of the EPICOR-II system which are not present in many radwaste systems and are more conservative than u

those systems evaluated in the SAR. System design provisions, such 1

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as hard piping of tank overflow lines directly into the chemical cleaning building sump, the use of welded stainless steel process piping, tank and sump level alanns, the use of drip pans to collect leakage from pumps and flanges, the use of in-line radiation monitors, a saspling system to sample t process streams, and the use of closed circuit TV monitors to monitor the operating areas inside and outside the chemical cleaning building should reduce the probability of conson radwaste accidents. However, in addition to'the above improved design features, operator training

-and system operating procedures have been evaluated and upgraded in relation to comon radwaste accidents. All system operators are currently going through or have' completed a comprehensive training program. The training program is being monitored by the NRC staff including a representative from the Operator Licensing Branch. To further assure that the system will be operated as designed, a number of systems procedures have been developed. These procedures can be categorized as follows: (1) EPICOR-II operations, (2) component - .

handling, (3) health physics / chemistry, (4) alann responses, (5) casualty, and (6) general emergency. All the procedures listed in each of the above categories will be reviewed and approved by the NRC staff prior to system operation should such operation be authorized.

An additional factor which should help reduce the likelihood of operational accidents is the attention being given to this operation by the NRC, the licensee, the State and other Federal agencies, and the public. Such attention will result in.a greater-than-normal management, supervisory, and operator attention to the process detail s . Thus, the probability of occurrence of an accident or malfunction in EPICOR-II is expected to be similar to or less than previously evaluated in the SAR for the existing radwaste system.

2. The Consequences of an Accident or Malfunction of Equipment

Assuming that the clean water receiving tank (133,000 gallons) is 80%

full, which is standard operating procedure, (i.e., contains 107,000 gallons), that this tank ruptures, and that the tank contents enter the ground water, the consequences of such a spill are expected to be less

- than the consequences of the shim bleed tank failure previously evaluated j in the SAR. This expectation is based on the assumption of a decon-tamination f actor (DF) of at least 1,000 for the EPICOR-II system. An assumed DF of 1,000 for the operation of EPICOR-II is conservative in that the operating experience of EPICOR-1 (a system with a single demineralized) has yielded system DF's on the order of 1,000 to 10,000.

Thus based on the measured activity in the water to be decontaminated by EPICOR-II, the maximum activity of water in the clean water receiving tank 1

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would be approximately 0.045 uCi/ml from processing the reactor coolant bleed tank water through the system. This water is significantly less radioactive than the water (0.6 uCi/al) previously evaluated in the SAR, and the tank volume is 107,000 gal compared to 6,000 gal (at 805 full) for the shim bleed tank of the existing system. Thus, the conse-quences of an accident or malfunction involving the EPICOR-II system would be equal to or less than that previously evaluated in the SAR.

r. 3. The Possible Creation of a Different Type of Accident or Malfunction The following EPICOR-II potential accidents were considered:

a) Accident involving spent resin and filter during removal and transfer to interim storage.

No new handling techniques are employed for EPICOR-II spent resin and filter removal and transfer, and they are not different from i normal raddaste system handling operations. Differences have been '

of a nature to upgrade reliability and to provide better operator protection thru shielding and remote handling capability. The consequences of a removal and/or transfer accident are not different since spent resin / filters from EPICOR-II are not more contaminated than from normal radwaste system operation and complete control over filter loading can be maintained at whatever level it desired.

l b) Accident involving spent resin and filters during storage.

Stored spent resin / filters are not more highly contaminated than normal radaaste system spent resin / filters. Therefore, since storege of this resin / filter material pending shipment is routine, and would be done for the normal radwaste system spent resins and  !

filters, such storage for EPICOR-II involves no different accident consequences than f rom the normal radwaste system, c) Rupture of transfer pipe. <

Since the EPICOR-II building is designed to seismic Category I criteria, the probability of rupture of pipes in that EPICOR-II building due to the effects of natural phenomena such as earthquakes, tornadoes, hurricanes, and floods would be less than normal radwaste system piping, which would not be on a seismic I foundation. The ,

piping carrying radwaste from the miscellaneous waste holdup tank ]

in the auxiliary building through the yard to EPICOR-II building is q t

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enclosed within a 4 inch' diameter guard pipe. The transfer pipe is designed and constructed to the same criteria as for normal liquid radwaste system piping and, thus, its probability of failure is the same. However, the volume (<100 gallons) and total activity of the radioactive waste from a ruptured transfer pipe for EPICOR-II does not result in the release of as much activity as the failure of the clean water, receiving tank (>100,000 gallons), discussed above as the bounding accident for the normal radwaste system.

Accordingly, use of EPICOR-II does not create the possibility of an accident or malfunction of a different type than previously analyzed in the SAR.

4. Reduction in Safety Margin Defined in Bases of Technical Specifications ,

l The focus of this criteria is on the margin of safety as defined in the bases for any technical specification. Since the radwaste system '

is not. addressed in technical specifications, this consideration is inapplicable.

Based on the foregoing considerations, we have determined that, .although no unreviewed safety question is involved in the use of EPICOR-II, a license amendment is necessary because the technical specifications should include the monitor included as part of the EPICOR ventilation system. The forego'ng analysis does, however, show that the license change does not involve unreviewed safety questions. In addition, the test as to whether an action involves a significant hazards consideration, and, therefore, must be prenoticed, is whether the action will significantly increase the probability or consequences of an accident or result in a significant decrease in a safety margin. This is essentially the test of 10 CFR 50.59(2)(i) and (iii) for an unreviewed safety question with the word "significant" inserted. Since, as shown above, the use of EPICOR-II does not involve any increase in the probability or conse-cuences of an accident or any decrease in safety margins, it does not involve significant hazards considerations and need not be prenoticed.

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arold R. Denton, Director Office of Nuclear Reactor Regulation cc: SECY OGC OPE