United States Nuclear Regulatory Commission - Protecting People and the Environment

Sampling Drywell Atmosphere Before a Release

HPPOS-170 PDR-9111220188

See the memorandum from L. J. Cunningham to R. B. Samworth dated November 3, 1988.

Sampling drywell atmosphere is required before each and every purging or venting. Furthermore, methodology and parameters in TS referencing the ODCM, should accurately represent the contents of the ODCM.

Region V requested assistance in interpretation of two current Washington Nuclear Plant - Unit 2 (WNP-2) Technical Specifications (TS): TS 3/4.11.2.1, and TS 3/4.11.2.8.

Specifically, Region V asked: "Does TS Section 4.11.21 and Table 4.11.2 require a sample of drywell atmosphere be taken and analyzed prior to each vent and/or purge operation through the Standby Gas Treatment (SGT) system?"

Region V also asked: "If prior-to-release samples are required, should this be reflected in the ODCM, along with an appropriate decontamination factor to account for SGT cleanup?"

NRR reviewed the Inspection Report documenting the positions of both the inspector and the licensee in regard to the subject question.

NRR agreed with the position expressed by the licensee's Corporate Nuclear Safety Review Board (CNSRB) member at the November 27, 1985 meeting of their Plant Operations Committee (POC) recorded on pages 10 and 11 of the Inspection Report. WPN-2 TS 4.11.2.1.2 with its Table 4.11.2 requires that a grab sample be taken prior to each purge and vent from primary containment. TS 4.11.2.8.3 provides additional requirements for the case of purging or venting through other than the SGTS, but says nothing about when the SGTS is used. The applicability of TS 3/4.11.2.1 is "At all times." Therefore, the answer to the first question of Region V is "yes."

In regard to the second question, TS 3/4.11.2.1.2 ties the sampling and analysis program of Table 4.11.2 to dose rate determinations "in accordance with the methodology and parameters in the ODCM." Thus, statements regarding these determinations should be incorporated in the ODCM.

Regulatory references: Technical Specifications

Subject codes: 7.3

Applicability: Reactors (BWR)

Page Last Reviewed/Updated Monday, June 15, 2015